Simplified molecular-input line-entry system
The simplified molecular-input line-entry system is a specification in the 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 been extended. In 2007, an open standard called. Other linear notations include the Wiswesser line notation, ROSDAL, SYBYL Line Notation; the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. Acknowledged for their parts in the early development were "Gilman Veith and Rose Russo and Albert Leo and Corwin Hansch for supporting the work, Arthur Weininger and Jeremy Scofield for assistance in programming the system." The Environmental Protection Agency funded the initial project to develop SMILES. It has since been modified and extended by others, most notably by Daylight Chemical Information Systems.
In 2007, an open 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 considered to have the advantage of being more human-readable than InChI; the term SMILES refers to a line notation for encoding molecular structures and specific instances should be called SMILES strings. However, the term SMILES is commonly used to refer to both a single SMILES string and a number of SMILES strings; the terms "canonical" and "isomeric" can lead to some confusion when applied to SMILES. The terms are not mutually exclusive. A number of 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; this SMILES is unique for each structure, although dependent on the canonicalization algorithm used to generate it, is termed the canonical SMILES.
These algorithms first convert the SMILES to an internal representation of the molecular structure. Various algorithms for generating canonical SMILES have been developed and include those by Daylight Chemical Information Systems, OpenEye Scientific Software, MEDIT, Chemical Computing Group, MolSoft LLC, the Chemistry Development Kit. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database; the original paper that described the CANGEN algorithm claimed to generate unique SMILES strings for graphs representing molecules, but the algorithm fails for a number of simple cases and cannot be considered a correct method for representing a graph canonically. There is 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, double bond geometry; these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES.
A notable feature of these rules is. The term isomeric SMILES is applied to SMILES in which isotopes are specified. In terms of a graph-based computational procedure, SMILES is a string obtained by printing the symbol nodes encountered in a depth-first tree traversal of a chemical graph; the chemical graph is first trimmed to remove hydrogen atoms and cycles are broken to turn it into a spanning tree. Where cycles have been broken, numeric suffix labels are included to indicate the connected nodes. Parentheses are used to indicate points of branching on the tree; the resultant SMILES form depends on the choices: of the bonds chosen to break cycles, of the starting atom used for the depth-first traversal, of the order in which branches are listed when encountered. Atoms are represented by the standard abbreviation of the chemical elements, in square brackets, such as for gold. Brackets may be omitted in the common case of atoms which: are in the "organic subset" of B, C, N, O, P, S, F, Cl, Br, or I, have no formal charge, have the number of hydrogens attached implied by the SMILES valence model, are the normal isotopes, are not chiral centers.
All other elements must be enclosed in brackets, have charges and hydrogens shown explicitly. For instance, the SMILES for water may be written as either O or. Hydrogen may be written as a separate atom; when brackets are used, the symbol H is added if the atom in brackets is bonded to one or more hydrogen, followed by the number of hydrogen atoms if greater than 1 by the sign + for a positive charge or by - for a negative charge. For example, for ammonium. If there is more than one charge, it is written as digit.
European Chemicals Agency
The European Chemicals Agency is an agency of the European Union which manages the technical and administrative aspects of the implementation of the European Union regulation called Registration, Evaluation and Restriction of Chemicals. ECHA is the driving force among regulatory authorities in implementing the EU's chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and addresses chemicals of concern, it is located in Finland. The agency headed by Executive Director Bjorn Hansen, started working on 1 June 2007; the REACH Regulation requires companies to provide information on the hazards and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most used substances have been registered; the information is technical but gives detail on the impact of each chemical on people and the environment.
This gives European consumers the right to ask retailers whether the goods they buy contain dangerous substances. The Classification and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU; this worldwide system makes it easier for workers and consumers to know the effects of chemicals and how to use products safely because the labels on products are now the same throughout the world. Companies need to notify ECHA of the labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100 000 substances; the information is available on their website. Consumers can check chemicals in the products. Biocidal products include, for example, insect disinfectants used in hospitals; the Biocidal Products Regulation ensures that there is enough information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation; the law on Prior Informed Consent sets guidelines for the import of hazardous chemicals.
Through this mechanism, countries due to receive hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have serious effects on human health and the environment are identified as Substances of Very High Concern 1; these are substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment and do not break down. Other substances considered. Companies manufacturing or importing articles containing these substances in a concentration above 0,1% weight of the article, have legal obligations, they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy. Once a substance has been identified in the EU as being of high concern, it will be added to a list; this list is available on ECHA's website and shows consumers and industry which chemicals are identified as SVHCs.
