69 research outputs found

    Vascular endothelium: the battlefield of dengue viruses

    Get PDF
    Increased vascular permeability without morphological damage to the capillary endothelium is the cardinal feature of dengue haemorrhagic fever (DHF)/dengue shock syndrome (DSS). Extensive plasma leakage in various tissue spaces and serous cavities of the body, including the pleural, pericardial and peritoneal cavities in patients with DHF, may result in profound shock. Among various mechanisms that have been considered include immune complex disease, T-cell-mediated, antibodies cross-reacting with vascular endothelium, enhancing antibodies, complement and its products, various soluble mediators including cytokines, selection of virulent strains and virus virulence, but the most favoured are enhancing antibodies and memory T cells in a secondary infection resulting in cytokine tsunami. Whatever the mechanism, it ultimately targets vascular endothelium (making it a battlefield) leading to severe dengue disease. Extensive recent work has been done in vitro on endothelial cell monolayer models to understand the pathophysiology of vascular endothelium during dengue virus (DV) infection that may be translated to help understand the pathogenesis of DHF/DSS. The present review provides a broad overview of the effects of DV infection and the associated host responses contributing towards alterations in vascular endothelial cell physiology and damage that may be responsible for the DHF/DSS

    Computer Simulation of Regeneration Processes for Ion Exchange Resins Used in Water Purification

    Get PDF
    School of Chemical Engineerin

    Secure Cloud Storage Scheme Based On Hybrid Cryptosystem

    Get PDF
    This paper presents a secure cloud storage scheme based on hybrid cryptosystem, which consists of Elliptic Curve Cryptography (ECC), Advanced Encryption Standard (AES), and one-way hash function. Here, the data owner exports large volume of encrypted data to a cloud storage provider. The exported encrypted data is over-encrypted by the cloud storage provider, and the data is sent to the requesting user. An existing hybrid cryptosystem based dynamic key management scheme with hierarchical access control has been incorporated in our scheme. The key management scheme groups users in various security classes, and helps to derive efficiently, as well as directly the secret keys of the lower order security classes. The incorporated key management scheme in our proposed scheme incurs low computational, communication, and storage overheads for key generation, and derivation purposes. The security analysis, and the simulation results run on the AVISPA tool (formal security verification tool) show that the proposed scheme is protected from the adversaries. This scheme is useful in `owner-write-users-read\u27 application areas, and the end users may use resource-constrained wireless mobile devices securely in this proposed scheme

    Performance of PLL based DSGCPS and FLL controlled SSGCPS under normal condition and different grid faults: A comparative study

    Get PDF
    This paper presents two separate studies to address the increasing need for renewable energy sources in the grid to cope with the rising energy consumption. Firstly, a Double Stage Grid Connected Photovoltaic System (DSGCPS) based on Phase Locked Loops (PLL) is developed using Matlab-Simulink. Secondly, a model of a single-stage grid-connected photovoltaic system (SSGCPS) controlled by a frequency locked loop (FLL) is created with comparable environmental parameters and a loading pattern. The research compares the active and reactive power flow dynamics and DC link voltage fluctuations of both systems. Results indicate that the SSGCPS is the preferred option due to its lower hardware requirements. However, it has a lower performance in cases of grid faults compared to DSGCPS. Moreover, the study analyzes the Total Harmonic Distortion (THD) of both models, a crucial factor for performance analysis. The comparative study shows that DSGCPS performs better than SSGCPS during fault in terms of THD. In conclusion, it can be inferred that both models have unique advantages and disadvantages, which are contingent on specific operating conditions

    Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

    Get PDF
    BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

    Webometric Study of World’s Top Daily Newspaper Websites: An Evaluation

    Get PDF
    This study aims to evaluate world top daily newspaper websites selected from newspaperland.com, a web directory of world newspapers, magazines, news sites, and newspaper publishers (https://www.newspapersland.com/). A total of 20 newspaper websites are selected and are to be evaluated on the basis of selected Alexa indexes from Alexa Internet tool for the purpose of this study. Data such as the traffic rank (both home country and global), search traffic percentage, sites linking in, bounce rate percentage, daily time on site, the average number of pages viewed by users, the percentage of home country users and the percentage of foreign users for each newspaper websites are to be collected from Alexa databank by searching each of the newspaper in Alexa Internet tool. To fulfill the objective of the study, the collected data are tabulated and analyzed. Based on the obtained data, it can be seen that in the case of home traffic rank (i.e., publication country) Daily Nation (Country: Kenya) and Philippine Daily Inquirer (Country: Philippines) both has the highest traffic rank (Rank: 05) whereas China Daily (Country: China) ranked lowest (Rank: 206). In global traffic ranking New York Times of U.S. ranked first (Ranking: 96). The search traffic percentage of Daily Post Nigeria and Daily Nation are very poor. The highest search traffic percentage is 71% for Hindustan Times. New York Times has maximum number of sites linking. The highest bounce rate of Irish Independent shows its performance is weak as compared to others. The daily time spent on a particular newspaper website by the visitors is maximum for Daily Nation of Kenya. The Asahi Shimbun of Japan has the height percentage of home country users. One can trace the dominance of Indian users on newspaper websites like People’s Daily, Khaleej Times, Dawn and USA Today

    Special Report - Human herpesvirus 6: Catalyst of genomic lesion in dysfunctional hematopoiesis ?

    No full text
    corecore