Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
J Supercomput ; 77(10): 11738-11755, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33814722

RESUMO

Online social network is one of the most prominent media that holds information about society's epidemic problem. Due to privacy reasons, most of the users will not disclose their location. Detecting the location of the tweet users is required to track the geographic location of the spreading diseases. This work aims to detect the spreading location of the COVID-19 disease from the Twitter users and content discussed in the tweet. COVID-19 is a disease caused by the "novel coronavirus." About 80% of confirmed cases recover from the disease. However, one out of every six people who get COVID-19 can become seriously ill, stated by the World health organization. Inferring the user location for identifying the spreading location for the disease is a very challenging task. This paper proposes a new technique based on a hypergraph model to detect the Twitter user's locations based on the spreading disease. This model uses hypergraph with weighting factor technique to infer the spreading disease's spatial location. The accuracy of prediction can be improved when a massive volume of streaming data is analyzed. The Helly property of the hypergraph was applied to discard less potential words from the text analysis, which claims this work of unique nature. A weighting factor was introduced to calculate the score of each location for a particular user. The location of each user is predicted based on the one that possesses the highest weighting factor. The proposed framework has been evaluated and tested for various measures like precision, recall and F-measure. The promising results obtained have substantiated the claim for this work compared to the state-of-the-art methodologies.

2.
Neurochem Int ; 74: 46-52, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24834867

RESUMO

This study primarily investigated the effects of intermittent cold exposure (ICE) on oxidative stress (OS) in the hippocampus(HC) and plasma lipid profile of old male rats. Secondly, it evaluated structural changes in the hippocampus region of the rat's brain. Thirdly, it attempted an evaluation of the effectiveness of the combined supplement of vitamins C and E in alleviating cold stress in terms of these biochemical parameters. Thirty male rats aged 24 months were divided into groups of five each: control (CON), cold-exposed at 10 °C (C10), cold-exposed at 5 °C (C5), supplemented control (CON+S), and supplemented cold-exposed at either 5 °C (C5+S) or 10 °C (C10+S). The rats were on a daily supplement of vitamin C and vitamin E. Cold exposure lasted 2 h/day for 4 weeks. Rats showed increased levels of hydrogen peroxide (H2O2), and thiobarbituric acid reactive substances (TBARS) in the HC at 10 °C with further increase at 5 °C. Cold also induced neuronal loss in the hippocampus with concomitant elevations in total cholesterol (TCH), triglycerides (TG) and low-density lipoproteins (LDL-C) levels, and a depletion in high-density lipoprotein (HDL-C). A notable feature was the hyperglycaemic effects of ICE and depleted levels of vitamins C and E in the hippocampus and plasma while supplementation increased their levels. More importantly, a positive correlation was observed between plasmatic LDL-C, TCH and TG and hippocampal TBARS and H2O2 levels. Further, intensity of cold emerged as a significant factor impacting the responses to vitamin C and E supplementation. These results suggest that cold-induced changes in the plasma lipid profile correlate with OS in the hippocampus, and that vitamin C and E together are effective in protecting from metabolic and possible cognitive consequences in the old under cold exposures.


Assuntos
Envelhecimento/metabolismo , Ácido Ascórbico/farmacologia , Temperatura Baixa , Hipocampo/efeitos dos fármacos , Lipídeos/sangue , Estresse Oxidativo , Vitamina E/farmacologia , Animais , Glicemia/metabolismo , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar
3.
Neurochem Res ; 38(4): 876-85, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23397286

RESUMO

This study investigated the effects of combined supplementation with vitamin E and C against oxidative stress (OS) caused by intermittent cold exposure (ICE) in the hypothalamus (HY) of aging male Wistar rats [adult (3-months), middle-aged (18-months) and old (24-months)]. Each age was divided into sub-groups: control (CON), cold-exposed at 10 °C (C10), cold-exposed at 5 °C (C5), supplemented control (CON+S) and supplemented cold-exposed at either 5 °C (C5+S) or 10 °C (C10+S). The supplement was a daily dose of 400 mg vitamin C and 50 IU of vitamin E/kg body weight. Cold exposure lasted 2 h/day for 4 weeks. All age groups exposed to cold showed increase in body mass and feeding efficiency. Feeding efficiency in the supplemented old group showed a statistically significant increase in the cold (p < 0.001). Age-related increases in levels of hydrogen peroxide (H2O2), protein carbonyl (PrC), advanced oxidation protein products and thiobarbituric acid reactive substances (TBARS) were further increased by cold in the HY. Cold reduced thiol(P-SH) levels and increased superoxide dismutase (SOD) and, catalase (CAT) activities as well as Hsp72 levels. However, supplementation lowered H2O2, PrC and TBARS with decreases in Hsp72 levels and in SOD and CAT activities. These changes were concomitant with elevations in P-SH, vitamin E and C levels. The results show that the OS caused by ICE in the HY and its subsequent protection following supplementation is related to the intensity of ICE as well as age of the animal. Immunohistochemical studies are underway to examine the findings on ICE-induced oxidative injury in the HY, and the prospects for vitamin E and C supplementation in the senescent.


