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   72篇
  免费   7篇
儿科学   1篇
基础医学   6篇
临床医学   8篇
内科学   9篇
神经病学   25篇
特种医学   4篇
外科学   8篇
综合类   1篇
预防医学   2篇
眼科学   2篇
药学   9篇
中国医学   2篇
肿瘤学   2篇
  2024年   1篇
  2023年   4篇
  2022年   7篇
  2021年   7篇
  2020年   3篇
  2019年   3篇
  2018年   5篇
  2017年   3篇
  2016年   7篇
  2015年   2篇
  2014年   5篇
  2013年   2篇
  2012年   5篇
  2011年   7篇
  2010年   2篇
  2009年   3篇
  2008年   6篇
  2007年   4篇
  2006年   1篇
  2004年   1篇
  2002年   1篇
排序方式: 共有79条查询结果,搜索用时 15 毫秒
41.
42.

Background  

The intent of this study was to predict conversion of laparoscopic cholecystectomy (LC) to open surgery employing artificial neural networks (ANN).  相似文献   
43.
In order to assess the role of nitric oxide/cyclicGMP signaling pathway in the anticonvulsant effect of benzodiazepines, we studied the potential interaction of a phosphodiesterase type 5 inhibitor, sildenafil with the effect of diazepam on a mouse model of clonic seizures induced by intravenous infusion of GABA antagonist, pentylenetetrazole (PTZ). Administration of sildenafil (10 mg/kg; per se effective on seizure threshold) could abolish the anticonvulsive effect of diazepam, and a subeffective dose (5 mg/kg), when added to NO precursor l-arginine (50 mg/kg) could cause the same effect. Conversely, subeffective doses of diazepam (0.02 mg/kg) and NO synthase inhibitor N(omega)-nitro-l-arginine methyl ester (L-NAME, 5 mg/kg), administered together, reversed the proconvulsive effect of sildenafil. Our findings indicate that the enhancement of NO/cGMP signaling pathway by sildenafil attenuates the anticonvulsant effect of the benzodiazepine prototype, diazepam. This suggests that the effects of facilitating GABAA-mediated inhibition and modulating NO pathways are additive and there might be a role for NO pathway in benzodiazepine effect against PTZ-induced seizures in mice.  相似文献   
44.
The role of the hippocampus in recollection and familiarity remains debated. Using functional magnetic resonance imaging (fMRI), we explored whether hippocampal activity is modulated by increasing recollection confidence, increasing amount of recalled information, or both. We also investigated whether any hippocampal differences between recollection and familiarity relate to processing differences or amount of information in memory. Across two fMRI tasks, we separately compared brain responses to levels of confidence for cued word recall and word familiarity, respectively. Contrary to previous beliefs, increasing confidence/accuracy of cued recall of studied words did not increase hippocampal activity, when unconfounded by amount recollected. In contrast, additional recollection (i.e., recollecting more information than the word alone) increased hippocampal activity, although its accuracy matched that of word recall alone. Unlike cued word recall, increasing word familiarity accuracy did increase hippocampal activity linearly, although at an uncorrected level. This finding occurred although cued word recall and familiarity memory seemed matched with respect to information in memory. The detailed characteristics of these effects do not prove that word familiarity is exceptional in having hippocampal neural correlates. They suggest instead that participants fail to identify some aspects of recollection, misreporting it as familiarity, a problem with word‐like items that have strong and recallable semantic associates.  相似文献   
45.
Introduction: Amyotrophic lateral sclerosis (ALS) is a debilitating neurologic disorder with poor survival rates and no clear biomarkers for disease diagnosis and prognosis. Methods: We compared serum microRNA (miRNA) expression from patients with ALS with healthy controls and patients with multiple sclerosis and Alzheimer disease. We also correlated miRNA expression in cross‐sectional and longitudinal cohorts of ALS patients with clinical parameters. Results: We identified 7 miRNAs (miR‐192‐5p, miR‐192‐3p, miR‐1, miR‐133a‐3p, miR‐133b, miR‐144‐5p, miR‐19a‐3p) that were upregulated and 6 miRNAs (miR‐320c, miR‐320a, let‐7d‐3p, miR‐425‐5p, miR‐320b, miR‐139‐5p) that were downregulated in patients with ALS compared with healthy controls, patients with Alzheimer disease, and patients with multiple sclerosis. Changes in 4 miRNAs (miR‐136‐3p, miR‐30b‐5p, miR‐331‐3p, miR‐496) correlated positively and change in 1 miRNA (miR‐2110) correlated negatively with changes in clinical parameters in longitudinal analysis. Discussion: Our findings identified serum miRNAs that can serve as biomarkers for ALS diagnosis and progression. Muscle Nerve 58 : 261–269, 2018  相似文献   
46.
Purpose: This study aimed to evaluate the effect of orbital vector and other biometric parameters (i.e. axial globe length, axial globe projection) on the development of involutional entropion or ectropion.

Methods: In this cross-sectional study, 167 eyes from 132 patients were included. Of these eyes, 128 had involutional entropion and 39 had involutional ectropion, all of lower lids. The axial globe projection was measured using Hertel exophthalmometry; axial globe length was assessed by A-mode ultrasound; and orbital vector was determined clinically. Patient-specific categorical variables and continuous variables were compared using the chi-square test and the two-sided t test, respectively. Correlations were derived using the Pearson correlation.

