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An interfacial C-S bond bridged ZnS/C 3 N 5 S-scheme heterojunction was constructed for photocatalytic H 2 evolution. Benefiting from the interfacial covalent bond, enhanced internal-electric-field strength, and accelerated surface photocatalytic reaction, the photocatalytic H 2 production of ZnS/C 3 N 5 was 3.2 and 2.5 times higher than those of ZnS/C 3 N 4 and ZnS/C 3 N 5 -300 without C-S bond. [Display omitted] • C-S bond is susceptive to preparation temperatures, and it is broken above 300 °C. • C-S bond promotes e − separation and improves H 2 O adsorption and activation behaviors. • IEF strength of ZnS/C 3 N 5 with opposite direction is 2.6 times than that of ZnS/C 3 N 4. • e − transfer respectively follow S-scheme and type-II pathway in ZnS/C 3 N 5 and ZnS/C 3 N 4. • H 2 yield of ZnS/C 3 N 5 is 3.2 and 2.5 times than ZnS/C 3 N 4 and ZnS/C 3 N 5 -300 without C-S. An interfacial C-S bond bridged ZnS/C 3 N 5 heterojunction was constructed for photocatalytic H 2 evolution. Different from traditional type-II ZnS/C 3 N 4 heterojunction, the electron transfer followed S-scheme pathway, due to opposite internal-electric-field (IEF) directions in these two heterojunctions. The C-S bond formation was carefully investigated, and they were susceptive to the preparation temperatures. In photocatalytic reaction, C-S bond was functioned as the "high-speed channel" for electron separation and transfer, and the IEF strength in ZnS/C 3 N 5 was 1.86 × 108 V/m, 2.6 times higher than that in ZnS/C 3 N 4. Moreover, the C-S bond also altered the surface molecular structure of ZnS/C 3 N 5 , and hence the surface reaction was accelerated via improving H 2 O adsorption and activation behaviors. Benefiting from the S-scheme pathway, enhanced IEF strength, and accelerated surface reaction, the photocatalytic H 2 production over ZnS/C 3 N 5 reached up to 20.18 mmol/g/h, 3.2 and 2.5 times higher than those of ZnS/C 3 N 4 and ZnS/C 3 N 5 -300 without C-S bond. [ABSTRACT FROM AUTHOR]

[Display omitted] • NH 4 BS can dissolve in basic electrolyte without cosolvent. • NH 4 BS can alleviate the passivation of electrode surfaces by dissolving Li 2. • NH 4 BS can increase the dissociation degree of long-chain polysulfides.NH4BS can increase the dissociation degree of long-chain polysulfides. Based on the dissolution and conversion mechanism of lithium-sulfur (Li-S) batteries, insulating solid short-chain polysulfides (Li 2 S 2 /Li 2 S) will continuously passivate and corrode the active interface of cathode and anode, which seriously affects its performance. Herein, ammonium benzenesulfonate (NH 4 BS) is proposed as a soluble ammonium salt to dissolve Li 2 S in the ether electrolyte, according to the inductive effect of NH 4 + cation and O atom on Li-S bond. This is beneficial to alleviate the interface problem of electrodes and irreversible loss of active materials. Noticeably, soluble Li 2 S regulates its deposition behavior from 2D to 3D, which is conducive to the more effective use of conductive surface. Moreover, the addition of NH 4 BS can increase the dissociation degree of long-chain polysulfides, so that the diffusion rate and reaction kinetics of active substances are improved. Profiting from these functions, the Li-S cells with NH 4 BS act out excellent cyclic stability in the long cycle of 0.5 C and 2 C. Under the extreme conditions of high sulfur loading and low electrolyte-sulfur ratio, the cells with NH 4 BS can cycle stably for 196 cycles, which significantly prolongs the battery life. The proposal of NH 4 BS broadens a new idea to solve the interface problem of Li-S cells and stimulate the research enthusiasm of developing soluble ammonium salt. [ABSTRACT FROM AUTHOR]

Heavy-duty land-based gas turbines with can-annular combustors typically exhibit a set of thermoacoustic modes with similar frequencies, due to their rotational symmetry and the weak coupling between neighbouring cans. The Bloch boundary condition is often used to simplify these combustors. Because the widely used (quasi-)one-dimensional model cannot naturally consider high-order modal components in the three-dimensional acoustic field, it is valid only when the frequency is sufficiently low and the length of the can-to-can interaction gap is sufficiently short. In this paper, we present a theoretical model using the mode-matching method to consider high-order modal components. A reflection coefficient matrix is used to accurately describe the acoustic characteristics of the gap area. This reflection coefficient matrix is found to depend on the nondimensional cross-sectional area ratio, the Helmholtz number based on the length of the gap area, and the Bloch number. To facilitate a full low-order network modelling of the high-frequency thermoacoustic modes in can-annular combustors, a flame transfer matrix is also used to describe the modal coupling effect across the flame. Based on this model, the thermoacoustic problem of a four-flame can-annular combustor is studied as an example. It is shown that the frequency and growth rate of the thermoacoustic modes can be predicted accurately using the reflection coefficient matrix and flame transfer matrix. The effects of high-order modal components across the flame and in the gap areas are studied separately. The results show that the model containing both of the two coupling effects has the widest range of validity. These couplings can be ignored if only low-frequency plane acoustic waves are considered but need to be carefully considered for higher frequency modes. Moreover, when multiple flames are considered, asymmetric flame distributions are found to more easily lead to modal coupling compared to symmetric flame distributions. All results are validated by comparing with the numerical solutions of the full two-dimensional Helmholtz equation using the finite element method. • The crosstalk effect in the gap area is modelled using the mode matching method. • The jump condition across multiple flames is modelled using the mode matching method. • The effect of modal coupling across the flame and in the gap area is investigated. • A 2D theoretical model is developed to predict the thermoacoustic mode in can-annular combustors. [ABSTRACT FROM AUTHOR]

Aboveground biomass (AGB) in grasslands directly reflects the net primary productivity, making it a sensitive indicator of grassland resource quality and ecological degradation. Accurately estimating AGB over large regions to reveal long-term AGB evolution trends remains a formidable challenge. In this study, we divided Inner Mongolia Autonomous Region (IMAR) grasslands into three study regions based on their spatial distribution of grassland types. We combined remote sensing data with ground-based sample data collected over the past 19 years from 6114 field plots using the Google Earth Engine platform. We constructed random forest (RF) and traditional regression AGB inversion models for each region and selected the best-performing model through accuracy assessment to estimate IMAR grassland AGB for the period 2000–2022. We also examined the trends in AGB changes and identified the driving forces affecting IMAR grasslands through the application of Theil-Sen estimation, Mann-Kendall trend analysis, and the Geodetector model. The main findings are as follows: (1) Compared with the univariate parametric traditional regression model, the AGB monitoring accuracy of the multivariate non-parametric RF model in the three study regions increased by 5.94%, 5.08% and 19.14%, respectively. (2) The average AGB per unit area of IMAR grasslands from 2000 to 2022 was 731.41 kg/hm2, with alpine meadow having the highest average AGB (1271.70 kg/hm2) and temperate grassland desertification having the lowest (469.06 kg/hm2). IMAR grasslands exhibited an overall increasing trend in AGB over the past 23 years (6.01 kg/hm2•yr), with the increasing trend covering 83.52% of the grassland area and the decreasing trend covering 16.48%. (3) Spatially, IMAR grassland AGB showed a gradual decline from northeast to southwest and exhibited an increasing trend with increasing longitude (45.423 kg/hm2 per degree) and latitude (71.9 kg/hm2 per degree). (4) Meteorological factors were the most significant factors affecting IMAR grassland AGB, with precipitation (five-year average q value of 0.61) being the most prominent. In the western part of IMAR, where precipitation is consistently limited throughout the year, the primary drivers of influence were human activities, with particular emphasis on the number of livestock (with a five-year average q value of 0.44). It is evident that reducing human activity disturbance and pressure in fragile grassland areas or implementing near-natural restoration measures will be beneficial for the sustainable development of grassland ecosystems. The results of this research hold substantial reference importance for the protection and restoration of grasslands, the supervision and administration of grassland resources, as well as the development of policies related to grassland management. [Display omitted] • The aboveground biomass (AGB) of grasslands in IMAR increased over the past 23 years. • IMAR grassland AGB shows an upward trend with increasing longitude and latitude. • Precipitation is the main factor affecting grassland AGB in IMAR. • Human activities have a greater impact on the grassland AGB in western IMAR. [ABSTRACT FROM AUTHOR]

