Acceptable Concentration Research Articles

Advanced technology for photocatalytic degradation of thiophanate-methyl: Degradation pathways, DFT calculations and embryotoxic potential

This study focuses on establishing an efficient two-step technology, which includes: (1) consecutive adsorption-desorption, using cellulose-based membranes, bCells, and (2) photocatalytic degradation of the fungicide thiophanate-methyl (TPM), using synthesized Ag-P25 and Ce-P25 catalysts. The catalysts, obtained by controlled deposition of Ag2O/Ag and CeO2 onto P25 TiO2 carrier (Degussa), were characterized using ATR-FTIR, XRPD, BET, FESEM, HRTEM, HAADF-EDS and UV–DRS techniques. In order to establish a feasible purification technology, preconcentration of TPM was performed by adsorption, achieving 75.5 and 92.9 mg/g of TPM removal using bCell-EpL and bCell–EpL–TA membranes, respectively, followed by efficient desorption (> 95%) that provided acceptable TPM concentration for photodegradation experiments. Under optimal conditions (0.07 g/L of both catalysts), complete degradation of TPM (5 mg/L) occurred within 2 h, compared to 4 h for the base TiO2 P25. Measurements of quantum yield and the results of HPLC-MS analysis, alongside DFT calculation, assisted in understanding the TPM degradation pathways. New degradation products were detected and proposed from HPLC–MS analysis. Embryotoxic assays, performed on zebrafish (Danio rerio), applied to estimate the toxicity evolution of time-dependent generated TPM degradation products, showed low embryotoxic potential. Chemical oxygen demand (26 mg O2/L) confirmed low ecotoxicological pressure of effluent water.

An evaluation of DNA extraction methods on historical and roadkill mammalian specimen

Guidelines identifying appropriate DNA extraction methods for both museum and modern biological samples are scarce or non-existent for mammalian species. Yet, obtaining large-scale genetic material collections are vital for conservation and management purposes. In this study, we evaluated five protocols making use of either spin-column, organic solvents, or magnetic bead-based methods for DNA extraction on skin samples from both modern, traffic-killed (n = 10) and museum (n = 10) samples of European hedgehogs, Ericaneus europaeus. We showed that phenol–chloroform or silica column (NucleoSpin Tissue) protocols yielded the highest amount of DNA with satisfactory purity compared with magnetic bead-based protocols, especially for museum samples. Furthermore, extractions using the silica column protocol appeared to produce longer DNA fragments on average than the other methods tested. Our investigation demonstrates that both commercial extraction kits and phenol–chloroform protocol retrieve acceptable DNA concentrations for downstream processes, from degraded remnants of traffic-killed and museum samples of mammalian specimens. Although all the tested methods could be applied depending on the research questions and laboratory conditions, commercial extraction kits may be preferred due to their effectiveness, safety and the higher quality of the DNA extractions.

Pesticide dynamics in three small agricultural creeks in Hesse, Germany.

Due to their high biodiversity, small water bodies play an important role for freshwater ecosystems. Nonetheless, systematic pesticide monitoring in small creeks with a catchment <30 km2 is rarely conducted. In this study, event-driven water samples were taken from May until November 2017 and March until July 2018 after 20 rain events at three sampling sites with catchment areas of <27 km2 in the Wetterau, a region with intensive agriculture in Southern Hesse, Germany. Additionally, enriched extracts of the native water samples from the campaign in 2018 were used for the Microtox assay to determine baseline toxicity to invertebrates over time and sum of toxic units (STU) were calculated to compare the potential toxicity of the samples. Overall, 37 pesticides and 17 transformation products were found, whereby the herbicide metamitron (79 µg/L) showed the highest concentration. Regularly, pesticide concentrations peaked at the time of the highest water level within each sampling event. Within each sampling event maximum pesticide concentration was mostly reached in water samples taken during the first two hours. The sum of the time-weighted mean concentration values of all pesticides was between 2.0 µg/L and 7.2 µg/L, whereby the measured concentrations exceeded their regulatory acceptable concentration (RAC) at 55% of all sampling events for at least one pesticide. The mean EC50 values varied between 28.6 ± 13.1 to 41.3 ± 12.1 REF (relative enrichment factor). The results indicated that several samples caused baseline toxicity, whereby the highest activity was measured at the time of highest water levels and pesticides concentrations, and then steadily decreased in parallel with the water level. Median STUs of invertebrates ranged from -2.10 to -3.91, of algae/aquatic plants from -0.79 to -1.84 and of fish from -2.47 to -4.24. For one of the three sampling sites, a significant linear correlation between baseline toxicity and STUinvertebratewas found (r2=0.48). The results of the present study suggest that (1) current pesticide monitoring programs underestimate risks posed by the exposure to pesticides for aquatic organisms and (2) pre-authorization regulatory risk assessment schemes are insufficient to protect aquatic environments.

