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   179337篇
  免费   10872篇
  国内免费   443篇
耳鼻咽喉   2351篇
儿科学   5732篇
妇产科学   3762篇
基础医学   24223篇
口腔科学   7765篇
临床医学   13584篇
内科学   39825篇
皮肤病学   4399篇
神经病学   15171篇
特种医学   5619篇
外国民族医学   26篇
外科学   22734篇
综合类   1472篇
现状与发展   1篇
一般理论   71篇
预防医学   18768篇
眼科学   3294篇
药学   10845篇
中国医学   695篇
肿瘤学   10315篇
  2023年   917篇
  2022年   1996篇
  2021年   3762篇
  2020年   2524篇
  2019年   3573篇
  2018年   4981篇
  2017年   3791篇
  2016年   3519篇
  2015年   4134篇
  2014年   5674篇
  2013年   7239篇
  2012年   11221篇
  2011年   11730篇
  2010年   5934篇
  2009年   5347篇
  2008年   9155篇
  2007年   9850篇
  2006年   9206篇
  2005年   9487篇
  2004年   8944篇
  2003年   8190篇
  2002年   6201篇
  2001年   5034篇
  2000年   5020篇
  1999年   4434篇
  1998年   1667篇
  1997年   1393篇
  1996年   1348篇
  1995年   1165篇
  1994年   1154篇
  1993年   1046篇
  1992年   2711篇
  1991年   2611篇
  1990年   2384篇
  1989年   2378篇
  1988年   2147篇
  1987年   1994篇
  1986年   1861篇
  1985年   1805篇
  1984年   1304篇
  1983年   1067篇
  1982年   629篇
  1981年   574篇
  1980年   552篇
  1979年   962篇
  1978年   655篇
  1977年   513篇
  1975年   574篇
  1974年   564篇
  1973年   578篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
81.
The aetiology of vitiligo has not been fully elucidated, and several hypotheses have been investigated; among them, the most explored assumes an autoimmune basis for the disease. Supporting this hypothesis is the frequent co-occurrence of autoimmune diseases with vitiligo. In addition, various genetic loci associated with vitiligo harbour key immune response genes. Our general hypothesis is that autoimmunity-associated genes participate in the control of vitiligo susceptibility. To investigate this hypothesis, we tested for association between vitiligo and genes CYP27B1, REL, TNFAIP3 and IL2/IL21, all previously related to autoimmune diseases associated with vitiligo. The study was performed using two independent population samples: a family-based discovery set (211 trios) and a replication set (131 cases/119 controls). Statistically significant association with vitiligo was detected between markers of the REL and IL2 gene in the family-based sample. Both association signals were concentrated among patients displaying autoimmune comorbidity and non-segmental vitiligo. Evidence for validation was detected for IL2 marker. Our findings suggest REL and IL2 as new vitiligo susceptibility genes and reinforce the hypothesis of a shared genetic mechanism controlling vitiligo and other autoimmune diseases.  相似文献   
82.
This study charts pathways through message resistance to enhance the persuasiveness of diabetes self-care messages. A 2 (narrative) × 2 (other-referencing) × 2 (message) × 4 (order) experiment with adult diabetics (= 58) tested whether packaging overt recommendations as a story rather than an informational argument (i.e., narrative structure) and highlighting the impact of health decisions on family and friends rather than the individual (i.e., other-referencing) can effectively attenuate psychological reactance to messages encouraging healthy diet and physical activity. Narrative and other-referencing each led to lower perceived threat to choice, less state anger and counterarguing, less negative cognitive responses, more positive attitudes toward the ad and the behaviors promoted, and greater intended compliance with message recommendations. Findings illustrate two strategies that communicators may employ in order to benefit from clear, direct health messages while avoiding the reactance they may provoke. Moreover, findings inform message design for diabetes self-care education.  相似文献   
83.
84.
Abstract

