Search

Frailty is a major health issue associated with aging. Diet affects frailty status; however, studies on the associations between the low-carbohydrate diet (LCD) score, low-fat diet (LFD) score and frailty in older Chinese adults are scarce. This study aimed to examine the associations between the LCD score, LFD score and risk of frailty in older Chinese adults. We analyzed data from 6414 participants aged ≥ 60 years from the China Northwest Natural Population Cohort: Ningxia Project. Frailty was measured using the frailty index (FI), calculated from 28 items comprising diseases, behavioral disorders and blood biochemistry and classified as robust, pre-frail and frail. LCD and LFD scores were calculated using a validated food frequency questionnaire (FFQ). Multiple logistic regression models were used to evaluate associations between LCD, LFD scores and frail or pre-frail status after adjusting for confounders. Participants’ mean age was 66.60 ± 4.15 years, and 47.8% were male. After adjusting for age, sex, educational level, drinking, smoking, BMI, physical activity and total energy, compared to the lowest quartile (Q1: reference), the odds ratios (ORs) for pre-frail and frail status in the highest quartile (Q4) of LCD score were 0.73 (95% confidence intervals: 0.61–0.88; p for trend = 0.017) and 0.73 (95%CI: 0.55–0.95; p for trend = 0.035), respectively. No significant associations were observed between LFD score and either pre-frail or frail status. Our data support that lower-carbohydrate diets were associated with lower pre-frail or frail status, particularly in females, while diets lower in fat were not significantly associated with the risk of either pre-frail or frail status in older Chinese adults. Further intervention studies are needed to confirm these results.

Purpose Accurate glide path tracking is vital to the automatic carrier landing task of unmanned aerial vehicle (UAV). The purpose of this paper is to develop a reliable flight controller that can simultaneously deal with external disturbance, structure fault and actuator fault. Design/methodology/approach The automatic carrier landing task is resolved into the glide path tracking problem and attitude tracking problem. The disturbance observer-based adaptive sliding mode control scheme is proposed for system stabilization, disturbance rejection and fault tolerance. Findings Both the Lyapunov method and exemplary simulations can prove that the disturbance estimation error and the attitude tracking error converge in finite time in the presence of external disturbances and various faults. Practical implications The presented algorithm is testified by a UAV automatic carrier landing simulation, which shows the potential of practical usage. Originality/value The barrier function is introduced to adaptively update both the sliding mode observer gain and sliding mode controller gain, so that the sliding mode surface could converge to a predefined region without overestimation. The proposed flight controller ensures a secure carrier landing task.

A composite control scheme based on a disturbance observer is presented in this paper to deal with the attitude control problem of flexible spacecraft. Specifically, a sliding mode disturbance observer (SMDO) is developed to attenuate the unmodeled system dynamics, parameter uncertainties, and multiple external disturbances. The key feature of this approach is to relax the assumption imposed on disturbance to be constant or changing at a slow rate, which is a typical assumption in this class of problems involving a disturbance observer. Then, an exclusive adaptive integral sliding mode controller is combined with the SMDO to get the improved closed-loop control performance of the system. The underlying benefit of the proposed control scheme is improved robustness against time-dependent external disturbances and system model uncertainties. The stability analysis of the closed-loop system is provided using Lyapunov’s stability theory. Simulation results are provided to show the effectiveness of the proposed control scheme, especially in comparison with existing results.

