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   120782篇
  免费   13172篇
  国内免费   4892篇
耳鼻咽喉   1261篇
儿科学   2828篇
妇产科学   1547篇
基础医学   9314篇
口腔科学   2410篇
临床医学   15942篇
内科学   14506篇
皮肤病学   1771篇
神经病学   5806篇
特种医学   4574篇
外国民族医学   1篇
外科学   12188篇
综合类   22196篇
现状与发展   13篇
一般理论   39篇
预防医学   16005篇
眼科学   1537篇
药学   11586篇
  119篇
中国医学   8500篇
肿瘤学   6703篇
  2024年   540篇
  2023年   1748篇
  2022年   3200篇
  2021年   4513篇
  2020年   3848篇
  2019年   2688篇
  2018年   3278篇
  2017年   3553篇
  2016年   3082篇
  2015年   4703篇
  2014年   5898篇
  2013年   7817篇
  2012年   9967篇
  2011年   10421篇
  2010年   8663篇
  2009年   7838篇
  2008年   8317篇
  2007年   8025篇
  2006年   7258篇
  2005年   6031篇
  2004年   4520篇
  2003年   3956篇
  2002年   3395篇
  2001年   2493篇
  2000年   1808篇
  1999年   1135篇
  1998年   699篇
  1997年   653篇
  1996年   681篇
  1995年   538篇
  1994年   470篇
  1993年   425篇
  1992年   546篇
  1991年   488篇
  1990年   510篇
  1989年   484篇
  1988年   404篇
  1987年   401篇
  1986年   345篇
  1985年   349篇
  1984年   291篇
  1983年   254篇
  1982年   213篇
  1981年   186篇
  1980年   170篇
  1979年   208篇
  1978年   175篇
  1977年   151篇
  1976年   136篇
  1974年   147篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
121.
122.
Myocarditis is a major cause of end-stage heart failure and is responsible for up to 10% of cases of idiopathic dilated cardiomyopathy (IDC). Worldwide, approximately 45% of all heart transplants are performed for IDC and up to 8% for myocarditis. Early reports suggested that survival after transplantation for myocarditis was poor and patients had an increased risk of rejection. More recently, larger case series suggest that overall survival after transplantation for myocarditis is similar to survival after transplantation for other causes. However, certain disorders, including cardiac sarcoidosis and giant cell myocarditis (GCM), require heightened surveillance for post-transplantation disease recurrence. We present the case of a 42-year-old man with recurrence of GCM 8 years after transplantation and review the literature on the role of cardiac transplantation for patients with myocarditis.  相似文献   
123.
乳腺病变X线立体定位钢丝置入移位的分析   总被引:1,自引:0,他引:1  
目的分析乳腺立体定位下钢丝置入移位的表现、原因、处理方法,提高术前定位的准确性。方法行立体定位置入钢丝患者79例,96个病变,发生钢丝移位13例。结果立体定位中发生钢丝移位5例,原因分别来自于患者和操作医师;立体定位完成后钢丝移位5例,原因是局麻注射药物过多,导致乳腺Z轴的深度与计算机提示的实际深度不符合、放置定位针的方法不正确、拔出钢丝外套针套时疏忽钢丝是否已锚定病变。处理方法:可按照钢丝提示位置向病变方向移位2cm以内进行手术,重新放置第2根钢丝,将双J型钢丝收入针套并取出体外,重新定位。手术中钢丝脱出2例,因术后过分提拉钢丝所致,放射科医师放置钢丝后应向外科医师准确描述深度、方向,并从距离钢丝头端距离皮肤最近处取切口手术。术后标本未见钙化1例,与钙化位于手术电刀破坏的腺体内有关,可扩大范围切除并短期复查,证实钙化是否完整切除。结论正确认识乳腺X线立体定位下钢丝移位的表现,熟练掌握其处理方法,可提高对不可触及的乳腺病变的定位准确性,正确引导外科手术。  相似文献   
124.
Non-selective inhibition of monoamine oxidase (MAO) enzymes (ie, isoforms A and B) in the brain are associated with clinically significant antidepressant effects. In the US, the selegiline transdermal system (STS; EMSAM) is the first antidepressant transdermal delivery system to receive Food and Drug Administration (FDA) approved labeling for the treatment of major depressive disorder (MDD). Currently, the use of orally administered MAO inhibitor antidepressants (eg, phenelzine, tranylcypromine) is limited by the risk of tyramine-provoked events (eg, acute hypertension and headache, also known as the “cheese reaction”) when combined with dietary tyramine. The selegiline transdermal system is the only MAOI available in the US for the treatment of MDD that does not require dietary restriction at the clinically effective dose of 6 mg/24 hours. Delivery of selegiline transdermally (EMSAM®) bypasses hepatic first pass metabolism, thereby avoiding significant inhibition of gastrointestinal and hepatic MAO-A activity (ie, reduced risk of tyramine-provoked events) while still providing sufficient levels of selegiline in the brain to produce an antidepressant effect. At dosages of 6–12 mg/24 hours, EMSAM has been shown to improve symptoms of depression, have good tolerability, and have high rates of medication adherence. However, at higher doses of EMSAM (ie, 9 mg/24 hours or more), dietary restriction of tyramine intake is recommended. The introduction of EMSAM overcomes many of the safety concerns affiliated with the conventional oral MAO inhibitors and EMSAM may be considered another strategy for the treatment of MDD, especially in patients who cannot tolerate oral antidepressants, are poorly adherent, who present with atypical depressive symptoms, or have failed other antidepressants.  相似文献   
125.
