Although near-infrared photons in telecommunication bands are required for long-distance quantum communication, various quantum information tasks have been performed by using visible photons for the past two decades. Recently, such visible photons from diverse media including atomic quantum memories have also been studied. Optical frequency downconversion from visible to telecommunication bands while keeping the quantum states is thus required for bridging such wavelength gaps. Here we report demonstration of a quantum interface of frequency down-conversion from visible to telecommunication bands by using a nonlinear crystal, which has a potential to work over wide bandwidths, leading to a highspeed interface of frequency conversion. We achieved the conversion of a picosecond visible photon at 780 nm to a 1,522-nm photon, and observed that the conversion process retained entanglement between the down-converted photon and another photon.

The one-dimensional 2 H double quantum filtered (DQF) spectroscopic imaging technique was used to study the orientation of collagen fibers in articular cartilage. The method detects only water molecules in anisotropic environments, which in cartilage is caused by their interaction with the collagen fibers. A large quadrupolar splitting was observed in the calcified zone and a smaller splitting in the radial zone. In the transitional zone the splitting was not resolved and a small splitting was again detected in the superficial zone. From measurements performed at two orientations of the plug relative to the magnetic field it was deduced that in the calcified and radial zones the fibers are oriented perpendicular to the bone, bending at the transitional zone and flattening at the superficial zone. The effect of load applied to the cartilage-bone plug was monitored by the same technique. At low loads there is a small decrease in the quadrupolar splitting in the calcified zone, a marked decrease in the radial zone, and an increase of the splitting accompanied by a thickening of the superficial zone. Under high loads, while the thickening and the splitting of the superficial zone further increase, the splitting in the radial and calcified zones completely Key words: DQF MRI; articular cartilage; compression; collagen orientationArticular cartilage is a dense connective tissue that coats the ends of bones in their joints. It is mainly composed of water (ϳ75%) and of a solid matrix of collagen fibrils (ϳ15%) and proteoglycans (PG) (ϳ10%). The fibrous, triple helix collagen molecules define the tissue's shape and provide its tensile strength. The PG are composed of a central protein core with many glycosaminoglycan (GAG) sulfated sidechains. These are highly negatively charged and thus attract high concentrations of positive ions and water molecules. Scanning electron microscopy (SEM) has shown that the collagen fibers rise vertically from the bone through the radial zone, then bend and flatten, forming the superficial tangential zone (1-3). This structure, together with the large osmotic pressure in the tissue, is responsible for the remarkable compressive strength of the tissue.In conventional MR images, articular cartilage has a laminated appearance (4 -14). The number of laminae, their relative thickness and intensity, vary from study to study and from sample to sample and are strongly dependent on the orientation of the tissue in the magnetic field. In collagen-containing tissues, it has been shown that the transverse relaxation rate is dominated by the residual dipolar interaction (6,8,15), which is a result of the anisotropic motion of the water molecules. Thus, T 2 depends on the orientation of the collagen fibers with respect to the magnetic field.The main function of cartilage is to withstand pressure. Direct visualization of the orientation of the collagen fibers in articular cartilage at rest and under applied load is obtained by SEM (2,3). MRI investigations of articular cartilage under various degrees of...

An anti-CEA antibody with affinity for cancerous lesions and labeled with ICG-sulfo-OSu can therefore be imaged using this infrared fluorescence endoscope. Specific antibodies tagged with ICG-sulfo-OSu can label cancer cells and can generate a strong enough fluorescent signal to detect small cancers when examined with an infrared fluorescence endoscope.

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Peripherally produced CRH acts as a local auto/paracrine proinflammatory agent. Urocortin is a new member of the CRH family that acts through the family of CRH receptors. In this study, we demonstrated that the expression of urocortin mRNA in synovia of patients with rheumatoid arthritis was greater than that of patients with osteoarthritis. Also, we detected urocortin and CRH receptor immunoreactivity in the synovial lining cell layer, subsynovial stromal cells, blood vessel endothelial cells, and mononuclear inflammatory cells from the joints of rheumatoid arthritis and osteoarthritis patients. The expression of immunoreactive urocortin was significantly greater in rheumatoid arthritis than osteoarthritis (P < 0.0001) and correlated with the extent of inflammatory infiltrate. CRH receptor immunoreactivity was strong in mononuclear inflammatory cells of rheumatoid arthritis synovia. Urocortin stimulated IL-1beta and IL-6 secretion by human peripheral blood mononuclear cells in vitro. These findings suggest that, like CRH, urocortin is present in peripheral inflammatory sites, such as rheumatoid synovium, and acts as an immune-inflammatory mediator.

