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   304017篇
  免费   28257篇
  国内免费   7396篇
耳鼻咽喉   4057篇
儿科学   5282篇
妇产科学   4520篇
基础医学   28344篇
口腔科学   10880篇
临床医学   30025篇
内科学   29226篇
皮肤病学   3672篇
神经病学   17383篇
特种医学   8781篇
外国民族医学   22篇
外科学   26992篇
综合类   47065篇
现状与发展   17篇
一般理论   26篇
预防医学   42947篇
眼科学   3172篇
药学   32779篇
  430篇
中国医学   30819篇
肿瘤学   13231篇
  2024年   824篇
  2023年   5696篇
  2022年   8984篇
  2021年   14974篇
  2020年   14410篇
  2019年   15235篇
  2018年   13663篇
  2017年   12635篇
  2016年   11672篇
  2015年   11076篇
  2014年   20784篇
  2013年   21908篇
  2012年   18895篇
  2011年   20207篇
  2010年   15869篇
  2009年   14127篇
  2008年   13294篇
  2007年   13370篇
  2006年   11446篇
  2005年   9752篇
  2004年   8145篇
  2003年   7333篇
  2002年   5661篇
  2001年   4959篇
  2000年   4192篇
  1999年   3515篇
  1998年   3050篇
  1997年   2740篇
  1996年   2273篇
  1995年   2121篇
  1994年   1977篇
  1993年   1648篇
  1992年   1545篇
  1991年   1356篇
  1990年   1170篇
  1989年   1159篇
  1988年   1029篇
  1987年   923篇
  1986年   811篇
  1985年   2146篇
  1984年   2339篇
  1983年   1453篇
  1982年   1898篇
  1981年   1336篇
  1980年   1164篇
  1979年   1017篇
  1978年   812篇
  1977年   603篇
  1976年   764篇
  1975年   503篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
The coronavirus disease 2019 (COVID-19) pandemic has rapidly created widespread impacts on global health and the economy. Data suggest that women are less susceptible to severe illness. However, sex-disaggregated data are incomplete, leaving room for misinterpretation, and focusing only on biologic sex underestimates the gendered impact of the pandemic on women. This narrative review summarizes what is known about gender disparities during the COVID-19 pandemic and the economic, domestic, and health burdens along with overlapping vulnerabilities related to the pandemic. In addition, this review outlines recommended strategies that advocacy groups, community leaders, and policymakers should implement to mitigate the widening gender disparities related to COVID-19.  相似文献   
23.
The coronavirus 2019 pandemic has affected almost every aspect of health care delivery in the United States, and the emergency medicine system has been hit particularly hard while dealing with this public health crisis. In an unprecedented time in our history, medical systems and clinicians have been asked to be creative, flexible, and innovative, all while continuing to uphold the important standards in the US health care system. To continue providing quality services to patients during this extraordinary time, care providers, organizations, administrators, and insurers have needed to alter longstanding models and procedures to respond to the dynamics of a pandemic. The Emergency Medicine Treatment and Active Labor Act of 1986, or EMTALA, is 1 example of where these alterations have allowed health care facilities and clinicians to continue their work of caring for patients while protecting both the patients and the clinicians themselves from infectious exposures at the same time.  相似文献   
24.
25.
The effect of tobacco smoking on foot and ankle procedures is likely to be more pronounced when compared to other orthopaedic surgery. This is due to the peripheral nature of the vasculature involved. This paper reviews the current clinical evidence on the effects of smoking foot and ankle surgery. In the trauma setting, the evidence suggests that wound complications and non-unions are significantly higher in the smoking population. In the elective setting there is a significantly increased risk of non-union in ankle and hindfoot arthrodeses in smokers. In the setting of diabetes, ulceration rate in smokers is higher and there may be a higher risk of amputation.  相似文献   
26.
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored.  相似文献   
27.
