High Se Research Articles

Carbon nanotubes/cellulose composite aerogels with controllable microstructure for electromagnetic interference shielding

AbstractIn this work, isotropic cellulose aerogels with microstructure from three‐dimensional (3D) sheet‐networks to 3D nanofibrous networks are obtained by adjusting the tertiary butanol content and using the homogenous freezing method. When changing the freezing method to unidirectional freezing, the microstructure of cellulose aerogels transforms from isotropic to oriented fibrous network structure. The mechanical performance of cellulose aerogels presents microstructure‐dependent behavior. Furthermore, serviceable conductivity and electromagnetic interference (EMI) shielding performance are imparted to cellulose aerogels by uniformly dispersing carbon nanotubes (CNTs) into cellulose matrixes. With the same CNT content (10 wt%), oriented CNTs/cellulose composite aerogels show higher EMI shielding efficiency (EMI SE) than that of isotropic composite aerogels. One possible reason is that oriented composite aerogels can reflect and absorb the electromagnetic waves much more times along the freezing direction. The specific SE (716 dB cm3 g−1) of oriented composite aerogel is higher than that of isotropic composite aerogel (539 dB cm3 g−1), which is the reason that oriented composite aerogel has lower density and higher SE. These advantages of lightweight, controllable microstructure, adjustable EMI shielding performance give CNTs/cellulose composite aerogels broad application prospects in the field of EMI shielding.

Effect of selenium accumulation on foraging behavior of pollinators and seed yield in Trifolium alexandrinum L.

Selenium (Se) is an essential nutrient for both plants and animals and is usually provided as a supplement to livestock. Se bioaccumulation promotes plant growth by enhancing the accumulation of organic solutes and the activation of antioxidant system. In animals, the Se supplements reduce the chances of mastitis and white muscle disease, and improve the immunity, health, and reproduction, particularly in lactating dairy cows. Therefore, the enrichment or biofortification of fodder crops with Se may improve the nutritional quality of forages and thereby reduce malnutrition in cattle. However, Se hyper-accumulation in plants or plant parts can cause direct toxic effects on insects especially bees. Berseem is a highly cross-pollinated fodder crop that attracts a large number of pollinators. However, little or no reports are available regarding the effects of Se biofortification on the foraging behavior of pollinators in berseem. Therefore, the current study was planned to evaluate the effect of exogenous application of Se on the foraging behavior of native pollinators visiting the berseem crop. Five different doses of Se were applied to evaluate its effect on abundance, foraging behavior (visit duration and visitation rate), and single-visit efficacy of native pollinators that may affect berseem seed yield. Our results showed maximum abundance of pollinators in plants supplemented with low Se level, i.e., 5gha-1 while the minimum abundance was observed at high Se doses (15 and 20gha-1). Also, the seed yield attributes, i.e., the number of seeds per head, seed weight per head, 1000 seed weight, were the highest in plants treated with a low dose of Se, whereas the seed yield of berseem decreased with an increase in Se concentrations. Hence, our study provides evidence that high doses of Se negatively affect the foraging behavior of pollinators (visitation rate and visit duration) in plants. We conclude that the application of moderate Se dose positively influences the pollination ecology of berseem, consequently improving seed yield. HIGHLIGHTS: Selenium (Se) is essential for animals and beneficial for plants and may become toxic at high level. Se is delivered to the environment due to agriculture. Se toxicity affected berseem growth and considerably reduced the seed yield. High dose of Se reduced the abundance of pollinators and negatively affected their foraging behavior.

Proteome profiles during early stage of somatic embryogenesis of two Eucalyptus species

BackgroundSomatic embryogenesis (SE) was recognized as an important tool for plants to propagate. However, our knowledge about the proteins involved in early SE including the callus dedifferentiation is still limited, especially in the economic woody tree – Eucalyptus.ResultsWe used the data-independent acquisition mass-spectrometry to study the different proteome profiles of early SE of two Eucalyptus species—E. camaldulensis (high regeneratively potential) and E. grandis x urophylla (low regenerative potential). Initially, 35,207 peptides and 7,077 proteins were identified in the stem and tissue-culture induced callus of the two Eucalyptus species. MSstat identified 2,078 and 2,807 differentially expressed proteins (DEPs) in early SE of E. camaldulensis and E. grandis x urophylla, respectively. They shared 760 upregulated and 420 downregulated proteins, including 4 transcription factors, 31 ribosomal proteins, 1 histone, 3 zinc finger proteins (ZFPs), 16 glutathione transferases, 10 glucosyltransferases, ARF19, WOX8 and PIN1. These proteins might be involved in the early SE of Eucalyptus. By combining the miRNA and RNA-Seq results, some miRNA ~ gene/protein regulatory networks were identified in early SE of Eucalyptus, such as miR160 ~ TPP2, miR164 ~ UXS2, miR169 ~ COX11 and miR535 ~ Eucgr.E01067. Further, we found SERK, WRKY, ZFP and ABC transporter might be related with high SE potential.ConclusionsOverall, our study identified proteins involved in the early SE and related to the high regeneration potential of Eucalyptus. It greatly enhanced our understanding of the early SE and the SE capacity of Eucalyptus.

