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   39694篇
  免费   2767篇
  国内免费   461篇
耳鼻咽喉   636篇
儿科学   602篇
妇产科学   521篇
基础医学   6587篇
口腔科学   657篇
临床医学   3420篇
内科学   7795篇
皮肤病学   1504篇
神经病学   3106篇
特种医学   2369篇
外国民族医学   2篇
外科学   5197篇
综合类   257篇
现状与发展   1篇
一般理论   4篇
预防医学   1795篇
眼科学   954篇
药学   3694篇
  1篇
中国医学   576篇
肿瘤学   3244篇
  2023年   243篇
  2022年   813篇
  2021年   1586篇
  2020年   825篇
  2019年   1127篇
  2018年   1254篇
  2017年   1009篇
  2016年   1554篇
  2015年   1968篇
  2014年   2241篇
  2013年   2528篇
  2012年   3799篇
  2011年   3544篇
  2010年   2029篇
  2009年   1680篇
  2008年   2460篇
  2007年   2217篇
  2006年   1998篇
  2005年   1800篇
  2004年   1553篇
  2003年   1372篇
  2002年   1173篇
  2001年   631篇
  2000年   592篇
  1999年   502篇
  1998年   249篇
  1997年   187篇
  1996年   168篇
  1995年   145篇
  1994年   107篇
  1993年   95篇
  1992年   137篇
  1991年   152篇
  1990年   111篇
  1989年   109篇
  1988年   110篇
  1987年   94篇
  1986年   77篇
  1985年   85篇
  1984年   56篇
  1983年   63篇
  1982年   41篇
  1981年   32篇
  1980年   38篇
  1979年   58篇
  1978年   30篇
  1976年   27篇
  1975年   22篇
  1970年   24篇
  1968年   22篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.

Objective

We aimed to examine the rates, correlates, methods, and precipitating factors of suicide attempts among adolescent patients admitted for psychiatric inpatient care from 1999 to 2010 in a university hospital in Korea.

Methods

The subjects consisted of 728 patients who were admitted for psychiatric inpatient care in a university hospital over a 12-year period and who were aged 10-19 years at the time of admission. We retrospectively investigated the information on suicidal behaviors and other clinical information by reviewing the subjects'' electronic medical records. Whether these patients had completed their suicide on 31 December 2010 was determined by a link to the database of the National Statistical Office.

Results

Among 728 subjects, 21.7% had suicidal ideation at admission, and 10.7% admitted for suicidal attempts. Female gender, divorced/widowed parents, and the presence of mood disorders were associated with a significantly increased likelihood of suicide attempts. Most common method of suicide attempts was cutting, and most common reason for suicide attempts was relationship problems within the primary support group. A diagnosis of schizophrenia was associated with increased risk of death by suicide after discharge.

Conclusion

These results highlight the role of specific psychosocial factor (e.g., relational problems) and psychiatric disorders (e.g., mood disorders) in the suicide attempts of Korean adolescents, and the need for effective prevention strategies for adolescents at risk for suicide.  相似文献   
992.
ObjectiveThe purpose of this study to develop new deep-brain stimulation system for long-term use in animals, in order to develop a variety of neural prostheses.MethodsOur system has two distinguished features, which are the fully implanted system having wearable wireless power transfer and ability to change the parameter of stimulus parameter. It is useful for obtaining a variety of data from a long-term experiment.ResultsTo validate our system, we performed pre-clinical test in Parkinson''s disease-rat models for 4 weeks. Through the in vivo test, we observed the possibility of not only long-term implantation and stability, but also free movement of animals. We confirmed that the electrical stimulation neither caused any side effect nor damaged the electrodes.ConclusionWe proved possibility of our system to conduct the long-term pre-clinical test in variety of parameter, which is available for development of neural prostheses.  相似文献   
993.

Objective

The purpose of this study was to investigate morphological change at the craniovertebral junction (CVJ) region using computed tomography.

