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991.
Xu S  Xue C  Li J  Bi Y  Cao Y 《Journal of virology》2011,85(1):276-285
Viruses cause about 15% of the cancers that are still the leading causes of human mortality. The discovery of viral oncogenes has enhanced our understanding of viral oncogenesis. However, the underlying molecular mechanisms of virus-induced cancers are complex and require further investigation. The present study has attempted to investigate the effects of the microRNAs (miRNAs) encoded by Marek's disease virus 1 (MDV1), a chicken herpesvirus causing acute T-cell lymphomas and solid visceral tumors in chickens, on anti-cancer drug-induced apoptosis and identify the targets of the miRNAs. The results showed that of the total 14 miRNAs encoded by MDV1, MDV1-miR-M3 significantly promoted cell survival under treatment with cisplatin, a widely used chemotherapy drug. MDV1-miR-M3 suppressed cisplatin-induced apoptosis by directly downregulating expression at the protein but not the mRNA level of Smad2, a critical component in the transforming growth factor β signal pathway. Our data suggest that latent/oncogenic viruses may encode miRNAs to directly target cellular factors involved in antiviral processes including apoptosis, thus proactively creating a cellular environment beneficial to viral latency and oncogenesis. Furthermore, the knowledge of the apoptosis resistance conferred by viral miRNAs has great practical implications for improving the efficacy of chemotherapies for treating cancers, especially those induced by oncogenic viruses.  相似文献   
992.
目的:探讨小鼠间充质干细胞(MSCs)定向诱导分化成脂肪细胞微小RNA(miRNA)表达的变化,为进一步研究miRNA调控MSCs向脂肪细胞分化的分子机制奠定基础。方法:采用全骨髓体外分离结合差速贴壁法纯化扩增C57BL/6小鼠MSCs,形态学观察细胞生长情况,并用免疫组化方法鉴定细胞表面抗原CD29、CIM4和CD34的表达。脂肪细胞分化诱导剂诱导MSCs分化为脂肪细胞,利用油红O染色,判断MSCs成脂分化情况。运用rrfiRNA芯片技术检测MSC8和脂肪细胞中差异表达的miRNA。结果:①倒置显微镜下观察,传5代后可获得均一性较高的MSCs;免疫组化显示90%以上的骨髓间质干细胞CD29、CD44阳性,CD34阴性。MSCs经脂肪诱导剂诱导后,胞内大量脂滴形成,油红O染色阳性;②基因微阵列分析表明,小鼠MSCs分化成脂肪细胞差异表达的miRNA共75个,其中20个表达上调、55个表达下调。结论:MSCs分化成脂肪细胞存在miRNA表达的变化,某些miRNA很可能具有重要的调控MSCs成脂分化的作用。  相似文献   
993.
BackgroundHepatitis B vaccine that contains an aluminum hydroxide adjuvant induces apoptotic death of Hepa 1–6 cells. Difficult-to-degrade chemical additives in vaccines effectively enhance vaccine immunogenicity, but also affect the host tissue. Identification of bio-molecules that are readily degraded and compatible in vivo as an adjuvant is important for vaccine research. The hapten–carrier effect suggests that stimulation of helper T (Th) cells by carrier adjuvants is feasible. Protein D (PD) of non-typeable Haemophilus influenzae covalently conjugated to some polysaccharide vaccines has been confirmed to convert T-cell independent (TI) antigens into T-cell dependent (TD) antigens, and elicit strong T-cell responses ultimately. Herein, we would substitube PD for aluminum hydroxide adjuvant in Hepatitis B vaccine.ConclusionsRecombinant truncated PD covalently conjugated to HBsAg antigen enhanced the immunogenicity of the antigen in mice simultaneously by humoral and cellular immune response, which would facilitate therapeutic hepatitis B vaccines.  相似文献   
994.
