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   779篇
  免费   28篇
  国内免费   4篇
耳鼻咽喉   30篇
儿科学   34篇
妇产科学   32篇
基础医学   55篇
口腔科学   12篇
临床医学   61篇
内科学   156篇
皮肤病学   20篇
神经病学   50篇
特种医学   42篇
外科学   166篇
综合类   10篇
预防医学   28篇
眼科学   33篇
药学   30篇
肿瘤学   52篇
  2023年   6篇
  2022年   17篇
  2021年   22篇
  2020年   24篇
  2019年   26篇
  2018年   25篇
  2017年   19篇
  2016年   21篇
  2015年   21篇
  2014年   17篇
  2013年   47篇
  2012年   67篇
  2011年   79篇
  2010年   30篇
  2009年   26篇
  2008年   60篇
  2007年   41篇
  2006年   55篇
  2005年   35篇
  2004年   31篇
  2003年   40篇
  2002年   35篇
  2001年   21篇
  2000年   13篇
  1999年   11篇
  1998年   2篇
  1997年   2篇
  1996年   3篇
  1995年   1篇
  1992年   1篇
  1991年   1篇
  1987年   1篇
  1986年   1篇
  1982年   1篇
  1977年   1篇
  1975年   1篇
  1974年   2篇
  1971年   1篇
  1970年   1篇
  1968年   2篇
  1966年   1篇
排序方式: 共有811条查询结果,搜索用时 0 毫秒
41.
42.
This analysis included 56 myelofibrosis (MF) patients transplanted from family mismatched donor between 2009 and 2015 enrolled in the European Society for Blood and Marrow Transplantation database. The median age was 57years (range, 38 to 72); 75% had primary MF and 25% had secondary MF. JAK2 V617F was mutated in 61%. Donors were HLA mismatched at 2 or more loci. Stem cells were sourced from bone marrow in 66% and peripheral blood in 34%. The median CD34+ cell dose was 4.8?×?106/kg (range, 1.7 to 22.9; n?=?43). Conditioning was predominantly myeloablative in 70% and reduced intensity in the remainder. Regimens were heterogeneous with thiotepa, busulfan, fludarabine, and post-transplant cyclophosphamide used in 59%. The incidence of neutrophil engraftment by 28days was 82% (range, 70% to 93%), at a median of 21days (range, 19 to 23). At 2years the cumulative incidence of primary graft failure was 9% (95% CI 1% to 16%) and secondary graft failure was 13% (95% CI 4% to 22%). The cumulative incidence of acute graft-versus-host disease (GVHD) grades II to IV and III to IV was 28% (95% CI 16% to 40%) and 9% (95% CI 2% to 17%) at 100days. The cumulative incidence of chronic GVHD at 1 year was 45% (95% CI 32% to 58%), but the cumulative incidence of death without chronic GVHD by 1 year was 20% (95% CI 10% to 31%). With a median follow-up of 32 months, the 1- and 2-year overall survival was 61% (95% CI 48% to 74%) and 56% (95% CI 41% to 70%), respectively. The 1- and 2- year progression-free survival was 58% (95% CI 45% to 71%) and 43% (95% CI 28% to 58%), respectively, with a 2-year cumulative incidence of relapse of 19% (95% CI 7% to 31%). The 2-year nonrelapse mortality was 38% (95% CI 24% to 51%). This retrospective study of MF allo-SCT using family mismatched donors demonstrated feasibility of the approach, timely neutrophil engraftment in over 80% of cases, and acceptable overall and progression-free survival rates with relapse rates not dissimilar to the unrelated donor setting. However, strategies to minimize the risk of graft failure and the relatively high nonrelapse mortality need to be used, ideally in a multicenter prospective fashion.  相似文献   
43.

Objective

The aim of the study was to investigate the effect of intragastric balloon therapy on left ventricular function and left ventricular mass in a cohort of morbidly obese patients.

Subjects and Methods

A prospective trial was performed in a cohort of 17 class II and class III morbidly obese individuals. The intragastric balloon was retained in the stomach for an average of 6 months. Conventional and tissue Doppler echocardiography were performed in all patients before and after the procedure.

Results

The mean age of the study participants was 36 ± 10 years (range: 18–55). The mean body mass index was significantly decreased following the intragastric balloon insertion procedure (44 ± 8 vs. 38 ± 5, p < 0.001). The left ventricular mass index and left atrial volume index were significantly decreased following the procedure (112 ± 21 vs. 93 ± 17, p = 0.001 and 20 ± 6 vs. 14 ± 5, p = 0.02, respectfully). In addition, the ratio of mitral peak early diastolic velocity to tissue Doppler-derived peak diastolic velocity and tissue Doppler echocardiography-derived left ventricular myocardial performance index were decreased significantly following the procedure (9.5 ± 1.9 vs. 7.7 ± 1.5, p = 0.002 and 0.57 ± 0.11 vs. 0.46 ± 0.06, p = 0.001, respectively).

