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   273篇
  免费   18篇
  国内免费   9篇
耳鼻咽喉   2篇
儿科学   11篇
妇产科学   1篇
基础医学   15篇
口腔科学   2篇
临床医学   12篇
内科学   45篇
皮肤病学   1篇
神经病学   10篇
特种医学   120篇
外科学   68篇
预防医学   7篇
药学   5篇
肿瘤学   1篇
  2023年   3篇
  2022年   3篇
  2021年   3篇
  2020年   4篇
  2019年   2篇
  2018年   5篇
  2017年   10篇
  2016年   7篇
  2015年   11篇
  2014年   13篇
  2013年   11篇
  2012年   15篇
  2011年   15篇
  2010年   13篇
  2009年   5篇
  2008年   14篇
  2007年   15篇
  2006年   11篇
  2005年   13篇
  2004年   15篇
  2003年   5篇
  2002年   8篇
  2001年   6篇
  2000年   10篇
  1999年   9篇
  1998年   2篇
  1997年   6篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   6篇
  1991年   15篇
  1990年   7篇
  1989年   3篇
  1988年   3篇
  1987年   1篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   5篇
  1980年   4篇
  1979年   2篇
  1978年   4篇
  1977年   3篇
  1976年   1篇
  1974年   1篇
  1965年   1篇
排序方式: 共有300条查询结果,搜索用时 0 毫秒
1.
Hormonal and metabolic response to operative stress in the neonate   总被引:1,自引:0,他引:1  
It is evident from this review that newborns, even those born prematurely, are capable of mounting an endocrine and metabolic response to operative stress. Unfortunately, many of the areas for which a relatively well-characterized response exists in adults are poorly documented in neonates. As is the case in adults, the response seems to be primarily catabolic in nature because the combined hormonal changes include an increased release of catabolic hormones such as catecholamines, glucagon, and corticosteroids coupled with a suppression of and peripheral resistance to the effects of the primary anabolic hormone, insulin.  相似文献   
2.
3.
Patients after kidney, heart and lung transplantation differ in their immunosuppressive drug regimens and in susceptibility to infectious complications with cytomegalovirus (CMV). In this study, CMV-specific T-cell responses were characterized in long-term transplant recipients and associated with the frequency of infectious complications. CMV-reactive CD4 T cells from 50 healthy controls, 68 renal, 14 heart and 24 lung transplant recipients were flow cytometrically quantified by the induction of cytokines after specific stimulation. Moreover, the immunosuppressive effect of calcineurin inhibitors on specific T-cell reactivity was quantified in vitro and compared with responses in vivo. Median CMV-specific T-cell frequencies in long-term renal (1.48%; range 0.06-17.26%) and heart transplant recipients (0.90%; 0.13-12.49%) did not differ from controls (1.82%; 0.26-21.00%). In contrast, CMV-specific T-cell levels were significantly lower in lung transplant recipients (0.50%; <0.05-4.98%) and showed a significant correlation with the frequency of infectious episodes (r =-0.57, p = 0.005). The differences within the groups were associated with increasing dosages of immunosuppressive drugs, as exemplified for calcineurin inhibitors that dose dependently reduced specific T-cell reactivity in vitro. In conclusion, monitoring CMV-specific CD4 T cells may serve as a measure for long-term disease susceptibility and may contribute to an improved management of CMV complications after lung transplantation.  相似文献   
4.
Previous investigators have suggested that opsonization of two Bacteroides species is mediated exclusively by the alternative complement pathway and requires immunoglobulins. In this study, the nature of the opsonic factors in nonimmune human serum for four species of Bacteroides was investigated by measuring uptake of [(3)H]thymidine-labeled bacteria by human polymorphonuclear leukocytes. Normal human serum, C2-deficient serum, immunoglobulin-deficient serum, and serum chelated with ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid (EGTA), MgEGTA, and ethylenediaminetetraacetic acid (EDTA) were used as opsonic sources. Heat inactivation of each of these sera significantly reduced its opsonic activity for all four Bacteroides species, suggesting that serum complement was essential for effective opsonization. All strains were opsonized in the absence of the classical complement pathway; however, kinetics studies revealed that opsonization proceeded at a significantly faster rate when the classical complement pathway was intact. Although two strains were opsonized in immunoglobulin-deficient sera, opsonization was less efficient and appeared to occur via the alternative complement pathway. Unexpectedly, all strains were well opsonized by the classical complement pathway in 10% serum which had been effectively chelated with EGTA or EDTA. The explanation for this finding is unknown; however, it is possible that cell wall cations of Bacteroides species may participate in the activation of complement in chelated serum, resulting in effective opsonization. It was also found that Bacteroides, when incubated with an Escherichia coli strain in normal serum, could compete for opsonins and thereby reduce phagocytosis of E. coli. It is possible that competition for opsonins among bacterial species contributes to the synergistic role these organisms share in mixed floral infections.  相似文献   
5.
