首页 | 官方网站   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   516篇
  免费   19篇
医药卫生   535篇
  2021年   7篇
  2020年   7篇
  2019年   14篇
  2018年   11篇
  2017年   5篇
  2015年   9篇
  2014年   10篇
  2013年   11篇
  2012年   21篇
  2011年   26篇
  2010年   13篇
  2009年   18篇
  2008年   23篇
  2007年   18篇
  2006年   20篇
  2005年   26篇
  2004年   19篇
  2003年   7篇
  2002年   17篇
  2001年   16篇
  2000年   12篇
  1999年   9篇
  1996年   5篇
  1995年   5篇
  1992年   15篇
  1991年   9篇
  1990年   15篇
  1989年   12篇
  1988年   15篇
  1987年   17篇
  1986年   12篇
  1985年   7篇
  1984年   5篇
  1980年   3篇
  1979年   13篇
  1978年   5篇
  1977年   7篇
  1976年   7篇
  1975年   7篇
  1974年   8篇
  1973年   5篇
  1972年   7篇
  1971年   4篇
  1970年   5篇
  1969年   3篇
  1968年   2篇
  1967年   2篇
  1966年   2篇
  1965年   2篇
  1962年   2篇
排序方式: 共有535条查询结果,搜索用时 162 毫秒
51.

Objectives Perinatal Quality Collaboratives across the United States are initiating projects to improve health and healthcare for women and infants. We compared an evidence-based group prenatal care model to usual individual prenatal care on birth outcomes in a multi-site expansion of group prenatal care supported by a state-wide multidisciplinary Perinatal Quality Collaborative. Methods We analyzed 15,330 pregnant women aged 14–48 across 13 healthcare practices in South Carolina (2013–2017) using a preferential-within cluster matching propensity score method and logistic regression. Outcomes were extracted from birth certificate data. We compared outcomes for (a) women at the intent-to-treat level and (b) for women participating in at least five group prenatal care visits to women with less than five group visits with at least five prenatal visits total. Results In the intent-to-treat analyses, women who received group prenatal care were significantly less likely to have preterm births (absolute risk difference ? 3.2%, 95% CI ? 5.3 to ? 1.0%), low birth weight births (absolute risk difference ? 3.7%, 95% CI ? 5.5 to ? 1.8%) and NICU admissions (absolute risk difference ? 4.0%, 95% CI ? 5.6 to ? 2.3%). In the as-treated analyses, women had greater improvements compared to intent-to-treat analyses in preterm birth and low birth weight outcomes. Conclusions for Practice CenteringPregnancy group prenatal care is effective across a range of real-world clinical practices for decreasing the risk of preterm birth and low birth weight. This is a feasible approach for other Perinatal Quality Collaboratives to attempt in their ongoing efforts at improving maternal and infant health outcomes.

  相似文献   
52.

Aims

To review the epidemiology and the clinical evidence regarding achieving blood pressure (BP) and blood glucose control in patients with chronic kidney disease (CKD) and diabetes mellitus (DM), with emphasis on adherence and barriers within the context of Australian clinical guidelines. This article then considers Australian services aimed at BP, DM, and CKD, guideline adherence and control.

Methods

Evidence from PubMed-listed articles published between 1994 and 2016 is considered, including original research, focusing on randomised controlled trials and prospective studies, review articles, meta- analyses, expert and professional bodies' guidelines as well as our experience.

Results

There have been no Australian studies that consider adherence to BP control in DM and CKD patients. This is a major limitation in preventing DM and renal disease progression. It is possible that Australian clinicians are not adhering to DM, hypertension (HT), and glucose recommendations, thus resulting in reduced patient outcomes.

Conclusions

It is hoped that future studies ascertain the extent to which the required BP and glucose control in patients is achieved, and the potential barriers to adherence. The significance of this is immense since the impact of failure to control blood glucose levels and BP leads to renal damage.  相似文献   
53.
The rapid advance of gene sequencing technologies has produced an unprecedented rate of discovery of genome variation in humans. A growing number of authoritative clinical repositories archive gene variants and disease phenotypes, yet there are currently many more gene variants that lack clear annotation or disease association. To date, there has been very limited coverage of gene-specific predictors in the literature. Here the evaluation is presented of "gene-specific" predictor models based on a na?ve Bayesian classifier for 20 gene-disease datasets, containing 3986 variants with clinically characterized patient conditions. The utility of gene-specific prediction is then compared with "all-gene" generalized prediction and also with existing popular predictors. Gene-specific computational prediction models derived from clinically curated gene variant disease datasets often outperform established generalized algorithms for novel and uncertain gene variants.  相似文献   
54.

Introduction

Silver dressings are an integral part of the management of burn patients. Package inserts assert a lack of compatibility and safety with magnetic resonance imaging (MRI) and recommend removal prior to any MRI procedure, although there is no clear evidence to support this recommendation. Dressing removal is associated with increased pain, anxiety, stress, and analgesia use. This study was to determine whether these products produce MRI image distortion or if the agitation of the silver particles generates enough heat which might produce further skin damage.

