Fast path and polarisation manipulation of telecom wavelength single photons in lithium niobate waveguide devices

We demonstrate fast polarisation and path control of photons at 1550 nm in lithium niobate waveguide devices using the electro-optic effect. We show heralded single photon state engineering, quantum interference, fast state preparation of two entangled photons and feedback control of quantum interference. These results point the way to a single platform that will enable the integration of nonlinear single photon sources and fast reconfigurable circuits for future photonic quantum information science and technology.Comment: 6 page

Nano-optical observation of cascade switching in a parallel superconducting nanowire single photon detector

The device physics of parallel-wire superconducting nanowire single photon detectors is based on a cascade process. Using nano-optical techniques and a parallel wire device with spatially-separate pixels we explicitly demonstrate the single- and multi-photon triggering regimes. We develop a model for describing efficiency of a detector operating in the arm-trigger regime. We investigate the timing response of the detector when illuminating a single pixel and two pixels. We see a change in the active area of the detector between the two regimes and find the two-pixel trigger regime to have a faster timing response than the one-pixel regime.Comment: 11 pages, 2 figure

The Antibacterial Effects of Zinc Ion Migration from Zinc-Based Glass Polyalkenoate Cements

Zinc-based glass polyalkenoate cements have been synthesised and their potential use in orthopaedic applications investigated. Zinc ions were released from the materials in a rapid burst over the first 24 h after synthesis, with the release rate falling below detectable levels after 7 days. Cement-implanted bone samples were prepared, and the released zinc was shown, using energy dispersive X-ray analysis, to penetrate from the cement into the adjacent bone by up to 40 μm. Finally, the cements exhibited antibacterial activity against Streptococcus mutans and Actinomyces viscosus that reflected the pattern of zinc release, with the inhibition of growth greatest shortly after cement synthesis and little or no inhibition measureable after 30 days. © Springer Science + Business Media, LLC 2006

A hydrogel-based optical fibre fluorescent pH sensor for observing lung tumor tissue acidity

Technologies for measuring physiological parameters in vivo offer the possibility of the detection of disease and its progression due to the resulting changes in tissue pH, or temperature, etc. Here, a compact hydrogel-based optical fibre pH sensor was fabricated, in which polymer microarrays were utilized for the high-throughput discovery of an optimal matrix for pH indicator immobilization. The fabricated hydrogel-based probe responded rapidly to pH changes and demonstrated a good linear correlation within the physiological pH range (from 5.5 to 8.0) with a precision of 0.10 pH units. This miniature probe was validated by measuring pH across a whole ovine lung and allowed discrimination of tumorous and normal tissue, thus offering the potential for the rapid and accurate observation of tissue pH changes.</p

Steam Turbine Risk Assessment - A Tool To Assist In Optimizing Inspection And Overhauls Of Industrial Steam Turbines.

LecturePg. 87-94There are currently no-or at best, very limited-industry guidelines or requirements on which to quantify the risk associated with turbine inspection intervals. Insurance industry data indicate that steam turbines are a major machinery loss item with underwriters. Thus, there are clear incentives to develop better tools within the industry to optimize the overhaul and inspection requirements for steam turbines. A steam turbine risk assessment project was initiated to develop a methodology to address the issue of optimization of overhauls by identifying and quantifying the risk associated with maintenance, operation, and engineering. Furthermore, this risk is related to the economic impact of the decision. The methodology followed is an adaptation of ASME RiskBased Inspection Guidelines. This process, in principle, has been previously applied in the petroleum industry for pressure vessel inspection. The process consists of five steps: • System definition • Qualitative risk assessment • Quantitative risk analysis, which includes failure modes, effects, and criticality analysis (FMECA) • Inspection program identification • Economic optimization. The result is incorporated into a computer model that will permit scenarios for individual turbines to be evaluated on a cost-riskbenefit basis. Beta testing is scheduled to begin in third quarter 1997

Loss of the Methylarginine Reader Function of SND1 Confers Resistance to Hepatocellular Carcinoma

