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   655篇
  免费   27篇
  国内免费   19篇
耳鼻咽喉   3篇
儿科学   32篇
妇产科学   4篇
基础医学   93篇
口腔科学   28篇
临床医学   50篇
内科学   108篇
皮肤病学   5篇
神经病学   116篇
特种医学   111篇
外科学   23篇
综合类   13篇
预防医学   39篇
眼科学   5篇
药学   26篇
中国医学   2篇
肿瘤学   43篇
  2022年   2篇
  2019年   12篇
  2018年   8篇
  2017年   7篇
  2016年   9篇
  2015年   11篇
  2014年   8篇
  2013年   24篇
  2012年   9篇
  2011年   12篇
  2010年   26篇
  2009年   27篇
  2008年   11篇
  2007年   23篇
  2006年   15篇
  2005年   14篇
  2004年   19篇
  2003年   13篇
  2002年   11篇
  2001年   7篇
  2000年   7篇
  1999年   10篇
  1998年   31篇
  1997年   33篇
  1996年   26篇
  1995年   25篇
  1994年   26篇
  1993年   20篇
  1992年   18篇
  1991年   19篇
  1990年   26篇
  1989年   27篇
  1988年   25篇
  1987年   16篇
  1986年   21篇
  1985年   25篇
  1984年   11篇
  1983年   11篇
  1982年   14篇
  1981年   10篇
  1980年   6篇
  1979年   5篇
  1978年   4篇
  1977年   3篇
  1976年   3篇
  1975年   8篇
  1973年   2篇
  1941年   1篇
排序方式: 共有701条查询结果,搜索用时 31 毫秒
31.
32.
Passive intestinal permeability in 33 newborn babies was studied using feeds containing lactulose and mannitol. Each marker is thought to pass across the gut wall by a different route; lactulose by a paracellular and mannitol by a transcellular pathway. Neither is metabolised and both are wholly and solely excreted by the kidney; urinary recovery is a measure of the intestinal uptake. Babies born before 34 weeks' gestation exhibited a higher intestinal permeability to lactulose than more mature babies, and all preterm babies showed an appreciable decline in lactulose absorption during the first week of oral feeds. Babies of 34 to 37 weeks' gestation achieved a 'mature' intestinal permeability to lactulose within four days of starting oral feeds. These findings may reflect the immaturity of the gut of the preterm baby rather than a process essential to adaptation to enteral nutrition.  相似文献   
33.
Especially in outpatient settings, dementia is still an underdiagnosed syndrome. The Micro-Mental Test has been developed as a short version of the Mini-Mental-Status Examination (MMSE). We examined the reliability and diagnostic validity of a German version (Mikro-Mental Test). We administered the MMSE and the German version of the Micro-Mental Test to 20 inpatients of a geriatric psychiatry hospital (mean age 74.8+/-8.1 years), 55 patients from a cognitive clinic (mean age 71.9+/-9.1 years), and 27 healthy older adults (mean age 68.5+/-4.1 years). Diagnoses made by an experienced psychiatrist according to ICD-10 criteria served as external criteria. The mean duration for testing with the Micro-Mental Test was 8 min, and with the MMSE 15 min. Test-retest analyses showed satisfactory reliability. With regard to sensitivity and specificity, we found comparable diagnostic validity for the MMSE and the Micro-Mental Test. We suggest that, due to its brevity and diagnostic validity, the Micro-Mental Test is a useful tool for dementia screening in an outpatient setting.  相似文献   
34.
The prevalence of dyslipidaemia in children with insulin dependent diabetes mellitus (IDDM) and its relation to glycaemic control was studied in a group of 51 diabetic children and a control population of 132 schoolchildren. The prevalence of dyslipidaemia in the fasting state was increased in the diabetic group (39%) compared with control subjects (17%). Serum cholesterol concentration alone was raised in 25% of diabetic subjects while serum cholesterol and triglycerides were raised in 14%, compared with 16% and 0.7% respectively in control subjects. Serum total cholesterol (5.1 v 4.5 mmol/l), low density lipoprotein cholesterol (3.2 v 2.6 mmol/l), non-esterified fatty acids (0.91 v 0.50 mmol/l), and triglycerides (0.94 v 0.76 mmol/l) were higher in diabetic children. Serum total cholesterol, triglycerides, and apolipoprotein (apo)B concentrations increased with worsening control, while serum high density lipoprotein cholesterol and apoA-I concentrations were unaltered. There were also positive correlations between glycated haemoglobin and total cholesterol, triglycerides, and apoB in diabetic children. Thus, abnormalities in circulating lipids are common in young subjects with IDDM but largely disappear if blood glucose concentrations are reasonably controlled.  相似文献   
35.
A total of 810 adults were examined by psychiatrists in the second stage of the Eastern Baltimore Mental Health Survey. A semistructured examination, the Standard Psychiatric Examination, was used. The relationships between obsessions and compulsions and personal characteristics, childhood behaviors, family history, and other psychopathology were evaluated. The estimated prevalence of obsessions and compulsions in this population was 1.5%. Cases were significantly more likely to report having had childhood fears, learning disabilities and a family history of alcoholism and suicidal behavior. There were significant positive relationships between scores on compulsive, borderline and histrionic personality disorder scales and the probability of obsessions and compulsions. These exploratory analyses in an epidemiologic sample may identify factors of etiologic importance in this condition.  相似文献   
36.
