Sebanyak 61 item atau buku ditemukan

Cobalt Organometallic Compounds by Electrochemistry

The electrochemical oxidation of CoCl2(PPh3)2 was investigated in a mixture of acetonitrile and pentanol (1:1) at a platinum disk working electrode using Cyclic Voltammetry (CV) and Chronoamperometry. Elemental Analysis and Infrared Spectroscopy were used to characterise the synthesized compounds i.e. CoCl2(PPh3)2 and CoCl(PPh3)3. Cyclic Voltammetry was utilised for the examination of different working electrode materials that could be used for the anodic voltammetric studies of CoCl2 (PPh3)2, to characterise the reactants and products of each electrode reaction, to investigate the chloride binding ability to a CoCl(PPh3)3 complex, and to evaluate the electrocatalytic substitution of chloride by PPh3 from the complex CoCl2(PPh3)2. Use of ferrocene as an internal standard during the anodic studies of CoCl2(PPh3)2 was also evaluated. The number of electron involved in the electrode process, CoII to CoIII from CoCl2(PPh3)2 and diffusion coefficient of ferrocene in a mixture of acetonitrile and pentanol (1:1) were determined using Chronoamperometry. Ultraviolet-Visible (UV-Vis) and 31P Nuclear Magnetic Resonance (31P NMR) spectra were used to assist with the characterisation of the electrode reactions involved during oxidation of CoCl2(PPh3)2.

Antigen Retrieval Immunohistochemistry Based Research and Diagnostics

The most complete, up-to-date reference on antigen retrieval and immunohistochemistry An antigen is a substance that prompts the generation of antibodies and can cause an immune response. The antigen retrieval (AR) technique is in wide use across the globe, and is a critical technique used in medical diagnosis of disease, particularly clinical targeted cancer treatment. Antigen Retrieval Immunohistochemistry Based Research and Diagnostics discusses several scientific approaches to the standardization of quantifiable immunohistochemistry (IHC). Based on the development and application of AR by the editors, this volume summarizes recent achievements in AR-IHC and analyzes numerous cutting-edge issues for future research projects. Featuring contributions from a worldwide group of leading experts and research scientists in the field, this important work: Summarizes the key problems in the four fields of antigen retrieval Discusses the advances of AR techniques and their applications Provides practical methods and protocols in AR-IHC, such as extraction of nucleic acids and proteins for molecular analysis, cell/tissue sample preparation, and standardization and development of various techniques to meet the future needs of¿clinical and research molecular analysis Encourages further research in AR and IHC, particularly how AR methods might be employed for improved test performance and the development of greater reliability and reproducibility of IHC Includes an appendix of related laboratory protocols Antigen Retrieval Immunohistochemistry Based Research and Diagnostics is intended for clinical pathologists, molecular cell biologists, basic research scientists, technicians, and graduate students who undertake tissue/cell morphologic and molecular analysis and wish to use and extend the power of immunohistochemistry. It is also pertinent for most biotechnology companies majoring in development of IHC products. Wiley Series in Biomedical Engineering and Multi-Disciplinary Integrated Systems / Kai Chang, Series Editor

Study of Factors Affecting Attitudes of Young Female Students Toward Chemistry at the High School Level

