1.
Zsolnay
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Zsolnay, or formally Zsolnay Porcelánmanufaktúra Zrt is a Hungarian manufacturer of porcelain, tiles, and stoneware. The company introduced the eosin glazing process and pyrogranite ceramics, the Zsolnay factory was established by Miklós Zsolnay in Pécs, Hungary, to produce stoneware and other ceramics in 1853. In 1863, his son, Vilmos Zsolnay joined the company and became its manager, in 1893, Zsolnay introduced porcelain pieces made of eosin. Tádé Sikorski married Vilmos’ daughter Júlia and became the chief designer, in 1900 Vilmos’ son Miklós took over. Frost-resisting Zsolnay building decorations were used in numerous buildings specifically during the art nouveau movement, by 1914, Zsolnay was the largest company in Austro-Hungary. During World War I production of pottery and building materials were curtailed, after World War I the fortunes of the factory declined due to the Serbian occupation, loss of markets, and difficulty to secure raw materials. However, after the depression, conditions improved, during World War II its site of production in Budapest was bombed. With the rule of communism the factory was nationalized in 1948, eventually, the Zsolnay name was dropped. The Pécsi Porcelángyár was used primarily to produce common tableware goods, however, in 1982 with the resumption of a market economy, the company regained its operational independence, was reorganized, and the Zsolnay name returned. In 1991, the Zsolnay Porcelain Manufacture became a stock company, in September 2008 a contract was concluded with the Swedish company, IKEA. According to the contract, Zsolnay will deliver 5,000 tonnes of ceramics per year from September 2009 and this deal will triple the sales of Ft 1,1 billion for Zsolnay. Beside the factory, there is also the Zsolnay Museum in Pécs, many Zsolnay ceramics are noted for the use of the eosin process that was introduced in 1893. The process results in a red iridescence of the first prepared hue. Different eosin colours and processes were developed over time, the eosin-based iridescence became a favourite of art nouveau and Jugendstil artists, among them Sándor Apáti Abt, Lajos Mack, Géza Nikelszky, and József Rippl-Rónai. The secret eosin glaze renders porcelain to appear iridescent metallic, in different colours that change with the angle of reflection, typical colours include shades of green, red, blue, and purple. Pyrogranite refers to a type of ceramics that were developed by Zsolnay. Fired at high temperature, this material remains acid and frost-resistant making it suitable for use as roof tiles, indoor and outdoor decorative ceramics. Architects that used the material in their buildings include Miklós Ybl, Ödön Lechner, Béla Lajta, Samu Pecz, and Imre Steindl
2.
Fluorescence
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Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence, in most cases, the emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation. Fluorescent materials cease to glow immediately when the radiation source stops, unlike phosphorescence, Fluorescence also occurs frequently in nature in some minerals and in various biological states in many branches of the animal kingdom. An early observation of fluorescence was described in 1560 by Bernardino de Sahagún and it was derived from the wood of two tree species, Pterocarpus indicus and Eysenhardtia polystachya. The chemical compound responsible for this fluorescence is matlaline, which is the product of one of the flavonoids found in this wood. The name was derived from the fluorite, some examples of which contain traces of divalent europium. In a key experiment he used a prism to isolate ultraviolet radiation from sunlight, the specific frequencies of exciting and emitted light are dependent on the particular system. S0 is called the state of the fluorophore, and S1 is its first excited singlet state. A molecule in S1 can relax by various competing pathways and it can undergo non-radiative relaxation in which the excitation energy is dissipated as heat to the solvent. Excited organic molecules can also relax via conversion to a triplet state, relaxation from S1 can also occur through interaction with a second molecule through fluorescence quenching. Molecular oxygen is an extremely efficient quencher of fluorescence just because of its unusual triplet ground state, in most cases, the emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation, this phenomenon is known as the Stokes shift. The emitted radiation may also be of the wavelength as the absorbed radiation. Molecules that are excited through light absorption or via a different process can transfer energy to a second sensitized molecule, the fluorescence quantum yield gives the efficiency of the fluorescence process. It is defined as the ratio of the number of photons emitted to the number of photons absorbed, Φ = Number of photons emitted Number of photons absorbed The maximum fluorescence quantum yield is 1.0, each photon absorbed results in a photon emitted. Compounds with quantum yields of 0.10 are still considered quite fluorescent, thus, if the rate of any pathway changes, both the excited state lifetime and the fluorescence quantum yield will be affected. Fluorescence quantum yields are measured by comparison to a standard, the quinine salt quinine sulfate in a sulfuric acid solution is a common fluorescence standard. The fluorescence lifetime refers to the time the molecule stays in its excited state before emitting a photon. This is an instance of exponential decay, various radiative and non-radiative processes can de-populate the excited state
3.
Lysine
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Lysine, encoded by the codons AAA and AAG, is an α-amino acid that is used in the biosynthesis of proteins. It contains a group, an α-carboxylic acid group. It is essential in humans, meaning the body cannot synthesize it, lysine is a base, as are arginine and histidine. The ε-amino group often participates in hydrogen bonding and as a base in catalysis. The ε-amino group is attached to the carbon from the α-carbon. O-Glycosylation of hydroxylysine residues in the endoplasmic reticulum or Golgi apparatus is used to mark certain proteins for secretion from the cell, deficiencies may cause blindness, as well as many other problems due to its ubiquitous presence in proteins. As an essential amino acid, lysine is not synthesized in animals, in plants and most bacteria, it is synthesized from aspartic acid, L-aspartate is first converted to L-aspartyl-4-phosphate by aspartokinase. ATP is needed as a source for this step. β-Aspartate semialdehyde dehydrogenase converts this into β-aspartyl-4-semialdehyde, energy from NADPH is used in this conversion. 4-hydroxy-tetrahydrodipicolinate synthase adds a pyruvate group to the β-aspartyl-4-semialdehyde, and a molecule is removed. This causes cyclization and gives rise to -4-hydroxy-2,3,4 and this product is reduced to 2,3,4, 5-tetrahydrodipicolinate by 4-hydroxy-tetrahydrodipicolinate reductase. This reaction consumes an NADPH molecule and releases a water molecule. Tetrahydrodipicolinate N-acetyltransferase opens this ring and gives rise to N-succinyl-L-2-amino-6-oxoheptanedionate, two water molecules and one acyl-CoA enzyme are used in this reaction. This reaction is catalyzed by the enzyme succinyl diaminopimelate aminotransferase, a glutamic acid molecule is used in this reaction and an oxoacid is produced as a byproduct. N-succinyl-LL-2, 6-diaminoheptanedionate is converted into LL-2, 6-diaminoheptanedionate by succinyl diaminopimelate desuccinylase, a water molecule is consumed in this reaction and a succinate is produced a byproduct. LL-2, 6-diaminoheptanedionate is converted by diaminopimelate epimerase into meso-2, 6-diamino-heptanedionate, finally, meso-2, 6-diamino-heptanedionate is converted into L-lysine by diaminopimelate decarboxylase. It is worth noting, however, that in fungi, euglenoids, lysine is metabolised in mammals to give acetyl-CoA, via an initial transamination with α-ketoglutarate. The bacterial degradation of lysine yields cadaverine by decarboxylation, allysine is a derivative of lysine, used in the production of elastin and collagen
4.
