A Novel Disturbance Observer Based Fixed-Time Sliding Mode Control for Robotic Manipulators With Global Fast Convergence

This paper proposes a new global fixed-time sliding mode control strategy for the trajectory tracking control of uncertain robotic manipulators.First,a fixed-time disturbance observer(FTDO) is designed to deal with the adverse effects of model uncertainties and external disturbances in the manipulator systems.Then an adaptive scheme is used and the adaptive FTDO(AFTDO) is developed,so that the priori knowledge of the lumped disturbance is not required.Further,a new non-singular fast terminal sliding mode(NFTSM) surface is designed by using an arctan function,which helps to overcome the singularity problem and enhance the robustness of the system.Based on the estimation of the lumped disturbance by the AFTDO,a fixed-time non-singular fast terminal sliding mode controller(FTNFTSMC)is developed to guarantee the trajectory tracking errors converge to zero within a fixed time.The settling time is independent of the initial state of the system.In addition,the stability of the AFTDO and FTNFTSMC is strictly proved by using Lyapunov method.Finally,the fixed-time NFESM(FTNFTSM) algorithm is validated on a 2-link manipulator and comparisons with other existing sliding mode controllers(SMCs) are performed.The comparative results confirm that the FTNFTSMC has superior control performance.

An improved TDE technique for derivation of 2D turbulence structures based on GPI data in toroidal plasma

This paper reports an improved time-delay estimation(TDE)technique for the derivation of turbulence structures based on gas-puff imaging data.The improved TDE technique,integrating an inverse timing search and hierarchical strategy,offers superior accuracy in calculating turbulent velocity field maps and analyzing blob dynamics,which has the power to obtain the radial profiles of equilibrium poloidal velocity,blob size and its radial velocity,even the fluctuation analysis,such as geodesic acoustic modes and quasi-coherent mode,etc.This improved technique could provide important 2D information for the study of edge turbulence and blob dynamics,advancing the understanding of edge turbulence physics in fusion plasmas.

Creation and annihilation of artificial magnetic skyrmions with the electric field

Recent theory and experiments show that artificial magnetic skyrmions can be stabilized at room temperature without the need for the external magnetic field,casting strong potentials for the device applications.In this work,we study the electric field manipulation of artificial magnetic skyrmions imprinted by Co disks on CoPt multilayers utilizing the micromagnetic simulations.We find that the reversible annihilation and creation of skyrmions can be realized with the electric field via the strain mediated magnetoelastic coupling.In addition,we also demonstrate controllable manipulation of individual skyrmion,which opens a new platform for constructing magnetic field-free and low-energy dissipation skyrmion based media.

Evaluating combined bevacizumab and XELOX in advanced colorectal cancer: Serum markers carcinoembryonic antigen, carbohydrate antigen 125, carbohydrate antigen 199 analysis

BACKGROUND Colorectal cancer ranks third and second among common and fatal cancers.The treatment of metastatic colorectal cancer(mCRC)is generally based on XELOX in clinical practice,which includes capecitabine(CAP)and oxaliplatin.Serum tumor markers carcinoembryonic antigen(CEA),carbohydrate antigen(CA)125 and CA199 are prognostic factors for various tumors.AIM To investigate evaluating combined bevacizumab(BEV)and XELOX in advanced colorectal cancer:Serum markers CEA,CA125,CA199 analysis.METHODS In this retrospective study,a total of 94 elderly patients diagnosed with mCRC were recruited and subsequently categorized into two groups based on the distinct treatment modalities they received.The control group was treated with XELOX plus CAP(n=47),while the observation group was treated with XELOX plus CAP and BEV(n=47).Several indexes were assessed in both groups,including disease control rate(DCR),incidence of adverse effects,serum marker levels(CEA,CA125,and CA19)and progression-free survival(PFS).RESULTS After 9 wk of treatment,the serum levels of CEA,CA199 and CA125 in the observation group were significantly lower than those in the control group(P<0.05).Moreover,the PFS of the observation group(9.12±0.90 mo)was significantly longer than that of the control group(6.49±0.64 mo).Meanwhile,there was no statistically significant difference in the incidence of adverse reactions and DCR between the two groups during maintenance therapy(P>0.05).CONCLUSION On the basis of XELOX treatment,the combination of BEV and CAP can reduce serum tumor marker levels and prolong PFS in patients with mCRC.

