A composition-dependent ``re-entrant'' crystallographic phase transition in the substitutional metal acetylacetonate complex (Cr1-xGax)(acac)(3)

The formation of a complete solid solution between acetylacetonate (acac) complexes of chromium and gallium, (Cr1-x,Ga-x)(acac)(3) for 0.1

Azide/thiocyanate incorporated cobalt(III)-Schiff base complexes: Characterizations and catalytic activity in aerobic epoxidation of olefins

Reaction of cobalt(II) perchlorate hexahydrate with a potentially tetradentate Schiff base ligand, HL (2-methoxy-6-(2-diethylaminoethylimino)methyl]phenol) in presence of sodium azide and sodium thiocyanate yields two complexes Co( L)( HL)(N-3)]center dot ClO4 ( 1) and Co( L)( HL)(NCS)] center dot ClO4 ( 2); both being characterized by different physicochemical methods. Crystal structure of 1 was determined by single crystal X-ray diffraction while that of 2 was reported earlier. In 1, the central cobalt(III) adopts slightly distorted octahedral geometry with same donor set to that of 2. Catalytic efficacy of the complexes towards epoxidation of different alkenes under aerobic condition were investigated in homogeneous medium which reveals that 1 is better catalyst than 2 with respect to alkene oxidation, reflected from the turn over frequencies (TOF) measured at an optimum temperature of 60 degrees C in acetonitrile. (C) 2014 Published by Elsevier B.V.

Spectral finite element based on an efficient layerwise theory for wave propagation analysis of composite and sandwich beams

In this paper, we present a spectral finite element model (SFEM) using an efficient and accurate layerwise (zigzag) theory, which is applicable for wave propagation analysis of highly inhomogeneous laminated composite and sandwich beams. The theory assumes a layerwise linear variation superimposed with a global third-order variation across the thickness for the axial displacement. The conditions of zero transverse shear stress at the top and bottom and its continuity at the layer interfaces are subsequently enforced to make the number of primary unknowns independent of the number of layers, thereby making the theory as efficient as the first-order shear deformation theory (FSDT). The spectral element developed is validated by comparing the present results with those available in the literature. A comparison of the natural frequencies of simply supported composite and sandwich beams obtained by the present spectral element with the exact two-dimensional elasticity and FSDT solutions reveals that the FSDT yields highly inaccurate results for the inhomogeneous sandwich beams and thick composite beams, whereas the present element based on the zigzag theory agrees very well with the exact elasticity solution for both thick and thin, composite and sandwich beams. A significant deviation in the dispersion relations obtained using the accurate zigzag theory and the FSDT is also observed for composite beams at high frequencies. It is shown that the pure shear rotation mode remains always evanescent, contrary to what has been reported earlier. The SFEM is subsequently used to study wavenumber dispersion, free vibration and wave propagation time history in soft-core sandwich beams with composite faces for the first time in the literature. (C) 2014 Elsevier Ltd. All rights reserved.

Role of surface chemistry in modulating drug release kinetics in titania nanotubes

Surface chemistry and the intrinsic porous architectures of porous substrates play a major role in the design of drug delivery systems. An interesting example is the drug elution characteristic from hydrothermally synthesised titania nanotubes with tunable surface chemistry. The variation in release rates of Ibuprofen (IBU) is largely influenced by the nature of the functional groups on titania nanotubes and pH of suspending medium. To elucidate the extent of interaction between the encapsulated IBU and the functional groups on titania nanotubes, the release profiles have been modelled with an empirical Hill equation. The analysis aided in establishing a probable mechanism for the release of IBU from the titania nanotubes. The study of controlled drug release from TiO2 has wider implication in the context of biomedical engineering. (C) 2014 Elsevier B.V. All rights reserved.

Supramolecular Gating of Ion Transport in Nanochannels

Several covalent strategies towards surface charge-reversal in nanochannels have been reported with the purpose of manipulating ion transport. However, covalent routes lack dynamism, modularity and post-synthetic flexibility, and hence restrict their applicability in different environments. Here, we introduce a facile non-covalent approach towards charge-reversal in nanochannels (< 10 nm) using strong charge-transfer interactions between dicationic viologen (acceptor) and trianionic pyranine (donor). The polarity of ion transport was switched from anion selective to ambipolar to cation selective by controlling the extent of viologen bound to the pyranine. We could also regulate the ion transport with respect to pH by selecting a donor with pH-responsive functional groups. The modularity of this approach further allows facile integration of various functional groups capable of responding to stimuli such as light and temperature to modulate the transport of ions as well as molecules.

