全文获取类型
收费全文 | 864篇 |
免费 | 119篇 |
出版年
2019年 | 10篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 20篇 |
2013年 | 27篇 |
2012年 | 49篇 |
2011年 | 39篇 |
2010年 | 17篇 |
2009年 | 25篇 |
2008年 | 28篇 |
2007年 | 58篇 |
2006年 | 35篇 |
2005年 | 24篇 |
2004年 | 30篇 |
2003年 | 32篇 |
2002年 | 36篇 |
2001年 | 24篇 |
2000年 | 20篇 |
1999年 | 23篇 |
1998年 | 11篇 |
1995年 | 10篇 |
1994年 | 15篇 |
1993年 | 10篇 |
1992年 | 13篇 |
1991年 | 20篇 |
1990年 | 15篇 |
1989年 | 20篇 |
1988年 | 14篇 |
1987年 | 15篇 |
1986年 | 12篇 |
1985年 | 17篇 |
1984年 | 22篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 19篇 |
1980年 | 12篇 |
1979年 | 16篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1974年 | 15篇 |
1973年 | 11篇 |
1972年 | 15篇 |
1971年 | 6篇 |
1970年 | 12篇 |
1969年 | 8篇 |
1968年 | 10篇 |
1967年 | 6篇 |
1966年 | 10篇 |
排序方式: 共有983条查询结果,搜索用时 695 毫秒
61.
J L McGuire P H Brookes R F McConnell D W Hahn J P DaVanzo S A Solomon G D Turner 《Theriogenology》1975,3(1):1-13
The concentrations of plasma estrogens, progesterone, and corticosteroids and of urinary pregnanediol, pregnanetriol, ketogenic steroids, and corticosteroids were determined as indicators of ovarian and adrenal function throughout a normal sow's estrous cycle. Two broad peaks of plasma estrogen, one lasting 11–12 days during estrus and another 6-day peak period during the early part of the luteal phase were detected. Plasma progesterone was elevated during the late follicular and luteal phase. Two broad peaks of plasma corticoids appeared, one following the decrease of plasma progesterone and the second 7–14 days later. Those elevations in plasma corticoids occurred when estrogen titres were elevated. Urinary determinations generally reflected plasma findings. Estrogen levels began to rise during the follicular phase while a reasonably high progesterone level was evident. Estrogen titres never decreased to non-detectable levels. An interrelationship between adrenal function and ovarian estrogen production is suggested. 相似文献
62.
J C Woodrow C A Clarke W T Donohow R Finn R B McConnell P M Sheppard D Lehane F M Roberts T M Gimlette 《BMJ (Clinical research ed.)》1975,2(5962):57-59
The mechanism by which Rh immunization is prevented by IgG anti-D was investigated by studying the specificity of immunosuppression. 62 D-negative Kell(K)-negative male volunteers were given two successive stimuli of 1 ml D-positive K-positive red cells. Thirty-one of the volunteers were also given 13-14 mug of IgG anti-K immediately after each stimulus, the others acting as controls. Anti-D developed in 11 of the 31 controls and in one of the 31 volunteers who had received anti-K. This marked suppression of the anti-D response by IgG anti-K was accompanied by the rapid clearance of the injected red cells to the spleen. This shows that the predominant mechanism that must be operating when IgG anti-D prevents Rh immunization is not antigen specific but is one that must involve the whole red cell, probably through destruction within splenic macrophages. 相似文献
63.
64.
65.
66.
Vivienne C.M. Neeve Angela Pyle Veronika Boczonadi Aurora Gomez-Duran Helen Griffin Mauro Santibanez-Koref Ulrike Gaiser Peter Bauer Andreas Tzschach Patrick F. Chinnery Rita Horvath 《Mitochondrion》2013,13(6):743-748
Exome sequencing identified compound heterozygous mutations in the recently discovered mitochondrial methionyl-tRNA formyltransferase (MTFMT) gene in two sisters with mild Leigh syndrome and combined respiratory chain deficiency. The mutations lead to undetectable levels of the MTFMT protein. Blue native polyacrylamide gel electrophoresis showed decreased complexes I and IV, and additional products stained with complex V antibodies, however the overall steady state level of mt-tRNAMet was normal. Our data illustrate that exome sequencing is an excellent diagnostic tool, and its value in clinical medicine is enormous, however it can only be optimally exploited if combined with detailed phenotyping and functional studies. 相似文献
67.