Substances placed on the Candidate List can move to another list. This means that, after a given date, companies will not be allowed to place the substance on the market or to use it, unless they have been given prior authorisation to do so by ECHA. One of the main aims of this listing process is to phase out SVHCs where possible. In its 2018 substance evaluation progress report, ECHA said chemical companies failed to provide “important safety information” in nearly three quarters of cases checked that year. "The numbers show a similar picture to previous years" the report said. The agency noted that member states need to develop risk management measures to control unsafe commercial use of chemicals in 71% of the substances checked. Executive Director Bjorn Hansen called non-compliance with REACH a "worry". Industry group CEFIC acknowledged the problem; the European Environmental Bureau called for faster enforcement to minimise chemical exposure. European Chemicals Bureau Official website
Abies alba, the European silver fir or silver fir, is a fir native to the mountains of Europe, from the Pyrenees north to Normandy, east to the Alps and the Carpathians, Croatia and Herzegovina, Montenegro and south to Italy, Bulgaria and northern Greece. Abies alba is a large evergreen coniferous tree growing to 40–50 m tall and with a trunk diameter up to 1.5 m. The largest measured tree had a trunk diameter of 3.8 m. It occurs at altitudes of 300–1,700 m, on mountains with rainfall over 1,000 millimetres per year; the leaves are needle-like, flattened, 1.8–3.0 cm long and 2.0 mm wide by 0.5 mm thick, glossy dark green above, with two greenish-white bands of stomata below. The tip of the leaf is slightly notched at the tip; the cones are 9–17 cm long and 3–4 cm broad, with about 150-200 scales, each scale with an exserted bract and two winged seeds. The wood is white, leading to the species name alba; when cultivated on Christmas Tree plantations, the tree forms a symmetrical triangle shape.
The trees are full and dense with strong evergreen fragrance, are known to be one of the longest lasting after being cut. In the forest the evergreen tends to form stands with other beeches, it is related to Bulgarian fir further to the southeast in the Balkan Peninsula, Spanish fir of Spain and Morocco and Sicilian fir in Sicily, differing from these and other related Euro-Mediterranean firs in the sparser foliage, with the leaves spread either side of the shoot, leaving the shoot visible from above. Some botanists treat Bulgarian fir and Sicilian fir as varieties of silver fir, as A. alba var. acutifolia and A. alba var. nebrodensis, respectively. Silver fir is an important component species in the dinaric calcareous block fir forest in the western Balkan Peninsula. In Italy, the silver fir is an important component of the mixed broadleaved-coniferous forest of the Apennine Mountains in northern Apennine; the fir prefer a humid climate, in northern exposition, with a high rainfall. In the oriental Alps of Italy, silver firs grow in mixed forests with Norway spruce and other trees.
Its cone scales are eaten by the caterpillars of the tortrix moth Cydia illutana, while C. duplicana feeds on the bark around injuries or canker. The bark and wood of silver fir are rich in antioxidative polyphenols. Six phenolic acids were identified, three flavonoids and eight lignans; the extract from the trunk was shown to prevent atherosclerosis in guinea pigs and to have cardioprotective effect in isolated rat hearts. Silver fir wood extract was found to reduce the post-prandial glycemic response in healthy volunteers. A resinous essential oil can be extracted; this pine-scented oil is used in perfumes, bath products, aerosol inhalants. Its branches were used for production of spruce beer. Silver fir is the species first used as a Christmas tree, but has been replaced by Nordmann fir, Norway spruce, other species; the wood is strong, light-colored, fine grained, even-textured and long fibered. The timber is used as construction wood, plywood and paper manufacture. Abies is derived from Latin, meaning ‘rising one’.
The name was used to refer to tall ships. Alba means ‘bright’ or ‘dead white’. Kunkar, Alp. Le piante officinali della Calabria. Laruffa Editore. ISBN 978-88-7221-140-3. Conifers.org: Abies alba botany.cz: Abies alba Mill photomazza.com: Abies alba conifersaroundtheworld.com: Abies alba - European White Fir. pfaf.org: Abies alba Mill. monumentaltrees.com: The thickest and oldest European silver fir trees baumkunde.de: Weiß-Tanne | In German Abies alba. Distribution map, genetic conservation units and related resources. European Forest Genetic Resources Programme
Flax known as common flax or linseed, is a member of the genus Linum in the family Linaceae. It is a fiber crop cultivated in cooler regions of the world; the textiles made from flax are known in the Western countries as linen, traditionally used for bed sheets and table linen. The oil is known as linseed oil. In addition to referring to the plant itself, the word "flax" may refer to the unspun fibers of the flax plant; the plant species is known only as a cultivated plant, appears to have been domesticated just once from the wild species Linum bienne, called pale flax. Several other species in the genus Linum are similar in appearance to L. usitatissimum, cultivated flax, including some that have similar blue flowers, others with white, yellow, or red flowers. Some of these are perennial plants, unlike L. usitatissimum, an annual plant. Cultivated flax plants grow to 1.2 m tall, with slender stems. The leaves are glaucous green, slender lanceolate, 20–40 mm long, 3 mm broad; the flowers are 15 -- 25 mm in diameter, with five petals.
