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Cr12MoV die steel is frequently used for cold stamping, cold extrusion, and other cold work applications. However, surface defects such as micro-pits and micro-cracks are easily produced during the cutting process, which impacts the fatigue resistance of die. The formation mechanisms and influencing factors of various surface defects of hardened die steel are investigated by a combination of high-speed ball-end milling experiment and simulation. Results show that there are mainly five kinds of defects on the machined surface: micro-pits, micro-cracks, grooves, surface texture, and surface material residues. Micro-pit defects are formed when carbide particles are integrally pulled out, or broken and then spalled. When the carbide particles are large in size or have sharp edges, local microscopic stress concentrations will be generated between the sharp edges and the material matrix, causing micro-cracks within and around the spalled pits. The form of carbide particles spalling is changed from brittle spalling to plastic plowing under the effect of thermal softening, which causes the formation of groove defects. However, with the aggravation of thermal softening effect, machined surface is highly susceptible to extrusion and scraping from tool flank, which results in an increase in the number of defects and increasingly pronounced textural features. The research has important implications for improving the fatigue life of die and optimizing the cutting process parameters. [ABSTRACT FROM AUTHOR]

Interface models of diamond-coated cemented carbide tool WC-Co / SiC/ Diamond with Co mass fraction of 6%, 8%, 10% and 12% were constructed. The influences of different deposition temperatures on the interface bonding strength were simulated with the molecular dynamics method, and the reasons were analyzed from perspectives of adhesion work and bond length distribution. The adhesion work analysis indicates that, compared with the other three Co content interface models, the two interfaces in WC-6% Co / SiC/ Diamond interface model have the highest adhesion work values at seven deposition temperatures. At different deposition temperatures, both interfaces of WC-6% Co / SiC and SiC/ Diamond in WC-6% Co / SiC/ Diamond have the highest adhesion work values of 2. 468 and 5. 394 J / m² at 1 123 and 1 173 K, respectively. The analysis results of bond length distribution indicate that, at any deposition temperature, compared with the other three Co content interface models, the maximum value of the bond length distribution range at each interface of WC-6% Co / SiC/ Diamond is smaller. The interface model obtained by sequentially depositing SiC layer on WC-6%Co substrate at 1 123 K and diamond coating on SiC layer at 1 173 K has the shortest interface bond length, the largest bond energy, and the best interface bonding property. Key words: diamond-coated cemented carbide; WC-Co / SiC/ Diamond; deposition temperature; Co content; interface [ABSTRACT FROM AUTHOR]

The interface models of diamond-coated WC-Co cemented carbide (DCCC) were constructed without intermediate layers and with different interface terminals, such as intermediate layers of TiC, TiN, CrN, and SiC. The adhesion work of the interface model was calculated based on the first principle. The results show that the adhesion work of the interface was increased after adding four intermediate layers. Their effect on improving the interface adhesion performance of cemented carbide coated with diamond was ranked in descending order as follows: SiC > CrN > TiC > TiN. The charge density difference and the density of states were further analyzed. After adding the intermediate layer, the charge distribution at the interface junction was changed, and the electron cloud at the interface junction overlapped to form a more stable chemical bond. Additionally, after adding the intermediate layer, the density of states of the atoms at the interface increased in the energy overlapping area. The formant formed between the electronic orbitals enhances the bond strength. Thus, the interface bonding performance of DCCC was enhanced. Among them, the most obvious was the interatomic electron cloud overlapping at the diamond/SiCC-Si/WC-Co interface, its bond length was the shortest (1.62 Å), the energy region forming the resonance peak was the largest (−5–20 eV), and the bonding was the strongest. The interatomic bond length at the diamond/TiNTi/WC-Co interface was the longest (4.11 Å), the energy region forming the resonance peak was the smallest (−5–16 eV), and the bonding was the weakest. Comprehensively considering four kinds of intermediate layers, the best intermediate layer for improving the interface bonding performance of DCCC was SiC, and the worst was TiN. [ABSTRACT FROM AUTHOR]

