全文获取类型
收费全文 | 269篇 |
免费 | 19篇 |
国内免费 | 4篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 17篇 |
2014年 | 25篇 |
2013年 | 15篇 |
2012年 | 18篇 |
2011年 | 14篇 |
2010年 | 18篇 |
2009年 | 16篇 |
2008年 | 14篇 |
2007年 | 10篇 |
2006年 | 13篇 |
2005年 | 18篇 |
2004年 | 11篇 |
2003年 | 5篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有292条查询结果,搜索用时 281 毫秒
101.
102.
103.
104.
Nihit Madireddi David K. Daniel Vani Sankar Albert Krastanov 《Engineering in Life Science》2012,12(5):529-533
The objective of this study was to quantify the effect of algal biomass concentration on the rheology of the algal culture broth. Batch cultivations of Chlorella minutissima were carried out with air and carbon dioxide in a stirred tank bioreactor with a working volume of 1.8 L. The apparent viscosity of the culture broth was significantly affected by the cell mass concentrations in the bioreactor. Culture broth containing 50 g/L cell mass from air fed was found to exhibit an apparent viscosity of 1.52 mPa.s. The apparent viscosity of the carbon‐dioxide‐fed cultivations was found to increase by 20% at a shear rate of 100 s?1. The flow behavior of the system was adequately described by the Herschel–Bulkley model with a small yield stress. 相似文献
105.
Padavala Ajay Babu Suma Sree Puppala Satyavarapu Lakshmi Aswini Metta Ramya Vani Chinta Narasimha Kumar Tallapragada Prasanna 《Bioinformation》2008,3(3):142-143
Marine compound database consists of marine natural products and chemical entities, collected from various literature sources,
which are known to possess bioactivity against human diseases. The database is constructed using html code. The 12 categories
of 182 compounds are provided with the source, compound name, 2-dimensional structure, bioactivity and clinical trial
information. The database is freely available online and can be accessed at
http://www.progenebio.in/mcdb/index.htm 相似文献
106.
Sarkar P Sarkar S Ramesh V Kim H Barnes S Kulkarni A Hall JC Wilson BL Thomas RL Pellis NR Ramesh GT 《Neurochemical research》2008,33(11):2335-2341
Exposure to altered microgravity during space travel induces changes in the brain and these are reflected in many of the physical
behavior seen in the astronauts. The vulnerability of the brain to microgravity stress has been reviewed and reported. Identifying
microgravity-induced changes in the brain proteome may aid in understanding the impact of the microgravity environment on
brain function. In our previous study we have reported changes in specific proteins under simulated microgravity in the hippocampus
using proteomics approach. In the present study the profiling of the hypothalamus region in the brain was studied as a step
towards exploring the effect of microgravity in this region of the brain. Hypothalamus is the critical region in the brain
that strictly controls the pituitary gland that in turn is responsible for the secretion of important hormones. Here we report
a 2-dimensional gel electrophoretic analysis of the mouse hypothalamus in response to simulated microgravity. Lowered glutathione
and differences in abundance expression of seven proteins were detected in the hypothalamus of mice exposed to microgravity.
These changes included decreased superoxide dismutase-2 (SOD-2) and increased malate dehydrogenase and peroxiredoxin-6, reflecting
reduction of the antioxidant system in the hypothalamus. Taken together the results reported here indicate that oxidative
imbalance occurred in the hypothalamus in response to simulated microgravity. 相似文献
107.