The fruit is a round, dry capsule 5–9 mm in diameter, containing several glossy brown seeds shaped like an apple pip, 4–7 mm long. The earliest evidence of humans using wild flax as a textile comes from the present-day Republic of Georgia, where spun and knotted wild flax fibers were found in Dzudzuana Cave and dated to the Upper Paleolithic, 30,000 years ago. Flax was first domesticated in the Fertile Crescent region. Evidence exists of a domesticated oilseed flax with increased seed size by 9,000 years ago from Tell Ramad in Syria. Use of the crop spread, reaching as far as Switzerland and Germany by 5,000 years ago. In China and India, domesticated flax was cultivated at least 5,000 years ago. Flax was cultivated extensively in ancient Egypt, where the temple walls had paintings of flowering flax, mummies were entombed in linen. Egyptian priests wore only linen. Phoenicians traded Egyptian linen throughout the Mediterranean and the Romans used it for their sails; as the Roman Empire declined, so did flax production, but Charlemagne revived the crop in the eighth century CE with laws designed to publicize the hygiene of linen textiles and the health of linseed oil.
Flanders became the major center of the linen industry in the European Middle Ages. In North America, flax was introduced by the colonists and it flourished there, but by the early 20th century, cheap cotton and rising farm wages had caused production of flax to become concentrated in northern Russia, which came to provide 90% of the world's output. Since flax has lost its importance as a commercial crop, due to the easy availability of more durable fibres. Flax is grown for its seeds, which can be ground into a meal or turned into linseed oil, a product used as a nutritional supplement and as an ingredient in many wood-finishing products. Flax is grown as an ornamental plant in gardens. Moreover, flax fibers are used to make linen; the specific epithet, means "most useful". Flax fibers taken from the stem of the plant are two to three times as strong as cotton fibers. Additionally, flax fibers are smooth and straight. Europe and North America both depended on flax for plant-based cloth until the 19th century, when cotton overtook flax as the most common plant for making rag-based paper.
Flax is grown on the Canadian prairies for linseed oil, used as a drying oil in paints and varnishes and in products such as linoleum and printing inks. Linseed meal, the byproduct of producing linseed oil from flax seeds, is used to feed livestock, it is a protein-rich feed for ruminants and fish. Flaxseeds occur in two basic varieties/colors: brown or yellow. Most types of these basic varieties have similar nutritional characteristics and equal numbers of short-chain omega-3 fatty acids; the exception is a type of yellow flax called solin, which has a different oil profile and is low in omega-3s. Flaxseeds produce a vegetable oil known as flaxseed oil or linseed oil, one of the oldest commercial oils, it is an edible oil sometimes followed by solvent extraction. Solvent-processed flaxseed oil has been used for many centuries as a drying oil in painting and varnishing. Although brown flaxseed varieties may be consumed as as the yellow ones, have been for thousands of years, its better-known uses are in paints, for fiber, for cattle feed.
A 100-gram portion of ground flaxseed supplies about 534 calories, 41 g of fat, 28 g of fiber, 20 g of protein. Flaxseed sprouts are edible and have a spicy flavor profile. Excessive consumption of flaxseeds with inadequate amounts of water may cause bowel obstruction. In northern India, called tisi or alsi, is traditionally roasted and eaten with boiled rice, a little water, a little salt. In India, linseed oil is known as javas in Marathi, it is used in Savji curries, such as mutton curries. Whole flaxseeds are chemically stable, but ground flaxseed meal, because of oxidation, may go rancid when left exposed to air at room temperature in as little as one week. Refrigeration and storage in sealed containers will keep ground flaxseed meal for a longer period before it turns rancid. Under conditions similar to those found in commercial bakeries, trained sensory panelists could not detect differences between bread made with freshly ground flaxseed and bread made with flaxseed, milled four months earlier and stored at room temperature.
This shows, if packed without exposure to air and light, milled flaxseed is stable against
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
The Jmol applet, among other abilities, offers an alternative to the Chime plug-in, no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, the Sculpt mode. Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS 9. Jmol operates on a wide variety of platforms. For example, Jmol is functional in Mozilla Firefox, Internet Explorer, Google Chrome, Safari. Chemistry Development Kit Comparison of software for molecular mechanics modeling Jmol extension for MediaWiki List of molecular graphics systems Molecular graphics Molecule editor Proteopedia PyMOL SAMSON Official website Wiki with listings of websites and moodles Willighagen, Egon. "Fast and Scriptable Molecular Graphics in Web Browsers without Java3D". Doi:10.1038/npre.2007.50.1