This study performed first-principle-based calculations of the interface adhesion work in interface models of three terminal systems: CrAlSiNSi/WC-Co, CrAlSiNN/WC-Co, and CrAlSiNAl/WC-Co. The results proved that the CrAlSiNSi/WC-Co and CrAlSiNAl/WC-Co interface models had the highest and lowest interface adhesion work values (4.312 and 2.536 J·m−2), respectively. Thus, the latter model had the weakest interface bonding property. On this basis, rare earth oxides CeO2 and Y2O3 were doped into the Al terminal model (CrAlSiNAl/WC-Co). Then, doping models of CeO2 and Y2O3 doped on the WC/WC, WC/Co, and CrAlSiNAl/WC-Co interfaces were established. The adhesion work value was calculated for the interfaces in each doping model. When CeO2 and Y2O3 were doped in the WC/WC and CrAlSiNAl/WC-Co interfaces, four doping models were constructed, each model contains interfaces withreduced adhesion work values, indicating deteriorated interface bonding properties. When the WC/Co interface was doped with CeO2 and Y2O3, the interface adhesion work values of the two doping models are both increased, and Y2O3 doping improved the bonding properties of the Al terminal model (CrAlSiNAl/WC-Co) more significantly than CeO2 doping. Next, the charge density difference and the average Mulliken bond population were estimated. The WC/WC and CrAlSiNAl/WC-Co interfaces doped with CeO2 or Y2O3, with decreased adhesion work, exhibited low electron cloud superposition and reduced values of charge transfer, average bond population, and interatomic interaction. When the WC/Co interface was doped with CeO2 or Y2O3, superposition of the atomic charge densities of electron clouds was consistently observed at the CrAlSiNAl/WC-Co interface in the CrAlSiNAl/WC/CeO2/Co and CrAlSiNAl/WC/Y2O3/Co models; the atomic interactions were strong, and the interface bonding strength increased. When the WC/Co interface was doped with Y2O3, the superposition of atomic charge densities and the atomic interactions were stronger than for CeO2 doping. In addition, the average Mulliken bond population and the atomic stability were also higher, and the doping effect was better. [ABSTRACT FROM AUTHOR]

Exploring highly efficient electromagnetic wave (EMW) absorbing materials with strong absorption and low density is a viable strategy to address the growing issue of electromagnetic pollution. A type of carbon-coated MnO (MnO@C) microspheres with enhanced EMW absorption properties was synthesized via the precipitation method, followed by a facile sol-gel process. The results demonstrate that the carbon source content is critical in determining the thickness of the carbon shell, which in turn has a great impact on impedance matching and attenuation constant. Due to the moderately complex permittivity of MnO@C microspheres, the minimum reflection loss (RL min) reaches − 43.69 dB at 15.03 GHz with an ultra-thin matching thickness of only 1.53 mm. Additionally, the corresponding effective absorption bandwidth (EAB) is 4.81 GHz. The enhanced performance can mainly be attributed to appropriate impedance matching and multiple attenuation mechanisms, including interfacial polarization, defect-induced polarization, and conduction loss. Therefore, the MnO@C microspheres are considered to be suitable for high-efficiency microwave absorbers. • The MnO@C microspheres were successfully fabricated via the precipitation method followed by the sol-gel process. • The uniform C layer was closely coated on the MnO surface and exhibited improvement in dielectric parameters. • The RL min of − 43.69 dB and EAB of 4.81 GHz can be achieved simultaneously with an ultrathin thickness of 1.53 mm. [ABSTRACT FROM AUTHOR]

The interface crack propagation problem in the cermet cladding material structure was studied. A comparative propagation property parameter (CP) suitable to judge the propagation direction of the interface crack in the cermet cladding material structure was proposed. The interface crack propagation criterion was established. Theoretical models of the CPs for the crack normal to and dwelling on the interface deflecting separately into the clad, the interface and the substrate were built, and the relations between the CPs and the load action angle, the clad thickness ratio and the load were investigated with an example. The research results show that, under the research conditions, the interface crack will more easily propagate into the clad layer than into the substrate. [ABSTRACT FROM AUTHOR]