Khairunadwa Jemon Vivienne Young Michelle Wilson Sara McKee Vernon Ward Margaret Baird Sarah Young Merilyn Hibma 《PloS one》2013,8(6)
Cervical cancer is caused by high-risk, cancer-causing human papillomaviruses (HPV) and is the second highest cause of cancer deaths in women globally. The majority of cervical cancers express well-characterized HPV oncogenes, which are potential targets for immunotherapeutic vaccination. Here we develop a rabbit haemorrhagic disease virus (RHDV) virus-like particle (VLP)-based vaccine designed for immunotherapy against HPV16 positive tumours. An RHDV-VLP, modified to contain the universal helper T cell epitope PADRE and decorated with an MHC I-restricted peptide (aa 48–57) from the HPV16 E6, was tested for its immunotherapeutic efficacy against the TC-1 HPV16 E6 and E7-expressing tumour in mice. The E6-RHDV-VLP-PADRE was administered therapeutically for the treatment of a pre-existing TC-1 tumour and was delivered with antibodies either to deplete regulatory T cells (anti-CD25) or to block T cell suppression mediated through CTLA-4. As a result, the tumour burden was reduced by around 50% and the median survival time of mice to the humane endpoint was almost doubled the compared to controls. The incorporation of PADRE into the RHDV-VLP was necessary for an E6-specific enhancement of the anti-tumour response and the co-administration of the immune modifying antibodies contributed to the overall efficacy of the immunotherapy. The E6-RHDV-VLP-PADRE shows immunotherapeutic efficacy, prolonging survival for HPV tumour-bearing mice. This was enhanced by the systemic administration of immune-modifying antibodies that are commercially available for use in humans. There is potential to further modify these particles for even greater efficacy in the path to development of an immunotherapeutic treatment for HPV precancerous and cancer stages. 相似文献
68.
Peter M. Bowers Tamlyn Y. Neben Geoffery L. Tomlinson Jennifer L. Dalton Larry Altobell Xue Zhang John L. Macomber Betty F. Wu Rachelle M. Toobian Audrey D. McConnell Petra Verdino Betty Chau Robert A. Horlick David J. King 《The Journal of biological chemistry》2013,288(11):7688-7696
A method for simultaneous humanization and affinity maturation of monoclonal antibodies has been developed using heavy chain complementarity-determining region (CDR) 3 grafting combined with somatic hypermutation in vitro. To minimize the amount of murine antibody-derived antibody sequence used during humanization, only the CDR3 region from a murine antibody that recognizes the cytokine hβNGF was grafted into a nonhomologous human germ line V region. The resulting CDR3-grafted HC was paired with a CDR-grafted light chain, displayed on the surface of HEK293 cells, and matured using in vitro somatic hypermutation. A high affinity humanized antibody was derived that was considerably more potent than the parental antibody, possessed a low pm dissociation constant, and demonstrated potent inhibition of hβNGF activity in vitro. The resulting antibody contained half the heavy chain murine donor sequence compared with the same antibody humanized using traditional methods. 相似文献
69.
David G. McLaren Sheng-Ping Wang Steven J. Stout Dan Xie Paul L. Miller Vivienne Mendoza Raymond Rosa Jose Castro-Perez Stephen F. Previs Douglas G. Johns Thomas P. Roddy 《Journal of lipid research》2013,54(1):276-281
Isotopic tracers have been used to examine lipid trafficking for many years, and data from those studies have typically yielded novel insight regarding the pathophysiology of dyslipidemia. Previous experimental designs were suitable for studies in humans because relatively large volumes of plasma could be regularly sampled. We have expanded on the earlier logic by applying high-throughput analytical methods that require reduced sample volumes. Specifically, we have examined the possibility of coupling gel-based separations of lipoproteins (e.g., lipoprint) with LC-MS/MS analyses of complex lipid mixtures as a way to routinely measure the labeling profiles of distinct lipids in discrete lipoprotein subfractions. We demonstrate the ability to measure the incorporation of [U-13C]oleate into triglycerides (TG), PLs (PL), and cholesterol esters (CE) in VLDL, LDL, and HDL particles in mice. Although rodent models of dyslipidemia are inherently different from humans because of alterations in enzyme activities and underlying metabolism, rodent models can be used to screen novel compounds for efficacy in altering a given biochemical pathway and therein enable studies of target engagement in vivo. We expect that it is possible to translate our approach for application in other systems, including studies in humans. 相似文献
70.
Yi Liu Vivienne Gianinazzi-Pearson Christine Arnould Daniel Wipf Bin Zhao Diederik van Tuinen 《Fungal biology》2013,117(1):22-31
Fluctuations in intracellular calcium levels generate signalling events and regulate different cellular processes. Whilst the implication of Ca2+ in plant responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary messenger in the fungal symbiont. The spatio-temporal expression pattern of putatively Ca2+-related genes of Glomus intraradices BEG141 encoding five proteins involved in membrane transport and one nuclear protein kinase, was investigated during the AM symbiosis. Expression profiles related to successful colonization of host roots were observed in interactions of G. intraradices with roots of wild-type Medicago truncatula (line J5) compared to the mycorrhiza-defective mutant dmi3/Mtsym13. Symbiotic fungal activity was monitored using stearoyl-CoA desaturase and phosphate transporter genes. Laser microdissection based-mapping of fungal gene expression in mycorrhizal root tissues indicated that the Ca2+-related genes were differentially upregulated in arbuscules and/or in intercellular hyphae. The spatio-temporal variations in gene expression suggest that the encoded proteins may have different functions in fungal development or function during symbiosis development. Full-length cDNA obtained for two genes with interesting expression profiles confirmed a close similarity with an endoplasmic reticulum P-type ATPase and a Vcx1-like vacuolar Ca2+ ion transporter functionally characterized in other fungi and involved in the regulation of cell calcium pools. Possible mechanisms are discussed in which Ca2+-related proteins G. intraradices BEG141 may play a role in mobilization and perception of the intracellular messenger by the AM fungus during symbiotic interactions with host roots. 相似文献