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In China, the land arrangement behavior of over 160 million rural-urban migrant workers is closely related to the optimal allocation of rural land resources and sustainable development of urban and rural areas. Although previous studies show that social capital affects migrant workers’ land arrangement behavior, few are empirical studies revealing the relationship between them, and the corresponding interventions remains unclear. Using survey data collected in China’s Henan Province and a multinomial Logit model, this study empirically analyzed the mechanism behind the impact of social capital on migrant workers’ land arrangement behavior from the perspective of social capital. Results illustrate that social capital has a significant impact on the land arrangement behavior of migrant workers. The behavior is significantly correlated with the scale of migrant workers' urban social networks, the degree of urban social trust and urban belonging. The more social capital in urban areas, the higher tendency migrant workers to abandon their land contracting rights and become permanent urban residents. This study reveals the mechanism of social capital affecting migrant workers’ land arrangement behavior, and provides a reference for decision-making with respect to guiding migrant workers’ land management behavior for other countries facing similar social problems.

In this article, a novel model-free dynamic inversion-based Q-learning (DIQL) algorithm is proposed to solve the optimal tracking control (OTC) problem of unknown nonlinear input-affine discrete-time (DT) systems. Compared with the existing DIQL algorithm and the discount factor-based Q-learning (DFQL) algorithm, the proposed algorithm can eliminate the tracking error while ensuring that it is model-free and off-policy. First, a new deterministic Q-learning iterative scheme is presented, and based on this scheme, a model-based off-policy DIQL algorithm is designed. The advantage of this new scheme is that it can avoid the training of unusual data and improve data utilization, thereby saving computing resources. Simultaneously, the convergence and stability of the designed algorithm are analyzed, and the proof that adding probing noise into the behavior policy does not affect the convergence is presented. Then, by introducing neural networks (NNs), the model-free version of the designed algorithm is further proposed so that the OTC problem can be solved without any knowledge about the system dynamics. Finally, three simulation examples are given to demonstrate the effectiveness of the proposed algorithm.

AIM Few studies have comprehensively evaluated the factors associated with health-related quality of life (HRQOL) in the elderly. The purpose of the study is to identify the factors associated with HRQOL using a comprehensive geriatric assessment of community-dwelling elderly people in Beijing, China. METHODS A cross-sectional survey of 896 community-dwelling elderly people in Beijing was conducted through face-to-face interviews. Data regarding sociodemographic factors, chronic disease (assessed by the Cumulative Illness Rating Scale for Geriatrics, CIRS-G), common geriatric syndromes and HRQOL (assessed by the EuroQol 5-Dimension questionnaire, EQ-5D) were collected using a structured questionnaire. Binary logistic regression analysis was used to identify the factors related to HRQOL. RESULTS The CIRS-G comorbidity index was negatively related to the EQ-5D index and EQ-Visual Analog Scale (VAS) (P

Designing a robot with the best accuracy is always the attractive research direction in robot community. In order to create a Gough-Stewart platform with guaranteed accuracy performance for a dedicated controller, this paper describes a novel advanced optimal design methodology: control-based design methodology. This advanced optimal design method considers the controller positioning accuracy in the design process for getting the optimal geometric parameters of the robot. In this paper, three types of visual servoing controllers are applied to control the motions of the Gough-Stewart platform: leg-direction-based visual servoing, line-based visual servoing and image moment visual servoing. Depend on these controllers, the positioning error models considering the camera observation error together with the controller singularities are analyzed. In the next step, the optimization problems are formulated in order to get the optimal geometric parameters of the robot and the placement of the camera for the Gough-Stewart platform for each type of controller. Then, we perform the co-simulations on the three optimized Gough-Stewart platforms in order to test the positioning accuracy and the robustness with respect to the manufacturing errors. It turns out that the optimal control-based design methodology helps getting both the optimum design parameters of the robot and the performance of the controller {robot + dedicated controller}.

Background Previous reports suggest that the attributes of frailty are multidimensional and include nutrition, cognition, mentality, and other aspects. We aim to develop an early warning model of frailty based on nutritional risk screening and apply the frailty early warning model in the clinic to screen high-risk patients and provide corresponding intervention target information. Methods The proposed study includes two stages. In the first stage, we aim to develop a prediction model of frailty among older inpatients with nutritional risk. Study data were collected from a population-based aging cohort study in China. A prospective cohort study design will be used in the second stage of the study. We will recruit 266 older inpatients (age 65 years or older) with nutritional risk, and we will apply the frailty model in the clinic to explore the predictive ability of the model in participants, assess patients’ health outcomes with implementation of the frailty model, and compare the model with existing frailty assessment tools. Patients’ health outcomes will be measured at admission and at 30-day follow-up. Discussion This project is the first to develop an early prediction model of frailty for older inpatients according to nutritional risk in a nationally representative sample of Chinese older inpatients of tertiary hospitals. The results will hopefully help to promote the development of more detailed frailty assessment tools according to nutritional risk, which may ultimately lead to reduced health care costs and improvement in independence and quality of life among geriatric patients. Trial registration Chinese Clinical Trial Registry, ChiCTR1800017682, registered August 9, 2018; and ChiCTR2100044148, registered March 11, 2021.

