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   11733篇
  免费   82篇
  国内免费   43篇
耳鼻咽喉   70篇
儿科学   496篇
妇产科学   296篇
基础医学   1273篇
口腔科学   397篇
临床医学   1051篇
内科学   1664篇
皮肤病学   251篇
神经病学   1106篇
特种医学   252篇
外科学   951篇
综合类   265篇
预防医学   736篇
眼科学   140篇
药学   1754篇
  1篇
中国医学   108篇
肿瘤学   1047篇
  2024年   64篇
  2023年   795篇
  2022年   551篇
  2021年   865篇
  2020年   1027篇
  2019年   1084篇
  2018年   1106篇
  2017年   741篇
  2016年   528篇
  2015年   466篇
  2014年   1006篇
  2013年   1873篇
  2012年   288篇
  2011年   120篇
  2010年   140篇
  2009年   110篇
  2008年   90篇
  2007年   96篇
  2006年   60篇
  2005年   122篇
  2004年   75篇
  2003年   54篇
  2002年   46篇
  2001年   52篇
  2000年   42篇
  1999年   49篇
  1998年   25篇
  1997年   21篇
  1996年   20篇
  1995年   16篇
  1994年   21篇
  1993年   10篇
  1991年   5篇
  1990年   10篇
  1989年   10篇
  1988年   8篇
  1987年   10篇
  1986年   4篇
  1985年   36篇
  1984年   40篇
  1983年   27篇
  1982年   30篇
  1981年   22篇
  1980年   22篇
  1979年   14篇
  1978年   12篇
  1977年   5篇
  1976年   12篇
  1975年   8篇
  1974年   12篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Purpose: Although research supports family–professional collaboration, challenges to implementation have been reported. The case reports describe the implementation of a 4-step practice model that incorporates specific strategies to facilitate family–professional collaboration.

Method: The participants were two mothers of children with physical disabilities and two physical therapists. Therapists received instruction in the strategies for collaboration including client-centred interview, visualising a preferred future, scaling questions, and family routine and activity matrix. The intervention was implemented during 6-weekly sessions. The 2nd and 5th sessions were videotaped to analyse the interactions between the parent and therapist using Response Class Matrix. Telephone interviews were conducted to explore participants’ experiences.

Results: Therapists were able to implement all strategies following 6 h of instruction. Analysis of the videotapes indicated that mother–therapist interactions were characterised by sharing information and open communication in a mutually supportive manner. Interviews with the mothers and therapists indicated that the therapists engaged the mothers in the intervention process and tailored interventions to child and family needs. The scaling questions were difficult to implement (therapists) and answer (parents).

Conclusion: The findings suggest that the strategies can be used by therapists to promote collaboration and involve parents in setting goals and the intervention process.

  • Implications for Rehabilitation
  • Strategies to promote parent–therapist collaboration include client-centred interview, visualising a preferred future, scaling questions, and family routine and activity matrix.

  • Therapists with no previous instruction or training on family-centred services successfully implemented the strategies following 6 h of instruction.

  • Interactions between two parent–physical therapist dyads were characterised by sharing information and open communication in a mutually supportive manner following therapist instruction in strategies for parent–therapist collaboration.