Hepatocyte apoptosis is a crucial factor affecting liver quality in brain-dead donors. The identification of key molecular proteins involved in brain-death (BD)-induced hepatocyte apoptosis may help determine an effective method for improving the quality of livers from brain-dead donors. In this study, we used in vivo and in vitro models to investigate the role of chitinase-3-like protein 1 (CHI3L1) in promoting liver cell apoptosis after BD. Chitin was used to inhibit CHI3L1 in a rat model of BD. Macrophage polarization of THP-1 cells and hypoxia/reoxygenation (H/R) of LO-2 cells were used to mimic BD-induced cell stress in liver. We found that CHI3L1 played a vital role in promoting liver cell apoptosis. Six hours after BD, CHI3L1 expression was significantly upregulated in liver macrophages and was associated with BD-induced M1 polarization of these cells. In liver cells cultured under H/R conditions, recombinant CHI3L1 activated the protease-activated receptor 2 (PAR2)/c-June N-terminal kinase (JNK) apoptotic pathway and aggravated apoptosis. Compared with the control group, chitin particles inhibited the expression of CHI3L1 in the liver of brain dead rats, thereby reducing activation of the hepatocyte surface receptor, PAR2, and its downstream JNK/caspase-3 signaling pathway, ultimately reducing hepatocyte apoptosis. In conclusion, our results indicate that CHI3L1 relies on a PAR2/JNK-mediated mechanism to promote BD-induced hepatocyte apoptosis. • CHI3L1 upregulated in liver macrophages after Brain death (BD). • CHI3L1 upregulation associated with BD-induced M1 polarization. • CHI3L1 activated PAR2/JNK pathway, promotes BD-induced hepatocyte apoptosis. • Chitin inhibits CHI3L1 expression and PAR2/JNK/caspase-3 signaling pathway. • Chitin reduces hepatocyte apoptosis. [ABSTRACT FROM AUTHOR]

A hybrid material of N -doped graphitic carbon shell-encapsulated FeCo alloy derived from metal–polyphenol network and melamine sponge is an effective electrocatalyst for ORR, OER, and HER. Exploiting low cost and durable electrocatalysts with high efficiency for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) is of great significance for energy conversion and storage applications. Herein, a hybrid electrocatalyst of FeCo alloy nanoparticles embedded in a porous N -doped carbon was prepared via a pyrolysis process of low-cost melamine sponge and mass-produced metal–polyphenol network. Benefting from the metal coordination of metal–polyphenol network and abundant N source of melamine sponge, the metal–N moiety and FeCo alloy nanoparticles (wtih a diameter around 50 nm) encapsulated in a N -doped graphene-like carbon layer were formed in-situ. Such intimate integration of graphene-like carbon-encapsulated FeCo alloys, metal–N active species, and porous structure is conducive to improve the catalytic activity and increase the catalytic durability in alkaline media. As a consequence, the as-prepared electrocatalyst exhibits the pronounced activity toward ORR, OER, and HER simultaneously under alkaline condition, particularly on the performances of potential, stability, and methanol tolerance. [ABSTRACT FROM AUTHOR]

We describe the heart of the canonical t -structure on the perfect derived category of a strictly positive graded algebra as the module category over the quadratic dual. Applying this result we obtain examples showing new phenomena on t -structures on derived categories of finite-dimensional algebras. [ABSTRACT FROM AUTHOR]

Bacterial resistance has become a serious threat to human health. In particular, the gradual development of resistance to polymyxins, the last line of defense for human infections, is a major issue. Secreted proteins contribute to the interactions between bacteria and the environment. In this study, we compared the secretomes of polymyxin B-sensitive and -resistant Escherichia coli strains by data-independent acquisition mass spectrometry. In total, 87 differentially expressed secreted proteins were identified in polymyxin B-resistant E. coli compared to the sensitive strain. A GO enrichment analysis indicated that the differentially expressed proteins were involved in biological processes, including bacterial-type flagellum-dependent cell motility, ion transport, carbohydrate derivative biosynthetic process, cellular response to stimulus, organelle organization, and cell wall organization or biogenesis. The differentially expressed secreted proteins in polymyxin B-resistant bacteria were enriched for multiple pathways, suggesting that the resistance phenotype depends on complex regulatory mechanisms. A potential biomarker or drug target (YebV) was found in polymyxin B-resistant E. coli. This work clarifies the secretome changes associated with the acquisition of polymyxin resistance and may contribute to drug development. • Quantitative secretome analysis of polymyxin B-resistant E. coli was firstly reported. • Polymyxins resistance is closely related to the improvement of antioxidant capacity. • Polymyxin B-resistant E. coli highly express YebV outside the cell. [ABSTRACT FROM AUTHOR]

Ginsenoside Rh2 (G-Rh2), a component of ginseng extraction, exerted anti-tumor property in the occurrence and progress of human tumors. Vestibular schwannoma (VS) is a kind of benign tumor. Extraction of traditional Chinese herb has been applied to treat VS as adjuvant therapy. Nevertheless, G-Rh2-related molecular mechanisms in VS progress are not yet clear. The purpose of current study is to unveil the function and potential molecular mechanism of Rh2 in VS cellular functions. At first, the viability and apoptosis of VS cells treated with different concentrations of Rh2 were assessed. Autophagy and DNA damage response can be induced by multiple drugs. Here, we observed the changes of autophagy and DNA damage in Rh2-induced VS cells. Based on the experimental data, treatment with Rh2 contributed to cell apoptosis by inducing DNA damage and suppressing DNA damage. LAMP2 (lysosomal associated membrane protein 2), an autophagy inducer, was downregulated in Rh2-treated VS cells. Through mechanism study, we determined that Rh2 led to the transcriptional inactivation of LAMP2 by downregulating its transcription activator NR2F2 (nuclear receptor subfamily 2 group F member 2). In addition, NR2F2 overexpression recovered the role of Rh2 in cell functions, which was further rescued by the silence of LAMP2. Collectively, our study unveiled a novel NR2F2/LAMP2 axis in Rh2-mediated VS cells, which potentially contributes to the therapy for VS. Image 1 • Rh2 induced apoptosis of primary VS cells by regulating DNA damage and autophagy. • LAMP2 was downregulated in Rh2-induced primary VS cells and its recovery attenuated Rh2-mediated cellular functions. • NR2F2 positively regulated LAMP2 expression through transcriptional activation. • NR2F2/LAMP3 axis regulated Rh2-mediated functions of primary VS cells. [ABSTRACT FROM AUTHOR]