Suitable Models for Describing Sulphate Desorption Kinetics in Selected Bauchi North Soils of Varying Parent Materials in the Nigerian Sudan Savanna

The modelling of sulphate desorption data is critical for a proper S diagnosis and fertilizer formulation to ensure profitable crop production. Five (5) models such as first-order, second-order, Elovich, fractional power, and parabolic diffusion were used to test the best model describing sulphate desorption kinetics in some soils from Bauchi-north, Sudan Savanna, Nigeria. To achieve this, soil samples were collected from three different parent materials namely Basement complex rock and two sedimentary rocks (Kerri-Kerri Formation and Chad Formation). The study showed that the parabolic diffusion and first-order models were found to describe S desorption data satisfactorily, characterized by relatively high R2 values and lowest S.E values by soil parent materials, respectively. While, the second-order, Elovich and Fractional power equations failed to describe the kinetics desorption of sulphate in all the studied soils, as judged by their high SE values. Therefore, the better fit of S desorption data to the first-order equation is an indication of probable ligand exchange of sulphate ion during the desorption process, and to parabolic diffusion equation suggests that diffusion-controlled phenomena are rate-limiting steps. Based on the findings, we concluded that the rate of sulphate desorption kinetics in these soils is mainly controlled by diffusion-controlled phenomena, which is critical for sulphate-based fertilizer formulations and applications.

Integrated eco-physiological, biochemical, and molecular biological analyses of selenium fortification mechanism in alfalfa.

Foliar Se (IV) application at 100mg/kg can act as a positive bio-stimulator of redox, photosynthesis, and nutrient metabolism in alfalfa via phenotypes, nutritional compositions, biochemistry, combined with transcriptome analysis. Selenium (Se) is an essential element for mammals, and plants are the primary source of dietary Se. However, Se usually has dual (beneficial/toxic) effects on the plant itself. Alfalfa (Medicago sativa L.) is one of the most important forage resources in the world due to its high nutritive value. In this study, we have investigated the effects of sodium selenite (Se (IV)) (0, 100, 200, 300, and 500mg/kg) on eco-physiological, biochemical, and transcriptional mechanisms in alfalfa. The phenotypic and nutritional composition alterations revealed that lower Se (IV) (100mg/kg) levels positively affected alfalfa; it enhanced the antioxidant activity, which may contribute to redox homeostasis and chloroplast function. At 100mg/kg Se (IV) concentration, the H2O2, and malondialdehyde (MDA) contents decreased by 36.72% and 22.62%, respectively, whereas the activity of glutathione peroxidase (GPX) increased by 31.10%. Se supplementation at 100mg/kg increased the plant pigments contents, the light-harvesting capacity of PSII (Fv/Fm) and PSI (ΔP700max), and the carbon fixation efficiency, which was demonstrated by enhanced photosynthesis (37.6%). Furthermore, alfalfa shifted carbon flux to protein synthesis to improve quality at 100mg/kg of Se (IV) by upregulating carbohydrate and amino acid metabolic genes. On the contrary, at 500mg/kg, Se (IV) became toxic. Higher Se (IV) disordered the plant antioxidant system, increasing H2O2 and MDA by 14.2 and 4.3%, respectively. Moreover, photosynthesis was inhibited by 20.2%, and more structural substances, such as lignin, were synthesized. These results strongly suggest that Se (IV) at a concentration of 100mg/kg act as the positive bio-stimulator of redox metabolism, photosynthesis, and nutrient in alfalfa.

Plasma Levels of CXC Motif Chemokine 1 (CXCL1) and Chemokine 8 (CXCL8) as Diagnostic Biomarkers in Luminal A and B Breast Cancer.