A double-coil inductive displacement transducer is a non-contact element for measuring displacement and is widely used in large power equipment systems such as construction machinery and agricultural machinery equipment. The type of coil excitation signal has an impact on the performance of the transducer, but there is little research on this. Therefore, the influence of the coil excitation signal on transducer performance is investigated. The working principle and characteristics of the double-coil inductive displacement transducer are analyzed, and the circuit simulation model of the transducer is established. From the aspects of phase shift, linearity, and sensitivity, the effects of a sine signal, a triangle signal, and a pulse signal on the transducer are compared and analyzed. The results show that the average phase shift, linearity, and sensitivity of the sine signal were 11.53°, 1.61%, and 0.372 V/mm, respectively; the average phase shift, linearity and sensitivity of the triangular signal were 1.38°, 1.56%, and 0.300 V/mm, respectively; and the average phase shift, linearity, and sensitivity of the pulse signal were 0.73°, 1.95%, and 0.621 V/mm, respectively. It can be seen that the phase shift of a triangle signal and a pulse signal is smaller than that of a sine signal, which can result in better signal phase-locked processing. The linearity of the triangle signal is better than the sine signal, and the sensitivity of the pulse signal is better than that of the sine signal. [ABSTRACT FROM AUTHOR]

Ginkgolic acid is an anacardic acid specifically distributes in the seeds, leaves and episperms of Ginkgo biloba L. Ginkgolic acid possesses multiple biological functions on disease resistance and pesticide. Ginkgolic acid is enriched in the episperm of G. biloba , which is usually disposed as garbage. Although enriched, the content of ginkgolic acid in episperm is still low, and the extraction process is tedious and costly, which limits its application. In this study, we systematically observed the development process of G. biloba episperm, and detected the variation of endogenous hormone and ginkgolic acid levels therein. The results indicated that auxin, cytokinin and gibberellin (GA 1 and GA 3) content dramatically varied during the whole development process, indicating their regulation roles in episperm development. Remarkably, the salicylic acid (SA) content showed a significantly positive correlation with ginkgolic acid content. Based on these findings, we implemented exogenous hormone treatment with an optimized combination (300 mg/L NAA + 100 mg/L 6-BA + 200 mg/L SA) on the developing fruits of G. biloba , which resulted in a 53.92% increase of episperm yield and a 21.63% increase of ginkgolic acid content. Our study not only clarified the key development events of G. biloba episperm, the ginkgolic acid content profile, and their relationship, but also provides a cheap and easy way to improve ginkgolic acid accumulation in G. biloba seeds. [ABSTRACT FROM AUTHOR]

Background: Endoplasmic reticulum (ER) stress is one of the major causes to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Our previous study showed that maintains the homeostasis of ER could effectively alleviate NAFLD. In this study, we found that the loss of FAM172A increased ER stress. Aims: The aims of this study were to explore whether FAM172A could improve NAFLD by inhibiting ER stress. Methods: The expression levels of FAM172A and ER stress were detected by western blot. The method of immunofluorescence was used to determine FAM172A location. The interacted proteins of FAM172A were identified by immunocoprecipitation. The methods of MTS and caspase-3/7 activity were taken to confirm the effect of FAM172A on cell viability and proliferation. The expression levels of inflammation were detected by qPCR. Results: We confirmed that FAM172A might alleviate NAFLD through inhibiting ER stress. Loss of FAM172A increased the expressions of ATF6, peIF2α, but decreased the expression of IRE1α. Then, it was shown that FAM172A located in ER and FAM172A directly interacted with ATF6 and peIF2α and IRE1α. More importantly, the binding of FAM172A and eIF2a in tunicamycin-treated group increased significantly compared with the control group. However, the binding of FAM172A and ATF6 or IRE1α did not change. Next, we found that the lack of FAM172A could produce more apoptosis and inflammation. Conclusions: Our results suggest that FAM172A improve steatosis by alleviating ER stress. [ABSTRACT FROM AUTHOR]

