Addition Of Selenium Research Articles

The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron

Sulfur, an element that belongs to group 16 (chalcogens) of the periodic table, is an excellent promoter of nucleation substrates for graphite in cast iron. In ductile iron, sulfur favors a higher nodule count, which inhibits the risk of carbides and of microporosity. It is reasonable to expect that other elements from group 16, such as selenium or tellurium, play similar roles in the nucleation of graphite. The objective of this paper was to investigate the effect of selenium on the process of graphite formation. Thermal analysis cups were poured to evaluate the nodule count and size distribution. Some of the cups were not inoculated, while others were inoculated with a Ce-bearing inoculant, or with the Ce inoculant and additions of Se. Cross-shaped castings were also poured to quantify the microporosity regions by tomography. It appears that selenium additions modify the number and size of graphite particles, as well as the volume of microshrinkage. Direct correlations between these three parameters were found. Advanced Extensive Field Emission Gun Scanning Electron Microscope (FEG-SEM) techniques were used to identify the nature of the main nucleation compounds. Selenides, combined with Mg and rare earths, were observed to serve as nuclei for graphite. Their presence was justified by thermodynamics calculations.

The Addition of Selenium to the Nutrient Solution Decreases Cadmium Toxicity in Pepper Plants Grown under Hydroponic Conditions

Cadmium is absorbed by plants rapidly and without control through the same channels as other essential metals, interfering with their transport and utilization. Many studies have shown that selenium could be utilized as a way to avoid this unwanted transport and other negative effects of Cd. For this reason, the present research study was conducted with four treatments (−Cd/−Se, +Cd/−Se, +Cd/+SeF, and +Cd/+SeR) to determine the type of application of Se that is best (foliarly and/or via the root) as regards the reduction of the toxic effects of Cd on plants. Our results showed that the Cd excess in the nutrient solution resulted in a decrease in the total dry biomass of the plants grown under these conditions, and this decrease was due to the reduction of the growth of the shoot (48% +Cd/−Se, 45% +Cd/+SeF, and 38% +Cd/+SeR, relative to −Cd/−Se). This reduction in growth was due to: (i) the toxicity of Cd itself and (ii) the nutritional disequilibrium suffered by the plants. It seems that under hydroponic conditions, the addition of Se to the nutrient solution, and therefore its absorption through the roots (lower antioxidant activity, superoxide dismutase, H2O2 concentration and higher catalase activity), greatly delayed and reduced the toxic effects of Cd on the pepper plants, as opposed to the foliar application of this element.

Vertical Gradient Freeze Growth of two inches Cd1−xZnxTe1−ySey ingots with different Se content

Two inches in diameter and four inches in length quaternary alloy Cd1−xZnxTe1−ySey (CZTS) ingots have been grown by the Vertical Gradient Freeze Method (VGF) for two different Se concentrations (y = 0.02 and 0.07). The compositional and crystallographic properties, as well as defect morphology of the ingots have been analysed using EDX, TXRF, XRD and IR microscopy. Despite of using these two extreme Se values proposed in the literature, CZTS continues to maintain the proper zinc blende structure of CZT. However, the addition of selenium has the effect of shifting the diffraction peaks to higher angles, or what is the same, to reduce the Cd1−xZnxTe (CZT) constant lattice. It is observed that the addition of Se also favours the reduction of bubble formation along the ingots due to cadmium deficiency and change in Zn concentration along the growth CZTS ingot direction respect to CZT ingot. The VGF growth method provides great confidence and reproducibility since both ingots share similar features in terms of dimensions and defects formation.

Combination of Selenium and UVA Radiation Affects Growth and Phytochemicals of Broccoli Microgreens.

Addition of selenium or application of ultraviolet A (UVA) radiation for crop production could be an effective way of producing phytochemical-rich food. This study was conducted to investigate the effects of selenium and UVA radiation, as well as their combination on growth and phytochemical contents in broccoli microgreens. There were three treatments: Se (100 μmol/L Na2SeO3), UVA (40 μmol/m2/s) and Se + UVA (with application of Se and UVA). The control (CK) was Se spraying-free and UVA radiation-free. Although treatment with Se or/and UVA inhibited plant growth of broccoli microgreens, results showed that phytochemical contents increased. Broccoli microgreens under the Se treatment had higher contents of total soluble sugars, total phenolic compounds, total flavonoids, ascorbic acid, Fe, and organic Se and had lower Zn content. The UVA treatment increased the contents of total chlorophylls, total soluble proteins, total phenolic compounds, and FRAP. However, the Se + UVA treatment displayed the most remarkable effect on the contents of total anthocyanins, glucoraphanin, total aliphatic glucosinolates, and total glucosinolates; here, significant interactions between Se and UVA were observed. This study provides valuable insights into the combinational selenium and UVA for improving the phytochemicals of microgreens grown in an artificial lighting plant factory.

