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   8325篇
  免费   765篇
  国内免费   231篇
耳鼻咽喉   37篇
儿科学   24篇
妇产科学   35篇
基础医学   245篇
口腔科学   373篇
临床医学   1498篇
内科学   2485篇
皮肤病学   20篇
神经病学   502篇
特种医学   167篇
外国民族医学   1篇
外科学   561篇
综合类   1465篇
预防医学   1046篇
眼科学   71篇
药学   459篇
  2篇
中国医学   195篇
肿瘤学   135篇
  2024年   47篇
  2023年   207篇
  2022年   198篇
  2021年   346篇
  2020年   341篇
  2019年   338篇
  2018年   332篇
  2017年   350篇
  2016年   339篇
  2015年   317篇
  2014年   513篇
  2013年   509篇
  2012年   487篇
  2011年   538篇
  2010年   352篇
  2009年   412篇
  2008年   450篇
  2007年   533篇
  2006年   385篇
  2005年   368篇
  2004年   312篇
  2003年   278篇
  2002年   235篇
  2001年   201篇
  2000年   138篇
  1999年   97篇
  1998年   103篇
  1997年   103篇
  1996年   63篇
  1995年   57篇
  1994年   72篇
  1993年   39篇
  1992年   48篇
  1991年   33篇
  1990年   32篇
  1989年   28篇
  1988年   25篇
  1987年   15篇
  1986年   23篇
  1985年   14篇
  1984年   13篇
  1983年   5篇
  1982年   6篇
  1981年   4篇
  1980年   3篇
  1978年   4篇
  1977年   3篇
  1976年   1篇
  1975年   2篇
  1973年   1篇
排序方式: 共有9321条查询结果,搜索用时 109 毫秒
61.
已婚育龄妇女避孕措施变化趋势分析   总被引:5,自引:1,他引:4  
目的:了解已婚育龄妇女避孕措施的变化趋势,为指导计划生育服务工作提供科学依据。方法:收集1983~2005年苏州市已婚育龄妇女避孕方法的资料,并用统计软件对其变化趋势进行了分析。结果:已婚育龄妇女节育率在88.38%~92.94%范围波动,长效避孕措施现用率从75.19%下降至71.27%,而短效避孕措施从12.86%上升至17.11%。宫内节育器的现用率从50.09%上升到66.50%;避孕套从1.94%上升到14.21%;其他避孕方法的现用率均呈下降趋势,其中女性绝育现用率从24.42%下降到4.50%。结论:节育率维持在较高水平;长效避孕措施现用率下降而短效避孕措施现用率上升;避孕方法使用趋于多样化,需要提供满足个性化需求的指导和服务。  相似文献   
62.
儿童感觉统合失调及其影响因素的调查分析   总被引:17,自引:1,他引:16  
目的 研究儿童感觉统合失调与学习障碍及环境因素的关系。方法 采用感觉统合评定量表和学习障碍(PRS)筛查量表,分别对755名学龄儿童进行检测、分析。结果 感觉统合严重失调率为13.25%;感觉统合正常与失调儿童的学习障碍有统计学差异(P<0.005);其中在LD儿童中感觉统合失调率占63.51%;感觉统合失调与母孕期的情绪、是否足月顺产、出生后的喂养方式、居住环境、孩子1岁内有无高热、家长对孩子的态度及期待等因素有关(P<0.05)。结论 儿童感觉统合失调与环境因素、学习障碍有一定的关系。  相似文献   
63.
目的:观察老年与成年精神病人服用抗精神病药物后的心电图(ECG)改变。方法:84例老年精神病病人(男性35,女性49例,年龄63±s3a)与100例成年精神病病人(男性50例,女性50例,年龄40±10a),服用抗精神病药物前及服2mo以上的首次ECG资料进行比较。抗精神病药包括吩噻嗪类、丁酰苯类及三环类抗抑郁剂和抗躁狂药等。结果:84例老年病人中ECG异常63例(75%),100例成年人中ECG异常46例(46%)(P<0.05)。结论:由于老年人服抗精神病药后易发生ECG异常,因此开始剂量宜低,增量要小,严密监测心脏功能。  相似文献   
64.
Abstract  Mini Mental State Examination (MMSE), Brief Psychiatric Rating Scale (BPRS) and subscales of the BPRS were performed on 73 elderly inpatients (mean age: 67.9 years; standard deviation: 7.2; range: 60–89) diagnosed with DSM-III-R chronic schizophrenia. Forty of the subjects were men and 33 were women. A significant negative correlation was observed between MMSE and the age, factor negative, factor depressive, and total score of BPRS. We believe, however, that it is relatively sufficient to screen for demented illness of schizophrenics using MMSE when considering the age and the psychiatric symptoms (especially negative or depressive symptoms). Forty-eight (66%) of the 73 patients were categorized as 'demented' by MMSE. These results suggest that the aged inpatients with schizophrenia in a hospital showed certain kinds of cognitive deficits (including senile dementia) more frequently than the general population.  相似文献   
65.
