849 research outputs found

    Thermo-coupled Temperature Sensors By Seven-core MCF Structures

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    In this paper, we present an enhanced sensitivity of temperature sensors based on thermo-coupled Multicore Fiber (MCF) structures. The sensors are all fabricated using a controlled arc power of a splicing device. Two different principles of a Mach-Zehnder interferometer (MZI) and Michelson interferometer (MI) have been observed experimentally. The MZI and MI structures exhibit temperature sensitivity as 136.67 pm/°C and 70.61 pm/°C, respectively, and found insensitive to the refractive index (RI). Also, its RI response can readily resolve the issues of cross-sensitivity

    A Design Of Taper-Like Etched Multicore Fiber Refractive Index-Insensitive A Temperature Highly Sensitive Mach-Zehnder Interferometer

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    We propose and demonstrate Mach-Zehnder interferometer (MZI), which is the refractive index (RI) insensitive and temperature highly sensitive based on etched multi-core fiber (MCF) structure. The MCF and Fiber Bragg Grating (FBG) are used as hybrid sensing elements. The fabrication of the interferometer is provided a new taper-like structure by etching the MCF to further expose the side cores to the surroundings. The interferometer has produced a sensitivity of 103.2pm/°C within the ambient temperature up-to 70°C. Moreover, the superior temperature sensitivity is 89.19pm/°C, 66.64pm/°C, 56.42pm/°C in the range of 24°C to 130°C, and RI-insensitive in the range of 1.34 to 1.38, for different waists of etched seven-core fiber interferometers (E7CFIs) \sim ~84.70\mu \text{m} , 93.10\mu \text{m} , 108.67\mu \text{m} , respectively. Compared with the conventional FBGs, the sensitivity of the interferometer is significantly improved by 8 times. E7CFI\u27s novel and advantageous features can easily be distinguished other devices. Besides, the proposed sensing architecture is compact, easy to fabricate, highly sensitive, easy to reproduce, and makes it an inexpensive fiber optic device

    Evaluation of nano-frictional and mechanical properties of a novel Langmuir-Blodgett monolayer/self-assembly monolayer composite structure

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    A novel stearic acid (SA)/3-aminopropyltrethoxysilane (APS) composite structure was fabricated using the combined method of the Langmuir-Blodgett technique and self-assembly monolayer (SAM) technique. Its frictional, adhesive properties and interface contact types between the atomic force microscope tip and the samples were evaluated based on Amonton's laws and the general Carpick's transition equation, respectively. The results showed that the tip-sample contacts corresponded to the Johnson-Kendall-Robert/Derjaguin-Muller-Toporov (DMT) transition model for SiO2, APS-SAMs, and the unheated SA-APS composite structure, and for the heated SA-APS bilayer to the DMT model. Frictional forces for the four samples were linearly dependent on external loads at higher loads, and at lower loads they were significantly affected by adhesive forces. Frictional and scratching tests showed that the heated SA-APS composite structure exhibited the best lubricating properties and adhesion resistance ability, and its wear resistance capacity was greatly improved due to the binding-mode conversion from hydrogen bonds to covalent bonds. Thus, this kind of composite bilayer might be promising for applications in the lubrication of nano/microelectromechanical systems. I.Comment: 8 pages, 8 figure

    Genetic polymorphism in the manganese superoxide dismutase gene, antioxidant intake, and breast cancer risk: results from the Shanghai Breast Cancer Study

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    INTRODUCTION: It has been suggested that oxidative stress and mitochondrial DNA damage play important roles in breast cancer carcinogenesis. Manganese superoxide dismutase (MnSOD) is a major enzyme that is responsible for the detoxification of reactive oxygen species in the mitochondria. A T → C substitution in the MnSOD gene results in a Val → Ala change at the -9 position of the mitochondrial targeting sequence (Val-9Ala), which alters the protein secondary structure and thus affects transport of MnSOD into the mitochondria. METHODS: We evaluated this genetic polymorphism in association with breast cancer risk using data from the Shanghai Breast Cancer Study, a population-based case–control study conducted in urban Shanghai from 1996 to 1998. The MnSOD Val-9Ala polymorphism was examined in 1125 breast cancer cases and 1197 age-frequency-matched control individual. RESULTS: Breast cancer risk was slightly elevated in women with Ala/Ala genotype (odds ratio [OR] 1.3, 95% confidence interval [CI] 0.7–2.3), particularly among premenopausal women (OR 1.8, 95% CI 0.9–3.7), as compared with those with Val/Val genotype. The increased risk with the Ala/Ala genotype was stronger among premenopausal women with a higher body mass index (OR 2.5, 95% CI 0.9–7.0) and more years of menstruation (OR 2.6, 95% CI 0.8–8.0). The risk among premenopausal women was further increased twofold to threefold among those with a low intake of fruits, vegetables, vitamin supplements, selenium, or antioxidant vitamins, including carotenes and vitamins A, C, and E. However, the frequency of the Ala allele was low (14%) in the study population, and most of the ORs provided above were not statistically significant. CONCLUSION: The present study provides some evidence that genetic polymorphism in the MnSOD gene may be associated with increased risk of breast cancer among Chinese women with high levels of oxidative stress or low intake of antioxidants. Studies with a larger sample size are needed to confirm the findings

    Inhibition of yes-associated protein suppresses brain metastasis of human lung adenocarcinoma in a murine model.

