32 research outputs found
Spatial Map of Human T Cell Compartmentalization and Maintenance over Decades of Life
SummaryMechanisms for human memory T cell differentiation and maintenance have largely been inferred from studies of peripheral blood, though the majority of T cells are found in lymphoid and mucosal sites. We present here a multidimensional, quantitative analysis of human T cell compartmentalization and maintenance over six decades of life in blood, lymphoid, and mucosal tissues obtained from 56 individual organ donors. Our results reveal that the distribution and tissue residence of naive, central, and effector memory, and terminal effector subsets is contingent on both their differentiation state and tissue localization. Moreover, T cell homeostasis driven by cytokine or TCR-mediated signals is different in CD4+ or CD8+ T cell lineages, varies with their differentiation stage and tissue localization, and cannot be inferred from blood. Our data provide an unprecedented spatial and temporal map of human T cell compartmentalization and maintenance, supporting distinct pathways for human T cell fate determination and homeostasis
CWキンセキガイセン レーザ オ モチイタ ブンコウシステム ト シンゴウショリ
In order to analyze spectral lines in the near infrared wavelength region, computer controllecd laser spectrometers with higher resolving power and precision than the classical ones were developed using a GaAs semiconductor laser and a tilanium sapphire ring laser. The systems operated in the wavelength region from 0.68 to 1.O5 μm and at 1.3μm. The lasers were automatically swept over several hundreds of wavenumber with a resolution better than several MHz. The accuracy of the wavenumber measrenment achieved using a wavelength meter combined with a Fabry^Perot interferometer was 0.0005 cm^. A novel double beam noise reduction technique was developed to eliminate interference noises and a noise reduction ratio of 50 dB was attained
Influence of humidity and of the electric and magnetic microwave radiation fields on the remediation of TCE-contaminated natural sandy soils.
The influence of moisture content (15% w/w) on the remediation (vaporization) of trichloroethylene (TCE) present in natural sands, chosen as a TCE-polluted model system for soils, was investigated with regard to applied microwave power levels, the depth of the sand sample, and the dielectric factors. The heating process occurring in the sand samples arises through the microwave conduction loss heating and dielectric loss heating mechanisms. The characteristic relevance of the electric and magnetic microwave radiation fields to the heating mechanisms was also examined. Heating by the magnetic microwave radiation field was considerable when magnetite was added to the dry and wet sand samples as the microwave absorber. Optimal microwave conditions are reported for a single-mode microwave applicator. Near-quantitative elimination of the TCE contaminant was achieved for sandy soils within a very short time
Influence of Humidity and of the Electric and Magnetic Microwave Radiation Fields on the Remediation of TCE-contaminated Natural Sandy Soils
The influence of moisture content (15% w/w) on the remediation (vaporization) of trichloroethylene (TCE) present in natural sands, chosen as a TCE-polluted model system for soils, was investigated with regard to applied microwave power levels, the depth of the sand sample, and the dielectric factors. The heating process occurring in the sand samples arises through the microwave conduction loss heating and dielectric loss heating mechanisms. The characteristic relevance of the electric and magnetic microwave radiation fields to the heating mechanisms was also examined. Heating by the magnetic microwave radiation field was considerable when magnetite was added to the dry and wet sand samples as the microwave absorber. Optimal microwave conditions are reported for a single-mode microwave applicator. Near-quantitative elimination of the TCE contaminant was achieved for sandy soils within a very short time
Optimization of Crystal Arrangement on 8-Layer DOI PET Detector
Previously, we proposed an 8-layer depth-of- interaction (DOI)encoding method for a PET detector and proved its validity. The layer ofinteraction is identified by hybrid method; the scintillation light controlby the original reflector arrangement for 4-layer DOI encoding and the pulseshape discrimination for 2-layer DOI encoding. Four layers then consist ofthe scintillator of different pulse shape from the scintillator for theother four layers. We investigated the effect of crystal arrangement difference ondetector performance to optimize the DOI detector. The two kind layers canbe arranged in two ways; stacked alternately or set in the upper and lowerfour layers respectively. Since the two crystal arrangements are supposed toshow different detector performance, we measured it on each arrangement. Theresults show better performance of the stacked arrangement in pulse shapediscrimination, while inferior in crystal identification among the same kindscintillation crystals composing four layers. There was no particulardifference between the two crystal arrangements in light outputs and energyresolutions of each layer.IEEE 2006 Nuclear Science Symposium and Medical Imaging Conferenc
Role of the Aromatic Ring of Tyr43 in Tetraheme Cytochrome c(3) from Desulfovibrio vulgaris Miyazaki F
Tyrosine 43 is positioned parallel to the fifth heme axial ligand, His34, of heme 1 in the tetraheme cytochrome c(3). The replacement of tyrosine with leucine increased the redox potential of heme 1 by 44 and 35 mV at the first and last reduction steps, respectively; its effects on the other hemes are small. In contrast, the Y43F mutation hardly changed the potentials. It shows that the aromatic ring at this position contributes to lowering the redox potential of heme 1 locally, although this cannot be the major contribution to the extremely low redox potentials of cytochrome c(3). Furthermore, temperature-dependent line-width broadening in partially reduced samples established that the aromatic ring at position 43 participates in the control of the kinetics of intramolecular electron transfer. The rate of reduction of Y43L cytochrome c(3) by 5-deazariboflavin semiquinone under partially reduced conditions was significantly different from that of the wild type in the last stage of the reduction, supporting the involvement of Tyr43 in regulation of reduction kinetics. The mutation of Y43L, however, did not induce a significant change in the crystal structure
PET detector with scintillation crystals cut in triangular prism
We propose a new depth of interaction (DOI) detector which is made of scintillation crystals cut in triangular prism. Preliminary study was carried out with Lu2xGd2(1-x)SiO5 (LGSO) crystals cut in three-square of 3.0 mm and 10.0 mm long. They are arranged in 3-layer DOI array and coupled to a position sensitive photomultiplier tube (PS-PMT). By removing some reflector from the crystal array to control scintillation light spread, we could obtain the 2-dimensional position histogram in which responses of the crystals in all layers are discriminated with only Anger-type calculation of the PS-PMT signals.2008 Nuclear Science Symposium, Medical Imaging Conferenc
Spatial resolution evaluation with a pair of two four-layer DOI detectors for small animal PET scanner: jPET-RD
We are developing a small animal PET scanner, "jPET-RD" to achieve high sensitivity as well as high spatial resolution by using four-layer depth-of-interaction (DOI) detectors. The jPET-RD is designed with two detector rings. Each detector ring is composed of six DOI detectors arranged hexagonally. The diameter of the field-of-view (FOV) is 8.8 cm, which is smaller than typical small animal PET scanners on the market now. Each detector module consists of a crystal block and a 256-channel flat panel position-sensitive photomultiplier tube. The crystal block, consisting of 32 x 32 x 4 crystal (4096 crystals, each 1.46 mm x 1.46 mm x 4.5 mm) and a reflector, is mounted on the 256ch FP-PMT.\nIn this study, we evaluated the spatial resolution of reconstructed images with the evaluation system of two four-layer DOI detectors which consist of 32 x 32 x 4 LYSO (Lu: 98%, Y: 2%) crystals coupled on the 256ch FP-PMT by using RTV rubber. The spatial resolution of 1.5 mm was obtained at the center of the FOV by the filtered back projection. The spatial resolution, better than 2 mm in the whole FOV, was also achieved with DOI while the spatial resolution without DOI was degraded to 3.3 mm