Vernonia guineensis Benth. (Asteraceae), locally known as ‘African ginseng’, is an herbaceous plant with various therapeutic properties, sold by herbalists, and used in several traditional African preparations. Nanosizing has the capability to potentiate those preparations in their pharmacological properties. Premilling and extensive grinding using a planetary ball mill were used to reduce the size of V. guineensis tubers towards antioxidant studies. Water was used as an environmental friendly, cost effective solvent and dispersant to generate a nanocolloidal suspension of V. guineensis tubers. Size and size distribution were determined via photon correlation spectroscopy at room temperature which allows discussion on stability by Zeta potential and polydispersity index. Phytochemical screening shows presence of alkaloids, coumarins, polyphenol, saponins, tanins, terpenes, and anthraquinones. The distribution curve in water shows a polydispersed system with large hydrodynamic particles of size close to 1000 nm and a Z-average of 484.5 nm. The preparation separate in two phases with polydispersity index 0.217 for the supernatant and 0.543 for the suspension. In the supernatant and suspension, the particles zeta potential were -12.3 mV and -13.7mV respectively. The Mastersizer analysis indicates that there are smaller particles in volume in the supernatant than in the suspension. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity shows an increase in antioxidant activity, compared to that of ascorbic acid, in the nanoformulated state. These findings allow us to conclude on the potential of size reduction when compared to solvent extraction in pharmacologic preparations.

ABSTRACT To substitute synthetic fibers, which are non-biodegradable and environmentally unfriendly, studies have been carried out to exploit vegetable fibers. Within this concept, this work investigates Sida rhombifolia as a case study. Previous studies showed that the fibers could be extracted only by cold water retting, but this study seeks to show that the boiling water extraction technique can also be used. The objective of this study is to characterize Sida rhombifolia fibers from the Center region of Cameroon, extracted with cold and boiling water, and compare their physico-chemical and mechanical properties with those of other vegetable fibers. The standard tests for the different characterizations have been respected. This study showed that the fibers extracted with cold water retting contained 70.16% cellulose, 16.70% hemicellulose, 10.86% lignin, and 1.47% pectin, while the fibers extracted by boiling water technique contained 68.71% cellulose, 17.48% hemicellulose, 11.26% lignin, and 2.01% pectin. Finally, extraction of fibers from the cold water retting technique gave 38.83% extraction yield, 1.33 g.cm−3 density, 11.23 tex linear mass, 11.73% water content, 118.53% rate of water absorption, and 21.45% humidity at a relative humidity of 75%. While fibers extracted by the boiling water technique had 33.74% extraction yield, 1.35 g.cm−3 density, 13.57 tex linear mass, 13.28% water content, 225.12% rate of water absorption, and 22.06% humidity at a relative humidity of 75%, statistical analysis by Student’s t-test showed a significant difference in the mechanical properties of the fibers depending on the extraction method. Sida rhombifolia fibers can be used in textiles and composites and can be extracted by the boiling water technique.

Abstract Severe cognitive decline (SVD) is a major cause of dependency in older people. The aim of this study was to identify factors associated with severe cognitive decline, as assessed by the mini-mental state examination (MMSE), in community-dwelling adults aged 55 + in Cameroon. Method: Data are from a cross-sectional survey carried out in Cameroon. The Cognitive status was assessed using the MMSE and a score of 18/30 or lower is considered as a proxy of severe cognitive decline Result: A total of 403 adults participated in the study. Of these, 16 (3.9%) had an MMSE score < 18 and were considered to have severe cognitive decline. The rate of severe cognitive decline increased with rising age, from 2.1% in those aged 55 to 64 years, to 3.3% in those aged 65 to 74, and 11% in those aged 75 and older. The factors associated with severe cognitive decline (MMSE score < 18) by multivariate analysis in our population are level of education (OR 0.10 (95%CI 0.02–0.37), p < 0.01), body mass index (OR 0.88 (95%CI 0.78–0.99), p = 0.03). and IADL score (OR 0.12 (95%CI 0.03–0.38), p < 0.001). Conclusion: The three main factors associated with cognitive decline were education, IADL dependency and BMI. This study shows that among older people in sub-Saharan Africa, the effect of BMI, IADL dependency and education on cognitive function appears similar to that observed in middle- and high-income countries.