Little is known about the current representative depression situation among Chinese older inpatients. The aim of this study is to examine prevalence of depression and associated risk factors among Chinese older inpatients by a large-scale cross-sectional national survey. This study is based on baseline survey data from a large-scale cohort study in a representative sample of Chinese older inpatients. The procedure of this study involves physical examination and face-to-face questionnaire interviews. Depression was assessed based on the Geriatric Depression Scale 15. Mixed-effect Poisson regression model was used to examine the relationship between depression and covariates by controlling the cluster effect of hospital wards. Of all 9727 respondents, the mean age of all respondents was 72.4±5.7 years, from 65 to 97. The average GDS score was 2 (1, 4). The prevalence rate of depression was 16.7% (95%CI: 15.8–17.4%) among older inpatients. The prevalence rates were 14.6% for males and 19.5% for females respectively. After controlling the cluster effect of hospital wards, age, gender, ADL score, educational level, BMI, frail, marriage, falls, alcohol drinking, cognitive function, living conditions, vision, hearing, sleep and defecation function were associated with depression. Emaciation (OR=1.176, 95%CI: 1.107–1.249), frail (OR=1.562, 95%CI: 1.489–1.639), divorced or widowed (OR=1.083 95%CI: 1.017–1.153), living in the bungalow (OR=1.075, 95%CI: 1.023–1.130), falls (OR=1.078, 95%CI: 1.030–1.128), cognitive function (OR=1.142, 95%CI: 1.091–1.195), vision dysfunction (OR=1.125, 95%CI: 1.076–1.177), hearing dysfunction (OR=1.061, 95%CI: 1.011–1.113), sleep dysfunction (OR=1.237, 95%CI: 1.194–1.282), defecation dysfunction (OR=1.160, 95%CI: 1.103–1.221) could increase prevalence risk of depression. There was a high prevalence of depression among Chinese older inpatients. Demographic characteristics, physical and mental conditions indicators have strong effect on prevalence and strength of depression. Therefore, it is essential to assess depression and perform comprehensive measures to improve physical and mental conditions in order to manage depressive symptoms in older inpatients.

In the present paper, a control-based design methodology is developed in order to create a DELTA robot with the best accuracy performance for a dedicated controller. The proposed control-based design methodology takes into account the accuracy performance of the controller in the design process to get the optimal geometric parameters of the robot. Three types of controllers are envisaged for the control of the motions of the DELTA robot: leg-direction-based visual servoing, line-based visual servoing and image moment visual servoing. Based on these three controllers, positioning error models taking into account the error of observation coming from the camera are developed. Then, design optimization problems are formulated in order to find the optimal geometric parameters and camera placement for the DELTA robot for each type of controller. Co-simulations of the robots optimized for the three types of controllers are finally performed in order to check the accuracy performance of the three robots.

Background There is still controversy about the relationship between aging and changes in functional ability. This study aims to describe the level of basic activities of daily living (ADL) and higher-level instrumental activities of daily living (IADL) in different age groups and explore the factors associated with functional disability in Chinese older inpatients. Methods This cross-sectional study surveyed 9996 older inpatients aged 65 years and older from six tertiary hospitals in China from October 2018 to February 2019. The levels of ADL and IADL were measured by scores of the Barthel index and Instrumental Activities of Daily Living Scale. A mixed-effect generalized linear model was used to examine the association between functional disability and covariates. Results The average ADL score was 89.51 ± 19.29 and the mean IADL score 6.76 ± 2.01 for all participants. There was a trend of decreasing scores along with aging, and significant differences between age groups were also observed (P Conclusions Functional ability declines with aging, older inpatients are low dependency upon ADL and IADL. There are several associated factors among the participants derived from this investigation of a large-scale, multicenter, nationally representative Chinese older inpatient population. These findings potentially have major importance for the planning of hospital services, discharge planning, and post-discharge care. Trial registration Chinese Clinical Trial Registry, ChiCTR1800017682, registered August 9, 2018.

