A knowledge-enhanced interpretable network for early recurrence prediction of hepatocellular carcinoma via multi-phase CT imaging.

BACKGROUND: Predicting early recurrence (ER) of hepatocellular carcinoma (HCC) accurately can guide treatment decisions and further enhance survival. Computed tomography (CT) imaging, analyzed by deep learning (DL) models combining domain knowledge, has been employed for the prediction. However, these DL models utilized late fusion, restricting the interaction between domain knowledge and images during feature extraction, thereby limiting the prediction performance and compromising decision-making interpretability. METHODS: We propose a novel Vision Transformer (ViT)-based DL network, referred to as Dual-Style ViT (DSViT), to augment the interaction between domain knowledge and images and the effective fusion among multi-phase CT images for improving both predictive performance and interpretability. We apply the DSViT to develop pre-/post-operative models for predicting ER. Within DSViT, to balance the utilization between domain knowledge and images within DSViT, we propose an adaptive self-attention mechanism. Moreover, we present an attention-guided supervised learning module for balancing the contributions of multi-phase CT images to prediction and a domain knowledge self-supervision module for enhancing the fusion between domain knowledge and images, thereby further improving predictive performance. Finally, we provide the interpretability of the DSViT decision-making. RESULTS: Experiments on our multi-phase data demonstrate that DSViTs surpass the existing models across multiple performance metrics and provide the decision-making interpretability. Additional validation on a publicly available dataset underscores the generalizability of DSViT. CONCLUSIONS: The proposed DSViT can significantly improve the performance and interpretability of ER prediction, thereby fortifying the trustworthiness of artificial intelligence tool for HCC ER prediction in clinical settings.

Serum bile acid and unsaturated fatty acid profiles of non-alcoholic fatty liver disease in type 2 diabetic patients.

BACKGROUND: The understanding of bile acid (BA) and unsaturated fatty acid (UFA) profiles, as well as their dysregulation, remains elusive in individuals with type 2 diabetes mellitus (T2DM) coexisting with non-alcoholic fatty liver disease (NAFLD). Investigating these metabolites could offer valuable insights into the pathophy-siology of NAFLD in T2DM. AIM: To identify potential metabolite biomarkers capable of distinguishing between NAFLD and T2DM. METHODS: A training model was developed involving 399 participants, comprising 113 healthy controls (HCs), 134 individuals with T2DM without NAFLD, and 152 individuals with T2DM and NAFLD. External validation encompassed 172 participants. NAFLD patients were divided based on liver fibrosis scores. The analytical approach employed univariate testing, orthogonal partial least squares-discriminant analysis, logistic regression, receiver operating characteristic curve analysis, and decision curve analysis to pinpoint and assess the diagnostic value of serum biomarkers. RESULTS: Compared to HCs, both T2DM and NAFLD groups exhibited diminished levels of specific BAs. In UFAs, particular acids exhibited a positive correlation with NAFLD risk in T2DM, while the ω-6:ω-3 UFA ratio demonstrated a negative correlation. Levels of α-linolenic acid and γ-linolenic acid were linked to significant liver fibrosis in NAFLD. The validation cohort substantiated the predictive efficacy of these biomarkers for assessing NAFLD risk in T2DM patients. CONCLUSION: This study underscores the connection between altered BA and UFA profiles and the presence of NAFLD in individuals with T2DM, proposing their potential as biomarkers in the pathogenesis of NAFLD.

Risk assessment and source analysis of heavy metals in soil around an asbestos mine in an arid plateau region, China.

