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101.
This study deals with the synthesis of benzophenone sulfonamides hybrids (131) and screening against urease enzyme in vitro. Studies showed that several synthetic compounds were found to have good urease enzyme inhibitory activity. Compounds 1 (N′-((4′-hydroxyphenyl)(phenyl)methylene)-4′′-nitrobenzenesulfonohydrazide), 2 (N′-((4′-hydroxyphenyl)(phenyl)methylene)-3′′-nitrobenzenesulfonohydrazide), 3 (N′-((4′-hydroxyphenyl)(phenyl)methylene)-4′′-methoxybenzenesulfonohydrazide), 4 (3′′,5′′-dichloro-2′′-hydroxy-N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide), 6 (2′′,4′′-dichloro-N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide), 8 (5-(dimethylamino)-N′-((4-hydroxyphenyl)(phenyl)methylene)naphthalene-1-sulfono hydrazide), 10 (2′′-chloro-N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide), 12 (N′-((4′-hydroxyphenyl)(phenyl)methylene)benzenesulfonohydrazide) have found to be potently active having an IC50 value in the range of 3.90–17.99?µM. These compounds showed superior activity than standard acetohydroxamic acid (IC50?=?29.20?±?1.01?µM). Moreover, in silico studies on most active compounds were also performed to understand the binding interaction of most active compounds with active sites of urease enzyme. Structures of all the synthetic compounds were elucidated by 1H NMR, 13C NMR, EI-MS and FAB-MS spectroscopic techniques.  相似文献   
102.
103.
This paper reviews the question of why the presentation of evolution in class frequently does not achieve acceptance of the evolutionary theory. In general, problems are twofold. Firstly, students may come to this particular topic with strong preconceptions, often based on specific religious teachings. Secondly, teachers may or may not bring an informed and/or dedicated approach to the teaching of evolution, relating to what they themselves were taught. Additional to our review of this topic and its problems, we suggest the use of a simple ‘test’ formulated, not on trying to impose knowledge and belief of evolution on the student, but on directing students towards the application of information on evolution to material already familiar to them. In this process, it is hoped that students will naturally incorporate at least some of the ideas of evolution into their own belief systems. Students are thus encouraged to assess or reassess evolution in terms of what they already consider to be true from their own experiences. Preliminary results (two trial runs) using this questionnaire indicate that students readily apply information with which they are familiar to Darwinian principles, and vice versa. These results, including verbal and written comments, also suggest that this ‘test’ may be meaningful as a first step towards acceptance of evolutionary theory. Teachers may find our questionnaire useful in determining a student's ability to understand evolutionary theory, and in exploring connections between understanding of and belief in evolution. Reviewed by Will H. Blackwell  相似文献   
104.
Terminal restriction fragment length polymorphism (T-RFLP) analysis is a common technique used to characterize soil microbial diversity. The fidelity of this technique in accurately reporting diversity has not been thoroughly evaluated. Here we determine if rare fungal species can be reliably detected by T-RFLP analysis. Spores from three arbuscular mycorrhizal fungal species were each mixed at a range of concentrations (1%, 10%, 50%, and 100%) with Glomus irregulare to establish a minimum detection threshold. T-RFLP analysis was capable of detecting diagnostic peaks of rare taxa at concentrations as low as 1%. The relative proportion of the target taxa in the sample and DNA concentration influenced peak detection reliability. However, low concentrations produced small, inconsistent electropherogram peaks contributing to difficulty in differentiating true peaks from signal noise. The results of this experiment suggest T-RFLP is a reproducible and high fidelity procedure, which requires careful data interpretation in order to accurately characterize sample diversity.  相似文献   
105.
During the 1920s and 1930s geneticist L.C. Dunn of Columbia University cautioned Americans against endorsing eugenic policies and called attention to eugenicists’ less than rigorous practices. Then, from the mid-1940s to early 1950s he attacked scientific racism and Nazi Rassenhygiene by co-authoring Heredity, Race and Society with Theodosius Dobzhansky and collaborating with members of UNESCO (United Nations Educational, Scientific, and Cultural Organization) on their international campaign against racism. Even though shaking the foundations of scientific discrimination was Dunn’s primary concern during the interwar and post-World War II years, his campaigns had ancillary consequences for the discipline. He contributed to the professionalization of genetics during the 1920s and 1930s and sought respectability for human genetics in the 1940s and 1950s. My article aims to elucidate the activist scientist’s role in undermining scientific discrimination by exploring aspects of Dunn’s scientific work and political activism from the 1920s to 1950s. Definitions are provided for scientific discrimination and activist scientist.  相似文献   
106.
