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The skeleton serves as a supportive and protective organ for the body. As individuals age, their bone tissue undergoes structural, cellular, and molecular changes, including the accumulation of senescent cells. Extracellular vesicles (EVs) play a crucial role in aging through the cellular secretome and have been found to induce or accelerate age-related dysfunction in bones and to contribute further via the circulatory system to the aging of phenotypes of other bodily systems. However, the extent of these effects and their underlying mechanisms remain unclear. Therefore, this paper attempts to give an overview of the current understanding of age-related alteration in EVs derived from bones. The role of EVs in mediating communications among bone-related cells and other body parts is discussed, and the significance of bones in the whole-body aging process is highlighted. Ultimately, it is hoped that gaining a clearer understanding of the relationship between EVs and aging mechanisms may serve as a basis for new treatment strategies for age-related degenerative diseases in the skeleton and other systems. An impairment of bone mass, quality and function can be observed during aging. Senescent extracellular vesicles (EVs) play a crucial role in bone aging and are closely related to whole-body aging. Senescent EVs are believed to be promising clinical tools for age-related diseases in testing, diagnosis, and therapy. Created with BioRender.com. [Display omitted] • Extracellular vesicles (EVs) derived from aged bone-related tissues/cells exhibit age-dependent changes in concentration, size and cargos. • Senescent EVs inhibit osteogenic effects in the aged bone. • Aged bones contribute to the aging process of the whole body through the release of EVs. • Senescent EVs may become promising biomarkers of age-related diseases and anti-aging therapy targets. [ABSTRACT FROM AUTHOR]

In this research, FeCoCrV high entropy alloy was prepared by casting and cold rolling, and heat treatment was used to control the phase partition of FeCoCrV alloy. Meanwhile, the wear resistance of FeCoCrV alloy under different phase partition was investigated. Metallographic microscope, X-ray diffractometer, Vickers microhardness tester and friction and wear testing machine were used to analyze the microstructure, phase fraction, hardness and wear resistance of the alloy. The results show that FeCoCrV high entropy alloy is mainly composed of FCC, BCC and SIGMA phases, and the phase partition can be controlled by appropriate heat treatment. It is found that the fraction of BCC phase decreases and FCC phase increases with the increase of heat treatment temperature. BCC phase fraction reaches up to 67.6% and the hardness is up to 709 HV after heat treatment at 600 °C for 1h. At the same time, the holding time also affects the compatibility of the alloy. When the heating temperature is 700 °C, the FCC fraction of the alloy initially increases and then tends to be stable with the extension of the holding time. The FCC phase volume fraction reaches up to 84%, resulting in a significant decrease of the hardness to 294 HV after heat treatment at 700 °C/50 h. In addition, it can be found that the wear resistance of FeCoCrV high entropy alloy is positively correlated with the hardness, the wear rate of the high-entropy alloy is 1.60 ×10-5mm3/N⋅m after heat treatment at 600 °C/1h, while the wear rate decreases to 2.43×10-5 mm3/N⋅m when heat treated at 700 °C/50h, increased by about 50%. And the main wear mechanism includes abrasive wear, fatigue wear and oxidation wear. • Phase partition of Fe44.6Co34.8Cr10.4V10.2 HEA can be regulated by different heat treatment. • The hardness and wear resistance of the alloy increases with the increase of hard BCC and Sigma phase and the decrease of soft FCC phase, vice versa. • The wear mechanism of the alloy includes abrasive wear, fatigue wear and oxidative wear. [ABSTRACT FROM AUTHOR]

