Bisphosphonium cation based metal halide glass scintillators with tunable melting points.

Organic-inorganic metal halide (OIMH) glass offers the advantages of large-scale production, high transparency, and minimal light scattering. However, undesired crystallization in OIMH glass can occur, leading to deteriorated transparency. Herein, a series of bisphosphonium organic cations were designed to construct Mn-based metal halide crystals with a photoluminescence quantum yield (PLQY) near unity, alongside the development of highly thermally stable OIMH glasses. Two strategies were employed to lower the melting point of OIMH: alkyl chain elongation and fluorine substitution. The (Hex-3,4-2F)MnBr4·MeOH (Hex-3,4-2F = hexane-1,6-diylbis((3,4-difluorobenzyl)diphenylphosphonium)) crystal delivers a glass transition temperature of 100 °C and the highest T g/T m ratio (0.82) among OIMHs. The resulting OIMH glass exhibits a PLQY of 47.6%, achieves an impressive resolution of 25 lp mm-1 in X-ray imaging, and remains transparent even after being heated at 90 °C for six weeks. These bisphosphonium-based OIMH glasses present a feasible design for the practical application of OIMH glasses in radiation detection.

Surface charge switchable fluorinated small molecular micelles for enhanced photodynamic therapy for bacterial infections.

Photodynamic therapy (PDT) employs reactive oxygen species (ROS) from a photosensitizer (PS) under light, inhibiting multi-drug resistance in bacteria. However, hypoxic conditions in infection sites and biofilms challenge PDT efficiency. We developed fluorinated small molecular micelles (PF-CBMs) as PS carriers to address this, relieving hypoxia and enhancing PS penetration into biofilms. Perfluorocarbons in PF-CBMs transport more oxygen due to their excellent oxygen-dissolving capability. Fluorination enhances loading capacity and serum stability, reduces premature release, and improves cellular uptake, to improve PDT efficacy. PF-CBMs, with acid-induced surface charge transformation, exhibit superior biofilm penetration, resulting in increased antibiofilm activity of PDT. Compared to fluorine-free micelles (PC-CBMs), PF-CBMs demonstrate better serum stability, higher drug loading, and reduced premature release, leading to significantly improved antibacterial efficacy in vitro and in vivo. In conclusion, fluorinated micelles with surface charge reversal enhance PDT for antibacterial and antibiofilm applications.

Comparison of percutaneous nephrolithotripsy combined with retrograde intrarenal surgery and multi-tract percutaneous nephrolithotripsy for octopus stone: A propensity score-matching study.

To compared the effectiveness and safety of single standard mini percutaneous nephrolithotripsy (SM-PCNL) combined with retrograde intrarenal surgery (RIRS) and multiple standard mini percutaneous nephrolithotomy (MSM-PCNL) in the treatment of octopus stone of 2 to 4 cm. The clinical data of SM-PCNL combined with RIRS and MSM-PCNL for octopus stone with a 2 to 4 cm diameter from October 2019 to December 2022 were analyzed retrospectively, and propensity score matching was used to screen patients. The matched patients were paired, and the operation time, complications, postoperative pain, tubeless rate, stone-free rate (SFR), and postoperative hospital stay were further compared between the 2 groups. 88 patients underwent SM-PCNL combined with RIRS (combined group), and 143 patients underwent MSM-PCNL (multiple channel group). After matching analysis, there were 49 patients in each group, and there was no significant difference in the general preoperative data between the 2 groups. The perioperative complications and stone-free rate were no statistical difference. In postoperative pain (4.00 ±â€…0.74 vs 5.00 ±â€…0.74, P = .00), tubeless rate (44.90% vs 20.41%, P = .01), hemoglobin drop (9.38 ±â€…7.48 vs 14.22 ±â€…7.69, P = .01), postoperative hospital stay (3.37 ±â€…1.09 vs 5.08 ±â€…1.29, P = .00), the combined group was significantly better than the multiple channel group. Regarding operation time, the combined group was more than the multiple channel group (103.27 ±â€…27.61 vs 78.39 ±â€…19.31, P = .000). For octopus stone with a diameter of 2 to 4 cm, the effectiveness and safety of SM-PCNL combined with RIRS were similar to those of MSM-PCNL The surgeon should carefully evaluate the patient's physical condition, stone characteristics, and expectations before the operation and assist the patient in choosing an appropriate plan.

