Search

Background: Recent studies have established a correlation between folate levels and the incidence of cervical cancer. Given that Human Papillomavirus (HPV) infection is a primary etiological factor in the development of cervical cancer, the nature of the relationship between dietary folate intake and HPV infection remains an area of ongoing investigation. Methods: To investigate the association between dietary folate intake and HPV infection, this study utilized data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2005 to 2016. Multivariate logistic regression analysis was employed to examine the potential associations. Furthermore, the use of restricted cubic splines (RCS) facilitated the exploration of any non-linear correlations. Additionally, subgroup analyses were used to explore this correlation in different populations. Results: The study encompassed a total of 6747 women aged between 18 and 59 years. For every one mcg increase in folate intake, the incidence of HPV infection is reduced by 1% (OR = 0.99, p<0.05). Besides, folate intake was categorized into quartiles as follows: Q1 (<211 mcg/day), Q2 (211–311 mcg/day), Q3 (311–448 mcg/day), and Q4 (>448 mcg/day). The adjusted odds ratios (OR) for the different folate levels were as follows: Q2: 0.94 (95% CI: 0.76–1.16), Q3: 0.84 (95% CI: 0.67–1.04), and Q4: 0.63 (95% CI: 0.49–0.81). The RCS analysis confirmed a nonlinear relationship between dietary folate intake and HPV infection risk. Notably, a significant inverse association was observed when dietary folate intake exceeded 193.847 mcg/day. Conclusions: In conclusion, the findings of this study indicate a negative association between dietary folate intake and the risk of HPV infection. This association demonstrates a nonlinear pattern, particularly evident at higher levels of folate consumption. [ABSTRACT FROM AUTHOR]

AIM: To explore the intensity-dependent effects of exercises to alleviate fear memory generalization in post-traumatic stress disorder (PTSD) and the underlying mechanism. METHODS: Male C57 BL/6J mice were randomly divided into the control group, PTSD group, high-intensity exercise (PTSD-High) group, and low-intensity exercise (PTSD-Low) group. PTSD model were created via using a combination of conditioned foot shock(CF) and single-prolonged stress (SPS). The contextual fear test was used to test the mice's ability to discriminate safety situations from fear condition. Immunofluorescence observed and quantified the newborn immature neurons in the DG area of the mice's hippocampus. ELISA was used to determine the secretion level of serum tissue adiponectin. RESULTS: (1) The immobility times for the PTSD-High and Control groups were significantly lower than those of the PTSD group. (2) Immunofluorescence analysis showed that the cell density, dendritic branching points and length of newborn immature neurons were elevated in High and Low groups compared to the PTSD group. (3) Adiponectin levels in the serum of the control and PTSD High group were significantly higher than those in the PTSD group and PTSD-Low group. CONCLUSION: Fear memory establishment in PTSD mice is associated with decreased hippocampal neurogenesis. High-intensity exercise ameliorated fear memory by enhancing adiponectin secretion and promoting hippocampal neurogenesis. High-intensity exercise exerted better improvement of brain functions to PTSD model. [ABSTRACT FROM AUTHOR]

Polymer‐derived ceramics (PDCs) have become promising candidates for electromagnetic wave (EMW) absorption due to their high thermal stability, design flexibility, and versatile functionality. However, the inevitable porous structure formed during pyrolysis greatly limits its mechanical performance. In this work, Ni–Fe–C/HfO2/SiCN ceramic was prepared by simultaneously doping nickel and iron‐containing metal‐organic framework (Ni–Fe–MOF) nanoparticles and hafnium dioxide (HfO2) nanoparticles into the ceramic precursor, thereby improving its intrinsic brittle structure while granting it extraordinary EMW absorption performance. The flexural strength, flexural modulus, and Vickers hardness of Ni–Fe–C/HfO2/SiCN ceramic were 101.06 MPa, 40.19 GPa, and 13.31 GPa, respectively. These values were 1 132%, 749%, and 191% higher than those of the initial SiCN ceramics. In addition, by optimizing the content of Ni–Fe–MOF, the Ni–Fe–C/HfO2/SiCN ceramic demonstrated satisfying EMW absorption performance from 25°C to 500°C. At 25°C, the minimum reflection loss (RLmin) and effective absorption bandwidth (EAB) were −54.07 dB and 3.95 GHz, covering 94% of the X‐band at a thickness of 2.27 mm. At 500°C, the RLmin and EAB were −33.72 dB and 1.82 GHz, still covering 43% of the X‐band at a thickness of only 1.65 mm. This work provides valuable insight into the integration of mechanical and EMW absorbing functions of PDC materials. [ABSTRACT FROM AUTHOR]

Inter-turn short circuit fault (ISCF) is the main fault type of dry-type air-core reactors (DARs), and the reactor burnout event caused by winding ISCF seriously threatens the safe and stable operation of the electric power system. In order to effectively curb the further worsening of ISCF in DARs, a fault detection method based on frequency response analysis was proposed. First, the effect of ISCF on the frequency response curve of the windings was investigated based on the distributed parameter model of DARs. Then, four sets of eigenvalues were proposed for ISCF diagnosis based on the influence law and curve data analysis theory. Finally, based on the eigenvalues, the support vector machine model optimized by the sparrow search algorithm was used to effectively classify the degree of ISCF of the reactor, and the accuracy reached 96%. Furthermore, a test platform was built based on the theoretical analysis for experimental verification, and the test results are consistent with the simulation results. Hence, the method proposed in this paper could effectively classify the ISCF and its severity in DARs. The research in this paper could provide effective guidance for the diagnosis of ISCF in DARs. [ABSTRACT FROM AUTHOR]

High temperature proton exchange membrane (HT-PEM) is a core component for high temperature proton exchange membrane fuel cells (HT-PEMFCs). Although phosphoric acid (PA) doped polybenzimidazole (PBI) membranes are widely applied in HT-PEMFCs, the synthetic procedure is rather tough and the carcinogenic monomer should be used. Thus, it is of significance to obtain cheaper and easily prepared HT-PEMs with moderate physicochemical properties and good fuel cell performance. Herein, using a straightforward Friedel-Crafts reaction between 4-acetylpyridine, biphenyl and para -terphenyl, a series of poly(biphenyl- co -terphenyl pyridine) copolymers (Co- x %BP- y %TP) are developed. The obtained Co- x %BP- y %TP membranes exhibit excellent capability of absorbing PA owing to the existence of pyridine units in polymers, and meanwhile PA absorption capacity of membranes increase with the increased percentage of the biphenyl moiety in copolymers. Through immersing in 85 wt% PA at 100 °C, the Co–25%BP-75%TP membrane achieves a PA uptake of 274%, displays a moderate tensile strength of 4.7 MPa and possesses a high conductivity of 0.099 S cm−1 at 180 °C. Consequently, under 200 °C and no backpressure condition, the peak power density of the H 2 –O 2 cell equipped with Co–25%BP-75%TP/274%PA membrane reached a high value of 773 mW cm−2, demonstrating a big potential to be operated in HT-PEMFCs. • Series of poly(biphenyl- co -terphenyl pyridine) copolymers are synthesized through one-step polymerization. • Co–25%BP-75%TP/274%PA shows a high conductivity of 0.099 S cm−1 at 180 °C. • HT-PEMFCl with Co–25%BP-75%TP/274%PA exhibits a high peak power density of 773 mW cm−2 at 200 °C. [ABSTRACT FROM AUTHOR]

