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1. Supranutritional Maternal Organic Selenium Supplementation during Different Trimesters of Pregnancy Affects the Muscle Gene Transcriptome of Newborn Beef Calves in a Time-Dependent Manner

   https://doi.org/10.3390/genes12121884  

   Diniz, Wellison J.; Bobe, Gerd; Klopfenstein, Joseph J.; Gultekin, Yunus; Davis, T. Zane; Ward, Alison K.; Hall, Jean A. (December 2021, Genes)

   Selenium (Se) is an essential micronutrient for growth and immune function in beef cattle. We previously showed that supranutritional maternal organic Se supplementation during late pregnancy improves immune function in their newborn calves; however, the effects of maternal organic Se-supplementation on fetal programming during different pregnancy stages have yet to be elucidated. Herein, we investigated the effects of supranutritional maternal organic Se-supplementation in different pregnancy trimesters on their beef calf’s genome-wide transcriptome profiles. Within 12 to 48 h of birth, whole blood and Longissimus dorsi (LD) muscle biopsies were collected from calves born to 40 crossbred Angus cows that received, except for the control group (CTR), Se-yeast boluses (105 mg of Se/wk) during the first (TR1), second (TR2), or third (TR3) trimester of gestation. Whole-blood Se concentrations of newborn calves increased from CTR, TR1, TR2 to TR3, whereas muscle Se concentrations of newborn calves were only increased in TR3 group. We identified 3048 unique differentially expressed genes (DEGs) across all group comparisons (FDR ≤ 0.05 and |log2FC| ≥ 1.5). Furthermore, we predicted 237 unique transcription factors that putatively regulate the DEGs. Independent of supplementation trimester, supranutritional maternal organic Se supplementation downregulated genes involved in adaptive immunity in all trimesters. Dependent on supplementation trimester, genes involved in muscle development were upregulated by TR3 Se supplementation and downregulated by TR1 Se-supplementation, and genes involved in collagen formation were downregulated by TR2 Se-supplementation. Supranutritional maternal organic Se supplementation in the last trimester of pregnancy resulted in upregulation of myosin and actin filament associated genes, potentially allowing for optimal muscle function and contraction. Our findings suggest a beneficial effect of supranutritional maternal organic Se supplementation during late gestation on Se-status and muscle development and function of newborn calves. 

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2. Reversible electrochemical conversion from selenium to cuprous selenide

   https://doi.org/10.1039/d1cc03983k  

   Sandstrom, Sean K.; Jiang, Heng; Lucero, Marcos; Xu, Yunkai; Gallagher, Trenton C.; Cao, Mengyuan; Feng, Zhenxing; Ji, Xiulei (October 2021, Chemical Communications)

   Using elemental selenium as an electrode, the redox-active Cu 2+ /Cu + ion is reversibly hosted via the sequential conversion reactions of Se → CuSe → Cu 3 Se 2 → Cu 2 Se. The four-electron redox process from Se to Cu 2 Se produces a high initial specific capacity of 1233 mA h g −1 based on the mass of selenium alone or 472 mA h g −1 based on the mass of Cu 2 Se, the fully discharged product. 

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3. Structural and Optical Properties of Two-Stage CuInSe ₂ Thin Films Studied by Real Time Spectroscopic Ellipsometry

   https://doi.org/10.1109/PVSC40753.2019.8980671  

   Sapkota, Dhurba R.; Collins, Robert W.; Pradhan, Puja; Koirala, Prakash; Irving, Richard; Phillips, Adam B.; Ellingson, Randy J.; Heben, Michael J.; Marsillac, Sylvain; Podraza, Nikolas J. (June 2019, 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC))

   CuInSe 2 (CIS) thin films ~ 500-650 Å in thickness have been deposited on c-Si substrates by two-stage thermal co-evaporation starting either from In 2 Se 3 [according to In 2 Se 3 + (2Cu+Se) → 2(CuInSe 2 )] or from Cu 2-x Se [according to Cu 2 Se + (2In+3Se) → 2(CuInSe 2 )]. The design of such processes is facilitated by accurate calibrations of Cu and In 2 Se 3 growth rates on substrate/film surfaces obtained by real time spectroscopic ellipsometry (RTSE). The two-stage deposited CIS films were also studied by RTSE to deduce (i) the evolution of film structure upon conversion of the starting In 2 Se 3 or Cu 2-x Se films to CIS via Cu+Se or In+Se co-evaporation, respectively, and (ii) the complex dielectric functions of the starting films as well as the resulting CIS. The goal is to fabricate CIS that develops large grains as early as possible during growth for high quality materials in tandem solar cell applications. Results indicate that by depositing Cu 2-x Se in the first stage and exposing the film to In+Se flux in the second stage [as in the third stage of a three-stage CIS process] well-defined bandgap critical points with no detectable subgap absorption are noted in films as thin as 650 Å. 

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4. The Long-Run Impacts of Special Education

   https://doi.org/10.1257/pol.20190603  

   Ballis, Briana; Heath, Katelyn (November 2021, American Economic Journal: Economic Policy)

   Over 13 percent of US students participate in special education (SE) programs annually, at a cost of $40 billion. However, due to selection issues the effect of SE placements remains unclear. This paper uses administrative data from Texas to examine the long-run effect of reducing SE access. Our research design exploits variation in SE placement driven by a unique state policy that required school districts to reduce SE caseloads to 8.5 percent. This policy led to sharp reductions in SE enrollment. These reductions generated significant reductions in educational attainment, suggesting that marginal participants experience long-run benefits from SE services. (JEL H75, I21, I28, J13, J14) 

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5. High-performance thermoelectric silver selenide thin films cation exchanged from a copper selenide template

   https://doi.org/10.1039/C9NA00605B  

   Chen, Nan; Scimeca, Michael R.; Paul, Shlok J.; Hafiz, Shihab B.; Yang, Ze; Liu, Xiangyu; Yang, Fan; Ko, Dong-Kyun; Sahu, Ayaskanta (January 2020, Nanoscale Advances)

   Over the past decade, Ag 2 Se has attracted increasing attention due to its potentially excellent thermoelectric (TE) performance as an n-type semiconductor. It has been considered a promising alternative to Bi–Te alloys and other commonly used yet toxic and/or expensive TE materials. To optimize the TE performance of Ag 2 Se, recent research has focused on fabricating nanosized Ag 2 Se. However, synthesizing Ag 2 Se nanoparticles involves energy-intensive and time-consuming techniques with poor yield of final product. In this work, we report a low-cost, solution-processed approach that enables the formation of Ag 2 Se thin films from Cu 2−x Se template films via cation exchange at room temperature. Our simple two-step method involves fabricating Cu 2−x Se thin films by the thiol-amine dissolution of bulk Cu 2 Se, followed by soaking Cu 2−x Se films in AgNO 3 solution and annealing to form Ag 2 Se. We report an average power factor (PF) of 617 ± 82 μW m −1 K −2 and a corresponding ZT value of 0.35 at room temperature. We obtained a maximum PF of 825 μW m −1 K −2 and a ZT value of 0.46 at room temperature for our best-performing Ag 2 Se thin-film after soaking for 5 minutes. These high PFs have been achieved via full solution processing without hot-pressing. 

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