Distribution and in-vitro bioaccessibility of potentially toxic metals in surface soils from a mining and a non-mining community in Ghana: implications for human health.

The concentration and bioaccessibility of potentially toxic metals, including As, Cd, Cr, Cu, Mn, Ni, Pb and Zn, were determined in surface soil samples from a mining community (Kenyasi) and a non-mining community (Sunyani) in Ghana, to investigate the contribution of mining activities to the environmental burden of potentially toxic metals. The study found significant differences in metal concentrations (p < 0.05) in As, Cd, Cu, Mn, Ni, and Zn, but no significant difference (p > 0.05) in Pb and Cr between the two communities. The study found a moderate correlation between pH and metal concentrations in the mining community and a moderate positive correlation with As, Cd, Cr, Cu, Ni, and Zn in the non-mining community. The distribution pattern revealed elevated levels of toxic metals in the southeastern corridor of the mining community, which is close to a gold mine. Most heavy metals were concentrated in the commercial community's southern zone, with more residents and private elementary schools. Metal bioaccessibility was variable, and except for Cu and Zn, the mean bioaccessibility was less than 50% for a given metal. Contamination factor, geoaccumulation index, and soil enrichment factor suggested very high contamination of Cd, and a considerable to moderate contamination of As, Ni, Zn, and Cu at both the mining and non-mining communities. The above observations and the pollution and risk indices employed in this study confirmed that the mining community was more polluted (PLI = 2.145) than the non-mining community (PLI = 1.372). The total metal hazard (HI) exceeded thresholds by three and four times at non-mining and mining sites. Regular monitoring is necessary, especially in the mining community, to prevent soil metal accumulation.

An exploratory study on excess weight gain: Experiences of Postmenopausal Women in Ghana.

INTRODUCTION: Excess weight gain is a problem with a significant impact on health and quality of life as well as the consequent economic burden on human populations. While society advocates preference for excess weight gain, limited evidence exists concerning postmenopausal women's experiences in Ghana. AIM: The current study explored the experiences regarding excess weight (overweight and obesity) gain among Ghanaian postmenopausal women in Bono East (Techiman) region. METHODS: This is a qualitative exploratory descriptive study where anthropometric measurements [body mass index (BMI), waist-to-height ratio (WHtR) and waist-to-hip ratio (WHR)] were determined and participants who were identified with excess weight (obesity and overweight) were recruited to participate in a focus group discussion (FGD). Four focus group discussions were held and 24 postmenopausal women (>45 years) in Techiman took part. Discussions were audio-recorded and transcribed for thematic analysis. RESULTS: From the qualitative analysis of the FGD, three major themes emerged from the study namely, (i) perception of body weight, (ii) measures to reduce body weight, and (iii) support to adhere to the weight management program. Sub-themes revealed that weight gained was viewed as the presence of diseases and admired by society as a culturally accepted body image. Diet-related changes, a combination of diet modification and physical activity, and weight management supplements emerged as measures to reduce excess weight. Support to adhere to the weight program included health education, access, affordable exercise facilities, and social support. CONCLUSIONS: Sociocultural norms influence the image perception and acceptance of weight gain among postmenopausal women in Ghana, but there is an acknowledgment of the perceived negative health implications of such excess weight. Measures for weight reduction and support to adhere to the weight reduction programme require attention in Ghana.

High Resistance to Antibiotics Recommended in Standard Treatment Guidelines in Ghana: A Cross-Sectional Study of Antimicrobial Resistance Patterns in Patients with Urinary Tract Infections between 2017-2021.

Management of urinary tract infections is challenged by increasing antimicrobial resistance (AMR) worldwide. In this study, we describe the trends in antimicrobial resistance of uropathogens isolated from the largest private sector laboratory in Ghana over a five-year period. We reviewed positive urine cultures at the MDS Lancet Laboratories from 2017 to 2021. The proportions of uropathogens with antimicrobial resistance to oral and parenteral antimicrobials recommended by the Ghana standard treatment guidelines were determined. The proportion of multi-drug resistant isolates, ESBL and carbapenemase-producing phenotypes were determined. Of 94,134 urine specimens submitted for culture, 20,010 (22.1%) were culture positive. Enterobacterales was the most common group of organisms, E. coli (70.6%) being the most common isolate and Enterococcus spp. the most common gram-positive (1.3%) organisms. Among oral antimicrobials, the highest resistance was observed to ciprofloxacin (62.3%) and cefuroxime (60.2%) and the least resistance to fosfomycin (1.9%). The least resistance among parenteral antimicrobials was to meropenem (0.3%). The highest multi-drug resistance levels were observed among Klebsiella spp. (68.6%) and E. coli (64.0%). Extended-spectrum beta-lactamase (ESBL) positivity was highest in Klebsiella spp. (58.6%) and E. coli (50.0%). There may be a need to review the Ghana standard treatment guidelines to reflect increased resistance among uropathogens to recommended antimicrobials.

Polarization-dependent wideband metamaterial absorber for ultraviolet to near-infrared spectral range applications.

