Fabrication of nanoconcave surface for cell immobilization in cell-based chip

Nanostructured surface such as nanoconcave shape can be utilized as a bioplatform to immobilize cells. In this study, we present fabrication of Au-coated nanoconcave surface and some possibility of cell immobilization. Long-range ordered periodic patterns with concave shape were formed on aluminum substrate by electrochemical anodization process. The morphology and topography of nanoconcave surface was investigated by atomic force microscopy and scanning electron microscopy. The pore-pore distance and the pore depth of nanoconcave pattern were measured at 105 +/- 5 nm and 30 +/- 2 nm, respectively. After Au deposition, the pore depth within Au-coated concave surface was 15 +/- 2 nm. The topography of HeLa cells immobilized on the nanoconcave surface was observed by AFM combined with confocal microscopy. The result expected that the Au-coated nanoconcave surface may be used as new culture substrate for cells immobilization in cell-based chip.     

Electrochemical sensor to detect neurotransmitter using gold nano-island coated ITO electrode

Parkinson disease is a chronic neurodegenerative disorder characterized by the loss of dopamine, which is a neurotransmitter in the substantia nigra. In this study, a simple, rapid and inexpensive method to fabricate gold nano-island film (GNIF) coated ITO electrode has been developed based on electrochemical deposition of Au onto ITO substrate. The nanostructured film surface was characterized by scanning electron microscopy (SEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the electrochemical behavior of induvidul dopamine and uric acid solution were studied. Moreover, GNIF/ITO electrode was applied to detecte DA in the presence of Bovine Serum Albumin (50 microM) as an interference. These results demonstrate that, interfering component has no effect on the determination of DA at GNIF electrode, hence this GNIF electrode is suitable for the determination of DA with high sensitivity and selectivity. Then, GNIF coated ITO electrode was applied to monitor the electrochemical simultaneous detection of dopamine and uric acid mixtures based on CV and DPV with high sensitivity. GNIF-modified ITO electrode showed a linear range for the determination of dopamine concentration from 0.1 microM to 40 microM in the presence of 50 microM of uric acid. Based on these results, the proposed technique can be a promising method to construct a highly sensitive biosensor as well as highly efficient protein chip.     

Surface-enhanced Raman scattering of dopamine on self-assembled gold nanoparticles

Dopamine, a potent neurotransmitter in the brain, influences a variety of motivated behaviors and plays a major role in Parkinson's disease. In this study, the Raman signal of dopamine was detected on a fabricated nanoparticle-immobilized glass surface by surface-enhanced raman spectroscopy (SERS). Amine-modified glass was prepared by the self-assembly of amine-terminated silane on substrate, followed by the deposition of gold nanoparticles. The gold nanoparticles deposited on the glass surface were functionalized by anti-dopamine or dopamine. The antigen-dopamine was captured by antibody-assembled gold substrate and detected by SERS. The optical properties and morpology of the glass substrate with immobilized gold nanoparticles were analyzed by scanning electron microscopy and UV-VIS absorption spectroscopy. The Raman spectrum of dopamine displayed broad bands at 1267, 1331, 1158, 1478, 1578 and 1584 cm(-1). The strongest peaks in the spectra (at 1267 and 1478 cm(-1)) were identified as phenolic carbon-oxygen and phenyl C=C stretches, respectively. A working curve of the SERS signal constructed from cathecol ring vibration versus antigen-dopamine concentration was obtained at 1478 cm(-1), and the non-optimized detection limit for anti-dopamine surface antigen was as low as 1 ng/ml. These results suggest that SERS-based immunosensor can be a promising tool for the detection and screening of neurotransmitters.     

Synthesis and characterization of PVA/YBCO nanocomposite for improvement of solar energy conversion

The development of nano‐metal oxide materials with unique optoelectronic properties such as highly solar energy absorption and generation of dense amount of electrons is one of the hottest topics now days. The incorporation of these nanomaterials into polymers results in an improvement of the properties of these polymers. Therefore, the understanding of their electronic properties is an essential demand to introduce these nanocomposites into service life. In this work, Yttrium barium copper oxide (YBCO) nanopowders with a uniform particle size of around 11 nm was prepared, sintered, and blended with polyvinyl alcohol (PVA) by casting technique. The characteristics of the structure and morphology of PVA/YBCO nanocomposite films are studied using X‐ray diffraction and transmission electron microscopy. The influence of YBCO nanoparticles on the thermal stability of PVA showed that the YBCO enhanced the thermal stability and reduced the rate of thermal degradation of PVA nanocomposites. Current–voltage behavior of PVA/YBCO nanocomposite films was measured at different temperatures. An explanation for the charge carrier concentration in the conduction band with the calculation of the barrier height, activation energy, and conversion and their dependence on temperature and applied field is presented.POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

The metamorphosis of the urban fabric in Arab-Muslim City: Riyadh, Saudi Arabia

Saudi Arabia has experienced rapid growth inurban development since the 1960s. This urbangrowth is not based on the traditional urbanplanning principles which have been followed inSaudi Arabia for many centuries. Instead,various imported urban forms and planningregulations have been implemented in thecountry. These relate neither to thetraditional built environment and culture norto the local climate of the city. As a result,major cultural and climatic problems haveoccurred. The aim of this paper is to identify andanalyze the types of built environment inRiyadh, as an example of Saudi Arabia's cities,and discuss the cultural conflicts resultingfrom the use of imported planning principlesand regulations. In light of this analysis anddiscussion, the planning regulations will bereviewed and recommendations will be made foramendments.     

