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91.
Bioactive thin film of acidic fibroblast growth factor fabricated by layer-by-layer assembly 总被引:5,自引:0,他引:5
A new class of bioactive thin films using growth factors as building blocks has been fabricated via layer-by-layer assembly (LBL) technique. Acid fibroblast growth factor (aFGF) in the presence of heparin was used as negatively charged polyelectrolytes, while poly(ethyleneimine) (PEI) was chosen as a positively charged counterpart. The self-deposition process and surface morphology of the resultant multilayers were monitored and detected by UV-vis absorbance spectra, advanced contact angle measurements, and scanning force microscopy (SFM) observations. Cell culture was performed to assess the efficiency of the growth factors. The fibroblasts proliferated faster on the surface assembled with five bilayers of (aFGF/heparin)/PEI with apparent higher cytoviability than on those surfaces modified by one bilayer of (aFGF/heparin)/PEI, five bilayers of aFGF/PEI, or five bilayers of heparin/PEI, and tissue culture polystyrene. Enhanced secretion of collagen type I and interleukin 6 (IL-6) by the fibroblasts seeded on the five bilayers of (aFGF/heparin)/PEI was also verified by immunohistochemical examination. The bioactivity of the (aFGF/heparin)/PEI multilayers could be largely preserved when stored at -20 degrees C. 相似文献
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94.
Zhang LX Tong XJ Sun XH Tong L Gao J Jia H Li ZH 《Cellular and molecular neurobiology》2008,28(4):501-509
Objectives To observe the effect of ultrashortwave (USW) therapy on nerve regeneration after acellular nerve allografts(ANA) repairing
the sciatic nerve gap of rats and discuss its acting mechanisms. Methods Sixteen Wistar rats weighing 180–220 g were randomly divided into four groups with four rats in each group: normal control
group; acellular group (ANA, treated by hypotonic-chemical detergent, was applied for bridging a 10 mm-long sciatic nerve
defect); USW group (After 24 h of ANA repairing the sciatic nerve gap, low dose USW was administrated for 7 min, once a day,
20 times a course of treatment, three courses of treatment in all); and autografts group. 12 weeks after operation, a series
of examinations was performed, including electrophysiological methods, the restoring rate of tibialis anterior muscle wet
weight, histopathological observation (myelinated nerve number, myelin sheath thickness, and axon diameter), vascular endothelial
growth factor (VEGF) mRNA expression of spinal cord, and muscle at injury site, and analyzed statistically. Results Compared to acellular nerve allografts alone, USW therapy can increase nerve conductive velocity, the restoring rate of tibialis
anterior muscle wet weight, myelinated nerve number, axon diameter, VEGF mRNA expression of spinal cord, and muscle at injury
site, the difference is significant. There were no differences between USW group and autografts group except myelin sheath
thickness. Conclusions USW therapy can promote nerve axon regeneration and Schwann cells proliferation after ANA repairing the sciatic nerve gap
of rats, the upregulation of VEGF mRNA expression of spinal cord and muscle may play an important role. 相似文献
95.
Yujing Zhang Pascal Benz Daniel Stehle Shang Yang Hendrikje Kurz Susanne Feil Georg Nagel Robert Feil Shiqiang Gao Markus Bender 《Open biology》2022,12(8)
Cyclic guanosine monophosphate (cGMP) signalling plays a fundamental role in many cell types, including platelets. cGMP has been implicated in platelet formation, but mechanistic detail about its spatio-temporal regulation in megakaryocytes (MKs) is lacking. Optogenetics is a technique which allows spatio-temporal manipulation of molecular events in living cells or organisms. We took advantage of this method and expressed a photo-activated guanylyl cyclase, Blastocladiella emersonii Cyclase opsin (BeCyclop), after viral-mediated gene transfer in bone marrow (BM)-derived MKs to precisely light-modulate cGMP levels. BeCyclop-MKs showed a significantly increased cGMP concentration after illumination, which was strongly dependent on phosphodiesterase (PDE) 5 activity. This finding was corroborated by real-time imaging of cGMP signals which revealed that pharmacological PDE5 inhibition also potentiated nitric oxide-triggered cGMP generation in BM MKs. In summary, we established for the first-time optogenetics in primary MKs and show that PDE5 is the predominant PDE regulating cGMP levels in MKs. These findings also demonstrate that optogenetics allows for the precise manipulation of MK biology. 相似文献
96.
