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   7868篇
  免费   513篇
  国内免费   52篇
耳鼻咽喉   71篇
儿科学   251篇
妇产科学   137篇
基础医学   884篇
口腔科学   277篇
临床医学   688篇
内科学   1865篇
皮肤病学   188篇
神经病学   435篇
特种医学   181篇
外国民族医学   4篇
外科学   1060篇
综合类   243篇
一般理论   4篇
预防医学   622篇
眼科学   228篇
药学   737篇
中国医学   96篇
肿瘤学   462篇
  2023年   117篇
  2022年   249篇
  2021年   411篇
  2020年   250篇
  2019年   316篇
  2018年   332篇
  2017年   252篇
  2016年   294篇
  2015年   311篇
  2014年   403篇
  2013年   463篇
  2012年   700篇
  2011年   734篇
  2010年   361篇
  2009年   295篇
  2008年   466篇
  2007年   416篇
  2006年   353篇
  2005年   328篇
  2004年   256篇
  2003年   207篇
  2002年   189篇
  2001年   35篇
  2000年   36篇
  1999年   45篇
  1998年   41篇
  1997年   29篇
  1996年   32篇
  1995年   28篇
  1994年   27篇
  1993年   28篇
  1992年   31篇
  1991年   25篇
  1990年   33篇
  1989年   38篇
  1988年   19篇
  1987年   38篇
  1986年   29篇
  1985年   15篇
  1984年   14篇
  1983年   21篇
  1982年   18篇
  1981年   18篇
  1980年   13篇
  1979年   15篇
  1978年   8篇
  1977年   10篇
  1974年   13篇
  1973年   8篇
  1971年   8篇
排序方式: 共有8433条查询结果,搜索用时 15 毫秒
21.
Older individuals are more vulnerable to severe coronavirus disease 2019 and medical complications. Vaccination stands as an efficient and safe vanguard against infection. However, negative attitudes and perceptions pertaining to available vaccines might hinder community inoculation. The aim of this study was to assess vaccine hesitancy and its psychosocial determinants among the elderly in Qatar.We conducted a cross-sectional study between October 15 and November 15, 2020, using a composite online survey including the Vaccine Attitudes Examination Scale in addition to questions on sociodemographic correlates and the role of healthcare professionals.The vaccine hesitancy rate was 19.5%. The main reasons for willingness to vaccinate included understanding the nature of disease and role of vaccination, in addition to information provided by physicians. Fears mainly centered around vaccine safety. Vaccine hesitators were more likely to be non-Qatari and having received the influenza vaccine at least once. Gender, marital status, socioeconomic status, educational level, and having completed childhood vaccinations were not associated with vaccine hesitancy.Efforts should be directed toward raising awareness of vaccine efficacy and safety profiles. Physicians should additionally be educated about their pivotal role in advocating vaccine acceptance. We recommend reassessing vaccine hesitancy and its associated factors following a year of campaigning and vaccine administration to identify and target vulnerable groups.  相似文献   
22.
Nor-pseudoephedrine, one of the active ingredients of khat (Catha edulis), was found to be excreted in breast-milk in several lactating women who were chewing the leaves of the shrub according to the local customs. The compound could be traced in the urine of one breast-fed infant. It is concluded that the use of khat during lactation should be discouraged until further research has clearly elucidated the potential health hazards.  相似文献   
23.
The Teleprimary Care—Oral Health Clinical Information System (TPC-OHCIS) is an updated electronic medical record (EMR) that has been applied in Malaysian primary healthcare. Recognizing the level of patient satisfaction following EMR implementation is crucial for assessing the performance of health care services. Hence, the main objective of this study was to compare the level of patient satisfaction between EMR-based clinics and paper-based clinics.The study was a quasi-experimental design that used a control group and was conducted among patients in 14 public primary healthcare facilities in the Seremban district of Malaysia from May 10, to June 30, 2021. Patient satisfaction was assessed using the validated Short-Form Patient Satisfaction Questionnaire, which consisted of 7 subscales. All data were analyzed using the IBM Statistical Package for Social Sciences version 21.A total of 321 patients consented to participate in this study, and 48.9% of them were from EMR clinics. The mean score for the communication subscale was the highest at 4.08 and 3.96 at EMR-adopted clinics and paper-based record clinics. There were significant differences in general satisfaction and communication subscales, with higher patient satisfaction found in clinics using EMR.With the utilization of EMR, patient satisfaction and communication in delivering healthcare services have improved.  相似文献   
24.
