High Activity Ti³⁺-Modified Brookite TiO₂/Graphene Nanocomposites with Specific Facets Exposed for Water Splitting

Brookite TiO₂ exhibits promising photocatalytic activity in photoreduction; however, it is least known due to poor stability. We have synthesized Ti³⁺-modified brookite TiO₂/graphene nanocomposites with specific facets exposed successfully. They show highly improved photoreduction activity for water splitting into H₂ with excellent stability. The well-crystallized brookite TiO₂ nanorods are surrounded by four reductive (211) facets with high conduction band potential and growth along the [001] direction, indicating that they have high photoreduction ability because more reductive electrons will be excited. By combining spectroscopic techniques and electrochemical analysis methods, the outstanding activity could be linked with the synergistic effects of highly exposed (211) facets, Ti³⁺ defects, and graphene. Their formation mechanism and the effects in the enhanced photoreduction activity have been discussed in detail. In addition to promoting the separation of photogenerated e^––h⁺ pairs effectively, the midgap state was introduced and the absorption ability was improved

NiO Matrix Decorated by Ru Single Atoms: Electron-Rich Ru-Induced High Activity and Selectivity toward Electrochemical N₂ Reduction

Developing a single-atom catalyst with electron-rich active sites is a promising strategy for catalyzing the electrochemical N2 reduction reaction (NRR). Herein, we choose NiO(001) as a model template and deposit a series of single transition metal (TM) atoms with higher formal charges to create the electron-rich active centers. Our first-principles calculations show that low-valent Ru (+2) on NiO(001) can significantly activate N2, with its oxidation states varying from +2 to +4 throughout the catalytic cycle. The Ru/NiO(001) catalyst exhibits the best activity with a relatively low limiting potential of −0.49 V. Furthermore, under NRR operating conditions, the Ru site is primarily occupied by *N2 rather than *H, indicating that NRR overwhelms the hydrogen evolution reaction and thus exhibits excellent selectivity. Our work highlights the potential of designing catalysts with electron-rich active sites for NRR

Chiral Sulfur Nanosheets for Dual-Selective Inhibition of Gram-Positive Bacteria

Elemental sulfur is the oldest known antimicrobial agent. However, conventional sulfur in the clinic suffers from poor aqueous solubility and limited antibacterial activity, greatly hindering its practical use. Herein, we report a reform strategy coupling dimension engineering with chirality transfer to convert conventional 3D sulfur particles into chiral 2D sulfur nanosheets (S-NSs), which exhibit 50-fold improvement of antibacterial capability and dual-selective inhibition against Gram-positive bacteria. Benefiting from the inherent selectivity of S-NSs and chirality selectivity from decorated d-histidine, the obtained chiral S-NSs are proven to precisely kill Gram-positive drug-resistant bacteria, while no obvious bacterial inhibition is observed for Gram-negative bacteria. Mechanism studies reveal that S-NSs produce numerous reactive oxygen specipoes and hydrogen sulfide after incubation with bacteria, thus causing bacterial membrane destruction, respiratory chain damage, and ATP production inhibition. Upon spraying chiral S-NSs dispersions onto MRSA-infected wounds, the skin healing process was greatly accelerated in 8 days due to metabolism inhibition and oxidative damage of bacteria, indicating the excellent treatment efficiency of MRSA-infected wounds. This work converts the traditional well-known sulfur into modern antibacterial agents with a superior Gram-selectivity bactericidal capability

Competition between Pauli Exclusion and H‑Bonding: H₂O and NH₃ on Silicene

We demonstrate that the competition between Pauli exclusion and H-bonding dominates the adsorption of H₂O on silicene through first-principles calculations. It explains the bewildering problem that isolated H₂O is inert on silicene while isolated NH₃ tends to chemisorption. Moreover, Pauli exclusion can be overcome by the synergetic effect of Si···O dative bonding and intermolecular H-bonding. As a result, H₂O molecules are readily to chemisorb in clusters. It is expected that the competition is in general polar molecule adsorption on silicene and, thus, crucial for the adsorption mechanism

