Photoluminescence measurement of ruby excited by duty ratio-controlled pulse light-emitting diodes (LED) light source.

Photoluminescence (PL) spectra from ruby were obtained using a highly stable LED light source, employing pulse width modulation technique for excitation. The temporal variation in PL intensity caused by the increasing temperature of the LED used for excitation can be mitigated by adjusting the duty ratio (%) of the pulsed LED light to below 10% for cooling the LED. Stable PL spectra measurements were achieved with a duty ratio of less than 10% using a duty ratio-controlled pulsed LED light source, as temperature fluctuations in LED light intensity are minimized at duty ratios less than 10%. Furthermore, fluctuations in the measured PL intensity were diminished by setting the frequency of the pulsed LED light source to greater than 1 kHz. This method enables more reliable, cost-effective, and stable PL measurements for material characterization in semiconductors, photonics, and nanotechnology.

[Surgical Replacement of Descending Aorta for Adult Aortic Coarctation by Using Three-dimensional Computer Graphics Reconstruction].

Aortic coarctation is diagnosed in approximately 5% of adult patients with congenital heart disease and is commonly diagnosed through the close examination of hypertension. Various surgical strategies for adult coarctation have been recently reported. Generally, aortic replacement may require blood transfusion in case of injury of the well-developed collateral vessels. Therefore, in order to secure an operative safety, we preoperatively used a medical image viewer to identify the abnormal vessels by three-dimensional computer graphics (3DCG) reconstruction. A 34-year-old male patient was referred to our hospital with hypertension and low ankle-brachial pressure index( ABI). Chest computed tomography( CT) scan showed aortic coarctation and development of abnormal collateral vessels. Descending aorta was replaced via a left third-fourth intercostal thoracotomy under partial extracorporeal circulation. As the image viewer depicted, anatomical abnormality of the collateral vessels was identified precisely, and surgically treated without any injury. The patient was discharged 10 days postoperatively without transfusion and with a normalized ABI.

Fluorescence-enhanced Si photodiodes for ultraviolet C rays (UVC) measurements.

The ultraviolet C rays (UVC, wavelength λ = 100-280 nm) light generated by a Hg lamp (λ = 254 nm) and UVC light-emitting diodes (LEDs, λ = 265 and 275 nm) was detected using a fluorescence-enhanced silicon photodiode (FE-PD). Ce-doped yttrium aluminum garnet (YAG:Ce), YAG:Pr, YAG:Eu, YAG:Tb, YAG:Cr, Al2O3:Ti, Al2O3:Cr, MgAl2O4:Ti, MgAl2O4:Cr, MgAl2O4:Mn, and commercial fluorescent acrylic resins were tested as phosphor sources to enhance the output signal intensity of the FE-PD irradiated with UVC light. The resulting output signal intensity increased linearly with the UVC light strength, which was adjusted by raising the input current of the UVC LEDs from 0 to 40 mA. The sensitivity of the fabricated UVC detectors, assessed based on the calibration curve slope, varied depending on the phosphor materials. The phosphors effectively enhanced the output signal intensity of the FE-PD, which was up to six times greater than that of the visible and near infrared Si-PD without phosphors; the stronger output signal intensity was achieved using YAG:Tb, YAG:Cr, and a red fluorescent acrylic resin. The visible light emitted by phosphors under UVC irradiation is useful for detecting UVC light by the eye when using FE-PD.

Fluorescence thermometry application of photoluminescence image from Cr-doped YAG.

The temperature dependence of a photoluminescence (PL) image from a Cr-doped Y3Al5O12 (YAG:Cr) crystal was evaluated for a fluorescence thermometry application. The brightness of a red PL image of YAG:Cr was found to be increased by increasing the temperature. Temperature variations of the peak intensity and peak area of red PL related to the PL peaks at λ = 680, 690, 708, and 725 nm were evaluated to reveal the cause of the increase in brightness of the PL image. While intensities of the PL peaks at λ = 690, 690, and 708 nm decreased with temperature due to thermal quenching, the peak intensity at λ = 725 nm and the peak area increased with temperature up to 250 °C. The latter factor greatly affects the temperature variation of the brightness of PL images. The increase in the brightness of the PL image with temperature is evidently linked with the thermal excitation of electrons at the 2E level responsible for the increase in the PL peak area. Cr concentration suitable for the temperature sensor is suggested based on the temperature variation of the PL peak area.

Clinical Application of Next-generation Sequencing for the Diagnosis of Lung Squamous Cell Carcinoma: Is It Primary or Secondary?

An 80-year-old man with a history of cutaneous squamous cell carcinoma (SCC) was referred to our department for a solitary lung nodule. The nodule was surgically resected and diagnosed as SCC. Because the lung lesion and a previous skin lesion showed similar histological findings, the origin of the lung tumor was uncertain. Next-generation sequencing using a targeted driver oncogene panel was applied for the further examination. The lung lesion was diagnosed as primary lung SCC, as the two tumors possessed distinct somatic mutations in TP53. Recent advances in clinical sequencing have enabled us to obtain an accurate diagnosis in pathologically challenging cases.

Non-destructive evaluation of tomato based on optical scattering.