The Kapitza resistance is of fundamental importance for the thermal stability of the interface between the ceramic top coat and the thermal growth oxide layer in the thermal barrier coating structure, which is widely used to protect high-temperature components in current gas turbine engines. The top coat typically consists of the ZrO $$_{\mathrm {2}}$$ partially stabilized by 8% Y $$_{\mathrm {2}}$$ O $$_{\mathrm {3}}$$ (YSZ), and the main component of the thermal growth oxide is $$\alpha $$ -Al $$_{\mathrm {2}}$$ O $$_{\mathrm {3}}$$ . In this work, the Kapitza resistance is found to be a small value of 0.69 $${\hbox {m}^{\mathrm {2}}}\cdot $$ K/GW for the YSZ/ $$\alpha $$ -Al $$_{\mathrm {2}}$$ O $$_{\mathrm {3}}$$ interface based on the heat dissipation simulation method. It indicates that the localization of thermal energy is rather weak, which is beneficial for the thermal stability of the YSZ/ $$\alpha $$ -Al $$_{\mathrm {2}}$$ O $$_{\mathrm {3}}$$ interface. This Kapitza resistance can be further reduced to 0.50 $${\hbox {m}^{\mathrm {2}}}\cdot $$ K/GW by a mechanical or thermal compressive strain of 8%. To explore the underlying mechanism for this strain effect, we analyze the phonon vibration and the microscopic deformation in the interface region. It is revealed that the interface becomes denser through the compression-induced twisting of some Al-O $$_{\mathrm {Zr}}$$ and Al-O $$_{\mathrm {Al}}$$ chemical bonds in the interface region, which is responsible for the reduction in the Kapitza resistance. The temperature effect and crystal size effect on the Kapitza resistance of the YSZ/ $$\alpha $$ -Al $$_{\mathrm {2}}$$ O $$_{\mathrm {3}}$$ interface are also systematically studied. These findings shall provide valuable information for further understanding of the thermal conductivity and thermal stability of the thermal barrier coating structures.

Brassica napus L. (rapeseed) is one of the most important oil crops with large cultivated area in China. Seed size and seed weight play crucial roles for yield and harvest. In this study, a type of 15 bp-deletion in BnaGRF7.C02 coding region was identified through sequence alignment of BnaGRF7.C02 in 42 rapeseed varieties, and association analysis indicated that the 15 bp-deletion was related to the rapeseed Thousand-Seed Weight (TSW) phenotype. Furthermore, we developed two InDel markers to identify this 15 bp InDel. The tissue-specific expression patterns showed that BnaGRF7.C02 prominently expressed in the late stage of seed development. These findings may assist in InDel markers-based breeding efforts to select higher TWS varieties and improve the crop yield of B. napus.

This paper studies a novel learning observer-based fault-tolerant tracking control strategy for a hypersonic vehicle attitude system with external disturbance, parameter uncertainty and actuator faults. Without obtaining the prior knowledge of lumped disturbance, a novel learning observer combined with the barrier function is first proposed to estimate the attitude angular velocities and reconstruct lumped disturbance accurately and quickly. By introducing the estimation value into the controller design process, a backstepping fault-tolerant tracking controller is developed to solve the attitude tracking problem of hypersonic vehicle. The stability of the hypersonic vehicle faulty attitude system using the observer-based fault-tolerant control method is analyzed by Lyapunov framework. Finally, the feasibility and superiority of the fault-tolerant control scheme is proved by comparing with different existing observer and control strategy through numerical simulations.