A Grassmann path from AdS(3) to flat space

We show that interpreting the inverse AdS(3) radius 1/l as a Grassmann variable results in a formal map from gravity in AdS(3) to gravity in flat space. The underlying reason for this is the fact that ISO(2, 1) is the Inonu-Wigner contraction of SO(2, 2). We show how this works for the Chern-Simons actions, demonstrate how the general (Banados) solution in AdS(3) maps to the general flat space solution, and how the Killing vectors, charges and the Virasoro algebra in the Brown-Henneaux case map to the corresponding quantities in the BMS3 case. Our results straightforwardly generalize to the higher spin case: the recently constructed flat space higher spin theories emerge automatically in this approach from their AdS counterparts. We conclude with a discussion of singularity resolution in the BMS gauge as an application.

GHG footprint of major cities in India

Concentration of greenhouse gases (GHG) in the atmosphere has been increasing rapidly during the last century due to ever increasing anthropogenic activities resulting in significant increases in the temperature of the Earth causing global warming. Major sources of GHG are forests (due to human induced land cover changes leading to deforestation), power generation (burning of fossil fuels), transportation (burning fossil fuel), agriculture (livestock, farming, rice cultivation and burning of crop residues), water bodies (wetlands), industry and urban activities (building, construction, transport, solid and liquid waste). Aggregation of GHG (CO2 and non-CO2 gases), in terms of Carbon dioxide equivalent (CO(2)e), indicate the GHG footprint. GHG footprint is thus a measure of the impact of human activities on the environment in terms of the amount of greenhouse gases produced. This study focuses on accounting of the amount of three important greenhouses gases namely carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and thereby developing GHG footprint of the major cities in India. National GHG inventories have been used for quantification of sector-wise greenhouse gas emissions. Country specific emission factors are used where all the emission factors are available. Default emission factors from IPCC guidelines are used when there are no country specific emission factors. Emission of each greenhouse gas is estimated by multiplying fuel consumption by the corresponding emission factor. The current study estimates GHG footprint or GHG emissions (in terms of CO2 equivalent) for Indian major cities and explores the linkages with the population and GDP. GHG footprint (Aggregation of Carbon dioxide equivalent emissions of GHG's) of Delhi, Greater Mumbai, Kolkata, Chennai, Greater Bangalore, Hyderabad and Ahmedabad are found to be 38,633.2 Gg, 22,783.08 Gg, 14,812.10 Gg, 22,090.55 Gg, 19,796.5 Gg, 13,734.59 Gg and 91,24.45 Gg CO2 eq., respectively. The major contributors sectors are transportation sector (contributing 32%, 17.4%, 13.3%, 19.5%, 43.5%, 56.86% and 25%), domestic sector (contributing 30.26%, 37.2%, 42.78%, 39%, 21.6%, 17.05% and 27.9%) and industrial sector (contributing 7.9%, 7.9%, 17.66%, 20.25%, 1231%, 11.38% and 22.41%) of the total emissions in Delhi, Greater Mumbai, Kolkata, Chennai, Greater Bangalore, Hyderabad and Ahmedabad, respectively. Chennai emits 4.79 t of CO2 equivalent emissions per capita, the highest among all the cities followed by Kolkata which emits 3.29 t of CO2 equivalent emissions per capita. Also Chennai emits the highest CO2 equivalent emissions per GDP (2.55 t CO2 eq./Lakh Rs.) followed by Greater Bangalore which emits 2.18 t CO2 eq./Lakh Rs. (C) 2015 Elsevier Ltd. All rights reserved.

Chemical-free graphene by unzipping carbon nanotubes using cryo-milling

Current paper reports synthesis of chemical free graphene by unzipping of the carbon nanotubes (CNTs) using high strain rate deformation at 150K. A specially designed cryomill operating at 150 K was used for the experiments. The mechanism of unzipping was further explored using molecular dynamics (MD) simulations. Both experimental and simulation results reveal two modes of unzipping through radial and shear loading. (C) 2015 Elsevier Ltd. All rights reserved.