INFLUENCE OF ORGANIC SELENIUM ON RABIES HUMORAL IMMUNE RESPONSE OF EWES

The objective was to evaluate the effectiveness of mineral supplementation with organic selenium (Se) on rabies humoral immune response in ewes. It was randomly selected 18 Texel ewes without antirabic vaccination in the last 12 months and divided into 2 groups: treated group (TG) supplemented with a mineral mixture additioned of organic selenium and immunized against rabies and a control group (CG) supplemented with mineral mixture without organic selenium addition and immunized. Determination of Se serum was obtained by the enzyme glutathione peroxidase (GSH-Px) activity in two moments, the title and the persistence of anti-rabies neutralizing antibodies in five times by the Rapid Fluorescent Focus Inhibition Test (RFFIT). The mean values found in D210 GSH-Px were higher in TG with 981.8 ± 105.2 U/g Hb and 628.2 ± 188.2 U/g Hb in the CG (p-value < 0.001). The mean values of titers of anti-rabies neutralizing antibodies 30 days after primary vaccination, demonstrated statistically similar titles in the GT and GC, 1,020 IU/ mL in GT and 1,885 IU/ mL CG. Oral mineral supplementation of organic selenium during 210 days did not enhance the humoral immune response and persistence of evidence of rabies neutralizing antibodies, however caused increased serum retention of selenium in ewes.

Evaluation of the influence of trace metals on methane production from domestic sewage, using the Plackett-Burman experimental design

Methanogenesis involves several enzymes with trace metal components that catalyze major metabolic pathways and, therefore, requires a sufficient supply of micronutrients such as iron, nickel or cobalt. The statistically-based Plackett-Burman experimental design was adopted in this study to identify which trace metal have a statistically significant effect on the maximum methane production from domestic sewage. The addition of Barium (Ba), Cobalt (Co), Copper (Cu), Iron (Fe), Manganese (Mn), Nickel (Ni) and Selenium (Se) was tested in batch reactors using domestic sewage as the substrate and sewage sludge as the inoculum. The results showed that the addition of Fe was statistically significant, positively affecting the maximum CH4 production (p-value 0.05). The results are expressed in L of CH4 per g of Chemical Oxygen Demand added, increasing it from 0.10 to 0.13 LCH4 gCODadd−1. In L of CH4 per g of Volatile Solids, increased it from 0.031 to 0.040 LCH4 gVS−1. The addition of Se was statistically significant, but with a negative effect on the maximum methane production (p-value 0.002), which decreased from 0.13 to 0.10 LCH4.gCODadd−1. Moreover, six different Fe concentrations (0, 40, 80, 120, 160 and 200 mgL−1) were tested, showing that the addition of 120 mgL−1 had the greatest effect for statistically improving the maximum methane production, with 33% improvement (0.12 ± 0.003 to 0.16 ± 0.012 LCH4 gCODadd−1) compared to no addition of Fe and the specific CH4 production to 0.040 ± 0.001 LCH4 gVS−1.

The effect of selenium on salinity stress and selenate – sulfate comparision in kale

Increased salinity is a threat to arid and semiarid zone agriculture worldwide. Kale consumption has increased as its nutritional and antioxidant benefits become more widely known. Compared with other vegetables, it is relatively salt tolerant. However, there is limited information on its salt tolerance, nutrient uptake under saline conditions, and physiological response. We examined the yield response, physiological parameters, and mineral nutrient content of kale grown under variable conditions of salt and Se addition in a greenhouse study. The experiment consisted of four salinity levels, four Se levels, and combined salinity treatments for a total of 16 treatments each with four replications. Salinity decreased yield when irrigated at 6 and 9 dS m−1 but not at 3 dS m−1. Selenium addition increased yield at all salinity levels but did not increase salt tolerance. Addition of 0.25 mg Se per kg of soil, corresponding to leaf Se concentrations of 1 mg kg−1, was sufficient to increase yield by an average of 11% relative to control. Kale yield loss began between 3 and 6 dS m−1 irrigation water salinity and 50% yield loss occurred at EC 6.

