Pilot Trial on the Efficacy and Safety of a Natural Mineral Water Rich in Hydrogen Carbonate on Functional Dyspepsia and Heartburn

Background: Dyspepsia and heartburn are among the most frequent complaints of the upper gastrointestinal tract impacting quality of life. The present study aimed to investigate the impact of drinking a natural mineral water (medicinal product category “Heilwasser” in Germany) high in hydrogen carbonate (Staatl. Fachingen STILL) on functional dyspeptic complaints and heartburn. Methods: 56 men and women with self-reported heartburn were enrolled to this one-arm pilot study. They had to drink 1.5 L of a hydrogen carbonate rich mineral water each day over a course of six weeks. Participants reported the number and duration of heartburn episodes in a daily dairy. The Reflux Disease Questionnaire (RDQ), Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD) and the Gastrointestinal Quality of Life Index (GILQI) were used to assess the therapeutic course of the treatment and the Short Form Health Survey (SF-12) to assess general quality of life. Mean ± standard deviation were calculated and pre- and post-treatment changes were compared using the Wilcoxon test. Results: The consumption of a hydrogen carbonate rich mineral water decreased the number of heartburn episodes per week significantly by 4.8 ± 8.2 at the end of the study (p < 0.001). The duration of episodes was also significantly reduced by 25.7 minutes after six weeks of intervention (p < 0.001). Accordingly, the subjectively perceived severity of heartburn, regurgitation and dyspeptic complaints as well as the GERD dimension as assessed by Reflux Disease Questionnaire improved significantly. There was a significant improvement in the disease-specific quality of life as measured by the Gastrointestinal Quality of Life Index (p < 0.001) and by the Quality Of Life in Reflux and Dyspepsia (p < 0.001) questionnaires and the general health-related quality of life as assessed by SF-12 (p < 0.007). Conclusions: The present pilot study provides evidence that supplementation with natural mineral water rich in hydrogen carbonate may improve heartburn and dyspeptic symptoms, which finally resulted in an improvement of the subjectively perceived quality of life. Drinking mineral water rich in hydrogen carbonate may be an alternative remedy for the treatment of dyspeptic symptoms and heartburn. Trial Registration: Eudra CT No 2013-001256-36.

Efficacy and tolerability of hydrogen carbonate-rich waterfor heartburn

AIM To investigate the efficacy and safety of mineralwater with a high content of hydrogen carbonate inpatients with heartburn.METHODS： This open, single-center, single-armclinical pilot study enrolled 50 patients, 18-64 yearsold, who had been suffering from heartburn at leasttwice a week for at least 3 mo before entering thestudy. Pharmacological treatment of heartburn was notpermitted, and patients with severe organic diseaseswere excluded. After a run-in period of one week, theparticipants received 1.5 L of the test water for thefollowing 6 wk; 300 mL with meals t.i.d., the remainderto be drunk throughout the day. During the trial, therewere five visits at the study center （screening, baseline,two interim visits and the final visit）. The efficacyendpoints included incidence and duration of heartburnepisodes per week by patient＇s self-assessment （heartburndiary） as well as changes in symptom severity asper symptom specific questionnaires [Reflux Disease Questionnaire （RDQ）; Quality of Life in Reflux andDyspepsia （QOLRAD）; Gastrointestinal Quality of LifeIndex] and overall health-related quality of life per SF-12（12-question short form） at each visit. At the end of thestudy, patients and investigators independently ratedthe overall efficacy of the test water on a 4-point Likertscale. Safety was assessed by evaluation of adverseevents （AEs）, vital signs （heart rate, blood pressure）and laboratory parameters. Changes from initial to finalexaminations were assessed by the non-parametricWilcoxon test; categorical variables were comparedusing the χ 2 test, and for more than 5 categories, by theU-test.RESULTS： Twenty-eight participants were men, 22women. The mean age of the patients in the fullanalysis set/intention-to treat population （FAS/ITT） was40.6 years. Forty-two participants completed the studyaccording to the study protocol and formed the perprotocolset （PP population）; 48 participants drank thewater at least once as requested and were analyzedas ITT population. The occurrence of heartburn wasstatistically significantly reduced at wk 6 in both the ITTand the PP populations. At wk 6, the mean number ofheartburn episodes/week decreased by 5.1 episodes（P 〈 0.001） and the mean duration of heartburnsymptoms by 19 min （ITT） （P = 0.002）. The frequencyof heartburn symptoms was reduced in 89.6% of thepatients （P 〈 0.001）, and the duration of symptoms in79.2% of patients （ITT） （P 〈 0.001）. All dimensions ofthe RDQ （heartburn, regurgitation, gastro-esophagealreflux disease symptoms, dyspepsia） showed asignificant improvement at 6 wk. Likewise, diseasespecificquality of life improved significantly （QOLRAD,GIQLI）. Overall, 89.4% of patients rated the efficacyof the test water as ＂good＂ or ＂very good＂, as did theinvestigators for 91.5% of the patients. There wereno serious AEs. After 6 wk, systolic and diastolic bloodpressure values decreased slightly but significantly [-3.5and -3.0 mmHg, respectively （P = 0.008 and P = 0,002）].Ninety-six percent of patients and investigators for thesame percentage of patients rated the tolerability of thewater as ＂good＂ or ＂very good＂.CONCLUSION： The data demonstrate effectiveness ofa hydrogen carbonate-rich mineral water in alleviatingheartburn frequency and severity, thereby improvingquality of life. The water has excellent tolerability.