The dynein protein plays a key role in the degradation pathway by attaching to targeted molecules and transporting the autophagosome to the centrosome. Aging plays an important role in the pathogenesis of Parkinson's disease (PD), but its effect on dynein is not clear. In this study we analyzed behavioral characteristics using the rod endurance test and climbing rod time test in different aged mice (3 months, 12 months, 20 months), and measured protein expression of dynein, α-synuclein, Tctex-1, and LC3 in the substantia nigra of the mice by Western blot. The mRNA levels of dynein, α-synuclein, LC3 and Tctex-1 were measured by quantitative real time reverse transcription PCR, and detecting expression of dynein and α-synuclein by immunofluorescence. We found the motor functions of A53T mutant mice, in 12 months and 20 months, decreased more significantly compared with normal mice (p < 0.05). In addition, the expression of dynein, LC3-Ⅱ and Tctex-1 proteins in the substantia nigra of the two groups decreased with age. However, α-synuclein protein increased gradually with age, with significantly higher levels in the PD groups compared with age matched controls (p < 0.05). These results were confirmed by immunofluorescence. Our data demonstrates that dynein and other autophagy proteins change with age, and this is associated with increased α-synuclein. Therefore, therapeutics that prevent dynein dysfunction may offer novel treatments for PD and other autophagy related diseases. [ABSTRACT FROM AUTHOR]

With the rapid development of electronic technology, wearable electronic devices have been widely used in the lives of people. However, integrating multiple functions, such as flexible sensing and electromagnetic protection, into a single device remains challenging. Herein, silver nanowires and cobalt-nickel@carbon were assembled into a conductive and magnetic composite aerogel enhanced by aramid nanofibers and cellulose nanofibrils by freeze-drying. It exhibited an excellent electromagnetic wave absorption ability with an optimal minimum reflection loss of −51.6 dB. Then, polydimethylsiloxane (PDMS) was introduced in the subsequent vacuum-assisted impregnation process to obtain a compressible aerogel elastomer with excellent mechanical and electrical properties. It was not only used as a piezoresistive sensor for different application scenes (e.g. , human behavior monitoring, pressure array identification, and parking location recognition) but also as a triboelectric nanogenerator for high-performance energy harvesting. Such a unique and multifunctional composite aerogel elastomer will open up new potential applications for electromagnetic protection, blue energy harvesting, and piezoresistive sensing. [Display omitted] • Highly compressible composite aerogel elastomers for multifunctional applications. • Multi-scale heterostructures for effective electromagnetic wave absorption. • Stable output performance for energy harvesting. • Sensing applications for human motion monitoring and parking location recognition. [ABSTRACT FROM AUTHOR]

Urbanization results in a considerable economic disparity between urban and rural areas in developing countries, which has had a consequent significant impact on CO 2 emissions. To accommodate this directly, this paper presents a modified version of the Kaya Identity formula, U-Kaya, that includes a direct urbanization factor to determine the relationship between energy consumption intensity, population growth, urbanization rates, urban and rural GDP per capita and the volume of carbon emissions, for application in the dynamic forecasting of carbon emissions by Monte Carlo simulation. The method is demonstrated in forecasting China's likely carbon emissions in 2020 by three different modes of urbanization policy: the government-dominant mode, market-dominant mode and a hybrid government market-dominant mode. The results indicate that a higher urbanization rate, energy carbon emission coefficient and energy intensity will lead to increased carbon emissions. Finally, three policy implications are identified, comprising the narrowing of the economic gap between urban and rural areas, adjustments to the energy structure and technical innovation, which will provide a valuable reference for developing countries in their efforts to reduce carbon emissions. [ABSTRACT FROM AUTHOR]

