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   44119篇
  免费   4214篇
  国内免费   2642篇
耳鼻咽喉   377篇
儿科学   562篇
妇产科学   531篇
基础医学   4853篇
口腔科学   942篇
临床医学   5394篇
内科学   6865篇
皮肤病学   614篇
神经病学   2635篇
特种医学   1918篇
外国民族医学   15篇
外科学   6104篇
综合类   6747篇
现状与发展   7篇
一般理论   9篇
预防医学   2904篇
眼科学   930篇
药学   3991篇
  45篇
中国医学   2063篇
肿瘤学   3469篇
  2024年   149篇
  2023年   730篇
  2022年   1685篇
  2021年   2286篇
  2020年   1810篇
  2019年   1514篇
  2018年   1567篇
  2017年   1395篇
  2016年   1443篇
  2015年   2039篇
  2014年   2422篇
  2013年   2503篇
  2012年   3585篇
  2011年   3723篇
  2010年   2495篇
  2009年   2144篇
  2008年   2543篇
  2007年   2475篇
  2006年   2354篇
  2005年   2131篇
  2004年   1627篇
  2003年   1564篇
  2002年   1324篇
  2001年   850篇
  2000年   744篇
  1999年   667篇
  1998年   430篇
  1997年   383篇
  1996年   316篇
  1995年   295篇
  1994年   240篇
  1993年   161篇
  1992年   211篇
  1991年   147篇
  1990年   127篇
  1989年   118篇
  1988年   93篇
  1987年   110篇
  1986年   93篇
  1985年   93篇
  1984年   57篇
  1983年   43篇
  1982年   30篇
  1981年   30篇
  1980年   29篇
  1979年   39篇
  1978年   14篇
  1974年   12篇
  1973年   10篇
  1968年   12篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
乳腺癌X线表现分析   总被引:20,自引:3,他引:17  
目的分析乳腺癌典型及不典型X线征象,提高对乳腺癌不典型X线表现的认识。方法对61例经手术病理证实的乳腺癌资料进行回顾性分析。结果61例乳腺癌主要X线征象:肿块39例;微小钙化30例;不伴肿块及微小钙化的乳腺局部结构紊乱4例、星芒征3例、非对称性密度增高3例。结论肿块及微小钙化是乳腺癌最主要、最直接的X线征象,但部分乳腺癌X线上缺乏上述2种表现,单纯以结构紊乱、非对称性密度增高或星芒征为主要表现。提高对此类乳腺癌不典型X线表现的认识,有利于防止误、漏诊。  相似文献   
2.
3.
The objective of this study is to assess the efficacy and safety of herbal medicines (HMs), as a monotherapy or adjunct therapy, compared to placebo or conventional approaches in the treatment of idiopathic Parkinson's disease (PD). We conducted a systematic review of randomized controlled trials from both conventional and alternative medicine sources. Outcome measures were overall improvement, quality of life, reduction of levodopa dose, and adverse events. Nine studies were included, each testing a different HM. Six of the trials had limited internal validity due to major flaws in design, including the lack of proper randomization; insufficient blinding; unclear inclusive criteria in terms of diagnostic criteria, baseline staging, and duration of disease; lack of proper sample size calculation; and insufficient data analysis. Imbalances in gender and ethnicity among the patients in the included trials were observed. No major adverse events emerged, and no specific pattern was detected from the trials describing such data. In addition to major methodological defects, heterogeneity in (1) HM tested, (2) control treatment, and (3) outcome measure hindered in-depth data analysis and synthesis. Current evidence is insufficient to evaluate the efficacy and safety of various HMs. Further studies with improved trial design and reporting, with assessment on cost-effectiveness, quality of life, and qualitative data are warranted.  相似文献   
4.
目的:探讨nm23-H1基因转染对人胆管癌细胞系QBC939体外浸润能力的影响。方法:将含有全长nm23-H1 cDNA的真核表达载体通过脂腩体法转染人胆管癌细胞系。结果:转染成功的QBC939细胞,其nm23-Hl基因的mRNA、蛋白表达明显增加,转染nm23-H1基因的胆管癌细胞体外浸润能力下降,穿越matrigel的细胞数明显低于亲本QBC939细胞,代表浸润能力的IV型胶原酶(MMP-9)分泌量下降。结论:nm23-Hl基因可以抑制胆管癌细胞的体外浸润能力。  相似文献   
5.
