A centrifuge is a piece of equipment that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis of spin that can be strong. The centrifuge works using the sedimentation principle, where the centrifugal acceleration causes denser substances and particles to move outward in the radial direction. At the same time, objects that are less dense move to the center. In a laboratory centrifuge that uses sample tubes, the radial acceleration causes denser particles to settle to the bottom of the tube, while low-density substances rise to the top. There are three types of centrifuge designed for different applications. Industrial scale centrifuges are used in manufacturing and waste processing to sediment suspended solids, or to separate immiscible liquids. An example is the cream separator found in dairies. High speed centrifuges and ultracentrifuges able to provide high accelerations can separate fine particles down to the nano-scale, molecules of different masses.
Large centrifuges are used to simulate high acceleration environments. Medium-sized centrifuges are used in washing machines and at some swimming pools to wring water out of fabrics. Gas centrifuges are used for isotope separation, such as to enrich nuclear fuel for fissile isotopes. English military engineer Benjamin Robins invented a whirling arm apparatus to determine drag. In 1864, Antonin Prandtl proposed the idea of a dairy centrifuge to separate cream from milk; the idea was subsequently put into practice by his brother, Alexander Prandtl, who made improvements to his brother's design, exhibited a working butterfat extraction machine in 1875. A centrifuge machine can be described as a machine with a rotating container that applies centrifugal force to its contents. There are multiple types of centrifuge, which can be classified by intended use or by rotor design: Types by rotor design: Fixed-angle centrifuges are designed to hold the sample containers at a constant angle relative to the central axis.
Swinging head centrifuges, in contrast to fixed-angle centrifuges, have a hinge where the sample containers are attached to the central rotor. This allows all of the samples to swing outwards. Continuous tubular centrifuges do not have individual sample vessels and are used for high volume applications. Types by intended use: Laboratory centrifuges, are general-purpose instruments of several types with distinct, but overlapping, capabilities; these include superspeed centrifuges and preparative ultracentrifuges. Analytical ultracentrifuges are designed to perform sedimentation analysis of macromolecules using the principles devised by Theodor Svedberg. Haematocrit centrifuges are used to measure the volume percentage of red blood cells in whole blood. Gas centrifuges, including Zippe-type centrifuges, for isotopic separations in the gas phase. Industrial centrifuges may otherwise be classified according to the type of separation of the high density fraction from the low density one. There are two types of centrifuges: the filtration and sedimentation centrifuges.
For the filtration or the so-called screen centrifuge the drum is perforated and is inserted with a filter, for example a filter cloth, wire mesh or lot screen. The suspension flows through the filter and the drum with the perforated wall from the inside to the outside. In this way the solid material can be removed; the kind of removing depends on the type of centrifuge, for example manually or periodically. Common types are: Screen/scroll centrifuges Pusher centrifuges Peeler centrifuges Inverting filter centrifuges Sliding discharge centrifuges Pendulum centrifugesIn the sedimentation centrifuges the drum is a solid wall; this type of centrifuge is used for the purification of a suspension. For the acceleration of the natural deposition process of suspension the centrifuges use centrifugal force. With so-called overflow centrifuges the suspension is drained off and the liquid is added constantly. Common types are: Pendulum centrifuges. Though most modern centrifuges are electrically powered, a hand-powered variant inspired by the whirligig has been developed for medical applications in developing countries.
