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   470408篇
  免费   58207篇
  国内免费   31946篇
耳鼻咽喉   4550篇
儿科学   6678篇
妇产科学   7003篇
基础医学   47679篇
口腔科学   14132篇
临床医学   61853篇
内科学   59220篇
皮肤病学   4882篇
神经病学   23364篇
特种医学   18392篇
外国民族医学   266篇
外科学   54211篇
综合类   97151篇
现状与发展   195篇
一般理论   15篇
预防医学   36246篇
眼科学   13415篇
药学   46228篇
  1287篇
中国医学   23426篇
肿瘤学   40368篇
  2024年   2030篇
  2023年   14504篇
  2022年   26958篇
  2021年   29252篇
  2020年   29584篇
  2019年   17193篇
  2018年   16916篇
  2017年   14730篇
  2016年   17000篇
  2015年   16117篇
  2014年   39717篇
  2013年   34679篇
  2012年   48434篇
  2011年   48439篇
  2010年   35189篇
  2009年   28188篇
  2008年   20672篇
  2007年   26404篇
  2006年   20288篇
  2005年   14042篇
  2004年   12288篇
  2003年   10413篇
  2002年   8196篇
  2001年   7160篇
  2000年   5686篇
  1999年   3001篇
  1998年   2267篇
  1997年   1781篇
  1996年   1413篇
  1995年   1186篇
  1994年   867篇
  1993年   701篇
  1992年   698篇
  1991年   711篇
  1990年   644篇
  1989年   449篇
  1988年   532篇
  1987年   530篇
  1986年   473篇
  1985年   138篇
  1984年   260篇
  1983年   130篇
  1982年   183篇
  1981年   221篇
  1980年   122篇
  1979年   27篇
  1978年   51篇
  1977年   45篇
  1976年   42篇
  1975年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
IntroductionChronic treatment with phosphodiesterase type 5 inhibitors (PDE5) is effective in an animal model of diabetes‐induced erectile dysfunction (DMED). In addition, recent research indicates that glycemic control can restore DMED.AimsWe evaluated the effect of chronic administration of PDE5 combined with glycemic control on DMED.MethodsSprague‐Dawley rats (8 weeks old) were divided into five groups (n = 10 each): normal control (C), diabetes (DM), DM treated with insulin (DM‐I), DM treated with PDE5 (DM‐P), and DM treated with insulin and PDE5 (DM‐I + P). Rats in the diabetic groups received an injection of streptozotocin (45 mg/kg). After 10 weeks of induced diabetes, the DM‐I group was treated with a daily injection of neutral protamine Hagedorn, and the DM‐P group was treated with a daily dosage of 20 mg/kg PDE5 (DA‐8159) for 4 weeks. The DM‐I + P group was treated with both treatments simultaneously. After 14 weeks of induced diabetes, an evaluation of erectile function and histological and biochemical markers of corporal tissue was performed.Main Outcome MeasuresErectile function and histological and biochemical markers in corporal tissue.ResultsRats in the DM group showed markedly lower erectile parameters than those in the C group, whereas rats in the DM‐I and DM‐P groups showed intermediate erectile function between the DM and C groups. Rats in the DM‐I + P group showed restored erectile function, comparable with group C. A comparison of apoptotic index, expression of the endothelial marker, and phosphorylation of endothelial nitric oxide synthase and Akt displayed a similar pattern with the results from cavernosometry (DM < DM‐I = DM‐P < DM‐I + P = C, P < 0.05). The distribution of phosphorylated myosin phosphatase target subunit 1 was in the reverse order.ConclusionsChronic administration of PDE5 or glycemic control with insulin resulted in restoration of overt DMED. The combination of both treatments was superior to monotherapy with insulin or PDE5. Choi WS, Kwon OS, Cho SY, Paick J‐S, and Kim SW. Effect of chronic administration of PDE5 combined with glycemic control on erectile function in streptozotocin‐induced diabetic rats. J Sex Med 2015;12:600–610.  相似文献   
13.