• Clusters that are well approximated as tetrairidium were synthesized from Ir(C 2 H 4) 2 complexes anchored to the Zr 6 O 8 nodes of the metal organic framework UiO-67. • The supported clusters catalyze ethylene conversion at 298 K and atmospheric pressure, with the turnover frequency (per Ir atom) characterizing the clusters being twice that of the mononuclear iridium complexes. • The clusters are active exclusively for hydrogenation whereas the mononuclear iridium complexes are active for both dimerization and hydrogenation. • DFT calculations of the reaction energetics are in good accord with experiment, showing that the rate-determining step for the hydrogenation on the isolated iridium complexes is the H 2 activation on iridium, whereas the hydrogenation of an iridium-bound ethyl ligand is rate determining for the cluster. Clusters that are well approximated as tetrairidium were synthesized from Ir(C 2 H 4) 2 complexes anchored to the Zr 6 O 8 nodes of the metal organic framework (MOF) UiO-67 by treatment in H 2 at 353 K. The conversion taking place within the porous MOF structure was monitored by infrared and X-ray absorption spectroscopies, which provide evidence of tetrairidium clusters formed from the mononuclear precursors. The supported clusters were tested in a flow reactor as catalysts for ethylene conversion at 298 K and atmospheric pressure with a 1:1 M feed ratio of H 2 to ethylene. The results show that the turnover frequency (per Ir atom) characterizing the clusters is twice that of the mononuclear iridium complexes, with both catalysts being active for hydrogenation and dimerization and the clusters being less selective than the complexes for dimerization. Density functional theory calculations of the reaction energetics are in good accord with experiment, showing that the rate-determining step for the hydrogenation on the isolated iridium complexes is the H 2 activation on iridium, whereas the hydrogenation of an iridium-bound ethyl ligand is rate determining for the cluster. [ABSTRACT FROM AUTHOR]

Thermoacoustic instabilities in annular gas turbine combustors often involve modes which vary in both the longitudinal and circumferential directions. Recent experimental studies show that during limit cycle oscillations, different thermoacoustic modes may be uncoupled, as is the case in purely longitudinal or circumferential spinning modes. They may also be coupled, for example two counter-rotating circumferential modes combining to give standing or mixed modes, and coupling between circumferential and longitudinal modes giving rise to the slanted mode. Accurately predicting such modal couplings and the resulting spatial pattern of limit cycle oscillations remains an open challenge. This work uses a 2-D low-order network model based on modal expansions, validated against a full 3-D Helmholtz solver, to systematically investigate these couplings. For the first time, low-order network modelling is shown to capture limit cycle oscillations exhibiting both uncoupled and nonlinearly coupled modes, the latter including coupling between counter-rotating circumferential modes and between longitudinal and circumferential modes. It is shown that limit cycle solutions with totally different mode patterns (longitudinal, circumferential spinning, circumferential standing and slanted) can all exist in a given thermoacoustic system, with switches between modal patterns arising from slight changes in parameters such as the flame time delay. [ABSTRACT FROM AUTHOR]

Abstract Helmholtz resonators (HRs) are widely used to damp acoustic oscillations, including in the combustors of aero-engines and power gas turbines where they damp thermoacoustic oscillations. The geometries of such combustors are often annular in shape, which means that low frequency acoustic modes exhibit both longitudinal and circumferential modeshapes, the latter across different circumferential wave numbers. For linear acoustic disturbances downstream of the flame, the presence of HRs leads to modal coupling and mode shape shifts, which makes design and placement of multiple HRs very complicated. A procedure which ensures that the design and placement of the HRs can be optimised for good acoustic damping performance would be very valuable, and such a procedure is presented in this work. A simplified linear, low-dimensional model for the acoustic behaviour in a hot annular duct sustaining a mean flow is extended to account for the attachment of multiple HRs. The HRs are assumed to sustain a cooling mean bias flow through them, towards the combustor, such that they can be modelled using linear, lumped element Rayleigh conductivity models. An optimisation method based on the gradient derived from adjoint sensitivity analysis is then applied to the low order network acoustic modelling framework for hot annular ducts incorporating HR models, for the first time. It is used to optimise over multiple HR geometry and placement parameters, to obtain optimum acoustic damping over all acoustic modes in a given frequency range. These optimisation procedures are validated via multi-dimensional parameter sweep results. Thus a novel and efficient tool for HR optimisation for thin annular ducts is presented. [ABSTRACT FROM AUTHOR]

Abstract Recent clinical researches demonstrated "obesity paradox" in chronic obstructive pulmonary disease (COPD) patients. However, why obesity is beneficial to COPD development remains unclear. Obesity is distinguished by hyperinsulinemia, and cellular senescence of airway epithelial cells (AEC) is involved in COPD progression. In this study, we aim to investigate the roles of insulin in high concentration in AEC cellular senescence. Human bronchial epithelial cells (BEAS-2B) and small airway epithelial cells (HSAEpiC) were used for experiments and treated with insulin in indicated time period and concentration with or without 1% cigarette smoke extract (CSE) exposure, and autophagy activator (rapamycin) or inhibitor (chloroquine) after exposed to 1% CSE. The expression of senescence protein (p21), cell cycle related protein (cyclinE), and autophagy protein (LC3B, Beclin-1 and p62) were determined by western blot. Cellular senescence was detected by Senescence-β-Galactosidase staining. Autophagy level was detected by GFP-LC3B fluorescent light. Results showed that insulin receded cellular senescence in different time and concentration, as indicated by decreased expression of p21, increased expression of cyclinE and down-regulated ratio of SA-β-Gal stained cells in BEAS-2B and HSAEpiC under physiological or CSE exposure condition. 5 μg/ml insulin treated for 48 h up-regulated the ratio of LC3B II/I, Beclin-1 and number of spot dots of GFP-LC3B, and down-regulated the level of p62 in AEC cells after 1% CSE exposure, while 1% CSE showed an opposite effect. Activating autophagy receded cellular senescence, and vice versa. Meanwhile, the effect of 5 μg/ml insulin on receding cellular senescence could be alleviated by autophagy inhibitor chloroquine or reinforced by autophagy activator rapamycin. In conclusion, insulin in high concentration could reduce the CSE induced cellular senescence of human airway epithelial cells through autophagy pathway. Highlights • Cellular senescence in human epithelial cells wasreducedby high concentration of insulinwith or without CSE exposure. • Autophagy was activated by high concentration of insulinin human epithelial cellsafter CSE exposure. • Cellular senescence was modulatedby autophagyin human epithelial cells. • Insulin could reduce cellular senescence in human epithelial cells though autophagy pathway. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The MoP/CN samples exhibit superior activity in CO 2 reduction and H 2 evolution. • The CO 2 adsorption and conversion progress is well revealed in the photoreaction. • The efficient co-catalyst MoP facilitates the separation and transfer of charges. Abstract Photoreduction CO 2 to hydrocarbons and photosplitting water for H 2 production are the most promising, sustainable approaches for environmental pollution alleviation and solar-to-chemical energy conversion. However, developing low-cost, high efficient and stable photocatalysts remains a great challenge. Herein, we reported a novel visible-light activated MoP co-catalyst loaded g-C 3 N 4 photocatalyst for CO 2 reduction and water splitting under simulated irradiation firstly. Experimental results demonstrated that the composites were highly active and exhibited superior stability. The maximum CO and H 2 evolution rates of 0.92 μmol h−1 and 40.38 μmol h−1 were achieved on MoP/CN-15% catalyst, which were 4.5-fold and 74.5-fold higher than the pure g-C 3 N 4 , and the corresponding apparent quantum efficiencies (AQE) were 3.5% and 18.3% at 420 nm, respectively. In situ FTIR analysis disclosed the CO 2 adsorption and conversion progress, in which the COO− acted as a major intermediate. Furthermore, comprehensive characterization analysis revealed the introduction of MoP facilitated the separation and transfer of photogenerated electron-hole pairs, and the theoretical calculation by density functional theory (DFT) also confirmed that MoP could effectively separate the photoexcited charges from g-C 3 N 4. Combining with experimental and DFT calculations results, a new way to design cost-effective photocatalysts has been enlightened. [ABSTRACT FROM AUTHOR]