Chemokines are involved in the regulation of immune balance and in triggering an immune response. CXCL1 and CXCL8 belong to the ELR-motif-containing group of CXC chemokines, which, in breast cancer (BC), stimulate angiogenesis and increase migration and invasiveness of tumor cells. The aim of this study was to evaluate CXCL1, CXCL8 and comparative marker CA 15-3 plasma concentrations in BC patients with luminal subtypes A and B. The study group consisted of 100 patients with BC, and the control group of 50 subjects with benign breast lesions and 50 healthy women. Chemokines concentrations were determined by ELISA method; CA15-3-by CMIA. Concentrations of CXCL8 and CA15-3 were significantly higher in BC total group and luminal B (for CA15-3 also in luminal A) subtype of BC than in healthy controls and subjects with benign lesions. In the total BC group, the highest SE, PPV and NPV were observed for CXCL8 (70%, 77.78%, 50%, resp.). A combined analysis of tested chemokines with CA 15-3 increased SE and NPV values (96%, 69.23%, resp.). The diagnostic power of the test (measured by area under ROC curve (AUC)) showed the highest value for CXCL8 in the total BC group (0.6410), luminal A (0.6120) and B subgroup of BC (0.6700). For the combined parameter, the AUC was increasing and reached the highest value for CXCL1 + CXCL8 + CA15-3 combination (0.7024). In light of these results, we suggest that CXCL8 could be used as an additional diagnostic marker that would positively influence the diagnostic utility of CA 15-3, especially in luminal B subtype of BC.

Dietary selenium levels modulates antioxidant, cytokine and immune response and selenoproteins mRNA expression in rats under heat stress condition

BackgroundHigher environmental temperature is a major abiotic stress factor for animals and human beings. The selenium (Se) is an important trace mineral having diverse health promoting effects under stress conditions. However, studies on dietary requirement of selenium under prolonged heat stress condition are lacking. Present study discern the effect of higher dietary Se levels on antioxidant, cytokine, haemato-biochemical profile, and immune response, and the selenoproteins mRNA expression in rats under prolonged heat stress (HS) condition. MethodsWeaned Wistar rats (4 wk age; 67.6 ± 1.53 g BW; n = 72) housed under thermoneutral (TN) or HS conditions and fed with purified diets containing three graded Se levels were divided in six experimental groups. The groups were 1) TN control with 138 ppb Se (TN_CON), 2) HS control with 138 ppb Se (HS_CON), 3) TN with higher Se @ 291 ppb (TN_Se1), 4) HS with higher Se @ 291 ppb (HS_Se1) 5) TN with higher Se @ 460 ppb (TN_Se2), 6) HS with higher Se @ 460 ppb (HS_Se2). Rats in all the six groups were maintained in TN environmental conditions (57.3 ± 0.22 temperature humidity index; THI) for initial 28 days period. Subsequently, rats of HS groups were exposed to 77.0 ± 0.11 THI for 6 h/d in a psychrometric chamber for last fourteen days. ResultsHigher dietary Se (291 and 460 ppb) significantly improved the blood hemoglobin concentration and reduced serum alanine aminotransferase activity of rats under HS conditions. The serum triiodothyronine and insulin levels were significantly higher in high dietary Se groups irrespective of the environmental conditions. Similarly, the serum reduced glutathione levels, and catalase and superoxide dismutase enzyme activity were increased and malondialdehyde levels were reduced in high dietary Se groups irrespective of stress conditions. The glutathione peroxidase (GPx) activity was significantly higher in 460 ppb dietary Se groups as compared to other groups. The serum pro-inflammatory cytokine interleukin (IL)− 1 was declined, whereas the anti-inflammatory cytokine IL-10 level was increased in high dietary Se fed rats under both HS and TN conditions with 460 ppb dietary Se groups showing pronounced effects. Further, there was heat stress- and dietary Se level dependent- up regulation in hepatic GPx and iodothyronine deiodinase-II mRNA expression and similar pattern was noticed in hepatic thioredoxin reductase mRNA expression. The selenoprotein-P mRNA expression was up regulated in 460 ppb Se fed HS group as compared to CON and Se1_C groups. High dietary Se improved the humoral immune response 7d after antigen inoculation under HS conditions whereas cell-mediated immune response was augmented in rats fed higher Se under TN condition. ConclusionIt is concluded that under prolonged heat stress conditions the dietary requirement of Se may be increased to 460 ppb for improving the antioxidant status and humoral immune response, cytokine levels, modulating the thyroid and insulin hormone, and the selenoproteins mRNA expression of rats.