目的通过研究辛伐他汀对动脉粥样硬化大鼠血管壁中细胞凋亡相关基因Fas及FasL蛋白表达产物的影响,探讨其在预防动脉粥样硬化发生中的可能机制。方法复制动脉粥样硬化大鼠模型,以辛伐他汀干预,取胸主动脉,观察其斑块变化,采用免疫组化Elivision法测定动脉粥样硬化血管壁中Fas、FasL蛋白表达。结果Fas蛋白表达在实验组明显高于对照组及干预组(P<0.01,P<0.05),实验组FasL蛋白表达也明显高于对照组及干预组(P<0.05)。结论Fas及FasL基因通过促进细胞凋亡作用而诱发动脉粥样硬化过程,辛伐他汀可通过调节细胞凋亡过程发挥抗动脉粥样硬化作用。 相似文献
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98.
The Rhesus (Rh) blood group system is the most important blood group system in hemolytic disease of the fetus and newborn (HDFN). In clinical transfusions, the D antigen in the Rh blood group system comes third, behind antigens A and B which from ABO blood group system. Over the past decade, molecular technologies have been used to investigate the RHD allele in different ethnic groups. This review first introduces the basic structure of RhD protein and coding genes, then focuses on D-negative, weak D, partial D, DEL, RhDnull variants reported in the Chinese population. To date, more than 460 RHD variants have been reported around the world, but less than 70 RHD variants have been reported in the Chinese population. Further research is needed to identify more RHD polymorphism and establish criteria for blood detection and transfusion guidelines for RHD variants. Only in this way can we better guarantee the safety of blood transfusion and prevent the occurrence of HDFN. With the accumulation of research and clinical data, we should be clearer which RHD variants are to be regarded as RhD negative and which need to be regarded as RhD positive. 相似文献
99.
Glycolipid transfer protein (GLTP) accelerates glycosphingolipid (GSL) intermembrane transfer via a unique lipid transfer/binding fold (GLTP-fold) that defines the GLTP superfamily and is the prototype for GLTP-like domains in larger proteins, i.e. phosphoinositol 4-phosphate adaptor protein-2 (FAPP2). Although GLTP-folds are known to play roles in the nonvesicular intracellular trafficking of glycolipids, their ability to alter cell phenotype remains unexplored. In the present study, overexpression of human glycolipid transfer protein (GLTP) was found to dramatically alter cell phenotype, with cells becoming round between 24 and 48 h after transfection. By 48 h post transfection, ~70% conversion to the markedly round shape was evident in HeLa and HEK-293 cells, but not in A549 cells. In contrast, overexpression of W96A-GLTP, a liganding-site point mutant with abrogated ability to transfer glycolipid, did not alter cell shape. The round adherent cells exhibited diminished motility in wound healing assays and an inability to endocytose cholera toxin but remained viable and showed little increase in apoptosis as assessed by poly(ADP-ribose) polymerase cleavage. A round cell phenotype also was induced by overexpression of FAPP2, which binds/transfers glycolipid via its C-terminal GLTP-like fold, but not by a plant GLTP ortholog (ACD11), which is incapable of glycolipid binding/transfer. Screening for human protein partners of GLTP by yeast two hybrid screening and by immuno-pulldown analyses revealed regulation of the GLTP-induced cell rounding response by interaction with δ-catenin. Remarkably, while δ-catenin overexpression alone induced dendritic outgrowths, coexpression of GLTP along with δ-catenin accelerated transition to the rounded phenotype. The findings represent the first known phenotypic changes triggered by GLTP overexpression and regulated by direct interaction with a p120-catenin protein family member. 相似文献
100.
干旱对小麦幼苗诱导蛋白表达与某些生理特性的初步探讨 总被引:5,自引:0,他引:5
试验以-1.2MPaPEG6000处理动小麦种子(TriticumaestlivumL.).SDS-PAGE图谱分析表明,水分胁迫诱导幼芽及整株均产生48.4kD、41.5kD二个蛋白质亚基。在幼根中未出现以上二个蛋白亚基。胁迫48h后,根干重/芽干重比呈上升趋势,幼芽细胞膜楔对透性增大和相对含水量降幅度均大于幼根。 相似文献