Optimal Implementation of Intervention to Control the Self-harm Epidemic

AbstractObjectivesDeliberate self-harm (DSH) of a young person has been a matter of growing concern to parents and policymakers. Prevention and early eradication are the main interventional techniques among which prevention through reducing peer pressure has a major role in reducing the DSH epidemic. Our aim is to develop an optimal control strategy for minimizing the DSH epidemic and to assess the efficacy of the controls.MethodsWe considered a deterministic compartmental model of the DSH epidemic and two interventional techniques as the control measures. Pontryagin's Maximum Principle was used to mathematically derive the optimal controls. We also simulated the model using the forward-backward sweep method.ResultsSimulation results showed that the controls needed to be used simultaneously to reduce DSH successfully. An optimal control strategy should be adopted, depending on implementation costs for the controls.ConclusionThe long-term success of the optimum control depends on the implementation cost. If the cost is very high, the control could be used for a short term, even though it fails in the long run. The control strategy, most importantly, should be implemented as early as possible to attack a comparatively fewer number of addicted individuals

Synthesis and characterization of PEEK containing imidazole moiety and effect of functional groups

Anion exchange membrane fuel cells (AEMFCs) are considered as one of the alternative power generation systems due to their high efficiency. Anion exchange membrane (AEM) is a key component in fuel cells for the transfer of anion which is effect to the performance of the fuel cell system. \Therefore, it needs to have high chemical, mechanical, and thermal stabilities, as well as excellent electrochemical properties. For these reasons, various types of novel polymeric materials have been developed for the anion exchange membrane fuel cells. Especially, hydrocarbon based polymer materials such as poly(arylene ether sulfone), poly(ether ether ketone)(PEEK), polybenzimidazole (PBI) have been fabricated for use as electrolytes in fuel cell systems. Also, a number of preparation methods have been developed to enhance the performance of fuel cell membranes. In this study, we modified the monomer by chemical modification reaction and we synthesized the PEEK based polymer with different amination degree. Also we compared the chemical stability of the PEEK based membrane with different functional groups such as ammonium and imidazolium. Finally, the effect of the contents of the anion exchange groups in the PEEK based polymer was evaluated in terms of morphology, water behavior, mechanical properties, chemical stability and ion conductivity. Please click Additional Files below to see the full abstract

Stability Analysis of a Vector-Borne Disease with Variable Human Population

A mathematical model of a vector-borne disease involving variable human population is analyzed. The varying population size includes a term for disease-related deaths. Equilibria and stability are determined for the system of ordinary differential equations. If R0≤1, the disease-“free” equilibrium is globally asymptotically stable and the disease always dies out. If R0>1, a unique “endemic” equilibrium is globally asymptotically stable in the interior of feasible region and the disease persists at the “endemic” level. Our theoretical results are sustained by numerical simulations

Mathematical Model of COVID-19 Transmission Dynamics in South Korea: The Impacts of Travel Restrictions, Social Distancing, and Early Detection

The novel coronavirus disease (COVID-19) poses a severe threat to public health officials all around the world. The early COVID-19 outbreak in South Korea displayed significant spatial heterogeneity. The number of confirmed cases increased rapidly in the Daegu and Gyeongbuk (epicenter), whereas the spread was much slower in the rest of Korea. A two-patch mathematical model with a mobility matrix is developed to capture this significant spatial heterogeneity of COVID-19 outbreaks from 18 February to 24 March 2020. The mobility matrix is taken from the movement data provided by the Korea Transport Institute (KOTI). Some of the essential patch-specific parameters are estimated through cumulative confirmed cases, including the transmission rates and the basic reproduction numbers (local and global). Our simulations show that travel restrictions between the epicenter and the rest of Korea effectively prevented massive outbreaks in the rest of Korea. Furthermore, we explore the effectiveness of several additional strategies for the mitigation and suppression of Covid-19 spread in Korea, such as implementing social distancing and early diagnostic interventions

Effect of Salicornia herbacea on Osteoblastogenesis and Adipogenesis in Vitro

Bone-related complications are among the highest concerning metabolic diseases in the modern world. Bone fragility and susceptibility to fracture increase with age and diseases like osteoporosis. Elevated adipogenesis in bone results in osteoporosis and loss of bone mass when coupled with lack of osteoblastogenesis. In this study the potential effect of Salicornia herbacea extract against osteoporotic conditions was evaluated. Adipogenesis inhibitory effect of S. herbacea has been evidenced by decreased lipid accumulation of differentiating cells and expression levels of crucial adipogenesis markers in 3T3-L1 pre-adipocytes. S. herbacea treatment reduced the lipid accumulation by 25% of the control. In addition, mRNA expression of peroxisome proliferator-activated receptor (PPAR)γ, CCAAT/enhancer-binding protein (C/EBP)α and sterol regulatory element binding protein (SREBP)1c were inhibited by the presence of S. herbacea. Bone formation enhancement effect of S. herbacea was also confirmed in MC3T3-E1 pre-osteoblasts. The presence of S. herbacea significantly elevated the alkaline phosphatase (ALP) activity by 120% at a concentration of 100 μg/mL in differentiating osteoblasts. S. herbacea also significantly increased the expression of osteoblastogenesis indicators, ALP, bone morphogenetic protein (BMP)-2, osteocalcin and collagen type I (collagen-I). In conclusion, S. herbacea possess potential to be utilized as a source of anti-osteoporotic agent that can inhibit adipogenesis while promoting osteoblastogenesis

Size-Dependent Interactions between Au Nanoparticles and DNA in Electrochemical Oxidation by Metal Complexes

