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   1003篇
  免费   358篇
  国内免费   12篇
耳鼻咽喉   4篇
儿科学   27篇
妇产科学   94篇
基础医学   48篇
口腔科学   5篇
临床医学   704篇
内科学   151篇
皮肤病学   11篇
神经病学   105篇
特种医学   45篇
外科学   37篇
综合类   18篇
预防医学   73篇
眼科学   1篇
药学   18篇
中国医学   1篇
肿瘤学   31篇
  2023年   3篇
  2022年   5篇
  2021年   13篇
  2020年   7篇
  2019年   17篇
  2018年   72篇
  2017年   100篇
  2016年   116篇
  2015年   103篇
  2014年   93篇
  2013年   118篇
  2012年   54篇
  2011年   57篇
  2010年   72篇
  2009年   95篇
  2008年   73篇
  2007年   63篇
  2006年   48篇
  2005年   36篇
  2004年   44篇
  2003年   15篇
  2002年   10篇
  2001年   11篇
  2000年   8篇
  1999年   8篇
  1998年   14篇
  1997年   19篇
  1996年   18篇
  1995年   10篇
  1994年   9篇
  1993年   8篇
  1992年   3篇
  1991年   1篇
  1990年   4篇
  1989年   5篇
  1988年   5篇
  1987年   7篇
  1986年   2篇
  1985年   8篇
  1984年   4篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1980年   2篇
  1978年   2篇
  1977年   2篇
  1975年   1篇
  1970年   1篇
排序方式: 共有1373条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
In 1977 Wijngaarden et al. reported a Dutch family with a congenital myopathy characterized by external ophthalmoplegia and a remarkable histological feature, focal loss of cross-striations. A small number of other families with similar clinical and pathological features led to the consideration of this congenital myopathy as a distinct entity. Here we present more than 30 years of follow-up from the Dutch family and report recently identified compound heterozygous mutations in the skeletal muscle ryanodine receptor (RYR1) gene, c.10627-2A>G and p.Arg3539His (c.10616G>A). Focal loss of cross-striations on muscle biopsy is another histopathological feature that should raise the possibility of RYR1 involvement.  相似文献   
55.

Background

Effects of different sources of medical uncertainty on people’s health-related cognitions, emotions, and decision making have yet to be systematically examined.

Purpose

The aim of this study is to examine how uncertainties arising from different sources are associated with decision making regarding stem cell transplantation in Fanconi anemia, a rare, inherited bone marrow failure syndrome that typically presents during childhood.

Methods

Data were collected through a cross-sectional survey of 178 parents of 126 Fanconi anemia patients.

Results

Two distinct sources of uncertainty were associated with decision outcomes: probability was associated with a lower likelihood of choosing stem cell transplantation, and ambiguity due to conflicting expert opinions was associated with greater decision-making difficulty. Concern about transplantation may mediate these associations.