Graphene quantum dots (GQDs) have been synthesized reproducibly by chemical oxidation (CO) of carbon nano-onions (nCNOs) and a one-step pulsed laser ablation (LA) of nCNOs in deionized water. The photoluminescence (PL) spectra show that the LA-GQDs have blue shifted emission relative to the CO-GQDs which is attributed to the effects of both particle sizes and surface functional groups. The CO-GQDs have an average diameter of 4.1(8) nm and a thickness corresponding to two or three graphene layers, while the LA-GQDs have an average diameter of 1.8(6) nm and a thickness comparable to a single layer of graphene. The CO-GQDs favor the presence of carboxylic groups and have a higher fraction of sp 2 carbons, while the LA-GQDs prefer the presence of hydroxyl groups and have a higher fraction of sp 3 carbons. PL lifetime data suggests that surface functional groups are the main source of radiative deactivation and the sp 2 carbon domains are mainly responsible for non-radiative decay. PL lifetimes are measured to be 7.9(6) ns for the emission from the carboxylic groups and 3.18(10) ns from the hydroxyl groups. Compared to CO, liquid-phase LA is a faster and cleaner one-step method for producing GQDs with fewer starting chemicals and byproducts. [ABSTRACT FROM AUTHOR]

A novel ultra-low specific on-resistance ( R on,sp ) trench lateral double-diffused MOSFET with P/N pillars and dual trench gates (P/N DTG-T LDMOS) based on silicon-on-insulator technology is proposed in this paper. The new structure features dual trench gates and heavily doping P/N pillars. The P/N pillars are inserted into the drift region under the P-well. The P-pillar causes an assistant depletion effect on the drift region. The N-pillar can not only improve the breakdown voltage (BV) by modulating the electric field but also significantly reduce the R on,sp by increasing the doping concentration of the drift region. Furthermore, the dual trench gates form dual conduction channels and the heavily doping N-pillar provides a lower resistance region for the carriers, which can both reduce the R on,sp . Consequently, compared with the conventional trench LDMOS, a lower R on,sp of 0.58 mΩ cm 2 and a higher the figure of merit (FOM, FOM=BV 2 / R on,sp ) of 62.9 MW/cm 2 are obtained for the P/N DTG-T LDMOS, which are improved by 74.8% and 308.4% respectively. Meanwhile, the BVs of the both structures are maintained at a same level of 190 V. [ABSTRACT FROM AUTHOR]

Under stressful conditions, bacteria can enter viable but non-culturable (VBNC) state to survive. VBNC cells lost ability to grow on routine culture medium but are still alive and may revive in suitable conditions. The revived cells can consume nutrients or produce toxins, leading to food spoilage or human illness, posing great risk to food safety and public health. Previously, we have reported that high pressure carbon dioxide (HPCD), an environment-friendly sterilization technology, can induce VBNC formation. However, the underlying mechanism is unclear. By performing a comprehensive transcriptomic analysis, we revealed that HPCD initiated high expression of asr , encoding an acid shock protein, could promote VBNC formation of E. coli O157:H7. Quantitative reverse transcription PCR analysis suggested that high expression of asr (i) inhibited acid resistance (AR) systems, resulting in endogenous proton accumulation; (ii) inhibited hchA expression, a protein stabilizing factor. The two effects resulted in endogenous protein aggregation, which was highly correlated to VBNC formation. Accordingly, HPCD-stressed cells exhibited decreased efficiency of electron transfer chain and ATP production, which was also contributory to cytoplasmic protein aggregation. Taken together, HPCD-initiated high expression of Asr coupled with decreased ATP production led to protein aggregation, finally promoted the cells to enter VBNC state. • Molecular responses of E. coli O157:H7 to HPCD were investigated to explore crucial factors regulating VBNC formation. • Acid shock protein Asr was found to be involved in regulating HPCD induced VBNC formation. • Asr inhibited AR systems / protein stabilizer HchA to facilitate endogenous protein aggregation to promote VBNC formation. [ABSTRACT FROM AUTHOR]

The sound generated or absorbed by short circular holes with a mean flow passing through them is relevant in many practical applications. Analytical models for their acoustic response often ignore the fact that such holes open to a confined or finite space either side, or account for this effect simply by adding an end mass inertial correction. The vortex–sound interaction within a short hole has been recently shown to strongly affect the acoustic response at low frequencies (D. Yang, A.S. Morgans, J. Sound Vib. 384 (2016) 294–311 [ 19] ). The present study considers a semi-analytical model based on Green's function method to investigate how the expansion ratios either side of a short hole affect the vortex–sound interaction within it. After accounting for expansions to confined spaces using a cylinder Green's function method, the model is substantially simplified by applying a half-space Green's function for expansions to large spaces. The effect of both the up- and downstream expansion ratios on the acoustics of the hole is investigated. These hole models are then incorporated into a Helmholtz resonator model, allowing a systematic investigation into the effect of neck-to-cavity expansion ratio and neck length. Both of these are found to affect the resonator damping. [ABSTRACT FROM AUTHOR]

This study is concerned with the theoretical modelling and experimental verification of the coupled vibrations of building and elevator ropes. The elevator ropes consist of a main rope which supports the cage and the compensation rope which is connected to the compensation sheave. The elevator rope is a flexible wire with a low damping, so it is prone to vibrations. In the case of a high-rise building, the rope length also increases significantly, so that the fundamental frequency of the elevator rope approaches the fundamental frequency of the building thus increasing the possibility of resonance. In this study, the dynamic model for the analysis of coupled vibrations of building and elevator ropes was derived by using Hamilton's principle, where the cage motion was also considered. An experimental testbed was built to validate the proposed dynamic model. It was found that the experimental results are in good agreement with the theoretical predictions thus validating the proposed dynamic model. The proposed model was then used to predict the vibrations of real building and elevator ropes. [ABSTRACT FROM AUTHOR]

The acoustic response of a circular hole with mean flow passing through it is highly relevant to Helmholtz resonators, fuel injectors, perforated plates, screens, liners and many other engineering applications. A widely used analytical model [M.S. Howe. “Onthe theory of unsteady high Reynolds number flow through a circular aperture”, Proc. of the Royal Soc. A. 366, 1725 (1979), 205‐223] which assumes an infinitesimally short hole was recently shown to be insufficient for predicting the impedance of holes with a finite length. In the present work, an analytical model based on Green׳s function method is developed to take the hole length into consideration for “short” holes. The importance of capturing the modified vortex noise accurately is shown. The vortices shed at the hole inlet edge are convected to the hole outlet and further downstream to form a vortex sheet. This couples with the acoustic waves and this coupling has the potential to generate as well as absorb acoustic energy in the low frequency region. The impedance predicted by this model shows the importance of capturing the path of the shed vortex. When the vortex path is captured accurately, the impedance predictions agree well with previous experimental and CFD results, for example predicting the potential for generation of acoustic energy at higher frequencies. For “long” holes, a simplified model which combines Howe׳s model with plane acoustic waves within the hole is developed. It is shown that the most important effect in this case is the acoustic non-compactness of the hole. [ABSTRACT FROM AUTHOR]

This paper analyzes how to achieve the cost-effectiveness by initial allocation of CO 2 emission permits when a single dominant firm in production market has market power in auction, and compare two prevalent allocation patterns, mixed allocation and single auction. We show how the firm with market power may manipulate the auction price, thereby this leads to fail to achieve cost-effective solution by auction unless the total permits for allocation equal to the effective emissions cap. Provided that the market power firm receives strictly positive free permits, the effective emissions cap of mixed allocation is larger than that of single auction. The production market share of dominant firm is increasing with the free permits it holds. Finally, we examine the compliance costs and welfare of mixed allocation and single auction, the result show that the former is preferred to the later when policy makers consider economic welfare without welfare cost due to CO 2 emissions. [ABSTRACT FROM AUTHOR]

Let R be an isolated Gorenstein singularity with a non-commutative resolution A = End R ( R ⊕ M ) . In this paper, we show that the relative singularity category Δ R ( A ) of A has a number of pleasant properties, such as being Hom-finite. Moreover, it determines the classical singularity category D s g ( R ) of Buchweitz and Orlov as a certain canonical quotient category. If R has finite CM type, which includes for example Kleinian singularities, then we show the much more surprising result that D s g ( R ) determines Δ R ( Aus ( R ) ) , where Aus ( R ) is the corresponding Auslander algebra. The proofs of these results use dg algebras, A ∞ Koszul duality, and the new concept of dg Auslander algebras, which may be of independent interest. [ABSTRACT FROM AUTHOR]

