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   181篇
  免费   9篇
  国内免费   61篇
儿科学   4篇
妇产科学   15篇
基础医学   32篇
临床医学   45篇
内科学   71篇
皮肤病学   3篇
神经病学   5篇
外科学   9篇
综合类   13篇
预防医学   4篇
眼科学   2篇
药学   39篇
肿瘤学   9篇
  2022年   4篇
  2021年   3篇
  2020年   3篇
  2019年   5篇
  2018年   3篇
  2017年   3篇
  2016年   8篇
  2015年   5篇
  2014年   4篇
  2013年   11篇
  2012年   12篇
  2011年   9篇
  2010年   10篇
  2009年   5篇
  2008年   8篇
  2007年   46篇
  2006年   7篇
  2005年   15篇
  2003年   1篇
  2002年   3篇
  2001年   3篇
  2000年   8篇
  1999年   5篇
  1998年   10篇
  1997年   4篇
  1996年   6篇
  1995年   3篇
  1994年   4篇
  1993年   5篇
  1992年   6篇
  1991年   5篇
  1990年   1篇
  1989年   5篇
  1988年   1篇
  1987年   5篇
  1986年   4篇
  1985年   3篇
  1984年   3篇
  1983年   1篇
  1982年   3篇
  1973年   1篇
排序方式: 共有251条查询结果,搜索用时 515 毫秒
1.
2.
Background. Although some patients with end-stage heart disease will benefit from a partial left ventriculectomy, no criteria have been found for identifying this group preoperatively. Our experience with partial left ventriculectomy at two institutions—the Texas Heart Institute in Houston, TX, USA, and Dedinje Cardiovascular Institute in Belgrade, Yugoslavia—showed a higher survival rate and better postoperative myocardial function in the Yugoslavian patients.

Methods. We reviewed data from 42 patients (21 at each center) who had idiopathic cardiomyopathy, a left ventricular end-diastolic dimension of more than 70 mm, wall thickness of 1 cm or greater, and New York Heart Association class III or IV symptoms. The only significant difference in preoperative status between the two groups was duration of symptoms. Histologic specimens, blinded as to origin, were graded with regard to myocyte hypertrophy, cytoplasmic vacuolation, and fibrosis. Computer-assisted myocyte and nuclear morphometry was also performed.

Results. Immediately postoperatively, there were no significant intergroup differences in the reduction in cardiac dimension or in corrections of mitral regurgitation. During 6-month follow-up, however, the Texas Heart Institute patients had a lower cardiac index (1.8 versus 3.0 L·min−1·m−2; p = 0.001) and left ventricular ejection fraction (24% versus 34%; p = 0.006) than the Dedinje Cardiovascular Institute patients. The Texas Heart Institute patients differed from the Dedinje Cardiovascular Institute patients in the degree of severe or moderate changes in myocyte hypertrophy (90% versus 29%; p = 0.0003) and fibrosis (71% versus 29%; p = 0.006), as well as in the measurements of median myocyte diameter (35 ± 7 μm versus 27 ± 4 μm; p = 0.0002) and median nuclear size (15 ± 4 μm versus 12 ± 2 μm; p = 0.0029).

Conclusions. In the Texas Heart Institute patients, the significant intergroup difference in clinical outcome may have been related to increased myocyte hypertrophy and fibrosis. Further studies should be performed to determine the usefulness of these criteria in selecting patients for partial left ventriculectomy.  相似文献   