Improved Electrochemical Performance of Spinel LiNi_0.5Mn_1.5O₄ Cathode Materials with a Dual Structure Triggered by LiF at Low Calcination Temperature

High-voltage spinel LiNi0.5Mn1.5O4 (LNMO), which has the advantages of high energy density, low cost, environmental friendliness, and being cobalt-free, is considered one of the most promising cathode materials for the next generation of power lithium-ion batteries. However, the side reaction at the interface between the LNMO cathode material and electrolyte usually causes a low specific capacity, poor rate, and poor cycling performance. In this work, we propose a facilitated method to build a well-tuned dual structure of LiF coating and F– doping LNMO cathode material via simple calcination of LNMO with LiF at low temperatures. The experimental results and DFT analysis demonstrated that the powerful interface protection due to the LiF coating and the higher lithium diffusion coefficient caused by F– doping effectively improved the electrochemical performance of LNMO. The optimized LNMO-1.3LiF cathode material presents a high discharge capacity of 140.3 mA h g–1 at 1 C and 118.7 mA h g–1 at 10 C. Furthermore, the capacity is retained at 75.4% after the 1000th cycle at 1 C. Our research provides a concrete guidance on how to effectively boost the electrochemical performance of LNMO cathode materials

Image_1_Genomic characterization of intracranial teratomas using whole genome sequencing.tiff

BackgroundIntracranial teratoma is a rare neoplasm of the central nervous system, often classified into mature and immature types and occurs mainly in children and adolescents. To date, there has been no comprehensive genomic characterization analysis of teratoma due to its rarity of the cases.MethodsForty-six patients with intracranial teratomas were collected and 22 of them underwent whole-exome sequencing, including 8 mature teratomas and 14 immature teratomas. A comprehensive analysis was performed to analyze somatic mutations, copy number variants (CNVs), mutational signatures, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway in our cohort.ResultsThe most common somatic mutated gene in intracranial teratomas was CARD11 (18%) and IRS1 (18%), followed by PSMD11, RELN, RRAS2, SMC1A, SYNE1 and ZFHX3, with mutation rates of 14% for the latter six genes. Copy number variation was dominated by amplification, among which ARAF (50%), ATP2B3 (41%), GATA1 (41%), ATP6AP1 (36%), CCND2 (36%) and ZMYM3 (36%) were the most frequently amplified genes. Copy number deletion of SETDB2 and IL2 only appeared in immature teratoma (43% and 36%, respectively), but not in mature teratoma (p = 0.051 and 0.115, respectively). Prognostic analysis showed that TP53 mutations might be associated with poor prognosis of intracranial teratomas patients.ConclusionsOur study revealed the genetic characteristics of intracranial teratoma which might be valuable for guiding future targeted therapies.</p

DataSheet_1_Genomic characterization of intracranial teratomas using whole genome sequencing.xlsx

BackgroundIntracranial teratoma is a rare neoplasm of the central nervous system, often classified into mature and immature types and occurs mainly in children and adolescents. To date, there has been no comprehensive genomic characterization analysis of teratoma due to its rarity of the cases.MethodsForty-six patients with intracranial teratomas were collected and 22 of them underwent whole-exome sequencing, including 8 mature teratomas and 14 immature teratomas. A comprehensive analysis was performed to analyze somatic mutations, copy number variants (CNVs), mutational signatures, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway in our cohort.ResultsThe most common somatic mutated gene in intracranial teratomas was CARD11 (18%) and IRS1 (18%), followed by PSMD11, RELN, RRAS2, SMC1A, SYNE1 and ZFHX3, with mutation rates of 14% for the latter six genes. Copy number variation was dominated by amplification, among which ARAF (50%), ATP2B3 (41%), GATA1 (41%), ATP6AP1 (36%), CCND2 (36%) and ZMYM3 (36%) were the most frequently amplified genes. Copy number deletion of SETDB2 and IL2 only appeared in immature teratoma (43% and 36%, respectively), but not in mature teratoma (p = 0.051 and 0.115, respectively). Prognostic analysis showed that TP53 mutations might be associated with poor prognosis of intracranial teratomas patients.ConclusionsOur study revealed the genetic characteristics of intracranial teratoma which might be valuable for guiding future targeted therapies.</p

