首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   477篇
  免费   16篇
各国政治   17篇
工人农民   4篇
世界政治   12篇
外交国际关系   65篇
法律   248篇
中国共产党   5篇
中国政治   11篇
政治理论   90篇
综合类   41篇
  2024年   1篇
  2023年   3篇
  2022年   10篇
  2021年   12篇
  2020年   27篇
  2019年   34篇
  2018年   29篇
  2017年   6篇
  2016年   8篇
  2015年   12篇
  2014年   15篇
  2013年   26篇
  2012年   21篇
  2011年   29篇
  2010年   20篇
  2009年   27篇
  2008年   54篇
  2007年   73篇
  2006年   26篇
  2005年   12篇
  2004年   5篇
  2003年   5篇
  2002年   1篇
  2001年   13篇
  2000年   4篇
  1999年   4篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1984年   1篇
  1981年   3篇
  1978年   2篇
排序方式: 共有493条查询结果,搜索用时 296 毫秒
61.
62.
63.
The EU and the United States have implemented data breach notification rules that cover the health sectors. Nevertheless, data breach incidents involving medical data continue to rise, especially in the US and the UK. The HITECH Act, Pub. L. 111-5 Title XIII is the first federal health breach notification law in the US to be characterized by less government intrusions, while the revised EU Privacy Directive, 2009/136/EC calls for tougher privacy protection for data held by electronic communication providers. While the EU law sets a global de facto standard, the law remains toothless without strong enforcement mechanisms.  相似文献   
64.
Abstract: The quality and efficiency of a standard organic DNA isolation method and a silica‐based method using the QIAGEN Blood Maxi Kit were compared to obtain human DNA and short tandem repeats (STRs) profiles from 39 exhumed bone samples for paternity testing. DNA samples were quantified by real‐time PCR, and STR profiles were obtained using the AmpFlSTR® Identifiler® PCR amplification kit. Overall, the silica‐based method recovered less DNA ranging from 0 to 147.7 ng/g (average 7.57 ng/g, median = 1.3 ng/g) than did the organic method ranging from 0 to 605 ng/g (average 44.27 ng/g, median = 5.8 ng/g). Complete profiles (16/16 loci tested) were obtained from 37/39 samples (95%) using the organic method and from 9/39 samples (23%) with the silica‐based method. Compared with a standard organic DNA isolation method, our results indicate that the published silica‐based method does not improve neither the quality nor the quantity of DNA for STR profiling.  相似文献   
65.
Few cases of natural sudden death presenting as an undiagnosed lymphoma have been reported in the literature, especially in adolescents. Herein we provide a report of sudden death caused by undiagnosed classic Hodgkin lymphoma (cHL). We describe an 18-year-old female who collapsed after several weeks of weight loss, decreased appetite, and dyspnea. At autopsy, a bulky mass arising in the mediastinum and neck compressed the esophagus and trachea, surrounded the great vessels, obliterated the pericardial sac, and infiltrated the myocardium. The lungs were collapsed and large pleural effusions were present. The tumor burden, which weighed at least 2710 g in aggregate, was entirely above the diaphragm. Microscopic examination of the masses showed features typical for nodular sclerosis cHL including large bands of sclerosis, numerous Hodgkin/Reed-Sternberg (HRS) cells, and an eosinophil-rich mixed inflammatory cell infiltrate. Immunohistochemical stains showed the HRS cells to be uniformly positive for CD30 and CD15 and negative for CD3, CD20, CD45, and PAX5. This case exemplifies a rare sudden natural death due to previously undiagnosed cHL in a young patient.  相似文献   
66.
Understanding what stimulates agribusiness firms to lobby the government and what makes the government responsive to lobbying are the two issues that have been discussed extensively in the debates concerning determinants of biotechnology policy. This paper examines the factors influencing agribusiness firms' lobbying and government response using econometric modeling on a new data set of 160 leading agribusiness firms in the food, feed, chemical, and seed industries in China. The results show that approximately 10% of agribusiness firms lobbied the government about biotechnology policy and regulations and over half of those that lobbied received a verbal or written acknowledgment from government agencies. Seed and feed companies are more likely to engage in lobbying than chemical companies. Owning GM patents not only has a positive impact on firms' lobbying activities, but firms with these patents are more likely to receive a government response to their lobbying efforts. The experience of selling GM products does not significantly influence lobbying activities or response from the government.  相似文献   
67.
68.
