Science Bulletin最新文献

The prevalence of persistent organic pollutants in water bodies demands advanced oxidation processes that are both highly efficient and environmentally sustainable. Single-atom manganese catalysts can enable the green activation of peracetic acid (PAA), a promising alternative oxidant, but the catalytic performance is often limited by the inherent chemical inertness of the Mn sites. In this study, we modulated the electronic structure of the coordination microenvironment of ecofriendly and low-toxicity manganese single-atom catalysts through O doping. This strategy enhanced the electron delocalization ability of tricoordinated MnN₂O, established a built-in electric field to strengthen the Mn-O covalency, and significantly boosted its intrinsic mechanism for activating PAA to selectively generate singlet oxygen (¹O₂). The remarkable Fenton-like performance of MnN₂O was reflected by an 8.8-9.9 fold improvement in the bisphenol A (BPA) degradation kinetic rate. Moreover, the practical application potential of this proposed Fenton-like process is enhanced by the average BPA removal rate of 97.96% ± 2.65% for tap water and 95.46% ± 4.96% for the secondary effluent of a sewage treatment plant over 120 h in a continuous-flow device. Density functional theory calculations elucidated that the tricoordinated structure and electron delocalization of MnN₂O can effectively optimize the d-band electronic structure of adjacent Mn centers and promote the formation of ¹O₂ through a Mn-O covalence-dependent mechanism. This study breaks the symmetric coordination constraint to optimize the electron distribution, unlocking broad avenues for designing PAA-based Fenton-like process catalysts.

Aqueous Zn-I₂ batteries are promising candidates for large-scale energy storage owing to their high safety and low cost. However, uncontrolled zinc dendrite growth and severe polyiodide shuttle effects continue to hinder their long-term stability and Coulombic efficiency (CE). Here we report a unified quasi-solid electrolyte that simultaneously stabilizes both the Zn anode and the I₂ cathode. The polymeric matrix, constructed from quaternized chitosan and tannic acid, provides abundant hydroxyl and quaternary ammonium groups that coordinate Zn²⁺ and strongly immobilize polyiodide species through electrostatic and hydrogen-bonding interactions, thereby effectively suppressing the polyiodide shuttle. This dual regulation boosts the Zn²⁺ transference number to 0.55, suppresses interfacial side reactions, and mitigates dendrite growth. Consequently, Zn symmetric cells exhibit ultralong cycling stability over 2000 h at a low current density of 0.25 mA cm^-2, while Zn-I₂ full cells deliver a high average CE of 99.87% and stable cycling for 4000 cycles at 1 A g^-1. This work establishes a molecularly engineered quasi-solid electrolyte framework that bridges anode and cathode regulation, offering a general design principle to overcome the issues of dendrite growth and shuttle effect in aqueous metal-halogen batteries.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative therapy for severe aplastic anemia (SAA), with donor sources including matched sibling donors (MSDs), haploidentical donors (HIDs), and unrelated donors (URDs). However, the optimal criteria for donor selection remain undefined. We performed a multicenter retrospective study of 795 consecutive SAA patients who underwent allo-HSCT between 2012 and 2020 across 11 transplant centers in China. The overall survival (OS), failure-free survival (FFS), and GVHD-free/FFS (GFFS) rates were 85.2%, 83.6%, and 76.1%, respectively. Donor-related variables including relationship, age, sex match, blood type, and HLA mismatches were evaluated. Multivariable Cox regression identified donor age ≥50 years as an independent risk factor for inferior GFFS (HR = 2.13), OS (HR = 2.09), and FFS (HR = 2.18) (all P < 0.001). To directly compare the prognostic weight of donor age versus HLA compatibility, we stratified patients into four subgroups according to donor type (HID vs. MSD) and donor age (<50 vs. ≥50 years). Kaplan-Meier analysis with log-rank testing revealed that recipients of haploidentical grafts from younger donors achieved superior OS and FFS compared with those transplanted from older HLA-matched sibling donors. These findings demonstrate that donor age has a greater influence on transplant outcomes than HLA matching. With continuous improvements in haploidentical transplantation techniques, selecting younger haploidentical donors may represent a more favorable strategy than choosing older matched sibling donors.