Counterion Distribution in the Stern Layer on Charged Surfaces.

Counterion adsorption at the solid-liquid interface affects numerous applications. However, the counterion adsorption density in the Stern layer has remained poorly evaluated. Here we report the direct determination of surface charge density at the shear plane between the Stern layer and the diffuse layer. By the Grahame equation extension and streaming current measurements for different solid surfaces in different aqueous electrolytes, we are able to obtain the counterion adsorption density in the Stern layer, which is mainly related to the surface charge density but is less affected by the bulk ion concentration. The charge inversion concentration is further found to be sensitive to the ion type and ion valence rather than to the charged surface, which is attributed to the ionic competitive adsorption and ion-ion correlations. Our findings offer a framework for understanding ion distribution in many physical and chemical processes where the Stern layer is ubiquitous.

Three-Dimensional Reconstruction and Visualization of Underwater Bridge Piers Using Sonar Imaging.

The quality of underwater bridge piers significantly impacts bridge safety and long-term usability. To address limitations in conventional inspection methods, this paper presents a sonar-based technique for the three-dimensional (3D) reconstruction and visualization of underwater bridge piers. Advanced MS1000 scanning sonar is employed to detect and image bridge piers. Automated image preprocessing, including filtering, denoising, binarization, filling, and morphological operations, introduces an enhanced wavelet denoising method to accurately extract the foundation contour coordinates of bridge piers from sonar images. Using these coordinates, along with undamaged pier dimensions and sonar distances, a model-driven approach for a 3D pier reconstruction algorithm is developed. This algorithm leverages multiple sonar data points to reconstruct damaged piers through multiplication. The Visualization Toolkit (VTK) and surface contour methodology are utilized for 3D visualization, enabling interactive manipulation for enhanced observation and analysis. Experimental results indicate a relative error of 13.56% for the hole volume and 10.65% for the spalling volume, demonstrating accurate replication of bridge pier defect volumes by the reconstructed models. Experimental validation confirms the method's accuracy and effectiveness in reconstructing underwater bridge piers in three dimensions, providing robust support for safety assessments and contributing significantly to bridge stability and long-term safety assurance.

Phosphonium Iodide Featuring Blue Thermally Activated Delayed Fluorescence for Highly Efficient X-Ray Scintillator.

Organic scintillators are praised for their abundant element reserves, facile preparation procedures, and rich structures. However, the weak X-ray attenuation ability and low exciton utilization efficiency result in unsatisfactory scintillation performance. Herein, a new family of highly efficient organic phosphonium halide salts with thermally activated delayed fluorescence (TADF) are designed by innovatively adopting quaternary phosphonium as the electron acceptor, while dimethylamine group and halide anions (I-) serve as the electron donor. The prepared butyl(2-[2-(dimethylamino)phenyl]phenyl)diphenylphosphonium iodide (C4-I) exhibits bright blue emission and an ultra-high photoluminescence quantum yield (PLQY) of 100 %. Efficient charge transfer is realized through the unique n-π and anion-π stacking in solid-state C4-I. Photophysical studies of C4-I suggest that the incorporation of I accounts for high intersystem crossing rate (kISC) and reverse intersystem crossing rate (kRISC), suppressing the intrinsic prompt fluorescence and enabling near-pure TADF emission at room temperature. Benefitting from the large Stokes shift, high PLQY, efficient exciton utilization, and remarkable X-ray attenuation ability endowed by I, C4-I delivers an outstanding light yield of 80721 photons/MeV and a low limit of detection (LoD) of 22.79 nGy ⋅ s-1. This work would provide a rational design concept and open up an appealing road for developing efficient organic scintillators with tunable emission, strong X-ray attenuation ability, and excellent scintillator performance.

Ultralow-Friction at Cryogenic Temperature Induced by Hydrogen Correlated Quantum Effect.