Conclusions

Intragastric balloon therapy resulted in significant weight reduction in morbidly obese patients. This weight reduction was associated with improved left ventricular function.Key Words: Obesity, Intragastric balloon therapy, Echocardiography, Tissue Doppler  相似文献   
44.
BACKGROUND: Protein energy malnutrition (PEM) is a common pediatric health problem in developing countries. Although the clinical features of PEM are well known, its pathophysiology is still unclear. Free radicals have been implicated in pathogenesis of PEM. In the present study, oxidant/anti-oxidant status in marasmus was investigated. METHODS: Red cell glutathione, glutathione peroxidase and superoxide dismutase and their related cofactors, serum selenium and copper, were studied in marasmic and control children. Serum lipid peroxidation was also evaluated to assess oxidative stress. RESULTS: The red cell glutathione levels and glutathione peroxidase activities were found to be significantly lower in the marasmic children than in the controls. Red cell superoxide dismutase (SOD) activity was not different between two groups. Serum selenium and copper concentrations were significantly lower in the marasmic children than in the control subjects. The malondialdehyde concentration, which is an index of lipid peroxidation, was significantly higher in the marasmic group compared with the controls. CONCLUSION: The anti-oxidant defense system was affected in marasmic children. Reduced anti-oxidant status and increased oxidative stress occurs in marasmic children.  相似文献   
45.
46.
OBJECTIVE: The aim of this work was to determine the radiation dose received by infants from radiographic exposure and the contribution from scatter radiation due to radiographic exposure of other infants in the same room. MATERIALS AND METHODS: We retrospectively evaluated the entrance skin doses (ESDs) and effective doses of 23 infants with a gestational age as low as 28 weeks. ESDs were determined from tube output measurements (ESD(TO)) (n = 23) and from the use of thermoluminescent dosimetry (ESD(TLD)) (n = 16). Scattered radiation was evaluated using a 5 cm Perspex phantom. Effective doses were estimated from ESD(TO) by Monte Carlo computed software and radiation risks were estimated from the effective dose. ESD(TO) and ESD(TLD) were correlated using linear regression analysis. RESULTS: The mean ESD(TO) for the chest and abdomen were 67 microGy and 65 microGy per procedure, respectively. The mean ESD(TLD) per radiograph was 70 microGy. The measured scattered radiation range at a 2 m distance from the neonatal intensive care unit (NICU) was (11-17 microGy) per radiograph. Mean effective doses were 16 and 27 microSv per procedure for the chest and abdomen, respectively. ESD(TLD) was well correlated with ESD(TO) obtained from the total chest and abdomen radiographs for each infant (R(2) = 0.86). The radiation risks for childhood cancer estimated from the effective dose were 0.4 x 10(-6) to 2 x 10(-6) and 0.6 x 10(-6) to 2.9 x 10(-6) for chest and abdomen radiographs, respectively. CONCLUSION: The results of our study show that neonates received acceptable doses from common radiological examinations. Although the contribution of scatter radiation to the neonatal dose is low, considering the sensitivity of the neonates to radiation, further protective action was performed by increasing the distance of the infants from each other.  相似文献   
47.
Patient to patient transmission of hepatitis C virus in hemodialysis units.   总被引:1,自引:0,他引:1  
AIMS: In dialysis patients, blood transfusions and long-term dialysis are well known risk factors for transmission of hepatitis C virus. In this study the impact of use of dedicated hemodialysis (HD) units on the anti-HCV conversion rates was studied in patients of two different hemodialysis units in a city, Kayseri, between October 1995, and March 1999. MATERIALS AND METHODS: In the HD Unit of Erciyes University (HUEU), anti-HCV-positive and -negative patients were dialyzed on the dedicated machines in the same big room and seropositive patients for HBsAg in isolated rooms. In the HD Unit of Kayseri State Government Hospital (HUSH) only seronegative for anti-HCV and hepatitis B patients were treated. If a patient became positive, the patient was transferred to HUEU. Seventy-five patients have been receiving hemodialysis therapy in HUEU. Thirteen HBsAg-positive and 62 HBsAg-negative patients were dialyzed in separate rooms. Of 62 HBsAg-negative patients, 22 (35.5%) were already positive for HCV antibody when they started dialysis or before the study period. Forty seronegative patients (64.5%) for anti-HCV (23 males, 17 females) were treated with 22 anti-HCV-positive patients in the same room in HUEU. The mean duration of dialysis treatment was 24.7 +/- 21.0 months (range 4 to 96 months). Of the 40 patients, 28 (70%) became positive during the study period. Of 28 patients who became seropositive, 10 (35.7%) had a history of blood transfusion. Fifty-four patients (21 males, 33 females) were treated in HUSH during the study period. The mean duration of dialysis treatment was 19.3 +/- 9.6 months (range 5 41). Eight patients (14.8%) became anti-HCV-positive. Of these, 7 had received blood transfusion (88%). RESULTS: The seroconversion rate of patients in HUEU was higher than that of HUSH (odds ratio 3) (p < 0.05). Data derived from our patients showed that contamination appeared to be both transfusional and nosocomial and that there is a possibility of transmitting HCV infection in hemodialyzed patients never submitted to blood or blood products transfusion. Nosocomial spread of HCV in HD units which both seropositive and seronegative patients treated together was higher than that of dedicated unit. This is true even though we separated anti-HCV-positive dialysis machine.  相似文献   
48.
49.
50.
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