Achieving absorption-type electromagnetic shielding performance in silver micro-tubes/barium Ferrites/Poly(lactic acid) composites via enhancing impedance matching and electric-magnetic synergism

High conductivity can give materials excellent electromagnetic shielding performance, but it leads to serious impedance mismatching and causes inevitable secondary pollution. Developing materials with both excellent microwave absorption and microwave shielding performance remains a formidable challenge. Herein, absorption-type electromagnetic shielding materials with high electromagnetic shielding effectiveness (EMW SE) values were successfully prepared by combining hollow silver micro-tubes and magnetic nano-barium ferrites. The electromagnetic parameters and impedance matching of the composites could be easily regulated by changing the ratio of silver micro-tubes (C) and nano-barium ferrites (M). Thanks to micro-tube structure and the electric-magnetic synergism of the fillers, the composites with the C:M ratio of 9:1 exhibited a high absorption coefficient (A) value of ∼0.77 and a high EMW SE value of ∼100 dB, simultaneously. The absorption-type shielding mechanism of the composites was also evaluated via discussing real and imaginary parts of complex permittivity, real and imaginary parts of complex permeability, and Cole-Cole curves. Furthermore, the composites with the C:M ratio of 3:7 exhibited excellent microwave adsorption performance with the minimum reflection loss of −46.3 dB at thickness of 3.0 mm and a maximum effective absorption band-width of 6.13 GHz.

MiR-129-3p regulates ferroptosis in the liver of Selenium-deficient broilers by targeting SLC7A11

Selenium (Se) has been proven to be an essential trace element for organism. Se deficiency in poultry can cause widespread damage, such as exudative diathesis. The liver is not only the main organ of metabolism, but also one of the organs with high Se content in organism. Recent studies have shown that solute carrier family 7 member 11 (SLC7A11) plays a key role in the negative regulation of ferroptosis. In order to explore the mechanism of Se deficiency induces liver ferroptosis in broilers, and the role of microRNAs (miRNAs) in this process, we divided broilers into 2 groups: control group (0.2 mg/kg Se) and Se deficiency group (0.03 mg/kg Se). Hematoxylin-Eosin staining detected liver tissue damage in broilers. Predicted and verified the targeting relationship between miR-129-3p and SLC7A11 through miRDB and dual luciferase report experiments. The genes related to ferroptosis were detected by qRT-PCR and Western Blot. The results showed that the expression level of miR-129-3p mRNA in Se-deficient liver was significantly increased. To understand whether the miR-129-3p/SLC7A11 axis could involve in the process of ferroptosis, our further research showed that overexpression of miR-129-3p could reduce the expression of SLC7A11 and its downstream GCL, GSS, and GPX4, thereby inducing ferroptosis. These data indicates that miR-129-3p affected ferroptosis under Se deficiency conditions through the SLC7A11 pathway. Our research provides a new perspective for the mechanism of Se deficiency on the liver damage.

Secondary Metabolite Profile and Pharmacological Opportunities of Lettuce Plants following Selenium and Sulfur Enhancement.

Selenium (Se) is an essential trace nutrient for humans and animals owing to its role in redox regulation, thyroid hormone control factors, immunity, inflammatory reactions, brain activities, and carbohydrate regulation. It is also important to support muscle development, as well as for reproductive and cardiovascular well-being. Furthermore, sulfur is known to be a healing element, due to the remarkable function of specialized and secondary S-containing compounds. The scope of the current study was to determine the impact of Se and S enrichment on the secondary metabolite accumulation and antibacterial and NO inhibition activities in green and red leaf lettuce (V1 and V2, respectively). The plants were grown in a hydroponic system supplied with different S concentrations (S0: 0, S1: 1 mM and S2: 1.5 mM K2SO4) via the nutrient solution and foliar-applied varying levels of Se (0, 0.2 and 2.6 µM). Electrospray ionization-quadrupole time-of-flight mass spectrometry (ESI-QTOF/MS) combined with ultra-performance liquid chromatography (UPLC) was used to identify the secondary metabolites in green and red lettuce. The results indicated that extracts of the biofortified lettuce were not cytotoxic to Vero kidney cells at the highest concentration tested of 1 mg/mL. The ESI/MS of the tentatively identified metabolites showed that the response values of 5-O-caffeoylquinic acid, cyanidin 3-O-galactoside, quercetin 3-O-(6''-acetyl-glucoside) and quercetin 3-O-malonylglucoside were induced synergistically under higher Se and S levels in red lettuce plants. The acetone extract of red lettuce had antibacterial activity against Pseudomonas aeruginosa, with a minimum inhibitory concentration (MIC) of 0.156 and 0.625 μg/mL under S2/Se1 and S2/Se2 treatments, respectively. As with antibacterial activity, the acetone extract of green (V1) lettuce treated with adequate (S1) and higher S (S2) under Se-limiting conditions showed the ability to inhibit nitric oxide (NO) release from macrophages. NO production by macrophages was inhibited by 50% at respective concentrations of 106.1 ± 2.4 and 101.0 ± 0.6 μg/mL with no toxic effect on the cells, in response to S1 and S2, respectively, under Se-deficient conditions (Se0). Furthermore, the red cultivar (V2) exhibited the same effect as the green cultivar (V1) regarding NO inhibition, with IC50 = 113.0 ± 4.2 μg/mL, in response to S1/Se2 treatments. Collectively, the promising NO inhibitory effect and antibacterial activity of red lettuce under the above-mentioned conditions might be attributed to the production of flavonoid glycosides and phenylpropanoic acid esters under the same condition. To the best of our knowledge, this is the first report to show the novel approach of the NO inhibitory effect of Se and S enrichment in food crops, as an indicator for the potential of Se and S as natural anti-inflammatory agents.

