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   3724篇
  免费   308篇
  国内免费   7篇
耳鼻咽喉   23篇
儿科学   110篇
妇产科学   115篇
基础医学   535篇
口腔科学   48篇
临床医学   471篇
内科学   645篇
皮肤病学   58篇
神经病学   492篇
特种医学   71篇
外科学   367篇
综合类   37篇
一般理论   22篇
预防医学   409篇
眼科学   69篇
药学   282篇
中国医学   1篇
肿瘤学   284篇
  2023年   50篇
  2022年   62篇
  2021年   113篇
  2020年   75篇
  2019年   103篇
  2018年   92篇
  2017年   77篇
  2016年   96篇
  2015年   90篇
  2014年   116篇
  2013年   161篇
  2012年   219篇
  2011年   223篇
  2010年   135篇
  2009年   131篇
  2008年   196篇
  2007年   235篇
  2006年   219篇
  2005年   230篇
  2004年   185篇
  2003年   180篇
  2002年   148篇
  2001年   61篇
  2000年   43篇
  1999年   57篇
  1998年   38篇
  1997年   25篇
  1996年   24篇
  1995年   23篇
  1994年   28篇
  1993年   17篇
  1992年   33篇
  1991年   38篇
  1990年   38篇
  1989年   53篇
  1988年   43篇
  1987年   33篇
  1986年   17篇
  1985年   22篇
  1984年   28篇
  1983年   22篇
  1981年   13篇
  1980年   13篇
  1979年   21篇
  1978年   14篇
  1977年   16篇
  1975年   17篇
  1974年   19篇
  1973年   14篇
  1972年   13篇
排序方式: 共有4039条查询结果,搜索用时 15 毫秒
1.
Sixteen patients with stable chronic asthma participated in a double blind crossover study comparing the new inhaled long acting beta 2 agonist formoterol with salbutamol. Inhaled (n = 15) and oral steroid (n = 1) treatment were maintained at the same daily dose throughout the study. For four weeks the patients received either formoterol 24 micrograms twice daily or salbutamol 400 micrograms twice daily, plus additional puffs (with the same drug) when needed. Asthma symptoms, additional puffs of beta 2 agonist, peak expiratory flow (PEF), and side effects were recorded daily. During treatment with formoterol the patients used fewer additional puffs of beta 2 agonist, had better symptom scores, less disturbed sleep, more days without additional aerosol, and higher PEF both morning and evening than during salbutamol treatment. Thus formoterol 24 micrograms twice daily gave long lasting bronchodilatation and asthma symptoms were well controlled with regular twice daily administration.  相似文献   
2.
Background and objective  The purpose of this study is to assess whether Chinese children with high apnea–hypopnea index (AHI) are sleepier by a modified Epworth Sleepiness Scale (ESS). Materials and methods  Records were retrospectively reviewed. We included children who were between 3 and 12 years old, admitted for overnight polysomnogram because of suspected obstructive sleep apnea syndrome (OSAS). A modified ESS was used to assess excessive daytime sleepiness (EDS) of the children. Results  One hundred ninety-two Chinese children were included. Children with high AHI, defined as AHI > 5.0, were sleepier than children with AHI less than or equal to 5. After adjustment by age, gender, and obesity, children with high AHI remained significantly sleepier. Modified ESS was significantly correlated with AHI (rho = 0.124, 95% CI = 0.004–0.281). Modified ESS score of >8 was the best cutoff point with the sensitivity and specificity of 0.29 and 0.91, respectively. The odds ratio of children with modified ESS > 10 having high AHI was 4.231 (95%CI = 1.248 to 14.338) and children with modified ESS > 8 had the highest odds ratio, 4.295(95%CI = 1.66 to 11.1), of having high AHI. Conclusion   Chinese children with high AHI appear to be sleepier than children with low AHI. Children with suspected OSAS and high modified ESS, i.e., ESS > 8, had significantly higher odds ratio of having high AHI. Increased sleepiness is a specific but not a sensitive symptom in snoring children with high AHI. Screening for EDS in snoring children may help us identify those with high AHI and prioritize the management of those children. All authors worked and the study was carried out in Kwong Wah Hospital in Hong Kong. There was no conflict of interest and no specific source of funding for the study.  相似文献   
3.
4.
Clinical practice guidelines have been proposed to significantly reduce the gap between available scientific evidence and clinical practice. Evidence-based guidelines are also being produced at an ever-increasing pace. However, guidelines do not implement themselves, and the research to support implementation does not provide straightforward answers. What works in one setting does not necessarily work in another. In short, guideline implementation and change of practice is complex and messy. The purpose of this article is to discuss the implementation of clinical practice guidelines using the Promoting Action on Research Implementation in Health Services framework. More specifically, 3 key components are highlighted: (1) the evidence base for guideline recommendations, (2) the clinical context where guidelines are to be implemented, and (3) the nature of facilitation needed to ensure a successful change process. An overview of the literature in the field is provided, and the authors' experiences are shared, and a few recommendations are tentatively provided.  相似文献   
5.