Asbestos is widely used in construction, manufacturing, and other common industrial fields. Human activities such as mining, processing, and transportation can release heavy metals from asbestos into the surrounding soil environment, posing a health hazard to the mining area's environment and its surrounding residents. The purpose of the present study was to determine the extent of ecological and human health damage caused by asbestos pollution, as well as the primary contributors to the contamination, by examining a large asbestos mine and the surrounding soil in China. The level of heavy metal pollution in soil and sources were analyzed using methods such as the geo-accumulation index (Igeo), potential ecological risk index (RI), and positive matrix factorization (PMF) model. A Monte Carlo simulation-based health risk model was employed to assess the health risks of heavy metals in the study area's soil to human beings. The results showed that the concentrations of As, Pb, Cr, Cu, and Ni in the soil were 1.74, 0.13, 13.31, 0.33, and 33.37 times higher than the local soil background values, respectively. The Igeo assessment indicated significant accumulation effects for Ni, Cr, and As. The RI evaluation revealed extremely high comprehensive ecological risks (RI ≥ 444) in the vicinity of the waste residue heap and beneficiation area, with Ni exhibiting strong individual potential ecological risk (Eir ≥ 320). The soil health risk assessment demonstrated that As and Cr posed carcinogenic risks to adults, with mean carcinogenic indices (CR) of 1.56E - 05 and 4.14E - 06, respectively. As, Cr, and Cd posed carcinogenic risks to children, with mean CRs of 1.08E - 04, 1.61E - 05, and 2.68E - 06, respectively. Cr also posed certain non-carcinogenic risks to both adults and children. The PMF model identified asbestos contamination as the primary source of heavy metals in the soil surrounding the asbestos mining area, contributing to 79.0%. According to this study, it is recommended that management exercise oversight and regulation over the concentrations of Ni, Cr, Cd, and As in the soil adjacent to asbestos mines, establish a designated control zone to restrict population activities, and locate residential zones at a safe distance from the asbestos mine production zone.

Differences in the perceptions of patients with primary biliary cholangitis and physicians from various hospital departments: An online survey.

OBJECTIVES: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease that affects the quality of life (QoL) of patients. This study aimed to evaluate the differences in perceptions of PBC among physicians from different hospital departments and patients with PBC. METHODS: An online survey regarding the general knowledge, diagnosis, and management of PBC was completed by physicians and patients. RESULTS: A total of 239 patients with PBC and 239 physicians from eight hospital departments (gastroenterology, infectious diseases, rheumatology, hepatobiliary surgery, pathology, clinical laboratory, ultrasound, and radiology) completed the survey. The results showed that physicians from departments other than gastroenterologists and rheumatologists lacked knowledge of PBC, and that junior gastroenterologists were uncertain about the diagnostic and treatment pathways of PBC. Importantly, the lack of knowledge significantly impacted the QoL of patients, especially the emotional scores of PBC-40 (odds ratio -2.556, 95% confidence interval -3.852 to -1.260, P < 0.001). In addition, there was a perceived knowledge gap between patients and gastroenterologists. CONCLUSIONS: Physicians must improve their awareness of PBC. Patient education and patient-physician communication are important for improving the patient's QoL.

Can we redevelop ammonia nitrogen contaminated sites without remediation? The key role of subsurface pH in human health risk assessment.

Nitrogen fertilizer supports global food production, but its manufacturing results in substantial ammonia nitrogen (AN) contaminated sites which remain largely unexplored. In this study, ten representative AN contaminated sites were investigated, covering a wide range of subsurface pH, temperature, and AN concentration. A total of 7232 soil samples and 392 groundwater samples were collected to determine the concentration levels, migration patterns, and accurate health risks of AN. The results indicated that AN concentrations in soil and groundwater reached 12700 mg/kg and 12600 mg/L, respectively. AN concentrations were higher in production areas than in non-production areas, and tended to migrate downward from surface to deeper soil. Conventional risk assessment based on AN concentration identified seven out of the ten sites presenting unacceptable risks, with remediation costs and CO2 emissions amounting to $1.67 million and 17553.7 tons, respectively. A novel risk assessment model was developed, which calculated risks based on multiplying AN concentration by a coefficient fNH3 (the ratio of NH3 to AN concentration). The mean fNH3 values, primarily affected by subsurface pH, varied between 0.02 and 0.25 across the ten sites. This new model suggested all investigated sites posed acceptable health risks related to AN exposure, leading to their redevelopment without AN-specific remediation. This research offers a thorough insight into AN contaminated site, holds great realistic significance in alleviating global economic and climate pressures, and highlights the need for future research on refined health risk assessments for more contaminants.

Comprehensive distribution characteristics and factors affecting the migration of chromium in a typical chromium slag-contaminated site with a long history in China.

