Exploring the Effect of Operational Factors and Characterization Imperative to the Synthesis of Silver Nanoparticles

The synthesis and application of silver nanoparticles are increasingly becoming attractive. Hence, a critical examination of the various factors needed for the synthesis of silver nanoparticles as well as the characterization is imperative. In light of this, we addressed in this chapter, the nitty-gritty on the operational parameters (factors) and characterization relevant to synthesis of silver nanoparticle. The following characterization protocols were discussed in the context of silver nanoparticle synthesis. These protocols include spectroscopic techniques such as ultraviolet visible spectroscopy (UV –Vis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS)

Effects of Calcitriol Supplementation on the Hematological Parameters of Sleep Deprived Wistar Rats

The present study investigates the hematologic effect of Calcitriol on rats undergoing sleep deprivation. Male Wistar rats were treated with Calcitriol 120 ng/kg and subjected to sleep deprivation for four successive days. Twenty four hour after last injection, animals were sacrificed and blood was collected for haematological analysis. A four-day sleep restriction caused a decline in total white cell count and increased mean cell hemoglobin and mean cell volume. Furthermore, red blood cell count, packed cell volume, hemoglobin concentration and mean cell hemoglobin concentration also declined in sleep deprived rats. Peripheral blood cell examination revealed that these effects were mild in rats treated with calcitriol. Our findings showed that a four-day paradoxical sleep restriction altered the biochemical integrity of erythrocytes. The observed immunosuppressive effects of sleep deprivation were reversed by exogenous vitamin D supplement, calcitriol. However, only the functional haemoglobin component of red cells was enhanced by a high dose of calcitriol which appears unbeneficial for other units of the erythroid-forming processes. It is therefore possible that the erythrocytic enhancing power of calcitriol is dose dependent and we suggest that lower doses (<120ng/kg) may be required to produce beneficial effects on erythropoiesis

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

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Kinetics and Equilibrium Models for Sorption of Cu(II) onto a Novel Manganese Nano-adsorbent

The studies of kinetics and equilibrium sorption of Cu(II) were undertaken using nanoscale zerovalent manganese (nZVMn) synthesized by chemical reduction in a single pot system. nZVMn was characterized using scanning electron microscopy, energy dispersive x-ray, and surface area determined by Brunauer–Emmett–Teller. The effect of pH, contact time, adsorbent dose, agitation speed, initial Cu(II) concentrations, temperature, and ionic strength on the sorption of Cu(II) onto nZVMn were investigated in a batch system. The kinetic data followed pseudo-second-order. The mechanism was governed by pore diffusion. The equilibrium sorption data were tested by Freundlich, Langmuir, Temkin, Dubinin–Kaganer–Raduskevich, and Halsey isotherm models. The Langmuir monolayer adsorption capacity (Qmax = 181.818 mg/g) is much greater compared to other nano-adsorbents used in sorption of Cu(II). The thermodynamic parameters (∆Ho, ∆So, ∆Go) revealed a feasible, spontaneous, and endothermic adsorption process. nZVMn has a great potential for effective removal of copper (II) in aqueous solution

Risky sexual behaviors and prevalence of chlamydia trachomatis antibodies among students in a tertiary institution

Chlamydia infection is a common sexually transmitted infection in humans caused by Chlamydia trachomatis. This infection occurs frequently in sexually active adolescent and young adults. This study determined the prevalence of Chlamydia trachomatis antibodies among students involved in risky sexual behavior in a tertiary institution. A total of 92 students consisting of 46 males and 46 females between ages 16 and 25 years who were involved in risky sexual behaviors were investigated. Gamma immunoglobulin (IgG) and Mu immunoglobulin (IgM) antibodies to Chlamydia trachomatis were assayed in the serum of the students using enzyme linked immunosorbent assay. Of the total students, 71.9% had multiple sex partners while 28.3% had single sex partners. The overall prevalence of Chlamydia trachomatis IgG and IgM antibodies were 56.5% and 40.2% respectively. Prevalence of Chlamydia trachomatis IgG and IgM, though more in ages 16-20 is not statistically significant (p&gt;0.05) over higher ages. No significant difference was recorded in the prevalence of Chlamydia trachomatis antibodies among gender. A very significant difference (p&lt;0.05) was recorded among students involved in multiple sex partnership in relation to those having single sex partners. Risk of Chlamydia trachomatis was high among sexually active students especially among students involved in multiple sex partnership behavior. In view of the subtle nature of Chlamydia trachomatis infection and the long term deleterious effects it may produce, it is pertinent to campaign against risky sexual activities, especially among students in higher institutions to reduce the rate of infection and safeguard their future

KINETICS AND ISOTHERM MODELING OF ADSORPTION OF RHODAMINE B DYE ONTO CHITOSAN SUPPORTED ZEROVALENT IRON NANOCOMPOSITE (C-nZVI)

The kinetics and isotherm modeling ofadsorption ofRhodamine B (RhB) Dye onto chitosan supported zerovalent iron nanocomposite (C-nZVI) was successfully studied in a batch technique. The quantity adsorbed increased with increase in initial concentration from 49.33 mg – 242.37 mg for 200 ppm to 1000 ppm and high percentage removal efficiency (%RE) of 99.72% attained at 90 minutes contact time. Equilibrium data were analyzed by six isotherm models: Langmuir, Freundlich, Temkin, Dubinin-Kaganer-Raduskevich (DKR), Redlich-peterson and Halsey isotherm model. Equilibrium data best fitted to Freundlich isotherm supported by Halsey isotherm model. Langmuir monolayer adsorption capacity (256.41 mg/g) of C-nZVI obtained greater than most adsorbent reported for adsorption of RhB. The mean adsorption free energy, E per molecule evaluated from DKR model was less than 8 KJmol-1 indicating a physisorption mechanism. The kinetic data best fitted to pseudo second-order kinetic model as validated by sum of square error (SSE) statistical model and the mechanism controlled by pore diffusion. The study revealed the great potential of C-nZVI for effective removal of RhB dye. C-nZVI is therefore recommended for civic and industrial effluents treatment

