Robust Ru/Ce@Co Catalyst with an Optimized Support Structure for Propane Oxidation.

Short carbon chain alkanes, as typical volatile organic compounds (VOCs), have molecular structural stability and low molecular polarity, leading to an enormous challenge in the catalytic oxidation of propane. Although Ru-based catalysts exhibit a surprisingly high activity for the catalytic oxidation of propane to CO2 and H2O, active RuOx species are partially oxidized and sintered during the oxidation reaction, leading to a decrease in catalytic activity and significantly inhibiting their application in industrial processes. Herein, the Ru/Ce@Co catalyst is synthesized with a specific structure, in which cerium dioxide is dispersed in a thin layer on the surface of Co3O4, and Ru nanoparticles fall preferentially on cerium oxide with high dispersity. Compared with the Ru/CeO2 and Ru/Co3O4 catalysts, the Ru/Ce@Co catalyst demonstrates excellent catalytic activity and stability for the oxidation of propane, even under severe operating conditions, such as recycling reaction, high space velocity, a certain degree of moisture, and high temperature. Benefiting from this particular structure, the Ru/Ce@Co (5:95) catalyst with more Ce3+ species leads to the Ru species being anchored more firmly on the CeO2 surface with a low-valent state and has a strong potential for adsorption and activation of propane and oxygen, which is beneficial for RuOx species with high activity and stability. This work provides a novel strategy for designing high-efficiency Ru-based catalysts for the catalytic combustion of short carbon alkanes.

Highly Efficient Oxidation of Propane at Low Temperature over a Pt-Based Catalyst by Optimization Support.

Pt-based catalysts have attracted widespread attention in environmental protection applications, especially in the catalytic destruction of light alkane pollutants. However, developing a satisfying platinum catalyst with high activity, excellent water-resistance, and practical suitability for hydrocarbon combustion at low temperature is challenging. In this study, the Pt catalyst supported on the selected Nb2O5 oxide exhibited an efficient catalytic activity in propane oxidation and exceeded that of most catalysts reported in the literature. More importantly, the Pt/Nb2O5 catalyst maintained excellent activity and durability even after high-temperature aging at 700 °C and under harsh working conditions, such as a certain degree of moisture, high space velocity, and composite pollutants. The excellent performance of the Pt/Nb2O5 catalyst was attributed to the abundant metallic Pt species stabilized on the surface of Nb2O5, which prompted the C-H bond dissociation ability as the rate-determining step. Furthermore, propane was initially activated via oxidehydrogenation and followed the acrylate species path as a more efficient propane oxidation path on the Pt/Nb2O5 surface. Overall, Pt/Nb2O5 can be considered a promising catalyst for the catalytic oxidation of alkanes from industrial sources and could provide inspiration for designing superb catalysts for the oxidation of light alkanes.

The tailored synthesis of nanosized SAPO-34 via time-controlled silicon release enabled by an organosilane precursor.

Phenyltrimethoxysilane as a Si source can significantly slow down the crystallization process for SAPO-34 synthesis, leading to the formation of agglomerated nanocrystals (<100 nm). The obtained nanosized SAPO-34 shows enhanced catalytic stability in methanol-to-olefin conversion under industrially relevant conditions.

Time and energy-efficient homogeneous transesterification of cellulose under mild reaction conditions.

In this research, cellulose aliphatic esters (CEs) were synthesized efficiently in an N, N-dimethylacetamide/lithium chloride system (DMAc/LiCl) with vinyl esters (VEs, number of carbon atoms ranging from 4 to 12) as acylation reagent and 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU) as catalyst. The structures and properties of the products have been characterized by various analytical techniques. The key concept in this cellulose modification was the achievement the degree of substitution (DS) >2.75 at much milder temperature and shorter reaction time (under 30°C within 15min-30min), other than previous research. Generally, the DS of obtained CEs showed a reverse trend with the length of the aliphatic chain increasing. The priority of reactions in three positions of the CEs followed the same order of C6>C2>C3 for a homogeneous conversion. There was no decrease of molecule weight under this mild reaction. This research provides a novel homogeneous technology to synthesize various CEs efficiently.

Realizing both selective adsorption and efficient regeneration using adsorbents with photo-regulated molecular gates.

A new generation of smart adsorbents was designed by grafting photo-responsive molecules onto the pore entrances of mesoporous silica. These molecules act as the gates of the mesopores, which are reversibly closed/opened upon light irradiation. Our smart adsorbents thus realize both selective adsorption and efficient desorption, which is highly expected for adsorption but impossible for traditional adsorbents with fixed pore entrances.

Promoter Hypermethylation of FANCF and Susceptibility and Prognosis of Epithelial Ovarian Cancer.

