全文获取类型
收费全文 | 415篇 |
免费 | 20篇 |
国内免费 | 4篇 |
专业分类
439篇 |
出版年
2022年 | 5篇 |
2021年 | 13篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 16篇 |
2014年 | 29篇 |
2013年 | 28篇 |
2012年 | 30篇 |
2011年 | 33篇 |
2010年 | 26篇 |
2009年 | 21篇 |
2008年 | 24篇 |
2007年 | 12篇 |
2006年 | 19篇 |
2005年 | 20篇 |
2004年 | 12篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1962年 | 1篇 |
1956年 | 1篇 |
1955年 | 1篇 |
1952年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有439条查询结果,搜索用时 15 毫秒
1.
2.
3.
David Yang-Wei Fann Yun-An Lim Yi-Lin Cheng Ker-Zhing Lok Prasad Chunduri Sang-Ha Baik Grant R. Drummond S. Thameem Dheen Christopher G. Sobey Dong-Gyu Jo Christopher Li-Hsian Chen Thiruma V. Arumugam 《Molecular neurobiology》2018,55(2):1082-1096
Multi-protein complexes, termed “inflammasomes,” are known to contribute to neuronal cell death and brain injury following ischemic stroke. Ischemic stroke increases the expression and activation of nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) Pyrin domain containing 1 and 3 (NLRP1 and NLRP3) inflammasome proteins and both interleukin (IL)-1β and IL-18 in neurons. In this study, we provide evidence that activation of either the NF-κB and MAPK signaling pathways was partly responsible for inducing the expression and activation of NLRP1 and NLRP3 inflammasome proteins and that these effects can be attenuated using pharmacological inhibitors of these two pathways in neurons and brain tissue under in vitro and in vivo ischemic conditions, respectively. Moreover, these findings provided supporting evidence that treatment with intravenous immunoglobulin (IVIg) preparation can reduce activation of the NF-κB and MAPK signaling pathways resulting in decreased expression and activation of NLRP1 and NLRP3 inflammasomes, as well as increasing expression of anti-apoptotic proteins, Bcl-2 and Bcl-xL, in primary cortical neurons and/or cerebral tissue under in vitro and in vivo ischemic conditions. In summary, these results provide compelling evidence that both the NF-κB and MAPK signaling pathways play a pivotal role in regulating the expression and activation of NLRP1 and NLRP3 inflammasomes in primary cortical neurons and brain tissue under ischemic conditions. In addition, treatment with IVIg preparation decreased the activation of the NF-κB and MAPK signaling pathways, and thus attenuated the expression and activation of NLRP1 and NLRP3 inflammasomes in primary cortical neurons under ischemic conditions. Hence, these findings suggest that therapeutic interventions that target inflammasome activation in neurons may provide new opportunities in the future treatment of ischemic stroke. 相似文献
4.
5.
6.
Yulan?Xiao Yee?Hin?Lok Toyoki?KozaiEmail author 《In vitro cellular & developmental biology. Plant》2003,39(2):186-192
Summary Explants of sugarcane, a C4 plant, were cultured in vitro for 18d on Floridalite (a solid cube consisting of vermiculite and cellulose fibers) used as supporting material with sugar-free
Murashige and Skoog liquid medium with double-strength KH2PO4, MgSO4, FeSO4, and Na2-EDTA in the vessel with enhanced natural ventilation. CO2 concentration in the culture room was kept at 1500 μmol mol−1 (four times the atmospheric CO2 concentration) during the photoperiod. A factorial experiment was designed with two levels of photosynthetic photon flux
(PPF) and three levels of N (number of air exchanges of the vessel). The results were compared with those in the control treatment (photomixotrophic
culture using sugar-containing agar medium under low PPF and low N). PPF and N showed significant positive effects on the growth of sugarcane plantlets in vitro. In the photoautotrophic (using sugar-free medium) treatments with relatively high PPF (200–400 μmol m−2 s−1) and high N (2–10 h−1), the growth of plantlets was four to seven times greater than that in the control. Also, the culture period for multiplication
and rooting was shortened from 30 d in the control to 18 d or less in the photoautotrophic, high PPF, and high N treatments. Use of porous supporting material in photoautotrophic treatments promoted rooting and plantlet growth significantly. 相似文献
7.
8.
Abstract An efficient alternative which makes use of the reliable 3J1′2′. value to derive the endocyclic torsion angle constraints is proposed in this study. Based on the information embedded in the two plots, (i) the vicinal proton-proton J-couplings, 3J1′2′., 3J1′2″., 3J2′3′., 3J2”3′ and 3J3′4′ against the pseudorotation phase angle, and (ii) 3J1′2″, 3J2′3′., 3J2″3′ and 3J3′4′ against 3J1′2′; using the calculated J-couplings obtained for a range of sugar geometries of deoxyribose ring in nucleosides and nucleotides encountered along the pseudorotation itinerary [J. van Wijk, B.D. Huckriede, J.H. Ippel and C. Altona, Methods Enzymol. 211, 286–306 (1992)], it is suggested that the vicinal 3J1′2′ possesses structural information other than the vicinal torsion angle φ1′2′. This study is divided into two parts. In Part I, a correlation diagram between the endocyclic torsion angles vi (i=0,1,2,3,4) and the restrained vicinal torsion angle φ1′2′ is obtained through the use of the J-coupling restrained molecular mechanics (JrMM) protocol. The established φ1′2′.-vi correlation shows vi can be deduced from the reliable 3J1′2′. value and it forms the basis for developing an alternative protocol to derive endocyclic torsion angle constraints. In Part II of this series, extensive testing demonstrating the validity of the JrMM protocol to derive Vi for defining the sugar geometry of solution DNA molecules is presented. 相似文献
9.
Victor A. Kostyuchenko Qian Zhang Joanne L. Tan Thiam-Seng Ng Shee-Mei Lok 《Journal of virology》2013,87(13):7700-7707
Dengue virus is a major human pathogen that has four serotypes (DENV1 to -4). Here we report the cryoelectron microscopy (cryo-EM) structures of immature and mature DENV1 at 6- and 4.5-Å resolution, respectively. The subnanometer-resolution maps allow accurate placement of all of the surface proteins. Although the immature and mature viruses showed vastly different surface protein organizations, the envelope protein transmembrane (E-TM) regions remain in similar positions. The pivotal role of the E-TM regions leads to the identification of the start and end positions of all surface proteins during maturation. 相似文献
10.
Guntur Fibriansah Thiam-Seng Ng Victor A. Kostyuchenko Jaime Lee Sumarlin Lee Jiaqi Wang Shee-Mei Lok 《Journal of virology》2013,87(13):7585-7592
Previous binding studies of antibodies that recognized a partially or fully hidden epitope suggest that insect cell-derived dengue virus undergoes structural changes at an elevated temperature. This was confirmed by our cryo-electron microscopy images of dengue virus incubated at 37°C, where viruses change their surface from smooth to rough. Here we present the cryo-electron microscopy structures of dengue virus at 37°C. Image analysis showed four classes of particles. The three-dimensional (3D) map of one of these classes, representing half of the imaged virus population, shows that the E protein shell has expanded and there is a hole at the 3-fold vertices. Fitting E protein structures into the map suggests that all of the interdimeric and some intradimeric E protein interactions are weakened. The accessibility of some previously found cryptic epitopes on this class of particles is discussed. 相似文献