Background: The diseased bile duct in bilobar congenital biliary dilatation is extensive and often requires major hepatectomy or liver transplantation associated with a higher risk. We aimed to evaluate the safety and benefit of modified mesohepatectomy, in comparison with trisectionectomy, to treat bilobar congenital biliary dilatation. Methods: This study included 28 patients with type IV and V bilobar congenital biliary dilatation. An innovative mesohepatectomy comprising the hepatectomy technique beyond the P/U point and bile duct shaping was applied to 14 patients to address the extensively diseased bile duct and difficulty in hepaticojejunostomy. Another 14 patients received trisectionectomy. The perioperative and long‐term outcomes of these patients were compared. Results: The ratio of residual liver volume to standard liver volume in the mesohepatectomy group was higher (78.68% vs. 40.90%, p = 0.005), while the resection rate of the liver parenchyma was lower (28.25% vs. 63.97%, p = 0.000), than that in trisectionectomy group. The mesohepatectomy group had a lower severe complication (>Clavein III, 0% vs. 57.70%, p = 0.019) and incidence of posthepatectomy liver failure (7.14% vs. 42.86%, p = 0.038). No significant difference was observed in blood loss and bile leakage (p > 0.05). All the patients in the mesohepatectomy group achieved optimal results in the long‐term follow‐up. Conclusions: mesohepatectomy provides an efficient treatment option for bilobar congenital biliary dilatation and can achieve radical resection, retain more liver parenchyma, and reduce the difficulty of hepaticojejunostomy, especially for patients that are not eligible for major hepatectomy and liver transplantation. [ABSTRACT FROM AUTHOR]

The Phyllanthus emblica, which is a dual-use resource for medicine and food, is a dried and mature fruit of Phyllanthus emblica in Euphorbiaceae plant. It is rich in various compounds, including amino acids, flavonoids, terpenoids, volatile oils, etc. Phyllanthus emblica extract has various biological activities, including anti microbial infection, antioxidation, anti-tumor, lowering blood lipids and blood sugar, lowering blood pressure and tonifying. The commonly used extraction methods for different components include solvent method, ultrasonic assisted method, impregnation method, enzyme assisted method, subcritical water extraction method, microwave assisted method, reflux method, decompression method, etc. The article provides a summary of the various chemical components in Phyllanthus emblica, outlines the extraction methods for each component, discusses the optimal extraction conditions, and compares the advantages and disadvantages of different methods, summarizes the research of Phyllanthus emblica in animal husbandry, to provide reference for the application of Phyllanthus emblica extract in animal husbandry production. [ABSTRACT FROM AUTHOR]

This study uses root exudates and radial oxygen loss (ROL) produced by plants to increase the amount of power produced by sediment microbial fuel cells (SMFCs) and improve copper removal. Among the three plants tested, which are commonly found in wetlands, Ipomoea aquatica produces the highest yield of root exudates and ROL, with respective values of 8.54 mg/(g‧d) and 2.1 μmol/(g‧h) at 50-mg/L Cu inhibition. The maximum power density of an SMFC with 450 mg/kg of copper-containing sediment and Ipomoea aquatica planted at the anode is 58.4 mW/m3, which is three times greater than that of an SMFC with Ipomoea aquatica planted at the cathode. This demonstrates that plant root exudates provide anodic microorganisms with easily decomposed organic matter, which increases the amount of power. The presence of a bioelectrochemical process is demonstrated by the presence of Cu(II) reduction deposits on the cathode surface. According to the findings, planting Ipomoea aquatica at the anode produces more electricity and removes slightly less copper than planting it at the cathode. It is concluded that planting Ipomoea aquatica at the anode is more effective than planting it at the cathode. [Display omitted] [ABSTRACT FROM AUTHOR]

Fouling is inevitable on the surfaces of industrial equipment, especially on heat-exchanging surfaces in contact with fluids, which causes water pollution and destroys the ecological environment. In this paper, a novel fouling-removal methodology for plate structure based on cavitation by multi-frequency ultrasonic guided waves is proposed, which can remove fouling on stainless steel plates. A numerical simulation method has been developed to study the acoustic pressure distribution on a steel plate. According to the simulation results, the distribution of sound pressure on the plate under triple-frequency excitation is denser and more prone to cavitation than in single-frequency cases and dual-frequency cases, which improves fouling removal rate. The stainless steel plate is immersed in water for the descaling experiment, and the results show that the fouling removal rates of three water-loaded stainless steel plates under different single-frequency excitation seem unsatisfactory. However, the multi-frequency excitation improves the descaling performance and the removal rate of fouling reaches 80%. This new method can be applied to the surface descaling of large equipment plates, which is of great significance for purifying water quality and protecting the ecological environment. [ABSTRACT FROM AUTHOR]

Simple Summary: Smell is an important sense for insects. The olfactory sense of insects is involved in their feeding, mating, egg-laying, predation avoidance, and communication behaviors. The use of insect-specific odorants to control insect behavior is an important control method. Here, we built iORandLigandDB, a platform for the batch prediction of insect-specific odorants based on artificial intelligence technology. The 3D structure of existing ORs in insects and the docking data with relevant odorants can be retrieved from the database. The use of insect-specific odorants to control the behavior of insects has always been a hot spot in research on "green" control strategies of insects. However, it is generally time-consuming and laborious to explore insect-specific odorants with traditional reverse chemical ecology methods. Here, an insect odorant receptor (OR) and ligand database website (iORandLigandDB) was developed for the specific exploration of insect-specific odorants by using deep learning algorithms. The website provides a range of specific odorants before molecular biology experiments as well as the properties of ORs in closely related insects. At present, the existing three-dimensional structures of ORs in insects and the docking data with related odorants can be retrieved from the database and further analyzed. [ABSTRACT FROM AUTHOR]

Background: Chinese medicinal retention enemas have gradually attracted the attention of clinicians as an alternative approach for tubal obstructive infertility. The purpose of this study was to investigate the efficacy and safety of conventional surgery combined with traditional Chinese medicinal retention enemas for the treatment of tubal obstructive infertility. Materials and methods: Eight electronic databases were searched from their inception to November 30, 2022. To assess the efficacy and safety of different treatments, following outcomes were measured: clinical pregnancy rate, clinical total effective rate, incidence of ectopic pregnancy, the improvement of Traditional Chinese Medicinal (TCM) symptoms, the improvement of the signs of obstructive tubal infertility and side effects. Results: A total of 23 Randomized Controlled Trials (RCTs) with 1909 patients met the inclusion criteria. The pooled results showed a higher pregnancy rate in the experimental group than in the control group (RR 1.75, 95% CI [1.58, 1.94], Z = 10.55, P<0.00001). The clinical total effective rate in the experimental group was higher than that in the control group (RR 1.28, 95% CI [1.23, 1.34], Z = 11.07, P<0.00001). The incidence of ectopic pregnancy in the experimental group was lower than that in the control group (RR 0.40, 95% CI [0.20, 0.77], Z = -2.73, P = 0.01). Conclusion: Based on current evidence, we concluded that conventional surgery combined with traditional Chinese medicinal retention enema for tubal obstructive infertility was superior to conventional surgery alone in improving the clinical pregnancy rate, improving clinical total effective rate, improving TCM symptoms, improving the signs of obstructive tubal infertility and lowering the incidence of ectopic pregnancy. However, further clinical trials with high-quality methodologies need to be conducted. [ABSTRACT FROM AUTHOR]

