Comparative Analysis of Corrosion Behavior of Martensitic and Annealed Stainless Steel in H2SO4 and NaOH

Using weight lose techniques (WLT), the comparative analysis of the corrosion characterization behavior of cast stainless steel (70.90% Fe, 19% Cr 10%Ni, 0.0% C) alloys in ( 0.25M- 0.5M)   H2SO4 and NaOH has been evaluated. The cast stainless steel specimen was sectioned  into three sets labeled M, A, U and machined to the same cross sectional area. M and A is subjected to a temperature of 900oC (1173K or 1652oF) where the grains forms austenitic phase which was further heat- treated  to form martensitic stainless steel (M) and annealed stainless steel (A) test coupon respectively. Then, (U) is left untreated as a control test coupon sample. These preweighed test coupon samples were immersed in 0.25M and 0.5M simulated  tetraoxosulphate (vi) acid (H2SO4) and sodium hydroxide (NaOH) respectively. The experimental process is allowed for a total of 168hr with each set withdrawn 24hr interval for weight lose analysis. The findings showed that of a passivating metals with initial steady rise in corrosion penetration rate (CPR) followed by gradual decrease in CPR which increases as molar concentration increase for the annealed specimen(A) in  H2S04 while the martensitic test specimen(M) is severely attacked in NaOH. The annealed specimen exhibit high passivity in   H2S04 with lowest CPR of 0.0071mm/yr. The severe attack of the annealed specimen is due to increase in ionization which results in redistribution of grain boundary structure. Key words: Passivation, Corrosion  kinetics, Basic Environment, Acidic Environment, Martensitic, Annealing, Weight Lose Techniques, Austenitic phase

Effect of Vernonia amygdalina Ethanolic Root Extract on the Hepato- and Nephro-Protective Properties of Albino Rats (Rattus novergicus)

The hepato- and nephro-protective potentials of Vernonia amygdalina ethanolic root extract was evaluated for 14 days using standard bioassay in 45 normal male albino rats. The rats were divided into four treatment groups I – IV and a control group V. Groups I – IV were given 100mg.kg-1, 200mg.kg-1, 400mg.kg-1 and 600mg.kg-1 body weight, respectively while the control (group V) was given equal volume of feed and water. The extracts were administered orally to the animals for 14 days. Blood samples were collected using the ocular puncture method before and weekly after administration to evaluate the extracts’ effects on aspartate transaminase (AST), acid phosphatase (ACP), alanine transaminase (ALT), alkaline phosphatase (ALP), bilirubin, creatinine and blood urea nitrogen (BUN) levels. The mean serum levels of the liver marker enzymes AST, ACP, ALT, ALP, total bilirubin and direct bilirubin ranged from 10.00±0.53 to 11.44±0.44, 31.29±0.64 to 33.14±0.56, 27.22±0.94 to 29.67±0.37 and 37.83±0.59 to 40.57±1.02, 3.42±0.08 to 3.61±0.07 and 2.06±0.11 to 2.51±0.05 respectively. The mean levels of the nephrotic enzymes, creatinine and BUN also ranged from 39.87±1.79 to 43.04±1.57 and 6.62±0.21 to 15.98±0.17 accordingly. Although no significant difference (p>0.05) was observed in the serum levels of the liver marker enzymes and creatinine when compared with the control, a dose and duration dependent significant increase (p<0.05) occurred in the BUN level. This tends to suggest that the ethanolic root extract of Vernonia amygdalina on a short term basis has some hepato-protective property while its nephro-protective ability is still doubtful. Keywords: Vernonia amygdalina, Ethanolic root extract, Liver maker enzymes, Nephrotic enzymes, Albino rat

The trend of collapse of buildings in concrete materials in Lagos State, Nigeria (2013-2019)

