全文获取类型
收费全文 | 850篇 |
免费 | 160篇 |
国内免费 | 5篇 |
出版年
2023年 | 3篇 |
2022年 | 12篇 |
2021年 | 20篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 11篇 |
2016年 | 26篇 |
2015年 | 49篇 |
2014年 | 25篇 |
2013年 | 49篇 |
2012年 | 70篇 |
2011年 | 61篇 |
2010年 | 38篇 |
2009年 | 37篇 |
2008年 | 44篇 |
2007年 | 42篇 |
2006年 | 48篇 |
2005年 | 39篇 |
2004年 | 31篇 |
2003年 | 34篇 |
2002年 | 29篇 |
2001年 | 24篇 |
2000年 | 28篇 |
1999年 | 15篇 |
1998年 | 10篇 |
1997年 | 17篇 |
1996年 | 14篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 24篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 20篇 |
1988年 | 17篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 13篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有1015条查询结果,搜索用时 15 毫秒
101.
102.
Azalina Zainuddin Kien Hui Chua Norhazira Abdul Rahim Suzana Makpol 《BMC molecular biology》2010,11(1):59
Background
Several genes have been used as housekeeping genes and choosing an appropriate reference gene is important for accurate quantitative RNA expression in real time RT-PCR technique. The expression levels of reference genes should remain constant between the cells of different tissues and under different experimental conditions. The purpose of this study was to determine the effect of different experimental treatments on the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA so that the reliability of GAPDH as reference gene for quantitative real time RT-PCR in human diploid fibroblasts (HDFs) can be validated. HDFs in 4 different treatment groups viz; young (passage 4), senescent (passage 30), H2O2-induced oxidative stress and γ-tocotrienol (GTT)-treated groups were harvested for total RNA extraction. Total RNA concentration and purity were determined prior to GAPDH mRNA quantification. Standard curve of GAPDH expression in serial diluted total RNA, melting curve analysis and agarose gel electrophoresis were used to determine the reliability of GAPDH as reference gene. 相似文献103.
Marielle C. Gold Stefania Cerri Susan Smyk-Pearson Meghan E. Cansler Todd M. Vogt Jacob Delepine Ervina Winata Gwendolyn M. Swarbrick Wei-Jen Chua Yik Y. L. Yu Olivier Lantz Matthew S. Cook Megan D. Null David B. Jacoby Melanie J. Harriff Deborah A. Lewinsohn Ted H. Hansen David M. Lewinsohn 《PLoS biology》2010,8(6)
Control of infection with Mycobacterium tuberculosis (Mtb) requires Th1-type immunity, of which CD8+ T cells play a unique role. High frequency Mtb-reactive CD8+ T cells are present in both Mtb-infected and uninfected humans. We show by limiting dilution analysis that nonclassically restricted CD8+ T cells are universally present, but predominate in Mtb-uninfected individuals. Interestingly, these Mtb-reactive cells expressed the Vα7.2 T-cell receptor (TCR), were restricted by the nonclassical MHC (HLA-Ib) molecule MR1, and were activated in a transporter associated with antigen processing and presentation (TAP) independent manner. These properties are all characteristics of mucosal associated invariant T cells (MAIT), an “innate” T-cell population of previously unknown function. These MAIT cells also detect cells infected with other bacteria. Direct ex vivo analysis demonstrates that Mtb-reactive MAIT cells are decreased in peripheral blood mononuclear cells (PBMCs) from individuals with active tuberculosis, are enriched in human lung, and respond to Mtb-infected MR1-expressing lung epithelial cells. Overall, these findings suggest a generalized role for MAIT cells in the detection of bacterially infected cells, and potentially in the control of bacterial infection. 相似文献
104.
Jennifer W. Hill Carol F. Elias Makoto Fukuda Kevin W. Williams Eric D. Berglund William L. Holland You-Ree Cho Jen-Chieh Chuang Yong Xu Michelle Choi Danielle Lauzon Charlotte E. Lee Roberto Coppari James A. Richardson Jeffrey M. Zigman Streamson Chua Philipp E. Scherer Bradford B. Lowell Jens C. Brüning Joel K. Elmquist 《Cell metabolism》2010,11(4):286-297
105.
Necrostatin-1 protects against glutamate-induced glutathione depletion and caspase-independent cell death in HT-22 cells 总被引:3,自引:0,他引:3
Xu X Chua CC Kong J Kostrzewa RM Kumaraguru U Hamdy RC Chua BH 《Journal of neurochemistry》2007,103(5):2004-2014
Glutamate, a major excitatory neurotransmitter in the CNS, plays a critical role in neurological disorders such as stroke and Parkinson's disease. Recent studies have suggested that glutamate excess can result in a form of cell death called glutamate-induced oxytosis. In this study, we explore the protective effects of necrostatin-1 (Nec-1), an inhibitor of necroptosis, on glutamate-induced oxytosis. We show that Nec-1 inhibits glutamate-induced oxytosis in HT-22 cells through a mechanism that involves an increase in cellular glutathione (GSH) levels as well as a reduction in reactive oxygen species production. However, Nec-1 had no protective effect on free radical-induced cell death caused by hydrogen peroxide or menadione, which suggests that Nec-1 has no antioxidant effects. Interestingly, the protective effect of Nec-1 was still observed when cellular GSH was depleted by buthionine sulfoximine, a specific and irreversible inhibitor of glutamylcysteine synthetase. Our study further demonstrates that Nec-1 significantly blocks the nuclear translocation of apoptosis-inducing factor (a marker of caspase-independent programmed cell death ) and inhibits the integration of Bcl-2/adenovirus E1B 19 kDa-interacting protein 3 (a pro-death member of the Bcl-2 family) into the mitochondrial membrane. Taken together, these results demonstrate for the first time that Nec-1 prevents glutamate-induced oxytosis in HT-22 cells through GSH related as well as apoptosis-inducing factor and Bcl-2/adenovirus E1B 19 kDa-interacting protein 3-related pathways. 相似文献
106.
