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The integrated gate commutated thyristor (IGCT) is promising in dc grids nowadays. However, to meet the increasing demands for handling high fault currents, the turn-off capability of IGCT still needs to be optimized, which is affected by transient turn-off current redistribution significantly. This article proposes an experiment method based on an isolated anode design for detecting the turn-off current redistribution characteristics of IGCT. Influences of ON-state current density and commutation impedance distribution on IGCT’s turn-off current redistribution characteristics are explored in detail. The results show that when IGCT’s turn-off process satisfies the “hard” gate drive condition, the anode current redistribution gets changed mainly in the current commutation period and the anode voltage rising period of the turn-off process, before IGCT’s dynamic avalanche phenomenon happens. Though the anode current distribution experiences large fluctuations during the commutation period, it will achieve a new balancing state at the end of this period, which almost does not affect the following periods. When IGCT goes into the anode voltage rising period, the ON-state current density distribution will affect the turn-off current redistribution. Under the effects of carrier extraction speed differences, the current density distribution throughout the chip tends to reduce its initial difference, which leads to the phenomenon of “current self-balancing.” Meanwhile, the region with the highest ON-state current density dominates the anode voltage’s building-up speed. To increase IGCT’s turn-off capability, improving the ON-state anode current density uniformity utilizing an optimized layout or cell structure is one of the effective methods.

Esophageal squamous cell carcinoma (ESCC) is a deadly malignancy with notable metabolic reprogramming, yet the pivotal metabolic feature driving ESCC progression remains elusive. Here, we show that methionine cycle exhibits robust activation in ESCC and is reversely associated with patient survival. ESCC cells readily harness exogenous methionine to generate S-adenosyl-methionine (SAM), thus promoting cell proliferation. Mechanistically, methionine augments METTL3-mediated RNA m6A methylation through SAM and revises gene expression. Integrative omics analysis highlights the potent influence of methionine/SAM on NR4A2 expression in a tumor-specific manner, mediated by the IGF2BP2-dependent stabilization of methylated NR4A2mRNA. We demonstrate that NR4A2 facilitates ESCC growth and negatively impacts patient survival. We further identify celecoxib as an effective inhibitor of NR4A2, offering promise as a new anti-ESCC agent. In summary, our findings underscore the active methionine cycle as a critical metabolic characteristic in ESCC, and pinpoint NR4A2as a novel methionine-responsive oncogene, thereby presenting a compelling target potentially superior to methionine restriction.

Esophageal squamous cell carcinoma(ESCC) is a major histological subtype of esophageal cancer with a poor prognosis. Although several serum metabolomic investigations have been reported, ESCC tumor-associated metabolic alterations and predictive biomarkers in sera have not been defined. Here, we enrolled 34 treatment-naive patients with ESCC and collected their pre- and post-esophagectomysera together with the sera from 34 healthy volunteers for a metabolomic survey. Our comprehensive analysis identified ESCC tumor-associated metabolic alterations as represented by a panel of 12 serum metabolites. Notably, postoperative abrosia and parenteral nutrition substantially perturbed the serum metabolome. Furthermore, we performed an examination using sera from carcinogen-induced mice at the dysplasia and ESCC stages and identified three ESCC tumor-associated metabolites conserved between mice and humans. Notably, among these metabolites, the level of pipecolic acidwas observed to be progressively increased in mouse sera from dysplasia to cancerization, and it could be used to accurately discriminate between mice at the dysplasia stage and healthy control mice. Furthermore, this metabolite is essential for ESCC cells to restrain oxidative stress-induced DNA damage and cell proliferation arrest. Together, this study revealed a panel of 12 ESCC tumor-associated serum metabolites with potential for monitoring therapeutic efficacy and disease relapse, presented evidence for refining parenteral nutrition composition, and highlighted serum pipecolic acid as an attractive biomarker for predicting ESCC tumorigenesis.