The need for wideband metamaterial absorbers (WBMA) for applications other than sensing and filtering has demanded modifications to the conventional three-layer metal-insulator-metal (MIM) absorber configuration. This modification often results in complex geometries and an increased number of layers requiring complex lithographic processes for fabrication. Here, we show that a metamaterial absorber with rectangular geometry in the simple MIM configuration can provide wideband absorption covering the ultraviolet and near-infrared spectral range. Due to its asymmetric nature, the WBMA is sensitive to the polarization of the incident light and independent of the angle of incidence up to about 45° depending on the polarization of the incident light. The characteristics of the WBMA presented here may be useful for applications such as detectors for wide spectral band applications.

Optical Monitoring of Microplastics Filtrated from Wastewater Sludge and Suspended in Ethanol.

The abundance of microplastics (MPs) in the atmosphere, on land, and especially in water bodies is well acknowledged. In this study, we establish an optical method based on three different techniques, namely, specular reflection to probe the medium, transmission spectroscopy measurements for the detection and identification, and a speckle pattern for monitoring the sedimentation of MPs filtrated from wastewater sludge and suspended in ethanol. We used first Raman measurements to estimate the presence and types of different MPs in wastewater sludge samples. We also used microscopy to identify the shapes of the main MPs. This allowed us to create a teaching set of samples to be characterized with our optical method. With the developed method, we clearly show that MPs from common plastics, such as polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), and polyethylene (PE), are present in wastewater sludge and can be identified. Additionally, the results also indicate that the density of the plastics, which influences the sedimentation, is an essential parameter to consider in optical detection of microplastics in complex natural environments. All of the methods are in good agreement, thus validating the optics-based solution.

Towards the Development of Portable and In Situ Optical Devices for Detection of Micro and Nanoplastics in Water: A Review on the Current Status.

The prevalent nature of micro and nanoplastics (MP/NPs) on environmental pollution and health-related issues has led to the development of various methods, usually based on Fourier-transform infrared (FTIR) and Raman spectroscopies, for their detection. Unfortunately, most of the developed techniques are laboratory-based with little focus on in situ detection of MPs. In this review, we aim to give an up-to-date report on the different optical measurement methods that have been exploited in the screening of MPs isolated from their natural environments, such as water. The progress and the potential of portable optical sensors for field studies of MPs are described, including remote sensing methods. We also propose other optical methods to be considered for the development of potential in situ integrated optical devices for continuous detection of MPs and NPs. Integrated optical solutions are especially necessary for the development of robust portable and in situ optical sensors for the quantitative detection and classification of water-based MPs.

Double resonant plasmonic lattices for Raman studies.

We demonstrate radiation induced enhancement of both the in coupling of Raman excitation wavelength and Raman signal in plasmonic nanoparticle lattices. Rectangular nanoparticle lattices show two independently controllable lattice resonances, which we tune to be resonant with both the Raman excitation wavelength and the Raman transitions of rhodamine 6G molecules. We demonstrate that these narrow and intense resonances produced by the nanoparticle lattices allow for Raman transition specific enhancements. The system allows for independent tuning of both resonance conditions, enabling an efficient and versatile platform for Raman studies of various molecules.

Optically induced crossover from weak to strong coupling regime between surface plasmon polaritons and photochromic molecules.

We demonstrate optically induced crossover from a weak to a strong coupling regime in a single photonic system consisting of propagating surface plasmon polaritons (SPPs) on a planar silver film and ultraviolet (UV)-switchable photochromic molecules. A gradual increase is observed in the vacuum Rabi splitting upon increasing UV exposure, along with intriguing behavior, where the reflectivity initially decreases due to increased losses at the weak coupling regime, and then increases due to the emergence of strongly coupled modes and the associated band gap formation at the resonance frequency of the uncoupled states. This work explicitly demonstrates the optical tunability of the degree of hybridization of the SPP and exciton modes, spanning the range from weak to intermediate and finally to the strong coupling regime.

On optical sensing of surface roughness of flat and curved microplastics in water.

The growth of microplastic (MP) pollution is of increasing concern and represents a global challenge. In situ detection of these small particles is difficult because of their sizes, shapes, transparency or translucency, surface texture and ambient conditions. We propose and demonstrate the use of a prototype optical sensor to detect flat, nearly flat, curved and rough MPs prepared from commercial polyethylene terephthalate (PET) plastics and PET bottles in water. The prototype measures the specular reflection of a laser radiation incident on MPs, with a photodiode, and the transmitted laser speckle pattern, with a charge-coupled device (CCD) camera. The presence of the MPs as well as the optical surface roughness are determined from the specular reflection. Additionally, the so-called speckle contrast calculated from the speckle pattern, as a promising tool, is used to rank the rough MPs according to the different average surface roughness, to approximately twice the wavelength of the probing light. The novel application of laser speckle contrast and the optical roughness estimation allows the description of MP surface roughness in water. Moreover, in combination with earlier studies, these results, therefore, pave a way for the complete and a relatively easier description of MPs properties optical and also advances our step towards the development of simple and robust optical monitoring techniques for micro and nanoplastics in open and wastewater.

Optical screening for presence of banned Sudan III and Sudan IV dyes in edible palm oils.

