Synthesis of Unsymmetric Thiosulfonates Starting from N-Substituted O-Thiocarbamates: Easy Access to the S-SO2 Bond.

Using phenyliodine diacetate as an oxidant and nickel acetate as a promoter, a wide range of unsymmetric thiosulfonates could be furnished easily in moderate to excellent yields starting from N-substituted O-thiocarbamates and sodium sulfinates. This protocol features mild conditions, short reaction times, and high atomic utilization, which can provide an alternative method for the synthesis of unsymmetric thiosulfonates. In addition, the reaction could be scaled up on a gram scale, showing potential application value in industry.

Carboxymethyl chitosan composited poly(ethylene oxide) electrolyte with high ion conductivity and interfacial stability for lithium metal batteries.

Low ionic conductivity and poor interface stability of poly(ethylene oxide) (PEO) restrict the practical application as polymeric electrolyte films to prepare solid-state lithium (Li) metal batteries. In this work, biomass-based carboxymethyl chitosan (CMCS) is designed and developed as organic fillers into PEO matrix to form composite electrolytes (PEO@CMCS). Carboxymethyl groups of CMCS fillers can promote the decomposition of Lithium bis(trifluoromethane sulfonimide) (LiTFSI) to generate more lithium fluoride (LiF) at CMCS/PEO interface, which not only forms ionic conductive network to promote the rapid transfer of Li+ but also effectively enhances the interface stability between polymeric electrolyte and Li metal. The enrichment of carboxyl, hydroxyl, and amidogen functional groups within CMCS fillers can form hydrogen bonds with ethylene oxide (EO) chains to improve the tensile properties of PEO-based electrolyte. In addition, the high hardness of CMCS additives can also strengthen mechanical properties of PEO-based electrolyte to resist penetration of Li dendrites. LiLi symmetric batteries can achieve stable cycle for 2500 h and lithium iron phosphate full batteries can maintain 135.5 mAh g-1 after 400 cycles. This work provides a strategy for the enhancement of ion conductivity and interface stability of PEO-based electrolyte, as well as realizes the resource utilization of biomass-based CMCS.

Renewable galactomannan-based biogums with structure regulation to protect zinc metal anodes via blocking and confinement effect.

Galactomannan-based biogums were derived from fenugreek, guar, tara, and carob and consisted of mannose and galactose with different ratios, as well as the implementation of high-value utilization was very significant for sustainable development. In this work, renewable and low-cost galactomannan-based biogums were designed and developed as functional coatings protected on the Zn metal anodes. The molecule structure of galactomannan-based biogums were explored on the effect of anticorrosion ability and uniform deposition behavior through the introduction of fenugreek gum, guar gum, tara gum, and carob gum with different ratios of mannose to galactose as 1.2:1, 2:1, 3:1, and 4:1. The existence of biogum protective layers can reduce the contact area between Zn anodes and aqueous electrolyte to enhance the anticorrosion ability of Zn anodes. Rich oxygen-containing groups in galactomannan-based biogums can coordinate with Zn2+ and Zn atoms to form ion conductivity gel layer and adsorb closely on the surface of Zn metal, which can induce uniform deposition of Zn2+ to avoid dendrite growth. Zn electrodes protected by biogums can cycle impressively for 1980 h with 2 mA cm-2 and 2 mAh cm-2. This work can provide a novel strategy to enhance Zn metal anodes' electrochemical performance, as well as implement the high-value application of biomass-based biogums as functional coatings.

The timing of oesophageal dilatations in anastomotic stenosis after one-stage anastomosis for congenital oesophageal atresia.

BACKGROUND: In infants with congenital oesophageal atresia, anastomotic stenosis easily occurs after one-stage oesophageal anastomosis, leading to dysphagia. In severe cases, oesophageal dilatation is required. In this paper, the timing of oesophageal dilatation in infants with anastomotic stenosis was investigated through retrospective data analysis. METHODS: The clinical data of 107 infants with oesophageal atresia who underwent one-stage anastomosis in our hospital from January 2015 to December 2018 were retrospectively analysed. Data such as the timing and frequency of oesophageal dilatation under gastroscopy after surgery were collected to analyse the timing of oesophageal dilatation in infants with different risk factors. RESULTS: For infants with refractory stenosis, the average number of dilatations in the early dilatation group (the first dilatation was performed within 6 months after the surgery) was 5.75 ± 0.5, which was higher than the average of 7.40 ± 1.35 times in the normal dilatation group (the first dilatation was performed 6 months after the surgery), P = 0.038. For the infants with anastomotic fistula and anastomotic stenosis, the number of oesophageal dilatations in the early dilatation group was 2.58 ± 2.02 times, which was less than the 6.38 ± 2.06 times in the normal dilatation group, P = 0.001. For infants with non-anastomotic fistula stenosis, early oesophageal dilatation could not reduce the total number of oesophageal dilatations. CONCLUSION: Starting to perform oesophageal dilatation within 6 months after one-stage anastomosis for congenital oesophageal atresia can reduce the required number of dilatations in infants with postoperative anastomotic fistula and refractory anastomotic stenosis.