Bromine
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Bromine is a chemical element with symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that readily to form a similarly coloured gas. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig and Antoine Jérôme Balard, its name was derived from the Ancient Greek βρῶμος stench, referencing its sharp and disagreeable smell. Elemental bromine is very reactive and thus does not occur free in nature, while it is rather rare in the Earths crust, the high solubility of the bromide ion has caused its accumulation in the oceans. Commercially the element is easily extracted from brine pools, mostly in the United States, Israel, the mass of bromine in the oceans is about one three-hundredth of that of chlorine. At high temperatures, organobromine compounds readily convert to free bromine atoms and this effect makes organobromine compounds useful as fire retardants and more than half the bromine produced worldwide each year is put to this purpose. Unfortunately, the same property causes sunlight to convert volatile organobromine compounds to free bromine atoms in the atmosphere, as a result, many organobromide compounds—such as the pesticide methyl bromide—are no longer used. Bromine compounds are used in well drilling fluids, in photographic film. Bromine has sometimes been considered to be essential in humans, but with the support of only limited circumstantial evidence. As a pharmaceutical, the bromide ion has inhibitory effects on the central nervous system. They retain niche uses as antiepileptics, bromine was discovered independently by two chemists, Carl Jacob Löwig and Antoine Balard, in 1825 and 1826, respectively. Löwig isolated bromine from a water spring from his hometown Bad Kreuznach in 1825. Löwig used a solution of the mineral salt saturated with chlorine, after evaporation of the ether a brown liquid remained. With this liquid as a sample for his work he applied for a position in the laboratory of Leopold Gmelin in Heidelberg, the publication of the results was delayed and Balard published his results first. Balard found bromine chemicals in the ash of seaweed from the marshes of Montpellier. The seaweed was used to produce iodine, but also contained bromine, Balard distilled the bromine from a solution of seaweed ash saturated with chlorine. In his publication, Balard states that he changed the name from muride to brôme on the proposal of M. Anglada, brôme derives from the Greek βρωμος
5.
Cytoplasm
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In cell biology, the cytoplasm is the material within a living cell, excluding the cell nucleus. It comprises cytosol and the organelles – the cells internal sub-structures, all of the contents of the cells of prokaryotic organisms are contained within the cytoplasm. Within the cells of organisms the contents of the cell nucleus are separated from the cytoplasm. The cytoplasm is about 80% water and usually colorless, the submicroscopic ground cell substance or cytoplasmatic matrix which remains after exclusion the cell organelles and particles is groundplasm. It is within the cytoplasm that most cellular activities occur, such as many metabolic pathways including glycolysis, the concentrated inner area is called the endoplasm and the outer layer is called the cell cortex or the ectoplasm. Movement of calcium ions in and out of the cytoplasm is an activity for metabolic processes. In plants, movement of the cytoplasm around vacuoles is known as cytoplasmic streaming, the term was introduced by Rudolf von Kölliker in 1863, originally as a synonym for protoplasm, but later it has come to mean the cell substance and organelles outside the nucleus. There has been disagreement on the definition of cytoplasm, as some authors prefer to exclude from it some organelles. The physical properties of the cytoplasm have been contested in recent years and it remains uncertain how the varied components of the cytoplasm interact to allow movement of particles and organelles while maintaining the cell’s structure. The flow of cytoplasmic components plays an important role in cellular functions which are dependent on the permeability of the cytoplasm. An example of function is cell signalling, a process which is dependent on the manner in which signaling molecules are allowed to diffuse across the cell. While small signaling molecules like calcium ions are able to diffuse with ease, larger molecules, the irregular dynamics of such particles have given rise to various theories on the nature of the cytoplasm. There has long been evidence that the cytoplasm behaves like a sol-gel and it is thought that the component molecules and structures of the cytoplasm behave at times like a disordered colloidal solution and at other times like an integrated network, forming a solid mass. Recently it has proposed that the cytoplasm behaves like a glass-forming liquid approaching the glass transition. A cells ability to vitrify in the absence of activity, as in dormant periods. There has been examining the motion of cytoplasmic particles independent of the nature of the cytoplasm. In such an approach, the aggregate random forces within the cell caused by motor proteins explain the non-Brownian motion of cytoplasmic constituents. The three major elements of the cytoplasm are the cytosol, organelles and inclusions, the cytosol is the portion of the cytoplasm not contained within membrane-bound organelles
6.
Collagen
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Collagen /ˈkɒlədʒᵻn/ is the main structural protein in the extracellular space in the various connective tissues in animal bodies. As the main component of tissue, it is the most abundant protein in mammals. Depending upon the degree of mineralization, collagen tissues may be rigid, compliant, Collagen, in the form of elongated fibrils, is mostly found in fibrous tissues such as tendons, ligaments and skin. It is also abundant in corneas, cartilage, bones, blood vessels, the gut, intervertebral discs, in muscle tissue, it serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue, and accounts for 6% of the weight of strong, tendinous muscles, the fibroblast is the most common cell that creates collagen. Gelatin, which is used in food and industry, is collagen that has been irreversibly hydrolyzed, Collagen also has many medical uses in treating complications of the bones and skin. The name collagen comes from the Greek κόλλα, meaning glue and this refers to the compounds early use in the process of boiling the skin and sinews of horses and other animals to obtain glue. Collagen occurs in places throughout the body. Over 90% of the collagen in the body, however, is type I. So far,28 types of collagen have been identified and described, type IV, forms basal lamina, the epithelium-secreted layer of the basement membrane. Type V, cell surfaces, hair and placenta The collagenous cardiac skeleton which includes the four valve rings, is histologically, elastically and uniquely bound to cardiac muscle. The cardiac skeleton also includes the separating septa of the heart chambers – the interventricular septum, Collagen contribution to the measure of cardiac performance summarily represents a continuous torsional force opposed to the fluid mechanics of blood pressure emitted from the heart. With support from collagen, atrial fibrillation should never deteriorate to ventricular fibrillation, Collagen is layered in variable densities with cardiac muscle mass. The mass, distribution, age and density of collagen all contribute to the required to move blood back. Individual cardiac valvular leaflets are folded into shape by specialized collagen under variable pressure, gradual calcium deposition within collagen occurs as a natural function of aging. Pathology of the underpinning of the heart is understood within the category of connective tissue disease. Collagen has been used in cosmetic surgery, as a healing aid for burn patients for reconstruction of bone and a wide variety of dental, orthopedic. Both human and bovine collagen is used as dermal fillers for treatment of wrinkles
7.
Microscope
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A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy, microscopic means invisible to the eye unless aided by a microscope. There are many types of microscopes, the most common is the optical microscope, which uses light to image the sample. Other major types of microscopes are the microscope, the ultramicroscope. The earliest microscopes were single lens magnifying glasses with limited magnification which date at least as far back as the wide use of lenses in eyeglasses in the 13th century. Compound microscopes, which combine an objective lens with an eyepiece to view a real image, the actual inventor of the compound microscope is unknown although many claims have been made over the years. These include what may be a claim by the son of Zacharias Janssen that his father invented the microscope and telescope as early as 1590. Historians note the compound microscope did not appear in the Netherlands until the 1620s, giovanni Faber coined the name microscope for the compound microscope Galileo submitted to the Accademia dei Lincei in 1625. The first detailed account of the construction of living tissue based on the use of a microscope did not appear until 1644, in Giambattista Odiernas Locchio della mosca. It was not until the 1660s and 1670s that the microscope was used extensively for research in Italy, marcello Malpighi in Italy began the analysis of biological structures, beginning with the lungs. Robert Hookes Micrographia had an impact, largely because of its impressive illustrations. A significant contribution came from Antonie van Leeuwenhoek who achieved up to 300 times magnification using a single lens microscope. He sandwiched a very small glass ball lens between the holes in two metal plates riveted together, and with a needle attached to mount the specimen. Then, Van Leeuwenhoek re-discovered red blood cells and spermatozoa, on 9 October 1676, he reported the discovery of micro-organisms. The performance of light microscopy depends as much on how the sample is illuminated as on how it is observed, early instruments were limited until this principle was fully appreciated and developed, and until electric lamps were available as light sources. In 1893 August Köhler developed a key principle of sample illumination, Köhler illumination and this method of sample illumination produces even lighting and overcomes the limited contrast and resolution imposed by early techniques of sample illumination. In the early 20th century a significant alternative to light microscopy was developed, ernst Ruska started development of the first electron microscope in 1931 which was the transmission electron microscope. The transmission electron microscope works on the principle as an optical microscope but uses electrons in the place of light
8.
