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[Display omitted] • Crystallization stress by ice expansion in biomass pores was modeled. • The stress by freeze pretreatment was calculated as 22.5–38.3 MPa at −20– −40 °C. • Specific surface area of rice straw increased by 1.2-fold after pretreatment. • Combined pretreatment achieved 97.2% cellulose recovery & 72% lignin removal. • Glucose yield via hydrolysis rose to 91.1% by 4.3 times that for original straw. Freeze pretreatment combined with alkaline-hydrothermal method of rice straw for enzymatic hydrolysis was studied. Crystallization stress in the rice stem pores caused by water freezing at −20– −40 °C was modeled to illustrate the destruction mechanism. The stress was calculated as 22.5–38.3 MPa that were higher than the tensile yield stress of untreated stems (3.0 MPa), indicating ice formation damaging pore structure. After freeze at −20 °C, rice straw was further hydrothermally treated at 190 °C with 0.4 M Na 2 CO 3 , achieving 72.0 % lignin removal and 97.2 % cellulose recovery. Glucose yield rose to 91.1 % by 4.3 times after 24 h hydrolysis at 10 FPU loading of Cellic®CTec2 cellulase. The specific surface area of rice straw was 2.6 m2/g increased by 1.2 times after freeze. Freeze combined with alkaline-hydrothermal treatment is a green and energy-efficient method for improving enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

To explore the association of single nucleotide polymorphisms (SNPs) of the vitamin D receptor gene (VDR) with circulating lipids considering gender differences. Of the Han Chinese adults recruited from a health examination center for inclusion in the study, the circulating lipids, 25-hydroxyvitamin D (25OHD), and other parameters were measured. The VDR SNPs of Cdx2 (rs11568820), Fok1 (rs2228570), Apa1 (rs7975232), and Taq1 (rs731236) were genotyped with a qPCR test using blood DNA samples, and their associations with lipids were analyzed using logistic regression. In the female participants (n = 236 with dyslipidemia and 888 without dyslipidemia), multiple genotype models of Fok1 indicated a positive correlation of B (not A) alleles with LDLC level (P < 0.05). In the male participants (n = 299 with dyslipidemia and 564 without dyslipidemia), the recessive model of Cdx2 and the additive and recessive models of Fok1 differed (P < 0.05) between the HDLC-classified subgroups, respectively, and Fok1 BB and Cdx2 TT presented interactions with 25OHD in the negative associations with HDLC (P < 0.05). In the Chinese Han adults included in the study, the Fok1 B-allele of VDR was associated with higher LDLC in females, and the Fok1 B-allele and the Cdx2 T-allele of VDR were associated with lower HDLC in males. The interaction of VD and Fok1 BB or Cdx2 TT in males synergistically decreased HDLC levels. [ABSTRACT FROM AUTHOR]

• New acoustic membrane design using mixed foil sound resonators enhances sound absorption and insulation in low to medium frequency range. • Parametric study using FEM simulation shows broadband sound transmission loss can be adjusted by modifying thickness and back air cavity depth. • Experimental validation in anechoic chamber aligns with simulation results, indicating exceptional sound insulation performance with Avg. STL of more than 40 dB ∼ 45 dB achieved within low to medium frequency bandwidth of 500 Hz ∼ 3200 Hz. • Mixed single-layer square wedge-shaped foil resonator based acoustic membrane has potential in acoustics and noise control applications. This study presents a novel design for an acoustic membrane structure that employs a parallel-arrangement of mixed foil sound resonators to improve sound absorption and insulation capabilities in the low to medium frequency range. The structure is composed of a single layer of parallel-arranged mixed foil wedge-shaped coffers and a bottom flat panel separated by an air cavity. The mixed thickness-based foil resonators are treated as a combination of independent resonators with unique resonance frequency, resulting in improved sound insulation with broadband efficacy. A comprehensive parametric analysis was carried out using the Finite Element Method (FEM) based COMSOL Multiphysics, yielding the anticipated outcomes. The study revealed that the broadband Sound Transmission Loss (STL) can be tailored by varying the thickness of the top and side walls, the bottom plate thickness, and the depth of the rear air cavity. The findings suggest that existing acoustic membrane design can be highly efficient, achieving, and average STL of over 40 dB ∼ 45 dB across the low to medium frequency range of 500 Hz to 3000 Hz. The experimental validation was conducted in an anechoic chamber, and the results were found to be in close agreement with the FEM simulation results. In comparison to conventional uniform foil sound resonator based acoustic membrane structure, this mixed single-layer square wedge-shaped foil resonator based acoustic membrane exhibits outstanding sound insulation performances in the low to medium frequency range, owing to its lightweight structure and availability of conventional manufacturing techniques. This advanced version of the foil sound resonator based acoustic membrane holds immense promise for the use in acoustics and noise control applications across domestic, commercial, and industrial environments. [ABSTRACT FROM AUTHOR]

