Investigation of eco-friendly cellulosic nanoparticles potential as reinforcement agent in the production of natural rubber composites

This research focuses on the use of cellulosic nanoparticles obtained from coconut husk, bamboo and cotton linter as reinforcing phase in natural rubber composites with the objective to study the effect of these cellulosic particles and loading ratio on the mechanical, thermal and morphological properties of the resultant composites. Vulcanized natural rubber composites were prepared using cellulosic nanoparticles obtained from bamboo (BNC), coconut husk (CHNC), cotton linter (CLNC) and carbon black (CB) as reinforcing material/fillers. These reinforcing material/fillers were compounded alongside with vulcanizing agents using two roll mixing mill and subsequently cured in order to introduce crosslinks into rubber chains. Scanning electron microscope (SEM) revealed that the free volume holes in the neat rubber were drastically reduced by incorporation of these nanoparticles into the rubber matrix. The differential scanning calorimetric (DSC) study showed a slight shift in the melting temperature of bamboo based composite from 360 to 350 oC while thermo gravimetric analysis (TGA) showed that the incorporation of bamboo and cotton linter based nanoparticles shifted the thermal stability of neat rubber matrix from 266 to 299 and 300 oC respectively. Coconut husk based composites showed a trend of increase in tensile strength from 1.8 to 3.82 MPa with filler loading of 0 to 25 weight %, while bamboo, cotton linter and carbon black based nanocomposites gave their highest values of 3.16, 3.92 and 4.50 MPa respectively at filler content of 30 weight %.Cellulosic nanoparticles obtained from biomass studied in this experiment can replace or serve as alternative materials to carbon black especially in moderate load bearing rubber articlesKeywords: Mechanical Properties; Cellulosic Nanoparticles; Rubber-Matrix Composites; Carbon Blac

Determinants of Treatment Outcomes among Drug-Susceptible Tuberculosis Patients on Directly Observed Treatment Short-Course at Federal Medical Centre, Abeokuta, South-West, Nigeria

Background: Surveillance of tuberculosis treatment outcomes is very crucial in evaluating successes of tuberculosis (TB) intervention programmes  as well as assessing progress towards achieving the Sustainable Development Goals target of ending TB infection by 2030. The study assessed  treatment outcomes of tuberculosis and the determinants among tuberculosis patients on Directly Observed Treatment Short-course (DOTs) at  Federal Medical Centre, Abeokuta South-West, Nigeria. Methods: This was a retrospective review of treatment outcomes of patients managed for Tuberculosis at the facility between January 2015 and  December 2019. Data were retrieved from the treatment register and analysed using IBM® SPSS software version 23. Results were presented using  frequencies and percentages, while the Chi-square test was used to test for association between the treatment outcomes and the independent variables. Binary logistics regression was used to assess for determinants of treatment outcomes at a level of significance of p<0.05. Results: A total of 726 records were reviewed. The median age of the patients was 35.0 years (IQR 25). The treatment success rate (TSR) and cure  rate were 83.2% and 43.7% respectively. TB patients with negative HIV status were about two times more likely to have successful treatment  outcomes (OR=1.86, 95%CI=1.20-2.88). Conclusion: The TSR and cure rate obtained in this study were below the national targets set by the World Health Organization, and HIV co-infection  was a threat to successful treatment outcomes among TB patients. Ensuring optimized antiretroviral therapy, prompt diagnosis and  treatment of TB in HIV patients will go a long way in improving treatment outcomes

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background: Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. Methods: The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model—a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates—with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality—which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. Findings: The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2–100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1–290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1–211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4–48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3–37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7–9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. Interpretation: Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. Funding: Bill & Melinda Gates Foundation

Antimicrobial activity of the ethanol extract of the aerial parts of sida acuta burm.f. (malvaceae)

Purpose: The antimicrobial activity of the 90 % ethanol extract of the aerial parts of sida acuta Burm. F. (Malvaceae) was investigated in other to verify its claimed ethno medicinal use in the treatment of microbial infections. Method: The antimicrobial activity of the extract was tested against standard strains and clinical isolates of some aerobic bacteria and a fungus using the Agar well diffusion method. Commercial antibiotics were used as positive reference standards to determine the sensitivity of the strains. Results: The extracts showed significant inhibitory activity against standard strains and clinical isolates of Staphylococcus aureus, clinical isolates of Bacillus subtilis and Streptococcus faecalis. The MIC values obtained using the Agar-dilution test ranged from 5.0 mg/ml. -10.0 mg/ml. Neither the concentrated extract nor its dilutions inhibited Escherichia coli , Klebsiella pneumonia , Pseudomonas aeruginosa and Candida albicans Conclusion: The results demonstrate that the crude extract of the aerial parts of Sida acuta has a narrow spectrum of activity and suggest that it may be useful in the treatment of infections caused by Gram positive aerobic bacteria