Currently, the energy crisis is a hot topic for researchers because we are facing serious problems due to overpopulation and natural energy sources are vanishing day-by-day. To overcome the energy crisis, biofuel production from non-edible plant seeds is the best solution for the present era. In the present study, we select the non-edible seeds of Acacia farnesiana for biofuel production from different areas of Pakistan with better oil production results. Different kinds of analytical method, like the American Standard for Testing and Materials and techniques like Fourier transform infra-red spectroscopy, nuclear magnetic resonance spectroscopy, gas chromatography, and inductively coupled plasma optical emission spectrometry, were used to evaluate the chemical compositions. The maximum oil extraction rate (23%) was produced by petroleum ether. Potassium hydroxide exhibited the best conversion result of 96% fatty acid methyl ester. The transesterification method was used for the preparation of fatty acid methyl ester (96%) using potassium hydroxide and methanol. The viscosity and density of Acacia farnesiana seed oil biodiesel was comparable to American Standard for Testing Material biodiesel standards. By using gas chromatography-mass spectrometry, five fatty acids were detected comprising palmitic acid (6.85%), stearic acid (2.36%), oleic acid (12.13%), linoleic acid (46.85%), and α-linolenic acid (1.23%). This study concludes that Acacia farnesiana seed oil biodiesel could be an intriguing raw material for yielding Acacia farnesiana seed oil methyl ester as an alternative fuel source.

Currently, the energy crisis is a hot topic for researchers because we are facing serious problems due to overpopulation and natural energy sources are vanishing day-by-day.  相似文献   
25.
[Purpose] This study aimed to determine the effect of delayed visual feedback on the center of pressure and sitting balance in patients with stroke. [Participants and Methods] This was a single-blinded, randomized crossover trial. The duration of each intervention in real-time visual feedback and delayed visual feedback conditions while sitting on the platform was five days. We measured the center of pressure, function in sitting test, and functional independence measure for physiotherapy assessment. [Results] Twenty patients with stroke were included in this study. The delayed visual feedback condition improved the center of pressure for lateral distance, function in sitting test, and functional independence measure. The lateral center of pressure deviation increased significantly after 500 ms of intervention. The function in sitting test evaluated the interaction between pre- and post-training, and these conditions revealed that timing and condition factors contributed to the improvement. Sitting balance training affected the functional independence measure. [Conclusion] Sensory-motor and cognitive learning was facilitated through balance training with delayed visual feedback, and the internal model was updated with the efference copy of error correction. Sensory-motor feedback to visual stimulation can improve postural control, balance, and activities of daily living.  相似文献   
26.
IntroductionBronchoscopic lung volume reduction (BLVR) with endobronchial valves (EBVs) has emerged as an important treatment method for patients with severe chronic obstructive pulmonary disease (COPD). Acute exacerbations of COPD (AECOPD) are a frequent complication following BLVR with EBV. However, there is no consensus on the prevention of AECOPD.ObjectivesOur study aims to compare the outcomes of different prophylactic measures on the occurrence of AECOPD after BLVR with EBV.MethodsWe conducted a multicenter, retrospective study of patients who underwent BLVR with EBV at six different institutions. Emphasis was directed towards the specific practices aimed at preventing AECOPD: antibiotics, steroids, antibiotics plus steroids, or no prophylaxis. Subgroups were compared, and odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated.ResultsA total of 170 patients were reviewed. The rate of AECOPD was 21.2% for the full cohort. Patients who received prophylaxis had a significantly lower rate of AECOPD compared with those who did not (16.7% vs. 46.2%; p = 0.001). The rate was lowest in patients who received antibiotics alone (9.2%). There was no significant difference in the rate of AECOPD between patients who received steroids alone or antibiotics plus steroids, compared with the other subgroups. The OR for AECOPD was 4.3 (95% CI: 1.8–10.4; p = 0.001) for patients not receiving prophylaxis and 3.9 (95% CI: 1.5–10.1; p = 0.004) for prophylaxis other than antibiotics alone.ConclusionsAdministration of antibiotics after BLVR with EBV was associated with a lower rate of AECOPD. This was not observed with the use of steroids or in combination with antibiotics.  相似文献   
27.
Bacteria possess the ability to evolve varied and ingenious strategies to outwit the host immune system, instigating an evolutionary arms race. Proteases are amongst the many weapons employed by bacteria, which specifically cleave and neutralize key signalling molecules required for a coordinated immune response. In this article, we focus on a family of S8 subtilisin-like serine proteases expressed as cell-envelope proteases (CEPs) by group A and group B streptococci. Two of these proteases known as Streptococcus pyogenes CEP (SpyCEP) and C5a peptidase cleave the chemokine CXCL8 and the complement fragment C5a, respectively. Both CXCL8 and C5a are potent neutrophil-recruiting chemokines, and by neutralizing their activity, streptococci evade a key defence mechanism of innate immunity. We review the mechanisms by which CXCL8 and C5a recruit neutrophils and the characterization of SpyCEP and C5a peptidase, including both in vitro and in vivo studies. Recently described structural insights into the function of this CEP family are also discussed. We conclude by examining the progress of prototypic vaccines incorporating SpyCEP and C5a peptidase in their preparation. Since streptococci-producing SpyCEP and C5a peptidase are responsible for a considerable global disease burden, targeting these proteases by vaccination strategies or by small-molecule antagonists should provide protection from and promote the resolution of streptococcal infections.  相似文献   
28.
29.
30.
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