• Electron transfer velocity on milled surface were explained by plastic deformation. • Reversibility of electrochemical reaction was studied by cyclic voltammetry. • Electrochemical reaction products on milled surface of NiTi alloy were investigated. NiTi shape memory alloy is widely used in medical field because of its excellent properties. Milling machining has become one of the main processing methods in the medical field due to its good shape adaptability. However, the change of the shape and properties of milled surface affects its biocompatibility and corrosion resistance. Electrochemical machining is used as the follow-up process of milling machining. The polarization curve method, cyclic voltammetry method and constant potential electrolysis are used in this paper to study the electrochemical reaction mechanism of the NiTi alloy milled surface. The results show that the plastic deformation layer appears compared with the original material, making electrode reactions and electron transfer relatively difficult. The surface eventually forms TiO 2 , without the formation of Ni-related oxide. The electrochemical reaction mechanism of the NiTi alloy milled surface in the HClO 4 -CH 3 COOH system provide important theoretical guidance for the production and manufacturing of medical products. [ABSTRACT FROM AUTHOR]

A dual-coil inductive displacement transducer is a non-contact type measuring element for measuring displacement and is widely used in large power equipment systems such as construction machinery and agricultural equipment. However, the effect of the coil excitation method on the performance of dual-coil inductive displacement sensors has not been studied. This paper investigates the impact of different coil excitation methods on the operating performance of displacement transducers. The working principle, electromagnetic characteristics, and electrical characteristics were analyzed by building a mathematical model. A transducer measurement device was used to determine the relationship between core displacement and coil inductance. Three coil excitation methods were proposed, and the effects of the three coil excitation methods on the amplitude variation, phase shift, linearity, and sensitivity of the output signal were studied by simulation based on the AD630 chip as the core of the conditioning circuit. Finally, the study's feasibility was demonstrated by comparing the experiment to the simulation. The results show that, under the uniform magnetic field strength distribution in the coil, the coil voltage variation is proportional to the inductive core displacement. The amplitude variation is the largest for the dual-coil series three-wire (DCSTW) and is the same for the dual-coil series four-wire (DCSFW) and dual-coil parallel differential (DCPD). DCSFW has an enormous phase shift. DCSTW has the best linearity. The research in this paper provides a theoretical basis for selecting a suitable coil excitation, which is conducive to further improving the operating performance of dual-coil inductive displacement transducers. [ABSTRACT FROM AUTHOR]

In order to clarify the influence of feed rate on a hydrocyclone flow field, numerical simulation was employed to model the influence of feed rate on the pressure field, velocity field, air column, turbulent kinetic energy, and split ratio. The results revealed that static pressure, tangential velocity, and radial velocity increased with an increase in the feed rate. When the feed rate at the inlet increases from 1 m/s to 5 m/s, the static pressure increases from 5.49 kPa to 182.78 kPa, tangential velocity increases from 1.97 m/s to 11.16 m/s, and radial velocity increases from 0.20 m/s to 1.16 m/s demonstrating that a high feed rate facilitated the strengthening separation of the flow field. Meanwhile, with the increase in the feed rate, the split ratio of the hydrocyclone decreased, indicating that the concentration effect of the hydrocyclone improved. Additionally, the formation time of the air column was reduced, and the flow field became more stable. Nevertheless, the axial velocity and the turbulent kinetic energy also increased with the increase in the feed rate, and the increase in the axial velocity reduced the residence time of the material in the hydrocyclone, which was not conducive to the improvement of separation accuracy. In addition, the increase in turbulent kinetic energy led to an increase in energy consumption, which was not conducive to the improvement of the comprehensive performance of the hydrocyclone. Therefore, choosing an appropriate feed rate is of great significance to the regulation of the flow field and the improvement of hydrocyclone separation performance. [ABSTRACT FROM AUTHOR]