Eosinophilic
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Eosinophilic refers to the staining of certain tissues, cells, or organelles after they have been washed with eosin, a dye. Eosin is a dye, thus, the structure being stained is basic. Eosinophilic describes the appearance of cells and structures seen in sections that take up the staining dye eosin. This is a dye that stains the cytoplasm of cells. Such eosinophilic structures are, in general, composed of protein, the stain eosin is usually combined with a stain called hematoxylin to produce a hematoxylin- and eosin-stained section. This is the most widely used stain in medical diagnosis, for example, when a pathologist examines a biopsy of a suspected cancer. Some structures seen inside cells are described as being eosinophilic, for example, Lewy bodies, some cells are also described as eosinophilic, such as Leukocytes
9.
Eos
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In Greek mythology, Ēōs is a Titaness and the goddess of the dawn, who rose each morning from her home at the edge of the Oceanus. Eos had a brother and a sister, Helios, god of the sun, Eos is cognate to the Vedic goddess Ushas, Lithuanian goddess Austrine, and Roman goddess Aurora, all three of whom are also goddesses of the dawn. All four are considered derivatives of the Proto-Indo-European stem *h₂ewsṓs, dawn and this agreement leads to the reconstruction of a Proto-Indo-European dawn goddess. The dawn goddess Eos was almost always described with rosy fingers or rosy forearms as she opened the gates of heaven for the Sun to rise, but soon as early Dawn appeared, the rosy-fingered, then gathered the folk about the pyre of glorious Hector. Hesiod wrote, And after these Erigeneia bore the star Eosphoros, thus Eos, preceded by the Morning Star, is seen as the genetrix of all the stars and planets, her tears are considered to have created the morning dew, personified as Ersa or Herse. Eos is the daughter of Hyperion, a bringer of light and her brother was the Sun god Helios, and her sister was Selene, the Moon goddess. Her team of horses pull her chariot across the sky and are named in the Odyssey as Firebright and Daybright. Eos is the daughter of Hyperion and Theia and sister of Helios the sun and Selene the moon, the generation of Titans preceded all the familiar deities of Olympus, who largely supplanted them. According to Pseudo-Apollodorus, Eos consorted with the war god Ares and was cursed with unsatisfiable sexual desire by the jealous Aphrodite. This caused her to abduct a number of young men, most notably Cephalus, Tithonus, Orion. The good-looking Cleitus was made immortal by her and she also asked for Tithonus to be made immortal, but forgot to ask for eternal youth, which resulted in him living forever as a helpless old man. According to Hesiod by Tithonus Eos had two sons, Memnon and Emathion, Memnon fought among the Trojans in the Trojan War and was slain. Her image with the dead Memnon across her knees, like Thetis with the dead Achilles are icons that inspired the Christian Pietà, in the literary myths Eos kidnapped Cephalus when he was hunting and took him to Syria. The second-century CE traveller Pausanias was informed that the abductor of Cephalus was Hemera, among the Etruscans, the generative dawn-goddess was Thesan. Depictions of the dawn-goddess with a young lover became popular in Etruria in the fifth century, on an Etruscan mirror Thesan is shown carrying off a young man, whose name is inscribed as Tinthu. The Roman equivalent of Eos is Aurora, also a cognate showing the characteristic Latin rhotacism, Dawn became associated in Roman cult with Matuta, later known as Mater Matuta. She was also associated with the sea harbors and ports, and had a temple on the Forum Boarium, on June 11, the Matralia was celebrated at that temple in honor of Mater Matuta, this festival was only for women during their first marriage. Tithonus Memnon Aurora Mater Matuta Zorya Dawn goddess Grimal, Pierre, The Dictionary of Classical Mythology, Wiley-Blackwell,1996, smith, William, Dictionary of Greek and Roman Biography and Mythology, London
10.
Ancient Greek
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Ancient Greek includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD. It is often divided into the Archaic period, Classical period. It is antedated in the second millennium BC by Mycenaean Greek, the language of the Hellenistic phase is known as Koine. Koine is regarded as a historical stage of its own, although in its earliest form it closely resembled Attic Greek. Prior to the Koine period, Greek of the classic and earlier periods included several regional dialects, Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical phases of the language, Ancient Greek was a pluricentric language, divided into many dialects. The main dialect groups are Attic and Ionic, Aeolic, Arcadocypriot, some dialects are found in standardized literary forms used in literature, while others are attested only in inscriptions. There are also several historical forms, homeric Greek is a literary form of Archaic Greek used in the epic poems, the Iliad and Odyssey, and in later poems by other authors. Homeric Greek had significant differences in grammar and pronunciation from Classical Attic, the origins, early form and development of the Hellenic language family are not well understood because of a lack of contemporaneous evidence. Several theories exist about what Hellenic dialect groups may have existed between the divergence of early Greek-like speech from the common Proto-Indo-European language and the Classical period and they have the same general outline, but differ in some of the detail. The invasion would not be Dorian unless the invaders had some relationship to the historical Dorians. The invasion is known to have displaced population to the later Attic-Ionic regions, the Greeks of this period believed there were three major divisions of all Greek people—Dorians, Aeolians, and Ionians, each with their own defining and distinctive dialects. Often non-west is called East Greek, Arcadocypriot apparently descended more closely from the Mycenaean Greek of the Bronze Age. Boeotian had come under a strong Northwest Greek influence, and can in some respects be considered a transitional dialect, thessalian likewise had come under Northwest Greek influence, though to a lesser degree. Most of the dialect sub-groups listed above had further subdivisions, generally equivalent to a city-state and its surrounding territory, Doric notably had several intermediate divisions as well, into Island Doric, Southern Peloponnesus Doric, and Northern Peloponnesus Doric. The Lesbian dialect was Aeolic Greek and this dialect slowly replaced most of the older dialects, although Doric dialect has survived in the Tsakonian language, which is spoken in the region of modern Sparta. Doric has also passed down its aorist terminations into most verbs of Demotic Greek, by about the 6th century AD, the Koine had slowly metamorphosized into Medieval Greek
11.
H&E stain
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Hematoxylin and eosin stain or haematoxylin and eosin stain is one of the principal stains in histology. A combination of hematoxylin and eosin, it produces blues, violets, the staining method involves application of hemalum, a complex formed from aluminum ions and hematein. Hemalum colors nuclei of cells blue, the nuclear staining is followed by counterstaining with an aqueous or alcoholic solution of eosin Y, which colors eosinophilic structures in various shades of red, pink and orange. The staining of nuclei by hemalum is ordinarily due to binding of the complex to DNA. The mechanism is different from that of nuclear staining by basic dyes such as thionine or toluidine blue, staining by basic dyes occurs only from solutions that are less acidic than hemalum, and it is prevented by prior chemical or enzymatic extraction of nucleic acids. The eosinophilic structures are composed of intracellular or extracellular protein. The Lewy bodies and Mallory bodies are examples of eosinophilic structures, most of the cytoplasm is eosinophilic. Red blood cells are stained intensely red, the structures do not have to be acidic or basic to be called basophilic and eosinophilic, the terminology is based on the affinity of cellular components for the dyes. Other colors, e. g. yellow and brown, can be present in the sample, they are caused by intrinsic pigments, some structures do not stain well. Basal laminae need to be stained by PAS stain or some silver stains, reticular fibers also require silver stain. Hydrophobic structures also tend to clear, these are usually rich in fats, e. g. adipocytes, myelin around neuron axons. Hematoxylin is a blue or violet stain that is basic/positive. DNA/RNA in the nucleus, and RNA in ribosomes in the endoplasmic reticulum are both acidic because the phosphate backbones of nucleic acids are negatively charged. The negatively charged backbones form salts with basic dyes containing positive charges, therefore, dyes like hematoxylin will bind to DNA and RNA and stain them violet. Eosin is a red or pink stain that is Acidic / Negative and it binds to acidophilic substances such as positively charged amino acid side chains. Most proteins in the cytoplasm of cells are basic because they are positively charged due to the arginine and lysine amino acid residues. These form salts with acid dyes containing negative charges, like eosin, therefore, eosin binds to these amino acids/proteins and stains them pink. This includes cytoplasmic filaments in muscle cells, intracellular membranes, kiernan JA Histological and Histochemical Methods, Theory and Practice
12.
