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   73293篇
  免费   6840篇
  国内免费   4366篇
耳鼻咽喉   574篇
儿科学   953篇
妇产科学   1063篇
基础医学   8140篇
口腔科学   1270篇
临床医学   8454篇
内科学   11342篇
皮肤病学   914篇
神经病学   3359篇
特种医学   2998篇
外国民族医学   35篇
外科学   8705篇
综合类   12048篇
现状与发展   17篇
一般理论   16篇
预防医学   5115篇
眼科学   1726篇
药学   8023篇
  70篇
中国医学   3857篇
肿瘤学   5820篇
  2024年   204篇
  2023年   943篇
  2022年   2388篇
  2021年   3271篇
  2020年   2465篇
  2019年   2197篇
  2018年   2373篇
  2017年   2162篇
  2016年   2124篇
  2015年   2992篇
  2014年   3784篇
  2013年   3809篇
  2012年   5334篇
  2011年   5628篇
  2010年   3798篇
  2009年   3219篇
  2008年   4102篇
  2007年   4225篇
  2006年   3923篇
  2005年   3550篇
  2004年   3135篇
  2003年   3064篇
  2002年   2743篇
  2001年   2190篇
  2000年   1931篇
  1999年   1582篇
  1998年   864篇
  1997年   878篇
  1996年   683篇
  1995年   571篇
  1994年   501篇
  1993年   347篇
  1992年   530篇
  1991年   436篇
  1990年   405篇
  1989年   357篇
  1988年   287篇
  1987年   265篇
  1986年   213篇
  1985年   161篇
  1984年   119篇
  1983年   87篇
  1982年   67篇
  1981年   76篇
  1980年   41篇
  1979年   75篇
  1978年   37篇
  1974年   39篇
  1973年   34篇
  1972年   42篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
目的探讨原发性高血压患者心电图心率校正QT间期(QTc)和贝那普利降压疗效之间的关系.方法采用前瞻性队列研究方法调查安徽A县899名高血压病患者的基线心电图、治疗15 d前后的血压变化及相关临床和流行病学特点等情况.结果 QTc和血压下降呈负相关.QTc每增加0.1秒1/2,收缩压和舒张压的下降值分别减少3.6 mmHg和3.3 mmHg,且差异均有显著性(P<0.05).将QTc三等分后,随着QTc等分的增加,收缩压和舒张压的下降值均逐渐减少,且差异具有显著性(P<0.05);将QTc等分后的变量放入方程中进行趋势性分析,发现在收缩压和舒张压组中的负相关关系具有显著性(P<0.05).随着QTc等级的增加,舒张压有效率逐渐降低,且有显著性差异(P<0.05),收缩压的效应关系不如舒张压明显.结论 QTc和贝那普利降压疗效呈负相关,对贝那普利短期降压疗效具有重要的预测价值.  相似文献   
82.
Summary;To investigate the distribution of possible novel mutations from parkin gene in variant sub-set of patients with Parkinson’s disease(PD)in China and explore whether parkin gene plays an im-portant role in the pathogenesis of PD,70 patients were divided into early-onset group and late-onsetgroup; 70 healthy subjects were included as controls.Genomic DNA from 70 normal controls andfrom those of PD patients were extracted from peripheral blood leukocytes by using standard proce-dures.Mutations of parkin gene(exon 1—12)in all the subjects were screened by PCR-single strandconformation polymorphism(SSCP),and further sequencing was performed in tue samples with ab-normal SSCP results,in order to confirm the mutation and its location.A new missense mutationGly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 pa-tients were found.All the DNA variants were sourced from the samples of the patients with early-on-set PD.It was concluded that Parkin point mutation a  相似文献   
83.
84.
Laparoscopic nephrectomy was performed in 15 male pigs, the procedure was successful in 14. Extraction of the intact kidney through a 5-cm lower abdomen incision was done in 7 animals; complete destruction and evacuation of the kidney was accomplished by a round-knife suction device through a 1-cm port in another 7 pigs. Grossly, the specimen consisted of sausage-like tubular renal tissue and a small amount of tissue debris. Pathology revealed that the glomerular and tubular structures were well preserved, no interstitial hematoma could be found. Four ports were usually used, one 1-cm umbilical camera port, one 0.5-cm port for ureter traction, and two 1-cm working ports along the midclavicular line. All the pigs recovered uneventfully. The average operation time was 3 h 20 min. The application of endo-GIA (United States Surgical Corporation) for renal hilum reduced the operative time to 2 h 20 min. Complications included renal vein tear during endoclip application and cutting in the first case, mild subcutaneous emphysema in 2 cases. This first pig received exploratory laparotomy for the repair and ligation of the renal vein. No more major complications occurred with increasing experience. From this porcine experiment, we conclude that the combination of laparoscopy, a tissue destroyer and an endobag for the entrapment of kidney seem to be a promising technique for clinical nephrectomy.  相似文献   
85.