Assuntos
Envelhecimento/efeitos dos fármacos , Ácido Ascórbico/farmacologia , Temperatura Baixa/efeitos adversos , Hipotálamo/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Vitamina E/farmacologia , Animais , Antioxidantes/farmacologia , Catalase/metabolismo , Peróxido de Hidrogênio , Masculino , Carbonilação Proteica , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
4.
Neurosci Lett ; 529(2): 155-60, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-23026027

RESUMO

This study examined the role of vitamins E and C in combating oxidative stress (OS) caused by intermittent cold exposure (ICE) in the frontoparietal cortex (FPC) of adult (3 months), late-adult (12 months), middle-aged (18 months) and old (24 months) male Wistar rats. Each age group was divided into sub-groups, control (CON), cold-exposed at 5°C (C5), control supplementees (CON+S) and cold-exposed supplementees (C5+S). The supplement was a daily dose of 400mg vitamin C and 50I.U.of vitamin E/kg body weight. Cold exposure lasted 2h/day for 4 weeks. All age groups except the old showed an increase in the final body mass in the cold-exposed. The feeding efficiency was higher in the cold-exposed irrespective of age. OS as reflected in age-related increased levels of hydrogen peroxide, protein carbonyl, advanced oxidation protein products and malondialdehyde showed further increase with ICE in the FPC. However, vitamins E and C supplementation attenuated the ICE-induced OS. ICE depleted the levels of tissue vitamins E and C while supplementation resulted in increased levels. Further age emerged as a significant factor in ICE-induced stress and also the response to vitamins E and C supplementation. Behavioral studies are underway to examine the findings on ICE-induced oxidative injury in the FPC, and the prospects for using vitamins E and C in cold exposures in the aged.


Assuntos
Envelhecimento/metabolismo , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Lobo Frontal/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Lobo Parietal/efeitos dos fármacos , Vitamina E/farmacologia , Vitaminas/farmacologia , Animais , Temperatura Baixa , Lobo Frontal/metabolismo , Masculino , Lobo Parietal/metabolismo , Ratos , Ratos Wistar
5.
Exp Gerontol ; 46(11): 958-64, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21871550

RESUMO

There is growing concern over the increasing instances of decline in cognitive abilities with aging in humans. The present study evaluated the benefits of the natural antioxidant, grape seed proanthocyanidin extract (GSPE) in treating the effects of age-related oxidative stress (OS) and accumulation of lipofuscin (LF) on the cognitive ability in rats. Female Wistar rats of 3- and 12-months of age received a daily oral supplement of GSPE until they attained 6- and 15-months of age. During this period, rats were tested for their cognitive ability. At the end of this period, blood glucose and markers of OS were assessed in the hippocampus. GSPE lowered blood glucose, lipid peroxidation, hydrogen peroxide level, and increased protein sulphydryl (P-SH) content in the hippocampus. In addition, GSPE significantly improved cognitive performance in the two age groups. These results demonstrate that the extent of OS-related LF accumulation is reducible by GSPE. They also suggest a critical role for GSPE as a neuroprotectant in the hippocampus and in preventing cognitive loss with aging.


Assuntos
Envelhecimento/efeitos dos fármacos , Antioxidantes/farmacologia , Extrato de Sementes de Uva/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Proantocianidinas/farmacologia , Envelhecimento/metabolismo , Envelhecimento/fisiologia , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Cognição/efeitos dos fármacos , Transtornos Cognitivos/prevenção & controle , Feminino , Peróxido de Hidrogênio/sangue , Peroxidação de Lipídeos , Aprendizagem em Labirinto , Estresse Oxidativo/efeitos dos fármacos , Oxirredutases/sangue , Ratos , Ratos Wistar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA