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   1103篇
  免费   69篇
  国内免费   4篇
耳鼻咽喉   29篇
儿科学   34篇
妇产科学   19篇
基础医学   155篇
口腔科学   8篇
临床医学   67篇
内科学   269篇
皮肤病学   8篇
神经病学   130篇
特种医学   51篇
外科学   144篇
综合类   1篇
预防医学   72篇
眼科学   1篇
药学   82篇
中国医学   2篇
肿瘤学   104篇
  2024年   3篇
  2023年   5篇
  2022年   19篇
  2021年   53篇
  2020年   23篇
  2019年   29篇
  2018年   45篇
  2017年   33篇
  2016年   34篇
  2015年   44篇
  2014年   53篇
  2013年   55篇
  2012年   90篇
  2011年   72篇
  2010年   46篇
  2009年   52篇
  2008年   76篇
  2007年   72篇
  2006年   54篇
  2005年   68篇
  2004年   59篇
  2003年   42篇
  2002年   37篇
  2001年   15篇
  2000年   17篇
  1999年   11篇
  1998年   4篇
  1997年   8篇
  1996年   8篇
  1995年   6篇
  1994年   4篇
  1993年   4篇
  1992年   9篇
  1991年   7篇
  1990年   6篇
  1989年   2篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1980年   1篇
  1979年   4篇
  1974年   1篇
排序方式: 共有1176条查询结果,搜索用时 15 毫秒
21.
22.
23.
Background: This narrative review presents the association between metabolic syndrome (MetS), along with its components, and cognition-related disorders, as well as the potential reversal role of diet against cognitive impairment by modulating MetS. Methods: An electronic research in Medline (Pubmed) and Scopus was conducted. Results: MetS and cognitive decline share common cardiometabolic pathways as MetS components can trigger cognitive impairment. On the other side, the risk factors for both MetS and cognitive impairment can be reduced by optimizing the nutritional intake. Clinical manifestations such as dyslipidemia, hypertension, diabetes and increased central body adiposity are nutrition-related risk factors present during the prodromal period before cognitive impairment. The Mediterranean dietary pattern stands among the most discussed predominantly plant-based diets in relation to cardiometabolic disorders that may prevent dementia, Alzheimer’s disease and other cognition-related disorders. In addition, accumulating evidence suggests that the consumption of specific dietary food groups as a part of the overall diet can improve cognitive outcomes, maybe due to their involvement in cardiometabolic paths. Conclusions: Early MetS detection may be helpful to prevent or delay cognitive decline. Moreover, this review highlights the importance of healthy nutritional habits to reverse such conditions and the urgency of early lifestyle interventions.  相似文献   
24.
European Archives of Psychiatry and Clinical Neuroscience - Cognitive deficits are increasingly recognized as a core dimension rather than a consequence of schizophrenia (SCZ). The previous...  相似文献   
25.
Journal of Neurology - MRI atrophy predicts cognitive status in AD. However, this relationship has not been investigated in early-onset AD (EOAD, < 65 years) patients...  相似文献   
26.
Benign prostatic hyperplasia is a prevalent disease that has received relatively little attention in spite of its morbidity and remarkable social impact. There are few animal models of prostatic hyperplasia. The dog is the only species, along with humans, in which prostatic hyperplasia develops spontaneously and almost universally with age. The aim of the present study has been to compare the ultrastructural findings in a model of experimentally induced canine prostatic hyperplasia with those of the spontaneously developed changes in untreated dogs. An experimental group of 5 male beagle dogs were castrated and treated with combined steroids (3 weekly doses for over 30 weeks). Prostate samples were surgically obtained every 42 days (experimental stages 0 through 6). The control group consisted of 3 noncastrated dogs that were treated with vehicle and in which samples were taken only at stages 0, 1, 4, and 6. Changes in the control groups were similar but of lower intensity compared to those of the experimental groups. In luminal cells, crowding with papillary projections, prominent, branching microvilli, and abundant, often compartmentalized granules were observed. The most striking change was the previously unreported finding of caveolae in basal cells. They were mostly located in the basal aspect of basal cells and were more prominent in the experimental group and in advanced stages of treatment. These ultrastructural findings have not been previously reported in canine or human prostatic hyperplasia and merit further research. The model of experimentally induced canine prostatic hyperplasia provides an adequate setting for the understanding of this disease.  相似文献   
27.
No specific diagnostic markers have been described in essential thrombocythemia (ET). PRV-1 (polycythemia rubra vera-1), TPO (thrombopoietin), and c-MPL (myeloproliferative leukemia virus oncogene) genes are candidate ET molecular markers because of their implication in the pathogenesis of ET. We have studied the status of PRV-1, TPO, and c-MPL genes in 30 ET patients by a fluorescence in situ hybridization (FISH) technique using three noncommercial, locus-specific probes for PRV-1 (BAC RP11-160A19, located at 19q13.2), TPO (BAC RP11-45NP16, located at 3q27), and c-MPL (BAC RP11-297L5, located at 1p34). FISH study showed no PRV-1, TPO, and c-MPL cytogenetic abnormalities in any of the analyzed cases. Our results suggest a lack of structural and numerical rearrangements (deletions, translocations, or amplifications) of PRV-1, TPO, and c-MPL genes in ET patients.  相似文献   
28.
The level of physical stress rules the adaptative response of peripheral nerves, which is crucial to assess their physiological and pathological states. To this aim, in this work, different computational approaches were presented to model the stress response of in vitro peripheral nerves undergoing longitudinal stretch. More specifically, the effects of geometrical simplifications were studied with respect to the amount of computational time needed to obtain relevant information. Similarly, the variation of compressibility of the peripheral nervous tissue was investigated with respect to the variation of longitudinal stress and transversal stretch variations, and with reference to the computational time needed for simulations. Finally, the effect of small dimensional changes was investigated to better understand whether the variation of time was only due to the amount of nodes or elements. In conclusion, since fast in silico models, able to assess the nerve stress, could be a strategic advantage in case of time constraints or on-line evaluation (e.g., surgical interventions), a synergistic use of these approaches was proposed as a possible strategy to decrease the computational time needed for simulations from minutes to seconds.
Graphical Abstract A synergistic approach involving both symmetry and tuning ofcompressibility allows the computational time to be considerably decreased
  相似文献   
29.
Metachromatic Leukodystrophy (MLD) is a rare inherited lysosomal storage disorder caused by the deficiency of Arylsulfatase A (ARSA). The disease manifests itself with a broad spectrum of clinical variants, all characterized by progressive neurodegeneration in the central and peripheral nervous systems. The correlation between mutations in the ARSA gene, residual enzymatic activity associated with the mutated alleles and patients' phenotype, which has been extensively drawn for common ARSA mutations, has recently been expanded to rare ones. In this context, functional studies on the rare allelic variances acquire particular relevance for patients' prognostic evaluation. Here we have characterized eight newly identified ARSA mutations, through lentiviral vector‐based expression studies on cell lines and ARSA defective murine fibroblasts. In each case, the residual activity associated with the new mutant allele correlates well with the patient's phenotype. Therefore, our results confirm the importance of functional characterization of mutant alleles for a precise genotype‐based classification and definition of prognosis in MLD patients, which is particularly relevant for pre‐symptomatic diagnosis. © 2009 Wiley‐Liss, Inc.  相似文献   
30.
Background: Previous studies comparing the neonatal outcome of very low birth weight (VLBW) multiples and singletons have suggested a worse outcome for multiples at gestational ages on the limits of viability.