Xiaoxia Li,1,2,&ast; Yixuan Xue,1,&ast; Yuanyuan Dang,1 Wanlu Liu,1 Qingan Wang,1,2 Yi Zhao,1,2 Yuhong Zhang1,2 1Department of Epidemiology and Health Statistics, School of Public Health and Management of Ningxia Medical University, Yinchuan, People’s Republic of China; 2Key Laboratory of Environmental Factors and Chronic Disease Control, School of Public Health and Management of Ningxia Medical University, Yinchuan, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Yuhong Zhang, Department of Epidemiology and Health Statistics School of Public Health and Management, Ningxia Medical University, 1160 Shengli Street, Xingqing District, Yinchuan, 750004, People’s Republic of China, Tel +86951-6980144, Fax +86951-6980144, Email zhabour@163.comObjective: Three non-insulin-based insulin resistance (IR) indices, ie, triglyceride-glucose (TyG) index, triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-C) ratio, and metabolic score for IR (METS-IR), were considered powerful and simplified alternatives for IR. However, evidence for the association between the three IR indices and incident type 2 diabetes mellitus (T2DM), especially impaired fasting glucose (IFG), remains limited. Therefore, this study aimed to explore the association among IR indices, incident IFG, and T2DM in a rural population cohort.Methods: We analyzed data from 2209 adults (aged 24– 75 years) at baseline and from 1205 normoglycemic participants who were followed up. Cox proportional hazards models were used to evaluate the associations between the three indices and IFG or T2DM. Restricted cubic spline curves based on the Cox regression model were used to examine the association between baseline indices and incident T2DM.Results: For the baseline data, logistic analyses demonstrated that the TyG index, TG/HDL-C ratio, and METS-IR had a significantly positive correlation with IFG or T2DM after multivariable adjustment. During a median follow-up of 12.17 years, 157 incident cases of IFG and 97 incident cases of T2DM were noted. The risk of T2DM, but not IFG, was strongly associated with the baseline TyG index in the adjusted model, and participants with the TyG index in the third tertile had a higher risk of developing T2DM (adjusted hazards ratio, 2.84; 95% confidence intervals, 1.26– 6.37; p for trend < 0.001) than those in the lowest tertile (reference). Moreover, a linear relationship was observed between the TyG index and T2DM incidence. The TG/HDL-C ratio and METS-IR had no significant relationship with the risk of IFG or T2DM.Conclusion: The TyG index is more useful than the TG/HDL-C ratio and METS-IR in predicting T2DM in the normoglycemic population.Keywords: triglyceride-glucose index, triglyceride-to-high-density lipoprotein cholesterol, metabolic score for insulin resistance, impaired fasting glucose, type 2 diabetes mellitus

Two-dimensional lateral heterostructures exhibit novel electronic and optical properties that are induced by their in-plane interface for which the mechanical properties of the interface are important for the stability of the lateral heterostructure. Therefore, we performed molecular dynamics simulations and developed a convolutional neural network-based machine learning model to study the fracture properties of the interface in a graphene/hexagonal boron nitride lateral heterostructure. The molecular dynamics (MD) simulations show that the shape of the interface can cause an 80% difference in the fracture stress and the fracture strain for the interface. By using 11 500 training samples obtained with help of high-cost MD simulation, the machine learning model is able to search out the strongest interfaces with the largest fracture strain and fracture stress in a large sample space with over 150 000 structures. By analyzing the atomic configuration of these strongest interfaces, we disclose two major factors dominating the interface strength, including the interface roughness and the strength of the chemical bond across the interface. We also explore the correlation between the fracture properties and the thermal conductivity for these lateral heterostructures by examining the bond type and the shape of the graphene/hexagonal boron nitride interface. We find that interfaces comprised of stronger bonds and smoother zigzag interfaces can relieve the abrupt change of the acoustic velocity, leading to the enhancement of the interface thermal conductivity. These findings will be valuable for the application of the two-dimensional lateral heterostructure in electronic devices.

This article studies the cooperative search-attack mission problem with dynamic targets and threats, and presents a Distributed Intelligent Self-Organized Mission Planning (DISOMP) algorithm for multiple Unmanned Aerial Vehicles (multi-UAV). The DISOMP algorithm can be divided into four modules: a search module designed based on the distributed Ant Colony Optimization (ACO) algorithm, an attack module designed based on the Parallel Approach (PA) scheme, a threat avoidance module designed based on the Dubins Curve (DC) and a communication module designed for information exchange among the multi-UAV system and the dynamic environment. A series of simulations of multi-UAV searching and attacking the moving targets are carried out, in which the search-attack mission completeness, execution efficiency and system suitability of the DISOMP algorithm are analyzed. The simulation results exhibit that the DISOMP algorithm based on online distributed down-top strategy is characterized by good flexibility, scalability and adaptability, in the dynamic targets searching and attacking problem. Keywords: Ant Colony Optimization (ACO), Cooperative control, Mission planning, Search-attack integration, Self-organized, Unmanned Aerial Vehicle (UAV)

This paper studies an automatic carrier landing control problem of fixed-wing aircraft with system uncertainties under the airwake and deck motion disturbances. A robust preview control scheme and an autoregressive (AR) model prediction scheme are originally applied to the automatic carrier landing system (ACLS). The AR model is used to predict the deck motion, which corrects the reference glide slope for relative motion compensation. A novel robust preview control scheme based on the linear matrix inequality (LMI) is proposed for the uncertain nonlinear systems with external disturbances, to make the aircraft track the corrected reference glide slope and reject the airwake disturbance. Simulation results exhibit the better carrier landing performance of the robust preview control scheme than the PID control and robust control schemes.

