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Attachment of Docetaxel to Multiwalled Carbon Nanotubes for Drug Delivery Applications
No full textIn this manuscript we report the development of multiwalled carbon nanotubes-docetaxel conjugate by covalent interaction, involving nucleophilic substitution reaction mechanism. The surface functionalization of nanotubes was carried out by enrichment of carboxylic groups with optimized oxidation treatment. The carboxyl groups were converted to acyl groups followed by covalent attachment of docetaxel to multiwalled carbon nanotubes with a cleavable ester linkage. The drug carbon nanotube conjugate was characterized by Fourier Transform Infra red, UV-Visible, Raman spectroscopy, Scanning and Transmission electron microscopy. The drug release from the conjugate was studied in vitro in phosphate buffers having pH 5, 6.8 and 7.4. It was demonstrated that conjugate showed drug release faster in acidic pH, which resembles the pH of cancerous cells, as compared to buffer of normal cell pH. This property would reduce the drug dosage thereby substantially benefit the antitumor effect and would boost significantly the applications of carbon nanotubes in the biomedicine field
Indigenous Development of Integrated Medical Linac System for Cancer Therapy
No full text6MV Integrated Medical LINAC system was developed for Cancer Therapy jointly by CSIR-CSIO Chandigarh and SAMEER Mumbai under the Jai Vigyan Programme of the Government of India.
Six machines were originally planned to be commissioned in six cancer hospitals in the country. Two machines, namely SIDDHARTH I & SIDDHARTH II, have already been developed and deployed at MGIMS, Sevagram, Wardha (Maharashtra) and at Cancer Institute (WIA), Adyar, Chennai. These machines are working satisfactorily since their installation. Four more machines namely SIDDHARTH III - VI, are under way which will be commissioned in four national cancer institutes by the end of next year. This paper describes in brief the scientific principles of LINAC machines and technological challenges involved in the design and development of such a system of multi disciplinary activities
Bioconjugation of InGaP quantum dots for molecular sensing
No full textFluorescence-based molecular sensing and cellular imaging are commonly carried out with the application of organic dyes. Quantum dots (QDs) are now recognized as better tools because they are brighter, size tunable, and more photostable than dyes. Most of the proposed QD-based biosensing systems involve elements of known toxicity. The present work reports the functionalization of biocompatible InGaPanS core-shell QDs with anti-bovine serum albumin (anti-BSA) to exploit them as fluorescent probes for antigen detection. Successful bioconjugation was characterized with the absorption and emission spectra showing blue shifts of around 40 and 30 nm, respectively. Gel electrophoresis and particle size distribution studies further confirmed the mass increment of QDs after their functionalization with anti-BSA. Surface plasmon resonance spectrometry has been used to study the affinity of QD-(anti-BSA) probes for bovine serum albumin (BSA). Photoluminescence quenching of the developed probe is observed in the presence of BSA. (C) 2011 Elsevier Inc. All rights reserved
Grey Relational Analysis of Micro-EDM Machining of Ti-6Al-4V Alloy
No full textIn the present work, micro-electric discharge machining micro-EDM) of Ti-6Al-V alloy with tungsten carbide electrode has been performed. Ti-6Al-4V, which is difficult to machine via conventional machining techniques, however, can be easily machined via EDM machining, with careful selection of machining parameters for getting optimum results. In this study, the effect of various input parameters; current, voltage, frequency, and width, on output parameter viz., metal removal rate (MRR), tool wear rate (TWR), and overcut (OC) are studied. Grey relational analysis and analysis of variance (ANOVA) have been performed to optimize the levels of input parameters
Prediction model for moisture determination of Indian wheat based on electrical properties variations
No full textMeasurement of moisture is an important aspect in harvesting, drying, storing and processing of grains. The objective of this study was to develop a new method for the moisture measurement of Triticum aestivum, a cultivar of Indian wheat grain, by using measurements obtained by electrical spectroscopy. The relationship between electrical properties of Indian wheat and moisture content, with range 7.96% to 31.58%, was investigated within frequency range of 1 KHz to 1 MHz. An investigation of the effect of frequency characteristics on moisture content was performed and the best frequency was chosen for further investigations. Partial least square regression technique was applied to illustrate the dependence of electrical properties viz. capacitance, impedance, and dissipation factor on frequency and moisture content. Moisture prediction model using these properties was developed and it was observed that the new method increased accuracy of moisture measurement as compared with that obtained using a single parameter. The experimental samples were divided into three classes – low, medium and high moisture, and samples were reanalyzed to investigate range-specific precision of selected frequency. The developed model can estimate the moisture content within performance expected from a commercial moisture meter