The use of Saccharomyces cerevisiae fermented coconut dregs with the addition of sodium selenite as a source of selenium in broiler diets

Fermentation has been practised in feed technology to bioconvert the inorganic minerals to organic compounds. A study was done to determine the effect of Saccharomyces cerevisiae fermented coconut dregs with the addition of selenium on growth performance, feed digestibility and the intestinal response of broiler chickens. The study used 112-day old unsexed broiler chicks for 6 weeks. The broilers were fed with 4 different experimental diets. The diets were basal diet (T1), basal diet plus 0.5% coconut dregs (T2), basal diet plus 0.5% of 5 days fermented coconut dregs (T3) and basal diet plus 0.5% of 7 days fermented coconut dregs (T4). The broilers were fed ad libitum and tap water was offered at all times. The broiler chicks were vaccinated against New Castle Diseases on the fourth day. Feeders and drinkers were placed inside the pen. The feeders, drinkers, pens and surroundings were cleaned whenever necessary. A completely randomized design was used in this study with four different treatment diets, four replicate cages of 7 birds each. The data found in this study was analyzed using an analysis of variance. A Tukey test was applied once a significant effect was detected in the analysis of variance. Results of the study indicate that body weight gain and dry matter digestibility increased when the birds were fed the diets T3 and T4. The relative gizzard weight of birds fed the T3 and T4 was lighter than the birds fed the T1 and T2. Feed intake, feed conversion ratio, carcass percentage and relative intestine weight were not affected by the experimental diets. In conclusion, feeding the birds with diets supplemented with Saccharomyces cerevisiae-fermented coconut dregs with additional selenium improved feed quality and broiler performance.

The use of various forms of selenium in aquaculture

A study of the scientific literature on the use of nanotechnology methods for the cultivation of various aquaculture facilities has been generalized. The study was based on the addition of selenium to the diets of various shapes and origins.It is emphasized that modern scientific research on the use of nanoparticles in aquaculture emphasizes the accuracy of delivery and the appropriate number of trace elements, which in turn may reduce the cost of aquaculture products. It is pointed out that it is necessary to take into account the specifics of modern industrial aquaculture technologies, in which aquatic organisms are grown at high planting densities in pools, that means are constantly under stress, and one of the most common forms of stress leading to reduced productivity in aquaculture is oxidative stress. The review noted that selenium is one of the important micronutrients that can reduce the negative effects of oxidative stress. Studies by a number of authors on the positive effects of adding various forms of selenium to the diets of major aquaculture facilities have been analyzed. It is determined that biologically synthesized nanoselenium can be added to various commercial fish feeds to increase stress resistance and productivity of aquatic organisms, in addition, this product will meet the environmental needs of consumers. The advantage of using organic forms of selenium in aquaculture over inorganic ones has been established, as the former have higher bioavailability and better accumulation in fish tissues. A number of studies related to the determination of the toxic effects of various forms of selenium and its concentrations on aquatic organisms have been studied. It is emphasized that in aquaculture it is necessary to take into account that selenium particles must be non-toxic not only for the biological object itself, but also for other systems that are closely related to its vital activity. Key words: selenium, nanotechnology, aquaculture, fish, stress resistance, toxicity, growth rate, physiological indicators, immunological indicators.

Mid-infrared single-Mode As-S-Se glass fiber and its supercontinuum generation

Two kinds of single-mode (SMF) step-index(SIF) chalcogenide fibers based on S-rich and S-poor As-S-Se glass have been fabricated successfully by an isolated extrusion method. We experimentally explored the effects of S and Se weights on the IR light transmission in the infrared area of the waveguide medium. By exploring the infrared transmission. It is found that the As-S-Se system has a transmission varied range between full S-based (As2S3) and full Se-based (As2Se3) glasses. The results show that with the addition of selenium, the red-shift is observed in both the short-wavelength absorption edge and long-wave cut-off wavelength. This phenomenon can be sourced from the varying of optical band gaps and phonon energies. Simultaneously, single-mode fibers was employed to evaluate the attenuation and supercontinuum(SC). We found that S-rich fiber shows a lower optical loss of 0.67–1.5 dB/m in 4.1–5.9 μm region, with a minimum value of 0.67 dB/m at 4.6 μm than that of S-poor fiber does. Yet, the SC results of S-poor fiber shows a flatter and broader spectrum region than that of S-rich fiber does.