  相似文献   
992.
Iron is an essential trace element and involved in various key metabolic pathways in bacterial lifestyle. Within the human host, iron is extremely limited. Hence, the ability of bacteria to acquire iron from the environment is critical for a successful infection. Streptococcus pneumoniae (the pneumococcus) is a human pathobiont colonizing symptomless the human respiratory tract, but can also cause various local and invasive infections. To survive and proliferate pneumococci have therefore to adapt their metabolism and virulence factor repertoire to different host compartments. In this study, the response of S. pneumoniae to iron limitation as infection-relevant condition was investigated on the proteome level. The iron limitation was induced by application of the iron chelator 2,2′-bipyridine (BIP) in two different media mimicking different physiological traits. Under these conditions, the influence of the initial iron concentration on pneumococcal protein expression in response to limited iron availability was analyzed. Interestingly, one major difference between these two iron limitation experiments is the regulation of proteins involved in pneumococcal pathogenesis. In iron-poor medium several proteins of this group were downregulated whereas these proteins are upregulated in iron-rich medium. However, iron limitation in both environments led to a strong upregulation of the iron uptake protein PiuA and the significant downregulation of the non-heme iron-containing ferritin Dpr. Based on the results, it is shown that the pneumococcal proteome response to iron limitation is strongly dependent on the initial iron concentration in the medium or the environment.  相似文献   
993.
The hematopoietic cell transplantation–specific comorbidity index (HCT-CI) has been recently proposed to predict the probability of nonrelapse mortality (NRM) and overall survival (OS) in allogeneic hematopoietic stem cell transplantation (HSCT). However, the usefulness of the HCT-CI in single-unit umbilical cord blood transplantation (UCBT) remains unclear. We investigated the impact of the HCT-CI on the clinical outcomes of allogeneic HSCT in a single-center retrospective study including 53 recipients of UCBT (UCBT group) and 90 recipients of other HSCT (non-UCBT group). In the non-UCBT group 2-year OS rates for HCT-CI score <?3 and?≥3 were 67% (n?=?74; 95% confidence interval [CI], 54% to 78%) and 26% (n?=?16; 95% CI, 7% to 51%), respectively (P?=?.001). In the UCBT group these rates were 66% (n?=?39; 95% CI, 48% to 79%) and 69% (n?=?14; 95% CI, 36% to 87%), respectively (P?=?.73). In the non-UCBT group 1-year NRM rates for HCT-CI score <?3 and?≥3 were 14% (95% CI, 6.4% to 22%) and 37% (95% CI, 14% to 61%), respectively (P?=?.02). In the UCBT group these rates were 6.1% (95% CI, 3.4% to 24%) and 7.7% (95% CI, .4% to 29%), respectively (P?=?.78). Using multivariate analysis we showed that HCT-CI score ≥ 3 was significantly associated with lower OS (hazard ratio, 3.06; 95% CI, 1.47 to 6.38; P?=?.003) and higher NRM (hazard ratio, 2.87; 95% CI, 1.18 to 6.96; P?=?.02) for the non-UCBT group. UCBT showed good OS with low incidence of NRM, even in patients with high HCT-CI scores. Altogether, we propose single-unit UCB to be a promising stem cell source for improving survival in patients with multiple comorbidities.  相似文献   
994.
High-dose melphalan followed by autologous stem cell transplant (ASCT) is standard of care for eligible patients with multiple myeloma (MM). Evomela (propylene glycol–free melphalan HCl [PG-Free Mel]; Spectrum Pharmaceuticals, Irvine, CA) was approved by the US Food and Drug Administration as conditioning therapy for ASCT in MM in 2 daily 100-mg/m2 doses for a total dose of 200?mg/m2. In this phase II, open-label study PG-Free Mel (Evomela) conditioning was given at single dose of 200?mg/m2 on day ?2 pre-ASCT to establish pharmacokinetic (PK) parameters and safety. Twenty-four patients (median age, 64 years) were enrolled between August 2016 and February 2017. Myeloablation followed by successful neutrophil engraftment occurred at a median of 10 days in all patients. Peak melphalan concentration was observed at 10 minutes after infusion, whereas there was considerable variation in the maximum plasma concentration (Cmax) and area under concentration time curve (AUC). Median Cmax was 7380?ng/mL (interquartile range [IQR], 6522 to 8027). Similarly, median AUC was 533,552?ng/mL?min (IQR, 450,850 to 662,936). PG-Free Mel had an acceptable safety profile regardless of the exposure, with no mortality and an overall response rate of 96% and a very good partial response rate of 75%. In conclusion, although PG-Free Mel at a single dose of 200?mg/m2 was safe, considerable PK variability was observed with the highest quartile having an ~3-fold higher AUC than the first quartile, suggesting that strategies for higher targeted exposure could be explored in future trials to optimize clinical benefit.  相似文献   
995.
BackgroundDeriving suitable dosing regimens for antibiotic combination therapy poses several challenges as the drug interaction can be highly complex, the traditional pharmacokinetic–pharmacodynamic (PKPD) index methodology cannot be applied straightforwardly, and exploring all possible dose combinations is unfeasible. Therefore, semi-mechanistic PKPD models developed based on in vitro single and combination experiments can be valuable to suggest suitable combination dosing regimens.AimsTo outline how the interaction between two antibiotics has been characterized in semi-mechanistic PKPD models. We also explain how such models can be applied to support dosing regimens and design future studies.SourcesPubMed search for published semi-mechanistic PKPD models of antibiotic drug combinations.ContentThirteen publications were identified where ten had applied subpopulation synergy to characterize the combined effect, i.e. independent killing rates for each drug and bacterial subpopulation. We report the various types of interaction functions that have been used to describe the combined drug effects and that characterized potential deviations from additivity under the PKPD model. Simulations from the models had commonly been performed to compare single versus combined dosing regimens and/or to propose improved dosing regimens.ImplicationsSemi-mechanistic PKPD models allow for integration of knowledge on the interaction between antibiotics for various PK and PD profiles, and can account for associated variability within the population as well as parameter uncertainty. Decisions on suitable combination regimens can thereby be facilitated. We find the application of semi-mechanistic PKPD models to be essential for efficient development of antibiotic combination regimens that optimize bacterial killing and/or suppress resistance development.  相似文献   
996.

Background/Purpose

The purpose of this study was to review the management of obstructive symptoms and enterocolitis (HAEC) following pull-through for Hirschsprung's disease.

