Transfer hydrogenation of nitroarenes using cellulose filter paper-supported Pd/C by filtration as well as sealed methods

A reductive filter paper for selective nitro reduction has been prepared by modification of a pristine cellulose filter paper by Pd/C nanoparticles, as a portable catalyst. The reaction was performed in two different set-ups including (i) filtration and (ii) sealed systems, in the presence of ammonium formate and ex situ generated hydrogen gas reducing agents, respectively. In the sealed system in the presence of H₂ gas, the halogenated nitroarenes were completely reduced, while in the filtration system, different derivatives of the nitroarenes were selectively reduced to aryl amines. In both systems, the reduction of nitroarenes to aryl amines was performed with high efficiency and selectivity, comparable to a heterogeneous system. Reaction parameters were comprehensively designed using Design Expert software and then studied. The properties of the catalytic filter paper were studied in detail from the points of view of swellability, shrinkage, reusability, and stability against acidic, alkaline, and oxidative reagents.

A novel and efficient catalytic filtration has been developed for the selective reduction of nitro compounds on a Pd/C-doped cellulose filter paper.     

Vitamin C supplementation decreases insulin glycation and improves glucose homeostasis in obese hyperglycemic (ob/ob) mice

The effects of dietary vitamin C supplementation on glucose homeostasis and insulin glycation were examined in adult lean and obese hyperglycemic (ob/ob) mice. In lean mice, supplementation of the drinking water with vitamin C (25 g/L) for 14 days did not affect food intake, fluid intake, glycated hemoglobin, plasma glucose, or plasma insulin concentrations. Total pancreatic insulin content and the percentage of glycated pancreatic insulin were also similar to control lean mice. In ob/ob mice, vitamin C supplementation caused significant reductions by 26% to 48% in food intake and fluid intake, glycated hemoglobin, plasma glucose, and insulin concentrations compared with untreated control ob/ob mice. The total insulin content and the extent of insulin glycation in the pancreas of ob/ob mice were also significantly decreased by 42% to 45% after vitamin C supplementation. This change was accompanied by a significant 80% decrease in the percentage of glycated insulin in the circulation of vitamin C-supplemented ob/ob mice. These data demonstrate that vitamin C supplementation can decrease insulin glycation and ameliorate aspects of the obesity-diabetes syndrome in ob/ob mice.     

Efficacy of extract from Ononis spinosa L.on ethanol-induced gastric ulcer in rats

OBJECTIVE:To investigate the efficacy of the ex-tract from Ononis spinosa L.(O.spinosa)on etha-nol-induced gastric ulcer in rats.METHODS:Phytochemical constitue...     

Intermetallics Formation during Solidification of Al-Si-Cu-Mg Cast Alloys

The present study was undertaken to examine the effect of iron, manganese, copper and magnesium on the microstructural characteristics of Al-11%Si-2%Cu-Mg-based alloy referred to as 396 under different working conditions. The results show that strontium (Sr) has high affinity to react with magnesium (Mg), resulting in reduced effectiveness as eutectic silicon modifier or age hardening agent. In addition, Sr alters the sequence of the precipitation of the α-AlFeMnSi phase from post-eutectic to pro-eutectic which would harden the soft α-Aluminum matrix. The mechanism is still under investigation. The interactions between iron (Fe) and Mg and Sr-Mg result in the formation of serval dissolvable intermetallics during the solutionizing treatment such as β-AlFeSi, π-AlFeMgSi and Q-AlMgSiCu phases. The study also emphasizes the role of modification and grain refining as well as intermetallics in porosity formation and hardness of samples aged in the temperature range 155–240 °C.     

Reviewing a plethora of oxidative-type reactions catalyzed by whole cells of Streptomyces species

Selective oxidation reactions represent a challenging task for conventional organic chemistry. Whole-cell biocatalysis provides a very convenient, easy to apply method to carry out different selective oxidation reactions including chemo-, regio-, and enantio–selective reactions. Streptomyces species are important biocatalysts as they can catalyze these selective reactions very efficiently owing to the wide diversity of enzymes and enzymatic cascades in their cell niche. In this review, we present and analyze most of the examples reported to date of oxidative reactions catalyzed by Streptomyces species as whole-cell biocatalysts. We discuss 33 different Streptomyces species and strains and the role they play in different oxidative reactions over the past five decades. The oxidative reactions have been classified into seven categories that include: hydroxylation of steroids/non-steroids, asymmetric sulfoxidations, oxidation of aldehydes, multi-step oxidations, oxidative cleavage, and N-oxidations. The role played by Streptomyces species as recombinant hosts catalyzing bio-oxidations has also been highlighted.

Types of oxidation reactions catalyzed by whole cells of different Streptomyces species.     

Postburn leukoderma successfully treated with topical daylight psoralen UVA therapy

Postburn leukoderma is challenging to treat with different surgical and nonsurgical treatments resulting in variable outcomes. We report a case of a 56‐year‐old female with postburn leukoderma treated successfully with topical daylight psoralen UVA therapy for 6 months. The treatment was well tolerated and showed excellent improvement. In conclusion, we report the successful use of topical daylight PUVA for postburn leukoderma with almost complete repigmentation. This is a simple, convenient, and cheap nonsurgical treatment option.     

Neurocritical Care Resource Utilization in Pandemics: A Statement by the Neurocritical Care Society

Neurocritical Care -