A critical review on microbial degradation of petroleum-based plastics: quantitatively effects of chemical addition in cultivation media on biodegradation efficiency.

Petroleum-based plastics (PBP) with different properties have been developed to suit various needs of modern lives. Nevertheless, these well-developed properties also present the double-edged sword effect that significantly threatens the sustainability of the environment. This work focuses on the impact of microbial cultivating conditions (the elementary compositions and temperature) to provide insightful information for the process optimization of microbial degradation. The major elementary compositions in cultivation media and temperature from the literature were radically reviewed and assessed using the constructed supervised machine learning algorithm. Fifty-two literatures were collected as a training dataset to investigate the impact of major chemical elements and cultivation temperature upon PBP biodegradation. Among six singular parameters (NH4+, K+, PO43-, Mg2+, Ca2+, and temperature) and thirty corresponding binary parameters, four singular (NH4+, K+, PO43-, and Mg2+) and six binary parameters (NH4+/K+, NH4+/PO43-, NH4+/Ca2+, K+/PO43-, PO43-/Mg2+, Mg2+/Temp) were identified as statistically significant towards microbial degradation through analysis of variance (ANOVA). The binary effect (PO43-/Mg2+) is found to be the most statistically significant towards the microbial degradation of PBP. The concentration range, which locates at 0.1-0.6 g/L for Mg2+ and 0-2.8 g/L for PO43-, was identified to contribute to the maximum PBP biodegradation. Among all the investigated elements, Mg2+ is the only element that is statistically and significantly associated with the variations of cultivation temperature. The optimal preparation conditions within ± 20% uncertainties based upon the range of collected literature reports are recommended. Five representative cultivation elementary compositions (NH4+, K+, PO43-, Mg2+, and Ca2+) and temperature were reviewed from fifty two different literature reports to investigate their impacts on the microbial degradation of PBP using supervised machine learning algorithm. The optimal cultivation conditions based upon collected literature reports to achieve biodegradation over 80% were identified.

SCAPS-1D simulated organometallic halide perovskites: A comparison of performance under Sub-Saharan temperature condition.

Photovoltaic technology has been widely recognized as a means to advance green energy solutions in the sub-Saharan region. In the real-time operation of solar modules, temperature plays a crucial role, making it necessary to evaluate the thermal impact on the performance of the solar devices, especially in high-insolation environments. Hence, this paper investigates the effect of operating temperature on the performance of two types of organometallic halide perovskites (OHP) - formamidinium tin iodide (FASnI3) and methylammonium lead iodide (MAPbI3). The solar cells were evaluated under a typical Nigerian climate in two different cities before and after graphene passivation. Using a one-dimensional solar capacitance simulation software (SCAPS-1D) program, the simulation results show that graphene passivation improved the conversion efficiency of the solar cells by 0.51 % (FASnI3 device) and 3.11 % (MAPbI3 device). The presence of graphene played a vital role in resisting charge recombination and metal diffusion, which are responsible for the losses in OHP. Thermal analysis revealed that the MAPbI3 device exhibited an increased fill factor (FF) in the temperature range of 20-64 °C, increasing the power conversion efficiency (PCE). This ensured that the MAPbI3 solar cell performed better in the city and the season with harsher thermal conditions (Kaduna, dry season). Thus, MAPbI3 solar cells can thrive excellently in environments where the operating temperature is below 65 °C. Overall, this study shows that the application of OHP devices in sub-Saharan climatic conditions is empirically possible with the right material modification.

Updates on cowpea viruses in Southwest Nigeria: distribution, prevalence and coinfection.