The deciding role of texture on ductility in a Ce containing Mg alloy

This is the first successful attempt to produce Mg-Ce alloys of different texture through different processing routes while keeping the grain size and grain size distribution same. Tensile data shows that contribution of texture to ductility enhancement is primary and that of grain refinement is secondary. The texture resulting from multi-axial forging of extruded billets followed by annealing exhibits the highest ductility (similar to 40%) at room temperature. (C) 2015 Elsevier B.V. All rights reserved.

Role of Si modification on the compressive flow behavior of Al-Si based alloy

The flow characteristics of a near-eutectic heat-treated Al-Si based cast alloy have been examined in compression at strain rates varying from 3 x 10(-4) to 10(2) s(-1) and at three different temperatures, i.e., room temperature (RT), 100 degrees C and 200 degrees C. The dependence of flow behavior on modification is examined by testing the alloy in both the unmodified and modified conditions. Modification has strong influence on strain rate sensitivity (SRS), strength and work hardening behavior of the alloy. The strength of the alloy is found to increase with increase in strain rate for both the conditions. The increase is more rapid above the strain rate of 10(-1) s(-1) for the unmodified alloy at all the temperatures. This rapid increase is observed at 1 s(-1) at RT and 100 degrees C, and at 10(-2) s(-1) at 200 degrees C for the modified alloy. The thermally dependent process of the Al matrix is rate controlling in the unmodified alloy. On the other hand, the thermally dependent process of both Al matrix and Si particles are rate controlling, which is responsible for the higher strain rate sensitivity (SRS) in the modified alloy. The unmodified alloy exhibits a larger work hardening rate than the modified alloy during the initial stages of straining due to fiber loading of unmodified Si particles. However, the hardening rate decreases sharply at higher strains for the unmodified alloy due to a higher rate of Si particle fracture. Thermal softening is observed for both alloys at 200 degrees C due to precipitate coarsening, which leads to a decrease in SRS at higher temperatures. Stress simulations by microstructure based finite element method support the experimentally observed particle and matrix fracture behavior. Negative SRS and serrated flow are observed at lower strain rate regime (3 x 10(-4) to 10(-2) s(-1)) at RT and 100 degrees C, in both alloys. The critical onset strain is found to be lower and the magnitude of serration is found to be higher for the modified alloy, which suggests that, in addition to dynamic strain aging, Si particle size and morphology also play a role in serrated flow. (C) 2015 Elsevier Inc All rights reserved.

High voltage cathodes for Na-ion batteries: Na3V2O2x(PO4)2F3-2x system

254 p : il, graf. col.

Financial analysis of small-scale fish farming enterprises to alleviate poverty in homestead

This paper focuses on the financial analysis involved in setting up of fish farming on a small-scale in a homestead. About 0.5 acres of land was used for the construction of pond which as a stock of Clarias spp/ Heterobranchus spp and Tilapia spp at the ratio of one to three for a period of 12 months. The land/land development cost is N26,500.00, pond construction cost, N35,700.00, equipment cost, N2,650.00 and stock/Input requirement cost N155,727.00 while the revenue from sales is N376,000.00. A cash flow analysis is also calculated for the fish farm, which is N155,423.00 for first year cash flow, and appropriate profit/mosses were calculated for five-year production cycle of N1,036,515.00 million. At the end appreciable profit is realized from the enterprises. This type of enterprises is viable for small-scale farmers to practices and adopted for financial support for their family