Highlights • Longitudinal effect of individual variability at pubertal progression on depressive trajectory was examined. • Accelerated breast development with heightened stress reactivity associates with increased risk of depressive symptoms. • HPA axis reactivity plays a key role in the association between accelerated pubertal progression and depressive symptoms. Abstract Pubertal timing has been suggested as biological factors implicated in the onset of depression in girls. This study aims to examine the prospective association between accelerated pubertal progression with depressive symptoms, and to further explore the possible role of individual reactivity to social stress in this association. A total of 56 girls with early puberty timing (assessed through breast Tanner stage) and 56 age-matched normal breast development girls were recruited at Wave 1 (grade 3) and followed for 4 years biennially. Hypothalamic-pituitary-adrenal axis stress reactivity was indexed by four cortisol samples collected before, during and after the Groningen Social Stress Test (GSST) at Wave 1. Depressive symptoms were interviewed through Mood & Feeling Questionnaire (MFQ) at each wave. About 42.9% (24/56) from early pubertal timing group and 19.6% (11/56) from normal control group were found accelerated breast development during 4-year follow-up. Mixed effects linear models illustrated that among accelerated breast development girls, those with heightened stress reactivity is likely to have a 6.62 (95% CI, 1.14–12.11)-point higher MFQ scores, and 41.9% (95% CI : 25.2 to 58.6%) higher probability for depressive symptoms, compared with girls with persistent normal breast development and moderate stress reactivity. However, no similar effects were found in girls with accelerated breast development but attenuated stress reactivity. The finding suggests that heightened cortisol reactivity to social stress may represent a useful biomarker in identifying girls at greatest risk of development of depressive symptoms following accelerated pubertal progression. [ABSTRACT FROM AUTHOR]

Due to the critical importance of capturing radioiodine from aquatic environments for human health and ecosystems, developing highly efficient adsorbent materials with rapid kinetics for capturing iodide ions in aqueous solutions is urgently needed. Although extensive research has been conducted on iodine adsorption in gas and organic phases, limited research has been dedicated to adsorption in aqueous solutions. An effective technique for removing iodide was proposed using Ag@Cu-based MOFs synthesized by incorporating Ag into calcined HKUST-1 with varying mass ratios of Ag/Cu–C. Extensive characterization using SEM, XRD, XPS, and nitrogen adsorption-desorption analysis confirmed successful incorporation of Ag in Cu–C. Batch adsorption experiments were conducted, demonstrating that the 5% Ag@Cu–C material exhibited a high adsorption capacity of 247.1 mg g−1 at pH 3. Mechanism investigations revealed that Cu0 and dissolved oxygen in water generate Cu 2 O and H 2 O 2 , while Ag and a small amount of CuO generate Ag 2 O and Cu 2 O. Furthermore, iodide ions in the solution are captured by Cu+ and Ag+ adsorption sites. These findings highlighted the potential of Ag@Cu-based MOFs as highly effective adsorbents for iodine anions removal in radioactive wastewater. • Ag@Cu-based MOFs with varying mass ratios of Ag/Cu–C were successfully synthesized by modifying calcined HKUST-1 with Ag. • 5%Ag@Cu–C showed a high adsorption capacity of 247.1 mg g−1 at pH 3. • The superior iodine anion removal performance was attributed to the strong chemical affinity of Cu+ and Ag+ to iodide. • Ag@Cu–C had great potential as a selective iodide removal material for radioactive wastewater. [ABSTRACT FROM AUTHOR]

Thermal expansion properties of textile reinforced composites with certain structure symmetries can be efficiently calculated by a size-limited unit cell. In this paper, a general approach is developed for the establishment of such a unit cell model. For the derivation of unit cell boundary conditions, three rules are summarized according to the displacement fields in translational, reflectional and 180° rotational symmetric structures under a uniform temperature change loading. The application scope of present unit cell method is clarified from the thermal and mechanical point of views. Three typical composites, i.e., unidirectional fiber reinforced composite, plain woven composite and multi-harness (4HS, 5HS, 6HS, 7HS and 8HS) satin woven composites are then studied, and four, three and two size-reducing unit cells are formulated, respectively. The thermal expansion behaviors of each composite are analyzed, and the effective thermal expansion coefficients are predicted. The influence of structure symmetries on the deformation pattern of unit cell models is clarified. The numerical models are validated by the identical results obtained from unit cells of different sizes and also by the results available in literatures. The approach developed in this paper can be applied to thermal expansion studies of any other composites with relevant structure symmetries. [ABSTRACT FROM AUTHOR]

The traditional thermal protection system (TPS) of hypersonic flight vehicles is usually designed for thermal protection purpose only with low efficiency. In this paper, a thermoelectric material based multifunctional TPS structure concept is proposed and the evaluation approach of its mechanical-thermoelectric performance is developed based on a specific vehicle and a typical trajectory. The thermoelectric module in the structure can convert a certain amount of aerodynamic heat into electricity supply. The module consists of n -type Sr 0.9 La 0.1 TiO 3 compound which is fabricated based on the solid state reaction method, and the widely used p -type Ca 3 Co 4 O 9 . For a specific hypersonic flight vehicle with a typical trajectory curve, the aerodynamic heat is calculated by an engineering-based algorithm, the unsteady mechanical-thermoelectric characteristics of the structure is then analyzed based on a unit cell model and the thermoelectric conversion efficiency is finally evaluated. The results indicate that the multifunctional TPS structure has significant application potentials on the hypersonic flight vehicles. [ABSTRACT FROM AUTHOR]