Microencapsulation of Sodium Hydrogen Carbonate to Generate Carbon Dioxide with Thermal Responsible Shell Material

This paper tried to develop the optimum procedure for microencapsulating water soluble solid powder with the thermal responsible material by the melting dispersion cooling method. Sodium hydrogen carbonate was adopted as a water soluble solid powder instead of microencapsulating carbon dioxide gas. The shell material was composed of olefin wax and α-tocopherol. In the experiment, the concentration of oil soluble surfactant and the water soluble surfactant species were changed. Sodium hydrogen carbonate was treated in the aqueous solution dissolving the water soluble surfactant to form the finer sodium hydrogen carbonate powder and to increase the content. The microencapsulation efficiency could be increased with the concentration of oil soluble surfactant and considerably increased by treating sodium hydrogen carbonate with the water soluble surfactant. Sodium hydrogen carbonate was protected well from environmental water. The microcapsules showed the thermal responsibility to generate carbon dioxide.

Experimental investigation on the origin of carbonaceous materials in the fault zone of the Wenchuan earthquake

Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains unclear.In this study,we proposed a novel hypothesis for the formation of carbonaceous materials in fault gouge.Thus,we conducted a CO_(2) hydrogenation experiment in a high-temperature reactor at a co-seismic temperature,with fault gouge formed during the Wenchuan earthquake as the catalyst.Our experimental results demonstrate that carbonaceous materials in fault zones are formed on the fault gouge during the chemical reaction process,suggesting that the carbonaceous materials are possibly generated from the catalytic hydrogenation of CO_(2),followed by thermal cracking of its products.The results of this study provide a theoretical basis for understanding fault behavior and earthquake physics.

Pt nanoparticles entrapped in ordered mesoporous carbons:An efficient catalyst for the liquid-phase hydrogenation of nitrobenzene and its derivatives

Pt nanoparticles entrapped in ordered mesoporous CMK-3 carbons with p6mm symmetry were prepared using a facile impregnation method, and the resulting materials were characterized using X-ray diffraction spectroscopy, N2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The Pt nanoparticles were highly dispersed in the CMK-3 with 43.7% dispersion. The Pt/CMK-3 catalyst was an effective catalyst for the liquid-phase hydrogenation of nitrobenzene and its derivatives under the experimental conditions studied here. The Pt/CMK-3 catalyst was more active than commercial Pt/C catalyst in most cases. A highest turnover frequency of 43.8 s-1 was measured when the Pt/CMK-3 catalyst was applied for the hydrogenation of 2-methyl-nitrobenzene in ethanol under optimal conditions. It is worthy of note that the Pt/CMK-3 catalyst could be recycled easily, and could be reused at least fourteen times without any loss in activity or selectivity for the hydrogenation of nitrobenzene in ethanol.

Catalytic methanol decomposition to carbon monoxide and hydrogen over Pd/CeO_2-ZrO_2-La_2O_3 with different Ce/Zr molar ratios

Hairong Wang, Yaoqiang Chen, Qiulin Zhang, Qingchao Zhu, Maochu Gong, Ming Zhao（ Key Laboratory of Green Chemistry ＆ Technology of Ministry Education, College of Chemistry, Sichuan University, Chengdu 610064, Sichuan, China

An efficient and stable Cu/SiO_2 catalyst for the syntheses of ethylene glycol and methanol via chemoselective hydrogenation of ethylene carbonate