Esophageal squamous cell carcinoma(ESCC) is a major histological subtype of esophageal cancer with a poor prognosis. Although several serum metabolomic investigations have been reported, ESCC tumor-associated metabolic alterations and predictive biomarkers in sera have not been defined. Here, we enrolled 34 treatment-naive patients with ESCC and collected their pre- and post-esophagectomysera together with the sera from 34 healthy volunteers for a metabolomic survey. Our comprehensive analysis identified ESCC tumor-associated metabolic alterations as represented by a panel of 12 serum metabolites. Notably, postoperative abrosia and parenteral nutrition substantially perturbed the serum metabolome. Furthermore, we performed an examination using sera from carcinogen-induced mice at the dysplasia and ESCC stages and identified three ESCC tumor-associated metabolites conserved between mice and humans. Notably, among these metabolites, the level of pipecolic acidwas observed to be progressively increased in mouse sera from dysplasia to cancerization, and it could be used to accurately discriminate between mice at the dysplasia stage and healthy control mice. Furthermore, this metabolite is essential for ESCC cells to restrain oxidative stress-induced DNA damage and cell proliferation arrest. Together, this study revealed a panel of 12 ESCC tumor-associated serum metabolites with potential for monitoring therapeutic efficacy and disease relapse, presented evidence for refining parenteral nutrition composition, and highlighted serum pipecolic acid as an attractive biomarker for predicting ESCC tumorigenesis.

Conductive hydrogels are widely used in flexible sensors owing to their adjustable structure, good conductivity, and flexibility. The performance of excellent mechanical properties, high sensitivity, and elastic modulus compatible with human tissues is of great interest in the field of flexible sensors. In this paper, the functional groups of trisodium citrate dihydrate (SC) and MXene form multiple hydrogen bonds in the polymer network to prepare a hydrogel with mechanical properties (Young’s modulus (23.5–92 kPa) of similar human tissue (0–100 kPa)), sensitivity (stretched GF is 4.41 and compressed S1is 5.15 MPa–1), and durability (1000 cycles). The hydrogel is able to sensitively detect deformations caused by strain and stress and can be used in flexible sensors to detect human movement in real time such as fingers, wrists, and walking. In addition, the combination of matrix sensing and machine learning was successfully used for handwriting recognition with an accuracy of 0.9744. The combination of machine learning and flexible sensors shows great potential in areas such as healthcare, information security, and smart homes.

Increasing emphasis on users' preferences and the growth of services on the web make service composition a time consuming and complicated work. In this paper, an approach for web service composition that combines overall QoS and modified graphplan is proposed. Fuzzy logic is applied to handle uncertainty and support decision making. Specifically, values of overall QoS of services are generated by using fuzzy analytical hierarchy process, entropy and user's preferences. The graphplan is modified by pruning services according to the values of overall QoS of services in forward and backward expansions, while producing solutions of compositions. Furthermore, case studies and experiments are performed and show that our approach has better solutions compared with original graphplan and some other approaches.

Lightweight optimization and design on body in white (BIW) has a significant effect on reducing emissions, fuel consumption, and protecting the environment. Much lightweight study on complete BIW and single BIW parts has been done in recent years. However, the lightweight study of sub-modules is difficult for considering the complete BIW performances. The efficiency of sub-module lightweight optimization based on complete BIW is not high. A new method is proposed to conduct frontal sub-module lightweight optimization. Firstly, the implicit parametric frontal BIW structure is constructed by SFE-CONCEPT software. Then, the coupling BIW model is constructed by combining the above frontal BIW structure and rear finite element structure. The shape and thickness variables are extracted from the frontal BIW structure, and the performance of complete BIW can be analyzed. The efficiency of constructing BIW and the complete performances are all considered by the new method. In addition, a modular method is adopted to analyze performance. It can achieve the concept of “analysis leads design” to conduct lightweight optimization and design for frontal structure by combining with ISIGHT software. After lightweight optimization and design of BIW frontal structure, the weight is reduced by 4.91 kg, which is as much as 5.70%. The performances have little change; the improved maximum performance is 3.32%, and the reduced maximum performance is 1.81%.

