Liquid-phase exfoliation of WSe2 nanosheets for ITO/WSe2 photodetector

Journal of Materials Science: Materials in Electronics - The potential application of atomically thin two-dimensional (2D)-layered WSe2 in future wearable electronics has sparked a lot of interest....     

Surface patch binding‐induced exfoliation of nanoclays and enhancement of physical properties of gelatin organogels

Nanoclay‐containing organogels were prepared by exfoliating layered silicate nanoclay (Laponite^® and montmorillonite, aspect ratio 30 and 250) in organogels made in glycerol solutions. Zeta potential of the binding profile between clay and gelatin chains in the milieu of glycerol was consistent with a surface patch binding mechanism. To achieve customized thermal and viscoelastic properties, optimum binding of nanoclay to gelatin was probed, and it was noticed that [clay] = 0.03% (w/v) and [glycerol] = 30% (v/v) produced the best results. Gelation temperature T_gel (Laponite organogels) increased from 28 to 34 °C (ca 21% change) with a concomitant increase in gel elastic modulus from 400 to 1200 Pa (ca 300% change). For montmorillonite organogels, it was possible to raise T_gel further to 43 °C (56% change). X‐ray diffraction data and Cole–Cole plots indicated that clay platelets were homogeneously exfoliated in the organogel matrix. Thus, the thermoviscoelastic properties of gelatin organogels could be modulated to raise the gelation temperature to 43 °C, and gel strength to 1200 Pa by the addition of nanoclay whose concentration may not exceed 0.03% (w/v). Considering the wide application of gelatin gels in pharmaceuticals, food preservation and personal care products, the aforesaid enhancement in physical properties is significant. © 2016 Society of Chemical Industry     

Diminution of mouse epidermal superoxide dismutase and catalase activities by tumor promoters

The effects of phorbol ester tumor promoters and related compounds on superoxide dismutase (SOD) and catalase were examined. The treatment of adult mouse skin with 2 micrograms 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in a sustained decrease in the basal levels of both SOD and catalase activities in the epidermis. A decline in SOD activity occurred within 3 h after application and the maximum effect was seen at 16--17 h. The decrease in SOD activity was always accompanied by a similar decline in the epidermal catalase activity. The alterations in both enzymes occurred against a high background of enhanced protein synthesis which indicates that the effect of TPA is selective for SOD and catalase. Other tumor promoters such as phorbol 12,13-dibutyrate and the non-phorbol tumor promoter anthraline also lowered the activities of both the enzymes. Mezerein, a resiniferonol derivative with weak promoting activity but a potent stage-II promoter, appeared to be more potent than TPA in lowering the basal levels. These results indicate that damage which favors neoplastic progression could occur in TPA-treated mouse skin due to the accumulation of free radicals resulting from low levels of SOD and catalase activity. In addition, the TPA-caused decrease in the levels of SOD and catalase was not prevented by either retinoic acid, fluocinolone acetonide, tosyl amino-2-phenylethyl chloromethyl ketone, or butylated hydroxytoluene, suggesting that inhibition of tumor promotion by these agents is not mediated through alterations in the levels of enzymatic activities which decrease free radical concentrations.     

Ischemic fasciitis. Report of a case with fine needle aspiration findings

BACKGROUND: Ischemic fasciitis, also called atypical decubital fibroplasia, was recently described as a distinctive fibroblastic proliferation occurring predominantly in elderly, bed-ridden individuals. This entity can easily be misdiagnosed as a malignant process. CASE: A 70-year-old, white male presented with an enlarging right hip mass. Fine needle aspiration yielded spindled and ovoid cells with ample cytoplasm and occasional nuclear atypia. The histologic features of a subsequent biopsy and resection specimen included a zonal pattern of fibrinoid necrosis with surrounding reactive fibroblasts, histiocytes and vascular proliferation, which are characteristic of ischemic fasciitis. CONCLUSION: Ischemic fasciitis can be mistaken clinically, cytologically and histologically for sarcoma. The cytologic findings seen in this case, when combined with the clinical history, were sufficient to avoid misdiagnosis of malignancy in a benign, proliferative lesion.     

