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   66964篇
  免费   8306篇
  国内免费   1763篇
耳鼻咽喉   285篇
儿科学   1536篇
妇产科学   710篇
基础医学   3859篇
口腔科学   2607篇
临床医学   9034篇
内科学   7022篇
皮肤病学   1019篇
神经病学   3688篇
特种医学   1307篇
外国民族医学   14篇
外科学   5717篇
综合类   11295篇
现状与发展   9篇
一般理论   28篇
预防医学   6682篇
眼科学   1066篇
药学   10270篇
  480篇
中国医学   6320篇
肿瘤学   4085篇
  2024年   242篇
  2023年   1355篇
  2022年   2199篇
  2021年   3537篇
  2020年   3995篇
  2019年   2968篇
  2018年   2773篇
  2017年   3216篇
  2016年   3194篇
  2015年   2767篇
  2014年   4834篇
  2013年   5608篇
  2012年   4187篇
  2011年   4292篇
  2010年   3308篇
  2009年   3042篇
  2008年   2972篇
  2007年   3053篇
  2006年   2640篇
  2005年   2230篇
  2004年   1925篇
  2003年   1770篇
  2002年   1382篇
  2001年   1109篇
  2000年   907篇
  1999年   710篇
  1998年   662篇
  1997年   629篇
  1996年   534篇
  1995年   436篇
  1994年   440篇
  1993年   344篇
  1992年   395篇
  1991年   350篇
  1990年   311篇
  1989年   300篇
  1988年   298篇
  1987年   275篇
  1986年   222篇
  1985年   256篇
  1984年   251篇
  1983年   138篇
  1982年   188篇
  1981年   134篇
  1980年   133篇
  1979年   114篇
  1978年   76篇
  1977年   83篇
  1976年   74篇
  1975年   56篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
81.
目的:了解高海拔环境对精神分裂症的影响。方法:对106例高海拔地区精神分裂症患者(高海拔组)的临床特征、疗效、药物副作用进行调查,与同期106例平原精神分裂症患者(平原组)对照。结果:高海拔组临床症状以幻觉、疑病妄想、夸大妄想、紧张冲动行为及焦虑、抑郁等精神症状出现频率较高,而对照组以被害妄想、情感淡漠等精神症状出现频率较高(P<0.01或P<0.05);入院时高海拔组总体病情较重(P<0.01);两组间疗效无显著性差异;高海拔组药物不良反应多于平原组。结论:高海拔地区精神分裂症患者临床特征、总体病情严重程度、药物不良反应与平原地区有一定区别,可能与高海拔环境有关。  相似文献   
82.
The Present and Future of Clinical Psychology in Private Practice   总被引:1,自引:0,他引:1  
This article discusses clinical psychologists' current concerns, challenges, and opportunities in private practice. The future of clinicians in independent practice is presented within two paradigms, namely, psychology as a health profession, and psychology as life enhancement. Finally, the author argues that psychotechnology, corporate clinical psychology, and psychology as life enrichment will evolve within the future of clinical psychological independent practice.  相似文献   
83.
BACKGROUND: The validity of parent reports regarding children's attention-deficit/hyperactivity disorder (ADHD) symptoms has been questioned. This study assessed whether parent reports were as sensitive as teacher reports to document change in ADHD symptoms during clinical trials with atomoxetine. METHODS: Data were compared from two randomized, double-blind, placebo-controlled clinical trials of atomoxetine using different versions (parent or teacher) of the same rating scale (Attention-Deficit/Hyperactivity Disorder Rating Scale-IV [parent or teacher] Version: Investigator Administered and Scored - ADHD RS). Exclusion criteria included history of bipolar disorder, psychosis, seizures, alcohol abuse, or positive drug screen. Patients (6-16 years old) were treated with atomoxetine (titrated to a maximum dose of 1.8 mg/kg/day) administered once daily for up to 7 weeks. Parent and teacher ratings were compared using an analysis of covariance (ANCOVA) model. RESULTS: The analysis (n = 318) showed that treatment effects (mean change, baseline to endpoint) were similar between parent and teacher ratings (total, p = .762; inattention, p = .519; hyperactive/impulsive, p = .955). Effect sizes also were similar based on total scores (parent ratings = .69; teacher ratings = .63). CONCLUSIONS: Parent reports are as sensitive as teacher reports in assessing the efficacy of long-acting pharmacologic treatment for ADHD in children during clinical trials using the nonstimulant atomoxetine.  相似文献   
84.
目的 探讨肺上沟癌的临床特点及放疗疗效和不良反应。方法 回顾性分析 3 3例肺上沟癌住院病人的临床特征和常规放疗的疗效。结果 肺上沟癌占原发性支气管肺癌的 2 9% ,常见症状为 :患侧肩、背和上肢疼痛 ( 78 8% ) ,后 1,2 ,3肋骨或椎骨破坏( 5 7 6% ) ,Horner’s综合征 ( 3 6 7% ) ;少见的症状为 :咳嗽 ( 2 7% ) ,咯血 ( 9% ) ;中位生存期为 8 4月 ;1,3 ,5年生存率分别为 3 5 6% ,12 3 % ,4 6% ;放疗反应可耐受。结论 肺上沟癌相当少见 ,其临床特征基本符合pancoast综合症 ,本病预后差 ,但放疗可缓解疼痛 ,提高生存质量。  相似文献   
85.
