全文获取类型
收费全文 | 572篇 |
免费 | 20篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 41篇 |
妇产科学 | 27篇 |
基础医学 | 35篇 |
口腔科学 | 5篇 |
临床医学 | 62篇 |
内科学 | 166篇 |
皮肤病学 | 5篇 |
神经病学 | 33篇 |
特种医学 | 38篇 |
外科学 | 114篇 |
综合类 | 10篇 |
预防医学 | 16篇 |
眼科学 | 4篇 |
药学 | 19篇 |
肿瘤学 | 17篇 |
出版年
2023年 | 4篇 |
2022年 | 11篇 |
2021年 | 15篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 16篇 |
2016年 | 9篇 |
2015年 | 23篇 |
2014年 | 21篇 |
2013年 | 27篇 |
2012年 | 48篇 |
2011年 | 44篇 |
2010年 | 22篇 |
2009年 | 27篇 |
2008年 | 42篇 |
2007年 | 53篇 |
2006年 | 45篇 |
2005年 | 41篇 |
2004年 | 30篇 |
2003年 | 34篇 |
2002年 | 32篇 |
2001年 | 8篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1984年 | 3篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1969年 | 3篇 |
1939年 | 1篇 |
1934年 | 1篇 |
1927年 | 1篇 |
排序方式: 共有599条查询结果,搜索用时 15 毫秒
81.
Fujii T Kanda M Kodera Y Nagai S Sahin TT Hayashi M Kanzaki A Yamada S Sugimoto H Nomoto S Takeda S Morita S Nakao A 《Annals of surgical oncology》2012,19(1):176-183
Background
Pylorus-preserving pancreatoduodenectomy (PPPD) has replaced conventional pancreatoduodenectomy with a distal gastrectomy (cPD) as the most commonly performed procedure. However, there has been no evidence from prospective studies to indicate the overwhelming superiority of PPPD over cPD. A recent report revealed that resection of the pyloric ring reduced the incidence of delayed gastric emptying (DGE) in a randomized controlled trial.Methods
In 158 patients with pancreatic head cancer, the perioperative outcomes and long-term nutritional consequences were retrospectively compared among three types of pancreatoduodenectomy: cPD; PPPD; and subtotal stomach-preserving pancreatoduodenectomy (SSPPD), in which the pyloric ring and duodenum were removed and more than 90% of the stomach was preserved.Results
The incidence of DGE was significantly higher in the PPPD group than in the cPD and SSPPD groups (27.3 vs. 5.8 and 5.4%, respectively; P?=?0.0012). The serum albumin concentration and total lymphocyte count at 1?year postoperatively were significantly higher in the SSPPD group than in the PPPD group (P?=?0.0303 and P?=?0.0203, respectively). The patients in the SSPPD group showed longer survival times than the patients in the cPD and PPPD groups (median survival times, 21.3, 17.1, and 17.7?months, respectively), although the differences did not reach statistical significance.Conclusions
Our results suggest that preservation of the pyloric ring without vagal innervation has little significance, and that SSPPD with better perioperative and long-term outcomes is more suitable as a standard procedure for patients with pancreatic head cancer. 相似文献82.
83.
84.
Pedro F Ferreira Philip J Kilner Laura-Ann McGill Sonia Nielles-Vallespin Andrew D Scott Siew Y Ho Karen P McCarthy Margarita M Haba Tevfik F Ismail Peter D Gatehouse Ranil de Silva Alexander R Lyon Sanjay K Prasad David N Firmin Dudley J Pennell 《Journal of cardiovascular magnetic resonance》2014,16(1)
Background
Cardiac diffusion tensor imaging (cDTI) measures the magnitudes and directions of intramyocardial water diffusion. Assuming the cross-myocyte components to be constrained by the laminar microstructures of myocardium, we hypothesized that cDTI at two cardiac phases might identify any abnormalities of laminar orientation and mobility in hypertrophic cardiomyopathy (HCM).Methods
We performed cDTI in vivo at 3 Tesla at end-systole and late diastole in 11 healthy controls and 11 patients with HCM, as well as late gadolinium enhancement (LGE) for detection of regional fibrosis.Results
Voxel-wise analysis of diffusion tensors relative to left ventricular coordinates showed expected transmural changes of myocardial helix-angle, with no significant differences between phases or between HCM and control groups. In controls, the angle of the second eigenvector of diffusion (E2A) relative to the local wall tangent plane was larger in systole than diastole, in accord with previously reported changes of laminar orientation. HCM hearts showed higher than normal global E2A in systole (63.9° vs 56.4° controls, p = 0.026) and markedly raised E2A in diastole (46.8° vs 24.0° controls, p < 0.001). In hypertrophic regions, E2A retained a high, systole-like angulation even in diastole, independent of LGE, while regions of normal wall thickness did not (LGE present 57.8°, p = 0.0028, LGE absent 54.8°, p = 0.0022 vs normal thickness 38.1°).Conclusions
In healthy controls, the angles of cross-myocyte components of diffusion were consistent with previously reported transmural orientations of laminar microstructures and their changes with contraction. In HCM, especially in hypertrophic regions, they were consistent with hypercontraction in systole and failure of relaxation in diastole. Further investigation of this finding is required as previously postulated effects of strain might be a confounding factor.Electronic supplementary material
The online version of this article (doi:10.1186/s12968-014-0087-8) contains supplementary material, which is available to authorized users. 相似文献85.