The efficient synthesis of methanol and ethylene glycol via the chemoselective hydrogenation of ethylene carbonate（EC） is important for the sustainable utilization of CO_2 to produce commodity chemicals and fuels. In this work, a series of β-cyclodextrin-modified Cu/SiO_2 catalysts were prepared by ammonia evaporation method for the selective hydrogenation of EC to co-produce methanol and ethylene glycol. The structure and physicochemical properties of the catalysts were characterized in detail by N_2 physisorption, XRD, N_2O titration, H_2-TPR, TEM, and XPS/XAES. Compared with the unmodified 25 Cu/SiO_2 catalyst, the involvement of β-cyclodextrin in 5β-25 Cu/SiO_2 could remarkably increase the catalytic activity—excellent activity of 1178 mgEC g_（cat）^（–1） h^（–1） with 98.8%ethylene glycol selectivity, and 71.6% methanol selectivity could be achieved at 453 K. The remarkably improved recyclability was primarily attributed to the remaining proportion of Cu~＋/（Cu^0＋Cu~＋）. Furthermore, the DFT calculation results demonstrated that metallic Cu^0 dissociated adsorbed H_2, while Cu~＋ activated the carbonyl group of EC and stabilized the intermediates. This study is a facile and efficient method to prepare highly dispersed Cu catalysts—this is also an effective and stable heterogeneous catalyst system for the sustainable synthesis of ethylene glycol and methanol via indirect chemical utilization of CO_2.

Comparative Study of Hydrogen and Carbon Isotopic Composition of Gases Generated from the Pyrolysis of a Peat under Saltwater and Freshwater Conditions

To understand the influence of the diagenetic water medium on the isotopic compositions of thermogenic coalbed gas, both hydrous and anhydrous closed-system pyrolyses were performed at temperatures of 250°C to 650°C on an herbaceous marsh peat. Compared to the results of anhydrous pyrolysis, the hydrocarbon gases generated from hydrous pyrolyses have very different hydrogen isotopic compositions. However, the carbon isotopic compositions of the hydrocarbon gases became only slightly heavier in hydrous pyrolysis, compared to that from anhydrous pyrolysis. With the progress of thermal evolution from peat to a more advanced thermal maturity of vitrinite reflectance values（Ro） of 5.5% during the pyrolysis, the difference in the average δD value increased from 52‰ to 64‰ between the hydrous pyrolysis with saltwater and anhydrous pyrolysis and increased from 18‰ to 29‰ between the hydrous pyrolysis with freshwater and anhydrous pyrolysis, respectively. The difference in the average δ^（13）C value was only 1‰–2‰ between the hydrous and anhydrous pyrolysis. The relationships between the δD values of the generated hydrocarbon gases and Ro values as well as among δD values of the hydrocarbon gas species are established. The close relationships among these parameters suggest that the water medium had a significant effect on the hydrogen isotopic composition and a minimal effect on the carbon isotopic composition of the hydrocarbon gases. The results of these pyrolyses may provide information for the understanding of the genesis of coalbed gas from herbaceous marsh material with the participation of different diagenetic water media.

Influence of Microwave Power on the Properties of Hydrogenated Diamond-Like Carbon Films Prepared by ECR Plasma Enhanced DC Magnetron Sputtering

Electron cyclotron resonance （ECR） plasma was applied to enhance the direct current magnetron sputtering to prepare hydrogenated diamond-like carbon （H-DLC） films. For different microwave powers, both argon and hydrogen gas are introduced separately as the ECR working gas to investigate the influence of microwave power on the microstructure and electrical property of the H-DLC films deposited on P-type silicon substrates. A series of characterization methods including the Raman spectrum and atomic force microscopy are used. Results show that, within a certain range, the increase in microwave power affects the properties of the thin films, namely the sp3 ratio, the hardness, the nanoparticle size and the resistivity all increase while the roughness decreases with the increase in microwave power. The maximum of resistivity amounts to 1.1×10^9 Ω.cm. At the same time it is found that the influence of microwave power on the properties of H-DLC films is more pronounced when argon gas is applied as the ECR working gas, compared to hydrogen gas.

Catalytic Performance of Carbon Materials Supported Pd Nanoparticles in Selective Hydrogenation of Acetylene

Pd/C catalysts were prepared by deposited Pd nanoparticles （NPs） on different carbon supports including activated carbon （AC）, graphite oxide （GO）, and reduced graphite oxide （rGO） using sol-immobilization method. Through transmission electron microscopy, powder X-ray di raction, and X-ray photoelectron spectroscopy, the role of the carbon supports for the catalytic performances of Pd/C catalysts was examined in selective hydrogenation of acetylene. The results indicate that Pd/AC exhibited higher activity and selectivity than Pd/GO and Pd/rGO in the gas phase selective hydrogenation of acetylene. Thermal and chemical treatment of AC supports also have some effect on the catalytic performance of Pd/AC catalysts. The differences in the activity and selectivity of various Pd/C catalysts were partly attributed to the metal-support interaction.