Temperature is one of the governing factors affecting friction of solids. Undesired high friction state has been generally reported at cryogenic temperatures due to the prohibition of thermally activated processes, following conventional Arrhenius equation. This has brought huge difficulties to lubrication at extremely low temperatures in industry. Here, the study uncovers a hydrogen-correlated sub-Arrhenius friction behavior in hydrogenated amorphous carbon (a-C:H) film at cryogenic temperatures, and a stable ultralow-friction over a wide temperature range (103-348 K) is achieved. This is attributed to hydrogen-transfer-induced mild structural ordering transformation, confirmed by machine-learning-based molecular dynamics simulations. The anomalous sub-Arrhenius temperature dependence of structural ordering transformation rate is well-described by a quantum mechanical tunneling (QMT) modified Arrhenius model, which is correlated with quantum delocalization of hydrogen in tribochemical reactions. This work reveals a hydrogen-correlated friction mechanism overcoming the Arrhenius temperature dependence and provides a new pathway for achieving ultralow friction under cryogenic conditions.

Lipase and pH-responsive diblock copolymers featuring fluorocarbon and carboxyl betaine for methicillin-resistant staphylococcus aureus infections.

The emergence of multidrug-resistant bacteria along with their resilient biofilms necessitates the development of creative antimicrobial remedies. We designed versatile fluorinated polymer micelles with surface-charge-switchable properties, demonstrating enhanced efficacy against Methicillin-Resistant Staphylococcus Aureus (MRSA) in planktonic and biofilm states. Polymethacrylate diblock copolymers with pendant fluorocarbon chains and carboxyl betaine groups were prepared using reversible addition-fragmentation chain transfer polymerization. Amphiphilic fluorinated copolymers self-assembled into micelles, encapsulating ciprofloxacin in their cores (CIP@FCBMs) for antibacterial and antibiofilm applications. As a control, fluorine-free copolymer micelles loaded with ciprofloxacin (CIP@BCBMs) were prepared. Although both CIP@FCBMs and CIP@BCBMs exhibited pH-responsive surface charges and lipase-triggered drug release, CIP@FCBMs exhibited powerful antimicrobial and antibiofilm activities in vitro and in vivo, attributed to superior serum stability, higher drug loading, enhanced fluorination-facilitated cellular uptake, and lipase-triggered drug release. Collectively, reversing surface charge, on-demand antibiotic release, and fluorination-mediated nanoparticles hold promise for treating bacterial infections and biofilms.

Overview of mechanisms of Fe-based catalysts for the selective catalytic reduction of NOx with NH3 at low temperature.

With the increasingly stringent control of NOx emissions, NH3-SCR, one of the most effective de-NOx technologies for removing NOx, has been widely employed to eliminate NOx from automobile exhaust and industrial production. Researchers have favored iron-based catalysts for their low cost, high activity, and excellent de-NOx performance. This paper takes a new perspective to review the research progress of iron-based catalysts. The influence of the chemical form of single iron-based catalysts on their performance was investigated. In the section on composite iron-based catalysts, detailed reviews were conducted on the effects of synergistic interactions between iron and other elements on catalytic performance. Regarding loaded iron-based catalysts, the catalytic performance of iron-based catalysts on different carriers was systematically examined. In the section on iron-based catalysts with novel structures, the effects of the morphology and crystallinity of nanomaterials on catalytic performance were analyzed. Additionally, the reaction mechanism and poisoning mechanism of iron-based catalysts were elucidated. In conclusion, the paper delved into the prospects and future directions of iron-based catalysts, aiming to provide ideas for the development of iron-based catalysts with better application prospects. The comprehensive review underscores the significance of iron-based catalysts in the realm of de-NOx technologies, shedding light on their diverse forms and applications. The hope is that this paper will serve as a valuable resource, guiding future endeavors in the development of advanced iron-based catalysts.

Direct Visualization of Dark Interlayer Exciton Transport in Moiré Superlattices.

