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   335篇
  免费   29篇
  国内免费   3篇
耳鼻咽喉   5篇
儿科学   6篇
妇产科学   2篇
基础医学   50篇
口腔科学   8篇
临床医学   23篇
内科学   61篇
皮肤病学   7篇
神经病学   27篇
特种医学   24篇
外科学   60篇
综合类   8篇
一般理论   1篇
预防医学   25篇
眼科学   2篇
药学   16篇
中国医学   6篇
肿瘤学   36篇
  2023年   7篇
  2022年   17篇
  2021年   17篇
  2020年   15篇
  2019年   18篇
  2018年   21篇
  2017年   11篇
  2016年   5篇
  2015年   13篇
  2014年   16篇
  2013年   21篇
  2012年   22篇
  2011年   12篇
  2010年   5篇
  2009年   13篇
  2008年   18篇
  2007年   20篇
  2006年   12篇
  2005年   14篇
  2004年   16篇
  2003年   18篇
  2002年   5篇
  2001年   8篇
  2000年   10篇
  1999年   5篇
  1994年   1篇
  1993年   4篇
  1992年   4篇
  1991年   2篇
  1990年   4篇
  1989年   2篇
  1988年   4篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1972年   1篇
  1935年   1篇
排序方式: 共有367条查询结果,搜索用时 703 毫秒
81.
82.
BACKGROUND Colonoscopy is a safe and routine diagnostic and therapeutic procedure for evaluation of large bowel diseases.Most common procedure related complications include bleeding and perforation but rarely a splenic Injury.AIM To investigate the reason for colonoscopy,presentation of patient with spleen injury,types of injury,diagnosis,management and outcomes of patients METHODS A structured search on four databases was done and 45 articles with 68 patients were selected.The reason for colonoscopy,presentation of patient with spleen injury,types of injury,diagnosis,management and outcomes of patients were identified and analyzed using SPSS.RESULTS The mean age of the patients was 62.7 years with 64% females.Twenty two percent had a complete splenic rupture with colonoscopy while 63% had subcapsular hematoma,spleen laceration and spleen avulsion.The most common reason for colonoscopy was screening(46%) followed by diagnostic colonoscopy(28%).Eighty seven percent of patients presented with abdominal pain.Patients with spleen rupture mostly required splenectomy(47%),while minor spleen hematomas and lacerations were managed conservatively(38%).Six percent of the patients were managed with proximal splenic artery splenic embolization and4% were managed with laparoscopic repair.The overall mortality was 10% while77% had complete recovery.The reason of colonoscopy against presentation specifically,abdominal pain showed no statistical significance P = 0.69.The indication of colonoscopy had no significant impact on incidence of splenic injury(P = 0.89).Majority of the patients(47%) were managed with splenectomy while the rest were managed conservatively(P = 0.04).This association was moderately strong at a cramer's V test(0.34).The Fisher exact test showed a higher mortality with spleen rupture(P = 0.028).CONCLUSION Spleen rupture due to colonoscopy is a significant concern and is associated with high mortality.The management of the patients can be individualized based on clinical presentation.  相似文献   
83.

BACKGROUND CONTEXT

The retrotransverse foramen (RTF), arcuate foramen (AF), unclosed transverse foramen (UTF) and posterior atlas arch defects (PAAD) are anatomic variations of the atlas vertebra that surgeons must be aware of before spine surgery is performed.

PURPOSE

To analyze the prevalence of the AF, RTF, UTF, and PAAD.

STUDY DESIGN

Ex-vivo anatomical study.

PATIENT SAMPLE

Two hundred eighteen atlas vertebrae obtained from 100 Caucasian subjects and 118 sub-Saharan African subjects (48 Sotho subjects, 35 Xhosa subjects and 35 Zulu subjects).

METHODS

We studied 218 atlas vertebrae from skeletons of the Raymond A. Dart Collection in order to analyze the prevalence of AF, RTF, UTF, and PAAD in both Caucasian and sub-Saharan African subjects.

OUTCOME MEASURES

Not applicable.

