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Ultrafine powders of silicon carbide synthesized by microwave and conventional heating are described. Silicon carbide powders with diameters in the nanometer range were formed by reducing SiO2 with various forms of carbon in a nitrogen atmosphere. Ultrafine SiO2 powder, phenolformaldehyde resin and ultrafine carbon black were used as starting materials. The properties of the powders were determined by means of X-ray diffraction, TEM, etc. The results showed that the technique and conditions for preparing samples, as well as the temperature and type of heating, had obvious effects on the powders characteristics. [ABSTRACT FROM AUTHOR]

Suppression structure is widely used to inhibit the water spray generated by aircraft tires during aircraft takeoff from or landing on a contaminated runway. The full-scale aircraft test of water spray has shown that the chine tire can effectively suppress the water spray at several low taxiing speeds, whereas its effectiveness would decrease significantly at high taxiing speeds. In this study, vertical falling test of a model chine tire into a thin water layer is conducted to investigate the effectiveness of the chine tire. The coupled smoothed particle hydrodynamics/finite element method is used to analyze the mechanism of the decreasing effectiveness of chine tires at high taxiing speeds, in which the geometry of the side chine, depth of water, and taxiing speed are considered. It was found out that leakage of water is the main reason for the decreasing effectiveness; the increment of the side-chine height caused by hydroplaning at a high taxiing speed may lead to a large amount of water leaking from the length direction and further from the width direction. Based on this understanding, a new configuration of an aircraft chine tire is proposed to suppress the leakage of water and to keep the effectiveness of the side chine at a wide range of taxiing speeds. [ABSTRACT FROM AUTHOR]

High strain rate can be produced in many manufacturing processes, such as ultra-high-speed machining and ultra-precision machining. This paper reviews the high strain rate generated in different machining processes. Molecular dynamics (MD) and finite element (FE) for studying the mechanism and characteristics in manufacturing processes are analyzed; the ductile–brittle transition (DBT) and brittle-ductile transition (BDT) under high strain rate are also reviewed. And the machining characteristics in ultra-high-speed cutting and ultra-precision cutting are analyzed and compared, including cutting force, cutting heat, machined surface quality, tool wear, and chip formation. It is proposed that the DBT under high strain rate in ultra-high-speed machining is contradictory with the BDT in ultra-precision machining, because the reasons for producing a high strain rate are different. By increasing the cutting speed vc in ultra-precision cutting appropriately, the machinability of softer materials may be increased, and surface and subsurface damage can be reduced. [ABSTRACT FROM AUTHOR]

This paper investigated the removal mechanism and surface quality of single crystal 4 H-SiC during the grinding process, as well as the impact of the measurement area on surface roughness (S a) during surface morphology detection. This problem is relatively unexplored. Experimental findings suggest that when the measurement area is below 400 µm², there is a greater error in S a. Conversely, when the measurement area exceeds 400 µm², the error in S a values is relatively small and stable. The surface quality increases with the increase of wheel speed (v s) and decreases with the increase of workpiece feed rate (v w) and grinding depth (a p). This study finds that the material removal of monocrystalline single crystal 4 H-SiC during the grinding process occurs primarily through plastic deformation, accompanied by brittle fracture. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The structural properties of crystalline silicon (Si) films on bare and aluminum-doped zinc oxide (AZO)-coated glass substrates were comparatively investigated by X-ray diffractometer, Raman spectroscopy, and transmission electron microscope. It was observed that for the amorphous Si (a-Si) films on bare and AZO-coated glass substrates subjected to five-step rapid thermal annealing (RTA) at 750°C/60s, they were both polycrystalline in nature and, moreover, the Si characteristic peak intensity of Si films on AZO-coated glass was slightly higher than that of Si films on bare glass, while the crystalline volume fractions of Si films on both substrates were nearly similar. Furthermore, it was revealed that a-Si films on AZO-coated glass can be crystallized when subjected to five-step RTA 750°C/60s, while Zn2SiO4 new phase was formed at RTA temperature of 900°C or higher, which may influence the crystalline Si films property. [Copyright &y& Elsevier]

Abstract: The rapid thermal annealing (RTA) crystallization of sputtered amorphous silicon (a-Si) films on quartz glass deposited with different substrate biases (0–150W) and at different substrate temperatures (100–400°C) has been investigated in detail by an X-ray diffractometer, and Raman and transmission electron microscopes. It was found that only the a-Si film deposited under the optimal condition (substrate bias: 100W, substrate temperature: 300°C) attained noticeable degrees of crystallization during the post-deposition RTA at 750°C. The RTA crystallized a-Si film deposited under optimal condition possessed crystalline fraction of 94.1%, and was proved to be polycrystalline in nature. Furthermore, it was revealed that the structural property of Si film improved with post-deposition RTA time or temperature. [Copyright &y& Elsevier]

The white neutron beamline at the China Spallation Neutron Source will be used mainly for nuclear data measurements. It will be characterized by high flux and broad energy spectra. To exploit the beamline as a neutron imaging source, we propose a liquid scintillator fiber array for fast neutron resonance radiography. The fiber detector unit has a small exposed area, which will limit the event counts and separate the events in time, thus satisfying the requirements for single-event time-of-flight (SEToF) measurement. The current study addresses the physical design criteria for ToF measurement, including flux estimation and detector response. Future development and potential application of the technology are also discussed. [ABSTRACT FROM AUTHOR]

As a non-edible, degradable, and environment-friendly crop product, castor oil can be used as lubricating oil in material processing. However, its high viscosity results in poor flowability, thereby limiting its industrial applications. Although experiments have revealed the excellent lubrication performance of castor/soybean oil mixture, the volume ratio of castor oil and soybean oil can significantly influence their minimum quantity lubrication (MQL) grinding performance. In the current study, seven castor/soybean oil mixtures under different volume ratios ranging between 1:0.5 and 1:4 were prepared for MQL grinding of Ni-based alloy. The mixed oils were compared with pure castor oil (1:0) in terms of viscosity and tribological behaviors. The grinding experiment involved the evaluation of specific grinding force, surface roughness, surface microtopography, and grinding debris, conluding that the preferred castor/soybean volume ratios were found to be 1:0.5, 1:1, 1:1.5, and 1:2. The surface microtopographies of selected workpieces were analyzed further in terms of their fractal dimension and scale coefficient, finding that the maximum fractal dimension ( D = 1.31) and minimum scale coefficient ( G = 0.30) are achieved when the volume ratio is 1:2. Hence, the optimal volume ratio is determined. [ABSTRACT FROM AUTHOR]