  目的   分析血清异常凝血酶原(protein induced by vitamin K absence or antagonist-Ⅱ,PIVKA-Ⅱ)对原发性肝癌诊断的临床价值及意义。   方法   选取昆明医科大学附属曲靖医院诊治的150例患者,分为慢性乙型肝炎组50例,慢性丙型肝炎组50例,原发性肝癌组50例,同期选取50例健康体检者作为正常对照组。分别采用日本LUMIPULSE G1200全自动免疫分析仪检测血清PIVKA-Ⅱ浓度,德国罗氏Cobas e601全自动电化学发光免疫分析仪检测血清甲胎蛋白(alpha fetoprotein,AFP)浓度。   结果   原发性肝癌组血清PIVKA-Ⅱ和AFP浓度均明显高于慢性肝病组和正常对照组(P < 0.05)。PIVKA-Ⅱ诊断原发性肝癌的敏感性为94.0%,特异性为95.3%;AFP诊断原发性肝癌的敏感性为76.0%,特异性为90.0%。受试者工作特征曲线(ROC)分析结果显示,PIVKA-Ⅱ和AFP诊断原发性肝癌的曲线下面积分别为0.963和0.848。   结论   血清PIVKA-Ⅱ诊断原发性肝癌的临床价值优于AFP,值得临床研究推广。   相似文献   
14.
IntroductionDespite the high prevalence of hypoactive sexual desire disorder (HSDD), especially among women, this sexual disorder remains poorly understood. Among the multiple factors possibly involved in HSDD, particularities in the cognitive evaluations of social stimuli need to be better characterized. Especially, beauty and attractiveness judgments, two dimensions of interpersonal perception that are related but differ on their underlying motivational aspects, may vary according to the level of sexual desire.AimThe main goal of this study was to investigate whether women with and without HSDD differ in their evaluations of beauty and attractiveness of men's faces and voices.MethodsYoung women from the general population (controls, n = 16) and with HSDD (patients, n = 16) took part in the study. They were presented with a series of neutral/nonerotic voices and faces of young men from the GEneva Faces And Voices database.Main Outcome MeasuresRatings of beauty (i.e., assessments of aesthetic pleasure) and of attractiveness (i.e., assessments of the personal propensity to feel attracted to someone) and the frequency to which the participants pressed a key to see or listen to each stimulus again were the main outcome measures.ResultsRatings of attractiveness were lower than ratings of beauty in both groups of women. The dissociation between beauty and attractiveness was larger in women with HSDD than in control participants. Patients gave lower attractiveness ratings than the controls and replayed the stimuli significantly less often.ConclusionThese results suggest that women with HSDD are characterized by specific alterations of the motivational component of men's perception, very early in the process of interpersonal relationships. Our findings have significant implications, both in better understanding the specific cognitive processes underlying hypoactive sexual desire and more largely the evaluative processes involved in human mate choice. Ferdenzi C, Delplanque S, Vorontsova-Wenger O, Pool E, Bianchi-Demicheli F, and Sander D. Perception of men's beauty and attractiveness by women with low sexual desire. J Sex Med 2015;12:946–955.  相似文献   
15.
1. To investigate Genkwa Flos hepatotoxicity, a cell metabolomics strategy combined with serum pharmacology was performed on human HL-7702 liver cells in this study.

2. Firstly, cell viability and biochemical indicators were determined and the cell morphology was observed to confirm the cell injury and develop a cell hepatotoxicity model. Then, with the help of cell metabolomics based on UPLC-MS, the Genkwa Flos group samples were completely separated from the blank group samples in the score plots and seven upregulated as well as two down-regulated putative biomarkers in the loading plot were identified and confirmed. Besides, two signal molecules and four enzymes involved in biosynthesis pathway of lysophosphatidylcholine and the sphingosine kinase/sphingosine-1-phosphate pathway were determined to investigate the relationship between Genkwa Flos hepatotoxicity and these two classic pathways. Finally, the metabolic pathways related to specific biomarkers and two classic metabolic pathways were analyzed to explain the possible mechanism of Genkwa Flos hepatotoxicity.

3. Based on the results, lipid peroxidation and oxidative stress, phospholipase A2/lysophosphatidylcholine pathway, the disturbance of sphingosine-1-phosphate metabolic profile centered on sphingosine kinase/sphingosine-1-phosphate pathway and fatty acid metabolism might be critical participators in the progression of liver injury induced by Genkwa Flos.  相似文献   

16.