Staphylococcal nuclease Tudor domain containing 1 (SND1) protein is an oncogene that \u27reads\u27 methylarginine marks through its Tudor domain. Specifically, it recognizes methylation marks deposited by protein arginine methyltransferase 5 (PRMT5), which is also known to promote tumorigenesis. Although SND1 can drive hepatocellular carcinoma (HCC), it is unclear whether the SND1 Tudor domain is needed to promote HCC. We sought to identify the biological role of the SND1 Tudor domain in normal and tumorigenic settings by developing two genetically engineered SND1 mouse models, an Snd1 knockout (Snd1 KO) and an Snd1 Tudor domain-mutated (Snd1 KI) mouse, whose mutant SND1 can no longer recognize PRMT5-catalyzed methylarginine marks. Quantitative PCR analysis of normal, KO, and KI liver samples revealed a role for the SND1 Tudor domain in regulating the expression of genes encoding major acute phase proteins, which could provide mechanistic insight into SND1 function in a tumor setting. Prior studies indicated that ectopic overexpression of SND1 in the mouse liver dramatically accelerates the development of diethylnitrosamine (DEN)-induced HCC. Thus, we tested the combined effects of DEN and SND1 loss or mutation on the development of HCC. We found that both Snd1 KO and Snd1 KI mice were partially protected against malignant tumor development following exposure to DEN. These results support the development of small molecule inhibitors that target the SND1 Tudor domain or the use of upstream PRMT5 inhibitors, as novel treatments for HCC

Loss of the Methylarginine Reader Function of SND1 Confers Resistance to Hepatocellular Carcinoma

Staphylococcal nuclease Tudor domain containing 1 (SND1) protein is an oncogene that \u27reads\u27 methylarginine marks through its Tudor domain. Specifically, it recognizes methylation marks deposited by protein arginine methyltransferase 5 (PRMT5), which is also known to promote tumorigenesis. Although SND1 can drive hepatocellular carcinoma (HCC), it is unclear whether the SND1 Tudor domain is needed to promote HCC. We sought to identify the biological role of the SND1 Tudor domain in normal and tumorigenic settings by developing two genetically engineered SND1 mouse models, an Snd1 knockout (Snd1 KO) and an Snd1 Tudor domain-mutated (Snd1 KI) mouse, whose mutant SND1 can no longer recognize PRMT5-catalyzed methylarginine marks. Quantitative PCR analysis of normal, KO, and KI liver samples revealed a role for the SND1 Tudor domain in regulating the expression of genes encoding major acute phase proteins, which could provide mechanistic insight into SND1 function in a tumor setting. Prior studies indicated that ectopic overexpression of SND1 in the mouse liver dramatically accelerates the development of diethylnitrosamine (DEN)-induced HCC. Thus, we tested the combined effects of DEN and SND1 loss or mutation on the development of HCC. We found that both Snd1 KO and Snd1 KI mice were partially protected against malignant tumor development following exposure to DEN. These results support the development of small molecule inhibitors that target the SND1 Tudor domain or the use of upstream PRMT5 inhibitors, as novel treatments for HCC

Gallium Arsenide (GaAs) Quantum Photonic Waveguide Circuits

Integrated quantum photonics is a promising approach for future practical and large-scale quantum information processing technologies, with the prospect of on-chip generation, manipulation and measurement of complex quantum states of light. The gallium arsenide (GaAs) material system is a promising technology platform, and has already successfully demonstrated key components including waveguide integrated single-photon sources and integrated single-photon detectors. However, quantum circuits capable of manipulating quantum states of light have so far not been investigated in this material system. Here, we report GaAs photonic circuits for the manipulation of single-photon and two-photon states. Two-photon quantum interference with a visibility of 94.9 +/- 1.3% was observed in GaAs directional couplers. Classical and quantum interference fringes with visibilities of 98.6 +/- 1.3% and 84.4 +/- 1.5% respectively were demonstrated in Mach-Zehnder interferometers exploiting the electro-optic Pockels effect. This work paves the way for a fully integrated quantum technology platform based on the GaAs material system.Comment: 10 pages, 4 figure

Photon Pair Generation in Silicon Micro-Ring Resonator with Reverse Bias Enhancement

Photon sources are fundamental components for any quantum photonic technology. The ability to generate high count-rate and low-noise correlated photon pairs via spontaneous parametric down-conversion using bulk crystals has been the cornerstone of modern quantum optics. However, future practical quantum technologies will require a scalable integration approach, and waveguide-based photon sources with high-count rate and low-noise characteristics will be an essential part of chip-based quantum technologies. Here, we demonstrate photon pair generation through spontaneous four-wave mixing in a silicon micro-ring resonator, reporting a maximum coincidence-to-accidental (CAR) ratio of 602 (+-) 37, and a maximum photon pair generation rate of 123 MHz (+-) 11 KHz. To overcome free-carrier related performance degradations we have investigated reverse biased p-i-n structures, demonstrating an improvement in the pair generation rate by a factor of up to 2, with negligible impact on CAR.Comment: 5 pages, 3 figure