The contamination of abandoned chromium slag-contaminated sites poses serious threats to human health and the environment. Therefore, improving the understanding of their distribution characteristics and health risks by multiple information is necessary. This study explored the distribution, accumulation characteristic, and the role in the migration process of chromium. The results showed that the contents of total Cr and Cr (VI) ranged from 12.00 to 7400.00 mg/kg, and 0.25 to 2160.00 mg/kg, respectively. The average contents of both total Cr and Cr (VI) reached the highest value at the depth of 7-9 m, where the silt layer retaining total Cr and Cr (VI) was. The spatial distribution analysis revealed that the total contamination area percentages of total Cr and Cr (VI) reached 7.87% and 90.02% in the mixed fill layer, and reduced to 1.21% and 34.53% in the silty layer, and the same heavily polluted areas were located in the open chromium residue storage. Soil pH and moisture content were the major factors controlling the migration of total Cr and Cr(VI) in soils. Results of probabilistic health risk assessment revealed that carcinogenic risk was negligible for adults and children, and the sensitive analysis implied that the content of Cr(VI) was the predominant contributor to carcinogenic risk. The combination of chemical reduction and microbial remediation could be the feasible remediation strategy for soil Cr(VI) pollution. Overall, this study provides scientific information into the chromium post-remediation and pollution management for various similar chromium-contaminated sites.

Derivation of human health and odor risk control values for soil ammonia nitrogen by incorporating solid-liquid partitioning, ammonium/ammonia equilibrium: A case study of a retired nitrogen fertilizer site in China.

Nitrogen fertilizer supports agricultural intensification, but its manufacturing results in substantial contaminated sites. Ammonia nitrogen is the main specific pollutant in retired nitrogen fertilizer sites with potential human health and odor risks. However, few studies focus on ammonia nitrogen risk assessment at contaminated sites, particularly considering its solid-liquid partitioning process (Kd) and ammonium/ammonia equilibrium process (R) in the soil. This study took a closed nitrogen fertilizer factory site as an example and innovatively introduced Kd and R to scientifically assess the human health and odor risk of ammonia nitrogen. The risk control values (RCVs) of ammonia nitrogen based on human health and odor risk were also derived. The maximum concentration of ammonia nitrogen was 3380 mg/kg in the unsaturated soil, which was acceptable for human health because the health RCVs were 5589 ∼ 137,471 mg/kg in various scenarios. However, odor risk was unacceptable for RCVs were 296 ∼ 1111 mg/kg under excavation scenarios and 1118 ∼ 35,979 mg/kg under non-excavation scenarios. Of particular concern, introducing Kd and R in calculation increased the human health and odor RCVs by up to 27.92 times. Despite the advancements in ammonia risk assessment due to the introduction of Kd and R, odor risk during excavation remains a vital issue. These findings inform a more scientific assessment of soil ammonia risk at contaminated sites and provide valuable insights for the management and redevelopment of abandoned nitrogen fertilizer plant sites.

Determining priority control toxic metal for different protection targets based on source-oriented ecological and human health risk assessment around gold smelting area.

Determining the priority control source and pollutant is the key for the eco-health protection and risk management around gold smelting area. To this end, a case study was conducted to explore the pollution characteristics, source apportionment, ecological risk and human health risk of toxic metals (TMs) in agricultural soils surrounding a gold smelting enterprise. Three effective receptor models, including positive matrix factorization model (PMF), ecological risk assessment (ERA), and probabilistic risk assessment (PRA) have been combined to apportion eco-human risks for different targets. More than 95.0% of samples had a Nemerow pollution index (NPI) > 2 (NPImean=4.27), indicating moderately or highly soil TMs contamination. Four pollution sources including gold smelting activity, mining source, agricultural activity and atmosphere deposition were identified as the major sources, with the contribution rate of 17.52%, 44.16%, 13.91%, and 24.41%, respectively. For ecological risk, atmosphere deposition accounting for 30.8% was the greatest contributor, which was mainly loaded on Hg of 51.35%. The probabilistic health risk assessment revealed that Carcinogenic risks and Non-carcinogenic risks of all population were unacceptable, and children suffered from a greater health risk than adults. Gold smelting activity (69.2%) and mining source (42.0%) were the largest contributors to Carcinogenic risks and Non-carcinogenic risks, respectively, corresponding to As and Cr as the target pollutants. The priority pollution sources and target pollutants were different for the eco-health protection. This work put forward a new perspective for soil risk control and management, which is very beneficial for appropriate soil remediation under limited resources and costs.

Natural attenuation of BTEX and chlorobenzenes in a formerly contaminated pesticide site in China: Examining kinetics, mechanisms, and isotopes analysis.