Chemistry is a human endeavor that relies on basic human qualities like creativity, insights, reasoning, and skills. It depends on habits of the mind: skepticism, tolerance of ambiguity, openness to new ideas, intellectual honesty, curiosity, and communication. Young female students begin studying chemistry curiosity; however, when unconvinced, they become skeptical. Researches focused on gender studies have indicated that attitudes toward science education differ between males and females. A declining interest in chemistry and the under representation of females in the chemical science was found (Jacobs, 2000). This study investigated whether self-confidence toward chemistry, the influence of role models, and knowledge about the usefulness of chemistry were affecting the attitudes toward chemistry, of 183 high school young females across the United States. The young female students surveyed, had studied chemistry for at least one year prior to participating in the study during the fall semester of 2003. The schools were randomly selected represented diverse economic backgrounds and geographical locations. Data were obtained using Chemistry Attitude Influencing Factors (CAIF) instrument and from interviews with a focus group of three young female students about the effect of self-confidence toward chemistry, the influence of role models, and knowledge about the usefulness of chemistry on their decision to study chemistry. The CAIF instrument consisted of a 12-items self-confidence questionnaire (ConfiS), 12-items each of the influence of role models (RoMoS) and knowledge about usefulness of chemistry (US) questionnaire. ConfiS was adopted (with permission) from CAEQ (Coll & Dalgety, 2001), and both RoMoS and US were modified from TOSRA (Fraser, 1978), public domain document. The three young female students interviewed, gave detailed responses about their opinions regarding self-confidence toward chemistry, the influence of role models, and knowledge about the usefulness of chemistry on their attitudes toward the study of chemistry. Both quantitative (a Likert-type Scale questionnaire) and qualitative (open-ended questions) items were used to investigate the views of young female students. Results of the survey were analysed using a correlation test. Significant differences were found in the Likert-type scale scores, providing evidences supporting literature that suggests, self-confidence toward chemistry, the influence of role models, and knowledge about the usefulness of chemistry affect the decision of young female students about the study of chemistry. Interview responses corroborated the results from the survey. Strategies for addressing the problems and recommendations for further studies have been suggested.

The perceived relevance of scientific process and content to everyday life
experience is a factor in science interest and participation at both the pre-college
and collegiate levels (Gardner et al., 1989). The Approach to This Study
Explanations ...

Studies in Natural Products Chemistry

Stereoselective Synthesis (Part K)

In Volume 18 of this well-established series, Professor Atta-ur-Rahman again brings together the work of several of the world's leading authorities in organic chemistry. Their contributions demonstrate the rapid, ongoing development of this field by illustrating many of the latest advances in synthetic methods, total synthesis, structure determination, biosynthetic pathways, and biological activity. The opening chapter presents an overview of strategies for the synthesis of several classes of natural products with an emphasis on complex polycyclic systems. Subsequent chapters discuss the synthesis of specific classes of compounds, including morphine, polyketides, acetogenins, nonactic acid derivatives, complex spirocyclic ethers, ä-lactam and pyridone derivatives, inositol phosphates, sphingolipids, brassinosteroids, Hernandia lignans, and dimeric steroidal pyrazine alkaloids. Finally, the ever stronger links between chemistry and biology are reinforced by chapters on the origin and function of secondary metabolites, bioactive conformations of gastrin hormones, and immunochemistry.

J. Chem., 1980, 58,2732. 65 H. Ohrui, G. H. Jones, J. G. Moffatt, M. L. Maddox,
A. T. Christensen and S. K. Byram, J. Am. Chem. Soc., 1975, 97,4602. 66 F. W.
Eastwood, K. J. Harrington, J. S. Josan and J. L. Pura, Tetrahedron Lett, 1970,
5223.

Understanding Chemistry

This is the international edition of Prof Rao's popular science book, an elementary introduction intended for high school students and others interested in chemistry. Topics such as environment, energy, food and water are included. There are also life sketches of chemists and procedures for a few experiments.

The book is enlivened by colour illustrations, life sketches of scientists, description of experiments and discussion of popular subjects such a tea, soap, firecrackers and rockets.

Understanding Physical Chemistry

Understanding Physical Chemistry takes an innovative approach to teaching this fundamentally important subject, by stressing core ideas such as the entropic forces that drive all chemical processes and the quantum states that dictate the structures and colors of atoms and molecules. This elegant and streamlined textbook (of under 400 pages) aims to instill a deep understanding of physical chemistry by focusing exclusively on those ideas that are deemed to be either too important or too interesting to exclude. These core ideas are demystified by explaining where they come from, why they make sense, and how they may be applied to understanding topics ranging from molecular spectroscopy and chemical reactivity to biological self-assembly and liquid computer simulation strategies. Another unique feature of this groundbreaking textbook is the insight it provides into the scientific discovery process by highlighting the personal perspectives and conceptual struggles of people such as Gibbs, Einstein, and Schrödinger, who pioneered this interesting and practically important field.

Understanding Physical Chemistry takes an innovative approach to teaching this fundamentally important subject, by stressing core ideas such as the entropic forces that drive all chemical processes and the quantum states that dictate the ...