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1.
J Environ Manage ; 331: 117264, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36634422

RESUMO

Empirical evidence supporting the associations between malaria incidence and climatic factors has remained controversial, buffering the progress in the Global Malaria Program that aims to eliminate 90% of the world malaria burden by 2030. This study has aimed to evaluate the nature and extent at which these relations are maintained across all the malaria endemic countries of Africa and Asia-Pacific region. We have utilized the last two decades of malaria incidence, annual minimum temperature, and annual precipitation time series data (2000-2020) for the two most malaria-impacted regions. These data were fitted in the generalized linear model and the mixed effects model. The results showed that there exists a large heterogeneity in malaria incidence across the countries, and between the regions. Last two decadal tendencies showed significant reductions in the disease burden in almost all the countries in the Asia Pacific, with several exceptions or relatively slowed reductions in the Africa. We found significant changes in the positive linear associations between malaria incidence, annual minimum temperature, and annual precipitation across African countries. Many Asia-Pacific countries namely Bangladesh, Bhutan, Indonesia, South Korea, Nepal, Thailand, Vietnam showed negative effects in the associations with the annual precipitation. This study indicates that increasing temperature within the range of 12-30 °C can generate positive effects on malaria incidence, but the nature and extent of precipitation effects vary across countries and at a large regional scale.


Assuntos
Malária , Humanos , Incidência , Malária/epidemiologia , Indonésia , Tailândia , África/epidemiologia
2.
Sci Total Environ ; 828: 154430, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35276140

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) have posed serious risk to marine ecosystems due to their carcinogenic properties, and persistence in the environment and elevated bioaccumulation. It, therefore, becomes essential to examine spatial distribution, composition, and sources of PAHs. In this study, we have examined these PAH variations in the South China Sea (SCS) and East China Sea (ECS), that are experiencing rapid population and economic growth by the surrounding developing countries. It revealed high seasonal variations that significantly differ between dissolved and particulate PAHs concentrations. Spatial variations of PAHs across sites remain relatively insignificant. Persistently high particulate concentrations of the Naphthalene (Nap) were observed, whereas the dissolved concentrations of Fluorene (Flu) and Phenanthrene (Phen) remained prevalent across all the seasons. The result of non-metric multidimensional scaling (NMDS) strongly reflects the weak dispersions of PAHs across the seasons and the contrasting effects of the phase partitioning. Principal component analysis indicates that the primary source of PAH contamination is coal tar or petroleum distillation. However, estimated risk quotient (RQ) values of both the dissolved and particulate PAHs in all the seasons are far below the high-risk levels, while dissolved PAHs displayed relatively higher values. This study signifies the importance of phase petitioning for PAHs monitoring and potential risk assessments.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , China , Carvão Mineral/análise , Ecossistema , Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Estações do Ano , Poluentes Químicos da Água/análise
3.
Sensors (Basel) ; 22(5)2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35271104

RESUMO

Presently, lightweight devices such as mobile phones, notepads, and laptops are widely used to access the Internet throughout the world; however, a problem of privacy preservation and authentication delay occurs during handover operation when these devices change their position from a home mesh access point (HMAP) to a foreign mesh access point (FMAP). Authentication during handover is mostly performed through ticket-based techniques, which permit the user to authenticate itself to the foreign mesh access point; therefore, a secure communication method should be formed between the mesh entities to exchange the tickets. In two existing protocols, this ticket was not secured at all and exchanged in a plaintext format. We propose a protocol for handover authentication with privacy preservation of the transfer ticket via the Diffie-Hellman method. Through experimental results, our proposed protocol achieves privacy preservation with minimum authentication delay during handover operation.


Assuntos
Segurança Computacional , Privacidade
4.
J Theor Biol ; 474: 63-77, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-30980871

