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   800篇
  免费   59篇
  国内免费   6篇
耳鼻咽喉   1篇
儿科学   24篇
妇产科学   41篇
基础医学   130篇
口腔科学   12篇
临床医学   58篇
内科学   139篇
皮肤病学   23篇
神经病学   38篇
特种医学   24篇
外科学   197篇
综合类   33篇
预防医学   36篇
眼科学   16篇
药学   46篇
中国医学   6篇
肿瘤学   41篇
  2023年   13篇
  2022年   13篇
  2021年   44篇
  2020年   22篇
  2019年   39篇
  2018年   20篇
  2017年   23篇
  2016年   30篇
  2015年   27篇
  2014年   33篇
  2013年   37篇
  2012年   53篇
  2011年   72篇
  2010年   24篇
  2009年   30篇
  2008年   51篇
  2007年   33篇
  2006年   45篇
  2005年   43篇
  2004年   31篇
  2003年   30篇
  2002年   30篇
  2001年   13篇
  2000年   22篇
  1999年   11篇
  1998年   7篇
  1997年   4篇
  1994年   3篇
  1993年   2篇
  1992年   6篇
  1991年   3篇
  1990年   3篇
  1989年   2篇
  1988年   5篇
  1987年   3篇
  1986年   3篇
  1985年   5篇
  1984年   4篇
  1979年   3篇
  1978年   2篇
  1972年   3篇
  1971年   1篇
  1969年   2篇
  1968年   3篇
  1967年   1篇
  1966年   4篇
  1954年   1篇
  1948年   1篇
  1935年   1篇
  1929年   1篇
排序方式: 共有865条查询结果,搜索用时 15 毫秒
81.
Socioeconomic determinants of injury have been associated with risk of burn in the UK and USA, but the relative significance of this impact is largely unknown across Canadian populations. The purpose of this study is to determine the extent to which socioeconomic status (SES) is linked to risk of burn in the province of British Columbia (BC) and identify the extent to which these findings are generalizable across both urban and rural population groups. Measures of SES were based on province-wide comparisons using data obtained from the Canada Census using the Vancouver Area Neighbourhood Deprivation Index (VANDIX). Results illustrate that the effects of SES and increased injury risk are substantial, though the most pronounced variations were exhibited across each SES stratum for urban areas and with less demonstrable effect when itemized by injury type within rural areas. Although conservative, the results from this study illustrate that burns disproportionately affect populations of greater relative socioeconomic disadvantage and continued efforts to also address social inequities and their link to injury incidence is likely to be more effective than targeting individual behavior alone when trying to reduce and eliminate their occurrence.  相似文献   
82.
83.
84.
85.
AIM: To study the prevalence, predictors and control of bleeding following N-butyl 2 cyanoacrylate (NBC) sclerotherapy of gastric varix (GV). METHODS: We analyzed case records of 1436 patients with portal hypertension, who underwent endoscopy during the past five years for variceal screening or upper gastrointestinal (GI) bleeding. Fifty patients with bleeding GV underwent sclerotherapy with a mean of 2 mL NBC for control of bleeding. Outcome parameters were primary hemostasis (bleeding control within the first 48 h), recurrent bleeding (after 48 h of esophago- gastro-duodenoscopy) and in-hospital mortality were analyzed. RESULTS: The prevalence of GV in patients with portal hypertension was 15% (220/1436) and the incidence of bleeding was 22.7% (50/220). Out of the 50 bleeding GV patients, isolated gastric varices (IGV-I) were seen in 22 (44%), gastro-oesophageal varices (GOV) on lesser curvature (GOV-Ⅰ) in 16 (32%), and GOV on greater curvature (GOV-Ⅱ) in 15 (30%). IGV-Ⅰ was seen in 44% (22/50) patients who had bleeding as compared to 23% (39/170) who did not have bleeding (P < 0.003). Primary hemostasis was achieved with NBC in all patients. Re-bleeding occurred in 7 (14%) patients after 48 h of initial sclerotherapy. Secondary hemostasis was achieved with repeat NBC sclerotherapy in 4/7 (57%). Three patients died after repeat sclerotherapy, one during transjugular intrahepatic portosystemic stem shunt (TIPSS), one during surgery and one due to uncontrolled bleeding. Treatment failure-related mortality rate was 6% (3/50). CONCLUSION: GV can be seen in 15% of patients withportal hypertension and the incidence of bleeding is 22.7%. NBC is highly effective in controlling GV bleeding. In hospital mortality of patients with bleeding GV is 6%.  相似文献   
86.
Hepatitis is an important but uncommon manifestation of acute Epstein Barr infection. Infectious mononucleosis is usually a disease of young adults. We report a case of infectious mononucleosis in a 72-year old jaundiced gentleman with ferritin level of 2438 that normalised on clinical improvement.  相似文献   
87.
The time course of blood-brain barrier (BBB) and blood-CSF barrier (BCSFB) responses to hyperosmolar mannitol infusion (HMI; 1.6 M) during chronic hypertension was investigated using (14)C-sucrose as a marker of barrier integrity. (14)C-sucrose entry into CSF of both spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats 2 min after HMI increased approximately 7-fold compared to their respective control. The volume of distribution (V(d)) of (14)C-sucrose into brain cortex of SHR increased 13-fold 2 min after HMI while that in WKY rats increased only 4-fold. After HMI V(d) of (14)C-sucrose into the cortex of WKY, and CSF of both SHR and WKY remained steadily greater than their corresponding control for up to 30 min (p < 0.01), whereas in the cortex of SHR the V(d) of (14)C-sucrose reached control values 20 min after HMI (p > 0.05), indicating that after HMI the increase in paracellular diffusion of (14)C-sucrose into SHR cortex was not persistent, in contrast to WKY rats and CSF of both SHR and WKY rats. Electron microscopy of the brain cortex after HMI showed capillary endothelial cell shrinkage and perivascular swellings in the brain cortex, and in the choroid plexus opening of tight junctions were observed. Our results indicate disruption of both the BBB and the BCSFB after HMI in both SHR and WKY rats. The disruption remained persistent up to 25 min after HMI at the BBB of WKY rats and BCSFB in both animal groups, while in SHR the protective function of the BBB returned to control values 20 min after HMI.  相似文献   
88.
White spot syndrome virus (WSSV) is a large dsDNA virus responsible for white spot disease in shrimp and other crustaceans. VP28 is one of the major envelope proteins of WSSV and plays a crucial role in viral infection. In an effort to develop a vaccine against WSSV, we have constructed a recombinant baculovirus with an immediate early promoter 1 which expresses VP28 at an early stage of infection in insect cells. Baculovirus expressed rVP28 was able to maintain its structural and antigenic conformity as indicated by immunofluorescence assay and western blot analysis. Interestingly, our results with confocal microscopy revealed that rVP28 was able to localize on the plasma membrane of insect cells infected with recombinant baculovirus. In addition, we demonstrated with transmission electron microscopy that baculovirus successfully acquired rVP28 from the insect cell membrane via the budding process. Using this baculovirus displaying VP28 as a vaccine against WSSV, we observed a significantly higher survival rate of 86.3% and 73.5% of WSSV-infected shrimp at 3 and 15 days post vaccination respectively. Quantitative real-time PCR also indicated that the WSSV viral load in vaccinated shrimp was significantly reduced at 7 days post challenge. Furthermore, our RT-PCR and immunohistochemistry results demonstrated that the recombinant baculovirus was able to express VP28 in vivo in shrimp tissues. This study will be of considerable significance in elucidating the morphogenesis of WSSV and will pave the way for new generation vaccines against WSSV.  相似文献   
89.