Optimization of the Compton camera for measuring prompt gamma rays (0.478 MeV) emitted during boron neutron capture therapy (BNCT) was performed with Geant4. The parameters of the Compton camera were determined as follows: 3 cm thick – 10 cm wide scatter detector (Silicon), 10 cm thick – 10 cm wide absorber detector (Germanium), and 1 cm distance between the scatter and absorber detectors. For a typical brain tumor treatment, the overall detection efficiency of the optimized Compton camera was approximately 0.1425% using the Snyder's head phantom with a sphere tumor (4 cm diameter and ~1 cm depth). [ABSTRACT FROM AUTHOR]

In this paper, we present the recent progress of the evaluation of the multi Si PERCT technology in an industrial pilot production of the Chinese cell manufacturer Lu’an. Our technology is an alternative to the AlO x based PERC technology for improving multi-crystalline solar cell efficiencies above 18.5% and it is based on standard mass production equipment and wafer quality. An additional unique feature of this technology is the manufacture of bifacial multi-crystalline solar cells with screen-printed finger grid on the rear side instead of a full area Al-BSF. The PERCT cell architecture is based on a “passivated emitter rear totally diffused (PERT)” cell design for p-type wafers. The totally diffused BSF is realized by a cost effective and short BBr 3 boron diffusion step in a standard diffusion tube furnace - prior to the back side passivation and protection by a PECVD SiN x . RCT's multi PERCT technology upgrade is currently evaluated in an industrial pilot line of a Chinese cell manufacturer. Using the equipment available on site, an average efficiency of 18.4% could be achieved (without front side optimization). Accordingly an efficiency gain of 0.52% absolute was demonstrated on standard multi-crystalline wafer material. A unique feature of the PERCT technology is the opportunity to prepare bifacial cells on multi-crystalline wafer material. The world's first bifacial multi-crystalline solar cell with a screen printed Al-grid and a front side efficiency of 18% was realized. Up to 15% cost savings can be achieved by using the bifacial multi PERCT technology. [ABSTRACT FROM AUTHOR]

Abstract: Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50°C, and not detected at 54–68°C for 6–24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process [Copyright &y& Elsevier]

Abstract: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder of the elderly accounting for the vast majority of dementia. Recently, many studies have implicated the role of inflammatory response, especially neuroinflammatory response in the development and progression of AD. However, the underlying mechanism of how inflammatory response induces AD is unknown. Kynurenine pathway is a major route of the amino acid tryptophan catabolism, resulting in the production of nicotine adenine dinucleotide and other neuroactive intermediates: quinolinic acid (QA) and kynurenic acid (KA). QA exerts different toxic effects, including over-activation of N-methyl-d-aspartate (NMDA) receptor and excitotoxicity, synaptic dysfunction and neuronal death. On the other hand, KA is identified as the only endogenous NMDA receptor antagonist and could modulate neurotoxic effects of QA. We hypothesize that an activated kynurenine pathway induced by inflammatory cytokines would generate more neurotoxic metabolites, which could be closely related to the pathogenesis of AD in elderly patients. Moreover, some measures, which facilitate KA synthesis and reduce the formation of QA, may emerge as a new therapeutic strategy against AD. [Copyright &y& Elsevier]

• Recombinant E. coli HMFOMUT was constructed for selective oxidation of furans. • Whole-cells could tolerate furfural (50 mM) and 5-hydroxymethylfurfural (150 mM). • 5-Hydroxymethyl-2-furancarboxylic acid was biologically synthesized at 96.9% yield. • Furfural and furfuralcohol (50 mM) were completely converted to furoic acid at 30 °C. • E. coli HMFOMUT could synthesize furan-based carboxylic acids from furans. The main aim of this work was to firstly develop a selective oxidation approach for biologically converting 5-hydroxymethylfurfural and furfural into the corresponding furan-based carboxylic acids with recombinant Escherichia coli HMFOMUT. Whole-cells of this recombinant strain harbored good biocatalytic activity in a narrow pH range (pH 6.5–7.0), which had high tolerance toward furfural (up to 50 mM) and 5-hydroxymethylfurfural (up to 150 mM), well-known potential inhibitors against microorganisms. 5-Hydroxymethyl-2-furancarboxylic acid and furoic acid could be obtained at 96.9% and 100% yield from 5-hydroxymethylfurfural (150 mM) and furfural (50 mM) at 30 °C and pH 7.0. The improved substrate tolerance of Escherichia coli HMFOMUT is gaining a great interest to synthesize value-added furan-based carboxylic acids, which has potential industrial applications. [ABSTRACT FROM AUTHOR]