Approximately 30–40% of elderly patients with major depression have inadequate response to an initial therapeutic trial of antidepressant medication. In these cases augmentation of the antidepressant has been recommended as one way of improving the rate of response. This article reviews the literature on augmentation strategies in treatment-resistant geriatric depression. Successful augmentation with lithium, triiodothyronine, stimulants, carbamazepine, valproate and a tricyclic–serotonin reuptake inhibitor combination have been described. However, there have been no controlled trials and, with the exception of two open prospective studies of lithium potentiation, the literature consists entirely of case reports and retrospective case series. As a result, it is difficult to draw conclusions about the efficacy of these strategies in late life, especially since treatment failures seldom get reported. Side-effects may limit the usefulness of some augmentation regimens in old age—up to 25% of patients treated with lithium or carbamazepine discontinued these medications because of adverse events. There is a need for controlled studies to better determine the clinical utility of augmentation strategies in physically well depressed elderly, as well as those with depression complicating medical illness, dementia and other neurological disorders.  相似文献   
66.
华玲  万荣辉  郭军 《医学信息》2006,19(3):497-498
目的总结弛环充填式无张力修补术治疗老年腹股沟疝患者的经验。方法回顾分析2002年3月-2005年7月采用德国Braun公司生产的Braun mesh和plug治疗的86例老年腹股沟疝患者的临床资料。结果平均手术时间35min,术后8-10h下床活动,2周恢复日常生活,伤口均一期愈合,术后尿潴留15例,异物感3例,随访3—40个月无一例复发。结论疝环充填式无张力修补术操作方便,创伤小,恢复快,复发率低,是老年患者理想有效的疝修补术。  相似文献   
67.
刘淑琴  朱成 《解剖学杂志》1992,15(6):431-433
观察老年大鼠下丘脑视上核腹侧大细胞神经元和弓状核神经元的超微结构,结果显示:老年大鼠视上核腹侧血管加压素(VP)神经元的胞体较成年鼠大,胞质结构比较致密,内含许多核糖体颗粒,粗面内质网分散成小泡状,神经分泌颗粒增多,溶酶体、线粒体、高尔基氏复合体数量都较多.而弓状核内的暗细胞和亮细胞的核糖体减少,高尔基氏复合体和线粒体都变化,还有少数神经元固缩,细胞质内胞器明显减少,呈现变性现象.结果提示:老年期下丘脑视上核VP神经元机能增强;而弓状核内两种细胞都显示机能减弱的征象.老年时下丘脑各核团神经元的这种不协调性变化,可能是动物衰老的一种重要表现.  相似文献   
68.
目的:探讨文拉法辛缓释剂对伴有高血压的老年期抑郁症的疗效和安全性。方法:使用文拉法辛缓释剂对30例伴有高血压的老年期抑郁症和30例无高血压的老年期抑郁症患者进行为期6周的对照治疗,在治疗前及治疗后第1、2、4、6周末评定汉密尔顿抑郁量表(HAMD 17项),并进行临床疗效评定, 监测血压,记录不良反应。结果:高血压组和非高血压组患者的HAMD评分均从第1周末起明显下降(P< 0.05或P<0.01),且一直持续至治疗第6周末。两组6周末的有效率和临床治愈率差异无显著性(P> 0.05)。高血压组患者使用文拉法辛缓释剂治疗后第2周末收缩压变化值显著高于非高血压患者(0.9±0.4, 0.6±0.5,P=0.01)。两组间的不良反应发生率差异无统计学意义(P>0.05)。结论:文拉法辛缓释剂治疗老年期抑郁症疗效肯定,不良反应少,对血压无明显影响。  相似文献   
69.
The number of plaque-forming cells (PFC) developed in pokeweed mitogen (PWM)-activated unfractionated or T/B separated, 4:1 reconstituted cultures of peripheral blood lymphocytes (PBL) with well-characterized subpopulations obtained from healthy, aged subjects was compared to that of young blood donors. The absolute number of PBL in the aged was reduced by 36%, and the percentage of sheep erythrocyte-rosette-forming cells (E-RFC) by 27%, compared to the percentage obtained in young donors. The IgM-, IgG- and IgA-immunoglobulin (Ig) secretion was monitored with a protein A PFC assay. The number of PFC in PBL cultures of the aged was 58% of the number found in cultures of the young controls. The number of PFC generated in cultures of autologous irradiated T and untreated B cells showed a 104% increase in the aged whereas a 63% increase was obtained using cells from young individuals. Co-cultures of young B cells with untreated or irradiated young or aged T cells showed a significant rise in the PFC response in cultures with irradiated aged T cells, while an equal number of PFC was generated in cultures of young B cells with young or aged untreated T cells. Our results demonstrate a decreased number of PBL, especially T cells, an impaired B cell function and a pronounced enhancement of the PFC response in cultures of irradiated aged T cells and young or aged B cells, whereas the T helper function of untreated cells was found to be normal. The influence of monocytes on the PFC response did not differ in the two groups.  相似文献   
70.
Small pieces of tissue isolated from abdominal sympathetic ganglia in aged male patients were cultured in a chemically defined, serum-free medium. The growth of neurites from pieces of ganglia in cultures with and without 50 ng/ml mouse 2.5S nerve growth factor (NGF) was compared. The NGF stimulated significantly greater regeneration of neurites, causing the growth of long fibers from the ganglion pieces. Many short neurites grew, even in the absence of the NGF, but these were generally short, except for long neurites generated in several nerve cells. A method was devised for the evaluation of NGF-dependent growth of neurites in the culture. The rate of the NGF-dependent growth of neurites, which was calculated by the difference in the total lengths of the NGF-dependent neurites between 2- and 4-day-old cultures, was approximately 160 micron/day. The results indicate that although the growth of neurites from some sympathetic nerve cells of the aged human become independent of the NGF, most of the nerve cells remain dependent on the NGF, even in the stage of senescence.  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