Ultraviolet Circularly Polarized Luminescence in Chiral Perovskite Nanoplatelet-Molecular Hybrids: Direct Binding Versus Efficient Triplet Energy Transfer.

The development of ultraviolet circularly polarized light (UVCPL) sources has the potential to benefit plenty of practical applications but remains a challenge due to limitations in available material systems and a limited understanding of the excited state chirality transfer. Herein, by constructing hybrid structures of the chiral perovskite CsPbBr3 nanoplatelets and organic molecules, excited state chirality transfer is achieved, either via direct binding or triplet energy transfer, leading to efficient UVCPL emission. The underlying photophysical mechanisms of these two scenarios are clarified by comprehensive optical studies. Intriguingly, UVCPL realized via the triple energy transfer, followed by the triplet-triplet annihilation upconversion processes, demonstrates a 50-fold enhanced dissymmetry factor glum. Furthermore, stereoselective photopolymerization of diacetylene monomer is demonstrated by using such efficient UVCPL. This study provides both novel insights and a practical approach for realizing UVCPL, which can also be extended to other material systems and spectral regions, such as visible and near-infrared.

Starch-mediated colloidal chemistry for highly reversible zinc-based polyiodide redox flow batteries.

Aqueous Zn-I flow batteries utilizing low-cost porous membranes are promising candidates for high-power-density large-scale energy storage. However, capacity loss and low Coulombic efficiency resulting from polyiodide cross-over hinder the grid-level battery performance. Here, we develop colloidal chemistry for iodine-starch catholytes, endowing enlarged-sized active materials by strong chemisorption-induced colloidal aggregation. The size-sieving effect effectively suppresses polyiodide cross-over, enabling the utilization of porous membranes with high ionic conductivity. The developed flow battery achieves a high-power density of 42 mW cm-2 at 37.5 mA cm-2 with a Coulombic efficiency of over 98% and prolonged cycling for 200 cycles at 32.4 Ah L-1posolyte (50% state of charge), even at 50 °C. Furthermore, the scaled-up flow battery module integrating with photovoltaic packs demonstrates practical renewable energy storage capabilities. Cost analysis reveals a 14.3 times reduction in the installed cost due to the applicability of cheap porous membranes, indicating its potential competitiveness for grid energy storage.

Study on the Impact of Dietary Patterns on Cardiovascular Metabolic Comorbidities among Adults.

Background: The prevalence of cardiovascular metabolic comorbidities (CMM) among adults is relatively high, imposing a heavy burden on individuals, families, and society. Dietary patterns play a significant role in the occurrence and development of CMM. This study aimed to identify the combined types of CMM in adult populations and investigate the impact of dietary patterns on CMM. Methods: Participants in this study were from the sixth wave of the China Health and Nutrition Survey (CHNS). Dietary intake was assessed using a three-day 24-hour dietary recall method among 4,963 participants. Latent profile analysis was used to determine dietary pattern types. Two-step cluster analysis was performed to identify the combined types of CMM based on the participants' conditions of hyperuricemia, dyslipidemia, diabetes, renal dysfunction, hypertension, and stroke. Logistic regression analysis with robust standard errors was used to determine the impact of dietary patterns on CMM. Results: Participants were clustered into three dietary patterns (Pattern 1 to 3) and five CMM types (Class I to V). Class I combined six diseases, with a low proportion of diabetes. Class II also combined six diseases but with a high proportion of diabetes. Class III combined four diseases, with a high proportion of hypertension. Class IV combined three diseases, with the highest proportions of hyperuricemia, diabetes, and renal dysfunction. Class V combined two diseases, with high proportions of dyslipidemia and renal dysfunction. Patients with Class III CMM had a significantly higher average age than the other four classes (P ≤ 0.05). Compared to those with isolated dyslipidemia, individuals with a low-grain, high-fruit, milk, and egg (LCHFM) dietary pattern had a higher risk of developing dyslipidemia combined with renal dysfunction (Class V CMM) with an odds ratio of 2.001 (95% CI 1.011-3.960, P≤ 0.05). Conclusion: For individuals with isolated dyslipidemia, avoiding a low-grain, high-fruit, milk, and egg (LCHFM) dietary pattern may help reduce the risk of developing dyslipidemia combined with renal dysfunction (Class V CMM).

Halide Exchange in Perovskites Enables Bromine/Iodine Hybrid Cathodes for Highly Durable Zinc Ion Batteries.

With the increasing need for reliable storage systems, the conversion-type chemistry typified by bromine cathodes attracts considerable attention due to sizeable theoretical capacity, cost efficiency, and high redox potential. However, the severe loss of active species during operation remains a problem, leading researchers to resort to concentrated halide-containing electrolytes. Here, profiting from the intrinsic halide exchange in perovskite lattices, a novel low-dimensional halide hybrid perovskite cathode, TmdpPb2[IBr]6, which serves not only as a halogen reservoir for reversible three-electron conversions but also as an effective halogen absorbent by surface Pb dangling bonds, C─H…Br hydrogen bonds, and Pb─I…Br halogen bonds, is proposed. As such, the Zn||TmdpPb2[IBr]6 battery delivers three remarkable discharge voltage plateaus at 1.21 V (I0/I-), 1.47 V (I+/I0), and 1.74 V (Br0/Br-) in a typical halide-free electrolyte; meanwhile, realizing a high capacity of over 336 mAh g-1 at 0.4 A g-1 and high capacity retentions of 88% and 92% after 1000 cycles at 1.2 A g-1 and 4000 cycles at 3.2 A g-1, respectively, accompanied by a high coulombic efficiency of ≈99%. The work highlights the promising conversion-type cathodes based on metal-halide perovskite materials.