2,2-Diphenyl-1-picrylhydrazyl (DPPH) is a stable organic free radical widely used in various fields as a model free radical. There is scarce information about the stability of this compound in the chemical environments in which it is used. Side reactions between DPPH and other species can alter the precision of experiments that use DPPH, such as the evaluation of antioxidant properties amongst others. Following recent investigations highlighting reactions between DPPH and metal cations or Lewis acids, a quantitative reaction between DPPH and Fe3+ in acetonitrile was studied in the present work. UV-Vis spectroscopy and electrochemistry were used to monitor the reaction. The results obtained indicate a fast and multistep reaction between Fe3+ and DPPH that can be simplified as a simple redox reaction with the formation of Fe2+ and DPPH+. The reaction mechanism proposed follows complex steps involving two competing phenomena: a disproportionation which accelerates the reaction and an oxidation process that slows it down through DPPH regeneration.

The main challenge in manufacturing antennas in the sub-THz band is their small size, which requires adapted manufacturing tools. This paper proposes a uniform linear 3 × 1 traveling-wave antenna array (ULTWAA) for millimetre applications in the sub-THz band. The designed array allows a continuous beam orientation of ±46.1° in the E-plane. A small quarter-wave line added to the ends of the antenna allows the beam to be oriented towards the inside of the antenna, cancelling out surface waves and adapting the impedance to the scanning angle. Thanks to this device, the waves produced are progressive. The antenna manufactured at 100 GHz measures 13 × 9.7 × 0.125 mm. The measured peak gain is 14.2 dBi with 70% bandwidth. For in-phase radiation, the distances between the antenna units have been adjusted, but the adjustment process is tedious due to the interdependence between the antenna units.

Due to their significant health benefits, fish oils have garnered increasing interest in recent decades. However, Cameroon’s fish oil market remains insignificant, and the few available products are imported, despite the country’s abundant marine resources. Additionally, research on Cameroonian fish oils is relatively recent and scarce. Therefore, this manuscript provides an overview of research on fish oils in Cameroon, focusing on their physicochemical characteristics, as well as their nutritional and biological properties. As of March 2023, 26 studies on fish oils in Cameroon have been published, with a focus on 23 species collected in the littoral, far-north, and west regions of Cameroon. Filets were the main parts used, and the Bligh Dyer and Soxhlet methods were the primary oil extraction techniques. Depending on the species, tissues, and extraction methods, oil contents ranged from 4.57% to 32.10% dry matter or yielded 0.36% to 66.83% wet weight. These oils generally meet recommended standards for markers of acidity and oxidation. Fatty acid profiles from 16 species showed a total of 48 fatty acids, including those that are beneficial to human health. Oils from eight species were found to significantly reduce weight, hyperlipidemia, hyperglycemia, hepatomegaly, and adipomegaly, while four species showed activity against bacteria responsible for food poisoning. Future work should include all fish species found in Cameroon, with a focus on by-products, and explore the physicochemical, functional, nutritional, and biological properties of these oils.

Chronic venous disease is a global public health problem, with high morbidity and economic distress. There is scarcity of data on this disease in sub-Saharan Africa. We conducted the first population-based study over a period of 20months from 1st February 2020 to 30th September 2021 in the 10 regions of Cameroon. A stratify sampling method was chose to select study site. Socio-demographic data, personal and family history, anthropometric parameters, clinical signs, illustrative images, CEAP (Clinical-Etiological-Anatomical-Pathophysiological) classification revised in 2004, VCSS (venous Clinical Severity Score) and risk factor assessment score were used to construct the survey form. Chi-squared test and Fischer exact test were used to compare the prevalence of chronic venous disease across different potential risk factors (sex, age category, previous history of deep vein thrombosis, hypertension, diabetes, smoking status, obesity). Simple and multiple logistic regression models were used to obtain crude and adjusted odds ratio for risk factors associated with chronic venous insufficiency. Statistical analyses were done with R version 4.2 for Linux and the threshold for statistical significance was 0.05. A total of 6578 participants were included in the study, with a mean age of 41.09 ± 16.02years with female predominance (54.3%). The prevalence of chronic venous disease was 21.8% (95% CI: 20.8-22.9) and the prevalence of chronic venous insufficiency (C3-C6) was 7.02% (n = 462). Night cramps (43.2%), oedema (21.7%), lower limbs pain (20.4%) mostly worsens by walking and heavy legs (16.2%) were more common symptoms. The mean total venous clinical severity score was 0.69 ± 1.76 and this score had a significant positive correlation with C classification (p < .001). In the multivariate analysis, the following factors were independently associated with CVD: Male gender (aOR: 1.27; 95%CI: 1.04-1.56; p = .021), retired people (aOR: 46.9; 95% CI: 12.6-174.5; p < .001), hypertension (aOR: 289.5; 95%CI: 169.69-493.1; p < .001), diabetes (aOR: 2.19; 95% CI: 1.21-3.96; p = .009), obesity (aOR: 10.22; 95%CI: 7.67-13.62; p < .001). Smoking appears as a protective factor (aOR: 0.18; 95%CI: 0.10-0.30; p < .001). Chronic venous disease is frequent in Cameroon and main traditional cardiovascular risk factors are associated to this condition. Systematic screening of the CVD in these specific groups could reduce the burden of the disease and its economic impact.

