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Layered transition metal dichalcogenides are of intensive interest for potassium‐ion batteries (PIBs) due to their high theoretical capacity, relatively low working potential, and layered structures. However, the limited interlayer spacing poses challenges in accommodating large‐radius potassium ions, significantly affecting their rate and cycling performances, particularly for selenide counterparts. Herein, a class of the strongly coupled NbSe2 nanosheets (NSs)/graphene (G) heterostructure with expanded interlayer spacings and high electron conductivity for boosting the performance of potassium storage is reported. NbSe2 NSs/G delivers a reversible capacity of 348.4 mAh g−1 at 0.05 A g−1, exceptional rate performance (117.5 mAh g−1 at an ultrahigh current density of 10.0 A g−1), and excellent cycle stability (capacity retention of 167.8 mAh g−1 after 2350 cycles under 2.0 A g−1), placing it among the top performers in reported TMD‐based PIB anodes. In situ XRD and Raman measurements reveal the intercalation‐based mechanism in NbSe2 NSs/G and the introduction of graphene can alleviate the severe volume change, making it possess superior rate performance and cycle stability Prominently, full‐cell PIBs employing NbSe2 NSs/G anodes demonstrate remarkable rate capability, and achieve a high energy density of 103.0 Wh kg−1 and a high power density of 1140.6 W kg−1. [ABSTRACT FROM AUTHOR]

The shape of nanochannels plays a crucial role in the ion selectivity and overall performance of reverse electrodialysis (RED) systems. However, current research on two-dimensional nanochannel shapes is largely limited to a few fixed asymmetric forms. This study explores the impact of randomly shaped nanochannels using dimensionless methods, controlling their randomness by varying their length and shape amplitude. The research systematically compares how alterations in the nanochannel length and shape amplitude influence various system performance parameters. Our findings indicate that increasing the nanochannel length can significantly enhance the system performance. While drastic changes in the nanochannel shape amplitude positively affect the system performance, the most significant improvements arise from the interplay between the nanochannel length and shape amplitude. This compounding effect creates a local optimum, resulting in peak system performance. Within the range of dimensionless lengths from 0 to 30, the system reaches its optimal performance at a dimensionless length of approximately 25. Additionally, we explored two other influencing factors: the nanochannel surface charge density and the concentration gradient of the solution across the nanochannel. Optimal performance is observed when the nanochannel has a high surface charge density and a low concentration gradient, particularly with random shapes. This study advances the theoretical understanding of RED systems in two-dimensional nanochannels, guiding research towards practical operational conditions. [ABSTRACT FROM AUTHOR]

Background and Aims Emerging evidence has raised an obesity paradox in observational studies of body mass index (BMI) and health among the oldest-old (aged ≥80 years), as an inverse relationship of BMI with mortality was reported. This study was to investigate the causal associations of BMI, waist circumference (WC), or both with mortality in the oldest-old people in China. Methods A total of 5306 community-based oldest-old (mean age 90.6 years) were enrolled in the Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 1998 and 2018. Genetic risk scores were constructed from 58 single-nucleotide polymorphisms (SNPs) associated with BMI and 49 SNPs associated with WC to subsequently derive causal estimates for Mendelian randomization (MR) models. One-sample linear MR along with non-linear MR analyses were performed to explore the associations of genetically predicted BMI, WC, and their joint effect with all-cause mortality, cardiovascular disease (CVD) mortality, and non-CVD mortality. Results During 24 337 person-years of follow-up, 3766 deaths were documented. In observational analyses, higher BMI and WC were both associated with decreased mortality risk [hazard ratio (HR) 0.963, 95% confidence interval (CI) 0.955–0.971 for a 1-kg/m2 increment of BMI and HR 0.971 (95% CI 0.950–0.993) for each 5 cm increase of WC]. Linear MR models indicated that each 1 kg/m2 increase in genetically predicted BMI was monotonically associated with a 4.5% decrease in all-cause mortality risk [HR 0.955 (95% CI 0.928–0.983)]. Non-linear curves showed the lowest mortality risk at the BMI of around 28.0 kg/m2, suggesting that optimal BMI for the oldest-old may be around overweight or mild obesity. Positive monotonic causal associations were observed between WC and all-cause mortality [HR 1.108 (95% CI 1.036–1.185) per 5 cm increase], CVD mortality [HR 1.193 (95% CI 1.064–1.337)], and non-CVD mortality [HR 1.110 (95% CI 1.016–1.212)]. The joint effect analyses indicated that the lowest risk was observed among those with higher BMI and lower WC. Conclusions Among the oldest-old, opposite causal associations of BMI and WC with mortality were observed, and a body figure with higher BMI and lower WC could substantially decrease the mortality risk. Guidelines for the weight management should be cautiously designed and implemented among the oldest-old people, considering distinct roles of BMI and WC. [ABSTRACT FROM AUTHOR]