Polymers are known to adsorb spontaneously from liquid solutions in contact with high‐energy substrates to form configurationally complex, but robust phases that often exhibit higher durability than might be expected from the individual physical bonds formed with the substrate. Rational control of the physical, chemical, and transport properties of such interphases has emerged as a fundamental opportunity for scientific and technological advances in energy storage technology but requires in‐depth understanding of the conformation states and electrochemical effect of the adsorbed polymers. Here, we analyze the interfacial adsorption of oligomeric polyethylene glycol (PEG) chains of moderate sizes dissolved in protic and aprotic liquid electrolytes and find that there is an optimum polymer molecular weight of approximately 400 Da at which the highest columbic efficiency is achieved for both Zn and Li deposition. These findings point to a simple, versatile approach for extending the lifetime of batteries. [ABSTRACT FROM AUTHOR]

Polymers are known to adsorb spontaneously from liquid solutions in contact with high‐energy substrates to form configurationally complex, but robust phases that often exhibit higher durability than might be expected from the individual physical bonds formed with the substrate. Rational control of the physical, chemical, and transport properties of such interphases has emerged as a fundamental opportunity for scientific and technological advances in energy storage technology but requires in‐depth understanding of the conformation states and electrochemical effect of the adsorbed polymers. Here, we analyze the interfacial adsorption of oligomeric polyethylene glycol (PEG) chains of moderate sizes dissolved in protic and aprotic liquid electrolytes and find that there is an optimum polymer molecular weight of approximately 400 Da at which the highest columbic efficiency is achieved for both Zn and Li deposition. These findings point to a simple, versatile approach for extending the lifetime of batteries. [ABSTRACT FROM AUTHOR]

We systematically study the interaction behaviors between a point defect (PD) and two types of 1/2 〈111〉 {110} and 1/2 〈111〉 {112} edge dislocations using molecular dynamics (MD), elastic dipole tensor, and kinetic Monte Carlo (KMC) methods in tungsten (W). We first determine the capture region of a vacancy and four types of self-interstitial atoms (SIAs) by calculating their binding energies to both edge dislocations using MD. We then find anisotropic distributions of the diffusion energy barriers of PDs in dislocation systems employing the MD and elastic dipole tensor methods. Subsequently, we utilize the KMC method to obtain the lifetime of PDs and calculate the capture efficiencies of both edge dislocations to PDs at various temperatures and dislocation densities. Results show the capture efficiency of a vacancy decreases with increasing temperature, while it first increases and then decreases with increasing temperature for SIAs. As dislocation density increases, the capture efficiency of PDs increases. Ultimately, the swelling rate is estimated based on the capture efficiency and falls within the range of experimental data. The swelling rate increases first and then decreases with increasing temperature, and the maximum swelling rate occurs around 1200 K, while it increases with increasing the dislocation density. The present results are critical for understanding the interaction behaviors between PDs and 1/2 〈111〉 edge dislocations in W, which provide an essential database for large-scale simulation methods such as rate theory and phase-field simulations. [ABSTRACT FROM AUTHOR]

With the increased use of aniline, potential impacts on human health cannot be ignored. The hepatotoxicity of aniline is largely unknown and the underlying mechanism remains unclear. Therefore, the aim of the present study was to investigate the hepatotoxicity of aniline and elucidate the underlying mechanism. AML12 cells were exposed to different concentrations of aniline (0, 5, 10, or 20 mM) to observe changes to reactive oxygen species (ROS) production and the expression patterns of necroptosis-related proteins (RIPK1, RIPK3, and MLKL). The potential mechanism underlying aniline-induced hepatotoxicity was explored by knockout of RIPK1. The results showed that aniline induced cytotoxicity in AML12 cells in a dose-dependent manner in addition to the production of ROS and subsequent necroptosis of AML12 cells. Silencing of RIPK1 reversed upregulation of necroptosis-related proteins in AML12 cells exposed to aniline, demonstrating that aniline-induced ROS production was related to necroptosis of AML12. Moreover, aniline promoted intracellular RIPK1 activation, suggesting that the RIPK1/ROS pathway plays an important role in aniline-induced hepatotoxicity. NAC could quench ROS and inhibit necroptosis. These results provide a scientific basis for future studies of aniline-induced hepatotoxicity for the prevention and treatment of aniline-induced cytotoxicity. [ABSTRACT FROM AUTHOR]

• The flame charge is obtained by the method of charge density considering polarity. • The local area of the premixed flame exhibits either positive or negative polarity. • The polarity is regularly distributed in different zones of the premixed flame. • The regional polarity formation is related to the distribution of charged particle. The study of flame charge is helpful in analyzing the combustion regime, which is significant for optimizing energy conversion in the combustion. In this article, a method to calculate the charge density considering polarity (CDCP) for flame is presented. The charge in the flame local area is obtained by combining the effect of charged particles with positive and negative polarity. The CDCP in different zones of the premixed methane flame with three equivalence ratios of 0.9, 1.0, and 1.3 is measured in the Langmuir probe measurement experiment. The experiment result found that the regional polarity is shown in the premixed flame. Subsequently, the premixed methane flame was simulated using Fluent, and then the simulation distribution of CDCP in the premixed methane flame was obtained. The CDCP and polarity across the reactant, preheat, reaction, and product zones of the premixed flame are analyzed based on the experiment and simulation results. The CDCP of the reaction zone is greater than 0 C/m3 and reaches a peak, showing obvious positive polarity. The CDCP of the reactant zone is less than 0 C/m3, showing negative polarity. The CDCP changes rapidly from less than 0 C/m3 to greater than 0 C/m3 with the approach of the reactant zone to the preheating and reaction zones. The CDCP in the product zone gradually decreases with the increase of the distance from the reaction zone and finally less than and close to 0 C/m3, showing weak negative polarity. Finally, the cause of regional polarity formation is discussed based on the net production rate of charged particles and the velocity distribution of the flow field in the simulation results. The distribution of positive ions and electrons in the premixed flame is different due to the effect of the flow field and the different diffusion properties of charged particles. Thus, the regional polarity is exhibited in the premixed flame. [ABSTRACT FROM AUTHOR]