目的研究杜氏/贝氏进行性肌营养不良(DMD/BMD)携带者视网膜眼电图(ERG)的改变,探讨ERG对DMD/BMD携带者的诊断意义。方法对22个基因突变类型明确的DMD/BMD家系.用定量PCR法结合系谱分析将家系中女性成员分成肯定携带者和非携带者,对患者和家系女性成员进行详细的眼科检查和ERG检测,并用ERG国际测量标准记录结果。结果22名患者中17名出现异常ERG改变;11名肯定携带者中5名出现ERG异常,14名非携带者无ERG改变,两组无重叠。结论ERG是一项对DMD/BMD诊断非常敏感和特异的检查,而ERG对携带者的诊断也具有一定的临床意义。  相似文献   
86.
SARS家庭聚集型病例8例报告分析   总被引:1,自引:0,他引:1  
SARS是由变异冠状病毒引起的新型烈性传染病,具有在家庭和医院内聚集发病的特点。其影像学表现对于临床诊断和随诊观察具有重要价值。本文报告了分属3个家庭的8个病例发病早期(1周)影像学表现(包括胸部平片和CT)和部分临床表现资料,讨论并分析SARS早期影像学表现的若干特点及与临床表现之间的关系。  相似文献   
87.
Nuclear factor-kappaB (NF-kappaB) plays a key role in inflammation, which is involved in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). In the present study, we assessed the potential role of NF-kappaB in regulation of cerebral vasospasm. Nuclear factor-kappaB DNA-binding activity was measured in cultured vascular smooth muscle cells (VSMCs) treated with hemolysate and pyrrolidine dithiocarbamate (PDTC, 80 micromol/L), an inhibitor of NF-kappaB. Forty-two rabbits were divided into three groups: control, SAH, and PDTC groups (n=14 for each group). The caliber of the basilar artery was evaluated. Nuclear factor-kappaB DNA-binding activity and the gene expression levels of cytokines and adhesion molecules in the basilar artery were measured. Immunohistochemical study was performed to assess the expression and localization of tumor necrosis factor (TNF)-alpha, intercellular adhesion molecule (ICAM)-1, and myeloperoxidase (MPO). It was observed that NF-kappaB DNA-binding activity was significantly increased by treatment with hemolysate in cultured VSCMs, but this increase was suppressed by pretreatment with PDTC. Severe vasospasm was observed in the SAH group, which was attenuated in the PDTC group. Subarachnoid hemorrhage could induce increases of NF-kappaB DNA-binding activity and the gene expression levels of TNF-alpha, interleukin (IL)-1 beta, ICAM-1, and vascular cell adhesion molecule (VCAM)-1, which were reduced in the PDTC group. Immunohistochemical study demonstrated that the expression levels of TNF-alpha, ICAM-1, and MPO were all increased in the SAH group, but these increases were attenuated in the PDTC group. Our results suggest that NF-kappaB is activated in the arterial wall after SAH, which potentially leads to vasospasm development through induction of inflammatory response.  相似文献   
88.
Parkinson's disease (PD) is a major cause of disability. To date, there have been no large-scale efforts to measure the quality of PD care because of a lack of quality indicators for conducting an explicit review of PD care processes. We present a set of quality indicators for PD care. Based on a structured review of the medical literature, 79 potential indicators were drafted. Through a two-round modified Delphi process, an expert panel of seven movement disorders specialists rated each indicator on criteria of validity, feasibility, impact on outcomes, room for improvement, and overall utility. Seventy-one quality indicators met validity and feasibility thresholds. Applying thresholds for impact on outcomes, room for improvement, and overall utility, a subset of 29 indicators was identified, spanning dopaminergic therapy, assessment of functional status, assessment and treatment of depression, coordination of care, and medication use. Multivariable analysis showed that overall utility ratings were driven by validity and impact on outcomes (P < 0.01). An expert panel can reach consensus on a set of highly rated quality indicators for PD care, which can be used to assess quality of PD care and guide the design of quality improvement projects.  相似文献   
89.
From May 1, 1985 to December 31, 1991, a total of 4,962,707 serum samples from 8 population groups in Taiwan were tested for anti-human immunodeficiency virus type 1 (anti-HIV-1). In total, 256 samples were seropositive; of these individuals, 43 developed acquired immunodeficiency syndrome (AIDS): 29 were homosexuals; 5 were hemophiliacs; 8 were heterosexuals and 1 was of unknown risk. Although the prevalence of HIV-1 infection and AIDS remains low compared with other countries, since 1988 the increase has been rapid. Before 1977 the majority were homosexuals and hemophiliacs; thereafter the risk groups diversified, with a trend away from homosexuals and hemophiliacs towards heterosexuals and intravenous drug abusers (IVDAs). A few patients have caused serious social problems for the public, health care workers and families. Active community efforts are needed to achieve future success in the control of HIV-1 infection and AIDS in Taiwan.  相似文献   
90.
目的探讨代谢综合征(MS)患者中肾动脉狭窄的发生率及无创性筛检的必要性与可靠性。方法45例MS患者预行肾动脉螺旋CT血管造影(SCTA),对所检出的14例肾动脉狭窄者行肾动脉数字减影血管造影(DSA)对照,并对SCTA及DSA结果进行对比分析。结果45例MS患者中SCTA显示肾动脉正常31例,其余14例患者存在单侧或双侧肾动脉狭窄,DSA对照显示肾动脉正常6条,肾动脉狭窄22条,与SCTA显示的情况基本符合。结论MS患者中肾动脉狭窄的发生率约31.1%,对可疑患者应常规予以肾动脉SCTA检查。  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