全文获取类型
收费全文 | 620篇 |
免费 | 36篇 |
出版年
2019年 | 5篇 |
2017年 | 8篇 |
2016年 | 15篇 |
2015年 | 26篇 |
2014年 | 21篇 |
2013年 | 29篇 |
2012年 | 30篇 |
2011年 | 36篇 |
2010年 | 23篇 |
2009年 | 20篇 |
2008年 | 35篇 |
2007年 | 30篇 |
2006年 | 21篇 |
2005年 | 21篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 20篇 |
2001年 | 23篇 |
2000年 | 13篇 |
1999年 | 13篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1992年 | 11篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 15篇 |
1988年 | 13篇 |
1987年 | 8篇 |
1984年 | 5篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 12篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 8篇 |
1974年 | 5篇 |
1973年 | 8篇 |
1972年 | 4篇 |
1971年 | 6篇 |
1970年 | 5篇 |
1969年 | 4篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1966年 | 5篇 |
1965年 | 4篇 |
1957年 | 4篇 |
排序方式: 共有656条查询结果,搜索用时 15 毫秒
101.
Rudolf Berndt Hermann Severit E. Stresemann Werner Tautenhahn H. Bruns Karl Greve Wilfried Stichmann und Gerald Mayer 《Journal of Ornithology》1958,99(2):218-221
Ohne Zusammenfassung 相似文献
102.
Symposium on Relationship of Structure of Microorganisms to Their Immunological Properties: III. STRUCTURE AND BIOLOGICAL PROPERTIES OF SURFACE ANTIGENS FROM GRAM-NEGATIVE BACTERIA 总被引:9,自引:2,他引:7
下载免费PDF全文
![点击此处可从《Microbiological reviews》网站下载免费的PDF全文](/ch/ext_images/free.gif)
103.
JA Nboyine S Boyer D Saville MJ Smith SD Wratten 《New Zealand journal of zoology.》2016,43(4):336-350
The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation. 相似文献
104.
Distinguishing morphologically cryptic taxa, by definition, requires genetic data such as DNA sequences. However, DNA sequences may not be obtained easily for taxa from remote sites. Here we provide the details of a high-resolution melt-curve-based method using taxon-specific primers that can distinguish two taxa of Adélie penguins, and that will be usable in Antarctica when combined with some of the newly developed field-deployable thermal cyclers. We suggest that the wider adoption of field-deployable polymerase-chain-reaction-based techniques will enable faster assignation of haplotype to individuals in situ, and so allow the targeting of observations and sample collection to specimens relevant to the research question. Targeting individuals will also reduce the need to repeatedly handle animals and reduce the time and travel required to complete field work. 相似文献
105.
106.
107.
C W Liu R H Wang M Dohadwala A H Sch?nthal E Villa-Moruzzi N Berndt 《The Journal of biological chemistry》1999,274(41):29470-29475
We have shown earlier that, in cells expressing the retinoblastoma protein (pRB), a protein phosphatase (PP) 1alpha mutant (T320A) resistant to inhibitory phosphorylation by cyclin-dependent kinases (Cdks) causes G(1) arrest. In this study, we examined the cell cycle-dependent phosphorylation of PP1alpha in vivo using three different antibodies. PP1alpha was phosphorylated at Thr-320 during M-phase and again in late G(1)- through early S-phase. Inhibition of Cdk2 led to a small increase in PP1 activity and also prevented PP1alpha phosphorylation. In vitro, PP1alpha was a substrate for Cdk2 but not Cdk4. In pRB-deficient cells, phosphorylation of PP1alpha occurred in M-phase but not at G(1)/S. G(1)/S phosphorylation was at least partially restored after reintroduction of pRB into these cells. Consistent with this result, PP1alpha phosphorylated at Thr-320 co-precipitated with pRB during G(1)/S but was found in extracts immunodepleted of pRB in M-phase. In conjunction with earlier studies, these results indicate that PP1alpha may control pRB function throughout the cell cycle. In addition, our new results suggest that different subpopulations of PP1alpha regulate the G(1)/S and G(2)/M transitions and that PP1alpha complexed to pRB requires inhibitory phosphorylation by G(1)-specific Cdks in order to prevent untimely reactivation of pRB and permit transition from G(1)- to S-phase and/or complete S-phase. 相似文献
108.
