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31.

This study was to evaluate the effect of Streptococcus salivarius K12 on tongue coating–associated halitosis. Twenty-eight subjects having tongue coating–associated halitosis were randomly divided into either a test or control group. For each of the 30 days, the test subjects sucked S. salivarius K12 tablet while the control subjects sucked placebo tablets. All the subjects did not take physical (tongue scraping) and chemical (antiseptic mouth-rinse) oral cavity pretreatment prior to use of the tablets. At baseline, and on the 1st, 7th, and 14th day after completing the course of tablets, the subjects were assessed for their organoleptic test (OLT) scores, volatile sulfur compound (VSC) levels, and tongue coating scores (TCS). During the course, all subjects kept their routine oral care habits without scraping their tongue coating. Plaque index, probing depth, and bleeding index were recorded at baseline and at the completion of the trial. On the 1st day following the end of tablet use, the OLT scores and VSC levels had significantly decreased in the test group when compared with the baseline values (P = 0.001 and P = 0.012). The TCS in the test group were also significantly decreased (P = 0.05). At days 7 and 14, the OLT scores in the test group were still significantly lower than the baseline levels (P = 0.006 and P = 0.039 respectively). However, there were no statistical differences with OLT, VSC, and TCS between the test group and the placebo group by analysis of multi-level regression model. The use of S. salivarius K12 did not have significant effect on halitosis with tongue coating cause when the tongue coating was not physically or chemically pre-treated, which implies removing tongue coating is required before Streptococcus salivarius K12 use.

  相似文献   
32.
Zhang  Heng-Sheng  Ouyang  Bo  Ji  Xiong-Ying  Liu  Mei-Fang 《Neurochemical research》2021,46(7):1747-1758

Cerebral ischaemia/reperfusion (I/R) injury-induced irreversible brain injury is a major cause of mortality and functional impairment in ageing people. Gastrodin (GAS), derived from the traditional Chinese herbal medicine Tianma, has been reported to inhibit the progression of stroke, but the mechanism whereby GAS modulates the progression of cerebral I/R remains unclear. The middle cerebral artery occlusion method was used as a model of I/R in vivo. Rats were pretreated with GAS by intraperitoneal injection 7 days before I/R surgery and were then treated with GAS for 7 days after I/R surgery. Additionally, an oxygen–glucose deprivation/reoxygenation model using neuronal cells was established in vitro to simulate I/R injury. 2,3,5-Triphenyltetrazolium chloride and Nissl staining were used to evaluate infarct size and neuronal damage, respectively. Lactate dehydrogenase release and cell counting kit-8 assays were used to assess neuronal cell viability. Enzyme-linked immunosorbent assay, qPCR, flow cytometry and western blotting were performed to analyse the expression levels of inflammatory factors (IL-1β, IL-18), lncRNA NEAT1, miR-22-3p, NLRP3 and cleaved caspase-1. Luciferase reporter experiments were performed to verify the association between lncRNA NEAT1 and miR-22-3p. The results indicated that GAS could significantly improve the neurological scores of rats and reduce the area of cerebral infarction. Meanwhile, GAS inhibited pyroptosis by downregulating NLRP3, inflammatory factors (IL-1β, IL-18) and cleaved caspase-1. In addition, GAS attenuated I/R-induced inflammation in neuronal cells through the modulation of the lncRNA NEAT1/miR-22-3p axis. GAS significantly attenuated cerebral I/R injury via modulation of the lncRNA NEAT1/miR-22-3p axis. Thus, GAS might serve as a new agent for the treatment of cerebral I/R injury.

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33.
