| Papers [241-250] of 302 :: [Page 25 of 31] | | Go to page : <— 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 —> | |
|
|
Quality Initiatives in the Pharmaceutical Industry, 2002.
An analysis of the enormous demands placed on the pharmaceutical industry by the public and government agencies.
2,980 words (approx. 11.9 pages), 7 sources, MLA, $ 87.95
»
Click here to show/hide summary
Abstract
This paper describes the pharmaceutical industry's role as one of the largest contributors to economic growth in the United States. It illustrates the tremendous pressure the pharmaceutical industry is under, to meet the increasing demands for their product and maintain the quality standards of the regulatory agencies. The writer explains why it is in the best interest of the industry to attempt to maintain the high standards placed on them.
From the Paper
"According the US Business Reporter (2002), annual spending on prescription drugs is expanding at close to 14% on and annual basis. Several companies and drugs have led this increase, particularly Warner-Lambert's Lipitor, Eli Lilly's Zyprexa, Monsanto/ Pfizer's Celebrex, and Merck's Vioxx (US Business Reporter, 2002). The same article notes that the pharmaceutical industry typically operates on a 14-15% profit margin. This makes the pharmaceutical industry one of the largest contributors to economic growth in the Untied States."
| |
|
The Effects of a Neurotoxin on the Mammalian Brain, 2000.
A paper which studies the effects of the Superfund Neurotoxin Methylazoxymethanol (MAM) on brain dendritic spine density in long hooded Evans Rats Rattus norvegicus.
2,100 words (approx. 8.4 pages), 11 sources, APA, $ 65.95
»
Click here to show/hide summary
Abstract
The paper shows that in the study of structural development in the brain there have been several proposed biomarkers for quantifying brain plasticity. These include but are not limited to cortical thickness, dendritic length and branching, expression of neuronal proteins, and the presence of DNA adducts. The paper discusses the theory that a measure of brain plasticity emerging late in embryonic development will be a very sensitive biomarker for detecting subtle damage suffered by brain cells during earlier stages of brain development not detectable by other means. The paper shows that to test this, the effects of a neurotoxin on the late developing dendritic spines were studied. A significant decrease in spine density was observed as the neurotoxin, methylazoxymethanol, increased. The author of the paper shows how the implications are widespread in the study of neuro-degenerative disease.
From the Paper
"Fifty years ago, Donald Hebb demonstrated that the conditions under which laboratory rats were housed could significantly affect their performance in a variety of complex spatial tasks later in life (1). The complex environment rearing paradigm has been valuable in assessing plasticity of a variety of brain components including cerebral cortical microvasculature, astrocyetic morphology, dentritic branching patterns, synaptic number, and synaptic structure are all affected by complex environment rearing (2). It has been suggested that multiple synaptic contacts (spines) may play a role in the spread of the additive effect of learning known as potentiation, among neighboring unstimulated neurons. A lack of these spines and their connection with boutons of neighboring neurons could then result in a decrease in the capacity for learning. Some recent work has indicated that the presence of multiple synaptic contacts may be altered by experience. Most of this research has focused on structural changes in the hippocampus. Dendrtic spines show great variability in structure and connectivity, both within and across brain structures, including 10-fold differences in length and diameter as well as variations in the number of branches and spines per dendrite."
| |
|
Hemoglobin, Oxygen Transport and Nitric Oxide, 2001.
This paper presents electron paramagnetic resonance and oxygen binding studies of -nitrosyl hemoglobin - a novel oxygen carrier having NO (Nitric Oxide) assisted allosteric functions.
1,345 words (approx. 5.4 pages), 3 sources, APA, $ 45.95
»
Click here to show/hide summary
Abstract
This paper shows that Nitric Oxide (NO) is a very popular compound to investigate in the scientific community today. It is physiologically ubiquitous as a potent vasodilator, neurotransmitter, and immuno-active agent at low concentrations and it is produced and recycled in the respiratory tract to regulate the airway. This paper discusses in detail the mechanism behind oxygen binding and release by hemoglobin as it relates NO bound to the Hemoglobin. The oxygen affinity dynamics of native Hemoglobin and nitrosylated Hb are compared. The research also reveals that although NO has a much higher affinity than oxygen or carbon monoxide for Hemoglobin, NO behaves differently than these other ligands and is not as toxic to normal Hb oxygen binding as previously assumed.