Análise de polimorfismos e de expressão do gene p16INK4a em neoplasias cervicais

O câncer de colo do útero é o segundo carcinoma mais frequente em mulheres no mundo e um dos cânceres femininos mais incidentes no Brasil. Em lesões pré-malignas e malignas do colo uterino, a proteína p16INK4a, que participa do controle do ciclo celular, apresenta um aumento considerável de sua expressão, devido possivelmente à presença de oncoproteínas do papilomavírus humano (HPV). Dois polimorfismos no gene p16INK4a, p16 500C>G e p16 540C>T, estão localizados na região 3 não traduzida (3UTR), que está envolvida na regulação pós-transcricional da expressão gênica. O objetivo deste estudo foi avaliar possíveis associações entre os polimorfismos p16 500C>G e p16 540C>T e o desenvolvimento de neoplasias cervicais e/ou a severidade das lesões, considerando os níveis de expressão da proteína p16INK4a nas lesões cervicais e certos fatores de risco clássicos para o câncer cervical, incluindo a infecção pelo HPV. Para isso, foram selecionadas 567 mulheres residentes no Rio de Janeiro, 319 com citologia cervical alterada (grupo de casos) e 248 sem história prévia de alteração citológica do colo uterino (grupo de comparação). Amostras de sangue periférico de todas as participantes foram utilizadas na análise molecular dos polimorfismos p16 500C>G e p16 540C>T através da técnica de PCR-RFLP (reação em cadeia da polimerase - polimorfismo de comprimento de fragmento de restrição), usando as enzimas de restrição MspI e HaeIII, respectivamente. A expressão da proteína p16INK4a em 137 biópsias de mulheres pertencentes ao grupo de casos foi avaliada por imunohistoquímica. A detecção de DNA do HPV em células cervicais foi feita em todas as amostras do grupo de comparação e em 194 amostras do grupo de casos pela técnica de PCR, usando dois pares de oligonucleotídeos, MY09/MY11 e GP05+/GP06+. Os dois grupos de estudo se encontram em equilíbrio de Hardy-Weinberg. As distribuições genotípicas para p16 500C>G e p16 540C>T e as distribuições de combinações haplotípicas nos dois grupos não apresentaram diferenças significativas. A análise do subgrupo HSIL+câncer (casos com lesão intraepitelial de alto grau ou carcinoma invasivo) em comparação com o subgrupo LSIL (casos com lesão intraepitelial de baixo grau) revelou diferença significativa entre as distribuições das combinações haplotípicas (p = 0,036) e diferenças marginais entre as distribuições genotípicas para p16 500C>G (p = 0,071) e p16 540C>T (p = 0,051). O alelo p16 540G, em heterozigose ou homozigose (OR = 1,91, IC 95% = 1,08-3,37), e a combinação haplotípica p16 500C-540C 500G-540C (OR = 2,34, IC 95% = 1,202-4,555) mostraram-se associados com a severidade da lesões cervicais. Já o genótipo p16 540T/T (OR = 0,25, IC 95% = 0,08-0,79), e a combinação haplotípica p16 500C-540T 500C-540T (OR = 0,27, IC 95% = 0,088-0,827) exibiram papel protetor contra o desenvolvimento de lesões mais severas. As análises de interação entre os polimorfismos de p16INK4a e a expressão de p16 ou a infecção pelo HPV foram comprometidas pelo número reduzido de amostras analisadas. Não se observou qualquer interação entre os polimorfismos estudados e os fatores de risco clássicos para o câncer de colo uterino. Nossos resultados apontam para a importância dos polimorfismos do gene p16INK4a como marcadores de severidade da neoplasia cervical.

Estudo comparativo da citotoxicidade de cimentos obturadores sobre culturas de células endoteliais da linhagem ECV 304

Este estudo teve como objetivo avaliar, in vitro, a citotoxicidade dos cimentos endodônticos Densell Endo, Pulp-Fill, Endofill, Sealer 26, Pulp Canal Sealer e GuttaFlow após 12, 24 e 72 horas de tempo de contato, utilizando-se uma linhagem de células endoteliais ECV-304. Para a avaliação da viabilidade celular, utilizou-se o teste de citotoxicidade MTT. Para cada cimento foram preparados 12 corpos de prova que foram distribuídos em seis grupos experimentais de acordo com as marcas comerciais, sendo quatro para cada tempo. Foi criado um grupo controle que não foi submetido à ação de cimento. Para avaliação do efeito dos cimentos sobre as células endoteliais, os corpos de prova foram inseridos nos poços da placa cultura, incubados a 37C em presença de 5% de CO2 e 100% de umidade. Os testes MTT foram realizados, em quadruplicata, após 12, 24 e 72 horas de contato das amostras com o tapete celular. Foi utilizada a prova Two-Way Anova com o teste Post Hoc de Bonferroni com nível de significância de 5%. Na análise de 12 horas, foi possível observar que o cimento GuttaFlow apresentou média de absorbância de 0,055, seguido do Sealer 26 (média = 0,038). Os cimentos Pulp Canal Sealer e Densell Endo apresentaram a mesma média de absorbância (0,031). O Pulp Fill e o Endofill foram os cimentos que apresentaram maior citotoxicidade (média de absorbância = 0,024 e 0,021, respectivamente). O grupo controle apresentou média de absorbância de 0,158. Em 24 horas observou-se que os cimentos GuttaFlow e Sealer 26 apresentaram as maiores médias de absorbância (0,041 e 0,037, respectivamente), seguidos pelo cimento Pulp Canal Sealer que apresentou média de absorbância de 0,035. Já os cimentos Densell Endo e Pulp Fill apresentaram médias de absorbância de 0,033 e 0,032, respectivamente. O cimento Endofill apresentou uma média de 0,026 e o grupo controle de 0,086. Quando analisados em 72 horas, o cimento Pulp Canal Sealer obteve média de absorbância de 0,049, seguido dos cimentos GuttaFlow e Pulp Fill, ambos com 0,048. Os cimentos Densell Endo, Sealer 26 e Endofill apresentaram respectivamente, médias de 0,044, 0,040 e 0,036. O grupo controle diferenciou-se significativamente de todos os grupos em todos os tempos. Quando analisadas as médias gerais de absorbância dos grupos analisados observou-se que o cimento GuttaFlow se apresentou como o cimento com menor índice de citotoxicidade, apresentando média de absorbência de 0,048. Logo após, apresentando médias de absorbância iguais (0,038) encontraram-se os cimentos Pulp Canal Sealer e Sealer 26; seguidos do Densell Endo e do Pulp Fill, com 0,036 e 0,035, respectivamente. O grupo controle apresentou média de absorbância de 0,098. Portanto, tendo como base os resultados obtidos, pôde-se concluir que o cimento Endofill foi o que apresentou maior citotoxicidade e o cimento GuttaFlow, o menos citotóxico.