Due to the proven carcinogenicity of Sudan III and IV dyes, they are considered global public health issues. They are banned in all forms as food colourants. We propose the monitoring of simple and easy-to-measure optical properties of palm oils, such as the refractive indices and spectrophotometric properties, as efficient indicators to detect adulteration. Coupling these results with principal component analysis, excess refractive index, and integration of transmittance introduces a novel detection tool for the authentication of edible palm oil. This opens a new opportunity for accurate handheld devices to detect adulteration and provide control in the field. This work assessed in total of 49 samples, some collected from different parts of Ghana and others, in-house adulterated samples. The Ghana Food and Drugs Authority, who performed a complex and expensive chemical analysis of the samples, confirmed our results with good agreement.

Optical transmission spectra study in visible and near-infrared spectral range for identification of rough transparent plastics in aquatic environments.

Erosion of microplastics due to residence time in aquatic environments causes roughening of the microplastic. Unfortunately, currently used measurement methods do not provide information on the surface roughness of the microplastic embedded in water. In this study we propose a novel method by using transmittance to get information on the magnitude of the surface roughness of microplastics and to rank microplastics by thickness. For such a purpose, we studied optical properties such as dispersion, absorption of both plastics and water in the partial spectral range of visible light (Vis), transmission and scattering of light by plastic sheets, as well as, the calculated sample thickness in the Vis region. These were explored for the detection of both smooth and roughened plastic sheets immersed in water. Moreover, by using the transmission spectrum and refractive index of both plastic and water it is possible to estimate the average surface roughness of plastic samples. Our results suggest that the optical properties in the Vis region offer an interesting way for the detection of both rough and smooth plastic sheets and for ranking the type of plastics in an aquatic environment.

A prototype of a portable optical sensor for the detection of transparent and translucent microplastics in freshwater.

Microplastic pollution in water bodies is an alarming problem which needs to be addressed. However, issues such as size, shape and their appearance to light (transparent or translucent) make it difficult to be optically detected. Here, a feasibility study of a portable prototype optical sensor with the capability of measuring simultaneously specular laser light reflection and transmission from microplastic particles is presented. The specular reflection signal and the transmitted interference pattern were recorded with a photodiode and a CCD camera, respectively. With the combination of these two modes of detection, it is possible to screen the type, size, and nonplanarity of two microplastics types, i.e., transparent polyethylene terephthalate (PET) and translucent low-density polyethylene (LDPE), in a volume of freshwater, with high confidence. In principle, the prototype could be used for the detection of both floating microplastics as well as microplastics experiencing sedimentation in natural water bodies, and in water filtration in water treatment plants.

Examining and comparing the health and performance indices of university undergraduate students according to year of study and gender.

This study examined and compared, based on year of study and gender, the health and performance indices of university undergraduate students. Eighty-nine students (mean±standard deviation age, 22.47±2.22 years) were randomly selected for assessment prior to second semester examination of 2015/2016 academic year. body mass index, resting metabolic rate, visceral fat, skeletal muscle mass, body fat, systolic & diastolic blood pressure, resting heart rate, upper & lower body endurance, handgrip strength, and lower back and hamstring flexibility were assessed. The students had sedentary heart rate, low skeletal muscle mass, average upper and lower body endurance, and weak handgrip strength. Significant difference existed in the visceral fat (P=0.008) between third and fourth year students. There were significant gender differences in resting metabolic rate (P=0.000), skeletal muscle mass (P=0.000), body fat (P=0.000), systolic blood pressure (P=0.001), heart rate (P=0.005) and handgrip strength (P=0.000). There are gender differences in association between health and performance indices. Dependable health education and pragmatic involvement of undergraduate university students in structured exercise programmes are recommended.

Adjustable coordination of a hybrid phosphine-phosphine oxide ligand in luminescent Cu, Ag and Au complexes.

A potentially tridentate hemilabile ligand, PPh2-C6H4-PPh(O)-C6H4-PPh2 (P(3)O), has been used for the construction of a family of bimetallic complexes [MM'(P(3)O)2](2+) (M = M' = Cu (1), Ag (2), Au (3); M = Au, M' = Cu (4)) and their mononuclear halide congeners M(P(3)O)Hal (M = Cu (5-7), Ag (8-10)). Compounds 1-10 have been characterized in the solid state by single-crystal X-ray diffraction analysis to reveal a variable coordination mode of the phosphine-oxide group of the P(3)O ligand depending on the preferable number of coordination vacancies on the metal center. According to the theoretical studies, the interaction of the hard donor P[double bond, length as m-dash]O moiety with d(10) ions becomes less effective in the order Cu > Ag > Au. 1-10 exhibit room temperature luminescence in the solid state, and the intensity and energy of emission are mostly determined by the nature of metal atoms. The photophysical characteristics of the monometallic species were compared with those of the related compounds M(P(3))Hal (11-16) with the non-oxidized ligand P(3). It was found that in the case of the copper complexes 5-7 the P(3)O hybrid ligand introduces effective non-radiative pathways of the excited state relaxation leading to poor emission, while for the silver luminophores the P[double bond, length as m-dash]O group leads mainly to the modulation of luminescence wavelength.