Methods

Hind limbs from euthanized pigs were used in a 7 T MRI scanner with three standard silver wound dressings. Images were obtained with both dry and wet dressings. Temperature was assessed before and during MRI by probes inserted between the dressing and skin. Images were independently reviewed by a radiologist and MR physicist for distortion.

Results

None of the dressings exhibited significant temperature increases nor produced significant distortion that influenced imaging quality.

Conclusion

Our data suggests silver containing wound dressings do not cause a significant increase in dressing temperature or image distortion and thus their removal is not warranted for clinical MRI examinations.  相似文献   
55.
Amyloid fibrils are primarily known in a pathogenic context for their association with a wide range of debilitating human diseases. Here we show a marine invertebrate (Entobdella soleae) utilizes functional amyloid fibrils comparable to those of a unicellular prokaryote (Escherichia coli). Thioflavin-T binding and Raman spectroscopy provided evidence for the presence of amyloid in the adhesive of Entobdella soleae. We elucidated that for these two very different organisms, amyloid fibrils provide adhesive and cohesive strength to their natural adhesives. Comparing the nanoscale mechanical responses of these fibrils with those of pathogenic amyloid by atomic force microscopy revealed that the molecular level origin of the cohesive strength was associated with the generic intermolecular β-sheet structure of amyloid fibrils. Functional adhesive residues were found only in the case of the functional amyloid. Atomic force microscopy provided a useful means to characterize the internal structural forces within individual amyloid fibrils and how these relate to the mechanical performance of both functional and pathogenic amyloid. The mechanistic link of amyloid-based cohesive and adhesive strength could be widespread amongst natural adhesives, irrespective of environment, providing a new strategy for biomimicry and a new source of materials for understanding the formation and stability of amyloid fibrils more generally.  相似文献   
56.

Background and purpose:

Bisphosphonates (BPs) are highly effective inhibitors of bone resorption. Nitrogen-containing bisphosphonates (N-BPs), such as zoledronic acid, induce the formation of a novel ATP analogue (1-adenosin-5′-yl ester 3-(3-methylbut-3-enyl) ester triphosphoric acid; ApppI), as a consequence of the inhibition of farnesyl pyrophosphate synthase and the accumulation of isopentenyl pyrophosphate (IPP). ApppI induces apoptosis, as do comparable metabolites of non-nitrogen-containing bisphosphonates (non-N-BPs). In order to further evaluate a pharmacological role for ApppI, we obtained more detailed data on IPP/ApppI formation in vivo and in vitro. Additionally, zoledronic acid-induced ApppI formation from IPP was compared with the metabolism of clodronate (a non-N-BP) to adenosine 5′(β,γ-dichloromethylene) triphosphate (AppCCl2p).

Experimental approach:

After giving zoledronic acid in vivo to rabbits, IPP/ApppI formation and accumulation was assessed in isolated osteoclasts. The formation of ApppI from IPP was compared with the metabolism of clodronate in MCF-7 cells in vitro. IPP/ApppI and AppCCl2p levels in cell extracts were analysed by mass spectrometry.

Key results:

Isopentenyl pyrophosphate/ApppI were formed in osteoclasts in vivo, after a single, clinically relevant dose of zoledronic acid. Furthermore, exposure of MCF-7 cells in vitro to zoledronic acid at varying times and concentrations induced time- and dose-dependent accumulation of IPP/ApppI. One hour pulse treatment was sufficient to cause IPP accumulation and subsequent ApppI formation, or the metabolism of clodronate into AppCCl2p.

Conclusions and implications:

This study provided the first conclusive evidence that pro-apoptotic ApppI is a biologically significant molecule, and demonstrated that IPP/ApppI analysis is a sensitive tool for investigating pathways involved in BP action.  相似文献   
57.
58.

Background and Objective

Urban firefighters are routinely exposed to both physical and chemical hazards that can negatively impact lung health, but it is unclear if firefighters experience accelerated decline in spirometry parameters due to chronic exposure and acute insults. This study aimed to describe sub-groups of firefighters with differing spirometry trajectories and examine the relationship between the identified trajectories and demographic, lifestyle and occupational characteristics.

Methods

Data from six waves of the Respiratory Function Measurement and Surveillance for South Australian Metropolitan Fire Service Study (2007–2019) were used to identify spirometry parameter z-score trajectories, using group-based multi-trajectory modelling (GBMTM). Analysis of variance and chi-square statistics were used to assess trajectory group differences in baseline self-reported demographic, lifestyle and occupational characteristics.

Results

In the 669 included firefighters, we identified five trajectories for the combination of Forced Expiratory Volume in the first second z-score (FEV1z), Forced Vital Capacity z-score (FVCz) and the ratio of FEV1 and FVC z-score (FEV1/FVCz). There were three stable trajectories of low, average and very high lung function and two declining trajectories of average and high lung function. Analysis of subgroup characteristics revealed no significant differences between expected and actual group proportions for the occupational characteristics of years of service and respiratory protection use. Significant differences were seen in respiratory health and body mass index.

Conclusion

GBMTM defined distinct, plausible spirometry trajectory sub-groups. Firefighter longitudinal spirometry trajectory group membership was associated with BMI and respiratory disease or symptoms but not with self-reported smoking history or occupational factors.  相似文献   
59.
60.
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-23

京公网安备 11010802026262号