Inhibiting effect of tungstic compounds on glucose hydrogenation over Ru/C catalyst

The effect of acid component including various conventional acids and tungstic compounds on glucose hydrogenation over a series of binary catalyst system containing Ru/C catalyst was investigated. The results showed that HC1, H2SO4, H3BO3, H3PO4, and HNO3 had negligible effect, while all the tungstic compounds imposed inhibiting effects on the hydrogenation of glucose over Ru/C catalyst, and the suppressing effect followed the order of H2WO4〉HPW〉WO3〉AMT〉HSiW. This order is the same as the order of ethylene glycol （EG） yields in the one-pot conversion of glucose to EG, suggesting the important role of competition between glucose hydrogenation and retro-aldol condensation in controlling the selectivity of EG.

Irritable bowel syndrome and small intestinal bacterial overgrowth:Meaningful association or unnecessary hype

Irritable bowel syndrome (IBS) is a common condition characterized by abdominal pain or discomfort, bloating, and altered stool form and passage. Small intestinal bacterial overgrowth (SIBO) is a condition in which there is overgrowth of bacteria in small bowel in excess of 105 colony forming units per milliliter on culture of the upper gut aspirate. Frequency of SIBO varied from 4%-78% among patients with IBS and from 1%-40% among controls. Higher frequency in some studies might be due to fallacious criteria [post-lactulose breath-hydrogen rise 20 PPM above basal within 90 min (early-peak)]. Glucose hydrogen breath test (GHBT) has a low sensitivity to diagnose SIBO. Hence, studies based on GHBT might have under-estimated frequency of SIBO. Therefore, it is important to analyze these studies carefully to evaluate whether the reported association between IBS and SIBO is over or under-projected. This review evaluates studies on association between SIBO and IBS, discordance between different studies, their strength and weakness including methodological issues and evidence on therapeutic manipulation of gut flora on symptoms of IBS.

Thiourea Based Conjugated Polymer Fluorescent Chemosensor for Cu^＋ and Its Use for the Detection of Hydrogen Peroxide and Glucose

A novel conjugated polymer, poly（1）, containing thiourea moieties in main chain is synthesized via Suzuki coupling reaction. The addition of cuprous ion quenches the fluorescence of poly（1）, whereas the fluorescence changes slightly upon addition of other metal ions, exhibiting the fluorescent almost turn-off sensing ability towards Cu~＋. When hydrogen peroxide was added to the solution containing poly（1） and Cu~＋, Cu~＋ was oxidized into Cu^（2＋）, resulting in the fluorescence recovery. The H_2O_2 released from glucose oxidation by glucose oxidase（GOD） also recovered the fluorescence of poly（1）/Cu~＋ solution. The results indicated that the poly（1）/Cu~＋ solution could serve as a sensing platform for hydrogen peroxide and glucose.