Effect of annealing time on solute carbon in ultralow-carbon Ti-V and Ti-Nb steels

The influence of annealing temperature and time on solute carbon levels was investigated in four ultralow-carbon (ULC) bake-hardenable steels; two Ti-V ULC steels with different V/C levels and two Ti-Nb ULC steels with different Nb/C levels. Internal-friction and scanning transmission electron microscopy (STEM) techniques were used to understand the precipitation/dissolution behavior in the various steels. An effect of annealing time on the carbon Snoek-peak height was observed in both Ti-V steels and in the Ti-Nb steel having a lower Nb/C ratio. Despite differences between these steels resulting from their composition (and, thus, carbide solubility) differences, after cold rolling and annealing at different temperatures, the maximum Snoek-peak height was achieved after annealing for shorter times in each instance, on the order of 1 minute. The highly stabilized Ti-Nb ULC steel with a higher Nb/C ratio did not show the effect because of the absence of solute carbon. For the Ti-V steels, most of the precipitates examined using STEM contained both Ti and V. The energy-dispersive X-ray (EDX) analysis indicated that both the Ti-V steels annealed at 845 °C for 1 minute have greater Ti/V ratios compared to their corresponding Ti-V steels in the as-received (hot-rolled) condition. This behavior is consistent with dissolution of carbides causing the carbon in solution to increase, as indicated by a greater carbon Snoek-peak height for both Ti-V steels in the annealed condition. The reduction in Snoek-peak height at longer annealing times is believed to be associated with segregation to lower-energy defect sites.     

Peripheral mRNA Expression and Prognostic Significance of Emotional Stress Biomarkers in Metastatic Breast Cancer Patients

Emotional stress is believed to be associated with increased tumor progression. Stress-induced epigenetic modifications can contribute to the severity of disease and poor prognosis in cancer patients. The current study aimed to investigate the expression profiles along with the prognostic significance of psychological stress-related genes in metastatic breast cancer patients, to rationalize the molecular link between emotional stress and cancer progression. We profiled the expression of selected stress-associated genes (5-HTT, NR3C1, OXTR, and FKBP5) in breast cancer including the stress evaluation of all participants using the Questionnaire on Distress in Cancer Patients–short form (QSC-R10). A survival database, the Kaplan–Meier Plotter, was used to explore the prognostic significance of these genes in breast cancer. Our results showed relatively low expressions of 5-HTT (p = 0.02) and OXTR (p = 0.0387) in metastatic breast cancer patients as compared to the non-metastatic group of patients. The expression of NR3C1 was low in tumor grade III as compared to grade II (p = 0.04). Additionally, the expression of NR3C1 was significantly higher in patients with positive estrogen receptor status. However, no significant difference was found regarding FKBP5 expression in breast cancer. The results suggest a potential implication of these genes in breast cancer pathology and prognosis.     

Design,modeling, and analysis of a high performance piezoelectric energy harvester for intelligent tires

Basic parameters affecting vehicle safety and performance such as pressure, temperature, friction coefficient, and contact‐patch dimensions are measured in intelligent tires via sensors that require electric power for operation and wireless communication to be synchronized to the vehicle monitoring and control system. Piezoelectric energy harvesters (PEHs) can extract a fraction of energy that is wasted as a result of deflection during rolling of tires, and this extracted energy can be used to power up sensors embedded in intelligent tires. A new design of PEH inspired from Cymbal PEHs is introduced, and its performance is evaluated in this paper. Cymbal PEHs are proven to be useful in vibration energy harvesting, and in this paper, for the first time, the modified shape of Cymbal energy harvester is used as strain‐based energy harvester for the tire application. The shape of the harvester is adjusted in a way that it can be safely embedded on the inner surface of tires. In addition to the high performance, ease of manufacturing is another advantage of this new design. A multiphysics model is developed and validated to determine the output voltage, power, and energy of the designed PEH. The modeling results indicated that the maximum output voltage, the maximum electric power, and the accumulated harvested energy are about 3.5 V, 2.8 mW, and 24 mJ/rev, respectively, which are sufficient to power two sensors. In addition, the possibility is shown to supply power to five sensors by increase in piezoelectric material thickness. The effect of rolling tire temperature on the performance of the proposed PEH is also studied.     

Demanding applications in harsh environment – FeCrMnNiC amorphous equiatomic alloy thin film

An amorphous equiatomic FeCrMnNiC alloy thin film was synthesised on silica and silicon substrates by ion beam sputter deposition. Scanning electron microscopy energy-dispersive X-ray spectroscopy, X-ray diffraction, selected area electron diffraction and nano indentation were used to investigate the material. The produced film is amorphous and uniform on the atomic level without any detectable element segregation. The corrosion properties were assessed in 3.5% NaCl solution. The FeCrMnNiC alloy has corrosion resistance better than corrosion resistance of 304 SS. The thin film has hardness at around 12.3?±?0.5?GPa and reduced Young’s modulus at around 222?±?12?GPa.