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   9064篇
  免费   578篇
  国内免费   26篇
耳鼻咽喉   52篇
儿科学   288篇
妇产科学   238篇
基础医学   1001篇
口腔科学   415篇
临床医学   965篇
内科学   1668篇
皮肤病学   90篇
神经病学   825篇
特种医学   452篇
外科学   1266篇
综合类   396篇
一般理论   11篇
预防医学   943篇
眼科学   201篇
药学   465篇
中国医学   3篇
肿瘤学   389篇
  2021年   129篇
  2020年   62篇
  2019年   119篇
  2018年   130篇
  2017年   108篇
  2016年   111篇
  2015年   135篇
  2014年   175篇
  2013年   293篇
  2012年   408篇
  2011年   431篇
  2010年   239篇
  2009年   214篇
  2008年   380篇
  2007年   425篇
  2006年   412篇
  2005年   386篇
  2004年   374篇
  2003年   334篇
  2002年   346篇
  2001年   293篇
  2000年   281篇
  1999年   257篇
  1998年   122篇
  1997年   102篇
  1996年   98篇
  1995年   85篇
  1994年   90篇
  1993年   86篇
  1992年   225篇
  1991年   218篇
  1990年   239篇
  1989年   189篇
  1988年   209篇
  1987年   210篇
  1986年   193篇
  1985年   195篇
  1984年   101篇
  1983年   101篇
  1982年   73篇
  1981年   69篇
  1980年   66篇
  1979年   85篇
  1978年   83篇
  1977年   57篇
  1976年   52篇
  1974年   59篇
  1972年   59篇
  1971年   65篇
  1970年   49篇
排序方式: 共有9668条查询结果,搜索用时 8 毫秒
51.
52.
Data from the National Institute of Mental Health (NIMH) Epidemiologic Catchment Area Program, an epidemiologic survey of five communities, showed that four major disorders commonly begin in late adolescence or young adulthood. The median age at onset for anxiety disorders is 15 years; for major depressive episode, 24 years; for drug abuse or dependence, 19 years; and for alcohol abuse or dependence, 21 years. Findings also suggest that for respondents 18-30 years old, having a major depressive episode or anxiety disorder doubles the risk for later drug abuse or dependence.  相似文献   
53.
We describe a woman whose fatal post-liver transplantation cerebral edema was unexpected and of unusual pathogenesis. Her severe cerebral edema is of considerable pathophysiologic interest: 1) it developed in the setting of marked anasarca and persistent hypernatremia, and 2) although hepatic function was poor, it was not considered sufficiently deranged to induce cerebral edema. Furthermore, there was no histologic evidence of hepatic rejection or antemortem hepatic necrosis. We postulate that an impairment of the blood brain barrier in association with a degree of hepatic dysfunction insufficient by itself to cause cerebral edema permitted the brain interstitial fluid volume to increase pari passu with ECF expansion. Cytotoxic cerebral edema and vascular engorgement may also have contributed to a life-threatening increase in intracranial pressure.  相似文献   
54.
55.
The incidence of sudden death in athletes is low. Some pathologic conditions, such as hypertrophic cardiomyopathy, coronary artery anomalies, and right ventricular dysplasia may predispose to sudden death during exercise in young athletes. In older individuals, exercise may trigger terminal arrhythmias in patients with atherosclerosis. Screening programs for young individuals undertaking athletic regimens are currently recommended only for those with a suggestive clinical or family history. For older individuals, caution should be advised for patients with known or suspected atherosclerotic disease.  相似文献   
56.
OBJECTIVE: The purpose of this study was to pilot test an intervention to enhance the adherence of study participants to the hemodialysis dietary regimen. DESIGN: A single case study design was used to examine the potential effectiveness of the intervention over a 4-month period of time. SETTING: A dialysis center in southwestern Pennsylvania. PATIENTS: Of the five individuals entered into the study, one was male and four were female, four were black, and one was white. Participants were 63 to 70 years of age, and had been receiving dialysis for a median of 36 months (range, 18 to 84 months). INTERVENTION: The intervention included counseling to enhance self-efficacy, by a renal dietitian, paired with personal digital assistant-based dietary self-monitoring. Participants met twice per week with interventionists during the first 6 weeks, weekly during the second 6-week period, and biweekly in the final 4-week period. MAIN OUTCOME MEASURES: Monthly laboratory data regarding serum albumin, potassium, and phosphorus levels; Kt/V; and data on average monthly interdialytic weight gain were abstracted from the participants' medical records. C-reactive protein level was determined at baseline and at 4 months. RESULTS: Four of five study participants had an increase in serum albumin level from baseline to their final measurement, and one participant maintained a stable albumin level. Four of five participants also experienced a small increase in serum phosphorus level. Mixed results were obtained with regard to serum potassium and average monthly interdialytic weight gain. CONCLUSIONS: Because of the small sample and single case study design, caution must be used in drawing firm conclusions from this study. Data suggest that the intervention may result in improved dietary intake and improved serum albumin levels. With increased dietary intake, serum phosphorus levels may increase. Additional research is needed to determine the potential efficacy and cost-effectiveness of this intervention for improving dietary adherence.  相似文献   
57.
We present a technique aiding symmetrical accurate and atraumatic placement of the core suture during tendon repair. This technique facilitates a neat repair and avoids unnecessary contact with the tendon during the insertion of the core suture.  相似文献   
58.
OBJECTIVE: The outcome after surgical treatment of rectal cancer may be influenced by the technical difficulty of the operation, which is thought to be affected by pelvic size. The aim of this study was to examine the association between bony pelvic dimensions and CRM involvement. PATIENTS AND METHODS: All patients with primary rectal cancer between December 1999 and January 2002 were studied. Staging was performed by pelvic MRI. Nine pelvic dimensions were measured from the MR images on a workstation. Pathology reports were obtained for all patients and the mesorectal specimen was examined. Technical difficulty was assessed by circumferential resection margin (CRM) involvement. RESULTS: Of 126 patients with primary rectal cancer, 88 had staging MRI and rectal excision; there were significant differences between the sexes in all 9 pelvic dimensions (P < 0.05). In females, the interspinous diameter was significantly shorter in patients with CRM involvement compared with patients with a negative CRM. In female patients predicted to have a negative CRM, the anteroposterior diameter of the inlet, the anteroposterior diameter of the midplane and the transverse diameter of the midplane (interspinous distance) were significantly shorter in patients who actually had a positive CRM compared with those in whom the CRM was negative. In male patients, there was no correlation between pelvic dimensions and CRM status. CONCLUSIONS: In certain patients with rectal cancer, CRM positivity may be predicted from pre-operative MRI pelvic measurements. This may influence the choice of adjuvant therapy.  相似文献   
59.
60.
Wong  Joseph  Kuu  Wei-Youh  Burke  Ronald  Johnson  Robert  Wood  Ray W. 《Pharmaceutical research》1995,12(1):144-148
The primary objective of this work was to establish a method to simulate the plasma levels of cilastatin, a model drug, following an intravenous in-line delivery scheme. In-vivo data in dogs obtained from this work were used to demonstrate the validity of the proposed approach. The in-line drug delivery system consists of a drug containing device which is placed between a large volume parenteral and a patient. Numerous advantages have been identified for this automatic in-line reconstitution delivery system. The numerical convolution integral algorithm was used in this work to perform plasma profile simulation. The results indicated that the simulated cilastatin plasma profile following in-line delivery closely agreed with the in-vivo data.  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