Results: The percentage of females was 59% and 33.3% in the entropion group and in the ectropion group, respectively. A significant association was found between the gender and type of eyelid malposition (= 0.015). Exophthalmometry reading was greater in the ectropion group than in the entropion group (17.7 ± 2.5 versus 10.8 ± 3.7 mm, respectively; < 0.001). There was no significant correlation between axial globe length and exophthalmometry reading. Positive orbital vectors were observed in 87.5% of eyelids with involutional entropion. Negative orbital vectors were observed in 92.3% of eyelids with involutional ectropion (< 0.001). Patients with negative orbital vectors showed greater axial globe projection than patients with positive orbital vectors (18.0 ± 2.1 versus 10.6 ± 3.5 mm, respectively; < 0.001).

Conclusions: There is an association between orbital vector measurement and involutional entropion and ectropion. Measuring the orbital vector may help predict the development of these lid malpositions.  相似文献   

47.
48.
Herein, we studied a single-pot method with a dual catalysis process towards the conversion of primary aromatic alcohols to amides using ultrasmall PdNPs of controlled uniform size (1.8 nm) inside hybrid mesoporous organosilica nanotubes (MO-NTs). The catalyst exhibited excellent performance in water under mild conditions and showed high stability. The catalytic activity towards the tandem oxidation of alcohols in the presence of amine salts and H2O2 to their corresponding amides without producing byproducts was evaluated, and high yields were obtained for all products. The structure of the organosilica nanotubes containing palladium nanoparticles was investigated using various characterization techniques such as XRD, TEM, BET, solid-state 29Si NMR and solid-state 13C CP MAS NMR. Catalyst recycling tests showed that the catalytic power of PdNPs@B-SNTs was preserved after 8 cycles and a slight decrease in catalyst activity was observed.

Herein, we studied a single-pot method with a dual catalysis process towards the conversion of primary aromatic alcohols to amides using ultrasmall PdNPs of controlled uniform size (1.8 nm) inside hybrid mesoporous organosilica nanotubes (MO-NTs).  相似文献   
49.
As colorectal cancer (CRC) is largely due to modifiable lifestyle habits, the awareness on its risk factors is highly important. Dietary fatty acids have been linked to CRC risk. We explored the association between dietary trans fatty acids (TFAs) intake and CRC risk. We analyzed 865 CRC cases (434 in colon and 404 in rectum) and 3206 controls of the IROPICAN study, with data collected by trained interviewers using validated questionnaires. TFAs intake (industrial and ruminant types) was categorized into quartiles. Multivariate logistic regression models were built to calculate the odds ratios (OR) for the association between CRC and TFAs. We observed a positive association between industrial TFAs and colon cancer (OR for highest vs lowest quartile [ORQ4vsQ1] = 1.28, 95% confidence interval 1.07–1.54). A higher association was observed between industrial TFAs and CRC, occurring after 50 years of age. In addition, elaidic acid was associated with an increased risk of colon (ORQ4vsQ1 = 1.58, 1.24–2.02) and specifically of proximal colon cancer (OR Q4vsQ1 = 2.12, 1.40–3.20), as well as of rectum cancer (ORQ4vsQ1 = 1.40, 1.07–1.83). An inverse association was observed between ruminant TFAs intake and colon cancer risk (ORQ4vsQ1 = 0.80, 0.67–0.97). Industrial TFAs, such as semisolid/solid hydrogenated oils, may increase the risk of CRC, especially colon and proximal colon cancer. In contrast, ruminant TFAs do not appear to be associated with CRC. Awareness programs and regulatory actions regarding hydrogenated oils are warranted, given their high consumption through ultra-processed foods in more developed and less developed countries.  相似文献   
50.
Hippocampal synaptic dysfunction, oxidative stress, neuroinflammation, and neuronal loss play critical roles in the pathophysiology of diabetes-associated cognitive decline (DACD). The study aimed to investigate the effects of vanillic acid (VA), a phenolic compound, against DACD and explore the potential underlying mechanisms. Following confirmation of diabetes, rats were treated with VA (50 mg/kg/day; P.O.) or insulin (6 IU/rat/day; S.C.) for 8 consecutive weeks. The cognitive performance of the rats was evaluated using passive-avoidance and water-maze tasks. Long-term potentiation (LTP) was induced at hippocampal dentate gyrus (DG) synapses in response to high-frequency stimulation (HFS) applied to the perforant pathway (PP) to evaluate synaptic plasticity. Oxidative stress factors, inflammatory markers, and histological changes were evaluated in the rat hippocampus. This study showed that streptozotocin (STZ)-induced diabetes caused cognitive decline that was associated with inhibition of LTP induction, suppression of enzymatic antioxidant activities, enhanced lipid peroxidation, elevated levels of inflammatory proteins, and neuronal loss. Interestingly, chronic treatment with VA alleviated blood glucose levels, improved cognitive decline, ameliorated LTP impairment, modulated oxidative-antioxidative status, inhibited inflammatory response, and prevented neuronal loss in diabetic rats at a level comparable to insulin therapy. The results suggest that the antihyperglycemic, antioxidative, anti-inflammatory, and neuroplastic properties of VA may be the mechanisms behind its neuroprotective effect against DACD.  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