The amount of building floor space (BFS) plays a key role in the energy and material demand prediction. Unfortunately, BFS estimation has faced the challenge of ineffective and inadequate approaches, and thus reliable data concerning China&rsquo, s BFS is unavailable. This study proposes a new estimation method for China&rsquo, s BFS and then estimates historical BFS by type in China from 1996 to 2014. The results show that total Chinese BFS grew from 28.1 billion m2 in 1996 to 61.3 billion m2 in 2014, increasing more than twice, with an annual growth rate of 4.4% from 1996 to 2014. During 1996&ndash, 2014, urban residential BFS witnessed the highest annual increase rate (9.3%), while the growth rate for commercial and rural residential BFS was lower: 4.4% and 1.6%, respectively. By comparing with available statistics data, this study finds the model deviations are well below 5%, which indicates the reliability of the proposed method and robustness of the results. The proposed method not only can address the deficiencies of statistic yearbook and overcome the shortages of previous estimation approaches but also can derive more accurate and reliable data. This study lays a sound basis for the following study on building stock and building energy efficiency work.

Additional file 1 Demographic characteristics of the participants (N = 9996). Abbreviations, BMI, body mass index; ICU, Intensive care unit.

Background To date, most previous studies of frailty among hospitalized elderly Chinese patients have been conducted based on small samples, which cannot represent the elderly patient population. The aim of this study was to identify the prevalence of and risk factors for frailty among elderly patients in China. Study design and setting This cross-sectional study surveyed 9996 elderly patients from 6 tertiary-level hospitals in China. The prevalence of frailty among patients from selected wards was surveyed by trained investigators. A mixed-effects Poisson regression model was used to analyse the factors associated with frailty among elderly patients. Results The mean age of all subjects was 72.47 ± 5.77 years. The prevalence rate of frailty in this study was 18.02%. After adjustments were made for the confounding effect of the clustering of hospital wards, a mixed-effects Poisson regression model showed that the associated factors of frailty included the following: age (OR: 1.016, 95% CI: 1.012–1.020), BMI 28 (OR: 0.897, 95% CI: 0.856–0.940); higher education level, including middle school (OR: 0.915, 95% CI: 0.857, 0.977) and diploma and above (OR: 0.891, 95% CI: 0.821, 0.966); and current alcohol use (OR: 0.869, 95% CI: 0.815, 0.927). Conclusion We identified a relatively high prevalence of frailty among elderly patients, and there are several associated factors among the population derived from this investigation of a large-scale, multicentre, nationally representative Chinese elderly inpatient population. Trial registration Chinese Clinical Trial Registry, ChiCTR1800017682, registered 09 August 2018.

Clinical trials testing mesenchymal stem cell (MSC) as a cellular remedy for acute liver injury (ALI) are underway, but its underlying mechanism has not been thoroughly scrutinized. We highlight that the metabolomic profile of the liver-resident immune cells is significantly altered after MSC administration; its potential correlation with ALI remission is discussed in this study. C57BL/6 mice are randomly divided into three groups: the sham group, MSC-treated ALI group and PBS-treated ALI group; acute liver injury is induced by intraperitoneal injection of carbon tetrachloride. A high-performance chemical isotope labeling liquid chromatography-mass spectrometry (CIL LC-MS) is exploited to profile amine, phenol and carbonyl submetabolome of the liver-resident immune cells in different treatments. 4295 peak pairs are quantified and 2461 peak pairs are further identified in zero-reaction and one-reaction libraries. Clear separation of the three groups is observed in the global PCA and OPLS-DA analyses. We identified 256 metabolites to be candidate biomarkers for ALI-activated immunity and 114 metabolites to be candidate biomarkers for MSC-modulated immunity. Ariginine, aspartate and glutamate metabolism are most affected in both cases, with eight significantly regulated metabolites as joints (glutamic-gamma-semialdehyde, aspartate acid, glutamate acid, gamma-Aminobutyric acidorinithine, 2-keto-glutaramic acid, N-acetylornithine, citrulline and ornithine). These findings shed new light on the therapeutic benefit of immune modulation during ALI rescue. It needs to be further investigated whether exogenous supply of certain metabolites will exert a profound impact on the metabolic network, crosstalking with immune responses and modulating ALI prognosis.

Reliable and objective data regarding building stock is essential for predicting and analyzing energy demand and carbon emission. However, China's building stock data is lacking. This study proposes a set of China building floor space estimation method (CBFSM) based on the improved building stock turnover model. Then it measures China's building stocks by vintage and type from 2000 to 2015, as well as building energy intensity (national level and provincial level) and energy-efficient buildings. Results showed that total building stocks increased significantly, rising from 35.2 billion m2 in 2000 to 63.6 billion m2 in 2015, with the average growth rate 4.0%. The deviations were well below 10% by comparing with China Population Census, which validated the reliability of CBFSM and the results. As for energy intensity, urban dwellings and rural dwellings showed relatively stable and increasing trend respectively. The commercial building energy intensity saw a downward trend during “12th Five Year Plan” period. This indicated the effectiveness of building energy efficiency work for commercial buildings since 2005.38.6 billion m2 residential dwellings and 5.7 billion m2 commercial buildings still need to be retrofitted in future. CBFSM can overcome shortages in previous studies. It can also provide Chinese government with technical support and data evidence to promote the building energy efficiency work.