Numerous researchers have developed theoretical and experimental approaches to force prediction in surface grinding under dry conditions. Nevertheless, the combined effect of material removal and plastic stacking on grinding force model has not been investigated. In addition, predominant lubricating conditions, such as flood, minimum quantity lubrication, and nanofluid minimum quantity lubrication, have not been considered in existing force models. This work presents an improved theoretical force model that considers material-removal and plastic-stacking mechanisms. Grain states, including cutting and ploughing, are determined by cutting efficiency ( β ). The influence of lubricating conditions is also considered in the proposed force model. Simulation is performed to obtain the cutting depth ( a g ) of each “dynamic active grain.” Parameter β is introduced to represent the plastic-stacking rate and determine the force algorithms of each grain. The aggregate force is derived through the synthesis of each single-grain force. Finally, pilot experiments are conducted to test the theoretical model. Findings show that the model's predictions are consistent with the experimental results, with average errors of 4.19% and 4.31% for the normal and tangential force components, respectively. [ABSTRACT FROM AUTHOR]

This study investigates the critical maximum undeformed equivalent chip thickness for ductile-brittle transition ( DBh max -e ) of zirconia ceramics under different lubrication conditions. A DBh max -e model is developed through geometry and kinematics analyses of ductile-mode grinding. Result shows that DBh max -e decreases with increasing friction coefficient ( μ ). An experimental investigation is then conducted to validate the model and determine the effect of dry lubrication, minimum quantity lubrication (MQL), and nanoparticle jet minimum quantity lubrication (NJMQL) conditions on DBh max -e . According to different formation mechanisms of debris, the grinding behavior of zirconia ceramics is categorized into elastic sliding friction, plastic removal, powder removal, and brittle removal. Grinding forces per unit undeformed chip thickness ( F n/h and F t/h ) are obtained. The lubrication condition affects the normal force and ultimately influences the resultant force on workpiece. In comparison with dry grinding ( DBh max -e = 0.8 μm), MQL and NJMQL grinding processes increase DBh max -e by 0.99 and 1.79 μm respectively; this finding is similar to model result. The theoretical model is then assessed by different volume fractions of nanofluids under NJMQL condition with an average percentage error of less than 8.6%. [ABSTRACT FROM AUTHOR]

Lubricants play a critical role in machining, especially in the grinding process. As a result of the growing need for environmental protection and the increasing number of health problems faced by workers, traditional lubricants are gradually being replaced. Nanofluids, which contain nanoparticles in the proper base fluid, can serve as a low-carbon, “green” lubricant. As a lubricant, nanofluids show improved heat transfer capability and lubricating properties. Friction between abrasive grains and workpieces during grinding can directly influence grinding force, grinding wheel wear, and workpiece quality. Therefore, increasing lubricating effects is an effective way to improve machining performance. In this study, a nanofluid, as the lubricating fluid, is developed by adding 0.5 vol% to 4.0 vol% Al 2 O 3 nanoparticles to palm oil for the surface grinding of a Ni-based alloy in minimum quantity lubrication (MQL) mode. The tribological performance at the grinding wheel/workpiece interface under different concentrations of nanoparticles is studied on the basis of macroparameters (force ratio, specific energy, and G-ratio) and microparameters (surface quality, microstructure of abrasive grains and grinding debris, viscosity, and contact angle). Results show that the nanofluid flows through the grinding wheel and workpiece interface and forms a lubricating oil film that reduces friction significantly. An optimum concentration of nanoparticles is also achieved. The smallest force ratio of 0.281 is obtained when the volume concentration of the nanoparticles is 1.5%, whereas the minimum roughness of Ra = 0.301 μm, slender grinding debris, and maximum drop wetting area are realized when the volume concentration is 2.0%. Hence, the nanofluid exhibits excellent overall tribological performance. In addition, a nonlinear relationship exists between the lubricating effect and the concentration of the nanofluid. The appropriate concentration of Al 2 O 3 in the nanofluid thus provides good tribological performance and have both environmental and economic benefits for industrial applications. [ABSTRACT FROM AUTHOR]

Vegetable oil is employed as base fluid in precision grinding because of its biodegradability and non-pollutant properties. Castor oil exhibits superior lubrication performance to other vegetable oils, but its high viscosity and poor flow limit its application in industrial production. In this study, castor oil was used as base oil and individually mixed with six other kinds of vegetable oils (i.e., soybean, maize, peanut, sunflower, palm, and rapeseed oils) at a ratio of 1:1 to change the rheological properties of the former. Each mixture was obtained as base oil for minimum quantity lubrication grinding. The high-temperature nickel-based alloy GH4169 was used as workpiece to evaluate the lubrication performance at the grinding wheel/workpiece interface. The mechanism of lubrication was also studied based on the molecular structure of vegetable oil. Specific grinding force, specific grinding energy, surface roughness, surface microtopography, and grinding debris were compared among the experimental and comparison groups (castor oil). The workpiece surface profile was analyzed using the correlation function and cross-correlation coefficient. Results indicated that the comprehensive lubricating performance of mixed oil was superior to that of castor oil, and soybean/castor oil exhibited the optimal performance. The specific tangential grinding force and specific normal grinding force were 0.664 and 1.886 N/mm, respectively, with 27.03% and 23.15% reduction, respectively, with respect to those of castor oil. The surface profile curves of the workpiece obtained from four kinds of working conditions (castor oil, castor/soybean oil, castor/maize oil, and castor/palm oil) were also analyzed. The amplitude of the surface profile curve in castor/soybean oil is larger and the correlation coefficient is higher (0.51) than those under other mixed oils; hence, the workpiece showed the optimal surface quality. [ABSTRACT FROM AUTHOR]

