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   183篇
  免费   15篇
  国内免费   27篇
耳鼻咽喉   1篇
儿科学   29篇
基础医学   16篇
口腔科学   2篇
临床医学   28篇
内科学   32篇
皮肤病学   1篇
神经病学   6篇
特种医学   22篇
外科学   18篇
综合类   8篇
预防医学   14篇
药学   29篇
肿瘤学   19篇
  2023年   2篇
  2022年   2篇
  2021年   1篇
  2020年   5篇
  2018年   5篇
  2017年   2篇
  2016年   3篇
  2015年   3篇
  2014年   6篇
  2013年   9篇
  2012年   7篇
  2011年   13篇
  2010年   4篇
  2009年   7篇
  2008年   8篇
  2007年   25篇
  2006年   19篇
  2005年   15篇
  2004年   7篇
  2003年   5篇
  2002年   4篇
  2001年   3篇
  2000年   5篇
  1999年   5篇
  1998年   2篇
  1997年   3篇
  1996年   10篇
  1995年   11篇
  1994年   1篇
  1993年   6篇
  1992年   2篇
  1991年   4篇
  1990年   4篇
  1989年   3篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1980年   3篇
  1975年   2篇
排序方式: 共有225条查询结果,搜索用时 15 毫秒
91.
92.
To evaluate the outcome of children with high hyperdiploid acute lymphoblastic leukemia (hHDALL) treated at the author's institution. One hundred thirty-five consecutive children with B-precursor ALL were diagnosed between 1991 and 2002: 38 (28.1%) hHDALL and 97 (71.9%) non-hHDALL. In the hHDALL group, 11/38 (28.9%) relapsed at a median interval of 2.8 years (range: 0.8-5.0 years) with 9/11 relapses occurring at the end or after the completion of therapy. Three (27.3%) relapses were isolated hematopoietic (BM), while eight (72.7%) were either isolated extramedullary (EM) relapses (n=6; Testis: 4; CNS: 2) or combined hematopoietic and extramedullary relapses (n=2; BM + CNS: 1; BM + Testis: 1). For the non-hHDALL group, 29/97 (29.9%) relapsed. Unlike the hHDALL group, the non-hHDALL group experienced hematopoietic relapses (62%; n=18) more frequently than isolated extramedullary (27.5%; n=8: Testis: 1; CNS: 7) or combined hematopoietic and extramedullary relapses (10.3%; CNS + BM: 3), with 24/29 (82.8%) of the relapses occurring on therapy. Relapses in hHDALL frequently involved EM sites (P=0.053). Presence of triple trisomy of +4,+10,+17 at diagnosis had a protective effect against relapse (P<0.05). Five-year EFS for the hHDALL and non-hHDALL patients was similar, 70.5+/-7.5% and 66.4+/-4.9%, respectively. Five-year OS for the hHDALL patients was significantly higher than for the non-hHDALL patients, 92+/-4.5% vs. 74.1+/-4.5%, P=0.038. Biologically significant differences exist between relapse patterns of hHDALL and non-hHDALL cases related to relapse sites and time periods when relapses occur. hHDALL relapses continue to be chemo-sensitive.  相似文献   
93.
94.
95.
The myosin II motor from Dictyostelium discoideum has been engineered to contain single tryptophan residues at strategic locations to probe movements of switch 1 and switch 2. The tryptophan residue at W501 probes movement of the relay helix and indirectly reports on switch 2 movement. This probe suggests that there is an equilibrium between the switch 2 open- and closed-states when the γ-phosphate position is occupied. Actin does not appear to greatly affect this equilibrium directly, but has indirect influence via switch 1. The latter region has been probed by introducing tryptophan residues at positions 239 and 242. The kinetics of the actomyosin ATPase in solution is discussed with respect to recent crossbridge models based on high-resolution crystal structures. To whom correspondence should be addressed: Tel.: +44-(0)-116-229-7048; Fax: +44-(0)-116-229-7018; E-mail: crb5@le.ac.uk  相似文献   
96.
Clinical research examining the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute myeloid leukemia (AML) in children is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in the table entitled “Summary of Treatment Recommendations Made by the Expert Panel for Pediatric Acute Myeloid Leukemia” and were reached unanimously by a panel of experts in AML. The identified priority areas of needed future research in pediatric AML include: What is the role of risk group stratification, including the role of cytogenetics, in selection of patients for allogeneic SCT, especially those in first CR? What is the appropriate timing and use of alternative donor SCT, given that matched unrelated donor SCT appears to yield outcomes equivalent to matched related donor SCT? What is the role of reduced intensity SCT (including the use of fludarabine-based preparative regimens) and/or other immunomodulatory approaches to maximize the graft-versus-leukemic effect? and What is the role of biologically targeted agents (ie, tyrosine kinase inhibitors, farnesyl transferase inhibitors, Flt-3 inhibitors, etc) in the treatment of AML, including induction, consolidation, conditioning regimens, and after SCT?  相似文献   
97.