From the Paper
"Small, unicellular aerobic organisms can obtain oxygen required for metabolism by simple diffusion from the environment. Most multicellular organisms have too great a surface area and many cells not in contact with the environment. They require circulatory systems that transport oxygen from gas-exchange organs to other tissues. In vertebrates, oxygen is bound to molecules of Hemoglobin (Hb) or transport in Red Blood Cells. Mammalian Hemoglobin is a tetramer, consisting of four polypeptide chains; two a and two b. Six ligands are coordinated to the ferrous iron, with the ligands in octahedral geometry around the metal cation (figure 1). In aqueous solution, free heme does not does not reversibly bind oxygen. Instead the Fe(II) is rapidly oxidized to Fe(III) when it gives up an electron to oxygen. The quaternary structure of hemoglobin prevents formal transfer of an electron and allows it to reversibly bind O2. Positively charged amino acid residues stabilize to negatively charged diatomic oxygen without an ionic bond. Hemoglobin unbound to oxygen is called deoxyhemoglobin and has a low affinity for oxygen. Once one oxygen molecule binds to the Fe, the proximal Histadine (figure 1) moves closer to the porphyrin ring because the Fe is now bound to six ligands instead of five. This disrupts the stabilizing ions that interact with Hb. The remaining Heme groups have an increased affinity for Oxygen. In addition to this positive cooperatively of binding, allosteric interactions regulate the binding and release of oxygen by Hb (Horton, 1996)."
| |
|
Solid Propulsion, 2000.
An essay outlining the history and modern use of solid propulsion in comparison to other types of propulsion.
1,145 words (approx. 4.6 pages), 1 source, MLA, $ 39.95
»
Click here to show/hide summary
Abstract
The following paper examines the history of solid propulsion and black powder and discusses how it was used. It also looks at the advantages and disadvantages of solid propulsion in relation to its liquid counterparts.
From the Paper
"The first solid propulsion engines were invented by the Chinese early in the 13th century in use of fireworks. These homemade rockets were propelled by black powder. The first recorded military use was in 1232 in a military siege where the powder propelled rockets were used to set fire to tents. It wasn?t until years later around the early 15th century when they started becoming used in Europe and equipped with a payload. Gunpowder started being used as it burned slower than black powder. The two have same the same ingredients but in different proportions. A large step forward was when the solid propulsion rockets were used to carry rope from distressed ships to shore in stormy conditions. The sailors would use the rope as a lifeline in their rowboats. However this relied on the fact that the shore could only be as far away as the longest rope."
| |
|
Peter Debye, 2002.
A discussion on the life, achievements and research of Peter Debye, winner of 'The Nobel Prize' in Chemistry 1936.
750 words (approx. 3.0 pages), 4 sources, MLA, $ 26.95
»
Click here to show/hide summary
Abstract
The following paper discusses what Peter Debye was awarded the Nobel Prize for and lists the other awards he received throughout his lifetime. This paper also looks at Debye's early modification of a theory belonging to Einstein as well as contributions to chemistry.
From the Paper
"Peter Debye (1884-1966) was awarded The Nobel Prize in Chemistry 1936 for what the Nobel e-museum describes as his contributions to our knowledge of molecular structure through his investigations on dipole moments and on the diffraction of X-rays and electrons in gases.(Nobel e-museum) He has a chemical unit of measure named for him debye units (D) , which measures the dipole moment for polar molecules. (Chang, 308) Aside from The Nobel Prize in 1936, he received Honorary Doctorates from & Brussels and Liege; Oxford; Sofia; Maniz; Technische Hochschule, Aachen; Eidgenosissche Technische Hochschule, Switzerland; Harvard; St. Lawrence; Colgate; Notre Dame; Holy Cross; Brooklyn Polytechnic; Boston College, Providence College."
| |
|
Dimitri Mendeleev, 2002.
This paper discusses the life and contributions of Dimitri Mendeleev, the founder of the first Periodic Table of Elements.
940 words (approx. 3.8 pages), 4 sources, MLA, $ 33.95
»
Click here to show/hide summary
Abstract
This paper looks at the life-long contributions that Dimitri Mendeleev made to the field of chemistry. The author details Mendeleev's personal and professional biography including his battle against childhood disease which almost cost him his life. His family's struggle to insure that he was able to study at a prestigious university and to overcome the poverty into which he had been born influenced his drive to constantly work and succeed in his chosen field. In 1869 Mendeleev constructed the first Periodic Table of Elements. He also authored many books in the field of chemistry and predicted the discovery of many different elements, as well as weights and measure. The author also notes his many contributions to the advancement of technology in Russia.
From the Paper
Mendeleev was born in 1834 in Siberia. His family consisted of thirteen brothers and sisters, his mother and his father. The family was poor, his father eventually went deaf before he died, and yet Mendeleev?s mother insisted that her youngest child further his education. He hitchhiked over 14,000 miles across Russia to Moscow, only to be turned down by the University of Moscow because he was from Siberia. His mother never gave up, and the two of them traveled to St. Petersburg where he trained and eventually became a Professor of inorganic chemistry at the University of. St. Petersburg. (Chang, 233) During his third year of study there, Mendeleev fell ill, and was bedridden for the next year. He kept up with his studies, and graduated on time, and received the medal of excellence for being first in his class. (Rumppe, Sixtus
| |
|
Kekule and the Structure of Benzene, 2002.
