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   218篇
  免费   8篇
耳鼻咽喉   6篇
儿科学   11篇
基础医学   23篇
口腔科学   5篇
临床医学   15篇
内科学   34篇
皮肤病学   12篇
神经病学   18篇
特种医学   20篇
外科学   53篇
综合类   5篇
预防医学   3篇
眼科学   1篇
药学   6篇
中国医学   1篇
肿瘤学   13篇
  2023年   2篇
  2021年   5篇
  2020年   2篇
  2019年   3篇
  2018年   1篇
  2017年   2篇
  2016年   5篇
  2015年   9篇
  2014年   6篇
  2013年   10篇
  2012年   14篇
  2011年   21篇
  2010年   14篇
  2009年   10篇
  2008年   6篇
  2007年   12篇
  2006年   13篇
  2005年   14篇
  2004年   9篇
  2003年   13篇
  2002年   10篇
  2001年   7篇
  2000年   3篇
  1999年   7篇
  1998年   5篇
  1997年   2篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1992年   4篇
  1991年   4篇
  1989年   1篇
  1988年   4篇
  1986年   3篇
  1985年   1篇
排序方式: 共有226条查询结果,搜索用时 500 毫秒
1.
Skin is the most commonly used tissue for the transplantation. A meticulous care of the donor site is needed to prevent scarring, delayed healing, and pain. Various agents and dressing materials have been reported to help healing of skin graft donor sites. Sucralfate is an extensively used agent, which provides acute gastroprotection and acceleration of chronic ulcer healing. In this study, we assessed the effects of topical sucralfate on the healing of the split thickness skin graft donor sites in a prospective comparative way. The study was carried out on 32 randomly chosen patients undergoing surgery for various causes and requiring split thickness skin graft resurfacing. The upper halves of the skin graft donor sites on the thighs were simply covered with paraffin gauze and the lower half was covered with sucralfate-soaked paraffin gauzes. The day of full epithelization varied from 6 to 9 days and 8–12 days on the sucralfate-applied areas and on the control sites, respectively. The mean value of the healing was 7.01 days in the studied lower halves and 10.8 days in the upper halves. The healing rate was strikingly faster and less painful on the sucralfate-applied areas. We were able to discharge patients earlier than usual, and patients’ comfort increased. It seems that sucralfate is a promising topical agent to increase the healing rate and decrease the incidence of associated problems such as pain and hypertrophic scar.  相似文献   
2.
Despite the high incidence of leukaemic infiltration of the heart, only 8 cases of atrioventricular block due to leukaemia have been reported in the literature. Improvement in the heart block associated with disappearance of the leukaemic infiltrate has not been reported. A rest thallium-201 study was used in a 65-year-old man to demonstrate leukaemic infiltration of the heart which was associated with complete heart block. After chemotherapy, when the tumour burden was reduced and the leukaemia in remission, his heart block resolved, and a follow-up thallium scan was normal. Offprint requests to: A.C. Civelek  相似文献   
3.
This experimental study was designed to investigate the effects of vitamin E supplementation, especially on lipid peroxidation and antioxidant status elements 3/4 namely, glutathione (GSH), CuZn superoxide dismutase (CuZn SOD), and glutathione peroxidase (GSH Px), both in blood and liver tissues of streptozotocin (STZ) diabetic rats. The extent to which blood can be used to reflect the oxidative stress of the liver is also investigated. In diabetic rats, plasma lipid peroxide values were not significantly different,from control,whereas erythrocyte CuZn SOD (p < 0.01), GSH Px (p < 0.001) activities and plasma vitamin E levels (p < 0.001), were significantly more elevated than controls. Vitamin E supplementation caused significant decreases of erythrocyte GSH level (p < 0.01) in control rats and of erythrocyte GSH Px activity (p < 0.05) in diabetic rats. Liver findings revealed significantly higher lipid peroxide (p < 0.001) and vitamin E (p < 0.01) levels and lower GSH (p < 0.001), CuZn SOD (p < 0.001) and GSH Px (p < 0.01) levels in diabetic rats. A decreased hepatic lipid peroxide level (p < 0.01) and increased vitamin E/lipid peroxide ratio (p < 0.001) were observed in vitamin E supplemented, diabetic rats. A vitamin E supplementation level which did not cause any increase in the concentration of the vitamin in the liver or blood, was sufficient to lower lipid peroxidation in the liver. Vitamin E/lipid peroxide ratio is suggested as an appropriate index to evaluate the efficiency of vitamin E activity,independent of tissue lipid values. Further, the antioxidant components GSH, GSH Px and CuZn SOD and the relationships among them, were affected differently in the liver and blood by diabetes or vitamin E supplementation.  相似文献   
4.
Vascular smooth muscle cells (VSM) are normally exposed to transmural fluid flow shear stresses, and after vascular injury, blood flow shear stresses are imposed upon them. Since Ca2+ is a ubiquitous intracellular signaling molecule, we examined the effects of fluid flow on intracellular Ca2+ concentration in rat aortic smooth muscle cells to assess VSM responsiveness to shear stress. Cells loaded with fura 2 were exposed to steady flow shear stress levels of 0.5–10.0 dyn/cm2 in a parallel-plate flow chamber. The percentage of cells displaying a rise in cytosolic Ca2+ ion concentration ([Ca2+]i) increased in response to increasing flow, but there was no effect of flow on the ([Ca2+]i) amplitude of responding cells. Addition of Gd3+ (10 M) or thapsigargin (50 nM) significantly reduced the percentage of cells responding and the response amplitude, suggesting that influx of Ca2+ through ion channels and release from intracellular stores contribute to the rise in ([Ca2+]i) in response to flow. The addition of nifedipine (1 or 10 M) or ryanodine (10 M) also significantly reduced the response amplitude, further defining the role of ion channels and intracellular stores in the Ca2+ response. © 2002 Biomedical Engineering Society. PAC2002: 8716Uv, 8719Uv, 8716Dg, 8719Ff  相似文献   
5.