Impact of selenium addition to the cadmium-zinc-telluride matrix for producing high energy resolution X-and gamma-ray detectors

Both material quality and detector performance have been steadily improving over the past few years for the leading room temperature radiation detector material cadmium-zinc-telluride (CdZnTe). However, although tremendous progress being made, CdZnTe still suffers from high concentrations of performance-limiting defects, such as Te inclusions, networks of sub-grain boundaries and compositional inhomogeneity due to the higher segregation coefficient of Zn. Adding as low as 2% (atomic) Se into CdZnTe matrix was found to successfully mitigate many performance-limiting defects and provide improved compositional homogeneity. Here we report record-high performance of Virtual Frisch Grid (VFG) detector fabricated from as-grown Cd0.9Zn0.1Te0.98Se0.02 ingot grown by the Traveling Heater Method (THM). Benefiting from superior material quality, we achieved superb energy resolution of 0.77% at 662 keV (as-measured without charge-loss correction algorithms) registered at room temperature. The absence of residual thermal stress in the detector was revealed from white beam X-ray topographic images, which was also confirmed by Infra-Red (IR) transmission imaging under cross polarizers. Furthermore, neither sub-grain boundaries nor their networks were observed from the X-ray topographic image. However, large concentrations of extrinsic impurities were revealed in as-grown materials, suggesting a high likelihood for further reduction in the energy resolution after improved purification of the starting material.

The influence of selenium additives in compound feed on the chemical composition, energy and biological value of ducklings meat

According to modern classification of trace elements, which is based on their biological significance for living organisms, selenium is classified as a group of vital or biogenic elements. As a biotic element, it has unique physico-chemical and biochemical properties and, with adequate intake into the body of farm animals and poultry has a positive effect on a number of physiological processes. The discovery of biological properties of selenium became the basis for its use first in the prevention and treatment of many diseases associated with a deficiency of this trace element, and later – as a stimulator of growth and development of young animals, as well as in order to increase egg production, poultry safety, improve the incubation characteristics of eggs and several other productive qualities. Scientists who have studied the effects of selenium on poultry have paid relatively little attention to meat quality. The effect of additives of different selenium doses in compound feed on the chemical composition, energy and biological value of Ukrainian white breed ducklings’ meat was studied in the scientific and economic experiment. Four groups of ducklings with 100 heads in each groups were formed to conduct the scientific and economic experiment. The duration of the experiment was 56 days and corresponded to the period of raising ducklings for meat. The ducklings of the first control group did not receive selenium supplementation. Selenium was additionally introduced into compound feed for poultry of the experimental groups in the following amount, mg/kg: the second group – 0.2; the third – 0.4 and the fourth – 0.6. It was established that the introduction of selenium into compound feed in the studied dose did not significantly affect to the quality of ducklings’ meat, although it had a positive effect on some indicators that characterize its chemical composition, nutritional and biological value. Among the experimental groups, ducklings of the third and fourth groups, which were injected with selenium into compound feed at the rate of 0.4 and 0.6 mg/kg, stood out in terms of meat quality.

The effect of the addition of nano selenium and vitamin E on productive performance and the characteristics of the physical and chemical carcass of broilers

