A distributed terahertz metasurface with cold-electron bolometers for cosmology missions

We developed and tested a 2D periodic array of cold-electron bolometers arranged into a wideband frequency selective metasurface that absorbs more than 70% of the incident power in the frequency range 100–800 GHz. The array had 10 7 10 unit cells, each containing four bolometers incorporated into a ring. The chip with bolometers was mounted on the back side of the silicon lens without a back-reflector. Preliminary experiments demonstrated voltage responsivity as high as 10 V/W for the current-biased series array. Simulation of the noise performance shows realization of background noise-limited performance with NEP < NEP for the optical power load P > 15 pW. Results of numerical simulation made for the unit cell of the array are presented together with the equivalent diagram based on lumped network elements. The unit cell also was developed numerically to operate in two radiation modes

Posets pluton: a geochronological piece in the puzzle of the Axial Zone of the Pyrenees

[EN]A detailed geochronological study was conducted on zircons from a diorite sample of the Posets pluton (Axial Zone, Pyrenees). The extracted igneous zircons constrain the emplacement of the pluton to 302 +/- 2 Ma and 301 +/- 3 Ma, by means of U-Pb sensitive high-resolution ion microprobe (SHRIMP) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses, respectively. Considering the syn- to late-tectonic emplacement of the Posets pluton during the main Variscan deformation event (D-2), the obtained ages constrain the long-lasting D-2, associated with the dextral transpression registered through the Axial Zone of the Pyrenees.This work was supported by grants EHUA13/03 and GIU20/017 from the University of the Basque Country (UPV/EHU) and CGL2017-82976 from the Ministerio de Economia, Industria y Competitividad / Agencia Estatal de Investigacion / Fondo Europeo de Desarrollo Regional, European Union. E. Druguet, Y. Denele, an anonymous reviewer and the editor Olivier Lacombe are thanked for reviews and discussions that improved the final manuscript

Ni, Co and Ni-Co-Modified Tungsten Carbides Obtained by an Electric Arc Method as Dry Reforming Catalysts

075-15-2021-710. Research on the synthesis of tungsten carbide was supported by the RF Ministry of Education and Science project No FSWW-2022-0018Dry reforming of methane (DRM), to produce synthesis gas, is one of the most important chemical reactions used for the industrial production of hydrogen and leads to the synthesis of hydrocarbons (liquid fuels) and other valuable products. A cost-effective alternative to active and stable noble metal DRM catalysts, with comparable catalytic performance, can be composite materials based on nickel, cobalt and transition metal carbides. In this line, the present work proposes a non-standard way to obtain dry reforming catalysts of Ni, Co and Ni-Co-modified tungsten carbide (WC) produced by an electric arc method. Different amounts of nickel, cobalt and their mixtures were deposited on tungsten carbide by deposition-precipitation with NaOH (DP) and incipient wetness impregnation (IWI) methods. The resulting materials were characterized by N2 adsorption-desorption, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, and their performance was evaluated in DRM. The composition and preparation method of catalysts predetermined their structural, textural and electronic properties, playing a decisive role in their activity for DRM. DP-prepared 20%Ni/WC material remained resistant to oxidation, both that of the active metal (nickel) and of the tungsten carbide, as well as to coking during DRM. This sample proved to be the most active and stable among all studied materials. Possibly, the resistance to oxidation and coking was due to a more efficient implementation of the oxidation/(re)carbonization cycle on the surface of this catalyst.publishersversionpublishe

A new assay for measuring chromosome instability (CIN) and identification of drugs that elevate CIN in cancer cells.

