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991.
992.

Background

Transcranial direct current stimulation (tDCS) is investigated to modulate neuronal function by applying a fixed low-intensity direct current to scalp.

Objectives

We critically discuss evidence for a monotonic response in effect size with increasing current intensity, with a specific focus on a question if increasing applied current enhance the efficacy of tDCS.

Methods

We analyzed tDCS intensity does-response from different perspectives including biophysical modeling, animal modeling, human neurophysiology, neuroimaging and behavioral/clinical measures. Further, we discuss approaches to design dose-response trials.

Results

Physical models predict electric field in the brain increases with applied tDCS intensity. Data from animal studies are lacking since a range of relevant low-intensities is rarely tested. Results from imaging studies are ambiguous while human neurophysiology, including using transcranial magnetic stimulation (TMS) as a probe, suggests a complex state-dependent non-monotonic dose response. The diffusivity of brain current flow produced by conventional tDCS montages complicates this analysis, with relatively few studies on focal High Definition (HD)-tDCS. In behavioral and clinical trials, only a limited range of intensities (1-2?mA), and typically just one intensity, are conventionally tested; moreover, outcomes are subject brain-state dependent. Measurements and models of current flow show that for the same applied current, substantial differences in brain current occur across individuals. Trials are thus subject to inter-individual differences that complicate consideration of population-level dose response.

Conclusion

The presence or absence of simple dose response does not impact how efficacious a given tDCS dose is for a given indication. Understanding dose-response in human applications of tDCS is needed for protocol optimization including individualized dose to reduce outcome variability, which requires intelligent design of dose-response studies.  相似文献   
993.
994.
Recently, the beneficial effects of ginger on obesity is taken into consideration. Albeit, it seems that the anti‐obesity effect of ginger and its mechanism of action has not yet been reviewed. Therefore, the aim of this study was to systematically review the effect of Zingiber officinale Roscoe on obesity management. Databases including PubMed, Scopus, Google scholar, and Science Direct were searched from 1995 until May 2017 using the definitive keywords. Searching was limited to articles with English language. All of the relevant human and animal studies and also in vitro studies were included. Review articles, abstract in congress, and also other varieties of ginger were excluded. Eligibility of included articles were evaluated by 3 reviewers, which also extracted data. Articles were critically assessed individually for possible risk of bias. Twenty‐seven articles (6 in vitro, 17 animal, and 4 human studies) were reviewed. Most of the experimental studies supported the weight lowering effect of ginger extract or powder in obese animal models, whereas the results of the available limited clinical studies showed no changes or slight changes of anthropometric measurements and body composition in subjects with obesity. Ginger could modulate obesity through various potential mechanisms including increasing thermogenesis, increasing lipolysis, suppression of lipogenesis, inhibition of intestinal fat absorption, and controlling appetite. This review article provides some convincing evidence to support the efficacy of ginger in obesity management and demonstrates the importance of future clinical trials.  相似文献   
995.
Islet transplantation and antioxidant management: A comprehensive review   总被引:4,自引:2,他引:2  
Islet transplantation as a promising treatment for type 1 diabetes has received widespread attention.Oxidative stress plays an essential role in cell injury during islet isolation and transplantation procedures.Antioxidants have been used in various studies to improve islet transplantation procedures. The present study reviews the role of oxidative stress and the benefits of antioxidants in islet transplantation procedures. The bibliographical databases Pubmed and Scopus were searched up to November 2008.All relevant human and animal in-vivo and in-vitro studies, which investigated antioxidants on islets,were included. Almost all the tested antioxidants used in the in-vitro studies enhanced islet viability and insulin secretion. Better control of blood glucose after transplantation was the major outcome of antioxidant therapy in all in-vivo studies. The data also indicated that antioxidants improved islet transplantation procedures. Although there is still insufficient evidence to draw definitive conclusions about the efficacy of individual supplements, the benefits of antioxidants in islet isolation procedures cannot be ignored.  相似文献   
996.
Hypoglycemic neuropathy   总被引:1,自引:0,他引:1  
Hypoglycemia is a relatively common condition primarily affecting diabetic patients treated with insulin or other hypoglycemic drugs and insulinoma patients. Clinical experience and experimental studies show that hypoglycemia may cause alterations both in the central (CNS) and the peripheral (PNS) nervous system. Hypoglycemic effects on the CNS include various symptoms such as irritability and lack of concentration, disruption of cognitive functions, convulsions and unconsciousness. As for pathology, a loss of neurons has been noted, being more obvious in the cerebral cortex and the hippocampus than in the brain stem, cerebellum and spinal cord. Myelin damage and glial changes have also been observed in the CNS. The development of pathological changes in the brain has mainly been studied on autopsy material from patients who died in insulin coma and in animals exposed to a severe hypoglycemia and showing an isoelectric electroencephalogram. It has been suggested that hypoglycemic loss of neurons in the brain is related to excititoxic actions of aspartate on N-methyl-D-aspartate receptors. With respect to the PNS, scattered clinical observations in humans and experimental studies in animals show that hypoglycemia causes a distal axonopathy including both degenerative and regenerative events. In this respect, motor axons seem to be more vulnerable than sensory axons. Animal experiments show that a peripheral neuropathy may develop even in cases with a mild hypoglycemia compatible with a generally normal behavior. The cellular mechanisms behind the development of hypoglycemic PNS alterations are unknown. To elucidate the pathophysiology of hypoglycemic neuropathy more basic research is needed.  相似文献   
997.
998.
Colloid milium is a rare cutaneous deposit disease that usually presents clinically by the development of yellowish translucent or flesh‐colored papules or plaques on sun‐exposed skin. Histologically, it is characterized by the presence of colloid in the dermal papillae. In this case report, we present a 52‐year‐old man who presented with a nodule on his upper lip that mistakenly was diagnosed and treated as keloid.  相似文献   
999.
1000.
BackgroundDespite many efforts to discover the important role of the autophagy process in the pathogenesis of colorectal cancer (CRC), the exact involved molecular mechanism still remains to be elucidated. Recently, a limited number of studies have been employed to discover the impact of autophagy genes’ variants on the development and progression of CRC. Here, we evaluated the association between two single‐nucleotide polymorphisms (SNPs) in the main components of the autophagy genes, ATG16L1 rs2241880, and ATG5 rs1475270, and the CRC risk in an Iranian population.MethodsDuring this investigation, a total of 369 subjects, including 179 CRC patients and 190 non‐cancer controls have been genotyped using Tetra‐primer amplification refractory mutation system‐polymerase chain reaction (TP‐ARMS‐PCR) method.ResultThe results demonstrated that the T allele of the ATG16L1 rs2241880 was significantly associated with the increased risk of CRC in the studied population (OR 1.64, 95% CI: 1.21–2.22, = 0.0015). Moreover, ATG16L1 rs2241880 TT genotype increased the susceptibility to CRC (OR 3.31, 95% CI: 1.64–6.69, = 0.0008). Furthermore, a significant association was observed under the recessive and dominant inheritance models (= 0.0015 and = 0.017, respectively). No statistically significant differences were found in the ATG5 rs1475270 alleles and genotypes between the cases and controls.ConclusionThe results of the present study may be helpful concerning the risk stratification in CRC patients based on the genotyping approach of autophagy pathways and emphasize the need for further investigations among different populations and ethnicities to refine our conclusions.  相似文献   
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