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   1194篇
  免费   131篇
  国内免费   2篇
耳鼻咽喉   6篇
儿科学   91篇
妇产科学   7篇
基础医学   177篇
口腔科学   19篇
临床医学   138篇
内科学   183篇
皮肤病学   13篇
神经病学   55篇
特种医学   69篇
外科学   134篇
综合类   39篇
预防医学   147篇
眼科学   117篇
药学   68篇
肿瘤学   64篇
  2021年   15篇
  2019年   16篇
  2018年   24篇
  2017年   15篇
  2016年   18篇
  2015年   20篇
  2014年   39篇
  2013年   26篇
  2012年   48篇
  2011年   37篇
  2010年   31篇
  2009年   31篇
  2008年   45篇
  2007年   45篇
  2006年   45篇
  2005年   53篇
  2004年   27篇
  2003年   39篇
  2002年   33篇
  2001年   44篇
  2000年   34篇
  1999年   29篇
  1998年   26篇
  1997年   38篇
  1996年   33篇
  1995年   26篇
  1994年   31篇
  1993年   21篇
  1992年   23篇
  1991年   32篇
  1990年   18篇
  1989年   25篇
  1988年   20篇
  1987年   27篇
  1986年   22篇
  1985年   19篇
  1983年   17篇
  1982年   21篇
  1981年   13篇
  1980年   17篇
  1979年   10篇
  1978年   21篇
  1977年   17篇
  1976年   20篇
  1975年   11篇
  1974年   13篇
  1973年   9篇
  1972年   13篇
  1971年   10篇
  1970年   12篇
排序方式: 共有1327条查询结果,搜索用时 0 毫秒
61.
Gastrointestinal stromal tumors are increasingly being recognized because of their characteristic expression of KIT (CD 117). Most KIT-positive gastrointestinal stromal tumors have activating mutations in the c-kit gene. A subgroup of gastrointestinal stromal tumors are negative for KIT expression, and in these tumors, activating mutations in platelet-derived growth factor receptor α are common. Most platelet-derived growth factor receptor α mutation–positive gastrointestinal stromal tumors show an epithelioid histology and are located in the stomach. Herein, we describe an unusual gastric stromal tumor. The tumor was negative for KIT expression and the morphology did not show an epithelioid pattern but rather was composed of bland spindle cells reminiscent of a neurofibroma. Molecular analysis revealed a somatic mutation in platelet-derived growth factor receptor α exon 18 (D842F). Aside from demonstrating a new platelet-derived growth factor receptor α mutation, this case illustrates the usefulness of molecular testing as a diagnostic tool and clearly indicates the wide range of morphology that can be observed in gastrointestinal stromal tumors.  相似文献   
62.

Background  

Chronic heart failure (CHF) is the leading cause of all hospitalisations and readmissions in older people, accounting for a large proportion of developed countries' national health care expenditure. CHF can severely affect people's quality of life by reducing their independence and ability to undertake certain activities of daily living, as well as affecting their psychosocial and economic capacity. This paper reports the findings of a systematic narrative review of qualitative studies concerning people's experience of living with CHF, aiming to develop a wide-ranging understanding of what is known about the patient experience.  相似文献   
63.
64.
The burdens of increasing information overload, time constraints, and the high human and financial costs of medical error, mean that doctors cannot practice high quality evidence-based medicine without the aid of decision support systems at the point of care. The physician's role is to formulate a management plan based on clinical judgment, the patient's unique circumstances and preferences, and the best available evidence. Clineguide is a clinical knowledge system that will integrate into the workflow to improve patient outcomes, reduce variability of care, and promote efficiency in the health care process. This article discusses some of the issues surrounding the provision of rapid, accurate, and accessible information to health care professionals.  相似文献   
65.
66.
OBJECTIVE: To describe initial testing of the Assessment of Chronic Illness Care (ACIC), a practical quality-improvement tool to help organizations evaluate the strengths and weaknesses of their delivery of care for chronic illness in six areas: community linkages, self-management support, decision support, delivery system design, information systems, and organization of care. DATA SOURCES: (1) Pre-post, self-report ACIC data from organizational teams enrolled in 13-month quality-improvement collaboratives focused on care for chronic illness; (2) independent faculty ratings of team progress at the end of collaborative. STUDY DESIGN: Teams completed the ACIC at the beginning and end of the collaborative using a consensus format that produced average ratings of their system's approach to delivering care for the targeted chronic condition. Average ACIC subscale scores (ranging from 0 to 11, with 11 representing optimal care) for teams across all four collaboratives were obtained to indicate how teams rated their care for chronic illness before beginning improvement work. Paired t-tests were used to evaluate the sensitivity. of the ACIC to detect system improvements for teams in two (of four) collaboratives focused on care for diabetes and congestive heart failure (CHF). Pearson correlations between the ACIC subscale scores and a faculty rating of team performance were also obtained. RESULTS: Average baseline scores across all teams enrolled at the beginning of the collaboratives ranged from 4.36 (information systems) to 6.42 (organization of care), indicating basic to good care for chronic illness. All six ACIC subscale scores were responsive to system improvements diabetes and CHF teams made over the course of the collaboratives. The most substantial improvements were seen in decision support, delivery system design, and information systems. CHF teams had particularly high scores in self-management support at the completion of the collaborative. Pearson correlations between the ACIC subscales and the faculty rating ranged from .28 to .52. CONCLUSION: These results and feedback from teams suggest that the ACIC is responsive to health care quality-improvement efforts and may be a useful tool to guide quality improvement in chronic illness care and to track progress over time.  相似文献   
67.
68.
69.
Three hundred and ninety-six babies born in Sheffield between 1982 and 1990 identified as being at "very high risk" of unexpected infant death by means of a scoring system, received an intensive programme of health care including a case discussion between a paediatrician, the GP and the health visitor held in the family doctor's surgery, weekly visits from the health visitor and informal hospital admission. Significantly fewer sudden unexpected infant deaths occurred in this group than were expected by logistic regression anlysis or occurred in the best available control group with comparable scores ( p = 0.024). Problems in evaluation include identification of an adequate control population, ethical difficulties in introducing a controlled study when the programme is already perceived as effective, and the calculation of "expected death rates". The results of this study indicate that very energetic programmes of intervention may prevent some deaths in vulnerable infants.  相似文献   
70.
To determine the outcome of congenital lung abnormalities, data were collected retrospectively between January 1991 and December 1996 on any foetus found to have a lung lesion on antenatal ultrasound. A total of 23 foetuses had lung lesions on antenatal ultrasound. In two foetuses the antenatal ultrasound showed bilateral enlarged "bright" echogenic lungs with evidence of hydrops. Both pregnancies were terminated and tracheal atresia was confirmed. In 15 foetuses the antenatal ultrasound appearance was of a unilateral "bright" echogenic lung. There was one case of bronchial atresia and two cases of congenital lobar emphysema, which all had surgery. In nine cases there was a reduction in the size of the lesion on serial antenatal ultrasounds and no lesion was detected after birth. In three cases a small lesion was present after birth on chest radiography. In six foetuses the antenatal ultrasound appearance was of unilateral cystic or mixed cystic and echogenic lung lesions. Two pregnancies were terminated; both had congenital cystic adenomatoid malformation. Four pregnancies were continued and three infants had surgery soon after birth and were confirmed to have had congenital cystic adenomatoid malformation. One infant has been managed conservatively. In conclusion, a definitive diagnosis cannot usually be made antenatally. A large lesion on initial scan does not necessarily predict a poor outcome. The natural history of small asymptomatic postnatal lesions is unknown and a long-term prospective study is needed to determine the outcome of these lesions.  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