• A new Quantitative approach to weight its compositions changes by analyzed functional groups content percentage and to determine its reactivity ranking by analyzed functional groups activation rate. • The chain thermal reaction of ten active groups were analyzed to reveal the oxidation mechanism of functional groups in coal combustion spontaneous. • The inhibition reaction of magnesium chloride on coal samples was different from those of sodium chloride and potassium chloride, which led to the different temperature stages in which the blocking effect occurs. • The inhibition effect of sodium chloride and potassium chloride was mainly manifested in the two-stage involving dehydration/desorption and dynamic equilibrium (below T 3). • The inhibition effect of magnesium chloride presents in the whole coal-oxygen reaction. To study the inhibition characteristics of different chloride salts on the spontaneous combustion of coal and to further reveal why magnesium chloride shows a different inhibitory effect, coal samples from FuSheng Coal Mine No. 15 in Shanxi Province were selected. Based on the characteristics of functional group absorption peak at different temperature, the composition changes and reactivity ranking of the functional groups in oxidized coal samples were tested by thermal oxidation experiments and infrared spectroscopy and analyzed to obtain the chain thermal reactions of different active groups. The weight-loss process and heat release characteristics of raw coal and three chloride salt-containing coal samples (sodium chloride, potassium chloride, and magnesium chloride) were compared and analyzed by synchronous thermal analysis experiments, and their inhibition reaction mechanism were studied. The results showed that different functional groups reacted at different low-temperature stages, and the active groups containing C–H, O–H, C-O, and C = O bonds were important during the spontaneous combustion of coal. In the chain thermal reactions with different active groups, heat and oxidative cleavage of the C-O and O–H bonds determined the chain development of different functional groups, and the R·, RO·, H·, and ·OH, chain thermal reaction products again acted as reactants that promoted further development of the reaction. Sodium chloride and potassium chloride played inhibitory roles in the dehydration-desorption stage and dynamic equilibrium stage through water evaporation and heat absorption, while magnesium chloride participated in the whole coal-oxygen reaction process. The inhibitory mechanism included dehydration and heat absorption by MgCl 2 ·6H 2 O, the complex dehydration of active groups containing O–H, the precipitation and oxygen insulation of [(SH·) n ]Mg and Mg(OH) 2 , the nucleophilic substitution of α-H for RCH 3 and RCH 2 OH groups, and the formation of H...Cl...H bonds. [ABSTRACT FROM AUTHOR]

Rectifier-Less Synchronized Switch Harvesting on Inductor (ReL-SSHI) interface is one of the most efficient interfaces for weakly-coupled piezoelectric (PE) systems. However, ReL-SSHI interface has narrow optimal rectified voltage range. Therefore, in this paper a maximum power point tracking (MPPT) circuit is presented for ReL-SSHI interface. An envelope extractor and a hysteresis voltage controller are used in the MPPT, which can monitor the open circuit (OC) voltage of piezoelectric transducer (PZT) during Energy Harvesting (EH). Simulation shows the maximum MPPT efficiency can reach up to 99.1% and the Figure of Merit (FoM) factor can achieve 6.4. The measurements confirm the simplicity and efficiency of the proposed MPPT solution for the weakly-coupled piezoelectric energy harvesting (PEH). [ABSTRACT FROM AUTHOR]

A flexible micro-perforated material was fabricated for acoustic application in this study, which is different from the traditional perforated material whose general impression is rigid, dense and inflexible. The raw material is polyvinyl alcohol and develop into PVA nanofiber membranes by electrospinning. On this basis, flexible PVA micro-perforated membranes were fabricated through punching process. The structure combined nanofiber, porous material and perforated panel in an organic whole. And the effects of perforation rate, perforation diameter and cavity distance on the acoustic performance were studied in light of the experimental result. The acoustic-electric analogy model of the micro-perforated sound absorber was used for theoretical calculation and compared with the corresponding experimental results. As we studied, the flexible microperforated material had favorable sound absorption performance both in low and high frequency, which was a significant improvement over traditional perforated plate. Besides, the broadband sound absorption could be obtained with the properly selection and optimization of the structural parameters. These latent qualities of the flexible PVA micro-perforated membrane make it ideal for use in the noise reduction field as a flexible and lightweight acoustic material. [ABSTRACT FROM AUTHOR]

This systematic review and meta-analysis was performed to obtain updated evidence regarding the short-term effect of ozone on respiratory mortality in China. We systematically searched the Embase, PubMed, Scopus, Web of Science, China National Knowledge Internet, and Wanfang databases for relevant studies. After screening based on the inclusion criteria, 12 studies with 19 estimates were selected for further meta-analysis. The results revealed that respiratory mortality significantly increased by 0.55% (95% confidence interval: 0.24%–0.85%; Q = 39.47, I 2 = 54.4%, P = 0.002, tau 2 < 10−5) for every 10-μg/m3 increase in the maximum 8-h average concentration of ozone. Furthermore, differences in combined estimates were observed between various regions and lag structures. The combined effect of single-day lags was generally larger than that of multiday lags; the estimate of mortality for the population in the north was larger than that for the population in the south. The sensitivity analysis demonstrated that the main findings were stable; funnel plots with Egger's and Begg's tests indicated no significant publication bias in our analysis. [Display omitted] • Significant association was found between ozone and respiratory mortality. • The estimated risk in Northern China was larger than that in Southern China. • Higher estimated risk was found in the single-day lag structure. [ABSTRACT FROM AUTHOR]