Following the recorded progress in the prevention of mother-to-child transmission of HIV in Yaoundé, Cameroon, the proportion of HIV-exposed infants who are uninfected (UIH) is increasing. These children are subject to infectious and non-infectious fragility. The purpose of this study was to assess infectious morbidity and mortality rates among UIH in Yaoundé, Cameroon. We conducted a retrospective cohort study. Infants were included in the study and defined as the study subjects if they were between the ages of 24 months or younger, if they were born to HIV-positive mothers, and if they were confirmed to be HIV-negative. The main study outcomes were morbidity rate (defined as infectious, clinical events that required consultation or hospitalization) and death. Data were entered and saved in the Census and Survey Processing System (Cspro) 7.3. Statistical analyses were performed in R Software 3.6.2. The significance level was set at 0.05. In total, 240 subjects were recruited of whom 53.3% were males. Most of the HIV-positive mothers (95.7%) had used combination antiretroviral (ARV) therapy for at least four weeks during pregnancy. Among the subjects, 93.2% received ARV prophylaxis, 68.7% were exclusively breastfed for six months, 94.7% were fully vaccinated, and 60.6% had received cotrimoxazole up to the detection of the non-infection. Overall, the morbidity rate stood at 34.2%. The incidence of morbidity was 3 per 1,000 child months of the follow-up. The main pathologies were acute respiratory infections (60.79%) and malaria (17.65%). Three deaths were recorded, representing an overall mortality rate of 1.25% for an incidence of 1.1 per 1,000 child months of the follow-up (FU). Clinical events were more frequent in mothers diagnosed with HIV during pregnancy under the azidothymidine (AZT) + lamivudine (3TC) + névirapine (NVP) -based protocol (odds ratio of 3.83 [1.09-14.45; p = 0.039]). Morbidity was also higher for the follow-up periods of less than six months. The overall mortality rate among UIH was low. However, the morbidity rate was considerably higher. Emphasis should be focused on in-care retention for up to 24 months for all UIH, which should include monitoring of HIV-infected mothers prior to pregnancy.

Abstract The aim of this study was to determine the impact of leachates, produced by one of Cameroon's largest waste dumps (Nkolfoulou), on the water quality and the risks posed to public health. A cartographic analysis was carried out, comparing the land use in the area before the landfill was setup with that of the present day, followed by a hydrogeological study of the groundwater and an analysis of trace metals. A model estimating susceptibility to pollution was developed using the Analytic Hierarchy Process (AHP) method, and this susceptibility was mapped using the previously developed model, which was validated. Land use increased by 57% between 1985 and 2023. Most of the landfill leachate is discharged untreated into the Foulou and Kondi rivers, polluting surface waters. Average levels of trace metal elements such as Cd and Mn are 2 and 3.24 mg/l, respectively, in groundwater, 72.62 and 8.54 mg/l, respectively, in surface water, and 114, 49 and 15.41 mg/l in leachate. The model developed, which takes into account factors such as depth, distance, and geomorphology in brief, is consistent and valid for the study. This is followed by the mapping of the impact zone showing wells, with high copper concentrations in high-susceptibility areas.