Cleaner energy through liquefaction of Cocoa (Theobroma cacao) pod husk: Pretreatment and process optimization

The kinetics and isotherm modeling of adsorption of Rhodamine B (RhB) Dye onto chitosan supported zerovalent iron nanocomposite (C-nZVI) was successfully studied in a batch technique. The quantity adsorbed increased with increase in initial concentration from 49.33 mg – 242.37 mg for 200 ppm to 1000 ppm and high percentage removal efficiency (%RE) of 99.72% attained at 90 minutes contact time. Equilibrium data were analyzed by six isotherm models: Langmuir, Freundlich, Temkin, Dubinin-Kaganer-Raduskevich (DKR), Redlich-peterson and Halsey isotherm model. Equilibrium data best fitted to Freundlich isotherm supported by Halsey isotherm model. Langmuir monolayer adsorption capacity (256.41 mg/g) of C-nZVI obtained greater than most adsorbent reported for adsorption of RhB. The mean adsorption free energy, E per molecule evaluated from DKR model was less than 8 KJmol-1 indicating a physisorption mechanism. The kinetic data best fitted to pseudo second-order kinetic model as validated by sum of square error (SSE) statistical model and the mechanism controlled by pore diffusion. The study revealed the great potential of C-nZVI for effective removal of RhB dye. C-nZVI is therefore recommended for civic and industrial effluents treatment

Adoption of homestead grain storage technology in the south-west agricultural zone of Nigeria

The major types of grains and pulses that are stored in Ekiti, Ondo, Edo, Delta, Oyo, Ogun, Osun and Lagos states of Nigeria at homestead level are maize, guinea corn, rice, cowpea, Soya bean and groundnut. Bags, hermetic containers and room spaces are used for storage. The adoption of improved storage technology in hermetic containers, cold treatment, polythene lined bags and application of recommended chemicals was relatively low (45%) due to lack of/and inadequate knowledge of usage of these technologies, non-availability and high costs of storage inputs especially the recommended chemicals, and lack of awareness of the technologies. The training and visits (T&V) System of the Agricultural Development Project (ADP) was found to be the most prevalent source of information to the respondents, followed by the radio. Increased use of interpersonal communication as well as prompt and adequate intervention by government in the provision of credit facilities and subsidy on storage inputs among others will enhance the rate of adoption.. [JEXT Vol.1(1) 2000: 82-88

Novel acid treated biomass: Applications in Cu2+ scavenging, Rhodamine B/Cu binary solution and real textile effluent treatment

A novel adsorbent prepared from the waste of Irvingia gabonensis nut (ADN) was used for scavenging of Cu2+ from aqueous solution. Various adsorption operational parameters were investigated in order to establish the behavior of ADN before further studies. The efficacy of ADN in concurrent removal of rhodamine B (RhB) dye and Cu in a binary solution of RhB/Cu2+ was also investigated. Finally the potency of ADN in the treatment of real textile effluent was ascertained. Optimum adsorption of Cu2+ occurred at pH of 5.5 and high temperature favoured Cu removal. Pseudo second order kinetic best described the uptake of Cu2+ onto ADN. Maximum monolayer adsorption capacity was obtained to be 103.09 mg/g. The Dubinin Radushkevich (D-R) isotherm as well as thermodynamic parameter suggests that adsorption of Cu2+ onto ADN was chemical in nature. Percentage removal of Cu2+ in single solution at optimum time was 94.70 % while synergistic effect of RhB moved this to 99.54 % removal in the binary solution. ADN was highly efficient for the removal of dye and other organic pollutants in the real textile effluent with 100 % removal of some organic pollutant

Novel acid treated biomass: Applications in Cu2+ scavenging, Rhodamine B/Cu2+ binary solution and real textile effluent treatment

A novel adsorbent prepared from the waste of Irvingia gabonensis nut (ADN) was used for scavenging of Cu2+ from aqueous solution. Various adsorption operational parameters were investigated in order to establish the behavior of ADN before further studies. The efficacy of ADN in concurrent removal of rhodamine B (RhB) dye and Cu2+ in a binary solution of RhB/Cu2+ was also investigated. Finally the potency of ADN in the treatment of real textile effluent was ascertained. Optimum adsorption of Cu2+ occurred at pH of 5.5 and high temperature favored Cu2+ removal. Pseudo second order kinetic best described the uptake of Cu2+ onto ADN. Maximum monolayer adsorption capacity was obtained to be 103.09 mg/g. The Dubinin Radushkevich (D-R) isotherm as well as thermodynamic parameter suggests that adsorption of Cu2+ onto ADN was chemical in nature. Percentage removal of Cu2+ in single solution at optimum time was 94.70 % while synergistic effect of RhB moved this to 99.54 % removal in the binary solution. ADN was highly efficient for the removal of dye and other organic pollutants in the real textile effluent with 100 % removal of some organic pollutant