Rolled finger gloves were used as ring tourniquets on a case of amputation injury of bilateral thumbs. Necrosis of soft tissue of the right thumb occurred due to mistakenly prolonged use of the tourniquet. Later the patient successfully underwent a toe-to-thumb transfer (modified wraparound procedure). The precautions in using finger tourniquets are stressed.  相似文献   
6.
Thirty cases of large pressure sores were treated by myocutaneous flaps (39 flaps) and the cure rate was 92%. Of them, 15 pressure sores were treated by gluteus maximus myocutaneous flaps, 12 in the greater trochanteric area by tensor fascia lata myocutaneous flaps, 7 in the ischiatic area by gracilis myocutaneous flaps and 4 in the ischiatic area biceps femoris myocutaneous flaps, 2 by a abductor hallucis myocutaneous flap and a flexor digitorum brevis myocutaneous flap. In author's opinion, myocutaneous flap transposition is simple, safe and reliable method in treating large pressure sores. These flaps increased the blood flow on recipient sites through its own intrinsic blood vessels so as to accelerate wound healing.  相似文献   
7.
头皮脑回样病变畸形   总被引:3,自引:0,他引:3  
目的提高对头皮脑回样病变畸形的认识和治疗水平。方法复习有关文献,对头皮脑回样病变畸形的病因、临床表现、诊断、分类和治疗进行了分析,采用切除后植皮或扩张头皮瓣修复治疗6例。结果6例病变切除彻底,随访无复发。其中2例植皮病例患者导致局部秃发,4例扩张头皮瓣修复外形满意。结论头皮脑回样病变畸形是一种罕见的头皮良性病变,头皮扩张术是修复治疗头皮脑回样病变的理想方法。  相似文献   
8.
陈晨  汪凯 《中国卒中杂志》2007,15(11):1239-1243
尼麦角林是一种麦角生物碱衍生物,广泛应用于脑血管病患者认知障碍的治疗。多项临
床前研究显示,尼麦角林对于认知障碍的改善可能与以下因素有关:尼麦角林除能够改善脑循环,
促进神经递质释放外,还具有营养神经及抗氧化等作用。目前的研究认为,尼麦角林能够改善患者
卒中后抑郁相关的情绪障碍以及有效改善血管性痴呆,提高患者的日常生活能力。同时,尼麦角林具
有良好的安全性,目前暂无尼麦角林治疗导致纤维化或麦角中毒的研究报道。本文就尼麦角林在神
经系统的作用机制、临床疗效及安全性进行综述,以期为临床应用提供参考。  相似文献   
9.
The melt agglomeration process of lactose powder with hydrogenated cottonseed oil (HCO) as the hydrophobic meltable binder was investigated by studying the physicochemical properties of molten HCO modified by sucrose stearates S170, S770 and S1570. The size, size distribution, micromeritic and adhesion properties of agglomerates as well as surface tension, contact angle, viscosity and specific volume of molten HCO, with and without sucrose stearates, were examined. The viscosity, specific volume and surface tension of molten HCO were found to be modified to varying extents by sucrose stearates which are available in different HLB values and melt properties. The growth of melt agglomerates was promoted predominantly by an increase in viscosity, an increase in specific volume or a decrease in surface tension of the molten binding liquid. The agglomerate growth propensity was higher with an increase in inter-particulate binding strength, agglomerate surface wetness and extent of agglomerate consolidation which enhanced the liquid migration from agglomerate core to periphery leading to an increased surface plasticity for coalescence. The inclusion of high concentrations of completely meltable sucrose stearate S170 greatly induced the growth of agglomerates through increased specific volume and viscosity of the molten binding liquid. On the other hand, the inclusion of incompletely meltable sucrose stearates S770 and S1570 promoted the agglomeration mainly via the reduction in surface tension of the molten binding liquid with declining agglomerate growth propensity at high sucrose stearate concentrations. In addition to being an agglomeration modifier, sucrose stearate demonstrated anti-adherent property in melt agglomeration process. The properties of molten HCO and melt agglomerates were dependent on the type and concentration of sucrose stearate added.  相似文献   
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