A Score Index System for a Semi-Quantitative Assessment of Inhalation Risks at Contaminated Sites

Risk assessment of contaminated sites is typically applied following a tiered approach with increasing levels of complexity. In the standard risk-based corrective action (RBCA) procedure issued by the American Society for Testing and Materials (ASTM), the site-specific evaluation is carried out using fate and transport models that require a relatively large amount of input data. In this work, we introduce a site-specific score index system for a preliminary assessment of the inhalation risks related to contaminants in soil or groundwater that resembles the modeling approaches typically adopted for chemical risk assessment in the field of industrial hygiene. In the developed system, a risk index for the outdoor and indoor volatilization pathways is calculated as the ratio between the calculated concentration at the point of exposure for the contaminant of concern and the corresponding acceptable concentration in air. The concentration at the point of exposure for each contaminant of concern is estimated through simple algorithms that involve a limited number of indexes that depend on the parameters that affect the exposure scenario. This qualitative assessment is then converted into a semi-quantitative approach by introducing scaling factors that were calibrated using the ASTM RBCA fate and transport models. The procedure was validated against the standard RBCA procedure by performing a simple Monte Carlo analysis with 10,000 simulations with randomly varying site-specific parameters. The developed score index system resulted in a conservative estimate of the risks, with percentages of false negatives lower than 1% and false positives lower than 15%. This means that the developed system allows one to screen out sites from further evaluations in more than 80% of cases, while ensuring a conservative estimate of the expected risks. The application to a real case study of a contaminated site confirmed the suitability of the developed approach.

Occurrence, source identification and ecological risk assessment of heavy metals in water and sediments of Uchalli lake – Ramsar site, Pakistan

Uchalli Lake is an internationally significant Ramsar site that needs protection for supporting migratory birds. The current study aimed to assess wetland health by examining water and sediments utilizing total and labile heavy metals concentration, pollution indices, ecological risk assessment, water recharge and pollution induction sources through isotope tracer techniques. Al concentration in water was of serious concern as it was 440 times higher than the maximum acceptable concentration of Environmental Quality Standard of the UK for aquatic life in saline waters. Labile concentration predicted very severe enrichment of Cd, Pb, and moderate enrichment of Cu. Modified ecological risk index predicted very high ecological risk in sediments. The δ 18O, δ2H and D-excess values indicate that the lake was mainly recharged by local meteoric water. Enriched values of δ 18O and δ2H suggest a high evaporation of lake water, making lake sediments more enriched with metals. Isotopic and D-excess values of groundwater suggest a quick rainwater recharge to groundwater around the Uchalli Lake. Nitrates isotopes indicate that the rainwater runoff is main source of induction of fertilizers, pesticides and soil bonded metals in the lake system. The lake is recharged by rainwater runoff, from catchment areas, that erode the soil particles and agricultural residual waste dumped in the lake.

Determination the Optimum Conditions for β-glucan Production Extracted from Saccharomyces cerevisiae