Abiotic stress is one of the most important factors reducing soybean yield. It is essential to identify regulatory factors contributing to stress responses.A previous study found that the tandem CCCH zincfinger protein Gm ZF351 is an oil level regulator. In this study, we discovered that the Gm ZF351 gene is induced by stress and that the overexpression of Gm ZF351 confers stress tolerance to transgenic soybean. Gm ZF351 directly regulates the expression of Gm CIPK9 and Gm SnRK, leading to stoma...  相似文献   
995.
We studied effects of L-theanine, a unique amino acid in tea, on carbon tetrachloride (CCl(4))-induced liver injury in mice. The mice were pre-treated orally with L-theanine (50, 100 or 200 mg/kg) once daily for seven days before CCl(4) (10 ml/kg of 0.2% CCl(4) solution in olive oil) injection. L-theanine dose-dependently suppressed the increase of serum activity of ALT and AST and bilirubin level as well as liver histopathological changes induced by CCl(4) in mice. L-theanine significantly prevented CCl(4)-induced production of lipid peroxidation and decrease of hepatic GSH content and antioxidant enzymes activities. Our further studies demonstrated that L-theanine inhibited metabolic activation of CCl(4) through down-regulating cytochrome P450 2E1 (CYP2E1). As a consequence, L-theanine inhibited oxidative stress-mediated inflammatory response which included the increase of TNF-α and IL-1β in sera, and expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in livers. CCl(4)-induced activation of apoptotic related proteins including caspase-3 and PARP in mouse livers was also prevented by L-theanine treatment. In summary, L-theanine protects mice against CCl(4)-induced acute liver injury through inhibiting metabolic activation of CCl(4) and preventing CCl(4)-induced reduction of anti-oxidant capacity in mouse livers to relieve inflammatory response and hepatocyte apoptosis.  相似文献   
996.
本实验收集22例9周至28周龄人胎儿,用免疫组织化学PAP法研究了下丘脑结节区神经核团内生长抑素神经元的个体发生。结果表明。生长抑素免疫反应阳性神经元最早见于16周人胚的弓状校及腹内侧核,以后随胎龄增长数目逐渐增加。在22周时,腹内侧核内生长抑素免疫反应阳性神经元的数目达到高峰,弓状核内的该神经元在24周达到高峰。24周后阳性神经元数目呈递减趋向,免疫反应逐渐减弱。背内侧核及结节核内未见生长抑素免疫反应阳性神经元。生长抑素免疫反应阳性神经元形态多样,体积较小,其突起数目在发育过程中有较大变化。  相似文献   
997.
有或没有基细胞是毛鞘藻属与枝鞘藻属的区别之一。这里叙述了Mrozinska在其专著中,将Oedocladium indicum Kamat附图(即模式图)上的一个基细胞错误地移置到Oe.prescottii Islam上去的情况。  相似文献   
998.
999.
A key barrier against developing preventive and therapeutic human immunodeficiency virus (HIV) vaccines is the inability of viral envelope glycoproteins to elicit broad and potent neutralizing antibodies. However, in the presence of fusion inhibitor enfuvirtide, we show that the nonneutralizing antibodies induced by the HIV type 1 (HIV-1) gp41 N-terminal heptad repeat (NHR) domain (N63) exhibit potent and broad neutralizing activity against laboratory-adapted HIV-1 strains, including the drug-resistant variants, and primary HIV-1 isolates with different subtypes, suggesting the potential of developing gp41-targeted HIV therapeutic vaccines.  相似文献   
1000.
王文丽  毕富春 《昆虫知识》1996,33(6):345-347
测定了T-751(O-甲基-O-苯基-S-正丙基硫代磷酸酯)对4种害虫的杀虫活性。结果表明,T-751对东方家蝇、豆蚜和二斑叶螨的LD50分别为0.42、70.5、4.20mg/L。T-751对东方家蝇的杀虫活性要比杀螟硫磷高11倍。在剂量分别为2.95,7.37mg/m2时,该药对东方家蝇和美洲大蠊的KT50分别为13.57和30.83分钟。  相似文献   
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