A superior CeTaSb composite oxide catalyst prepared using homogeneous precipitation method exhibited excellent deNOxefficiency and nearly 100% N2selectivity with broad operation temperature window and better resistance to higher space velocity, meanwhile strong resistance to H2O and SO2. This catalyst was systematically characterized using XRD, N2adsorption, SEM, TEM, XPS, ESR, Raman, H2-TPR, NH3-TPD and in situDRIFTS. There exists a synergistic effect between Ce, Ta and Sb species. It is further indicated that the prominent deNOxperformance of the Ce3Ta3SbOxcatalyst is attributed to the elevated Ce3+concentrations, abundant active surface oxygen species, as well as surface acidity and reducibility, which is closely linked with the synergistic effect between Ce, Sb and Ta species. Results from DRIFTS reveal that the reaction mechanism of surface-adsorbed NH3and NOxspecies is linked to temperature, the L–H mechanism mainly occurs at low temperature (<300 °C), while the E–R mechanism occurs at high temperature (>300 °C). Overall, these findings indicate that Ce3Ta3SbOxis promising for NOxpractical abatement.

Based on gradient control of carbon partitioning between martensite and austenite during heat treatment of steels, a stepping-quenching-partitioning (S-Q-P) process is developed for high strength steels. The S-Q-P process involves several quenching processes at progressively lower temperatures between martensite-start (Ms) and martensite-finish (Mf) temperatures, each followed by a partitioning treatment at either the initial quenching temperature or above that temperature. A novel microstructure is designed based on the S-Q-P process. Sizes and distributions of retained austenite and high-carbon martensite surrounded by martensite laths can be manipulated by the partitioning duration and temperature, and quenching temperature of the S-Q-P process. Alloying element Si is employed in the S-Q-P steel to suppress formation of carbides and create suitable amount of retained austenite. A steel of 0.39C-1.22Mn-1.12Si-0.23Cr (wt.%) treated by the S-Q-P process is endowed with some special microstructural characteristics: some strips of retained austenite located at edges of martensite blocks with high density of dislocations and between martensite laths, some small blocks of twinned martensites distributed among bundles of the low-carbon martensite lath. The mechanical properties of the medium carbon steel after the S-Q-P process can reach ultimate tensile strength (Rm) of 1240 MPa, total elongation (EI) of 25%, and product of strength and ductility (PSD) of 31.2 GPa% that are much more improved than those after the conventional quenching-tempering (Q-T) and currently prevailing quenching-partitioning (Q-P) treatments. The PSDof the tested steel after the S-Q-P process increases by 67% and 32% as compared with those after the Q-T and Q-P processes, respectively.

Abstract: In this study, the three-windows method, the jump-ratio method and the R-map method in energy-filtered transmission electron microscopy (EFTEM) have been applied to mapping carbon distribution in 35SiMn steel after a quenching-partitioning treatment. The carbon contamination is successfully suppressed by using EFTEM and plasma-cleaning TEM samples. Compared to the three-windows method and the jump-ratio method, the R-map method provides carbon distribution with less noises, and is insensitive to changes in sample thickness. We have demonstrated that the R-map method is a better way for carbon mapping in middle-carbon steel without the influence of carbon contamination.

Abstract: A novel heat treatment process, stepping quenching and partitioning (S-Q-P), has been developed to manipulate microstructure and mechanical properties of steels. Based on incomplete partitioning of carbon from martensite to austenite, volume fraction and distribution of the retained austenite resulting from the following quenching of the steels could be effectively controlled, and then the synthesized mechanical properties of the steels would be improved. In this paper, 20SiMn2MoVA steel was treated with conventional quenching-tempering (Q-T), currently prevailing quenching-partitioning (Q-P) and S-Q-P processes, respectively. The results indicated that the volume fraction of the retained austenite of the steel treated by Q-P and S-Q-P processes increased significantly that resulted in the increase of ductility and decrease of strength. The product of strength and ductility of the steel treated by S-Q-P process reached 23.7GPa%, that was increased by about 13% and 7% compared with that after Q-T and Q-P processes, respectively. Compared with the great improvement of the synthesized mechanical property obtained by S-Q-P process with another steel 35SiMn, there would be some factors that deteriorated the effect of S-Q-P process on 20SiMn2MoVA steel. It was found by microstructural testing that the carbide forming elements V and Mo in the steel led to precipitation of carbides during partitioning period and lack of carbon in austenite. As a result, less austenite would remain after final quenching and mechanical properties of the steel would be influenced. The results would be beneficial for understanding the principle of S-Q-P process and improving the design of the S-Q-P steel compositions.

