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   1399篇
  免费   126篇
  国内免费   6篇
医药卫生   1531篇
  2023年   22篇
  2022年   26篇
  2021年   101篇
  2020年   48篇
  2019年   76篇
  2018年   76篇
  2017年   72篇
  2016年   79篇
  2015年   79篇
  2014年   111篇
  2013年   92篇
  2012年   136篇
  2011年   115篇
  2010年   65篇
  2009年   27篇
  2008年   47篇
  2007年   37篇
  2006年   37篇
  2005年   32篇
  2004年   29篇
  2003年   23篇
  2002年   19篇
  2001年   20篇
  2000年   18篇
  1999年   14篇
  1998年   12篇
  1997年   6篇
  1996年   4篇
  1995年   2篇
  1994年   3篇
  1992年   7篇
  1991年   6篇
  1990年   8篇
  1989年   12篇
  1988年   6篇
  1987年   11篇
  1986年   4篇
  1985年   10篇
  1984年   3篇
  1983年   3篇
  1980年   2篇
  1979年   5篇
  1977年   3篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   7篇
  1972年   1篇
  1967年   3篇
  1965年   4篇
排序方式: 共有1531条查询结果,搜索用时 31 毫秒
1.
Several studies have used a variety of neuroimaging techniques to measure brain activity during the voiding phase of micturition. However, there is a lack of consensus on which regions of the brain are activated during voiding. The aim of this meta‐analysis is to identify the brain regions that are consistently activated during voiding in healthy adults across different studies. We searched the literature for neuroimaging studies that reported brain co‐ordinates that were activated during voiding. We excluded studies that reported co‐ordinates only for bladder filling, during pelvic floor contraction only, and studies that focused on abnormal bladder states such as the neurogenic bladder. We used the activation‐likelihood estimation (ALE) approach to create a statistical map of the brain and identify the brain co‐ordinates that were activated across different studies. We identified nine studies that reported brain activation during the task of voiding in 91 healthy subjects. Together, these studies reported 117 foci for ALE analysis. Our ALE map yielded six clusters of activation in the pons, cerebellum, insula, anterior cingulate cortex (ACC), thalamus, and the inferior frontal gyrus. Regions of the brain involved in executive control (frontal cortex), interoception (ACC, insula), motor control (cerebellum, thalamus), and brainstem (pons) are involved in micturition. This analysis provides insight into the supraspinal control of voiding in healthy adults and provides a framework to understand dysfunctional voiding. Clin. Anat., 2018. © 2018 Wiley Periodicals, Inc.  相似文献   
2.
3.
ObjectiveTo compare image quality of free-breathing T2-weighted MultiVane-XD (MVXD) sequence (non-Cartesian k-space filling using radial rectangular blades) with conventional MR sequences (short tau inversion recovery [STIR],balanced true field echo [BTFE], T1 in phase fast field echo [T1 FFE], and T1-fat saturated postgadolinium [T1PG]) in MR imaging of chest.Materials and MethodsTwenty-one patients (10 men and 11 women) underwent chest MRI including T2W MVXD, STIR, BTFE (18/21), T1 FFE, T1PG (10/21) sequences at 1.5 T. Two reviewers (A.S.B and M.J. with 20 and 10 years of experience in pulmonary imaging, respectively) evaluated each sequence with respect to overall image quality, image sharpness, definition of mediastinal vessels including the aorta, pulmonary arteries, superior vena cava, intrapulmonary vessels; trachea, main bronchi, intrapulmonary airways; lung-mediastinal interface, pulmonary lesion detection, and artefacts in the upper, middle, and lower third of chest using 5-point scales. No sedation was given. Pairwise comparisons between T2W MVXD and the 4 conventional sequences were made using unpaired student's t test.ResultsMean age of patients was 30.67 years (range: 6-60 years). T2 MVXD showed significantly better overall image quality and sharpness than STIR, T1 FFE, and T1PG (P < 0.01) while it was comparable to BTFE. Mediastinal vessels were significantly better visualized on T2 MVXD as compared to STIR and T1 (P < 0.003). However, BTFE and T1PG were superior to T2 MVXD for visualization of great vessels, SVC, and intrapulmonary vessels (P < 0.01). Visualization of trachea, major bronchi, intrapulmonary airways as well as intrapulmonary lesion detection was significantly better on T2 MVXD images in comparison to any of the other 4 sequences (P < 0.03). Intrapulmonary artifacts were significantly lesser in BTFE images as compared to T2 MVXD (P < 0.01). No significant difference was found between the severity of intrapulmonary artifacts in other MR sequences as compared to T2 MVXD.ConclusionsBy virtue of its better overall image quality, sharpness, superior visualization of mediastinal airways, and lesion detection, T2 MultiVane-XD promises to be a robust addition in the armamentarium of thoracic radiologists.  相似文献   
4.