Data centers are energy-intensive facilities, and their thermal environment and energy efficiency are key research areas. In this study, the airflow distribution and energy consumption of a campus data room were experimentally investigated, and the results pertaining to raised-floor (before retrofitting) and row-based (after retrofitting) cooling were compared. The thermal environment was evaluated in terms of the rack cooling index (RCI), return temperature index (RTI) and supply heat index (SHI), and the energy efficiency was estimated using the power usage effectiveness (PUE) and mechanical load component (MLC). The results indicated that row-based cooling corresponded to a better thermal environment and higher energy efficiency compared with those of raised-floor cooling. The SHI decreased from 0.79 to 0.31, and the difference in the PUE and MLC values before and after retrofitting was 0.27 and 0.14, respectively. These benefits can translate into a total energy saving of 110,829 kWh per year. However, row-based cooling involves certain limitations, such as the presence of vortexing airflow, uneven air supply temperature, and interaction among different modules, which must be further examined. This paper proposes an index that can be used to evaluate the interaction among different modules. • Experimentally investigates the thermal environment and energy consumption of a data room. • Compares the thermal and energy characteristics between raised-floor and row-based cooling. • Row-based cooling provides better performance vs. raised-floor cooling. • Some problems of the application of the row-based cooling are found. • An index is proposed to evaluate the degree of the interaction between different modules. [ABSTRACT FROM AUTHOR]

Urbanization results in a considerable economic disparity between urban and rural areas in developing countries, which has had a consequent significant impact on CO 2 emissions. To accommodate this directly, this paper presents a modified version of the Kaya Identity formula, U-Kaya, that includes a direct urbanization factor to determine the relationship between energy consumption intensity, population growth, urbanization rates, urban and rural GDP per capita and the volume of carbon emissions, for application in the dynamic forecasting of carbon emissions by Monte Carlo simulation. The method is demonstrated in forecasting China’s likely carbon emissions in 2020 by three different modes of urbanization policy: the government-dominant mode, market-dominant mode and a hybrid government market-dominant mode. The results indicate that a higher urbanization rate, energy carbon emission coefficient and energy intensity will lead to increased carbon emissions. Finally, three policy implications are identified, comprising the narrowing of the economic gap between urban and rural areas, adjustments to the energy structure and technical innovation, which will provide a valuable reference for developing countries in their efforts to reduce carbon emissions. [ABSTRACT FROM AUTHOR]

Chinese urbanization has generated great impacts on the world since the reform and opening up. However, urban problems, e.g., environmental pollution, resources shortage, and traffic jam, have been more and more serious for urban management and development. Smart city has been put forward as an effective approach to achieve better urban management recently. Smart city aims to realize the integration of municipal service, business, transportation, water, energy source and other urban sub-systems through close combination of human wisdom and information communication techniques (ICTs). As a result, the link and synergy of information could be ultimately established with ICTs, e.g., internet, internet of things, cloud computing. Yet, few studies have been conducted to systematically link smart city with big data in China. This paper aims to put forward a development framework of smart city with Chinese characteristics against the background of big data. Key actions, including rational planning of city infrastructures, the establishment and improvement of long-acting mechanism, the effective performance of city managerial function, are proposed to realize the development idea. Meanwhile, this paper also investigates the risks embedded in development of smart city with Chinese characteristics, e.g., information safety, weak emergency responding capacity and poor independent research and development capacity of core technology. This study can facilitate Chinese local governments to systematically plan smart city before clinging the hot concept in a rush. [ABSTRACT FROM AUTHOR]