In this work, we investigate both numerically and theoretically the sound generated by entropy waves passing through sudden area expansions. This is a canonical configuration representing internal flows with flow separation and stagnation pressure losses. The numerical approach is based on a triple decomposition of the flow variables into a steady mean, a small-amplitude coherent part, and a stochastic turbulent part. The coherent part contains acoustic, vortical, and entropy waves. The mean flow is obtained as the solution of the Reynolds-Averaged Navier–Stokes (RANS) equations. The equations governing the coherent perturbations are linearised and solved in the frequency domain. To account for the effect of turbulence on the coherent perturbations, a frozen eddy viscosity model is employed. When entropy fluctuations pass through the area expansion, the generated entropy noise behaves as a low-pass filter. The numerical predictions of the noise at low frequencies are compared to the predictions of compact, quasi-one-dimensional, and isentropic theory and large discrepancies are observed. An alternative model for the generated entropy noise tailored for area expansions is then proposed. Such model is based on the conservation of mass, momentum, and energy written in integral form. The model assumes zero frequency and the one-dimensionality of the flow variables far upstream and downstream of the expansion. The predictions of this model agree well with the numerical simulations across a range of finite subsonic Mach numbers including low, intermediate, and high Mach numbers. The contributions of this work are both numerical and theoretical. Numerically, a triple decomposition adapted to high-Mach-number, compressible flows is introduced for the first time in the context of acoustic simulations. From a theoretical point of view, the quasi-steady model proposed here correctly captures the low-frequency entropy noise generated at sudden area expansions, including at high subsonic Mach numbers. • Isentropic, quasi-1D theory overpredicts the entropy noise at sudden area expansions • We propose a numerical approach based on a triple decomposition for compressible flows. • We propose an alternative compact analytical model tailored to area expansions. [ABSTRACT FROM AUTHOR]

Supported rhodium acetate dimers were prepared by the reaction of Rh 2 (OAc) 4 (OAc is acetate) with highly dehydroxylated MgO powder and characterized by extended X-ray absorption fine structure and infrared (IR) spectra, which show that the supported species were well represented as Rh 2 (OAc) 3 , with each Rh atom on average bonded to one oxygen atom of the MgO surface. Aberration-corrected scanning transmission electron microscopy gave images of Rh atoms in pairs on the MgO. The supported rhodium dimers were probed with a pulse of CO, and the IR spectra indicate a Rh(II) species with weakly bonded carbonyl ligands; the sharpness of the ν CO band indicates highly uniform surface species. Further treatment in CO led to breakup of the rhodium dimers into mononuclear species; such fragmentation took place in other treatment gases as well, with the degree of fragmentation decreasing in the order CO > C 2 H 4 > helium. The fragmentation is inferred on the basis of IR spectra to have proceeded through intermediate Rh 2 species without acetate ligands. In contrast, rhodium dimers were reduced and not fragmented in the presence of H 2 at 353 K, but at higher temperatures the rhodium aggregated to give larger clusters. The supported species catalyzed ethylene hydrogenation at 298 K and 1 bar at a H 2 :ethylene molar ratio of 4; after 27 h of catalysis in a once-through flow reactor, acetate ligands were removed from the dimers, and some of them fragmented, as shown by IR spectroscopy. The intermediate dirhodium species without acetate ligands are two or three orders of magnitude more active as catalysts than the supported mononuclear rhodium species or those present predominantly as Rh 2 (OAc) 3 , respectively. [ABSTRACT FROM AUTHOR]

In this paper, we aimed to explore whether progranulin (PGRN) could induce epithelial ovarian cancer cells to undergo an epithelial mesenchymal transition (EMT) program directly and through its activation of cancer associated fibroblasts (CAFs) indirectly. Immunohistochemistry(IHC) staining of tissue samples of 78 cases of epithelial ovarian cancer (EOC) patients found that PGRN expression levels were negatively correlated with E-cadherin levels (r = − 0.289, P = 0.013) and positively correlated with Slug levels (r = 0.332, P = 0.003); Cell experiments showed that PGRN overexpression could increase the migratory and invasive abilities of A2780 cells significantly. Moreover, high doses (62 ng/ml) of recombinant PGRN could induce 14.7 fold high expression of smooth muscle actin α (α-SMA) in human normal fibroblasts. In addition, patients with both high levels of PGRN and α-SMA in their tissue samples had the worst disease free survival (DFS) and overall survival (OS) than those with low levels of PGRN or α-SMA. All the results suggest that PGRN could promote invasiveness of EOC cells through an EMT program directly and through activation of CAFs indirectly. This may provide a new effective therapy target for EOC. [ABSTRACT FROM AUTHOR]

We consider optimal locations of heat diffusion and related optimal control to achieve null controllability for multi-dimensional heat equations. Both time optimal control and norm optimal control problems are considered. The reason behind combining these two problems together is that these two problems are actually equivalent: The energy to be used to drive the system to zero in minimal time interval is actually the minimal energy of driving the system to zero in this minimal time interval and visa versa. We formulate the optimal locations for time optimal control and norm optimal control into two types of shape optimization problems. One is seeking the optimal domain of heat diffusion with a fixed interior actuator domain. This can be considered as a domain perturbation problem in shape optimization. Another is to seek both the optimal locations of the optimal heat diffusion domain and the related optimal actuator domain. The existences of these two types of shape optimization problems over some class of open sets in general R N space have been proved separately. [ABSTRACT FROM AUTHOR]

The structural health monitoring (SHM) involves the sampled operational vibration measurements over time so that the structural features can be extracted accordingly. The recurrence plot (RP) and corresponding recurrence quantification analysis (RQA) have become a useful tool in various fields due to its efficiency. The threshold selection is one of key issues to make sure that the constructed recurrence plot contains enough recurrence points. Different signals have in nature different threshold values. This paper is aiming at presenting an approach to determine the optimal threshold for the operational vibration measurements of civil engineering structures. The surrogate technique and Taguchi loss function are proposed to generate reliable data and to achieve the optimal discrimination power point where the threshold is optimum. The impact of selecting recurrence thresholds on different signals is discussed. It is demonstrated that the proposed method to identify the optimal threshold is applicable to the operational vibration measurements. The proposed method provides a way to find the optimal threshold for the best RP construction of structural vibration measurements under operational conditions. [ABSTRACT FROM AUTHOR]

Tight junctions (TJ) are multiprotein complexes that function to regulate paracellular transport of molecules through epithelial and endothelial cell layers. Many new tight junction-associated proteins have been identified in the past few years, and their functional roles and interactions have just begun to be elucidated. In this paper, we describe a novel protein LYsine-RIch CEACAM1 co-isolated (LYRIC) that is widely expressed and highly conserved between species. LYRIC has no conserved domains that would indicate function and does not appear to be a member of a larger protein family. Data from analysis of rat and human tissue sections and cell lines show that LYRIC colocalizes with tight junction proteins ZO-1 and occludin in polarized epithelial cells, suggesting that LYRIC is part of the tight junction complex. LYRIC dissociates from ZO-1 when junctional complexes are disrupted, and as tight junctions reform, ZO-1 relocalizes before LYRIC. These results suggest that LYRIC is most likely not a structural component required for TJ formation, but rather is recruited during the maturation of the tight junction complex. [Copyright &y& Elsevier]

