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   817篇
  免费   23篇
耳鼻咽喉   1篇
儿科学   112篇
妇产科学   4篇
基础医学   61篇
口腔科学   7篇
临床医学   25篇
内科学   179篇
皮肤病学   10篇
神经病学   159篇
特种医学   10篇
外科学   96篇
综合类   24篇
一般理论   2篇
预防医学   33篇
眼科学   14篇
药学   56篇
中国医学   2篇
肿瘤学   45篇
  2023年   4篇
  2022年   11篇
  2021年   34篇
  2020年   7篇
  2019年   10篇
  2018年   12篇
  2017年   13篇
  2016年   15篇
  2015年   21篇
  2014年   31篇
  2013年   44篇
  2012年   52篇
  2011年   62篇
  2010年   31篇
  2009年   27篇
  2008年   47篇
  2007年   50篇
  2006年   55篇
  2005年   51篇
  2004年   31篇
  2003年   21篇
  2002年   32篇
  2001年   22篇
  2000年   25篇
  1999年   13篇
  1998年   9篇
  1997年   4篇
  1996年   4篇
  1995年   3篇
  1994年   2篇
  1992年   5篇
  1991年   12篇
  1990年   7篇
  1989年   8篇
  1988年   7篇
  1987年   10篇
  1986年   10篇
  1985年   9篇
  1984年   2篇
  1983年   4篇
  1979年   2篇
  1977年   4篇
  1976年   2篇
  1974年   3篇
  1973年   1篇
  1972年   1篇
  1967年   2篇
  1966年   5篇
  1965年   1篇
  1963年   1篇
排序方式: 共有840条查询结果,搜索用时 0 毫秒
21.

Background

Isolated left ventricular non-compaction has been reported extensively. However, apical non-compaction of both ventricles and the interventricular septum (IVS) is not often reported in the literature. The objective of our study is to evolve the echocardiographic diagnostic criteria and to assess the types and impact of the associated lesions in “apical non-compaction”.

Methods and results

Seventy consecutive cases that fulfilled standard echocardiographic criteria for non-compaction of the left ventricle and, in addition, N/C ratio of >3 for the right ventricle and apical IVS formed the material. The age of patients ranged from 3 days to 35 years, with 37 males and 33 females. The associated lesions were present in all 70 cases: 62 had acyanotic (88.6 %) and 8 had cyanotic congenital heart diseases (11.4 %). Of the 70 cases, 18 had pump failure (25.7 %): 8 cases had left ventricular dysfunction, 7 had right ventricular dysfunction, and 3 had biventricular dysfunction; 33 (47.1 %) had pulmonary hypertension, 2 (2.9 %) had thrombus, and 1 (1.4 %) had tachyarrhythmia. Pump failure was worsened by volume overload in 33.9 % and by pressure overload in 8.1 % of cases. Some very rare lesions were detected. All 70 cases had Swiss cheese appearance of the apical half of the IVS, looking like the delta of a river.

Conclusion

All of the apical non-compaction syndrome cases had associated lesions, mostly acyanotic congenital heart disease with volume overload, rather than obstructive lesions. Transthoracic echocardiography plays an important role in the diagnosis of apical non-compaction syndrome and associated lesions that worsen the pump failure.  相似文献   
22.
Despite safe and efficacious vaccines against peste des petits ruminants virus (PPRV), this virus has emerged as the cause of a highly contagious disease with serious economic consequences for small ruminant agriculture across Asia, the Middle East, and Africa. We used complete and partial genome sequences of all 4 lineages of the virus to investigate evolutionary and epidemiologic dynamics of PPRV. A Bayesian phylogenetic analysis of all PPRV lineages mapped the time to most recent common ancestor and initial divergence of PPRV to a lineage III isolate at the beginning of 20th century. A phylogeographic approach estimated the probability for root location of an ancestral PPRV and individual lineages as being Nigeria for PPRV, Senegal for lineage I, Nigeria/Ghana for lineage II, Sudan for lineage III, and India for lineage IV. Substitution rates are critical parameters for understanding virus evolution because restrictions in genetic variation can lead to lower adaptability and pathogenicity.  相似文献   
23.
Pulmonary complications are one of the most common causes of morbidity and mortality in patients undergoing peripheral blood stem cell transplantation. Both infective and non-infective etiologies can involve the lungs during this period and differentiating them clinically is a challenging task and management differs in each case. We present here a case of acute myeloid leukemia, in whom following allogeneic peripheral blood stem cell transplantation, diffuse alveolar hemorrhage developed.  相似文献   
24.