In Vitro Bioaccessibility of Selenium from Commonly Consumed Fish in Thailand.

Selenium (Se), abundantly obtained in fish, is a crucial trace element for human health. Since there are no data on Se bioaccessibility from commonly consumed fish in Thailand, this study assessed the in vitro bioaccessibility of Se using the equilibrium dialyzability method. The five fish species most commonly consumed in Thailand were selected to determine total Se content using several preparation methods (fresh, boiling, and frying). Equilibrium dialyzability was used to perform in vitro bioaccessibility using enzymatic treatment to simulate gastrointestinal digestion for all boiled and fried fish as well as measuring Se using inductively coupled plasma triple quadrupole mass spectrometry (ICP-QQQ-MS). Two-way ANOVA with interaction followed by Tukey's honestly significant difference (HSD) post hoc test revealed that boiled Indo-Pacific Spanish mackerel, longtail tuna, and short-bodied mackerel were significantly higher in Se content than striped snakehead and giant sea perch (p < 0.05). For fried fish, longtail tuna showed the highest Se content (262.4 µg/100 g of product) and was significantly different compared to the other fish (p < 0.05, estimated marginal means was 43.8-115.6 µg/100 g of product). Se bioaccessibilities from striped snakehead (70.0%) and Indo-Pacific Spanish mackerel (64.6%) were significantly higher than for longtail tuna (p < 0.05). No significant difference in bioaccessibility was found in terms of preparation method (i.e., boiling and frying). In conclusion, the fish included in this study, either boiled or fried, have high Se content and are good sources of Se due to high bioaccessibility.

Supplemental dietary Selenohomolanthionine affects growth and rumen bacterial population of Shaanbei white cashmere wether goats.

Selenium (Se) is an important trace element for all livestock growth. However, little is known about the dietary supplementation of Selenohomolanthionine (SeHLan) effect on growth and rumen microbiota of cashmere goats. In this study, thirty-two growing Shaanbei white cashmere wether goats with mean body weight (26.18 ± 2.71) kg were randomly assigned into 4 treatments, each with 8 replicates. The goats in 4 experimental groups were fed the basal diet (0.016 mg/kg Se) added with organic Se in the form of SeHLan, namely, control group (CG, added 0 mg/kg Se), low Se group (LSE, added 0.3 mg/kg Se), medium Se group (MSE, added 0.6 mg/kg Se), and high Se group (HSE, added 1.2 mg/kg Se). The feed experiment lasted for 70 days including 10-day adaptation, followed by 11 days digestibility trial including 7-day adaptation and 4-day collection period. On the last day of feeding experiment, rumen fluid was collected for microbial community analysis. The feed, orts, and fecal samples were collected for chemical analysis during digestibility trial. The results showed that average daily feed intake (ADFI) and the apparent digestibility of crude protein (CP) were both quadratic ally increased with increased SeHLan supply (P quadratic < 0.05), while average daily gain (ADG) and feed conversion ratio (FCR) showed a linear response (P linear < 0.05). The ADFI and ADG were all highest in the MSE group, which also had the lowest FCR (P < 0.05). Alpha diversity indices of the microbial community did not differ among four treatments. While principal coordinates analysis (PCoA) showed that rumen bacterial population differed among four groups. Taxonomic analysis revealed that Bacteroidetes, Firmicutes, and Euryarchaeota were the dominant phyla. The dominant families were Prevotellaceae, Selenomonadaceae, Methanobacteriaceae, and Bifidobacteriaceae. The significantly different rumen bacterial genera were found to be Methanobrevibacter, Quinella, Christensenellaceae_R-7_group, Veillonellaceae_UCG-001, and Succinivibrionaceae_UCG-002 (P < 0.05). In addition, Tax4fun analysis revealed that SeHLan supplemented groups enhanced the enrichment of genes related to energy metabolism, amino acid metabolism, carbohydrate metabolism, and enzymes. Twenty-eight pathways showed significant differences among four treatment groups (P < 0.05). In conclusion, dietary supplementation of medium SeHLan significantly affects rumen bacterial composition and ultimately promotes Shaanbei white cashmere wether goats nutrient digestibility and growth.