Histology
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Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is commonly performed by examining cells and tissues under a microscope or electron microscope, the specimen having been sectioned, stained. Histological studies may be conducted using tissue culture, where human or animal cells are isolated and maintained in an artificial environment for various research projects. The ability to visualize or differentially identify microscopic structures is frequently enhanced through the use of histological stains, histology is an essential tool of biology and medicine. Trained physicians, frequently licensed pathologists, are the personnel who perform histopathological examination and their field of study is called histotechnology. In the 17th century, Italian Marcello Malpighi invented one of the first microscopes for studying tiny biological entities, Malpighi analysed several parts of the organs of bats, frogs and other animals under the microscope. Malpighi, while studying the structure of the lung, noticed its membranous alveoli and his discovery established how the oxygen we breathe enters the blood stream and serves the body. In the 19th century, histology was a discipline in its own right. The French anatomist Bichat introduced the concept of tissue in anatomy in 1801, the 1906 Nobel Prize in Physiology or Medicine was awarded to histologists Camillo Golgi and Santiago Ramon y Cajal. They had dueling interpretations of the structure of the brain based in differing interpretations of the same images. Cajal won the prize for his theory and Golgi for the staining technique he invented to make it possible. There are four types of animal tissues, muscle tissue, nervous tissue, connective tissue. All tissue types are subtypes of these four basic tissue types and their structure is very different from animal tissues. The most common fixative for light microscopy is 10% neutral buffered formalin, for electron microscopy, the most commonly used fixative is glutaraldehyde, usually as a 2. 5% solution in phosphate buffered saline. These fixatives preserve tissues or cells mainly by irreversibly cross-linking proteins and this can be detrimental to certain histological techniques. Further fixatives are often used for electron microscopy such as osmium tetroxide or uranyl acetate Formalin fixation leads to degradation of mRNA, miRNA and DNA in tissues, however, extraction, amplification and analysis of these nucleic acids from formalin-fixed, paraffin-embedded tissues is possible using appropriate protocols. Frozen section procedure is a way to fix and mount histology sections using a refrigeration device called a cryostat. It is often used after surgical removal of tumors to allow determination of margin
13.
Tissue (biology)
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In biology, tissue is a cellular organizational level intermediate between cells and a complete organ. A tissue is an ensemble of similar cells from the origin that together carry out a specific function. Organs are then formed by the grouping together of multiple tissues. The study of tissue is known as histology or, in connection with disease, the classical tools for studying tissues are the paraffin block in which tissue is embedded and then sectioned, the histological stain, and the optical microscope. In the last couple of decades, developments in microscopy, immunofluorescence. With these tools, the appearances of tissues can be examined in health and disease. Animal tissues are grouped into four types, connective, muscle, nervous. Collections of tissues joined in structural units to serve a common function compose organs, while all animals can generally be considered to contain the four tissue types, the manifestation of these tissues can differ depending on the type of organism. For example, the origin of the cells comprising a particular type may differ developmentally for different classifications of animals. By contrast, a true epithelial tissue is present only in a layer of cells held together via occluding junctions called tight junctions. This tissue covers all surfaces that come in contact with the external environment such as the skin, the airways. It serves functions of protection, secretion, and absorption, and is separated from other tissues below by a basal lamina and they are made up of cells separated by non-living material, which is called an extracellular matrix. This matrix can be liquid or rigid, for example, blood contains plasma as its matrix and bones matrix is rigid. Connective tissue gives shape to organs and holds them in place, blood, bone, tendon, ligament, adipose and areolar tissues are examples of connective tissues. One method of classifying tissues is to divide them into three types, fibrous connective tissue, skeletal connective tissue, and fluid connective tissue. Muscle cells form the active contractile tissue of the known as muscle tissue or muscular tissue. Muscle tissue functions to force and cause motion, either locomotion or movement within internal organs. Cells comprising the nervous system and peripheral nervous system are classified as nervous tissue
14.
Cell nucleus
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In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. Eukaryotes usually have a nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei. Cell nuclei contain most of the genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones. The genes within these chromosomes are the nuclear genome and are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression—the nucleus is, therefore, because the nuclear membrane is impermeable to large molecules, nuclear pores are required to regulate nuclear transport of molecules across the envelope. The pores cross both nuclear membranes, providing a channel through which larger molecules must be transported by carrier proteins while allowing free movement of small molecules. Movement of large molecules such as proteins and RNA through the pores is required for gene expression and the maintenance of chromosomes. The best-known of these is the nucleolus, which is involved in the assembly of ribosomes. After being produced in the nucleolus, ribosomes are exported to the cytoplasm where they translate mRNA, the nucleus was the first organelle to be discovered. What is most likely the oldest preserved drawing dates back to the early microscopist Antonie van Leeuwenhoek and he observed a lumen, the nucleus, in the red blood cells of salmon. Unlike mammalian red blood cells, those of other vertebrates still contain nuclei, the nucleus was also described by Franz Bauer in 1804 and in more detail in 1831 by Scottish botanist Robert Brown in a talk at the Linnean Society of London. Brown was studying orchids under microscope when he observed an opaque area and he did not suggest a potential function. In 1838, Matthias Schleiden proposed that the plays a role in generating cells. He believed that he had observed new cells assembling around cytoblasts, Franz Meyen was a strong opponent of this view, having already described cells multiplying by division and believing that many cells would have no nuclei. The function of the nucleus remained unclear, between 1877 and 1878, Oscar Hertwig published several studies on the fertilization of sea urchin eggs, showing that the nucleus of the sperm enters the oocyte and fuses with its nucleus. This was the first time it was suggested that an individual develops from a nucleated cell, therefore, the necessity of the sperm nucleus for fertilization was discussed for quite some time. However, Hertwig confirmed his observation in other groups, including amphibians. Eduard Strasburger produced the results for plants in 1884
15.
Red blood cell
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RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucleus and most organelles, in order to accommodate maximum space for hemoglobin, they can be viewed as sacks of hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults, the cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 60 seconds, approximately a quarter of the cells in the human body are red blood cells. Nearly half of the volume is red blood cells. Red blood cells are known as RBCs, red cells, red blood corpuscles, haematids. Packed red blood cells are red blood cells that have donated, processed. Almost all vertebrates, including all mammals and humans, have red blood cells, red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish, they live in very cold water. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome, oxygen can easily diffuse through the red blood cells cell membrane. Myoglobin, a related to hemoglobin, acts to store oxygen in muscle cells. The color of red cells is due to the heme group of hemoglobin. However, blood can appear bluish when seen through the vessel wall, pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. The red blood cells of mammals are typically shaped as disks, flattened and depressed in the center, with a dumbbell-shaped cross section
16.
