Lassa virus, an arenavirus, represents the most prevalent human pathogen causing viral hemorrhagic fever. It is endemic in Nigeria and other West African countries. Despite the high burden of the ...disease, limited treatments are available and no approved vaccine for the prevention of this disease is available. In this study, an Immunoinformatics and reverse vaccinology pipeline was employed to predict a multi-epitope vaccine. Four fundamental virulent and proteogenic proteins (glycoprotein precursor, Viral matrix protein, viral RNA polymerase, and Nucleoprotein) were identified. Using various immunoinformatics tools, 12 CTL, 14 HTL, and six B-cell epitopes were predicted and connected via suitable linkers, together with an adjuvant to develop a 602 amino acids long vaccine construct (VC). The VC was assessed to be non-allergenic, non-toxic, stable, soluble, and highly antigenic. Molecular docking of VC with RIG-I, major histocompatibility complex class I and class II were carried out to validate the interactions with the receptors. The complex of VC-RIG-I was subjected to a dynamic stability test and the RMDS and RMSF results suggest that the complex is stable. Validation of the final vaccine construct was done through in silico cloning using E. coli as a host. A CAI value of 0.99 suggests that the vaccine construct expressed properly in the host. The immune simulation predicted significantly high levels of IgG1, T-helper, T-cytotoxic cells, INF-γ, and IL-2. This rigorous computational study suggests infection control by creating an effective immunological memory against Lassa virus infections. However, both in vitro and in vivo experiments are needed to validate the potential of the proposed vaccine.
Research on amphibian parasites has been on the increase because of the noticeable decline of amphibians. Studies on these parasites have been limited to their prevalence and infection patterns, and ...there is still a dearth of knowledge on the phenotypic variations. To characterise and investigate the genetic variability and relatedness of amphibian nematode parasites, two nematode parasites-suspected Cosmocerca sp. and suspected Rhabdias sp.-of the toad Schlerophrys regularis were investigated. One hundred and sixty-eight S. regularis were collected from three study areas: Ikorodu, Ojota and Badagry. Intestines were dissected to obtain the enteric parasites, and lungs were washed in saline solution. Parasites were labelled according to the location of collection (Badagry 5A-5I, Ikorodu 5J-5O, Ojota 5P and 5S) and were then preserved for further identification. Eighteen parasites were identified morphologically using standard keys and by amplification of the 18S small subunit (SSU) ribosomal DNA sequence. Phylogenetic analysis was done using the Neighbour-Joining method. From the sequence homology and phylogenetic analysis, the suspected Cosmocerca sp. shared the closest genetic relatedness with Aplectana chamaeleonis isolate AC3 with 100% similarities while the suspected Rhabdias sp. shared the closest genetic relatedness with Rhabditoides regina isolate DF5012 with 100% similarities. Based on location, four Aplectana chamaeleonis (5E, 5F, 5G, 5H) and five Rhabditoides regina (5A, 5B, 5C, 5D, 5I) were from Badagry, four Aplectana chamaeleonis (5J, 5M, 5N, 5O) and two Rhabditoides regina (5K, 5L) from Ikorodu, one Aplectana chamaeleonis (5S) and two Rhabditoides regina (5P, 5Q) from Ojota. We report that Rhabditoides regina, a parasite known to be associated with insects, was recovered in the lungs of toads. Further investigations to resolve the complexities of superfamily Cosmocercoidea are recommended. Relatedness was not influenced by collection location as parasites were not unique to a specific environment.
Mercury is an environmental neurotoxicant that triggers structural and physiological alterations in different brain parts. The hippocampus is associated with learning and memory, and injury to this ...brain part may lead to behavioural and cognitive changes. Phoenix dactylifera (date palm) has been demonstrated to possess a variety of medical benefits. This study comparatively assessed the neuroprotective property of aqueous and ethanol fruit pulp extracts of P. dactylifera in a rat model of mercury-triggered hippocampal changes using microscopic examinations. Twenty-eight Wistar rats were divided into seven groups (I-VII, n=4). Group I (control) was administered distilled water (2ml/kg); group II was administered mercuric chloride, HgCl2 (5mg/kg); group III was administered vitamin C (100mg/kg) as reference drug +HgCl2; groups IV and V were administered aqueous extract (250mg/kg and 500mg/kg, respectively) +HgCl2, while groups VI and VII were administered ethanol extract (250mg/kg and 500mg/kg, respectively) +HgCl2. Extracts' neuroprotective property were evaluated using histological and histometric assessments of CA1 and CA3 hippocampal sub-regions. Results revealed cytoarchitectural changes including karyopyknosis, basophilic necrosis and remarkably decreased histometric features of hippocampal pyramidal neurons in HgCl2-treated group relative to control. Administration of the extracts remarkably ameliorated mercury-induced degenerative changes by preservation of cytoarchitectural features comparable to reference drug. Comparatively, neuroprotective efficacies of the extracts are relatively similar, especially at doses of 500mg/kg and could be attributed to antioxidant activities of constituent phytochemicals. Results suggest that aqueous and ethanol fruit pulp extracts of P. dactylifera may prove efficacious in ameliorating mercury-triggered microscopic alterations in the hippocampus of Wistar rats.