Methods

A total of 238 patients were included in this study, and mean age was 47.8±21.3 months. Spinal canal diameter, Power''s ratio, McRae line, antero-posterior C1 ring height, atlantoaxial joint space, C2 growth, epidural space from the dens (M-PB-C2) and longitudinal distance (basion to C2 lower margin, B-C2) were measured. The mean value of each parameter was assessed for individual age groups. The cohorts were then divided into three larger age groups : infancy (I) (≤2 years), very early (VE) childhood (2-5 years) and early (E) childhood (5≥ years).

Results

Spinal canal diameter increased with age; however, this value did not increase with statistical significance after VE age. A significant age-related difference was found for all C2 body and odontoid parameters (p<0.05). Mean McRae line was 8.5, 8, and 7.5 mm in the I, VE, and E groups, respectively. The M-PB-C2 line showed up-and-down dynamic change during early pediatric periods.

Conclusion

Expansion of the spinal canal was restricted to the very early childhood period (less than 5 years) in the CVJ region; however, the C2 body and odontoid process increased continuously with age. The above results induced a dynamic change in the M-PB-C2 line. Although C2 longitudinal growth continued with age, the McRae line showed relatively little change.  相似文献   
994.
Pituitary apoplexy is a rare but potentially life-threatening clinical syndrome caused by the sudden enlargement of a pituitary adenoma secondary to hemorrhage or infarction. Pituitary apoplexy after cardiac surgery is a very rare perioperative complication. Factors associated with open heart surgery that may lead to pituitary apoplexy include hemodynamic instability during cardiopulmonary bypass and systemic heparinization. We report a case of pituitary apoplexy after mitral valvuloplasty with cardiopulmonary bypass. After early pituitary tumor resection and hormonal replacement therapy, the patient made a full recovery.  相似文献   
995.
Bone cement augmentation procedures have been getting more position as a minimally invasive surgical option for osteoporotic spinal fractures. However, complications related to these procedures have been increasingly reported. We describe a case of bone cement dislodgement following cement augmentation procedure for osteoporotic spinal fracture by reviewing the patient''s medical records, imaging results and related literatures. A 73-year-old woman suffering back and buttock pain following a fall from level ground was diagnosed as an osteoporotic fracture of the 11th thoracic spine. Percutaneous kyphoplasty was performed for this lesion. Six weeks later, the patient complained of a recurrence of back and buttock pain. Radiologic images revealed superior dislodgement of bone cement through the 11th thoracic superior endplate with destruction of the lower part of the 10th thoracic spine. Staged anterior and posterior fusion was performed. Two years postoperatively, the patient carries on with her daily living without any significant disability. Delayed bone cement dislodgement can occur as one of complications following bone cement augmentation procedure for osteoporotic spinal fracture. It might be related to the presence of intravertebral cleft, lack of interdigitation of bone cement with the surrounding trabeculae, and possible damage of endplate during ballooning procedure.  相似文献   
996.
The nonprogressive unilateral intracranial arteriopathy known as transient (focal) cerebral arteriopathy is not a well-recognized arteriopathy among practitioners of Korea and Japan, although it cannot be easily differentiated from early moyamoya disease. This review summarizes the nomenclature, pathophysiology, diagnostic evaluation, clinico-radiological features, and management of nonprogressive (reversible or stable) unilateral arteriopathy based on the relevant literature and our own experiences. Nonprogressive unilateral arteriopathy should be strongly suspected in children presenting with basal ganglia infarction and arterial beading. The early identification of patients likely to have nonprogressive or progressive arteriopathy would ensure proper management and guide further research for secondary stroke prevention.  相似文献   
997.

Objective

The purpose of our study was to assess prevalence of carotid intraplaque hemorrhage (IPH) and associations between territorial acute infarction and IPH on magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) in patients with acute neurologic symptoms.

Methods

83 patients with suspected acute neurologic symptoms were evaluated with both brain diffusion weighted imaging (DWI) and carotid MPRAGE sequences. Carotid plaque with high signal intensity on MPRAGE of >200% that of adjacent muscle was categorized as IPH. We analyzed the prevalence of IPH and its correlation with territorial acute infarction.

