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   3402篇
  免费   177篇
  国内免费   11篇
耳鼻咽喉   40篇
儿科学   195篇
妇产科学   50篇
基础医学   431篇
口腔科学   34篇
临床医学   191篇
内科学   501篇
皮肤病学   46篇
神经病学   244篇
特种医学   89篇
外科学   448篇
综合类   95篇
预防医学   193篇
眼科学   171篇
药学   448篇
中国医学   43篇
肿瘤学   371篇
  2023年   22篇
  2022年   51篇
  2021年   106篇
  2020年   55篇
  2019年   73篇
  2018年   95篇
  2017年   65篇
  2016年   98篇
  2015年   86篇
  2014年   106篇
  2013年   162篇
  2012年   252篇
  2011年   249篇
  2010年   152篇
  2009年   131篇
  2008年   177篇
  2007年   170篇
  2006年   153篇
  2005年   156篇
  2004年   140篇
  2003年   113篇
  2002年   89篇
  2001年   52篇
  2000年   66篇
  1999年   55篇
  1998年   30篇
  1997年   19篇
  1996年   23篇
  1995年   21篇
  1994年   20篇
  1993年   18篇
  1992年   45篇
  1991年   41篇
  1990年   33篇
  1989年   55篇
  1988年   44篇
  1987年   37篇
  1986年   32篇
  1985年   31篇
  1984年   28篇
  1983年   27篇
  1982年   15篇
  1981年   16篇
  1979年   34篇
  1978年   15篇
  1976年   14篇
  1974年   10篇
  1973年   15篇
  1972年   14篇
  1970年   10篇
排序方式: 共有3590条查询结果,搜索用时 31 毫秒
101.

Purpose

Very few studies have compared alumina-on-alumina ceramic and alumina-on-highly cross-linked polyethylene bearings in the same patient. The purpose of this prospective randomised study was to compare the clinical and radiographic results and the prevalence of osteolysis in cementless total hip arthroplasty using an alumina-on-alumina and alumina-on-highly cross-linked polyethylene bearings in young active patients.

Methods

We prospectively compared the results of 100 patients (200 hips) who had undergone a cementless total hip arthroplasty with an alumina-on-alumina ceramic bearing in one hip and an alumina-on-highly cross-linked polyethylene in the other. There were 66 men and 34 women with a mean age of 45.3 years (range, 21–49 years) at the time of surgery. The mean follow-up was 12.4 years (range, 11–13 years). The patients were assessed clinically and radiographically at three months, one year, and annually thereafter.

Results

Harris hip, Western Ontario and McMaster Universities Osteoarthritis Index, and University of California, Los Angeles activity scores did not show statistically significant differences between the two groups of bearings preoperatively or at the time of final follow-up. Radiographic findings of the component were not significantly different between the two groups. The mean polyethylene linear penetration was 0.031?±?0.004 mm per year. No hips in either group displayed osteolysis. The Kaplan-Meier survivorship with revision as the end point at 12.4 years was 100 % (95 % confidence interval [CI], 94–100 %) for the femoral component in both groups and 99 % (95 %CI, 93–100 %) for the acetabular component.

Conclusion

The clinical and radiographic results of using an alumina-on-alumina ceramic and alumina-on-highly cross-linked polyethylene bearings were similar.  相似文献   
102.
There is an increasing awareness for recognition of sleep disorders in India; however, there is still a huge gap in the number of people suffering from various sleep disorders, in the community versus those visiting hospital clinics for the same. Ours is a neurology services-based sleep disorders clinic, which has evolved successfully over the last decade. In this study, we aimed to evaluate the changes in referral patterns and distribution of various sleep disorders in the patients presenting to the clinic.

Materials and Methods:

This is a retrospective chart review-based study on all patients seen over an 8-year period, divided into 2 groups comprising of patients seen during the first 4 years versus those seen over the next 4 years. Only those patients who had the sleep disorder as their presenting manifestation and those who had been formally interviewed with a pre-structured questionnaire detailing about the main features of the common sleep disorders according to the ICSD-R were included. Patients, in whom the sleep disorder could be clearly attributable to another neurological or systemic disorder, were excluded. Statistical analysis was carried out to identify the differences between the two groups as regards the distribution of various sleep disorders and other clinical data.

Results:

Among 710 patients registered in the clinic, 469 were included for analysis and 222 patients formed group 1 while 247 formed group 2. The main differences observed were in the form of a clear increase in the percentage of patients with sleep-related breathing disorders, sleep-related movement disorder, and the hypersomnias on comparison of distribution over the first 4 years versus the last 4 years; while a clear decline was seen in the number of patients with insomnia and parasomnias. A 3-fold increase was observed in the number of patients in whom polysomnography was obtained.