Β-glucan is a natural polysaccharide composed of a group of glucose monomers linked by beta glycoside bonds that yeasts can be synthesized. The effect of different temperatures, inoculum size, glucose concentration, yeast extract concentration, pH, and culture media on the β-glucan production from saccharomyces cerevisiae was studied. In addition, the dry weight of biomass containing β-glucan was measured. The results showed that the optimum conditions for β-glucan production were when the cells were grown at 30 ºc for 48 hours and pH = 7 with 10 % inoculum size, 2% glucose, and 0.1% yeast extract. Furthermore, the best culture medium for β-glucan production was yeast extract-glucose medium with a dry weight of glucan 2.5mg/5ml. In addition, this study aimed to determine the best method for β-glucan extraction with acceptable purity and concentration. Β-glucan was extracted using two methods autolysis and alkali-acids extraction. The dried and weighed crude β-glucan was 6 gm/l, and 8 gm/l for autolysis of yeast cells, and alkali-acids extraction, respectively. The analysis of glucan by FT-IR and HPLC showed that the method of extraction by autolysis of yeast cells was successful to obtain β-glucan without the presence of the α-glucan with a concentration of β-glucan 10.8mg/gm, while in the extraction by alkali-acid were obtained mixtures of α-glucan and β-glucan with the concentration of β-glucan 7.4 mg/gm. The current study revealed that the optimum conditions of β-glucan production and the best culture medium for β-glucan production was yeast extract-glucose medium and the best method for β-glucan extraction was autolysis extraction.

Trophic status and lake depth play important roles in determining the nutrient-chlorophyll a relationship: Evidence from thousands of lakes globally

A fundamental problem in lake eutrophication management is that the nutrient-chlorophyll a (Chl a) relationship shows high variability due to diverse influences of for example lake depth, lake trophic status, and latitude. To accommodate the variability induced by spatial heterogeneity, a reliable and general insight into the nutrient-Chl a relationship may be achieved by applying probabilistic methods to analyze data compiled across a broad spatial scale. Here, the roles of two critical factors determining the nutrient-Chl a relationship, lake depth and trophic status, were explored by applying Bayesian networks (BNs) and a Bayesian hierarchical linear regression model (BHM) to a compiled global dataset from 2849 lakes and 25083 observations. We categorized the lakes into three groups (shallow, transitional, and deep) according to mean and maximum depth relative to mixing depth. We found that despite a stronger effect of total phosphorus (TP) and total nitrogen (TN) on Chl a when combined, TP played a dominant role in determining Chl a, regardless of lake depth. However, when the lake was hypereutrophic and/or TP was >40 μg/L, TN had a greater impact on Chl a, especially in shallow lakes. The response curve of Chl a to TP and TN varied with lake depth, with deep lakes having the lowest yield Chl a per unit of nutrient, followed by transitional lakes, while shallow lakes had the highest ratio. Moreover, we found a decrease of TN/TP with increasing Chl a concentrations and lake depth (represented as mixing depth/mean depth). Our established BHM may help estimating lake type and/or lake-specific acceptable TN and TP concentrations that comply with target Chl a concentrations with higher certainty than can be obtained when bulking all lake types.

Vermicompost Leachate a Viable Bio-stimulant for Tomato Growth and Yield (Solanum lycopersicum)

Background: The influence of inorganic fertilizer has posed considerable challenges on increasing food production worldwide. A careful plan is required to increase the yield and quality of crops. A profound knowledge on the use of organic manure involvement in plant growth and development could be beneficial for food production. The use of acceptable inorganic and different concentrations of vermicompost has been used in an attempt to enhance crop growth and development with the aim of increasing food production. The aim of the study was to investigate the impact of vermicompost tea concentrate extracted from cow manure and grass cutting on physiological responses of tomato (Solanum lycopersicum).Vegetative growth and yield of tomato was stimulated by mineralization of organic waste coupled with the mesophilic action of earthworm. Vermicompost is a by-product of earthworm tissues. It is a nutrient source rich in essential components for plant growth and development. Methods: An investigation was conducted in pot media under exposed natural conditions from August 2020 to November 2020 at Mangosuthu University of Technology. In this experiment, the growth of tomato plants were subjected to different vermicompost concentrations and amended with NPK fertilizer were studied. Sandy loam soil of about 5 kg were weighted into pot media (2.0mheight, 2.3m diameter). The experiment was set up in a completely randomized block design consisting of five treatments with five replicates per treatment. Treatments included: Positive control (PC), 5%VCL+NPK, 10% VCL+NPK, 20%VCL+NPK and the inorganic (NPK). Result: revealed that there were significant differences at (P less than 0.01) among the treatments with respect to plant height and number of leaves from week three to week eight. Similar trends were found with 5% VCL+NPK, 10% VCL+NPK, 20% VCL+NPK and the NPK treatments. This may be due to phytohormone release from earthworm tissue. Tomato flower inflorescence was significant at (P less than 0.01). Tomato fruit, different components at harvest which were, weight wet and dry weight were higher with NPK treated at (P less than 0.01) than the 5% VCL+NPK, 10% VCL+NPK. Root length in 20% concentration was considerably higher than the other treatments. The results showed that minimum supplementation with inorganic fertiliser may be necessary with vermicompost leachate in order to successfully grow crops in nutrient deficient soil.

