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71.
72.
为了探讨石菖蒲醇提物作为一种中药杀菌剂对病菌寄主植物本身防御酶体系的影响,该研究以番茄欧粉贝幼苗和川产道地中药石菖蒲为材料,采用冷浸法制备石菖蒲醇提物,经不同浓度石菖蒲醇提物对番茄幼苗进行处理,用比色法测定多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)和过氧化物酶(POD)的活性,并利用GC-MS联用技术,对石菖蒲醇提物的主要化学成分进行定性分析。结果表明:第1天,醇提物浓度在0.04~0.08 g·mL~(-1)时,PAL活性显著高于对照;随后PAL活性随浓度升高降低;当浓度在0.04~0.16 g·mL~(-1)时,POD活性与对照无显著差异;浓度为0.32 g·mL~(-1)时,POD活性显著高于对照;浓度为0.64 g·mL~(-1)时,POD活性显著低于对照;当浓度在0.04~0.32 g·mL~(-1)时,PPO活性显著高于对照;浓度为0.64 g·mL~(-1)时,PPO活性与对照无显著差异;随着时间的延长,三种酶各处理组之间的差异逐步减少。第4天时,各处理组之间PAI,的活性无显著差异;当浓度为0.04 g·mL~(-1)和0.64 g·mL~(-1)时,PPO活性与对照无显著差异,其余范围均显著高于对照;当浓度在0.08~0.32 g·mL~(-1)时,POD活性数值上均高于对照。以上表明在一定浓度范围内醇提物可以增强防御酶活性,未破坏植物的防御酶体系。因此,该醇提物作为一种新型的中药杀菌剂有巨大的开发和利用潜力。利用GC-MS联用技术,可从醇提物中鉴定出30种化学成分,这些物质中多为苯丙素类物质,如β-细辛醚、α-(细辛醚和顺式甲基异丁香油酚等,其中含量最高的物质为β-细辛醚(42.48%)。这提示在后续的研究中,可针对β-细辛醚等醇提物的主要化学成分进行。  相似文献   
73.
A novel Gram-positive, rod-shaped, motile, spore-forming, nitrogen-fixing bacterium, designated strain 112T, was isolated from cabbage rhizosphere in Beijing, China. The strain was found to grow at 10–40 °C and pH 4–11, with an optimum of 30 °C and pH 7.0, respectively. Phylogenetic analysis based on a fragment of the full-length 16S rRNA gene sequence revealed that strain 112T is a member of the genus Paenibacillus. High levels of 16S rRNA gene similarities were found between strain 112T, Paenibacillus sabinae DSM 17841T (97.82 %) and Paenibacillus forsythiae DSM 17842T (97.22 %). However, the DNA–DNA hybridization values between strain 112T and the type strains of these two species were 10.36 and 6.28 %, respectively. The predominant menaquinone was found to be menaquinone 7 (MK-7). The major fatty acids were determined to be anteiso-C15:0 and C16:0. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and unknown aminophospholipids. The cell wall peptidoglycan was found to contain meso-diaminopimelic acid. The DNA G+C content was determined to be 55.4 mol%. On the basis of its phenotypic characteristics, 16S rRNA gene sequence analysis and the value of DNA–DNA hybridization, strain 112T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus brassicae sp. nov. is proposed. The type strain is 112T (= ACCC 01125T = DSM 24983T).  相似文献   
74.
目的探讨EFS和DAP两种玻璃化冷冻方法对不同品系小鼠胚胎冷冻的效果。方法6个品系小鼠(KM、ICR、BALB/c、C57BL/6J、OB/OB、LAP/~TAOF59)的2-cell胚胎分别用EFS和DAP两种玻璃化冷冻方法进行冷冻和复苏,比较两种冷冻方法的胚胎复苏率和着床率。结果6个品系小鼠冷冻胚胎EFS方法的平均复苏率为69.97%(47.9%~83.6%),DAP方法的平均复苏率47.23%(26.3%-76.7%),EFS方法明显优于DAP方法。其中KM、ICR和BALB/c小鼠EFS方法的冷冻复苏率显著高于DAP方法(P〈0.01);冻融胚胎移植后EFS方法的平均着床率27.23%(1.75%一45.0%),DAP方法的平均着床率31.43%(7.0%一46.3%)。除KM、ICR小鼠外,其他4个品系小鼠的着床率DAP方法高于EFS方法。结论KM和ICR远交群小鼠胚胎适合用EFS方法冷冻保存;C57BL/6J、OB/OB、LAP/aTAOF59三个品系小鼠DAP方法优于EFS方法,但差异不大;BALB/c小鼠两种玻璃化冷冻方法的冻融胚胎着床率均较低,需进一步研究。  相似文献   
75.
三峡库区支流生境因子对库区蓄水的响应   总被引:2,自引:0,他引:2  
三峡水库的运行调度,使库区支流形成了截然不同的3种河段类型:完全受水库蓄水影响的145m回水段(完全河段),既受蓄水影响又受自然洪汛影响的145—175m回水段(双重河段)以及不受蓄水影响的大于175m的自然河流段(自然河段)。为明确库区蓄水对河流不同河段生境因子的影响程度及差异,对三峡库区36条重要支流的254个河段进行河流生境调查,进行不同河段下生境指标的因子分析,并进一步分析水文情势自然性与不同河段各生境因子的相关关系。结果表明,植被状况对3种不同河段来说均为重要生境因子,但受三峡水库蓄水影响,完全河段植被结构不完整;受库区蓄水影响,完全河段与双重河段及自然河段相比,流速流态状况、表层覆盖物状况、河岸带宽度、湿润率等生境因子有明显改变;水文情势自然性对不同河段生境因子的影响不同。  相似文献   
76.
77.
本文报道一例罕见复杂易位核型:46,XX,t(1;14;10).并结合以往资料,探讨和分析复杂易位和一般平衡易位对表型及生育的遗传效应.结果显示,一般易位导致智能低下和多发畸形的频率各为3.57%;复杂易位所致智能低下频率为21.73%,多发畸形的频率为17.39%.提示复杂易位所致智能低下和畸形频率明显高于一般易位。 Abstract:In this paper,we report a rare karyotype of complex translocation:46,XX,t(1;14;10).Based on sufficient published data,we discussed and analyzed the genetic effect of complex translocation and general balanced translocation on phenotype and fertilization.The results show that general balanced translocation caused 3.57% low intelligence and multi-deformation while complex translocation caused 21.73% low intelligence and 17.39% multi-deformation respectively.These results sugget that there is a higher incedence of low intelligence and multi-deformation caused by complex translocation than that caused by general balanced translocation.  相似文献   
78.