Multistimuli responsive materials based on the viologen coordination polymers have attracted much interest in the past few years due to the increasing demand for smart materials. In this paper, based on a viologen ligand 1-(3-carboxybenzyl)- 4,4′-bipyridinium chloride (Hcbbpy) and zinc(II) ion, a new crystalline complex, namely, {[Zn(cbbpy)Cl 2 ]·H 2 O} n (1) has been designed and synthesized. In complex 1 , every cbbpy ligand as a bridge links two Zn2+ ions via carboxylate O atom and pyridine N atom to extend to a 1D zigzag chain. The 1D chains are extended to 3D supramolecular structure through π···π stacking and hydrogen bonding. More importantly, 1 exhibits fast photochromic behaviors in response to UV and X-ray due to the formation of viologen radicals. Complex 1 also shows photo-modulated luminescence property in the solid state. In addition, complex 1 can be deposited on filter paper and displays the potential application as inkless print material. [Display omitted] • A new viologen complex was successfully synthesized and characterized. • Complex 1 shows fast response to UV light and X-ray irradiation. • Complex 1 can be deposited on filter paper and displays as inkless print material. [ABSTRACT FROM AUTHOR]

The active vibration control of a rectangular plate either partially or fully submerged in a fluid was investigated. Piezoelectric sensors and actuators were bonded to the plate, and the assumed mode method was used to derive a dynamic model for the submerged plate. The properties of the piezoelectric actuators and sensors, as well as their coupling to the structure, were used to derive the corresponding equations of their behaviour. The fluid effect was modelled according to the added virtual mass obtained by solving the Laplace equation. The natural vibration characteristics of the plate both in air and in water were obtained theoretically and were found to be consistent with the experimental results, and the changes in the natural frequencies resulting from submersion in fluid can be accurately predicted. A multi-input, multi-output positive position feedback controller was designed by taking the natural vibration characteristics into account and was then implemented by using a digital controller. The experimental results show that piezoelectric sensors and actuators along with the control algorithm can effectively suppress the vibration of a rectangular plate both in air and submerged in a fluid. [ABSTRACT FROM AUTHOR]

Background To explore the feasibility, safety, and indications of the modified Appleby operation for carcinoma of the body and tail of the pancreas and to identify prognostic factors. Material and methods Data from a total of 15 patients receiving the modified Appleby operation in our department were retrospectively analyzed. Correlation analyses and univariate and multivariate analyses of the survival time were performed to identify prognostic factors. Results The operations were successful in all 15 patients. The median survival time was 19 mo except in one case, where the patient died; and the 1- and 3-y survival rates were 86.7% (13/15) and 6.7% (1/15), respectively. A positive correlation was found between age and survival time (P = 0.037, Pearson correlation = 0.541). In addition, univariate analysis, age, operative time, and perineural invasion were correlated with survival time (P = 0.029, 0.035, and 0.049, respectively). Finally, multivariate analysis revealed that only age =60 y was correlated with survival (Hazard ratio = 0.263, P = 0.044). Conclusions The improved Appleby operation was feasible and safe when performed in experienced centers by experienced surgeons and can improve the patients' survival time and quality of life. Statistical analysis suggests that elderly patients may have a better prognosis than younger patients to some extent. [ABSTRACT FROM AUTHOR]

SHAPE technology was used to analyze RNA secondary structure of the 5′ most 474 nts of the MHV-A59 genome encompassing the minimal 5′ cis -acting region required for defective interfering RNA replication. The structures generated were in agreement with previous characterizations of SL1 through SL4 and two recently predicted secondary structure elements, S5 and SL5A. SHAPE provided biochemical support for four additional stem–loops not previously functionally investigated in MHV. Secondary structure predictions for 5′ regions of MHV-A59, BCoV and SARS-CoV were similar despite high sequence divergence. The pattern of SHAPE reactivity of in virio genomic RNA, ex virio genomic RNA, and in vitro synthesized RNA was similar, suggesting that binding of N protein or other proteins to virion RNA fails to protect the RNA from reaction with lipid permeable SHAPE reagent. Reverse genetic experiments suggested that SL5C and SL6 within the nsp1 coding sequence are not required for viral replication. [ABSTRACT FROM AUTHOR]

Helmholtz resonators with sound absorption materials filling the neck may have an improved sound absorption capacity. In this work, parallel perforated ceramics with different perforation diameters were installed into the neck of a Helmholtz resonator to improve its acoustic impedance to simultaneously achieve a better acoustic absorption coefficient and a wider absorption bandwidth. An experimental system was built to investigate the effect of the perforation diameters on the sound absorption performance of the resonator. It is found that nonlinear effects near the resonance frequency affect the resonator׳s neck mouth impedance and further its sound absorption performance significantly. For frequency range 50–500 Hz, a model of the neck mouth impedance is developed based on a revised Forchheimer relationship. The experimental results are in good agreement with the theoretical model. [ABSTRACT FROM AUTHOR]

Rabbits play a growing role in research into glaucoma surgical models and ocular drug delivery models. However, the lack of an accurate method for measuring intraocular pressure (IOP) in this animal has been a significant deficit. In this study we validated the use of the TonoVet rebound tonometer and provide conversion tables for its use in rabbits. Experiments were performed on 18 adult New Zealand White rabbits. The TonoVet measurements were obtained and compared to manometric readings by anterior chamber (AC) cannulation. The TonoVet position and ‘d’ (dog or cat) and ‘p’ (other species) modes were compared. The sensitivity of the TonoVet tonometer in assessing IOP changes was also tested. There was a strong linear correlation for both the ‘d’ mode (mean slope = 0.84 ± 0.03, r(2) = 0.99 ± 0.03) and the ‘p’ mode (mean slope = 0.64 ± 0.02, r(2) = 0.97 ± 0.01) of the TonoVet with manometric IOP. However, the TonoVet had a tendency to underestimate IOP compared to manometry and conversion formulae were possible to calculate for both modes. The orientation of the TonoVet handle had no effect on IOP reading, as long as the groove was horizontal. No significant differences were observed when comparing right and left eyes (P > 0.05). IOP recovered four days after cannulation. Younger rabbits had lower IOP compared with older rabbits (P < 0.01). Timolol produced a 2.5 mmHg reduction in IOP 2 h later as detected by the TonoVet. Using the conversion table presented, the TonoVet is a reliable and precise tool for the measurement of IOP in rabbits. [ABSTRACT FROM AUTHOR]

Abstract: This paper is concerned with the suppression of vibrations and radiated sound of a ring-stiffened circular cylindrical shell in contact with unbounded external fluid by means of piezoelectric sensors and actuators. The dynamic model of a circular cylindrical shell based on the Sanders shell theory was considered together with a ring stiffener model. The mass and stiffness matrices for a ring stiffener were newly derived in this study and added to the mass and stiffness matrices of the cylindrical shell, respectively. The fluid-added mass matrix, which was derived by using the baffled shell theory, was also added to the mass matrix. Finally, the equations representing the piezoelectric sensor measurement and piezoelectric actuation complete the theoretical model for the addressed problem. The natural vibration characteristics of the ring-stiffened cylindrical shell both in air and in water were investigated both theoretically and experimentally. The theoretical predictions were in good agreement with the experimental results. An active vibration controller which can cope with a harmonic disturbance was designed by considering the modified higher harmonic control, which is, in fact, a band rejection filter. An active vibration control experiment on the submerged cylindrical shell was carried out in a water tank and the digital control system was used. The experimental results showed that both vibrations and radiation sound of the submerged cylindrical shell were suppressed by a pair of piezoelectric sensor and actuator. [Copyright &y& Elsevier]

Abstract: We designed a series of mutations to separately destabilize two helical stems (designated S3 and S4) predicted by a covariation-based model of the coronavirus 3′UTR (Zust et al., 2008). Mouse hepatitis virus genomes containing three or four nucleotide mutations that destabilize either S3 or S4 were viable, whereas genomes carrying these mutations in both S3 and S4 were not viable. A genome carrying these mutations in S3 and S4 plus compensatory mutations restoring base-pairing yielded a virus with wild type phenotype. Larger mutations which completely disrupt S3 or S4 generated various phenotypes. Mutations opening up S3 were lethal. Disruptions of S4 generated both viable and lethal mutants. Genomes carrying the original mutations in S3 or S4 plus compensatory mutations restoring base pairing were viable and had robust growth phenotypes. These results support the Zust model for the coronavirus 3′UTR and suggest that the S3 stem is required for virus viability. [Copyright &y& Elsevier]