Oxidant-mediated apoptosis in proximal tubular epithelial cells following ATP depletion and recovery 总被引:2,自引:0,他引:2
Maenpaa CJ Shames BD Van Why SK Johnson CP Nilakantan V 《Free radical biology & medicine》2008,44(4):518-526
Oxidant-mediated apoptosis has been implicated in renal injury due to ischemia reperfusion (IR); however, the apoptotic signaling pathways following IR have been incompletely defined. The purpose of this study was to examine the role of oxidants on cell death in a model of in vitro simulated IR injury in renal proximal tubular epithelial cells by analyzing the effects of a cell-permeable superoxide dismutase mimetic, manganese (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride (MnTmPyP). Renal proximal tubular epithelial cells were ATP depleted for 2, 4, or 6 h, followed by 2 h of recovery. We found that MnTmPyP was effective in attenuating cytotoxicity (P<0.001) and decreasing steady-state oxidant levels (P<0.001) and apoptotic cell death (P<0.001) following ATP depletion-recovery. MnTmPyP treatment prevented the early cytosolic release of cytochrome c and increased Bcl-2 protein levels following short durations of ATP depletion-recovery. After longer periods of ATP depletion-recovery, we observed a significant increase in TNF-alpha protein levels (P<0.001) and caspase-8 activation (P<0.001), both of which were decreased (P<0.001) by treatment with MnTmPyP. Our results suggest that oxidant mediated apoptosis via the mitochondrial pathway during the early phase of ATP depletion and by activation of the receptor-mediated apoptotic pathway following longer durations of injury. 相似文献
108.
Sharma P Kumar J Garg G Kumar A Patowary A Karthikeyan G Ramakrishnan L Brahmachari V Sengupta S 《DNA and cell biology》2008,27(7):357-365
Epigenetic modifications, especially alteration in DNA methylation, are increasingly being recognized as a key factor in the pathogenesis of complex disorders, including atherosclerosis. However, there are limited data on the epigenetic changes in the coronary artery disease (CAD) patients. In the present study we evaluated the methylation status of genomic DNA from peripheral lymphocytes in a cohort of 287 individuals: 137 angiographically confirmed CAD patients and 150 controls. The differential susceptibility of genomic DNA to methylation-sensitive restriction enzymes was utilized to assess the methylation status of the genome. We observed that the genomic DNA methylation in CAD patients is significantly higher than in controls (p < 0.05). Since elevated homocysteine levels are known to be an independent risk factor for CAD and a key modulator of macromolecular methylation, we investigated the probable correlation between plasma homocysteine levels and global DNA methylation. We observed a significant positive correlation of global DNA methylation with plasma homocysteine levels in CAD patients (p = 0.001). Further, within a higher range of serum homocysteine levels (>/=12-50 muM), global DNA methylation was significantly higher in CAD patients than in controls. The alteration in genomic DNA methylation associated with cardiovascular disease per se appears to be further accentuated by higher homocysteine levels. 相似文献
109.
Neeraj Kumar Saini Monika Sharma Amita Chandolia Rashmi Pasricha Vani Brahmachari Mridula Bose 《BMC microbiology》2008,8(1):200
Background
The mce4 operon is one of the four homologues of mammalian cell entry (mce) operons of Mycobacterium tuberculosis. The mce4A (Rv3499c) gene within this operon is homologous to mce1A (Rv0169), that has a role in host cell invasion by M. tuberculosis. Our earlier reports show that mce4 operon is expressed during the stationary phase of growth of the bacillus in culture and during the course of infection in mammalian hosts. M. tuberculosis carrying mutation in mce4 operon shows growth defect and reduced survival in infected mice. However, the intracellular localization of Mce4A protein and its direct role in cell entry or survival of the bacillus has not been demonstrated so far. 相似文献110.
Maciel C de Oliveira Junior VX Fázio MA Nacif-Pimenta R Miranda A Pimenta PF Capurro ML 《PloS one》2008,3(9):e3296
Plasmodium species are the causative agents of malaria, the most devastating insect-borne parasite of human populations. Finding and developing new drugs for malaria treatment and prevention is the goal of much research. Angiotensins I and II (ang I and ang II) and six synthetic related peptides designated Vaniceres 1-6 (VC1-VC6) were assayed in vivo and in vitro for their effects on the development of the avian parasite, Plasmodium gallinaceum. Ang II and VC5 injected into the thoraces of the insects reduced mean intensities of infection in the mosquito salivary glands by 88% and 76%, respectively. Although the mechanism(s) of action is not completely understood, we have demonstrated that these peptides disrupt selectively the P.gallinaceum cell membrane. Additionally, incubation in vitro of sporozoites with VC5 reduced the infectivity of the parasites to their vertebrate host. VC5 has no observable agonist effects on vertebrates, and this makes it a promising drug for malaria prevention and chemotherapy. 相似文献