Accurate segmentation of tubular structures, such as blood vessels and bile ducts, is pivotal for clinical diagnosis and subsequent treatment. However, challenges arise from their unique structure and morphology. These structures are thin and elongated, and often exhibit complex branching patterns, making precise delineation difficult. Additionally, the intricate and often noisy backgrounds in medical images complicate the extraction of detailed and shape features. These challenges collectively hinder the effectiveness of automated segmentation methods. To address these issues, this paper introduces the shape-supervised feature fusion U-Net (SFU-Net), a novel approach that extends the traditional U-Net architecture. Our network incorporates a feature fusion module that effectively combines different semantic information in both the encoder and decoder paths, facilitating the capture of detailed geometric representations of tubular structures. Furthermore, a novel distance-based tubularity loss is designed to capture boundary information and supervise segmentation integrity by imposing shape constraints. We conducted comprehensive experiments on three tubular structure segmentation tasks in medical imaging, including the dilated biliary tree, hepatic vessel, and pulmonary artery. The experimental results illustrate that the proposed SFU-Net achieves the best performance in terms of accuracy and completeness, with Dice scores of 76.14%, 80.42%, and 83.79%, and HD95 values of 8.59 mm, 6.43 mm, and 4.31 mm across three datasets, respectively. Compared to traditional U-Net-based segmentation methods and other tubular segmentation approaches, our method exhibits superior performance, underscoring its effectiveness in medical image segmentation with tubular structures. [ABSTRACT FROM AUTHOR]

The development of high temperature proton exchange membranes (HT-PEMs) is crucial for the advancement of high temperature proton exchange membrane fuel cells (HT-PEMFCs). The conventional use of phosphoric acid (PA) doped polybenzimidazole (PBI) membranes in HT-PEMFCs is associated with challenges such as a demanding synthetic procedure and the need for carcinogenic monomer. Therefore, the quest for cost-effective and readily synthesizable HT-PEMs with satisfactory physicochemical properties and commendable fuel cell performance is of great importance. In this work, a series of pyridine-containing aromatic copolymers are synthesized using a straightforward Friedel-Crafts hydroxyalkylation reactions. Five different aryl derivates including biphenyl, m -terphenyl, dibenzo-18-crown-6, 9,9-dimethylfluorene, 1,2-diphenylethane are adopted as the comonomers along with p -terphenyl to copolymerize with 4-acetylpyridine. Thus, the effects of different backbone structures with rigid, flexible or bulky moieties on the resulting membrane properties is investigated systematically. The PA absorption capacity and conductivity of the copolymer membranes increases, attributed to the introduction of twisted, hydrophilic or bulky moieties in the copolymer structures. One of the membranes, the P(TP-co-DMF) membrane with 9,9-dimethylfluorene groups, achieves a good PA uptake of 194% when immersed in 85 wt% PA at 30 °C, which also exhibits a moderate tensile strength of 6.5 MPa and a high conductivity of 0.075 S cm−1 at 180 °C. Consequently, when tested in the H 2 –O 2 fuel cell under 180 °C and no backpressure condition, the P(TP-co-DMF)/194%PA membrane delivers a high peak power density of 947 mW cm−2. This performance highlights the significant potential of these copolymers for application in HT-PEMFCs. [Display omitted] • Series of poly(arylene pyridine) based copolymers are synthesized through one-step polymerization. • The introduced twisted, hydrophilic or bulky moieties in polymer backbones significantly affect the properties of HT-PEMs. • HT-PEMFC with dimethylfluorene containing P(TP-co-DMF)/194%PA exhibits a high peak power density of 947 mW cm−2 at 180 °C. [ABSTRACT FROM AUTHOR]

Quaternary siliconboron carbonitride (SiBCN) ceramics show excellent high‐temperature stability and oxidation resistance, indicating great potential as high‐temperature electromagnetic (EM) wave absorbing materials. In this contribution, an efficient and facile method was developed to prepare bulk iron‐containing SiBCN (Fe–SiBCN) ceramics with remarkable EM wave absorption at high temperature by pyrolyzing boron and iron containing precursors (PSZV‐B–Fe). The introduction of boron and iron not only improves the high‐temperature stability but also influences the complex permittivity and EM wave absorption. The minimum reflection coefficient (RCmin) is −61.05 dB, and the effective bandwidth absorption (EAB) is 3.35 GHz (9.05–12.4 GHz). The RCmin will be decreased to −52.3 dB at 600°C as well as the EAB covers more than 67% of the X band (2.8 GHz). The high‐temperature stable Fe–SiBCN ceramics with adjustable dielectric properties can be utilized as high‐performance EM wave‐absorbing materials in high‐temperature and harsh environments. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) Janus materials with mirror asymmetry exhibit fascinating physical properties, implying wide applications in nanoscale optoelectronic and piezoelectric devices. However, intrinsic ferromagnetic (FM) Janus monolayers with high Curie temperature (Tc) and large magnetic anisotropic energy (MAE) are rarely reported. By performing the first-principles calculations, the electronic structure and magnetic properties of stable Janus Mn2PAs monolayer were investigated. We found that Mn2PAs monolayer is FM half-metal with high Tc of 557 K and easy out-of-plane magnetization axis, as well as a small intrinsic electric polarization. Additionally, Mn2PAs monolayer under biaxial strain from -10% to 10% remains to be FM half-metallic. More importantly, the MAE reaches a maximum value of ~ 578 μeV per Mn atom under 8% tensile strain and changes direction under compressive strain larger than 2%, which mainly attributes to the variation of (py, pz)/(py, px) orbital matrix elements of As/P atom. The desired and robust ferromagnetism and half-metallicity with 100% spin-polarization of Janus Mn2PAs monolayer enrich the application of 2D Janus materials in nanoscale spintronic devices. [ABSTRACT FROM AUTHOR]

Aeromonas veronii has serious implications for food safety and the aquaculture industry. The iron uptake system can effectively regulate the life activities and pathogenicity of microorganisms, and Fur is one of the key proteins. In this experiment, we constructed the Δ fur mutant strain of A. veronii TH0426 using the pRE112 suicide plasmid and the C- fur complementary strain using the pBBR1-MCS generalized host expression plasmid to research the effects of fur gene on the biological function and mechanisms of virulence regulation of TH0426. It was found that when the fur gene was deleted, the polar flagella of TH0426 was disrupted and the biofilm formation ability was significantly reduced, with consequent changes in motility, flagellation-related gene expression, drug resistance, and tolerance. Transcriptome analysis of TH0426 wild-type and Δ fur mutant showed that fur gene could directly or indirectly regulate bacterial flagella assembly, antibiotic resistance, growth and metabolism. In the pathogenic test, compared with the TH0426 wild-type, Δ fur significantly reduced the cytotoxicity to EPC cells at 30 min, 1 h and 2 h, reduced the adhesion and invasion ability to EPC cells by 2.38-fold (P < 0.001), increased LD 50 of zebrafish by 58.33-fold (P < 0.001) and decreased bacterial load at 12 h, 24 h, and 48 h. Meanwhile, the result of C- fur was higher than that of Δ fur and lower than that of the TH0426 wild-type in all experiments. In summary, the fur gene is essential for flagellar assembly and biofilm formation and is able to indirectly affect some of the biological properties and animal pathogenicity of TH0426. This research helps to explain the function of the fur gene of the iron uptake system and its role in the pathogenesis of animal. • fur gene can directly regulate the assembly of polar flagella in A. veronii TH0426. • fur gene could directly regulate the biofilm formation of A. veronii. • Deletion of fur gene could significantly reduce the pathogenicity of A. veronii to crucian carp and zebrafish. • Deletion of fur gene can affect multiple metabolic pathways in A. veronii. [ABSTRACT FROM AUTHOR]

