Effects of environmental hypercapnia on hemato-immunological parameters,carbonic anhydrase,and Na+, K+-ATPase enzyme activities in rainbow trout (Oncorhynchus mykiss) tissues

In this study, the effects of environmental hypercapnia on hemato-immunological parameters and the activities of respiratory enzymes such as carbonic anhydrase (CA) and Na⁺, K⁺-ATPase were investigated in rainbow trout (Oncorhynchus mykiss) tissues (gill, liver and kidney). Batches of 12 fish were exposed to 4.5 mg L^?1 (control) and 14 mg L^?1 CO₂. No mortalities occurred during the 14 days of the experimental period. Red blood cell (RBC), hemoglobin (Hb), and hematocrit (Ht) levels, and innate immune parameters such as nitro blue tetrazolium (NBT), lysozyme, and myeloperoxidase activities, and the melano-macrophage frequency were negatively affected by elevated CO₂ levels. Patterns of change in CA activity differed among the gill, liver, and kidney. Compared with the activities of CA in the control group, the CA enzyme was significantly stimulated at day 7 in the gill tissue, whereas it was stimulated at day 14 of the experiment in the liver tissue of fish exposed to 14 mg L^?1 CO₂ (P < 0.05). In contrast to the pattern of CA enzyme activities, the Na⁺, K⁺-ATPase enzymes were stimulated significantly in the liver after day 7 but inhibited in the kidney and gill (P < 0.05). These results suggest that a subchronic exposure to hypercapnia of rainbow trout tissues may lead to adaptive changes in the respiratory enzymes and negatively affects hemato-immunological parameters.     

In vitro assessment of genotoxic and oxidative effects of zinc borate

Zinc borate is used as flame retardant for plastics and cellulose fibers, paper, rubber, and textiles. Despite its wide industrial use, there is limited information concerning its toxicity. The aim of the present study was to investigate the concentration dependence (0–280 mg L^?1) of its genotoxic activity on cultured human lymphocytes by using sister chromatid exchange and chromosomal aberration assays. Total antioxidant capacity and the extent of oxidative stress were also determined. Zinc borate was found to be non-genotoxic at all tested concentrations. It exhibited antioxidant activity at concentrations lower than 40 mg L^?1, and total oxidative stress levels were not changed at any applied concentration of zinc borate.     

Biosynthesis and Characterization of Poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) from Bacillus cereus S10

The biodegradable and biocompatible copolymer poly-(3-hydroxybutyrate-co-5 mol% 3-hydroxyvalerate), poly-(3HB-co-5 mol% 3HV), was synthesized by Bacillus cereus S10 and the highest yield was determined as 69.91 % at pH 7 and 30 °C after 48 h of incubation using a glucose as the sole carbon source. Poly-(3HB-co-5 mol% 3HV) was purified from bacterial biomass using chloroform. FTIR analysis showed absorption bands at 1,723, 1,274, 1,373, 1,453, 2,932 cm^?1 corresponding to C=O, C–O stretching, CH₃, –CH₂ and –CH groups, respectively. ¹H-NMR and ¹³C-NMR analysis confirmed that the copolymer was composed of 95 mol% of 3-hydroxybutrate and 5 mol% of 3-HV monomeric units. Poly-(3-HB-co-5 mol% 3HV) was used for nanoparticles preparation. The diameter of nanoparticles was 202 nm.     

Abundance,characteristics, and spatial–temporal distribution of microplastics in sea salts along the Cox’s Bazar coastal area,Bangladesh

Environmental Science and Pollution Research - Microplastics (MPs), together with microfibers, have emerged as a contaminant of concern all around the globe. MPs have been detected in freshwater,...     

Real‐Time Analysis of Energy Generation of a Photovoltaic System Installed in the City of Lajeado,Rio Grande do Sul

Considering successive and costly increases in electricity rates, this article evaluates the generation of electricity from a photovoltaic system using solar energy, a renewable source. The solar photovoltaic system is installed at UNIVATES University Center, a public university in the state of Rio Grande do Sul, Brazil, and it is also connected to the electrical grid. Data related to the climatic conditions of the location, such as incident solar radiation, rainfall, and mean temperature, were obtained during the system's evaluation period and used along with bibliographic research on similar systems installed in southern Brazil. Our study quantified the energy produced over one calendar year (2014) and related it to the climatic variables and the conversion efficiency achieved by the system's photovoltaic modules. Our results show that there is both a strong relationship between the production of energy and climatic conditions and that the city, Lajeado, and the Brazilian state of Rio Grande do Sul, have good potential to supply energy using photovoltaic systems connected to the electrical grid. The horizontal global solar radiation average obtained in the study location was 4.14 kilowatts per square meter per day (kWh/m²/day), and the average monthly production of energy reached 243.93 kWh/m²/month, with a total of 2,927.10 kWh produced in 2014, achieving a monthly average conversion efficiency of 11.07%. This conversion efficiency is close to the value of 12.6% obtained in 2013 in a similar study of the same solar photovoltaic system conducted over a shorter time period.     

