共查询到20条相似文献,搜索用时 31 毫秒
1.
Wilson WW 《Journal of structural biology》2003,142(1):56-65
Static and dynamic light scattering are discussed as particularly useful tools for studying various aspects of protein crystal growth. Specific applications for prenucleation assays as well as for monitoring postnucleation growth processes are presented. Protein-protein interactions determined by light scattering, which serve as a predictor for favorable crystallization conditions as well as for protein solubility behavior, are detailed. Several precautions regarding the practical aspects of light scattering and interpretation of data are also discussed. 相似文献
2.
The best known usage of members of the mustard group is as the basis for condiment, but some of the species are important as oil seeds. The leaves are widely used as a vegetable, especially in the Far East, while in temperate agriculture mustards are extensively used as green manures, cover crops, and fodder. Oilcake residues after expressing are used as fertilizers. 相似文献
3.
Carstensen B 《Biostatistics (Oxford, England)》2004,5(3):399-413
In studies designed to compare different methods of measurement where more than two methods are compared or replicate measurements by each method are available, standard statistical approaches such as computation of limits of agreement are not directly applicable. A model is presented for comparing several methods of measurement in the situation where replicate measurements by each method are available. Measurements are viewed as classified by method, subject and replicate. Models assuming exchangeable as well as non-exchangeable replicates are considered. A fitting algorithm is presented that allows the estimation of linear relationships between methods as well as relevant variance components. The algorithm only uses methods already implemented in most statistical software. 相似文献
4.
H Vinazzer 《Folia haematologica (Leipzig, Germany : 1928)》1986,113(1-2):30-37
The mode of action of the different thrombolytic substances which are presently available is described. Alterations of the clotting mechanism which are to be expected during thrombolytic therapy as well as possible side effects of the fibrinolytic drugs are listed. Laboratory tests necessary for the control of thrombolytic therapy as well as the different test methods and their normal ranges are mentioned in detail. 相似文献
5.
新药原料--低毒性、抗病毒、抗肿瘤失配双链核糖核酸的研究进展聂实践胡冬琴赵红罗薇(北京市营养源研究所真菌工程实验室)前言近年来,全球性病毒性疾病在不断增加,但对抗病毒药物的研究却进展缓慢。直至今日由病毒引起的恶性疾病(如恶性肿瘤,AIDS病等)仍无法医治,这已成为当今严重的社会问题。据统计约60%的流行性传染病都是由病毒感染引起的,细菌感染仅占15%。而目前世界各国批准使用的合成抗病毒药物仅... 相似文献
6.
New contemporary data about new infectious diseases of XXI century are presented. Data on morbidity and mortality from severe acute respiratory syndrome (SARS, atypical pneumonia) and avian influenza are analyzed and compared with World Health Organization data on human influenza. Biologic characteristics of avian influenza virus A/H5N1 are discussed as well as possibility of its human-to-human transmission. Principles of SARS and avian influenza infections transmission as zoonoses are described as well as mechanisms of transmission impeding their ability to infect humans. It has been argued that SARS should be regarded as contagious infection, whereas avian influenza - as non-contagious. Features of all stages of epidemic process of these infections are analyzed. 相似文献
7.
《MABS-AUSTIN》2013,5(6):594-606
G protein-coupled receptors (GPCRs) are one of the most important classes of targets for small molecule drug discovery, but many current GPCRs of interest are proving intractable to small molecule discovery and may be better approached with bio-therapeutics. GPCRs are implicated in a wide variety of diseases where antibody therapeutics are currently used. These include inflammatory diseases such as rheumatoid arthritis and Crohn disease, as well as metabolic disease and cancer. Raising antibodies to GPCRs has been difficult due to problems in obtaining suitable antigen because GPCRs are often expressed at low levels in cells and are very unstable when purified. A number of new developments in over-expressing receptors, as well as formulating stable pure protein, are contributing to the growing interest in targeting GPCRs with antibodies. This review discusses the opportunities for targeting GPCRs with antibodies using these approaches and describes the therapeutic antibodies that are currently in clinical development. 相似文献
8.
Jager JJ Jansen RL Arends JW 《Apoptosis : an international journal on programmed cell death》2002,7(4):361-365
Currently, the mainly used characteristics to predict outcome or treatment response in patients with breast cancer are tumor size, N-status, histological grade and receptor status (ER/PgR). However, these conventional clinico-pathological characteristics are of limited value. More accurate determinators are needed to select patients who are most likely to benefit from treatment in terms of prognosis as well as treatment response. Proliferation and apoptosis are assumed to play a key role in tumor progression as well as response to treatment. Currently, an increasing number of molecular factors controlling apoptosis as well as proliferation is known. The clinical relevance of apoptotic tumor markers in the treatment strategy of patients with breast cancer is the subject of this review. In addition, potential future developments are discussed. 相似文献
9.