Groundwater contamination from abandoned pesticide sites is a prevalent issue in China. To address this problem, natural attenuation (NA) of pollutants has been increasingly employed as a management strategy for abandoned pesticide sites. However, limited studies have focused on the long-term NA process of co-existing organic pollutants in abandoned pesticide sites by an integrated approach. In this study, the NA of benzene, toluene, ethylbenzene, and xylene (BTEX), and chlorobenzenes (CBs) in groundwater of a retired industry in China was systematically investigated during the monitoring period from June 2016 to December 2021. The findings revealed that concentrations of BTEX and CBs were effectively reduced, and their NA followed first-order kinetics with different rate constants. The sulfate-reducing bacteria, nitrate-reducing bacteria, fermenting bacteria, aromatic hydrocarbon metabolizing bacteria, and reductive dechlorinating bacteria were detected in groundwater. It was observed that distinct environmental parameters played a role in shaping both overall and key bacterial communities. ORP (14.72%) and BTEX (12.89%) were the main drivers for variations of the whole and key functional microbial community, respectively. Moreover, BTEX accelerated reductive dechlorination. Furthermore, BTEX and CBs exhibited significant enrichment of 13C, ranging from +2.9 to +27.3‰, demonstrating their significance in situ biodegradation. This study provides a scientific basis for site management.

Observation of an isothermal glass transition in metallic glasses.

Glass transition, commonly manifested upon cooling a liquid, is continuous and cooling rate dependent. For decades, the thermodynamic basis in liquid-glass transition has been at the center of debate. Here, long-time isothermal annealing was conducted via molecular dynamics simulations for metallic glasses to explore the connection of physical aging in supercooled liquid and glassy states. An anomalous two-step aging is observed in various metallic glasses, exhibiting features of supercooled liquid dynamics in the first step and glassy dynamics in the second step, respectively. Furthermore, the transition potential energy is independent of initial states, proving that it is intrinsic for a metallic glass at a given temperature. We propose that the observed dynamic transition from supercooled liquid dynamics to glassy dynamics could be glass transition manifested isothermally. On this basis, glass transition is no longer cooling rate dependent, but is shown as a clear phase boundary in the temperature-energy phase diagram. Hence, a modified out-of-equilibrium phase diagram is proposed, providing new insights into the nature of glass transition.

An Analysis of the Spatial Characteristics and Transport Fluxes of BTEX in Soil and Atmospheric Phases at a Decommissioned Steel Mill Site in China with a Long History.

BTEX (benzene, toluene, ethylbenzene, and xylene), as characteristic pollutants in chemical plant sites, are widely present in the environment and pose a serious threat to the health and safety of nearby residents. Studying the spatial distribution characteristics and transport fluxes of BTEX in soil and air at contaminated sites and the health risks they pose to humans is of great significance for fine pollution control and environmental management. This study took a typical decommissioned steel plant as a case study. A total of 23 soil and air samples were collected from different locations to investigate the spatial distribution characteristics of BTEX in soil and air. The transport and fate of BTEX in soil and air were evaluated using the fugacity model, and finally, a human health risk assessment was conducted. The results indicate a relatively severe level of benzene pollution in both soil and air. The maximum exceedance factor of benzene in soil samples is 31.5, with the concentration exceedance depth at 1.5 m. The maximum concentration of benzene in air samples is 4.98 µg·m-3. Benzene, at 5.9% of the site, shows a low flux with negative values, while other components at various locations all exhibit a trend of transport from the soil phase to the atmospheric phase. Benzene is the pollutant that contributes the most to the transport flux from soil to air within the site. The coking area and sewage treatment area are key areas within the steel mill where BTEX accumulate easily in the soil. The non-carcinogenic risk values of the individual components of BTEX in the soil are below the acceptable risk level. However, the carcinogenic risk value of benzene in the children's exposure scenario exceeds the carcinogenic risk level of 10-6. The carcinogenic risk range of various components of BTEX in the air is 2.63 × 10-6~3.88 × 10-5, with 28.6% of the locations exceeding the threshold of 10-6. The range of the total HI (hazard index) is 2.08 × 10-4~1.81 × 10-1, all of which is below the safety threshold of 1. The results of this study will provide scientific support for the fine pollution control and environmental management of industrial contaminated sites with BTEX as their typical pollutants.