Humans and mammals have sex-specific differences in cardiac electrophysiology, linked to the action of sex hormones in the cardiac muscle. These hormones can upregulate or downregulate the expression of ionic channels modulating the cardiac cycle through genomic and non-genomic interactions. Systematic search in PubMed, Medline and EMBASE including keywords pertaining to testosterone and QT interval. Included experimental studies and observation studies and case reports presenting the results of testosterone administration, excess or deficiency in humans and animals. Testosterone has been shown to shorten the action potential duration, by enhancing the expression of K+ channels and downregulating ICaL increasing the repolarization reserve of the cardiac muscle. This effect has been observed in both genders and animals. Testosterone deficient states can promote arrhythmogenesis. The evidence in this paper may be used to guide clinical considerations, such as increased clinical surveillance of patients in testosterone deficient states using ECG.  相似文献   
17.
18.
《Vaccine》2019,37(31):4382-4391
Cancer-associated fibroblasts (CAFs), major components of the tumor microenvironment (TME), promote tumor growth and metastasis and inhibit the anti-tumor immune response. We previously constructed a DNA vaccine expressing human FAPα, which is highly expressed by CAFs, to target these cells in the TME, and observed limited anti-tumor effects in the 4T1 breast cancer model. When the treatment time was delayed until tumor nodes formed, the anti-tumor effect of the vaccine completely disappeared. In this study, to improve the safety and efficacy, we constructed a new FAPα-targeted vaccine containing only the extracellular domain of human FAPα with a tissue plasminogen activator signal sequence for enhanced antigen secretion and immunogenicity. The number of CAFs was more effectively reduced by CD8+ T cells induced by the new vaccine. This resulted in decreases in CCL2 and CXCL12 expression, leading to a significant decrease in the ratio of myeloid-derived suppressor cells in the TME. Moreover, when mice were treated after the establishment of tumors, the vaccine could still delay tumor growth. To facilitate the future application of the vaccine in clinical trials, we further optimized the gene codons and reduced the homology between the vaccine and the original sequence, which may be convenient for evaluating the vaccine distribution in the human body. These results indicated that the new FAPα-targeted vaccine expressing an optimized secreted human FAPα induced enhanced anti-tumor activity by reducing the number of FAPα+ CAFs and enhancing the recruitment of effector T cells in the 4T1 tumor model mice.  相似文献   
19.
目的:比较双眼外直肌后徙术与常规疗法治疗斜视的临床疗效。方法:选取2016年6月-2017年6月笔者医院收治的128例斜视患者,按治疗方式不同分成对照组和研究组,每组各64例。其中对照组患者行常规单眼外直肌后徙联合内直肌缩短术(R&R),研究组患者行双眼外直肌后徙术(BLR-rec)。术后对患者随访1年,观察术后眼位正位率、欠矫率、过矫率,视觉功能恢复情况以及并发症发生率。结果:研究组患者正位率为89.06%高于对照组的68.75%,差异有统计学意义(P<0.05)。术前,对照组和研究组患者视近度、视远度和平均斜视度比较,两组患者融合功能和立体视功能占比比较,差异均无统计学意义(P>0.05)。术后,两组患者的斜视度较治疗前均出现了明显下降(P<0.05),且研究组治疗后斜视度下降幅度明显大于对照组(P<0.05);两组患者视觉功能恢复率均明显增加(P<0.05),且研究组恢复率明显大于对照组(P<0.05)。研究组并发症发生率明显低于对照组(P<0.05)。结论:双眼外直肌后徙术较单眼外直肌后徙联合内直肌缩短术有更好地临床效果,且安全性更高,值得临床推广。  相似文献   
20.
雄激素不敏感综合征(androgen insensitivity syndrome,AIS)又称为睾丸女性化综合征(testicular feminization syndrome,TFS),是一种X连锁遗传病,是男性假两性畸形中较常见的类型,可分为完全型AIS和不完全型AIS,其原因主要是雄激素受体(androgen receptor,AR)基因的突变导致其对雄激素产生抵抗和不应答。本文回顾南京医科大学附属妇产医院2例CAIS患者的临床资料及诊疗过程,以期能进一步提高对该病的认知及诊治水平。  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