Very Important Publication: Hypoiodite‐Catalyzed Regioselective Oxidation of Alkenes: An Expeditious Access to Aldehydes in Aqueous Micellar Media

A highly anti‐Markovnikov selective oxidation of alkenes based on in situ generated hypoiodite catalysis in aqueous micellar media under mild conditions has been described. This novel catalytic system realizes an efficient synthesis of aldehydes from alkenes in an economically viable and environmentally safe fashion. The preliminary mechanistic studies suggest that the reaction proceeds via tandem iodofunctionalization/1,2‐aryl or alkyl migration. The scope and limitations of this tandem process are demonstrated with various mono‐ and disubstituted (terminal and internal) olefins.

     

Synergism between resveratrol and other phytochemicals: implications for obesity and osteoporosis

Resveratrol, a phytoalexin, has gained much attention recently due to its effects on sirtuins. While the anti-cancer properties of resveratrol have been extensively investigated, the anti-adipogenic and osteogenic effects of resveratrol are also gaining considerable interest. The finding that resveratrol supplementation mimics caloric restriction prompted researchers to study the effects of resveratrol on lipid metabolism. Mesenchymal stem cells are the precursors for both adipocytes and osteoblasts. In the aging population, differentiation to adipocytes dominates over the differentiation to osteoblasts in bone marrow, contributing to the increased tendency for fractures to occur in the elderly. Thus, an inverse relationship exists between adipocytes and osteoblasts in the bone marrow. Resveratrol acts on several molecular targets in adipocytes and osteoblasts leading to a decrease in adipocyte number and size and an increase in osteogenesis. Furthermore, resveratrol in combination with genistein and quercetin synergistically decreased adipogenesis in murine and human adipocytes. A recent in vivo study showed that phytochemicals including resveratrol in combination with vitamin D prevented weight gain and bone loss in a postmenopausal rat model. Therefore, combinations of resveratrol with other phytochemicals may lead to potential novel potent therapies for both obesity and osteoporosis.     

STUDIES OF WHOLE CRAWFISH SHELLS FOR THE REMOVAL OF CHROMIUM,LEAD, AND SELENIUM IONS IN SOLUTION

The objective of this work was to investigate the absorption characteristics, primarily with lead but also chromium and selenium ions in solution, of whole crawfish shells. An increase in the lead concentration in spiked water showed an increase in the lead absorption level. Lead absorbed by 0.5 g of whole crawfish shells was far less when compared to absorption by 0.5 g of ground crawfish shell powder due to particle size. Some of the lead is most likely being precipitated and collected along with the powder. With increase in the volume of lead spiked water, absorption of lead by whole crawfish shells also increased. Results obtained from the pH studies indicated that basic conditions (pH 9.5) are favorable for absorption of lead by both whole crawfish shells and chitin. Crawfish shells exhibited more absorption of lead compared to commercially available (shrimp) chitin at pH 9.5.

Crawfish shells absorbed more lead, selenium, and chromium from analyte spiked water when compared to chitin. However, the amount of metal added was not always equal to the amount of metal dissolved. A higher amount of lead was absorbed when compared to chromium and selenium. If comparison was done in micrograms of analyte absorbed, then the absorption order can be given as lead>chromium>selenium. If comparison was done in micromoles of analyte absorbed, then the absorption order is as follows: chromium>lead>selenium. Results from the last experiment indicated that formation of lead precipitate increased proportionately with increase in the concentration of spiked water.     

A low-cost INS/GPS integration methodology based on random forest regression

This paper, for the first time, introduces a random forest regression based Inertial Navigation System (INS) and Global Positioning System (GPS) integration methodology to provide continuous, accurate and reliable navigation solution. Numerous techniques such as those based on Kalman filter (KF) and artificial intelligence approaches exist to fuse the INS and GPS data. The basic idea behind these fusion techniques is to model the INS error during GPS signal availability. In the case of outages, the developed model provides an INS error estimates, thereby maintaining the continuity and improving the navigation solution accuracy. KF based approaches possess several inadequacies related to sensor error model, immunity to noise, and computational load. Alternatively, neural network (NN) proposed to overcome KF limitations works unsatisfactorily for low-cost INS, as they suffer from poor generalization capability due to the presence of high amount of noise.In this study, random forest regression has shown to effectively model the highly non-linear INS error due to its improved generalization capability. To evaluate the proposed method effectiveness in bridging the period of GPS outages, four simulated GPS outages are considered over a real field test data. The proposed methodology illustrates a significant reduction in the positional error by 24–56%.     

Structural and optical properties of nanocrystalline WO<Subscript>3</Subscript> thin films

The nanocrystalline WO₃ thin films were deposited by r.f. magnetron sputtering on quartz and p- type Si (100) substrates at a constant power of 25 W and at three different sputtering pressures (0.05, 0.01 and 0.5 mbar) and post annealed at different temperatures. The deposited films were characterized by XRD, UV–VIS spectrophotometry, ellipsometry and atomic force microscopy (AFM). The structural studies from XRD spectra reveals that the films deposited at 0.05 mbar and post annealed at 573 and 673 K have the predominant orthorhombic phase, whereas at 0.1 mbar and 573, 673 K triclinic phase is predominant. When sputtering pressure is at 0.5 mbar the predominant phase is monoclinic when annealed at 473 K and triclinic at 673 K. The optical energy gap is influenced significantly by sputtering pressure and post annealing temperatures. The optical energy gap of the films deposited at higher sputtering pressures and post annealed at lower temperatures is high due to smaller crystallite sizes. The thickness of all deposited films at different conditions is around 200 nm.