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   1859篇
  免费   81篇
  国内免费   7篇
耳鼻咽喉   24篇
儿科学   34篇
妇产科学   37篇
基础医学   237篇
口腔科学   148篇
临床医学   109篇
内科学   374篇
皮肤病学   30篇
神经病学   293篇
特种医学   51篇
外科学   219篇
综合类   6篇
一般理论   1篇
预防医学   86篇
眼科学   94篇
药学   98篇
中国医学   19篇
肿瘤学   87篇
  2023年   14篇
  2022年   18篇
  2021年   49篇
  2020年   21篇
  2019年   42篇
  2018年   41篇
  2017年   23篇
  2016年   38篇
  2015年   59篇
  2014年   62篇
  2013年   95篇
  2012年   163篇
  2011年   160篇
  2010年   80篇
  2009年   80篇
  2008年   151篇
  2007年   113篇
  2006年   118篇
  2005年   105篇
  2004年   89篇
  2003年   92篇
  2002年   74篇
  2001年   36篇
  2000年   20篇
  1999年   30篇
  1998年   16篇
  1997年   13篇
  1996年   11篇
  1995年   3篇
  1994年   5篇
  1993年   8篇
  1992年   8篇
  1991年   9篇
  1990年   7篇
  1989年   8篇
  1988年   13篇
  1987年   8篇
  1986年   3篇
  1985年   5篇
  1984年   3篇
  1983年   6篇
  1980年   5篇
  1979年   10篇
  1978年   3篇
  1977年   3篇
  1976年   5篇
  1973年   5篇
  1972年   2篇
  1971年   3篇
  1970年   4篇
排序方式: 共有1947条查询结果,搜索用时 31 毫秒
61.
Purpose

Patients with chronic kidney disease are predisposed to heart rhythm disorders including atrial fibrillation (AF). Several studies have suggested that radiofrequency catheter ablation of AF improves renal function. However, little data exists for pulmonary vein isolation with cryoballoon ablation (CBA). The purpose of this study is to assess change in renal function following CBA for AF.

Method

This is a single-center retrospective study that included patients who underwent CBA for AF between 2011 and 2016. Patients were grouped by baseline-estimated glomerular filtration rate (eGFR): ≥?90 (Stage G1), 60–89.9 (Stage G2), and 30–59.9 mL/min/1.73 m2 (Stage G3). Change in eGFR was assessed >?3 months post-ablation.

Results

A total of 306 patients with both pre- and post-ablation serum creatinine measurements available were included. Baseline eGFRs for Stages G1, G2, and G3 patients were 103.5?±?12.9 (n?=?82), 74.7?±?8.2 (n?=?184), and 52.6?±?6.6 mL/min/1.73 m2 (n?=?40), respectively. Renal function was assessed 310.8?±?104.2 days post-ablation. Average intra-procedural contrast use was 58.4?±?23.8 mL. There was no significant change in eGFR following CBA in Stage G1 patients (p?=?0.10). For those with Stages G2 and G3 renal function, eGFR improved by 6.1% (4.2 mL/min/1.73 m2, p?<?0.01) and 13.8% (7.2 mL/min/1.73 m2, p?<?0.01), respectively. This improvement was seen regardless of the presence or absence of recurrent atrial arrhythmias.

Conclusions

CBA for AF may be associated with an improvement in renal function, particularly among those with a reduced baseline eGFR despite recurrence of atrial arrhythmias and intra-procedural contrast use.

