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   591篇
  免费   39篇
  国内免费   7篇
耳鼻咽喉   2篇
儿科学   22篇
妇产科学   9篇
基础医学   57篇
口腔科学   10篇
临床医学   66篇
内科学   82篇
皮肤病学   11篇
神经病学   35篇
特种医学   11篇
外科学   59篇
综合类   17篇
一般理论   1篇
预防医学   70篇
眼科学   42篇
药学   86篇
中国医学   20篇
肿瘤学   37篇
  2024年   1篇
  2023年   13篇
  2022年   19篇
  2021年   52篇
  2020年   29篇
  2019年   33篇
  2018年   48篇
  2017年   22篇
  2016年   25篇
  2015年   17篇
  2014年   28篇
  2013年   44篇
  2012年   63篇
  2011年   50篇
  2010年   25篇
  2009年   27篇
  2008年   33篇
  2007年   21篇
  2006年   20篇
  2005年   20篇
  2004年   17篇
  2003年   14篇
  2002年   7篇
  2000年   3篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1995年   1篇
  1990年   1篇
排序方式: 共有637条查询结果,搜索用时 93 毫秒
41.

Purpose  

The aim of this study was to identify the dominant factors affecting the stability of nanoemulsions, using artificial neural networks (ANNs).  相似文献   
42.
43.
Oxidative stress is believed to be implicated in the pathogenesis of postischaemic cerebral injury. Many antioxidants were shown to be neuroprotective in experimental models of cerebral ischaemia/reperfusion (I/R). The present study was designed to investigate the potential protective effects of curcumin (CUR) against I/R insult in rat forebrain. The model adopted was that of surgically-induced forebrain ischaemia, performed by means of bilateral common carotid artery occlusion (BCCAO) for 1 h, followed by reperfusion for another 1h. The effects of a single i.p. dose of CUR (50, 100 or 200 mg kg(-1)), administered 0.5 h after the onset of ischaemia, were investigated by assessing oxidative stress-related biochemical parameters in rat forebrain. CUR, at the highest dose level (200 mg kg(-1)), decreased the I/R-induced elevated xanthine oxidase (XO) activity, superoxide anion (O(2)*(-)) production, malondialdehyde (MDA) level and glutathione peroxidase (GPx), superoxide dismutase (SOD), and lactate dehydrogenase (LDH) activities. On the other hand, CUR did not affect the declined reduced glutathione (GSH) content due to I/R insult. Worth mentioning is that the activity of catalase (CAT) did not change in response to either I/R insult or drug treatment. In conclusion, CUR was found to protect rat forebrain against I/R insult. These protective effects may be attributed to its antioxidant properties and/or its inhibitory effects on xanthine dehydrogenase/xanthine oxidase (XD/XO) conversion and resultant O(2)*(-) production.  相似文献   
44.
BACKGROUND: The aim of our study was to evaluate, retrospectively, the frequency of anti-thyroid antibodies (ATA) in coeliac disease (CD) patients. METHODS: ELISA was used to determine the frequency of anti-thyroid stimulating hormone receptor antibodies, thyroperoxidase antibodies and thyroglobulin antibodies in sera of 104 adult patients with CD. Patients were divided into three groups: group I, 56 untreated patients; group II, 21 patients on a strict gluten-free diet (GFD); and group III, 27 patients who did not comply with a GFD. Sera of 189 healthy blood donors served as controls. RESULTS: Out of 104 patients with CD, five (4.8%) had ATA. The frequency of ATA found in the control group (1.6%) was not significantly different from that found in all CD patients. However, the frequency of ATA in CD patients on a GFD was significantly higher than that found in the control group (8.3% vs. 1.6%, p=0.03). The frequency of ATA in groups I, II and III was 1.8%, 9.5% and 7.4%, respectively. CONCLUSIONS: ATA were found in CD patients even on a GFD.  相似文献   
45.
46.
Journal of Behavioral Medicine - Medical avoidance is common among U.S. adults, and may be emphasized among members of marginalized communities due to discrimination concerns. In the current study,...  相似文献   
47.
