GPA

Nitridophosphates and nitridogermanates attract high interest in current research due to their structural versatility. Herein, the elastic properties of GeP2 N4 were investigated by single-crystal X-ray diffraction (XRD) upon compression to 44.4(1) GPa in a diamond anvil cell. Its isothermal bulk modulus was determined to be 82(6) GPa. At 44.4(1) GPa, laser heating resulted in the formation of multiple crystalline phases, one of which was identified as unprecedented germanium nitridophosphate GePN3 . Its structure was elucidated from single-crystal XRD data ( C 2/ c (no...

Carbonates are important carbon-bearing phases in the mantle. While their role in upper mantle petrologic processes has been well studied, their effect on phase relations, melting, and transport properties in the lower mantle is less understood. The stability of carbonates in the mantle depends on a host of factors, including pressure, temperature, oxygen fugacity, and reactions with surrounding mantle phases. To understand the stability of carbonates in the presence of metal in the lower mantle, carbonate-metal reaction experiments on the Fe-Si-Ca-Mg-C-O system were conducted up to 124 GPa and 3200 K...

Herein, we present the preparation and properties of an ultrathin, mechanically robust, quasi-solid composite electrolyte (SEO-QSCE) for solid-state lithium metal battery (SLB) from a well-defined polystyrene- b -poly(ethylene oxide) diblock copolymer (SEO), Li6.75 La3 Zr1.75 Ta0.25 O12 nanofiller, and fluoroethylene carbonate plasticizer. Compared with the ordered lamellar microphase separation of SEO, the SEO-QSCE displays bicontinuous phases, consisting of a Li+ ion conductive poly(ethylene oxide) domain and a mechanically robust framework of the polystyrene domain...

Scandium oxide (Sc2 O3 ) has a wide range of applications in metallurgy, chemical industry, electronics and many other high-tech fields. However, most Sc2 O3 materials exist in the powder or bulk form, while nanostructured Sc2 O3 has rarely been reported as there is a lack of a common method to control its dimensionality, hindering the understanding of new properties and potential applications of nano-Sc2 O3 materials. In this paper, we establish a procedure to synthesize a two-dimensional (2D) Sc2 O3 -covalent organic framework (COF) composite film where the crystal size of Sc2 O3 domains is as small as ∼3 nm...

Background and aim A healthy lifestyle is defined as a way of living that reduces the likelihood of severe illness or early death. Factors required for a healthy lifestyle, such as regular physical activity, better sleep patterns, improved dietary habits, probable caffeine consumption, and decreased feelings of anxiety, are generally assumed to be important for high academic performance. This study aims to investigate the correlation between a healthy lifestyle and academic success among health profession students at Umm Al-Qura University, Saudi Arabia...

BACKGROUND: Granulomatosis with polyangiitis (GPA) is characterized by necrotizing granulomatous inflammation with necrotizing vasculitis predominantly affecting small to medium vessels. The survival rates have drastically improved; however, GPA can be lethal, with older patients having a worse prognosis and higher mortality than younger patients. Moreover, the incidence of various cancers has been reported to increase in patients with GPA. We aimed to discuss possible associations between GPA and lung cancer and emphasize the associated diagnostic challenges...

A method to more easily separate vascular bundles and parenchyma was investigated for the purpose of proposing a sustainable and advanced utilization of oil palm trunk (OPT). In addition, particleboard made from vascular bundles was produced as one of the effective ways to utilize the obtained vascular bundles. The following results were obtained. A Zephyr rolling equipment was used for separation, and it was found that the vascular bundles could be easily separated with the veneer in a dry state. SEM observations showed that the vascular bundles could be separated while maintaining the tissue structure...

Evaluation of the impact of the latest root canal disinfectant, that is carbon quantum dots (CQDs), synchronized microbubble-photodynamic activation (SYMPA), and Nd: YAG laser along with ethylenediaminetetraacetic acid (EDTA) as a final irrigant on the Marten hardness (MH), smear layer (SL) removal, and extrusion bond strength (EBS) of zirconia post to the canal dentin. Eighty intact single-rooted premolars were obtained and disinfected using 0.5% chloramine-T solution. Root canal preparation was performed using ProTaper files followed by obturation...

Hexagonal boron nitride (hBN) and black phosphorus (bP) are crystalline materials that can be seen as ordered stackings of two-dimensional layers, which lead to outstanding anisotropic physical properties. Knowledge of the thermal equations of state of hBN and bP is of great interest in the field of 2D materials for a better understanding of their anisotropic thermo-mechanical properties and exfoliation mechanism towards the preparation of important single-layer materials like hexagonal boron nitride nanosheets and phosphorene...

Hard nitride coatings are commonly employed to protect components subjected to friction, whereby such coatings should possess excellent tribomechanical properties in order to endure high stresses and temperatures. In this study, WN/NbN coatings are synthesized by using the cathodic-arc evaporation (CA-PVD) technique at various negative bias voltages in the 50-200 V range. The phase composition, microstructural features, and tribomechanical properties of the multilayers are comprehensively studied. Fabricated coatings have a complex structure of three nanocrystalline phases: β-W2 N, δ-NbN, and ε-NbN...