Ethanol
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Ethanol, also called alcohol, ethyl alcohol, and drinking alcohol, is the principal type of alcohol found in alcoholic beverages. It is a volatile, flammable, colorless liquid with a characteristic odor. Its chemical formula is C 2H 6O, which can be written also as CH 3-CH 2-OH or C 2H 5-OH, ethanol is mostly produced by the fermentation of sugars by yeasts, or by petrochemical processes. It is a psychoactive drug, causing a characteristic intoxication. It is widely used as a solvent, as fuel, and as a feedstock for synthesis of other chemicals, the eth- prefix and the qualifier ethyl in ethyl alcohol originally come from the name ethyl assigned in 1834 to the group C 2H 5- by Justus Liebig. He coined the word from the German name Aether of the compound C 2H 5-O-C 2H5, according to the Oxford English Dictionary, Ethyl is a contraction of the Ancient Greek αἰθήρ and the Greek word ύλη. The name ethanol was coined as a result of a resolution that was adopted at the International Conference on Chemical Nomenclature that was held in April 1892 in Geneva, Switzerland. The term alcohol now refers to a class of substances in chemistry nomenclature. The Oxford English Dictionary claims that it is a loan from Arabic al-kuḥl, a powdered ore of antimony used since aniquity as a cosmetic. The use of alcohol for ethanol is modern, first recorded 1753, the systematic use in chemistry dates to 1850. Ethanol is used in medical wipes and most common antibacterial hand sanitizer gels as an antiseptic, ethanol kills organisms by denaturing their proteins and dissolving their lipids and is effective against most bacteria and fungi, and many viruses. However, ethanol is ineffective against bacterial spores, ethanol may be administered as an antidote to methanol and ethylene glycol poisoning. Ethanol, often in high concentrations, is used to dissolve many water-insoluble medications, as a central nervous system depressant, ethanol is one of the most commonly consumed psychoactive drugs. The amount of ethanol in the body is typically quantified by blood alcohol content, small doses of ethanol, in general, produce euphoria and relaxation, people experiencing these symptoms tend to become talkative and less inhibited, and may exhibit poor judgment. Ethanol is commonly consumed as a drug, especially while socializing. The largest single use of ethanol is as a fuel and fuel additive. Brazil in particular relies heavily upon the use of ethanol as an engine fuel, gasoline sold in Brazil contains at least 25% anhydrous ethanol. Hydrous ethanol can be used as fuel in more than 90% of new gasoline fueled cars sold in the country, Brazilian ethanol is produced from sugar cane and noted for high carbon sequestration
17.
Thymol
–
Thymol also provides the distinctive, strong flavor of the culinary herb thyme, also produced from T. vulgaris. Thymol is part of a naturally occurring class of known as biocides. In addition, thymol can reduce resistance to common drugs such as penicillin. Numerous studies have demonstrated the effects of thymol, ranging from inducing antibiotic susceptibility in drug-resistant pathogens to powerful antioxidant properties. This is especially relevant to Candida infections, carvacrol and thymol have been demonstrated to have an antimutagenic effect. In addition, there is evidence that thymol has antitumor properties, Thymol has antimicrobial activity because of its phenolic structure, and has shown antibacterial activity against bacterial strains including Aeromonas hydrophila and Staphylococcus aureus. In addition, thymol demonstrates considerable post antibacterial effect against some microorganisms and this antibacterial activity is caused by inhibiting growth and lactate production, and by decreasing cellular glucose uptake. Though the exact mechanism is unknown, some evidence suggests thymol effects at least some of its properties by membrane disruption. The antifungal nature of thymol is due to its ability to alter the morphology and cause hyphal aggregates, resulting in reduced hyphal diameters. Additionally, thymol is lipophilic, enabling it to interact with the membrane of fungus cells. Thymol has been shown to act as an allosteric modulator of GABAA in vitro. Research on rats concludes that thyme extract had relaxing effects on organs possessing β2-receptors, Thymol is only slightly soluble in water at neutral pH, but it is extremely soluble in alcohols and other organic solvents. It is also soluble in alkaline aqueous solutions due to deprotonation of the phenol. Thymol has a index of 1.5208 and an experimental dissociation exponent of 10.59 ±0.10. Thymol absorbs maximum UV radiation at 274 nm, Thymol is chemically related to the anesthetic propofol. Regions lacking natural sources of thymol obtain the compound via total synthesis, Thymol and carvacrol are now known to kill bacteria and fungi, making thyme well suited for such purposes. In Ancient Greece, thyme was used for its aromatic qualities. Thyme was also a symbol of courage and admiration, with the phrase the smell of thyme being a saying that reflected praise unto its subject
18.
Romanowsky stain
–
It was named after the Russian physician Dmitri Leonidovich Romanowsky, who invented it in 1891. Paul Ehrlich had used mixtures of acidic and basic dyes for this purpose in 1879, e. g. fuchsine and methylene blue. Requirement for the occurrence of the Romanowsky-Giemsa effect are, A cationic dye, The best dye is azure B and, though azure A gives the nuclear purple colour, no other cationic dye such as methylene blue is suitable. An anionic dye, Most commonly eosin Y is used, because the aqueous dye solutions were unstable, methanol was introduced as a solvent, and William Boog Leishman and James Homer Wright advocated its use as a fixative prior to staining. Gustav Giemsa improved this technique by standardizing the dye solutions and adding glycerol to increase stability, the demethylation of methylene blue in aqueous solution using heat and alkali produces a mixture of azure A, azure B, methylene violet, and methylene blue. Eosin Y is then added to produce a neutral dye, the working solution is stable for 3 hours. Immunochromatographic capture procedures are nonmicroscopic diagnostic options for the laboratory that may not have appropriate microscopy expertise available
19.
Merbromin
–
Merbromin is a topical antiseptic used for minor cuts and scrapes. Merbromin is an organomercuric disodium salt compound and a fluorescein and it is readily available in most countries but, because of its mercury content, it is no longer sold in Switzerland, France, Germany, and the United States. Merbromins best-known use is as an antiseptic to treat minor wounds, burns. It is also used in the antisepsis of the cord and the antisepsis of wound of difficult scar formation, like neuropathic ulcers. When applied on a wound, it stains the skin a distinctive carmine red and it is useful on infections of the finger or toe nails because of its permanence, and lethality to bacteria. It was known in households as monkey blood. In the United States, its use has been superseded by other agents. It is still an important antiseptic, particularly in developing nations, due to its low cost. ”Merbromin is also used as a biological dye to mark tissue margins. Merbromin is synthesized by combining dibromofluorescein with mercuric acetate and sodium hydroxide or alternatively, because of its anionic character, it is chemically incompatible with acids, the majority of alkaloid salts and most local anesthetics. Mercurochrome is a name of merbromin. The name is commonly used for over-the-counter antiseptic solutions consisting of merbromin dissolved in either ethyl alcohol or water. Its antiseptic qualities were discovered by Hugh H, young in 1918, while working at Johns Hopkins Hospital as a physician. The chemical soon became popular among parents and physicians for everyday antiseptic uses, sales were halted in Germany in 2003, and in France in 2006. It is readily available in most other countries, within the United States, products such as Humco Mercuroclear play on the brand recognition history of Mercurochrome, but substitute other ingredients with similar properties. Thiomersal, also known as Thimerosal or Merthiolate
20.