Hypertonic Activity of Injection Solutions Can Cause Post-injection Complications (Review)

Introduction. A review of the scientific literature showed that the current standards for assessing the quality of drugs does not include an assessment of the osmotic activity of drug solutions and their local irritant effect on tissues at the sites of subcutaneous, intramuscular and intravenous injections. Therefore, currently injectable solutions considered to be of high quality may not have isotonic activity and high postinjection safety.Text. A study of the concentration range of quality drug solutions ready for injection showed that the acceptable concentration value of the main ingredients is in the range of 0.01 to 76 %. Direct measurement with an osmometer of the osmotic activity of injection solutions, considered qualitative today, has shown that injection solutions can have hypotonic, isotonic and hypertonic activity and their osmotic activity can be in the range of 0 – 3900 mosmol/l water. Study of acidic activity of drug solutions showed that in accordance with pharmacopoeial requirements of drug quality modern quality drug solutions ready for injection can have acidic, neutral or alkaline activity. Solutions with hypertonic activity have been found to have a local irritant effect. Moreover, an increase in hypertonic activity of drug solutions increases their local irritant effect. It has been found that excessively high hypertonic activity of drug solutions may be the cause of the development of a local postinjection complication known as "Nicolaou syndrome", the cause of which has remained unknown for a long time. Nicolaou syndrome includes local pain syndrome, aseptic inflammation, necrosis, and abscess.Conclusion. The authors conducted a literature review, the results of which led to conclusions and assumptions. Solutions containing drugs in concentrations greater than 10 % may have the highest hypertonic activity, which can cause excessive dehydrating, local irritating and cauterizing effects. Therefore, injections of such drugs are most dangerous with the development of post-injection necroses and abscesses. That is why timely dilution of concentrated drug solutions with water by 2–10 times increases injection safety. It is proposed to include the assessment of osmotic activity and local irritant effect of drug solutions in the standard of drug quality control.

In vivo skin optical clearing efficacy quantification of clinically compatible agents using line-field confocal optical coherence tomography.

The clinical use of optical methods for in vivo skin imaging is limited by skin strong scattering properties, which reduce image contrast and probing depth. The efficiency of optical methods can be improved by optical clearing (OC). However, for the use of OC agents (OCAs) in a clinical setting, compliance with acceptable non-toxic concentrations is required. OC of in vivo human skin, combined with physical and chemical methods to enhance skin permeability to OCAs, was performed to determine the clearing-effectiveness of biocompatible OCAs using line-field confocal optical coherence tomography (LC-OCT) imaging. Nine types of OCAs mixtures were used in association with dermabrasion and sonophoresis for OC protocol on three volunteers hand skin. From 3D images obtained every 5min for 40min, the intensity and contrast parameters were extracted to assess their changes during the clearing process and evaluate each OCAs mixture's clearing efficacy. The LC-OCT images average intensity and contrast increased over the entire skin depth with all OCAs. The best image contrast and intensity improvement was observed using the polyethylene glycol, oleic acid, and propylene glycol mixture. Complex OCAs featuring reduced component concentrations that meet drug regulation-established biocompatibility requirements were developed and proved to induce significant skin tissues clearing. By allowing deeper observations and higher contrast, such OCAs in combination with physical and chemical permeation enhancers may improve LC-OCT diagnostic efficacy.

