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   9083篇
  免费   504篇
  国内免费   125篇
耳鼻咽喉   119篇
儿科学   193篇
妇产科学   197篇
基础医学   1049篇
口腔科学   178篇
临床医学   1142篇
内科学   1396篇
皮肤病学   70篇
神经病学   702篇
特种医学   278篇
外科学   749篇
综合类   770篇
现状与发展   1篇
预防医学   1680篇
眼科学   170篇
药学   531篇
  2篇
中国医学   85篇
肿瘤学   400篇
  2024年   15篇
  2023年   135篇
  2022年   245篇
  2021年   332篇
  2020年   320篇
  2019年   290篇
  2018年   274篇
  2017年   293篇
  2016年   299篇
  2015年   306篇
  2014年   554篇
  2013年   814篇
  2012年   481篇
  2011年   532篇
  2010年   400篇
  2009年   453篇
  2008年   466篇
  2007年   459篇
  2006年   348篇
  2005年   314篇
  2004年   273篇
  2003年   210篇
  2002年   194篇
  2001年   157篇
  2000年   133篇
  1999年   126篇
  1998年   118篇
  1997年   99篇
  1996年   76篇
  1995年   82篇
  1994年   74篇
  1993年   74篇
  1992年   65篇
  1991年   52篇
  1990年   48篇
  1989年   45篇
  1988年   35篇
  1987年   34篇
  1986年   57篇
  1985年   63篇
  1984年   57篇
  1983年   28篇
  1982年   48篇
  1981年   31篇
  1980年   41篇
  1979年   31篇
  1978年   25篇
  1977年   24篇
  1976年   17篇
  1974年   14篇
排序方式: 共有9712条查询结果,搜索用时 15 毫秒
91.
目的:分析桥本氏甲状腺炎(HT)在不同年龄男女性患者分布差异及相关抗体水平变化特点。方法:2014-01-01—2018-12-31五年间本院收治的HT患者共2705例,先按年龄分为儿童组(n=32)、青春期组(n=135)和成人组(n=2538),再将成人组中女性分为≤50岁组(n=1645)及>50岁组(n=519)两组,比较不同年龄组HT男女性占比差异,分析不同年龄组以及50岁前后女性甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TgAb)的水平变化。结果:在三年龄组中,HT总病例数以成人组最多,儿童组较少。各年龄组间男性、女性HT占比差异有统计学意义(P<0.01);各年龄组内女性占比均显著高于男性,尤以成人组女性占比最高(P<0.01)。三年龄组间TPOAb、TgAb水平有显著统计学意义(均P<0.01)。青春期组及成人组TPOAb水平均低于儿童组(P<0.01),成人组与青春期组TPOAb水平差异无统计学意义(P>0.05);青春期组TgAb水平低于儿童组(P<0.01),儿童组与成人组间、青春期组与成人组间TgAb水平的差异均无统计学意义(P>0.05)。≤50岁与>50岁女性的TPOAb和TgAb水平比较均无统计学差异(P>0.05)。结论:成年人(>18岁)HT明显多于非成年人,且女性占比显著高于男性。TPOAb下降可能是成人HT的内分泌影响因素之一。  相似文献   
92.
The effectiveness of DMPS (sodium 2,3-dimercaptopropane-1-sulfonate) in reducing inorganic mercury retention was studied in 2-, 6-, and 28-week-old albino rats. 203Hg was administered IP. The chelating agent DMPS was administered by IP injection at a dose of 250 mol/kg body weight three times, 1 day after 203Hg administration and at 24 h intervals thereafter. The whole body retention determined 1, 2, 3, and 6 days after 203Hg administration showed that DMPS decreased the body retention of mercury in all age groups, being about twice as effective in adult compared to suckling rats. The reduced effectiveness was due to the reduced efficacy of DMPS in reducing kidney retention in young animals. In other organs the effectiveness of DMPS was not age dependent. These and previous results obtained with different chelating agents and other metals indicate that age might be an important factor in chelation therapy in general.  相似文献   
93.
Rats were subjected to 4 h continuous or intermittent exposure to vinyl chloride (VC) at different time-weighted average concentrations (15, 50, 150, 500 and 15,000 mg/m3). Hepatic non-protein sulfhydryl content (NPSH) and excretion of thiodiglycolic acid (TdGA) in urine were determined. VC at concentrations from 50 mg/m3 to 15,000 mg/m3 caused a dose-dependent depression of NPSH, but no difference in the magnitude of this depression induced by continuous or intermittent exposure at the same average concentration of VC was noted. At average concentrations of 50 mg/m3 and 150 mg/m3, the urinary excretion of TdGA under continuous exposure did not differ from that under intermittent exposure, whereas at VC concentrations of 500 mg/m3 and 15,000 mg/m3 it was higher following continuous exposure.  相似文献   
94.
Twenty miles per hour (mph) speed limits can impact the health of the public (e.g., road safety, active travel). However, a better understanding of how individuals experience 20mph limits is required, to ensure interventions are cognisant of perceptions and potential un/intended outcomes. Focus groups (n = 9, 60 participants) to explore the Belfast 20mph intervention highlighted divergent perspectives and experiences including: 12 mechanisms (e.g., limited awareness), 15 pathways (e.g., reduced driving speed→improved liveability) and 10 public health outcomes (e.g., increased cyclist safety). Future interventions should consider un/intended outcomes and implement strategies to enhance effectiveness and mitigate harms (e.g., through training, enforcement).  相似文献   
95.