The infections caused by Gram-positive bacteria (G +) have seriously endangered public heath due to their high morbidity and mortality. Therefore, it is urgent to develop a multifunctional system for selective recognition, imaging and efficient eradication of G +. Aggregation-induced emission materials have shown great promise for microbial detection and antimicrobial therapy. In this paper, a multifunctional ruthenium (II) polypyridine complex Ru2 with aggregation-induced emission (AIE) characteristic, was developed and used for selective discrimination and efficient extermination of G + from other bacteria with unique selectivity. The selective G + recognition benefited from the interaction between lipoteichoic acids (LTA) and Ru2. Accumulation of Ru2 on the G + membrane turned on its AIE luminescence and allowed specific G + staining. Meanwhile, Ru2 under light irradiation also possessed robust antibacterial activity for G + in vitro and in vivo antibacterial experiments. To the best of our knowledge, Ru2 is the first Ru-based AIEgen photosensitizer for simultaneous dual applications of G + detection and treatment, and inspires the development of promising antibacterial agents in the future. [Display omitted] • A multifunctional ruthenium (II) polypyridine complex with aggregation-induced emission (AIE) characteristic was synthesized. • The selective discrimination and imaging of gram-positive bacteria was with Ru2. • Ru2 under light irradiation had the best antibacterial activity in vitro and in vivo. • Ru2 altered Gram-positive bacterial gene expression and successfully applied to S. aureus -infected wound treatment. [ABSTRACT FROM AUTHOR]

• The SiC Schottky diode detector was fabricated and used to monitor D-T fusion neutron yields by associated particle method. • Accurate neutron yields were obtained and the results were highly consistent with the conventional Si surface barrier detector. • A long service lifetime of SiC detector based neutron yields monitoring system can be expected. The associated particle method is proven to be one of ideal options for D-T fusion neutron detection, acquiring accurate neutron yields by monitoring α particle. Semiconductor detectors can be used to detect α particle for compact size, high energy-resolution, and stable response. SiC detector with high radiation resistance is benefit for long service time in fusion neutron monitoring. In this paper, a SiC Schottky diode detector is used to detect associated α particles for D-T fusion neutron monitoring, and successfully gets accurate neutron yields, being highly consistent with the conventional Si surface barrier detector. It is encouraging to find out SiC detector can afford 2.56 × 109 cm−2 α particles irradiation, with slight performance degradation of dark current and energy resolution, indicating that SiC detector is a promising candidate for fusion neutron detection. [ABSTRACT FROM AUTHOR]

Different nanoparticles exhibit various physicochemical properties (e.g., structure and shape), which can influence their lubricating properties. In this work, six nanofluids, namely, MoS 2 , SiO 2 , diamond, carbon nanotubes (CNTs), Al 2 O 3 , and ZrO 2 , were used as minimum quantity lubrication grinding fluids to select the kind of nanoparticles with optimum lubrication performance in grinding nickel alloy GH4169. Experimental results concluded the following: 1) Nanoparticles with spherical or sphere-like molecular structure and nanofluids with high-viscosity demonstrate superior lubrication performances. 2) The polishing effect of nanodiamond particles enhances their surface morphology. 3) The lubricating property of the six nanofluids is described in the following order: ZrO 2

The influences of dry grinding (DG), wet grinding (WG) and carbon nanofluid minimum quantity lubrication (CN-MQL) on the grinding performances of ceramic matrix composites are investigated in this paper. Thermal imager and thermocouple results show that the cooling effect of CN-MQL with a carbon concentration (C) of 5 g/L is not weaker than that of WG. The maximum temperature of 5 g/L CN-MQL is 250.41 °C, compared to 336.98 °C for DG. This configuration also results in the minimum surface roughness and grinding force. Normal grinding force F n and surface maximum height difference S z decrease from 44.9 N to 8.44 μm for DG to 20.3 N and 4.13 μm, respectively. The corresponding grinding performance is also substantially better than that of WG. The grinding surface morphology shows that CN-MQL is conducive to obtaining surface morphology with few surface defects. The specific grinding energy results show that the energy consumed by CN-MQL is significantly reduced when removing the same volume of material. Based on a comprehensive analysis of the grinding performance parameters, there is an optimal value of C. At lower values, a uniform and dense film cannot be formed between the abrasive tool and the workpiece. At higher values, the particles agglomerate, and the performance is reduced. The experimental results show that the optimal C is 5 g/L. Considering the high pollution and high cost of grinding fluids, CN-MQL technology has the advantages of a simple preparation process, green and pollution-free properties, and no professional disposal requirements. CN-MQL is also conducive to reducing energy consumption in the processing approach. This research shows that CN-MQL has good application prospects for grinding processes. [Display omitted] • Carbon nanoparticles MQL process improves eco-friendability of grinding process. • Effects of dry, wet and CN-MQL on the grinding performance were researched. • Influences of nanoparticles concentration of CN-MQL were studied. • CN-MQL with concentration of 5 g/L can achieve excellent grinding performance. [ABSTRACT FROM AUTHOR]

Monodisperse magnetic hydroxyapatite (HAp)/Fe 3 O 4 microspheres were successfully synthesized and explored for the removal of lead(II) from aqueous solution. The mechanism of Pb 2+ uptake was characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The sorption capacity toward Pb 2+ reached 440 mg/g at pH 3.0 and equilibrium was achieved within 1 h. The experimental data followed the Langmuir isotherm model ( R 2 = 0.9969) and the kinetic results accorded with the pseudo-second-order model ( R 2 = 0.9970). The sorption of Pb 2+ on the surfaces of HAp/Fe 3 O 4 and the following ion exchange are the primary mechanism at pH 3.0–6.0. The dissolution–precipitation mechanism response to the removal of Pb 2+ when pH varied from 3.0 to 2.0. The Pb 2+ -loaded magnetic HAp/Fe 3 O 4 could be separated conveniently. [ABSTRACT FROM AUTHOR]