Objective: The associations between plasma vitamin B12 level and anemia under different dietary patterns in elderly Chinese people are poorly understood. We aimed to examine the associations between plasma vitamin B12 levels and anemia under different dietary patterns in adults aged 65 years and older in nine longevity areas in China. Methods: A total of 2405 older adults completed a food frequency questionnaire at the same time as a face-to-face interview. The dietary diversity score (DDS) was assessed based on the food frequency questionnaire, with the low DDS group referring to participants with a DDS score ≤ 4 points. Vitamin B12 levels were divided into two groups of high (>295 pg/mL) and low (≤ 295 pg/mL) with the median used as the cut-off point. Sub-analyses were also performed on older adults divided into tertiles of vitamin B12 levels: low (< 277 pg/mL), medium (277–375 pg/mL) and high (> 375 pg/mL) to study the association of these levels with anemia. Results: Six hundred ninety-five (28.89%) of these people were diagnosed with anemia and had a mean age of 89.3 years. Higher vitamin B12 levels were associated with a decreased risk of anemia (multi-adjusted OR, 0.59, [95% CI, 0.45 ~ 0.77] P < 0.001) in older adults with a low DDS, whereas no significant association between vitamin B12 levels and anemia was found in older adults with a high DDS in a full-model after adjustment for various confounding factors (multi-adjusted OR, 0.88, [95% CI, 0.65 ~ 1.19], P = 0.41). Conclusion: The relationship between vitamin B12 levels and the prevalence of anemia was significant only when the level of dietary diversity in the older adults was relatively low. The dietary structure of the population should be taken into consideration in combination in order to effectively improve anemia status by supplementing vitamin B12. [ABSTRACT FROM AUTHOR]

Background and Objectives Physical function deterioration is always accompanied by a cognitive decline in older adults. However, evidence is lacking for the long-term simultaneous changing patterns of cognition and physical frailty and their associations with mortality among older adults. Research Design and Methods This study included 8,231 adults aged ≥65 with a baseline and at least one follow-up assessment of both cognition and physical frailty from the 2007–2018 Chinese Longitudinal Healthy Longevity Survey. Physical frailty (FRAIL phenotype) and cognition (Mini-Mental State Examination) were applied. Group-based joint trajectory modeling was used to fit the joint trajectories of cognition and physical frailty. Cox proportional hazards model was used to evaluate the trajectory-mortality associations. Results Three distinct joint trajectories were identified: no joint progression (34.4%), moderate joint progression (47.0%), and rapid joint progression (18.6%). During a median follow-up of 8.3 years, the rapid joint progression group, compared to the no joint progression , had the highest risk for all-cause mortality (hazard ratio (HR), 3.37 [95% CI: 2.99–3.81]), cardiovascular (CVD) mortality (3.21 [2.08–4.96]) and non-CVD mortality (2.99 [2.28–3.92]), respectively. Joint trajectory was found to be more predictive of mortality as compared to baseline measures of cognition and/or frailty (C -statistic ranged from 0.774 to 0.798). Higher changing rates of cognition and frailty were observed among all-cause decedents compared to CVD and non-CVD decedents over a 45-year span (aged 65–110) before death. Discussion and Implications Our study suggested that subjects with the worst cognitive decline and severest physical frailty progression were at the highest risk for all-cause and cause-specific mortality. Our findings expand the limited prior knowledge on the dynamic course of cognition and frailty. [ABSTRACT FROM AUTHOR]