Methods

A systematic review and meta-analysis (1992–2017) was performed. Included studies were: randomized controlled trials (RCT), retrospective/prospective case–control (C-C), case-series (C-S). Random-effect model was used to produce risk ratio (RR) [95% CI]. P?<?0.05 was considered significant.

Results

Twenty-nine studies were identified. Routine postoperative dilatations (5 C-S, 2 C-C; 405 patients): no effect on stricture incidence (RR 0.3 [0.02–5.7]; p?=?0.4). Routine postoperative rectal irrigations (2 C-C; 172 patients): reduced HAEC incidence (RR 0.2 [0.1–0.5]; p?=?0.001). Posterior myotomy/myectomy (4 C-S; 53 patients): resolved obstructive symptoms in 79% [60.6–93.5] and HAEC in 80% [64.1–92.1]. Botulinum toxin injection (9 C-S; 166 patients): short-term response in 77.3% [68.2–85.2], long-term response in 43.0% [26.9–59.9]. Topical nitric oxide (3 C-S; 13 patients): improvement in 100% of patients. Probiotic prophylaxis (3 RCT; 160 patients): no reduction in HAEC (RR 0.6 [0.2–1.7]; p?=?0.3). Anti-inflammatory drugs (1 C-S, sodium cromoglycate; 8 patients): improvement of HAEC in 75% of patients.

Conclusions

Several strategies with variable results are available in patients with obstructive symptoms and HAEC. Routine postoperative dilatations and prophylactic probiotics have no role in reducing the incidence of postoperative obstructive symptoms and HAEC.

Type of study

Systematic review and meta-analysis.

Level of evidence

Level II.  相似文献   
997.
998.
999.

Objectives

Ischemic mitral regurgitation (IMR) results from ischemic left ventricular (LV) distortion and remodeling, which displaces the papillary muscles and tethers the mitral valve leaflets apically. The aim of this experimental study was to examine efficacy of an adjustable novel polymer filled mesh (poly-mesh) device to reverse LV remodeling and reduce IMR.

Methods

Acute (N = 8) and chronic (8 weeks; N = 5) sheep models of IMR were studied. IMR was produced by ligation of circumflex branches to create myocardial infarction. An adjustable poly-mesh device was attached to infarcted myocardium in acute and chronic IMR models and compared with untreated sham sheep. Two- and 3-dimensional echocardiography and hemodynamic measurements were performed at baseline, post IMR, and post poly-mesh (humanely killed).

Results

In acute models, moderate IMR developed in all sheep and decreased to trace/mild (vena contracta: 0.50 ± 0.09 cm to 0.26 ± 0.12 cm; P < .01) after poly-mesh. In chronic models, IMR decreased in all sheep after poly-mesh, and this reduction persisted over 8 weeks (vena contracta: 0.42 ± 0.09 cm to 0.08 ± 0.12 cm; P < .01) with significant increase in the slope of end-systolic pressure–volume relationship (1.1 ± 0.5 mm Hg/mL to 2.9 ± 0.7 mm Hg/mL; P < .05). There was a significant reduction in LV volumes from chronic IMR to euthanasia stage with poly-mesh compared with sham group (%end-diastolic volume change ?20 ± 11 vs 15% ± 16%, P < .01; %end-systolic volume change ?14% ± 19% vs 22% ± 22%, P < .05; poly-mesh vs sham group) consistent with reverse remodeling.

Conclusions

An adjustable polymer filled mesh device reduces IMR and prevents continued LV remodeling during chronic follow-up.  相似文献   
1000.

Objectives

Readmission rates after cardiac surgery are being used as a quality indicator; they are also being collected by Medicare and are tied to reimbursement. Accurate knowledge of readmission rates may be difficult to achieve because patients may be readmitted to different hospitals. In our area, 81 hospitals share administrative claims data; 28 of these hospitals (from 5 different hospital systems) do cardiac surgery and share Society of Thoracic Surgeons (STS) clinical data. We used these 2 sources to compare the readmissions data for accuracy.

Methods

A total of 45,539 STS records from January 2008 to December 2016 were matched with the hospital billing data records. Using the index visit as the start date, the billing records were queried for any subsequent in-patient visits for that patient. The billing records included date of readmission and hospital of readmission data and were compared with the data captured in the STS record.

Results

We found 1153 (2.5%) patients who had STS records that were marked “No” or “missing,” but there were billing records that showed a readmission. The reported STS readmission rate of 4796 (10.5%) underreported the readmission rate by 2.5 actual percentage points. The true rate should have been 13.0%. Actual readmission rate was 23.8% higher than reported by the clinical database. Approximately 36% of readmissions were to a hospital that was a part of a different hospital system.

Conclusions

It is important to know accurate readmission rates for quality improvement processes and institutional financial planning. Matching patient records to an administrative database showed that the clinical database may fail to capture many readmissions. Combining data with an administrative database can enhance accuracy of reporting.  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