A controllable Am-Be neutron source was designed based on a hamburger structure including two Be pallets and a composite polymeric membrane carrying Am. The composite polymeric membrane was made of polyvinylidene fluoride (PVDF) and polyvinyl alcohol (PVA). PVDF polymeric membrane was used as the base film to load the mixed Am(NO)-PVA solution, which was coated on the PVDF polymeric membrane. The thickness of two layers was both about 5 μm. The correlative calculations were performed using the Geant4 code. A piece of composite membrane loading Am of 2.13 × 10 Bq was placed in the middle of two Be pallets just like a hamburger. Neutrons were produced continuously until the composite membrane was separated from Be pallets. The neutron yield of the controllable hamburger neutron source was measured as 54 n/(10α), which was 15.6 % lower than the calculation value. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the use of a combination of numerical calculations and experimental work to establish the optimum photovoltaic transmittance (T pv) and durability of the quarter wave, the quarter-half wave, and the non-quarter wave double-layer TiO2–SiO2 and ZrO2–SiO2 antireflective coatings (ARCs) on solar glass towards practical photovoltaic applications. Numerical calculations based on 4×4 propagation matrix method indicated that the non-quarter wave double-layer ARCs exhibited higher T pv values than those of the quarter wave and the quarter-half wave ARCs. Such calculated values are in good agreement with the experimental T pv values. For examples, the T pv values for the non-quarter wave double-layer TiO2–SiO2 and ZrO2–SiO2 ARCs prepared by sol–gel reached 94.4±0.1% and 94.3±0.1%, respectively. In terms of the coating durability, the non-quarter wave double-layer coatings with a dense and thicker TiO2 or ZrO2 barrier layer on solar glass exhibited less than 1% reduction in T pv after 96h highly-accelerated temperature and humidity stress test (HAST), as compared with the standard single-layer porous SiO2 used in industry which tested in the same HAST conditions to be greater than (15.4%) after 48h. Single crystalline Si modules encapsulated by the non-quarter wave TiO2–SiO2 or ZrO2–SiO2 AR-coated glass are more durable, with only less than 10% degradation in efficiency after 48h HAST, as compared with Si modules encapsulated by single-layer porous SiO2 AR-coated glass which have signification loss in efficiency (circa. 21.8%). [Copyright &y& Elsevier]

Abstract: The refractive index of transparent conductive oxides has a direct effect on the transmission of lights into thin film solar cells. Here we report the study of improving the refractive index of aluminum doped zinc oxide through titanium co-doping. The Al–Ti co-doped zinc oxide (ATZO) thin films with different Ti doping concentration were deposited on glass substrates by radio frequency magnetron sputtering with ATZO targets in an argon atmosphere. The structural, optical and electrical properties of the thin films were investigated using X-ray diffraction, ultraviolet–visible-near-infrared spectroscopy and hall measurements, respectively. The results showed that the as-deposited thin films were all textured along c-axis and perpendicular to the surface of substrate. The average transmittance in the visible region were more than 80% for all the ATZO thin films. The minimum resistivity of the obtained ATZO (1wt% TiO2 doping) thin films were 2.6×10−3 Ωcm and 1.4×10−3 Ωcm before and after annealing in vacuum, respectively. The refractive index of the thin films (at λ 0 =550nm) increased from 1.91 to 2.05 as the TiO2 content increased from 0wt% to 3wt%. [Copyright &y& Elsevier]

Abstract: In this paper, we report how the concentration of carbon-tetrafluoride (CF4) affects the primary scintillation from Ar+CF4 gas mixtures excited by proton and alpha particles. The single photon counting method was used to measure the time spectra of the primary scintillation from Ar, CF4 and their mixtures at atmospheric pressure. Pure Ar exhibits a fast decay time constant, which is approximately 6ns, and a slow decay time tail. Initially, increases in the concentration of CF4 increase the decay time of the Ar+CF4 gas mixture. However, when the concentration of CF4 exceeds a certain threshold, the decay time decreases to that of pure CF4, approximately 8–9ns. We also report the photon emission spectra of Ar+CF4 mixtures excited by protons. The emission spectrum of the primary scintillation from Ar is improved by CF4 in both the ultraviolet region and the visible to near-infrared region. [Copyright &y& Elsevier]

Abstract: The dependence of aluminum-doped zinc oxide (AZO) work function on surface treatment, i.e. acetone solvent cleaning and ultraviolet (UV)-ozone cleaning, was studied by ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy. Comparing different cleaning methods, UV-ozone treated AZO achieved relative higher work function of 4.26eV; whereas acetone solvent treated AZO had relative lower work function of 3.94eV. Two factors, stoichiometry ratio of [OZnAl]/[Zn]+1.5[Al] and carbon contamination on AZO surface, affected the work function and, moreover, the stoichiometry ratio was supposed to be the controlling factor. It was concluded that AZO with high stoichiometry ratio and reduced carbon concentration possessed high work function. [ABSTRACT FROM AUTHOR]

• High-performance and long-life alpha-voltaic cell based on SiC diode was fabricated. • The AV cell achieved excellent PCE of 0.88%, with a strikingly high V oc of 1.99 V. • Main factors that influence the performance of AV cell have been analyzed in depth. Alpha-voltaic cells have great potential in military, biomedical, and infrastructure applications due to their characteristics of long operating life, small volume, and superior adaptability. However, improvements in power conversion efficiency (PCE), and the balance between power density and stability have been a challenge owing to the 'poor-matching' between energy conversion transducers and alpha-emitting isotope sources, as well as the radiation damage to semiconductor devices. In this study, we report the electrical properties of a high-performance alpha-voltaic cell based on a 4H-SiC PIN junction diode energy conversion transducer (active area of 1 cm2) that has been experimentally validated by a He ions electrostatic accelerator. Remarkably, the alpha-voltaic cell displayed an excellent PCE of 0.88%, exhibiting a nearly 7-fold enhancement compared to alpha-voltaic cells of previous studies, with a strikingly high open-circuit voltage of 1.99 V, a short-circuit current of 13.64 nA/cm2, and a maximum output power density of 16.78 nW/cm2. [ABSTRACT FROM AUTHOR]

ZnO and Al‐doped ZnO ceramics with high density and fine grain size were prepared using a two‐step sintering method. ZnO ceramics with a grain size of 1.2 μm and a density greater than 99% were obtained. The kinetic window for a ZnO nanoparticle TSS process was determined in this study. Dense AZO ceramics with homogeneous Al distribution were obtained using a high sintering temperature (Tst) of 1323 K and a low sintering temperature (Tnd) of 1273 K. The activation energies for ZnO and AZO nanoparticle grain growth were determined to be 169 ± 18 kJ/mol and 374 ± 36 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