Cowpea is an important source of dietary proteins in the semi-arid regions of sub-Saharan Africa. Its productivity is constrained by several viral diseases and there are limited updates on the incidence and distribution of these diseases in Nigeria. This study assessed the distribution and prevalence of cowpea viruses in Southwest Nigeria. Field surveys were conducted in 2017 and 2018, in which a total of 600 leaf samples were randomly collected from 60 cowpea fields in four (Oyo, Ogun, Ondo and Osun) states at 15 fields per state and 10 samples per field. Disease incidence and severity were recorded while virus infections were confirmed by enzyme-linked immunosorbent assay or reverse transcription polymerase chain reaction. Viral disease symptoms of systemic mosaic, mottling, puckering, vein-banding, leaf deformation and stunted growth were observed. Highest virus incidence and severity (100% and 4.8 ± 0.4) were observed at Adeosun Avenue, Ondo state, whereas Boredun, Osun state had the least (80% and 3.8 ± 0.7), with some symptomless fields found among the states. Seven viruses, viz.: cowpea aphid-borne mosaic virus (CABMV), cowpea mild mottle virus (CPMMV), bean common mosaic virus-blackeye cowpea mosaic strain (BCMV-BlCM), cucumber mosaic virus (CMV), southern bean mosaic virus (SBMV), cowpea mottle virus (CMoV) and cowpea yellow mosaic virus (CYMV) were detected from 173 (28.8%) samples collected from 32 (53.3%) fields across the states. CPMMV was prevalent, detected from 30.0% of surveyed fields, whereas CYMV was the least prevalent (3.3%). Multiple infections of two to four viruses were observed among 12.5% of samples from 51.7% of fields. Highest incidence of single and multiple virus infections were observed in Ondo state. This updates on virus distributions in Southwest Nigeria will be useful for multiple virus resistance-breeding programs and other viral disease management strategies for improved cowpea productivity. Supplementary Information: The online version contains supplementary material available at 10.1007/s42360-022-00576-8.

Toxicological evaluation of aqueous leaf extract of Terminalia catappa linn (combretaceae) in pregnant rats.

Introduction: Terminalia catappa (T. catappa) leaves are used in the treatment of hypertension, diabetes, cough, jaundice, indigestion etc, while the bark is used to treat diarrhea, dysentery, abscesses etc. Due to the acceptance and increased use of medicinal plants in pregnancy, there is a need to evaluate their toxicological profiles in pregnancy for safe use. This study aims to evaluate the toxicological effects of aqueous leaf extract of T. catappa in pregnant rats. Methods: acute toxicity study was carried out using Organization of Economic Corporation Development (OECD) 423 guidelines. Seventy-five rats (50 females and 25 males) were used at the age of 2 weeks just after weaning. The male rats were separated from the female rats in different cages and allowed to mature for 10 weeks. Then the rats were allowed to mate. After mating, 20 female rats with viable spermatozoa counts were selected and divided into 4 groups of 5 rats each (n=5). The control group received distilled water while the treatment groups II, III, and IV were administered with aqueous leaf extract of T. catappa orally at graded doses of 100, 200, and 400 mg/kg respectively for 21 consecutive days. The daily food and water intake, and weight were recorded. On the 22th day, the rats were anesthetized by chloroform inhalation, and blood samples were collected for haematological and biochemical analysis. The maternal livers, kidneys, and hearts were collected and weighed, and histological studies were carried out. The fetuses were removed and examined. An isolated tissue experiment was carried out on the myometrium of the pregnant rat uterus. The isometric reading of the uterine contractions was recorded. Results: the oral LD50 was found to be ≤2000-5000 mg/kg. There was a significant (p<0.05) increase in the mean food intake at the 100, 200, and 400 mg/kg doses of the extract used on the 14th and 21st days when compared to the 7th day. The renal function test showed a significant (p<0.05) increase for chloride. The liver function test revealed that the extract at 100 mg/kg dose, significantly (p<0.05) increased only Alkaline Phosphatase (ALP) liver enzyme, while at 200 mg/kg dose, only AST liver enzyme was significantly (p<0.05) increased, while at 400 mg/kg dose, ALT, AST, ALP, and albumin increased significantly (p<0.05) when compared to the control group. There was a significant (p<0.05) decrease in the relative organ weight of the liver at 400 mg/kg dose of the extract. The liver histology showed moderate hepatic vacuolation and necrosis, while the histology of the kidney showed slight tubular necrosis. Conclusion: this study has shown that the aqueous leaf extract of T. catappa is relatively not safe in the pregnant rats. Although it is non-toxic to the fetus, it exhibited tocolytic effect by inhibiting uterine contractions, thus it should be used with caution during pregnancy, especially in the third trimester or during labor.

