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Heterogeneous uptake of SO.sub.2 on mineral dust is a predominant formation pathway of sulfates, whereas the contribution of photo-induced SO.sub.2 oxidation to sulfates on the dust interfaces still remains unclear. Here, we investigated heterogeneous photochemical reactions of SO.sub.2 on five mineral oxides (SiO.sub.2, kaolinite, Al.sub.2 O.sub.3, MgO, and CaO) without photocatalytic activity. Light enhanced the uptake of SO.sub.2, and its enhancement effects negatively depended on the basicity of mineral oxides. The initial uptake coefficient (γ.sub.0,BET) and the steady-state uptake coefficient (γ.sub.s,BET) of SO.sub.2 positively relied on light intensity, relative humidity (RH), and O.sub.2 content, while they exhibited a negative relationship with the initial SO.sub.2 concentration. Rapid sulfate formation during photo-induced heterogeneous reactions of SO.sub.2 with all mineral oxides was confirmed to be ubiquitous, and H.sub.2 O and O.sub.2 played key roles in the conversion of SO.sub.2 to sulfates. In particular, triplet states of SO.sub.2 (.sup.3 SO.sub.2) were suggested to be the trigger for photochemical sulfate formation. Atmospheric implications supported a potential contribution of interfacial SO.sub.2 photochemistry on non-photoactive mineral dust to atmospheric sulfate sources.

SO.sub.2 and NO.sub.2 are the critical precursors in forming sulfate and nitrate in ambient particles. We studied the mechanism of sulfate and nitrate formation during the co-uptake of NO.sub.2 and SO.sub.2 into NaCl droplets at different RHs under irradiation and dark conditions. A significant formation of nitrate attributable to NO.sub.2 hydrolysis was observed during the NO.sub.2 uptake under all conditions, and its formation rate increases with decreasing RH. The averaged NO.sub.2 uptake coefficient, γNO2, from the unary uptake of NO.sub.2 into NaCl droplets under dark conditions is 1.6 x 10.sup.-5, 1.9 x 10.sup.-5, and 3.0 x 10.sup.-5 at 80 %, 70 %, and 60 % RH, respectively. Chloride photolysis and nitrate photolysis play a crucial role in sulfate formation during the co-uptake. Nitrate photolysis generates reactive species (e.g., OH radicals, NO.sub.2, and N(III)) that directly react with S(IV) to produce sulfate. The OH radicals generated from nitrate photolysis can also react with chloride ions to form reactive chlorine species and then sulfate. To parameterize the role of nitrate photolysis and chloride photolysis in forming sulfate, the SO.sub.2 uptake coefficient, γSO2, as a function of the nitrate photolysis rate, PNO3- (jNO3- x [NO3-]), and chloride photolysis rate, PCl- (jCl- x [Cl.sup.- ]), was derived as γSO2 = 0.41 x PNO3- + 0.34 x PCl-. Our findings open up new perspectives on the formation of secondary aerosol from the combined effect of nitrate photolysis and chlorine chemistry.

The durability of C[sub.3]S-C[sub.3]A paste with varied C[sub.3]A content (0%, 5%, 10%, and 20%) against sulfate attack at various attack ages (3 d, 7 d, 28 d, and 180 d) was investigated in this study through the examinations of corrosion product composition, Ca/Si and Al/Si of calcium-(aluminum)-silicate-hydrate (C-(A)-S-H) gel, formation and evolution of microstructure, migration and transformation of Al containing phase products, and pore structure. The results indicated that sulfate attack can promote the hydration reaction in C[sub.3]S-C[sub.3]A paste, thus accelerating the production of C-(A)-S-H gel in the paste. With the increase of C[sub.3]A content, the acceleration effect becomes more significant. In addition, sulfate attack led to the dealumination and decalcification of C-(A)-S-H gel, resulting in the reduction of the gelling power of C-(A)-S-H gel. The degree of dealumination and decalcification of C-(A)-S-H gel increases with the increase of C3A content. At the same time, free Al and Ca promote the formation of expansive products such as ettringite and gypsum. Finally, under the action of sulfate, the pore characterization of C[sub.3]S-C[sub.3]A paste deteriorated, showing a decrease in specific surface area, cumulative pore volume and average pore diameter.

New 4-(benzoxazol-2-yl)phenyl 3-((3-chloro-1,4-naphthoquinon-2-yl)amino)phenyl sulfate was synthesized via the SuFEx click reaction between fluorosulfate-containing 1,4-naphthoquinone and 2-(4-hydroxyphenyl)benzoxazole. 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was used as an organic base, while triethylamine was inactive in this reaction.

Heparan and chondroitin sulfate proteoglycans (HSPGs and CSPGs, respectively) regulate numerous cell surface signaling events, with typically opposite effects on cell function. CSPGs inhibit nerve regeneration through receptor protein tyrosine phosphatase sigma (RPTPσ). Here we report that RPTPσ acts bimodally in sensory neuron extension, mediating CSPG inhibition and HSPG growth promotion. Crystallographic analyses of a shared HSPG-CSPG binding site reveal a conformational plasticity that can accommodate diverse glycosaminoglycans with comparable affinities. Heparan sulfate and analogs induced RPTPσ ectodomain oligomerization in solution, which was inhibited by chondroitin sulfate. RPTPσ and HSPGs colocalize in puncta on sensory neurons in culture, whereas CSPGs occupy the extracellular matrix. These results lead to a model where proteoglycans can exert opposing effects on neuronal extension by competing to control the oligomerization of a common receptor.

Background The quality of colonoscopy is significantly influenced by the effectiveness of bowel preparation. In this study, we aimed to evaluate the efficacy, safety, and tolerability of bowel cleansing between a new oral sulfate solution (OSS) and standard polyethylene glycol electrolyte powder (PEG). Methods This single center, randomized, superiority study recruited 679 outpatients who were assigned to either the new OSS group (Group A) or standard PEG group (Group B). The quality of bowel cleansing was evaluated using the Boston Bowel Preparation Scale (BBPS) and compared between the two groups. Furthermore, data pertaining to the duration of bowel preparation, patient tolerability, and the occurrence of adverse events were also analyzed. Results According to BBPS scores, group A demonstrated significantly higher bowel preparation cleanliness than group B. Additionally, group A achieved superior bowel cleansing, as evidenced by a greater proportion of patients with BBPS scores ≥ 8 compared to group B (75.3% vs. 55.2%, P  < 0.05). No severe adverse events were reported during examinations in either group. Conclusions The magnesium sulfate, sodium sulfate, and potassium sulfate concentrated oral solution is a novel, safe, and effective bowel preparation for colonoscopy. Trial registration This study was registered in the Chinese Clinical Trial Registry on 20/02/2024 (clinical trial registration number: ChiCTR2400081004).

Although glycosaminoglycans contribute to diverse physiological processes 1 , 2 , 3 , 4 , an understanding of their molecular mechanisms has been hampered by the inability to access homogeneous glycosaminoglycan structures. Here, we assembled well-defined chondroitin sulfate oligosaccharides using a convergent, synthetic approach that permits installation of sulfate groups at precise positions along the carbohydrate backbone. Using these defined structures, we demonstrate that specific sulfation motifs function as molecular recognition elements for growth factors and modulate neuronal growth. These results provide both fundamental insights into the role of sulfation and direct evidence for a 'sulfation code' whereby glycosaminoglycans encode functional information in a sequence-specific manner analogous to that of DNA, RNA and proteins.