The exponential progress in the field of space science and technology has facilitated the prolonged habitation of astronauts in the space environment. However, the neurological and cognitive impairments of astronauts have become major factor that directly impede the successful completion of space missions. Studies have demonstrated that microgravity can diminish neuronal functions and cognitive abilities by altering the microenvironment of the brain (BME). Microglia, vital immune cells responsible for regulating the integrity of the blood-brain barrier, have been identified as the principal contributing elements to the neurological deterioration observed in microgravity conditions. The primary objective of this study was to provide an understanding of the molecular processes underlying the behavior of microglia under conditions of microgravity. Using a Random Positioning Machine (RPM) to simulate microgravity, our study found that microgravity reduces BV2 microglial cell viability, induces M1 polarization, and significantly increases late apoptosis. Transcriptome analysis revealed 142 differentially expressed genes related to microglial phenotype and inflammation, with qPCR validating selected DEGs. These results elucidate the molecular mechanisms of microglial behavior under microgravity, highlighting gene expression changes and cellular damage. This study provides a conceptual framework for comprehending the influence of microgravity on the neurological system, establishing countermeasures against functional damage to the nervous system caused by space flight, and serving as a reference for future deep space exploration and long-term manned space medical support. [Display omitted] • Simulated microgravity (SMG) inhibits the viability of BV2 cells. • SMG induces late apoptosis and M1 activation of BV2 cells. • SMG alters DEGs related neuroinflammation of BV2 cells by transcriptome sequencing. [ABSTRACT FROM AUTHOR]

Highlights • Left-behind children in China offers "natural experiments" of maternal separation. • Parent-child separation in early childhood associated with shorter telomere length. • Shortened TL partially explained adverse effects of separation on psychopathology. • Shortened TL could also be a consequence of psychopathology associated with separation. Abstract Background Given the ethical limitations of exposing children to experimentally manipulated adverse experiences, evidence of the effects of parent-child separation on subsequent psychopathology are based mostly on animal studies. Left-behind children phenomenon resulting from rural-urban mobility in China offers unique "natural experiments" to explore the long-term physical and mental health consequences of parent-child separation in childhood. Objective To test the associations between parent-child separation with telomere length (TL) and psychopathology during adolescence. Method A total of 710 adolescents (age: M = 16.86, SD = 1.52) were recruited from local schools in rural area of Fuyang, one of the top inland areas for outward migration in Anhui province, China. Parent-child separation was collected through face to face interview. The MacArthur Health & Behavior Questionnaire (HBQ) was used to assess internalizing and externalizing symptoms. Quantitative polymerase chain reaction was used to measure buccal TL. Results Nearly 60% (399/695) of the participants experienced separation from both parents. Childhood or persistent separation from parents was associated with increased internalizing symptoms (childhood: β = 0.13, 95% CI : 0.02, 0.23; persistent: β = 0.23, 95% CI : 0.14, 0.31), increased externalizing symptoms (childhood: β = 0.17, 95% CI : 0.03, 0.32; persistent: β = 0.23, 95% CI : 0.10, 0.35) and shorter telomere length (childhood: β = −0.16, 95% CI : −0.26, −0.05; persistent: β = −0.13, 95% CI : −0.22, −0.03). Shortened TL was estimated to explain 15.2% and 12.7% of the total effect of separation on internalizing and externalizing symptoms, while internalizing and externalizing symptoms explained 23.4% and 12.3% of the effect of separation on shortened TL. Conclusion Childhood and persistent parent-child separation, as experienced by rural left-behind children in China, associates with increased vulnerability for psychopathological symptoms and makers of cellular aging. The challenge for future research is to determine whether short telomere length is in fact a long-term consequence or an underlying vulnerability factor for future mental disorders. [ABSTRACT FROM AUTHOR]

Highly efficient reactions of 4-hydroxycoumarin with hypervalent iodine reagents under mild conditions are described, which give rise to 4-aryloxycoumarins in good to excellent yields. [ABSTRACT FROM AUTHOR]

• The non-thermal damage is described by a stochastic model of size and volume fraction. • The thermal damage is characterized by a probability model considering probability gradient and temperature characteristic. • The effects of non-thermal and thermal damages on the HT performance are clarified. • Two damage tolerance indicating models considering HT performance are proposed. For reusable high-speed vehicles, the damage accumulation in heat transfer paths during multitudes of missions leads to resistance augment, performance undermining, and even failures of heat transport (HT) systems. The quantitative characterization of tolerance for various damages becomes crucial to a reliable HT system. In this work, a stochastic model of size and volume fraction is used to describe the non-thermal damage which is caused by various non-thermal loads like mechanical vibration, impact, corrosion, etc., and a probability model considering probability gradient and local, reference, limit, and constraint temperatures is developed to characterize the thermal damage which is generated with the temperature increasing. A dendritic HT system is obtained by topologic optimization with the objective of the lowest geometric average temperature, and the heat transfer with multiple distributions of non-thermal and thermal damages is analyzed. The effects of size and volume fraction for non-thermal damage and that of constraint temperature and probability gradient for thermal damage on the HT performance are clarified. Two damage tolerance indicating models considering HT performance are then proposed by polynomial fittings and validated by extended numerical data. [ABSTRACT FROM AUTHOR]

