The Optimal Cut-off Value of Upper Arm Circumference and Calf Circumference for Assessing Sarcopenia Among Chinese Community-Dwelling Older Adults.

Objective: To explore the cut-off values and health evaluations of upper arm circumference (AC) and calf circumference (CC) on sarcopenia in Chinese community-dwelling older people. Methods: In this cross-sectional study, AC, CC, handgrip strength, muscle mass and gait speed were measured in 1537 Chinese community-dwelling older people in Sub-study 1. Correlation analysis, receiver operator characteristic curve (ROC curve) analysis, and consistency analysis were used for determination of AC and CC cut-off values for sarcopenia diagnosis (sarcopenia-AC and CC). Thereafter, 269 participants accepted additional assessments on physical function, body composition and muscle strength in Sub-study 2. T-test or Mann-Whitney U-test was used to explore the differential effects of sarcopenia-AC and CC on health indicators between sarcopenic and non-sarcopenic participants. Results: In Sub-study 1, the Area Under ROC (AUC) of AC and CC for sarcopenia screening were greater than 0.700 (P<0.05). The cut-off values, sensitivity and specificity of AC and CC on sarcopenia in males were 25.9 cm (86.0%, 83.6%) and 33.7 cm (90.7%, 81.4%) whereas in females were 26.5 cm (70.8%, 69.7%) and 33.0 cm (86.5%, 69.4%), respectively. In Sub-study 2, the participants with sarcopenia-AC or sarcopenia-CC showed lower muscle strength and lower fat and muscle mass than the ones without (P<0.05). Additionally, males instead of females with sarcopenia-AC or sarcopenia-CC showed worse performance in time-up and go test and 6-Minute Walk Test (P<0.05). However, the 30-second chair stand test was not different between participants with and without sarcopenia-AC or sarcopenia-CC in both sexes. Conclusion: We found accurate and Chinese population targeted cut-off values of AC and CC on sarcopenia diagnosis (25.9 cm and 33.7 cm in males; 26.5 cm and 33.0 cm in females) and a good evaluation effect of AC and CC on fat and muscle mass, muscle strength and physical functions in males, not females.

Long-Life Lead-Carbon Batteries for Stationary Energy Storage Applications.

Owing to the mature technology, natural abundance of raw materials, high recycling efficiency, cost-effectiveness, and high safety of lead-acid batteries (LABs) have received much more attention from large to medium energy storage systems for many years. Lead carbon batteries (LCBs) offer exceptional performance at the high-rate partial state of charge (HRPSoC) and higher charge acceptance than LAB, making them promising for hybrid electric vehicles and stationary energy storage applications. Despite that, adding carbon to the negative active electrode considerably enhances the electrochemical performance. However, carbon brings some adverse effects, such as the severe hydrogen evolution reaction (HER) in the NAM due to the low overpotential of carbon material, promoting severe water loss in LCBs. From a practical application point of view, the irreversible sulfation of the negative active material (NAM) and extreme shedding and softening of the positive active material (PAM) are the main obstacles for next-generation LCBs. Recently, a lead-carbon composite additive delayed the parasitic hydrogen evolution and eliminated the sulfation problem, ensuring a long life of LCBs for practical aspects. This comprehensive review outlines a brief developmental historical background of LAB, its shifting towards LCB, the failure mode of LAB, and possible potential solutions to tackle the failure problems. The detailed LCB's development towards long life was discussed in light of the reported literature to guide the researcher to date progress. More emphasis was directed toward the new applications of LCBs for stationary energy storage applications. Finally, state-of-the-art progress and further research gaps were pointed out for future work in this exciting era.

A New CuSe-TiO2-GO Ternary Nanocomposite: Realizing a High Capacitance and Voltage for an Advanced Hybrid Supercapacitor.

A high capacitance and widened voltage frames for an aqueous supercapacitor system are challenging to realize simultaneously in an aqueous medium. The severe water splitting seriously restricts the narrow voltage of the aqueous electrolyte beyond 2 V. To overcome this limitation, herein, we proposed the facile wet-chemical synthesis of a new CuSe-TiO2-GO ternary nanocomposite for hybrid supercapacitors, thus boosting the specific energy up to some maximum extent. The capacitive charge storage mechanism of the CuSe-TiO2-GO ternary nanocomposite electrode was tested in an aqueous solution with 3 M KOH as the electrolyte in a three-cell mode assembly. The voltammogram analysis manifests good reversibility and a remarkable capacitive response at various currents and sweep rates, with a durable rate capability. At the same time, the discharge/charge platforms realize the most significant capacitance and a capacity of 920 F/g (153 mAh/g), supported by the impedance analysis with minimal resistances, ensuring the supply of electrolyte ion diffusion to the active host electrode interface. The built 2 V CuSe-TiO2-GO||AC-GO||KOH hybrid supercapacitor accomplished a significant capacitance of 175 F/g, high specific energy of 36 Wh/kg, superior specific power of 4781 W/kg, and extraordinary stability of 91.3% retention relative to the stable cycling performance. These merits pave a new way to build other ternary nanocomposites to achieve superior performance for energy storage devices.

Highly Stable Low-Cost Electrochemical Gas Sensor with an Alcohol-Tolerant N,S-Codoped Non-Precious Metal Catalyst Air Cathode.

The emerging applications of electrochemical gas sensors (EGSs) in Internet of Things-enabled smart city and personal health electronics bring out a new challenge for common EGSs, such as alcohol fuel cell sensors (AFCSs) to reduce the dependence on a pricy Pt catalyst. Here, for the first time, we propose a low-cost novel N,S-codoped metal catalyst (FeNSC) to accelerate oxygen reduction reaction (ORR) and replace the Pt catalyst in the cathode of an AFCS. The optimal FeNSC shows high ORR activity, stability, and alcohol tolerance. Furthermore, the FeNSC-based AFCS not only demonstrates excellent linearity, low detection limit, high stability, and superior sensitivity to that of the commercial Pt/C-based AFCS but also outperforms commercial Pt/C-based AFCS in the exposed cell regarding great linearity, high sensitivity, and great stability. Such a promising sensor performance not just proves the concept of the FeNSC-based ACFS but enlightens the next-generation designs toward low-cost, highly sensitive, and durable EGSs.