Members of parliament are key actors for the implementation of energy transitions, such as phasing out nuclear power. Before legislators can cast their maybe decisive vote in parliament, they need to run for office and actively strive for election. This paper assesses what political candidates oppose renewable energy transitions and questions whether the energy issue matters in national elections, and thus has consequences for the implementation of new sustainable energy sources. We analyze these questions by first describing the specific characteristics of political candidates. The paper then evaluates the relevance of the energy issue for electoral success in three national elections in Switzerland (2007, 2012, and 2015). Based on candidate data from the voting advice application smartvote.ch, we find that female candidates support ETs more than men do; that especially the French‐speaking part of the country is more in favor of a nuclear phase‐out, and that younger candidates are also more open toward restructuring the energy system than older candidates are. Our models further show that the energy issue does not matter in elections, independently from its salience in the respective election campaigns. Candidates are thus relatively free to choose their position on the issue and do not have to fear consequences at the ballot. However, candidates of center parties, in contrast to the pole parties, are sensitive to the energy issue and reflect public mood in their positions.  相似文献   
69.
目的 观察血管软化丸对miR-17-5p及其下游前蛋白转化酶枯草溶菌素(proprotein convertase subtillisin/kexin type 9,PCSK9)/极低密度脂蛋白受体(very low density lipoprotein receptor,VLDLR)信号通路的调控作用,揭示血管软化丸抗动脉粥样硬化(atherosclerosis,AS)的作用机制。方法 细胞实验:通过加入氧化型低密度脂蛋白构建血管平滑肌细胞损伤模型。根据不同干预方法将细胞分为4组:模型组、miR-17-5p抑制剂组、血管软化丸高剂量含药血清组和低剂量含药血清组;干预后检测各组细胞活性以及细胞miR-17-5p、VLDLR和PCSK9 mRNA和蛋白表达水平。动物实验:根据不同干预方法将小鼠分为模型组、miR-17-5p抑制剂组、血管软化丸高剂量组和低剂量组;干预8周后检测小鼠外周血清中白细胞介素-6 (interleukin-6,IL-6)、白细胞介素-10(interleukin-10,IL-10)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)水平和小鼠主动脉miR-17-5p、VLDLR和PCSK9表达水平,并观察各组小鼠病理学改变情况。结果 细胞实验:与模型组比较,miR-17-5p抑制剂组,血管软化丸高、低剂量含药血清组血管平滑肌细胞活性均明显升高(P<0.05),血管平滑肌细胞的miR-17-5p和VLDLR mRNA和蛋白表达水平均明显升高(P<0.05),血管平滑肌细胞的PCSK9 mRNA和蛋白表达水平均明显降低(P<0.05)。动物实验:与模型组比较,miR-17-5p抑制剂组和血管软化丸高、低剂量组外周血清中IL-6、TNF-α水平均明显降低(P<0.05),血清中IL-10水平均明显升高(P<0.05),主动脉miR-17-5p和VLDLR mRNA水平均明显降低(P<0.05),PCSK9 mRNA表达水平均明显升高(P<0.05);病理学观察发现模型组小鼠主动脉管径厚薄不均匀,内膜不光滑,管腔内可见明显AS斑块形成,斑块内可见浅染无定形物和钙化颗粒物,部分AS斑块截面积大于主动脉截面积。miR-17-5p抑制剂组和血管软化丸高、低剂量组AS病变程度明显较模型组减轻。  相似文献   
70.
目的 以自发性高血压大鼠(spontaneous hypertensive rat,SHR)为观察对象,探究针刺降压的钟基因调控作用。方法 将24只SHR随机分为针刺组和模型组,12只Wistar-Kyoto(WKY)大鼠作为正常组。针刺组选择辰时针刺SHR双侧曲池、足三里穴,模型组和正常组仅接受与针刺组同等强度的捆绑操作。4周后,各组分别在辰、酉时随机抽取6只大鼠,测量鼠尾收缩压(systolic blood pressure, SBP)和舒张压(diastolic blood pressure, DBP),然后检测血清5-羟色胺(5-hydroxytryptamine,5-HT)、褪黑素(melatonin, MT)的含量以及心脏生物钟基因Clock和Bmal1的表达水平。结果 分组因素对SBP、DBP、血清MT含量、Clock表达结果的RQ值、Bmal1表达结果的RQ值的主效应均有统计学意义(P<0.05),时辰因素对各指标的主效应和两者的交互作用均无统计学意义(P>0.05)。模型组辰、酉两个时辰的SBP和DBP均高于正常组(P<0.05),针刺组辰时的SBP和DBP及酉时的SBP均低于模型组(P<0.05)。模型组辰时MT含量较正常组降低,5-HT含量较正常组升高(P<0.05),针刺组辰时MT含量较模型组升高,5-HT含量较模型组降低(P<0.05);针刺组酉时的MT含量较模型组升高(P<0.05)。针刺组辰时心脏Clock基因表达水平和酉时心脏Bmal1基因表达水平较模型组升高(P<0.05)。结论 辰时针刺可以降低SHR的“双峰”血压,其作用机制可能与提高血清MT含量,减少5-HT含量以及提高心脏Clock和Bmal1基因的表达水平有关。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号