P92 PERIMYOCARDITIS AS FIRST MANIFESTATION OF DYSTHYROIDISM: AN UNUSUAL CASE

Abstract Thyroid and cardiovascular system are inextricably related and cardiovascular complications can occur in both subclinical and overt thyroid dysfunction. We report the case of a 42–year–old woman presenting with chest pain. She had a positive SARS–CoV–2 swab in June and she was hospitalised in suspicion of COVID–related pneumonia and pericarditis in July: treatment with ibuprofen and colchicine was started and patient was discharged. On July 26th, the patient came back to emergency department due to worsening chest pain and myalgias after therapy decalage. She had face edema and hoarse voice. 12–leads EKG was normal; echocardiography showed 8 mm pericardial effusion and normal ejection fraction. Blood testing revealed no inflammatory signs, a mild increase of Troponin (peak value 19.1 ng/L, n.v. 0–14) and a high value of CPK (peak value 2299 U/L, 464 U/L at time of discharge, n.v. 30–150). Moreover, she had a biohumoral profile of Hashimoto thyroiditis: severe hypothyroidism with increase in TSH levels (538 microU/ml peak value, 322 microU/ml at time of discharge, n.v. 0.27–4.2) and positivity to thyroid autoantibodies. The patient underwent a cardiac magnetic resonance imaging that was suggestive for acute perimyocarditis with biventricular diffuse myocardial edema, preserved biventricular function and mild–to–moderate pericardial effusion. Low dose L–T4 therapy was started together with liothyronine that was stopped after few days, once acceptable FT3 concentrations were obtained. At echocardiography control after 8 days, we registered a significant reduction of pericardial effusion (2 mm). Myocarditis is an inflammatory disease of the myocardium and it is predominantly mediated by viral infection. A rare cause of myocarditis is represented by dysthyroidism. In our case, the severe hypothyroidism seems to be the cause of myocardial and pericardial edema. The failure in diagnosis of this endocrinological disorder can determine a delay in specific therapy with possible serious cardiovascular manifestations. So, it would be reasonable to check the thyroid status of all patients presenting with myopericarditis, in the absence of another clearly identifiable aetiology. The role of to the prior SARS–CoV–2 infection in not certain in our case, but the quick recovery after specific endocrinological therapy suggests the low probability of perimyocarditis as SARS–CoV2 related manifestation.

Occurrence and environmental risk assessment of 22 pesticides in Brazilian freshwaters

Pesticide contamination in water resources is a global threat. Although usually found at low concentrations, pesticides raise considerable toxicological concerns, mainly when mixtures are considered. The occurrence of 22 pesticides (2,4 D, alachlor, aldicarb, aldrin, atrazine, carbendazim, carbofuran, chlordane, chlorpyrifos, DDT, diuron, glyphosate, lindane, mancozeb, methamidophos, metolachlor, molinate, profenofos, simazine, tebuconazole, terbufos, and trifluralin) was investigated, through consolidated database information, in surface freshwaters of Brazil. Moreover, scenarios of environmental risk assessment considering isolated compounds and mixtures were performed, as well as a meta-analytic approach for toxicity purposes. Pesticides in freshwater have been reported from 719 cities (12.9% of Brazilian cities), where 179 (3.2%) showed pesticide occurrence above the limit of detection or quantification. Considering cities with more than five quantified, 16 cities were prone to environmental risks considering individual risks. However, the number increased to 117 cities when the pesticide mixture was considered. The mixture risk was driven by atrazine, chlorpyrifos, and DDT. The national maximum acceptable concentrations (MAC) for nearly all pesticides are higher than the predicted no-effect concentration (PNEC) for the species evaluated, except aldrin. Our results show the need to consider mixtures in the environmental risk assessment to avoid underestimation and review MAC to protect aquatic ecosystems. The results presented here may guide the revision of the national environmental legislation to ensure the protection of Brazilian aquatic ecosystems.

CO2 concentration as an indicator of indoor ventilation performance to control airborne transmission of SARS-CoV-2