This experiment was conducted in private poultry farms / Sharqat district during the period from 8/15/2020 to 19/9/2020 The aim of this study is to find out the effect of adding two levels of nano-selenium and securing E in the diet on productive, physiological and immunological performance in addition to the carcass’s physical and chemical characteristics. For meat broilers (Ross 308.) 234 birds of broiler meat were used in the experiment (Ross 308), one day old, not nationalized and equipped from the Mardin company hatchery / Erbil governorate and distributed randomly into 6) factors for each treatment (3) replicates of (13) birds for each Duplicate. The first treatment was the control treatment and the second treatment was a basic diet to which a supplement of nano-selenium was added at a concentration of 0.25 mg / kg, and the third treatment was a basic diet to which a supplement of nano-selenium was added at a concentration of 0.35 mg / kg, and the fourth treatment was a basic diet to which a supplement was added with a supplement with a vitamin E at a concentration of 300 mg / kg. The fifth and sixth are basic diets to which add nano-selenium at a concentration of 0.25 and 0.35 mg / kg + with insurance E at a concentration of 300 mg / kg, respectively. The results of the statistical analysis indicated that there were no significant differences in the production performance at this level of nano-selenium and vitamin E, while it showed The fifth treatment was significantly higher in the amount of feed consumed in the first and fourth weeks. As for the results of the statistical analysis of blood tests, it indicated that the number of red blood cells, the size of compact cells, and the hemoclopin ratio of the trial treatments improved significantly compared to the control treatment, while the white blood cells and lymphocytes showed significant differences (P ≤ 0.05) compared to the control treatment. As for the biochemical characteristics, we note that All treatments significantly outperformed (P ≤ 0.05) over the control treatment, but no significant differences were observed between the experimental treatments in the characteristic of low-density lipoproteins. As for the physical properties of the meat, there were significant differences (P ≤ 0.05) in favor of the nano-selenium treatments, where the sixth treatment recorded the highest concentration of selenium in the breast meat tissue, while the second, fourth and fifth treatments recorded a significant decrease (P ≤ 0.05) in the pH of the meat compared with the control treatment. This reduces the microbial activity and prolongs the storage and preservation period of meat, and in the chemical properties the results indicated the presence of significant differences (P ≤ 0.05) in the percentage of protein, moisture, fat and ash, and therefore our results showed that the use of nano-selenium and vitamin E led to the improvement of most of the biochemical and immunological properties of blood, in addition to To improve the physical and chemical properties of broiler carcasses.

Generator of an H2Se–H2 Mixture, Based on Packing with Selenium Reflux. Part 1. Development of the Design and Experimental Study of the Generator

Generators of an H2Se–H2 mixture, based on a packing with liquid selenium reflux and addition of selenium from an external source, are considered. Generators of such type can be used in various processes including those requiring prolonged continuous generation of a mixture with highly stable characteristics, which cannot be ensured by generators of other types. The best procedures for selenium addition and reflux were found; they consist in controlled supply of the starting selenium from an external source through an H2 inlet tube directly into the reactor boiler, wherefrom it evaporates in the boiling mode, ascends to the higher-lying synthesis and condensation zones, and participates in the selenium circulation in the form of countercurrents of the vapor and melt reflux in the packing. Procedures were determined for continuous determination of the molten selenium level in the boiler using a combined thermocouple with several junctions in the zone of possible position of the level and of the characteristics of the generated mixture using rotameters at the generator inlet and outlet. It is possible and appropriate to make the generators of quartz glass. The best generator designs were found. Problems arising in the development and practical use of generators of this type were considered, and ways to solve them were suggested.

Вплив прооксидантно-антиоксидантного гомеостазу на функціональну активність сперміїв кнурів за корекції мінерального живлення

The use of chelated compounds of trace elements as an alternative to mineral salts can increase their conversion, reduce the content in feed and prevent environmental pollution. However, it remains relevant to study the effect of these substances on the reproductive capacity of pigs. The aim of the study was to determine the effect of prooxidant-antioxidant homeostasis (PAH) on the functional activity of sperm of boars in the correction of mineral nutrition. The study used adult boars of the Large White breed. The duration of the experiment was 120 days, including: preparatory - 30, basic - 60 (feeding lactates of Zinc, Selenium, Copper and Iron) and final - 30 days. In the main period of the experiment, the diet of animals in the control group remained unchanged, and two experimental were with the addition of lactates Zinc, Selenium, Copper and Iron. The level of biologically active components in the diet of the experimental groups was higher by 10% and 20% compared with the control group. In the obtained blood samples it was determined the state of PAG. The functional activity of sperm in stored spermatozoa at 170C after 3 hours of incubation was determined by their activity and survival by testing for heat resistance, heat stress resistance, the number of anomalies and the integrity of acrosomes. It was found that the introduction of lactates of Zinc, Selenium, Copper and Iron in the feed mixture to boars significantly changes the state of PAG in blood depending on the number of additionally fed lactates of trace elements. The addition of these biologically active substances by 10% above the norm after 60 days of feeding helps to preserve the content of antioxidant vitamins, reduced glutathione, stimulates the functional activity of superoxide dismutase by 50% and catalase by 23.6% and is accompanied by a slight decrease in peroxidation processes. conjugates and TBC-active complexes. The addition of lactates of micronutrients to the feed mixture is by 20% more than norma for boars, compared with the control group, after 30 days of use stimulates peroxidation, accompanied by intensive use of non-enzymatic - vitamin A (p <0,05-0,01) and activation of enzymatic antioxidants - superoxide dismutase (p <0.05-0.01) and catalase, which lasts for 90 days. The viability of sperm is significantly correlated with the number of additionally fed lactates of trace elements. The addition of these biologically active substances by 10% more than normal after 60 days of feeding helps to increase the functional activity of sperm for 3 hours at a temperature of 170C storage, heat resistance (p <0.05), heat stress resistance, increases their ability to fertilize. The addition of lactates of micronutrients in the feed mixture is by 20% more than the norm for boars in comparison with the control group after two months of feeding increases the number of pathological forms of sperm (p <0,005), acrosome damage (p <0,05), reduces heat resistance and heat stress resistance of sperm <0.05), which reduces their fertility. It was found the fact that the processes of peroxidation in blood of boars are significantly interrelated with the functional activity of sperm in stored spermatozoa. The content of primary and secondary peroxidation products significantly correlates with the fertilizing ability of sperm in the range of r = 0.95… 0.99. The activity of superoxide dismutase and catalase are significantly interrelated with the fertilizing ability of sperm: in animals of the second group, the correlation coefficients were respectively r = 0.98 and r = 0.97, the third - r = 0.12 and r = 0.96, the first - r = - 0.58 and r = 0.80.