Simplified molecular-input line-entry system
–
The simplified molecular-input line-entry system is a specification in form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors for conversion back into two-dimensional drawings or three-dimensional models of the molecules, the original SMILES specification was initiated in the 1980s. It has since modified and extended. In 2007, a standard called OpenSMILES was developed in the open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. The Environmental Protection Agency funded the project to develop SMILES. It has since modified and extended by others, most notably by Daylight Chemical Information Systems. In 2007, a standard called OpenSMILES was developed by the Blue Obelisk open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, in July 2006, the IUPAC introduced the InChI as a standard for formula representation. SMILES is generally considered to have the advantage of being slightly more human-readable than InChI, the term SMILES refers to a line notation for encoding molecular structures and specific instances should strictly be called SMILES strings. However, the term SMILES is also used to refer to both a single SMILES string and a number of SMILES strings, the exact meaning is usually apparent from the context. The terms canonical and isomeric can lead to confusion when applied to SMILES. The terms describe different attributes of SMILES strings and are not mutually exclusive, typically, a number of equally valid SMILES strings can be written for a molecule. For example, CCO, OCC and CC all specify the structure of ethanol, algorithms have been developed to generate the same SMILES string for a given molecule, of the many possible strings, these algorithms choose only one of them. This SMILES is unique for each structure, although dependent on the algorithm used to generate it. These algorithms first convert the SMILES to a representation of the molecular structure. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database, there is currently no systematic comparison across commercial software to test if such flaws exist in those packages. SMILES notation allows the specification of configuration at tetrahedral centers, and these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES
21.
PubMed Identifier
–
PubMed is a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States National Library of Medicine at the National Institutes of Health maintains the database as part of the Entrez system of information retrieval, from 1971 to 1997, MEDLINE online access to the MEDLARS Online computerized database primarily had been through institutional facilities, such as university libraries. PubMed, first released in January 1996, ushered in the era of private, free, home-, the PubMed system was offered free to the public in June 1997, when MEDLINE searches via the Web were demonstrated, in a ceremony, by Vice President Al Gore. Information about the journals indexed in MEDLINE, and available through PubMed, is found in the NLM Catalog. As of 5 January 2017, PubMed has more than 26.8 million records going back to 1966, selectively to the year 1865, and very selectively to 1809, about 500,000 new records are added each year. As of the date,13.1 million of PubMeds records are listed with their abstracts. In 2016, NLM changed the system so that publishers will be able to directly correct typos. Simple searches on PubMed can be carried out by entering key aspects of a subject into PubMeds search window, when a journal article is indexed, numerous article parameters are extracted and stored as structured information. Such parameters are, Article Type, Secondary identifiers, Language, publication type parameter enables many special features. As these clinical girish can generate small sets of robust studies with considerable precision, since July 2005, the MEDLINE article indexing process extracts important identifiers from the article abstract and puts those in a field called Secondary Identifier. The secondary identifier field is to store numbers to various databases of molecular sequence data, gene expression or chemical compounds. For clinical trials, PubMed extracts trial IDs for the two largest trial registries, ClinicalTrials. gov and the International Standard Randomized Controlled Trial Number Register, a reference which is judged particularly relevant can be marked and related articles can be identified. If relevant, several studies can be selected and related articles to all of them can be generated using the Find related data option, the related articles are then listed in order of relatedness. To create these lists of related articles, PubMed compares words from the title and abstract of each citation, as well as the MeSH headings assigned, using a powerful word-weighted algorithm. The related articles function has been judged to be so precise that some researchers suggest it can be used instead of a full search, a strong feature of PubMed is its ability to automatically link to MeSH terms and subheadings. Examples would be, bad breath links to halitosis, heart attack to myocardial infarction, where appropriate, these MeSH terms are automatically expanded, that is, include more specific terms. Terms like nursing are automatically linked to Nursing or Nursing and this important feature makes PubMed searches automatically more sensitive and avoids false-negative hits by compensating for the diversity of medical terminology. The My NCBI area can be accessed from any computer with web-access, an earlier version of My NCBI was called PubMed Cubby
22.
Antiseptic
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Antiseptic are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction. Disinfectants do not kill bacterial spores e. g. on surgical instruments, even sterilization may not destroy prions. Some antibiotics are true germicides, capable of destroying microbes, while others are bacteriostatic, antibacterials are antiseptics that have the proven ability to act against bacteria. Microbicides which destroy virus particles are called viricides or antivirals, antisepsis was recommended by Hungarian physician Ignaz Semmelweis in 1847 but, tragically, he was ignored. In this paper, Lister advocated the use of acid as a method of ensuring that any germs present were killed. Some of this work was anticipated by, Ancient Greek physicians Galen and Hippocrates and their theories were bitterly opposed by Galenist Guy de Chauliac and others trained in the classical tradition. Joseph Smith alluded to the use of alcohol as an antiseptic in February 1833, specifically, verse 7 states, And, again, strong drinks are not for the belly, but for the washing of your bodies. More commonly, 3% solutions of hydrogen peroxide have been used in household first aid for scrapes, however, the strong oxidization causes scar formation and increases healing time during fetal development. Iodine is usually used in a solution or as Lugols iodine solution as a pre-. Some people do not recommend disinfecting minor wounds with iodine because of concern that it may induce scar tissue formation, however, concentrations of 1% iodine or less have not been shown to increase healing time and are not otherwise distinguishable from treatment with saline. Polyhexanide is a compound suitable for clinical use in critically colonized or infected acute. The physicochemical action on the bacterial envelope prevents or impedes the development of resistant bacterial strains, balsam of Peru is a mild antiseptic. By continued exposure to antibiotics, bacteria may evolve to the point where they are no longer harmed by these compounds, bacteria can also develop a resistance to antiseptics, but the effect is generally less pronounced. The mechanism by which bacteria evolve may vary in response to different antiseptics, low concentrations of an antiseptic may encourage growth of a bacterial strain that is resistant to the antiseptic, where a higher concentration of the antiseptic would simply kill the bacteria. In addition, use of a high concentration of an antiseptic may cause tissue damage or slow the process of wound healing
23.
Disinfectant
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Disinfectants are antimicrobial agents that are applied to the surface of non-living objects to destroy microorganisms that are living on the objects. Disinfectants are different from other agents such as antibiotics, which destroy microorganisms within the body, and antiseptics. Disinfectants are also different from biocides — the latter are intended to destroy all forms of life, Disinfectants work by destroying the cell wall of microbes or interfering with the metabolism. Sanitizer are substances that simultaneously clean and disinfect, Disinfectants are frequently used in hospitals, dental surgeries, kitchens, and bathrooms to kill infectious organisms. Bacterial endospores are most resistant to disinfectants, but some viruses, an alternative term used in the sanitation sector for disinfection of waste streams, sewage sludge or fecal sludge is sanitisation or sanitization. A perfect disinfectant would also complete and full microbiological sterilisation, without harming humans and useful form of life, be inexpensive. However, most disinfectants are also, by nature, potentially harmful to humans or animals, most modern household disinfectants contain Bitrex, an exceptionally bitter substance added to discourage ingestion, as a safety measure. Those that are used indoors should never be mixed with other cleaning products as chemical reactions can occur, the choice of disinfectant to be used depends on the particular situation. Some disinfectants have a spectrum, while others kill a smaller range of disease-causing organisms but are preferred for other properties. There are arguments for creating or maintaining conditions that are not conducive to survival and multiplication. Bacteria can increase in very quickly, which enables them to evolve rapidly. Should some bacteria survive an attack, they give rise to new generations composed completely of bacteria that have resistance to the particular chemical used. Under a sustained attack, the surviving bacteria in successive generations are increasingly resistant to the chemical used. For this reason, some question the wisdom of impregnating cloths, cutting boards, air disinfectants are typically chemical substances capable of disinfecting microorganisms suspended in the air. Disinfectants are generally assumed to be limited to use on surfaces, in 1928, a study found that airborne microorganisms could be killed using mists of dilute bleach. An air disinfectant must be dispersed either as an aerosol or vapour at a sufficient concentration in the air to cause the number of infectious microorganisms to be significantly reduced. In principle, these substances are ideal air disinfectants because they have both high lethality to microorganisms and low mammalian toxicity. The engineering challenge associated with creating a sufficient concentration of the glycol vapours in the air have not to date been sufficiently addressed, Alcohols are most effective when combined with distilled water to facilitate diffusion through the cell membrane, 100% alcohol typically denatures only external membrane proteins
24.