BackgroundThe Wells-Riley equation has been extensively used to quantify the infection risk of airborne transmission indoors. This equation is difficult to apply to actual conditions because it requires measurement of the outdoor air supply rate, which vary with time and are difficult to quantify. The method of determining the fraction of inhaled air that has been exhaled previously by someone in a building using a CO2 concentration measurement can solve the limitations of the existing method. Using this method, the indoor CO2 concentration threshold can be determined to keep the risk of infection below certain conditions. MethodsBased on the calculation of the rebreathed fraction, an appropriate mean indoor CO2 concentration and required air exchange rate to control SARS-CoV-2 airborne transmission was calculated. The number of indoor occupants, ventilation rate, and the deposition and inactivation rates of the virus-laden aerosols were considered. The application of the proposed indoor CO2 concentration-based infection rate control was investigated through case studies in school classrooms and restaurants. ResultsIn a typical school classroom environment with 20–25 occupants and an exposure time of 6–8 h, the average indoor CO2 concentration should be kept below 700 ppm to control the risk of airborne infection indoors. The ASHRAE recommended ventilation rate is sufficient when wearing a mask in classrooms. For a typical restaurant with 50–100 occupants and an exposure time of 2–3 h, the average indoor CO2 concentration should be kept below about 900 ppm. Residence time in the restaurant had a significant effect on the acceptable CO2 concentration. ConclusionGiven the conditions of the occupancy environment, it is possible to determine an indoor CO2 concentration threshold, and keeping the CO2 concentration lower than a certain threshold could help reduce the risk of COVID-19 infection.

Effects of a realistic pesticide spraying sequence for apple crop on stream communities in mesocosms: negligible or notable?

BackgroundSeveral large-scale studies revealed impacts and risks for aquatic communities of small rural lakes and streams due to pesticides in agricultural landscapes. It appears that pesticide risk assessment based on single products does not offer sufficient protection for non-target organisms, which are exposed repeatedly to pesticide mixtures in the environment. Therefore, a comprehensive stream mesocosm study was conducted in order to investigate the potential effects of a realistic spraying sequence for conventional orchard farmed apples on a stream community using pesticides at their regulatory acceptable concentrations (RACs). Eight 74-m-long stream mesocosms were established with water, sand, sediment, macrophytes, plankton and benthic macroinvertebrates. In total, nine fungicidal, four herbicidal and four insecticidal pesticides were applied in four of the eight stream mesocosms on 19 spraying event days in the period from April to July while the remaining four stream mesocosms served as controls. The community composition, the abundance of benthos, periphyton and macrophytes, the emergence of insects, physico-chemical water parameters, and drift measurements of aquatic invertebrates were measured.ResultsThe pesticide spraying sequence induced significant effects on invertebrates, periphyton, and macrophytes as well as on the water ion composition especially in the second half of the experiment. It was not possible to relate the observed effects on the community to specific pesticides applied at certain time points and their associated toxic pressure using the toxic unit approach. The most striking result was the statistically significant increase in variation of population response parameters of some taxa in the treated mesocosms compared to the controls. This inter-individual variation can be seen as a general disturbance measure for the ecosystem.ConclusionsThe pesticide spraying sequence simulated by using RAC values had notable effects on the aquatic stream community in the conducted mesocosm study. The results indicate that the current risk assessment for pesticides may not ensure a sufficient level of protection to the field communities facing multiple pesticide entries due to spraying sequences and other combined stress. Hence, there is still room for improvement regarding the prospective risk assessment of pesticides to further reduce negative effects on the environment.

Visible Laser Light Mediated Cancer Therapy via Photothermal Effect of Tannin-Stabilized Magnetic Iron Oxide Nanoparticles.

Super-paramagnetic iron oxide nanoparticles (SPIONs/Fe3O4) were synthesized in aqueous medium under a nitrogen atmosphere. These particles were made water-dispersible by cladding them with tannic acid (TA). The synthesized nanoparticles were characterized for their size and surface charge using HRTEM and zetasizer. It was found that the size of the particles formed was around 15 nm with almost spherical morphology and negative surface charge. Vibrating sample magnetometer (VSM) data attributed a super-paramagnetic nature to these nanoparticles. The photo-thermal dynamics of these magnetite (Fe3O4) nanoparticles was characterized by exciting their dispersions with laser radiation in the visible region (635 nm). Remarkably, 17 min of laser irradiation of the dispersion raised its temperature by ~25 °C (25 to 49.8 °C), whereas for the solvent, it was limited to not more than 4 °C (after 60 min). Thus, the Fe3O4 nanoparticles generated localized hyperthermia for potential use in cancer therapy of tumor management. The photo-thermal dynamics of these nanoparticles was investigated in-vitro for cancer therapy, and it was clearly shown that cancer cell growth was inhibited, and considerable cellular damage occurred when cells were incubated with laser-activated magnetic nanoparticles. No noticeable innate toxicity of the nanoparticles was observed on cancer cell lines. The effectiveness of these nanoparticles was studied on several malignant cell lines, and an acceptable Fe3O4 concentration range was subsequently determined for generating substantial cell death by hyperthermia, but not inherent toxicity. Therefore, we concluded that this nano-system is effective and less time consuming for the treatment of malignant diseases such as cancer.