The aim of this study was to address the problem of weighting disputes in the evaluation of rockburst-induced coal and gas outburst as well as to improve the rationality and accuracy of the risk identification results. Hence, we developed a risk identification method for rockburst-induced coal and gas outburst, considering the influence of multiple factors based on poset decision-making theory. The risk identification index system was established according to stress factors, gas factors, and physical and mechanical properties of coal, including 12 indexes and 4 risk grades. The poset adopted implicit weighting to store the weight information. The proposed method was applied to identify risks in an engineering case study. Thus, we determined the outburst risk grade and compared the case study results with the actual situation of the working surface. The comparison and analyses showed that the outburst risk grade of the case study working surface under gas factors was grade Ⅱ, the outburst risk grade under stress factors and the physical and mechanical properties of coal was grade Ⅲ, and the outburst risk grade under comprehensive factors was grade Ⅲ. The results of the risk identification of rockburst-induced coal and gas outburst based on poset were consistent with the results obtained by the method used in the case study and the actual situation of the working surface. This study extends the methods for accurately identifying risks of rockburst-induced coal and gas outburst and facilitates the formulation of effective preventive measures. [ABSTRACT FROM AUTHOR]

In recent years, China has undergone an extremely rapid phase of urbanization, which has caused many acute problems between urban and rural areas. This paper identifies three categories of social, economic and environmental conflict, and investigates their significance according to the views of two different populations using a questionnaire survey and interviews. Using fuzzy set theory, the key causes of urban-rural conflict related to urbanization in China are identified. The differences in urban and rural people's perceptions of these key factors are discussed and the factors underlying these perceptions are analyzed. [ABSTRACT FROM AUTHOR]

• The mass variation of all BFRP rebar types was similar in air atmosphere while Phenolic-BFRP rebars decomposed more slowly in nitrogen atmosphere. • Phenolic-BFRP rebars exhibited a much higher glass transition temperature (375 °C) which delayed the initiation of interfacial bonding failure up to 300 °C. • No reduction in tensile strength occurred in P-BFRP rebars up to 300 °C, while V-BFRP and E-BFRP rebars experienced a significant degradation of tensile strength at around 100 °C already. An experimental investigation was conducted on the thermophysical and thermomechanical properties of phenolic-basalt fiber-reinforced polymer (P-BFRP) rebars subjected to high temperature. As a comparison, vinyl-BFRP (V-BFRP) and epoxy-BFRP (E-BFRP) rebars were also investigated within the same program. The mass variation of all BFRP rebar types was similar in air atmosphere while P-BFRP rebars decomposed more slowly in nitrogen atmosphere. All BFRP rebar types were found to have a similar specific heat and thermal conductivity up to 350 °C. P-BFRP rebars exhibited a much higher glass transition temperature compared with the other two types of BFRP rebars. Three failure modes could be differentiated for all BFRP rebar types according to three temperature ranges, the latter were shifted to higher values for P-BFRP rebars. No reduction in tensile strength occurred in P-BFRP rebars up to 300 °C, while V-BFRP and E-BFRP rebars experienced a significant degradation of tensile strength at around 100 °C already. This advantage of P-BFRP rebars was mainly caused by the much higher T g which delayed the initiation of interfacial bonding failure up to 300 °C. The elastic modulus of all BFRP rebar types exhibited a similar degradation, which was caused by progressive fiber and fiber bundle failure due to non-uniform stress distributions. [ABSTRACT FROM AUTHOR]

Synchronized Switching Harvesting on Inductor (SSHI) and Synchronous Electric Charge Extraction (SECE) are two classic interface circuit techniques for Piezoelectric energy harvesting. But the former has high peak output power with narrow rectified voltage range, while the latter has wide rectified voltage range with lower peak output power. This paper presents a self-powered interface circuit for piezoelectric energy harvesting to achieve a good balance between the two. The proposed interface circuit is based on the Series-SSHI (S–SSHI) and SECE. The circuit proposed can harvest energy through S–SSHI and SECE in positive and negative half cycles, respectively. Moreover, the figure of merit (FOM), optimal rectified voltage range (ORVR) and region of interest (S RoI) of simulation and experiment results are discussed. The maximum FOM of the proposed circuit is as high as 2.15, which is 1.68 times that of the SECE, and it can reach 6 times the ORVR of the S–SSHI. S RoI factor of the proposed circuit show that the proposed method has better performance. In addition, the circuit shows a simpler implementation compared with state-of-the-art designs. [ABSTRACT FROM AUTHOR]