Acridine
–
Acridine is an organic compound and a nitrogen heterocycle with the formula C13H9N. Acridines are substituted derivatives of the parent ring and it is a planar molecule that is structurally related to anthracene with one of the central CH groups replaced by nitrogen. Like the related molecule pyridine and quinoline, acridine is mildly basic and it is an almost colorless solid. There are no applications of acridines but at one time acridine dyes were popular. Carl Gräbe and Heinrich Caro first isolated acridine in 1870 from coal tar, acridine is separated from coal tar by extracting with dilute sulfuric acid. Addition of potassium dichromate to this solution precipitates acridine bichromate, the bichromate is decomposed using ammonia. Acridine and its derivatives can be prepared by many synthetic processes, in the Bernthsen acridine synthesis, diphenylamine is condensed with carboxylic acids in the presence of zinc chloride. When formic acid is the acid, the reaction yields the parent acridine. With the higher larger carboxylic acids, the derivatives substituted at the carbon atom are generated. Another classic method for the synthesis of acridones is the Lehmstedt-Tanasescu reaction, acridine displays the reactions expected of an unsaturated N-heterocycle. It undergoes N-alkylation with alkyl iodides to form alkyl acridinium iodides, acridine and its homologues are weakly basic. Acridine is a photobase which have a ground state pKa of 5.1, which is similar to that of pyridine and it also shares properties with quinoline. Acridines can be reduced to the 9, 10-dihydroacridines, sometimes called leuco acridines, reaction with potassium cyanide gives the 9-cyano-9, 10-dehydro derivative. On oxidation with permanganate, it yields acridinic acid otherwise known as quinoline-1. Acridine is easily oxidized by peroxymonosulfuric acid to the amine oxide. The carbon 9-position of acridine is activated for addition reactions, several dyes and drugs feature the acridine skeleton. Many acridines, such as proflavine, also have antiseptic properties, acridine and related derivatives bind to DNA and RNA due to their abilities to intercalate. Acridine orange is a nucleic acid-selective metachromatic stain useful for cell cycle determination, at one time acridine dyes were commercially significant, but they are now uncommon because they are not lightfast
25.
Ethacridine lactate
–
Ethacridine lactate is an aromatic organic compound based on acridine. Its formal name is 2-ethoxy-6, 9-diaminoacridine monolactate monohydrate and it forms orange-yellow crystals with a melting point of 226 °C and it has a stinging smell. Its primary use is as an antiseptic in solutions of 0. 1% and it is effective against mostly gram-positive species like Streptococci and Staphylococci and ineffective against gram-negative. Ethacridine is also used as an agent for second trimester abortion, up to 150 ml of a 0. 1% solution is instilled extra-amniotically using a foley catheter. After 20 to 40 hours, mini labor ensues, in China, an intra-amniotic method has also been used. Ethacridine as an abortifacient is found to be safer and better tolerated than 20% hypertonic saline, tien, K. H. Intraamniotic injection of ethacridine for second-trimester induction of labor. Adarchenko AA, Krasilnikov AP, Sobeshchuk OP
26.
Biguanide
–
Biguanide is the organic compound with the formula HN2. It is a solid that dissolves in water to give highly basic solution. These solutions slowly hydrolyse to ammonia and urea, a variety of derivatives of biguanide are used as pharmaceutical drugs. The term biguanidine often refers specifically to a class of drugs function as oral antihyperglycemic drugs used for diabetes mellitus or prediabetes treatment. In the 1920s, guanidine compounds were discovered in Galega extracts, animal studies showed that these compounds lowered blood glucose levels. Some less toxic derivatives, synthalin A and synthalin B, were used for diabetes treatment, biguanides were reintroduced into Type 2 diabetes treatment in the late 1950s. Initially phenformin was widely used, but its potential for sometimes fatal lactic acidosis resulted in its withdrawal from most pharmacopeias, metformin has a much better safety profile, and it is the principal biguanide drug used in pharmacotherapy worldwide. Biguanides do not affect the output of insulin, unlike other hypoglycemic agents such as sulfonylureas, therefore, they are effective in Type 2 diabetics, and in Type 1 diabetes when used in conjunction with insulin therapy. The mechanism of action of biguanides is not fully understood, however, in hyperinsulinemia, biguanides can lower fasting levels of insulin in plasma. Their therapeutic uses derive from their tendency to reduce gluconeogenesis in the liver, biguanides also tend to make the cells of the body more willing to absorb glucose already present in the blood stream, and there again reducing the level of glucose in the plasma. The most common effect is diarrhea and dyspepsia, occurring in up to 30% of patients. The most important and serious side effect is lactic acidosis, therefore metformin is contraindicated in renal insufficiency, renal functions should be assessed before starting metformin. Phenformin and buformin are more prone to cause acidosis than metformin, however, when metformin is combined with other drugs, hypoglycemia and other side effects are possible. Some biguanides are also used as antimalarial drugs, examples include, Proguanil Chlorproguanil The disinfectants chlorhexidine, polyaminopropyl biguanide, polihexanide, and alexidine feature biguanide functional groups
27.
Amidine
–
Amidines are a class of oxoacid derivatives. The oxoacid from which an amidine is derived must be of the form RnEOH, the −OH group is replaced by an −NH2 group and the =O group is replaced by =NR, giving amidines the general structure RnENR2. The simplest amidine is formamidine, HCNH2, examples of amidines include, DBU diminazene benzamidine Pentamidine Paranyline The most common way to make primary amidines is by the Pinner reaction. Reaction of the nitrile with acidic alcohol gives an iminoether, treatment of this with ammonia then completes the conversion to the amidine, amidines are much more basic than amides and are among the strongest neutral bases. Protonation occurs onto the sp² hybridized nitrogen and this occurs because the positive charge can be delocalized onto both nitrogen atoms. The resulting cationic species is known as an ion and possesses identical C-N bond lengths. An notable subclass of amidinium ions are the cations, which can be represented by the chemical formula +. Deprotonation of these gives stable carbenes which can be represented by the chemical formula R2N-C, an amidinate salt has the general structure M+− and can be accessed by reaction of a carbodiimide with an organometallic compound such as methyl lithium. They are used widely as ligands in organometallic complexes, guanidines — a similar group of compounds where the central Carbon is bonded to three Nitrogens
28.
Dibrompropamidine
–
Dibrompropamidine is an antiseptic and disinfectant. As dibrompropamidine isethionate, it is used in eyedrops and ointment for the treatment of eye and eyelid infections in adults. In the UK, such preparations are sold under the brand names Brolene, Golden Eye, a white or almost white, crystalline powder, odourless or almost odourless. Freely soluble in water, soluble in glycerol, sparingly soluble in ethanol, practically insoluble in chloroform, in ether, in liquid paraffin and in fixed oils
29.