Washed microbiota transplantation for Clostridioides difficile infection: A national multicenter real-world study.

OBJECTIVES: Fecal microbiota transplantation (FMT) has been recommended for the treatment of recurrent Clostridioides difficile infection (CDI). We aimed to evaluate the therapeutic efficacy and safety of washed microbiota transplantation (WMT), a new method of FMT, for CDI across various medical settings. METHODS: This multicenter real-world cohort study included CDI patients undergoing WMT. The primary outcome was the clinical cure rate of CDI within 8 weeks after WMT. Secondary outcomes included the CDI recurrence rate and reduction in total abdominal symptom score (TASS) during the follow-up period. Adverse events related to WMT were recorded. RESULTS: Altogether 90.7% (49/54) of CDI patients achieved clinical cure after treated with WMT. The cure rate was 83.3% for cases with severe and complicated CDI (ScCDI) (n = 30) and 100% for non-ScCDI cases (n = 24) (P = 0.059). No difference was observed in the clinical cure rate between patients with first and recurrent CDI (91.9% vs 88.2%, P = 0.645). One week post-WMT, TASS showed a remarkable decrease compared to that at baseline (P < 0.001). Totally, 8.2% (4/49) of patients suffered CDI recurrence during the follow-up period. A WHO performance score of 4, age ≥65 years, higher TASS score, and higher Charlson comorbidity index score were potential risk factors for efficacy (P = 0.018, 0.03, 0.01, 0.034, respectively). Four (3.8%) transient adverse events related to WMT were observed. CONCLUSIONS: This study emphasizes the attractive value of WMT for CDI. Early WMT may be recommended for CDI, especially for those in serious condition or with complex comorbidities. TRIAL REGISTRATION: ClinicalTrials.gov, no. NCT03895593 (registered on 27 March 2019).

Satellite cell-derived exosome-mediated delivery of microRNA-23a/27a/26a cluster ameliorates the renal tubulointerstitial fibrosis in mouse diabetic nephropathy.

Renal tubulointerstitial fibrosis (TIF) is considered as the final convergent pathway of diabetic nephropathy (DN) without effective therapies currently. MiRNAs play a key role in fibrotic diseases and become promising therapeutic targets for kidney diseases, while miRNA clusters, formed by the cluster arrangement of miRNAs on chromosomes, can regulate diverse biological functions alone or synergistically. In this study, we developed clustered miR-23a/27a/26a-loaded skeletal muscle satellite cells-derived exosomes (Exos) engineered with RVG peptide, and investigated their therapeutic efficacy in a murine model of DN. Firstly, we showed that miR-23a-3p, miR-26a-5p and miR-27a-3p were markedly decreased in serum samples of DN patients using miRNA sequencing. Meanwhile, we confirmed that miR-23a-3p, miR-26a-5p and miR-27a-3p were primarily located in proximal renal tubules and highly negatively correlated with TIF in db/db mice at 20 weeks of age. We then engineered RVG-miR-23a/27a/26a cluster loaded Exos derived from muscle satellite cells, which not only enhanced the stability of miR-23a/27a/26a cluster, but also efficiently delivered more miR-23a/27a/26a cluster homing to the injured kidney. More importantly, administration of RVG-miR-23a/27a/26a-Exos (100 µg, i.v., once a week for 8 weeks) significantly ameliorated tubular injury and TIF in db/db mice at 20 weeks of age. We revealed that miR-23a/27a/26a-Exos enhanced antifibrotic effects by repressing miRNA cluster-targeting Lpp simultaneously, as well as miR-27a-3p-targeting Zbtb20 and miR-26a-5p-targeting Klhl42, respectively. Knockdown of Lpp by injection of AAV-Lpp-RNAi effectively ameliorated the progression of TIF in DN mice. Taken together, we established a novel kidney-targeting Exo-based delivery system by manipulating the miRNA-23a/27a/26a cluster to ameliorate TIF in DN, thus providing a promising therapeutic strategy for DN.

Asbestos-Environment Pollution Characteristics and Health-Risk Assessment in Typical Asbestos-Mining Area.

