Using in-plane anisotropy to engineer Janus monolayers of rhenium dichalcogenides

The new class of Janus two-dimensional (2D) transition-metal dichalcogenides with two different interfaces are currently gaining increasing attention due to their distinct properties different from the typical 2D materials. Here, we show that in-plane anisotropy of a 2D atomic crystal, like ReS$_{2}$ or ReSe$_{2}$, allows formation of a large number of inequivalent Janus monolayers. We use first-principles calculations to investigate the structural stability of 29 distinct ReX$_{2-x}$Y$_{x}$ ($\mathrm{X,Y \in \{S,Se\}}$) structures, which can be obtained by selective exchange of exposed chalcogens in a ReX$_{2}$ monolayer. We also examine the electronic properties and work function of the most stable Janus monolayers and show that the large number of inequivalent structures provides a way to engineer spin-orbit splitting of the electronic bands. We find that the breaking of inversion symmetry leads to sizable spin splittings and spontaneous diople moments than are larger than those in other Janus dichalcogenides. Moreover, our caluclations suggest that the work function of the Janus monolayers can be tuned by varying the content of the substituting chalcogen. Our work demonstrates that in-plane anisotropy provides additional flexibility in sub-layer engineering of 2D atomic crystals

Charting the Irreversible Degradation Modes of Low Bandgap Pb‐Sn Perovskite Compositions for De‐Risking Practical Industrial Development

The commercialization of a solar technology necessitates the fulfillment of specific requirements both regarding efficiency and stability to enter and gain space in the photovoltaic market. These aims are heavily dependent on the selection of suitable materials, which is critical for suppressing any reliability risks arising from inherent instabilities. Focusing on the absorber material, herein the most suitable low bandgap lead‐tin composition candidate for all‐perovskite tandem applications is investigated by studying their degradation mechanisms with both widely available and advanced characterization techniques. Three irreversible degradation processes are identified in narrow bandgap Pb‐Sn perovskite absorbers: 1) Tin (Sn) oxidation upon air exposure, 2) methylammonium (MA) loss upon heat exposure, and 3) formamidinium (FA) and cesium (Cs) segregation leading to impurity phase formation. From an industrial perspective, it is proposed to refocus attention on FASn0.5Pb0.5I3 which minimizes all three effects while maintaining a suitable bandgap for a bottom cell and good performance. Moreover, a practical and highly sensitive characterization method is proposed to monitor the oxidation, which can be deployed both in laboratory and industrial environments and provide useful information for the technological development process, including, the effectiveness of encapsulation methods, and the acceptable time windows for air exposure

Synthesis and Optical Properties of One Year Air-Stable Chiral Sb(III) Halide Semiconductors

Chiral hybrid metal-halide semiconductors (MHS) pose as ideal candidates for spintronic applications owing to their strong spin-orbit coupling (SOC), and long spin relaxation times. Shedding light on the underlying structure-property relationships is of paramount importance for the targeted synthesis of materials with an optimum performance. Herein, we report the synthesis and optical properties of 1D chiral ( -/ -THBTD)SbBr (THBTD = 4,5,6,7-tetrahydro-benzothiazole-2,6-diamine) semiconductors using a multifunctional ligand as a countercation and a structure directing agent. ( -/ -THBTD)SbBr feature direct and indirect band gap characteristics, exhibiting photoluminescence (PL) light emission at RT that is accompanied by a lifetime of a few ns. Circular dichroism (CD), second harmonic generation (SHG), and piezoresponse force microscopy (PFM) studies validate the chiral nature of the synthesized materials. Density functional theory (DFT) calculations revealed a Rashba/Dresselhaus (R/D) spin splitting, supported by an energy splitting ( ) of 23 and 25 meV, and a Rashba parameter (α ) of 0.23 and 0.32 eV·Å for the and analogs, respectively. These values are comparable to those of the 3D and 2D perovskite materials. Notably, ( -THBTD)SbBr has been air-stable for a year, a record performance among chiral lead-free MHS. This work demonstrates that low-dimensional, lead-free, chiral semiconductors with exceptional air stability can be acquired, without compromising spin splitting and manipulation performance