《Clinical neurophysiology》2021,132(9):2003-2011
ObjectiveA large N20 and P25 of the median nerve somatosensory evoked potential (SEP) predicts short survival in amyotrophic lateral sclerosis (ALS). We investigated whether high frequency oscillations (HFOs) over N20 are enlarged and associated with survival in ALS.MethodsA total of 145 patients with ALS and 57 healthy subjects were studied. We recorded the median nerve SEP and measured the onset-to-peak amplitude of N20 (N20o-p), and peak-to-peak amplitude between N20 and P25 (N20p-P25p). We obtained early and late HFO potentials by filtering SEP between 500 and 1 kHz, and measured the peak-to-peak amplitude. We followed up patients until endpoints (death or tracheostomy) and analyzed the relationship between SEP or HFO amplitudes and survival using a Cox analysis.ResultsPatients showed larger N20o-p, N20p-P25p, and early and late HFO amplitudes than the control values. N20p-P25p was associated with survival periods (p = 0.0004), while early and late HFO amplitudes showed no significant association with survival (p = 0.4307, and p = 0.6858, respectively).ConclusionsThe HFO amplitude in ALS is increased, but does not predict survival.SignificanceThe enlarged HFOs in ALS might be a compensatory phenomenon to the hyperexcitability of the sensory cortex pyramidal neurons.  相似文献   
28.
29.
ObjectiveTo investigate the presence of symptoms of moral injury in obstetric and neonatal nurses.DesignA secondary qualitative analysis using an analytic expansion of three primary studies.SettingPostal mail and electronic surveys.ParticipantsI used three primary studies: participants in the first consisted of 78 labor and delivery nurses, participants in the second consisted of 75 nurse-midwives, and participants in the third consisted of 22 NICU nurses.MethodsI used Krippendorff’s content analysis method for qualitative data to reanalyze the three primary data sets. The categories I used in this analysis were the 10 symptoms of moral injury that are assessed by the Moral Injury Symptoms Scale–Health Professionals Version.ResultsWhen combining the three types of obstetric and neonatal participants, the top three most frequently cited symptoms of moral injury were moral concern, guilt, and self-condemnation. For participants in labor and delivery units and NICUs, moral concern was the most often described symptom, whereas for participants in midwifery it was guilt. None of the participants reported loss of meaning in their lives, loss of faith, or religious struggle. Participants who worked in NICUs did not describe any symptoms of shame or difficulty forgiving.ConclusionIn addition to the primary symptoms of moral injury, reported secondary consequences of moral injury can include depression, anxiety, anger, self-harm, and social problems. Interventions such as acceptance and commitment therapy are needed to help nurses address the potential for moral injury and repair its effects. Since the COVID-19 pandemic, now more than ever, moral injury needs to be recognized in obstetric and neonatal nurses and not just in the military population.  相似文献   
30.
《Digestive and liver disease》2022,54(11):1486-1493
BackgroundCold snare polypectomy (CSP) is a promising technique for the removal of sessile serrated polyps (SSPs) ≥ 10 mm. However, the efficacy and safety of this technique remain undetermined.AimsWe aimed to comprehensively evaluate the efficacy and safety of CSP for SSPs ≥ 10 mm.MethodsPubMed, EMBASE, Web of Science and Cochrane Library were searched up to January 2021.ResultsA total of 10 studies consisting of 1727 SSPs (range, 10–40 mm) from 1021 patients were included. The overall rates of technical success, adverse events (AEs) and residual SSPs were 100%, 0.7% and 2.9%, respectively. Subgroup analysis showed that the rates of technical success and AEs were comparable between CSP and cold endoscopic mucosal resection (EMR) (99.9% vs. 100% and 1.3% vs. 0.5%, respectively), between the proximal and distal colon (100% vs. 99.9% and 0.3% vs. 0, respectively), and between polyps of 10–19 mm and ≥20 mm (99.8% vs. 100% and 0.9% vs. 0, respectively). However, subgroup analysis showed that the rate of residual SSPs was slightly lower in CSP compared with cold EMR (1.3% vs. 3.9%), as well as in polyps of 10–19 mm compared with those ≥20 mm (3.1% vs. 4.7%).ConclusionCSP was an effective and safe technique for removing SSPs ≥ 10 mm.  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