crystals

Pauling and Corey expected that a racemic mixture would result in a rippled β-sheet, however, it has been known from experiments that the racemic mixtures of triphenylalanine lead to a herringbone structure. Because of the theoretical limitations concerning crystal structures such as rippled β-sheet, it is inevitable to understand how the interplay of the amino acids prefers a specific structural motif. In this paper we use molecular dynamics to understand the sequence- and enantiomer-dependent structures by comparisons between rippled β-sheet and pleated β-sheet, solvated and anhydrous rippled β-sheet, and rippled β-sheet and the herringbone structure, based on thermodynamics and structures at the atomic level...

The scarcity of Te hampers the widespread use of Bi2 Te3 -based thermoelectric modules. Here, the thermoelectric module potential of PbSe is investigated by improving its carrier mobility. Initially, large PbSe crystals are grown with the temperature gradient method to mitigate grain boundary effects on carrier transport. Subsequently, light doping with <1mole‰ halogens (Cl/Br/I) increases room-temperature carrier mobility to ~1600 cm2  V-1  s-1 , achieved by reducing carrier concentration compared to traditional heavy doping...

The challenge of developing phosphors with tailored near-infrared (NIR) emission ranges to meet the diverse demands of various applications is a paramount concern in the contemporary realm of NIR phosphor research. A strong dependence of NIR emission on Cr3+ concentration has been demonstrated in Sc2- x Si2 O7 : x Cr3+ , which exhibits an NIR emission band at 840 nm for low Cr3+ doping concentrations ( x = 0.001-0.01) and an anomalous NIR emission band at 1300 nm for high Cr3+ doping concentrations ( x = 0...

Two-dimensional (2D) van der Waals materials are increasingly seen as potential catalysts due to their unique structures and unmatched properties. However, achieving precise synthesis of these remarkable materials and regulating their atomic and electronic structures at the most fundamental level to enhance their catalytic performance remain a significant challenge. In this study, we synthesized single-crystal bulk PtTe crystals via chemical vapor transport and subsequently produced atomically thin, large PtTe nanosheets (NSs) through electrochemical cathode intercalation...

Localized excitation in traditional organic photocatalysts typically prevents the generation and extraction of photo-induced free charge carriers, limiting their activity enhancement under illumination. Here, we enhance delocalized photoexcitation of small molecular photovoltaic catalysts by weakening their electron-phonon coupling via rational fluoro-substitution. The optimized 2FBP-4F catalyst we develop here exhibits a minimized Huang-Rhys factor of 0.35 in solution, high dielectric constant and strong crystallization in the solid state...

Here, we report a proof-of-concept resistive pulse method for analyzing chiral amino acids utilizing metal-amino acid crystallization differences. This method involves introducing an amino acid sample solution into a micropipette through a pressure-driven flow. The sample then mixes with a metal ion solution inside the pipette, forming metal-amino acid crystals. The crystal size depends on the enantiomeric excess ( x ) of chiral amino acid samples. Large x values lead to large crystals. The crystal size difference is then reflected in the resistive pulse size as they block the ionic transport in a micropipette to different extents...

Auxetic crystals exhibiting highly positive lateral expansivity when stretched are an experimentally elusive class of two-dimensional (2D) materials with tremendous potential, for example in the direct transduction of electric signals and the compensation of thermal expansion at the nanoscale. 2D tungsten semi-carbide (W2 C) was theoretically predicted to exhibit giant auxetic behavior, but has yet to be synthesized, as the corresponding full carbide (WC) is energetically favored under thermodynamic equilibrium synthesis processes such as furnace-based chemical vapor deposition...

No abstract text is available yet for this article.

This study presents a comprehensive structural analysis of the adducts formed upon the reaction of two Ru(III) complexes [HIsq][ trans -RuIII Cl4 (dmso)(Isq)] ( 1 ) and [H2 Ind][ trans -RuIII Cl4 (dmso)(HInd)] ( 2 ) (where HInd-indazole, Isq-isoquinoline, analogs of NAMI-A) and two Ru(II) complexes, cis -[RuCl2 (dmso)4 ] ( c ) and trans -[RuCl2 (dmso)4 ] ( t ), with hen-egg white lysozyme (HEWL). Additionally, the crystal structure of an adduct of human lysozyme (HL) with ruthenium complex, [H2 Ind][ trans -RuCl4 (dmso)(HInd)] was solved...

ReAV, the inducible Class-3 L-asparaginase from the nitrogen-fixing symbiotic bacterium Rhizobium etli , is an interesting candidate for optimizing its enzymatic potential for antileukemic applications. Since it has no structural similarity to known enzymes with this activity, it may offer completely new ways of approach. Also, as an unrelated protein, it would evade the immunological response elicited by other asparaginases. The crystal structure of ReAV revealed a uniquely assembled protein homodimer with a highly specific C135/K138/C189 zinc binding site in each subunit...