Comparison of three different combination therapies in the treatment of human brucellosis 总被引:2,自引:0,他引:2
The efficacy and tolerability of three different combination treatment regimens in human brucellosis were compared in 118 uncomplicated patients enrolled in a prospective study between May 1997 and December 2002. Brucellosis was diagnosed using standard clinical and microbiological findings. Patients with central nervous system involvement, spondylitis, endocarditis or children under 16 years of age were excluded from the study. Patients were randomly assigned to receive 400 mg of ofloxacin plus 600 mg of rifampicin (OR, n = 41), 200 mg of doxycycline plus 600 mg of rifampicin (DR, n = 45) or 1g intramuscularly streptomycin (administered for three weeks) plus 200 mg doxycycline (DS, n = 32) daily for 6 weeks. All patients were followed up at least 6 months after cessation of therapy.There was no statistical difference between the groups on relapse rates and clinical response to the treatment (P>0.05). Five patients in OR (12.8%), six patients in DR (14.3%) and three patients in DS groups (9.7%) suffered relapse. The side-effects were seen in eight (19.5%), 21 (46.7%) and eight (25.0%) patients of OR, DR and DS groups, respectively.The use of combination therapy of ofloxacin plus rifampicin for 6 weeks was found to be as effective as DR and DS. The side-effects of therapy in OR and DS groups was less severe than in the DR group. 相似文献
86.
Local recurrence and survival rates after extended systematic lymph-node dissection for surgical treatment of rectal cancer 总被引:2,自引:0,他引:2
BACKGROUND/AIMS: Extended systematic lymph-node dissection (ESLND) is a surgical procedure aimed at decreasing the local recurrence rate of rectal cancer and increasing the survival rate. However, it is criticized because it has not shown the expected effects on survival, and it has been shown to increase the proportion of complications in rectal cancer surgery. This study was designed to determine incidence and patterns of recurrence after curative resection with or without ESLND for rectal cancer. METHODOLOGY: A total of 184 patients with rectal cancer were reviewed with respect to surgical procedures, local recurrence and survival rates. RESULTS: 170 of 184 patients with rectal cancer were administered curative surgical resection. ESLND was added to the surgical procedure of 24 of these 170 patients. The local recurrence rate of the patients who did not receive lymph-node dissection was 15%, and the survival rate over 5 years was 58.9%. The local recurrence rate of the patients receiving ESLND was 12.5%, and the survival rate over 5 years was found to be 55.7% (p>0.05). CONCLUSIONS: Because ESLND is a procedure added on to curative resection in the surgical treatment of rectal cancer, it increases the general anesthesia and length of surgery, and it is possible that some complications due to the operation itself may arise. In the current study and in a large amount of research in the literature, a statistically significant effect on the survival rate has not been found. In conclusion, the opinion has been reached that ESLND does not have an important benefit in the curative surgical treatment of rectal cancer. 相似文献
87.
