Helicobacter pylori in the population of the developmental age

Helicobacter pylori – Gram-negative rod, discovered more than 30 years ago, has a proven influence on inflammation of gastric and duodenal mucosa. The worldwide prevalence of H. pylori infection in the human population is estimated at 50% and is considered to be one of the most frequent bacterial infections in people. Many studies suggest that infection takes place in the early childhood within the family. The gastric mucosa is its natural habitat. In last time more and more findings about existence of this bacteria in another places of gastrointestinal tract and correlation with many diseases, especially an inflammation of oral cavity. The percentage of H. pylori detectability in the oral cavity ranges from 0 to 100%. Thus, more studies aimed at final determination of the bacterium reservoir in the oral cavity seem to be necessary

Supported H3PW12O40 for 2-propanol (photo-assisted) catalytic dehydration in gas-solid regime: the role of the support and of the pseudo-liquid phase in the (photo)activity

Catalytic and photocatalytic 2-propanol dehydration was carried out by using a supported Keggin heteropolyacid H3PW12O40(PW12). Binary materials were prepared by impregnation and/or solvothermal treatment by using commercial supports: SiO2(Mallinckrodt), TiO2(Evonik P25) and multiwall carbon nanotubes (Sunnano) or home solvothermically prepared SiO2and TiO2. All the materials have beencharacterized by X-ray diffraction (XRD), scanning electron microscopy observations (SEM) coupled withEDX microanalysis, specific surface area measurements, diffuse reflectance spectroscopy (DRS), FTIR and Raman spectroscopy. (Photo)catalytic 2-propanol dehydration was studied in gas-solid regime by using a continuous (photo)reactor working at atmospheric pressure and 80\u25e6C. FTIR spectra of the gas-phase over the PW12-support composites, where 2-propanol had been previously adsorbed, were recorded. Propene and diisopropyl ether were the main reaction products. For the continuous photo-assisted runsthe reactor was also illuminated with UV light. The apparent activation energy of 2-propanol catalytic and photocatalytic dehydration was determined in the range 60\u2013120\u25e6C.The irradiance increased significantly the dehydration reaction rate. Important differences were observed between the different supported materials. The Keggin heteropolyacid species played a keyrole both for the catalytic and the photo-assisted catalytic reactions; in fact, the acidity of the cluster accounts for the catalytic role, whereas both the acidity of the cluster and the oxidant ability of PW12wereresponsible for the increase of the reaction rate of the photo-assisted catalytic reaction. Moreover, thephoto-generated electrons on the solid semiconductor conduction band can account for a further increase of the reaction rate, when the heteropolyacid was supported on TiO2. Formation of a pseudo-liquid phase played an important role to determine the (photo)activit

Comparison between catalytic and photocatalytic activity in gas-solid regime of semiconductor oxides and carbon nanotubes supported Keggin heteropolyacid.

Catalytic and photocatalytic 2-propanol dehydration was carried out by using a supported Keggin heteropolyacid H3PW12O40 (PW12). Binary materials were prepared by impregnation and/or solvothermal treatment by using commercial supports: SiO2 (Mallinckrodt), TiO2 (Evonik P25) and multiwall carbon nanotubes (Sunnano) or home solvothermically prepared SiO2 and TiO2. All the materials have been characterized by X-ray diffraction (XRD), scanning electron microscopy observations (SEM) coupled with EDX microanalysis, specific surface area measurements, diffuse reflectance spectroscopy (DRS), FTIR and Raman spectroscopy. (Photo)catalytic 2-propanol dehydration was studied in gas-solid regime by using a continuous (photo)reactor working at atmospheric pressure and 80 \ub0C. FTIR spectra of the gas-phase over the HPA-support composites, where 2-propanol had been previously adsorbed, were recorded. Propene and diisopropyl ether were the main reaction products. For the continuous photo-assisted runs the reactor was also illuminated with UV light. The apparent activation energy of 2-propanol catalytic and photocatalytic dehydration was determined in the range 60-120 \ub0C. The irradiance increased significantly the dehydration reaction rate. Important differences were observed between the different supported materials. The Keggin heteropolyacid species played a key role both for the catalytic and the photo-assisted catalytic reactions; in fact, the acidity of the cluster accounts for the catalytic role, whereas both the acidity of the cluster and the oxidant ability of PW12 were responsible for the increase of the reaction rate of the photo-assisted catalytic reaction. Moreover, when the heteropolyacid was supported on TiO2 the photo-generated electrons on the solid semiconductor conduction band, can account for a further increase in the reaction rate. Formation of a pseudo-liquid phase played an important role to determine the (photo)activity

Confronto tra attività catalitica e fotocatalitica dell’eteropoliacido di Keggin H3PW12O40 supportato su ossidi o su nanotubi di carbonio

Catalytic and catalytic photo-assisted dehydration of 2-propanol to form propene in gas-solid regime at atmospheric pressure and 80°C was carried out by using a Keggin heteropolyacid H3PW12O40 (PW12) supported on different oxides. Binary materials have been prepared by impregnation of PW12 on different commercial and home prepared supports (TiO2, SiO2 or carbon nanotubes). The supported Keggin PW12 species played a key role both for the catalytic and the photo-assisted catalytic reactions, due to their strong acidity and ability to form strong oxidant species under UV irradiation, respectively. The contemporary presence of heat and UV light improved the activity of almost all POM supported materials