Atomistic simulations were employed to investigate the stress field spatial distributions, strain energy of the 1/2 〈1 1 1〉 {1 1 0} edge dislocation, and the binding energies between the edge dislocation and the point defects in tungsten, based on two different embedded-atom method (EAM) potentials. The basic static properties are consistent with the elastic theory of dislocations for these two potentials. Comparatively speaking, the map of the binding energy between the edge dislocation and the monovacancy illustrates that the results based on the Marinica's potential fits better with the elastic theory. In addition, we obtained the radii of absorption between the point defects and the edge dislocation in the slip plane (the maximum value is 19 Å for the monovacancy, while 34 Å for the self-interstitial atom (SIA)) at 0 K. By calculating the binding energy and the interaction radii, we found the intensity of the interaction between the SIA and the edge dislocation is stronger than that of the vacancy and the edge dislocation. [ABSTRACT FROM AUTHOR]

Aeromonas veronii has a serious impact on the aquaculture industry and human public health. The type VI secretory system (T6SS) is the virulence regulation system of gram-negative bacteria, of which hcp is the core component. In this study, we constructed the mutant (Δ hcp1) and complemented (C- hcp1) strains of A. veronii TH0426 were using homologous recombination to study the effect of hcp1 gene on the virulence of TH0426. We found that deletion of the hcp1 gene caused fracture of the flagella of TH0426 and significantly affected basic biological characteristics, including motility, biofilm formation, bacterial competition, and flagellate-related gene expression., In terms of pathogenicity, compared with wild-type strain, LD 50 of Δ hcp1 decreased 17.5-fold (P < 0.001), adhesion and invasion of EPC ability of the Δ hcp1 significantly decreased 1.5-fold (P < 0.001), and both the bacterial load at 12 h and 24 h and the cytotoxicity of Δ hcp1 decreased significantly. In conclusion, the hcp1 gene can affect the basic biological characteristics and animal pathogenicity of TH0426 cells by regulating flagella assembly. This study is helpful to explaining the gene function of hcp1 in the T6SS and its mechanism of action in animal pathogenesis. • hcp1 gene affects the motility, biofilm formation ability and bacterial competition of A. veronii TH0426. • hcp1 gene is involved in regulating the formation of flagella in A. veronii TH0426. • hcp1 gene negatively regulates flagellar component-related genes in A. veronii TH0426. • hcp1 gene can regulate the virulence of A. veronii TH0426. [ABSTRACT FROM AUTHOR]

Abstract In this paper, a tunable electromagnetically induced transparency (EIT) structure using coupling hybrid graphene-nanostrip is proposed. The structure comprises of a vertical graphene strip (VGS) and a pair of horizontal graphene strips (HGSs), the horizontal graphene strips placed alternately on both sides of vertical graphene strip. The EIT-like effect could be turned by changing the Fermi level of graphene instead of refabricating the geometrical parameter of structure, and the significant merits of proposed structure is distinct EIT-like effect could be observed in two perpendicular polarization directions, the influence of electron mobility on transparency windows is also analyzed. This work demonstrate a novel EIT-like phenomenon based on metamaterial and opens a new perspective in EIT effect applications. Highlights • A tunable EIT structure base on graphene is proposed. • EIT windows are observed in two perpendicular polarization directions. • Influence of electron mobility on transparency windows is analyzed. [ABSTRACT FROM AUTHOR]

Aeromonas veronii (A. veronii), a highly pathogenic bacteria with a wide range of hosts, widely exists in the environment of humans, animals and aquatic animals, and can cause a variety of diseases. In this study, the receptor regulator ompR in the envZ / ompR of two-component system was selected to construct a mutant strain (Δ ompR) and a complement strain (C- ompR) to explore the regulatory effect of ompR on the biological characteristics and virulence of TH0426. The results showed that the ability of biofilm formation and osmotic stress of TH0426 were significantly reduced (P < 0.001), the resistance to ceftriaxone and neomycin were slightly down-regulate when the ompR gene was deleted. At the same time, animal pathogenicity experiments showed that the virulence of TH0426 was significantly down-regulated (P < 0.001). These results indicated that ompR gene regulates the biofilm formation of TH0426, and regulates some biological characteristics of TH0426, including drug sensitivity, resistance to osmotic stress, and also affects its virulence. • The ompR gene is a response regulator in a two-component system. • ompR gene could regulate the biofilm formation of TH0426. • ompR gene can regulate the multidrug resistance of TH0426. • ompR gene can regulate the virulence of TH0426. [ABSTRACT FROM AUTHOR]

Handle-driven image warping based on linear blending is widely used in many applications because of its merits on intuitiveness, efficiency, and ease of implementation. In this paper, we develop a method to compute high-quality weights within a closed domain for image warping. The property of C2 continuity in weights is guaranteed by the carefully formulated basis functions. The efficiency of our algorithm is ensured by a closed-form formulation of the computation for weights. The cost of inserting a new handle is only the time to evaluate the distances from the new handle to all other sample points in the domain. A virtual handle insertion algorithm is developed to allow users to freely place handles within the domain while preserving the satisfaction of all expected criteria on weights for linear blending. Experimental examples for real-time applications are shown to demonstrate the effectiveness of this method. [ABSTRACT FROM PUBLISHER]

Thermal desorption of deuterium in tungsten pre-irradiated with the inert gas (helium, neon, argon) is modelled by TMAP (Tritium Migration & Analysis Program). Each TMAP model incorporates three activation energies linked with three types of traps respectively. First-principles method is performed to calculate the activation energies of deuterium detrapping from different kinds of defects. By comparing the activation energies modelled in TMAP with that obtained from first-principles method, the types of traps are determined. The pre-irradiation of helium can suppress the deuterium retention in vacancy clusters. Neon and argon pre-irradiation suppresses deuterium retention in mono-vacancies due to decreasing the number of mono-vacancies caused by the occupation of the inert gas atoms into mono-vacancies. The pre-irradiation of neon can facilitate deuterium retention in vacancy clusters through generating vacancy clusters during the injection process. Argon pre-irradiation facilitates deuterium retention mainly through generating voids, which are of a larger scale than vacancy clusters and can serve as effective traps. [ABSTRACT FROM AUTHOR]

The recombination of one Frenkel pair in tungsten has been investigated through first-principles simulation. Two different recombination types have been identified: instantaneous and thermally activated. The small recombination barriers for thermally activated recombination cases indicate that recombination can occur easily with a slightly increased temperature. For both of the two recombination types, recombination occurs through the self-interstitial atom moving towards the vacancy. The recombination process can be direct or through replacement sequences, depending on the vertical distance between the vacancy and the 〈1 1 1〉 line of self-interstitial atom pair. [ABSTRACT FROM AUTHOR]