Synergistic analysis of SeaWiFS chlorophyll concentration and NOAA-AVHRR SST features for exploring marine living resources

Near-synchronous Sea-viewing Wide Field-of-View Sensor (SeaWiFS) derived chlorophyll concentration and National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) derived sea surface temperature (SST) images were used to understand patterns, persistence and inter-relationship between ocean colour and thermal features. Different types of oceanic features were observed on chlorophyll concentration and SST images. An inverse relationship between chlorophyll concentration and SST features was observed. The features observed in the chlorophyll concentration images were well defined and appeared to contained more information than those on the SST images. The frontal zone positions on the chlorophyll concentration images coincided with temperature boundaries at some locations. This coincidence indicates that the physical and bio-chemical processes are closely coupled at these locations. High fish catch points were found in the vicinity of these features. A synergistic analysis of chlorophyll concentration and SST may increase our understanding of the inter-relationship between environmental variables for locating potential fishing grounds.     

Deterministic beam fanning in Fe-doped stoichiometric lithium niobate crystals

We investigated the beam-fanning effect in Fe-doped stoichiometric lithium niobate (Fe:SLN) crystals that were grown by the top-seeded solution growth method. Deterministic beam fanning (DBF) was measured in Z-cut Fe:SLN crystal for incident light propagating along the c+ and c- axes. The dependence of beam-fanning factors on incident power density was also studied. The experimental results of DBF in the Z-cut Fe:SLN crystal were in good agreement with a theoretical simulation based on a two-wave mixing model. The results compared with those for Fe-doped congruent lithium niobate crystals indicate that the beam-fanning process in Fe:SLN is deterministic because of its much-reduced intrinsic density of defects.     

INSAT-3D and MODIS retrieved sea surface temperature validation and assessment over waters surrounding the Indian subcontinent

The INSAT-3D imager (4 km) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on-board Aqua and Terra space-platforms level-2 (1 km) sea surface temperature (SST_skin) product accuracy has been analysed over waters surrounding the Indian subcontinent by indirect comparison method using collocated bulk in-situ measurements (SST_depth) for 3 years (October 2013–October 2016). Statistical results show that root mean square error of all the three satellites is in range of around 0.60–0.70°C. Retrieval error is found to be slightly more in case of validation against iQuam data set. INSAT-3D is showing more underestimation with bias ranging from about ?0.16°C to ?0.20°C than MODIS sensor having bias in range of about 0.06°C to ?0.12°C. All the three missions are slightly underestimating over open-ocean with bias ranging in 0–0.17°C. INSAT-3D is significantly underestimating in-situ observations over the Arabian Sea (approximate bias = 0.27°C). Seasonal validation analysis reveals relatively high retrieval error during monsoon season than pre-monsoon and post-monsoon seasons. MODIS sensor is showing significant underestimation during monsoon with bias ranging from approximately ?0.29°C to ?0.58°C. Overall, all the three missions are performing similarly well over the study area.     

Synthesis and characterization of bisitaconimides. I

This article describes the synthesis and characterization of bisitaconimides on the basis of 4,4′‐diaminodiphenylether, 2,2′‐bis[4‐(4‐aminophenoxy)phenyl]propane, 1,3‐bis(4‐aminophenoxy)benzene, and 1,4‐bis (4‐aminophenoxy)benzene. Isomerization of the itaconimides to citraconimides (varying in the range of 25–40%) was observed during synthesis. The curing exotherm and thermal stability of the cured resins depended on the backbone structure of itaconimides. The curing exotherm immediately followed the melting endotherms. These resins cured at lower temperatures than bismaleimides but thermal stability of cured bismaleimides was higher than bisitaconimides. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2277–2282, 2002     

Functionalized polyacrylonitrile‐nanofiber based immunosensor for Vibrio cholerae detection

Polyacrylonitrile nanofibers (PANnf's) were electrospun directly onto an indium tin oxide (ITO)‐coated glass substrate. The PANnf/ITO electrode was partially hydrolyzed with an NaOH aqueous solution at ambient temperature to convert the nitrile groups of the PANnf's into carboxyl groups was confirmed by Fourier transform infrared spectroscopy. Furthermore, 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide–N‐hydroxy succinimide chemistry was used to activate the ? COOH groups of PANnf's for the covalent co‐immobilization of monoclonal antibodies against Vibrio cholerae and bovine serum albumin for V. cholerae toxin detection. Structural, functional, and electrochemical studies of the PANnf/ITO electrode and BSA/Ab/PANnf/ITO immunoelectrode were performed, and found a uniform distribution of nanofibers with diameter of 325 ± 7.7% nm. The electrochemical response studies showed an improved sensing performance of the immunoelectrode with a detection of 6.25–500 ng/mL, a low limit of detection of 0.22 ng/mL, a sensitivity of 90 nA ng^?1 mL cm^?2, an association constant of 45.2 ng/mL, and a dissociation constant of 8 ng/mL. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44170.