3.
BACKGROUND: Most studies have shown that early post-infarction angina (EPA) implies an unfavorable long-term prognosis among patients with acute myocardial infarction (AMI). However, some studies have failed to establish a link between the occurrence of EPA and increased mortality and recurrent infarction rates. METHODS AND RESULTS: In order to evaluate a long-term prognosis in patients with EPA, we assessed the 5-year prognosis of 80 patients with AMI by the presence or absence of EPA. During the 5-year follow up, the occurrence of death, cardiac death, recurrent infarction, unstable angina, heart failure, revascularization and cardiac events were recorded. A cardiac event was defined as an occurrence of any of the following events: cardiac death, recurrent infarction, unstable angina, heart failure and revascularization. Survival analysis showed no differences between patients with and without EPA in the probability of death (p=NS), cardiac death (p=NS), recurrent myocardial infarction (p=NS) and unstable angina (p=NS). Patients with EPA had a higher probability of developing cardiac events (p=0.0285) and undergoing revascularization procedures (p=0.0188). CONCLUSIONS: EPA increases the risk of patients developing cardiac events and undergoing revascularization procedures, and thereby implies a poor long-term prognosis for patients with AMI.  相似文献   
4.
A patient with a lifelong bleeding disorder was diagnosed as having Type II von Willebrand disease. The larger multimers of von Willebrand factor were absent from her plasma but present in platelets. A high- resolution electrophoretic technique was used to study the complex structure of individual von Willebrand factor multimers. In normal plasma, each multimer could be resolved into five bands: a more intense central one and four less intense, two moving faster and two slower than the central band. In normal platelets, each multimer could also be resolved into five bands. The central one had a mobility similar to that in plasma, whereas the four satellite bands had a mobility that differed from that of the corresponding plasma bands. In the patient, platelet von Willebrand factor antigen content and ristocetin cofactor activity were normal, and von Willebrand factor showed the same structure of individual multimers as seen in normal platelets. On the other hand, plasma von Willebrand factor antigen and ristocetin cofactor activity were decreased, and the structure of individual von Willebrand factor multimers was different from that of normal plasma and similar to that seen in normal and patient's platelets. After infusion of 1-deamino-8-D-arginine vasopressin, the largest von Willebrand factor multimers, as well as new satellite bands with a mobility similar to those in normal plasma, appeared in the patient plasma, and the levels of von Willebrand factor antigen and ristocetin cofactor activity became normal. Yet no relevant change in the prolonged bleeding time was observed. This new variant of von Willebrand disease, therefore, is characterized by the presence of a dysfunctional von Willebrand factor molecule that exhibits unique structural abnormalities in plasma but appears to be normal in platelets. The designation of Type IIF is proposed for this type of von Willebrand disease in accordance with the terminology that has been previously used.  相似文献   
5.
Some primary malignant or benign tumours of bone contain numerous multinucleated cells. These “giant cell-rich tumours of bone” have overlapping features and clinical and radiological data are needed to reach an accurate pathological diagnosis. We studied the potential contribution of p63 immunohistochemistry to the reliability of the histological diagnosis. We performed a multicentric retrospective study of 291 giant cell-rich tumours of bone which included 119 giant cell tumours of bone (GCTB), 76 aneurysmal bone cysts (ABC), 49 chondroblastomas (CB), 15 nonossifying fibromas (NOF), 10 giant cell reparative granulomas (RG) of jaws, 1 giant cell lesion of small bones, 2 hyperparathyroidism-related brown tumours (BT), 17 bone sarcomas with numerous osteoclasts and 2 malignant giant cell tumours of bone. p63 is expressed in ABC, CB, NOF, RG, BT and GCTB, but its expression in more than 50 % of mononuclear cells is strongly suggestive of a diagnosis of GCTB. In contrast, malignant GCTB were mostly negative. Our results show that p63 is expressed in a broad range of benign giant cell-rich tumours of bone, consistent with data in the recent literature, while infrequent in malignant tumours. With a cut-off 50 %, the presence of p63 positive cells is useful in supporting a diagnosis of giant cell-rich tumour of bone. However, a final diagnosis cannot be made without due consideration of all clinical/radiological and pathological data.  相似文献   
6.
Mandibulofacial dysostosis, Guion‐Almeida type (MFDGA) is a recently delineated multiple congenital anomalies/mental retardation syndrome characterized by the association of mandibulofacial dysostosis (MFD) with external ear malformations, hearing loss, cleft palate, choanal atresia, microcephaly, intellectual disability, oesophageal atresia (OA), congenital heart defects (CHDs), and radial ray defects. MFDGA emerges as a clinically recognizable entity, long underdiagnosed due to highly variable presentations. The main differential diagnoses are CHARGE and Feingold syndromes, oculoauriculovertebral spectrum, and other MFDs. EFTUD2, located on 17q21.31, encodes a component of the major spliceosome and is disease causing in MFDGA, due to heterozygous loss‐of‐function (LoF) mutations. Here, we describe a series of 36 cases of MFDGA, including 24 previously unreported cases, and we review the literature in order to delineate the clinical spectrum ascribed to EFTUD2 LoF. MFD, external ear anomalies, and intellectual deficiency occur at a higher frequency than microcephaly. We characterize the evolution of the facial gestalt at different ages and describe novel renal and cerebral malformations. The most frequent extracranial malformation in this series is OA, followed by CHDs and skeletal abnormalities. MFDGA is probably more frequent than other syndromic MFDs such as Nager or Miller syndromes. Although the wide spectrum of malformations complicates diagnosis, characteristic facial features provide a useful handle.  相似文献   
7.
We report the case of a 33-year-old pregnant woman. The third-trimester ultrasound scan during pregnancy revealed fetal bilateral ventricular dilatation, macrosomia and a transverse diameter of the cerebellum at the 30th centile. A brain MRI scan at 31 weeks of gestation led to a diagnosis of hypoplasia of the cerebellar vermis without hemisphere abnormalities and a non compressive expansion of the cisterna magna. The fetal karyotype was 46,XX. The pregnancy was terminated and array-CGH analysis of the fetus identified a 238 kb de novo deletion on chromosome Xp12, encompassing part of OPHN1 gene. Further studies revealed a completely skewed pattern of X inactivation. OPHN1 is involved in X-linked mental retardation (XLMR) with cerebellar hypoplasia and encodes a Rho-GTPase-activating protein called oligophrenin-1, which is produced throughout the developing mouse brain and in the hippocampus and Purkinje cells of the cerebellum in adult mice. Neuropathological examination of the female fetus revealed cerebellar hypoplasia and the heterotopia of Purkinje cells at multiple sites in the white matter of the cerebellum. This condition mostly affects male fetuses in humans. We report here the first case of a de novo partial deletion of OPHN1, with radiological and neuropathological examination, in a female fetus.  相似文献   
8.
9.
We examined changes in weight‐specific health‐related quality of life (HRQOL) and the relation to weight loss in a Serbian population undergoing diet‐induced weight loss treatment. HRQOL was assessed at intake and after 1 year using the Impact of Weight on Quality of Life‐Lite (IWQOL‐Lite) questionnaire. Study sample consists of 135 obese patients. After 1 year of diet therapy, patients experienced an average weight loss of ~12%, and significant improvements were noted in all IWQOL‐Lite domains (Physical Function, Self‐esteem, Sexual Life, Public Distress and Work). Amount of weight loss was closely linked to all domains (F = 27.49; p < 0.001), except Sexual Life (F = 2.08; p = 0.108). In patients with weight reductions of 5%–9.99%, there was a great improvement in physical function and self‐esteem. In those with ≥10% weight loss, there was improvement in all dimensions of IWQOL‐Lite. With the prevalence of obesity rising worldwide, including in Serbia, the positive effects of weight loss on weight‐specific HRQOL are encouraging. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.  相似文献   
10.

