Gold nano-popcorn attached SWCNT hybrid nanomaterial for targeted diagnosis and photothermal therapy of human breast cancer cells

Breast cancer presents greatest challenge in health care in today's world. The key to ultimately successful treatment of breast cancer disease is an early and accurate diagnosis. Current breast cancer treatments are often associated with severe side effects. Driven by the need, we report the design of novel hybrid nanomaterial using gold nano popcorn-attached single wall carbon nanotube for targeted diagnosis and selective photothermal treatment. Targeted SK-BR-3 human breast cancer cell sensing have been performed in 10 cancer cells/mL level, using surface enhanced Raman scattering of single walls carbon nanotube's D and G bands. Our data show that S6 aptamer attached hybrid nanomaterial based SERS assay is highly sensitive to targeted human breast cancer SK-BR-3 cell line and it will be able to distinguish it from other non targeted MDA-MB breast cancer cell line and HaCaT normal skin cell line. Our results also show that 10 min of photothermal therapy treatment by 1.5 W/cm(2) power, 785 nm laser is enough to kill cancer cells very effectively using S6 aptamer attached hybrid nanomaterials. Possible mechanisms for targeted sensing and operating principle for highly efficient photothermal therapy have been discussed. Our experimental results reported here open up a new possibility for using aptamers modified hybrid nanomaterial for reliable diagnosis and targeted therapy of cancer cell lines quickly.     

Mapping the dynamics of knowledge base of innovations of R&;D in Bangladesh: triple helix perspective

Triple helix (TH) collaborations involving university, industry and government provide a networked infrastructure for shaping the dynamic fluxes of knowledge base of innovations locally and these fluxes remain emergent within the domains. This study maps these emergence dynamics of the knowledge base of innovations of Research & Development (R&D) by exploring the longitudinal trend of systemness within the networked research relations in Bangladesh on the TH model. The bibliometric data of publications collected from the Science Citation Index (SCI), the social sciences and the arts and humanities for analysis of science indicators and the patent data collected from the US Patent Office to analyze the patent success ratio as a measure of innovation within TH domains. The findings show that the network dynamics have varied considerably according to the R&D policies of the government. The collaboration patterns of co-authorship relations in the SCI publications prominently increased, with some variation, from 1996 to 2006. Nevertheless, inter-institutional collaboration negatively influenced by the national science and technology (S&T) research policies in the last 5 years due to their evaluation criteria. Finally, the findings reveal that the R&D system of Bangladesh is still undergoing a process of institutionalizing S&T and has failed to boost its research capacity for building the knowledge base of innovations by neglecting the network effects of TH dynamics.     

EFFECTS OF HALL CURRENT AND CHEMICAL REACTION ON OSCILLATORY MIXED CONVECTION-RADIATION OF A MICROPOLAR FLUID IN A ROTATING SYSTEM

This article is concerned with the analysis of the effects of thermal radiation on oscillatory mixed convection flow of a micropolar fluid in a rotating frame of reference in the presence of transverse magnetic field and Hall current. The influence of a first-order homogeneous chemical reaction and heat source effects is also analyzed. The governing partial differential equations with the appropriate boundary conditions are reduced to a set of ordinary differential equations using similarity transformations. The dimensionless governing equations for this investigation are solved analytically after using small perturbation approximation. The effects of various parameters on the velocity, temperature, and concentration fields as well as on skin-friction coefficient, Nusselt number, and Sherwood number with their amplitude and phase are discussed in detail. Numerical results are discussed with the help of graphs and tables. Present results are also compared with previously published work.     

Hydromagnetic convective diffusion of species in Darcy–Forchheimer porous medium with non-uniform heat source/sink and variable viscosity

In this paper we have analyzed the combined effects of magnetic field and convective diffusion of species through a non-Darcy porous medium over a vertical stretching sheet with temperature dependent viscosity and non-uniform heat source/sink. The boundary layer equations are transformed into ordinary differential equations using self-similarity transformation which are then solved numerically using fifth-order Runge–Kutta Fehlberg method with shooting technique for various values of the governing parameters. The effects of electric field parameter, non-uniform heat source/sink parameters and Schmidt number on concentration profiles are analyzed and discussed graphically. Favorable comparisons with previously published work on various special cases of the problem are obtained.     

Preface

Microsystem Technologies -     

Oxidative degradation of polyaniline during the chemical oxidative polymerization of aniline in aqueous methanol medium

The course of chemical oxidative polymerization of aniline using ammonium persulfate as the initiator in acidic (1 M HCl) aqueous methanol (30 to 70 vol%) was studied spectrophotometrically. It was found that at temperatures greater than about 10 °C the reaction leads to degradation of polyaniline, the effect being greater with increasing methanol concentration. This is quite unlike the situation in aqueous ethanol where the product is the usual emeraldine hydrochloride form of polyaniline. Copyright © 2005 Society of Chemical Industry     

Numerical computation of free meandering channels with the application of slump blocks on the outer bends

Application of slump failure mechanism in the numerical modeling of the free meandering is the recent advancement towards dealing the real phenomena on the outer bends of meandering rivers with the numerical models. Recently numerous numerical simulations are performed using two-dimensional morphodynamic model for bed and bank with consideration of effects of slump blocks. Four different cases are simulated separately for steady and unsteady flow condition for about 6 h with and without slump block consideration. The measured bank erosion, channel migration and the channel width evolution show significant difference in the results due to inclusion of slump block effects. Long term simulation has been performed for 24 h to predict the free meandering behavior with variation of different slump block parameters. The result shows clear bar formation and projection, channel formation and migration towards the outer bends, making longer length of the flow path and increasing the sinuosity with the time which is very similar with the natural rivers.     

Development of an alkali-metal-free bath for electroless deposition of Co-W-P capping layers for copper interconnections

A bath containing alkali-metal-free chemicals was developed for electroless deposition of Co-W-P thin films on a copper substrate and an optimisation of bath compositions was made. Ammonium cobalt sulphate, ammonium tungstate and ammonium hypophosphite were used as the precursors of cobalt, tungsten and phosphorus, respectively. Dimethylamine borane and ammonium citrate were used as reducing and complexing agents, respectively. It was found that the cobalt content, film thickness and grain size increased with increase in cobalt ion concentration in the bath. Tungsten in the films increased from 1 to 6 at.% when its concentration in the bath was increased from 0.001 to 0.009 M. A variation of phosphorus content from 2 to 12 at.% was made by increasing its concentration from 0.01 to 0.05 M. It was found that the deposition rate decreased with increasing citrate ion concentration. Amorphous films were obtained when the combined amount of phosphorus and tungsten exceeded 12 at.% in the films. The crystalline film had small spherical crystallites with diameter less than 40 nm.     

Special issue on computing,communication and sensor network: CCSN,Puri, Odisha,India, 2014

Microsystem Technologies -     

Simple procedures to remove mimosine from young leaves, pods and seeds of Leucaena leucocephala used as food

The effect of boiling and soaking in water on the mimosine and protein contents of young leaves, pods and seeds of the tropical leguminous tree Leucaena leucocephala (leucaena) was investigated. It was observed that the soluble protein content in leucaena tissue was overestimated because of the presence of mimosine. A more accurate method of determining the soluble protein content in leucaena tissue containing mimosine was developed and used in this study. It was found that boiling removed mimosine from young leaves, pods and seeds of leucaena but it also reduced the amount of soluble protein significantly. Soaking in water for 24 h eliminated 97% of mimosine from young leaves, pods and split seeds of leucaena, and up to 20% of mimosine from the whole young seeds without significantly reducing the soluble protein content.