In a patient with primary hyperparathyroidism an attempt was made to ablate a middle mediastinal parathyroid gland by forceful staining with radiographic contrast material. The gland was stained on two separate occasions, two weeks apart. Both times the serum calcium level temporarily fell to the normal range but reverted to abnormal levels. The patient ultimately required surgery for correction of hypercalcemia. The mechanism of staining and possible reasons for failure as well as potential complications are discussed.  相似文献   
37.
Background Patients with prostate cancer with a pre-operative prostate-specific antigen (PSA) τ;15ng/ml who undergo radical retropubic prostatectomy (RRP) generally do not have a good outcome, yet may have organ-confined cancer and should be offered the option of surgery. Aim To assess the outcome of patients who underwent RRP with a pre-operative PSA ≥ 15ng/ml. Methods Thirty-four patients, mean pre-operative PSA: 25.46ng/ml (15.03–76.6) and mean Gleason score: 6.4 (5–9) were assessed. Results Two groups were identified. Group I: 41% (14/34) have no biochemical recurrence to mean follow up of 58 months (30–106). Mean PSA: 18.8ng/ml (15.03–25.84). Mean Gleason score: 6.1 (5–7). Clinical stage: T1c in 80%. No patient had seminal vesicle or lymph node involvement. Group II: 59% (20/34) have biochemical recurrence or died (3) from their disease to mean follow up of 66 months (36–98). Mean PSA: 28.9ng/ml (15.28–76.6). Mean Gleason score: 6.7 (5–9). Clinical stage: T1c in 25%. Eleven patients had seminal vesicle (8) involvement or positive lymph nodes (3) or both (2). Conclusion RRP seems feasible in patients whose pre-operative PSA is between 15 and 25ng/ml with stage T1c, Gleason score ≤ 7 and negative lymph node frozen section.  相似文献   
38.
For a subset of headache patients, an understanding of psychological antecedents and interpersonal difficulties is an important part of the headache evaluation. This subset includes patients with chronic headache, frequent headache, treatment-refractory headache, analgesic misuse problems, and serious compliance issues. Inadequate coping with stress is central to the persistence of headache in many such patients. Other patients present to the headache specialist but actually suffer from a serious comorbid psychiatric disorder, such as major depression, panic disorder, substance abuse, or personality disorder. For successful treatment of headache, it is important that these related problems be detected and either treated (as outlined here) or referred to a specialist for treatment.  相似文献   
39.
Emotional distress in patients with retinal disease   总被引:1,自引:0,他引:1  
PURPOSE: To investigate the prevalence of, and potential risk factors for, emotional distress among patients with retinal disease. DESIGN: Cross-sectional study. METHODS: Cases consisted of 86 consecutive patients at Wilmer Eye Institute Retinal Vascular Center. Fifty-one controls with normal visual acuity and no known ocular disease were frequency-matched to the cases by age, sex, and race. Subjects were interviewed using the Community Disability Scale, a functional status questionnaire, and the General Health Questionnaire, a questionnaire assessing emotional distress. RESULTS: The prevalence of probable (General Health Questionnaire score 4 or greater and less than 10) or definite (General Health Questionnaire score 10 or greater) emotional distress was 59.3% among ophthalmic patients and 2.0% among controls. There were significant relationships between emotional distress, as assessed by General Health Questionnaire score, and degree of 1) visual impairment, as assessed by weighted bilateral average logarithm of minimal angle of resolution (logMAR), and 2) functional impairment, as assessed by Community Disability Scale score (P =.001). Univariate analyses identified significant predictors of emotional distress: shorter duration of ocular disease (P =.019), worse visual acuity (P =.001), increased systemic comorbidities (P =.001), and increased functional impairment (P <.001). Multiple regression analysis demonstrates that worse visual acuity, increased systemic comorbidities, and shorter duration of ocular disease each explain over 10% of the variability in General Health Questionnaire score (r(2) = 0.15, 0.12, and 0.11, respectively). Addition of Community Disability Scale score to the regression model eliminates the significance of visual acuity and systemic comorbidities; Community Disability Scale score explains nearly 30% of the variability in emotional distress, as assessed by General Health Questionnaire score (r(2) = 0.29). CONCLUSIONS: Emotional distress is prevalent among patients with retinal disease; potential risk factors for emotional distress among such patients include shorter duration of ocular disease, worse visual acuity, increased systemic comorbidities, and increased functional impairment.  相似文献   
40.
Somatostatinomas are rare neuroendocrine tumors; they are essentially located in the pancreas and in the duodenum. The association with a neurofibromatosis type I is especially observed when the tumor is located in the ampulla of Vater. These tumors are not associated with a "somatostatin syndrome", but often present with gastrointestinal bleeding, abdominal pain and obstructive jaundice. The diagnosis is confirmed by immunohistochemical studies. The aim of this study is to report 2 cases of metastazing duodenal periampullary somatostatinomas associated with von Recklinghausen's disease and to discuss the prognosis of these tumors. Future genetic research are necessary as point out the familial feature of this association in one of our cases.  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