The Effect of High Glycemic Modified Breakfast Menu on Increasing Learning Concentration of Junior High School Students Insan Cendekia Mandiri (ICM) Sarirogo – Sidoarjo

The nutritional adequacy of the Insan Cendekia Mandiri (ICM) junior high school students is obtained from the provision of food in the dormitory. One way to increase the acceptance of food intake organized by the boarding institution at the Insan Cendekia Mandiri Junior High School (ICM) is to modify the food menu. The provision of food doesn’t escape the standard portion for each individual so takes a portion of food that is by the RDA, so that it can be seen whether the individual needs of junior high school students have been met or not. This study aims to analyze the effect of modifying the menu of a high-glycemic meal on the acceptability and increase in learning concentration in students of SMP Insan Cendekia Mandiri in Sarirogo, Sidoarjo. This research method uses a pre-experimental design with a one-group pretest-posttest to determine the quality of the modification of the high-glycemic plate menu through the level of preference, acceptance of the increase in learning concentration of junior high school students at Insan Cendekia Mandiri (ICM) Sarirogo, Sidoarjo. The research sample was 37 junior high school students taken by simple random sampling using a formula to meet the inclusion and exclusion criteria. The variables in this study consisted of independent variables, namely modification of high glycemic prescriptions, the dependent variable was acceptance and learning concentration. The research instrument used is a 7-day menu cycle using organoleptic tests by conducting pre and posttest. The result is The breakfast menu from ICM has a lower glycemic index than the modified menu because of the ingredients used. There is a difference in the average energy value in the modified menu, which is 102.5 kcal compared to the breakfast menu from ICM, 2,94 grams of protein average higher than the breakfast menu on ICM, 10,9 grams of fat higher than the breakfast menu on ICM and then 10,76 grams of carbohydrate average lower than breakfast menu on ICM, and student concentration has increased because of the modified menu which has a high glycemic index.

Efficiency of portable air purification on public buses: A pilot study

High concentrations of fine particulate matter (PM2.5) have been frequently reported in public transit systems and can cause adverse health effect. The portable air purifier is an inexpensive solution that could potentially clean in-cabin PM2.5. This study aims to find the PM2.5 removal efficiency of portable air purifiers in a public transit bus. In various scenarios, after artificially preloading the in-cabin PM2.5 concentration to 400 μg/m3, the concentrations were measured every 10 s, with and without the intervention of air purifiers. In a test bus with a volume of approximately 62.5 m3, three portable air purifiers were capable of reducing the average concentration of PM2.5 by 42–74%, from 400 μg/m3, to levels below 15 μg/m3, the acceptable short-term exposure concentration recommended by WHO. When high concentrations of outdoor PM2.5 entered the bus, purifiers maintained a relatively low level of in-cabin PM2.5. Air purifiers were more effective in reducing in-cabin PM2.5 than traditional air filtration and ventilation methods (air conditioning system filtration and door opening) in public transit buses. The deployed air purifiers reduced the concentration of particulate matter inside the bus, which may reduce the health risk of PM2.5 exposure and the spreading of airborne infections in public transit, thus, implying the potential to enhance passengers' and drivers' health.

Effects of Ammonia on Juvenile Sunray Surf Clam (Mactra chinensis Philippi) in Laboratory Tests