Liao P Yu D Li G Yong TF Soon JL Chua YL Soong TW 《The Journal of biological chemistry》2007,282(48):35133-35142
Native smooth muscle L-type Ca(v)1.2 calcium channels have been shown to support a fraction of Ca(2+) currents with a window current that is close to resting potential. The smooth muscle L-type Ca(2+) channels are also more susceptible to inhibition by dihydropyridines (DHPs) than the cardiac channels. It was hypothesized that smooth muscle Ca(v)1.2 channels exhibiting hyperpolarized shift in steady-state inactivation would contribute to larger inhibition by DHP, in addition to structural differences of the channels generated by alternative splicing that modulate DHP sensitivities. In addition, it has also been shown that alternative splicing modulates DHP sensitivities by generating structural differences in the Ca(v)1.2 channels. Here, we report a smooth muscle L-type Ca(v)1.2 calcium channel splice variant, Ca(v)1.2SM (1/8/9(*)/32/Delta33), that when expressed in HEK 293 cells display hyperpolarized shifts for steady-state inactivation and activation potentials when compared with the established Ca(v)1.2b clone (1/8/9(*)/32/33). This variant activates from more negative potentials and generates a window current closer to resting membrane potential. We also identified the predominant cardiac isoform Ca(v)1.2CM clone (1a/8a/Delta9(*)/32/33) that is different from the established Ca(v)1.2a (1a/8a/Delta9(*)/31/33). Importantly, Ca(v)1.2SM channels were shown to be more sensitive to nifedipine blockade than Ca(v)1.2b and cardiac Ca(v)1.2CM channels when currents were recorded in either 5 mM Ba(2+) or 1.8 mM Ca(2+) external solutions. This is the first time that a smooth muscle Ca(v)1.2 splice variant has been identified functionally to possess biophysical property that can be linked to enhanced state-dependent block by DHP. 相似文献
107.
Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique namely Random Amplified Polymorphic DNA (RAPD) to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively' uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA done based on the RAPD makers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution. 相似文献
108.
Wang YJ Hua FL Tsang YF Chan SY Sin SN Chua H Yu PH Ren NQ 《Bioresource technology》2007,98(8):1690-1693
Polyhydroxyalkanoates (PHAs) production was carried out under various C:N ratios. A ratio of 100 resulted best polymer yield. C-source was an important factor in synthesis. For example, as the ratio of valeric acid (C5) to butyric acid (C4) in N-free medium was increased, the mole fraction of HV in the copolymer increased. When soy waste was used as a C-source a copolymer, a high HV mole fraction (HB:HV, 75:25) was produced while when malt waste was used, a much lower HV mole fraction (HB:HV, 90:10) was generated. It was concluded that activated sludge bacteria could be induced to produce PHAs using food wastes as C-sources and this could be the basis for production of biodegradable plastics. 相似文献
109.
110.
Chua PR Roof DM Lee Y Sakowicz R Clarke D Pierce D Stephens T Hamilton M Morgan B Morgans D Nakai T Tomasi A Maxon ME 《Molecular microbiology》2007,65(2):347-362
Kinesins from the bipolar (Kinesin-5) family are conserved in eukaryotic organisms and play critical roles during the earliest stages of mitosis to mediate spindle pole body separation and formation of a bipolar mitotic spindle. To date, genes encoding bipolar kinesins have been reported to be essential in all organisms studied. We report the characterization of CaKip1p, the sole member of this family in the human pathogenic yeast Candida albicans. C. albicans Kip1p appears to localize to the mitotic spindle and loss of CaKip1p function interferes with normal progression through mitosis. Inducible excision of CaKIP1 revealed phenotypes unique to C. albicans, including viable homozygous Cakip1 mutants and an aberrant spindle morphology in which multiple spindle poles accumulate in close proximity to each other. Expression of the C. albicans Kip1 motor domain in Escherichia coli produced a protein with microtubule-stimulated ATPase activity that was inhibited by an aminobenzothiazole (ABT) compound in an ATP-competitive fashion. This inhibition results in 'rigor-like', tight association with microtubules in vitro. Upon treatment of C. albicans cells with the ABT compound, cells were killed, and terminal phenotype analysis revealed an aberrant spindle morphology similar to that induced by loss of the CaKIP1 gene. The ABT compound discovered is the first example of a fungal spindle inhibitor targeted to a mitotic kinesin. Our results also show that the non-essential nature and implementation of the bipolar motor in C. albicans differs from that seen in other organisms, and suggest that inhibitors of a non-essential mitotic kinesin may offer promise as cidal agents for antifungal drug discovery. 相似文献