Elemental composition and in vitro bioaccessibility assessment of holothuroids

The elemental composition and bioaccessibility of the wild holothuroids Holothuria arguinensis, Holothuria forskali, and Holothuria mammata was studied. Nutritional and toxicological aspects were evaluated. H. mammata was the richest in Mn, Ni, As, Cd, Pb, and Hg; H. forskali had the highest Cu and I contents, 4.12–4.93 mg/kg dw and 28.02–28.26 mg/kg dw, respectively; and Summer H. arguinensis had high Se content, 4.26 ± 0.08 mg/kg dw. Holothuroids as food may be a dietary Se and I source, with Pb as main hazard. In order to meet the Se Recommended Daily Allowance (RDA), 15–18 g of dried H. arguinensis and 18–33 g of dried H. mammata would have to be consumed everyday. For I, 10 g of dried H. arguinensis, 6–11 g of dried H. forskali, and 20–21 g of dried H. mammata everyday would be required to achieve the I Dietary Recommended Intake (DRI). For meeting Cu dietary requirements, consumption frequencies would have to exceed 330 g dw/day in the most favourable case (Winter H. forskali). Regarding other essential elements, quantities would be much higher. Regarding contaminants, a consumption above 20–21 g/day of dried H. mammata would constitute a Pb risk. Overall, holothuroids can substantially contribute to elemental nutritional requirements.

Ore‑forming process revealed by sphalerite texture and geochemistry: A case study at the Kangjiawan Pb–Zn deposit in Qin-Hang Metallogenic Belt, South China

The origin of the abundant hydrothermal vein-type Pb–Zn deposits in the Qin-Hang Metallogenic Belt (QHMB) in South China remains disputed due to the poor constraints on the ore-forming process. The Kangjiawan (1.96 Mt @ 4.70% Zn and 6.02% Pb), is a representative Pb–Zn deposit in the central QHMB, and its mineralization can be divided into three stages: (I) pre-ore quartz-pyrite, (II) main-ore quartz-pyrite-galena-sphalerite, and (III) Late ore calcite-pyrite-galena-sphalerite. Stage II sphalerite (Sp2) commonly coexists with pyrite and chalcopyrite, and shows a homogeneous internal texture. Stage III sphalerite (Sp3) comprises two generations of sphalerite, namely the earlier, texturally homogeneous Sp3a (coexists with “chalcopyrite disease”), and the younger Sp3b that replaced Sp3a and coexists with galena.Sp2 is Fe-Mn-Co-In-rich, and characterized by the high In/Ga (avg. 2.6) and Zn/Cd (avg. 242.0), but low Zn/Fe (avg. 12.2) ratios, suggesting high ore-forming temperature, consistent with the results of the sphalerite GGIMFis geothermometer (307–314 ℃ with an average of 310 ℃). Sp3a has higher Se, Co, and Ni contents than Sp3b, implying the possible decline of temperature from Sp3a to Sp3b. Meanwhile, the Kangjiawan sphalerite geochemistry suggests a decreasing trend of fS2 from Sp2 (lg fS2 = − 10.5 to − 12.4) to Sp3 (lg fS2 = − 17.2 to − 20.3). These results indicate a dramatic change in the temperature and fS2 from the main-ore to the late-ore stage, probably caused by the mixing between meteoric water and magmatic-hydrothermal fluids in Stage III, as supported by published HO isotope data. The ubiquitous hydrothermal breccias with fine-grained pyrite cement suggest fluid boiling in Stage II. The Kangjiawan sphalerite geochemistry is similar to that of skarn-type sphalerite, consistent with the close spatial–temporal link between the Kangjiawan mineralization and the Shuikoushan granodiorite stock. Therefore, we inferred that the Kangjiawan is a Pb–Zn skarn deposit genetically related to the Shuikoushan granodiorite, with the ore precipitation caused by fluid boiling and meteoric water incursion.

Bayesian Evaluation of Three Serological Tests for Diagnosis of Brucella infections in Dromedary Camels Using Latent Class Models

Brucellosis is a zoonotic disease with significant economic and public health impacts. The disease has been found in ruminants, including camels, but clinical diagnosis of camel brucellosis is difficult due to the lack of clinical signs. Thus, this study aimed to estimate the sensitivity (Se) and specificity (Sp) of the Buffered Plate Antigen Test (BPAT), Rose Bengal Test (RBT), and indirect ELISA (i-ELISA) for the diagnosis of Brucella infection in dromedary camels imported from Sudan to Egypt. The secondary objective of the study was to calculate the animal-level true prevalence of Brucella infection in imported camels. A cross-sectional study was carried out on 921 apparently healthy camels randomly selected from those imported from Sudan and kept in the quarantine stations in the Shalateen area of the Red Sea Governorate, Egypt, between June 2018 and January 2019. Serum samples were collected and analyzed using BPAT, RBT, and i-ELISA. The posterior estimates [medians and 95% Bayesian probability intervals (95% BPI)] for Se and Sp of the three serological tests were obtained using Bayesian latent class models (BLCMs). The BLCM was fitted with the assumption that the BPAT and RBT tests were conditionally dependent on the true brucellosis status of camels. All tests had comparable and high Se (>86%) and Sp (>98%). The animal-level true prevalence of Brucella infection in imported camels was 8.6% (95% BPI: 6.8 – 10.7). Based on these findings, the three assays could be used for the initial screening of Brucella infection in camels. However, the BPAT and RBT are more suitable for use in camel brucellosis control and eradication program in Egypt because of their low unit cost and fast turnaround time compared to the i-ELISA. In addition, BPAT and RBT could be performed in the field where in-vivo tests are rarely used due to logistic and management constraints.