Buildings are essential structures that provide mankind with accommodation in the form of offices, factories, residences, etc. Building Infrastructure aid to increase the Gross domestic product of nations by meeting the present needs as well as helping in the reduction of future deficiencies. Unfortunately, in developing countries like Nigeria, regular occurrence of collapse of buildings in concrete materials have dealt a terrible blow to the nation, leading to losses in the form of death and damage to properties. This study aims to show the trend within the period of 2013 to 2019. This study used statistical methods to assess the fatality rate, types of buildings affected, frequency of occurrences and the causative factors. The result indicates that the year2017 witnessed 14 collapse incidences making it the highest within the study period in Lagos state. Furthermore, 204 persons lost their lives in 2014, making it the highest within the period. The results obtained showed that the risk of collapse and fatality rises as the building height goes up and when unauthorized floors are added to an existing building

Methods used in prevalence studies of disrespect and abuse during facility based childbirth: lessons learned

Background: Several recent studies have attempted to measure the prevalence of disrespect and abuse (D&A) of women during childbirth in health facilities. Variations in reported prevalence may be associated with differences in study instruments and data collection methods. This systematic review and comparative analysis of methods aims to aggregate and present lessons learned from published studies that quantified the prevalence of Disrespect and Abuse (D&A) during childbirth. Methods: We conducted a systematic review of the literature in accordance with PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. Five papers met criteria and were included for analysis. We developed an analytical framework depicting the basic elements of epidemiological methodology in prevalence studies and a table of common types of systematic error associated with each of them. We performed a head-to-head comparison of study methods for all five papers. Using these tools, an independent reviewer provided an analysis of the potential for systematic error in the reported prevalence estimates. Results: Sampling techniques, eligibility criteria, categories of D&A selected for study, operational definitions of D&A, summary measures of D&A, and the mode, timing, and setting of data collection all varied in the five studies included in the review. These variations present opportunities for the introduction of biases – in particular selection, courtesy, and recall bias – and challenge the ability to draw comparisons across the studies’ results. Conclusion: Our review underscores the need for caution in interpreting or comparing previously reported prevalence estimates of D&A during facility-based childbirth. The lack of standardized definitions, instruments, and study methods used to date in studies designed to quantify D&A in childbirth facilities introduced the potential for systematic error in reported prevalence estimates, and affected their generalizability and comparability. Chief among the lessons to emerge from comparing methods for measuring the prevalence of D&A is recognition of the tension between seeking prevalence measures that are reliable and generalizable, and attempting to avoid loss of validity in the context where the issue is being studied. Electronic supplementary material The online version of this article (10.1186/s12978-017-0389-z) contains supplementary material, which is available to authorized users

Mucin-Grafted Polyethylene Glycol Microparticles Enable Oral Insulin Delivery for Improving Diabetic Treatment

In this study, different ratios of mucin-grafted polyethylene-glycol-based microparticles were prepared and evaluated both in vitro and in vivo as carriers for the oral delivery of insulin. Characterization measurements showed that the insulin-loaded microparticles display irregular porosity and shape. The encapsulation efficiency and loading capacity of insulin were >82% and 18%, respectively. The release of insulin varied between 68% and 92% depending on the microparticle formulation. In particular, orally administered insulin-loaded microparticles resulted in a significant fall of blood glucose levels, as compared to insulin solution. Subcutaneous administration showed a faster, albeit not sustained, glucose fall within a short time as compared to the polymeric microparticle-based formulations. These results indicate the possible oral delivery of insulin using this combination of polymers.Tertiary Education Trust Fund (TETFUND)–National Research Fund (NFR)Ministerio de Ciencia, Innovación y Universidade

Validation of coronavirus-2019 phobia scale using preschool practitioners in urban and rural communities in Nigeria Implication for educational sociologists