Design of a below elbow myoelectric arm with proportional grip force
No full textThis study presents complete design of a myoelectric arm with proportional grip force feature. Electronic assembly of the arm consists of the analog and digital signal processing and a control circuit. EMG signal from residual stump of patient is picked up by surface electrodes, amplified and an artifacts free signal is digitized in a controlled manner so that minimum signal loss occurs during processing. Mechanical assembly consists of a screw arrangement connected to a low power DC motor and gear assembly to open or close the hand. Wrist is rotated in a direction suitable to pick up the objects
Highly reflective titania nanoparticle-based coating
No full textPurpose – The purpose of this paper is to investigate the reflective properties of titania (TiO2) nanoparticle-based coating.Design/methodology/approach – TiO2 nanoparticles, synthesised by sol-gel method, were characterised by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and ultraviolet-visible absorption spectroscopy (UV-vis). The coating material has been prepared by dispersing titania nanoparticles in an acrylic binder with different pigment to binder weight ratio. The reflectors were prepared by applying this coating material to different coating thicknesses to aluminium sheets. Findings – In the study reported here, the coating material could produce reflectors with diffuse reflectance, ~99 per cent, using coating material, having binder by weight ratio between 14 and 20 per cent, and thickness, 0.15?mm. On exposing the developed reflectors to different levels of illumination (upto 20,000 lux), they were still found to have diffuse reflectance of more than 96 per cent almost throughout the visible spectrum.
Practical implications – The fabricated reflectors find applications in commercial optical products, such as: reflective panels, luminaries, etc. Originality/value – As of today, the reflective coatings used are of conventional type, which employ bulk TiO2 particles. In this study, we are reporting TiO2 nanoparticle-based highly reflective coating. This is an original work, and, to the best of our knowledge, no one has ever reported on “TiO2 nanoparticle-based reflective coatings”
Effect of flushing condition on deep hole micro-EDM drilling
No full textThis paper describes the effect of various flushing conditions on the accuracy of deep holes drilled via micro electrical discharge machining (EDM) machining. Copper tubes were used for deep hole drilling in copper. Various dielectric flushing conditions (side jet flushing, through flushing, through flushing combined with side jet flushing, immersion flushing) were evaluated for their effect on the diameter variation, overcut and circularity at workpiece entrance and exit of deep hole drilled. Through flushing and immersion flushing were observed suitable for deep hole drilling whereas side flushing and its combination with through flushing were observed unsuitable for higher aspect ratios holes
Optimization of surface roughness in turning unidirectional glass fiber reinforced plastics (UD-GFRP) composites using polycrystalline diamond (PCD) cutting tool
No full textGlass fiber reinforced plastic (GFRP) composite materials are a feasible alternative to engineering materials and are being extensively used in variety of engineering applications. Machining of unidirectional glass fiber reinforced plastic (UD-GFRP) composites is different from that of conventional materials and causes excessive tool wear. A study is conducted in the machining of unidirectional glass fiber reinforced plastic (UD-GFRP) composite material to investigate the effect of tool nose radius, tool rake angle, feed rate, cutting speed, depth of cut and along with cutting environment (dry, wet and cooled (5-7°C) temperature) on the surface roughness produced. The experimental results reveal that the most significant machining parameters for surface roughness is feed rate followed by cutting speed. Cutting environment does not influence the surface roughness significantly. The predicted values and measured values are in good agreement as observed by further confirmation experiment
Highly Sensitive Glucose Sensing With Multi-Walled Carbon Nanotubes – Polyaniline Composite
No full textMulti-walled carbon nanotubes (MWCNTs) have been carboxylated and then immobilized with glucose oxidase (GOx) by amine coupling through EDC-NHS chemistry. These functionalized MWCNTs have been introduced into polyaniline matrix by electrochemical method. The different involved steps have been characterized with molecular and electronic spectroscopy. Prepared thin films preserved the enzymatic activity of GOx and their average electrical conductivity was measured as 3.78 × 10−1 S cm−1. Observed response time was 5 s and a linear pattern of current vs. concentration was recorded for 0.5–22 mM glucose