We experimentally demonstrate a high-fidelity visible-to-telecommunication wavelength conversion of a photon by using a solid-state-based difference frequency generation. In the experiment, one half of a pico-second visible entangled photon pair at 780 nm is converted to a 1522-nm photon, resulting in the entangled photon pair between 780 nm and 1522 nm. Using superconducting single-photon detectors with low dark count rates and small timing jitters, we selectively observed well-defined temporal modes containing the two photons. We achieved a fidelity of 0.93 ± 0.04 after the wavelength conversion, indicating that our solid-state-based scheme can be used for faithful frequency down-conversion of visible photons emitted from quantum memories composed of various media.Wavelength conversion of photons in a quantum regime [1] has been actively studied [2-10] as a quantum interface for application of quantum information processing and communications. Especially, such a conversion aiming at near-infrared photons in telecommunication bands are essential for transmitting quantum information over long-distance optical fiber networks with quantum repeaters [11][12][13]. In the quantum repeaters, the photon sent to a relay point through an optical fiber needs to be entangled with a quantum memory. At present, many of quantum memories and processors based on alkaline atoms, trapped ions and solid states have successfully created entanglement with photons at around visible wavelengths [14][15][16][17][18][19][20]. Thus, a quantum interface for the wavelength conversion from visible to telecommunication bands with a high fidelity has attracted much interest for its applications. So far such a quantum interface has been demonstrated by using four wave mixing with a cold atomic cloud [6] or difference frequency generation (DFG) from a nonlinear optical crystal [7]. Among them, nonlinear optical crystals with waveguide structure have practically desirable features. They can operate near room temperature and do not require laser cooling configuration, enabling a compact setup and integration into a photonic quantum circuit on a chip using waveguide structures [21]. In addition, they have a wider bandwidth, compatible with wide-band quantum memories [22,23], resulting in high-clock-rate quantum information processing. Such kind of solid-state-based optical quantum interface lead to development of a mature quantum information technology. However, in several demonstrations of the solid-state-based wavelength conversion [4,7,[24][25][26], they suffered from degradation of an observed fidelity of a reconstructed quantum state after the wavelength conversion due to background noises caused by Raman scattering of a strong cw pump light and relatively high dark count rate of an InGaAs/InP avalanche photodiode (APD) for photon detection at the telecommunication band. Therefore the observed fidelity of the state after the wavelength conversion is degraded.In this Letter, we demonstrate almost noiseless wavelength conversion by suppressing t...

Objective. To investigate the role of c-myc in the pathogenesis of rheumatoid arthritis (RA) and the mechanism of synovial apoptosis.Methods. Using cultured human synoviocytes from patients with RA and c-myc antisense oligodeoxynucleotides (AS ODN), we examined the inhibition of cell proliferation by the MTT assay and the induction of apoptosis with TUNEL staining and fluorescence microscopy. In addition, the effect of c-myc on downregulation of Fas expression was analyzed by flow cytometry, cytotoxicity assay, and reverse transcriptasepolymerase chain reaction.Results

Saline solutions of manganese ions (Mn2+) were used as articular contrast agents in magnetic resonance microscopy (9.4 T) of cartilage of chicken femoral condyles and pig temporomandibular joints. The diffusion of Mn2+ from the articular surface into the cartilage matrix led to a strong contrast enhancement in the cartilage. The combination of the high spatial resolution and the contrast enhancement allowed the visualization of fine structures (tissue types) in the cartilage, which correlate with the tissue zones in histological sections stained with cationic dyes. We assume that the electrostatic interactions between the negatively charged groups of the proteoglycans and Mn2+ are most important for the mechanism of contrast enhancement. Hence, the different signal intensities of the various zones of cartilage indicate differences in density of proteoglycans. The intraarticular injection of the cationic contrast agent could improve the possibility of an early diagnosis of cartilage dysfunction and degeneration.