BACKGROUND: Aneuploidy is a feature of most cancer cells that is often accompanied by an elevated rate of chromosome mis-segregation termed chromosome instability (CIN). While CIN can act as a driver of cancer genome evolution and tumor progression, recent findings point to the existence of a threshold level beyond which CIN becomes a barrier to tumor growth and therefore can be exploited therapeutically. Drugs known to increase CIN beyond the therapeutic threshold are currently few in number, and the clinical promise of targeting the CIN phenotype warrants new screening efforts. However, none of the existing methods, including the in vitro micronuclei (MNi) assay, developed to quantify CIN, is entirely satisfactory. METHODS: We have developed a new assay for measuring CIN. This quantitative assay for chromosome mis-segregation is based on the use of a non-essential human artificial chromosome (HAC) carrying a constitutively expressed EGFP transgene. Thus, cells that inherit the HAC display green fluorescence, while cells lacking the HAC do not. This allows the measurement of HAC loss rate by routine flow cytometry. RESULTS: Using the HAC-based chromosome loss assay, we have analyzed several well-known anti-mitotic, spindle-targeting compounds, all of which have been reported to induce micronuclei formation and chromosome loss. For each drug, the rate of HAC loss was accurately measured by flow cytometry as a proportion of non-fluorescent cells in the cell population which was verified by FISH analysis. Based on our estimates, despite their similar cytotoxicity, the analyzed drugs affect the rates of HAC mis-segregation during mitotic divisions differently. The highest rate of HAC mis-segregation was observed for the microtubule-stabilizing drugs, taxol and peloruside A. CONCLUSION: Thus, this new and simple assay allows for a quick and efficient screen of hundreds of drugs to identify those affecting chromosome mis-segregation. It also allows ranking of compounds with the same or similar mechanism of action based on their effect on the rate of chromosome loss. The identification of new compounds that increase chromosome mis-segregation rates should expedite the development of new therapeutic strategies to target the CIN phenotype in cancer cells

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

The acid–base neutralization reaction of commercially available disodium 2,6-naphthalenedisulfonate (NDS, 2 equivalents) and the tetrahydrochloride salt of tetrakis(4-aminophenyl)methane (TAPM, 1 equivalent) in water gave a novel three-dimensional charge-assisted hydrogen-bonded framework (CAHOF, F-1). The framework F-1 was characterized by X-ray diffraction, TGA, elemental analysis, and 1H NMR spectroscopy. The framework was supported by hydrogen bonds between the sulfonate anions and the ammonium cations of NDS and protonated TAPM moieties, respectively. The CAHOF material functioned as a new type of catalytically active Brønsted acid in a series of reactions, including the ring opening of epoxides by water and alcohols. A Diels–Alder reaction between cyclopentadiene and methyl vinyl ketone was also catalyzed by F-1 in heptane. Depending on the polarity of the solvent mixture, the CAHOF F-1 could function as a purely heterogeneous catalyst or partly dissociate, providing some dissolved F-1 as the real catalyst. In all cases, the catalyst could easily be recovered and recycled

Some features of the diagnosis and clinical manifestations of pathological fractures of the spine in Bekhterev's disease (а clinical case)

Background: A prolonged course of the autoimmune inflammatory process in Bekhterev's disease is accompanied by calcification of the vertebral column’s ligaments, damage to the costovertebral and true joints of the spine, and their ankylosis, that ultimately leads to a decrease in the support capacity of the spine, so that even a minor injury can lead to a fracture. Spinal fractures in ankylosing spondylitis often have an unstable character and a high risk of the spinal cord injury. The main methods for diagnosing the spinal instability in Bekhterev's disease are multispiral computed tomography and magnetic resonance imaging, since the informative significance of survey radiography is not high. An early surgical treatment is the method of choice for unstable fractures in ankylosing spondylitis, despite the comorbid pathology and age, which significantly burden the prognosis. Сlinical case description: Patient K., born in 1969, injured on October 07, 2021 as a result of falling on his back from a height of 2 meters. An MSCT study of the thoracolumbar spine revealed a fracture of the ThXII–LI vertebrae, rupture of the anterior longitudinal ligament, and instability of the ThXII–LI vertebral-motor segment. The following diagnosis was established: closed uncomplicated injury of the thoracolumbar spine; grade I unstable compression fracture of the ThXII, LI vertebrae with a damage to the posterior support complex against the background of ankylosing spondylitis; grade I kyphotic deformity of the thoracolumbar spine; bilateral vertebrogenic lumboishialgia syndrome; pronounced persistent pain and muscle-tonic syndromes. A surgical treatment was applied which included correction of the spinal deformity and stabilization of the thoracolumbar spine using a transpedicular fixation system. The pain vertebrogenic syndrome and clinical neurological disorders regressed. The MSCT control was carried out in 6 months with the detected completed fusion at the ThXII–LI level. Conclusion: A timely diagnosis using multispiral computed tomography and magnetic resonance imaging data allows us to assess the full picture of traumatic changes in the spinal column and choose the most effective type of surgical intervention, using, if necessary, stabilizing systems