RESUMO

Psoriasis is a chronic skin condition that produces plaques of condensed, scaling skin due to excessively rapid proliferation of keratinocytes. During the disease progression, keratinocyte proliferation is influenced by many immune cells and cytokines. This article deals with a five dimensional deterministic model, which has been derived using quasi-steady-state approximation for describing the dynamics of psoriasis in various cytokines environment. Equilibrium analysis of the system shows that either the system converges to a stable steady state or exhibits a periodic oscillation depending upon system parameters. Finally, introducing a one dimensional impulsive system, we have determined the perfect dose and perfect dosing interval for biologic (TNF-α inhibitor) therapy to control the hyper-proliferation of keratinocytes. We have studied the effect of TNF-α inhibitor by considering both perfect and imperfect dosing during the inductive phase. The maximum possible number of drug holidays and the minimal number of doses that must subsequently be taken while avoiding drug resistance have been calculated for imperfect dosing. Since, psoriasis is non-curable but treatable disease, so the aim is to investigate the minimum dose with highest efficacy and proper dosing interval of TNF-α inhibitor for a psoriatic patient. Through numerical simulations, we have given a detailed prediction about the maximum drug holidays, tolerable for a patient, without loss of previous drug effects. Our theoretical predictions and numerical outcomes may be useful in guiding the design of future clinical trials.


Assuntos
Citocinas/imunologia , Queratinócitos , Modelos Imunológicos , Psoríase , Fator de Necrose Tumoral alfa , Animais , Humanos , Queratinócitos/imunologia , Queratinócitos/patologia , Psoríase/tratamento farmacológico , Psoríase/imunologia , Psoríase/patologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/imunologia
5.
Math Biosci Eng ; 15(3): 717-738, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30380327

RESUMO

Psoriasis is an autoimmune disorder, characterized by hyper-proli-feration of Keratinocytes for the abnormal activation of T Cells, Dendritic Cells (DCs) and cytokine signaling. Interaction of DCs and T Cells enable T Cell to differentiate into Type 1 (Th1), Type 2 (Th2) helper T Cell depending on cytokine release. Hyper-proliferation of Keratinocytes may occur due to over expression of pro-inflammatory cytokines secreted by Th1-Cells viz. Interferon gamma (IFN-γ), Transforming growth factor beta (TGF-ß) and Tumor necrosis factor alpha (TNF-α) etc. Deregulation of epidermal happens due to signaling of anti-inflammatory cytokines like Interleukin 10 (IL-10), Interleukin 4 (IL-4) etc., released by Th2-Cells. In this article, we have constructed a set of nonlinear differential equations involving the above cell population for better understanding the impact of cytokines on Psoriasis. System is analyzed introducing therapeutic agent (Biologic / IL-10) for reducing the hyper-proliferation of Keratinocytes. Effect of Biologic is used as a surrogate of control parameter to reduce the psoriatic lesions. We also studied its effect both in continuous and impulsive dosing method. Our study reveals that impulsive dosing is more applicable compare with continuous dosing to prevent Psoriasis.


Assuntos
Modelos Imunológicos , Psoríase/imunologia , Células Th1/imunologia , Células Th2/imunologia , Simulação por Computador , Citocinas/imunologia , Células Dendríticas/imunologia , Humanos , Interleucina-10/imunologia , Interleucina-10/uso terapêutico , Queratinócitos/imunologia , Queratinócitos/patologia , Conceitos Matemáticos , Dinâmica não Linear , Psoríase/patologia , Psoríase/terapia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/uso terapêutico
6.
J Environ Biol ; 23(4): 411-6, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12674383

RESUMO

Aluminium toxicity is a major deterrent for plant growth in acid soils below pH 5.0. This study deals with effect of aluminium toxicity on growth of mungbean (Vigna radiata L. Wilczek) seedlings. Seed germination (in %) declined with increased content of Al2(SO4)3, while promotive effect was observed at very low dosage. Different concentrations of aluminum sulphate salt were applied to mungbean seeds. Measurement of aluminium content in mungbean leaves was done through atomic absorption spectrophotometer. Root length (root and hypocotyl length) and shoot length (shoot and epicotyl length) was measured at seven days old seedling stage. Different concentrations of Al2(SO4)3 were found to have significant effect both on shoot and root length. Leaf area, fresh and dry weight was significantly reduced. Increased stomatal frequency and trichome density with an increase in concentrations of Al2(S04)3 was observed through scanning electron microscope.


Assuntos
Alumínio/toxicidade , Fabaceae/crescimento & desenvolvimento , Poluentes do Solo/toxicidade , Relação Dose-Resposta a Droga , Fabaceae/fisiologia , Concentração de Íons de Hidrogênio , Microscopia Eletrônica , Folhas de Planta/anatomia & histologia , Plântula/crescimento & desenvolvimento
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