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   483360篇
  免费   29912篇
  国内免费   7276篇
耳鼻咽喉   4904篇
儿科学   13543篇
妇产科学   15403篇
基础医学   60479篇
口腔科学   12385篇
临床医学   48503篇
内科学   87162篇
皮肤病学   10080篇
神经病学   39920篇
特种医学   19615篇
外国民族医学   24篇
外科学   64282篇
综合类   23819篇
现状与发展   46篇
一般理论   300篇
预防医学   30654篇
眼科学   9400篇
药学   32049篇
  106篇
中国医学   19226篇
肿瘤学   28648篇
  2023年   14801篇
  2022年   21579篇
  2021年   25314篇
  2020年   24745篇
  2019年   16029篇
  2018年   16123篇
  2017年   16433篇
  2016年   16934篇
  2015年   18354篇
  2014年   31798篇
  2013年   28242篇
  2012年   26204篇
  2011年   25221篇
  2010年   23621篇
  2009年   21057篇
  2008年   17282篇
  2007年   18382篇
  2006年   16033篇
  2005年   13688篇
  2004年   11890篇
  2003年   10933篇
  2002年   10468篇
  2001年   9988篇
  2000年   9669篇
  1999年   8930篇
  1998年   4705篇
  1997年   3713篇
  1996年   3762篇
  1995年   3468篇
  1994年   2722篇
  1993年   2403篇
  1992年   6065篇
  1991年   5715篇
  1990年   5653篇
  1989年   4817篇
  1988年   4724篇
  1987年   2100篇
  1986年   751篇
  1985年   1288篇
  1984年   1406篇
  1983年   1140篇
  1982年   1121篇
  1981年   1053篇
  1980年   984篇
  1979年   956篇
  1978年   873篇
  1977年   725篇
  1976年   680篇
  1974年   710篇
  1973年   639篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
95.
96.
Autoantibodies against 3?hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and the signal recognition particle (SRP) are representative antibodies causing immune-mediated necrotizing myopathies (IMNM), called as anti-HMGCR and anti-SRP myopathies, respectively. Here, we analyzed the differences in routine blood test results between 56 anti-HMGCR and 77 anti-SRP myopathy patients. A higher alanine transaminase (ALT) level and a lower aspartate transaminase (AST)/ALT ratio were observed in anti-HMGCR myopathy patients [ALT, 265.7 ± 213.3 U/L (mean ± standard deviation); AST/ALT ratio, 0.88 ± 0.32] than in anti-SRP-myopathy patients (ALT, 179.3 ± 111.2 U/L, p < 0.05; AST/ALT ratio, 1.28 ± 0.40, p < 0.01). In the active phase, anti-HMGCR myopathy often showed ALT predominance, whereas anti-SRP myopathy often showed AST predominance. In addition, there were differences in erythrocyte sedimentation rate (ESR), total cholesterol (TChol) level, and high-density lipoprotein (HDL) level between anti-HMGCR and anti-SRP myopathies (ESR: HMGCR, 24.4 ± 20.8 mm/1 h; SRP, 35.7 ± 26.7 mm/1 h, p = 0.0334; TChol: HMGCR, 226.7 ± 36.6 mg/dL; SRP, 207.6 ± 40.8 mg/dL, p = 0.0163; HDL: HMGCR, 58.4 ± 13.9 mg/dL; SRP, 46.2 ± 17.3 mg/dL, p < 0.01). Additional studies on the differences in routine blood test results may further reveal the pathomechanisms of IMNM.  相似文献   
97.