The occupational hazards and respiratory symptoms of domestic cleaners in USA are largely unknown. We conducted a cross-sectional study among 56 Hispanic female domestic cleaner on their health status and frequency of cleaning products used and tasks performed. While women used multi-use products (60.0%) and toilet bowl cleaners (51.8%) most days of the week, many (39.3%) reported not using personal protective equipment while cleaning. Itchy/watery eyes (61.8%) and itchy nose (56.4%) were the most frequently reported symptoms. A history of physician-diagnosed asthma was reported by 14.3% while 33.9% had symptoms of bronchial hyperresponsiveness (BHR). In conclusion, this vulnerable population has high prevalence of physician-diagnosis asthma and BHR symptoms and is potentially exposed to myriad occupational hazards. Further research exploring associations between products use, cleaning tasks and respiratory symptoms is warranted.  相似文献   
85.
Purpose

Robotic approaches have been steadily replacing laparoscopic approaches in metabolic and bariatric surgeries (MBS); however, their superiority has not been rigorously evaluated. The main goal of the study was to evaluate the 5-year utilization trends of robotic MBS and to compare to laparoscopic outcomes.

Methods

Retrospective analysis of 2015–2019 MBSAQIP data. Kruskal-Wallis test/Wilcoxon and Fisher’s exact/chi-square were used to compare continuous and categorical variables, respectively. Generalized linear models were used to compare surgery outcomes.

Results

The use of robotic MBS increased from 6.2% in 2015 to 13.5% in 2019 (N= 775,258). Robotic MBS patients had significantly higher age, BMI, and likelihood of 12 diseases compared to laparoscopic patients. After adjustment, robotic MBS patients showed higher 30-day interventions and 30-day readmissions alongside longer surgery time (26–38 min).

Conclusion

Robotic MBS shows higher intervention and readmission even after controlling for cofounding variables.

Graphical Abstract
  相似文献   
86.
87.
Multi-day signals, generally with duration of 2-10 days, are a prominent temporal variation type of radon (Rn) in geogas in the unsaturated zone. Rare multi-day Rn signals have been found which are characterized by: (a) a declining limb lasting up to 10 days which conforms to the radioactive decay of Rn, (b) recurs at the same location and (c) is recorded in diverse situations-volcanic and seismogenic. It suggested that a Rn blob is injected at a lower level on a steady upward flow of geogas whereby the rise and final fall of the signal are attributed to the edges of the blob while the central Rn-decay segment records the passing of the decaying blob itself. Rn-decay signals are a small subset of multi-day Rn signals which are considered as highly irregular and unusable for the understanding of geophysical processes. In difference, it is concluded that multi-day Rn signals are probably proxies of subtle geodynamic processes at upper crustal levels and are therefore significant for studying such processes.  相似文献   
88.
Aim: To examine relationships among physical growth indicators and ages of achievement of six gross motor milestones in the WHO Child Growth Standards population. Methods: Gross motor development assessments were performed longitudinally on the 816 children included in the WHO Child Growth Standards. Six milestones (sitting without support, hands-and-knees crawling, standing with assistance, walking with assistance, standing alone, walking alone) were assessed monthly from 4 until 12 mo of age and bimonthly thereafter until children could walk alone or reached 24 mo. Failure time models were used 1) to examine associations between specified ages of motor milestone achievement and attained growth z scores and 2) to quantify these relationships as delays or accelerations in ages of milestone achievement. Results: Statistically significant associations were noted between ages of achievement of sitting without support and attained weight-for-age, weight-for-length and BMI-for-age z scores. An increase of one unit z score in these indicators was associated with 3 to 6 d acceleration in the respective achievement age. Statistically significant associations also were noted between various milestone achievement ages and growth when 3- or 6-mo and birth length-for-age z scores were entered jointly in the failure time models. In these analyses, one unit z-score increase in length-for-age was associated with 1 to 3 d delay in the respective achievement age.
Conclusion: Sporadic, significant associations were observed between gross motor development and some physical growth indicators, but these were quantitatively of limited practical significance. These results suggest that, in healthy populations, the attainment of these six gross motor milestones is largely independent of variations in physical growth.  相似文献   
89.
90.
Summary We present a case of blindness and Anton’s syndrome in a psychiatric patient with late diagnosis of a giant frontal meningioma. The criteria for advanced diagnostic imaging in the psychiatric population are discussed. We conclude that MR or CT scan is indicated in psychiatric in-patients who fail to improve with standard psychiatric treatment. This strategy should be submitted to a cost-benefit analysis.  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