The Effects of Te^(2−) and I^− Substitutions on the Electronic Structures, Thermoelectric Performance, and Hardness in Melt-Quenched Highly Dense Cu_(2-x)Se

A systematic study has been carried out on the electronic band structure and density of states, crystal structures, thermoelectric properties, and hardness of the Cu_(2-x)Se system with and without Te^(2−) or I^− substitutions for Se^(2−). Density functional theory calculations indicate that stoichiometric Cu_2Se is a zero-gap material, and copper-deficient Cu_(1.875)Se is a p-type conductor. Te^(2–) substitution increases the total density of states at the Fermi level, whereas, the I^− substitution leads to the reduction of the total and partial density of states for both Se and Cu. Highly dense undoped, Te-doped, and I-doped Cu_(2-x)Se bulks have been fabricated by a melt-quenching method which only takes a few minutes. Rietveld refinements of the X-ray diffraction patterns reveal that the unit cells are expanded after doping. All the fabricated bulks are p-type conductors in accordance with band structure calculations, and they all have figure of merit, zT, values over or close to 1.0 at T = 973 K, except for the Cu_(2-x)Te_(0.16)Se_(0.84). Furthermore, the hardness is distinctly improved by the doping approach, with a maximum value of ca. 0.66 GPa for the Cu_(2-x)Te_(0.16)Se_(0.84), which is higher than those of polycrystalline Bi_2Te_3 and PbTe bulks

Interruption of anti-thymocyte globuline treatment in solid organ transplantation is effectively monitored through a low total lymphocyte count

Introduction: Anti-Thymocyte Globulin (ATG) is a cornerstone in immune suppression for solid organ transplantation. The treatment is a delicate balance between complications arising from over-immunosuppression such as infections and cancer versus rejection stemming from under-immunosuppression. CD3+ T-lymphocyte measurements are frequently employed for treatment monitoring. However, this analysis is costly and not always accessible. The aim of this study was to investigate whether the total count of lymphocytes could replace CD3+ T-lymphocyte measurements based on data from our transplantation center combined with a review of the literature. The hypothesis was that the total lymphocyte count could serve as a diagnostic surrogate marker for CD3+ T-lymphocytes.Methods: A retrospective cohort study was conducted, including patients who underwent kidney and/or a pancreas transplantation and received ATG as induction therapy or for rejection treatment. The inclusion criterium was that the total lymphocyte count and CD3+ T-lymphocyte measurements were measured simultaneously on the same day. Additionally, PubMed and Embase were searched up to 18/10/2023 for published studies on solid organ transplantation, ATG, T-lymphocytes, lymphocyte count, and monitoring. In the retrospective cohort study, a total of 91 patients transplanted between 2016 and 2023, with 487 samples, were included.Results: Total lymphocyte counts below 0.3 x 109/L had a high sensitivity (86%) as a surrogate marker of CD3+ T-lymphocytes below 0.05 x 109/L, but the specificity was low (52%) for total lymphocyte counts above 0.3 x 109/L as a surrogate marker for CD3+ T-lymphocytes above 0.05 x 109/L. A review of the literature identified seven studies comparing total lymphocyte counts and CD3+ T-lymphocytes in ATG monitoring. These studies supported the use of a low total lymphocyte count as a surrogate marker for CD3+ T-lymphocytes and an indicator to omit ATG treatment. However, there was no consensus regarding high total lymphocyte counts as an indicator for continued treatment.Discussion: Results supports that the total lymphocyte count can be used to omit ATG treatment when below 0.3 x 109/L whereas the CD3Introduction: Anti-Thymocyte Globulin (ATG) is a cornerstone in immune suppression for solid organ transplantation. The treatment is a delicate balance between complications arising from over-immunosuppression such as infections and cancer versus rejection stemming from under-immunosuppression. CD3+ T-lymphocyte measurements are frequently employed for treatment monitoring. However, this analysis is costly and not always accessible. The aim of this study was to investigate whether the total count of lymphocytes could replace CD3+ T-lymphocyte measurements based on data from our transplantation center combined with a review of the literature. The hypothesis was that the total lymphocyte count could serve as a diagnostic surrogate marker for CD3+ T-lymphocytes. Methods: A retrospective cohort study was conducted, including patients who underwent kidney and/or a pancreas transplantation and received ATG as induction therapy or for rejection treatment. The inclusion criterium was that the total lymphocyte count and CD3+ T-lymphocyte measurements were measured simultaneously on the same day. Additionally, PubMed and Embase were searched up to 18/10/2023 for published studies on solid organ transplantation, ATG, T-lymphocytes, lymphocyte count, and monitoring. In the retrospective cohort study, a total of 91 patients transplanted between 2016 and 2023, with 487 samples, were included. Results: Total lymphocyte counts below 0.3 x 109/L had a high sensitivity (86%) as a surrogate marker of CD3+ T-lymphocytes below 0.05 x 109/L, but the specificity was low (52%) for total lymphocyte counts above 0.3 x 109/L as a surrogate marker for CD3+ T-lymphocytes above 0.05 x 109/L. A review of the literature identified seven studies comparing total lymphocyte counts and CD3+ T-lymphocytes in ATG monitoring. These studies supported the use of a low total lymphocyte count as a surrogate marker for CD3+ T-lymphocytes and an indicator to omit ATG treatment. However, there was no consensus regarding high total lymphocyte counts as an indicator for continued treatment. Discussion: Results supports that the total lymphocyte count can be used to omit ATG treatment when below 0.3 x 109/L whereas the CD3+ T-lymphocyte analysis should be reserved for higher total lymphocyte counts to avoid ATG overtreatment.</p

