全文获取类型
收费全文 | 531篇 |
免费 | 38篇 |
国内免费 | 2篇 |
出版年
2021年 | 14篇 |
2020年 | 12篇 |
2019年 | 5篇 |
2018年 | 12篇 |
2017年 | 10篇 |
2016年 | 23篇 |
2015年 | 20篇 |
2014年 | 19篇 |
2013年 | 37篇 |
2012年 | 22篇 |
2011年 | 25篇 |
2010年 | 15篇 |
2009年 | 14篇 |
2008年 | 13篇 |
2007年 | 20篇 |
2006年 | 17篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 15篇 |
2002年 | 21篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 9篇 |
1995年 | 8篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 14篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1982年 | 11篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1972年 | 3篇 |
1968年 | 4篇 |
1967年 | 5篇 |
1966年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有571条查询结果,搜索用时 15 毫秒
171.
An antiserum raised against purified lipopolysaccharide (LPS) of a Vibrio cholerae O1 strain (Co366) induced passive protection against challenge with the parent as well as other O1 organisms but not against O139 or non-O1/non-O139 organisms. A considerable level of protection against O1 strains was also observed with the IgG fraction of the antiserum which inhibited intestinal adherence and colonisation. The monovalent Fab(IgG) fragment, on the other hand, showed only a low level of protection. Interestingly, purified LPS failed to inhibit intestinal colonisation by the parent strain (Co366), thereby suggesting that the cell surface LPS moieties of vibrios may not be directly involved in the colonisation process. It may be concluded that the anti-LPS antibodies induce passive protection through microagglutination and/or immobilisation of vibrios which do not allow the organisms to adhere to and colonise the intestine. 相似文献
172.
Overexpression and purification of recombinant eel calcitonin and its phylogenetic analysis 总被引:1,自引:0,他引:1
Calcitonin (CT), a peptide hormone that is widely used for the treatment of osteoporosis, Paget's disease, hypercalcemic shock and chronic pain in terminal cancer patients, is produced by the para-follicular cells of the thyroid gland in mammals and by the ultimobranchial gland of birds and fish. Fish calcitonin, like eel calcitonin (eCT), is more potent and longer lasting than human CT and is one of the many bioactive peptides that require C-terminal amidation for full biological activity. In this study we describe the over-expression and over-production of C-terminal amidated eCT in recombinant Streptomyces avermitilis. A phylogenetic analysis was performed with all the known CT amino acid sequences. 相似文献
173.
The Multiplexed Proteomics (MP) technology is a new approach that permits quantitative, multicolor fluorescence detection of proteins in one-dimensional or two-dimensional gels. This methodology allows for multiplexed identification and differential analysis of phosphoproteins, glycoproteins, and total proteins within a single gel electrophoresis experiment. Here the MP system was applied to the differential proteomic analysis of pregnancy-induced refractoriness to breast cancer using a rat model system. Differential analyses identified multiple proteins with altered phosphorylation, glycosylation, or protein expression patterns. 相似文献
174.
In silico proteomics complements computational genomics in characterizing genome evolution. Here we examine cluster patterns in archaeal and bacterial proteomes using compositional properties of protein sequences in contrast to the traditionally used sequence alignment procedures. Application of standard Principal Component Analysis to the multi-dimensional data identified cluster patterns. Two types of cluster patterns exist in bacterial proteomes. Proteomes of type I have one major cluster with few isolated points in space revealing an underlying largely homogeneous compositional structure. In type II proteomes two clusters of protein distribution were discernible. The two clusters differ in size and were separated from each other although the boundary was somewhat fuzzy. Proteins falling in the major cluster were labeled as 'typical' and proteins of the minor cluster were called 'atypical'. The atypical proteins were mapped to Cluster of Orthologous Groups. Species distribution in COGs maps with respect to atypical proteins illuminated the biological relationships of extreme diversity among the archaeal members and of diversity among bacteria in relation to their niche. Amino acids that were over-represented in the atypical proteins had higher biosynthetic cost compared to 'typical' ribosomal proteins. However, archaea and bacteria economize by preferring the less costly amino acid to others closely related in chemical structure. Further, over-representation of serine in atypical proteins of archaeal members suggests re-examining these proteomes for the presence of Serine/Threonine phosphatases and kinases in Archaea. Our computational procedure can serve as a useful addition to the existing tools for carrying out in silico proteomics. 相似文献
175.