Fluorinated liquid crystals and their mixtures giving polar phases with enhanced low-temperature stability

The fluid ferroelectrics, called ferroelectric nematics (NF), have recently become available by incorporating strong polarity into rod-shaped liquid crystal molecules. Its unprecedented electro-optic properties have created significant excitement in soft matter research. The further progression from the NF phase to the antiferroelectric smectic Z (SmZA) phase, and ultimately to the ferroelectric Smectic A (SmAF) phase, represents a remarkable journey in emerging polar liquid crystal states. Nevertheless, the limitation of NF liquid crystal materials remains one of the prominent obstacles to physical property optimization and optoelectronic device development. In this work, we synthesized a series of fluorinated liquid crystal molecules with large dipole moments and systematically investigated their phase behavior. We designed them with a similar fluorinated aromatic skeleton and varied the structures of the terminal group and bridging bond. We found that the dipole moment density and shape anisotropy significantly affect the phase behavior. Notably, diverse polar liquid crystal phases, including NF, SmZA, and SmAF were observed. Through a multi-component mixing strategy, we successfully achieved a much-expanded temperature window and improved low-temperature stability not only in the NF phase but also in the SmZA and SmAF phases.</p

Tuning UV Pump X‑ray Probe Spectroscopy on the Nitrogen K Edge Reveals the Radiationless Relaxation of Pyrazine: <i>Ab Initio</i> Simulations Using the Quasiclassical Doorway–Window Approximation

Transient absorption UV pump X-ray probe spectroscopy has been established as a versatile technique for the exploration of ultrafast photoinduced dynamics in valence-excited states. In this work, an ab initio theoretical framework for the simulation of time-resolved UV pump X-ray probe spectra is presented. The method is based on the description of the radiation–matter interaction in the classical doorway–window approximation and a surface-hopping algorithm for the nonadiabatic nuclear excited-state dynamics. Using the second-order algebraic–diagrammatic construction scheme for excited states, UV pump X-ray probe signals were simulated for the carbon and nitrogen K edges of pyrazine, assuming a duration of 5 fs of the UV pump and X-ray probe pulses. It is predicted that spectra measured at the nitrogen K edge carry much richer information about the ultrafast nonadiabatic dynamics in the valence-excited states of pyrazine than those measured at the carbon K edge

Production of Hydrogen Peroxide in Groundwater at Rifle, Colorado

The commonly held assumption that photodependent processes dominate H₂O₂ production in natural waters has been recently questioned. Here, we present evidence for the unrecognized and light-independent generation of H₂O₂ in groundwater of an alluvial aquifer adjacent to the Colorado River near Rifle, CO. In situ detection using a sensitive chemiluminescent method suggests H₂O₂ concentrations ranging from lower than the detection limit (<1 nM) to 54 nM along the vertical profiles obtained at various locations across the aquifer. Our results also suggest dark formation of H₂O₂ is more likely to occur in transitional redox environments where reduced elements (e.g., reduced metals and NOM) meet oxygen, such as oxic–anoxic interfaces. A simplified kinetic model involving interactions among iron, reduced NOM, and oxygen was able to reproduce roughly many, but not all, of the features in our detected H₂O₂ profiles, and therefore there are other minor biological and/or chemical controls on H₂O₂ steady-state concentrations in such aquifer. Because of its transient nature, the widespread presence of H₂O₂ in groundwater suggests the existence of a balance between H₂O₂ sources and sinks, which potentially involves a cascade of various biogeochemically important processes that could have significant impacts on metal/nutrient cycling in groundwater-dependent ecosystems, such as wetlands and springs. More importantly, our results demonstrate that reactive oxygen species are not only widespread in oceanic and atmospheric systems but also in the subsurface domain, possibly the least understood component of biogeochemical cycles