Traditional bridge health monitoring is both expensive and time-consuming because of the need for installing a large quantity of sensors on the bridge. The indirect monitoring method as a feasible alternative has become popular over the last decade, as useful information can be gathered from moving vehicles installed with sensors by considering vehicle-bridge interaction. This paper describes an indirect time-varying modal parameter identification method for bridges under a moving test vehicle. A novel reference-driven S-transform is proposed for the parametric modal identification of time-varying structural systems with non-stationary characteristics based on a multisensory arrangement, comprising a fixed reference sensor installed on the bridge and another movable sensor installed on a moving test vehicle. By the phase-preservation property of S-transform and the multisensory time-frequency analysis, the proposed iterative reference-driven S-transform can be used to extract the time-varying modal parameters of the vehicle-bridge system when the vehicle moves on the bridge. Based on the coherence between measurements from the sensors mounted on the bridge and vehicle, one can track the time-varying characteristics by combining the spatial and time-frequency information obtained by the multisensory array. The efficiency of the proposed reference-driven S-transform method is validated by numerical simulations and laboratory experiments using a simply supported beam with a moving vehicle. The effects of the vehicle property, driving speed, road roughness and measurement noise are discussed. The numerical and experimental results have demonstrated that the proposed method is useful for time-varying parameter extraction with a multisensory system. This will be useful to structural condition monitoring of bridges. [ABSTRACT FROM AUTHOR]

Our previous that HMMR upregulation independently predicts poor survival in patients with papillary muscle-invasive bladder cancer (MIBC). In this study, we explored its downstream regulations and the potential transcriptional factors activating its expression. MIBC derived T24 cells, and non-MIBC (NMIBC) derived RT4 cells were used for in vitro and in vivo studies. HMMR expression enhanced cell proliferation, the expression of mesenchymal markers, and cell invasion. It induced the nuclear entry of β-catenin, increased its active form in the nuclear part, and elevated the relative TOP/FOP activity. The promoter region of HMMR has a canonical FKH motif. FOXM1 bound to this site and activated HMMR transcription. HMMR knockdown significantly weakened FOXM1 overexpression induced bladder cancer growth, invasion, partial epithelial-to-mesenchymal transition (pEMT), as well as the activation of the Wnt/β-catenin signaling pathway. In conclusion, the findings in this study expanded our understanding of the mechanisms underlying HMMR dysregulation and the functional role of the FOXM1-HMMR axis in bladder cancer. [ABSTRACT FROM AUTHOR]

• An S-transform-based time-varying characteristic analysis method is proposed to extract the frequency fluctuations. • The approximation description between structural instantaneous frequency and S-transform is deducted. • A novel Gaussian window function is proposed for S-transform to improve the time-frequency resolution. • The laboratory vehicle-bridge dynamic interaction experiment is conducted for verification. • Parametric study involving road surface roughness are discussed in the numerical simulation. The health monitoring of bridge under moving vehicles demands a high-efficient time-varying characteristic analysis method to extract the frequency fluctuations caused by vehicle-bridge dynamic interaction effect. Characteristics identification of structures becomes a challenging task especially when time-varying vibration modes are involved. For this purpose, an instantaneous frequency identification technique based on modified S-transform reassignment is presented in this paper. Firstly, the general approximation between structural instantaneous frequency and S-transform is deduced. The Gaussian window is employed in S-transform and a novel first-order frequency function with two parameters is added into the Gaussian window function to improve the time–frequency resolution. The added function makes the Gaussian window scalable-sliding and the optimal values of the parameters are selected based on time–frequency concentration criterion. Considering the Rényi entropy as the measurement of criterion, the information performance extracted from S-transform spectrogram is evaluated. Then the time–frequency reassignment technique is applied to improve the readability of S-transform spectrogram to assure the accuracy of the extracted instantaneous characteristics, which enhances the time–frequency concentration efficiently. The proposed method is verified by numerical simulation, the results obtained by the spectrograms derived from short-time Fourier transform, wavelet transform, modified S-transform and reassigned modified S-transform are compared. Afterwards, the time-varying frequency components related to the vehicle-bridge interaction are extracted from the response signal. Numerical simulations involving different parameter analysis and laboratory experiments are conducted to validate the flexibility of the technique in vehicle-bridge system. The effect of vehicle weight, speed and road surface roughness on the identified results are discussed. Both numerical and experimental results have demonstrated that a higher time–frequency concentration in the spectrogram can be observed of the proposed modified S-transform reassignment method than other time–frequency methods, and subsequently a higher accuracy of instantaneous frequency identification is achieved which provides a good tool for time-varying characteristic analysis in bridge health monitoring. [ABSTRACT FROM AUTHOR]

Abstract: The free flexural vibration of a cantilever plate partially submerged in a fluid is investigated. The fluid is assumed to be inviscid and irrotational. The virtual mass matrix is derived by solving the boundary-value problem related to the fluid motion using elliptical coordinates. The introduction of the elliptical coordinates naturally leads to the use of the Mathieu function. Hence, the virtual mass matrix which reflects the effect of the fluid on the natural vibration characteristics is expressed in analytical form in terms of the Mathieu functions. The virtual mass matrix is then combined with the dynamic model of a thin rectangular plate obtained by using the Rayleigh–Ritz method. This combination is used to analyze the natural vibration characteristics of a partially submerged cantilever plate qualitatively. Also, the non-dimensionalized added virtual mass incremental factors for a partially submerged cantilever plate are presented to facilitate the easy estimation of natural frequencies of a partially submerged cantilever plate. It is found that the numerical results are in good agreement with the previous results, thus validating the proposed approach. [Copyright &y& Elsevier]

Abstract: Full mechanistic understanding of methanol-to-olefins (MTO) conversion is urgently required, not least for the precise control of product selectivity and rational design of zeolite catalysts. Due to its complex nature, the MTO reaction mechanism is still a hot area of dispute. It was traditionally believed that the MTO reaction proceeds through hydrocarbon pool mechanism and methylbenzenes (MBs) are the predominant hydrocarbon pool species. However, by extensive periodic density functional theory (DFT) calculations in HSAPO-34 catalyst, this work indicates that olefins themselves other than MBs are likely to be the dominating hydrocarbon pool species. A full reaction network is established, and the routes to produce olefins, alkanes, and aromatics are formulated. We find that light olefins such as ethene and propene are mainly produced through the scission of cracking precursors (carbenium ions, alkoxides, and higher olefins), and which are formed by the methylation of lighter olefins. The distribution of these cracking precursors as the number of carbon atoms in the pore of catalysts influences the product selectivity from the reaction point of view. A decrease trend in the cracking energy barriers is observed with the carbon atom number of cracking precursors. Hydride transfer between two olefins results in the formation of alkanes and dienes and the latter are likely to be the precursors to form aromatics and subsequently leading to the deactivation of catalysts. This reaction network allows us to rationalize some experimental findings, and more importantly, provides clues on the understanding of selectivity and deactivation. [Copyright &y& Elsevier]

Abstract: Optical back propagation techniques that utilize two highly nonlinear fibers to compensate for transmission fiber nonlinear effects are analyzed. When the step-size is equal to the amplifier spacing, inline compensation of fiber nonlinearity without inline dispersion compensation provides the best performance. [Copyright &y& Elsevier]

Abstract: Long organization names are often abbreviated in spoken Chinese, and abbreviated utterances cannot be recognized correctly if the abbreviations are not included in the recognition vocabulary. Therefore, it is very important to automatically generate and add abbreviations for organization names to the vocabulary. Generation of Chinese abbreviations is much more complex than English abbreviations which are mostly acronyms and truncations. In this paper, we propose a new hybrid method for automatically generating Chinese abbreviations and we perform vocabulary expansion using output of the abbreviation model for voice search. In our abbreviation modeling, we treat the abbreviation generation problem as a tagging problem and use conditional random fields (CRF) as the tagging tool, the output of which is then re-ranked by a length model and web information. In the vocabulary expansion, considering the multiple abbreviation phenomenon and limited coverage of the top-1 abbreviation candidate, we add top-10 candidates into the vocabulary. In our experiments, for the abbreviation modeling, we achieved a top-10 coverage of 88.3% with the proposed method. For the voice search using abbreviated utterances, we improved the full-name search accuracy from 16.9% to 79.2% by incorporating the top-10 abbreviation candidates to the vocabulary. [Copyright &y& Elsevier]