• A multifunctional TPS concept with the integration of thermoelectric module is developed. • The structural details and their influences on concept performance are considered. • A multi-scale method is developed to obtain the accurate in-plane mechanical boundary conditions. • The thermal, electrical and mechanical performances of the concept are evaluated under hypersonic conditions. In this paper, a multifunctional thermal protection system (MTPS) concept with additional functions of thermoelectric (TE) conversion and load bearing is developed for a hypersonic launch vehicle. The concept is a plate in macroscale and a unit in mesoscale. The mesoscopic unit consists of a TE module and a TPS gap. The TE module consists of an alumina ceramic layer and a fiber insulation layer to dissipate certain amount of the aerodynamic heat, a high-temperature and a mid-temperature TE layers to efficiently convert aerodynamic heat into electric energy, a load-bearing frame and honeycomb cores to improve the load bearing capacity, embedded electricity conducting plates in TE materials and low-modulus high-temperature adhesives to alleviate the thermal stress. The mechanical-thermal-electrical performance of the MTPS is evaluated based on the multi-scale analysis of the flight vehicle, MTPS plate and MTPS unit, and the transfer method of mechanical boundary conditions between different scales is developed. The results show that the multi-scale analysis is essential to ensure the accuracy of boundary conditions, and the developed MTPS concept has multi effective functions of load bearing, heat protection and power supply. [ABSTRACT FROM AUTHOR]

The optimization of structures with beam-like force transfer paths for flight vehicles is closely dependent on the hierarchy decomposition and interaction effects of variables. In this work, the variable of a rudder structure with radial beams is decomposed into conventional hierarchies of topology and size and a new unconventional hierarchy of angle, which is a representational variable with implicit expression for radial beam direction. A unified code form is proposed for discrete variable, i.e., topology and continuous variables, i.e., angle and size, and then an integrated optimization method of multi-hierarchy variables is developed based on the genetic algorithm and the interaction effects between different hierarchies are fully considered. A two-hierarchy optimization model of topology and size and a three-hierarchy optimization model of topology, size and angle are then constructed, respectively. The statics problem with objective of minimum structural mass and constraints of stress and displacement, and the static aeroelastic problem with objective of minimum influence quantity and constraints of structural mass, stress and displacement are solved. The results show that the three-hierarchy optimization model is more efficient than the two-hierarchy one with structural mass reduction of 18.9 % and aeroelastic influence quantity reduction of 4.3 %. [ABSTRACT FROM AUTHOR]

The objective of this longitudinal study was to identify the contribution of individual, cumulative and patterns of adverse childhood experiences (ACEs) exposure in the prediction of psychopathological outcomes during adolescence in the context of Chinese culture. Children from 3 large elementary schools of Bengbu, Anhui Province, China were enrolled in the 3 waves survey from 2013 (mean age = 8.15 years, SD = 0.88) to 2017 (mean age = 11.92 years, SD = 0.88). Latent class analysis (LCA) was used to identify homogeneous, mutually exclusive "classes" of 10 most common ACEs. Logistic regression was used to examine the association between individual, cumulative and patterns of ACEs and depressive and externalizing symptoms at Wave 3. Of the 1766 respondents included in the sample, 75% had at least 1 and 21.5% reported 4 or more ACEs. We found the dose-response relationship between cumulative ACEs and psychopathological outcomes. Results from LCA revealed three high-risk profiles and one low-risk profile, which were labeled: high ACEs (5.7%), highly abusive and adverse events (20.1%), highly abusive and neglected (21.3%), and low ACEs (52.9%). Compared to low ACEs class, each high-risk profile was differentially associated with psychopathological outcomes over 4-year period. Children exposed to high ACEs were at higher risk for future depressive and externalizing symptoms than other classes. This study provides evidence for the predictive impact of ACEs on adolescent psychopathological symptoms in Chinese culture. Clinicians should routinely assess for ACEs to identify children exposed to the most problematic ACE patterns and provide preventive intervention immediately, rather than provide treatment later in life. [ABSTRACT FROM AUTHOR]

• A thermal contact model encompassing multi-interfacial and near-field effects of TEGs is established. • The near-field thermal radiation effects are quantitatively counted considering heat transfer paths at heterogeneous interfaces. • The real-topology-based thermal contact resistance model is experimentally validated in typical hypersonic conditions. High efficiency heat harvest of hypersonic vehicles claims elaborate design of thermoelectric (TE) conversion process. A thermoelectric generator (TEG) contains multi-interfaces in the heat transfer path and the interfacial thermal contacts with certain amount of nanoscale effects have significant influence on its TE conversion process. In this paper, a thermal contact model encompassing near-field thermal radiation (NFTR) effects of TEGs with heterogeneous interfaces between substrates, electrodes and TE legs is established and experimentally validated in hypersonic conditions. First, a real-topology-based thermal contact resistance (TCR) prediction model is developed and the far- and near-field radiative heat transfer at heterogeneous interfaces is considered by the fluctuational electrodynamics, and the model is validated by direct and indirect experimental measurements. Second, the effects of average interfacial temperature, clearance distance and opposite heat transfer paths on the thermal radiation are analyzed, and the influences of average interfacial temperature, loading pressure and clearance mediums on the TCR are then clarified. Third, the TCR is equivalently considered in a TEG performance evaluation model and the NFTR effects is quantitatively counted. The result shows that: with the consideration of the NFTR, the TCRs between TE legs and electrodes, substrates and electrodes decrease by about 3.90% to 17.0% and 0.510% to 6.40% under vacuum clearance, 1.30% to 5.50% and 0.220% to 2.00% under air clearance, respectively; and the maximum output power of the TEG increases by about 8.02% and 1.29% under vacuum and air clearance (0.1 MPa, 650 K), respectively. [ABSTRACT FROM AUTHOR]

