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   32327篇
  免费   3235篇
  国内免费   126篇
耳鼻咽喉   347篇
儿科学   1108篇
妇产科学   648篇
基础医学   4523篇
口腔科学   418篇
临床医学   3902篇
内科学   6937篇
皮肤病学   763篇
神经病学   3431篇
特种医学   1122篇
外国民族医学   1篇
外科学   4765篇
综合类   263篇
一般理论   29篇
预防医学   2829篇
眼科学   397篇
药学   1944篇
中国医学   62篇
肿瘤学   2199篇
  2023年   104篇
  2022年   89篇
  2021年   490篇
  2020年   483篇
  2019年   871篇
  2018年   974篇
  2017年   813篇
  2016年   817篇
  2015年   1017篇
  2014年   1233篇
  2013年   1731篇
  2012年   2025篇
  2011年   2236篇
  2010年   1433篇
  2009年   1310篇
  2008年   1940篇
  2007年   2012篇
  2006年   1945篇
  2005年   2015篇
  2004年   1941篇
  2003年   1949篇
  2002年   2014篇
  2001年   321篇
  2000年   256篇
  1999年   308篇
  1998年   349篇
  1997年   303篇
  1996年   234篇
  1995年   333篇
  1994年   273篇
  1993年   262篇
  1992年   204篇
  1991年   223篇
  1990年   205篇
  1989年   173篇
  1988年   183篇
  1987年   181篇
  1986年   171篇
  1985年   162篇
  1984年   173篇
  1983年   133篇
  1982年   185篇
  1981年   181篇
  1980年   157篇
  1979年   108篇
  1978年   104篇
  1977年   96篇
  1976年   83篇
  1973年   68篇
  1972年   75篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.

Chronic granulomatous disease (CGD) is an inherited immunodeficiency due to defective leukocyte NADPH responsible for recurrent infections and aberrant inflammation. Mutations in the CYBB gene are responsible for the X-linked CGD and account for approximately 70% of the cases. CGD is diagnosed during childhood in males. Female carriers may have biased X-inactivation and may present with clinical manifestations depending on the level of residual NADPH oxidase activity. We report the case of a previously asymptomatic female carrier who was diagnosed at age 67 with a skin infection with the rare fungus Paecilomyces lilacinus as the first manifestation of CGD. Dihydrorhodamine 123 (DHR) activity was below 10%. Next-generation sequencing (NGS) revealed mutations in DNMT3A, ASXL1, and STAG2 suggesting that clonal hematopoiesis could be responsible for a progressive loss of NADPH oxidase activity and the late onset of X-linked CGD in this patient. Long-term follow-up of asymptomatic carrier women seems to be essential after 50 years old.

  相似文献   
3.

Objectives

To examine the potential added value of a simple 5-item questionnaire for sarcopenia screening (SARC-F) to the Fracture Risk Assessment Tool (FRAX) for hip fracture risk prediction, in order to identify at-risk older adults for screening with dual-energy x-ray absorptiometry (DXA).

Design

A prospective cohort study.

Setting and participants

Two thousand Chinese men and 2000 Chinese women aged 65 years or older were recruited from local communities and were prospectively followed up for about 10 years.

Measures

Areal bone mineral density (BMD) of hip and lumbar spine were measured by DXA at baseline. Ten-year FRAX probability of hip fracture was calculated using the baseline risk factors. Information from the baseline questionnaire was extracted to calculate a modified SARC-F score. The independent predictive values of SARC-F and FRAX questionnaire were evaluated using multivariate survival analysis. The added predictive values of SARC-F to FRAX for pre-DXA screening were examined.

Results

During the follow-up, 63 (3.2%) men and 69 (3.5%) women had at least 1 incident hip fracture. SARC-F had an independent value of FRAX for hip fracture risk prediction, with an adjusted hazard ratio [95% confidence interval (CI)] of 1.24 (1.02, 1.52) and 1.15 (0.99, 1.13) in men and women, respectively. Compared with using FRAX, using SARC-F in conjunction with FRAX made the sensitivity for prediction rise from 58.7% to 76.2% in men and from 69.6% to 78.3% in women, with a nondecreased area under receiver operating characteristic curve of 0.67. Prescreening using FRAX in conjunction with SARC-F could save more than half of the DXA assessment than with no prescreening.