Imre Vallikivi Ülo Lille Aivar Lookene Andrus Metsala Peeter Sikk Vello Tugu Heiki Vija Ly Villo Omar Parve 《Journal of Molecular Catalysis .B, Enzymatic》2003,22(5-6):279-298
Approaches for improving methodologies of kinetic resolution of enantiomers as well as of regioselective protection of functional groups of complex chiral molecules involving lipase-catalytic reactions are highlighted. Decyclization of hemiacetals by lipase as well as exclusive pathways of lipase-catalyzed derivatization of prostanoids are brought out. Lipase-triggered cascade-reactions are noticed. 相似文献
10.
11.
Stevioside 总被引:14,自引:0,他引:14
Geuns JM 《Phytochemistry》2003,64(5):913-921
Stevioside is a natural sweetener extracted from leaves of Stevia rebaudiana (Bertoni) Bertoni. The literature about Stevia, the occurrence of its sweeteners, their biosynthetic pathway and toxicological aspects are discussed. Injection experiments or perfusion experiments of organs are considered as not relevant for the use of Stevia or stevioside as food, and therefore these studies are not included in this review. The metabolism of stevioside is discussed in relation with the possible formation of steviol. Different mutagenicity studies as well as studies on carcinogenicity are discussed. Acute and subacute toxicity studies revealed a very low toxicity of Stevia and stevioside. Fertility and teratogenicity studies are discussed as well as the effects on the bio-availability of other nutrients in the diet. The conclusion is that Stevia and stevioside are safe when used as a sweetener. It is suited for both diabetics, and PKU patients, as well as for obese persons intending to lose weight by avoiding sugar supplements in the diet. No allergic reactions to it seem to exist. 相似文献
12.
This paper is a discussion of the utility of biomarkers as a component of the ecological risk assessment process. Both the pros and the cons of biomarkers are discussed, as well as consideration of some of the sources of variability. In the end, biomarkers are considered useful as long as we are aware of their limitations and sources of uncontrolled variability. 相似文献
13.
G protein-coupled receptors (GPCRs) are one of the most important classes of targets for small molecule drug discovery, but many current GPCRs of interest are proving intractable to small molecule discovery and may be better approached with bio-therapeutics. GPCRs are implicated in a wide variety of diseases where antibody therapeutics are currently used. These include inflammatory diseases such as rheumatoid arthritis and Crohn disease, as well as metabolic disease and cancer. Raising antibodies to GPCRs has been difficult due to problems in obtaining suitable antigen because GPCRs are often expressed at low levels in cells and are very unstable when purified. A number of new developments in overexpressing receptors, as well as formulating stable pure protein, are contributing to the growing interest in targeting GPCRs with antibodies. This review discusses the opportunities for targeting GPCRs with antibodies using these approaches and describes the therapeutic antibodies that are currently in clinical development.Key words: G protein-coupled receptor, transmembrane spanning domain, chemokine receptor, extracellular domain, extracellular loop 相似文献
14.
D. Carter 《The Yale journal of biology and medicine》1981,54(3):173-180
Controversy surrounds the diagnosis, classification, and therefore the epidemiology of those tumors which have been designated as mesotheliomas. The group includes lesions which are as broadly different as benign fibrous lesions which some authors refer to as fibromas and anaplastic tumors which are extremely difficult to differentiate from peripheral lung cancers. The former are benign tumors which are usually readily resected and therefore cured. The latter are unresectable tumors which are invariably fatal and which may terminate with extensive metastatic disease. The reasons for including all of these lesions under the category of mesothelioma and the differential diagnosis of the various types is discussed. 相似文献
15.
Production of renewable polymers from crop plants 总被引:6,自引:3,他引:3
Plants produce a range of biopolymers for purposes such as maintenance of structural integrity, carbon storage, and defense against pathogens and desiccation. Several of these natural polymers are used by humans as food and materials, and increasingly as an energy carrier. In this review, we focus on plant biopolymers that are used as materials in bulk applications, such as plastics and elastomers, in the context of depleting resources and climate change, and consider technical and scientific bottlenecks in the production of novel or improved materials in transgenic or alternative crop plants. The biopolymers discussed are natural rubber and several polymers that are not naturally produced in plants, such as polyhydroxyalkanoates, fibrous proteins and poly-amino acids. In addition, monomers or precursors for the chemical synthesis of biopolymers, such as 4-hydroxybenzoate, itaconic acid, fructose and sorbitol, are discussed briefly. 相似文献
16.