Coronavirus-2019 (COVID-19) emerged in December 2019, causing significant changes in people’s social lives and other human activities. The outbreak halted educational activities throughout the world. The Nigerian experience was unique in that most people were skeptical about the pandemic’s existence. This practice contributed to the Nigerian people’s fear of the COVID-19 outbreak. However, in Nigeria, there has never been a validated or established Covid-19 phobia scale, necessitating this study. This study was a pure validation study on COVID-19 phobia scale (C19PS). The study area was south-east states and a sample of 386 preschool practitioners in urban and rural communities of South East States, Nigeria participated in the study. The eligibility criteria include being a preschool teacher and demonstrating signs of COVID-19 phobia. The validation of the C19PS was done by subjecting the data gathered to principal axis factoring analysis with varimax rotation. The model fit for the data was tested using root mean square error of approximation and comparative fit index. It was found that the Kaiser-Meyer-Olkin value of .845 for the measure of the adequacy of the sample size. There was also a significant Bartlett’s test of sphericity (P<.05). This implies that the correlation matrix for the C19PS is not an identity matrix. It was revealed that C19PS had good overall reliability (a=.896) and model fit (Root mean square error of approximation=.042, comparative fit index=.943) in a sample of Nigerian preschool practitioners. As a result, C19PS was recommended as a trustworthy tool for identifying persons who suffer from COVID-19 phobia.https://www.journals.elsevier.com/medicineam2023Science, Mathematics and Technology Educatio

Carbapenem resistance expressed by Gram-negative bacilli isolated from a cohort of Libyan patients

Background and objectives: Carbapenem-resistant Enterobacteriaceae (CRE) and other Gram-negative bacteria are among the most common pathogens responsible for both community and hospital acquired infection. The global spread of cephalosporinases in Enterobacteriaceae has led to the increased use of carbapenems resulting in the emergence and rapid spread of CRE. This has become an alarming public health concern, yet the condition in Libya remains unclear. The aim of this study was to obtain a better understanding of CRE strains prevalent in Libyan patients by investigating their phenotypic characteristics and antibiograms. Methods: Gram-negative bacterial species were collected from Misrata Central Hospital, Misrata Cancer Centre and Privet Pathology Laboratories. Clinical samples and swabs were obtained from hospitalised and non-hospitalised patients and from mechanical ventilation and suction machines. Patients who had received antibiotic therapy for at least three days prior to the study were excluded. The identification and characterization of the isolated species were achieved using the growth characteristics on MacConkey and blood agar, spot tests and API 20E or API 20NE biochemical testing systems. Screening for carbapenem resistance was performed using the disk diffusion method with carbapenem 10 μg and cephalosporin 30 μg disks and minimum inhibitory concentrations (MIC) determined using the Sensititre Gram-negative Xtra plate format (GNX2F). All strains demonstrating resistance or reduced susceptibility to one of the four carbapenems were subjected to carbapenememase activity detection using the RAPIDEC CARBA NP test, Modified Hodge test and carbapenem inactivation methods. Results: A total of one hundred and forty isolates representing fourteen bacterial species were isolated from 140 non-duplicated specimens. Clinical specimens included urine samples (96/140, 68.57%), sputum (15/140, 10.71%), surgical wound swabs (18/140, 12.85%), foot swabs from diabetes mellitus (DM) patients (6/140, 4.29%), ear swabs (3/140, 2.14%) and wound swabs (2/140, 1.43%). Thirty-four (24.29%) isolates demonstrated resistance to at least one of the four carbapenems with Klebsiella pneumoniae representing 73.53% (25 isolates) of all carbapenem resistant species, followed by 8.82% for Pseudomonas aeruginosa (3 isolates), 5.88% for both Proteus mirabilis (2 isolates) and Escherichia coli (2 isolates) and 2.94% for both Citrobacter koseri (1 isolate) and Rahnella aquatilis (1 isolate). The other isolates were either susceptible or cephalosporinase producers. Conclusion: This study has revealed the high rate of carbapenem resistance amongst Libyan patients and emphasizes the crucial need for accurate screening, identification and susceptibility testing to prevent further spread of nosocomial and community acquired resistance. This may be achieved through the establishment of antibiotic stewardship programmes along with firm infection control practices.National Research Foundation of South Africa; Libyan GovernmentWeb of Scienc

A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa.

The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century