Loop-punching is the manner a helium (He) bubble enlarges itself through emitting a dislocation loop during its growth in metals. It has been demonstrated that there are two types of loop-punching: the two-stage loop-punching for small bubbles and the direct loop-punching for large bubbles. In this work, via the molecular dynamics (MD) simulations of helium bubble growth in tungsten (W), we revealed the crucial process from the bubble-attached self-interstitial atoms (SIAs) to the escapable dislocation loop in the two-stage loop-punching. Different from the conventional theory that the loop is merely the collection of the sequentially kicked-out SIAs, it is formed by the synergistic action of the atomic plane on the bubble surface being pushed into interstitial sites and the attached SIA cluster slipping. Building on this, two plastic deformation (PD) modes, the tangential PD and the normal PD, are extracted due to the generated SIAs' directions tangent or normal to the bubble surface. The SIA-accumulation stage and the loop-emission stage of the two-stage loop-punching correspond to the tangential PD and the normal PD, respectively, while the direct loop-punching merely consists of the normal PDs. Therefore, the direct loop-punching is only a special form of the two-stage loop-punching that contains zero previous tangential PDs. Further, it is found the temperature plays an important role in the PD mode switch, suggesting the modes compete on the energy barriers, which accounts for the detachment of the attracted SIA cluster from the bubble. [Display omitted] • The critical process from SIAs to dislocation loop in loop-punching is proposed. • Two plastic deformation modes are extracted for loop-punching. • Plastic deformation modes compete on reaction energy barriers. [ABSTRACT FROM AUTHOR]

A high hydrogen concentration at the sub-surface layers of tungsten plasma facing materials has been previously observed by experiments. We have performed the first-principles calculations to understand this experimental phenomenon. The layer-dependent hydrogen dissolution energies, vacancy formation energies and hydrogen trapping energies are calculated for the W(110) surface. Our results show that hydrogen dissolving into the vacancy-free sub-surfaces is energetically unfavorable. A surface tungsten vacancy is easier to form than in the bulk and has a large trapping effect on hydrogen dissolving. The present work demonstrates the important role of surface vacancies on the hydrogen retention in the tungsten sub-surfaces. [ABSTRACT FROM AUTHOR]

Based on the theory of transformation optics, a type of homogeneous illusion device exhibiting transformed and shifted scattering effect is proposed in this paper. The constitutive parameters of the proposed device are derived, and full-wave simulations are performed to validate the electromagnetic properties of transformed and shifted scattering effect. The simulation results show that the proposed device not only can visually shift the image of target in two dimensions, but also can visually transform the shape of target. It is expected that such homogeneous illusion device could possess potential applications in military camouflage and other field of electromagnetic engineering. [ABSTRACT FROM AUTHOR]

The effects of hydrogen induced vacancy formation in tungsten have been investigated with a first-principles method based on the density functional theory. Hydrogen is demonstrated to assist the formation of vacancy and such effect is enhanced with increasing of hydrogen concentration. Using the energy of a single tungsten atom for the bulk as the reference energy, a spontaneous vacancy formation in tungsten is observed when more than two hydrogen atoms are introduced. These results provide a good explanation for creation of super-abundant vacancies in tungsten and can contribute to understand the mechanism of hydrogen bubble formation. [ABSTRACT FROM AUTHOR]

Background: Downstaging of hepatocellular carcinoma (HCC) makes it possible for patients beyond the criteria to have the chance of liver transplantation (LT) and improved outcomes. Thus, a procedure to predict the prognosis of the treatment is an urgent requisite. The present study aimed to construct a comprehensive framework with clinical information and radiomics features to accurately predict the prognosis of downstaging treatment. Methods: Specifically, three-dimensional (3D) tumor segmentation from contrast-enhanced computed tomography (CT) is employed to extract spatial information of the lesions. Then, the radiomics features within the segmented region are calculated. Combining radiomics features and clinical data prompts the development of feature selection to enhance the robustness and generalizability of the model. Finally, we adopt the support vector machine (SVM) algorithm to establish a classification model for predicting HCC downstaging outcomes. Results: Herein, a comparative study was conducted on three different models: a radiomics features-based model (R model), a clinical features-based model (C model), and a joint radiomics clinical features-based model (R-C model). The average accuracy of the three models was 0.712, 0.792, and 0.844, and the average area under the receiver-operating characteristic (AUROC) of the three models was 0.775, 0.804, and 0.877, respectively. Conclusions: The novel and practical R-C model accurately predicted the downstaging outcomes, which could be utilized to guide the HCC downstaging toward LT treatment. [ABSTRACT FROM AUTHOR]

The regular operation of transformers is significantly impacted by the insulation effectiveness of the transformer insulation oil–paper. In order to explore the mechanism of the influence of an electric field on the thermal decomposition performance of insulating oil–paper, this paper simulated the process of electrothermal coupling decomposition of insulating oil–paper from the micro-level based on molecular dynamics. It was determined that the insulating oil is made up of three 16-carbon hydrocarbon molecules, while the insulating paper is made up of 30 fibrous disaccharide molecules. Using the molecular dynamics simulation approach, the pyrolysis of the insulating oil and insulating paper under various electric field strengths was simulated, and the lysis of reactants and the distribution of products were statistically examined. This paper also studied how the electric field affected the microscopic process of the insulating oil–paper pyrolysis. The findings demonstrate that under the influence of electrothermal coupling, the big molecules of the insulating oil and insulating paper are pyrolyzed to produce a variety of tiny molecules. For the insulating oil, it is easily subject to electron displacement polarization under the influence of an external electric field since it contains non-polar molecules, especially impacted by an electric field of 100 V/m. For the insulating paper, its polar nature, on the other hand, makes itself a good candidate for guiding polarization when exposed to an external electric field. So, the greater the electric field strength is, the greater the impact on the thermal decomposition of the insulating paper is. [ABSTRACT FROM AUTHOR]

In layer-based additive manufacturing (AM), supporting structures need to be inserted to support the overhanging regions. The adding of supporting structures slows down the speed of fabrication and introduces artifacts onto the finished surface. We present an orientation-driven shape optimizer to slim down the supporting structures used in single material-based AM. The optimizer can be employed as a tool to help designers to optimize the original model to achieve a more self-supported shape, which can be used as a reference for their further design. The model to be optimized is first enclosed in a volumetric mesh, which is employed as the domain of computation. The optimizer is driven by the operations of reorientation taken on tetrahedra with ‘facing-down’ surface facets. We formulate the demand on minimizing shape variation as global rigidity energy. The local optimization problem for determining a minimal rotation is analyzed on the Gauss sphere, which leads to a closed-form solution. Moreover, we also extend our approach to create the functions of controlling the deformation and searching for optimal printing directions. [ABSTRACT FROM AUTHOR]