Asbestos has been confirmed as a major pollutant in asbestos-mining areas that are located in western China. In general, asbestos-fibre dust will is released into the environment due to the effect of intensive industrial activities and improper environmental management, such that the health of residents in and around mining areas is jeopardised. A typical asbestos mining area served as an example in this study to analyse the content and fibre morphology of asbestos in soil and air samples in the mining area. The effects of asbestos pollution in and around the mining areas on human health were also assessed based on the U.S. Superfund Risk Assessment Framework in this study. As indicated by the results, different degrees of asbestos pollutions were present in the soil and air, and they were mainly concentrated in the mining area, the ore-dressing area, and the waste pile. The concentration of asbestos in the soil ranged from 0.3% to 91.92%, and the concentration of asbestos fibres in the air reached 0.008-0.145 f·cc-1. The results of the scanning-electron microscope (SEM) energy suggested that the asbestos was primarily strip-shaped, short columnar, and granular, and the asbestos morphology of the soils with higher degrees of pollution exhibited irregular strip-shaped fibre agglomeration. The excess lifetime cancer risk (ELCR) associated with the asbestos fibres in the air of the mining area was at an acceptable level (10-4-10-6), and 40.6% of the monitoring sites were subjected to unacceptable non-carcinogenic risks (HQ > 1). Moreover, the waste pile was the area with the highest non-carcinogenic risk, followed by the ore dressing area, a residential area, and a bare-land area in descending order. In the three scenarios of adult offices or residences in the mining area, adults' outdoor activities in the peripheral residence areas, and children's outdoor activities, the carcinogenic-and non-carcinogenic-risk-control values in the air reached 0.1438, 0.2225 and 0.1540 f·cc-1, and 0.0084, 0.0090 and 0.0090 f·cc-1, respectively. The results of this study will lay a scientific basis for the environmental management and governance of asbestos polluted sites in China.

Spatiotemporal characteristics and dynamic risk assessment of a multi-solvents abandoned pesticide-contaminated site with a long history, in China.

With the development of the economy and the adjustment of urban planning and layout, abandoned pesticide sites are widely distributed in major and medium cities in China. Groundwater pollution of a large number of abandoned pesticide-contaminated sites has caused great potential risks to human health. Up to now, few relevant studies concerned the spatiotemporal variation of risks exposure to multi-pollutants in groundwater using probabilistic methods. In our study, the spatiotemporal characteristics of organics contamination and corresponding health risks in the groundwater of a closed pesticide site were systematically assessed. A total of 152 pollutants were targeted for monitoring over a time span up to five years (i.e., June 2016-June 2020). BTEX, phenols, chlorinated aliphatic hydrocarbons, and chlorinated aromatic hydrocarbons were the main contaminants. The metadata was subjected to health risk assessments using the deterministic and probabilistic methods for four age groups, and the results showed that the risks were highly unacceptable. Both methods showed that children (0-5 years old) and adults (19-70 years old) were the age groups with the highest carcinogenic and non-carcinogenic risks, respectively. Compared with inhalation and dermal contact, oral ingestion was the predominant exposure pathway that contributed 98.41%-99.69% of overall health risks. Spatiotemporal analysis further revealed that the overall risks first increased then decreased within five years. The risk contributions of different pollutants were also found to vary substantially with time, indicating that dynamic risk assessment is necessary. Compared with the probabilistic method, the deterministic approach relatively overestimated the true risks of OPs. The results provide a scientific basis and practical experience for scientific management and governance of abandoned pesticide sites.

Influences of point defects on electron transport of two-dimensional gep semiconductor device.

The quantum transport properties of defective two-dimensional (2D) GeP semiconductor nanodevice consisting of typical point defects, such as antisite defect, substitutional defect, and Schottky defect, have been studied by using density functional theory combined with non-equilibrium Green's function calculation. The antisite defect has indistinctive influences on electron transport. However, both substitutional and Schottky defect have introduced promising defect state at the Fermi level, indicating the possibility of improvement on the carrier transport. Our quantitative quantum transport calculations ofI-Vbbehavior have revealed that the electrical characters are enhanced. Moreover, the P atom vacancy could induce significant negative differential resistance phenomenon, and the physical mechanism is unveiled by detailed analysis. The transfer characteristic properties could be prominently improved by substitutional defect and vacancy defect. Most importantly, we have proposed a computational design of GeP-based electronic device with improved electrical performance by introducing vacancy defect. Our findings could be helpful to the practical application of novel 2D GeP semiconductor nanodevice in future.