GLS-Se optical fibre from extruded glass structured preforms and rods for the IR region

Depending on composition, chalcogenide glasses have been proven as a reliable medium to transmit light in the range from the visible to the long-wave infrared (LWIR), specialty glasses based on gallium lanthanum sulfide (GLS) with a selenium (Se) addition. This family of glasses offers a broad transparency window depending on the composition. Their optical, mechanical, and thermal properties have been exploited in their bulk form. In this paper, we demonstrate the fabrication of optical fibres from extruded structured (core-clad) preforms and rods, with an emphasis on maintaining the intrinsic characteristics of the glass and exploiting the optical fibre geometry for light delivery.

Selenium-enriched Lactobacillus plantarum improves the antioxidant activity and flavor properties of fermented Pleurotus eryngii

The effects of selenium (Se) addition methods on antioxidant activity and flavor properties of fermented Pleurotus eryngii (P. eryngii) using Lactobacillus plantarum (L. plantarum) inoculated and natural fermentation were investigated. After fermentation, the Se-enrichment rates in fruiting bodies of Se-added fermented P. eryngii were all more than 50%. Se addition, especially in the form of Se-enriched L. plantarum inoculation, had a significantly positive effect on total phenolic content and DPPH radical scavenging activity. Non-volatiles analysis revealed that the highest ration of lactic acid to acetic acid and the highest umami intensity were observed in P. eryngii fermented by inoculating Se-enriched L. plantarum (Lp-Se). Principal components analysis and cluster analysis of volatiles clearly separated Se-treated and plain experiments, which mainly due to dissimilarities in alcohols, aldehydes and ketones. Additionally, Lp-Se obtained the highest alcohols, especially 1-octen-3-ol with mushroom flavor. In short, Se-enriched L. plantarum inoculation could produce high-quality fermented P. eryngii.

Effects of Administration of Sildenafil Citrate on the Histological Structure of the Testis and the Possible Protective Rule of Selenium in Adult Albino Rat by Histological and Immuno-Histological Methods