甘肃矿产资源丰富,矿区酸性矿坑水(acid mine drainage,AMD)及周边土壤中嗜酸微生物种类丰富,具有相当大的研究价值.本研究通过Illumina高通量测序方法,对甘肃省4个矿区AMD及周边土壤中的细菌群落组成、相似性及功能组成进行分析.结果 表明,煤矿样品GNM细菌物种组成最为丰富,金矿样品LNJ1与紫金矿样品LNZJK细菌组成最相似,与属于铜矿的BYT物种较相近,与LNJ1同地区的LNJ2样品细菌组成相比较远.所有样品细菌主要分为放线菌门(Actinobacteria)、拟杆菌门(Bacteriodetes)、厚壁菌门(Firmicutes)和变形菌门(Proteobacteria)四大门,其中变形菌门(Proteobacteria)丰度最高.放线菌门(Actinobacteria)中不动杆菌属(Acinetobacter)、类诺卡氏属(Nocardioides)和芽球菌属(Blastococcus)表现出较高丰度;厚壁菌门(Firmicutes)中微小杆菌属(Exiguobacterium)和芽孢杆菌属(Bacillus)表现出较高丰度,且微小杆菌属(Exiguobacterium)丰度极高.通过功能预测发现,与煤矿样品GNM相比,LNJ1、LNJ2、BYT和LNZJK4个金属矿区样品中的微生物具有较强的氨基酸与碳源的转运与代谢、转录等功能以及较低的能量生产与转运、无机离子转运与代谢能力.通过探究AMD中的细菌多样性及其与重金属之间的相互关系,了解AMD采样区微生物群落结构,以期挖掘出更为丰富的具有重金属抗性的菌株资源,以应用于生物浸矿和环境修复等领域.  相似文献   
34.
探究植物功能性状的种内和种间变异不仅有助于揭示植物对环境的适应, 也能够反映植物的生态策略, 但不同菌根类型树木生长过程中根叶形态学功能性状的适应策略仍有待探究。本研究依托中国亚热带森林生物多样性与生态系统功能实验研究平台(BEF-China)选取7种丛枝菌根(AM)树木和7种外生菌根(EM)树木的纯林, 测定各个树种的比叶面积、叶干物质含量、比根长、根系直径、树高生长速率、地径生长速率及细根生物量等根叶形态学功能性状和生长指标, 探讨了两种菌根类型树种间的根叶形态学特征的差异。结果表明: 与AM树种相比, EM树种具有较小的比叶面积、吸收根平均直径和生长速率, 但具有更大的叶干物质含量; 两种菌根树种之间的比根长和细根生物量无显著差异。比叶面积、叶干物质含量、树高生长速率、地径生长速率和细根生物量等功能性状及生长指标在不同菌根类型、树种及二者的交互作用中均存在显著差异; 且树种、根功能型、菌根类型及三者之间的交互作用均对根功能性状有显著影响。EM树种地上指标的种内变异均大于种间变异, 而AM树种地上指标的种内和种间变异程度类似; 但两种菌根树种细根生物量的种间变异均大于种内变异。尽管两种菌根树种地上部分生长速率较快通常表现为较低的叶干物质含量, 但AM树种通常拥有较高的吸收根比根长, 而EM树种拥有较粗的运输根平均直径。吸收根比根长越低, 两类菌根树种的细根生物量就越多。由此可见, 根叶功能性状对植物地上部分的生长具有一定的协同效应, 其中运输根主要在EM树种地上生长过程中发挥重要作用, 吸收根主要与AM树种的地上部分生长有关; 但两类菌根树种的地下细根生物量均与吸收根有关。  相似文献   
35.
沿长江中下游(宜昌-铜陵段)13座城市共37个位点,分别于丰水期和枯水期对岸带的湿生植物进行调查,从物种和系统发育2个维度研究群落的构建机制,并结合环境和空间因子探讨其驱动因素。结果显示:(1)丰水期湿生植物群落的α多样性高于枯水期,且丰水期α多样性主要与水分条件呈正相关,而枯水期则主要与温度和土壤总氮含量有关。(2)丰水期的系统发育结构指数呈聚集趋势,暗示生境过滤起着主导作用,而枯水期的NRI(net relatedness index)和NTI(nearest taxon index)呈不同趋势,暗示存在近期的群落分化。(3)群落的α多样性在物种层面和系统发育层面存在显著关联性,其多样性水平可在一定程度上互为表征。(4)长江中下游沿岸湿生植物群落的构建机制在不同时期存在差异,丰水期的群落构建是环境筛选和扩散限制共同作用的结果,且以环境筛选作用占主导,而枯水期的群落构建仅在物种层面受一定程度环境筛选作用的影响。(5)大生境的温度变化、微生境的土壤水分和养分条件是影响长江中下游岸带湿生植物群落差异的主要驱动因素。该研究结果可为长江中下游岸带湿地生态系统的管理和保护提供科学支持。  相似文献   
36.