Demir T Oztunç F Eroğlu AG Saltik L Ahunbay G Kutluğ S Güzeltaş A Altun G 《Cardiology in the young》2008,18(1):75-78
OBJECTIVE: Our aim was to investigate the change in diameter of holes within the oval fossa, and the role of aneurismal formation in reducing the size of the hole, in patients diagnosed during infancy with isolated defects in the floor of the fossa. PATIENTS: In a retrospective study, we included 100 patients diagnosed during the first year of life with an isolated defect in the floor of the oval fossa who had subsequently been observed for at least 5 years. There were 56 females and 44 males. They had been admitted to hospital because of a murmur in 65, heart failure in 9, and other reasons in 17. The remaining 9 patients were referred from other institutions with an established diagnosis of defects within the oval fossa. Patients were grouped according to the size of the deficiency in the floor of the fossa. Defects of diameter less than 5 mm were considered to be small, and 20 patients had such defects. Medium sized defects were judged to be between 5 and 8 mm, with 26 patients fulfilling this criterion, with the other 54 patients having large defects with diameters greater than 8 mm. RESULTS: The overall spontaneous rate of closure was 27%. Of those with medium defects, half closed spontaneously, but only 7.5% of those with large defects showed such closure. Of the patients who were diagnosed with heart failure, 9 had defects measuring 7 mm, and of these, 6 required surgical closure, 1 patient had spontaneous closure, while the defect became smaller in the remaining 2. On the other hand, in 9 out of 10 patients who had aneurysms, the diameter of the defect was between 7 and 15 mm. Amongst these patients, the defect closed spontaneously in 3, and reduced in size in the others. CONCLUSION: When holes within the oval fossa measure 8 mm or below, the majority of patients with experience either spontaneous closure or show decrease in size of the defect. In those with larger defects, the size usually increases, and surgery is needed for closure. If there is aneurismal formation, however, even when the defect measures more than 8 mm, the defect usually closes on its own or gets smaller. 相似文献
88.
Eva C. Sammut Adriana D.M. Villa Gabriella Di Giovine Luke Dancy Filippo Bosio Thomas Gibbs Swarna Jeyabraba Susanne Schwenke Steven E. Williams Michael Marber Khaled Alfakih Tevfik F. Ismail Reza Razavi Amedeo Chiribiri 《JACC: Cardiovascular Imaging》2018,11(5):686-694
Objectives
This study sought to evaluate the prognostic usefulness of visual and quantitative perfusion cardiac magnetic resonance (CMR) ischemic burden in an unselected group of patients and to assess the validity of consensus-based ischemic burden thresholds extrapolated from nuclear studies.Background
There are limited data on the prognostic value of assessing myocardial ischemic burden by CMR, and there are none using quantitative perfusion analysis.Methods
Patients with suspected coronary artery disease referred for adenosine-stress perfusion CMR were included (n = 395; 70% male; age 58 ± 13 years). The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, aborted sudden death, and revascularization after 90 days. Perfusion scans were assessed visually and with quantitative analysis. Cross-validated Cox regression analysis and net reclassification improvement were used to assess the incremental prognostic value of visual or quantitative perfusion analysis over a baseline clinical model, initially as continuous covariates, then using accepted thresholds of ≥2 segments or ≥10% myocardium.Results
After a median 460 days (interquartile range: 190 to 869 days) follow-up, 52 patients reached the primary endpoint. At 2 years, the addition of ischemic burden was found to increase prognostic value over a baseline model of age, sex, and late gadolinium enhancement (baseline model area under the curve [AUC]: 0.75; visual AUC: 0.84; quantitative AUC: 0.85). Dichotomized quantitative ischemic burden performed better than visual assessment (net reclassification improvement 0.043 vs. 0.003 against baseline model).Conclusions
This study was the first to address the prognostic benefit of quantitative analysis of perfusion CMR and to support the use of consensus-based ischemic burden thresholds by perfusion CMR for prognostic evaluation of patients with suspected coronary artery disease. Quantitative analysis provided incremental prognostic value to visual assessment and established risk factors, potentially representing an important step forward in the translation of quantitative CMR perfusion analysis to the clinical setting. 相似文献89.
Increased secretion of insulin during oral glucose tolerance test can be a predictor of stent restenosis in nondiabetic patients. 总被引:1,自引:0,他引:1
Erhan Babalik Tevfik Gürmen Lütfullah Orhan Hüseyin Bulur Murat Gülbaran Murat Ersanli Servet Oztürk 《Catheterization and cardiovascular interventions》2003,58(3):306-312
Insulin is known to stimulate proliferation and migration of vascular smooth muscle cells. As the predominant mechanism of restenosis after stent implantation is neointimal tissue proliferation, one can expect a relationship between hyperinsulinemia and restenosis in these patients. The aim of this study was to determine whether hyperinsulinemia during oral glucose tolerance test is a predictor of the development of restenosis after stent implantation in nondiabetic patients. We prospectively studied 52 nondiabetic patients with effort angina who underwent elective stent implantation for single-vessel coronary artery disease. In order to increase the statistical power of the study, numerous exclusion criteria were applied. All patients were subjected to a 75 g oral glucose tolerance test a day before the stent implantation and underwent follow-up angiography 6 months later. Plasma insulin levels in fasting (6.77 +/- 1.57 vs. 5.36 +/- 1.35 micro U/ml; P = 0.005), at 30 min (102.48 +/- 10.6 vs. 47.74 +/- 12.75 micro U/ml; P = 0.001), 1 hr after (120.23 +/- 14.1 vs. 63.08 +/- 12.62 micro /ml; P = 0.001), 2 hr after (63.58 +/- 8.64 vs. 34.88 +/- 6.82 micro /ml; P = 0.001), and 3 hr after (25.71 +/- 5.65 vs. 23.02 +/- 4.61 micro /ml; P = 0.04) loading were significantly higher in patients with stent restenosis than in patients without stent restenosis. Insulin area and insulin area/glucose area were also significantly higher in patients with stent restenosis than in patients without (219.5 +/- 23.8 vs. 118.9 +/- 21.8, P = 0.001, and 0.62 +/- 0.09 vs. 0.33 +/- 0.06, P = 0.001, respectively). By multiple logistic regression analysis, insulin area during oral glucose tolerance test was found to be an independent predictor of stent restenosis (OR = 1.12; 95% CI = 1.01-1.25; P = 0.031). In conclusion, nondiabetic patients with hyperinsulinemia during oral glucose tolerance test have a high risk for restenosis after stent implantation, and performing this simple test before intervention may be useful for the prediction of stent restenosis. 相似文献
90.