Since the International Conference on Population and Development held in Cairo in 1994, and the Fourth World Conference on Women held in Beijing in 1995, the international organizations and public health communities have paid more attention to reproductiv…  相似文献   
86.
BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials.  相似文献   
87.
目的观察CT增强时对静脉选择及对造影剂的不良反应,并制定出相关的护理措施。方法2003年2月-2004年8月间,对460例行CT增强扫描的患者,根据检查部位、病情、体质、年龄,调节注射量及速度、选择不同的注射部位及不同造影剂,并及时了解患者的思想动态,做好心理护理。结果静脉穿刺成功率达95%,对1例重度碘过敏患者的抢救及时,处置恰当。结论做好CT增强扫描的观察及护理工作,是保证增强扫描顺利进行并获得满意结果的必要条件。  相似文献   
88.
BACKGROUND: The recurrent chronic orofacial swelling caused by orofacial granulomatosis (OFG) can cause significant cosmetic and functional problems but can be prevented if the disease is diagnosed early and promptly treated. Although the enlargement of the lips is described to be the most common presenting complaint, the clinical onset of OFG may be characterized by minor associated mucosal and neurological manifestations, making early diagnosis very difficult or, sometimes, merely presumable. PATIENTS AND METHODS: We retrospectively analyzed the clinical manifestations of 19 patients with OFG, who were examined at our institution between 1998 and 2002, in order to determine their initial manifestations and presenting symptoms. RESULTS: A total of 10 patients showed classical recurrent enlargement of the lips (six lower; four upper) as presenting symptom. In the other nine patients, OFG onset was characterized by transient unilateral facial nerve palsy (two cases), intraoral manifestations (two cases), recurrent swelling of the periorbital area (two cases), of the chin (one case), of the zygomatic area (one case), and of the cheeks (one case). CONCLUSION: Our data underlined that OFG onset could be frequently characterized by widely variable, multiform, and temporary clinical findings. Involvement of atypical sites of the orofacial region and presence of single minor manifestations may occur as presenting symptoms, often preceding the development of traditional clinical findings.  相似文献   
89.
BACKGROUND: We proposed diagnostic criteria for immune thrombocytopenic purpura (ITP) by modifying the existing guidelines for diagnosis of ITP and by incorporating laboratory tests found useful for predicting its diagnosis, for example erythrocyte count, leukocyte count, anti-GPIIb/IIIa antibody-producing B cells, platelet-associated anti-GPIIb/IIIa antibodies, percentage of reticulated platelets, and plasma thrombopoietin. OBJECTIVE AND METHODS: To validate our criteria, we conducted a multi-center prospective study involving 112 patients with thrombocytopenia and a morphologically normal peripheral blood film at the first visit. Each patient underwent a physical examination, routine laboratory tests, and specialized tests for the anti-GPIIb/IIIa antibody response and platelet turnover. RESULTS: Ninety-one patients (81%) satisfied the proposed criteria at first visit. Clinical diagnosis was made by skilled hematologists > 6 months after the first visit; ITP was diagnosed in 88 patients and non-ITP disorders in 24. The proposed criteria had 98% sensitivity, 79% specificity, a 95% positive predictive value, and a 90% negative predictive value. A relatively low specificity appears to be attributed to a few patients who had both ITP and aplastic anemia or myelodysplastic syndrome. CONCLUSIONS: Our preliminary diagnostic criteria based on ITP-associated laboratory findings were useful for the differential diagnosis of ITP, but additional evaluations and modifications will be necessary to develop criteria that can be used routinely.  相似文献   
90.
OBJECTIVES: Physicians commonly use etomidate for adult rapid-sequence intubation (RSI), but the manufacturer does not recommend its use for children under 10 years of age due to a lack of data. The authors present their experience with etomidate for pediatric RSI in order to further develop its risk-benefit profile in this age group. METHODS: Trained abstractors reviewed the medical records for all children under 10 years old who received etomidate for RSI between July 1996 and April 2001. RESULTS: 105 children, with an average age of 3 (+/-2.9) years, received a median dose of 0.32 (+/-0.12) mg/kg of etomidate. The systolic blood pressure increased an average of 4 mm Hg (95% CI = -3.3 to 9.2); the diastolic blood pressure increased 7 mm Hg (95% CI = -3.1 to 11) within 10 minutes of receiving etomidate. The heart rate increased an average of 10 beats/min (95% CI = 4.0 to 17.4). Complications included three patients who vomited within 10 minutes of etomidate administration. There were no cases of documented myoclonus, status epilepticus, or new-onset seizures. Thirty-eight patients received corticosteroids during the hospital course, none for suspected adrenal insufficiency. Three patients died, all from severe brain injury. CONCLUSIONS: In children less than 10 years old, etomidate seems to produce minimal hemodynamic changes, and appears to have a low risk of clinically important adrenal insufficiency, myoclonus, and status epilepticus. The association between etomidate and emesis (observed in less than 3% of enrolled patients) remains unclear. For clinical situations in which minimal blood pressure changes during RSI are critical, etomidate appears to have a favorable risk-benefit profile for children under 10 years old.  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