28 research outputs found
3D Nonwoven Fabrics for Biomedical Applications
Fibrous materials are attractive for biomedical applications owing to their structural superiorities, which include large surface-area-to-volume ratio, high porosity, and pore interconnectivity in a controlled manner. Among the various methods of fiber fabrication, electrospinning has emerged as an attractive nanotechnology to produce ultrafine fibrous materials for myriad applications, including tissue scaffolding. In this technique, processing parameters, such as the solution properties, tip-to-collector distance, applied voltage, etc., can be tailored to obtain the fibers of the desired morphology and physicochemical properties. Ideal scaffolds should meet the basic requirements, such as three-dimensional (3D) architecture, proper mechanical properties and biodegradability, and the sufficient surface characteristics for cell adhesion and proliferation. However, most of the electrospun nanofiber-based scaffolds have densely packed two-dimensional (2D) array which hinders the cell infiltration and growth throughout the scaffolds, thereby limiting their applicability in tissue regeneration. To overcome this problem, several attempts have been made to develop a biomimetic three-dimensional, nanofibrous scaffold. This chapter deals with noble techniques including gas foaming (GF), charge repulsion-assisted fabrication, post-processing, liquid-assisted collection, collector modification, and porogen-assisted methods for the fabrication of 3D nanofibrous scaffold for biomedical applications
Optimal Control of An Sir Model With Changing Behavior Through An Education Campaign
An SIR type model is expanded to include the use of education or information given to the public as a control to manage a disease outbreak when effective treatments or vaccines are not readily available or too costly to be widely used. The information causes a change in behavior resulting in three susceptible classes. We study stability analysis and use optimal control theory on the system of differential equations to achieve the goal of minimizing the infected population (while minimizing the cost). We illustrate our results with some numerical simulations
Factors Influencing Food Insecurity in Nepal
Nepal has been persistently encountering food insecurity and under-nutrition. It is therefore utmost important to determine the factors responsible for influencing food insecurity in Nepal. This study examines the factors determining food insecurity in Nepal applying binary logistic models for food poverty, household with inadequate food consumption and poor dietary diversity using data from Nepal Living Standard Survey 2010/11. Food security was determined to be strongly associated with education level and age of household head, household with higher female education level, larger farm size with higher ratio of irrigated land, better access to markets, roads and cooperatives, better household assets and remittance recipient households. Food insecure is relatively more prevalent in rural areas with higher dependent on rain-fed agriculture, higher dependency ratio and larger family size. Improving both physical and economic access to foods, together with investment in education and agriculture could help to reduce food insecurity and hunger from Nepal
Determinants of Per Capita Food Expenditure to Assess Food Security Status of Nepal
Food security is the global issue as the Sustainable Development Goal (SDG) has explicitly considered zero hunger in the Goal 2. Nonetheless, in the recent years, the number of hunger population is in constant rise. Therefore, the paper attempts to estimate the determinants of the per capita food expenditure from the household expenditure. The data of National Living Standard Survey 2010/11 by the Central Bureau of Statistics Nepal has been used for the study. The multiple regression analysis has been performed. The per capita food expenditure has been used as the dependent variable. The model was found significant and the R-squared value was found 0.77. All the explanatory variables – except gender and education level (completed grade 5-7), were found significant. The number of households, area related variables urban rural and few development regions were found negatively associated with the per capita food expenditure
Understanding COVID-19 Situation in Nepal and Implications for SARS-CoV-2 Transmission and Management
CC BY-NC 4.0Emerging infectious diseases (EIDs) present one of the greatest challenges to public health in the 21st century. An emerging virus, depending on its potential to spread among humans, may cause individual or sporadic cases, culminating in a localized outbreak requiring public health intervention, or, in the worst-case scenario, a widespread epidemic, or worldwide pandemic.1 The novel Coronavirus Disease 2019 (COVID-19) is a new respiratory disease caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) that is causing worldwide public health and economic challenges and has been recognized as a pandemic by the World Health Organization.2 The virus was first reported in Wuhan, Hubei Province, China, in December 2019.2,3 SARS-CoV-2 is an enveloped and positive single-stranded RNA virus belonging to the ß-coronavirus genus.2-4 SARS-CoV-2 holds high homology with SARS-CoV and targets angiotensin-converting enzyme receptor-2 (ACE2) for the viral attachment.4 A schematic depicting SARS-CoV-2 structure and pathogenesis is presented in Figure 1.5 There are very few studies on the transmission of SARS-CoV-2 through treated or untreated wastewater from advanced countries; however, COVID-19 surveillance of wastewater in developing countries has not been reported adequately.6 There is thus a need to study the presence of SARS-CoV-2 in wastewater in the developing countries like Nepal.OA publication support through Carolina Consortium agreement with Sag