Evaluation of Trace Elements in the Soil of Typical Peach Orchards in Zunyi City

[Objectives]This study was conducted to clarify the enrichment and paucity of trace elements in the soil environment of peach orchards in Zunyi City,and to provide reference for supplementary application of microelement fertilizers and high-quality peach production in peach orchards.[Methods]Taking the soil of three typical peach orchards(Taoli Renjia peach orchard,Pengrui peach orchard and Taohuadao peach orchard)in Shenxi Town,Honghuagang District,Zunyi City as the research object,the contents of trace elements in soil were analyzed through field sampling and indoor determination of trace elements.[Results]The effective contents of trace elements in the soil of peach orchard bases in the study area were at a medium level,and the soil of the peach orchards was rich in available Fe and Se.The contents of available Cu,Mo and Mn were relatively rich.The contents of available B were not high overall.The contents of available Zn were at a moderate to low level overall.The soil of Taoli Renjia peach orchard was relatively rich in trace elements.[Conclusions]The research results can provide a scientific basis for the production of high-quality crispy peaches in peach orchards.

Development of Spraying Devices for Interplantation in Forest

Honghuagang District,Zunyi City,Guizhou Province,develops the characteristic industry of crispy peaches,and at the same time develops the forest economy and promotes the model of planting soybeans in peach orchards to promote rural revitalization.However,due to the different pests and diseases occurring in peach trees and soybeans,the control drugs used are also different,and the existing technology for spraying and controlling peach or soybean seedlings is operated separately and cannot be sprayed together at the same time.This study,based on the actual situation of forest land,develops a spraying device for interplantation in forest(peach tree and soybean)from the aspects of technical solutions,working principles and beneficial effects,in order to solve the problem of low spraying efficiency of spraying control of peach tree or soybean seedlings in the existing technology.

Conjunctival microbiome changes associated with fungal keratitis: metagenomic analysis

AIM: To investigate the ocular surface microbiome profile of patients with fungal keratitis(FK) through bacterial 16 S r DNA sequencing. METHODS: The swab samples were collected from 8 patients with FK(Group 1 from the corneal ulcer, Group 2 from the conjunctival sac of the infected eyes, and Group 3 from the conjunctival sac of the fellow eyes) and 10 healthy eyes(Group 4 from the conjunctival sac). Bacterial 16 S rDNA V4-V5 region sequencing was performed to characterize the bacterial communities on the ocular surfaces of the patients with FK. RESULTS: Our metagenomic data showed that 97% of the sequence reads were categorized into 245 distinct bacterial genera, with 67.75±7.79 genera detected in Group 1, 73.80±13.44 in Group 2, 74.57±14.14 in Group 3, and 89.60±27.49 in Group 4. Compared with the healthy eyes(Group 4), both infected(Groups 1 and 2) and fellow eyes(Group 3) of the patients with FK showed reduced bacterial diversity and altered ocular surface microbiota compositions, with lower abundance of Corynebacterium and Staphylo coccus and higher abundances of Pseudomonas, Achromobacter, Caulobacter and Psychrobacter. CONCLUSION: Our report depicts the altered ocular surface bacterial community structures both in the affected and fellow eyes of patients with FK. These changes may contribute to the pathogenesis of FK or the increased risk for FK.