Seizures, ataxia and parvalbumin-expressing interneurons respond to selenium supply in Selenop-deficient mice

Mice with constitutive disruption of the Selenop gene have been key to delineate the importance of selenoproteins in neurobiology. However, the phenotype of this mouse model is exquisitely dependent on selenium supply and timing of selenium supplementation. Combining biochemical, histological, and behavioral methods, we tested the hypothesis that parvalbumin-expressing interneurons in the primary somatosensory cortex and hippocampus depend on dietary selenium availability in Selenop−/− mice. Selenop-deficient mice kept on adequate selenium diet (0.15 mg/kg, i.e. the recommended dietary allowance, RDA) developed ataxia, tremor, and hyperexcitability between the age of 4–5 weeks. Video-electroencephalography demonstrated epileptic seizures in Selenop−/− mice fed the RDA diet, while Selenop± heterozygous mice behaved normally. Both neurological phenotypes, hyperexcitability/seizures and ataxia/dystonia were successfully prevented by selenium supplementation from birth or transgenic expression of human SELENOP under a hepatocyte-specific promoter. Selenium supplementation with 10 μM selenite in the drinking water on top of the RDA diet increased the activity of glutathione peroxidase in the brains of Selenop−/− mice to control levels. The effects of selenium supplementation on the neurological phenotypes were dose- and time-dependent. Selenium supplementation after weaning was apparently too late to prevent ataxia/dystonia, while selenium withdrawal from rescued Selenop−/− mice eventually resulted in ataxia. We conclude that SELENOP expression is essential for preserving interneuron survival under limiting Se supply, while SELENOP appears dispensable under sufficiently high Se status.

PSIII-A-11 Effects of Maternal Nutrition and Selenium Status on Postnatal Muscle Growth and Meat Quality

Abstract To investigate the effects of maternal nutritional plane and selenium (Se) level on offspring muscle development in first parity ewes, Rambouillet ewes (n = 84) were stratified by BW and randomized to receive diets formulated to contain adequate Se (ASe) or high Se (HSe) initiated at breeding. On d 40 of gestation, ewes were assigned randomly within Se treatments supply 60% (RES), 100% (CON), or 140% (HI) of NRC requirements. Offspring were slaughtered at 180 ± 2.2 d of age. Psoas major (PM), longissimuss dorsi (LD), and semimembranosus (SM) samples were snap frozen and analyzed for fiber diameter and type, celluarity, calpain 1 autolysis, and calpastatin expression. Within the PM RNA was increased (P=0.04) in HSe vs. ASe and CON vs. HI. Protein was greater (P=0.05) in ASe than HSe within HI. RES had greater (P=0.09) protein than CON. Calpain 1 had more autolysis in HSe vs. ASe (P≤0.03) in CON and HI. Calpastatin with lower molecular weights was greater (P≤0.01) in the Ase than HSe from CON. Within the SM, ASe had greater (P≤0.05) DNA and RNA concentrations than HSe within HI. Calpastatin immunoreactivity was less (P=0.04) for RES-ASe than all treatments except CON-HSe. Within the LD, calpain 1 had more (P≤0.01) autolytic degradation in CON-ASe than other treatments. Maternal diet did not influence fiber type or diameter. The influence of treatments on skeletal muscle cellularity and calpain system activation is not consistent between muscle types. The PM was most influenced by selenium in the HI group. Conversely, the LD showed more activation of calpain in the CON-ASe. Maternal diet and selenium possibly changed muscle development in offspring which could result in altered quality and yield of lamb produced.

