Sustainable and Printable Nanocellulose-Based Ionogels as Gel Polymer Electrolytes for Supercapacitors

A new gel polymer electrolyte (GPE) based supercapacitor with an ionic conductivity up to 0.32–0.94 mS cm−2 has been synthesized from a mixture of an ionic liquid (IL) with nanocellulose (NC). The new NC-ionogel was prepared by combining the IL 1-ethyl-3-methylimidazolium dimethyl phosphate (EMIMP) with carboxymethylated cellulose nanofibers (CNFc) at different ratios (CNFc ratio from 1 to 4). The addition of CNFc improved the ionogel properties to become easily printable onto the electrode surface. The new GPE based supercapacitor cell showed good electrochemical performance with specific capacitance of 160 F g−1 and an equivalent series resistance (ESR) of 10.2 Ω cm−2 at a current density of 1 mA cm−2. The accessibility to the full capacitance of the device is demonstrated after the addition of CNFc in EMIMP compared to the pristine EMIMP (99 F g−1 and 14.7 Ω cm−2).

Urinary Organophosphate Metabolites and Metabolic Biomarkers of Conventional and Organic Farmers in Thailand

Organophosphate (OP) pesticides are used by most farmers to remove insects and to increase productivity; however, questions remain on the long-term health impacts of their use. This study assessed the relationship between OP biomarker levels and metabolic biomarker parameters. Conventional farmers (n = 213) and organic farmers (n = 225) were recruited, interviewed, and had physical health examinations. Serum glucose and lipid profiles, triglycerides, total cholesterol, high-density lipoproteins (HDL), and low-density lipoproteins (LDL) were measured. The average age, gender, education, and self-reported agricultural work time, work in second jobs, smoking status, alcohol consumption, insecticide use at home, home location near farmlands and years of pesticide use were significantly different between the conventional and organic farmers. The urinary OP metabolite levels were also significantly different between the two groups. With an increase in urinary diethyl phosphate, dimethyl phosphate and dialkyl phosphate metabolites, the total cholesterol, LDL and HDL, were significantly increased for all farmers after controlling for age, gender, alcohol consumption, years of pesticide use, and home location near farmlands. The results are consistent with our previous studies which suggests that pesticide usage, especially organophosphates, may increase the risk of cardiovascular disease and stroke among Thai farmers.

Invitro Toxicity of Binary Mixtures of Glyphosate and 2, 2 Dichlorovinyl Dimethyl Phosphate on Bacterial Isolates

The in vitro toxicity of glyphosate (Gly) and 2, 2 Dichlorovinyl dimethyl phosphate (DDVP) single compound and binary mixtures was assessed against Pseudomonas sp. and Bacillus sp. isolated from Otamiri River, Imo state, Nigeria was investigated. The toxicity response was assessed using the inhibitory effect of the single and binary mixtures on isolates dehydrogenase activity; and 2,3,5 triphenyltetrazolium chloride (TTC) was used as the artificial electron acceptor. The binary mixtures were composed using fixed ratios of glyphosate and 2, 2 Dichlorovinyl dimethyl phosphate in ratios of 20% Gly:80% DDVP, 40% Gly: 60% DDVP, 50% Gly: 50% DDVP, 60% Gly: 40% DDVP and 80% Gly: 20% DDVP. Results obtained showed that the isolates exhibited different degrees of logistic and sigmoidal toxicity trends with areas of hormesis at low concentrations of the toxicants. Furthermore, isobolographic analysis on the toxic interaction of the mixtures presented both synergism and antagonism, based on the relative ratio of the component mixtures. Increasing concentration of glyphosate in the binary mixture caused a shift in the interaction effect from antagonism to synergism. Our findings showed that isolates exhibited tolerance to glyphosate and 2,2 dichlorovinyl dimethyl phosphate and their binary mixtures exposure at concentration range of 0-1000mg/L; above which has deleterious effects on the aquatic organisms. It is evident that there are considerable differences in pesticide sensitivity among the bacterial species and that the presence of glyphosate and 2, 2-dichlorovinyl dimethyl phosphate in the aquatic environment may present toxicological risk to microbial diversity.

