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991.
Young Sik Cho Seung Yeon Park Hee Suk Shin Francis Ka-Ming Chan 《Molecules and cells》2010,29(4):327-332
Cell death occurs spontaneously or in response to external stimuli, and can be largely subdivided into apoptosis and necrosis
by the distinct morphological and biochemical features. Unlike apoptosis, necrosis was recognized as the passive and unwanted
cell demise committed in a non-regulated and disorganized manner. However, under specific conditions such as caspase intervention,
necrosis has been proposed to be regulated in a well-orchestrated way as a backup mechanism of apoptosis. The term programmed
necrosis has been coined to describe such an alternative cell death. Recently, at least some regulators governing programmed
necrosis have been identified and demonstrated to be interconnected via a wide network of signal pathways by further extensive
studies. There is growing evidence that programmed necrosis is not only associated with pathophysiological diseases, but also
provides innate immune response to viral infection. Here, we will introduce recent updates on the molecular mechanism and
physiological significance of programmed necrosis. 相似文献
992.
Ri-Zhong Zeng Han Geun Kim Na Ra Kim Hae Young Lee Bong Jun Jung Mi Yeon Ko Seung Yeon Lee Dae Kyun Chung 《Molecules and cells》2010,29(6):585-594
Lipoteichoic acid (LTA) from Staphylococcus aureus (aLTA) and from Lactobacillus plantarum LTA (pLTA) are both recognized by Toll-like receptor 2 (TLR2), but cause different stimulatory effects on the innate immune
and inflammatory responses, and their underlying cellular mechanisms are unknown. In this study, comparative proteome analysis
was performed using two-dimensional gel electrophoresis and mass spectrometry on protein extracts from human monocyte THP-1
cells stimulated with either aLTA or pLTA. Differentially expressed proteins might be involved in innate immunity and inflammation.
Cells treated with aLTA and with pLTA showed different protein expression profiles. Of 60 identified proteins, 10 were present
only in treated cells (8 in aLTA-treated only, and 2 in pLTA-treated only), 1 protein (IMPDH2) was suppressed by pLTA, and
49 were up- or down-regulated more than three-fold by aLTA- or pLTA- stimulation. Several proteins involved in immunity or
inflammation, antioxidation, or RNA processing were significantly changed in expression by aLTA- or pLTA-stimulation, including
cyclophilin A, HLA-B27, D-dopachrome tautomerase, Mn- SOD, hnRNP-C, PSF and KSRP. These data demonstrated that aLTA and pLTA
had different effects on the protein profile of THP-1 cells. Comparison of the proteome alterations will provide candidate
biomarkers for further investigation of the immunomodulatory effects of aLTA and pLTA, and the involvement of aLTA in the
pathogenesis of Staphylococcus aureus sepsis. 相似文献
993.
Gracilaria vermiculophylla (Ohmi) Papenf., an agar‐producing red alga introduced from northeast Asia to Europe and North America, is often highly abundant in invaded areas. To assay its genetic diversity and identify the putative source of invasive populations, we analyzed the mitochondrial cytochrome c oxidase subunit I (cox1) gene from 312 individuals of G. vermiculophylla collected in 37 native and 32 introduced locations. A total of 19 haplotypes were detected: 17 in northeast Asia and three in Europe and eastern and western North America, with only one shared among all regions. The shared haplotype was present in all introduced populations and in ~99% of individuals in the introduced areas. This haplotype was also found at three native locations in east Korea, west Japan, and eastern Russia. Both haplotype and nucleotide diversities were extremely low in Europe and North America compared to northeast Asia. Our study indicates that the East Sea/Sea of Japan is a likely donor region of the invasive populations of G. vermiculophylla in the east and west Atlantic and the east Pacific. 相似文献
994.
995.
Wentao Gao Jeong Han Kang Yong Liao Wen-Xing Ding Andrea A. Gambotto Simon C. Watkins Yong-Jian Liu Donna B. Stolz Xiao-Ming Yin 《The Journal of biological chemistry》2010,285(2):1371-1383
Autophagosomes and their precursors are best defined by electron microscopy but may also be traced in living cells based on the distribution of specific autophagy molecules. LC3, the most commonly examined autophagy marker in mammalian cells, labels structures that are frequently manifested as dots or rings using light microscopy; however, the nature of these structures is not entirely clear. We reported here a novel approach to examine the LC3-positive compartment in cell-free lysates, which revealed that they were actually tubulovesicular structures with considerable heterogeneity. Using affinity purification, we isolated these membranes for electron microscopy, which indicated that they possessed ultrastructural features consistent with autophagosomal membranes at various maturation stages. Further biochemical and proteomics analyses demonstrated the presence of multiple autophagy-related and other functional molecules. The different distribution patterns of Atg5, Atg16, Atg9, and p62/SQSTM1 on the LC3-positive compartment provided new clues on how these molecules might be involved in the dynamics of the autophagosomal membranes. Finally, several morphologically unique groups of LC3-positive membranes were categorized. Their topological configurations suggested that double-membrane vesicles could be derived from single membrane compartments via different means, including tubule-to-vesicle conversion, whose presence was supported by live cell imaging. These findings thus provide new information on the dynamics of the autophagosomal compartment. 相似文献
996.
997.
998.
Chong Han Kim Yong Pyo Shin Mi Young Noh Yong Hun Jo Yeon Soo Han Yeon Sun Seong In Hee Lee 《The Journal of biological chemistry》2010,285(33):25243-25250
We characterize a novel pathogen recognition protein obtained from the lepidopteran Galleria mellonella. This protein recognizes Escherichia coli, Micrococcus luteus, and Candida albicans via specific binding to lipopolysaccharides, lipoteichoic acid, and β-1,3-glucan, respectively. As a multiligand receptor capable of coping with a broad variety of invading pathogens, it is constitutively produced in the fat body, midgut, and integument but not in the hemocytes and is secreted into the hemolymph. The protein was confirmed to be relevant to cellular immune response and to further function as an opsonin that promotes the uptake of invading microorganisms into hemocytes. Our data reveal that the mechanism by which a multiligand receptor recognizes microorganisms contributes substantially to their phagocytosis by hemocytes. A better understanding of an opsonin with the required repertoire for detecting diverse invaders might provide us with critical insights into the mechanisms underlying insect phagocytosis. 相似文献
999.
Fumihiro Kawai David I. Roper Kwang Yeon Hwang Eiji Obayashi Jeremy R.H. Tame 《Journal of molecular biology》2010,396(3):634-645
We have determined high-resolution apo crystal structures of two low molecular weight penicillin-binding proteins (PBPs), PBP4 and PBP5, from Haemophilus influenzae, one of the most frequently found pathogens in the upper respiratory tract of children. Novel β-lactams with notable antimicrobial activity have been designed, and crystal structures of PBP4 complexed with ampicillin and two of the novel molecules have also been determined. Comparing the apo form with those of the complexes, we find that the drugs disturb the PBP4 structure and weaken X-ray diffraction, to very different extents. PBP4 has recently been shown to act as a sensor of the presence of penicillins in Pseudomonas aeruginosa, and our models offer a clue to the structural basis for this effect. Covalently attached penicillins press against a phenylalanine residue near the active site and disturb the deacylation step. The ready inhibition of PBP4 by β-lactams compared to PBP5 also appears to be related to the weaker interactions holding key residues in a catalytically competent position. 相似文献
1000.