Moiré superlattices have emerged as an unprecedented manipulation tool for engineering correlated quantum phenomena in van der Waals heterostructures. With moiré potentials as a naturally configurable solid-state that sustains high exciton density, interlayer excitons in transition metal dichalcogenide heterostructures are expected to achieve high-temperature exciton condensation. However, the exciton degeneracy state is usually optically inactive due to the finite momentum of interlayer excitons. Experimental observation of dark interlayer excitons in moiré potentials remains challenging. Here we directly visualize the dark interlayer exciton transport in WS2/h-BN/WSe2 heterostructures using femtosecond transient absorption microscopy. We observe a transition from classical free exciton gas to quantum degeneracy by imaging temperature-dependent exciton transport. Below a critical degeneracy temperature, exciton diffusion rates exhibit an accelerating downward trend, which can be explained well by a nonlinear quantum diffusion model. These results open the door to quantum information processing and high-precision metrology in moiré superlattices.

Nonmonotonic Effects of Atomic Vacancy Defects on Friction.

The presence of defects such as vacancies has a significant impact on the frictional properties of 2D materials that are excellent solid lubricants. In this study, we demonstrate that the nonmonotonic effect of Te vacancy defects on the friction of MoTe2 is related to the change in the maximum sliding energy barrier due to the variation in tip position. The experimental results of atomic force microscopy suggest that the friction shows an overall increasing trend with the increase in Te vacancy density, but this variation is nonmonotonic. Molecular dynamics simulations show that the increase in friction force with defect density can be attributed to the large and more sliding energy barriers that the tip has to overcome. Furthermore, the nonmonotonic variation of friction with defect density is dominated by the change of the maximum sliding potential barrier caused by the variation of tip position perpendicular to the sliding direction during the sliding process. Additionally, the uneven charge distribution due to charge transfer occurring at the defect also contributes to the increase in friction. This work shows the mechanism of the effect of Te vacancy defects on the friction of MoTe2, which provides guidance for the modulation of the frictional properties of solid lubricants.

Successful surgical treatment of extensive idiopathic scrotal calcinosis: A case report.

We admitted a 41-year-old man with a chief complaint of multiple nodules found in the scrotum, accompanied by itching discomfort, occasionally some nodules discharged white secretions. Physical examination revealed extensive nodules of scrotal skin, approximately 2.0 cm in diameter in the largest, grayish white, textured hard, no pain, no breakdown of skin. Due to the wide distribution of scrotal nodules in this patient, there was a large deletion in the scrotal skin after intraoperative removal of all nodules; the skin was submitted to V and Z-sutures, and the scrotum was finally successfully reconstructed.

The Effect of the Microstructure Formed in the Forging-Healing Process on the Mechanical Properties of Heavy Forgings.

The forging-healing of the internal porosity defects affects the tensile, impact and fatigue properties of heavy forgings. In the present work, the effect of deformation process on the microstructure in the joint area as well as the tensile strength, impact toughness and fatigue strength was studied experimentally. It is shown that the tensile strength is restored once the porosity defects were healed, and the impact toughness is recovered when the flat grain band is eliminated. The fatigue strength can be restored if a uniform grain structure can be achieved in both the joint area and the matrix, whereafter precipitate become the key factor affecting the fatigue strength. A complete healing of the porosity defects, a uniform grain structure in the joint area and the matrix, and a fully controlled precipitate are essential to guarantee the mechanical properties and in-service performance of the heavy forgings.

Macroscale Superlubricity of Hydrated Anions in the Boundary Lubrication Regime.

Cations can achieve excellent hydration lubrication at smooth interfaces under both microscale and macroscale conditions due to the boundary layer composed of hydration shells surrounding charges, but what about anions? Commonly used friction pairs are negatively charged at the solid/solution interface. Achieving anionic adsorption through constructing positively charged surfaces is a prerequisite for studying the hydration lubrication of anions. Here we report the hydration layer composed of anions adsorbed on the positively charged polymer/sapphire interface at acidic electrolyte solutions with pH below the isoelectric point, which contributes to the hydration lubrication of anions. Strongly hydrated anions (for the case of SO42-) exhibit stable superlubricity comparable to cations, with strikingly low boundary friction coefficient of 0.003-0.007 under contact pressures above 15 MPa without a running-in period. The hydration lubrication performance of anions is determined by both the ionic hydration strength and ion adsorption density based on the surface potential and tribological experiments. The results shed light on the role of anions in superlubricity and hydration lubrication, which may be relevant for understanding the lubrication mechanism and improving lubrication performance in acidic environments, for example, in acid pumps, sealing rings of compressors for handling acidic media, and processing devices of nuclear waste.