Chlorhexidine
–
Chlorhexidine is a disinfectant and antiseptic that is used for skin disinfection before surgery and to sterilize surgical instruments. It may be used both to disinfect the skin of the patient and the hands of the healthcare providers and it is also used for cleaning wounds, preventing dental plaque, treating yeast infections of the mouth, and to keep urinary catheters from blocking. It is used as a liquid or powder, side effects may include skin irritation, teeth discoloration, and allergic reactions. May cause eye problems if direct contact occurs, use in pregnancy appears to be safe. Chlorhexidine may come mixed in alcohol, water, or surfactant solution and it is effective against a range of microorganisms though does not inactivate spores. Chlorhexidine came into use in the 1950s. It is on the World Health Organizations List of Essential Medicines, chlorhexidine is available over the counter. The wholesale cost in the world is about 2.20 to 4.10 USD per liter of 5% solution. In the United Kingdom this amount costs the NHS about £4.80, chlorhexidine is used in disinfectants, cosmetics, and pharmaceutical products. In endodontics chlorhexidine is used for root canal irrigation and as an intracanal dressing, there is tentative evidence that it is more effective than povidone-iodine. Chlorhexidine is active against Gram-positive and Gram-negative organisms, facultative anaerobes, aerobes and it is particularly effective against Gram-positive bacteria. Significantly higher concentrations are required for Gram-negative bacteria and fungi, chlorhexidine is ineffective against polioviruses and adenoviruses. The effectiveness against herpes viruses has not yet been established unequivocally, chlorhexidine, like other cation-active compounds, remains on the skin. It is frequently combined with alcohols, chlorhexidine is often used as an active ingredient in mouthwash designed to reduce dental plaque and oral bacteria. It has been shown to have a bactericidal action and a prolonged bacteriostatic action due to adsorption onto the pellicle-coated enamel surface. If it is not deactivated, chlorhexidine lasts longer in the mouth than other mouthwashes, to treat periodontal pockets equal or greater than 5 mm, chlorhexidine is also available in high concentration in a gelatin chip. These conditions included gingivitis, periodontitis, dental traumas, oral cysts, the clinical efficacy of the application of chlorhexidine as a component of oral rinses is well documented by many clinical studies summarized by review articles. The brownish discoloration of teeth and tongue is due to the disintegration of bacterial membranes, at the same time, disulfide functions are reduced to thiol functions that form dark complexes with iron ions found in saliva
30.
Polyhexanide
–
Polyhexanide is a polymer used as a disinfectant and antiseptic. In dermatological use, it is spelled polihexanide and sold under such as Lavasept, Serasept. PHMB eye drops have been used as a treatment for eyes affected by Acanthamoeba keratitis, branded as Baquacil, it also has an application as a swimming-pool and spa water sanitizer in place of chlorine- or bromine-based products. It is available as Baqua-Spa 3 sanitize, as Revacil Spa 3 sanitizer, PHMB is also used as an ingredient in some contact lens cleaning products, cosmetics, personal deodorants and some veterinary products. The PHMB hydrochloride salt is used in the majority of formulations, polyaminopropyl biguanide, a related biguanide disinfectant
31.
Phenol
–
Phenol, also known as carbolic acid, is an aromatic organic compound with the molecular formula C6H5OH. It is a crystalline solid that is volatile. The molecule consists of a phenyl group bonded to a hydroxyl group and it is mildly acidic and requires careful handling due to its propensity to cause chemical burns. Phenol was first extracted from tar, but today is produced on a large scale from petroleum. It is an important industrial commodity as a precursor to many materials and it is primarily used to synthesize plastics and related materials. Phenol and its derivatives are essential for production of polycarbonates, epoxies, Bakelite, nylon, detergents, herbicides such as phenoxy herbicides. Phenol is appreciably soluble in water, with about 84.2 g dissolving in 1000 mL, homogeneous mixtures of phenol and water at phenol to water mass ratios of ~2.6 and higher are possible. The sodium salt of phenol, sodium phenoxide, is far more water-soluble and it reacts completely with aqueous NaOH to lose H+, whereas most alcohols react only partially. One explanation for the increased acidity over alcohols is resonance stabilization of the anion by the aromatic ring. In this way, the charge on oxygen is delocalized on to the ortho. In another explanation, increased acidity is the result of orbital overlap between the lone pairs and the aromatic system. The pKa of the enol of acetone is 10.9, the acidities of phenol and acetone enol diverge in the gas phase owing to the effects of solvation. About 1⁄3 of the acidity of phenol is attributable to inductive effects. Phenolate esters are more stable toward hydrolysis than acid anhydrides and acyl halides but are sufficiently reactive under mild conditions to facilitate the formation of amide bonds, Phenol exhibits keto-enol tautomerism with its unstable keto tautomer cyclohexadienone, but only a tiny fraction of phenol exists as the keto form. The equilibrium constant for enolisation is approximately 10−13, meaning only one in every ten trillion molecules is in the keto form at any moment. The small amount of stabilisation gained by exchanging a C=C bond for a C=O bond is more than offset by the large destabilisation resulting from the loss of aromaticity, Phenol therefore exists essentially entirely in the enol form. Phenoxides are enolates stabilised by aromaticity, under normal circumstances, phenoxide is more reactive at the oxygen position, but the oxygen position is a hard nucleophile whereas the alpha-carbon positions tend to be soft. Phenol is highly reactive toward electrophilic aromatic substitution as the oxygen atoms pi electrons donate electron density into the ring, by this general approach, many groups can be appended to the ring, via halogenation, acylation, sulfonation, and other processes
32.
Hexachlorophene
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Hexachlorophene, also known as Nabac, is an organochlorine compound that was once widely used as a disinfectant. The compound occurs as an odorless solid, although commercial samples can be off-white. It is insoluble in water but dissolves in acetone, ethanol, diethyl ether, in medicine, hexachlorophene is a useful as a topical anti-infective, anti-bacterial agent, often used in soaps and toothpaste. It is also used in agriculture as a fungicide, plant bactericide. In 1972, the U. S. Food and Drug Administration halted the production and distribution of products containing more than 1% of hexachlorophene, after that point, most products that contain hexachlorophene were available only by prescription from a doctor. The restrictions were enacted after 15 deaths in the United States and 39 deaths in France were reported following brain damage caused by hexachlorophene, at least two companies manufactured over-the-counter preparations incorporating hexachlorophene. One product was Baby Magic Bath by The Mennen Company, Mennen recalled the product in 1971, and it was removed from retail distribution. Immediately after the withdrawal, there was an outbreak of Staphylococcus infections in hospitals across the USA, in the US during the 1960s, both were available over the counter. In the European Community countries during the 1970s and 1980s, pHisoHex was available over the counter, a related product, pHisoAc, was used as a skin mask to dry and peel away acne lesions. Another preparation, pHiso-Scrub, was a sponge for scrubbing, has since been discontinued. Several substitute products were developed, but none had the capability of hexachlorophene. Sanofi-Aventis was the manufacturer of pHisoHex, while The Mentholatum Company owns the pHisoDerm brand today. Sanofi-Aventis discontinued production of several forms of pHisoHex in August 2009, the formula for Dial soap was changed to remove hexachlorophene after the FDA put an end to over-the-counter availability in 1972. In Germany, cosmetics containing hexachlorophene have been forbidden since 1985, in Austria, sale of drugs containing the substance has been forbidden since 1990. Hexacholorophene is produced by alkylation of 2,4, 5-trichlorophenol with formaldehyde, related antiseptics are prepared similarly, e. g. bromochlorophene and dichlorophene. The LD50 is 59 mg/kg, indicating that the compound is relatively toxic and it is not mutagenic nor teratogenic according to Ullmanns Encyclopaedia, but embryotoxic and produces some teratogenic effects according to the International Agency for Research on Cancer. Trade names for hexachlorophene include, Acigena, Almederm, AT7, AT17, Bilevon, Exofene, Fostril, Gamophen, G-11, Germa-Medica, Hexosan, K-34, Septisol, Surofene
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Policresulen
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Policresulen is a topical haemostatic and antiseptic. It is indicated for common anal disorders, such as hemorrhoids, in some countries it is marketed under the trade name Albothyl or Polilen or Faktu. Policresulen is often used for gynecological infections, while it has some controversies, it is also used to treat canker sore in some countries. It is known to have an immense pain after the application on canker sore, the chain of Policresulen is negatively charged, making it acidic. Its pKa is less than 0, yet it is considered a weak acid, the mechanism of action is that normal cells are negatively charged, therefore repelling each other. However, wounded and damaged cells are positively charged, causing the Policresulen to be attracted, Policresulen works by making a slight chemical burn on the wounded area, which kills the bacteria and makes the area antiseptic
. PMID 6769391.