Conclusions/Implications

SARC-F is associated with a modest increase in hip fracture risk, especially in men. Conjoint evaluation for sarcopenia in addition to FRAX screening may help identify older adults at higher risk of hip fracture for more intensive screening and/or preventive interventions.  相似文献   
4.
5.
6.

Background

The purpose of the study was to evaluate the association between fetal echocardiographic measurements and the need for intervention (primary coarctation repair, staged coarctation repair, or catheter intervention) in prenatally diagnosed coarctation of the aorta.

Methods

A single-centre retrospective cohort study (2005-2015) of 107 fetuses diagnosed with suspected coarctation of the aorta in the setting of an apex-forming left ventricle and antegrade flow across the mitral and aortic valves.

Results

Median gestational age at diagnosis was 32 weeks (interquartile range, 23-35 weeks). Fifty-six (52%) did not require any neonatal intervention, 51 patients (48%) underwent a biventricular repair. In univariable analysis, an increase in ascending aorta (AAo) peak Doppler flow velocity (odds ratio [OR], 1.40 [95% confidence interval [CI], 1.05-1.91] per 20 cm/s; P = 0.03) was associated with intervention. No intervention was associated with larger isthmus size (OR, 0.23; P < 0.001), transverse arch diameter (OR, 0.23; P < 0.001), and aortic (OR, 0.72; P = 0.02), mitral (OR, 0.58; P = 0.001), and AAo (OR, 0.53; P < 0.001) z-scores. In multivariable analysis, higher peak AAo Doppler (OR, 2.51 [95% CI, 1.54-4.58] per 20 cm/s; P = 0.001) and younger gestational age at diagnosis (OR, 0.81 [95% CI, 0.70-0.93] per week; P = 0.005) were associated with intervention, whereas a higher AAo z-score (OR, 0.65 [95% CI, 0.43-0.94] per z; P = 0.029) and transverse arch dimension (OR, 0.44 [95% CI, 0.18-0.97]; P = 0.05) decreased the risk of intervention.

Conclusions

In prenatally suspected coarctation, the variables associated with intervention comprised smaller AAo and transverse arch size, earlier gestational age at diagnosis, and the additional finding of a higher peak AAo Doppler.  相似文献   
7.
Purpose: Beyond promising experimental results of sensory passive stimulations in spatial cognition disorders, some questions still remain regarding interests of these stimulations during the daily activities in neglect. The aim of this case-study was to evaluate the effects of a protocol combining left neck-muscle vibration with daily simple movements, like arm pointing movements, on perceptivo-locomotor deficits in a left spatial neglect patient.

Materials and methods: Two neuropsychological tests, one subjective straight-ahead pointing (SSA) test and one wheelchair navigation test were carried out before the combination protocol, immediately after, 1?h later, and 24?h later.

Results: The results showed a reduction of neglect spatial bias following the protocol lasted at least 24?h in all the tests (except for the SSA test due to the unavailability of the pointing device).

Conclusions: The range of improvements in the symptoms of spatial neglect suggests that this therapeutic intervention based on the combining neck-muscle vibration to voluntary arm movements could be a useful treatment for this condition. One of future investigation axes should be the development of a vibratory tool in order to facilitate the combining this proprioceptive stimulation to daily activities.

  • Implications for rehabilitation
  • Spatial neglect is a perplexing neuropsychological syndrome, affecting different domains of spatial cognition and impacting also the functional domain.

  • The treatments based on neck-muscle vibration are simple to use, non-invasive and requires none active participation of patient.

  • A therapeutic intervention based on the combining left neck-muscle vibration and voluntary arm movements in a left-spatial-neglect show a lasting reduction of symptoms especially in daily activities.

  • The combination of treatments based on the Bottom–Up approach opens innovative perspectives in rehabilitation.

  相似文献   
8.
We report a case of benign lymphoplasmacytic plaque (LPP) in a child. These asymptomatic erythematous papulonodular lesions are an emerging clinicopathological entity. Herein, we describe a previously unreported site for LPP lesions, namely, the volar wrist and the distal ipsilateral palm.  相似文献   
9.
10.
Cardiac hemangioma is rare, even more when leading to a cardiovascular collapse in a seemingly healthy newborn. A 6-day-old neonate had a tamponade caused by a basolateral hemangioma of the left ventricle. Partial surgical resection was performed. A congenital lobular capillary hemangioma was diagnosed upon histologic examination. The patient recovered completely and shows normal development at the 12-month follow-up.  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