MYO5B, STX3, and STXBP2 mutations reveal a common disease mechanism that unifies a subset of congenital diarrheal disorders:A mutation update

Microvillus inclusion disease (MVID) is a rare but fatal autosomal recessive congenital diarrheal disorder caused by MYO5B mutations. In 2013, we launched an open-access registry for MVID patients and their MYO5B mutations (www.mvid-central.org). Since then, additional unique MYO5B mutations have been identified in MVID patients, but also in non-MVID patients. Animal models have been generated that formally prove the causality between MYO5B and MVID. Importantly, mutations in two other genes, STXBP2 and STX3, have since been associated with variants of MVID, shedding new light on the pathogenesis of this congenital diarrheal disorder. Here, we review these additional genes and their mutations. Furthermore, we discuss recent data from cell studies that indicate that the three genes are functionally linked and, therefore, may constitute a common disease mechanism that unifies a subset of phenotypically linked congenital diarrheal disorders. We present new data based on patient material to support this. To congregate existing and future information on MVID geno-/phenotypes, we have updated and expanded the MVID registry to include all currently known MVID-associated gene mutations, their demonstrated or predicted functional consequences, and associated clinical information.</p

Distinct Behaviour of the Homeodomain Derived Cell Penetrating Peptide Penetratin in Interaction with Different Phospholipids

Penetratin is a protein transduction domain derived from the homeoprotein Antennapedia. Thereby it is currently used as a cell penetrating peptide to introduce diverse molecules into eukaryotic cells, and it could also be involved in the cellular export of transcription factors. Moreover, it has been shown that it is able to act as an antimicrobial agent. The mechanisms involved in all these processes are quite controversial.In this article, we report spectroscopic, calorimetric and biochemical data on the penetratin interaction with three different phospholipids: phosphatidylcholine (PC) and phosphatidylethanolamine (PE) to mimic respectively the outer and the inner leaflets of the eukaryotic plasma membrane and phosphatidylglycerol (PG) to mimic the bacterial membrane. We demonstrate that with PC, penetratin is able to form vesicle aggregates with no major change in membrane fluidity and presents no well defined secondary structure organization. With PE, penetratin aggregates vesicles, increases membrane rigidity and acquires an α-helical structure. With PG membranes, penetratin does not aggregate vesicles but decreases membrane fluidity and acquires a structure with both α-helical and β–sheet contributions.These data from membrane models suggest that the different penetratin actions in eukaryotic cells (membrane translocation during export and import) and on prokaryotes may result from different peptide and lipid structural arrangements. The data suggest that, for eukaryotic cell penetration, penetratin does not acquire classical secondary structure but requires a different conformation compared to that in solution

