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   10313篇
  免费   1157篇
  国内免费   264篇
耳鼻咽喉   28篇
儿科学   280篇
妇产科学   323篇
基础医学   1320篇
口腔科学   97篇
临床医学   840篇
内科学   1538篇
皮肤病学   262篇
神经病学   1007篇
特种医学   132篇
外国民族医学   2篇
外科学   661篇
综合类   1190篇
预防医学   2170篇
眼科学   63篇
药学   749篇
  11篇
中国医学   824篇
肿瘤学   237篇
  2024年   14篇
  2023年   221篇
  2022年   214篇
  2021年   428篇
  2020年   532篇
  2019年   487篇
  2018年   444篇
  2017年   484篇
  2016年   475篇
  2015年   358篇
  2014年   600篇
  2013年   1014篇
  2012年   544篇
  2011年   585篇
  2010年   488篇
  2009年   386篇
  2008年   418篇
  2007年   443篇
  2006年   412篇
  2005年   312篇
  2004年   309篇
  2003年   264篇
  2002年   218篇
  2001年   204篇
  2000年   163篇
  1999年   125篇
  1998年   95篇
  1997年   108篇
  1996年   94篇
  1995年   103篇
  1994年   95篇
  1993年   98篇
  1992年   73篇
  1991年   84篇
  1990年   65篇
  1989年   65篇
  1988年   57篇
  1987年   64篇
  1986年   63篇
  1985年   60篇
  1984年   70篇
  1983年   24篇
  1982年   50篇
  1981年   60篇
  1980年   61篇
  1979年   42篇
  1978年   39篇
  1977年   38篇
  1976年   34篇
  1975年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Acute coronary syndrome (ACS) remains one of the leading causes of death in the United States. With its heightened prevalence, considerable variabilities in the disease process exist across ethnicities, sex, and age. This creates substantial disparities in the recognition and management of ACS, which consequently contributes to poor outcomes. It is of utmost importance that nurse practitioners remain vigilant, cognizant, and maintain a high index of suspicion to accurately identify ACS presentations and thus efficaciously intervene to successfully manage the disease process.  相似文献   
2.
《Vaccine》2022,40(33):4889-4896
BackgroundDuring the COVID-19 pandemic, the number of hepatitis B virus (HBV) vaccinations among men who have sex with men (MSM) has been considerably lower than before the pandemic. Moreover, less frequent HBV testing and a reduction in numbers of sex partners have been reported. We assessed the impact of these COVID-19-related changes on HBV transmission among MSM in the Netherlands.MethodsWe estimated the changes in sexual activity, HBV testing, and HBV vaccination among MSM during the pandemic from Dutch data. We used a deterministic compartmental model and investigated scenarios with small or large declines in sexual activity, testing, and vaccination for the current phase of the pandemic (without available data). We examined the increase in HBV vaccinations needed to prevent further increase in HBV incidence.ResultsWith a decrease in numbers of sex partners of 15–25% during the first lockdown and 5% during the second lockdown, we found a decline of 6.6% in HBV incidence in 2020, despite a >70% reduction in HBV testing and vaccination during the first lockdown. With numbers of sex partners rebounding close to pre-pandemic level in 2021, and a reduction of 15% in testing and 30% in vaccination in 2021, we found an increase of 1.4% in incidence in 2021 and 3.1% in 2026. With these changes, an increase of ≥60% in HBV vaccinations in 2022 would be needed to bring the HBV incidence in 2023 back to the level that it would have had if the COVID-19-related changes had not occurred.ConclusionsDespite reductions in sexual activity during the COVID-19 pandemic, the decrease in HBV vaccinations may result in a small increase in HBV incidence after 2021, which may persist for years. It is important to restore the vaccination level and limit further increase in HBV transmission among MSM.  相似文献   
3.
Child sex trafficking (CST) has become a global public health crisis and is a $150 billion criminal enterprise. Nurse practitioners are key in the recognition and prevention of CST in health care settings. Evidence demonstrates that up to 80% of CST victims have had a recent health care encounter. It is the role of the NP in practice to understand risk factors, screen for CST, and educate parents and caregivers on signs of victimization and prevention.  相似文献   
4.
5.
目的:探讨不同分期结直肠癌患者肿瘤组织内CD73表达分布情况及其与患者临床病理参数、预后之间的关系。方法:选取2012年1月至2013年6月于本院就诊并行手术治疗的结直肠癌患者共60例作为研究对象,于术中取其肿瘤组织和癌旁组织样本,使用免疫组化法检测收集的所有样本中CD73分布与表达情况,并分析CD73与结直肠癌患者临床病理参数及预后的关系。结果:TNM分期越高的结直肠癌患者病灶组织CD73阳性率越高(P<0.05),癌旁组织中CD73阳性率明显低于结直肠癌患者(P<0.05);CD73在结直肠癌中的阳性表达率与年龄、组织分化程度无相关(P>0.05);与浸润深度、淋巴结转移和临床分期有重要联系(P<0.05);CD73表达阳性组术后存活时间明显短于阴性组(P<0.05);疾病复发率明显高于阴性组(P<0.05);阳性组5年存活率也明显低于阴性组(P<0.05),提示CD73呈阳性高表达的结直肠癌患者预后往往较差。结论:CD73在结直肠癌患者肿瘤组织中的表达量明显升高,可作为评估患者预后的独立预测因子,临床医师可根据结直肠癌患者病理组织中CD73表达量对其预后进行判断和评估,具有推广价值。  相似文献   
6.
