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   15755篇
  免费   1676篇
  国内免费   533篇
耳鼻咽喉   67篇
儿科学   94篇
妇产科学   66篇
基础医学   1330篇
口腔科学   948篇
临床医学   1300篇
内科学   1013篇
皮肤病学   78篇
神经病学   542篇
特种医学   607篇
外科学   1010篇
综合类   2311篇
一般理论   3篇
预防医学   2402篇
眼科学   106篇
药学   3831篇
  21篇
中国医学   1948篇
肿瘤学   287篇
  2024年   8篇
  2023年   333篇
  2022年   391篇
  2021年   686篇
  2020年   703篇
  2019年   644篇
  2018年   607篇
  2017年   646篇
  2016年   635篇
  2015年   684篇
  2014年   1070篇
  2013年   1602篇
  2012年   1065篇
  2011年   1135篇
  2010年   824篇
  2009年   838篇
  2008年   925篇
  2007年   844篇
  2006年   718篇
  2005年   643篇
  2004年   455篇
  2003年   363篇
  2002年   345篇
  2001年   304篇
  2000年   231篇
  1999年   175篇
  1998年   130篇
  1997年   130篇
  1996年   95篇
  1995年   85篇
  1994年   90篇
  1993年   84篇
  1992年   70篇
  1991年   45篇
  1990年   43篇
  1989年   45篇
  1988年   49篇
  1987年   38篇
  1986年   31篇
  1985年   30篇
  1984年   24篇
  1983年   14篇
  1982年   13篇
  1981年   16篇
  1980年   21篇
  1979年   6篇
  1978年   5篇
  1977年   7篇
  1976年   7篇
  1974年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
The Extracellular Vesicle Flow Cytometry Working Group ( http://www.evflowcytometry.org ) is formed by members of the International Society for Extracellular Vesicles (ISEV), the International Society for Advancement of Cytometry (ISAC), and the International Society on Thrombosis and Haemostasis (ISTH). This working group of flow cytometry experts develops guidelines for best practices regarding flow cytometry detection of extracellular vesicles. To improve rigor and standardization, this working group published a framework outlining the minimal information to report about a flow cytometry experiment on extracellular vesicles (MIFlowCyt-EV) in the Journal of Extracellular Vesicles, the ISEV journal, in 2020. In parallel, an article explaining MIFlowCyt-EV was published in Cytometry Part A, one of the ISAC journals, and now will be introduced to the ISTH as an SSC Communication in the Journal of Thrombosis and Haemostasis. The goal of this SSC Communication is to explain why flow cytometry is becoming the instrument of choice to characterize single extracellular vesicles, the obstacles that have been identified and (mostly) overcome by developing procedures to calibrate flow cytometers, and the relevance of reporting minimal information to improve reliability and reproducibility of experiments in which flow cytometers are used for characterization of extracellular vesicles.  相似文献   
2.
ObjectivesPreclinical and clinical studies indicate a role for MLC901 (NeuroAiD II) in Alzheimer's disease (AD). The primary aim was to investigate its safety as add-on therapy to standard treatment and the secondary aims its effect on cognition and slowing disease progression.DesignRandomized double-blind placebo-controlled delayed-start study.Setting and ParticipantPatients with mild to moderate probable AD by NINCDS-ADRDA criteria, stable on acetylcholinesterase inhibitors or memantine (n = 125), were randomized to receive MLC901 (early starters) or placebo (delayed starters) for 6 months, followed by a further 6 months when all patients received MLC901, in a delayed-start design (clinical trial registration: ClinicalTrials.gov, NCT03038035).MethodsThe primary outcome measure was occurrence of serious adverse events (SAEs) at 6 months. Secondary outcomes included the Alzheimer's Disease Assessment Scale–Cognitive subscale (ADAS-Cog) and other assessment scales.ResultsThere was no significant difference in the risk of SAEs between early and delayed starters at month (M) 6 (22.6% vs 27.0%, risk difference ?4.4%, 90% CI –16.9% to 8.3%). Similarly, there was no significant difference in the risk of adverse events and the occurrence of stroke or vascular events between early and delayed starters throughout the 12-month study period. Early starters did not differ significantly on ADAS-Cog from delayed starters at M6 [mean difference (MD) ?1.0, 95% CI –3.3 to 1.3] and M12 (MD –2.35, 95% CI –5.45 to 0.74) on intention-to-treat analysis. Other cognitive assessment scales did not show significant differences.Conclusions and ImplicationsThis study of 125 persons with dementia found no evidence of a significant increase in adverse events between MLC901 and placebo, thus providing support for further studies on both efficacy and safety. Analyses suggest the potential of MLC901 in slowing down AD progression, but this requires further confirmation in larger and longer studies using biomarkers for AD.  相似文献   
3.
Acute diarrhea is a condition of increased water stool content, stool volume, and number of bowel movements that lasts less than 14 days. Mild diarrhea is usually self-limiting; however, undertreated moderate to severe diarrhea may cause severe dehydration and lead to hypovolemic shock. In order to prevent severe dehydration and treat patients appropriately, it is crucial for health care providers to determine the right diagnosis of patients with acute diarrhea. This article focuses on pathophysiology, general patient presentation, diagnostic tests and differential diagnosis lists of acute diarrhea to discuss which diagnosis should be made based on patient presentation and objective data.  相似文献   
4.
