A method has been developed for the direct conversion of aldehydes to thioesters via integration of organocatalysis and electrosynthesis. The thiazolium precatalyst was found to facilitate oxidation ...of thiolate anions, leading to deleterious formation of disulfide byproducts. By circumventing this competing reaction, thioesters were obtained in good-to-excellent yields for a broad range of aldehyde and thiol substrates. This approach provides an atom-efficient thioesterification that circumvents the need for stoichiometric exogenous oxidants, high cell potentials, or redox mediators.
Organocatalyzed Anodic Oxidation of Aldehydes Finney, Eric E; Ogawa, Kelli A; Boydston, Andrew J
Journal of the American Chemical Society,
08/2012, Volume:
134, Issue:
30
Journal Article
Peer reviewed
A method for the catalytic formation of electroauxiliaries and subsequent anodic oxidation has been developed. The process interfaces N-heterocyclic carbene-based organocatalysis with electro-organic ...synthesis to achieve direct oxidation of catalytically generated electroactive intermediates. We demonstrate the applicability of this method as a one-pot conversion of aldehydes to esters for a broad range of aldehyde and alcohol substrates. Furthermore, the anodic oxidation reactions are very clean, producing only H2 gas as a result of cathodic reduction.
The probiotic Lactobacillus gasseri SBT2055 (LG2055) has a protective effect against metabolic syndrome in rats and humans. Metabolic syndrome increases the risk of type 2 diabetes mellitus. In this ...study, Goto-Kakizaki rats were used as a diabetic model and fed diets containing LG2055-fermented or nonfermented skim milk for 4 wk. Indices of diabetes such as blood glucose levels, serum glucagon levels, plasma levels of insulin, C-peptide, and glucagon-like peptide-1, tissue glycogen contents, and pancreatic mRNA levels were measured. The plasma C-peptide levels and pancreatic mRNA levels of insulin genes (Ins1 and Ins2) and Pdx1 (a transcriptional factor of insulin genes) were increased in LG2055 diet-fed rats. The increase in insulin secretion corresponded to an improvement in serum and pancreatic inflammatory status, associated with decreases in serum levels of serum amyloid P and pancreatic levels of granulocyte colony-stimulating factor. Insulin resistance in Goto-Kakizaki rats was ameliorated by increased glycogen storage in the liver and quadriceps femoris muscles and decreased serum free fatty acid levels. This improvement may be related to the increased cecal production of short-chain fatty acids. In conclusion, dietary LG2055 improved insulin secretion in diabetic rats by improving the inflammatory status in the pancreas and serum.
Dopamine in prefrontal cortices is implicated in cognitive and emotional functions, and the dysfunction of prefrontal dopamine has been associated with cognitive and emotional deficits in mental ...illnesses. These findings have led to clinical trials of dopamine-targeting drugs and brain imaging of dopamine receptors in patients with mental illnesses. Rodent studies have suggested that dopaminergic pathway projecting to the medial prefrontal cortex (mPFC) suppresses stress susceptibility. Although various types of mPFC neurons express several dopamine receptor subtypes, previous studies neither isolated a role of dopamine receptor subtype nor identified the site of its action in mPFC. Using social defeat stress (SDS) in mice, here we identified a role of dopamine D1 receptor subtype in mPFC excitatory neurons in suppressing stress susceptibility. Repeated social defeat stress (R-SDS) reduces the expression of D1 receptor subtype in mPFC of mice susceptible to R-SDS. Knockdown of D1 receptor subtype in whole neuronal populations or excitatory neurons in mPFC facilitates the induction of social avoidance by SDS. Single social defeat stress (S-SDS) induces D1 receptor-mediated extracellular signal-regulated kinase phosphorylation and c-Fos expression in mPFC neurons. Whereas R-SDS reduces dendritic lengths of mPFC layer II/III pyramidal neurons, S-SDS increases arborization and spines of apical dendrites of these neurons in a D1 receptor-dependent manner. Collectively, our findings show that D1 receptor subtype and related signaling in mPFC excitatory neurons mediate acute stress-induced dendritic growth of these neurons and contribute to suppression of stress susceptibility. Therefore, we propose that D1 receptor-mediated dendritic growth in mPFC excitatory neurons suppresses stress susceptibility.
