The Distinctive Effects of Glucose-Derived Carbon on the Performance of Ni-Based Catalysts in Methane Dry Reforming

International audienceThis study aimed to investigate the effect of carbon derived from glucose (C) on the physicochemical characteristics and catalytic activity of Ni, supported over SiO2, ZSM-5, and TiO2 in methane dry reforming. Among the Ni catalysts without C, Ni/SiO2 exhibited the highest CH4-CO2 conversion and stability at all experimented temperatures. On the other hand, the C-incorporated catalysts prepared by glucose impregnation, followed by pyrolysis, showed dissimilar performances. C improved the stability of Ni/SiO2 in the reforming at 650 °C and 750 °C and increased the CH4 and CO2 conversion to the level close to the thermodynamic equilibrium at 850 °C. However, this element did not substantially affect the activity of Ni/ZSM-5 and exerted a retarding effect on Ni/TiO2. Characterizations with H2-TPD, XRD, EXAFS, and STEM-EDS revealed that the different influences of C by the supports were attributed to the extent of metal dispersion and metal-support interaction

Therapeutic effects of one-year alendronate treatment in three cases of osteoporosis with parietal thinning of skull

We studied the therapeutic effects of one-year alendronate treatment in three cases (two males and one female) of osteoporosis with parietal thinning of skull. Plain radiography and three dimensional computed tomography revealed asymmetric external thinning of the posteromedial part of the bilateral parietal bones. Technetium-99m methylenediphosphate bone scintigraphy did not show any changes in these three cases. Pretreatment levels of urinary type I collagen cross-linked N-telopeptides (NTX) in all three cases were high compared to the normal range. Pretreatment levels of serum bonespecific alkaline phosphatase (BAP) in the two male patients were high in contrast to the normal values in the female patient. Pretreatment mean bone mineral density (BMD) values of the 2nd to 4th lumbar vertebrae (L2-4BMD), head BMD, femoral neck BMD, and whole body BMD of all three patients were low compared with the respective normal ranges. One-year alendronate treatment decreased both urinary NTX and serum BAP in all three cases to normal values. Treatment also increased the whole body BMD in all three cases, the L2-4BMD of the female patient, the femoral neck BMD of the female patient and one male patient, and the head BMD of the female patient when compared to pretreatment levels

Local Resection by Combined Laparoendoscopic Surgery for Duodenal Gastrointestinal Stromal Tumor

Combined laparoendoscopic surgery is a novel surgical method which consists of both endoscopic surgery from inside the gastrointestinal tract and laparoscopic surgery from the outside. We report a case of duodenal GIST, in which combined laparoendoscopic local resection was attempted. The lesion was resected endoscopically using endoscopic submucosal dissection technique under laparoscopic assistance. Laparoscope was used for originating the orientation of the tumor, intra-operative EUS, and monitoring serosal injury from the peritoneal cavity. Postoperative hemorrhage occurred; however, precise orientation of the lesion helped us to manage the patient with minimal invasive reoperation. And thus, the bowel integrity was completely preserved, by avoiding segmental duodenal resection and pancreaticoduodenectomy. This novel, less invasive surgical procedure may become an attractive option for the lesions originating in the anatomically challenging portion of the GI tract for endoscopic or laparoscopic surgery alone

R : Homogeneous catalyst modifier for alkyne semi-hydrogenation : systematic screening in an automated flow reactor and computational study on mechanisms

The selectivity of palladium catalysed hydrogenation can be improved by adding a homogeneous modifier (or poison) such as quinoline to the reaction mixture. Although such selectivity improvement by modifiers (selective catalyst poisoning) has been known for decades, we still know little about them. We, ultimately, cannot select a modifier to improve a particular process. In this study, 21 types of modifiers are screened for the semi-hydrogenation of alkynes with varying catalyst type, reaction time, and target substrate using an automated flow reactor system. All of the studied variables changed affected hydrogenation activity and selectivity confirming the effectiveness of a multi-parameter optimization. 1,10-phenanthroline marked the best selectivity beyond quinoline. The density functional theory (DFT) calculations suggest that 1,10-phenanthroline has a remarkable ability to adsorb on the irregular surface of the catalyst that effects undesirable reaction

Mechanistic origins of accelerated hydrogenation of mixed alkylaromatics by synchronised adsorption over Rh/SiO2

Catalytic reactions of mixed substrates sometimes behave differently from those of individual substrates. For example, the hydrogenation of propylbenzene over Rh/SiO2 proceeds 120% faster in the presence of toluene. Such an acceleration effect does not agree with the well-accepted Langmuir–Hinshelwood reaction model. In this paper, we examined its mechanism experimentally and computationally. The hydrogenation experiment of vaporised aromatics confirmed that the acceleration was specific to the liquid phase with the isopropanol solvent. Direct adsorption measurements revealed that toluene adsorption synchronises with propylbenzene adsorption. Density functional theory calculations confirmed the associates of toluene and propylbenzene on the catalyst surface in the polar environment. The formation of associates increased the adsorption energy of toluene and decreased that of propylbenzene. Lowered adsorption energy reduces the activation barrier for catalytic reaction and intensifies the reaction rate beyond the Langmuir–Hinshelwood model prediction

Prolonged Tachycardia with Higher Heart Rate Is Associated with Higher ICU and In-hospital Mortality

Tachycardia is common in intensive care units (ICUs). It is unknown whether tachycardia or prolonged tachycardia affects patient outcomes. We investigated the association between tachycardia and mortality in critically ill patients. This retrospective cohort study’s primary outcome was patient mortality in the ICU and the hospital. We stratified the patients (n=476) by heart rate (HR) as LowHR, MediumHR, and HighHR groups. We also stratified them by their durations of HR >100 (prolonged HR; tachycardia): MildT, ModerateT, and SevereT groups. We determined the six groups’ mortality. The ICU mortality rates of the LowHR, MediumHR, and HighHR groups were 1.0%, 1.5%, and 7.9%, respectively; significantly higher in the HighHR vs. LowHR group. The in-hospital mortality rates of these groups were 1%, 4.5%, and 14.6%, respectively; significantly higher in the HighHR vs. LowHR group. The ICU mortality rates of the MildT, ModerateT, and SevereT groups were 0.9%, 5.6%, and 57.1%, respectively. The mortality of the HRT=0 (i.e., all HR ≤ 100) patients was 0%. The in-hospital mortality rates of the MildT, ModerateT, and SevereT groups were 1.8%, 16.7%, and 85.7%, respectively; that of the HRT=0 patients was 0.5%. Both higher HR and prolonged tachycardia were associated with poor outcomes