PpTCP18 is upregulated by lncRNA5 and controls branch number in peach (Prunus persica) through positive feedback regulation of strigolactone biosynthesis

Branch number is an important agronomic trait in peach(Prunus persica)trees because plant architecture affects fruit yield and quality.Although breeders can select varieties with different tree architecture,the biological mechanisms underlying architecture remain largely unclear.In this study,a pillar peach(‘Zhaoshouhong’)and a standard peach(‘Okubo’)were compared.‘Zhaoshouhong’was found to have significantly fewer secondary branches than‘Okubo’.Treatment with the synthetic strigolactone(SL)GR24 decreased branch number.Transcriptome analysis indicated that PpTCP18(a homologous gene of Arabidopsis thaliana BRC1)expression was negatively correlated with strigolactone synthesis gene expression,indicating that PpTCP18 may play an important role in peach branching.Yeast one-hybrid,electrophoretic mobility shift,dual-luciferase assays and PpTCP18-knockdown in peach leaf buds indicated that PpTCP18 could increase expression of PpLBO1,PpMAX1,and PpMAX4.Furthermore,transgenic Arabidopsis plants overexpressing PpTCP18 clearly exhibited reduced primary rosette-leaf branches.Moreover,lncRNA sequencing and transient expression analysis revealed that lncRNA5 targeted PpTCP18,significantly increasing PpTCP18 expression.These results provide insights into the mRNA and lncRNA network in the peach SL signaling pathway and indicate that PpTCP18,a transcription factor downstream of SL signaling,is involved in positive feedback regulation of SL biosynthesis.This role of PpTCP18 may represent a novel mechanism in peach branching regulation.Our study improves current understanding of the mechanisms underlying peach branching and provides theoretical support for genetic improvement of peach tree architecture.

Calcitriol attenuates liver fibrosis through hepatitis C virus nonstructural protein 3-transactivated protein 1-mediated TGF β1/Smad3 and NF-κB signaling pathways

BACKGROUND Hepatic fibrosis is a serious condition,and the development of hepatic fibrosis can lead to a series of complications.However,the pathogenesis of hepatic fibrosis remains unclear,and effective therapy options are still lacking.Our group identified hepatitis C virus nonstructural protein 3-transactivated protein 1(NS3TP1) by suppressive subtractive hybridization and bioinformatics analysis,but its role in diseases including hepatic fibrosis remains undefined.Therefore,additional studies on the function of NS3TP1 in hepatic fibrosis are urgently needed to provide new targets for treatment.AIM To elucidate the mechanism of NS3TP1 in hepatic fibrosis and the regulatory effects of calcitriol on NS3TP1.METHODS Twenty-four male C57BL/6 mice were randomized and separated into three groups,comprising the normal,fibrosis,and calcitriol treatment groups,and liver fibrosis was modeled by carbon tetrachloride(CCl4).To evaluate the level of hepatic fibrosis in every group,serological and pathological examinations of the liver were conducted.TGF-β1 was administered to boost the in vitro cultivation of LX-2 cells.NS3TP1,α-smooth muscle actin(α-SMA),collagen I,and collagen Ⅲ in every group were examined using a Western blot and real-time quantitative polymerase chain reaction.The activity of the transforming growth factor beta 1(TGFβ1)/Smad3 and NF-κB signaling pathways in each group of cells transfected with pcDNA-NS3TP1 or siRNA-NS3TP1 was detected.The statistical analysis of the data was performed using the Student’s t test.RESULTS NS3TP1 promoted the activation,proliferation,and differentiation of hepatic stellate cells(HSCs)and enhanced hepatic fibrosis via the TGFβ1/Smad3 and NF-κB signaling pathways,as evidenced by the presence of α-SMA,collagen I,collagen Ⅲ,p-smad3,and p-p65 in LX-2 cells,which were upregulated after NS3TP1 overexpression and downregulated after NS3TP1 interference.The proliferation of HSCs was lowered after NS3TP1 interference and elevated after NS3TP1 overexpression,as shown by the luciferase assay.NS3TP1 inhibited the apoptosis of HSCs.Moreover,both Smad3 and p65 could bind to NS3TP1,and p65 increased the promoter activity of NS3TP1,while NS3TP1 increased the promoter activity of TGFβ1 receptor I,as indicated by coimmunoprecipitation and luciferase assay results.Both in vivo and in vitro,treatment with calcitriol dramatically reduced the expression of NS3TP1.Calcitriol therapy-controlled HSCs activation,proliferation,and differentiation and substantially suppressed CCl4-induced hepatic fibrosis in mice.Furthermore,calcitriol modulated the activities of the above signaling pathways via downregulation of NS3TP1.CONCLUSION Our results suggest that calcitriol may be employed as an adjuvant therapy for hepatic fibrosis and that NS3TP1 is a unique,prospective therapeutic target in hepatic fibrosis.