Introduction Obese individuals may have normal insulin–glucose homeostasis, insulin resistance, or diabetes mellitus. Whereas gastric bypass cures insulin resistance and diabetes mellitus, its effects on normal physiology have not been described. We studied insulin resistance and β-cell function for patients undergoing gastric bypass. Methods One hundred thirty-eight patients undergoing gastric bypass had fasting insulin and glucose levels drawn on days 0, 12, 40, 180, and 365. Thirty-one (22%) patients with diabetes mellitus were excluded from this analysis. Homeostatic model of assessment was used to estimate insulin resistance, insulin sensitivity, and β-cell function. Based on this model, patients were categorized as high insulin resistance if their insulin resistance was >2.3. Results Body mass index did not correlate with insulin resistance. Forty-seven (34%) patients were categorized as high insulin resistance. Correction of insulin resistance for this group occurred by 12 days postoperatively. Sixty (43%) patients were categorized as low insulin resistance. They demonstrated an increase of β-cell function by 12 days postoperatively, which returned to baseline by 6 months. At 1 year postoperatively, the low insulin resistance group had significantly higher β-cell function per degree of insulin sensitivity. Conclusions Adipose mass alone cannot explain insulin resistance. Severely obese individuals can be categorized by degree of insulin resistance, and the effect of gastric bypass depends upon this preoperative physiology.  相似文献   
126.
先天性肩胛骨高位症1例   总被引:1,自引:0,他引:1  
马素凤 《医学影像学杂志》2007,17(12):1377-1377
患者男,37岁。因雷管爆炸致全身多发皮肤金属伤入院,胸部X线示:右侧肩胛骨明显抬高,肩胛骨上端平颈6椎体上缘水平,肩胛骨与颈椎间可见骨性条形影,左侧肩胛骨未见明显异常。双侧胸部可见多发点状、不规则形高密度影。诊断:右侧肩胛骨高位伴“肩椎骨”形成;双侧胸部多发异物影,结合病史考虑为多发皮肤内金属影。讨论:先天性肩胛骨高位症又称肩胛骨下降不全,本病是肩胛骨在胚胎发育过程中,由于受到某种因素的影响,如宫内压增高,肩胛带肌肉发育不良,肩胛骨与脊柱之间有异常连接而发生下降障碍所至。单侧发病者多表现为双侧颈肩部不对称,患侧颈…  相似文献   
127.
医院用血液制品HCV污染情况的调查   总被引:1,自引:0,他引:1  
目的调查医院治疗用血液制品HCV污染情况.方法临床治疗所用的血液制品,在输完后留容器之残液备检.采用酶标免疫法(ELISA)检测.对ELISA检测之阳性标本及在阴性标本中随机抽取9份,采用逆转录双PCR方法检测HCV_RNA.结果血浆白蛋白抗_HCV阳性率458%,新鲜血浆阳性率26%.两种方法检测同一标本,ELISA检测阳性的血液制品中,用PCR证实,并非都有病毒复制;而在ELISA检测的阴性标本中,仍旧有较高的PCR阳性检出.结论血液制品存在着HCV污染,抗_HCV对于HCV感染的诊断价值很高.检测血液制品中的抗_HCV,合理使用血液成份,可防止HCV在医院内传播.  相似文献   
128.
The public sector in Britain has been subjected to over a decade of major reform aimed at breaking up public service monopolies, at containing costs while at the same time opening services up to greater consumer choice. Health and social services have not been exempt from this revolution in the organization and management of public sector services. The long-standing policy of care in the community is being subjected to market principles and the introduction of a ‘contract culture’ very similar to the NHS reforms introduced in 1991. This paper reviews the origins of these developments in the doctrines of ‘new public management’, a movement which has proved attractive to policy-makers in many countries. Local authority social services departments have been identified as the lead agency for the development of a mixed economy of care following a review of community care policy by the government's health adviser, Sir Roy Griffiths, and a subsequent white paper. This paper examines the limited empirical evidence available on how managers and providers are meeting the challenge bestowed upon them, and concludes that most authorities are moving ahead cautiously if at all. Only a handful of authorities studied have embraced the reforms with any degree of enthusiasm. The paper concludes with an assessment of the reforms from two perspectives: a pessimistic one and an optimistic one. There are many worrying features of the reforms, not least among these being a lack of clarity over their intended purpose. Tensions and contradictions are plentiful, which places in jeopardy the certainty of the reforms in becoming user led rather than provider driven. A more optimistic scenario is that the changes are leading to a loosening up of services and practices which have often suffered from sclerotic tendencies, paternalism and sometimes complacency. If the reform process is skilfully handled and not rushed and if the ends are clearly established and communicated then users and carers could prove to be the principal beneficiaries.  相似文献   
129.
Twenty patients received transduodenal sphincteroplasty and transampullary septectomy between 1987 and 1993. Seven patients had post-cholecystectomy pain which was much improved or abolished in 5 of 7 patients at a mean follow-up of 4 years and 5 months. Four of five patients with chronic pancreatitis were improved at 3 years and 2 months. Three of five patients with recurrent acute pancreatitis were improved at 4 years and 5 months. One of three patients with chronic abdominal pain of hepatobiliary origin was improved at 3 years. Transduodenal sphincteroplasty and transampullary septectomy can relieve pain in patients with post-cholecystectomy pain, recurrent acute pancreatitis, chronic pancreatitis, and chronic abdominal pain of hepatobiliary origin, presumably by improving drainage of the obstructed ducts.  相似文献   
130.
The development and implementation of effective community support systems are goals of many public mental health authorities who are attempting to shift the focus and dollars for mental health services from inpatient to community care. This article presents the results of a survey which asked 90 community mental health agency case managers to assess the community support and residential needs of over 1400 of their clients. Medication monitoring and therapy were rated high priority needs. Psychosocial treatment, day and vocational activities also ranked high. Survey responses regarding residential services indicated a need for more supported and supervised options.The study reported was a collaborative effort by county and agency staff.  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