Magnetyczne wzbogacanie skalenia z AinBarbar

Though Algeria has many mineral resources which have been already developed, there are other resources that have to be valued such as feldspar. This paper deals with potassium feldspar from Ain Barbar deposit. The demand for feldspar as a raw material for the ceramic industry is continuously increasing, which implies an increase in the imports of this material. It became therefore imperative to develop the deposit in question. The ore contains essentially quartz, potassium oxide and iron with respective grades: 74.97% SiO2, 10.43% K2O and 0.60% Fe2O3. This latter is one of the principal impurities which will impart color and in turn degrade the quality of the ore. The objective of this work is to reduce the iron found in oxide form. For this purpose, we used High Gradient Magnetic Separation (HGMS), firstly by the dry process. This operation has allowed to reduce the iron content, from 0.60 to 0.40% Fe2O3, which is acceptable only for stoneware tiles paste of type “porcellenato”. To further reduce this iron oxide content, a wet HGMS has been realized on a finer grain size (-40+20μm) and allowed to obtain a product with 0.19% Fe2O3, which can be used in the sanitary ceramics industry.Chociaż Algieria posiada wiele zasobów mineralnych, które są rozwijane, istnieją inne zasoby, które muszą zostać ocenione takie jak skaleń. Artykuł ten zajmuje się skaleniem potasowym ze złoża AinBarbar. Zapotrzebowanie na skaleń jako surowiec w przemyśle ceramicznym nieprzerwanie rośnie, co skutkuje wzrostem importu tego materiału. Stało się więc koniecznym aby rozwinąć wspomniane złoże. Ruda ta zawiera zasadniczo kwarc, tlenek potasu i żelaza w następującym stopniu: 74,97% SiO2, 10,43% K2O i 0,60% Fe2O3. Ostatni z nich jest głównym zanieczyszczeniem, które wpływa na kolor oraz zmniejsza jakość rudy. Celem tej pracy jest redukcja żelaza, które znajduje się w formie tlenku. W tym celu użyto wysoko-gradientowej separacji magnetycznej (HGMS), najpierw w procesie suchym. Operacja ta pozwoliła na zmniejszenie zawartości żelaza, z 0,60 do 0,40% Fe2O3, co mogło zostać zaakceptowane jedynie dla wyrobów kamionkowych typu porcellenato. Aby dodatkowo zmniejszyć zawartość tlenku żelaza, mokra metoda HGMS została zrealizowana na próbkach o mniejszej wielkości ziarna (-40+20μm) co pozwoliło uzyskać produkt z 0,19% Fe2O3, który może zostać użyty w przemyśle ceramiki sanitarnej

Approche globale et approche ciblée dans la gestion des effluents hospitaliers : application centre de transfusion sanguine, laboratoire sérologie, CHU de Blida

Des études récentes révèlent un danger certain lié aux résidus médicamenteux, produits chimiques, radionucléides, bio films, bactéries résistantes et virus, en aval des stations d’épuration (STEP). Ces résultats confirment l'existence de substances dangereuses dans les effluents hospitalières. Le Centre hospitalo-universitaire Frantz Fanon de Blida s’étale sur superficie de 35 Hectares, d'une capacité globale de 1613 lits, se situe en un point sensible de la Mitidja, Cette plaine s’étend sur une superficie de 1450 km2, d’une épaisseur de 100 à 150 m avec 5 millions habitants. Les potentialités en eau souterraine de cette nappe sont 328 millions m3/an. La production de solutions nuisibles par le C.H.U est estimée à 100 litre par lit et par jour, les rejets peuvent contaminés les eaux de surfaces (Oued Sidi El Kebir, Oued Mazafran) et les eaux souterraines via l’infiltration et la nature perméable des sols. Il est à craindre que les courants souterrains contaminent à long terme une grande partie du sous-sol de la Mitidja. Devant l'urgence et le risque qu'ils représentent, nous avons développé une approche dite ciblée pour une gestion plus efficace des effluents hospitaliers. En effet, dans l’approche globale les effluents hospitaliers sont collectés par un réseau d'assainissement, traités dans une station d'épuration avant d'être rendus dans le mitan naturel. L’approche ciblée évite les rejets dans le réseau d’assainissement de l’hôpital et la STEP, elle neutralise la pollution chimique et biologique à la sortie de chaque enceinte. Par ailleurs, la réalisation d’un laveur désinfecteur d’endoscope adapté à la spécificité des protocoles (exploration digestive, bronchique…) représente une application de l’approche ciblée. En effet, La gestion de la solution désinfectante par asservissement électrotechnique en circuit fermé permet la maitrise de la pollution biologique (ΣBi) et chimique (ΣCi). Il parait que l’évolution des sciences médicales s’accompagne de nouveaux soucis, en plus de la pollution biologique bactérienne et virale en parle aujourd’hui des protéines pathogènes et résistantes au procédés de désinfection usuels. L’approche ciblée reste de mise et insiste sur le développement et l’adaptation de nouvelle technologie dans la procédure de désinfectio