681 research outputs found

    Carbon Nanotube/PEDOT: PSS Composite-based Flexible Temperature Sensor with Enhanced Response and Recovery Time

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    Temperature sensors with good mechanical flexibility, high sensitivity, fast response and recovery time are essential features for real time measurements by electronic Skin (eSkin). This paper presents the fabrication and characterization of a flexible temperature sensor using PEDOT: PSS and carbon nanotube (CNT) at 1:1 mixing ratio. In order to establish the performance enhancement capability of this composition, a comparative study was carried out. This was done by fabricating two flexible temperature sensors each on ~175μm-thick PVC substrate using only CNT and then with CNT/PEDOT: PSS polymer composite following simple drop casting technique. Both sensors show good sensitivity ~0.27(%)oC -1 )) for CNT and ~0.64(%)oC -1 )) for CNT/PEDOT: PSS for temperatures varying from 20°C to 80°C. Although both the sensors, CNT and CNT/PEDOT: PSS composite revealed fast response and recovery time, the latter shows a higher sensitivity (~0.64 (%)oC -1 )). Further, a comparison of the sensor made with CNT/PEDOT: PSS with similar works in literature reveals that the presented sensor exhibits relatively faster response (~4.8s) and recovery (~2.5s) time. This response enhancement can provide a biomimetic eSkin with unique feature

    Highly Sensitive Flexible Capacitive Pressure Sensor with ZnO NW interlayers

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    Pressure or force sensors that can reliably detect a broad range of pressure with high sensitivity are prerequisite for applications such as human-machine interface, electronic skin in robotics, and health monitoring. This paper presents a novel approach to fabricate a highly sensitive capacitive pressure sensor by introducing a zinc oxide nanowire (ZnO NW) interlayers between the polydimethylsiloxane (PDMS)/electrodes interface in the conventional metal-insulator-metal architecture. The sensing performances of PDMS-based pressure sensors with and without ZnO NW interlayers were investigated. The ZnO NW interlayers reinforced the electrical connection from metal to PDMS to significantly enhance the device performance with ~50 times improvement in sensitivity (from 0.125 %kPa -1 to 5.6452 %kPa -1 at a low-pressure range (0-10 kPa)) with respect to conventional PDMS only dielectric-based capacitive sensors

    MicroRNA-383 located in frequently deleted chromosomal locus 8p22 regulates CD44 in prostate cancer.

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    A major genomic alteration in prostate cancer (PCa) is frequent loss of chromosome (chr) 8p with a common region of loss of heterozygosity (LOH) at chr8p22 locus. Genomic studies implicate this locus in the initiation of clinically significant PCa and with progression to metastatic disease. However, the genes within this region have not been fully characterized to date. Here we demonstrate for the first time that a microRNA component of this region-miR-383-is frequently downregulated in prostate cancer, has a critical role in determining tumor-initiating potential and is involved in prostate cancer metastasis via direct regulation of CD44, a ubiquitous marker of PCa tumor-initiating cells (TICs)/stem cells. Expression analyses of miR-383 in PCa clinical tissues established that low miR-383 expression is associated with poor prognosis. Functional data suggest that miR-383 regulates PCa tumor-initiating/stem-like cells via CD44 regulation. Ectopic expression of miR-383 inhibited tumor-initiating capacity of CD44+ PCa cells. Also, 'anti-metastatic' effects of ectopic miR-383 expression were observed in a PCa experimental metastasis model. In view of our results, we propose that frequent loss of miR-383 at chr8p22 region leads to tumor initiation and prostate cancer metastasis. Thus, we have identified a novel finding that associates a long observed genomic alteration to PCa stemness and metastasis. Our data suggest that restoration of miR-383 expression may be an effective therapeutic modality against PCa. Importantly, we identified miR-383 as a novel PCa tissue diagnostic biomarker with a potential that outperforms that of serum PSA

    Superoxide dismutase analog (Tempol: 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine 1-oxyl) treatment restores erectile function in diabetes-induced impotence.

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    We hypothesized that the administration of the superoxide dismutase (SOD) mimetic Tempol (4-hydroxy-2, 2, 6, 6-tetramethylpiperidine 1-oxyl) may reverse diabetes-induced erectile dysfunction. To test this hypothesis, reactive oxygen species-related genes (SOD1, SOD2, GP x 1, CAT, NOS2, NOS3) were tested, erectile functional studies and immunohistochemical analysis were carried out in diabetic rats treated with or without Tempol. Thirty Sprague-Dawley (3-4 months old) rats were divided into three groups (n=10 each), 20 with diabetes (diabetic control and Tempol treatment) and 10 healthy controls. At 12 weeks after the induction of diabetes by streptozotocin and Tempol treatment, all groups underwent in vivo cavernous nerve stimulation. Rat crura were harvested and the expression of antioxidative defense enzymes were examined by semi-quantitative reverse transcriptase PCR (RT-PCR). To confirm the RT-PCR results, we carried out immunohistochemistry (IHC) for catalase (CAT) and iNOS (NOS2). Nitration of tyrosine groups in proteins was also examined by IHC. Mean intracavernous pressure in the diabetic group was significantly lower than in the healthy controls (P <0.001) and was reversed by Tempol treatment (P <0.0108). NOS2 protein expression was significantly increased in diabetic animals compared with healthy controls and Tempol restored NOS2 protein level. Nitrotyrosine was also higher in diabetic animals and although Tempol treatment decreased its formation, it remained higher than that found in healthy controls. This study suggests that Tempol treatment increased erectile function through modulating oxidative stress-related genes in diabetic rats. This is the first report about the relationship between diabetes-induced erectile dysfunction and oxidative stress, and antioxidative therapy using the superoxide dismutase mimetic, Tempol, to restore erectile function