Overview of mycotoxin methods, present status and future needs 总被引:2,自引:0,他引:2
Gilbert J 《Natural toxins》1999,7(6):347-352
This article reviews current requirements for the analysis for mycotoxins in foods and identifies legislative as well as other factors that are driving development and validation of new methods. New regulatory limits for mycotoxins and analytical quality assurance requirements for laboratories to only use validated methods are seen as major factors driving developments. Three major classes of methods are identified which serve different purposes and can be categorized as screening, official and research. In each case the present status and future needs are assessed. In addition to an overview of trends in analytical methods, some other areas of analytical quality assurance such as participation in proficiency testing and reference materials are identified. 相似文献
17.
G. S. Lingappaiah 《Biometrical journal. Biometrische Zeitschrift》1981,23(7):635-644
Firstly, a modified bivariate discrete distribution is considered where a set of counts are misreported as another set of counts with different modification rates. Variances and covariances are put in the closed form and for the case when all modification rates are the same, these variances and covariances are expressed as parabolic functions and they are actually evaluated for the bivariate negative binomial. Regarding the asymptotic distributions of the estimates, elements of variance-covariance matrix are obtained. Next, a multivariate inflated discrete distribution is taken up. For the case of inflated multivariate negative binomial, Bayesian estimates of inflation as well as those of parameters are given. 相似文献
18.
Sidney Horenstein 《Evolution》2008,1(4):520-530
Cities large and small have a treasure trove of building stones both local as well as imported from various regions of the
country as well as foreign sources. Many of them contain fossils which are easily available for teachers to utilize for class
field trips. For some areas guidebooks exist which are listed in the attached appendix. Even for localities where no guidebook
exists these published guides can be helpful especially if they are illustrated. Field trips are a useful learning tool and
teachers are encouraged to create various lesson plans utilizing this generally unrecognized resource. 相似文献
19.
Ovchinnikov DA 《Genesis (New York, N.Y. : 2000)》2008,46(9):447-462
Originally recognized as an essential part of the innate and acquired immune systems, macrophages emerged as omnipresent and influential regulators of embryo- and organo-genesis, as well as of tissue and tumor growth. Macrophages are present essentially in all tissues, beginning with embryonic development and, in addition to their role in host defense and in the clearance of apoptotic cells, are being increasingly recognized for their trophic function and role in regeneration. Some tissue macrophages are also found to possess a substantial potential for autonomous self-renewal. Macrophages are associated with a significant proportion of malignant tumors and are widely recognized for their angiogenesis-promoting and trophic roles, making them one of the new promising targets for cancer therapies. Recent expression profiling of embryonic macrophages from different tissues revealed remarkable consistency of their gene expression profiles, independent of their tissue of origin, as well as their similarities with tumor-associated macrophages. Macrophages are also capable of fusion with other cells in tissue repair and metastasizing tumors, as well as with each other in the immune response and osteoclastogenesis. 相似文献
20.
Anterior pituitary glands of male rats (2, 3, 5, 8, 12, 25, 36, 52, 56, and 62 days of age) were processed for electron microscopy. During early postnatal stages secretory cells are found in various stages of differentiation and comparatively few secretory granules are seen. Nuclei are mostly irregular, and the nucleo-cytoplasmic ratio is large. Many free ribosomes are present; the endoplasmic reticulum is generally sparse and the Golgi complex small or invisible. Cells are of variable shape, and numerous cytoplasmic processes project into large intercellular spaces. Many electron-dense cells which often contain myelinlike figures are seen. Lysosomes and lysosomal precursors are frequently found in secretory cells, predominantly in somatotrophs, of all immature glands. Mitotic figures are numerous in early stages after brith and decrease in number as the gland grows in size. A gradual increase in cytoplasmic volume with concomitant differentiation of cytoplasmic components as well as accumulation of secretory granules, accompanied by loss of myelin-like figures and decrease in the number of electron-dense cells, is observed as the animal reaches the prepuberal stage. Few lysosomes are seen in cells of mature glands. At 36 days of age all secretory cells seem to have differentiated, and morphological features as well as granule content show little change until puberty is reached. Gonadotrophs attain their characteristic morphology later than other cells. Cilia are observed in all developmental stages but are relatively infrequent in the mature gland. The described ultrastructural characteristics reflect the degree of maturation as well as the functional capacities of secretory cells at particular stages of development. 相似文献