Self-Adaptive Macroscale Superlubricity Based on the Tribocatalytic Properties of Partially Oxidized Black Phosphorus.

The high-flash heat generated by direct contact at asperity tips under high contact stress and shear significantly promotes the tribocatalytic reaction between a lubricating medium and a friction interface. Macroscale superlubricity can be achieved by using additives with good lubrication properties to promote the decomposition and transformation of a lubricating medium to form an ultralow shear interface during the friction process. This paper proposed a way to achieve self-adaptive oil-based macroscale superlubricity on different tribopairs, including steel-steel and steel-DLC (diamond-like carbon), which is based on the excellent lubricating performance of black phosphorus with active oxidation and the catalytic cleavage behavior of oil molecules on the surface of oBP. This work potentially expands the industrial application of superlubricity.

Hydration layer structure modulates superlubrication by trivalent La3+ electrolytes.

Water-based lubricants provide lubrication of rubbing surfaces in many technical, biological, and physiological applications. The structure of hydrated ion layers adsorbed on solid surfaces that determine the lubricating properties of aqueous lubricants is thought to be invariable in hydration lubrication. However, we prove that the ion surface coverage dictates the roughness of the hydration layer and its lubricating properties, especially under subnanometer confinement. We characterize different hydration layer structures on surfaces lubricated by aqueous trivalent electrolytes. Two superlubrication regimes are observed with friction coefficients of 10-4 and 10-3, depending on the structure and thickness of the hydration layer. Each regime exhibits a distinct energy dissipation pathway and a different dependence to the hydration layer structure. Our analysis supports the idea of an intimate relationship between the dynamic structure of a boundary lubricant film and its tribological properties and offers a framework to study such relationship at the molecular level.

A review of regeneration mechanism and methods for reducing soot emissions from diesel particulate filter in diesel engine.

With the global emphasis on environmental protection and the proposal of the climate goal of "carbon neutrality," countries around the world are calling for reductions in carbon dioxide, nitrogen oxide, and particulate matter pollution. These pollutants have severe impacts on human lives and should be effectively controlled. Engine exhaust is the most serious pollution source, and diesel engine is an important contributor to particulate matter. Diesel particulate filter (DPF) technology has proven to be an effective technology for soot control at the present and in the future. Firstly, the exacerbating effect of particulate matter on human infectious disease viruses is discussed. Then, the latest developments in the influence of key factors on DPF performance are reviewed at different observation scales (wall, channel, and entire filter). In addition, current soot catalytic oxidant schemes are presented in the review, and the significance of catalyst activity and soot oxidation kinetic models are highlighted. Finally, the areas that need further research are determined, which has important guiding significance for future research. Current catalytic technologies are focused on stable materials with high mobility of oxidizing substances and low cost. The challenge of DPF optimization design is to accurately calculate the balance between soot and ash load, DPF regeneration control strategy, and exhaust heat management strategy.

Antibiotic-based small molecular micelles combined with photodynamic therapy for bacterial infections.

The appearance of multidrug-resistant bacteria and the formation of bacterial biofilms have necessitated the development of alternative antimicrobial therapeutics. Antibiotics conjugated with or embedded in nano-drug carriers show a great potential and advantage over free drugs, but the mass proportion of carriers generally exceeds 90% of the nano-drug, resulting in low drug loading and limited therapeutic output. Herein, we fabricated a nanocarrier using antibiotics as the building blocks, minimizing the use of carrier materials, significantly increasing the drug loading content and treatment effect. Firstly, we conjugated betaine carboxylate with ciprofloxacin (CIP) through an ester bond to form the amphiphilic conjugate (CIP-CB), which self-assembled into micelles (CIP-CBMs) in aqueous solutions, with a CIP loading content as high as 65.4% and pH-induced surface charge reversal properties. Secondly, a model photosensitizer (5, 10, 15, 20-tetraphenylporphyrin (TPP)) was encapsulated in CIP-CBMs, generating infection-targeted photodynamic/antibiotic combined nanomedicines (denoted as TPP@CIP-CBMs). Upon accumulation at infection sites or in deep bacterial biofilms, the ester bond between the betaine carboxylate and CIP is cleaved to release free TPP and CIP, leading to a synergetic antibacterial and antibiofilm activity in vitro and in vivo.