    Flexible FETs using ultrathin Si microwires embedded in solution processed dielectric and metal layers

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    This work presents a novel manufacturing route for obtaining high performance bendable field effect transistors (FET) by embedding silicon (Si) microwires (2.5 μm thick) in layers of solution-processed dielectric and metallic layers. The objective of this study is to explore heterogeneous integration of Si with polymers and to exploit the benefits of both microelectronics and printing technologies. Arrays of Si microwires are developed on silicon on insulator (SOI) wafers and transfer printed to polyimide (PI) substrate through a polydimethylsiloxane (PDMS) carrier stamp. Following the transfer printing of Si microwires, two different processing steps were developed to obtain top gate top contact and back gate top contact FETs. Electrical characterizations indicate devices having mobility as high as 117.5 cm2 V−1 s−1. The fabricated devices were also modeled using SILVACO Atlas. Simulation results show a trend in the electrical response similar to that of experimental results. In addition, a cyclic test was performed to demonstrate the reliability and mechanical robustness of the Si μ-wires on flexible substrates

    Adjusting Pigeonpea Sowing Time to Manage Pod Borer Infestation

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    In on-farm field trials in the 1995 and 1996 rainy seasons in the Sonipat District, Haryana, Cajanus cajan was sown in the first week of May, mid-May or mid-June and pod borer (Helicoverpa armigera) infestation was recorded on 10 randomly selected plants at each sowing. Averaged over the 2 years pod borer damage was 6.5, 25 and 38% for the 3 sowing dates, respectively. Grain yield decreased with delay in sowing from 1.6 t/ha with early sowing to 1.0 t/ha with late sowing in mid-June. It was concluded that sowing C. cajan early is an important management strategy to control pod borer in C. cajan

    Nod2 Downregulates TLR2/1 Mediated IL1β Gene Expression in Mouse Peritoneal Macrophages

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    Nod2 is a cytosolic pattern recognition receptor. It has been implicated in many inflammatory conditions. Its signaling has been suggested to modulate TLR responses in a variety of ways, yet little is known about the mechanistic details of the process. We show in this study that Nod2 knockdown mouse peritoneal macrophages secrete more IL1β than normal macrophages when stimulated with peptidoglycan (PGN). Muramyl dipeptide (MDP, a Nod2 ligand) + PGN co-stimulated macrophages have lower expression of IL1β than PGN (TLR2/1 ligand) stimulated macrophages. MDP co-stimulation have similar effects on Pam3CSK4 (synthetic TLR2/1 ligand) mediated IL1β expression suggesting that MDP mediated down regulating effects are receptor dependent and ligand independent. MDP mediated down regulation was specific for TLR2/1 signaling as MDP does not affect LPS (TLR4 ligand) or zymosan A (TLR2/6 ligand) mediated IL1β expression. Mechanistically, MDP exerts its down regulating effects by lowering PGN/Pam3CSK4 mediated nuclear cRel levels. Lower nuclear cRel level were observed to be because of enhanced transporting back rather than reduced nuclear translocation of cRel in MDP + PGN stimulated macrophages. These results demonstrate that Nod2 and TLR2/1 signaling pathways are independent and do not interact at the level of MAPK or NF-κB activation

    Chiral symmetry in linear Sigma model in magnetic environment

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    We study the chiral symmetry structure in a linear sigma model with fermions in the presence of an external, uniform magnetic field in the 'effective potential' approach at the one loop level. We also study the chiral phase transition as a function of density in the core of magnetized neutron stars.Comment: LaTex2e file with six postscript figures. journal ref: Physical Review D 62 (2000) 02502

    Mechanism of single-spin asymmetries generation in the inclusive hadron processes

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    We discuss a nonperturbative mechanism for generation of the single-spin asymmetries in hadron interactions. It is based on the chiral quark model combined with unitarity and impact parameter picture and provides explanation for the experimental regularities observed under the measurements of the spin asymmetries.Comment: 20 pages, 7 figure

    Extra-short-duration pigeonpea for diversifying wheat-based cropping systems in the sub-tropics

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    The performance of newly developed extra-short-duration pigeonpea (Cajanus cajan) genotypes and traditional short-duration pigeonpea cultivars was compared in rotation with wheat in on-farm trials conducted in 1996–97 and 1997–98 in Sonepat (28° N) district in Haryana, and in 1996–97 at Ludhiana (30° N) district in Punjab, India. At both locations, a wheat crop (Triticum aestivum cv. HD 2329) followed pigeonpea. At Sonepat, an indeterminate extra-short-duration genotype ICPL 88039 matured up to three weeks earlier, yet gave 12% higher yield (1.57 t ha−1) and showed less susceptibility to borer damage than did the short-duration cv. Manak. At Ludhiana, extra-short-duration pigeonpea genotypes, ICPL 88039, ICPL 85010 and AL 201 gave similar grain yields to the short-duration T 21 in spite of maturing three to four weeks earlier. Yields of wheat crops following extra-short-duration genotypes were up to 0.75 t ha−1 greater at Sonepat and up to 1.0 t ha−1 greater at Ludhiana. The results of the study provide empirical evidence that extra-short-duration pigeonpea genotypes could contribute to higher productivity of pigeonpea–wheat rotation systems. Most of the farmers who grew on-farm trials in Sonepat preferred extra-short-duration to short-duration pigeonpea types for their early maturity, bold seed size, and the greater yield of the following wheat crop
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