Stefan Knapp Pekka T. Mattson Petya Christova Kurt D. Berndt Andrej Karshikoff Mauno Vihinen C.I. Edvard Smith Rudolf Ladenstein 《Proteins》1998,31(3):309-319
The thermal unfolding of three SH3 domains of the Tec family of tyrosine kinases was studied by differential scanning calorimetry and CD spectroscopy. The unfolding transition of the three protein domains in the acidic pH region can be described as a reversible two-state process. For all three SH3 domains maximum stability was observed in the pH region 4.5 < pH < 7.0 where these domains unfold at temperatures of 353K (Btk), 342K (Itk), and 344K (Tec). At these temperatures an enthalpy change of 196 kJ/mol, 178 kJ/mol, and 169 kJ/mol was measured for Btk-, Itk-, and Tec-SH3 domains, respectively. The determined changes in heat capacity between the native and the denatured state are in an usual range expected for small proteins. Our analysis revealed that all SH3 domains studied are only weakly stabilized and have free energies of unfolding which do not exceed 12–16 kJ/mol but show quite high melting temperatures. Comparing unfolding free energies measured for eukaryotic SH3 domains with those of the topologically identical Sso7d protein from the hyperthermophile Sulfolobus solfataricus, the increased melting temperature of the thermostable protein is due to a broadening as well as a significant lifting of its stability curve. However, at their physiological temperatures, 310K for mesophilic SH3 domains and 350K for Sso7d, eukaryotic SH3 domains and Sso7d show very similar stabilities. Proteins 31:309–319, 1998. © 1998 Wiley-Liss, Inc. 相似文献
109.
Yadong Sun Niklas Berleth Wenxian Wu David Schlütermann Jana Deitersen Fabian Stuhldreier Lena Berning Annabelle Friedrich Seda Akgün María Jos Mendiburo Sebastian Wesselborg Marcus Conrad Carsten Berndt Bjrn Stork 《Cell death & disease》2021,12(11)
Ferroptosis is a form of regulated cell death that emerges to be relevant for therapy-resistant and dedifferentiating cancers. Although several lines of evidence suggest that ferroptosis is a type of autophagy-dependent cell death, the underlying molecular mechanisms remain unclear. Fin56, a type 3 ferroptosis inducer, triggers ferroptosis by promoting glutathione peroxidase 4 (GPX4) protein degradation via a not fully understood pathway. Here, we determined that Fin56 induces ferroptosis and autophagy in bladder cancer cells and that Fin56-triggered ferroptosis mechanistically depends on the autophagic machinery. Furthermore, we found that autophagy inhibition at different stages attenuates Fin56-induced oxidative stress and GPX4 degradation. Moreover, we investigated the effects of Fin56 in combination with Torin 2, a potent mTOR inhibitor used to activate autophagy, on cell viability. We found that Fin56 synergizes with Torin 2 in cytotoxicity against bladder cancer cells. Collectively, our findings not only support the concept that ferroptosis is a type of autophagy-dependent cell death but imply that the combined application of ferroptosis inducers and mTOR inhibitors is a promising approach to improve therapeutic options in the treatment of bladder cancer.Subject terms: Macroautophagy, Macroautophagy 相似文献
110.
The invasive freshwater snail Tarebia granifera (Lamarck, 1822) was first reported in South Africa in 1999 and it has become widespread across the country, with some evidence to suggest that it reduces benthic macroinvertebrate biodiversity. The current study aimed to identify the primary abiotic drivers behind abundance patterns of T. granifera, by comparing the current abundance of the snail in three different regions, and at three depths, of the highly modified Nseleni River in KwaZulu-Natal, South Africa. Tarebia granifera was well established throughout the Nseleni River system, with an overall preference for shallow waters and seasonal temporal patterns of abundance. Although it is uncertain what the ecological impacts of the snail in this system are, its high abundances suggest that it should be controlled where possible and prevented from invading other systems in the region. 相似文献