Engineering Active-Site-Induced Homogeneous Growth of Polydopamine Nanocontainers on Loading-Enhanced Ultrathin Graphene for Smart Self-Healing Anticorrosion Coatings.

Engineering nanocontainers with encapsulated inhibitors onto graphene has been an emerging technology for developing self-healing anticorrosion coatings. However, the loading contents of inhibitors are commonly limited by inhomogeneous nanostructures of graphene platforms. Here, we propose an activation-induced ultrathin graphene platform (UG-BP) with the homogeneous growth of polydopamine (PDA) nanocontainers encapsulated with benzotriazole (BTA). Ultrathin graphene prepared by catalytic exfoliation and etching activation provides an ideal platform with an ultrahigh specific surface area (1646.8 m2/g) and homogeneous active sites for the growth of PDA nanocontainers, which achieves a high loading content of inhibitors (40 wt %). The obtained UG-BP platform exhibits pH-sensitive corrosion inhibition effects due to its charged groups. The epoxy/UG-BP coating possesses integrated properties of enhanced mechanical properties (>94%), efficient pH-sensitive self-healing behaviors (98.5% healing efficiency over 7 days), and excellent anticorrosion performance (4.21 × 109 Ω·cm2 over 60 days), which stands out from previous related works. Moreover, the interfacial anticorrosion mechanism of UG-BP is revealed in detail, which can inhibit the oxidation of Fe2+ and promote the passivation of corrosion products by a dehydration process. This work provides a universal activation-induced strategy for developing loading-enhanced and tailor-made graphene platforms in extended smart systems and demonstrates a promising smart self-healing coating for advanced anticorrosion applications.

Counterion-induced antibiotic-based small-molecular micelles for methicillin-resistant Staphylococcus aureus infections.

A new counterion-induced small-molecule micelle (SM) with surface charge-switchable activities for methicillin-resistant Staphylococcus aureus (MRSA) infections is proposed. The amphiphilic molecule formed by zwitterionic compound and the antibiotic ciprofloxacin (CIP), via a "mild salifying reaction" of the amino and benzoic acid groups, can spontaneously assemble into counterion-induced SMs in water. Through vinyl groups designed on zwitterionic compound, the counterion-induced SMs could be readily cross-linked using mercapto-3, 6-dioxoheptane by click reaction, to create pH-sensitive cross-linked micelles (CSMs). Mercaptosuccinic acid was also decorated on the CSMs (DCSMs) by the same click reaction to afford charge-switchable activities, resulting in CSMs that were biocompatible with red blood cells and mammalian cells in normal tissues (pH 7.4), while having strong retention to negatively charged bacterial surfaces at infection sites, based on electrostatic interaction (pH 5.5). As a result, the DCSMs could penetrate deep into bacterial biofilms and then release drugs in response to the bacterial microenvironment, effectively killing the bacteria in the deeper biofilm. The new DCSMs have several advantages such as robust stability, a high drug loading content (∼ 30%), easy fabrication, and good structural control. Overall, the concept holds promise for the development of new products for clinical application. STATEMENT OF SIGNIFICANCE: We fabricated a new counterion-induced small-molecule micelle with surface charge-switchable activities (DCSMs) for methicillin-resistant Staphylococcus aureus (MRSA) infections. Compared with reported covalent systems, the DCSMs not only have improved stability, high drug loading content (∼ 30%), and good biosafety, but also have the environmental stimuli response, and antibacterial activity of the original drugs. As a result, the DCSMs exhibited enhanced antibacterial activities against MRSA both in vitro and in vivo. Overall, the concept holds promise for the development of new products for clinical application.