PSII-A-6 Evaluation of Maternal Plane of Nutrition and Selenium Supplementation on the Neonatal Fragment Crystallizable Receptor (Fcrn) in ewe Mammary Tissue

Abstract Maternal immunoglobulin G (IgG) in livestock species is transferred to the offspring exclusively through colostrum. In ruminants, a highly selective mammary barrier allows only immunoglobulin G1 to enter colostrum in substantial amounts. The neonatal fragment crystallizable receptor (FcRn) is responsible for the bidirectional transport of IgG; however, its role in concentrating IgG into colostrum is not well described. The objective of this study was to evaluate maternal nutrition and supranutritional selenium (Se) supplementation on FcRn abundance in mammary tissue. Pregnant Rambouillet ewes (n = 80) were used in a 2 x 3 factorial treatment arrangement which included the main effects of dietary Se [adequate Se (9.5 µg/kg of BW) vs. high Se (81.8 µg/kg of BW)] and plane of nutrition [60%, 100%, and 140% of requirements]. After parturition, ewe mammary glands were collected, and tissue samples were fixed in 10% NBF before paraffin embedding and sectioning. Cross-sections (5 μm) were mounted onto glass slides, deparaffinized, stained for FcRn, and counterstained with DAPI. Areas of tissue cross-sections were captured with Plan-Apochromat 20x/0.8 NA lens using the tiling module of Zeiss software. Images were analyzed using ImagePro Premiere software. Relative fluorescence within the areas of interest was used as an indicator of FcRn abundance with data presented as receptor abundance per glandular tissue area. Data were analyzed using the general linear model procedure of SAS. High Se supplementation increased FcRn abundance per glandular area (P = 0.01). Abundance of mammary FcRn was not influenced by maternal plane of nutrition. Mammary FcRn was positively correlated (r2 = 0.25; P = 0.02) with IgG concentration in colostrum. Results indicate the presence of FcRn in ewe mammary tissue and correlation with colostral IgG. Further evaluation of the role of supranutritional Se and the FcRn is needed.

Trace Elements in Pregnant and Non-pregnant Sheep and Goats and Their Relation to Steroid Hormones

Background: One of the major factors affecting the physiology of pregnancy and reproductive cycle is the trace elements intake and their levels in serum of brood ewes and does. The main objective of this investigation was to study the association between serum concentration of trace elements, ovarian findings, stage of pregnancy and steroid hormones in sheep and goats. Methods: Total of 129 ewes (68 pregnant and 61 non-pregnant) and 54 does (32 pregnant and 22 non-pregnant) were examined clinically and ultrasonographically for pregnancy diagnosis and monitoring the ovarian findings. Pregnant animals were categorized according to the gestational stage into 1 to 2, greater than 2 to 3, greater than 3 to 4 and greater than 4 months. According to the ovarian findings, non-pregnant animals were categorized as having mature corpus luteum (CL), large follicle ( greater than 5 mm) and corpus luteum (CL+F), growing follicles (GF, less than 5.mm) and mature follicle (MF, greater than 5 mm). Animals were bled and serum was harvested and assayed for estrogen (E2), progesterone (P4), manganese (Mn), selenium (Se), iron (Fe) and zinc (Zn) levels. Result: Mn (P=0.01), Fe (P=0.05) and Zn (P=0.001) were lower in pregnant compared with non-pregnant ewes. Fe was significantly higher (P=0.03) in non-pregnant compared with pregnant does at any gestational stage. Ewes with MF had higher Se (P=0.02) and Fe (P=0.001) compared with other ewes. Fe (P=0.001) and Zn (P=0.000) were higher in does having MF compared with other does. A positive association between E2 and serum Fe in non-pregnant ewes (P=0.03) and does (P=0.05) was found. It can be concluded that pregnancy associated with a decrease in serum trace elements in sheep and goats.

Role of carbonaceous fillers in electromagnetic interference shielding behavior of polymeric composites: A review

AbstractIn this review, the EMI shielding properties of the various carbonaceous fillers are thoroughly reviewed. Electromagnetic interference (EMI) had been a cause of major concern in the live broadcasting, entertainment, aviation and defense industries since vital radio signals could create more interference, which could lead to poor performance. To reduce the effect of EMI, the organic polymeric composites along with the carbonaceous fillers are mostly used since they are flexible, low denser, high mechanical strength, high thermo‐stability, high electrical and thermal conductivity, excellent fracture toughness, and high friction/wear resistance. There are lot of carbon based materials are being used as EMI shielding material in mono and compound form. This review gives a broad understanding of the utilization of carbonaceous fillers in polymer matrixes. Thus, the overall coverage on this carbon based materials and their effectiveness could help the researchers to find right carbon material for suitable application. According to this review, the absorption mechanism is vital to achieve high EMI shielding effect. The fillers such as graphene and CNTs are most preferable EMI shielding filler, according to the vast coverage of previous articles. However, there are more magnetoelectric materials also evolved recently, having combined properties of both conductive and magnetic, yielding high SE at elevated frequencies.