A wide variety of laboratory-scale centrifuges are used in chemistry, biology and clinical medicine for isolating and separating suspensions and immiscible liquids. They vary in speed, temperature control, other characteristics. Laboratory centrifuges can accept a range of different fixed-angle and swinging bucket rotors able to carry different numbers of centrifuge tubes and rated for specific maximum speeds. Controls vary from simple electrical timers to programmable models able to control acceleration and deceleration rates, running speeds, temperature regimes. Ultracentrifuges spin the rotors under vacuum, eliminating air resistance and enabling exact temperature control. Zonal rotors and continuous flow systems are capable of handing bulk and larger sample volumes in a laboratory-scale instrument. Another application in laboratories is blood separation. Blood separates into cells and proteins
Düsseldorf is the capital and second-largest city of the most populous German federal state of North Rhine-Westphalia after Cologne, as well as the seventh-largest city in Germany. With a population of 617,280. At the confluence of the Rhine and its tributary Düssel, the city lies in the centre of both the Rhine-Ruhr and the Rhineland Metropolitan Regions with the Cologne Bonn region to its south and the Ruhr to its north. Most of the city lies on the right bank of the Rhine; the city is the largest in the German Low Franconian dialect area. "Dorf" meaning "village" in German, the "-dorf" suffix is unusual in the German-speaking area for a settlement of Düsseldorf's size. Mercer's 2012 Quality of Living survey ranked Düsseldorf the sixth most livable city in the world. Düsseldorf Airport is Germany's third-busiest airport after those of Frankfurt and Munich, serving as the most important international airport for the inhabitants of the densely populated Ruhr, Germany's largest urban area. Düsseldorf is an international business and financial centre, renowned for its fashion and trade fairs, is headquarters to one Fortune Global 500 and two DAX companies.
Messe Düsseldorf organises nearly one fifth of premier trade shows. As second largest city of the Rhineland, Düsseldorf holds Rhenish Carnival celebrations every year in February/March, the Düsseldorf carnival celebrations being the third most popular in Germany after those held in Cologne and Mainz. There are 22 institutions of higher education in the city including the Heinrich-Heine-Universität Düsseldorf, the university of applied sciences, the academy of arts, the university of music; the city is known for its pioneering influence on electronic/experimental music and its Japanese community. When the Roman Empire was strengthening its position throughout Europe, a few Germanic tribes clung on in marshy territory off the eastern banks of the Rhine. In the 7th and 8th centuries, the odd farming or fishing settlement could be found at the point where the small river Düssel flows into the Rhine, it was from such settlements. The first written mention of Düsseldorf dates back to 1135. Under Emperor Friedrich Barbarossa the small town of Kaiserswerth to the north of Düsseldorf became a well-fortified outpost, where soldiers kept a watchful eye on every movement on the Rhine.
Kaiserswerth became a suburb of Düsseldorf in 1929. In 1186, Düsseldorf came under the rule of the Counts of Berg. 14 August 1288 is one of the most important dates in the history of Düsseldorf. On this day the sovereign Count Adolf VIII of Berg granted the village on the banks of the Düssel town privileges. Before this, a bloody struggle for power had taken place between the Archbishop of Cologne and the count of Berg, culminating in the Battle of Worringen; the Archbishop of Cologne's forces were wiped out by the forces of the count of Berg who were supported by citizens and farmers of Cologne and Düsseldorf, paving the way for Düsseldorf's elevation to city status, commemorated today by a monument on the Burgplatz. The custom of turning cartwheels is credited to the children of Düsseldorf. There are variations of the origin of the cartwheeling children. Today the symbol represents the story and every year the Düsseldorfers celebrate by having a cartwheeling contest. After this battle the relationship between the four cities deteriorated, because they were commercial rivals.
Today, it finds its expression in a humorous form and in sports. A market square sprang up on the banks of the Rhine and the square was protected by city walls on all four sides. In 1380, the dukes of Berg moved their seat to the town and Düsseldorf was made regional capital of the Duchy of Berg. During the following centuries several famous landmarks were built, including the Collegiate Church of St Lambertus. In 1609, the ducal line of the United Duchies of Jülich-Cleves-Berg died out, after a virulent struggle over succession, Jülich and Berg fell to the Wittelsbach Counts of Palatinate-Neuburg, who made Düsseldorf their main domicile after they inherited the Electorate of the Palatinate, in 1685, becoming now Prince-electors as Electors Palatine. Under the art-loving Johann Wilhelm II, a vast art gallery with a huge selection of paintings and sculptures, were housed in the Stadtschloss. After his death, the city fell on hard times again after Elector Charles Theodore inherited Bavaria and moved the electoral court to Munich.