We give an abstraction of verifiable multi-secret sharing schemes that is accessible to a fully mechanized analysis. This abstraction is formalized within the applied pi-calculus by using an equational theory which characterizes the cryptographic semantics of secret share. We also present an encoding from the equational theory into a convergent rewriting system, which is suitable for the automated protocol verifier ProVerif. Based on that, we verify the threshold certificate protocol in ProVerif.

AbstractWe give an abstraction of verifiable multi-secret sharing schemes that is accessible to a fully mechanized analysis. This abstraction is formalized within the applied pi-calculus by using an equational theory which characterizes the cryptographic semantics of secret share. We also present an encoding from the equational theory into a convergent rewriting system, which is suitable for the automated protocol verifier ProVerif. Based on that, we verify the threshold certificate protocol in ProVerif.

Sodium-dependent phosphate transport in NHERF-1−/−proximal tubule cells does not increase when grown in a low phosphate media and is resistant to the normal inhibitory effects of parathyroid hormone (PTH). The current experiments employ adenovirus-mediated gene transfer in primary cultures of mouse proximal tubule cells from NHERF-1 null mice to explore the specific role of NHERF-1 on regulated Npt2a trafficking and sodium-dependent phosphate transport. NHERF-1 null cells have decreased sodium-dependent phosphate transport compared with wild-type cells. Infection of NHERF-1 null cells with adenovirus-GFP-NHERF-1 increased phosphate transport and plasma membrane abundance of Npt2a. Adenovirus-GFP-NHERF-1 infected NHERF-1 null proximal tubule cells but not cells infected with adenovirus-GFP demonstrated increased phosphate transport and Npt2a abundance in the plasma membrane when grown in low phosphate (0.1 mM) compared with high phosphate media (1.9 mM). PTH inhibited phosphate transport and decreased Npt2a abundance in the plasma membrane of adenovirus-GFP-NHERF-1-infected NHERF-1 null proximal tubule cells but not cells infected with adenovirus-GFP. Interestingly, phosphate transport is inhibited by activation of protein kinase A and protein kinase C in wild-type proximal tubule cells but not in NHERF-1−/−cells. Together, these results highlight the requirement for NHERF-1 for physiological control of Npt2a trafficking and suggest that the Npt2a/NHERF-1 complex represents a unique PTH-responsive pool of Npt2a in renal microvilli.

NHERF-1 binds numerous renal protein targets, including the proximal tubule transporters Na+/H+exchanger 3 (NHE3) and Na+-phosphate cotransporter 2a (Npt2a). Young NHERF-1−/−male mice display defective targeting of Npt2a to apical membranes in the renal proximal tubule and manifest hypophosphatemia and increased urinary excretion of phosphate. The present studies describe the changes in the urinary excretion of phosphate, calcium, uric acid, and sodium in male and female wild-type and NHERF-1 null mice over a time period from 12 to 54 wk of age. Young male and female NHERF-1−/−mice demonstrated increased urinary excretion of phosphate and urine phosphate/creatinine ratios. There was an age-related decline in the phosphate/creatinine ratio in mutant mice such that there were no differences between wild-type and NHERF-1−/−by 24 to 30 wk of age despite the continued presence of hypophosphatemia. Male and female NHERF-1 null mice also demonstrate increased urine calcium/creatinine and uric acid/creatinine ratios compared with wild-type controls. These studies indicate defects in the renal tubule transport of phosphate, calcium, and uric acid in NHERF-1−/−male and female mice that could account for the increased deposition of calcium in the papilla of null mice.

