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   64129篇
  免费   5214篇
  国内免费   1615篇
耳鼻咽喉   707篇
儿科学   995篇
妇产科学   1349篇
基础医学   9484篇
口腔科学   1608篇
临床医学   5392篇
内科学   12820篇
皮肤病学   1196篇
神经病学   4909篇
特种医学   2130篇
外国民族医学   6篇
外科学   8821篇
综合类   4189篇
现状与发展   1篇
一般理论   10篇
预防医学   4353篇
眼科学   1587篇
药学   5586篇
中国医学   811篇
肿瘤学   5004篇
  2023年   261篇
  2022年   271篇
  2021年   733篇
  2020年   483篇
  2019年   866篇
  2018年   1533篇
  2017年   1161篇
  2016年   1115篇
  2015年   1259篇
  2014年   1643篇
  2013年   2110篇
  2012年   2929篇
  2011年   2982篇
  2010年   1767篇
  2009年   1650篇
  2008年   2633篇
  2007年   2833篇
  2006年   2619篇
  2005年   2315篇
  2004年   2148篇
  2003年   2108篇
  2002年   1974篇
  2001年   4901篇
  2000年   4889篇
  1999年   4152篇
  1998年   1441篇
  1997年   1029篇
  1996年   611篇
  1995年   547篇
  1994年   505篇
  1993年   453篇
  1992年   2026篇
  1991年   1753篇
  1990年   1590篇
  1989年   1557篇
  1988年   1342篇
  1987年   1230篇
  1986年   1107篇
  1985年   932篇
  1984年   608篇
  1983年   479篇
  1982年   270篇
  1981年   206篇
  1980年   151篇
  1979年   305篇
  1978年   105篇
  1976年   91篇
  1974年   91篇
  1973年   108篇
  1972年   90篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Peng  L. Q.  Wu  X. X.  Chen  G.  Cai  H. Z.  Tang  Y. P.  Chen  Q. Y.  Chen  X. Y. 《Bulletin of experimental biology and medicine》2022,173(3):335-340
Bulletin of Experimental Biology and Medicine - This study aimed to explore the effects of Wenyang Zhenshuai granules (WZG) on the morphology of cardiomyocytes, cell viability, and the expression...  相似文献   
2.
Journal of Digital Imaging - Scoliosis is a condition of abnormal lateral spinal curvature affecting an estimated 2 to 3% of the US population, or seven million people. The Cobb angle is the...  相似文献   
3.

Objectives

Short successive periods of skeletal muscle disuse have been suggested to substantially contribute to the observed loss of skeletal muscle mass over the life span. Hospitalization of older individuals due to acute illness, injury, or major surgery generally results in a mean hospital stay of 5 to 7 days, during which the level of physical activity is strongly reduced. We hypothesized that hospitalization following elective total hip arthroplasty is accompanied by substantial leg muscle atrophy in older men and women.

Design and participants

Twenty-six older patients (75 ± 1 years) undergoing elective total hip arthroplasty participated in this observational study.

Measurements

On hospital admission and on the day of discharge, computed tomographic (CT) scans were performed to assess muscle cross-sectional area (CSA) of both legs. During surgery and on the day of hospital discharge, a skeletal muscle biopsy was taken from the m. vastus lateralis of the operated leg to assess muscle fiber type–specific CSA.

Results

An average of 5.6 ± 0.3 days of hospitalization resulted in a significant decline in quadriceps (?3.4% ± 1.0%) and thigh muscle CSA (?4.2% ± 1.1%) in the nonoperated leg (P < .05). Edema resulted in a 10.3% ± 1.7% increase in leg CSA in the operated leg (P < .05). At hospital admission, muscle fiber CSA was smaller in the type II vs type I fibers (3326 ± 253 μm2 vs 4075 ± 279 μm2, respectively; P < .05). During hospitalization, type I and II muscle fiber CSA tended to increase, likely due to edema in the operated leg (P = .10).

Conclusions

Six days of hospitalization following elective total hip arthroplasty leads to substantial leg muscle atrophy in older patients. Effective intervention strategies are warranted to prevent the loss of muscle mass induced by short periods of muscle disuse during hospitalization.  相似文献   
4.
5.
Lionfish is an invasive and predatory species with low local consumption due to a lack of culinary knowledge of its preparation. A new way to prepare lionfish was proposed to increase variety and provide added value. The aim of this study was to evaluate the effect of high power ultrasound application on the textural properties measured by the texture profile analysis, sensory attributes, and shape preference of surimi patties (rounded and square) made from lionfish. Patties were prepared using lionfish surimi processed with ultrasound (37 kHz; 150 W), sodium citrate (0.3%), sucrose (1%), and salt (2%). Ultrasound exposure increased the hardness of the patties by 35.1%, decreased cohesiveness by 89.7%, and decreased the chewiness by 49.1%. Results show that high power ultrasound showed potential as an environmentally friendly technology to create surimi as a base for patties with sensory and textural appropriateness, increasing the potential culinary applications of lionfish.  相似文献   
6.
7.
8.
Our knowledge of the radiological spectrum of myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD) is growing rapidly. An update on the radiological features of the disease, and its evolution is thus necessary. Magnetic resonance imaging (MRI) has an increasingly important role in the differential diagnosis of MOGAD particularly from aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD), and multiple sclerosis (MS). Differentiating these conditions is of prime importance because the management is different between the three inflammatory diseases, and thus could prevent further attack-related disability. Therefore, identifying the MRI features suggestive of MOGAD has diagnostic and prognostic implications. We herein review optic nerve, spinal cord and the brain MRI findings from MOGAD adult patients, and compare them to AQP4-NMOSD and MS.  相似文献   
9.

Purpose

Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.

Methods

Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.

Results

CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.

Conclusion

PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.  相似文献   
10.
The microRNA miR‐8‐3p is conserved among insects and closely involved in development and immunity, but its functions in vivo are unexplored in the red flour beetle, Tribolium castaneum. Here, we show that miR‐8‐3p was highly expressed in late larva and early adult stages, as determined by quantitative real‐time PCR. It was enriched in the fat body and cuticle in late larval tissues and abundant in the head and cuticle in early adult tissues, indicating this microRNA plays important roles during T. castaneum development. Specific inhibition of miR‐8‐3p in late larvae led to metamorphosis defects in the development of wings, eyes, legs and embryo. Moreover, a series of genes related to organism development were identified as miR‐8‐3p targets by computational prediction and microRNA–messenger RNA interaction validation, including Wingless, Eyg, Fpps and Sema‐1a. These genes were critical for the regulation of the larva‐to‐adult transition. Eyg, as a functional target of miR‐8‐3p, participates in eye development, which was further confirmed by luciferase assay and loss‐of‐function analyses. In brief, miR‐8‐3p is broadly involved in the development of wings, eyes and legs through its target genes and has extensive regulatory roles during T. castaneum development.  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