We have performed a first-principles investigation with a zero point energy correction on dissolution and diffusion of hydrogen (H) in a Σ5 (3 1 0)/[0 0 1] molybdenum (Mo) symmetrical tilt grain boundary (STGB). H prefers to stay at the interstitial site in the vacant space of the Mo GB with a negative solution energy (−0.42 eV) and segregation energy (−1.16 eV), which are decreased in the presence of vacancy in the GB. Furthermore, the H solution energy at the vacancy in the Mo GB is lower than that in the Mo bulk, suggesting a larger trapping capability for H of the vacancy in the Mo GB. The dissolving stability of H in the Mo GB can be explained by the low charge density that the GB provides for H. Kinetically, H prefers to easily diffuse within the vacant space along the Mo GB with a small diffusion barrier (0.04 eV), and to migrate to the GB from the bulk. These results provide a systematically exploration and analysis of H behaviors in the Mo GB at an atomic scale, which suggest that the Mo GB can serve as a trapping center for H, similar to the vacancy. In particular, a detailed comparison of H dissolution and diffusion behaviors in a Mo GB with those in a tungsten GB is performed. This can be helpful in understanding the experimentally observed H bubble formation in the Mo GB from the microscopic view. [ABSTRACT FROM AUTHOR]

Based on transformation optics theory, a kind of N-sided irregular polygonal cavity camouflage coating is proposed in this paper. The constitutive tensors of the camouflage coating are derived, and the functionality of the proposed coating is validated by full wave simulations. Simulation results show that the designed camouflage coating all has the same near and far field distributions with that of the bare PEC cavity in different incident angles and directions. In addition, this approach can be further to design N-sided irregular polygonal ground plane cloak with homogeneously anisotropic parameters. In order to apply at optical wavelength, the performance of the nonmagnetic camouflage coating is also verified. The simulations show that the reflective fields of nonmagnetic camouflage coating well agree with that of ideal coating except for incident direction because of the boundary impedance mismatching. Since the parameters of the designed camouflage coating are homogeneously anisotropic, it is expected that the proposed camouflage coating may find potential applications in the electromagnetic field engineering. [ABSTRACT FROM PUBLISHER]

Techniques have been developed to deform a mesh with multiple types of constraints. One limitation of prior methods is that the accuracy of demanded metrics on the resultant model cannot be guaranteed. Adding metrics directly as hard constraints to an optimization functional often leads to unexpected distortion when target metrics differ significant from what are on the input model. In this paper, we present an effective framework to deform mesh models by enforcing demanded metrics on length area and volume. To approach target metrics stably and minimize distortion, an iterative scale-driven deformation is investigated, and a global optimization functional is exploited to balance the scaling effect at different parts of a model. Examples demonstrate that our approach provides a user-friendly tool for designers who are used to semantic input. [ABSTRACT FROM AUTHOR]

Abstract: Based on the theory of transformation optics and concept of complementary medium, a kind of electromagnetic refractor and wave splitter using homogeneous metamaterials with negative refraction index is proposed. The operating mechanisms are described and constitutive tensors of the complementary medium are derived. Full wave simulations are performed to confirm the functionality of the proposed devices. Simulation and calculation results verified that this approach can be further utilized to design novel waveguide bends structure with different cross section width and angle using homogeneous metamaterials with negative refraction index, in addition, the simulations results show that nearly all the energies are transmitted and there is no wave fronts distortion when wave transmits through the bend. [Copyright &y& Elsevier]

Active and selective manipulation of dual–spectral electromagnetically induced transparency (EIT) metamaterial constructed by three graphene strips and vanadium dioxide (VO 2) layer is proposed and demonstrated numerically. Simulation results illustrate that the dual-spectral EIT-like effect are induced by adjacent graphene strips acted as bright and bright mode and excited opposite-phase electric field distributions. One or two of EIT-like windows can be modulated by selectively varying graphene strip's Fermi energy. Meanwhile, the Fermi energies of three graphene strips are varying simultaneously, the position of dual transparency windows as a whole obviously exhibit blue shift. Moreover, the amplitude of dual–spectral EIT windows can be simultaneously manipulated while frequency remain rough constant during the phase transition process of VO 2. The physical mechanism underneath the phenomenon of actively and selectively tunable EIT, which is revealed by theoretically calculated results based on the classical three-oscillator model, can be attributed to the variation of resonance frequency, coupling coefficient and losses of the resonators caused by varying Fermi energy of graphene strips and conductivity of VO 2. [ABSTRACT FROM AUTHOR]

• Machine learning driven study is developed to optimize the interfacial thermal transport between solid/solid heterostructure via interfacial nanostructuring. • Diverse guidance for the optimization of interfacial thermal transport via interfacial structural parameters and contact area are proposed. • The optimization of interfacial thermal transport is uncovered from the phonon mode mismatch and wavelength of phonons. Heat dissipation through interfaces becomes challenging in nanodevices which impedes the dissipation of waste heat. Accordingly, effective approaches are needed to optimize interfacial thermal transport. In this work, by combining the molecular dynamics simulations and machine learning technique, we systematically study the optimization of interfacial thermal transport in Si/Ge heterostructures through interfacial nanostructuring. Three structural parameters are proposed to describe the nanostructures at interfaces and applied to the machine learning driven predictions. The results demonstrate that the interfacial thermal transport significantly depends on the interfacial nanostructures and diverse guidances are discovered for the optimization. When fixing the density of nanostructures, the interfacial thermal resistance has a minimum at specific heights of nanostructures with small angles, while the minimum is gradually disappeared for the nanostructures with larger angles. When fixing the height of nanostructures, there is also a minimum versus density but gradually disappeared with increasing angles. The nonmonotonic dependences on density and height open spaces for the optimization of interfacial thermal transport. Our spectral decomposition analysis provides physical insights into machine learning predictions and optimizations. Finally, we also summarize the machine learning predictions from the perspective of contact area, in which the distinct dependencies on nanostructuring angle and height manifest the feasibility for the further optimization of interfacial thermal transport. Our machine learning driven study provides comprehensive knowledge and guidances for the optimization of interfacial heat dissipation in nanodevices through nanostructuring. [ABSTRACT FROM AUTHOR]

We propose a vacancy trapping mechanism for carbon-vacancy (C-V) complex formation in copper (Cu) according to the first-principles calculations of the energetics and kinetics of C-V interaction. Vacancy reduces charge density in its vicinity to induce C nucleation. A monovacancy is capable of trapping as many as four C atoms to form CnV (n=1, 2, 3, 4) complexes. A single C atom prefers to interact with neighboring Cu at a vacancy with a trapping energy of -0.21 eV. With multiple C atoms added, they are preferred to bind with each other to form covalent-like bonds despite of the metallic Cu environment. For the CnV complexes, C2V is the major one due to its lowest average trapping energy (1.31 eV). Kinetically, the formation of the CnV complexes can be ascribed to the vacancy mechanism due to the lower activation energy barrier and the larger diffusion coefficient of vacancy than those of the interstitial C. [ABSTRACT FROM AUTHOR]