Brain invasion has not been recognized as a standalone criterion for atypical meningioma by the WHO classification until 2016. Since the 2007 edition suggested that meningiomas harboring brain invasion could be classified as grade 2, brain invasion study was progressively strengthened in our center, based on a strong collaboration between neurosurgeons and neuropathologists regarding sample orientation and examination. Practice changes were considered homogeneous enough in 2011. The aim of the present study was to evaluate the impact of gross practice change on the clinical and pathological characteristics of intracranial meningiomas classified as grade 2.

The characteristics of consecutive patients with a grade 2 meningioma surgically managed before (1998–2005, n?=?125, group A) and after (2011–2014, n?=?166, group B) practices changed were retrospectively reviewed.

Sociodemographical and clinical parameters were comparable in groups A and B, and the median age was 62 years in both groups (p?=?0.18). The 5-year recurrence rates (23.2% vs 29.5%, p?=?0.23) were similar. In group A, brain invasion was present in 48/125 (38.4%) cases and was more frequent than in group B (14/166, 8.4%, p?<?0.001). In group A, 33 (26.4%) meningiomas were classified as grade 2 solely based on brain invasion (group ASBI), and 92 harbored other grade 2 criteria (group AOCA). Group ASBI meningiomas had a similar median progression-free survival compared to groups AOCA (68 vs 80 months, p?=?0.24) and to AOCA and B pooled together (n?=?258, 68 vs 90 months, p?=?0.42).

An accurate assessment of brain invasion is mandatory as brain invasion is a strong predictor of meningioma progression.

  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