A discussion on Kekule?s structure theory of Benzene.
855 words (approx. 3.4 pages), 5 sources, MLA, $ 30.95
»
Click here to show/hide summary
Abstract
The following paper discusses Friedrich Kekule?s interest in chemistry and examines how he came to be the originator of the structure theory for his study on chemical bonds. However this paper also examines how Kekule?s formula for the structure of benzene was wrong. This paper provides the reader with the correct formula and explains what Kekulu?s formula was missing.
From the Paper
?The charred body of a woman is found and the trial began. Friedrich Kekule testified before the grand jury. Many believed her death was caused by combustion from overdrinking of alcohol. However, Justus von Liebig and Kekule believed otherwise. This testimony incriminated a servant who had stolen from the woman. This began the turning point in Kekule?s life as he pursued his new interest of chemistry and the beginning formula of benzene (Lienhard 1).
"Friedrich August Kekule has been said to be the originator of the structure theory and for his study on chemical bonds. Kekule was born on September 7, 1829 in Germany. Kekule attended school at Darmstadt. He was intelligent and spoke French, Italian, and English. Kekule in 1847 attended the University of Giessen and studied architecture (Ulearntoday 1)?
| |
|
Friedrich August Kekule, 2002.
A paper on Friedrich August Kekule, a German chemist known for his work with benzene.
820 words (approx. 3.3 pages), 4 sources, MLA, $ 29.95
»
Click here to show/hide summary
Abstract
The following paper takes a look at the life of Friedrich August Kelule, known as the originator of the structure theory of benzene. This essay discusses Kelule?s interest in chemistry, beginning with a trial concerning a charred woman?s body.
From the Paper
?Kelule went to a trial about a woman?s charred body. Many believed she had combustion because she drank too much alcohol. However, Justus von Liebig testified in this trial and ignited Kekule?s interest in chemistry. He changed his studies from architecture to chemistry. Charles Gerhardt and Jean-Baptiste Dumas taught him the unitary theory of chemistry. From 1855 to 1858 Kekule debated with JFW von Baeyer until 1858 and was professor at Ghent and Bonn (Ulearntoday 1)."
| |
|
Linus Pauling, 2002.
This paper introduces and discusses the life of Nobel Prize winning scientist, Linus Pauling.
925 words (approx. 3.7 pages), 3 sources, MLA, $ 32.95
»
Click here to show/hide summary
Abstract
The following paper discusses the life of Linus Pauling, focusing on his achievements and discoveries. The writer discusses how in 1954, Pauling was awarded the Nobel Prize in chemistry for his work in chemical bonds and in 1962 he won the Nobel Peace Prize for his efforts on behalf of a nuclear test ban treaty. This paper also discusses his book "The Nature of the Chemical Bond and the Structure of Molecules and Crystals".
From the Paper
"Linus Pauling was born in Portland, Oregon, on February 28, 1901. When he was nine, his father died, and his mother eventually lost the drugstore her husband had owned. The family, consisting of Linus, his two sisters, and his mother, had to move into a smaller house. His mother took in borders, and money was always a constant worry for the family. Pauling was a good student, and loved to read anything he could get his hands on. He said, "I have always wanted to know as much as possible about the world. As a child, I enjoyed reading and going to school... Possibly I am a scientist because I was curious when I was young... When I was eleven, with no outside inspiration - just library books - I started collecting insects... When I was twelve I began reading about rocks and minerals and started collecting them"
| |
|
The Kinetics of Chemical Reactions., 2001.
An investigation into the kinetics of the reaction between hydrogen peroxide and potassium iodide in an acidified solution.
4,500 words (approx. 18.0 pages), 14 sources, $ 117.95
»
Click here to show/hide summary
Abstract
The paper deals with a very detailed investigation into how the kinetics of a reaction changes from alterationss in pH, the concerntration of reactants and the addition of a catlyst in a homogenous solution. Also included is the most effective, yet efficient manner, of determining the rate of the reaction including detailed mathematical calculations. There is a lot of experimental data as evidence included and a detailed practical guide of how the investigation was undertaken and numerous discussions.This paper is essential as a reference for those studying reaction kinetics.
From the Paper
"Investigate the kinetics of the above reaction and thus attempt to find a rate equation for the reaction and also establishing the best method to determine the rate of the reaction. I will do this by varying the concentrations of Iodide ions, H+ ions and Hydrogen Peroxide to generate the rate equation, I will also try to find the effect of a catalyst: Molybdate ion on the rate of reaction and also if the amount of catalyst is relevant in a homogenous reaction. The rate will be found using the iodine clock reaction and also by the use of a pH meter and a colorimeter, and these methods will be assessed to help determine the best method of analysis."
|
|
|