A power cycling apparatus, capable of simultaneously assessing the thermal performance and long-term reliability of up to four die-attachment interfaces has been developed and utilized to evaluate ...various types of bonding materials. A standard lead-based solder (SnPb), lead-free solder (SnAgCu), eutectic braze alloy (AuSn), a polyimide (Epo-Tek's P-1011), a conductive epoxy (Epo-Tek's H20E), and a nanoparticle silver paste are the materials chosen for comparison. In addition, a preliminary investigation into the thermal performance and reliability of a novel, lead-free "universal" solder for power electronics packaging is included. A direct comparison is made between this material, a Sn3.5Ag0.5Cu-RE (SAC-RE) solder with small additions (0.5 to 2.0 wt%) of a rare earth element, and the conventional solder, Sn3.0Ag0.5Cu (SAC-305). Depending on the form of each joining material, the bonding was either performed manually in atmosphere or inside a vacuum-pressure furnace. Scanning acoustic microscopy and/or x-ray analysis are used for void characterization of each interface. Before and after power cycling assessments and die-shear analysis are used to assess the strength of bonded joints. Failure analysis showed a correlation between a 10% increase in thermal impedance and significant void growth for SnAgCu solder. Despite a large percent voiding before power cycling, AuSn performed without failure to 20K cycles. Die cracking and debonding were experienced with H20E and nanoparticle silver paste, respectively. Improvements were not observed with SAC-RE over SAC-305 in regards to bonding strength, however, power cycling performance of the "universal" solder continued to up 38K cycles without failure at the bonding interface.
Background Pregnancy can be associated with anxiety symptoms because of anticipated uncertainty.Aim This study investigated pregnancy-related anxiety symptoms (PRASs) and their associated factors ...amongst pregnant women.Setting Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria.Methods This cross-sectional survey involved 230 pregnant women attending antenatal clinic at a tertiary teaching hospital in Nigeria. Pregnancy-related anxiety symptoms, maternal worries, personality traits and social support were measured by using Perinatal Anxiety Screening Scale (PASS), Cambridge Worry Scale (CWS), Big Five Personality Inventory (BFI-10) and Maternal Social Support Scale (MSSS) respectively. Socio-demographic and obstetric details were also obtained. The Chi-square, t-test and logistic regression were used.Results Respondents’ mean age was 28.2 ± 5.4 years, whilst 192 (83.5%) were of Yoruba ethnicity. Twenty-four respondents (10.4%) were in the first trimester, 85 (37.0%) in the second and 121 (52.6%) in the third trimester. Some 154 (67.0%) were parous. The prevalence of PRAS and major maternal worries were 43.5% and 55.7% respectively. The socio-demographic factors significantly associated with PRAS were age (p = 0.004), ethnicity (p = 0.001), educational level (p = 0.011) and living arrangement (p = 0.029). Associated obstetric factors include trimester (p = 0.01), hypertension (p = 0.006), past miscarriage(s) (p = 0.013) and past pregnancy complication (p = 0.030). Significant psychosocial factors were partner social support (p = 0.038), maternal worries (p<0.001) and extraversion (p = 0.016). Factors that contributed significantly to regression models were older maternal age and socio-medical worries.Conclusion High level of PRAS and major maternal worries were common amongst antenatal clinic attendees of a tertiary teaching hospital in Nigeria. Older maternal age and socio-medical maternal worries are important predictors of PRAS.
•A hybrid energy system combining grid and solar PV/Battery was designed for powering commercial building loads.•An integrated energy management scheme based on fuzzy logic control was designed for ...commercial load demand management.•A techno-economical analysis was performed to determine the cost-saving potentials.•Capacity planning was highly prioritized, considering energy, economy, environment and grid dependence.