Background Association of oxidative stress biomarkers with aging and several age-related diseases is well documented. However, the possible role of these factors on frailty status in older adults has not been extensively studied. Objective To evaluate whether urinary 8-oxo-7,8-dihydroguanosine (8-oxo-Gsn), a biomarker of RNA oxidative damage, was independently associated with frailty. Methods In this cross-sectional analysis, frailty phenotype was assessed among 230 participants living in a senior community. Participants received a comprehensive geriatric assessment. Serum high-sensitivity C-reactive protein (hsCRP), white blood cell count (WBC), urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine, and 8-oxo-Gsn were measured. Results Participants’ mean age was 83.9 ± 4.4 years. In total, 33 % were frail, 45 % were pre-frail, and 22 % were non-frail. Urinary 8-oxo-Gsn, serum hsCRP, and WBC were significantly higher in the frail group than in the non-frail and pre-frail groups (p-values Conclusion Urinary 8-oxo-Gsn level was independently associated with frailty. This urinary biomarker may be a promising indicator of frailty.

This study investigates the characteristics of the cost performance of megatransport infrastructure projects in Hong Kong and performs dependence analysis of cost overruns. It is based on 5...

The tedious and costly route of the general nanocasting method hinders the commercial application of mesoporous non-precious metal catalysts based on transition metal-coordinating nitrogen-doped carbons (MN/C). Here, a simple, economic and sustainable hydrothermal carbonization (HTC)/soft templating method is demonstrated for the direct preparation of mesoporous FeN/C materials (FeN/MC). By this method, FeN/MC materials with high specific surface area, hierarchically mesoporous structure, and appropriate iron and nitrogen contents are prepared. The optimized FeN/MC materials exhibit superior catalytic performance in the oxygen reduction reaction (ORR) to commercial Pt/C in 0.1 M KOH. This confirms that the materials are one of the most efficient non-precious metal catalysts for the ORR in alkaline electrolyte. In addition, considerable durability and ORR activity are demonstrated by the FeN/MC materials in 0.1 M HClO4. Thus, this HTC/soft templating method has great promise for the practical application of this kind of non-precious metal catalysts in the ORR.

Background: China is experiencing a rapid growth of elder people which demands suitable health care models for the disabled community seniors to meet the government’s “aging at home” policy.

In this paper, a circulating current elimination scheme for common dc bus parallel inverter system is proposed. A dead-time elimination sinusoidal pulse width modulation (SPWM) is presented to overcome the circulating current caused by dead-time effects. The circulating current elimination scheme combines dead-time elimination SPWM and double loop control method, which is compose of an outer voltage loop and an inner current loop. Synchronizing the pulse width modulation (PWM) signals of each parallel unit, the instantaneous output PWM voltages of the parallel units can be kept the same, apart from the zero crossing of load current. The proposed scheme is easy to be implemented on the digital control board using digital signal processing (DSP) and field-programmable gate array (FPGA). Experimental results are depicted to demonstrate the validity and features of the proposed circulating current elimination scheme.

Hydrothermal carbonization (HTC) of carbohydrates is an economic and sustainable technique for the synthesis of carbon materials. However, the assembly of carbohydrates with soft templates is susceptible to hydrolysis, degradation, and relatively high HTC temperature. Thus, it is still challenging to control the HTC/soft templating of carbohydrates and prepare mesoporous carbon with specific properties. Herein, a simple and effective self-transformation strategy is proposed to improve the HTC/soft templating, which introduces an insoluble melamine sulfate into the formation processes. Mechanism studies indicate that the assembly of d-fructose with soft templates is greatly promoted by coassembling with the gradually released melamine sulfate. As a result, carbonaceous composites with a flower-like structure and N-doping were synthesized. Further, ordered mesoporous carbons with N-doping are obtained after calcination. The obtained carbons exhibit outstanding ability for heavy metal adsorption and supercap...

The configuration of parallel inverter system (PIS) with common dc link and no isolation measure is proposed. The gate control signals for switches in parallel inverters are synchronised to achieve ideal parallel operation status. Adopting the double loop control method which is composed of an outer voltage loop and an inner current loop, PIS has good dynamic response and robustness. In addition, the circulating current caused by the delay time of control signal transmission is studied in detail. The proposed operation method is easy to be implemented on the digital control board using digital signal processing and field-programmable gate array. The simulation and experimental results are presented to demonstrate the validity and features of the proposed operation method.