RESULTS

Sixty-nine (31.2%) atlases presented anatomical variants: 64 (29.3%) presented one anatomical variant, 4 (1.8%) presented two, and 1 (0.5%) presented three. AF, RTF, UTF, Type A and Type E defects were present in 35 (16.1%), 17 (7.8%), 17 (7.8%), 5 (2.3%), and 1 (0.5%) vertebrae, respectively. The vertebrae with two anatomical variants presented a bilateral UTF and a Type A defect, a bilateral AF and a Type A defect, a right UTF and a left AF, and a right UTF and a Type E defect. The vertebra with three anatomical variants presented a bilateral RTF, a left UTF, and a left AF. No sex differences in prevalence of the RTF (p=.775), AF (p=.605), UTF (p=.408) and Type A defects (p=1.000) were found in the sub-Saharan African and Caucasian groups (RTF, p=.306; AF, p=.346; UTF, p=.121; Type A defects, p=.561). Comparison between the sub-Saharan African (all subjects) and the Caucasian group revealed no differences in the UTF (p=.105), AF (p=.144), RTF (p=.542) and Type A defects (p=.521) prevalence. Also, no differences in the prevalence of the UTF (p=.515), AF (p=.278), and RTF (p=.857) between Zulu, Xhosa and Sotho subjects were found. Neither were found sex differences in the prevalence of UTF, RTF and AF in Zulu (p=.805, p=.234, p=.129), Xhosa (p=.269, p=.181, p=.309), and Sotho subjects (p=.062, p=.590, p=.106).