Purpose

The purpose of the study was to analyze the surgical outcomes in children (≤18 years) with brachial plexus injury operated between April 2008 and March 2012 at our center.

Methods

All children <18 years of age admitted to our center and surgically treated with a diagnosis of posttraumatic brachial plexus injury were included in the study. The demographic details of these patients were retrieved from the computerized database of our hospital. The results were analyzed in terms of the mode of injury, type of injury, surgical procedure performed, and motor recovery after the surgery (MRC Grading). Motor recovery with MRC >3/5 was termed as good outcome.

Observations

A total of 33 patients were surgically treated. The mean age at presentation was 15.1 (range 4–18) years. Boys constituted 79 % (n?=?26) of our patient population. High-velocity injury was the commonest mode of injury. Panbrachial injury was the commonest seen in 82 % (n?=?27) of patients. Mean duration between injury and surgical intervention was 6 (range 2–13, SD?±?2.6) months. Majority of patients underwent neurotization procedure. Mean follow-up was 32 (range 6–51) months.

Conclusions

High-velocity trauma is the most common mode on injury. Global palsy involving all the plexal elements was present in 82 % of the children. Neurotization was the most commonly performed surgical procedure. Good motor outcome (MRC grade ≥3/5) was seen in 62 % of patients.  相似文献   
25.

Purpose

Intracranial aneurysms in children are not as common as in adults and there are many differences in the etiology, demographic variables, aneurysm location, aneurysm morphological characteristics, clinical presentation, and outcome in pediatric and adult intracranial aneurysms.

Methods

All children (≤18 years) suffering from intracranial aneurysm managed at our center from July 2001 through June 2013 were included in the study, and the details of these patients were retrieved from the computerized database of our hospital.

Observations

A total of 62 pediatric patients were treated for 74 aneurysms during the study period and constituted 2.3 % of all intracranial aneurysms treated during the same period. The mean age at presentation was 13.5 years. Headache (82 %) was the commonest presenting feature; other symptoms included seizures (21 %), ictal loss of consciousness (27 %), and motor/cranial nerve deficits (22.6 %). Computed tomogram revealed subarachnoid hemorrhage in 58 % of patients. Eighty-two percent of aneurysms were in anterior circulation. Sixty-seven percent of aneurysms were complex aneurysms. Fifty-eight percent of patients underwent surgical intervention while 30 % underwent endovascular procedures. Twenty-one percent of the patients developed vasospasm. There was no postoperative mortality. Favorable outcome was seen in 72 % of the patients.