Background

Several epidemiological studies have been conducted to address the later effect of anesthesia on neurodevelopment in children. However, the results are still inconclusive.

Methods

We here conducted a systematic review and meta-analysis to summarize the currently available clinical and epidemiologic evidence on the association of anesthesia/surgery with neurodevelopmental outcomes in children by searching PubMed, EMBASE, and Web of Science database (from January-1 2000 to February-1, 2013). The evaluation of neurodevelopment includes language and learning disabilities, cognition, behavioral development, and academic performance. Both retrospective and prospective studies were included. Data were abstracted from seven eligible studies. We estimated the synthesized hazard ratios (HR) and 95% confidence interval (CI) according to inter-study heterogeneity.

Results

The pooled HR for the association of anesthesia/surgery with an adverse behavioral or developmental outcome was 1.25 (95% CI, 1.13–1.38, P<0.001; random-effects model) in children undergoing the first anesthesia before the age of 4-year. Then we analyzed the factors for this association using meta-regression method. It showed that it was the number of times of exposure (HR = 1.75, 95% CI 1.31–2.33; P<0.001) rather than the time at exposure before 4-year (HR = 1.08, 95% CI 0.87–1.34 for the effect of per 1-year early exposure; P = 0.47) is a risk factor for neurodevelopmental impairment.

Conclusion

The current clinical evidence suggests modestly elevated risk of adverse neurodevelopmental outcomes in children who were exposed to anesthesia/surgery during early childhood, especially for those with multiple times of exposure. Due to limitation of retrospective studies, prospective investigations are needed to determine whether anesthesia/surgery is causative.  相似文献   
79.
MTOR, a central regulator of autophagy, is involved in cancer and cardiovascular and neurological diseases. Modulating the MTOR signaling balance could be of great significance for numerous diseases. No chemical activators of MTOR have been found, and the urgent challenge is to find novel MTOR downstream components. In previous studies, we found a chemical small molecule, 3-benzyl-5-((2-nitrophenoxy) methyl)–dihydrofuran-2(3H)-one (3BDO), that inhibited autophagy in human umbilical vein endothelial cells (HUVECs) and neuronal cells. Here, we found that 3BDO activated MTOR by targeting FKBP1A (FK506-binding protein 1A, 12 kDa). We next used 3BDO to detect novel factors downstream of the MTOR signaling pathway. Activation of MTOR by 3BDO increased the phosphorylation of TIA1 (TIA1 cytotoxic granule-associated RNA binding protein/T-cell-restricted intracellular antigen-1). Finally, we used gene microarray, RNA interference, RNA-ChIP assay, bioinformatics, luciferase reporter assay, and other assays and found that 3BDO greatly decreased the level of a long noncoding RNA (lncRNA) derived from the 3′ untranslated region (3′UTR) of TGFB2, known as FLJ11812. TIA1 was responsible for processing FLJ11812. Further experiments results showed that FLJ11812 could bind with MIR4459 targeting ATG13 (autophagy-related 13), and ATG13 protein level was decreased along with 3BDO-decreased FLJ11812 level. Here, we provide a new activator of MTOR, and our findings highlight the role of the lncRNA in autophagy.  相似文献   
80.
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