Objective To induce islet allograft long- term survival through cotransplantation of islet cells with sertoli cells. Methods Testicular sertoli cells were prepared by digestion with collagenase, trypsin an d DNase, and were cultured for 48 hours. Collagenase digested and Ficoll purifi ed donor (Wistar rat) islets were cotransplanted with allogeneic sertoli cells i n the absence of systemic immunosuppression. Terminal deoxynucleotidyl transfer ase- mediated X- dUTP nick- end labeling (TUNEL) was used to label apoptosis of lymphocytes surrounding the islet graft. Results Cotransplantation of islets and 1×10(7) sertoli cells reversed the diabetic sta te for more than 60 days in 100% (6/6) of the chemically diabetic Sprague Dawley rats. Grafts consisting of islets alone or islets plus 1×10(5) sertoli cells survived only for 5-6 days. Apoptosis of lymphocytes surrounding the islets was quite clear. Conclusion Cotransplantation of islets with FasL[+] sertoli cells induces local immune priv ilege and allows long- term graft survival without systemic immunosuppression.  相似文献   
98.
PURPOSE: A previous Pediatric Oncology Group (POG) study showed high incidence of secondary acute myelogenous leukemia (AML) in children treated for T-cell acute lymphoblastic leukemia (T-ALL) or higher-stage lymphoblastic lymphoma. To prevent secondary neoplasms, induce prolonged asparagine depletion, and maintain high event-free survival (EFS) in children with newly diagnosed T-ALL or higher-stage non-Hodgkins lymphoma (NHL), we designed this pilot study to determine feasibility and safety of substituting methotrexate/mercaptopurine for teniposide/cytarabine and PEG-asparaginase for native asparaginase. PATIENTS AND METHODS: Forty-five patients were entered, 29 with T-ALL and 16 with higher-stage NHL. Forty-two of 45 patients achieved complete remission (CR), and 27 completed the therapy in continuous CR. Treatment consisted of 4-week induction then 6 weeks consolidation and ten 9-week maintenance cycles. Therapy primarily comprised antimetabolites, anthracyclines, alkylating agents, and asparaginase. Expected chemotherapy duration was 100 weeks. RESULTS: Forty-two of 45 patients achieved CR, and 27 completed therapy. The most common toxicities were Grade 3 or 4 myelosuppression after cyclophosphamide/cytarabine and allergic reactions to asparaginase. Two died of sepsis early in maintenance. Five-year EFS was 68.5% (SE 9.1%) for T-ALL and 81.3% (SE 9.8%) for NHL. Five-year EFS was 73.1% (SE 6.8%) for the entire cohort. No patients treated entirely on this study developed secondary neoplasms. One patient taken off study for asparaginase toxicity was treated with multiagent therapy that contained teniposide, and died from secondary myelodysplasia (sMDS)/AML. CONCLUSION: Substituting methotrexate/mercaptopurine for teniposide/cytarabine and PEG-asparaginase for native asparaginase in a dose-intensive regimen was feasible in children and young adults with newly diagnosed T-ALL or higher-stage NHL. EFS was not compromised and secondary neoplasms were decreased.  相似文献   
99.
MDA Publications     
This article evaluates all the EEG parameters suggested in the literature that undergo changes due to anaesthetic dose, and suggests a set of EEG parameters that act as best signatures of anaesthetic state of a patient. This set of EEG parameters is validated by an artificial neural network.

Primary objective: The purpose of this study is to arrive at a set of EEG parameters that ‘best’ distinguish between awake and anaesthetized states of human patients for halothane anaesthesia.

Methods and procedures: A total of 21 EEG parameters were evaluated for 40 patients. Stepwise discriminant analysis (SDA) pruned them to a set of five parameters. They were fed to a 5–3–1 artificial neural network (ANN) for classification into awake and anaesthetized state. To confirm the results, variance analysis was applied to the set of 21 parameters. Five parameters were finalized after validation by the ANN.

Main outcomes and results: The classification accuracy of the ANN with SDA parameters was found to be 96%. With variance analysis parameters, it returned an accuracy of 100%.

Conclusion: The set of five EEG parameters - approximate entropy, average frequency, Lempel Ziv (LZ) complexity, delta power and beta power forms the best set to distinguish between awake and anaesthetized state of human patients. Variance analysis is a better tool to converge at the optimal set than SDA.  相似文献   
100.

Background  

The number of hip fractures during recent decades has been reported to be increasing, partly because of an increasing proportion of elderly women in the society. However, whether changes in hip fracture annual incidence in women are attributable to secular changes in the prevalence of osteoporosis is unclear.  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