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   1937篇
  免费   99篇
  国内免费   149篇
耳鼻咽喉   23篇
儿科学   62篇
妇产科学   28篇
基础医学   134篇
口腔科学   55篇
临床医学   197篇
内科学   572篇
皮肤病学   31篇
神经病学   46篇
特种医学   317篇
外科学   121篇
综合类   57篇
预防医学   232篇
眼科学   41篇
药学   187篇
  1篇
肿瘤学   81篇
  2022年   14篇
  2021年   17篇
  2019年   18篇
  2018年   22篇
  2017年   17篇
  2016年   36篇
  2015年   26篇
  2014年   42篇
  2013年   65篇
  2012年   45篇
  2011年   56篇
  2010年   65篇
  2009年   62篇
  2008年   75篇
  2007年   171篇
  2006年   73篇
  2005年   93篇
  2004年   58篇
  2003年   39篇
  2002年   47篇
  2001年   46篇
  2000年   41篇
  1999年   32篇
  1998年   81篇
  1997年   76篇
  1996年   73篇
  1995年   63篇
  1994年   42篇
  1993年   55篇
  1992年   20篇
  1991年   25篇
  1990年   28篇
  1989年   60篇
  1988年   46篇
  1987年   47篇
  1986年   38篇
  1985年   32篇
  1984年   30篇
  1983年   17篇
  1982年   32篇
  1981年   16篇
  1980年   16篇
  1979年   11篇
  1977年   20篇
  1976年   32篇
  1975年   26篇
  1971年   19篇
  1970年   19篇
  1969年   16篇
  1968年   12篇
排序方式: 共有2185条查询结果,搜索用时 0 毫秒
101.
Massive hemorrhage is an unusual complication of tracheotomy, and the most common causes are injury to the anterior jugular veins and the thyroid isthmus, or unrecognized variations of the vascular structures, such as the arteria thyroidea ima. We present a case of high-running innominate artery that ascends until the third tracheal ring and courses horizontally anterior to the trachea in a patient with laryngeal carcinoma. If not noticed during tracheolaryngeal surgery, trauma to this vessel and subsequent hemorrhage may be fatal. In this report, the case is presented and the surgical significance of this anomaly is emphasized.  相似文献   
102.
CONTEXT: The distinction between a substance-induced psychosis and a primary psychotic disorder that co-occurs with the use of alcohol or other drugs is critical for understanding illness course and planning appropriate treatment, yet there has been little study and evaluation of the differences between these 2 diagnostic groups. OBJECTIVE: To identify key demographic, family, and clinical differences in substance-induced psychosis and primary psychotic disorders diagnosed according to DSM-IV criteria using a research diagnostic instrument for psychiatric and substance use comorbidity. DESIGN: Data on demographic, family, and clinical factors were gathered at baseline as part of a 3-year longitudinal study of early-phase psychosis and substance use comorbidity in New York, NY. SETTING: Psychiatric emergency department admissions. PARTICIPANTS: The study is based on a referred sample of 400 subjects interviewed at baseline. Participants had at least 1 psychotic symptom assessed during administration of the research protocol, had used alcohol and/or other drugs within the past 30 days, and had no psychiatric inpatient history before the past 6 months. Subject race included 43.5% black, 42.0% Hispanic, and 14.5% white or other. MAIN OUTCOME MEASURE: Psychotic disorders defined by the DSM-IV. RESULTS: Overall, 169 (44%) were diagnosed as having substance-induced psychosis and 217 (56%), as having primary psychosis. Significant differences were observed in all 3 domains. Multivariate analysis using logistic regression identified the following 3 key predictors as being greater in the substance-induced group: parental substance abuse (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.00-2.85), a diagnosis of dependence on any drug (OR, 9.41; 95% CI, 5.26-16.85), and visual hallucinations (OR, 2.13; 95% CI, 1.10-4.13). The key predictor of total positive and negative symptom score was greater in the primary psychosis group (OR, 0.96; 95% CI, 0.94-0.97). CONCLUSIONS: Differences in demographic, family, and clinical domains confirm substance-induced and primary psychotic disorders as distinct entities. Key predictors could help emergency clinicians to correctly classify early-phase psychotic disorders that co-occur with substance use.  相似文献   
103.
A case of pulmonary hyalinizing granuloma associated with posterior uveitis   总被引:2,自引:0,他引:2  
A 48-year-old male was admitted to our hospital because of abnormal pulmonary shadows and a decrease in visual acuity. He had a history of tuberculosis 20 years ago. The chest roentgenogram showed multiple pulmonary nodules throughout both lung fields. No definitive diagnosis was established either by brushing cytology or biopsy through bronchoscopy or percutaneous needle biopsy. Pathological examination of open lung biopsy specimen revealed that extensive, hyalinized lamellar collagen bundles arranged in whorls, parallel arrays. Plasma cells and lymphocytes were found between the collagen bands and germinal centers were seen at the periphery of the lesion. A definitive diagnosis of pulmonary hyalinizing granuloma was made on the basis of these histopathological findings. Although there is no established treatment for pulmonary hyalinizing granuloma, during 1 month of follow-up, posterior uveitis mildly resolved with glucocorticoid treatment and there had been a slight increase in visual acuity.  相似文献   
104.
105.
Commentary: Epidemiology: More than Etiology   总被引:1,自引:1,他引:0  
  相似文献   
106.
107.
The purpose of this study was to assess HIV-infected patients' discontinuation of their primary care. One hundred ninety-eight consecutive outpatients were interviewed on initial HIV primary care presentation, assessed after six months about their discontinuation from primary care, and had characteristics associated with discontinuation determined. Primary care was not continued in 20 percent (40/198) of the cases. Cohort characteristics included 25 percent women; 44 percent black, 28 percent white, 25 percent Hispanic; 69 percent with highest yearly income < or = $16,000; 47 percent injection drug users; and median CD4 count 285/microL. Characteristics significantly associated (p < or = 0.05) with discontinuation were higher CD4 count, less education, no history of victimization, previous jail time, and site of medical care. One-fifth of HIV-infected patients did not remain engaged in primary care after establishing this essential link to treatment.  相似文献   
108.
109.
Myoepithelial carcinoma in the nasopharynx: an unusual localization   总被引:1,自引:0,他引:1  
Myoepithelial carcinoma is an extremely rare, malignant epithelial tumor which is usually encountered in the parotid region. In this report, a myoepithelial carcinoma arising from a minor salivary gland in the nasopharynx is presented, along with a discussion of the clinical, histopathological and immunocytochemical characteristics of this rare disorder. Larger clinical series and longer follow-up periods are needed in order to establish the best therapy option for these patients.  相似文献   
110.
A retrospective review was done of 34 extremities studied between 1981 and 1985 with technetium-99m pyrophosphate scanning; 22 were subsequently amputated. Results of detailed pathologic examination or immediate postoperative examination of the resected extremity were available in 16 cases. In these cases, scanning had allowed correct prediction of the level of amputation and of the specific areas of muscle infarction in 13 cases. In the one case in which amputation was performed for infection rather than muscle necrosis, the lack of necrosis was correctly predicted with the scan. The limited results of this study indicate that the Tc-99m pyrophosphate scan allows the location of necrotic muscle to be predicted accurately and may therefore be a useful adjunct in determining the best level for ultimate amputation. Special caution is required in those cases in which muscle necrosis is due to acute causes (e.g., traumatic thrombosis) rather than chronic vascular disease.  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