Conclusions

Pediatric intracranial aneurysms are uncommon as compared to in adult patients. Seizures and cranial nerve involvement are seen more often as the presenting features in children. Posterior circulation aneurysms are more common in children, as are the internal carotid artery bifurcation aneurysms. There is high incidence of giant, posttraumatic, and mycotic aneurysms in children.  相似文献   
26.
27.
A case of fourteen year old healthy girl with complaint of a discharging sinus on the lower right side of face is reported. All teeth were vital and there was no evidence of periodontitis. There was no history of extraction of a tooth. Total leucocyte count, differential leucocyte count, fasting blood sugar, chest x-ray and routine urine examination were within normal limits. Actinomycosis and scrofuloderma which simulate such a condition were ruled out by culture study. The intraoral periapical x-ray of mandibular molar showed questionable periapical changes at the time of presentation. But definite osteolysis was observed in the repeat radiograph after three months. It was decided to extract the second molar and curette the sinus tract. The extraction proved to be difficult. On examination of the extracted tooth, it was found that the mandibular second molar and second premolar were fused together. The radiograph of the tooth taken after extraction showed confluence of the premolar pulp with the periodontal membrane. On follow up, the lesion was found to heal satisfactorily.  相似文献   
28.
29.
Several single nucleotide polymorphisms of the TP53 gene have been reported, amongst which polymorphism in codon 72 (rs1042522) has received significant attention and shown to be associated with disease susceptibility in different cancer types. However, there are variable reports on this polymorphism in gliomas from worldwide with inconsistent results. In addition, the implications of other polymorphic loci are not much explored in gliomas. Hence, in the present study the TP53 sequence was analyzed for all polymorphism and mutations in a total of 84 gliomas of different types and grades from patients of Indian origin. The complete sequence of all coding exons (2 to 11) and introns 2, 3, 5 and 8 of TP53 gene were studied while for introns 1, 4, 6, 7, 9 and 10, only exon flanking regions could be studied. The polymorphic loci were compared with control population. In addition to the well known codon 72 polymorphism (rs1042522), three other polymorphisms rs1642785, rs1800370 and a 16 base pair insertion in intron-3 were found. At codon 72, our study showed higher Arg/Arg genotype in gliomas compared to normal population (38% versus 13%). The Arg allele frequency in glioma patients was comparatively higher than controls (0.55 versus 0.45; P = 0.037). The Arg allele frequency was also high in adult glioblastomas compared to paediatric counterparts (0.55 versus 0.36). However, there was no significant association of TP53 mutations with any genotype of codon 72. At rs1642785, the G allele frequency was significantly higher in gliomas than in control population (0.55 versus 0.36, P = 0.005). The genotype at a 16 base pair insertion in intron-3 was almost similar in case and control. However, the polymorphism at rs1800370 was exclusive to gliomas. This is the first report of TP53 gene polymorphism in glioma patients from India. Our study also delineates the frequency of four polymorphisms in gliomas for the first time. The codon 72 variant (rs1042522) and rs1642785 polymorphisms possibly poses risk to glioma development in Indian population. However, the functional significance of these polymorphism needs further elucidation.  相似文献   
30.

Introduction:

Life-threatening, space occupying, infarction develops in 10-15% of patients after middle cerebral artery infarction (MCAI). Though decompressive craniectomy (DC) is now standard of care in patients with non-dominant stroke, its role in dominant MCAI (DMCAI) is largely undefined. This may reflect the ethical dilemma of saving life of a patient who may then remain hemiplegic and dysphasic. This study specifically addresses this issue.

Materials and Methods:

This retrospective analysis studied patients with DMCAI undergoing DC. Patient records, operation notes, radiology, and out-patient files were scrutinized to collate data. Glasgow outcome scale (GOS), Barthel index (BI) and improvement in language and motor function were evaluated to determine functional outcome.

Results:

Eighteen patients between 22 years and 72 years of age were included. 6 week, 3 month, 6 month and overall survival rates were 66.6% (12/18), 64% (11/17), 62.5% (10/16) and 62.5% (10/16) respectively. Amongst ten surviving patients with long-term follow-up, 60% showed improvement in GOS, 70% achieved BI score >60 while 30% achieved full functional independence. In this group, motor power and language function improved in 9 and 8 patients respectively. At last follow-up, 8 of 10 surviving patients were ambulatory with (3/8) or without (5/8) support. Age <50 years corresponded with better functional outcome amongst survivors (P value –0.0068).

Conclusion:

Language and motor outcomes after DC in patients with DMCAI are not as dismal as commonly perceived. Perhaps young patients (<50 years) with DMCAI should be treated with the same aggressiveness that non-DMCAI is currently dealt with.Key Words: Craniectomy, dominant, middle cerebral artery, outcome, stroke  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