目的 运用代谢组学技术分析乙肝肝硬化患者肝肾阴虚及肝胆湿热两种典型证候(同病异证)的血清差异代谢产物及其代谢通路,探寻虚、实两种典型证候的内在物质基础,以期从代谢水平上为中医证候分类提供客观依据。方法 对符合纳入标准的111例不同证候的乙肝肝硬化患者(肝胆湿热证40例,肝肾阴虚证41例,隐证(无证可辨)者30例)中医症状及体征进行描述性分析,发现两种不同证型的临床信息分布规律及证候特征;采用气相色谱-飞行时间质谱联用(GC-TOF/MS)技术对乙肝肝硬化患者,以及与之相匹配的60例健康人的血清样本进行检测,经非监督的主成分分析(Principal Components Analysis,PCA)、有监督的偏最小二乘判别分析(Partial Least Square Discriminant Analysis,PLS-DA)及监督的正交偏最小二乘法(Orthogonal Partial Least SquareDiscriminant Analysis,OPLS-DA)分析,找出与乙肝肝硬化疾病本身及其两种典型证候相关的差异性物质;运用MetaboAnalyst 3.0数据库,寻找并解析肝胆湿热及肝肾阴虚虚实两种证候间差异性物质的相关代谢通路。结果 (1)肝胆湿热证中出现频率较高(50%以上)的症状为小便色黄,口干,口苦,口臭或有异味等。肝肾阴虚证中出现频率较高的症状为口干、腰酸、乏力、腿软等。两证共见症/征为口干、尿黄、易怒、舌红。(2)各组间丙氨酸氨基转移酶(Alanine Aminotransferase,ALT)数值无统计学差异(P > 0.05);与健康组比较,隐证组中白蛋白(Albumin,ALB),肝胆湿热证中总胆红素(Total Bilirubin,TBil)、直接胆红素(Direct Bilirubin,DBil)、谷草转氨酶(Aspartate Transaminase,AST)、碱性磷酸酶(Alkaline Phosphatase,ALP)、谷氨酰转肽酶(Gamma-Glutamyl Transpeptidase,GGT)、总胆汁酸(Total Biliary Acid,TBA)及ALB,肝肾阴虚证TBil、ALP、GGT、TBA、ALB值差异均有统计学意义(P < 0.05);与隐证比较,肝胆湿热证TBil、DBil、AST、ALP、TBA、ALB,肝肾阴虚证TBA、ALB差异有统计学意义(P < 0.05);肝胆湿热证与肝肾阴虚证相比,TBil、DBil差异有统计学意义(P < 0.05)。(3)代谢组学检测及代谢通路分析,发现各组之间代谢谱均有良好的区分,并获得各组间的差异性物质。发现肝胆湿热及肝肾阴虚两典型证的共同物质10个,去除疾病(隐证)的信息,则得到两证共同物质6个,涉及的代谢通路为甘氨酸、丝氨酸及苏氨酸代谢和苯丙氨酸代谢;同时,分别获得两证各自特异性的代谢物质各8个,分别涉及亚油酸代谢和甘氨酸、苏氨酸及丝氨酸代谢。结论 运用代谢组学技术,发现肝胆湿热及肝肾阴虚不同证之间既存在病的共同物质(同病),也存在证的差异物质(异证),从而在代谢层面上为中医证候分类的科学性提供科学依据。  相似文献   
7.
During prenatal and early postnatal periods of development, multiple environmental factors have profound and long‐lasting effects on the immune and reproductive functions. The aim of this study was to investigate the effects of maternal lipopolysaccharide (LPS) exposure (50 mg/kg, i.p.) at day 12 of pregnancy and estradiol antagonist treatment (fulvestrant, 1.5 mg/kg, s.c. in neck) at postnatal days 5–14 (PND5–14) with high estradiol levels on reproductive parameters in adult rat males. Serum steroid concentrations were measured in male offspring at PND80 by ELISA. Body, testis weights and ano‐genital distance (AGD) were recorded at different stages of postnatal development. Testis was also processed to cytohistological studies at PND80. Our results demonstrate that body weight was decreased from PND14 to 30 after prenatal LPS treatment and was increased after fulvestrant treatment. AGD was decreased after prenatal LPS treatment and was increased after fulvestrant injections. Testis weight, testosterone level, seminiferous tubule diameter, and number of Sertoli and spermatid cells were also decreased in rats exposed prenatally to LPS and were restored to the normal control level after fulvestrant treatment. According to results, we can conclude that the development of sexual disorders in males after prenatal immune stress is potentiated by estradiol during the pre‐pubertal period.  相似文献   
8.
9.
10.
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