Evaluation of the Effect of Using 2,3-dichlorovinyl Dimethyl Phosphate (sniper) as Storage Insecticide on Quality of Cowpea (Vigna unguiculata (L.) Walp) Nutritional Content

The effect of 2, 3-dichlorovinyl dimethyl phosphate (sniper) application on the nutritional contents of cowpea over a period of time has been investigated. The chemical free cowpea samples were purchased directly from local farmers in Mubi town, Adamawa State. Three different treatment rates of 5, 10 and 15 ml of sniper were used. Each of the treatment rates was applied to 13 kg of cowpea and was placed in an air tight galloon. Another galloon containing 13 kg of cowpea without chemical treatment was used as the control sample. These were kept for a period of 30 and 60 days before analysis. The proximate and mineral components of the cowpea were analyzed using standard procedures. Assessment of the proximate composition revealed varied concentrations of protein, carbohydrate, ash, fat, crude fibre and moisture that ranges between 22.79-26.16%, 58.85-60.86%, 3.85-5.88%, 2.25-2.53%, 1.52-1.76% and 5.90-6.85%, respectively. Most of the proximate compositions were observed to decrease with increase in sniper concentration and storage duration. The proximate contents at 60 days after treatment application were observed to be significantly lower than that at 30 days. The mineral components analyzed ranges between 185.03-195.54 mg/100 g (P), 226.32-245.76 mg/100 g (Ca), 80.76-85.92 mg/100 g (Mg) and 595.25-642.34 mg/100 g (K) respectively; and at day 60 it ranges between 186.54-198.65 mg/100g, 251.07-262.73 mg/100 g, 86.48-90.12 mg/100 g and 650.06-700.04 mg/100 g respectively. The mineral contents were observed to increase with increase in treatment concentrations as well as storage duration. Therefore, sniper has significant effect on the proximate and mineral contents of cowpea. The effect depends on the rate and duration of storage. The use of sniper as an insecticide in the storage of cowpea should therefore be discouraged.

Quantification of Pesticide Residues in Retail Samples of Cowpea - Vigna unguiculata (L.) Walp

Quantification of pesticide residues in retail samples of food is one way to determine the level of human exposure to these chemicals and hence their potential health hazards. The study was aimed at quantifying the level of some known pesticides in retail samples of Vigna unguiculata (L.) Walp. (Cowpea) from two cropping seasons. Five cultivars of cowpea from two different harvest seasons (2016/2017 and 2017/2018) were purchased from Ogige Market, Nsukka, Enugu State, Nigeria. The cowpeas were identified based on city/state where they were cultivated. Two foreign samples were also purchased from London, UK. The pesticide residues were determined using gas chromatography coupled with electron capturing detector (GC-ECD). The results showed that the retail samples of cowpea contained residues of one or more organochlorines and organophosphates. The levels of post-harvest pesticides, 2, 2-dichlorovinyl dimethyl phosphate (DDVP) in 2016/17 season (0.02 μg/g) exceeded the international permissible standards (0.01 μg/g). The levels of the pre-harvest pesticides, glyphosate was low in both seasons (0.01 μg/g) when compared to the international permissible standards (0.1 μg/g). The DDVP was not detected in the two foreign samples. HCB (Hexachlorobenzene), α-HCH (alpha-Hexachlorocyclohexane), Chlorpyrifos, g-chlordane, t-nonachlor, p-p’-DDT (Dichlorodiphenyltrichloroethane), p-p’-DDE (Dichlorodiphenyldichlo-rowthylene), and p-p’-DDD (Dichlorodiphenyldichloroethane) were detected in the cowpea from two cropping seasons despite being banned from agricultural use. This could be due to the additional application of pesticides during storage of the cowpeas. The findings concludes that the levels of some of the residues exceeded the safety limits while some were below the safety limits, suggesting that some of samples of the cowpea were not safe for human consumption as bioaccumulation, persistence, and toxicity of these residues was likely to pose serious health risks to the consumers. Generally, cowpea from the 2016/17 season contained higher pesticide residues than those from the 2017/18 season.