Single-stranded oligonucleotides (ssDNA) containing guanine bases in their sequences were adsorbed onto gold nanoparticles (AuNPs) by electrostatic interaction. Cyclic voltammetry of Ru­(bpy)₃²⁺ in the presence of the ssDNA-AuNP complex resulted in an enhanced anodic current due to the oxidation of the guanine bases of DNA. The current obtained with ssDNA-AuNP appeared much smaller than the corresponding ssDNA alone. This current reduction was due to the decrease in solvent accessibility of the guanines in ssDNA immobilized to AuNPs. A progressive decrease in the current was observed in the titration of AuNPs to ssDNA, and a minimum current was eventually obtained, indicating complete binding of ssDNA. The size dependences of AuNPs on the interaction between ssDNA and AuNP were also studied, and the ssDNA adsorbed to 5 nm AuNPs was more solvent-accessible for the Ru mediator than 13 and 30 nm AuNPs

Chitooligosaccharides attenuate UVB-induced damages in human dermal fibroblasts

As a continuation of our research on chitooligosaccharides (COS), this study focused on the protective effect of COS of various molecular weights (1–3, 3–5, and 5–10 kDa) on cellular damage caused by ultraviolet B (UVB)-induced oxidative stress in human dermal fibroblast cells. The results show that the protective effect of COS on UVB-stressed human fibroblasts was dependent on molecular weight. COS suppressed UVB irradiation-induced reactive oxygen species generation and DNA damage, accompanied by the downregulation of matrix metalloproteinase (MMP)-1 and MMP-13. In a comparative analysis, COS (3–5 kDa) exhibited the most potent protective effect on UVB-stressed fibroblasts. The presence of COS (3–5 kDa) attenuated UVB-induced collagenolytic MMP production and collagen degradation. The photoprotective activity of COS (3–5 kDa) was confirmed by transcriptional phosphorylation of mitogen-activated protein kinase-responsive signaling pathways

Dioxinodehydroeckol protects human keratinocyte cells from UVB-induced apoptosis modulated by related genes Bax/Bcl-2 and caspase pathway

Although ultraviolet B (UVB) has a low level of skin penetration, it readily results in epidermal sunburn of keratinocytes that are destined to apoptosis after sun expose, and leads to DNA damage. Dioxinodehydroeckol (DHE), a phlorotannin from Ecklonia cava has been explored for its preventive activity against UVB-induced apoptosis in human keratinocyte (HaCaT) cells; however, the protective effects of treatment with low doses of DHE on UVB-damaged cells post-UVB exposure and their underlying mechanisms still remain unclear. The HaCaT cells were exposed to 20 mJ cm of UVB irradiation which is the minimal erythema dose (MED) for individuals to be able to tan, and the expression levels of Bax/Bcl-2 and caspase-3,-8, -9 which are associated genes with apoptosis were investigated when we either treated cells with DHE doses after UVB irradiation or exposed them to UVB only. Our results suggest insight into proposed mechanistic pathway of protective activity of DHE on the HaCaT cells from UVB-induced apoptosis, indicating the benefit of DHE as a repair agent for skin damage against UVB

Anti-Inflammatory Effect of By-Products from Haliotis discus hannai in RAW 264.7 Cells

Several reports promoted the potential of shellfish due to their ability to act as antioxidant, anti-inflammatory, and antimicrobial agents. Pacific abalone, Haliotis discus hannai viscera is, reported to possess bioactivities such as antioxidative stress and anti-inflammatory. In this study, anti-inflammatory potential of mucus-secreting glands from shell-shucking waste of H. discus hannai was evaluated using RAW 264.7 mouse macrophage cell model. Results indicated that presence of H. discus hannai mucosubstance by-products (AM) significantly lowered the nitric oxide (NO) production along the expressional suppression of inflammatory mediators such as cytokines TNF-α, IL-1β, and IL-6 and enzymes iNOS and COX-2. Also, AM was shown to increase expression of anti-inflammatory response mediator HO-1. Presence of AM also scavenged the free radicals in vitro. In conclusion, by-products of H. discus hannai are suggested to possess notable anti-inflammatory potential which promotes the possibility of utilization as functional food ingredient

Phlorofucofuroeckol A from Edible Brown Alga Ecklonia Cava Enhances Osteoblastogenesis in Bone Marrow-Derived Human Mesenchymal Stem Cells

The deterioration of bone formation is a leading cause of age-related bone disorders. Lack of bone formation is induced by decreased osteoblastogenesis. In this study, osteoblastogenesis promoting effects of algal phlorotannin, phlorofucofuroeckol A (PFF-A), were evaluated. PFF-A was isolated from brown alga Ecklonia cava. The ability of PFF-A to enhance osteoblast differentiation was observed in murine pre-osteoblast cell line MC3T3-E1 and human bone marrow-derived mesenchymal stem cells (huBM-MSCs). Proliferation and alkaline phosphatase (ALP) activity of osteoblasts during differentiation was assayed following PFF-A treatment along extracellular mineralization. In addition, effect of PFF-A on osteoblast maturation pathways such as Runx2 and Smads was analyzed. Treatment of PFF-A was able to enhance the proliferation of differentiating osteoblasts. Also, ALP activity was observed to be increased. Osteoblasts showed increased extracellular mineralization, observed by Alizarin Red staining, following PFF-A treatment. In addition, expression levels of critical proteins in osteoblastogenesis such as ALP, bone morphogenetic protein-2 (BMP-2), osteocalcin and β-catenin were stimulated after the introduction of PFF-A. In conclusion, PFF-A was suggested to be a potential natural product with osteoblastogenesis enhancing effects which can be utilized against bone-remodeling imbalances and osteoporosis-related complications