With him he took the art collection. Destruction and poverty struck Düsseldorf after the Napoleonic Wars. Napoleon made Düsseldorf its capital. Johann Devaranne, a leader of Solingen's resistance to Napoleon's conscription decrees, was executed here in 1813. After Napoleon's defeat, the whole Rhineland including Berg was given to the Kingdom of Prussia in 1815; the Rhine Province's parliament was established in Düsseldorf. By the mid-19th century, Düsseldorf enjoyed a revival thanks to the Industrial Revolution as the city boasted 100,000 inhabitants by 1882.
Kobe Bean Bryant is an American former professional basketball player. He played his entire 20-year career with the Los Angeles Lakers of the National Basketball Association, he won five NBA championships. Bryant is an 18-time All-Star, 15-time member of the All-NBA Team, 12-time member of the All-Defensive team, he led the NBA in scoring during two seasons and ranks third on the league's all-time regular season scoring and fourth on the all-time postseason scoring list. He is regarded as one of the greatest basketball players of all time. Bryant is the first guard in NBA history to play at least 20 seasons. Bryant is the son of former NBA player Joe Bryant, he enjoyed a successful high school basketball career at Lower Merion High School in Pennsylvania, where he was recognized as the top high school basketball player in the country. Upon graduation, he declared for the NBA draft and was selected by the Charlotte Hornets in the 13th overall pick in the 1996 NBA draft; the Hornets traded him to the Lakers.
As a rookie, Bryant earned himself a reputation as a high-flyer and a fan favorite by winning the 1997 Slam Dunk Contest, he was named an All-Star by his second season. Despite a feud between the two players and Shaquille O'Neal led the Lakers to three consecutive NBA championships from 2000 to 2002. In 2003, Bryant was accused of sexual assault, but the charges were dropped, a civil suit was settled out of court. After the Lakers lost the 2004 NBA Finals, O'Neal was traded to the Miami Heat and Bryant became the cornerstone of the Lakers, he led the NBA in scoring during the 2005 -- 2006 -- 07 seasons. In 2006, he scored a career-high 81 points against the Toronto Raptors, the second most points scored in a single game in league history behind Wilt Chamberlain's 100-point game in 1962. Bryant was awarded the regular season's Most Valuable Player Award in 2008. After losing in the 2008 NBA Finals, he led the Lakers to two consecutive championships in 2009 and 2010, earning the Finals MVP Award on both occasions.
He continued to be among the top players in the league through 2013 until he suffered a torn Achilles tendon at age 34. Although he recovered, his play was limited the following two years by season-ending injuries to his knee and shoulder, respectively. Citing his physical decline, he announced. At 34 years and 104 days of age, Bryant became the youngest player in league history to reach 30,000 career points, he became the all-time leading scorer in Lakers franchise history on February 1, 2010, when he surpassed Jerry West. During his third year in the league, Bryant was chosen to start the All-Star Game, he would continue to be selected to start that game for a record 18 consecutive appearances until his retirement, his four All-Star MVP Awards are tied for the most in NBA history. At the 2008 and 2012 Summer Olympics, he won gold medals as a member of the U. S. national team. In 2018, Bryant won the Academy Award for Best Animated Short Film for his film Dear Basketball. Bryant was born in 1978 in Philadelphia.
He is the maternal nephew of basketball player John "Chubby" Cox. His parents named him after the famous beef of Kobe, which they saw on a restaurant menu, his middle name, Bean, is derived from his father's nickname "Jellybean". Bryant was raised Roman Catholic; when Bryant was six, his father retired from the NBA and moved his family to Rieti in Italy to continue playing professional basketball at a lower level. Kobe learned to speak fluent Italian. During summers, he would come back to the United States to play in a basketball summer league. Bryant started playing basketball when he was 3 years old, the Lakers were his favorite team when he was growing up. Bryant's grandfather would mail him videos of NBA games. At an early age, he learned to play soccer and his favorite team was A. C. Milan; when Kobe's father Joe retired as a player in 1991, the family moved back to the United States. Bryant earned national recognition during a spectacular high school career at Lower Merion High School in Ardmore, located in the Philadelphia suburb of Lower Merion.
