Dual‐energy CT imaging of nasopharyngeal cancer cells using multifunctional gold nanoparticles

The purpose of this study is to measure the concentration of gold nanoparticles (AuNPs) attached to folic acid through cysteamin as the linker (FA‐Cys‐AuNPs) and AuNPs in KB human nasopharyngeal cancer cells using dual‐energy CT (DECT). In this study, nanoparticles with a size of ∼15 nm were synthesized and characterised using UV‐Vis, TEM, FTIR and ICP‐OES analyses. The non‐toxicity of nanoparticles was confirmed by MTT assay under various concentrations (40– 100 µg/ml) and incubation times (6, 12 and 24 h). To develop an algorithm for revealing different concentrations of AuNPs in cells, a corresponding physical phantom filled with 0.5 ml vials containing FA‐Cys‐AuNPs was used. The CT scan was performed at two energy levels (80 and 140 kVp). One feature of DECT is material decomposition, which allows separation and identification of different elements. The values obtained from the DECT algorithm were compared with values quantitatively measured by ICP‐OES. Cells were also incubated with AuNPs and FA‐Cys‐AuNPs at different concentrations and incubation times. Subsequently, by increasing the incubation time in the presence of FA‐Cys‐AuNPs, in comparison with AuNPs, DECT pixels were increased. Thus, FA‐Cys‐AuNPs could be a suitable candidate for targeted contrast agent in DECT molecular imaging of nasopharyngeal cancer cells.Inspec keywords: biomedical materials, phantoms, nanoparticles, computerised tomography, nanomedicine, cancer, toxicology, nanofabrication, gold, cellular biophysics, ultraviolet spectra, visible spectra, transmission electron microscopy, Fourier transform infrared spectraOther keywords: Au, time 24.0 hour, time 12.0 hour, time 6.0 hour, head cancer cells, DECT molecular imaging, DECT algorithm, material decomposition, physical phantom, MTT assay, ICP‐OES analyses, FTIR spectra, TEM, UV‐vis spectrophotometry, cysteamin, folic acid, gold nanoparticle concentration, nasopharyngeal cancer cells, dual‐energy CT imaging, neck cancer cells, KB human nasopharyngeal cancer cells, multifunctional gold nanoparticles     

Comparative Studies of Mechanical and Interfacial Properties Between Jute Fiber/PVC and E-Glass Fiber/PVC Composites

Composites (50 wt% fiber) of jute fiber reinforced polyvinyl chloride (PVC) matrix and E-glass fiber reinforced PVC matrix were prepared by compression molding. Mechanical properties such as tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of both types of composites was evaluated and compared. Values of TS, TM, BS, BM and IS of jute fiber/PVC composites were found to be 45 MPa, 802 MPa, 46 MPa, 850 MPa and 24 kJ/m², respectively. It was observed that TS, TM, BS, BM and IS of E-glass fiber/PVC composites were found to increase by 44, 80, 47, 92 and 37.5%, respectively. Thermal properties of the composites were also carried out, which revealed that thermal stability of E-glass fiber/PVC system was higher. The interfacial adhesion between the fibers (jute and E-glass) and matrix was studied by means of critical fiber length and interfacial shear strength that were measured by single fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were investigated by Scanning Electron Microscopy.     

Linseed amide diol/DGEBA epoxy blends for coating applications: Preparation,characterization, ageing studies and coating properties

Linseed amide diol [HELA] was used as modifier for conventionally available epoxy resin [DGEBA] by blending in different ratio. Blends [DGEBA/HELA] were subjected to spectral, physico-chemical, ageing and antibacterial studies. Interesting features of the blends were complete miscibility of HELA with DGEBA, principally due to hydrogen bonding and chemical reaction between the two constituents, and their moderate antibacterial activity against S. aureus. DGEBA/HELA blends were further treated with triethylenetetramine [TETA-A] [DGEBA/HELA/A] as curing agent to evaluate their performance as corrosion protective coating materials. DGEBA/HELA/A coatings showed good physico-mechanical and chemical resistance behavior, in particular against alkaline media. Thermal analysis of DGEBA/HELA/A revealed their single to multi-step degradation behavior with safe usage upto 220 °C. Our investigations confirm the dual role of HELA as environment-friendly, reactive-modifier and mild curing agent for epoxy resins. Besides, DGEBA/HELA/A may find potential applications as “solvent free”, ambient temperature cured antibacterial coating materials.     

Characteristics of the carbon nanotubes supported Pt−Ni and Ni electrocatalysts for DMFC

Electrocatalysts, Pt−Ni and Ni, catalysts loaded separately about 20 wt.% onto carbon nanotubes (CNTs) by the impregnation method for a direct methanol fuel cell (DMFC). The particles size and morphology of these catalysts were confirmed by XRD and TEM analysis. From the X-ray diffraction analysis, the peaks of Pt−Ni and Ni were displayed separately for each catalyst. TEM images showed that the metal catalysts were loaded uniformly and finely onto carbon nanotubes with sizes ranging from 2 to 4 nm. Finally, an electrochemical analysis was performed to determine catalytical activity of these catalysts by the cyclic voltammogram (CV).     

