Skin Cancer Awareness Among 1 271 Black Africans in South Africa

Little is known about levels of awareness and perceptions of skin cancer among Africans living in Africa. This study assessed skin cancer awareness among 1271 deeply pigmented South Africans. Participants (n = 642 males vs n = 629 females) were aware of skin cancer (79%) with more females than males being aware of skin cancer (P = 0.02). Majority of all participants had never checked their skin for signs or symptoms of skin cancer (90%). Palms of hands and soles of feet were the least recognized anatomic sites for skin cancer development, despite these sites being the common sites for acral lentiginous melanoma in individuals with deeply pigmented skin. Results suggest a need for targeted skin cancer awareness among population groups with dark skin on identification, screening, and early detection, professional training for healthcare personnel and content on skin cancer in deeply pigmented skin in medical curricula.     

A generalization of sumset and its applications

Let A be a nonempty finite subset of an additive abelian group G and let r and h be positive integers. The generalized h-fold sumset of A, denoted by \(h^{(r)}A\), is the set of all sums of h elements of A, where each element appears in a sum at most r times. The direct problem for \(h^{(r)}A\) is to find a lower bound for \(|h^{(r)}A|\) in terms of |A|. The inverse problem for \(h^{(r)}A\) is to determine the structure of the finite set A for which \(|h^{(r)}A|\) is minimal with respect to some fixed value of |A|. If \(G = \mathbb {Z}\), the direct and inverse problems are well studied. In case of \(G = \mathbb {Z}/p\mathbb {Z}\), p a prime, the direct problem has been studied very recently by Monopoli (J. Number Theory, 157 (2015) 271–279). In this paper, we express the generalized sumset \(h^{(r)}A\) in terms of the regular and restricted sumsets. As an application of this result, we give a new proof of the theorem of Monopoli and as the second application, we present new proofs of direct and inverse theorems for the case \(G = \mathbb {Z}\).     

Traceability and Authentication of Manila Clams from North-Western Adriatic Lagoons Using C and N Stable Isotope Analysis

In the Adriatic lagoons of northern Italy, manila clam (Ruditapes philippinarum) farming provides important socio-economic returns and local clams should be registered with the Protected Designations of Origin scheme. Therefore, there is a need for the development of rapid, cost-effective tests to guarantee the origin of the product and to prevent potential fraud. In this work, an elemental analysis (EA) coupled with isotope ratio mass spectrometry (IRMS) was employed to identify the isotopic fingerprints of clams directly collected onsite in three Adriatic lagoons and bought at a local supermarket, where they exhibited certification. In particular, a multivariate analysis of C/N, δ¹³C and δ¹⁵N in manila clam tissues as well as δ¹³C in shells and Δ¹³C (calculated as δ¹³C_shell–δ¹³C_tissues) seems a promising approach for tracking the geographical origin of manila clams at the regional scale.     

Green's function approach to study the propagation of SH‐wave in piezoelectric layer influenced by a point source

Green's function technique serves as a powerful tool to find the particle displacements due to SH‐wave propagation in layer of a shape different from the space between two parallel planes. Therefore, the present paper undertook to study the propagation of SH‐wave in a transversely isotropic piezoelectric layer under the influence of a point source and overlying a heterogeneous substrate using Green's function technique. The coupled electromechanical field equations are solved with the aid of Green's function technique. Expression for displacements in both layer and substrate, scalar potential and finally the dispersion relation is obtained analytically for the case when wave propagates along the direction of layering. Numerical computations are carried out and demonstrated with the aid of graphs for six different piezoelectric materials namely PZT‐5H ceramics, Barium titanate (BaTiO₃) ceramics, Silicon dioxide (SiO₂) glass, Borosilicate glass, Cobalt Iron Oxide (CoFe₂O₄), and Aluminum Nitride (AlN). The effects of heterogeneity, piezoelectric and dielectric constants on the dispersion curve are highlighted. Moreover, comparative study is carried out taking the phase velocity for different piezoelectric materials on one hand and isotropic case on the other. Dispersion relation is reduced to well‐known classical Love wave equation with a view to illuminate the authenticity of problem. Copyright © 2017 John Wiley & Sons, Ltd.     

Superconducting linear accelerator system for NSC

This paper reports the construction of a superconducting linear accelerator as a booster to the 15 UD Pelletron accelerator at Nuclear Science Centre, New Delhi. The LINAC will use superconducting niobium quarter wave resonators as the accelerating element. Construction of the linear accelerator has progressed sufficiently. Details of the entire accelerator system including the cryogenics facility, RF electronics development, facilities for fabricating niobium resonators indigenously, and present status of the project are presented.     