Adjusting oxygen vacancies in perovskite LaCoO_(3)by electrochemical activation to enhance the hydrogen evolution reaction activity in alkaline condition

Developing highly-active,earth-abundant non-precious-metal catalysts for hydrogen evolution reaction(HER)in alkaline solution would be beneficial to sustainable energy storage.Perovskite oxides are generally regarded as low-active HER catalysts,due to their inapposite hydrogen adsorption and water dissociation.Here,we report a detailed study on perovskite LaCoO_(3)epitaxial thin films as a model catalyst to significantly enhance the HER performance via an electrochemical activation process.As a result,the overpotential for the activation films to achieve a current density of 0.36 m A/cm^(2)is 238 m V,reduced by more than 200 m V in comparison with that of original samples.Structural characterization revealed the activation process dramatically increases the concentration of oxygen vacancies(Vo)on the surface of LaCoO_(3).We established the relationship between the electronic structure induced by Vo and the enhanced HER activity.Further theoretical calculations revealed that the Vo optimizes the hydrogen adsorption and dissociation of water on the surface of LaCoO_(3)thin films,thus improving the HER catalytic activity.This work may promote a deepened understanding of perovskite oxides for HER mechanism by Vo adjusting and a new avenue for designing highly active electrochemical catalysts in alkaline solution.

Molecular insight into the GaP(110)-water interface using machine learning accelerated molecular dynamics

GaP has been shown to be a promising photoelectrocatalyst for selective CO_(2)reduction to methanol.Due to the relevance of the interface structure to important processes such as electron/proton transfer,a detailed understanding of the GaP(110)-water interfacial structure is of great importance.Ab initio molecular dynamics(AIMD)can be used for obtaining the microscopic information of the interfacial structure.However,the GaP(110)-water interface cannot converge to an equilibrated structure at the time scale of the AIMD simulation.In this work,we perform the machine learning accelerated molecular dynamics(MLMD)to overcome the difficulty of insufficient sampling by AIMD.With the help of MLMD,we unravel the microscopic information of the structure of the GaP(110)-water interface,and obtain a deeper understanding of the mechanisms of proton transfer at the GaP(110)-water interface,which will pave the way for gaining valuable insights into photoelectrocatalytic mechanisms and improving the performance of photoelectrochemical cells.

New role of α phase in the fracture behavior and fracture toughness of a β-type bio-titanium alloy

The role of α precipitates formed during aging in the fracture toughness and fracture behavior of β-type bio-titanium alloy Ti–29Nb–13Ta–4.6Zr(TNTZ) was studied. Results showed that the fracture toughness of the TNTZ alloy aged at 723 K decreases to the minimum of 72.07–73.19 kJ·m^(-2)when the aging time is extended to 4–8 h and then gradually increases and reaches 144.89 kJ·m^(-2)after 72 h. The decrease in fracture toughness within the aging time of 4–8 h is caused by the large stress concentration at the tip of acicular α precipitates with a high aspect ratio and the preferential crack propagation along the inhomogeneous acicular α precipitates distributed in “V-shape” and “nearly perpendicular shape”. When the aging time is extended to 8–72 h, the precrack tip is uniformly blunted, and the crack is effectively deflected by α precipitates with multi long axis directions, more high homogeneity, low aspect ratio, and large number density. Analysis of the effect of αprecipitates on the fracture behavior suggested that the number of long axis directions of α precipitates is the key controlling factor for the fracture behavior and fracture toughness of the TNTZ alloy aged for different times.