Objectives: The objective of this study is to determine the neonatal mortality and morbidity of VLBW multiples compared to singletons.

Methods: This is a retrospective study including all infants registered in the Spanish network for infants under 1500?g (SEN1500), over a 12-year period (from 2002 to 2013). Mortality and major morbidities were compared between singletons and multiples.

Results: About 32,770 infants were included: 21,123 singletons (64.5%) and 11,647 multiples (35.5%), with a mean gestational age of 29.5 weeks (22–38), and mean birth weight of 1115?g (340–1500). When adjusted by other perinatal factors, multiple pregnancy has a significantly higher risk of mortality than singleton pregnancy (odds ratio (OR) 1.15; IC 95% 1.05–1.26, p?=?.002), but not a higher risk of major morbidity or composite adverse outcome. In the subgroup of infants born before 26 weeks, multiples showed a higher risk of mortality (63.9% versus 51%, OR 1.7; 95% CI 1.47–1.96) and a higher risk of composite adverse outcome (88.9% versus 81.5%, OR 1.82, 95% CI 1.28–2.24).

Conclusions: In preterm infants born with less than 1500?g, multiple pregnancy is a prognostic factor that can slightly increase mortality. Extremely preterm infants born before 26 weeks have a greater risk of mortality and major morbidity if they come from a multiple pregnancy.  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