Edwardsiella tarda ( E. tarda ) can infect humans and a variety of animals, including fish, amphibians, reptiles, birds, and mammals. However, a more highly sensitive, specific, and repeatable test for its detection is lacking. The objective of this study was to develop a highly sensitive, specific, and repeatable droplet digital polymerase chain reaction (ddPCR)-based method for the quantitative detection of E. tarda . The gyrB gene was selected as the target gene, and primers and probe were designed and synthesized. Using E. tarda genomic DNA as templates, the reaction method was optimized to establish a linear relationship with real-time PCR detection methods. The sensitivity, specificity, and repeatability of the method were analyzed, and clinical samples were tested. When the primer and probe concentrations were 900 and 300 nM, respectively, and the annealing temperature was 57°C, the efficiency of the ddPCR amplification reaction was highest and the boundary between positive and negative droplet distribution was clearest. The sensitivity was high, with detection limit being as low as 0.56 copies·μL -1 ; additionally, and a good linear relationship ( R 2  = 0.9962) between ddPCR and real-time PCR detection, within the range of 1-25,000 copies·μL -1 , was evident. The repeatability was good, with a detection coefficient of variation of 2.74%. There was no cross-reactivity with 15 other common pathogenic microorganisms in aquatic animals ( Streptococcus agalactiae , Streptococcus iniae , Streptococcus suis type 2, Nocardia seriolae , Vibrio parahaemolyticus , Aeromonas sobria , red sea bream iridovirus, decapod iridescent virus 1, enterocytozoon hepatopenaei, carp edema virus, Koi herpesvirus, goldfish hematopoietic necrosis virus, tilapia lake virus, viral nervous necrosis virus, or grass carp reovirus) in positive samples. Among the 48 clinical samples, including Bahaba taipingensis and its live food fish, pond water samples, and routine monitoring samples (Koi), 21 were positive for E. tarda , consistent with the bacterial isolation and identification results. The E. tarda ddPCR detection method has high specificity, sensitivity, and repeatability, can more accurately quantify E. tarda , and provides a useful reference for research related to this bacterium., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Li, Li, Ye, Yin, Mo, Xie, Zhu, Zhong, Zhang and Bi.)

G-quadruplexes (G4s) are non-canonical nucleic acids secondary structures that involve in the regulation of some key biological processes, such as replication, transcription, and translation. G4s have been extensively described in the genomes of human and related diseases. In recent years, G4s were identified in several livestock viruses, including those of the emerging epidemics, like Nipah virus (NiV). Since their discovery, G4s have been developed as the potential antiviral targets, and the employment of G4 ligands or interacting proteins has helped to expound the viral infectivity and pathogenesis through G4-mediated mechanisms, and highlight the potential as therapeutic approaches. However, the comprehensively studies of G4s in livestock viruses have not been summarized. This review delves into the reported literatures of G4s in livestock viruses, particular focus on the presence, biophysical identification, and possible function of G4s in viral genome, summarizing the G4 ligands, interacted proteins and aptamers on antiviral applications. The strengths and the challenges of G4 targeting in this field are also discussed. Therefore, this review will shed new light on the future development of highly potent and targeting antiviral therapy., Competing Interests: Declaration of competing interest All authors have reviewed the final version of the manuscript and approved it to submission. All authors have declared no conflict interest., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Background: A high-altitude environment has inhibitory effects on obesity. Tibetans are not a high-risk population for obesity, but there are still obese individuals within that population. Obesity has become a worldwide health problem, and previous studies have found that obesity is closely associated with hereditary factors. Few studies have investigated obesity in Tibetans, and the association between gene polymorphisms and obesity in Tibetans remains unclear. Methods: Our study investigated the fat mass of 140 native Tibetan individuals (70 men and 70 women) from Lhasa and analyzed the associations between polymorphisms of melanocortin 4 receptor (MC4R), Src homology 2B adapter protein 1 (SH2B1), and neuronal growth regulator 1 (NEGR1) and obesity. Result: Among Tibetan individuals, there were differences in genotype and allele frequencies between those in the obesity group and those in the healthy group at MC4R (rs17782313) and SH2B1 (rs7359397). The polymorphisms of MC4R (rs17782313) were associated with fat mass and obesity in Tibetan men and women, and there was an association between SH2B1 (rs7359397) polymorphisms and fat mass and obesity in Tibetan men. However, polymorphisms of NEGR1 (rs3101336) were not associated with fat mass or obesity in Tibetan individuals. Conclusion: Among Tibetan individuals, polymorphisms of MC4R (rs17782313) and SH2B1 (rs7359397) were associated with obesity, but NEGR1 (rs3101336) polymorphisms were not associated with obesity.

Poor cellular permeability greatly hampers the utilization of anionic Ir(III) complexes, though efficiently emissive and remarkably stable, in cell-based diagnosis. To overcome this barrier, we present the development of an alkaline phosphatase (ALP)-responsive, anionic, and aggregation-induced emission (AIE)-active Ir(III) complex (Ir1) for specific recognition of osteosarcoma cells. Containing phosphate moieties, Ir1 exhibits a net -1 charge, enabling charge repulsion from the cell membrane and resulting in low cellular uptake and good biocompatibility in normal osteoblast cells. Upon ALP-mediated hydrolysis of phosphate groups, the resulting dephosphorylated product, Ir2, demonstrates a positive charge and increased lipophilicity, promoting cellular uptake and activating its AIE properties for specific recognition of osteosarcoma cells that express elevated levels of ALP. This study elucidates the role of ALP as an ideal trigger for enhancing the cellular permeability of phosphate ester-containing Ir(III) complexes, thus expanding the potential of anionic Ir(III) complexes for biomedical applications.