He played on the varsity basketball team as a freshman. He became the first freshman in decades to start for Lower Merion's varsity team, but the team finished with a 4–20 record; the following three years, the Aces compiled a 77–13 record, with Bryant playing all five positions. During his junior year, he averaged 31.1 points, 10.4 rebounds, 5.2 assists and was named Pennsylvania Player of the Year, attracting attention from college recruiters in the process. Duke, North Carolina and Villanova were at the top of his list. At Adidas ABCD camp, Bryant earned the 1995 senior MVP award while playing alongside future NBA teammate Lamar Odom. While in high school 76ers coach John Lucas invited Bryant to work out and scrimmage with the team, where he played one-on-one with Jerry Stackhouse. In his senior year of high school, Bryant led the Aces to their first state championship in 53 years. During the run, he averaged 30.8 points, 12 rebounds, 6.5 assists, 4 steals, 3.8 blocked shots in leading the Aces to a 31–3 record.
Bryant ended his high school career as Southeastern Pennsylvania's all-time leading scorer at 2,883 points, surpassing both Wilt Chamberlain and Lionel Simmons. Bryant received several awards for his outstanding performance during his senior year at Lower Merion; the awards included being na
Freddie H. Fu is a Hong Kong-American doctor and academic, he is the David Silver Professor and chairman of the Department of Orthopaedic Surgery at the University of Pittsburgh School of Medicine. In 2010, he was appointed by the University of Pittsburgh as the eighth distinguished service professor. Fu was president of the Pennsylvania Orthopaedic Society and, in 2008, assumed the presidency of the American Orthopaedic Society for Sports Medicine and was the first foreign-born president in AOSSM's 40-year history. In 2009, he was named president of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine. In 2011, he received the American Academy of Orthopaedic Surgeons' Diversity Award. In 2012, Fu received the Sports Leadership Award from Dapper Dan Charities, subsequently re-named the Freddie Fu Sports Leadership Award and will remain in perpetuity, his team has more than 100 studies completed or underway to evaluate the merits of the anatomic approach by viewing the knee as an organ.
He has ongoing collaborations with K. Christopher Beard, Ph. D. a vertebrate paleontologist, other curators at the Carnegie Museum of Natural History and veterinarians at the Pittsburgh Zoo. Additionally Fu is working with C. Owen Lovejoy, Ph. D. an anthropologist at Kent State University, who reconstructed the skeleton of “Lucy”, the nearly complete fossil of a human ancestor that walked upright more than three million years ago. Such collaborations allow for detailed study of evolution and bony and soft tissue anatomy of the knee. Orthonet Anatomic Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction Patient Handout 2011 Pittsburgh Magazine - May 2011 - Doc Star Freddie Fu Pitt Magazine - Fall 2010 - Man in Motion Pittsburgh Magazine - May 2011 - A Day in the Life of Freddie Fu
Molecular biology is a branch of biology that concerns the molecular basis of biological activity between biomolecules in the various systems of a cell, including the interactions between DNA, RNA, proteins and their biosynthesis, as well as the regulation of these interactions. Writing in Nature in 1961, William Astbury described molecular biology as:...not so much a technique as an approach, an approach from the viewpoint of the so-called basic sciences with the leading idea of searching below the large-scale manifestations of classical biology for the corresponding molecular plan. It is concerned with the forms of biological molecules and is predominantly three-dimensional and structural – which does not mean, that it is a refinement of morphology, it must at the same time inquire into function. Researchers in molecular biology use specific techniques native to molecular biology but combine these with techniques and ideas from genetics and biochemistry. There is not a defined line between these disciplines.