Collagen β (1-O) galactosyltransferase 1 (GLT25D1) has been reported to transfer galactose to hydroxylysine residues via β (1-O) linkages in collagen. The present study investigated the function of the collagen galactosyltransferase activity of GLT25D1 against carbon tetrachloride (CCl4)-induced acute liver injury in vitro. Glt25d1+/− mice and wild-type (WT) mice were injected intraperitoneally with the same dose of CCl4. The grade of hepatic injury and the extent of hepatocyte necrosis in the acute phase were assessed 48 h following CCl4 injection. Hepatocyte necrosis was evaluated by histological examination and by serum alanine aminotransferase and aspartate aminotransferase levels, which were higher in the Glt25d1+/− mice compared with those in the WT mice. Reverse transcription-quantitative polymerase chain reaction was performed, and the results demonstrated that the mRNA expression levels of inflammatory cytokines, including tumor necrosis factor-α and interleukin-6 were significantly increased in the Glt25d1+/− mice. Furthermore, western blot analyses were performed, and the results demonstrated that the protein levels of cleaved caspase-3 and −9 were also markedly increased in the Glt25d1+/− liver, indicating that hepatocyte apoptosis was induced. Additionally, the expression levels of transforming growth factor (TGF)-β1 and phosphorylated small mothers against decapentaplegic (Smad)2 were markedly upregulated, indicating activation of the TGF-β1/Smad2 signaling pathway during CCl4-induced acute liver injury in Glt25d1+/− mice. CCl4 administration also resulted in severe damage to Glt25d1+/− primary hepatocytes in vitro. Taken together, the downregulation of Glt25d1 deteriorated CCl4-induced liver injury in mice, which may involve triggering inflammatory responses, apoptosis and TGF-β1/Smad2 signaling pathway activation. [ABSTRACT FROM AUTHOR]

The vast majority of current research on hydrocyclone field centrifugal separation focuses on low concentration fluids having volume fraction less than 3%. For high-concentration fluids having volume fractions greater than 10%, which are often encountered in engineering, the law governing particle motion and the classification mechanism are still unclear. In order to gain insights into the interaction between fine particles in the high concentration hydrocyclone field and to improve the hydrocyclone separation performance of these particles, a Dense Discrete Phase Model (DDPM) of the Euler-Eulerian method under the Ansys Fluent 14.5 software was employed. Numerical simulations were carried out to study the characteristics of the hydrocyclone field of dense particles and the influence of parameters, such as the diameter of the overflow outlet, diameter of the underflow outlet, and material concentration, on separation performance. The trajectories and separation efficiencies of two kinds of fine particles with different densities and six different particle sizes at high concentration were obtained. The results show that for the hydrocyclone classification of high-concentration fine particles, particles with large density and small particle size are more likely to enter the internal cyclone and discharge from the overflow. Particles with small density and large particle size are more likely to enter the external cyclone and discharge from the underflow. The research results of this topic could provide a feasible reference and theoretical basis for the centrifugal separation of high-concentration fine particle fluid. [ABSTRACT FROM AUTHOR]

Protein glycosylation is involved in immunological recognition and immune cell activation. The role of O-glycosylation in Concanavalin A (Con A)-induced autoimmune hepatitis (AIH) was elucidated in the present study. Mice were intravenously injected with Con A (10 mg/kg) to establish an AIH mouse model. Here, 24 h prior to administration of Con A, experimental mice were intragastrically administrated with O-glycosylation inhibitor (benzyl-α-GalNAc) at doses of 1 and 5 mg/kg, respectively, while control mice were administrated with the same volume of saline. Before and after administration of Con A for 6 and 12 h, mice were sacrificed and their plasma and livers were collected to score liver injury. Peripheral blood, spleen, and thymus were collected for flow cytometry analysis. The expression levels of neutrophilic alkaline phosphatase-3 (NALP3) and NALP6 in liver were evaluated as well. Pre-treatment with benzyl-α-GalNAc increased the serum transaminase levels and induced more infiltration and necrosis in livers of Con A administrated mice. The levels of some pro-inflammation cytokines also increased in administrated mice. In addition, pretreatment with benzyl-α-GalNAc up-regulated the expression levels of NALP3 and NALP6. And benzyl-α-GalNAc inhibited the levels of apoptosis of thymus cells and influenced activation of T cells in peripheral blood and spleen of Con A administrated mice, especially that accelerated the physiological progression of CD4+CD25−CD69+ subset. The present research demonstrated that benzyl-α-GalNAc aggravated Con A-induced AIH, and the role of the O-glycosylation inhibitor as the aggravation may be related to regulation of the levels of cytokines, as well as influencing proliferation of T cells. [ABSTRACT FROM AUTHOR]