The effect of auxins [indole-3-butyric acid (IBA) and -naphthaleneacetic acid (NAA)], phenolics (phloroglucinol and coumarin), a combination of auxins and phenolics, and a systemic fungicide (Bavistin, containing 50% carbendazim) on adventitious root formation in stem cuttings (current season's growth) of Cedrus deodara L. during winter and monsoon (rainy) seasons has been examined. Significant stimulation of rooting due to treatments was observed in cuttings planted in winter in the following order: 0.25 mM IBA (87.5% rooting) > 5 mM coumarin (70.8%) > IBA (0.5 mM) + coumarin (5 mM) (50.0%). In cuttings planted in monsoon only 0.05% Bavistin was found to be effective in inducing rooting (83.3%). Other treatments were ineffective and in some treatments drying of cuttings was noticed. 相似文献
176.
The prion protein has RNA binding and chaperoning properties characteristic of nucleocapsid protein NCP7 of HIV-1 总被引:12,自引:0,他引:12
177.
Adhip P. Nandi Majumdar Atif M. Nakhla 《Biochemical and biophysical research communications》1977,76(1):71-77
Eight hours after a single tube-feeding of tryptophan the activity of acetylcholinesterase in the cerebral hemisphere of well-fed (non-fasted) normal and adrenalectomized rats was 28 and 53% higher, respectively, compared to the corresponding water-fed control. On the other hand, the enzyme activity in the cerebellum of both normal and adrenalectomized rats remained essentially unchanged following tryptophan administration. Pretreatment of adrenalectomized rats with actinomycin-D totally abolished the tryptophan-mediated stimulation of cerebral acetylcholinesterase activity. The pattern of response of cerebral acetylcholinesterase in well-fed adrenalectomized rats over a period of 24-hr following a dose of tryptophan was found to be biphasic. 相似文献
178.
179.
180.
Rekha Gautam Bhagawat Chandrasekar Mukta Deobagkar-Lele Srabanti Rakshit Vinay Kumar B. N. Siva Umapathy Dipankar Nandi 《PloS one》2012,7(9)
Acetaminophen is a widely prescribed drug used to relieve pain and fever; however, it is a leading cause of drug-induced liver injury and a burden on public healthcare. In this study, hepatotoxicity in mice post oral dosing of acetaminophen was investigated using liver and sera samples with Fourier Transform Infrared microspectroscopy. The infrared spectra of acetaminophen treated livers in BALB/c mice show decrease in glycogen, increase in amounts of cholesteryl esters and DNA respectively. Rescue experiments using L-methionine demonstrate that depletion in glycogen and increase in DNA are abrogated with pre-treatment, but not post-treatment, with L-methionine. This indicates that changes in glycogen and DNA are more sensitive to the rapid depletion of glutathione. Importantly, analysis of sera identified lowering of glycogen and increase in DNA and chlolesteryl esters earlier than increase in alanine aminotransferase, which is routinely used to diagnose liver damage. In addition, these changes are also observed in C57BL/6 and Nos2
−/− mice. There is no difference in the kinetics of expression of these three molecules in both strains of mice, the extent of damage is similar and corroborated with ALT and histological analysis. Quantification of cytokines in sera showed increase upon APAP treatment. Although the levels of Tnfα and Ifnγ in sera are not significantly affected, Nos2
−/− mice display lower Il6 but higher Il10 levels during this acute model of hepatotoxicity. Overall, this study reinforces the growing potential of Fourier Transform Infrared microspectroscopy as a fast, highly sensitive and label-free technique for non-invasive diagnosis of liver damage. The combination of Fourier Transform Infrared microspectroscopy and cytokine analysis is a powerful tool to identify multiple biomarkers, understand differential host responses and evaluate therapeutic regimens during liver damage and, possibly, other diseases. 相似文献