37.
With a pace of about twice the observed rate of global warming, the temperature on the Qinghai‐Tibetan Plateau (Earth's ‘third pole’) has increased by 0.2 °C per decade over the past 50 years, which results in significant permafrost thawing and glacier retreat. Our review suggested that warming enhanced net primary production and soil respiration, decreased methane (CH4) emissions from wetlands and increased CH4 consumption of meadows, but might increase CH4 emissions from lakes. Warming‐induced permafrost thawing and glaciers melting would also result in substantial emission of old carbon dioxide (CO2) and CH4. Nitrous oxide (N2O) emission was not stimulated by warming itself, but might be slightly enhanced by wetting. However, there are many uncertainties in such biogeochemical cycles under climate change. Human activities (e.g. grazing, land cover changes) further modified the biogeochemical cycles and amplified such uncertainties on the plateau. If the projected warming and wetting continues, the future biogeochemical cycles will be more complicated. So facing research in this field is an ongoing challenge of integrating field observations with process‐based ecosystem models to predict the impacts of future climate change and human activities at various temporal and spatial scales. To reduce the uncertainties and to improve the precision of the predictions of the impacts of climate change and human activities on biogeochemical cycles, efforts should focus on conducting more field observation studies, integrating data within improved models, and developing new knowledge about coupling among carbon, nitrogen, and phosphorus biogeochemical cycles as well as about the role of microbes in these cycles.  相似文献   
38.
Interleukin (IL)-15 is a ubiquitously expressed cytokine that in the basal state is mainly localized intracellularly, including the nucleus. Unexpectedly, tumor necrosis factor-α (TNF) time-dependently induced nuclear export of IL-15Rα and IL15. This process was inhibited by leptomycine B (LMB), a specific inhibitor of nuclear export receptor chromosomal region maintenance 1 (CRM1). In the presence of TNF, LMB co-treatment led to accumulation of both IL-15Rα and IL-15 in the nucleus of HeLa cells, suggesting that CRM1 facilitates nuclear export and that TNF enhances CRM1 activity. Once in the cytoplasm, IL-15 showed partial co-localization with late endosomes but very little with other organelles tested 4 h after TNF treatment. IL-15Rα showed co-localization with both early and late endosomes, and to a lesser extent with endoplasmic reticulum and Golgi. This indicates different kinetics and possibly different trafficking routes of IL-15 from its specific receptor. The TNF-induced secretion of IL-15 was attenuated by pretreatment of cells by brefeldin A that inhibits ER-to-Golgi transport, or by use of domain negative ADP-ribosylation factor 6 (ARF6) that interferes with exocytotic sorting. We conclude that TNF abolishes nuclear localization of IL-15 and IL-15Rα by acting on CRM1, and it facilitates exocytosis of IL-15 with the involvement of ARF6.  相似文献   
39.
Transient global ischemia (which closely resembles clinical situations such as cardiac arrest, near drowning or severe systemic hypotension during surgical procedures), often induces delayed neuronal death in the brain, especially in the hippocampal CA1 region. The mechanism of ischemia/reperfusion (I/R) injury is not fully understood. In this study, we have shown that the P2X7 receptor antagonist, BBG, reduced delayed neuronal death in the hippocampal CA1 region after I/R injury; P2X7 receptor expression levels increased before delayed neuronal death after I/R injury; inhibition of the P2X7 receptor reduced I/R-induced microglial microvesicle-like components, IL-1β expression, P38 phosphorylation, and glial activation in hippocampal CA1 region after I/R injury. These results indicate that antagonism of the P2X7 receptor and signaling pathways of microglial MV shedding, such as src-protein tyrosine kinase, P38 MAP kinase and A-SMase, might be a promising therapeutic strategy for clinical treatment of transient global cerebral I/R injury.  相似文献   
40.
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