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171.
We recently isolated a polypeptide from the earthworm Lumbricus terrestris that is structurally similar to defensin, a well-known antibacterial peptide. An 11-mer antibacterial peptide (NH2-RNRRWCIDQQA), designated Lumbricusin, was synthesized based on the amino acid sequence of the isolated polypeptide. Since we previously reported that CopA3, a dung beetle peptide, enhanced neuronal cell proliferation, we here examined whether Lumbricusin exerted neurotropic and/or neuroprotective effects. Lumbricusin treatment induced a time-dependent increase (∼51%) in the proliferation of human neuroblastoma SH-SY5Y cells. Lumbricusin also significantly inhibited the apoptosis and decreased viability induced by treatment with 6-hydroxy dopamine, a Parkinson’s disease-mimicking agent. Immunoblot analyses revealed that Lumbricusin treatment increased ubiquitination of p27Kip1 protein, a negative regulator of cell-cycle progression, in SH-SY5Y cells, and markedly promoted its degradation. Notably, adenoviral-mediated over-expression of p27Kip1 significantly blocked the antiapoptotic effect of Lumbricusin in 6-hydroxy dopamine-treated SH-SY5Y cells. These results suggest that promotion of p27Kip1 degradation may be the main mechanism underlying the neuroprotective and neurotropic effects of Lumbricusin.  相似文献   
172.
To characterize the luminescence properties of nanoKAZ, a 16 amino acid substituted mutant of the catalytic 19 kDa protein (KAZ) of Oplophorus luciferase, the effects of each mutated amino acid were investigated by site-specific mutagenesis. All 16 single substituted KAZ mutants were expressed in Escherichia coli cells and their secretory expressions in CHO-K1 cells were also examined using the signal peptide sequence of Gaussia luciferase. Luminescence activity of KAZ was significantly enhanced by single amino acid substitutions at V44I, A54I, or Y138I. Further, the triple mutant KAZ-V44I/A54I/Y138I, named eKAZ, was prepared and these substitutions synergistically enhanced luminescence activity, showing 66-fold higher activity than wild-KAZ and also 7-fold higher activity than nanoKAZ using coelenterazine as a substrate. Substrate specificity of eKAZ for C2- and/or C6-modified coelenterazine analogues was different from that of nanoKAZ, indicating that three amino acid substitutions may be responsible for the substrate recognition of coelenterazine to increase luminescence activity. In contrast, these substitutions did not stimulate protein secretion from CHO-K1 cells, suggesting that the folded-protein structure of KAZ might be different from that of nanoKAZ.  相似文献   
173.
TcrX/Y is one of the twelve two component system (TCS) present in Mycobacterium tuberculosis. We have investigated the TcrX/Y interaction by in silico studies, pull down assay, radioactive phosphotransfer, surface plasmon resonance as well as crosstalk analysis of TcrY with TcrA – a non-cognate response regulator. Sequence alignment of TcrY with other histidine kinases revealed His256 as the residue responsible for autophosphorylation. The modeled structure of TcrX/Y was docked with each other by GRAMM-X revealing the interaction of TcrY/His256 with TcrX/Asp54. TcrY dimerization via the formation of four helix bundle was also observed by protein–protein docking. Autophosphorylation of TcrY has been observed followed by the phosphate transfer from TcrY to TcrX. The phosphorylation process required divalent metal ions like Mg2+ or Ca2+ ions as evident from the radioactive phosphorylation studies. Interaction was not observed between TcrY and TcrA suggesting the signal transduction process is specific in TcrX/Y system. TcrY hydrolyzes ATP and the Km value has been found to be 10 mM which is comparable to that of Hsp104. TcrX/Y interaction has been determined by surface plasmon resonance and dissociation constant (KD) was evaluated to be 3.6 μM. We conclude from our results that TcrX and TcrY are part of the same signal transduction pathway without their involvement in crosstalk with non-cognate counterpart.  相似文献   
174.
175.
Since their domestication in the Neolithic, cattle have belonged to our cultural heritage. The reconstruction of their history is an active field of research 1 that contributes to our understanding of human history. Archeological data are now supplemented by analyses of modern and ancient samples of cattle with DNA markers of maternal, paternal, or autosomal inheritance. The most recent genetic data suggest that maternal lineages of taurine cattle originated in the Fertile Crescent with a possible contribution of South‐European wild cattle populations, while zebu cattle originate from the Indus Valley. Subsequently, cattle accompanied human migrations, which led to the dispersal of domestic cattle of taurine, indicine, or mixed origin over Asia, Africa, Europe, and the New World. This has resulted in their adaptation to different environments and considerable variation in appearance and performance. More recently, rational management of breeding led to international movements of sires, which again changed the global patterns of genetic diversity.  相似文献   
176.
In this study, we examined the response of glioma C6 cells to 2′,3′-O-(4-benzoylbenzoyl)-ATP (BzATP) and showed that the BzATP-induced calcium signaling does not involve the P2X7 receptor activity. We show here that in the absence of extracellular Ca2+, BzATP-generated increase in [Ca2+]i via Ca2+ release from intracellular stores. In the presence of calcium ions, BzATP established a biphasic Ca2+ response, in a manner typical for P2Y receptors. Brilliant Blue G, a selective antagonist of the rat P2X7 receptor, did not reduce any of the two components of the Ca2+ response elicited by BzATP. Periodate-oxidized ATP blocked not only BzATP- but also UTP-induced Ca2+ elevation. Moreover, BzATP did not open large transmembrane pores. What is more, a cross-desensitization between UTP and BzATP occurred, which clearly shows that in glioma C6 cells BzATP activates most likely the P2Y2 but not the P2X7 receptors.  相似文献   
177.
