Tetrahedrite Nanocomposites for High Performance Thermoelectrics.

Thermoelectric (TE) materials offer a promising solution to reduce green gas emissions, decrease energy consumption, and improve energy management due to their ability to directly convert heat into electricity and vice versa. Despite their potential, integrating new TE materials into bulk TE devices remains a challenge. To change this paradigm, the preparation of highly efficient tetrahedrite nanocomposites is proposed.

Short-term effects of home-based pulmonary rehabilitation during outpatient-managed exacerbations of COPD: a randomised controlled trial.

Background: Uncertainty exists about the beneficial effects of delivering pulmonary rehabilitation (PR) during exacerbations of chronic obstructive pulmonary disease (ECOPD). This study explored the short-term effects and self-reported impact of a home-based PR programme for people with outpatient-managed ECOPD.

Methods: We conducted a mixed-methods randomised controlled trial in people with outpatient-managed ECOPD.

Thermoelectric Properties of Nickel and Selenium Co-Doped Tetrahedrite.

As the search continues for novel, cheaper, more sustainable, and environmentally friendly thermoelectric materials in order to expand the range of applications of thermoelectric devices, the tetrahedrite mineral (CuSbS) stands out as a potential candidate due to its high abundance, low toxicity, and good thermoelectric performance. Unfortunately, as most current thermoelectric materials achieve zTs above 1.0, ternary tetrahedrite is not a suitable alternative.

Computer Simulations of Silicide-Tetrahedrite Thermoelectric Generators.

With global warming and rising energy demands, it is important now than ever to transit to renewable energy systems. Thermoelectric (TE) devices can present a feasible alternative to generate clean energy from waste heat. However, to become attractive for large-scale applications, such devices must be cheap, efficient, and based on ecofriendly materials.

An Electrical Contacts Study for Tetrahedrite-Based Thermoelectric Generators.

High electrical and thermal contact resistances can ruin a thermoelectric device's performance, and thus, the use of effective diffusion barriers and optimization of joining methods are crucial to implement them. In this work, the use of carbon as a CuMnSbS tetrahedrite diffusion barrier, and the effectiveness of different fixation techniques for the preparation of tetrahedrite/copper electrical contacts were investigated. Contacts were prepared using as jointing materials Ni and Ag conductive paints and resins, and a Zn-5wt% Al solder.

Laser Heating Study of the High-Temperature Interactions in Nanograined Uranium Carbides.

Nanograined nuclear materials are expected to have a better performance as spallation targets and nuclear fuels than conventional materials, but many basic properties of these materials are still unknown. The present work aims to contribute to their better understanding by studying the effect of grain size on the melting and solid-solid transitions of nanograined UC. We laser-heated 4 nm-10 nm grain size samples with UC as the main phase (but containing graphite and UO as impurities) under inert gas to temperatures above 3000 K, and their behavior was studied by thermal radiance spectroscopy.

Uranium Carbide Fibers with Nano-Grains as Starting Materials for ISOL Targets.

This paper presents an experimental study about the preparation, by electrospinning, of uranium carbide fibers with nanometric grain size. Viscous solutions of cellulose acetate and uranyl salts (acetate, acetylacetonate, and formate) on acetic acid and 2,4-pentanedione, adjusted to three different polymer concentrations, 10, 12.5, and 15 weight %, were used for electrospinning.

Drought Drives Spatial Variation in the Millet Root Microbiome.

Efforts to boost crop yield and meet global food demands while striving to reach sustainability goals are hindered by the increasingly severe impacts of abiotic stress, such as drought. One strategy for alleviating drought stress in crops is to utilize root-associated bacteria, yet knowledge concerning the relationship between plant hosts and their microbiomes during drought remain under-studied. One broad pattern that has recently been reported in a variety of monocot and dicot species from both native and agricultural environments, is the enrichment of Actinobacteria within the drought-stressed root microbiome.

Structure and properties of a novel boride: ThNiB.

Investigation of the system Th-Ni-B prompted a novel ternary compound ThNiB. X-ray structure analysis of single crystals obtained by the mechanical fragmentation of an as-cast sample revealed a fully ordered CeNiB-type structure (space group Cmc2, no. 36; a = 0.

Stabilization of Metastable Thermoelectric Crystalline Phases by Tuning the Glass Composition in the Cu-As-Te System.

Recrystallization of amorphous compounds can lead to the stabilization of metastable crystalline phases, which offers an interesting way to unveil novel binary or ternary compounds and control the transport properties of the obtained glass ceramics. Here, we report on a systematic study of the Cu-As-Te glassy system and show that under specific synthesis conditions using the spark-plasma-sintering technique, the α-AsTe and β-AsTe binary phases and the previously unreported AsTe phase can be selectively crystallized within an amorphous matrix. The microstructures and transport properties of three different glass ceramics, each of them containing one of these phases with roughly the same crystalline fraction (∼30% in volume), were investigated in detail by means of X-ray diffraction, scanning electron microscopy, neutron thermodiffraction, Raman scattering (experimental and lattice-dynamics calculations), and transport-property measurements.

Effect of Isovalent Substitution on the Electronic Structure and Thermoelectric Properties of the Solid Solution α-AsTeSe (0 ≤ x ≤ 1.5).

We report on the influence of Se substitution on the electronic band structure and thermoelectric properties (5-523 K) of the solid solution α-AsTeSe (0 ≤ x ≤ 1.5). All of the polycrystalline compounds α-AsTeSe crystallize isostructurally in the monoclinic space group C2/m (No.

TERT promoter mutations in pancreatic endocrine tumours are rare and mainly found in tumours from patients with hereditary syndromes.