In previous studies, encapsulated Staphylococcus aureus strains have been shown to resist phagocytosis. In this investigation, the nature of the interference with phagocytosis by human polymorphonuclear leukocytes was examined by studying the opsonization of two pairs of unencapsulated (Smith compact and M variant) and encapsulated (Smith diffuse and M) S. aureus strains. The uptake of [3H]glycine-labeled bacteria by normal leukocytes was quantitatively measured after incubation of bacteria in pooled serum, C2-deficient serum, immunoglobulin-deficient serum, and serum from a rabbit immunized with S. aureus M. The presence of a capsule was found to interfere with opsonization by both the classical and alternative pathways of complement as well as by heat-stable opsonic factors in nonimmune human serum. This interference was significantly greater in the case of the S. aureus M strain than in the case of the Smith diffuse strain. The only effective opsonic source for S. aureus M was immune rabbit serum. It is proposed that encapsulation of S. aureus strains interferes with phagocytosis by preventing effective bacterial opsonization.  相似文献   
6.
It is unknown if solid organ transplant recipients are at higher risk for severe COVID-19. The management of a lung transplantation (LTx) program and the therapeutic strategies to adapt the immunosuppressive regimen and antiviral measures is a major issue in the COVID-19 era, but little is known about worldwide practice. We sent out to 180 LTx centers worldwide in June 2020 a survey with 63 questions, both regarding the management of a LTx program in the COVID-19 era and the therapeutic strategies to treat COVID-19 LTx recipients. We received a total of 78 responses from 15 countries. Among participants, 81% declared a reduction of the activity and 47% restricted LTx for urgent cases only. Sixteen centers observed deaths on waiting listed patients and eight centers performed LTx for COVID-19 disease. In 62% of the centers, COVID-19 was diagnosed in LTx recipients, most of them not severe cases. The most common immunosuppressive management included a decreased dose or pausing of the cell cycle inhibitors. Remdesivir, hydroxychloroquine, and azithromycin were the most proposed antiviral strategies. Most of the centers have been affected by the COVID-19 pandemic and proposed an active therapeutic strategy to treat LTx recipients with COVID-19.  相似文献   
7.
Arteriovenous malformations are vascular anomalies characterised by the presence of an arteriovenous shunt in the absence of a normally structured capillary bed. The prevalence of manifestations in the brain is given in specialist literature with a high level of variability. Brain hemorrhages resulting from a lesion of a cerebral arteriovenous malformation and leading to sudden unexpected death are relatively seldom in forensic autopsy material. The forensic significance of this syndrome may be illustrated by the example of a 16-year-old female who was found dead in the bathroom of her parents?? home for reasons which were initially unexplained.  相似文献   
8.
9.
10.
To characterize the clinical features and outcomes of childhood-onset primary Sjögren’s syndrome (pSS). Patients less than 18 years old who were diagnosed with pSS by paediatric rheumatologists were included, and all patients were applied the 2002 American-European Consensus Group (ACEG) criteria, the 2016 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria for pSS, or the 1999 proposed juvenile pSS criteria. The electronic medical records of patients with pSS from 2013 to 2020 were collected and analysed. Thirty-nine patients were included. Of them, 27 (69.2%), 38 (97.4%) and 35 (89.7%) patients fulfilled the AECG criteria, ACR/EULAR criteria and proposed juvenile pSS criteria, respectively. The female:male ratio was 3.9:1. The median ages at first signs or symptoms and at diagnosis were 9.2 (4.7, 14.5) years and 10.9 (6.3, 15.0) years, respectively. The main clinical manifestations were rash or purpura (20, 51.3%), followed by fever (12, 30.8%), glandular enlargement/recurrent parotitis (10, 25.6%), and dry mouth and/or dry eyes (9, 23.1%). Twenty-eight (56.4%) patients had systemic damage, the most common of which was haematological involvement (14, 35.9%), followed by hepatic (13, 33.3%) and renal involvement (8, 20.5%). Thirty-eight (97.4%) patients underwent labial minor salivary gland biopsy, and all exhibited focal lymphocytic sialadenitis. All patients had a global ESSDAI score ≥ 1 at diagnosis, and the median total score at diagnosis was 8 (2, 31). Thirty-six (92.3%) patients were followed up for a median time of 23.6 (7.9, 79.5) months, and three patients developed systemic lupus erythematosus (SLE) at follow-up times of 13.3, 38.8 and 63.8 months. The presentation of childhood-onset pSS is atypical, and extraglandular manifestations and systemic involvement are more common than in adult-onset pSS. Labial salivary gland biopsy is vital for patients with probable pSS. Some patients may develop SLE over time.  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