Results

Of 166 arteries, 39 had a carotid artery plaque. Of these arteries, 26 had carotid artery stenosis less than 50%. In all carotid arteries, MR-depicted IPH was found in 7.2% (12/166). High-signal intensity on DWI was found in 17.5% (29/166). Combined lesion with ipsilateral high-signal intensity on DWI and IPH on carotid MPRAGE sequence was found in 6 lesions (6/166, 3.6%). Of patients with carotid artery plaque, MR-predicted IPH was found in 30.8% (12/39) and match lesions with high-signal intensity on DWI and MPRAGE was found in 15.4% (6/39). MR-predicted IPH was significantly higher prevalence in high-grade stenosis group (p=0.010). Relative risk between carotid MPRAGE-positive signal and ipsilateral high-signal intensity on DWI in arteries with carotid artery plaques was 6.8 (p=0.010).

Conclusion

Carotid MPRAGE-positive signal in patients was associated with an increased risk of territorial acute infarction as detected objectively by brain DWI. The relative risk of stroke was increased in high-grade stenosis categories.  相似文献   
998.
BACKGROUND AND SIGNIFICANCE: Treatment of multidrug-resistant tuberculosis (MDR-TB) is challenging because of the toxicity of second-line medications. Little is known about whether adverse events impact treatment outcome. METHODS: We conducted a retrospective case series of 244 MDR-TB patients enrolled in Tomsk between 10 September 2000 and 10 September 2002. Adverse reactions were determined by laboratory data and/or clinical criteria. A multiple logistic regression model was performed to determine whether the occurrence of adverse reactions was associated with poor treatment outcome. RESULTS: In this cohort, 76.0% were cured, 6.6% failed, 4.9% died and 11.5% defaulted. Adverse events were observed in 73.3% of patients, occurring in 74.8% of patients who were adherent (taking at least 80% of prescribed doses) and 59.1% of non-adherent individuals (P = 0.11). The impact of adverse events on outcome was modified by non-adherence; among adherent patients, the occurrence of any adverse reaction was associated with treatment cure (adjusted odds ratio 3.24, 95% confidence interval 1.56-6.70). CONCLUSION: Adverse reactions occurred frequently in MDR-TB patients in Tomsk, Russia, but did not negatively impact treatment outcome. The occurrence of adverse reactions among adherent patients was associated with treatment cure.  相似文献   
999.
Cha JK  Jo WS  Shin HC  Bae HR  Ho JM  Kim JW 《Platelets》2004,15(1):3-7
Platelet activation is an important process in the pathogenesis of atherothrombosis. However, the serial changes of platelet activation in atherosclerotic ischemic stroke have not been determined. In this study, we measured serially platelet expression of CD63 and P-selectin and platelet aggregability to ADP and collagen. Measurements were made 24 and 72 h and 7 and 90 days after the ischemic event in 29 patients with atherosclerotic ischemic stroke. Platelet aggregability was significantly decreased after 72 h compared to that at 24 h of stroke onset. However, platelet CD63 and P-selectin expression remained high even 90 days after the events. These findings suggest that platelet hyperactivation in atherosclerotic ischemic stroke may be sustained for a considerable period.  相似文献   
1000.
SETTING: Multidrug-resistant tuberculosis (MDR-TB) is a major problem in countries of the former Soviet Union in both the civilian and prison sectors. OBJECTIVE: To evaluate outcomes of the MDR-TB treatment program (DOTS-Plus) in Tomsk, Russia. DESIGN: Retrospective case series of all patients enrolled in this program between 10 September 2000 and 10 September 2002. The program involves both the civilian and penitentiary TB services in Tomsk. Poor treatment outcome was defined as death, default and treatment failure. RESULTS: Among the 244 patients who received treatment, 77% were cured, 5% died, 7% failed, and 12% defaulted. In a multivariable analysis, alcohol consumption during treatment and the presence of both cavitary and bilateral disease were found to be the strongest predictors of poor treatment outcome. CONCLUSIONS: The integration of civilian and penitentiary TB services in the Tomsk MDR-TB treatment program has resulted in high cure rates and low rates of default. However, alcohol use among patients with MDR-TB is associated with poor treatment outcomes. Better understanding and programmatic alcohol interventions are needed if large-scale treatment of MDR-TB is to be successful in areas with high rates of alcohol use disorders.  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