描述了苦苣苔科(Gesneriaceae)石蝴蝶属(Petrocosmea Oliv.)一新种——黄斑石蝴蝶(P.xanthomaculata G.Q.Gou et X.Y.Wang)。新种与贵州石蝴蝶(P.cavaleriei Lévl.)相近,但叶多数,20~40枚,叶基心形,花冠白色,在裂片之间具明显黄色斑纹,苞片小,长约1 mm,花柱除上部外密被开展的白色长柔毛而不同。  相似文献   
178.
The interaction of the antitumoural metallocene dihalides, titanocene dichloride (Cp2TiCl2) and Titanocene Y (bis-[(p-methoxybenzyl)cyclopentadienyl]titanium(IV) chloride), with bis(4-nitrophenyl) phosphate (BNPP), which is a widely used model for the phosphate diester linkages in DNA, has been studied. Cp2TiCl2 has been shown to promote the cleavage of the phosphate diester in weakly acidic solution. At pH 4, 37 °C, a 106-fold rate acceleration over the uncatalysed reaction was observed under pseudo-first-order conditions, when freshly prepared solutions of Cp2TiCl2 were applied. The activity of aged solutions dropped significantly due to the formation of insoluble precipitates of hydrolysed Ti species. The precipitates isolated from aged solutions were shown to act as moderately active, heterogeneous catalysts for BNPP cleavage. By contrast, no hydrolysis of the phosphate diester could be observed in the presence of Titanocene Y. Implications for the mode of action of the apoptosis-inducing metallocene dihalides are discussed.  相似文献   
179.
【目的】建立单纯疱疹病毒Ⅱ型(HSV-2)潜伏感染人神经母细胞瘤细胞株SH-SY5Y及激活的细胞模型。【方法】分别加入20,40,60,80,100,120,140μmol/L的阿昔洛韦(ACV),观察对SH-SY5Y细胞生物性状的影响;在ACV存在的情况下,分别将含有0.1、1、10、100MOI的病毒液接种SH-SY5Y细胞,运用相差显微镜观察病毒对细胞的影响,确定潜伏的建立;分别用41℃、42℃、43℃、44℃、45℃加热0.5h、1.0h、1.5h、2.0h、2.5h,观察加热时间及温度诱导HSV-2在SH-SY5Y细胞中激发的最适条件;加入25、50、75、100、125μmol/L福斯高林(Forskolin)诱导病毒在细胞中激活,探讨诱导的最佳浓度;对HSV-2在SH-SY5Y细胞中的潜伏及激发进行验证并测序;运用相差显微镜观察病毒激活后细胞形态的变化。【结果】60μmol/LACV的存在最适合HSV-2在SH-SY5Y细胞中建立潜伏状态;1-10MOI的感染量均能取得较好的病毒潜伏及激发效果;通过观察,病毒在SH-SY5Y细胞中最长可潜伏14d;43℃,1.5h及75μmol/LForskolin均为诱导病毒潜伏激发的最佳条件;相差显微镜观察病毒激发后细胞病变,从24h到72h,细胞变性、坏死的程度、数量随感染时间延长而增加;HSV-2LAT、gG基因PCR扩增及电泳结果,证实病毒在细胞中的潜伏及激活。【结论】初步在人神经母细胞瘤细胞株SH-SY5Y上建立了HSV-2潜伏感染及激活的细胞模型,为下一步研究HSV-2的潜伏与激发机理,了解HSV-2的致病机制打下基础。  相似文献   
180.
The name “Wampanoag” means “Eastern People” or “People of the First Light” in the local dialect of the Algonquian language. Once extensively populating the coastal lands and neighboring islands of the eastern United States, the Wampanoag people now consist of two federally recognized tribes, the Aquinnah and Mashpee, the state‐recognized Seaconke Wampanoag tribe, and a number of bands and clans in present‐day southern Massachusetts. Because of repeated epidemics and conflicts with English colonists, including King Philip's War of 1675–76, and subsequent colonial laws forbidding tribal identification, the Wampanoag population was largely decimated, decreasing in size from as many as 12,000 individuals in the 16th century to less than 400, as recorded in 1677. To investigate the influence of the historical past on its biological ancestry and native cultural identity, we analyzed genetic variation in the Seaconke Wampanoag tribe. Our results indicate that the majority of their mtDNA haplotypes belongs to West Eurasian and African lineages, thus reflecting the extent of their contacts and interactions with people of European and African descent. On the paternal side, Y‐chromosome analysis identified a range of Native American, West Eurasian, and African haplogroups in the population, and also surprisingly revealed the presence of a paternal lineage that appears at its highest frequencies in New Guinea and Melanesia. Comparison of the genetic data with genealogical and historical information allows us to reconstruct the tribal history of the Seaconke Wampanoag back to at least the early 18th century. Am J Phys Anthropol 142:579–589, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
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