Triphalangeal thumb-polysyndactyly (TPT-PS) is an isolated limb malformation consisting of pre- and postaxial polysyndactyly of hands and feet. The only family reported so far is of Dutch origin, and the genetic mapping study localized the TPT-PS locus at chromosome region 7q36 where the isolated triphalangeal thumb (TPT) anomaly has also been mapped. It was suggested that TPT-PS is a phenotypic variation of isolated TPT, and the same ancestral mutation may produce both phenotypes. Here we report on the second family with this malformation from the Turkish population. The characteristic findings in this family are triphalangeal thumb, webbing between 3rd, 4th, and 5th fingers associated with bony synostosis in the distal phalanges of the same fingers, and pre- and postaxial polysyndactyly of feet. Some individuals show a more severe phenotype with a complete syndactyly of all fingers giving a "cup-like" appearance to the hands. Genetic linkage study with DNA markers D7S1823, D7S550, D7S559, and D7S2423 demonstrated that this family is also linked to chromosome band 7q36. Identification of a second family from a distinct ethnic background suggests that TPT-PS and isolated TPT are not caused by the same ancestral mutation as it was originally anticipated.  相似文献   
6.
BackgroundEmerging evidence suggests that sex steroid hormones may influence respiratory symptoms. The existing literature about the role of oral contraceptive pill (OCP) on respiratory disease is scarce and conflicting especially during the adolescent period. In this study, we aimed to investigate the effect of OCPs on current wheezing among adolescents and young adults.MethodsA questionnaire was administered face-to-face to adolescents and young women by a physician. The questionnaire included ISAAC survey-comprised questions on ever wheezing, current wheezing, allergic diseases, smoking history (active or passive), and family history of allergic diseases and questions on OCP usage status. The effect of OCPs on wheezing was evaluated by logistic regression analysis.ResultsA total of 487 subjects aged between 11.3 and 25.6 years participated in the study and 196 (40.2%) reported that they had used OCPs. 7.4% of the participants had physician-diagnosed asthma and 10.3% of them were active smokers. It was detected that OCPs were associated with increased risk for current wheezing (odds ratio, 2.36; 95% CI, 1.25–4.47 adjusted for asthma and current smoker) and this risk was related with the usage during the past year.ConclusionYoung women taking oral contraceptives had a higher rate of current wheezing, suggesting that sex steroids may be of importance for respiratory health.  相似文献   
7.
8.
Objective: The role of coronary artery bypass grafting (CABG) in patients with severe left ventricular dysfunction was evaluated. Methods: Two hundred and twelve patients (152 men, 60 women; age 35 to 82, mean 55) with ejection fraction (EF) of less than 30% underwent CABG between January 1996 and February 2001 by a single surgeon (SA). They compromised of 12% of 1759 patients operated on in this period. EF ranged from 17% to 30% (mean 25%). Preoperatively 68% had congestive heart failure and 72% had severe angina (CCS 3 or 4). A left main lesion was found in 26% of the cases. The mean number of grafts was 3.18 per patient. The left internal mammary artery (LIMA) was used on 107 patients (50.4%). Preoperative intraaortic balloon pump (IABP) was used on 32 patients (15%). Endarterectomy was performed on 53 patients (25%). The patients were followed for up to 58 months (mean 28.7). Results: Twelve patients died in hospital (5.6%). Survival was 94%, 87%, 80% and 73% at 1, 2, 3 and 4 years respectively. Among the preoperative variables survival was negatively affected by chronic renal failure, older age, congestive heart failure, elevated pulmonary artery pressure and recent myocardial infarction, by means of multivariate analysis. Preoperative IABP support improved the operative mortality significantly (P=0.002). Use of LIMA did not have any influence on survival. Conclusion: CABG on patients with poor left ventricular function: (1) Can be performed with an acceptable mortality. (2) Mid term results are encouraging. (3) Preoperative IABP support improves the chance of survival.  相似文献   
9.
10.
The main function of white adipose tissue is to store nutrient energy in the form of triglycerides. The mechanism by which free fatty acids (FFA) move into and out of the adipocyte has not been resolved. We show here that changes in intracellular pH (pH1) in adipocytes correlate with the movement of FFA across cellular membranes as predicted by the Kamp and Hamilton model of passive diffusion of FFA. Exposure of fat cells to lipolytic agents or external FFA results is a rapid intracellular acidification that is reversed by metabolism of the FFA or its removal by albumin. In contrast, insulin causes an alkalinization of the cell, consistent with its main function to promote esterification. Inhibition of Na+/H+ exchange in adipocytes does not prevent the changes in pHi caused by FFA, lipolytic agents, or insulin. A fatty acid dimer, which diffuses into the cell but is not metabolized, causes an irreversible acidification. Taken together, the data suggest that changes in pHi occur in adipocytes in response to the passive diffusion of un-ionized FFA (flip-flop) into and out of the cell and in response to their metabolism and production within the cell. These changes in pHi may, in turn, modulate hormonal signaling and metabolism with significant impact on cell function.  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