  相似文献   
62.
63.
The Brugada syndrome is a congenital syndrome displaying an autosomal dominant mode of transmission in patients with a structurally normal heart. The disease has been linked to mutations in SCN5A , a gene located on the short arm of chromosome 3 (p21-24) that encodes for the alpha subunit of the sodium channel. The syndrome is characterized by a dynamic ST-segment elevation (accentuated J wave) in leads V 1 to V 3 of the ECG followed by negative T wave. Right bundle-branch block of varying degrees is observed in some patients. The syndrome is associated with syncope and a relatively high incidence of sudden cardiac death secondary to the development of polymorphic ventricular tachycardia that may degenerate into ventricular fibrillation. An acquired form of the Brugada syndrome is also recognized, caused by a wide variety of drugs and conditions that alter the balance of currents active during the early phases of the action potential. Among patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia, there is a subpopulation with a clinical and electrocardiographic pattern similar to that of the Brugada syndrome. These cases of arrhythmogenic right ventricular cardiomyopathy/dysplasia are thought to represent an early or concealed form of the disease. This review examines the overlap between these 2 syndromes.  相似文献   
64.
Domino liver transplantation (DLT) has been performed for selected recipients at several centers, but de novo amyloidosis in recipients of livers from patients with familial amyloid polyneuropathy (FAP) remains a serious concern. AIM: To evaluate the occurrence of de novo amyloidosis in recipients of DLT. PATIENTS AND METHODS: Seven recipients of FAP livers were followed for clinical and electroneuromyographic signs of FAP and also for de novo amyloid deposition in the gut. RESULTS: No signs and symptoms of de novo FAP nor any evidence of amyloid deposits in the gut were observed in recipients of DLT after a mean follow-up of 24 [12-40] months. CONCLUSIONS: Signs and symptoms of FAP do not occur early in recipients of DLT. These livers could therefore be offered to patients suitable for conventional LT, particularly older subjects in whom the event of de novo amyloidosis would seem improbable.  相似文献   
65.
Central nervous system (CSN) involvement in schistosomiasis is an ectopic manifestation with a large variety of clinical forms, including pseudotumoral, which occurs in isolated cases and is rare. Three patients with epidemiological indications of this pathology were examined; the clinical picture included lower-back pain irradiating to lower limbs, associated with progressive flaccid paraparesis and sphincterial disturbances in cases in which the spinal chord was involved; while in cases with encephalitic impairment, headache, dizziness and cerebellar syndrome, characterized by dysarthria and right-side dysgraphia, were present. Magnetic resonance imaging (MRI) showed a growing process in all cases; cerebrospinal fluid (CSF) characteristics and biological markers were compatible with neuroschistosomiasis (NS). Biopsy of the lesions confirmed this diagnosis in one case. After specific treatment with schistosomicides and corticosteroids, clinical, radiological and laboratorial improvement was observed.  相似文献   
66.
There are many diseases related to ion‐channel disorders, so‐called “channelopathies.” Hereditary short QT syndrome is a clinical‐electrocardiographic entity with autosomal‐dominant mode of transmission and it is the most recently described channelopathy. The syndrome may affect infants, children, or young adults with strong positive family background of sudden cardiac death. Short QT syndrome is characterized by short QT and heart‐rate‐corrected QTc intervals. It is frequently associated with tall‐, peaked‐, and narrow‐based T waves that are reminiscent of the typical “desert tent” T waves of hyperkalemia. There is a high tendency for paroxysmal atrial fibrillation due to the heterogeneous abbreviation of action potential duration and refractoriness of atrial myocytes. The arrhythmia can also be induced by programmed electrical stimulation. The safest treatment suggested is an implantable cardioverter defibrillator, though the possibilities of inappropriate shocks have caused some concern, especially in teenagers. The ability of quinidine to prolong the QT interval has the potential to be an effective therapy for patients with short QT syndrome. This is particularly important in developing countries, where the implantable cardioverter‐defibrillator therapy is not always available. Since these patients are at risk of sudden cardiac death from birth, and implantable cardioverter‐defibrillator implantation has a lot of limitations in very young children, the utility of quinidine has to be evaluated further. Clinicians need to be aware of this deadly electrocardiographic (ECG) pattern as it portends a high risk of sudden cardiac death in otherwise healthy subjects with structurally normal hearts.  相似文献   
67.
68.

Background

Pulmonary arterial hypertension (PAH) is a disease that results in right ventricular (RV) dysfunction. While pulmonary vascular disease is the primary pathological focus, RV hypertrophy and RV dysfunction are the major determinants of prognosis in PAH. The aim of this study was to investigate the effects of (E)-N′-(3,4-dimethoxybenzylidene)-4-methoxybenzohydrazide (LASSBio-1386), an N-acylhydrazone derivative, on the lung vasculature and RV dysfunction induced by experimental PAH.

Methods

Male Wistar rats were injected with a single dose (60 mg/kg, i.p.) of monocrotaline (MCT) and given LASSBio-1386 (50 mg/kg, p.o.) or vehicle for 14 days. The hemodynamic, exercise capacity (EC), endothelial nitric oxide synthase (eNOS), adenosine A2A receptor (A2AR), sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA2a), phospholamban (PLB) expression, Ca2 +-ATPase activity and vascular activity of LASSBio-1386 were evaluated.

Results and conclusions

The RV systolic pressure was elevated in the PAH model and reduced from 49.6 ± 5.0 mm Hg (MCT group) to 27.2 ± 2.1 mm Hg (MCT + LASSBio-1386 group; P < 0.05). MCT administration also impaired the EC, increased the RV and pulmonary arteriole size, and promoted endothelial dysfunction of the pulmonary artery rings. In the PAH group, the eNOS, A2AR, SERCA2a, and PLB levels were changed compared with the control; in addition, the Ca2 +-ATPase activity was reduced. These alterations were related with MCT-injected rats, and LASSBio-1386 had favorable effects that prevented the development of PAH. LASSBio-1386 is effective at preventing endothelial and RV dysfunction in PAH, a finding that may have important implications for ongoing clinical evaluation of A2AR agonists for the treatment of PAH.  相似文献   
69.
70.
We have reported encouraging results of unrelated cord blood transplantation for patients with lymphoid malignancies. Whether those outcomes are comparable to matched unrelated donor transplants remains to be defined. We studied 645 adult patients with mature lymphoid malignancies who received an allogeneic unrelated donor transplant using umbilical cord blood (n=104) or mobilized peripheral blood stem cells (n=541) after a reduced-intensity conditioning regimen. Unrelated cord blood recipients had more refractory disease. Median follow-up time was 30 months. Neutrophil engraftment (81% vs. 97%, respectively; P<0.0001) and chronic graft-versus-host disease (26% vs. 52%; P=0.0005) were less frequent after unrelated cord blood than after matched unrelated donor, whereas no differences were observed in grade II–IV acute graft-versus-host disease (29% vs. 32%), non-relapse mortality (29% vs. 28%), and relapse or progression (28% vs. 35%) at 36 months. There were also no significant differences in 2-year progression-free survival (43% vs. 58%, respectively) and overall survival (36% vs. 51%) at 36 months. In a multivariate analysis, no differences were observed in the outcomes between the two stem cell sources except for a higher risk of neutrophil engraftment (hazard ratio=2.12; P<0.0001) and chronic graft-versus-host disease (hazard ratio 2.10; P=0.0002) after matched unrelated donor transplant. In conclusion, there was no difference in final outcomes after transplantation between umbilical cord blood and matched unrelated donor transplant. Umbilical cord blood is a valuable alternative for patients with lymphoid malignancies lacking an HLA-matched donor, being associated with lower risk of chronic graft-versus-host disease.  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