Conclusions

Different sources of uncertainty have different effects on Fanconi anemia treatment decisions, which may be mediated by parents’ emotional reactions. Further research is needed to elucidate these effects and help Fanconi anemia families cope with uncertainty.  相似文献   
56.
The objective of this study was to compare isoflurane with a combination of dexmedetomidine and ketamine, administered intramuscularly, for anesthesia in chinchillas (Chinchilla lanigera). In a prospective, complete crossover study, adult chinchillas (n = 8; age, 2 to 5 y) were anesthetized with a combination of dexmedetomidine (0.015 mg/kg IM) and ketamine (4 mg/kg IM). Atipamezole (0.15 mg/kg) was injected subcutaneously 45 min after dexmedetomidine–ketamine administration. For comparison, anesthesia also was induced and maintained with isoflurane in 100% oxygen, delivered by facemask. Anesthetic and physiologic parameters were recorded during each anesthesia, including various reflexes, heart rate, respiratory rate, body temperature, and SpO2. Food intake, fecal output, and body weight were recorded daily for 6 d after each anesthetic trial. Induction time, heart rate, respiratory rate, and body temperature did not differ significantly between the 2 anesthetic protocols. Recovery times were shorter and SpO2 was higher in animals that received isoflurane delivered in 100% oxygen. Food intake and fecal output were reduced in the dexmedetomidine–ketamine group for as long as 3 d after anesthesia, whereas isoflurane had no signifcant effect on food intake or fecal output. Both anesthetic protocols provided effective anesthesia in chinchillas. However, when anesthetized with dexmedetomidine–ketamine, chinchillas received room air and became hypoxemic. Future studies are needed to evaluate the effect of oxygen supplementation on anesthetic recovery and on the recovery of food intake and fecal output in chinchillas.Abbreviation: DK, dexmedetomidine–ketamineChinchillas are used extensively in research to study otitis media, hearing loss, and ototoxicity.1,11,19,25 In addition, chinchillas are becoming increasingly popular as companion animals and, therefore, are more frequently presented for veterinary care. Common diseases of chinchillas include dental disease, gastrointestinal disorders, and ocular disorders.13,14 Chemical immobilization is often required to perform diagnostic (for example, radiography, CT), therapeutic, or experimental procedures.3,5,7,21 Research regarding the efficacy and safety of anesthetic protocols in chinchillas is limited and currently recommended protocols rely largely on extrapolation from other species or anecdotal reports.13,21,27Isoflurane is used routinely in chinchillas for the induction and maintenance of anesthesia. A study investigating the echocardiographic effects of isoflurane in chinchillas found significant effects on several echocardiographic parameters, but no complications or other side effects were reported.12 Isoflurane typically is delivered by facemask to chinchillas, given that endotracheal intubation is technically challenging and therefore not performed routinely.10,21 However, using a facemask increases the risk of exposure of the veterinary staff to waste gases, which is a significant occupational health concern.20,23 Therefore, alternative anesthetic protocols that reduce waste-gas exposure are desired, such as exclusively using injectable anesthetic drugs for induction and maintenance of anesthesia. Intravascular access is challenging to obtain in conscious chinchillas, and thus parenteral, nonvascular protocols provide the most accommodating route for anesthesia induction and maintenance.14 Only one study in chinchillas has investigated the effects of various injectable anesthetics: a combination of medetomidine (0.06 mg/kg) and ketamine (5 mg/kg) was compared with other parenteral protocols.14 Although anesthesia was successful with this protocol, the authors reported respiratory and cardiac depression in the animals. Furthermore, although atipamezole is commonly administered in clinical and research settings to promote rapid recovery and prevent complications, such as hypothermia, it was not used in the cited study.14To our knowledge, no studies have been published that assess the effects of anesthetic protocols on recovery of food intake and fecal output in chinchillas. The objective of this study was to compare the anesthesia induced in chinchillas by using either dexmedetomidine and ketamine or isoflurane and to evaluate the effects of both anesthetic protocols on subsequent food intake, fecal output, and body weight.  相似文献   
57.
PROBLEM: Little is known about the effectiveness of a comprehensive psychoeducational intervention on depression, self-esteem, and parenting attitudes/beliefs of at-risk pregnant and parenting adolescents. METHODS: Adolescents (N = 41) attending either a residential treatment facility (RTF) or a rural alternative school (RAS) participated in a psychoeducational parenting group using Bavolek's Nurturing Program during Phase I. Phase II included health promotion issues, infant massage, and CPR. FINDINGS: Using the Parenting Semantic Differential and the AAPI-2, there was significant improvement in parenting attitudes and beliefs. No significant change was found in self-esteem. CONCLUSIONS: A comprehensive psychoeducational parenting group can be effective in changing parenting attitudes and beliefs, which suggests an ultimate improvement in health promotion and disease prevention in adolescent women and their children.  相似文献   
58.
59.

Purpose of Review

Endoscopic management of infected necrotizing pancreatitis has evolved rapidly over the past years and there have been interesting innovations in this field. This review provides an update on the most recently published literature regarding endoscopic management of infected necrotizing pancreatitis.

Recent Findings

A recent randomized trial demonstrated no difference in mortality and major morbidity between endoscopic and surgical step-up treatment of infected necrotizing pancreatitis. However, endoscopic therapy resulted in shorter hospital stay and less pancreatic fistulas. Various innovations have been investigated with the aim to further optimize endoscopic therapy, in particular lumen-apposing metal stents. While major stent-related complications were also reported, findings from recent studies indicated that their use was associated with higher resolution rates of walled-off necrosis compared to double-pigtail stents. Other innovations, such as the multiple gateway technique and dual-modality mode, can be considered for treatment of particular cases. Furthermore, research suggests that irrigation of walled-off necrosis can be performed by using a nasocystic tube and discontinuation of proton-pump inhibitors may be considered.

Summary

Endoscopic treatment should be the preferred treatment modality in patients with infected necrotizing pancreatitis who are eligible for endoscopic drainage. Although data suggests that lumen-apposing metal stents are superior to double-pigtail stents, prospective multicenter studies focusing on safety as well as long-term follow-up are first needed.
  相似文献   
60.
Stakeholders engaged in funding health programs and investing in human capital are concerned that their investments lead to beneficial long-term outcomes and do not fade from existence when funding streams dry up. However, dissemination and implementation researchers often pay little attention to what happens after programs are implemented. An essential function of the public health nurse operating at the executive management or leadership level is to evaluate overall effectiveness, quality, and sustainability of programs and to design systems-level quality initiatives and evaluation plans that foster program sustainability. This article applies a conceptual framework for sustainability to an oral health program serving persons experiencing homelessness, exploring the essential programmatic, community, and organizational factors that have positively impacted the long-term sustainability of the program. Lessons learned from a model program that has thrived in a political and economic resource poor climate may assist the public health nurse in planning and developing health programs that can withstand the test of time even in the most challenging of circumstances.  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