Conclusion:

The distribution of various sleep disorders as seen in a neurology service-based sleep clinic is demonstrated in this study. Increasing referrals for sleep-disordered breathing, restless legs syndrome, and fewer referrals for insomnia and parasomnias might reflect on changing physician and patient awareness in our community.  相似文献   
103.
A facile method was developed for the synthesis of quinazolinone derivatives in a one-pot condensation reaction via in situ amine generation using ammonia as the amine source and with the formation of four new C–N bonds in good to excellent yields. With the optimised method, we synthesized a library of piperazine linked quinazoline derivatives and the synthesized compounds were evaluated for their inhibitory activity against Mycobacterium tuberculosis. The compounds 8b, 8e, 8f, 8m, 8n and 8v showed potent anti-mycobacterial activity with MIC values of 2–16 μg mL−1. All the synthesized compounds follow Lipinski''s rules for drug likeness.

A facile method was developed for the synthesis of quinazolinone derivatives in a one-pot condensation reaction via in situ amine generation using ammonia as the amine source and with the formation of four new C–N bonds in good to excellent yields.  相似文献   
104.
Bulletin of Environmental Contamination and Toxicology - The safe utilization and risk assessment of produced water (PW) from oil and gas fields for desert irrigation have received increasing...  相似文献   
105.
ObjectiveWe aimed to formulate a practical clinical treatment algorithm for Holmes tremor (HT) by reviewing currently published clinical data.Materials and MethodsWe performed a systematic review of articles discussing the management of HT published between January 1990 and December 2018. We examined data from 89 patients published across 58 studies detailing the effects of pharmacological or surgical interventions on HT severity. Clinical outcomes were measured by a continuous 1-10 ranked scale. The majority of studies addressing treatment response were case series or case reports. No randomized control studies were identified.ResultsOur review included 24 studies focusing on pharmacologic treatments of 25 HT patients and 34 studies focusing on the effect of deep brain stimulation (DBS) in 64 patients. In the medical intervention group, the most commonly used drugs were levetiracetam, trihexyphenidyl, and levodopa. In the surgically treated group, the thalamic ventralis intermedius nucleus (VIM) and globus pallidus internus (GPi) were the most common brain targets for neuromodulation. The two targets accounted for 57.8% and 32.8% of total cases, respectively. Overall, compared to the medically treated group, DBS provided greater tremor suppression (p = 0.025) and was more effective for the management of postural tremor in HT. Moreover, GPi DBS displayed greater benefit in the resting tremor component (p = 0.042) and overall tremor reduction (p = 0.022).ConclusionsThere is a highly variable response to different medical treatments in HT without randomized clinical trials available to dictate treatment decisions. A variety of medical and surgical treatment options can be considered for the management of HT. Collaborative research between different institutions and researchers are warranted and needed to improve our understanding of the pathophysiology and management of this condition. In this review, we propose a practical treatment algorithm for HT based on currently available evidence.  相似文献   
106.
107.

Background

Dopa responsive dystonia is characterized by progressive disabling dystonia, diurnal variation and a dramatic response to Levodopa.

Case characteristics

Two siblings presented with regression of motor milestones and hypertonia in lower limbs. History of diurnal variation was present in elder sibling.

Outcome

Both responded dramatically to Levodopa. The genomic DNA analysis of elder sibling revealed a novel mutation.

Message

A trial of Levodopa should be considered in a child with motor regression with diurnal variation, in the presence of extrapyramidal features.
  相似文献   
108.
Melioidosis is an infectious disease caused by gram-negative soil-dwelling bacillus Burkholderia pseudomallei. Musculoskeletal melioidosis mimics other infections both clinically and radiologically. An extensive literature review has been performed over musculoskeletal melioidosis through various search engines such as Pubmed, Embase, Medscape, Altavista and Google. Diagnosis requires a high index of clinical suspicion and is dependent on microbiological confirmation. Prompt treatment with long-term combination antibiotics in high dosages and surgical drainage of abscesses improves survival.  相似文献   
109.
110.
Purpose: Fingertip injuries are common in industrial production activities as well as in domestic work. Loss of pulp hampers daily life activities. Functional and aesthetic aspects are important in fingertip reconstruction. The bone is usually exposed along with soft tissue loss. Therefore to reconstruct the pulp flap with adequate bulk is required. Methods: We reported a case series of 12 patients with the injury over the volar aspect of distal phalanx of the index or middle finger. In all cases, laterally based thenar flap was chosen. The flap donor site was closed primarily in most of cases, while 4 patients required skin graft. The flap was detached between 2-3 weeks. Functional assessment was done using static and dynamic 2-point discrimination and range of motion at each joint. The aesthetic outcome was assessed through questionnaire. The results were analyzed using the unpaired t-test (SPSS version 21). Results: Partial necrosis occurred in 2 cases while rest of flaps survived successfully. Static 2-point discrimination ranged from 6e10 mm, mean 8.6 mm; and dynamic 2-point discrimination ranged from 8-10 mm, mean 8.9 mm. The mean satisfaction score was (4.0 ± 0.55). Conclusion: Thenar flap is a good choice for reconstruction of the finger pulp as it provides the bulk with good functional and aesthetic outcome.  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