Análisis del nivel de sedentarismo mediante acelerometría y cuestionario IPAQ en personas con hipertensión primaria y sobrepeso u obesidad

Antecedentes: La hipertensión arterial y el sobrepeso u obesidad son considerados factores de riesgo cardiovascular, asociados de forma clara con el sedentarismo en la población adulta. La valoración del sedentarismo se puede realizar a través de métodos objetivos y subjetivos. Objetivos: Analizar el nivel de sedentarismo, mediante el cuestionario internacional de actividad física (AF) (IPAQ, método subjetivo) y acelerometría (método objetivo) en personas con HTA primaria y sobrepeso u obesidad. Determinar si existen diferencias entre ambos métodos de valoración y entre sexos. Métodos: Se llevaron a cabo las dos pruebas de valoración a 48 participantes del estudio EXERDIET-HTA (edad 51,9 ± 8,1 años). 1) Cuestionario IPAQ en versión corta que mide la AF realizada durante los últimos siete días. Los datos se clasificaron en tiempo sedentario, ligero, moderado o intenso según las recomendaciones generales de la Organización Mundial de la Salud. 2) Acelerometría triaxial durante siete días portado en la muñeca no dominante. El tiempo dedicado a conductas sedentarias, así como las diferentes intensidades de AF (ligera, moderada, vigorosa y muy vigorosa), Kcal, METs y tiempo de sueño se calcularon para los días laborables y de fin de semana. Resultados: IPAQ presentó una media de 6 h/día en comportamientos sedentarios en ambos sexos. No se presentaron diferencias entre sexos. El 85,4% resulta sedentario. Acelerometría: Los participantes presentan 1,7±0,2 MET de media al día, considerado un valor metabólico de gasto calórico ligero. El tiempo de sueño diario fue de 6,6h. El gasto calórico diario se corresponde con comportamientos sedentarios entre semana para hombres y mujeres (2038,5±801,6 kcal) y sólo los hombres incrementan el gasto el fin de semana (P=0,036). Se observó que las mujeres realizan más minutos de AF a intensidad moderada que los hombres durante toda la semana (P=0,029). Se observaron diferencias de actividad entre los días entre semana y el fin de semana, con más tiempo de sedentarismo entre semana (P=0,040) y más AF ligera el fin de semana (P=0,003), resultando esta diferencia debida al cambio de actividad en los hombres pero no en las mujeres. Todos los participantes superan los 150 minutos de AF moderada que se recomienda en las guías mundiales según la acelerometría. Conclusiones: Las personas hipertensas y con sobrepeso u obesidad presentan en general conductas sedentarias. Los patrones de sueño podrían estar relacionados con la enfermedad. Sería necesario reducir las conductas sedentarias como prevención de la obesidad y del desarrollo prematuro de enfermedades cardiovasculares, fomentando la práctica regular de AF y mejorando los hábitos de alimentación.