This is shown in the following schematic that depicts one possible view of the relationships between the fields: Biochemistry is the study of the chemical substances and vital processes occurring in live organisms. Biochemists focus on the role and structure of biomolecules; the study of the chemistry behind biological processes and the synthesis of biologically active molecules are examples of biochemistry. Genetics is the study of the effect of genetic differences in organisms; this can be inferred by the absence of a normal component. The study of "mutants" – organisms which lack one or more functional components with respect to the so-called "wild type" or normal phenotype. Genetic interactions can confound simple interpretations of such "knockout" studies. Molecular biology is the study of molecular underpinnings of the processes of replication, transcription and cell function; the central dogma of molecular biology where genetic material is transcribed into RNA and translated into protein, despite being oversimplified, still provides a good starting point for understanding the field.
The picture has been revised in light of emerging novel roles for RNA. Much of molecular biology is quantitative, much work has been done at its interface with computer science in bioinformatics and computational biology. In the early 2000s, the study of gene structure and function, molecular genetics, has been among the most prominent sub-fields of molecular biology. Many other areas of biology focus on molecules, either directly studying interactions in their own right such as in cell biology and developmental biology, or indirectly, where molecular techniques are used to infer historical attributes of populations or species, as in fields in evolutionary biology such as population genetics and phylogenetics. There is a long tradition of studying biomolecules "from the ground up" in biophysics. One of the most basic techniques of molecular biology to study protein function is molecular cloning. In this technique, DNA coding for a protein of interest is cloned using polymerase chain reaction, and/or restriction enzymes into a plasmid.
A vector has 3 distinctive features: an origin of replication, a multiple cloning site, a selective marker antibiotic resistance. Located upstream of the multiple cloning site are the promoter regions and the transcription start site which regulate the expression of cloned gene; this plasmid can be inserted into either bacterial or animal cells. Introducing DNA into bacterial cells can be done by transformation via uptake of naked DNA, conjugation via cell-cell contact or by transduction via viral vector. Introducing DNA into eukaryotic cells, such as animal cells, by physical or chemical means is called transfection. Several different transfection techniques are available, such as calcium phosphate transfection, electroporation and liposome transfection; the plasmid may be integrated into the genome, resulting in a stable transfection, or may remain independent of the genome, called transient transfection. DNA coding for a protein of interest is now inside a cell, the protein can now be expressed.
A variety of systems, such as inducible promoters and specific cell-signaling factors, are available to help express the protein of interest at high levels. Large quantities of a protein can be extracted from the bacterial or eukaryotic cell; the protein can be tested for enzymatic activity under a variety of situations, the protein may be crystallized so its tertiary structure can be studied, or, in the pharmaceutical industry, the activity of new drugs against the protein can be studied. Polymerase chain reaction is an versatile technique for copying DNA. In brief, PCR allows a specific DNA sequence to be modified in predetermined ways; the reaction is powerful and under perfect conditions could amplify one DNA molecule to become 1.07 billion molecules in less than two hours. The PCR technique can be used to introduce restriction enzyme sites to ends of DNA molecules, or to mutate particular bases of DNA, the latter is a method referred to as site-directed mutagenesis. PCR can be used to determine whether a particular DNA fragment is found in a cDNA library.
PCR has many variations, like reverse transcription PCR for amplification of RNA, more quantitative PCR which allow for quantitative measurement of DNA or RNA molecules. Gel electrophoresis is one of the principal tools of molecular biology; the basic principle is that DNA, RNA, proteins can all be separated by means of an electric field and size. In agarose gel electrophoresis, DNA and RNA can be separated on th
Health insurance is an insurance that covers the whole or a part of the risk of a person incurring medical expenses, spreading the risk over a large number of persons. By estimating the overall risk of health care and health system expenses over the risk pool, an insurer can develop a routine finance structure, such as a monthly premium or payroll tax, to provide the money to pay for the health care benefits specified in the insurance agreement; the benefit is administered by a central organization such as a government agency, private business, or not-for-profit entity. According to the Health Insurance Association of America, health insurance is defined as "coverage that provides for the payments of benefits as a result of sickness or injury, it includes insurance for losses from accident, medical expense, disability, or accidental death and dismemberment". A health insurance policy is: A contract between an insurance provider and an individual or his/her sponsor; the contract can be renewable or lifelong in the case of private insurance, or be mandatory for all citizens in the case of national plans.