ObjectivesThe study aimed to identify changes in health literacy (HL) and associated variables during the first year following a kidney transplantation.MethodsA total of 196 transplant recipients were included in a prospective follow-up study. The patients answered the Health Literacy Questionnaire (HLQ) at 5 days, 8 weeks, 6 and 12 months following the kidney transplantation. Mixed linear models were used to analyze changes in HL and backward elimination was used to identify variables associated with HL.ResultsTwo main patterns of change were identified: a) HL increased during the first 8 weeks of close follow-up and b) in several domains, the positive increase from 5 days to 8 weeks flattened out from 5 days to 6 and 12 months. Self-efficacy, transplant-related knowledge, and general health were core variables associated with HL.ConclusionsOverall, HL increased during the 8 weeks of close follow-up following the kidney transplantation, while 6 months seem to be a more vulnerable phase. Furthermore, low self-efficacy, less knowledge, and low self-perceived health may represent vulnerable characteristics in patients.Practical implicationsFuture kidney transplant care should take into account patients’ access to and appraisal of health information and social support, and draw attention to potentially vulnerable groups.  相似文献   
5.
6.
Background  The data visualization literature asserts that the details of the optimal data display must be tailored to the specific task, the background of the user, and the characteristics of the data. The general organizing principle of a concept-oriented display is known to be useful for many tasks and data types. Objectives  In this project, we used general principles of data visualization and a co-design process to produce a clinical display tailored to a specific cognitive task, chosen from the anesthesia domain, but with clear generalizability to other clinical tasks. To support the work of the anesthesia-in-charge (AIC) our task was, for a given day, to depict the acuity level and complexity of each patient in the collection of those that will be operated on the following day. The AIC uses this information to optimally allocate anesthesia staff and providers across operating rooms. Methods  We used a co-design process to collaborate with participants who work in the AIC role. We conducted two in-depth interviews with AICs and engaged them in subsequent input on iterative design solutions. Results  Through a co-design process, we found (1) the need to carefully match the level of detail in the display to the level required by the clinical task, (2) the impedance caused by irrelevant information on the screen such as icons relevant only to other tasks, and (3) the desire for a specific but optional trajectory of increasingly detailed textual summaries. Conclusion  This study reports a real-world clinical informatics development project that engaged users as co-designers. Our process led to the user-preferred design of a single binary flag to identify the subset of patients needing further investigation, and then a trajectory of increasingly detailed, text-based abstractions for each patient that can be displayed when more information is needed.  相似文献   
7.
The selection and implementation of a plan for maxillary surgery is of the utmost importance in achieving the desired outcome for the patient undergoing two-jaw orthognathic surgery. Some splint-based and splintless methods, accompanied by computer-assisted techniques, are helpful in improving surgical plan implementation. However, randomized controlled trials focused on this procedure are lacking. This study included 61 patients who underwent bimaxillary surgeries. The patients were randomly assigned to a conventional resin occlusal splint (CROS) group, a digital occlusal splint (DOS) group, or a digital templates (DT) group, in a 1:1:1 ratio. The mean linear distance between the planned and actual postoperative positions of eight selected points on the surfaces of the maxillary teeth was selected as the outcome measure. The distance was significantly smaller in the DT group (1.17 ± 0.66 mm) when compared to both the CROS group (2.55 ± 0.95 mm, P < 0.05) and DOS group (2.15 ± 1.12 mm, P < 0.05). However, the difference between the CROS group and DOS group was not statistically significant. These findings indicate that using digital templates results in the best performance in transferring the surgical plan to the operation environment as compared to the other two types of splints. This suggests that the application of digital templates could provide a reliable treatment option.  相似文献   
8.
9.
《Saudi Pharmaceutical Journal》2022,30(11):1603-1611
This study was performed with the main objective of formulating and evaluating the potential of ethosomesl gel (Etho gel) to deliver nimodipine (NiM) for cardiovascular disease, a potent water insoluble anti-hypertensive drug via skin to reach the deeper layers of skin. The Box-Behnken design (BBD) was used to optimize the NiM-Eth to determine the impact of the independent and depended variables. The effectiveness of drug entrapment, vesicle size, and cumulative drug release were assessed for the NiM loaded ethosomes and NiM-Eth gel using carbopol 934 as a gelling agent. Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Power X-ray diffraction (PXRD), and scanning electron microscopy (SEM) analysis were performed and analysed their physicochemical characters. Rat abdomen skin was used to investigate drug permeability and deposition. As compared to marketed products, NiM-Eth gel produced an improved drug permeability in ex vivo experiments. The mean AUC0 to AUC0-∞ of NiM-Eth gel when compared to oral formulation (Nymalize oral preparation) was found to be increased from 4.1 to 5.9 folds which was found to be resulted from first pass effect. Histophatlogical findings revealed that the maximum amount of NiM penetrated the stratum corneum of the skin and create drug depots in the deep layer. In summary, it can be said that NiM might be successfully prepared in NiM-Eth gel for transdermal drug delivery.  相似文献   
10.
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