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    Yes-associated protein (YAP) is a main mediator of the Hippo pathway and promotes cancer development and progression in human lung cancer. We sought to determine whether inhibition of YAP suppresses metastasis of human lung adenocarcinoma in a murine model. We found that metastatic NSCLC cell lines H2030-BrM3(K-rasG12C mutation) and PC9-BrM3 (EGFRΔexon19 mutation) had a significantly decreased p-YAP(S127)/YAP ratio compared to parental H2030 (K-rasG12C mutation) and PC9 (EGFRΔexon19 mutation) cells (P < .05). H2030-BrM3 cells had significantly increased YAP mRNA and expression of Hippo downstream genes CTGF and CYR61 compared to parental H2030 cells (P < .05). Inhibition of YAP by short hairpin RNA (shRNA) and small interfering RNA (siRNA) significantly decreased mRNA expression in downstream genes CTGF and CYR61 in H2030-BrM3 cells (P < .05). In addition, inhibiting YAP by YAP shRNA significantly decreased migration and invasion abilities of H2030-BrM3 cells (P < .05). We are first to show that mice inoculated with YAP shRNA-transfected H2030-BrM3 cells had significantly decreased metastatic tumour burden and survived longer than control mice (P < .05). Collectively, our results suggest that YAP plays an important role in promoting lung adenocarcinoma brain metastasis and that direct inhibition of YAP by shRNA suppresses H2030-BrM3 cell brain metastasis in a murine model

    Structural Interaction and Functional Regulation of Polycystin-2 by Filamin

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    Filamins are important actin cross-linking proteins implicated in scaffolding, membrane stabilization and signal transduction, through interaction with ion channels, receptors and signaling proteins. Here we report the physical and functional interaction between filamins and polycystin-2, a TRP-type cation channel mutated in 10–15% patients with autosomal dominant polycystic kidney disease. Yeast two-hybrid and GST pull-down experiments demonstrated that the C-termini of filamin isoforms A, B and C directly bind to both the intracellular N- and C-termini of polycystin-2. Reciprocal co-immunoprecipitation experiments showed that endogenous polycystin-2 and filamins are in the same complexes in renal epithelial cells and human melanoma A7 cells. We then examined the effect of filamin on polycystin-2 channel function by electrophysiology studies with a lipid bilayer reconstitution system and found that filamin-A substantially inhibits polycystin-2 channel activity. Our study indicates that filamins are important regulators of polycystin-2 channel function, and further links actin cytoskeletal dynamics to the regulation of this channel protein

    Rechargeable Li/Cl2_2 battery down to -80 {\deg}C

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    Low temperature rechargeable batteries are important to life in cold climates, polar/deep-sea expeditions and space explorations. Here, we report ~ 3.5 - 4 V rechargeable lithium/chlorine (Li/Cl2) batteries operating down to -80 {\deg}C, employing Li metal negative electrode, a novel CO2 activated porous carbon (KJCO2) as the positive electrode, and a high ionic conductivity (~ 5 to 20 mS cm-1 from -80 {\deg}C to 25 {\deg}C) electrolyte comprised of 1 M aluminum chloride (AlCl3), 0.95 M lithium chloride (LiCl), and 0.05 M lithium bis(fluorosulfonyl)imide (LiFSI) in low melting point (-104.5 {\deg}C) thionyl chloride (SOCl2). Between room-temperature and -80 {\deg}C, the Li/Cl2 battery delivered up to ~ 30,000 - 4,500 mAh g-1 first discharge capacity and a 1,200 - 5,000 mAh g-1 reversible capacity (discharge voltages in ~ 3.5 to 3.1 V) over up to 130 charge-discharge cycles. Mass spectrometry and X-ray photoelectron spectroscopy (XPS) probed Cl2 trapped in the porous carbon upon LiCl electro-oxidation during charging. At lower temperature down to -80 {\deg}C, SCl2/S2Cl2 and Cl2 generated by electro-oxidation in the charging step were trapped in porous KJCO2 carbon, allowing for reversible reduction to afford a high discharge voltage plateau near ~ 4 V with up to ~ 1000 mAh g-1 capacity for SCl2/S2Cl2 reduction and up to ~ 4000 mAh g-1 capacity at ~ 3.1 V plateau for Cl2 reduction. Towards practical use, we made CR2032 Li/Cl2 battery cells to drive digital watches at -40 {\deg}C and light emitting diode at -80 {\deg}C, opening Li/Cl2 secondary batteries for ultra-cold conditions
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