Simultaneous determination of sulfamethoxazole and trimethoprim in microgram quantities from low plasma volume by liquid chromatography–tandem mass spectrometry

A highly sensitive, selective and high-throughput liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for simultaneous quantification of sulfamethoxazole (SMZ) and trimethoprim (TMP) has been developed and validated using imipramine as an internal standard. The analytes were extracted from 50 µL human plasma using solid phase extraction (SPE) and separated on Thermo Hypersil Gold C18 (50 mm × 4.6 mm, 5 μm) column under isocratic conditions in a run time of 2.5 min. Detection was carried out by tandem mass spectrometer, interfaced with electro spray ionization and operating in positive ionization mode. The calibration curves were linear over the concentration range of 0.88–80 µg/mL for SMZ and 0.03–30 µg/mL for TMP. The intra- and inter-day accuracy and precision (% CV) evaluated at four quality control levels were within 93.5–105.0% and 1.3–7.2% respectively. The absolute recovery was greater than 81% for both the analytes at two concentration levels. Stability of SMZ and TMP was assessed under different storage conditions. The validated method was successfully applied for a bioavailability study in 12 healthy volunteers after oral administration of 800 mg of SMZ and 160 mg of TMP succinate tablet formulations under fasting condition.     

A highly selective and sensitive in vivo fluorosensor for zinc(II) without cytotoxicity

A highly selective and sensitive fluorescent Zn(2+) sensor, 2,6-bis(2-hydroxy-benzoic acid hydrazide)-4-methylphenol (1), was designed and synthesized. In aqueous THF (4 : 6 v/v) ligand 1 induces a 2 : 1 complex formation with respect to Zn(2+) at physiological pH. This probe features visible light excitation(390 nm) and emission (490 nm) profiles, excellent selectivity responses for Zn(2+)over other competing biological metal ions with K(d) < 1 pM(2), LOD < 1 ng L(-1) and about 680 fold enhancement in fluorescent intensity upon Zn(2+) binding. It also exhibits cell permeability and intracellular Zn(2+) sensing in A375 human melanoma cancer cell.     

Propagation of SH-wave in a corrugated viscous sandy layer sandwiched between two elastic half-spaces

The present paper attempts to investigate the effect of sandiness, corrugated boundary surfaces, heterogeneity, and gravity on phase velocity and attenuation of SH-wave propagating in a viscous sandy layer with corrugated upper and lower boundary surfaces sandwiched between an upper heterogeneous elastic half-space and lower viscoelastic half-space under gravity. Heterogeneity associated with the upper half-space is due to exponentially varying density which is a function of depth; but the rigidity is constant. The closed form of dispersion relation is established and found to be in complex form. Real part and imaginary part of the dispersion relation correspond to dispersion curve and attenuation curve, respectively. One of the salient points of present study is the use of DEBYE asymptotic expansion to establish that the obtained dispersion relation is in well-agreement with the classical Love wave equation in isotropic case. The effect of presence and absence of corrugated boundary surfaces, measured by initial flatness parameter, on dispersion and attenuation curves have been meticulously examined. Moreover, the substantial effect of heterogeneity, sandiness, internal friction, and Biot’s gravity parameter on phase velocity and attenuation coefficient of SH-wave has been studied and demonstrated by means of graphical illustration and numerical computations.     

A rapid and selective method for simultaneous determination of six toxic phenolic compounds in mainstream cigarette smoke using single-drop microextraction followed by liquid chromatography–tandem mass spectrometry

Cigarette smoke contains several toxic phenolic compounds, measurements of which are essential from a public health standpoint. This article describes a simple and selective analytical method for quantitative determination of six toxic phenolic compounds (phenol, catechol, resorcinol, hydroquinone, o-cresol, and p-cresol) from mainstream cigarette smoke using single-drop microextraction in combination with liquid chromatography–tandem mass spectrometry. Single-drop microextraction was applied prior to analysis by liquid chromatography–tandem mass spectrometry for the extraction and preconcentration of target phenolic compounds from raw cigarette smoke extract. The effects of the extraction solvent, sampling time, solution pH, salt addition, sample agitation rate, and temperature on the extraction efficiency were examined and optimized. The identification of each analyte was established by chromatographic retention times, analyte-specific fragmentation patterns, and relative peak area ratios of two product/precursor ion pairs. Analytical parameters such as the detection limit, relative recovery, reproducibility, linearity, and enrichment factor were evaluated under the optimized experimental conditions. 1-Decanol was selected as the extraction solvent and the limits of detection were found to be in the range of 0.05-0.3 ng mL^-1 using an extraction time of 12 min. Gradient chromatographic conditions were optimized for the separation of the six phenolic compounds in a run time of 10 min including reequilibration of the column. The present method for determination of phenolic compounds from mainstream cigarette smoke is simple and specific and shows good reproducibility, with relative standard deviations less than 10 % for all targeted phenolics.