广西壮族人群血清HBsAg阳性与 ABO血型相关性研究   总被引:2,自引:0,他引:2  
目的 探讨广西壮族人群血清HBsAg与ABO血型分布之关系。方法 采用卡方(x^2)检验方法与Woolf统计方法对578例HBsAg阳性携带者血清的ABO血型分布及男女性别的关系进行系统分析。结果 男性携带者血型呈O>B>A>AB型分布,女性携带者呈O>A>B>AB型分布。A、B、O和AB血型人相对危险率分别为1.1531、1.0458、0.9238和0.7365。结论:血清HBsAg阳性携带者与ABO血型间存在一定关系且与性别有关,尤以A型血女性感染乙肝病毒的危险性更大,具有重要流行病学意义。  相似文献   
96.
目的 :研究正常人扩展高频听敏度 ,观察扩展高频听力随年龄增加的细微变化。方法 :用意大利Amplaid - 4 6 0型听力计 ,频率范围 8~ 18kHz。测试正常人 12 8人、2 5 6耳 ,17~ 5 0岁 ,男 92人 ,女 36人 ,其中17~ 2 9岁 90人 ,30~ 5 0岁 38人 ,12 5Hz~ 8kHz纯音各频率听阈≤ 2 0dBHL ,声导抗测听正常。以 5岁为一年龄段分 5组进行分析。结果 :1 正常年轻人 (17~ 2 9岁 )高频听阈总的趋势是随频率提高 ,听阈逐渐增加 ,出现率逐渐下降 ,在 14kHz以上频率更为显著 ;2 正常人 17~ 19岁、2 0~ 2 4岁、2 5~ 2 9岁、30~ 34岁、35岁以上各年龄组间 12、14、16、18kHz听阈相比差异有显著性 (P <0 0 5 ) ,随年龄增加听阈逐渐提高 ,高频听阈出现率逐渐下降 ,随频率增加各年龄组差距逐渐明显 ,14kHz以上频率最为明显。结论 :人耳的老化是一个逐渐的过程 ,随年龄增加听阈提高。频率越高受影响越明显。扩展高频纯音测听结果可反映耳蜗亚临床病理状态 ,有利于早期发现听觉感受器病变 ,可用于临床监测耳毒性听力损失和早期诊断梅尼埃病等  相似文献   
97.
PurposeThis study aimed to investigate the association between clinical factors and temporary changes in functional performance in patients undergoing hemodialysis.MethodsThis was a retrospective, longitudinal observational study conducted from 2015 to 2017. Eight-two patients undergoing hemodialysis in the outpatient clinic were enrolled. Functional performance was measured using the Karnofsky Performance Status (KPS) scale. Collected data for analysis included demographics, laboratory parameters, and KPS scale scores. All participants were grouped into a high KPS cluster and a low KPS cluster based on dynamic changes in KPS scales from 2015 to 2017.ResultsParticipants in the high KPS cluster demonstrated an approximate trend, and those in the low KPS cluster demonstrated a low pattern. By stepwise selection model analysis, age (OR 1.12, 95% CI 1.03–1.23, p = 0.011), serum BUN (OR 1.08, 95% CI 1.02–1.16, p = 0.015), calcium levels (OR 3.24, 95% CI 1.2–8.73, p = 0.02), and beta-2-microglobulin (OR > 1.0, CI >1.00-<1.01, p = 0.031) showed risk for the low KPS cluster. Male sex (OR 0.20, 95% CI 0.04–0.96, p = 0.045) and albumin level (OR 0.02, 95% CI 0–0.4, p = 0.009) showed a low risk for the low KPS cluster.ConclusionsA different trajectory pattern was observed between the high and low KPS clusters in a 3-year period. Risk factors for the low KPS cluster were age, serum BUN, calcium, and beta-2-microglobulin levels. Male sex and serum albumin levels reduced the risk for the low KPS cluster.  相似文献   
98.
99.
ObjectiveTo understand the consequences of the COVID-19 pandemic lockdown on the self-care of people living with chronic diseases and on their self-perceived health, and to identify factors that may influence the management of their disease in emergency situations.MethodA qualitative study conducted in 2020 (March and April) in Andalusia (Spain) during the COVID-19 pandemic lockdown, through virtual focus groups, using the Zoom telematics tool. Three virtual focus groups were conducted, including 34 patients from Andalusia with different chronic conditions such as arthritis, diabetes, cardiovascular disease, inflammatory bowel disease, breast cancer and fibromyalgia.ResultsPeople with chronic diseases reported effects of the lockdown in relation to their emotional experience, their coping resources, the information they received, the difficulties to manage self-care, and the contact or access to health services. They also suggested some lessons learned for the future. The need for more and better information, patient training, involving patient associations, and improving telematics access to health services are the main areas for improvement to minimize the impact of future quarantines on the self-care and the health of people with chronic diseases.ConclusionsBesides the risk of contracting COVID-19, the difficulties encountered by people with chronic diseases during the lockdown include interferences in the self-care and the health care received. Health crisis situations demand more information, training for patients and improvements in the health services accessibility for patients with chronic conditions.  相似文献   
100.
This paper empirically investigates the long-run effects of major health improvements on income growth in the United States. To isolate exogenous changes in health, the econometric model uses quasi-experimental variation in cardiovascular disease mortality across states over time. Based on data for the white population, the results show that there is a causal link between health and income per person, and they provide novel evidence that health dynamics shape life-cycle incomes. Life-cycle income profiles slope more strongly at the beginning and at the end of work life in 2000 than in 1960, indicating that age becomes a more prominent determinant of income dynamics over this period. The channels for this transformation include better health, higher educational attainment, and changing labor supply.  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