首页 | 官方网站   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   85340篇
  免费   8247篇
  国内免费   6298篇
医药卫生   99885篇
  2024年   109篇
  2023年   1441篇
  2022年   2087篇
  2021年   4141篇
  2020年   3455篇
  2019年   3042篇
  2018年   3130篇
  2017年   2867篇
  2016年   2608篇
  2015年   4120篇
  2014年   4915篇
  2013年   4189篇
  2012年   6305篇
  2011年   7129篇
  2010年   4271篇
  2009年   3268篇
  2008年   4190篇
  2007年   4488篇
  2006年   4416篇
  2005年   4544篇
  2004年   2788篇
  2003年   2549篇
  2002年   2212篇
  2001年   1902篇
  2000年   2143篇
  1999年   2493篇
  1998年   1651篇
  1997年   1599篇
  1996年   1232篇
  1995年   1078篇
  1994年   908篇
  1993年   628篇
  1992年   718篇
  1991年   613篇
  1990年   556篇
  1989年   491篇
  1988年   410篇
  1987年   354篇
  1986年   266篇
  1985年   197篇
  1984年   97篇
  1983年   82篇
  1982年   52篇
  1981年   50篇
  1980年   37篇
  1979年   32篇
  1978年   8篇
  1977年   6篇
  1976年   11篇
  1975年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
We aim to assess the safety and efficacy of proxalutamide, a novel androgen receptor antagonist, for men with metastatic castration-resistant prostate cancer (mCRPC) in a multicenter, randomized, open-label, phase 2 trial. In our study, the enrolled mCRPC patients were randomized to 100, 200 and 300 mg dose groups at 1:1:1. The primary efficacy endpoint was prostate-specific antigen (PSA) response rate. The secondary endpoints included objective response rate (ORR), disease control rate (DCR) and time to PSA and radiographic progression. Safety and pharmacokinetics were also assessed. Finally, there were 108 patients from 17 centers being enrolled. By week 16, there were 13 (35.1%), 12 (36.4%) and 15 (42.9%) patients with confirmed 50% or greater PSA decline in 100 mg (n = 37), 200 mg (n = 33) and 300 mg (n = 35) groups, respectively. Among the 19 patients with target lesions at study entry, three (15.8%) had a partial response and 12 (63.2%) had stable disease. The ORRs of 20.0%, 22.2%, 0% and DCRs of 80.0%, 88.9%, 60.0% were, respectively, achieved in 100, 200 and 300 mg groups. By the maximum follow-up time of 24 weeks, there were 42.6% and 10.2% of cases experiencing PSA progression and radiographic progression, respectively. Overall, adverse events (AEs) were experienced by 94.4% of patients, most of which were mild or moderate. There were 28 patients experiencing ≥grade 3 AEs. The most common AEs were fatigue (17.6%), anemia (14.8%), elevated AST (14.8%) and ALT (13.0%), decreased appetite (13.0%). These findings preliminarily showed the promising antitumor activity of proxalutamide in patients with mCRPC with a manageable safety profile. The proxalutamide dose of 200 mg daily is recommended for future phase 3 trial (Clinical trial registration no. CTR20170177).  相似文献   
42.
随着压力性损伤的研究重心逐渐向细胞水平转移,发现力学因素下细胞结构和功能改变在压力性损伤发展过程中起重要作用。综述力学因素下压力性损伤发生机制、影响因素、评估以及预防管理。旨在提高护理人员对压力性损伤更为深入地认知,从而推动压力性损伤研究多元化发展。  相似文献   
43.
44.
45.

Aim

Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an immune inhibitory receptor which is expressed within most types of hematopoietic cells and negatively regulates immune responses. Recently, we found LAIR-1 expression to be present within tumors of nonhematopoietic lineages. However, the roles of LAIR-1 in hepatocellular carcinoma (HCC) have yet to be examined. The purpose of this study was to investigate the expression of LAIR-1 in HCC tissue and assess its clinical significance at this site.

Materials and methods

Expression levels of LAIR-1 within HCC samples collected from 90 patients and compared with that of slides of normal liver tissue collected from 9 non-HCC patients were measured by immunohistochemistry using tissue microarrays. A semiquantitative score was assigned, as was based on staining intensity and percent of positive cells and a Spearman Rank correlation test was used to assess any potential significant correlations between LAIR-1 expression and clinicopathological factors. Overall survival analysis was performed using the Kaplan-Meier and Log Rank statistical test.

Results

LAIR-1 expression was detected in cancer tissue and adjacent tumor tissue, but not in normal liver tissue. The percent of LAIR-1-positive expression in cancer tissue of HCC samples was 97.78% (88/90) while that in adjacent tumor tissue was 96.67% (87/90). Significantly greater expression levels of LAIR-1 were obtained from cancer tissue (Mean?±?SD?=?5.722?±?2.145) than that in adjacent tumor tissue (4.141?±?1.486). In addition, LAIR-1 expression was found to be significantly correlated with pathological grade of HCC, T stage, and age. Expression levels of LAIR-1 were related with worse overall survival rates of HCC patients, especially in HCC patients with hepatic cirrhosis.