Kultigin Turkmen Huseyin Oflaz Bora Uslu Arif O. Cimen Ali Elitok Erdem Kasikcioglu Sabahat Alisir Fatih Tufan Sule Namli Mukremin Uysal Tevfik Ecder 《Clinical journal of the American Society of Nephrology》2008,3(4):986-991
Background and objectives: Cardiovascular problems are a major cause of morbidity and mortality in patients with autosomal dominant polycystic kidney disease. Endothelial dysfunction, an early and reversible feature in the pathogenesis of atherosclerosis, is associated with increased vascular smooth muscle tone, arterial stiffening, and increased intima-media thickness. Coronary flow velocity reserve is a noninvasive test showing endothelial function of epicardial coronary arteries and coronary microcirculatory function. The aim of the study was to investigate the carotid intima-media thickness and coronary flow velocity reserve in patients with autosomal dominant polycystic kidney disease.Design, setting, participants, & measurements: Thirty normotensive patients with autosomal dominant polycystic kidney disease (10 male, 20 female) with well-preserved renal function and 30 healthy subjects (12 male, 18 female) were included in the study. Coronary flow velocity reserve was measured at baseline and after dipyridamole infusion by echocardiography. Coronary flow velocity reserve was calculated as the ratio of hyperemic to baseline diastolic peak velocities.Results: Carotid intima-media thickness was significantly higher in patients than in control subjects (0.80 ± 0.29 versus 0.54 ± 0.14 mm, respectively; P < 0.001). Moreover, coronary flow velocity reserve was significantly lower in patients than in control subjects (1.84 ± 0.39 versus 2.65 ± 0.68, respectively; P < 0.001).Conclusions: Normotensive patients with autosomal dominant polycystic kidney disease with well-preserved renal function have significantly increased carotid intima-media thickness and significantly decreased coronary flow velocity reserve compared with healthy subjects. These findings suggest that atherosclerosis starts at an early stage in the course of their disease in patients with autosomal dominant polycystic kidney disease.Autosomal-dominant polycystic kidney disease (ADPKD) is a hereditary renal disease that occurs in 1 of 400 to 1000 individuals (1,2). Cardiovascular problems are a major cause of morbidity and mortality in patients with ADPKD (3). Hypertension, a common finding in patients with ADPKD, often occurs before the onset of renal insufficiency and is associated with faster progression to ESRD and increased cardiovascular mortality (4,5). Activation of the renin-angiotensin-aldosterone system (RAAS) caused by cyst expansion and local ischemia has been proposed to play an important role in the development of hypertension in ADPKD (6). The RAAS is stimulated at an early stage of ADPKD, even before the onset of hypertension and clinical findings (7,8). Likewise, increased left ventricular mass indexes and biventricular diastolic dysfunction have been reported before the development of hypertension in patients with ADPKD with well-preserved renal function (9–16). Moreover, endothelial dysfunction (ED), which is an early manifestation of vascular injury, occurs in both normotensive and hypertensive patients with ADPKD, before the onset of renal failure (17).Coronary flow velocity reserve (CFVR) represents the capacity of the coronary circulation to dilate after an increase in myocardial metabolic demands (18). Although CFVR was measured invasively until recently, it can be evaluated noninvasively by using Doppler and vasodilator stress, such as dipyridamole or adenosine (19). By using this method, impairment of CFVR can be assessed before development of angiographically detectable stenosis in epicardial coronary arteries. The aim of this study was to investigate the CFVR in patients with ADPKD, with well-preserved renal function. 相似文献