The design of the guide sign system is essential to ensure a good interaction mechanism between the user, the space and the sign guidance system, which helps the user complete the spatial positioning and path finding behavior through systematic information transfer. Based on the concept of campus guide sign system, the factors affecting system performance are summarized in the paper. The good strategies of Korean university sign guidance systems are analyzed from function, vision and culture. It is proposed that the college sign guidance system should be designed from the three dimensions of information interaction, visual expression and cultural inheritance considering the relationship between people and campus space, which can become a card to convey the charm of the campus.

Based on the analysis of gesture types and gesture recognition technology, this paper divides the function of TV operation interface, designs two sets of gestures based on wearable devices and bare-hand. Using the method of subjective and objective testing, it tests the user fatigue of the two sets of gestures. Finally, experimental results showed that bare-hand gesture interaction technology with its emphasis on natural, comfortable advantage, would become the main way of future home appliance gesture interaction.

In this study, the thermo-breathing vibration of carbon nanoscrolls (CNSs) is studied by molecular dynamics (MD) simulations and continuum modeling. The breathing vibration strongly depends on the competition between the cohesive energy among the graphene layers of CNSs and the bending energy of CNSs, where the explicit expressions for the total cohesive energy of CNSs are derived by using Gaussian quadrature based on van der Waals interlayer interactions. In particular, the interlayer amplitudes on the breathing vibration of CNSs at different temperatures are obtained by continuum modeling with the equipartition theorem. Checking against our MD simulations shows that the present theoretical model has high accuracy. The analytical solutions show that the temperatures have no effect on the nature frequency of CNSs, but have a great effect on the vibration amplitude of CNSs. The obtained results should be of great importance for understanding the thermo-mechanical vibration of nanosized devices.In this study, the thermo-breathing vibration of carbon nanoscrolls (CNSs) is studied by molecular dynamics (MD) simulations and continuum modeling. The breathing vibration strongly depends on the competition between the cohesive energy among the graphene layers of CNSs and the bending energy of CNSs, where the explicit expressions for the total cohesive energy of CNSs are derived by using Gaussian quadrature based on van der Waals interlayer interactions. In particular, the interlayer amplitudes on the breathing vibration of CNSs at different temperatures are obtained by continuum modeling with the equipartition theorem. Checking against our MD simulations shows that the present theoretical model has high accuracy. The analytical solutions show that the temperatures have no effect on the nature frequency of CNSs, but have a great effect on the vibration amplitude of CNSs. The obtained results should be of great importance for understanding the thermo-mechanical vibration of nanosized devices.

Strain engineering shows distinct advantages in thermal management by tuning thermal resistance in a wide range. Till now, most of the relative studies were concentrated in uniform deformation, wherein the effects of the localized strain field are rarely exploited. Herein, by using non-equilibrium molecular dynamics simulations, we explore the local strain field engineering effects on the interfacial thermal resistance (ITR) of graphene nanoribbons (GNRs). The model of GNRs employed in this work contains extended drag threads, which are used to create a local strain field. Our simulation results show that the ITR has a quasi-linear relationship with the local tensile strain. GNRs are very sensitive to the local strain field in terms of ITR with a maximum enhancement factor of ∼1.5 at the strain of 10%. The ITR is found to depend linearly on the local strain. This phenomenon is thoroughly explained by micro-structure deformation, heat flux scattering, and phonon density of state overlapping. Our findings h...