Abstract Background: Sildenafil citrate is used for the treatment of erectile dysfunction as it maintains a long lasting erection. This drug causes nitric oxide release from the penile tissue as it acting as phosphodiestrase-5 inhibitor causing erection. Selenium plays an essential micronutrient for humans and animals acting as anti-oxidant. Aim of Study: To study the possible protective effects of selenium on the testis of the albino rats treated with sildenafil citrate by light microscopic examination and immuno-histological study. Material and Methods: Thirty adult albino rats were obtained and isolated at Faculty of Medicine, Assuit University in 2017. The animal were divided into three equal groups: group I (control group), group II; received sildenafil citrate orally in a dose of 10mg/kg body weight for 8 weeks, group III: Received selenium in a dose of 10 microgram/kg orally 8 weeks before the treatment with sildenafil citrate. Sildenafil was obtained in the form of commercially packed tablets (Viagra). Each tablet contains 100mg of sildenafil. The tablet was grinded and dissolved in 50ml saline; hence each ml of the solution contains 2mg of the drug. Each rat received 1.25ml of the prepared solution. Selenium was obtained in the form of commercially packed tablets (selenium). Each tablet contains 60 micro-grams. The tablet was grinded and dissolved in 30ml of saline, hence each ml of the solution contains 2 microgram of the drug. Each rat received 1.25ml of the prepared solution. At the end of the experiment, the testes were obtained and subjected to the light microscopic and immuno-histochemical studies using Fas-Ligand stain for detection of apoptotic cells. Results: Administration of sildenafil citrate results in loss of the normal pattern of the germinal epithelium, thickening of the connective tissue capsule and loss of some of the germinal cells. The spermatogonia appear away from the basement membrane with pyknotic nucleus and vacuolated cytoplasm. The spermatogenic cells appear with pyknotic nuclei and vacuolated cytoplasm. The interstitial tissue shows acidophilic exudates, congested blood vessels and some of the tubules appear empty. With the usage of the immuno-histochemistry, there is an increase in the number of apoptotic cells. Addition of selenium partially restored the normal contour of the tubules and normal distribution of the germinal epithelium. The thickness of the connective tissue capsule appears nearer to the normal thickness. With the usage of the immuno-histochemistry, there is a decrease in the number of apoptotic cells. Conclusion: - Sildenafil citrate has a toxic effect on all of the germinal cells. - Administration of selenium partially improves these toxic effects.

Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials

ABSTRACTBackgroundAntioxidants have been promoted for cardiovascular disease (CVD) risk reduction and for the prevention of cancer. Our preliminary analysis suggested that only when selenium was present were antioxidant mixtures associated with reduced all-cause mortality.ObjectiveWe conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the effect of selenium supplementation alone and of antioxidant mixtures with or without selenium on the risk of CVD, cancer, and mortality.MethodsWe identified studies using the Cochrane Library, Medline, and Embase for potential CVD outcomes, cancer, and all-cause mortality following selenium supplementation alone or after antioxidant supplement mixtures with and without selenium up to June 5, 2020. RCTs of ≥24 wk were included and data were analyzed using random-effects models and classified by the Grading of Recommendations, Assessment, Development, and Evaluation approach.ResultsThe meta-analysis identified 9423 studies, of which 43 were used in the final analysis. Overall, no association of selenium alone or antioxidants was seen with CVD and all-cause mortality. However, a decreased risk with antioxidant mixtures was seen for CVD mortality when selenium was part of the mix (RR: 0.77; 95% CI: 0.62, 0.97; P = 0.02), with no association when selenium was absent. Similarly, when selenium was part of the antioxidant mixture, a decreased risk was seen for all-cause mortality (RR: 0.90; 95% CI: 0.82, 0.98; P = 0.02) as opposed to an increased risk when selenium was absent (RR: 1.09; 95% CI: 1.04, 1.13; P = 0.0002).ConclusionThe addition of selenium should be considered for supplements containing antioxidant mixtures if they are to be associated with CVD and all-cause mortality risk reduction. This trial was registered at https://www.crd.york.ac.uk/PROSPERO/ as CRD42019138268.

Influence of Organic Selenium Application in Concentrate Mixtures on Selenium Content in Blood Plasma and Duck Feces

The aim of this study was to investigate the effect of the addition of different amounts of organic selenium (ALKOSEL® R397) in concentrate mixtures on the selenium content in the blood plasma and feces of ducks. The experiment was performed on 240 one-day-old ducklings (Cherry Valley) which were freely selected into 4 groups, one control K0 group, and three experimental K1, K2 and K3 groups. In two phases of feeding in fattening, ducklings were fed with two and nutritionally different concentrate feed mixtures: starter (from 1 to 14 days) and finisher (from 15 to 49 days of fattening). The control group of ducklings (K0) during feeding received food without added organic selenium in both phases of fattening. In both phases of fattening, the experimental group of ducks K1 was fed with food as well as the control group, but with the addition of 0.2 mg/kg of organic selenium, while the experimental group K2 used food with 0.4 mg/kg, and the experimental group K3 with 0.6 mg/kg of organic selenium. The addition of organic selenium to duck feed had the effect of increasing selenium content in both blood plasma and duck feces. The highest content of selenium in blood plasma and feces was determined in the group of ducks that received the highest amount of organic selenium through food during the entire experiment.