Evolution of edge turbulent transport induced by L-mode detachment in the HL-2A tokamak

This paper presents the characteristics of L-mode detachment,together with the behavior of edge turbulent transport and plasma confinement on the HL-2A tokamak.Partially detached and pronounced detached states have been achieved in L-mode plasma.Stored energy was maintained before and after detachment.Edge turbulence and its transport have increased obviously in the partially detached state.In the pronounced detached state,redistribution of the density and temperature profiles due to detachment leads to low amplitude of electron temperature and pressure,as well as very weak edge turbulence and transport.Despite strong plasma radiation in the pronounced detached state,reduced edge turbulent transport contributes to maintaining stored energy in detached L-mode plasma in HL-2A.Different detachment states play an important role in the redistribution of density and temperature profiles,which requires further study.

Effects of sawtooth heat pulses on edge flows and turbulence in a tokamak plasma

Enhancements of edge zonal flows,radial electric fields,and turbulence are observed in electron cyclotron resonance heating-heated plasmas(Zhao et al 2013 Nucl.Fusion 53083011).In this paper,the effects of sawtooth heat pulses on flows and turbulence are presented.These experiments are performed using multiple Langmuir probe arrays in the edge plasmas of the HL-2A tokamak.The edge zonal flows,radial electric fields,and turbulence are all enhanced by sawteeth.Propagation of the zonal flow and turbulence intensities is also observed.The delay time of the maximal intensity of the electric fields,zonal flows,and turbulence with respect to the sawtooth crashes is estimated as~1 ms and comparable to that of the sawtooth-triggered intermediate phases.Not only the zonal flows but also the radial electric fields lag behind the turbulence.Furthermore,the intensities of both the zonal flows and electric fields nearly linearly increase/decrease with the increase/decrease of the turbulence intensity.A double-source predator-prey model analysis suggests that a relatively strong turbulence source may contribute to the dominant zonal flow formation during sawtooth cycles.

Correlation analysis of mental health conditions and personality of patients with alcohol addiction

BACKGROUND Alcohol addiction,or alcohol dependence,refers to a psychological state of strong craving for alcohol caused by drinking when both the drinking times and alcohol consumption reach a certain level.Alcohol addiction can cause irreversible damage,leading to mental illness or mental disorders,negative changes in their original personality,and a tendency to safety incidents such as committing suicide or violent attacks on others.Significant attention needs to be given to the mental health of alcohol addicts,which could reflect their abnormal personality traits.However,only a few papers on this issue have been reported in China.AIM To investigate the correlation between mental health and personality in patients with alcohol addiction.METHODS In this single-center observational study,we selected 80 patients with alcohol addiction as the research subjects,according to the criteria of the K10 scale to evaluate the mental health of patients with alcohol addiction,and divided these patients into four groups based on the evaluation results:Good,average,relatively poor and bad.And then analyzed the correlation between mental health conditions and personality characteristics from these four groups of patients.RESULTS The average score of the K10 scale(Kessler 10 Simple Psychological Status Assessment Scale)in 80 patients with alcohol addiction was 25.45 points,the median score was 25 points,the highest score was 50 points,and the lowest score was 11 points.Pearson's analysis showed that the K10 score was positively correlated with the scores of these two subscales,such as the P-subscale and the N-subscale(P<0.05).In contrast,the K10 score had no significant correlation with the scores from the E-subscale and the L-subscale(P>0.05).CONCLUSION The mental health conditions of patients with alcohol addiction are positively correlated with their personality characteristics.