Association of RT-qPCR Ct Values and Disease Severity among COVID-19 Patients Visiting a Tertiary Care Hospital in Nepal
COVID-19 pandemic due to SARS-CoV-2 has been one of the major global health issues of this aeon. The aim of this study was to evaluate the association of SARS-CoV-2 cycle threshold (Ct) values with multiple factors among COVID-19 patients visiting a tertiary care hospital in Sudurpashchim province of Nepal. A retrospective analysis was performed on the data of randomly selected COVID-19 cases among the total RT-qPCR tested patients from March 2020 to April 2022. The Ct values at the time of patient admission and their clinical outcomes (discharge or death) were compared. Among the COVID-19 patients, survivor group had significantly higher initial Ct value compared to non-survivors [median Ct values 23.21 and 24.39 (P < 0.0001)]. Selected haematological parameters; white blood cells (P<001), neutrophils (P<001), and monocytes (P<0.0001), and all the biochemical parameters were significantly different between these two groups (p < 0.005). Furthermore, significantly increased CRP (61.54±63.00, P<0.0017), D-dimer levels (0.8979± 1.480, P<0.0001), creatinine (0.7931±0.2551, P<0.0001), monocytes (0.6782±0.7981, P<0.0001), and random blood sugar (152.4±34.32, P<0.0001) were observed among non-survivors indicating as cause of disease severity in COVID-19. The findings of this study imply that the Ct value, CRP and D-dimer levels could be a crucial marker for the early detection of severe COVID-19 patients or those at higher risk of developing severe disease. This will eventually help to identify cases requiring immediate and critical medical care and reduce mortality
First Case of COVID-19 in the Far Western Province of Nepal
Recently emerged worldwide public health problem coronavirus disease (COVID-19) is an infectious disease caused by a severe acute respiratory syndrome coronavirus 2(SARS Cov-2); end of 2019 it was identified as the cause of a cluster of pneumonia cases in Wuhan, a city in the Hubei Province of China. It rapidly spread, resulting in an epidemic throughout China, followed by pandemic throughout the world as well as in Nepal. Finally far western province became the fourth case of Nepal and index case of this province. A 34 year old male presented Seti Provincial hospital fever clinic with the complaints of fever, cough, sore throat and history of travel from Dubai to Nepal. He was kept in isolation and throat swab result was positive for SARS CoV-2. Other systemic examination and routine investigation were within normal. Course of illness was uneventful and managed conservatively. First, second and third RT-PCR became positive and fourth and fifth turned into negative and discharged at the 29th day of admission
Optimal Control Problems in PDE and ODE Systems
This dissertation contains three separate optimal control problems involving partial differential equations (PDEs) or ordinary differential equations (ODEs). In each problem, an objective functional representing the goal of the control process is minimized. First, a system of ordinary differential equations which describe the interaction of Human Immunodeficiency Virus (HIV) and CD4+T-cells in the human immune system is studied. Two controls representing drug treatment strategies of this model are explored. Existence and uniqueness results for the optimal control pair are established. The optimality system is derived and then solved numerically using an iterative method with the Runge-Kutta fourth order scheme.
Second, an unknown coefficient of the interaction term of a parabolic system with a Neumann boundary condition in a multi-dimensional bounded domain is identified. The solution of this system represents the concentrations of predator and prey populations. Given partial (perhaps noisy) observations of the true solution in a subdomain, we seek to “identify” the coefficient of the interaction term using an optimal control problem technique. This method of solving this identification problem is based on Tikhonov’s regularization and the optimal control for a fixed regularization parameter represents the approximate solution of the inverse problem. The existence and uniqueness of the optimal control are established, and an optimality system is derived. As the regularization parameter goes to zero, the identification problem is solved, and an example illustrating how to find a solution numerically is presented.
Third, a problem involving optimal control of a convective velocity coefficient depending on space and time in a parabolic equation is treated. This work applies to a one dimensional fluid flow through a soil-packed tube in which a contaminant is initially distributed. The existence of an optimal control and an optimality system are derived. This problem requires more regularity on the control set which results in a PDE characterization of an optimal control