Epoxy resin is extensively applied in the electronics and electrical fields because of its outstanding comprehensive performance. However, the low thermal conductivity (TC) limits its application in thermal interface materials. In the present work, epoxy-based hybrid composites with high TC were prepared by using expanded graphite (EG) and copper (Cu) nanoparticles as thermally conductive hybrid fillers via hot blending and compression-curing processes. Additionally, the influence of the Cu content on the thermal properties, mechanical properties, and morphology of each epoxy/EG/Cu composite was investigated...

The covalent bonding framework of crystalline single-bonded cubic AsN, recently synthesized under high pressure and high temperature conditions in a laser-heated diamond anvil cell, is here studied by means of density functional theory calculations and compared to single crystal X-ray diffraction data. The precise localization of the nonbonding electron lone pairs and the determination of their distances and orientations are related to the presence of characteristic structural motifs and space regions of the unit cell dominated by repulsive electronic interactions, with the relative orientation of the electron lone pairs playing a key role in minimizing the energy of the structure...

Pressure induced amorphization provides a distinct route to prepare novel amorphous materials. Single crystals of the porous aluminophosphate AlPO4 -17 directly transform to an amorphous state beginning at 0.6 GPa, without fragmentation into polycrystalline material. Apart from a reduction in dimensions, the amorphous material retains the form of the initial single crystal. Remnant crystalline domains in the amorphous material also preserve the initial orientation of the single crystal. X-ray diffraction indicates the compression of the structure around the empty pores in the xy plane and such an amorphization mechanism is consistent with a direct structural relationship between the single crystal and amorphous forms...

CONTEXT: In order to study the relationship between the sensitivity and pressure of energetic materials, six kinds of energetic materials were selected as the research object. The crystal structure, electronic, and phonon properties under hydrostatic pressure of 0 ~ 45 GPa were calculated by first principles. The calculation results show that the lattice parameters and band gap values of these six energetic materials decrease with the increase of pressure. The peak of the density of states decreases and moves to the low energy direction, and the electrons become more active...

Rhenium (Re) shows the richest valence states from +2 to +7 in compounds, but its mixed-valence states are still missing thus far. In this work, we have explored the Re-O phase diagram with a wide range of stoichiometric compositions under high pressure through first-principles structural search calculations. Besides identifying two novel high-pressure phases of ReO2 and ReO3 , we reveal two hitherto unknown Re-rich Re3 O2 and O-rich ReO4 compounds. Re atoms in Re3 O2 show mixed-valence states due to their inequivalent coordination environments, the first example in Re-based compounds...

This study was conducted at AU to estimate the prevalence of stress and burnout among medical students during the COVID-19 pandemic. This study aimed to provide insights into the levels of stress and burnout experienced by medical students at AU and identify potential risk factors. The research methodology involved a cross-sectional survey using a self-administered questionnaire among 215 College of Medicine AU students. The findings indicated that many participants experienced moderate stress levels, as revealed by data collected on a Likert scale...

We present here the solution structures of the protein thioredoxin-1 from Plasmodium falciparum (PfTrx-1), in its reduced and oxidized forms. They were determined by high-resolution NMR spectroscopy at 293 K on uniformly 13C-, 15N-enriched, matched samples allowing to identification of even small structural differences. PfTrx-1 shows an α/β-fold with a mixed five-stranded β-sheet that is sandwiched between 4 helices in a β1 α1 β2 α2 β3 α3 β4 β5 α4 topology...

BACKGROUND: Unhealthy dietary habits, decreased physical activity, poor sleep quality, and increasing levels of stress and burnout have all been identified as major concerns of medical students. Due to the rigorous environment of medical school, maintaining a well-balanced and nutritious diet is often replaced by more convenient and nutrient-poor options. Improper dietary habits and a sedentary lifestyle both play an essential role in the development of type II diabetes, obesity, hypertension, and hyperlipidemia...

Composite films of nanofibrillated cellulose (NFC) and chitosan (CS) were prepared by spray deposition method, and the influence of polymers ratio and protonation degree (α) of chitosan was evaluated. Films were characterized using morphological, mechanical, and surface techniques. Higher NFC content increased Young's modulus of film composites and reduced air permeability, while higher CS content increased water contact angle. Variations in the degree of protonation of chitosan from non-protonated (α = 0) to fully protonated (α = 1) in the NFC/CS composite film with a fixed composition allowed to modulate surface, mechanical, and structural properties, such as water contact angle (31...

The scarcity of superhard materials with magnetism or a narrow band gap, despite their potential applications in various fields, makes it desirable to design such materials. Here, a series of C1+ x N1- x compounds are theoretically designed by replacing different numbers of nitrogen atoms with carbon atoms in the synthesized C1 N1 compound. The results indicate that the compounds C5 N3 and C7 N1 possess both superhardness and antiferromagnetic ordering due to the introduction of low-coordinated carbon atoms...