全文获取类型
收费全文 | 3665篇 |
免费 | 248篇 |
国内免费 | 5篇 |
专业分类
3918篇 |
出版年
2024年 | 2篇 |
2023年 | 14篇 |
2022年 | 52篇 |
2021年 | 84篇 |
2020年 | 37篇 |
2019年 | 59篇 |
2018年 | 92篇 |
2017年 | 65篇 |
2016年 | 111篇 |
2015年 | 172篇 |
2014年 | 191篇 |
2013年 | 244篇 |
2012年 | 302篇 |
2011年 | 330篇 |
2010年 | 203篇 |
2009年 | 164篇 |
2008年 | 233篇 |
2007年 | 259篇 |
2006年 | 261篇 |
2005年 | 239篇 |
2004年 | 210篇 |
2003年 | 170篇 |
2002年 | 196篇 |
2001年 | 24篇 |
2000年 | 9篇 |
1999年 | 21篇 |
1998年 | 28篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1995年 | 13篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1960年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有3918条查询结果,搜索用时 0 毫秒
91.
Brandstaetter Christian Fricko Nora Rahimi Mohammad J. Fellner Johann Ecker-Lala Wolfgang Druzhinina Irina S. 《Biodegradation》2022,33(1):71-85
Biodegradation - Biological waste degradation is the main driving factor for landfill emissions. In a 2-year laboratory experiment simulating different landfill in-situ aeration scenarios, the... 相似文献
92.
Violeta Datcheva Aleksei Kamernitskii Radoslav Vlahov Natalia Voishvillo Vera Levi Irina Reshetova Elena Chernoburova 《Applied microbiology and biotechnology》1986,25(1):14-17
Summary A high-yield microbiological transformation of polyfunctional 5-3-acetoxy steroids, containing an additional ring E, by Corynebacterium mediolanum strain B-964 was carried out, resulting in the corresponding 4-3-ketones. It was shown that the type of transformation and the yield of the reaction depend on the degree of saturation of the ring E and on the position of the oxygen-containing substituents in it. 相似文献
93.
94.
95.
Studneva Irina M. Veselova Oksana M. Dobrokhotov Igor V. Serebryakova Larisa I. Palkeeva Marina E. Molokoedov Alexander S. Azmuko Andrey A. Ovchinnikov Michael V. Sidorova Maria V. Pisarenko Oleg I. 《Biochemistry. Biokhimii?a》2022,87(4):346-355
Biochemistry (Moscow) - Neuropeptide galanin and its N-terminal fragments reduce the generation of reactive oxygen species and normalize metabolic and antioxidant states of myocardium in... 相似文献
96.
Belokopytova Irina I. Kondaurova Elena M. Kulikova Elizabeth A. Ilchibaeva Tatiana V. Naumenko Vladimir S. Popova Nina K. 《Biochemistry. Biokhimii?a》2022,87(10):1206-1218
Biochemistry (Moscow) - The mechanisms of autism are of extreme interest due to the high prevalence of this disorder in the human population. In this regard, special attention is given to the... 相似文献
97.
Petrosal and inner ear anatomy and allometry amongst specimens referred to Litopterna (Placentalia) 下载免费PDF全文
Guillaume Billet Christian de Muizon Rico Schellhorn Irina Ruf Sandrine Ladevèze Lilian Bergqvist 《Zoological Journal of the Linnean Society》2015,173(4):956-987
New isolated petrosals from the Itaboraí beds of Brazil (late Palaeocene or early Eocene) are here described and referred to the early diverging litoptern Miguelsoria parayirunhor, based on phylogenetic, size, and abundance arguments. Both the external and internal anatomy of these specimens were investigated, which for the first time document many details of the auditory region of a Palaeogene litoptern. Our cladistic analysis, which included our new observations, failed to recover a monophyletic Litopterna but did not exclude it. A constrained analysis for the monophyly of this order showed that several features such as a (sub)quadrangular and anteroposteriorly elongated tensor tympani fossa and a large notch in the vicinity of the external opening of the cochlear canaliculus may constitute synapomorphies for Litopterna. The evolution of several other auditory characters amongst Litopterna is discussed and the relative dimensions of the inner ear and surrounding petrosal in the group were also investigated. This allowed detection of negative allometry of the bony labyrinth within the petrosal, which was confirmed by measurements and regression analysis across a larger sample of placental mammals. This scaling effect probably has an important influence on several characters of the bony labyrinth and petrosal, amongst which are the length of the vestibular aqueduct and cochlear canaliculus. It demonstrates that many aspects of the morphological variation of the bony labyrinth need to be thoroughly investigated before being incorporated into phylogenetic analyses. © 2015 The Linnean Society of London 相似文献
98.