NHERF-1 binds numerous renal protein targets, including the proximal tubule transporters Na+/H+ exchanger 3 (NHE3) and Na+-phosphate cotransporter 2a (Npt2a). Young NHERF-1–/– male mice display defective targeting of Npt2a to apical membranes in the renal proximal tubule and manifest hypophosphatemia and increased urinary excretion of phosphate. The present studies describe the changes in the urinary excretion of phosphate, calcium, uric acid, and sodium in male and female wild-type and NHERF-1 null mice over a time period from 12 to 54 wk of age. Young male and female NHERF-1–/– mice demonstrated increased urinary excretion of phosphate and urine phosphate/creatinine ratios. There was an age-related decline in the phosphate/creatinine ratio in mutant mice such that there were no differences between wild-type and NHERF-1–/– by 24 to 30 wk of age despite the continued presence of hypophosphatemia. Male and female NHERF-1 null mice also demonstrate increased urine calcium/creatinine and uric acid/creatinine ratios compared with wild-type controls. These studies indicate defects in the renal tubule transport of phosphate, calcium, and uric acid in NHERF-1–/– male and female mice that could account for the increased deposition of calcium in the papilla of null mice.

The sodium-dependent renal phosphate transporter (Npt2, Na-Pi IIa) is the major regulated phosphate transporter in the renal proximal convoluted tubule. Npt2 associates with a number of PDZ-containing proteins including Na+H+exchanger regulatory factor-1 (NHERF-1). To determine whether NHERF-1 is involved in the acute regulation of phosphate transport, wild-type and NHERF-1 (–/–) mice were stabilized on a high-phosphate diet and then acutely changed to a low-phosphate diet. At 24 h after the change to a low-phosphate diet, there was a significant decrease in the urinary excretion of phosphate in both groups but the urinary excretion of phosphate in NHERF-1 (–/–) mice was significantly higher than in wild-type animals (1,097 ± 356 vs. 255 ± 54 ng/min, P< 0.05). Renal mRNA levels and total cellular Npt2 protein did not differ between the animal groups or in response to the changes in diet. Renal brush-border membrane (BBM) expression of Npt2 protein, however, was lower in NHERF-1 (–/–) mice compared with wild-type. In addition, with both the high- and low-phosphate diets, there was increased detection of Npt2 in submicrovillar domains that were particularly prominent in NHERF-1 (–/–) mice compared with wild-type animals. On the other hand, a change from a low-phosphate diet to a high-phosphate diet was associated with a similar increase in the urinary excretion of phosphate in wild-type and NHERF-1 (–/–) animals. These experiments demonstrate that full renal adaptation to a low-phosphate diet requires NHERF-1, which serves to increase BBM expression of Npt2.

According to the requirements of the mobile robot complete coverage path planning for some special missions, this paper introduces a bounded strategy based on the integration of the Lorenz dynamic system and the robot kinematics equation. Chaotic variables of the Lorenz system are confined in a limited range, while when they are used to produce the robot's coordinate position, the trajectory range is determined by the starting point, iterative times, and iterative step. The proposed bounded strategy can constrain all the robot positions in the workplace by a mirror mapping method that can reflect the overflow waypoints returning to it. Moreover, the statistical characteristics of the Lorenz chaotic variables and the robot trajectory are discussed in order to choose the best mapping variable. The simulation results show that the bounded strategy that uses the chosen variable can achieve a higher coverage rate contrary to other similar works.

This paper presents a chaotic motion path planner based on a Logistic Map (SCLCP) for an autonomous mobile robot to cover an unknown terrain randomly, namely entirely, unpredictably and evenly. The path planner has been improved by arcsine and arccosine transformation. A motion path planner based only on the Logistic Chaotic Map (LCP) can show chaotic behaviour, which possesses the chaotic characteristics of topological transitivity and unpredictability, but lacks better evenness. Therefore, the arcsine and arccosine transformations are used to enhance the randomness of LCP. The randomness of the followed path planner, LCP, the improved path planner SCLCP and the commonly used Random Path Planner (RP) are discussed and compared under different sets of initial conditions and different iteration rounds. Simulation results confirm that a better evenness index of SCLCP can be obtained with regard to previous works.