Inhibiting Residual Solvent Induced Side Reactions in Vinylidene Fluoride-Based Polymer Electrolytes Enables Ultra-Stable Solid-State Lithium Metal Batteries.

Residual solvents in vinylidene fluoride (VDF)-based solid polymer electrolytes (SPEs) have been recognized as responsible for their high ionic conductivity. However, side reactions by the residual solvents with the lithium (Li) metal induce poor stability, which has been long neglected. This study proposes a strategy to achieve a delicate equilibrium between ion conduction and electrode stability for VDF-based SPEs. Specifically, 2,2,2-trifluoro-N,N-dimethylacetamide (FDMA) is developed as the nonside reaction solvent for poly(vinylidene fluoride-co-hexafluoropropylene) (PVHF)-based SPEs, achieving both high ionic conductivity and significantly improved electrochemical stability. The developed FDMA solvent fosters the formation of a stable solid electrolyte interphase (SEI) through interface reactions with Li metal, effectively mitigating side reactions and dendrite growth on the Li metal electrode. Consequently, the Li||Li symmetric cells and Li||LiFePO4 cells demonstrate excellent cycling performance, even under limited Li (20 µm thick) supply and high-loading cathodes (>10 mg cm-2, capacity >1 mAh cm-2) conditions. The stable Li||LiCoO2 cells operation with a cutoff voltage of 4.48 V indicates the high-voltage stability of the developed SPE. This study offers valuable insights into the development of advanced VDF-based SPEs for enhanced lithium metal battery performance and longevity.

Quantifying Asymmetric Zinc Deposition: A Guide Factor for Designing Durable Zinc Anodes.

Zinc metal is recognized as the most promising anode for aqueous energy storage but suffers from severe dendrite growth and poor reversibility. However, the coulombic efficiency lacks specificity for zinc dendrite growth, particularly in Zn||Zn symmetric cells. Herein, a novel indicator (fD) based on the characteristic crystallization peaks is proposed to evaluate the growth and distribution of zinc dendrites. As a proof of concept, triethylenetetramine (TETA) is adopted as an electrolyte additive to manipulate the zinc flux for uniform deposition, with a corroborating low fD value. A highly durable zinc symmetric cell is achieved, lasting over 2500 h at 10 mA cm-2 and 400 h at a large discharge of depth (10 mA cm-2, 10 mAh cm-2). Supported by the low fD value, the Zn||TETA-ZnSO4||MnO2 batteries overcome the sudden short circuit and fast capacity fading. The study provides a feasible method to evaluate zinc dendrites and sheds light on the design of highly reversible zinc anodes.

The effects of living arrangements and leisure activities on depressive symptoms of Chinese older adults: Evidence from panel data analysis.

BACKGROUND: Livable environment and ways, as the necessary conditions for the elderly to enjoy their old age, have a significant impact on their mental health and happiness. It's crucial to understand how living arrangements affect depressive symptoms in China. Studies on how various leisure activities modify this association are yet limited. METHODS: This study relies on panel data derived from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), collected during waves spanning 2008/2009, 2011/2012, 2014, and 2018. The primary objective is to examine the relationship between living arrangements, leisure activities, and depressive symptoms of elderly individuals. Linear mixed-effects models were used to analyze the data. RESULTS: A total of 26,342 observations aged 65 and over were included in this paper. Older adults living alone (ß = 0.66, 95 % CI: 0.55, 0.76) or living in institutions (ß = 0.69, 95 % CI: 0.40, 0.98) had more depressive symptoms than those living with family. Leisure activities were negatively associated with depressive symptoms (ß = -0.16, 95 % CI: -0.18, -0.15). Moreover, there was significant interactions between living arrangements and leisure activities. No matter which kind of living arrangements, participating in physical, productive or social activity was associated with a lower risk of depressive symptoms. LIMITATIONS: Study design might introduce bias, and it cannot establish causality between the tested variables. CONCLUSIONS: Older adults living alone or in institutions have more possibility to develop depressive symptoms than those living with family, and such a relationship among Chinese older adults can be moderated by participating in leisure activities.

Dual-Atom Co/Ni Electrocatalyst Anchored at the Surface-Modified Ti3C2Tx MXene Enables Efficient Hydrogen and Oxygen Evolution Reactions.

Dual-atom catalytic sites on conductive substrates offer a promising opportunity for accelerating the kinetics of multistep hydrogen and oxygen evolution reactions (HER and OER, respectively). Using MXenes as substrates is a promising strategy for depositing those dual-atom electrocatalysts, if the efficient surface anchoring strategy ensuring metal-substrate interactions and sufficient mass loading is established. We introduce a surface-modification strategy of MXene substrates by preadsorbing L-tryptophan molecules, which enabled attachment of dual-atom Co/Ni electrocatalyst at the surface of Ti3C2Tx by forming N-Co/Ni-O bonds, with mass loading reaching as high as 5.6 wt %. The electron delocalization resulting from terminated O atoms on MXene substrates, N atoms in L-tryptophan anchoring moieties, and catalytic metal atoms Co and Ni provides an optimal adsorption strength of intermediates and boosts the HER and OER kinetics, thereby notably promoting the intrinsic activity of the electrocatalyst. CoNi-Ti3C2Tx electrocatalyst displayed HER and OER overpotentials of 31 and 241 mV at 10 mA cm-2, respectively. Importantly, the CoNi-Ti3C2Tx electrocatalyst also exhibited high operational stability for both OER and HER over 100 h at an industrially relevant current density of 500 mA cm-2. Our study provided guidance for constructing dual-atom active metal sites on MXene substrates to synergistically enhance the electrochemical efficiency and stability of the energy conversion and storage systems.