Improved thermoelectric performance of Bi-deficient BiCuSeO material doped with Nb, Y, and P

Thermoelectric materials convert waste heat into electric energy. Oxyselenide-based material, specially, p-type BiCuSeO, is one of the most promising materials for these applications. There are numerous approaches to improve the heat-to-electricity conversion performance. Usually, these approaches are applied individually, starting from the pure intrinsic material. Higher performance could, however, be reached by combining a few strategies simultaneously. In the current work, yttrium, niobium, and phosphorous substitutions on the bismuth sites in already bismuth-deficient Bi1-xCuSeO systems were investigated via density functional theory. The bismuth-deficient system was used as the reference system for further introduction of substitutional defects. The substitution with phosphorous showed a decrease of up to 40 meV (11%) in the energy gap between conduction and valence bands at the highest substitution concentration. Doping with niobium led to the system changing from a p-type to an n-type conductor, which provides a possible route to obtain n-type BiCuSeO systems.Funding Agencies|Knut &amp; Alice Wallenberg FoundationKnut &amp; Alice Wallenberg Foundation; Swedish Foundations Consolidator Fellowship; LTU Lab fund program; Kempe Foundation; Swedish National Infrastructure for Computing (SNIC) [SNIC 2019/3-450, SNIC 201 9/3-684]; Ministry of Education and Science of the Russian FederationMinistry of Education and Science, Russian Federation [14.Y26.31.0005]; Eli Lilly and CompanyEli Lilly; EU-program Interreg Nord; Knut, and Alice Wallenberg FoundationKnut &amp; Alice Wallenberg Foundation; Kempe Foundations; Swedish Research CouncilSwedish Research CouncilEuropean Commission [2018-05973]</p

A unified approach to the synthesis of amines through a highly selective and broadly applicable imine reduction using modified Pd-nanoparticles

A remarkably broad range of substrates is facilitated in a highly selective imine reduction using PVP stabilised Pd nanoparticles, molecular hydrogen at 1 atm, at just above RT in aqueous ethanol. Very good yields are achieved across previously-problematic substrate classes, and the protocol circumvents issues associated with more popular synthetic approaches. The utility of this system was further demonstrated in the context of late-stage functionalisation of APIs, deuterium incorporation and one-pot multi-step reaction sequences. Through a combination of synthetic mechanistic studies, surface analysis and computational approximations, insights into the features governing the selectivity of this system, and the key binding interactions between the PVP and Pd surface have been gleaned

Resistive graphene humidity sensors with rapid and direct electrical readout

We demonstrate humidity sensing using a change of the electrical resistance of single-layer chemical vapor deposited (CVD) graphene that is placed on top of a SiO2 layer on a Si wafer. To investigate the selectivity of the sensor towards the most common constituents in air, its signal response was characterized individually for water vapor (H2O), nitrogen (N-2), oxygen (O-2), and argon (Ar). In order to assess the humidity sensing effect for a range from 1% relative humidity (RH) to 96% RH, the devices were characterized both in a vacuum chamber and in a humidity chamber at atmospheric pressure. The measured response and recovery times of the graphene humidity sensors are on the order of several hundred milliseconds. Density functional theory simulations are employed to further investigate the sensitivity of the graphene devices towards water vapor. The interaction between the electrostatic dipole moment of the water and the impurity bands in the SiO(2)d substrate leads to electrostatic doping of the graphene layer. The proposed graphene sensor provides rapid response direct electrical readout and is compatible with back end of the line (BEOL) integration on top of CMOS-based integrated circuits