Induced lysosomal membrane permeabilization (LMP) by peptide self-assembly has emerged as an effective platform for lysosome-targeted cancer therapy. In this study, we shift this strategical paradigm and present an innovative approach to LMP induction through amino acid-based self-assembly. Pyrene-capped tyrosine (Py-Tyr), as a proof-of-concept molecule, is designed with acidity-responsive self-assembly. Under acidic conditions (pH 4), Py-Tyr is protonated with reduced charge repulsion, and self-assembles into micrometer-scaled aggregates, which exceed the biological size of lysosomes. Cell experiments showed that Py-Tyr specifically accumulates in lysosomes and induces lysosome rupture, leading to the release of cathepsin B into the cytoplasm for subsequent apoptosis activation in cancer cells. This study capitalizes on the concept of amino acid assembly for efficient LMP induction, providing a simple and versatile platform for precise and effective therapeutic interventions in cancer therapy., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Monitoring radioactivity levels in the environment around nuclear power plants is of great significance to assessing environmental safety and impact. Shidaowan nuclear power plant is currently undergoing commissioning; however, the baseline soil radioactivity is unknown. The naturally occurring radionuclides 238U, 232Th, 226Ra and 40K, and artificial radionuclide (AR) 137Cs in soil samples around the Shidaowan nuclear power plant were measured to establish the baseline levels. Human health hazard indices such as external hazard indices (Hex), Radium equivalent (Raeq), outdoor absorbed dose rate (Dout), annual effective dose (AED) and excess lifetime cancer risk (ELCR) were estimated. The average concentration of 232Th, 40K, 137Cs, 238U and 226Ra were 42.6 ± 15, 581 ± 131, 0.68 ± 0.38, 40.13 ± 9.07 and 40.8 ± 12.8 Bq per kg, respectively. The average Hex, Raeq, Dout, AED and ELCR were 0.40, 146 Bq per kg, 68.8 nGy per h, 0.09 mSv per y and 3.29E-04, respectively. These data showed an acceptable level of risk to residents near the nuclear power plant and that the current radioactivity in the soil may not pose immediate harm to residents living close to the nuclear power plant. The observed lower AED and 40 K and 137Cs concentrations were comparable to other studies, whilst ELCR was higher than the world average of 2.9E-04. The commissioning of the Shidaowan nuclear power plant is potentially safe for the surrounding residents; further continuous monitoring is recommended., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Plant viruses seriously disrupt crop growth and development, and classic protein-targeted antiviral drugs could not provide complete protection against them. It is urgent to develop antiviral compounds with novel targets. Photodynamic therapy shows potential in controlling agricultural pests, but nonselective damage from reactive oxygen species (ROS) unexpectedly affects healthy tissues. A G-quadruplex (G4)-forming sequence in the tobacco mosaic virus (TMV) genome was identified to interfere the RNA replication in vitro, and affect the proliferation of TMV in tobacco. N-methyl mesoporphyrin IX stabilizing the G4 structure exhibited inhibition against viral proliferation, which was comparable to the inhibition effect of ribavirin. This indicated that G4 could work as an antiviral target. The large conjugate planes shared by G4 ligands and photosensitizers (PSs) remind us that the PSs could work as antiviral agents by targeting G4 in the genome of TMV. Chlorin e6 (Ce6) was identified to stabilize the G4 structure in the dark and selectively cleave the G4 sequence by producing ROS upon LED-light irradiation, leading to 92.2% inhibition against TMV in vivo, which is higher than that of commercial ningnanmycin. The inhibition of Ce6 was lost against the mutant variants lacking the G4-forming sequence. These findings indicated that the G-quadruplex in the TMV genome worked as an important structural element regulating viral proliferation, and could act as the antiviral target of photodynamic therapy., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Xie et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: The Qinghai-Tibet Plateau is one of the last terrestrial environments conquered by modern humans. Tibetans are among the few high-altitude settlers in the world, and understanding the genetic profile of Tibetans plays a pivotal role in studies of anthropology, genetics, and archaeology. Methods: In this study, we investigated the maternal genetic landscape of Tibetans based on the whole mitochondrial genome collected from 145 unrelated native Lhasa Tibetans. Molecular diversity indices, haplotype diversity (HD), Tajima's D and Fu's Fs were calculated and the Bayesian Skyline Plot was obtained to determining the genetic profile and population fluctuation of Lhasa Tibetans. To further explore the genetic structure of Lhasa Tibetans, we collected 107 East Asian reference populations to perform principal component analysis (PCA), multidimensional scaling (MDS), calculated Fst values and constructed phylogenetic tree. Results: The maternal genetic landscape of Tibetans showed obvious East Asian characteristics, M9a (28.28%), R (11.03%), F1 (12.41%), D4 (9.66%), N (6.21%), and M62 (4.14%) were the dominant haplogroups. The results of PCA, MDS, Fst and phylogenetic tree were consistent: Lhasa Tibetans clustered with other highland Tibeto-Burman speakers, there was obvious genetic homogeneity of Tibetans in Xizang, and genetic similarity between Tibetans and northern Han people and geographically adjacent populations was found. In addition, specific maternal lineages of Tibetans also be determined in this study. Discussion: In general, this study further shed light on long-time matrilineal continuity on the Tibetan Plateau and the genetic connection between Tibetans and millet famers in the Yellow River Basin, and further revealed that multiple waves of population interaction and admixture during different historical periods between lowland and highland populations shaped the maternal genetic profile of Tibetans., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Zhang, Yu, Ye, Huang, Chen, Liu and Wen.)

Magnetic tunnel junctions (MTJs) with conventional bulk ferromagnets separated by a nonmagnetic insulating layer are key building blocks in spintronics for magnetic sensors and memory. A radically different approach of using atomically-thin van der Waals (vdW) materials in MTJs is expected to boost their figure of merit, the tunneling magnetoresistance (TMR), while relaxing the lattice-matching requirements from the epitaxial growth and supporting high-quality integration of dissimilar materials with atomically-sharp interfaces. We report TMR up to 192% at 10 K in all-vdW Fe 3 GeTe 2 /GaSe/Fe 3 GeTe 2 MTJs. Remarkably, instead of the usual insulating spacer, this large TMR is realized with a vdW semiconductor GaSe. Integration of semiconductors into the MTJs offers energy-band-tunability, bias dependence, magnetic proximity effects, and spin-dependent optical-selection rules. We demonstrate that not only the magnitude of the TMR is tuned by the semiconductor thickness but also the TMR sign can be reversed by varying the bias voltages, enabling modulation of highly spin-polarized carriers in vdW semiconductors., (© 2023. Springer Nature Limited.)