Abstract: We show that Derksen–Weyman–Zelevinsky''s mutations of quivers with potential yield equivalences of suitable 3-Calabi–Yau triangulated categories. Our approach is related to that of Iyama–Reiten and ‘Koszul dual’ to that of Kontsevich–Soibelman. It improves on previous work by Vitória. In Appendix A, the first-named author studies pseudo-compact derived categories of certain pseudo-compact dg algebras. [Copyright &y& Elsevier]

Abstract: The performance of orthogonal frequency-division multiplexing (OFDM) and single-carrier (SC) fiber-optic transmission systems with digital backward propagation (DBP) are compared. Sixteen quadrature amplitude modulation (QAM) is used for both systems with the bit rate of 100Gb/s. The results show that OFDM and SC with Nyquist pulses (SC-Nyquist) have a superior performance as compared to SC with raised-cosine pulses (SC-NRZ) when the DBP is used. We also studied the impact of electrical filter bandwidth and nonlinear phase/amplitude noise on the performance. As the filter bandwidth increases, the performance improves for the case of ideal BP for both OFDM and SC systems when the signal-to-noise ratio (SNR) is large. The analysis of nonlinear phase/amplitude noise revealed that it causes significant impairments for SC-NRZ systems and less impact on OFDM and SC-Nyquist systems, which explains the performance advantage of OFDM/SC-Nyquist over SC-NRZ when the DBP is used. [ABSTRACT FROM AUTHOR]

Abstract: As an attractive alternative to produce light olefins, methanol-to-olefins (MTO) conversion catalyzed by zeolites or zeotype materials was recently proposed to follow a hydrocarbon pool mechanism. In this contribution, the effect of the structure of methylbenzenes (MBs) in the pore of HSAPO-34 catalyst on the MTO activity and selectivity is investigated by first-principle calculations and kinetic simulations. We demonstrate that MBs with five or six methyl groups are not more active than those with fewer methyl groups. Propene is intrinsically more favorable than ethene when the reaction is not diffusion limited based on the side-chain hydrocarbon pool mechanism. Our theoretical results are consistent with some experimental observations and can be rationalized based on the shape selectivity of key reaction intermediates and transition states in the pore of catalyst. [Copyright &y& Elsevier]

Abstract: The nanocomposites of multi-walled carbon nanotubes (MWNTs) decorated with nickel nanoparticles were conveniently prepared by a chemical reduction of nickel salt in the present of poly(acrylic acid) grafted MWNTs (PAA-g-MWNTs). Due to the strong interaction between Ni2+ and –COOH, PAA-g-MWNTs became an excellent supporting material for Ni nanoparticles. The morphology and distribution of Ni nanoparticles on the surface of MWNTs were greatly influenced by the reduction temperatures, the experimental results also showed that the distribution of Ni nanoparticles was greatly improved while the MWNTs were modified by poly(acrylic acid) (PAA). The hydrogenation activity and selectivity of MWNTs decorated with Ni nanoparticles (Ni-MWNTs) for α, β-unsaturated aldehyde (citral) were also studied, and the experimental results showed that the citronellal, an important raw material for flavoring and perfumery industries, is the favorable product with a percentage as high as 86.9%, which is 7 times higher than that of catalyst by Ni-supported active carbon (Ni-AC). [Copyright &y& Elsevier]

Abstract: Eyes absent 2 (Eya2) is a transcription factor involved in a number of cellular and developmental processes. We have previously shown that Eya2 is up-regulated during regression of cardiac hypertrophy and blocks phenylephrine-induced development of cardiomyocyte hypertrophy in vitro, suggesting that Eya2 is a negative regulator of cardiac hypertrophy. In this study, we generated transgenic mice with cardiac-specific overexpression of Eya2 to elucidate the in vivo function of Eya2 in cardiac remodeling. Mild cardiac hypertrophy developed in Eya2 transgenic mice under baseline conditions with no obvious structural or functional defects. Eya2 overexpression inhibited development of cardiac hypertrophy as judged by the abrogation of increases in heart weight and cross-sectional cell surface areas and re-activation of fetal genes under pressure overload (4 weeks). Eya2 overexpression also prevented wall thinning, ventricular dilation, and deterioration of cardiac function as well as fibrosis and inflammation in the heart under long-term pressure overload (12 weeks). Gene expression profiling using the parametric analysis of gene set enrichment (PAGE) method revealed that gene sets related to mitochondrial biogenesis and metabolism were elevated in the Eya2 transgenic mice. We also observed that the PI3K/Akt/mTOR signaling cascade was preserved in the Eya2 transgenic mice, while it was significantly reduced in the wild type littermates under pressure overload. These results demonstrate that Eya2 prevents adverse cardiac remodeling under pressure overload partly through altering metabolic gene expression and preserving PI3K/Akt/mTOR signaling pathway. [Copyright &y& Elsevier]

The acoustic characteristics of bluff-body burners play a critical role in the combustion stability for combustors using this type of burners. The acoustic modelling of an axisymmetric bluff-body burner entails properly capturing the sound-vortex interaction for the flow through the annular aperture of the burner. Such a problem pertaining to annular apertures can also be of relevance to other engineering applications, such as acoustic dampers or turbofan duct systems. The methodology of combining suitable acoustic Green's functions with a vortex sheet model has been applied extensively in previous theoretical studies of the acoustic response of a short circular orifice with a mean flow passing through it. In this work, the Green's function and vortex sheet model theory is generalised in order to efficiently predict the acoustic characteristics of thin annular apertures sustaining a mean flow, which effectively emulate the typical axisymmetric bluff-body burner configurations in realistic combustors. This requires the incorporation of multiple Kutta conditions for modelling the vortex shedding and multiple vortex sheets for modelling the interaction of the shed vorticity and the acoustics. A high-resolution compressible Large Eddy Simulation (LES) of a simplified representative geometry is performed for validation; the analytical prediction and numerical findings show very good agreement, and the LES further provides key insights into the speed with which vortical disturbances convect downstream. [ABSTRACT FROM AUTHOR]

Abstract: The epithelial Ca2+ channel TRPV6 constitutes the apical Ca2+ entry mechanism in active Ca2+ transport in kidney and intestine, but little is known about regulation mechanism of TRPV6. We performed yeast two-hybrid screen with TRPV6 C-terminus since TRPV6 has PDZ (Post-synaptic density-95, Drosophila discs-large protein, Zonula occludens protein 1) binding motif at its C terminal end. As a result, we found that 4 PDZ domain-containing protein, PDZK2, interacts with TRPV6 through its fourth PDZ domain. Glutathione S-transferase pull-down assay shows that TRPV6 and PDZK2 directly interact and that TRPV6 C-terminal PDZ binding motif is primarily responsible for this interaction. Mutant Δ4 lacking last 4 amino acid EYQI did not interact with PDZK2. Heterologous overexpression of both TRPV6 and PDZK2 did not show any effect on the activation of TRPV6. On the other hand, the peak current amplitude of mutant Δ4 decreased compared with that of WT TRPV6. When introduced into HEK293 cells expressing TRPV6, PDZ binding motif peptide (EYQI) markedly reduced the peak current amplitude in divalent free (DVF) solution. Knocking down the endogenous PDZK2 of HEK293 cells by RNAi significantly decreased DVF current density. Taken together, we propose that PDZK2 is an essential TRPV6 interacting protein as a physiological modulator of TRPV6. [Copyright &y& Elsevier]