Objective

Our primary objective was to evaluate demographic and causal factors of inhospital mortality for significant firearm-related injuries (i.e., those with an Injury Severity Score [ISS] > 12) in Canadian trauma centres.

Methods

We analyzed data submitted to the Canadian Institute for Health Information (CIHI) in the National Trauma Registry for all firearm-injured patients for fiscal years 1999–2003. Univariate and bivariate adjusting for ISS and multivariate logistic regression were performed.

Results

Men accounted for 94% of the 784 injured. In all patients, the percentages of self-inflicted, intentional, unintentional and unknown injuries were 27.8%, 60.3%, 6.1% and 5.7%, respectively. The inhospital fatality rate was 39.8%, with 83% of fatalities occurring on the first day. Two-thirds of patients were discharged home. Univariate and adjusted analysis found that ISS, first systolic blood pressure (BP), first systolic BP under 100, first Glasgow Coma Scale (GCS) score, age over 45 years, self-inflicted injury, intentional injury and injury at home significantly worsened the odds ratio of death in hospital and that police shooting was relatively beneficial. BP under 100, age over 45 years and a low GCS score had an adjusted odds ratio of death of 4.12, 1.99 and 0.64 per point increase, respectively. The multivariate model showed that ISS, BP under 100, first GCS score, sex and self-inflicted injury were significant in predicting inhospital death.

Conclusion

A predominance of young men are injured intentionally with handguns in Canada, whereas older patients suffer self-inflicted injuries with long guns. The significant number of firearm deaths, largely in the first day, highlights the importance of preventative strategies and the need for rapid transport of patients to trauma centres for urgent care.  相似文献   
90.

Introduction  

HGFIN, previously identified as nmb, and its homolog osteoactivin are single transmembrane proteins that are expressed in differentiated immune cells. These proteins exhibit properties that could potentiate tumorigenesis or decrease invasiveness. These seemingly opposing roles of HGFIN suggest that this protein might be central to malignancies and might also behave as a tumor suppressor. Consistent with the reported roles for HGFIN is the fact that this gene is regulated by p53 through multiple binding sites in the 5' flanking region, and is expressed in osteoblasts.  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