A new kinetic model for direct CO2 hydrogenation to higher hydrocarbons on a precipitated iron catalyst:Effect of catalyst particle size

The kinetic of the direct COhydrogenation to higher hydrocarbons via Fischer–Tropsch synthesis（FTS）and reverse water-gas shift reaction（RWGS） mechanisms over a series of precipitated Fe/Cu/K catalysts with various particle sizes was studied in a well mixed, continuous spinning basket reactor. The iron catalysts promoted with copper and potassium were prepared via precipitation technique in various alcohol/water mixtures to achieve a series of catalyst particle sizes between 38 and 14 nm. A new kinetic model for direct COhydrogenation was developed with combination of kinetic model for FTS reaction and RWGS equilibrium condition. For estimate of structure sensitivity of indirect COhydrogenation to higher hydrocarbons, the kinetic parameters of developed model are evaluated for a series of iron catalysts with various particle sizes. For kinetic study a wide range of syngas conversions have been obtained by varying experimental conditions. The results show that the new developed model fits favorably with experimental data. The values of activation energies for indirect COhydrogenation reaction are fall within the narrow range of 23–16 kJ/mol.

THE IMPROVEMENT OF ELECTRON FIELD EMISSION FROM AMORPHOUS CARBON FILMS DUE TO HYDROGEN PLASMA CHEMICAL ANNEALING EFFECT

Hydrogenated amorphous carbon films were fabricated by using layer-by-layer deposition method and hydrogen dilution method in a small d.c.-assisted plasma enhanced chemical vapor deposition system. It was found that the hydrogen plasma treatment could change the sp2/sp3 ratio to some extent by chemical etching. The improvements of field emission characteristics were observed compared with that from conventionally deposited a-C films, which can be attributed to the large field enhancement effect due to the inhomogeneous distribution of nanometer scale sp2 clusters and the reduction of the surface emission barrier due to the hydrogen termination.

CO_x-Free Hydrogen and Carbon Nanofibers Produced from Direct Decomposition of Methane on Nickel-Based Catalysts

Direct decomposition of methane was carried out using a fixed-bed reactor at 700 ℃ for the production of COx-free hydrogen and carbon nanofibers. The catalytic performance of NiO-M/SiO2 catalysts （where M=AgO, CoO, CuO, FeO, MnOx and MoO） in methane decomposition was investigated. The experimental results indicate that among the tested catalysts, NiO/SiO2 promoted with CuO give the highest hydrogen yield. In addition, the examination of the most suitable catalyst support, including Al2O3, CeO2, La2O3, SiO2, and TiO2, shows that the decomposition of methane over NiO-CuO favors SiOx support. Furthermore, the optimum ratio of NiO to CuO on SiO2 support for methane decomposition was determined. The experimental results show that the optimum weight ratio of NiO to CuO fell at 8：2 （w/w） since the highest yield of hydrogen was obtained over this catalyst.

Direct carbon dioxide hydrogenation to produce bulk chemicals and liquid fuels via heterogeneous catalysis

The hydrogenation of carbon dioxide(CO_(2))to produce chemicals and transportation liquid fuels in huge demand via heterogeneous thermochemical catalysis achieved using renewable energy has received increasing attention,and substantial advances have been made in this research field in recent years.In this study,we summarize our progress in the rational design and construction of highly efficient catalysts for CO_(2) hydrogenation to methanol,lower olefins,aromatics,and gasolineand jet fuel-range hydrocarbons.The structure‐performance relationship,nature of the active sites,and mechanism of the reactions occurring over these catalysts are explored by combining computational and experimental evidence.The results of this study will promote further fundamental studies and industrial applications of heterogeneous catalysts for CO_(2) hydrogenation to produce bulk chemicals and liquid fuels.

Effect of alkali metals on the performance of CoCu/TiO_2 catalysts for CO_2 hydrogenation to long-chain hydrocarbons

CoCu/TiO_2 catalysts promoted using alkali metals（Li, Na, K, Rb, and Cs） were prepared by the homogeneous deposition-precipitation method followed by the incipient wetness impregnation method. The influences of the alkali metals on the physicochemical properties of the CoCu/TiO_2 catalysts and the catalytic performance for CO_2 hydrogenation to long-chain hydrocarbons（C_（5＋））were investigated in this work. According to the characterization of the catalysts based on X-ray photoelectron spectroscopy, X-ray diffraction, CO_2 temperature-programmed desorption（TPD）, and H_2-TPD, the introduction of alkali metals could increase the CO_2 adsorption and decrease the H_2 chemisorption, which could suppress the formation of CH_4, enhance the production of C_（5＋）, and decrease the hydrogenation activity. Among all the promoters, the Na-modified CoCu/TiO_2 catalyst provided the maximum C_（5＋） yield of 5.4%, with a CO_2 conversion of 18.4% and C_（5＋） selectivity of42.1%, because it showed the strongest basicity and a slight decrease in the amount of H_2 desorption;it also exhibited excellent catalytic stability of more than 200 h.