Distinct relaxation mechanism at room temperature in metallic glass.

How glasses relax at room temperature is still a great challenge for both experimental and simulation studies due to the extremely long relaxation time-scale. Here, by employing a modified molecular dynamics simulation technique, we extend the quantitative measurement of relaxation process of metallic glasses to room temperature. Both energy relaxation and dynamics, at low temperatures, follow a stretched exponential decay with a characteristic stretching exponent ß = 3/7, which is distinct from that of supercooled liquid. Such aging dynamics originates from the release of energy, an intrinsic nature of out-of-equilibrium system, and manifests itself as the elimination of defects through localized atomic strains. This finding is also supported by long-time stress-relaxation experiments of various metallic glasses, confirming its validity and universality. Here, we show that the distinct relaxation mechanism can be regarded as a direct indicator of glass transition from a dynamic perspective.

Enhanced Fuzzy Fault Estimation of Discrete-Time Nonlinear Systems via a New Real-Time Gain-Scheduling Mechanism.

The problem of enhancing the robust performance of nonlinear fault estimation (FE) is addressed by proposing a novel real-time gain-scheduling mechanism for discrete-time Takagi-Sugeno fuzzy systems. The real-time status of the operating point for the considered nonlinear plant is characterized by using these available normalized fuzzy weighting functions at both the current and the past instants of time. To achieve this, the developed fuzzy real-time gain-scheduling mechanism produces different switching modes by introducing key tunable parameters. Thus, a pair of exclusive FE gain matrices is designed for each switching mode on the strength of time-varying balanced matrices developed in this study, respectively. Since the implementation of more FE gain matrices can be scheduled according to the real-time status of the operating point at each sampling instant, the robust performance of nonlinear FE will be enhanced over the previous methods to a great extent. Finally, considerable numerical comparisons are implemented in order to illustrate that the proposed method is much superior to those existing ones reported in the literature.

Distributed robust group output synchronization control for heterogeneous uncertain linear multi-agent systems.

This paper investigates the distributed robust group output synchronization problem of heterogeneous uncertain linear leader-follower multi-agent systems (MASs), whose followers have nonidentical and parameter uncertain dynamics. To achieve cooperative tracking with multiple targets, a new group synchronization framework based upon the output regulation technique is established. In the underlying directed communication topology, all nonidentical followers are divided into several subgroups. Meanwhile, each subgroup has its output tracking objective generated by an autonomous exosystem which is seen as the leader of each subgroup. Since not all followers can access their exosystems directly, the distributed exosystem observer based on the algebraic Riccati inequality (ARI) is designed to obtain the information of exosystems. Moreover, to compensate for parameter uncertainties for different group topologies, the p-copy internal model is synthesized into distributed control laws, i.e., dynamic state feedback control protocol under an acyclic directed graph and dynamic output feedback control protocol under a general directed graph. It is shown that group synchronization can be respectively achieved with these controllers under acyclic and general partitions regardless of parameter uncertainties. Finally, some examples are provided to verify the validity of the analytic results.

Distributed Fault-Tolerant Bipartite Output Synchronization of Discrete-Time Linear Multiagent Systems.

This article studies the distributed fault-tolerant bipartite output synchronization problem of discrete-time linear multiagent systems (MASs) with process faults under a general directed signed graph. The reference signal is generated by an autonomous exosystem, which can also be seen as a leader. All followers are divided into two subgroups with antagonistic interactions, and the followers in each subgroup are cooperative. We aim to solve the bipartite fault-tolerant control (FTC) problem via the output regulation theory such that bipartite output synchronization can be achieved in the presence of process faults, that is, the outputs of followers with different subgroups can approach the output of exosystem with the same magnitude and the opposite sign regardless of process faults. To estimate the states and the faults of each follower, a simultaneous state and fault estimator based on the neighboring signed output estimation error and the standard discrete-time algebraic Riccati equation (ARE) is designed. Besides, a new exosystem observer with two classes of convergence conditions relying on the respective solutions of standard and modified AREs is provided. All eigenvalues of the exosystem matrix can lie completely outside the unit circle. Based on these estimations, we present a distributed fault-tolerant output feedback controller, which can overcome the no-loops constraint. Finally, simulation results are given to demonstrate the analytic results.