Attenuating effects of Azanza garckeana fractions on glycemo-impaired-associated dyslipidemia, hepatopathy, and nephropathy.

OBJECTIVES: The use of medicinal plants for diabetes treatment is increasing owing to their effectiveness and safety compared to synthetic drugs. Thus, the ameliorative effects of Azanza garckeana (F. Hoffm.) fractions in diabetes-induced dyslipidemia, hepatopathy, and nephropathy in rats were evaluated in this study. METHODS: Rats with alloxan (120 mg/kg body weight (BW))-induced diabetes were randomized into different groups (n=5) and treated with the crude methanolic extract, and fractions (n-hexane, ethyl acetate, and aqueous fractions) of A. garckeana each at 100, 200, and 400 mg/kg BW. Glibenclamide (5 mg/kg BW) was used as a reference drug, and all treatments were administered orally daily for 6 weeks. RESULTS: Our data revealed that treatment with the crude extract caused a dose-dependent hypoglycemic effect of 61.32±3.45%, 76.05±3.05%, and 78.59±5.90% at 100, 200, and 400 mg/kg BW, respectively and improved the BW of the animals. The extract also ameliorated the elevated cholesterol, triglyceride, low-density lipoprotein cholesterol, and increased serum levels of high-density lipoprotein cholesterol compared with untreated control animals. The extract also reversed serum biochemical alterations in aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine, total and direct bilirubin, urea, and uric acid that were observed in untreated diabetic rats. Interestingly, the A. garckeana fraction also exhibited significant protection against diabetes-induced dyslipidemia, hepatopathy, and nephropathy in rats, with the ethyl acetate fraction exhibiting a remarkable protective effect. The LC-MS characterisation of the active fraction identified the presence of various phenolic and flavonoid compounds that could be responsible for the bioactivity of the fraction. CONCLUSION: Collectively, this study suggests the potential application of A. garckeana for effective treatment of diabetic nephropathy, with the ethyl acetate fraction of this plant representing a reserve of potential candidates for developing new drugs.

Study of the effect of ceria on the activity and selectivity of Co and Ce co-doped birnessite manganese oxide for formaldehyde oxidation.

Catalytic oxidation is a promising approach to eliminating formaldehyde (HCHO) to improve indoor air quality. Herein, CeO2 was explored due to its remarkable properties for oxygen storage and oxygen transfer capability for co-doping δ-MnO2 alongside cobalt for enhanced low-temperature oxidation of HCHO. Various characterization techniques were deployed to understand the morphology and physicochemical properties of the synthesized catalysts. The Co-Ce co-doped catalysts with low CeO2 loading (0.05 and 0.1) showed higher catalytic activity for HCHO oxidation due to their higher concentration of surface-active oxygen species. Catalytic oxidation results showed that the presence of CeO2 leads to the generation of methanol as a secondary hazardous pollutant. Methanol selectivity increases with increasing CeO2 loading in the catalysts. The results from in-situ DRIFTS confirmed the formation of methoxy species in the presence of CeO2, which are intermediates for methanol generation. Considering the recent interest in CeO2 as a potential catalyst for practical abatement of HCHO from the indoor environment, this work has thus raised questions on the safety of using CeO2 as a catalytic material for HCHO oxidation. It also provides insights into the surface reaction mechanism leading to the generation of methanol in the presence of CeO2.

Non-compartmental toxicokinetic studies of the Nigerian Naja nigricollis venom.