Current treatments for orthopaedic illnesses frequently result in poor prognosis, treatment failure, numerous relapses, and other unpleasant outcomes that have a significant impact on patients' quality of life. Cell-free therapy has emerged as one of the most promising options in recent decades for improving the status quo. As a result, using exosomes produced from various cells to modulate ferroptosis has been proposed as a therapeutic method for the condition. Exosomes are extracellular vesicles that secrete various bioactive chemicals that influence disease treatment and play a role in the genesis and progression of orthopaedic illnesses. Ferroptosis is a recently defined kind of controlled cell death typified by large iron ion buildup and lipid peroxidation. An increasing number of studies indicate that ferroptosis plays a significant role in orthopaedic illnesses. Exosomes, as intercellular information transfer channels, have been found to play a significant role in the regulation of ferroptosis processes. Furthermore, accumulating research suggests that exosomes can influence the course of many diseases by regulating ferroptosis in injured cells. In order to better understand the processes by which exosomes govern ferroptosis in the therapy of orthopaedic illnesses. This review discusses the biogenesis, secretion, and uptake of exosomes, as well as the mechanisms of ferroptosis and exosomes in the therapy of orthopaedic illnesses. It focuses on recent research advances and exosome mechanisms in regulating iron death for the therapy of orthopaedic illnesses. The present state of review conducted both domestically and internationally is elucidated and anticipated as a viable avenue for future therapy in the field of orthopaedics. [ABSTRACT FROM AUTHOR]

There is a large amount of population moved from countryside to cities in China during its urbanization in the past two decades. The majority of these people have no formal qualifications for city residency, and they are so-called ‘floating population’. The increase of this group of people has induced the pressure of land use in cities, and the contradiction between the demand and the supply of urban land has been intensifying particularly in those developed regions in China. This paper examines the impacts of floating population on urban land by presenting the interrelations between floating population and urban land expansion from the perspective of production land and living land. Structural equation model (SEM) is employed in conducting the analysis. The result shows that the floating population alone does not have direct effect on urban land expansion, but have indirect impacts through engaging in the production or living process. It is particularly interesting that floating people's living conditions have no direct positive effect on the increase of construction land. Based on the research results, suggestions are offered for improvements in government policy towards a more sustainable and integrated urbanization, including the provision of housing support, the formation of more urbanized society and sustainable development. [ABSTRACT FROM AUTHOR]

Particulate matter with a diameter of ≤2.5 μm (PM 2.5) is a critical air pollutant that adversely affects human health and the ecological environment. Using the data of daily air pollutant concentration and meteorological elements from 2013 to 2020 in Lanzhou, China, we employed the generalized additive model (GAM) and gradient boosting machine (GBM) approaches to analyze the relationship between PM 2.5 concentration and environmental factors. The results revealed that the annual average PM 2.5 concentration in Lanzhou, China, decreased by 3.98 μg/m3 per year during the study period and the variation of PM 2.5 concentration was influenced by many factors. Mean temperature, air pressure, relative humidity, and O 3 concentration had significantly negative effects on PM 2.5 concentration, whereas CO and NO 2 concentrations had significant positive effects. PM 2.5 concentration was also high during static winds or high-speed winds. Among these influencing factors, the interactions of meteorological factors and air pollution also had strong correlations with PM 2.5 concentration. We found that the multi-factor model could better explain the influence of environmental factors on PM 2.5 concentration than the single-factor model. The fitting degree of the GBM was better than that of the GAM model; their mean absolute errors were 11.30 and 11.85, respectively. We also found that the GBM model was more precise for estimating daily PM 2.5 concentration, whereas the GAM was more suitable for long-term trend analysis. • The variation of PM 2.5 concentration is influenced by multiple factors and their interactions. • The multi-factor model could better explain the influence of environmental factors on PM 2.5 concentration. • The fitting degree of the GBM was better than that of the GAM model. • GBM was more suitable for short-term prediction, whereas GAM was more suitable for long-term trend analysis. [ABSTRACT FROM AUTHOR]