The current study aimed to determine the acute and sub-chronic toxicity of ammonia to juvenile surf clams (Mactra chinensis Philippi). Acute toxicity tests were conducted with seven concentrations of ammonium chloride using a 96 h static-renewal approach. Sub-chronic ammonia exposure tests (20 d exposures) were conducted with 6 concentrations at 20 °C. The 96 h median lethal concentration (96 h LC50) was 11.1 (10.0; 12.0) mg/L total ammonia nitrogen (TAN) and 0.56 (0.50; 0.60) mg/L unionized ammonia (NH3). The relative growth rate was significantly reduced at concentrations higher than 1.6 mg/L TAN (0.075 mg/L NH3) in the 20 d tests. The estimated maximum acceptable toxicant concentration (MATC) based on the reduced growth of juvenile M. chinensis was between 0.8 and1.6 mg/L TAN (0.038–0.075 mg/L NH3). Histopathological changes were evaluated in the surviving clams after 20 days of exposure. Exposure to 14.1 mg/L TAN (0.661 mg/L NH3) resulted in changes in the mantle, foot and digestive diverticulum. We also examined the antioxidant enzyme activities of superoxide dismutase (SOD) and catalase (CAT) in 10 d and 20 d at 6 different levels (plus a control) of ammonia from 0.8 mg/L to 14.1 mg/L TAN. Ammonia exposure at 0.8 mg/L TAN (0.038 mg/L NH3) significantly affected SOD and CAT activities. The level of enzymic activity decreased with the increasing concentration of TAN. The results improved our understanding of oxidative damage under ammonia exposure and provided data for the aquaculture of sunray surf clams.

Influence of Water Hardness on Chronic Toxicity of Potassium Chloride to a Unionid Mussel (Lampsilis siliquoidea).

Elevated concentrations of potassium (K) often occur in effluents from wastewater treatment plants, oil and gas production operations, mineral extraction processes, and other anthropogenic sources. Previous studies have demonstrated that freshwater mussels are highly sensitive to K in acute and chronic exposures, and that acute toxicity of K decreases with increasing water hardness. However, little is known about the influence of hardness on the chronic toxicity of K. The objective of our study was to evaluate the chronic toxicity of K (tested as KCl) to a commonly tested unionid mussel (fatmucket, Lampsilis siliquoidea) at five hardness levels (25, 50, 100, 200, and 300 mg/L as CaCO3 ) representing most surface waters in the United States. Chronic 28-day K toxicity tests were conducted with 3-week-old juvenile fatmucket in the five hardness waters using an ASTM International standard method. The maximum acceptable toxicant concentrations (geometric mean of the no-observed-effect concentration and the lowest-observed-effect concentration) increased from 15.1 to 69.3 mg K/L for survival and from 15.1 to 35.8 mg K/L for growth (length and dry wt) and biomass when water hardness was increased from 25 mg/L (soft) to 300 mg/L (very hard). These results provide evidence to support water hardness influence on chronic K toxicity to juvenile fatmucket. However, the chronic effect concentrations based on the more sensitive endpoint (growth or biomass) increased only 2.4-fold from the soft water to the very hard water, indicating that water hardness had a limited influence on the chronic toxicity of K to the mussels. These results can be used to establish chronic toxicity thresholds for K across a broad range of water hardness and to derive environmental guideline values for K to protect freshwater mussels and other organisms. Environ Toxicol Chem 2023;42:1085-1093. Published 2023. This article is a U.S. Government work and is in the public domain in the USA.

Acceptable Concentrations of Cu and Ni in Corrosion Resistance of Mg–6 mass% Zn Alloy

Cu and Ni impurities in Mg alloys are deleterious contaminants that reduce the corrosion resistance of the alloy. Mg2Cu and Mg2Ni precipitates can cause significant anodic dissolution of the Mg matrix, owing to their potential difference. Suppression of these phases can prevent the deterioration of corrosion resistance. The neutralization of these impurities through the formation of Mg–Zn intermetallic phases has been studied, because the atomic radii of Cu and Ni are similar to that of Zn. As a result, the MgZn2 phase may precipitate during the rapid cooling that occurs during the solidification of the Mg–6 mass% Zn alloy, and introduce substitutional impurity atoms in the crystal lattice. Mg(Zn, Cu)2 and Mg(Zn, Ni)2 phases can be formed instead of Mg2Cu and Mg2Ni, in the presence of both of Zn and these impurities. The microstructures and corrosion properties of the Mg–6 mass% Zn alloy with various Cu or Ni concentrations are investigated in this work. The Cu and Ni impurities are concentrated into MgZn2 phase in the Mg–6 mass% Zn alloy without Mg2Cu or Mg2Ni formation when the concentrations of these impurities are within acceptable limits. Consequently, the corrosion rate of the Mg–6 mass% Zn alloy with 1.4 mass% Cu or 0.25 mass% Ni is almost the same as that of the alloy without Cu and/or Ni contaminations.