The panel vibration of air intake system that excitated by fluid-structural interaction, engine thrust variation and noise has decisive influences on the performance of an air-breathing hypersonic vehicle. The design of such type of intake system should contain the determination of configurational parameters and physical dimensions by considering both flow and structural vibrations, and a clear design path is still absent. In this paper, an intake system with three-stage external compression ramps is designed under Mach number of 6 and flight altitude of 24 km, and the configurational parameters are determined based on the shock-on-lip criterion, Oswatitsch criterion and viscous effects modification. The mode vibration characteristics of external compression ramps with panel thicknesses of 0.002 to 0.03 m are analyzed, and appropriate natural frequencies are obtained by constraint conditions of fixed four side boundaries with an additional and more realistic constraint of strengthened internal boundary. The flow field of the intake system with forced panel vibrations of compression ramps is simulated, and the effects of vibration amplitude of 0 to 0.11 m and frequency of 10 to 250 Hz on the intake performance, i.e., total pressure recovery coefficient and mass flow coefficient are clarified. The vibration effects of hypersonic flow on the compression ramp structure and intake performance are studied by fluid-structural coupling simulations. Finally, the available physical dimensions of external compression ramps are determined and a design path of intake system is developed by considering both the structural and intake performance. [ABSTRACT FROM AUTHOR]

This paper was aimed to explore the physics of Cherenkov radiation and its potential application in boron neutron capture therapy (BNCT). The Monte Carlo toolkit Geant4 was used to simulate the interaction between the epithermal neutron beam and the phantom containing boron-10. Results showed that Cherenkov photons can only be generated from secondary charged particles of gamma rays in BNCT, in which the 2.223 MeV prompt gamma rays are the main contributor. The number of Cherenkov photons per unit mass generated in the measurement region decreases linearly with the increase of boron concentration in both water and tissue phantom. The work presented the fundamental basis for applications of Cherenkov radiation in BNCT. [ABSTRACT FROM AUTHOR]

Catalytic properties of halophilic exoglucanase from a marine Aspergillus niger and the secondary structure change caused by high salinity was analyzed under high salinities condition. Exoglucanase activity in 12% NaCl solution (w/v) was 1.32 folds higher of that in NaCl free solution. Half-life time in 12% NaCl solution (w/v) was over 1.41 folds higher of that in NaCl free solution. The exoglucanase had not endoglucanase activity. Gibbs free energy change of exoglucanase denaturation, △ G , in 12% NaCl solution (w/v) was about 1.0 kJ/mol more than that in NaCl free solution at 45 °C, 50 °C, 55 °C and 60 °C. Melt temperature in 12% NaCl solution (w/v), 48.02 °C, was 3.32 °C higher than that in NaCl free solution, 44.70 °C. High salinity made contents of β-sheet and α-helix increased. The secondary structure change caused by high salinities improved exoglucanase thermostability and activity. The halostable exoglucanase from a marine Aspergillus niger was valuable for cellulose hydrolysis at high salinities. [ABSTRACT FROM AUTHOR]

• The real-topology-based numerical prediction models of TCR between TE legs and electrodes are established. • A novel indirect approach and a corresponding platform of TCR test are developed. • Two simplified formulas are proposed to quantitatively express the contact effects on TEG. The precise quantitative description of contact effects at heterogeneous interfaces is the crucial issue in developing thermoelectric generators (TEGs) with potential of hypersonic aerodynamic heat harvest. In this paper, the thermal and electrical contact effects between thermoelectric (TE) legs and electrodes are studied by real-topology-based numerical predictions and novel indirect experimental tests, and two simplified formulas are proposed to quantitatively express their effects on TEG. First, the thermal and electrical contact resistances under different temperatures, pressures, gap mediums and thermal radiation conditions are predicted. Second, a novel indirect thermal contact resistance (TCR) test approach relying on the TE conversion characteristics is developed, a corresponding platform is established and the numerical models are then validated. Third, the TE conversion process of TEG is simulated with considering the contact effects by equivalent layers, the TCR test platform is developed to measure the out power of TEG and the numerical models are then validated. Finally, two prediction formulas for the maximum output power prediction of TEGs with considering the contact effects are derived, and good agreement with numerical results is obtained by the maximum deviation of 7.7%. [ABSTRACT FROM AUTHOR]