BackgroundOlder adults benefit most from engaging in higher-intensity physical activity, which is often determined using step rate thresholds. Fixed step rate thresholds that correspond to moderate (MPA) and vigorous-intensity physical activity (VPA) have been developed for heuristic activity promotion. The activPAL monitor uses step rate thresholds to determine activity intensity. Stepping thresholds may also vary based on body mass index (BMI) or aerobic fitness level in older adults. Despite the various thresholds used in the literature, it is unclear whether they produce similar outcomes.Research QuestionHow does time spent in physical activity intensities compare between different step rate thresholds in older adults?MethodsThirty-eight participants (24♀; 67 ± 4 years; BMI: 26.6 ± 4.4 kg/m2) wore an activPAL monitor 24-hr/day for up to 7-d (total: 205-d). Aerobic fitness (V̇O2max: 23 ± 8 ml/kg/min) was determined via indirect calorimetry during a maximal, graded cycling test. Time spent in each intensity category (light-physical-activity [LPA], MPA, VPA) was determined using the fixed (MPA/VPA) 100/130, 110/130, and activPAL step rate thresholds (74/212), as well as BMI-adjusted absolute (108.5 ± 2.5/134.0 ± 4.8) and BMI-adjusted relative (40%/60% V̇O2max; 111.4 ± 14.7/132.0 ± 19.0) cut-offs. Times spent in each intensity category were compared between methods.ResultsThe activPAL and 100/130 thresholds yielded less LPA and more MPA than all other methods. The activPAL had no time spent in VPA at all. The BMI-adjusted absolute and relative thresholds produced statistically equivalent time in LPA and MPA (via equivalence testing), but not VPA. No two methods yielded similar time spent in LPA, MPA, or VPA.SignificanceThe choice of step rate threshold has a major impact on physical activity intensity outcomes in older adults. Inherently, strategies that adjust for older adults’ body size and/or aerobic fitness level provide a more individualized data processing strategy than fixed thresholds that assume the same threshold for all older adults  相似文献   
98.
99.
《Ticks and Tick》2022,13(3):101934
Anaplasmosis is a tick-transmitted disease due to several species of the genus Anaplasma. In 2019, we demonstrated the presence of Anaplasma capra in two deer species at a zoological park in mainland France. As we suspected its presence in Corsica, we surveyed 11 geographically distant sheep or goat farms. Using molecular tools such as nested PCR targeting 16S ribosomal RNA (rRNA), citrate synthase (gltA) and heat-shock protein (groEL) genes, we detected the presence of A. capra on 5/11 farms, in 26/108 blood samples (24%), in sheep as well as in goats. Genotyping and phylogenetic analysis of A. capra revealed that isolates from Corsica island grouped closely with A. capra isolates reported in red deer and swamp deer from a zoological reserve in mainland France, as well as in roe deer from Spain, in a separate and well supported clade within A. capra clade II. This third report of the tick-borne bacterium A. capra in Europe suggests a potentially larger presence of this pathogen on the European continent, on domestic, native as well as wild ruminants, a broad host range already described in Asian countries for this species.  相似文献   
100.
BackgroundOne in two people with multiple sclerosis (PwMS) will fall in a three-month period. Predicting which patients will fall remains a challenge for clinicians. Standardized functional assessments provide insight into balance deficits and fall risk but their use has been limited to supervised visits.Research questionThe study aim was to characterize unsupervised 30-second chair stand test (30CST) performance using accelerometer-derived metrics and assess its ability to classify fall status in PwMS compared to supervised 30CST.MethodsThirty-seven PwMS (21 fallers) performed instrumented supervised and unsupervised 30CSTs with a single wearable sensor on the thigh. In unsupervised conditions, participants performed bi-hourly 30CSTs and rated their balance confidence and fatigue over 48-hours. ROC analysis was used to classify fall status for 30CST performance.ResultsNon-fallers (p = 0.02) but not fallers (p = 0.23) differed in their average unsupervised 30CST performance (repetitions) compared to their supervised performance. The unsupervised maximum number of 30CST repetitions performed optimized ROC classification AUC (0.79), accuracy (78.4%) and specificity (90.0%) for fall status with an optimal cutoff of 17 repetitions.SignificanceBrief durations of instrumented unsupervised monitoring as an adjunct to routine clinical assessments could improve the ability for predicting fall risk and fluctuations in functional mobility in PwMS.  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