Demand-side energy management techniques, such as load shielding, shifting, and delaying appliance operation during peak periods, are typically used to reduce electricity costs at the expense of users’ comfort. To address these challenges, especially where operational delays are unacceptable, distributed generation (DG) is frequently incorporated into the grid system to improve power balance and total energy costs. However, dynamic load demands and varying outputs from renewable DG sources such as solar photovoltaic (PV) systems make energy management in microgrids (MGs) extremely challenging. Moreover, most of the existing studies in this domain focus on objective functions that are geared on optimising the economic balance between cost and value of MG operation over a certain time period. Nevertheless, research that took into consideration the stochastic behaviour of DG’s subsystems in addition to cost and benefit of MG operation are still limited. This current study proposed a fuzzy logic control (FLC) integrated energy management system (EMS) for commercial loads with hybrid grid-solar PV/battery energy system. The proposed technique intelligently selects energy sources using the grid energy cost and the state of charge (SoC) of the solar PV/battery at any time of the day. The EMS operate the loads at a reduced cost without any operational delay or shifting. The system was implemented in the MATLAB/Simulink environment, and the techno-economic feasibility of energy cost savings was investigated by comparing the developed scheme with the Homer hybrid energy system model for a hotel building. The developed EMS reduced energy costs by an average of 11.87 % per day and 7.94 % over a 20-year lifetime.
To identify the qualitative and quantitative contributions of conventional risk factors for occurrence of ischemic stroke and its key pathophysiologic subtypes among West Africans.
The SIREN (Stroke ...Investigative Research and Educational Network) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with ischemic stroke who were etiologically subtyped using the A-S-C-O-D classification into atherosclerosis, small-vessel occlusion, cardiac pathology, other causes, and dissection. Controls were age- and gender-matched stroke-free adults. Detailed evaluations for vascular, lifestyle, and psychosocial factors were performed. We used conditional logistic regression to estimate adjusted odds ratios with 95% CI.
There were 2431 ischemic stroke case and stroke-free control pairs with respective mean ages of 62.2±14.0 versus 60.9±13.7 years. There were 1024 (42.1%) small vessel occlusions, 427 (17.6%) large-artery atherosclerosis, 258 (10.6%) cardio-embolic, 3 (0.1%) carotid dissections, and 719 (29.6%) undetermined/other causes. The adjusted odds ratio (95% CI) for the 8 dominant risk factors for ischemic stroke were hypertension, 10.34 (6.91-15.45); dyslipidemia, 5.16 (3.78-7.03); diabetes, 3.44 (2.60-4.56); low green vegetable consumption, 1.89 (1.45-2.46); red meat consumption, 1.89 (1.45-2.46); cardiac disease, 1.88 (1.22-2.90); monthly income $100 or more, 1.72 (1.24-2.39); and psychosocial stress, 1.62 (1.18-2.21). Hypertension, dyslipidemia, diabetes were confluent factors shared by small-vessel, large-vessel and cardio-embolic subtypes. Stroke cases and stroke-free controls had a mean of 5.3±1.5 versus 3.2±1.0 adverse cardio-metabolic risk factors respectively (
<0.0001).
Traditional vascular risk factors demonstrate important differential effect sizes with pathophysiologic, clinical and preventative implications on the occurrence of ischemic stroke among indigenous West Africans.
Objectives: The study aimed to examine health workers’ perceptions of the coronavirus disease 2019 (COVID-19) vaccine in Nigeria and their willingness to receive the vaccine when it becomes ...available.Methods: This multi-center cross-sectional study used non-probability convenience sampling to enroll 1,470 hospital workers aged 18 and above from 4 specialized hospitals. A structured and validated self-administered questionnaire was used for data collection. Data entry and analysis were conducted using IBM SPSS ver. 22.0.Results: The mean age of respondents was 40±6 years. Only 53.5% of the health workers had positive perceptions of the COVID-19 vaccine, and only slightly more than half (55.5%) were willing to receive vaccination. Predictors of willingness to receive the COVID-19 vaccine included having a positive perception of the vaccine (adjusted odds ratio AOR, 4.55; 95% confidence interval CI, 3.50−5.69), perceiving a risk of contracting COVID-19 (AOR, 1.50; 95% CI, 1.25–3.98), having received tertiary education (AOR, 3.50; 95% CI, 1.40−6.86), and being a clinical health worker (AOR, 1.25; 95% CI, 1.01−1.68).Conclusion: Perceptions of the COVID-19 vaccine and willingness to receive the vaccine were sub-optimal among this group. Educational interventions to improve health workers' perceptions and attitudes toward the COVID-19 vaccine are needed.
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