An enormous amount of aerodynamic heat is produced on the surface of hypersonic vehicles, and the thermoelectric generator (TEG) technique holds the potential to convert aerodynamic heat into electric energy. In a TEG, the micrometer-scale roughness on TE legs and electrodes surfaces leads to the constriction of interfacial electric current and brings about electrical contact resistance (ECR). The heat transfer and conversion processes of a TEG are greatly influenced by such type of ECR. In this work, a TEG includes two ceramic substrates and a middle TE layer is established, and the TE layer consists of insulation material, N - and P -type TE legs and electrodes to connect the TE legs. The ECR and its effects on the TEG performance are studied by two-scale numerical simulations and experimental measurements. First, the practical topography of rough surfaces for TE legs and electrodes is measured, and the micrometer-scale ECR prediction numerical models are established based on the reconstructed topography. An ECR measurement platform is developed and the platform consists of a pressure device, power supply and data acquisition system which are used to provide loading pressures, voltage, and acquisition of electric current and voltage signals, respectively. The ECRs under different temperatures, loading pressures and gap mediums are then predicted and the numerical models are validated by a series of measurements. Second, the TE conversion process of TEG is simulated by a millimeter-scale model including insulation materials, TE legs, electrodes, and equivalent interfacial layers of ECR. The influence of ECR on the TE performance of TEG for the hypersonic vehicle is thus clarified. [ABSTRACT FROM AUTHOR]

• A method to assess deterioration of concrete based on X-CT scanning ultrasonic testing and sulfate attack model is proposed. • An image processing analysis method is demonstrated to quantitatively differentiate the different constituents of concrete. • The deterioration mechanism and durability of tunnel segmental lining under sulfate attack are studied. Accurately assess the concrete deterioration of segmental lining under sulfate attack environment is important for tunnel construction and operation. Ultrasonic testing of concrete samples is generally used to determine the sulfate resistance of concrete materials. However, concrete is a porous medium material, and the internal coarse aggregate and pores will affect the sulfate attack velocity, so the ultrasonic velocity cannot directly assess the local deterioration of concrete structure under sulfate attack. In this study, the durability of concrete samples exposed to sulfate attack and wetting-drying test was studied by using the comprehensive assessment method of X-ray computed tomography (X-CT) scanning and ultrasonic testing. The ultrasonic attenuation velocity and internal pore change of deteriorated concrete were measured, and the sulfate attack depth was calculated. Test results indicate that the newly defined ultrasonic velocity after removing coarse aggregate and pores through X-CT results is a suitable index to describe the non-uniform deterioration behavior of sulfate-attacked concrete. A local deterioration assessment method of concrete structural based on X-CT, ultrasonic velocity and sulfate attack model is proposed, which provides a potential application for the deterioration assessment of sulfate-attacked tunnel segmental lining based on laboratory accelerated test results. [ABSTRACT FROM AUTHOR]

Purpose According to the developmental origins of health and disease theory, fetal nutrition is associated with obesity and chronic diseases in children and adults. However, previous findings regarding the association between birth weight and childhood obesity have been inconsistent. The aim of the present study was to investigate the relationship between birth weight and childhood obesity in China. Methods The 16,580 subjects (8477 boys and 8103 girls) aged 7–17 years, who participated in this study were recruited from a cross-sectional study in six cities in China. Epidemiological data, including birth information, were collected through face-to-face interviews, and anthropometric indices were measured by trained physicians. Overweight and obese cases were defined using sex-specific and age-specific 85th and 95th percentile body mass index (BMI) cutoffs for Han children and adolescents. Central obesity was defined using sex-specific waist-to-height ratio (WHtR) cutoffs (WHtR ≥0.48 in boys and WHtR ≥0.46 for girls). Results The overall rate of overweight status and obesity was 20.3% in the Chinese children and adolescents and that of central obesity was 18.9%. Subjects were stratified into eight groups according to weight at birth. J-shaped relationships were observed between birth weight and BMI for age Z-score and WHtR. After adjusting for confounders such as gender, gestational age, parental factors, and dietary factors, the risk of overweight and obese status was still higher in the children with higher birth weights than in children with birth weights of 3000–3499 g (3500–3999 g: odds ratio [OR] = 1.14, 95% confidence interval [CI] = 1.02–1.28; 4000–4499 g: OR = 1.39, 95% CI = 1.19–1.63; and 4500–4999 g: OR = 1.36, 95% CI = 1.06–1.76). Moderately high birth weight also increased the risk of central obesity. Relative to the children with normal birth weights (3000–3499 g), the adjusted OR and 95% CI were 1.33 (1.13–1.56) in children with birth weights of 4000–4499 g. Children with very low birth weight (lower than 1500 g) had the highest risk of central obesity. The adjusted OR was 2.30 (95% CI: 1.03–5.14) relative to children with birth weights of 3000–3499 g. Conclusions Birth weight was associated with obesity in Chinese children and adolescents. J-shaped relationships were observed between birth weight and BMI and WHtR in childhood, and very low birth weight was associated with a mild increase in the risk of central obesity in Chinese children and adolescents. [ABSTRACT FROM AUTHOR]