The exact risk association of coronavirus disease 2019 (COVID-19) for surgeons is not quantified which may be affected by their risk of exposure and individual factors. The objective of this review is to quantify the risk of COVID-19 among surgeons, and explore whether facemask can minimise the risk of COVID-19 among surgeons. A systematised review was carried out by searching MEDLINE to locate items on severe acute respiratory syndrome coronavirus 2 or COVID-19 in relation to health care workers (HCWs) especially those work in surgical specialities including surgical nurses and intensivists. Additionally, systematic reviews that assessed the effectiveness of facemask against viral respiratory infections, including COVID-19, among HCWs were identified. Data from identified articles were abstracted, synthesised and summarised. Fourteen primary studies that provided data on severe acute respiratory syndrome coronavirus 2 infection or experience among surgeons and 11 systematic reviews that provided evidence of the effectiveness of facemask (and other personal protective equipment) were summarised. Although the risk of COVID-19 could not be quantified precisely among surgeons, about 14% of HCWs including surgeons had COVID-19, there could be variations depending on settings. Facemask was found to be somewhat protective against COVID-19, but the HCWs’ compliance was highly variable ranging from zero to 100%. Echoing surgical societies’ guidelines we continue to recommend facemask use among surgeons to prevent COVID-19.  相似文献   
48.
The aim of this work was to incorporate a hydrophobic compound benzophenone (BP) into core-shell nanoparticles (NPs) and to study its release. The core of these NPs is based on polylactic acid (PLA) and serves as a nanocontainer to accommodate BP. The shell is constituted of a β-cyclodextrin polymer (Poly-β-CD) which ensures the control of BP release through non-covalent host-guest interactions. Studies were focused on the preparation, physico-chemical analysis of the BP-loaded NPs and on the elucidation of the release mechanisms. The main features which are the slow kinetics, the dilution-induced release and the total release of encapsulated BP are in good agreement with a mechanism mainly controlled by diffusion of BP and by its binding with the β-CDs cavities present at the surface of NPs.  相似文献   
49.
Background/aim  This retrospective study was conducted to assess the efficacy and safety of immunosuppression conversion on progression of chronic allograft nephropathy (CAN). Methods  One-hundred and seventy-four cyclosporin (CsA)-treated renal transplant recipients were studied. Patients were included if they had a biopsy-proven CAN (mild to moderate) with serum creatinine ≤3.5 mg/dL. Patient treatment was switched to either: (A) MMF/reduced dose CsA (MMF for azathioprine (Aza); n = 132); or (B) Aza/Tac for CsA (n = 42). Patient records were checked for graft function and survival, and for co-morbidities after conversion. Results  Mean follow-up before conversion was 52.2 ± 31.1 and 47.9 ± 27.4 months for groups A and B, respectively. There was significant deterioration of graft function in group B after five years (< 0.5). Ten-year actuarial graft survival was 38% in group A and 19% in group B (= 0.04). Nine patients (five patients and four patients in groups A and B, respectively) started dialysis within 12 months. Tacrolimus-treated patients had a lower insignificant incidence of hyperlipidemia (P = 0.05), but a significantly higher incidence of diabetes mellitus (= 0.04).There was no significant change or difference in blood pressure between groups. Conclusions  Our results suggest that in patients with CAN and deteriorating allograft function, CsA minimization and addition of MMF achieved favorable efficacies in retarding the decline of graft function. Further prospective studies with larger cohorts are needed for validation.  相似文献   
50.
Background/Aims  Posttransplantation anemia (PTA) frequently occurs. We aimed to assess the prevalence of anemia at 6 months of transplantation in patients under different protocols of immunosuppression, and to determine the impact of anemia on long-term patient and graft survival. Methods  We included 832 renal transplant recipients who were categorized at 6 months according to hemoglobin (Hb) level into two groups: the first group, with Hb >13 g/dl in males and >12 g/dl in females (group I, 385 cases); and the second group, with Hb <13 g/dl in males and <12 g/dl in females (group II, 447 cases). We compared the two groups regarding posttransplant complications as well as patient and graft survival. Results  Although there was no significant difference between the two groups regarding acute rejection episodes, chronic allograft nephropathy was significantly higher in the anemic group. Other posttransplant medical complications were comparable in both groups. Graft survival was significantly higher in the nonanemic group. However, no difference in patient survival was detected. Conclusion  From this study, we can conclude that prevalence of PTA is high, especially in females and those receiving calcineurine inhibitors (CNI) and mycophenolate mofetil (MMF), and that it was associated with poorer graft outcome but with no effect on patient survival.  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