A comparative study of trace metals in male and female Caspian kutum (<Emphasis Type="Italic">Rutilus frisii kutum</Emphasis>) from the southern basin of Caspian Sea

This study focuses on the extent of zinc (Zn), copper (Cu), cadmium (Cd), cobalt (Co), manganese (Mn), lead (Pb), mercury (Hg), and arsenic (As) bioaccumulation in edible muscles of Caspian kutum (Rutilus frisii kutum), in both male and female sexes at Noor and Babolsar coastal regions from the southern basin of Caspian Sea. These values were compared with the WHO and the UNFAO safety standards regarding the amount of the abovementioned heavy metals in fish tissues (mg/kg ww). Results showed that the accumulation of these elements (except for Zn) was not significantly different between sexes of male and female in Babolsar coastal regions (P?>?0.05). In the other hand, accumulation of Hg and As at edible muscles of Caspian kutum has significant difference between two sexes of male and female in Noor coastal regions (P?<?0.05), the female had higher concentration than the male. Furthermore, it was not significantly correlated with sex and rivers in length and weight of fish (R ²?<?0.50; P?>?0.05). Based on the results, the concentration of heavy metals in the studied fish tissues proved to be significantly lower than international standards (P?<?0.05), so its consumption is not a threat to the health of consumers.     

Effect of PCM on temperature fluctuation during the door opening of a household refrigerator

Temperature fluctuation inside the cabinet of a household refrigerator significantly affects the quality of preserved food. Phase change material (PCM) is a latent heat storage system that can store and release the heat energy by changing its phase from liquid to solid and solid to liquid respectively. Therefore, use of PCM inside the refrigerator cabinet has the potential for minimizing the temperature fluctuation during the door opening and the power failure. However, very few studies in the literature were dedicated to investigating the role of PCM to reduce the temperature fluctuation. The aim of this work is to experimentally investigate the effects of PCM on temperature fluctuation inside the cabinet of a household refrigerator during the door opening and power failure. The results found that a significantly lower temperature fluctuation can be obtained using PCM. It was found that during the door opening condition the air temperature in the cabinet rose rapidly. However, when a PCM container was used, temperature variation was reduced to 3–5°C. During the power failure, the system with PCM maintained a lower temperature inside the storage chamber for a long period of time (about 2 hours). Moreover, the test results indicate that PCM maintains more stable temperature in the foodstuffs inside the refrigerator. This reduction of temperature fluctuation ultimately improves the quality of preserved food.     

Evaluation of the interaction between soil and antibiotics

The aim of this study was to investigate the occurrence of tetracycline and sulfonamide antibiotics in 13 different soil samples collected from agricultural fields. As well as the antibiotic analysis 18 different physicochemical properties of the soil samples were determined in order to establish a relationship between the recovery rates of antibiotics from the samples and the characteristics of the samples that provide critical information for the reliability of an applied antibiotic analysis method. While the concentrations of tetracyclines were 0.025–0.105 mg kg^?1 sulfonamide antibiotics were not detected in any investigated soil samples. The mean recovery rates of tetracyclines and sulfonamides were 84.57 ± 14.92% and 65.88 ± 8.56%, respectively. Although, the organic carbon contents and cation exchange capacities of the soil samples exhibited a great variation the results of multivariate statistical analysis indicated that the metal content of soils was the major factor significantly influenced the recovery rates of the antibiotics. The sulfonamide recovery rates were positively influenced by the calcium and magnesium amounts in the soil samples, whereas tetracycline recovery rates were markedly diminished by increasing the amount of these polyvalent metals.     

Interconversions and toxicity changes in hexachlorocyclohexane isomers on dispersion in water

Abstract

Studies on the transformations of hexachlorocyclohexane isomers, α‐, β‐, γ‐ and δ‐, in aqueous solution were carried out at 25 ± 1°C over a period of four weeks. Gas liquid chromatographic technique was used for analysis. The results indicated a loss as well as interconversion of all the four isomers with time. The resulting changes in toxicity of the aqueous solution were studied against Drosophila using topical application. Toxicity studies with aqueous solution of technical hexachlorocyclohexane were simultaneously carried out for comparison. Toxicity of the aqueous solutions of α‐, β‐, and δ ‐isomers showed an increase while that of the γ‐isomer decreased significantly during the four week experimental period. Aqueous solution of technical HCH was equally toxic as that of the γ‐isomer initially and did not show much decrease in its toxicity at the end. Changes in toxicity of the individual isomer solutions were considered to be due, in part, to interconversions of HCH isomers.     

Assessment of imidacloprid toxicity on reproductive organ system of adult male rats

In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.