Both genetic predisposition and lifestyle factors are associated with the risk for obesity. Multiple obesity loci have been identified using genome-wide association studies mainly in European populations. The aims of this study were to examine the associations of these loci with obesity and gene × dietary behavior interactions among Chinese children and adolescents. Nineteen candidate SNPs were genotyped using Sequenom technology in the Chinese children (N = 2977, 853 obese and 2124 controls, aged 7–17). Dietary behaviors were assessed using self-administered questionnaires. After adjusting for age, sex and multiple testing, MC4R rs17782313, SEC16B rs543874, MAP2K5 rs2241423 and KCTD15 rs11084753 were associated with obesity and obesity-related traits (all P < 0.005), with odd ratios ranging from 1.22 to 2.15. Dose–response association was significant between genetic risk score, which was calculated by summing the risk alleles, and the risk of obesity ( P < 0.001). Multiplicative interaction was found between rs543874 and salt preference on obesity with an OR of 4.40 (95% CI, 1.12–17.30). Additive interactions with salt preference were found in rs17782313 and rs11084753. Our findings indicated that rs17782313, rs543874, rs2241423 and rs11084753 were associated with the risk for children obesity in China, and interaction of genetic variants with diet behaviors on obesity. [ABSTRACT FROM AUTHOR]

Abstract: This study was carried out to investigate whether the congenital HCMV infection affect the induction and maintenance of LTP /DP. Rat models of Sprague–Dawley rats congenitally infected by HCMV were made. Field excitatory postsynaptic potentials (EPSPs) were recorded in the hippocampal slices of offspring rats (50–65days) to study alterations of LTP /DP in area dentate gyrus (DG) of the hippocampus after congenital infection. The Ca2+ and mRNA level of calmodulin (CaM) in the hippocampus neurons of the experiment group (congenital infected by HCMV) and the control group were measured;The input/output (I/O) curves of the EPSP slope PS amplitude in area DG in experiment group were significantly depressed when compared to control group (P <0.05). LTP of the EPSP slope and PS amplitude in area DG of the hippocampus was 137±4% (EPSP) and 225±11% (PS) in control rats and 115±9% (EPSP) and 163±7% (PS) in experiment rats (EPSP: F =25.29,P <0.05;PS: F =74.33 P <0.05, two-way ANOVA with Tukey test); DP of the EPSP slope and PS amplitude was 86±3% (EPSP) and 85±2% (PS) in control rats and 94±5% (EPSP) and 93±4% (PS) in congenitally infected rats (EPSP: F =5.62, P <0.05;PS: F =4.22, P <0.05, two-way ANOVA with Tukey test) . At the same time, intracellular [Ca2+] and mRNA level of CaM in the hippocampus neurons of the experiment group were significantly increased than that of in the controls ([Ca2+]: P <0.01;CaM mRNA: P <0.01) . The results demonstrate that congenital HCMV infection could reduce the range of synaptic plasticity in the Sprague–Dawley rats, which may trigger the dysfunction of learning and memory through disrupting the calcium balance. [Copyright &y& Elsevier]

Abstract: Moisture is an important factor that influences the safe operation of transformers. In this study, molecular dynamics was employed to investigate the diffusion behavior of water molecules in the oil–paper insulation materials of transformers. Two oil–cellulose models were built. In the first model, water molecules were initially distributed in oil, and in the second model, water molecules were distributed in cellulose. The non-bonding energies of interaction between water molecules and oil, and between water molecules and cellulose, were calculated by the Dreiding force field. The interaction energy was found to play a dominant role in influencing the equilibrium distribution of water molecules. The radial direction functions of water molecules toward oil and cellulose indicate that the hydrogen bonds between water molecules and cellulose are sufficiently strong to withstand the operating temperature of the transformer. Mean-square displacement analysis of water molecules diffusion suggests that water molecules initially distributed in oil showed anisotropic diffusion; they tended to diffuse toward cellulose. Water molecules initially distributed in cellulose diffused isotropically. This study provides a theoretical contribution for improvements in online monitoring of water in transformers, and for subsequent research on new insulation materials. [Copyright &y& Elsevier]

The thermal energy management (TM) of a hypersonic vehicle should concern the full process of the heat dissipation, transport and reuse. In this paper, the aerodynamic heat of a hypersonic cruiser is dissipated by passive thermal protection system (TPS), transported by regenerative cooling (RC) network, and reused by RC network and thermoelectric (TE) conversion component. The TM system accordingly includes three subsystems of TPS, RC network and TE component. An equivalent thermal equilibrium model and an overall equivalent heat transfer coefficient are developed to build up the mutual correlation between the aerodynamic heating and TM system instead of the one-way influence, and account for the coupling design rationale of the TM subsystems. For passive TPS, the distribution, area and weight of relevant concepts are obtained; for RC network, the determination method of the heat capacity and coolant mass-flow-rate is developed, and the heat transport performance at specific vehicle regions is numerically analyzed by using hydrocarbon and liquid hydrogen fuel as coolants; for TE component, a TE-AFRSI concept is established by integrating mid- and low-temperature TE stages into the advanced flexible reusable surface insulation (AFRSI), and the concept is optimized by considering the thermal protection, weight increment and heat reuse performance. The design roadmap of TM system is finally proposed and the influence of the overall equivalent heat transfer coefficient is clarified. The results show that the aerodynamic heat and the transported or reused heat proportion will increase, while the scale of passive TPS will be reduced by the increase of overall equivalent heat transfer coefficient. [ABSTRACT FROM AUTHOR]