The type and amount of health care costs that will be covered by the health insurance provider are specified in writing, in a member contract or "Evidence of Coverage" booklet for private insurance, or in a national health policy for public insurance. Provided by an employer-sponsored self-funded ERISA plan; the company advertises that they have one of the big insurance companies. However, in an ERISA case, that insurance company "doesn't engage in the act of insurance", they just administer it. Therefore, ERISA plans are not subject to state laws. ERISA plans are governed by federal law under the jurisdiction of the US Department of Labor; the specific benefits or coverage details are found in the Summary Plan Description. An appeal must go through the insurance company to the Employer's Plan Fiduciary. If still required, the Fiduciary's decision can be brought to the USDOL to review for ERISA compliance, file a lawsuit in federal court; the individual insured person's obligations may take several forms: Premium: The amount the policy-holder or their sponsor pays to the health plan to purchase health coverage.
Deductible: The amount that the insured must pay out-of-pocket before the health insurer pays its share. For example, policy-holders might have to pay a $500 deductible per year, before any of their health care is covered by the health insurer, it may take several doctor's visits or prescription refills before the insured person reaches the deductible and the insurance company starts to pay for care. Furthermore, most policies do not apply co-pays for doctor's visits or prescriptions against your deductible. Co-payment: The amount that the insured person must pay out of pocket before the health insurer pays for a particular visit or service. For example, an insured person might pay a $45 co-payment for a doctor's visit, or to obtain a prescription. A co-payment must be paid each time. Coinsurance: Instead of, or in addition to, paying a fixed amount up front, the co-insurance is a percentage of the total cost that insured person may pay. For example, the member might have to pay 20% of the cost of a surgery over and above a co-payment, while the insurance company pays the other 80%.
If there is an upper limit on coinsurance, the policy-holder could end up owing little, or a great deal, depending on the actual costs of the services they obtain. Exclusions: Not all services are covered. Billed items like use-and-throw, etc. are excluded from admissible claim. The insured are expected to pay the full cost of non-covered services out of their own pockets. Coverage limits: Some health insurance policies only pay for health care up to a certain dollar amount; the insured person may be expected to pay any charges in excess of the health plan's maximum payment for a specific service. In addition, some insurance company schemes have annual or lifetime coverage maxima. In these cases, the health plan will stop payment when they reach the benefit maximum, the policy-holder must pay all remaining costs. Out-of-pocket maximum: Similar to coverage limits, except that in this case, the insured person's payment obligation ends when they reach the out-of-pocket maximum, health insurance pays all further covered costs.
Out-of-pocket maximum can be limited to a specific benefit category or can apply to all coverage provided during a specific benefit year. Capitation: An amount paid by an insurer to a health care provider, for which the provider agrees to treat all members of the insurer. In-Network Provider: A health care provider on a list of providers preselected by the insurer; the insurer will offer discounted coinsurance or co-payments, or additional benefits, to a plan member to see an in-network provider. Providers in network are providers who have a contract with the insurer to accept rates further discounted from the "usual and customary" charges the insurer pays to out-of-network providers. Prior Authorization: A certification or authorization that an insurer provides prior to medical service occurring. Obtaining an authorization means that the insurer is obligated to pay for the service, assuming it matches what was authorized. Many smaller, routine services do not require authorization. Explanation of Benefits: A document that may be sent by an insurer to a patient explaining what was covered for a medical service, how payment amount and patient responsibility amount were determined.
Prescription drug plans are a form of insurance offered through some health ins