Massimo Maddaloni Irina Kochetkova SangMu Jun Gayle Callis Theresa Thornburg David W. Pascual 《PloS one》2015,10(1)
Autoimmune diseases arise from the loss of tolerance to self, and because the etiologies of such diseases are largely unknown, symptomatic treatments rely on anti-inflammatory and analgesic agents. Tolerogenic treatments that can reverse disease are preferred, but again, often thwarted by not knowing the responsible auto-antigens (auto-Ags). Hence, a viable alternative to stimulating regulatory T cells (Tregs) is to induce bystander tolerance. Colonization factor antigen I (CFA/I) has been shown to evoke bystander immunity and to hasten Ag-specific Treg development independent of auto-Ag. To translate in treating human autoimmune diseases, the food-based Lactococcus was engineered to express CFA/I fimbriae, and Lactococcus-CFA/I fermented milk fed to arthritic mice proved highly efficacious. Protection occurred via CD39+ Tregs producing TGF-β and IL-10 to potently suppress TNF-α production and neutrophil influx into the joints. Thus, these data demonstrate the feasibility of oral nutraceuticals for treating arthritis, and potency of protection against arthritis was improved relative to that obtained with Salmonella-CFA/I. 相似文献
99.
Leelahavanichkul A Bocharov AV Kurlander R Baranova IN Vishnyakova TG Souza AC Hu X Doi K Vaisman B Amar M Sviridov D Chen Z Remaley AT Csako G Patterson AP Yuen PS Star RA Eggerman TL 《Journal of immunology (Baltimore, Md. : 1950)》2012,188(6):2749-2758
Class B scavenger receptors (SR-Bs), such as SR-BI/II or CD36, bind lipoproteins but also mediate bacterial recognition and phagocytosis. In evaluating whether blocking receptors can prevent intracellular bacterial proliferation, phagocyte cytotoxicity, and proinflammatory signaling in bacterial infection/sepsis, we found that SR-BI/II- or CD36-deficient phagocytes are characterized by a reduced intracellular bacterial survival and a lower cytokine response and were protected from bacterial cytotoxicity in the presence of antibiotics. Mice deficient in either SR-BI/II or CD36 are protected from antibiotic-treated cecal ligation and puncture (CLP)-induced sepsis, with greatly increased peritoneal granulocytic phagocyte survival (8-fold), a drastic diminution in peritoneal bacteria counts, and a 50-70% reduction in systemic inflammation (serum levels of IL-6, TNF-α, and IL-10) and organ damage relative to CLP in wild-type mice. The survival rate of CD36-deficient mice after CLP was 58% compared with 17% in control mice. When compensated for mineralocorticoid and glucocorticoid deficiency, SR-BI/II-deficient mice had nearly a 50% survival rate versus 5% in mineralo-/glucocorticoid-treated controls. Targeting SR-B receptors with L-37pA, a peptide that functions as an antagonist of SR-BI/II and CD36 receptors, also increased peritoneal granulocyte counts, as well as reduced peritoneal bacteria and bacterium-induced cytokine secretion. In the CLP mouse sepsis model, L-37pA improved survival from 6 to 27%, reduced multiple organ damage, and improved kidney function. These results demonstrate that the reduction of both SR-BI/II- and CD36-dependent bacterial invasion and inflammatory response in the presence of antibiotic treatment results in granulocyte survival and local bacterial containment, as well as reduces systemic inflammation and organ damage and improves animal survival during severe infections. 相似文献
100.
Sergiev PV Lesnyak DV Burakovsky DE Svetlov M Kolb VA Serebryakova MV Demina IA Govorun VM Dontsova OA Bogdanov AA 《Journal of molecular biology》2012,416(5):656-667
Catalysis of peptide bond formation in the peptidyl transferase center is a major enzymatic activity of the ribosome. Mutations limiting peptidyl transferase activity are mostly lethal. However, cellular processes triggered by peptidyl transferase deficiency in the bacterial cell are largely unknown. Here we report a study of the lethal G2061C mutant of Escherichia coli 23S ribosomal RNA (rRNA). The G2061C mutation completely impaired the puromycin reaction and abolished formation of the active firefly luciferase in an in vitro translation system, while poly(U)- and short synthetic mRNA-directed peptidyl transferase reaction with aminoacylated tRNAs in vitro was seemingly unaffected. Study of the cellular proteome upon expression of the 23S rRNA gene carrying the G2061C mutation compared to cells expressing wild-type 23S rRNA gene revealed substantial differences. Most of the observed effects in the mutant were associated with reduced expression of stress response proteins and particularly proteins associated with the ppGpp-mediated stringent response. 相似文献