On the Nehari manifold for a logarithmic fractional Schrödinger equation with possibly vanishing potentials

summary:We study a class of logarithmic fractional Schrödinger equations with possibly vanishing potentials. By using the fibrering maps and the Nehari manifold we obtain the existence of at least one nontrivial solution

On a viscoelastic heat equation with logarithmic nonlinearity

This work deals with the following viscoelastic heat equations with logarithmic nonlinearity ut − ∆u + Z t 0 g(t − s)∆u(s)ds = |u| p−2u ln |u|. In this paper, we show the effects of the viscoelastic term and the logarithmic nonlinearity to the asymptotic behavior of weak solutions. Our results extend the results of Peng and Zhou [Appl. Anal. 100(2021), 2804–2824] and Messaoudi [Progr. Nonlinear Differential Equations Appl. 64(2005), 351–356.]

Existence and nonexistence of global solutions for doubly nonlinear diffusion equations with logarithmic nonlinearity

In this paper, we study an initial-boundary value problem for a doubly nonlinear diffusion equation with logarithmic nonlinearity. By using the potential well method, we give some threshold results on existence or nonexistence of global weak solutions in the case of initial data with energy less than or equal to potential well depth. In addition, the asymptotic behavior of solutions is also discussed

Synthesis of para-menthane 3,8 - diol from Eucalyptus citriodora essential oil for application in mosquito repellent products

To repel mosquitoes, there have been many highly effective chemical repellent products, but they carry the potential risk of being unsafe for humans and harmful to the environment. Insect repellent products derived from natural sources that are safe for humans and environmentally friendly are becoming increasingly popular. PMD is a broad-spectrum and effective insect repellent but is present in small amounts in the Eucalyptus citriodora essential oil (EO). In this study, we investigated and evaluated the conditions for synthesizing PMD from EO raw materials in an acidic environment to achieve the highest synthesis efficiency of 76.3%, and the PMD product was 96.4% pure after being converted for 5 hours at 50°C in a 0.25% H2SO4 solution. Additionally, the study also separated the two cis and trans isomers of PMD by column chromatography and determined their structures using infrared spectroscopy (IR) and nuclear magnetic resonance (NMR)

Secondary Network Throughput Optimization of NOMA Cognitive Radio Networks Under Power and Secure Constraints

Recently, the combination of cognitive radio networks with the nonorthogonal multiple access (NOMA) approach has emerged as a viable option for not only improving spectrum usage but also supporting large numbers of wireless communication connections. However, cognitive NOMA networks are unstable and vulnerable because multiple devices operate on the same frequency band. To overcome this drawback, many techniques have been proposed, such as optimal power allocation and interference cancellation. In this paper, we consider an approach by which the secondary transmitter (STx) is able to find the best licensed channel to send its confidential message to the secondary receivers (SRxs) by using the NOMA technique. To combat eavesdroppers and achieve reasonable performance, a power allocation policy that satisfies both the outage probability (OP) constraint of primary users and the security constraint of secondary users is optimized. The closed-form formulas for the OP at the primary base station and the leakage probability for the eavesdropper are obtained with imperfect channel state information. Furthermore, the throughput of the secondary network is analyzed to evaluate the system performance. Based on that, two algorithms (i.e., the continuous genetic algorithm (CGA) for CR NOMA (CGA-CRN) and particle swarm optimization (PSO) for CR NOMA (PSO-CRN)), are applied to optimize the throughput of the secondary network. These optimization algorithms guarantee not only the performance of the primary users but also the security constraints of the secondary users. Finally, simulations are presented to validate our research results and provide insights into how various factors affect system performance

Secondary Network Throughput Optimization of NOMA Cognitive Radio Networks Under Power and Secure Constraints

Recently, the combination of cognitive radio networks with the nonorthogonal multiple access (NOMA) approach has emerged as a viable option for not only improving spectrum usage but also supporting large numbers of wireless communication connections. However, cognitive NOMA networks are unstable and vulnerable because multiple devices operate on the same frequency band. To overcome this drawback, many techniques have been proposed, such as optimal power allocation and interference cancellation. In this paper, we consider an approach by which the secondary transmitter (STx) is able to find the best licensed channel to send its confidential message to the secondary receivers (SRxs) by using the NOMA technique. To combat eavesdroppers and achieve reasonable performance, a power allocation policy that satisfies both the outage probability (OP) constraint of primary users and the security constraint of secondary users is optimized. The closed-form formulas for the OP at the primary base station and the leakage probability for the eavesdropper are obtained with imperfect channel state information. Furthermore, the throughput of the secondary network is analyzed to evaluate the system performance. Based on that, two algorithms (i.e., the continuous genetic algorithm (CGA) for CR NOMA (CGA-CRN) and particle swarm optimization (PSO) for CR NOMA (PSO-CRN)), are applied to optimize the throughput of the secondary network. These optimization algorithms guarantee not only the performance of the primary users but also the security constraints of the secondary users. Finally, simulations are presented to validate our research results and provide insights into how various factors affect system performance

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

The influence of human genetic variation on early transcriptional responses and protective immunity following immunization with Rotarix vaccine in infants in Ho Chi Minh City in Vietnam : a study protocol for an open single-arm interventional trial [awaiting peer review]

Background: Rotavirus (RoV) remains the leading cause of acute gastroenteritis in infants and children aged under five years in both high- and low-middle-income countries (LMICs). In LMICs, RoV infections are associated with substantial mortality. Two RoV vaccines (Rotarix and Rotateq) are widely available for use in infants, both of which have been shown to be highly efficacious in Europe and North America. However, for unknown reasons, these RoV vaccines have markedly lower efficacy in LMICs. We hypothesize that poor RoV vaccine efficacy across in certain regions may be associated with genetic heritability or gene expression in the human host. Methods/design: We designed an open-label single-arm interventional trial with the Rotarix RoV vaccine to identify genetic and transcriptomic markers associated with generating a protective immune response against RoV. Overall, 1,000 infants will be recruited prior to Expanded Program on Immunization (EPI) vaccinations at two months of age and vaccinated with oral Rotarix vaccine at two and three months, after which the infants will be followed-up for diarrheal disease until 18 months of age. Blood sampling for genetics, transcriptomics, and immunological analysis will be conducted before each Rotarix vaccination, 2-3 days post-vaccination, and at each follow-up visit (i.e. 6, 12 and 18 months of age). Stool samples will be collected during each diarrheal episode to identify RoV infection. The primary outcome will be Rotarix vaccine failure events (i.e. symptomatic RoV infection despite vaccination), secondary outcomes will be antibody responses and genotypic characterization of the infection virus in Rotarix failure events. Discussion: This study will be the largest and best powered study of its kind to be conducted to date in infants, and will be critical for our understanding of RoV immunity, human genetics in the Vietnam population, and mechanisms determining RoV vaccine-mediated protection. Registration: ClinicalTrials.gov, ID: NCT03587389. Registered on 16 July 2018