Snakebite envenoming (SBE) is a neglected public health problem, especially in Asia, Latin America and Africa. There is inadequate knowledge of venom toxicokinetics especially from African snakes. To mimic a likely scenario of a snakebite envenoming, we used an enzyme-linked immunosorbent assay (ELISA) approach to study the toxicokinetic parameters in rabbits, following a single intramuscular (IM) administration of Northern Nigeria Naja nigricollis venom. We used a developed and validated non-compartmental approach in the R package PK to determine the toxicokinetic parameters of the venom and subsequently used pharmacometrics modelling to predict the movement of the toxin within biological systems. We found that N. nigricollis venom contained sixteen venom protein families following a mass spectrometric analysis of the whole venom. Most of these proteins belong to the three-finger toxins family (3FTx) and venom phospholipase A2 (PLA2) with molecular weight ranging from 3 to 16 kDa. Other venom protein families were in small proportions with higher molecular weights. The N. nigricollis venom was rapidly absorbed at 0.5 h, increased after 1 h and continued to decrease until the 16th hour (Tmax), where maximum concentration (Cmax) was observed. This was followed by a decrease in concentration at the 32nd hour. The venom of N. nigricollis was found to have high volume of distribution (1250 ± 245 mL) and low clearance (29.0 ± 2.5 mL/h) with an elimination half-life of 29 h. The area under the curve (AUC) showed that the venom remaining in the plasma over 32 h was 0.0392 ± 0.0025 mg h.L-1, and the mean residence time was 43.17 ± 8.04 h. The pharmacometrics simulation suggests that the venom toxins were instantly and rapidly absorbed into the extravascular compartment and slowly moved into the central compartment. Our study demonstrates that Nigerian N. nigricollis venom contains low molecular weight toxins that are well absorbed into the blood and deep tissues. The venom could be detected in rabbit blood 48 h after intramuscular envenoming.

Current progress on catalytic oxidation of toluene: a review.

Toluene is one of the pollutants that are dangerous to the environment and human health and has been sorted into priority pollutants; hence, the control of its emission is necessary. Due to severe problems caused by toluene, different techniques for the abatement of toluene have been developed. Catalytic oxidation is one of the promising methods and effective technologies for toluene degradation as it oxidizes it to CO2 and does not deliver other pollutants to the environment. This paper highlights the recent progressive advancement of the catalysts for toluene oxidation. Five categories of catalysts, including noble metal catalysts, transition metal catalysts, perovskite catalysts, metal-organic frameworks (MOFs)-based catalysts, and spinel catalysts reported in the past half a decade (2015-2020), are reviewed. Various factors that influence their catalytic activities, such as morphology and structure, preparation methods, specific surface area, relative humidity, and coke formation, are discussed. Furthermore, the reaction mechanisms and kinetics for catalytic oxidation of toluene are also discussed.

Kinetic Study of Product Distribution Using Various Data-Driven and Statistical Models for Fischer-Tropsch Synthesis.

Three modeling techniques, namely, a radial basis function neural network (RBFNN), a comprehensive kinetic with genetic algorithm (CKGA), and a response surface methodology (RSM), were used to study the kinetics of Fischer-Tropsch (FT) synthesis. Using a 29 × 37 (4 independent process parameters as inputs and corresponding 36 responses as outputs) matrix with total 1073 data sets for data training through RBFNN, the established model is capable of predicting hydrocarbon product distribution i.e., the paraffin formation rate (C2-C15) and the olefin to paraffin ratio (OPR) within acceptable uncertainties. With additional validation data sets (15 × 36 matrix with total 540 data sets), the uncertainties of using three different models were compared and the outcomes were: RBFNN (±5% uncertainties), RSM (±10% uncertainties), and CKGA (±30% uncertainties), respectively. A new effective strategy for kinetic study of the complex FT synthesis is proposed: RBFNN is used for data matrix generation with a limited number of experimental data sets (due to its fast converge and less computation time), CKGA is used for mechanism selections by the Langmuir-Hinshelwood-Hougen-Watson (LHHW) approach using a genetic algorithm to find out potential reaction pathways, and RSM is used for statistical analysis of the investigated data matrix (generated from RBFNN through central composite design) upon responses and subsequent singular/multiple optimizations. The proposed strategy is a very useful and practical tool in process engineering design and practice for the product distribution during FT synthesis.