TiO_2/石墨烯纳米复合材料对UV固化水性聚氨酯的改性

通过溶胶-凝胶法制备了锐钛矿型的纳米TiO_2,用改进的Hummers法制备了氧化石墨烯,用水热法合成了纳米TiO_2/石墨烯复合材料。采用异佛尔酮二异氰酸酯和聚乙二醇1000为反应单体,二月桂酸二丁基锡为催化剂,二羟甲基丙酸作为扩链剂,并以甲基丙烯酸羟乙酯封端,成功制备出水性聚氨酯预聚体。将TiO_2/石墨烯复合材料引入UV固化聚氨酯体系,制备了含有不同质量分数复合材料的聚氨酯涂层。采用扫描电子显微镜、X射线粉末衍射、傅里叶变换红外光谱、紫外-可见分光光度计等手段对样品进行表征,分析了材料的形貌、组成、结构及光催化降解性能。结果表明,TiO_2/石墨烯复合材料改性水性聚氨酯涂料表现出了较好的光催化性能。280nm紫外光照射下24h之内对甲基橙降解率达到77.20%,而在可见光条件下复合材料对甲基橙降解率达到57.52%。经改性的聚氨酯涂层的各项力学性能有了不同程度的提高。

电磁导航支气管镜在外周肺病变诊治中的临床应用进展

随着计算机断层扫描的筛查应用普及,越来越多的外周肺部病变被发现,外周肺病变的诊断和治疗是目前临床较为棘手的问题之一。电磁导航支气管镜以电磁定位技术为基础,经支气管到达外周肺部病变进行活检或治疗,为肺部可疑病灶提供了新的微创诊治方法。本文将综述电磁导航支气管镜在外周肺病变诊治中的临床应用现状及进展。

MicroRNA-185-5p mediates regulation of SREBP2 expression by hepatitis C virus core protein

AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.

Hepatitis B surface antigen clearance in inactive hepatitis B surface antigen carriers treated with peginterferon alfa-2a

AIM: To examine the association between interferon(IFN) therapy and loss of hepatitis B surface antigen(HBs Ag) in inactive HBs Ag carriers. METHODS: This was a retrospective cohort study in inactive HBs Ag carriers, who were treatment-naive, with a serum HBs Ag level < 100 IU/m L and an undetectable hepatitis B virus(HBV) DNA level(< 100 IU/m L). All the 20 treated patients received subcutaneous PEG-IFN alfa-2a 180 μg/wk for 72 wk and were then followed for 24 wk. There were 40 untreated controls matched with 96 wk of observation. Serum HBs Ag, HBV DNA, and alanine aminotransferases were monitored every 3 mo in the treatment group and every 3-6 mo in the control group. RESULTS: Thirteen(65.0%) of 20 treated patients achieved HBs Ag loss, 12 of whom achieved HBs Ag seroconversion. Mean HBs Ag level in treated patients decreased to 6.69 ± 13.04 IU/m L after 24 wk of treatment from a baseline level of 26.22 ± 33.00 IU/m L. Serum HBV DNA level remained undetectable(< 100 IU/m L) in all treated patients during the study. HBs Ag level of the control group decreased from 25.72 ± 25.58 IU/m L at baseline to 17.11 ± 21.62 IU/m L at week 96(P = 0.108). In the control group, no patient experienced HBs Ag loss/seroconversion, and two(5.0%) developed HBV reactivation.CONCLUSION: IFN treatment results in HBs Ag loss and seroconversion in a considerable proportion of inactive HBs Ag carriers with low HBs Ag concentrations.

Composite solid electrolyte of Na3PS4-PEO for all-solid-state SnS2/Na batteries with excellent interfacial compatibility between electrolyte and Na metal

High ionic conductivity and superior interfacial stability of solid electrolytes at the electrodes are crucial factors for high-performance all-solid-state sodium batteries. Herein, a composite solid electrolyte Na3PS4-polyethylene oxide is synthesized by the solution-phase reaction method with an improved ionic conductivity up to 9.4 × 10-5 S/cm at room temperature. Moreover, polyethylene oxide polymer layer is wrapped homogeneously on the surface of Na3PS4 particles, which could effectively avoid the direct contact between Na3PS4 electrolyte and sodium metal, thus alleviate their side reactions. We demonstrate that all-solid-state battery SnS2/Na with the composite solid electrolyte Na3PS4-polyethylene oxide delivers an enhanced electrochemical performance with 230 m Ah/g after 40 cycles.