Quantification of Pesticide Residues in Retail Samples of Cowpea - Vigna unguiculata (L.) Walp

Quantification of pesticide residues in retail samples of food is one way to determine the level of human exposure to these chemicals and hence their potential health hazards. The study was aimed at quantifying the level of some known pesticides in retail samples of Vigna unguiculata (L.) Walp. (Cowpea) from two cropping seasons. Five cultivars of cowpea from two different harvest seasons (2016/2017 and 2017/2018) were purchased from Ogige Market, Nsukka, Enugu State, Nigeria. The cowpeas were identified based on city/state where they were cultivated. Two foreign samples were also purchased from London, UK. The pesticide residues were determined using gas chromatography coupled with electron capturing detector (GC-ECD). The results showed that the retail samples of cowpea contained residues of one or more organochlorines and organophosphates. The levels of post-harvest pesticides, 2, 2-dichlorovinyl dimethyl phosphate (DDVP) in 2016/17 season (0.02 μg/g) exceeded the international permissible standards (0.01 μg/g). The levels of the pre-harvest pesticides, glyphosate was low in both seasons (0.01 μg/g) when compared to the international permissible standards (0.1 μg/g). The DDVP was not detected in the two foreign samples. HCB (Hexachlorobenzene), α-HCH (alpha-Hexachlorocyclohexane), Chlorpyrifos, g-chlordane, t-nonachlor, p-p’-DDT (Dichlorodiphenyltrichloroethane), p-p’-DDE (Dichlorodiphenyldichlo-rowthylene), and p-p’-DDD (Dichlorodiphenyldichloroethane) were detected in the cowpea from two cropping seasons despite being banned from agricultural use. This could be due to the additional application of pesticides during storage of the cowpeas. The findings concludes that the levels of some of the residues exceeded the safety limits while some were below the safety limits, suggesting that some of samples of the cowpea were not safe for human consumption as bioaccumulation, persistence, and toxicity of these residues was likely to pose serious health risks to the consumers. Generally, cowpea from the 2016/17 season contained higher pesticide residues than those from the 2017/18 season.

Graphitic-Phase C3N4 Nanosheets Combined with MnO2 Nanosheets for Sensitive Fluorescence Quenching Detection of Parathion-Methyl

In this study, we have developed a sensitive approach to measure organophosphorus pesticides (OPs) using graphitic-phase C3N4 nanosheets (g-C3N4) combined with a nanomaterial-based quencher MnO2 nanosheets (MnO2 NS). Because MnO2 NS could quench the fluorescence of g-C3N4 via the inner-filter effect (IFE), the enzymatic hydrolysate (thiocholine, TCh) can efficiently trigger the decomposition of MnO2 nanosheets in the presence of acetylcholinesterase (AChE) and acetylthiocholine, resulting in the fluorescence recovery of g-C3N4. OPs, as inhibitors for AChE activity, can prevent the generation of TCh and decomposition of MnO2 nanosheets, accompanied by fluorescence quenching again. So the AChE-ATCh-MnO2-g-C3N4 system can be utilized to detect OPs quantitatively based on the g-C3N4 fluorescence. Under the optimum conditions, the linear range for the determination of parathion-methyl (PM) and 2,2-dichlorovinyl dimethyl phosphate (DDVP) were found in the range of 0.1-2.1 ng/mL with a limit of detection of 0.069 ng/mL, and 0.5-16 ng/mL with a limit of detection of 0.069 ng/mL, respectively. Finally, this method was exploited for the monitoring of PM in real samples. The advantages of the assay are user-friendly, easy-to-ease, cost-effective compared to sophisticated analytical instruments.