• Complete deletion of the Glt25d1 gene resulted in embryonic lethality at E11.5. • Down-regulation of GLT25D1 aggravated CCl 4 -induced liver injury. • Down-regulation of GLT25D1 may inhibit collagen secretion during liver fibrogenesis. Collagen β (1-O) galactosyltransferase 1 (GLT25D1) has been reported to transfer galactose to hydroxylysine residues via β (1-O) linkages in collagen. However, the role of Glt25d1 in liver fibrogenesis is still unknow. Recently, we generated a Glt25d1 knockout mouse to elucidate the role of Glt25d1 in vivo. However, we found that complete deletion of the Glt25d1 gene resulted in embryonic lethality at E11.5. Histopathological analysis revealed that dysplasia in Glt25d1−/− labyrinth with defects of the vascular network. Immunohistochemical showed that the decrease in proliferation of Glt25d1−/− liver and the developing central nervous system (CNS). The role of Glt25d1 in liver fibrogenesis was explored by Glt25d1+/− mice. Glt25d1+/− mice and wild-type (WT) mice were injected intraperitoneally with the same dose of CCl 4. The higher level of serum alanine aminotransferase was observed in Glt25d1+/− mice. Reverse transcription-quantitative polymerase chainreaction demonstrated that the mRNA expression levels of the inflammatory cytokines such as, Tnf-α, Cxcl-1 and Mcp-1, showed a significantly increase in CCl 4 -treated Glt25d1+/− mice. Collagen-I, collagen-III and α-SMA transcripts accumulation was markedly increased in the Glt25d1+/− mice. However, Masson's trichrome staining revealed a trend to decrease in the ECM proteins deposition of Glt25d1+/− liver. Immunohistochemistry and Western blots revealed that the protein expression of Collagen-III was reduced and a trend to a decrease in collagen-I was observed in the Glt25d1+/− liver compared with those of WT mice. Our results demonstrate that Glt25d1 knockout results in embryonic lethality and down-regulation of Glt25d1 may inhibit collagen secretion during liver fibrogenesis. [ABSTRACT FROM AUTHOR]

Background: The preventive effects of antiviral therapy to reduce rebleeding rate in patients with hepatitis B-related cirrhosis undergoing endoscopic treatment have not yet been reported.Methods: In this retrospective cohort study, 1139 patients with chronic hepatitis B with first acute variceal bleeding after endoscopic therapy from September 2008 to December 2017 were included. Among them, 923 who received and 216 who did not receive antiviral therapy were followed up for rebleeding. Cumulative rebleeding rate was calculated using the Kaplan-Meier method. Univariate and multivariate logistic regression analyses were performed to estimate the effects of antiviral therapy on rebleeding risk. The propensity score matched method and inverse probability of treatment weighting analysis were used to calculate the rebleeding rate between the antiviral and non-antiviral groups.Results: The rebleeding rates were 40.5, 60.7, 72.6, and 89.2% in antiviral group at 1, 2, 3, and 5 years, respectively. The corresponding rebleeding rates in the non-antiviral group were 54.2, 72.4, 84.4, and 93.3%, respectively. The multivariate logistic regression analysis revealed that antiviral therapy was an independent protective factor associated with rebleeding.Conclusion: Antiviral treatment significantly reduced rebleeding rate in patients with HBV-related cirrhosis who received endoscopic treatment after the first variceal bleeding. [ABSTRACT FROM AUTHOR]

A traditional hydrocyclone can only generate two products with different size fractions after one classification, which does not meet the fine classification requirements for narrow size fractions. In order to achieve the fine classification, a multi-product hydrocyclone with double-overflow-pipe structure was designed in this study. In this work, numerical simulation and experimental test methods were used to study the internal flow field characteristics and distribution characteristics of the product size fraction. The simulation results showed that in contrast with the traditional single overflow pipe, there were two turns in the internal axial velocity direction of the hydrocyclone with the double-overflow-pipe structure. Meanwhile, the influence rule of the diameter of the underflow outlet on the flow field characteristics was obtained through numerical simulation. From the test, five products with different size fractions were obtained after one classification and the influence rule of the diameter of the underflow outlet on the size fraction distribution of multi-products was also obtained. This work provides a feasible research idea for obtaining the fine classification of multiple products. [ABSTRACT FROM AUTHOR]