OBJECTIVE: To assess the 5' CpG island methylation of Fanconi anemia, complementation group F (FANCF) gene in epithelial ovarian cancer (EOC) tissues and normal ovarian tissues and to investigate the relationship between FANCF methylation and clinicopathologic features and prognosis of EOC. METHODS: The experiment was performed with 112 EOC tissue samples (case group) and 60 normal ovarian tissues (control group). With methylation-specific polymerase chain reaction (MSP), FANCF methylation status of cases and controls was assessed. And the association between FANCF methylation and the clinicopathological features of EOC was investigated with univariate survival analysis and Cox regression model analysis. RESULTS: The methylation-positive rate of the case group was significantly higher than that of the control group (P = 0.015). The FANCF promoter methylation rates showed significant differences in the comparisons stratified by age, International Federation of Gynecology and Obstetrics (FIGO) staging, histopathological classification, and lymph node metastasis (all P < .05). Univariate survival analysis showed there were significant differences in mean survival time between the groups based on FIGO staging, histopathological classification, lymph node metastasis, and FANCF methylation (all P < .05). Cox regression model analysis suggested that FIGO staging and FANCF methylation were independent risk factors for EOC prognosis. CONCLUSION: CpG island methylation of FANCF gene promoter region is strongly associated with the susceptibility and clinicopathologic features of EOC. The FIGO staging and FANCF methylation are independent risk factors for EOC prognosis.

Systems biochemical responses of rats to Kansui and vinegar-processed Kansui exposure by integrated metabonomics.

ETHNOPHARMACOLOGICAL RELEVANCE: The dried root of Kansui (Euphorbia kansui L.) is an effective and commonly used traditional Chinese medicine. Even so, Kansui cannot be satisfactorily applied clinically because of toxic side effects. In China, the most common Kansui-processing method uses vinegar to reduce its toxicity. The present study was designed to investigate the toxic effects caused by Kansui and evaluate detoxification of Kansui by vinegar processing of Kansui. MATERIALS AND METHOD: Thirty male Sprague Dawley (SD) rats were randomly assigned to five groups of six rats. Two experimental groups were oral gavaged with 7.875 and 15.75 g Kansui/kg body weight, two treated with 7.875 and 15.75 g VP-Kansui/kg body weight for 14 d, and the control group concurrently subjected to oral gavage with only distilled water. On day 14, plasma, liver and kidney tissues were collected from all rats for biochemistry assessments, histopathological examination, and NMR analyses. RESULTS: The metabonome of rats treated with Kansui and vinegar-processed (VP-) Kansui was found to differ from that of controls. In liver extracts, the variational metabolites included elevated concentrations of isoleucine, leucine, valine, glutamate, and phenylalanine, with decreased taurine, glucose, and glycogen. However, changes in lysine, methionine, choline, phosphorylcholine, and tyrosine were only observed in Kansui-treated rats. In kidney extracts, prominent changes included elevations in isoleucine, leucine, valine, methionine, creatine/creatinine, and phenylalanine as well as decreased glutamine. Only Kansui treatment induced variations in alanine, lysine, acetate, choline, and phosphorylcholine. CONCLUSION: Perturbations in endogenous metabolites induced by Kansui correlated with disturbances in glycolysis and amino acid and lipid metabolism, while biochemical pathway disorders caused by VP-Kansui only involved glycolysis and amino acid metabolism. All results were confirmed by histopathological examination of liver and kidney tissues and clinical biochemistry analyses.

1H NMR-based metabonomics study of the urinary biochemical changes in Kansui treated rat.

ETHNOPHARMACOLOGICAL RELEVANCE: The dried root of Kansui (Euphorbia kansui L.) is a commonly used and effective traditional Chinese medicine (TCM). AIM OF THE STUDY: We combined the urinary metabolites alteration and traditional assays of Kansui-induced rats to discuss the mechanism of toxicity of Kansui. MATERIALS AND METHODS: The Sprague-Dawley rats were dosed with 7.875g Kansui/kg weight and 15.75g Kansui/kg weight. Urine samples were collected at day -1 (before treatment), and days 7, 14 and 21 for NMR analysis. Plasma and liver and kidney tissues were collected at day 14 for biochemical assays and histopathological examination, respectively. RESULTS: The metabonome of rats treated with Kansui differed markedly from that of the controls. This was confirmed by the histopathology of liver and kidney tissue and clinical biochemistry analysis. The toxicity of Kansui accumulated with dosing time, and persisted even when treatment was stopped. The corresponding biochemical pathways alterations included inhibited TCA cycle, increased anaerobic glycolysis, and perturbed amino acids metabolism. CONCLUSION: The biochemical pathways disorder conjunction with histopathology changes provides new clues to evaluate the toxicity of Kansui from a systematic and holistic view.