Sulfonated carbon catalyzed oxidation of aldehydes to carboxylic acids by hydrogen peroxide

Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via the carbonization of starch followed by sulfonation with concentrated sulfuric acid. N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence and acid-base titration were used to characterize the obtained materials. The catalytic activity of sulfonated carbon was studied in the oxidation of aldehydes to carboxylic acids using 30 wt% H2O2 as oxidant. This oxidation protocol works well for various aldehydes including aromatic and aliphatic aldehydes. The sulfonated carbon can be recycled for three times without obvious loss of activity.

Catalytic carbon dioxide hydrogenation to methane: A review of recent studies

Recently, various efforts have been put forward on the development of technologies for the synthesis of methane from CO2 and H-2, since it can offer a solution for renewable H-2 storage and transportation. In parallel, this reaction is considered to be a critical step in reclaiming oxygen within a closed cycle. Over the years, extensive fundamental research works on CO2 methanation have been investigated and reported in the literatures. In this updated review, we present a comprehensive overview of recent publications during the last 3 years. Various aspects on this reaction system are described in detail, such as thermodynamic considerations, catalyst innovations, the influence of reaction conditions, overall catalytic performance, and reaction mechanism. Finally, the future development of CO2 methanation is discussed. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

Selective hydrogenation of biomass-derived 5-hydroxymethylfurfural using palladium catalyst supported on mesoporous graphitic carbon nitride

Selective hydrogenation of biomass-derived 5-hydroxymethylfurfural（HMF） to 2,5-dihydroxymethyltetrahydrofuran（DHMTHF） with 96% selectivity and a complete HMF conversion is obtained over palladium catalyst supported on mesoporous graphitic carbon nitride（Pd/mpg-C_3N_4） under pressured hydrogen atmosphere in aqueous media. The excellent catalytic performance of Pd/mpg-C_3N_4 is attributed to hydrogen bonding-related competitive interactions between reactant HMF and “intermediate” 2,5-dihydroxymethylfuran（DHMF） with the support mpg-C_3N_4, which leads to a deep hydrogenation of DHMF to DHMTHF.

Facile synthesis of molybdenum carbide nanoparticles in situ decorated on nitrogen-doped porous carbons for hydrogen evolution reaction

Molybdenum-based electrocatalysts are promising candidates of platinum (Pt)-based materials in electrocatalyzing hydrogen evolution reaction (HER), due to their cost-efficient and resembled electronic properties. Reported herein is the preparation of molybdenum carbide nanoparticles uniformly decorated on nitrogen-modified carbons (Mo2C/NC) through the carbonization of Mo-based polymers under hydrogen atmosphere by using poly(p-phenylenediamine) and ammonium heptamolybdate polymer analogue as precursors. And the molybdenum nitride nanoparticles loaded on porous N-doped carbons (Mo2N/NC) are also fabricated by calcination the polymer precursors in nitrogen gas. The Mo2C/NC shows more excellent electrocatalytic activity than Mo2N/NC in 0.5 M H2SO4, together with robust long-term durability. The well-crystalline nanoparticles and the increased electron conductivity are the main characters responded for the high catalytic efficiency of the fabricated electrocatalysts. This easily fabrication procedure may provide a facile route to prepare non-noble metal carbide/nitride catalysts featuring wellengineered structural and textural peculiarities for realistic energy conversion system.

Interaction of hydrogen molecules on Ni-doped single-walled carbon nanotube

Adsorption of hydrogen molecules on an Ni-doped （8,0） single-walled carbon nanotube （SWNT） is investigated by using first-principles density functional calculations. The result shows that a single Ni atom adsorbed on the bridge site of the tube could cannot dissociate the H2, however it can chemisorb three H2 at most, with the average binding energy per H2 suitable for the hydrogen storage at the room temperature. More H2 would physisorb around an Ni atom weakly. As for the SWNT with an Ni dimer adsorbed, we find that when the H2 approaches the Ni Ni bond, it dissociates without overcoming any barrier and makes bonds with Ni atom.