Intrauterine adhesion (IUA) is the fibrosis within the uterine cavity. It is the second most common cause of female infertility, significantly affecting women's physical and mental health. Current treatment strategies fail to provide a satisfactory therapeutic outcome for IUA patients, leaving an enormous challenge for reproductive science. A self-healing adhesive hydrogel with antioxidant properties will be highly helpful in IUA prevention. In this work, we prepare a series of self-healing hydrogels (P10G15, P10G20, and P10G25) with antioxidant and adhesive properties. Those hydrogels exhibit good self-healing properties and can adapt themselves to different structures. They possess good injectability and fit the shape of the human uterus. Moreover, the hydrogels exhibit good tissue adhesiveness, which is desirable for stable retention and therapeutic efficacy. The in vitro experiments using P10G20 show that the adhesive effectively scavenges ABTS+, DPPH, and hydroxyl radicals, rescuing cells from oxidative stress. In addition, P10G20 offers good hemocompatibility and in vitro and in vivo biocompatibility. Furthermore, P10G20 lowers down the in vivo oxidative stress and prevents IUA with less fibrotic tissue and better endometrial regeneration in the animal model. It can effectively downregulate fibrosis-related transforming growth factor beta 1 (TGF-β1) and vascular endothelial growth factor (VEGF). Altogether, these adhesives may be a good alternative for the clinical treatment of intrauterine adhesion., Competing Interests: All authors declared no competing interests., (© 2023 The Authors.)

Shape memory sponges are very promising in stopping the bleeding from noncompressible and narrow entrance wounds. However, few shape memory sponges have fast degradable properties in order to not hinder tissue healing. In this work, based on cryopolymerization, a succinic ester-based sponge (Ssponge) is fabricated using gelatin and bi-polyethylene glycol-succinimidyl succinate (Bi-PEG-SS). Compared with the commercially available gelatin sponge (Csponge), Ssponge possesses better water/blood absorption ability and higher mechanical pressure over the surrounding tissues. Moreover, in the models of massive liver hemorrhage after transection and noncompressive liver wounds by penetration, Ssponge exhibits a better hemostasis performance than Csponge. Furthermore, in a liver regeneration model, Ssponge-treated livers shows higher regeneration speed compared with Csponge, including a lower injury score, more cavity-like tissues, less fibrosis and enhanced tissue regeneration. Overall, it is shown that Ssponge, with a fast degradation behavior, is not only highly efficient in stopping bleeding but also not detrimental for tissue healing, possessing promising clinical translational potential., (© 2022 Wiley-VCH GmbH.)

Hydroxyapatite (HAp) as natural bone composition is highly osteoinductive. To harvest its osteoinductivity in bone regenerative engineering, the HAp-supporting hydrogel is urgently needed to minimize inhomogeneous aggregation of HAp. Here, we developed a HAp-stabilizing hydrogel based on peptide self-assembly. FmocFFRR was efficient for HAp-capping due to arginine-phosphate interaction. Tethering FmocFFRR on the HAp surface facilitated self-assembly to form FmocFFRR/HAp hybrid hydrogel, enabling stable dispersion of HAp in it. The molecular interactions between FmocFFRR and HAp particles were studied using microscopic and spectral characterizations. FmocFFRR/HAp hydrogel exhibited more enhanced mechanical properties than FmocFFRR. The biocompatibility of FmocFFRR/HAp hydrogel was verified using an ATP assay and live-dead staining assay. More importantly, FmocFFRR/HAp hydrogel not only enabled cell attachment on its surface, but also supported 3D cell culturing inside the hydrogel. Further, 3D culturing of MC3T3-E1 preosteoblasts inside FmocFFRR/HAp hydrogel significantly enhanced the expressions of osteogenesis markers, including alkaline phosphate (ALP), type-I collagen (COL1), and osteocalcin (OCN), demonstrating the promoting effect of osteoblast differentiation. These findings inspire its potential application in bone regenerative engineering.

The Mongolian population exceeds six million and is the largest population among the Mongolic speakers in China. However, the genetic structure and admixture history of the Mongolians are still unclear due to the limited number of samples and lower coverage of single-nucleotide polymorphism (SNP). In this study, we genotyped genome-wide data of over 700,000 SNPs in 38 Mongolian individuals from Fuxin in Liaoning Province to explore the genetic structure and population history based on typical and advanced population genetic analysis methods [principal component analysis (PCA), admixture, F ST , f 3 -statistics, f 4 -statistics, qp Adm/ qp Wave, qp Graph, ALDER, and TreeMix]. We found that Fuxin Mongolians had a close genetic relationship with Han people, northern Mongolians, other Mongolic speakers, and Tungusic speakers in East Asia. Also, we found that Neolithic millet farmers in the Yellow River Basin and West Liao River Basin and Neolithic hunter-gatherers in the Mongolian Plateau and Amur River Basin were the dominant ancestral sources, and there were additional gene flows related to Eurasian Steppe pastoralists and Neolithic Iranian farmers in the gene pool of Fuxin Mongolians. These results shed light on dynamic demographic history, complex population admixture, and multiple sources of genetic diversity in Fuxin Mongolians., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Hou, Zhang, Li, Huang, Li, Zhang, Huang and Wen.)