The British Society for Clinical Cytology Code of Practice on fine needle aspiration cytology complements that on exfoliative cytopathology, which was published in the last issue ( Cytopathology 2009; 20 :211–23). Both have been prepared with wide consultation within and outside the BSCC and have been endorsed by the Royal College of Pathologists. A separate code of practice for gynaecological cytopathology is in preparation. Fine needle aspiration (FNA) cytology is an accepted first line investigation for mass lesions, which may be targeted by palpation or a variety of imaging methods. Although FNA cytology has been shown to be a cost-effective, reliable technique its accurate interpretation depends on obtaining adequately cellular samples prepared to a high standard. Its accuracy and cost-effectiveness can be seriously compromised by inadequate samples. Although cytopathologists, radiologists, nurses or clinicians may take FNAs, they must be adequately trained, experienced and subject to regular audit. The best results are obtained when a pathologist or an experienced and trained biomedical scientist (cytotechnologist) provides immediate on-site assessment of sample adequacy whether or not the FNA requires image-guidance. This COP provides evidence-based recommendations for setting up FNA services, managing the patients, taking the samples, preparing the slides, collecting material for ancillary tests, providing rapid on-site assessment, classifying the diagnosis and providing a final report. Costs, cost-effectiveness and rare complications are taken into account as well as the time and resources required for quality control, audit and correlation of cytology with histology and outcome. Laboratories are expected to have an effective quality management system conforming to the requirements of a recognised accreditation scheme such as Clinical Pathology Accreditation (UK) Ltd.  相似文献   
107.
Julian Huxley’s (1887–1975) contribution to twentieth-century biology and science popularisation is well documented. What has not been appreciated so far is that despite Huxley’s eminence as a public scientific figure and the part that he played in the rise of experimental zoology in Britain in the 1920s, his own research was often heavily criticised in this period by his colleagues. This resulted in numerous difficulties in getting his scientific research published in the early 1920s. At this time, Huxley started his popular science career. Huxley’s friends criticised him for engaging in this actively and attributed the publication difficulties to the time that he allocated to popular science. The cause might also have its roots in his self-professed inability to delve deeply into the particularities of research. This affected Huxley’s standing in the scientific community and seems to have contributed to the fact that Huxley failed twice in the late 1920s to be elected to the Royal Society. This picture undermines to some extent Peter J. Bowler’s recent portrayal of Huxley as a science populariser.  相似文献   
108.
The publication of Volume 50 of the Biometrical Journal (formerly Biometrische Zeitschrift) in 2008 provides the perfect opportunity to describe the history of the present journal. We report on the long period of preparation for the journal within the German Region (DR) of the International Biometric Society (IBS). A special paragraph is dedicated to the first ten volumes. We emphasize the role of the journal as a bond between German biometricians on both sides of the border between the two German nations and IBS regions at that time. Furthermore, we report on the development of its thematic spectrum and impact factors and provide citation frequencies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
109.
中国桂花的研究历史、现状与桂花品种国际登录   总被引:14,自引:1,他引:13  
简要回顾了中国桂花(Osmanthus fragrans Lour.)的研究历史,对桂花品种研究的现状和存在的问题进行了评述,介绍了申报桂花品种国际登录工作的意义和目前的工作进展。桂花品种的现代分类始于20世纪80年代,除了传统的形态分类以外,同工酶、分子标记等技术已用于桂花品种亲缘关系的研究中,但目前仍缺乏合理的品种分类原则和分类系统,品种调查、记载和命名比较混乱,因此应加强桂花品种形态学的基础研究。  相似文献   
110.
We report the results of molecular monitoring of 'whalemeat' markets in the Republic of (South) Korea based on nine systematic surveys from February 2003 to February 2005. As Korea has no programme of commercial or scientific whaling and there is a closure on the hunting of dolphins and porpoises, the only legal source of these products was assumed to be incidental fisheries mortalities ('bycatch') as reported by the government to the International Whaling Commission. Species identification of 357 products using mitochondrial DNA control region or cytochrome b sequences and the web-based programme DNA-surveillance revealed three species of baleen whales (North Pacific minke, common form Bryde's and humpback), three species of beaked whales (Cuvier's, Stejneger's and Blainville's), seven species of dolphins (short-finned pilot, false killer and killer whales; Risso's, bottlenose, common and Pacific white-sided dolphins) and two species of porpoises (harbour and finless). Comparison of market products with official records revealed a number of discrepancies. Of the eight species identified on the markets in 2003, three were not reported in official records for that year. Of the 11 species identified in 2004, five were not reported as bycatch, although one species, a humpback whale, was reported as 'stranded'. We also found significant inconsistencies in the expected frequencies of products from most species, including a large over-representation of finless porpoises and false killer whales. We suggest ways in which market surveys could be improved to provide better information on the magnitude of fisheries bycatch and other illegal, unregulated and unreported (IUU) exploitation of wildlife.  相似文献   
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