OBJECTIVE: To evaluate the antibacterial effect of Tanreqing (TRQ) against K. pneumoniae and its inhibition activity on bacterial biofilm formation in vitro and in vivo , and to explore the mechanism of the inhibitory effects of TRQ on K. pneumoniae biofilm formation. METHODS: An in vitro biofilm model of K. pneumoniae was established, and the impact of TRQ on biofilm formation was evaluated using crystal violet staining and scanning electron microscopy (SEM). Furthermore, the clearance effect of TRQ against K...

This study investigates the characteristics of the Ba0.67 Ni0.33 Mn1- x Fe x O3 perovskite compound, focusing on its structural and electrical aspects under varying Fe doping levels at the Mn-site ( x = 0, 0.2). X-ray diffraction patterns confirm the material's consistent structure, with Fe3+ ions substituting Mn3+ ions while maintaining their identical ionic radius. Nano-crystallinity studies reveal single-phase crystallization in the orthorhombic structure with space group Imma . Samples are prepared through conventional solid-state sintering...

In this research, we explain the production of sodium-doped hydroxyapatite (Na_HAp) via wet chemical precipitation, followed by crystal modification. To enhance its photocatalytic activity different % of (0.25, 0.5, 1, and 2) sodium doped into HAp crystal. It has been demonstrated that doping is an effective method for modifying the properties of nanomaterials, such as their optical performance and chemical reactivity. Several instrumental approaches were used to characterize this newly synthesized sodium-doped HAp (Na_HAp), e...

Mechanically responsive molecular crystals have attracted increasing attention for their potential as actuators, sensors, and switches. However, their inherent structural rigidity usually makes them vulnerable to external stimuli, limiting their usage in many applications. Here, we present the mechanically compliant single crystals of penciclovir, a first-line antiviral drug, achieved through an unconventional ferroelastic transformation with inverse temperature symmetry breaking. These crystals display a diverse set of self-restorative behaviors well above room temperature (385 K), including ferroelasticity, superelasticity, and shape memory effects, suggesting their promising applications in high-temperature settings...

Since ethylene (C2 H4 ) is important feedstock in the chemical industry, developing economical and energy-efficient adsorption separation techniques based on ethane (C2 H6 )-selective adsorbents to replace the energy-intensive cryogenic distillation is highly demanded, which however remains a daunting challenge. While previous anionic boron cluster hybrid microporous materials display C2 H4 -selective features, we herein reported that the incorporation of a neutral para -carborane backbone and aliphatic 1,4-diazabicyclo[2...

Di- tert -butyldiphosphatetrahedrane ( t BuCP)2 (1) is a mixed carbon- and phosphorus-based tetrahedral molecule, isolobal to white phosphorus (P4 ). However, despite the fundamental significance and well-explored reactivity of the latter molecule, the precise structure of the free ( t BuCP)2 molecule (1) and a detailed analysis of its electronic properties have remained elusive. Here, single-crystal X-ray structure determination of 1 at low temperature confirms the tetrahedral structure. Furthermore, quantum chemical calculations confirm that 1 is isolobal to P4 and shows a strong largely isotropic diamagnetic response in the magnetic field and thus pronounced spherical aromaticity...

Interferometry offers a precise means of interrogating resonances in dielectric and plasmonic metasurfaces, surpassing spectrometer-imposed resolution limits. However, interferometry implementations often face complexity or instability issues due to heightened sensitivity. Here, we address the necessity for noise compensation and tolerance by harnessing the inherent capabilities of photonic resonances. Our proposed solution, termed "resonant phase noise matching," employs optical referencing to align the phases of equally sensitive, orthogonal components of the same mode...

BACKGROUND: Gout is a chronic inflammatory diseases caused by monosodium urate crystal deposition. However, the role of interleukin (IL)-36 in gout has not dbeen elucidated. METHODS: We enrolled 75 subjects, including 20 healthy controls (HC), 30 patients with acute gout attack and 25 patients in remission. Baseline data were obtained through clinical interrogation and laboratory data were obtained through tests of blood samples. Serum levels of IL-36α were detected using enzyme-linked immunosorbent assay...

No abstract text is available yet for this article.

Refinement of intermetallic compounds (IMCs) through enhancing heterogeneous nucleation during casting process is an important approach to improve the properties of aluminium alloys, which greatly increases the economy value of recycled Al-alloys. However, heterogeneous nucleation of IMCs is inherently more difficult than that of a pure metal or a solid solution. It requires not only creation of a crystal structure but also the positioning of 2 or more different types of atoms in the lattice with specific composition close to that of the nucleated IMCs...