Abstract: The eye lens is a sensitive tissue to ionizing radiation and recently has been recognized as more radiosensitive than previously considered. The International Commission on Radiological Protection (ICRP) has recommended a considerable reduction in the equivalent dose limit of eye lens from 150 mSv y -1 to 20 mSv y -1 , averaged over a defined period of 5 y. In this paper, the eye lens dose of interventional radiology workers in China during 2017-2019 is analyzed to understand the current status of eye lens occupational exposure and to provide decision-making suggestions for health supervision departments using data obtained from the National Radiological Health Information Platform in China. A total of 3,026 eye lens dose records of interventional radiology workers were collected. The average annual eye lens dose (AAELD) for interventional radiology workers ranged from 1.07 to 1.51 mSv during 2017-2019 and was 1.44 mSv for all monitored interventional radiology workers, with 2,973 records (98.2%) lower than the public limit of 15 mSv and 33 records (1.1%) exceeding the newly revised occupational eye lens dose limit of 20 mSv y -1 . During the period of 2017-2019, the AAELDs of interventional radiologists (1.61 mSv) and of interventional cardiologists (1.59 mSv) were significantly higher than that of other interventional workers (0.62 mSv); the AAELD of doctors (1.50 mSv) was significantly higher than that of nurses (1.01 mSv); the AAELD of western China (2.00 mSv) was significantly higher than that of eastern (1.11 mSv) and central China (1.27 mSv); and the AAELD of males (1.59 mSv) was significantly higher than that of females (0.84 mSv). The eye lens dose of interventional radiology workers meets the Chinese standard limit of 150 mSv y -1 , while some cases exceed the one recommended by ICRP. The study shows that the interventional radiology workers' eye lens dosimetry data complied with the existing Chinese eye lens dose limits. However, education, training, and supervision of radiation protection also should be strengthened continuously for interventional radiology workers, especially for the interventional radiologists and interventional cardiologists. Significant attention should be paid to the radiation protection of underdeveloped regions in China in future works., Competing Interests: Conflicts of Interest and Sources of Funding: No conflicts of interest or sources of funding are declared., (Copyright © 2022 Health Physics Society.)

The efficient detection of Fe 3+ and MnO 4 - in a water environment is very important and challenging due to their harmful effects on the health of humanity and environmental systems. Good biocompatibility, sensitivity, selectivity, and superior photophysical properties were important attributes of carbon dot-based CDs sensors for sensing applications. In this work, we synthesized N, P- co -doped carbon dots (N/P CDs) with guanosine 5'-monophosphate (GMP) as a green carbon source, with high fluorescence quantum yield in water (QY, 53.72%). First, the luminescent N/P CDs showed a three-state "on-off-on" fluorescence response upon the sequential addition of Fe 3+ and F - , with a low detection limit of 12 nM for Fe 3+ and 8.5 nM for F - , respectively. Second, the N/P CDs also exhibited desirable selectivity and sensitivity for toxic MnO 4 - detection with the limit of detection of 18.2 nM, through a turn-off mechanism. Moreover, the luminescent N/P CDs successfully monitored the aforementioned ions in environmental water samples and in Escherichia coli ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Liu, Nong, Song, Zhang, Shen, Jian, Chen, Li and Xu.)

Sherpa people, one of the high-altitude hypoxic adaptive populations, mainly reside in Nepal and the southern Tibet Autonomous Region. The genetic origin and detailed evolutionary profiles of Sherpas remain to be further explored and comprehensively characterized. Here we analyzed the newly-generated InDel genotype data from 628 Dingjie Sherpas by merging with 4222 worldwide InDel profiles and collected genome-wide SNP data (approximately 600K SNPs) from 1612 individuals in 191 modern and ancient populations to explore and reconstruct the fine-scale genetic structure of Sherpas and their relationships with nearby modern and ancient East Asians based on the shared alleles and haplotypes. The forensic parameters of 57 autosomal InDels (A-InDels) included in our used new-generation InDel amplification system showed that this focused InDel panel is informative and polymorphic in Dingjie Sherpas, suggesting that it can be used as the supplementary tool for forensic personal identification and parentage testing in Dingjie Sherpas. Descriptive findings from the PCA, ADMIXTURE, and TreeMix-based phylogenies suggested that studied Nepal Sherpas showed excess allele sharing with neighboring Tibeto-Burman Tibetans. Furthermore, patterns of allele sharing in f-statistics demonstrated that Nepal Sherpas had a different evolutionary history compared with their neighbors from Nepal (Newar and Gurung) but showed genetic similarity with 2700-year-old Chokhopani and modern Tibet Tibetans. QpAdm/qpGraph-based admixture sources and models further showed that Sherpas, core Tibetans, and Chokhopani formed one clade, which could be fitted as having the main ancestry from late Neolithic Qijia millet farmers and other deep ancestries from early Asians. Chromosome painting profiles and shared IBD fragments inferred from fineSTRUCTURE and ChromoPainter not only confirmed the abovementioned genomic affinity patterns but also revealed the fine-scale genetic microstructures among Sino-Tibetan speakers. Finally, natural-selection signals revealed via iHS, nSL and iHH12 showed natural selection signatures associated with disease susceptibility in Sherpas. Generally, we provided the comprehensive landscape of admixture and evolutionary history of Sherpa people based on the shared alleles and haplotypes from the InDel-based genotype data and high-density genome-wide SNP data. The more detailed genetic landscape of Sherpa people should be further confirmed and characterized via ancient genomes or single-molecule real-time sequencing technology., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Manchu is the third-largest ethnic minority in China and has the largest population size among the Tungusic-speaking groups. However, the genetic origin and admixture history of the Manchu people are far from clear due to the sparse sampling and a limited number of markers genotyped. Here, we provided the first batch of genome-wide data of genotyping approximate 700,000 single-nucleotide polymorphisms (SNPs) in 93 Manchu individuals collected from northeast China. We merged the newly generated data with data of publicly available modern and ancient East Asians to comprehensively characterize the genetic diversity and fine-scale population structure, as well as explore the genetic origin and admixture history of northern Chinese Manchus. We applied both descriptive methods of ADMIXTURE, fineSTRUCTURE, F ST , TreeMix, identity by decedent (IBD), principal component analysis (PCA), and qualitative f -statistics ( f 3 , f 4 , qpAdm, and qpWave). We found that Liaoning Manchus have a close genetic relationship and significant admixture signal with northern Han Chinese, which is in line with the cluster patterns in the haplotype-based results. Additionally, the qpAdm-based admixture models showed that modern Manchu people were formed as major ancestry related to Yellow River farmers and minor ancestry linked to ancient populations from Amur River Bain, or others. In summary, the northeastern Chinese Manchu people in Liaoning were an exception to the coherent genetic structure of Tungusic-speaking populations, probably due to the large-scale population migrations and genetic admixtures in the past few hundred years., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, He, Li, Wang, Li, Chen, Qu, Wang, Xi, Wang and Wen.)