Conclusion

Results of this study show that LAIR-1 is expressed in HCC tissues and that high levels of LAIR-1 expression are associated with the poor cancer differentiation. In addition, overexpression of LAIR-1 was significantly associated with worse overall survival in the patients with HCC. These data suggest that LAIR-1 may be an independent predictor for clinical outcomes in patients with HCC.  相似文献   
46.
目的探讨全腹腔镜胃癌根治术(TLG)、腹腔镜辅助胃癌根治术(LAG)与传统开腹术(TOS)对Ⅱ、Ⅲ期胃癌的近期及远期疗效。 方法回顾性分析2013年1月至2016年6月陕西中医药大学附属医院行胃癌根治术的患者共136例,根据患者手术方式的不同分为TLG组(45例),LAG组(40例),TOS组(51例)。观察和比较3组患者手术时间、出血量、淋巴结清扫数、术后排气时间、住院时间、术后并发症发生情况,采用Kaplan-Meier法对患者术后5年远期疗效进行生存分析。 结果TLG组患者出血量、排气时间及住院时间低于TOS组及LAG组,LAG组患者手术时间高于TLG组及TOS组,差异均有统计学意义(P<0.05);3组患者术后并发症发生率比较,差异无统计学意义。共129例获得随访,其中TLG组失访2例,LAG组2例,TOS组3例。TLG、LAG、TOS组平均无瘤生存时间为(53.4±2.1)个月(95%CI=50.45~58.22个月)、(54.3±2.0)个月(95%CI= 47.99~56.18个月)、(52.3±2.1)个月(95%CI=50.98~55.65个月),3组患者无瘤生存时间比较,差异无统计学意义(F=0.519,P=0.772)。 结论TLG术能够在保证患者术后疗效的同时,降低患者术中出血量、排气时间及术后住院时间,TLG术治疗Ⅱ、Ⅲ期胃癌安全可行,疗效显著,值得推广。  相似文献   
47.
正【内容简介】腹腔镜全腹膜外疝修补术(totally extraperitoneal, TEP)是目前较为理想的疝修补术,但面临腹膜前间隙结构解剖复杂、空间狭小、手术难度大、学习曲线长等问题。该手术视频案例直观细致地剖析了腹股沟区的膜结构与弓状线、腹壁下血管、Retzius和Bogros间隙关系等,旨在通过充分熟悉腹股沟区膜结构的解剖情况从而提高手术的安全性和有效性,减少手术并发症和复发率。  相似文献   
48.
目的探讨加速康复外科(ERAS)在肾移植术后静脉补液中的应用。 方法回顾性分析陆军军医大学第一附属医院124例肾移植受者临床资料。根据肾移植术后多尿期每24小时静脉补液量分为3组,A组每24小时静脉补液量2 500~<4 000 mL,术后6 h进食流质;B组每24小时补液量4 000~6 000 mL,肛门排气后进食;C组每24小时补液量>6 000 mL,肛门排气后进食。采用单因素方差分析比较3组受者术后1周中心静脉压(CVP)、心率、血压、尿量和血糖以及平均特护时间、平均住院日和术后1个月血清肌酐。采用χ2检验比较3组受者性别、供肾类型以及术后高血糖、伤口延迟愈合和移植肾功能延迟恢复(DGF)发生率。P<0.05为差异有统计学意义。 结果A、B和C组受者术后1个月血清肌酐分别为(110±23)、(114±22)和(118±22)μmol/L,差异无统计学意义(F=1.19,P>0.05)。A组受者术后1周CVP、收缩压、尿量和血糖均低于B、C组(P均<0.05),平均特护时间和平均住院日均短于B、C组(P均<0.05)。3组受者术后高血糖和DGF发生率差异均无统计学意义(χ2=4.581和0.404,P均>0.05),A组受者伤口愈合延迟发生率低于C组(χ2=7.303,P<0.017)。仅C组1例受者因心力衰竭和肺水肿死亡。 结论ERAS适用于肾移植受者术后静脉补液策略,鼓励受者尽早饮水进食,在保证血压正常或偏高的情况下,适当减少静脉补液量,有利于减少并发症,促进受者恢复。  相似文献   
49.
目前,国内外肝移植学界对肝移植术后急性排斥反应(AR)的机制阐释为T细胞介导的细胞免疫应答,但为获得长期生存仍需长期乃至终身服用免疫抑制剂。即使如此,临床上AR仍时有发生,并导致相当一部分受者移植肝功能丧失,更重要的是受者术后还受到感染、肿瘤和其他一系列不良反应及沉重经济负担的影响。因此,为肝移植AR机制提出新的理论解释,更全面深入阐明肝移植免疫排斥反应的内在机制,进而依据新的机制研制出新型免疫抑制剂已势在必行。本文就B细胞介导的体液免疫应答在肝移植AR中的作用作一综述。  相似文献   
50.
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-23

京公网安备 11010802026262号