Equipment for the non-destructive evaluations of a tomato has been developed based on the scattering spectra, the angular distributions of the scattering intensities, and the scattering images from the specimens. The sugar concentrations of tomato can be estimated optically based on the scattering intensities using a halogen lamp, a white light-emitting diode (white LED), a yellow LED, a red LED, and near infrared LEDs (λ = 850 nm and 940 nm) as the incident lights. The scattering intensity is found to vary linearly with sugar concentrations of tomato with any wavelengths at which the scattering light can be observed. The gradient of calibration lines of the sugar concentrations against the scattering intensities varies with scattering angles, θ. Evaluations at around θ = 160° are found to be suitable because of the large gradient and good linearity with the correlation coefficient, R, close to 1.

The potential role of temperate Japanese regions as refugia for the coral Acropora hyacinthus in the face of climate change.

As corals in tropical regions are threatened by increasing water temperatures, poleward range expansion of reef-building corals has been observed, and temperate regions are expected to serve as refugia in the face of climate change. To elucidate the important indicators of the sustainability of coral populations, we examined the genetic diversity and connectivity of the common reef-building coral Acropora hyacinthus along the Kuroshio Current, including recently expanded (<50 years) populations. Among the three cryptic lineages found, only one was distributed in temperate regions, which could indicate the presence of Kuroshio-associated larval dispersal barriers between temperate and subtropical regions, as shown by oceanographic simulations as well as differences in environmental factors. The level of genetic diversity gradually decreased towards the edge of the species distribution. This study provides an example of the reduced genetic diversity in recently expanded marginal populations, thus indicating the possible vulnerability of these populations to environmental changes. This finding underpins the importance of assessing the genetic diversity of newly colonized populations associated with climate change for conservation purposes. In addition, this study highlights the importance of pre-existing temperate regions as coral refugia, which has been rather underappreciated in local coastal management.

X-ray detector based on Mn doped MgAl2O4 and Si photodiode.

Luminescence properties of Mn doped MgAl2O4 crystals connected with the Si PIN photodiode (PD) have been evaluated for X-ray detector applications. Mn doped MgAl2O4 crystals emit green colored luminescence peaking at around λ = 520 nm with CuKα irradiation. The intensity of the output signal from Si PD increases linearly with the X-ray intensity of CuKα generated with the X-ray tube at a current from 2 mA to 40 mA. The intensity of the X-ray excited luminescence is strongest in the specimen with 3.0 mol. % Mn. Afterglow luminescence is weak in the specimen with 2.0 mol. % Mn. Mn doped MgAl2O4 crystals connected with the Si PD is considered to be a useful X-ray detector.

Fiber-optic thermometer application of thermal radiation from rare-earth end-doped SiO2 fiber.

Visible light thermal radiation from SiO2 glass doped with Y, La, Ce, Pr, Nd, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu were studied for the fiber-optic thermometer application based on the temperature dependence of thermal radiation. Thermal radiations according to Planck's law of radiation are observed from the SiO2 fibers doped with Y, La, Ce, Pr, Eu, Tb, and Lu at the temperature above 1100 K. Thermal radiations due to f-f transitions of rare-earth ions are observed from the SiO2 fibers doped with Nd, Dy, Ho, Er, Tm, and Yb at the temperature above 900 K. Peak intensities of thermal radiations from rare-earth doped SiO2 fibers increase sensitively with temperature. Thermal activation energies of thermal radiations by f-f transitions seen in Nd, Dy, Ho, Er, Tm, and Yb doped SiO2 fibers are smaller than those from SiO2 fibers doped with Y, La, Ce, Pr, Eu, Tb, and Lu. Thermal radiation due to highly efficient f-f transitions in Nd, Dy, Ho, Er, Tm, and Yb ions emits more easily than usual thermal radiation process. Thermal radiations from rare-earth doped SiO2 are potentially applicable for the fiber-optic thermometry above 900 K.

Fiber-optic thermometry using thermal radiation from Tm end doped SiO2 fiber sensor.

Fiber-optic thermometry based on temperature dependence of thermal radiation from Tm(3+) ions was studied using Tm end doped SiO2 fiber sensor. Visible light radiation peaks due to f-f transition of Tm(3+) ion were clearly observed at λ = 690 and 790 nm from Tm end doped SiO2 fibers sensor at the temperature above 600 °C. Thermal radiation peaks are assigned with f-f transition of Tm(3+) ion, (1)D2-(3)H6, and (1)G4-(3)H6. Peak intensity of thermal radiation from Tm(3+) ion increases with temperature. Intensity ratio of thermal radiation peaks at λ = 690 nm against that at λ = 790 nm, I790/690, is suitable for the temperature measurement above 750 °C. Two-dimensional temperature distribution in a flame is successfully evaluated by Tm end doped SiO2 fiber sensor.

A carbosilane dendrimer and a silacyclopentadiene analog carrying peripheral lactoses as drug-delivery systems.

A carbosilane dendrimer (4a) and its silacyclopentadiene analog (4b), both functionalized with lactoses, were tested for their abilities to act as drug-delivery systems. The critical micelle concentrations of 4a and 4b were measured using the drop-volume method in water and were 1.7 and 2.9 µM, respectively, suggesting that they could act as aggregates of glycoclusters. The amounts of the hydrophobic dye Orange OT loaded onto aqueous micelles of 4a and 4b and the stabilities of the dye/micelle complexes were determined by extracting the dyes from the complexes into chloroform. The particle sizes were measured for the loaded micelles by dynamic light scattering. Transfer of the dye from the micelles to peanut agglutinin was observed by fluorescence microscopy. Given the abilities of micelles of 4a and 4b to bind and release Orange OT, these glycocluster micelles may find use as drug-delivery systems.