We present measurements of bulk properties of the matter produced in Au+Au collisions at $\sqrt{s}$$_ {NN}$= 7.7, 11.5, 19.6, 27, and 39 GeV using identified hadrons (π±, K±, p, and $\bar{p}$) from ...the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (| y | < 0.1) results for multiplicity densities dN / dy, average transverse momenta $\langle$pT$\rangle$, and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.
Background/Objectives: In spite of the much evidence for the beneficial effects of probiotics, their anti-obesity effects have not been well examined. We evaluated the effects of the probiotic ...Lactobacillus gasseri SBT2055 (LG2055) on abdominal adiposity, body weight and other body measures in adults with obese tendencies. Subjects/Methods: We conducted a multicenter, double-blind, randomized, placebo-controlled intervention trial. Subjects (n=87) with higher body mass index (BMI) (24.2–30.7 kg/m2) and abdominal visceral fat area (81.2–178.5 cm2) were randomly assigned to receive either fermented milk (FM) containing LG2055 (active FM; n=43) or FM without LG2055 (control FM; n=44), and were asked to consume 200 g/day of FM for 12 weeks. Abdominal fat area was determined by computed tomography. Results: In the active FM group, abdominal visceral and subcutaneous fat areas significantly (P<0.01) decreased from baseline by an average of 4.6% (mean (confidence interval): −5.8 (−10.0, −1.7) cm2) and 3.3% (−7.4 (−11.6, −3.1) cm2), respectively. Body weight and other measures also decreased significantly (P<0.001) as follows: body weight, 1.4% (−1.1 (−1.5, −0.7) kg); BMI, 1.5% (−0.4 (−0.5, −0.2) kg/m2); waist, 1.8% (−1.7 (−2.1, −1.4) cm); hip, 1.5% (−1.5 (−1.8, −1.1) cm). In the control group, by contrast, none of these parameters decreased significantly. High-molecular weight adiponectin in serum increased significantly (P<0.01) in the active and control groups by 12.7% (0.17 (0.07, 0.26) μg/ml) and 13.6% (0.23 (0.07, 0.38) μg/ml), respectively. Conclusion: The probiotic LG2055 showed lowering effects on abdominal adiposity, body weight and other measures, suggesting its beneficial influence on metabolic disorders.
This study investigated the local failure of short polypropylene (PP) fiber-reinforced concrete (PPFRC) plates that were subjected to high-velocity impact using a steel projectile. To examine the ...differences in the mechanical properties of the PPFRC obtained under static and dynamic loadings, static and rapid-speed uniaxial compressive and tensile tests were conducted. Subsequently, high-velocity impact tests were conducted to investigate the impact resistance performance of the PPFRC plates. In a series of tests, a steel projectile, with a mass of 46 g, collided into a PPFRC plate, with a thickness of 60 mm or 80 mm. The impact velocity was set between 190 m/s and 420 m/s to examine the variation in the failure modes of the PPFRC plate. The experimental results revealed that the scabbing damage induced by the impact was significantly suppressed for the PPFRC plate compared with that of a plain concrete (PC) plate. High-velocity impact tests were also conducted on short PP fiber-reinforced mortar (PPFRM) plates to investigate how the matrix type influences the local failure. To evaluate the scabbing and perforation limit thicknesses of the PPFRC plates, we proposed an assessment method, in which the modified formula, developed by the US National Defense Research Committee (NDRC), is multiplied by a reduction factor. Furthermore, the relationship between the limit thickness of a PPFRC plate and the kinetic energy of a projectile was formulated based on the proposed method.
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To emphasize the coffee flavor, many milk coffee beverages contain coffee extracts; these are the so-called “rich milk coffee” beverages. When the content of the coffee extracts ...increases, milk coffee beverages become unstable. The milk ring formation, or oiling off, is accelerated in these kinds of drinks. We prepared a “rich milk coffee” beverage and studied the stability of the emulsion. We also investigated the influence of the food emulsifiers on the stability of the emulsion. We tried to test the emulsifier system in order to improve the emulsion stability. When the milk coffee beverage with a low light value for the roasted coffee beans sterilized by UHT was stored at a low temperature, the milk component strongly separated. We found that the sucrose monoester with a high HLB and diglycerol monoester accelerated the milk separation, and the decaglycerol monoester controlled the milk separation. We discussed the milk separation mechanism and showed that maintaining the hydration of the hydrophilic group in the rich milk coffee beverage was related to the combination of emulsifiers that control the milk separation.
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