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1.
Chem Commun (Camb) ; 59(72): 10817-10820, 2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37602683

RESUMO

A metal-free method for the dual activation of aryl phosphinate has been developed; the P-H and P-O bonds are sequentially activated by the Tf2O/DMSO system. Without the requirement of metals and unstable P-reagents, this one-pot procedure provides a convenient and practical access to a variety of aryl phosphonates. A mechanism involving twice generation of electrophilic P-species and two SN-processes is proposed on the basis of the control experiments.

2.
Can Liver J ; 4(4): 370-380, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35989896

RESUMO

INTRODUCTION: To determine predictors of hepatic steatosis by the computed attenuation parameter (CAP) and fibrosis via transient elastography (TE) in persons on methotrexate (MTX) therapy with rheumatologic and dermatologic diseases. METHODS: A single-centred retrospective cohort study was performed. Patients on >6 months of MTX for a rheumatologic or dermatologic disease who had undergone TE from January 2015 to September 2019 were included. Multivariate analysis was performed to determine predictors of steatosis and fibrosis. RESULTS: A total of 172 patients on methotrexate were included. Psoriasis was the most frequent diagnosis (n = 55), followed by rheumatoid arthritis (n = 45) and psoriatic arthritis (n = 34). Steatosis (CAP ≥245 dB/m) was present in 69.8% of patients. Multivariate regression analysis revealed that diabetes mellitus (OR 10.47, 95% CI 1.42-75.35), hypertension (OR 5.15, 95% CI 1.75-15.38), and BMI ≥30 kg/m2 (OR 16.47, 95% CI 5.56-45.56) were predictors of steatosis (CAP ≥245 dB/m). Predictors of moderate to severe fibrosis (Metavir ≥F2 = TE ≥8.0 kPa) by multivariate regression analysis included moderate to severe steatosis (CAP ≥270 dB/m) (OR 8.36, 95% CI 1.88-37.14), diabetes mellitus (OR 2.85, 95% CI 1.09-7.48), hypertension (OR 5.4, 95% CI 2.23-13.00), dyslipidemia (OR 3.71, 95% CI 1.50-9.18), and moderate alcohol use (OR 3.06, 95% CI 1.2-7.49). CONCLUSIONS: In patients on MTX for rheumatologic and dermatologic diseases, hepatic steatosis as measured by CAP was common and moderate to severe steatosis predicted moderate to severe fibrosis.

3.
IEEE Trans Neural Netw Learn Syst ; 32(3): 1389-1399, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32310795

RESUMO

A single feature is hard to describe the content of images from an overall perspective, which limits the retrieval performances of single-feature-based methods in image retrieval tasks. To fully describe the properties of images and improve the retrieval performances, multifeature fusion ranking-based methods are proposed. However, the effectiveness of multifeature fusion in image retrieval has not been theoretically explained. This article gives a theoretical proof to illustrate the role of independent features in improving the retrieval results. Based on the theoretical proof, the original ranking list generated with a single feature greatly influences the performances of multifeature fusion ranking. Inspired by the principle of three degrees of influence in social networks, this article proposes a reranking method named k -nearest neighbors' neighbors' neighbors' graph (N3G) to improve the original ranking list by a single feature. Furthermore, a multigraph fusion ranking (MFR) method motivated by the group relation theory in social networks for multifeature ranking is also proposed, which considers the correlations of all images in multiple neighborhood graphs. Evaluation experiments conducted on several representative data sets (e.g., UK-bench, Holiday, Corel-10K, and Cifar-10) validate that N3G and MFR outperform the other state-of-the-art methods.

4.
Med Hypotheses ; 78(4): 489-93, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22285196

RESUMO

It is recognized that alcohol consumption during pregnancy is associated with fetal alcohol syndrome (FAS). Alcohol can trigger a pattern of neurodegeneration in rat brains similar to other known gamma-aminobutyric acid (GABA) specific agonists. However this does not seem to explain FAS entirely, as impoverished care-giving environments have been shown to increase the risk of FAS. Individuals living under the poverty level are at risk for micronutrient deficiencies due to insufficient intake. In particular, three nutrients commonly found to be deficient are folate, choline and vitamin A. There is evidence to suggest that ethanol alone may not explain the entire spectrum of anomalies seen in individuals with FAS. It is hypothesized that FAS may be caused more by the nutritional deficiencies that are exacerbated by alcohol than by direct alcoholic neurotoxicity. It is known that ethanol inhibits folate, choline, and vitamin A/retinoic acid metabolism at multiple steps. Additionally, mice exposed to ethanol demonstrated epigenetic changes, or variations in the methylation of DNA to control gene expression. Folate is important in the production of methyl groups, which are subsequently used to create and methylate DNA. Choline (which is metabolized to acetylcholine) is important in neurotransmission and neurodevelopment. It is also involved in an alternative pathway in the production of methyl groups. In fact a study by Thomas et al. in 2009 found that nutritional supplementation with choline in rats exposed to ethanol in utero almost completely mitigated the degenerative effects of ethanol on development and behaviour. Lastly, vitamin A and retinoic acid metabolism is associated with the regulation of one sixth of the entire proteome. Thus supplementation of folate, choline and vitamin A to mothers may mitigate the effects of the alcohol and reduce the severity or prevalence of FAS.


Assuntos
Deficiência de Vitaminas/tratamento farmacológico , Colina/uso terapêutico , Transtornos do Espectro Alcoólico Fetal/prevenção & controle , Ácido Fólico/uso terapêutico , Vitamina A/uso terapêutico , Animais , Deficiência de Vitaminas/complicações , Epigênese Genética , Feminino , Transtornos do Espectro Alcoólico Fetal/etiologia , Humanos , Camundongos , Gravidez , Ratos , Fatores de Risco , Fatores Socioeconômicos
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