Physico-chemical,thermal, and mechanical properties of PLA-nHA nanocomposites: Effect of glass fiber reinforcement

In this study, tri-layered composites were prepared by reinforcing poly-lactic acid (PLA) nano-hydroxyapatite (n-HA) (1 and 5 wt%) and 20 mol% continuous phosphate glass fibers (PGF). Initially, the effect of addition of 1 and 5% n-HA on the structural, thermal, mechanical, and thermo-mechanical properties of 100% PLA was investigated. With 5 wt% n-HA addition the tensile modulus (TM), flexural modulus (FM), tensile strength (TS), and flexural strength (FS) of 100% PLA was improve by 14.9, 47.4, 6, and 32.9%, respectively. Whereas, the un-notched impact strength of the nanocomposites suffer 2% deterioration. However, T _g decreased by 0.3°C and T _c increased by 10°C as 5 wt% n-HA was added to 100% PLA. Afterwards, the 5% n-HA/PLA composite were reinforced with 20 mol% continuous PGF and the TM, FM, TS, and FS of the tri-layered composites were 162.6, 412.5, 28.4, and 157.4% higher as compared to 100%PLA. Furthermore, the storage modulus of the 1% n-HA-filled composites was 500 MPa lower than 100%PLA, while 5 wt% n-HA-filled composites showed similar storage modulus as 100% PLA. 5 wt% n-HA-filled composite showed the highest peak of loss modulus which may be attribute to the chain segment of PLA matrix after the incorporation of HA. Thus, n-HA and PGF reinforcement resulted in improved mechanical properties of the composites and have great potential as biodegradable bone fixation device with enhanced load-bearing ability.     

Double gene targeting multiplex PCR-RFLP detects Crocodylus porosus in chicken meatball and traditional medicine

Crocodiles have been hunted and consumed for centuries for skins, nutrients, and medicines. These indomitable trends have overpowered restrictions from wildlife and conservation agencies, continuing the illegal trades of crocodiles across the world. This paper described the development of a very stable, fast, and secured polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay for the confirmed detection of Crocodylus porosus under any matrices and decomposing treatments. Two very short-sites (77 and 127-bp) of atp6 and cytb genes of C. porosus were controlled digested with AciI enzyme; producing distinctive RFLP patterns (83, 54, 44 & 23 bp). The enzyme digested assay was stable following extreme boiling, autoclaving, and microwaving treatments that break down DNA. The sensitivity was tested and validated in model meatballs and it was suitable for detecting 0.01% crocodile meatball matrices. The optimized RFLP assay was used to screen 3 commercial meatballs and 21 traditional medicines (TM). While no crocodile DNA was found in commercial chicken meatballs, 4/21 TM products were found correctly labelled to contain C. porosus DNA. The novel assay demonstrated sufficient merit to be used by regulatory agencies for any forensic and/or archaeological identification of C. porosus even under the state of decomposition.     

Synthesis,formulation, and characterization of siloxane‐modified epoxy‐based anticorrosive paints

Diglycidyl ether of bisphenol A epoxy (E) was modified with hydroxyl‐terminated polydimethylsiloxane through a ring‐opening addition polymerization reaction. The structural elucidation of the siloxane‐modified epoxy resin (ES) was carried out with Fourier transform infrared, ¹H‐NMR, and ¹³C‐NMR spectroscopy techniques. The physicochemical characterization of the synthesized resin (ES) was performed with standard methods. E and ES were subjected to paint formulation with the help of a rutile (TiO₂) pigment. The formulated paint systems were cured at room temperature with 1,6‐diaminohexane (AH) and 1,3‐diaminopropane (AP), which were used as curatives. The E–AH, E–AP, ES–AH, and ES–AP paint systems were applied to mild steel strips. The physicomechanical and anticorrosive performance of the coated panels was evaluated with standard methods. The thermal analysis of these E–amine and ES–amine systems was carried out via thermogravimetric analysis. The effects of siloxane incorporation and amine curatives on the coating properties of the paint systems were also investigated. The ES–AP system exhibited good thermal and corrosion stability performance among all the E and ES paint systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4981–4991, 2006     

Development and characterization of boron incorporated linseed oil polyurethanes

The aim of this work was to investigate the structures and properties of boron incorporated linseed oil polyols (BPEPs) and their polyurethanes (BPEPUs). Hydroxylation was performed in situ using H₂O₂ and acetic acid; the syntheses of BPEPs and BPEPUs involves polyesterification and polyaddition reactions following “single‐pot, multi‐step” reactions strategy. Spectral (IR, ¹H‐NMR, and ¹³C‐NMR), physicochemical, thermal (TGA, DSC), physico‐mechanical analyses and corrosion/chemical resistance performance of aforementioned resins confirmed the incorporation of boron in polyol and polyurethane backbone. BPEPUs followed a clear cut “three step‐ambient temperature” curing strategy. They showed very good resistance to 5 wt % HCl, 3.5 wt % NaCl (unaffected for 16 and 14 days, respectively), moderate alkali resistance and moderate to good antibacterial activity against E. coli and S. aureus. Our investigations reveal that (i) the incorporation of boron has significant influence on the structural, physicochemical aspects, physico‐mechanical, chemical resistance behavior, and thermal stability of polyurethanes, (ii) boron linkages play dual role, both as cross linker and modifier, and (iii) BPEPUs may serve as efficient corrosion protective material, which may be safely employed upto 230°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Plant oil polyol nanocomposite for antibacterial polyurethane coating

Some preliminary investigations on “green” preparation, morphology and antibacterial behavior of Linseed polyol nanocomposite [LMPOL] for antibacterial polyurethane coatings are summarised. Nanocomposite is prepared in situ with Linseed polyol [LP] matrix as organic and Copper acetate as inorganic constituent by “solventless one-pot” chemical reaction. The presence of characteristic absorption bands in FTIR spectra confirmed the formation of LMPOL. TEM analysis showed the presence of nano-sized metal oxide in LMPOL. LMPOL showed good antibacterial behavior against E. coli and S. aureus. The interactions between LMPOL and bacterial surfaces lead to good antibacterial efficacy, suggesting membrane disruption based cell death. LMPOL may serve as an excellent starting material for antibacterial polyurethane coating. The approach is an excellent example for the preparation of “green” polyol from “green” resource en route Green Chemistry for protective polyurethane coatings.