XYZ antiferromagnetic Heisenberg chains and the one in a magnetic field models under linear spin-wave frame are shown explicitly to possess Su(1,2) and So(3,2) algebraic structures respectively. Their algebra solutions related to Sp(2 n, R) Lie algebra are derived. The energy spectra of these two models are determined by one-boson excitation energies, which are built on vector coherent states of Sp(6, R)⊃U(1,2) and Sp(8, R)⊃O(3,2), respectively. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the trapping behaviors of hydrogen (H) in molybdenum (Mo) and tungsten (W) using a first-principles method with a zero point energy correction as well as the molecular dynamics (MD) method. The H trapping is found to generally satisfy the “optimal charge density” rule at the vacancy, and a monovacancy is shown to simultaneously trap 14 H with a H2 molecule formed at the vacancy center in both Mo and W. On the other hand, the MD simulation shows the temperature decreases the number of trapped H at the vacancy. We further propose a generic vacancy trapping mechanism for H bubble formation in metals. The H atoms will first saturate the internal surface of the vacancy (or other vacancy-type defects) to form a “screening layer”, which can screen the interaction between the further trapped H and the surrounding metal atoms. This leads to the formation of H2 molecule at the vacancy center, which can be considered as the preliminary stage of H bubble nucleation. [Copyright &y& Elsevier]

Abstract: We have investigated diffusion and permeation behaviors of hydrogen (H), deuterium (D), and tritium (T) in bulk molybdenum (Mo) by a first-principles calculations combined with simplified models. The H diffusion energy barrier with quantum correction is shown to be 0.12eV, in good agreement with the value of 0.11eV obtained from experiment. According to the diffusion theory presented by Wert and Zener, the diffusion coefficients of H, D and T are estimated, respectively. The H diffusion coefficient is found to be , which is also basically consistent with the experiment. Permeability Φ can be approximately evaluated in terms of Φ = SD, where S and D are the solubility and the H diffusion coefficient, respectively. We found that H has the low solubility in bulk Mo, consistent with the results at the temperature from 900K to 1500K in the earlier experiment. The permeability of H isotopes are calculated to be one order of magnitude larger than those of the experimental values. Such discrepancy should stem from that the “defect-free” Mo in the present calculations is considered. The permeation flux of H isotopes are finally examined. At the temperature of 1200K, the fluxes of H, D, and T are calculated to be 1.27×10−6 molm−2 s−1, 8.95×10−7 molm−2 s−1, and 7.30×10−7 molm−2 s−1, respectively. [Copyright &y& Elsevier]

We investigate the stability, diffusion, and impurity concentration of nitrogen in intrinsic tungsten single crystal employing a first-principles method, and find that a single nitrogen atom is energetically favourable for sitting at the octahedral interstitial site. A nitrogen atom prefers to diffuse between the two nearest neighboring octahedral interstitial sites with a diffusion barrier of 0.72 eV. The diffusion coefficient is determined as a function of temperature and expressed as D(N) = 1.66 × 10-7 exp(-0.72/kT). The solubility of nitrogen is estimated in intrinsic tungsten in terms of Sieverts' law. The concentration of the nitrogen impurity is found to be 4.82 × 10-16 A-3 at a temperature of 600 K and a pressure of 1 Pa. A single nitrogen atom can easily sit in an off-vacancy-centre position close to the octahedral interstitial site. There exists a strong attraction between nitrogen and a vacancy with a large binding energy of 1.40 eV. We believe that these results can provide a good reference for the understanding of the behaviour of nitrogen in intrinsic tungsten. [ABSTRACT FROM AUTHOR]

Antiferromagnet-antiferromagnet-ferromagnet (AF-AF-F) quantum Heisenberg chains in linear spin-wave frame is shown explicitly to have an su(1,2) algebraic structure, and its algebra solutions related to the Sp(6,R) Lie algebra are derived by using an algebraic method. It is found that the energy spectrum of the system is determined by one-boson excitation energies built on a vector coherent state of Sp(6,R)⊃U(1,2). [ABSTRACT FROM AUTHOR]

Abstract: A first-principles computational tensile test has been preformed to investigate the effects of hydrogen on a tungsten grain boundary. It has been found that the maximum ideal tensile strength of the tungsten grain boundary with hydrogen atom segregation was 32.85 GPa, which was about 9% lower than that of the clean tungsten grain boundary (36.23 GPa). This indicated that the theoretical strength of the tungsten grain boundary became weaker in the presence of the hydrogen atom. Atomic configuration analysis showed that the grain boundary fracture was caused by the interfacial bond breaking. The Griffith fracture energy was calculated to be 161 meV/Å2 (2.58 J/m2) and 155 meV/Å2 (2.48 J/m2) for the tungsten grain boundary without and with the hydrogen atom segregation, respectively. The solution energy of the hydrogen atom in a fracture free surface was −0.31 eV, which was 0.08 eV lower than that of the hydrogen atom in a tungsten grain boundary. This indicated that hydrogen was a grain boundary embrittler according to the Rice-Wang thermodynamic theory. The Bader charge analysis suggested that the physical origin for hydrogen-induced embrittlement was the charge transfer induced by hydrogen in the tungsten grain boundary. [Copyright &y& Elsevier]

Abstract: Sr2−x Ca x Bi4Ti5O18(x =0, 0.05) powders synthesized by solid state route were uniaxially pressed and sintered at 1225°C for 2h. The obtained dense ceramics exhibited crystallographic anisotropy with a dominant c axis parallel to the uniaxial pressing direction which was quantified in terms of the Lotgering factor. Microstructure anisotropy of both compositions (x =0, 0.05) consisted of plate like grains exhibiting their larger surfaces mostly perpendicular to the uniaxial pressing direction. Dielectric and ferroelectric properties of Sr2−x Ca x Bi4Ti5O18 ceramics were measured under an electric field (E) applied parallel and perpendicularly to uniaxial pressing direction. The obtained dielectric ɛ R(T) and polarization (P–E) curves depended strongly on E direction thus denoting a significant effect from microstructure and crystallographic texture. Sr2−x Ca x Bi4Ti5O18 properties were also significantly affected by Ca content (x): Curie temperature increased from 280°C (x =0) to 310°C (x =0.05) while ɛ R and remnant polarization decreased for x =0.05. The present results are discussed within the framework of the processing and crystal structure–properties relationships of Aurivillius oxides ceramics. [Copyright &y& Elsevier]

The present study is, to the best of our knowledge, the first report of a rare, transient form of unilateral facial paralysis induced by perimesencephalic non-aneurysmal subarachnoid hemorrhage. The paralysis may have resulted from the compression of a part of the facial nerve by the low of the hemorrhage into the cavum subarachnoidale; alternatively, the paralysis may have been caused by disorder of the blood supply of the facial nucleus, with the hemorrhage leading to brainstem vasospasm. The patient underwent hemostatic therapy, administration of a symptomatic antiemetic and dehydration. The facial nerve compression was released due to the absorption of the hemorrhage or the rapid improvement of the facial nucleus blood supply following the resolution of the vasospasm. Consequently, the facial nerve function was fully recovered, and the facial paralysis disappeared. [ABSTRACT FROM AUTHOR]