CONCLUSIONS

The present study has revealed no sex differences in the prevalence of AF, UTF, RTF or PAAD in both Caucasian and sub-Saharan African subjects. This research has also indicated no differences in the prevalence of the UTF, AF and RTF between Zulu, Xhosa and Sotho subjects. In addition, this study has revealed no differences in the Type A, UTF, AF, and RTF prevalence between the sub-Saharan African (all subjects) and the Caucasian subjects. These variations may be known by surgeons before spine surgery for better planning.  相似文献   
84.
OBJECTIVE: Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autosomal-dominant autoinflammatory condition caused by mutations in the TNFRSF1A gene. The cellular mechanisms by which mutations in this gene trigger inflammation are currently unclear. Because NF-kappaB is the major intracellular signaling component inducing secretion of proinflammatory cytokines, we sought to determine whether differences in the clinical phenotype of patients with TRAPS may be attributable to variable effects of TNFRSF1A mutations on TNFRI expression, localization, or NF-kappaB activity. METHODS: Peripheral blood mononuclear cells were obtained from patients (following informed consent), and cellular nuclear and cytosolic fractions were generated by subcellular fractionation. Localization of IkappaBalpha and NF-kappaB was determined by Western blotting of the resultant fractions. NF-kappaB subunit activity was determined by enzyme-linked immunosorbent assay analysis and confirmed by electrophoretic mobility shift assay. Subcellular localization of TNFRI was determined by immunofluorescence confocal microscopy or by immunoblotting following affinity isolation of plasma membrane by subcellular fractionation. RESULTS: Cells from patients with the fully penetrant C73R mutation had marked activation of the proinflammatory p65 subunit of NF-kappaB. In contrast, cells from patients with the low-penetrant R92Q mutation displayed high levels of DNA binding by the p50 subunit, an interaction previously linked to repression of inflammation. Interestingly, although cells from patients with the C73R mutation have no TNFRI shedding defect, there was nonetheless an unusually high concentration of functional TNFRI at the plasma membrane. CONCLUSION: High levels of TNFRI at the cell surface in patients with the C73R mutation hypersensitizes cells to stimulation by TNF, leading to increased NF-kappaB p65 subunit activation and an exaggerated proinflammatory response.  相似文献   
85.
Two arms of the immune system, innate and adaptive immunity, differ in their mode of immune recognition. The innate immune system recognizes a few highly conserved structures on a broad range of microorganisms. On the other hand, recognition of self or autoreactivity is generally confined to the adaptive immune response. Whilst autoimmune features are relatively common, they should be distinguished from autoimmune disease that is infrequent. Type 1 diabetes is an immune-mediated disease due to the destruction of insulin secreting cells mediated by aggressive immune responses, including activation of the adaptive immune system following genetic and environmental interaction. Hypotheses for the cause of the immune dysfunction leading to type 1 diabetes include self-reactive T-cell clones that (1) escape deletion in the thymus, (2) escape from peripheral tolerance or (3) escape from homeostatic control with an alteration in the immune balance leading to autoimmunity. Evidence, outlined in this review, raises the possibility that changes in the innate immune system could lead to autoimmunity, by either priming or promoting aggressive adaptive immune responses. Hostile microorganisms are identified by genetically determined surface receptors on innate effector cells, thereby promoting clearance of these invaders. These innate effectors include a few relatively inflexible cell populations such as monocytes/macrophages, dendritic cells (DC), natural killer (NK) cells, natural killer T (NKT) cells and gammadelta T cells. Recent studies have identified abnormalities in some of these cells both in patients with type 1 diabetes and in those at risk of the disease. However, it remains unclear whether these abnormalities in innate effector cells predispose to autoimmune disease. If they were to do so, then modulation of the innate immune system could be of therapeutic value in preventing immune-mediated diseases such as type 1 diabetes.  相似文献   
86.
87.
Deep brain stimulation (DBS) may improve disabling tics in severely affected medication and behaviorally resistant Tourette syndrome (TS). Here we review all reported cases of TS DBS and provide updated recommendations for selection, assessment, and management of potential TS DBS cases based on the literature and implantation experience. Candidates should have a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM V) diagnosis of TS with severe motor and vocal tics, which despite exhaustive medical and behavioral treatment trials result in significant impairment. Deep brain stimulation should be offered to patients only by experienced DBS centers after evaluation by a multidisciplinary team. Rigorous preoperative and postoperative outcome measures of tics and associated comorbidities should be used. Tics and comorbid neuropsychiatric conditions should be optimally treated per current expert standards, and tics should be the major cause of disability. Psychogenic tics, embellishment, and malingering should be recognized and addressed. We have removed the previously suggested 25‐year‐old age limit, with the specification that a multidisciplinary team approach for screening is employed. A local ethics committee or institutional review board should be consulted for consideration of cases involving persons younger than 18 years of age, as well as in cases with urgent indications. Tourette syndrome patients represent a unique and complex population, and studies reveal a higher risk for post‐DBS complications. Successes and failures have been reported for multiple brain targets; however, the optimal surgical approach remains unknown. Tourette syndrome DBS, though still evolving, is a promising approach for a subset of medication refractory and severely affected patients. © 2014 International Parkinson and Movement Disorder Society  相似文献   
88.
89.
90.
Endoplasmic reticulum aminopeptidase 1 (ERAP1) processes peptides for major histocompatibility complex (MHC) class I presentation and promotes cytokine receptor ectodomain shedding. These known functions of ERAP1 may explain its genetic association with several autoimmune inflammatory diseases. In this study, we identified four novel alternatively spliced variants of ERAP1 mRNA, designated as ΔExon-11, ΔExon-13, ΔExon-14 and ΔExon-15. We also observed a rapid and differential modulation of ERAP1 mRNA levels and spliced variants in different cell types pretreated with lipopolysaccharide (LPS). We have studied three full-length allelic forms of ERAP1 (R127-K528, P127-K528, P127-R528) and one spliced variant (ΔExon-11) and assessed their interactions with tumour necrosis factor receptor 1 (TNF-R1) in transfected cells. We observed variation in cellular expression of different ERAP1 isoforms, with R127-K528 being expressed at a much lower level. Furthermore, the cellular expression of full-length P127-K528 and ΔExon-11 spliced variant was enhanced significantly when co-transfected with TNF-R1. Isoforms P127-K528, P127-R528 and ΔExon-11 spliced variant associated with TNF-R1, and this interaction occurred in a region within the first 10 exons of ERAP1. Supernatant-derived vesicles from transfected cells contained the full-length and ectodomain form of soluble TNF-R1, as well as carrying the full-length ERAP1 isoforms. We observed marginal differences between TNF-R1 ectodomain levels when co-expressed with individual ERAP1 isoforms, and treatment of transfected cells with tumour necrosis factor (TNF), interleukin (IL)-1β and IL-10 exerted variable effects on TNF-R1 ectodomain cleavage. Our data suggest that ERAP1 isoforms may exhibit differential biological properties and inflammatory mediators could play critical roles in modulating ERAP1 expression, leading to altered functional activities of this enzyme.  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