One of the hallmarks of cancer is its unlimited replicative potential that needs a compensatory mechanism for the consequential telomere erosion. Telomerase promoter (TERTp) mutations were recently reported as a novel mechanism for telomerase re-activation/expression in order to maintain telomere length. Pancreatic endocrine tumors (PETs) were so far recognized to rely mainly on the alternative lengthening of telomeres (ALT) mechanism.

Polymorphism in Thermoelectric As2Te3.

Metastable β-As2Te3 (R3̅m, a = 4.047 Å and c = 29.492 Å at 300 K) is isostructural to layered Bi2Te3 and is known for similarly displaying good thermoelectric properties around 400 K.

Synthesis and structural/physical properties of U3Fe2Ge7: a single-crystal study.

A single crystal of U3Fe2Ge7 was synthesized by the tin-flux method, and its structural and electronic properties were studied. The compound crystallizes in the orthorhombic crystal structure of La3Co2Sn7 type with two Wyckoff sites for the U atoms. U3Fe2Ge7 displays a ferromagnetic order below TC = 62 K.

Thorium and uranium carbide cluster cations in the gas phase: similarities and differences between thorium and uranium.

Laser ionization of AnC4 alloys (An = Th, U) yielded gas-phase molecular thorium and uranium carbide cluster cations of composition An(m)C(n)(+), with m = 1, n = 2-14, and m = 2, n = 3-18, as detected by Fourier transform ion-cyclotron-resonance mass spectrometry. In the case of thorium, Th(m)C(n)(+) cluster ions with m = 3-13 and n = 5-30 were also produced, with an intriguing high intensity of Th13C(n)(+) cations. The AnC13(+) ions also exhibited an unexpectedly high abundance, in contrast to the gradual decrease in the intensity of other AnC(n)(+) ions with increasing values of n.

HOLZ rings in EBSD patterns of the UFeB₄ compound: association with a random distribution of planar defects.

The UFeB₄ phase present in different alloys of the B-Fe-U system was studied by powder X-ray diffraction (PXRD) and scanning electron microscopy complemented with energy-dispersive spectroscopy and electron backscattered diffraction (EBSD). The PXRD data showed that the ternary compound crystallized adopting essentially the YCrB₄-type structure. However, microstructural observations revealed that under high undercooling conditions the UFeB₄ phase exhibits a random distribution of defects parallel to, which are consistently associated with intense higher-order Laue zone rings in EBSD patterns.

Electron diffraction of ThMn₁₂/Th₂Zn₁₇-type structures in the Nd-Fe-Ti system.

Nd:11Fe:Ti alloys prepared by arc melting followed by splat quenching and annealing have been investigated by electron microscopy. The as-cast microstructure evidenced an α-Fe(Ti) --> NdFe₁₁Ti --> Nd₂(Fe,Ti)₁₇ solidification sequence compatible with a cascade of peritectic reactions. The Nd₂(Fe,Ti)₁₇ phase was not detected in the microstructure of the splat-quenched materials, but after annealing the ternary compound grains consisted of a mixture of ThMn₁₂-type and Th₂Zn₁₇-type structures exhibiting a consistent (020)₁:₁₂//(003)₂:₁₇ and [100]₁:₁₂//[110]₂:₁₇, orientation relation, with the invariant plane sitting at (022)₁:₁₂//(333)₂:₁₇.

Synergistic growth inhibition of cancer cells harboring the RET/PTC1 oncogene by staurosporine and rotenone involves enhanced cell death.

TPC-1 is a highly proliferative thyroid papillary carcinoma-derived cell line. These cells express the RET/PTC1 fusion protein, whose isoforms are characterized in this work. The bacterial alkaloid staurosporine and the plant extract rotenone are death-inducing drugs that have an inhibitory synergistic effect on the growth of TPC-1 cells.

Orthovanadate-induced cell death in RET/PTC1-harboring cancer cells involves the activation of caspases and altered signaling through PI3K/Akt/mTOR.

Aims: Oncogenic RET/PTC1 chromosomal rearrangements are hallmarks of thyroid papillary carcinoma. The resulting protein, mainly through tyrosine 451, is responsible for the activation of pathways controlling cell survival, including the PI3K/Akt/mTOR cascade. Vanadium compounds were shown to have anti-neoplastic potential.

Infrared spectra and quantum chemical calculations of the uranium-carbon molecules UC, CUC, UCH, and U(CC)2.

Laser evaporation of carbon rich uranium/carbon alloy targets into condensing argon or neon matrix samples gives weak infrared absorptions that increase on annealing, which can be assigned to new uranium carbon bearing species. New bands at 827.6 cm(-1) in solid argon or 871.

Involvement of p53 in cell death following cell cycle arrest and mitotic catastrophe induced by rotenone.

In order to investigate the cell death-inducing effects of rotenone, a plant extract commonly used as a mitochondrial complex I inhibitor, we studied cancer cell lines with different genetic backgrounds. Rotenone inhibits cell growth through the induction of cell death and cell cycle arrest, associated with the development of mitotic catastrophe. The cell death inducer staurosporine potentiates the inhibition of cell growth by rotenone in a dose-dependent synergistic manner.

Infrared spectra and quantum chemical calculations of the uranium carbide molecules UC and CUC with triple bonds.

Laser evaporation of carbon-rich uranium/carbon alloys followed by atom reactions in a solid argon matrix and trapping at 8 K gives weak infrared absorptions for CUO at 852 and 804 cm(-1). A new band at 827 cm(-1) becomes a doublet with mixed carbon 12 and 13 isotopes and exhibits the 1.0381 isotopic frequency ratio, which is appropriate for the UC diatomic molecule, and another new band at 891 cm(-1) gives a three-band mixed isotopic spectrum with the 1.