5.
6.
7.
Congenital dermal melanocytosis (CDM) is a birthmark composed of macular blue‐grey hyperpigmentation commonly observed in the lumbosacral region of infants. Generally resolving by childhood, it is traditionally considered a benign condition, but it may be a sign of underlying lysosomal storage disease. We report a case of biopsy‐confirmed CDM in a 2‐month‐old girl of Brazilian descent later diagnosed with infantile GM1 gangliosidosis.  相似文献   
8.
Quality of life (QoL) encompasses the physical, psychosocial, social and spiritual dimensions of life lived by a person. Cancer pain is one of the physical component has tremendous impact on the QoL of the patient. Cancer pain is multifaceted and complex to understand and managing cancer pain involves a tool box full of pharmacological and non pharmacological interventions but still there are 50-70% of cancer patients who suffer from uncontrolled pain and they fear pain more than death. Aggressive surgeries, radiotherapy and chemotherapy focus more on prolonging the survival of the patient failing to realize that the QoL lived also matters equally. This paper reviews complementary and alternative therapy approaches for cancer pain and its impact in improving the QoL of cancer patients.  相似文献   
9.
BackgroundPhysiologic changes quantified by diffusion and perfusion MRI have shown utility in predicting treatment response in glioblastoma (GBM) patients treated with cytotoxic therapies. We aimed to investigate whether quantitative changes in diffusion and perfusion after treatment by immune checkpoint inhibitors (ICIs) would determine 6-month progression-free survival (PFS6) in patients with recurrent GBM.MethodsInclusion criteria for this retrospective study were: (i) diagnosis of recurrent GBM treated with ICIs and (ii) availability of diffusion and perfusion in pre and post ICI MRI (iii) at ≥6 months follow-up from treatment. After co-registration, mean values of the relative apparent diffusion coefficient (rADC), Ktrans (volume transfer constant), Ve (extravascular extracellular space volume) and Vp (plasma volume), and relative cerebral blood volume (rCBV) were calculated from a volume-of-interest of the enhancing tumor. Final assignment of stable/improved versus progressive disease was determined on 6-month follow-up using modified Response Assessment in Neuro-Oncology criteria.ResultsOut of 19 patients who met inclusion criteria and follow-up (mean ± SD: 7.8 ± 1.4 mo), 12 were determined to have tumor progression, while 7 had treatment response after 6 months of ICI treatment. Only interval change of rADC was suggestive of treatment response. Patients with treatment response (6/7: 86%) had interval increased rADC, while 11/12 (92%) with tumor progression had decreased rADC (P = 0.001). Interval change in rCBV, Ktrans, Vp, and Ve were not indicative of treatment response within 6 months.ConclusionsIn patients with recurrent GBM, interval change in rADC is promising in assessing treatment response versus progression within the first 6 months following ICI treatment.Key Points• In recurrent GBM treated with ICIs, interval change in rADC suggests early treatment response.• Interval change in rADC can be used as an imaging biomarker to determine PFS6.• Interval change in MR perfusion and permeability measures do not suggest ICI treatment response.  相似文献   
10.
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes.  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-23

京公网安备 11010802026262号