All 170 patients (212 hips) treated between 1946 and 1992 for slipped capital femoral epiphysis (SCFE) with fixation in situ with a single device were reviewed to evaluate the incidence of further slipping of the epiphysis after primary treatment. In 154 hips, a smooth device without anchorage in the epiphysis was used and in 58, a device anchored in the epiphysis. In 3 hips, further slipping of the epiphysis occurred after primary treatment with no obvious cause. In 10 hips, an obvious cause for further slipping of the epiphysis was found. These 10 hips were re-operated due to the loss of epiphyseal grip in 6 hips, unsatisfactory placement of the device in 1, while in the remaining 3 hips, the device was removed before physeal closure. Twenty-six hips (12.3%) were re-operated because the device had lost its epiphyseal grip before physeal closure, and in 25 of these hips the device was smooth and had no anchorage in the epiphysis. The conclusion of this study is that a single device with anchorage in the epiphysis is stable enough to prevent further slipping of the epiphysis in hips with SCFE.  相似文献   
6.
7.
This study examines how acute hand injuries affect patients in their roles as spouse, caregiver, and/or worker. Qualitative data from patient interviews were used to analyze how these life roles were affected by the individuals' hand injuries. Data were extracted from interviews of three hand patients who had one or more roles of spouse, caregiver, and/or worker affected by their injury. Data were then examined and categorized for each life role by participant. Participants' views of how hand therapy affected their recovery and resumption of occupational role performance were also examined. Results showed that the participants expressed profound degrees of change in their ability to perform satisfactorily in their various life roles.  相似文献   
8.
It has been postulated that patients with chronic renal failure,even in the absence of cardiopulmonary symptoms, accumulateinterstitial pulmonary fluid, which is removed by haemodialysis.To test this hypothesis we used the indocyanine green (ICG)-heavywater double indicator dilution method to measure lung water,cardiac output, and central blood volume in relation to haemodialysis.Ten uraemic patients, without cardiopulmonary symptoms, wereinvestigated at the beginning and end, and 2 h after, a regulardialysis session. A group of 18 surgical patients about to undergoelective abdominal surgery served as controls. Despite normalgas exchange, central blood volume, and cardiac output at thestart of dialysis the mean (SD) lung water was significantlyhigher than in the control group [4.8 (0.9) compared with 3.6(0.7) ml/kg, P<0.001]. There was no correlation between weightgain between sessions of dialysis and the magnitude of lungwater at the start of dialysis. Lung water decreased (P <0.001)to the level of the control group in response to dialysis. Therewas no correlation between weight loss and reduction in lungwater induced by dialysis. In conclusion, we have verified thepresence of subclinical pulmonary oedema which was removed bydialysis in a group of patients with established renal failure.The variations in lung water cannot be explained by hydrostaticmechanisms alone.  相似文献   
9.
BACKGROUND AND OBJECTIVES: Apolipoprotein E (apoE) has been implicated in regenerative processes in the brain after trauma, as well as in the pathogenesis of Alzheimer's disease. Inheritance of a specific apo epsilon allele (apo epsilon 4) determines in part the risk and the mean age at onset of Alzheimer's disease. ApoE has been found to bind isoform specifically to beta-amyloid protein, the major component of senile plaques, and to the microtubule associated protein tau, which forms paired helical filaments and neurofibrillary tangles. The aim was to further examine the relation between apo epsilon alleles, especially apo epsilon 4, and the development of neuropathological changes associated with Alzheimer's disease. METHODS: Brains of patients with Alzheimer's disease (n = 44) and vascular dementia (n = 11) and of age matched controls (n = 29) were studied. Senile plaques and neurofibrillary tangles in the hippocampus and frontal cortex were quantified. RESULTS: No correlation was found between the number of apo epsilon 4 alleles and the number of senile plaques and neurofibrillary tangles in the hippocampus or the frontal cortex of patients with Alzheimer's disease, or vascular dementia, or control groups. No significant differences in duration or severity of dementia were found between patients with or. without the apo epsilon 4 allele. No increased frequency of apo epsilon 4 was found in vascular dementia. CONCLUSION AND COMMENT: Although the apo epsilon genotype clearly affects whether Alzheimer's disease will develop or not, the present study suggests that it has no influence on pathology or clinical intellectual status, once the dementia has manifested itself. No increased apo epsilon 4 allele frequency was found in neuropathologically diagnosed patients with vascular dementia in whom concomitant Alzheimer's disease can be excluded.  相似文献   
10.
A case of nephrotic syndrome and acute renal failure in a 74-year-old man with latent syphilis is described. A renal biopsy demonstrated focal global sclerosis in three of nine glomeruli, however, the remaining glomeruli revealed typical lesions of minimal change disease. Previous reports of renal involvement in syphilis have described membranous glomerulonephritis, mesangial and endothelial cell proliferative glomerulonephritis, and, recently, rapidly progressive glomerulonephritis. The proteinuria and renal failure resolved after penicillin therapy alone. This response strongly suggested that there was a causal relationship between the syphilis and the nephrotic syndrome. This is the first report of such a relationship.  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