Blood fluke infection is one of the main causes of mortality in cultured juvenile Pacific bluefin tuna Thunnus orientalis (PBT) in Japan. We investigated 532 wild juvenile PBT of four different fish groups caught for tuna culture seed stock from off the Goto Islands, Nagasaki, Japan between 2011 and 2014, to determine whether they were infected with blood flukes. We detected the blood flukes, Cardicola orientalis and C. opisthorchis, from all four fish groups investigated. From this, it is suggested that bluefin tuna blood flukes are brought into tuna farms with the infected wild seed stock.

Energy-discriminating x-ray camera is useful for performing monochromatic radiography using polychromatic x-rays. The x-ray camera was developed to carry out K-edge radiography using iodine-based contrast media. In this camera, objects are exposed by a cerium x-ray generator, and penetrating x-rays are detected by a cadmium telluride (CdTe) detector with an amplifier unit. The optimal x-ray photon energy and energy width are selected out using a multichannel analyzer (MCA), and the photon number is counted by a counter board (CB). Radiography was performed by the detector scanning using an x-y stage driven by a two-stage controller, and x-ray images obtained by energy discriminating are shown in a personal-computer (PC) monitor. Cerium K-series characteristic x-rays are absorbed effectively by iodine based contrast media, and iodine K-edge radiography was performed using x-rays with photon energies just beyond K-edge energy 33.2 keV.

We investigated the geographical origin and migration of anchovy Engraulis japonicus in Tachibana Bay, western Japan, using carbon and nitrogen stable isotope ratios (δ13C and δ15N, respectively). Stable isotope ratios of anchovy varied among seasonal samples for both δ13C and δ15N. In particular, the δ13C values were clearly segregated; winter samples showed higher values (δ13C>−17.5‰) than spring samples (δ13C<−18.2‰). Moreover, these differences corresponded to the geographical variations in previously reported stable isotope ratios for anchovy; higher values in winter corresponded to the values of inshore habitat and lower values in spring corresponded to those of the offshore habitat. Therefore the spring population is considered to have originated from the offshore region and recently migrated to the sampling regions, while the winter population would have experienced the inshore region over an extended period. Our results support the general concept of the migration of anchovy populations deduced by the fishermen of Tachibana Bay.

An energy-discriminating K-edge x-ray Computed Tomography (CT) system is useful for increasing contrast resolution of a target region and for diagnosing cancers utilizing a drug delivery system. The CT system is of the first generation type and consists of an x-ray generator, a turn table, a translation stage, a two-stage controller, a cadmium telluride (CdTe) detector, a charge amplifier, a shaping amplifier, a multi-channel analyzer (MCA), a counter board (CB), and a personal computer (PC). The K-edge CT is accomplished by repeating translation and rotation of an object. Penetrating x-ray spectra from the object are measured by a spectrometer utilizing the CdTe detector, amplifiers, and MCA. Both the photon energy and the energy width are selected by the MCA for discriminating photon energy. Enhanced iodine K-edge x-ray CT was performed by selecting photons with energies just beyond iodine K-edge energy of 33.2 keV.

X-Ray Fluorescence (XRF) analysis is useful for measuring density distributions of contrast media in vivo. An XRF camera was developed to carry out mapping for iodine-based contrast media used in medical angiography. In this camera, objects are exposed by an x-ray beam formed using a 3.0-mm-diameter lead hole. Next, cerium K-series characteristic x-rays are absorbed effectively by iodine media in objects, and iodine fluorescences are produced from the objects. Iodine Kα fluorescences are selected out using a 58-μm-thick stannum filter and are detected by a cadmium telluride (CdTe) detector. Kα rays are discriminated out by a multichannel analyzer (MCA), and photon number is counted by a counter board (CB). The objects are moved and scanned using an x-y stage driven by a two-stage controller, and x-ray images obtained by iodine mapping are shown in a personal computer (PC) monitor. In particular, iodine fluorescences were produced from remanent iodine elements in a cancer region of a rabbit ear.

A preliminary experiment for producing narrow-photon-energy cone-beam x-rays using a silicon single crystal is described. In order to produce low-photon-energy x-rays, a 100-mu m-focus x-ray generator in con unction with a (111) plane silicon crystal is employed. The x-ray beams from the source are confined by an x-y diaphragm, and monochromatic cone beams are formed by the crystal and three lead plates. The x-ray generator consists of a main controller and a unit with a high-voltage circuit and a 100-mu m-focus x-ray tube. In this experiment, the maximum tube voltage and current were 35 kV and 0.50 mA, respectively, and the x-ray intensity of the microfocus generator was 343 mu Gy/s at 1.0 m from the source with a tube voltage of 30 kV and a current of 0.50 mA. ne effective photon energy is determined by Bragg's angle, and the photon-energy width is regulated by the angle delta. Using this generator in conjunction with a computed radiography system, quasi-monochromatic radiography was performed using a cone beam with an effective energy of approximately 15.5 keV.

Novel monochromatic x-ray generators and their applications to high-speed radiography are described. The five generators are as follows: a weakly ionized linear plasma x-ray generator,. a monochromatic compact flash x-ray generator, a super-fluorescent plasma generator, a cerium x-ray generator using a 3.0-mm-thick aluminum filter, and a 100 mu m-focus x-ray generator utilizing the filter. Using the linear plasma generator with a copper target, we observed clean K lines and their harmonics, and soft flash radiography was performed with pulse widths of approximately 500 ns. The compact monochromatic flash x-ray generator produced clean molybdenum K lines easily, and high-speed radiography was performed with pulse widths of approximately 100 ns. Using a steady-state cerium x-ray generator, we performed real-time angiography utilizing an image intensifier and a high-sensitive camera (MLX) made by NAC Image Technology Inc. with a capture time of 1 ms. Finally, real-time magnification radiography was performed by twofold magnification imaging using a 100-mu m-focus x-ray generator and the high-sensitive camera.

The samarium-target x-ray tube is useful in order to perform cone-beam K-edge angiography because K-series characteristic x-rays from the samarium target are absorbed effectively by iodine-based contrast media. This generator consists of the following components: a constant high-voltage power supply, a filament power supply, a turbomolecular pump, and an x-ray tube. The x-ray tube is a demountable diode which is connected to the turbomolecular pump and consists of the following major devices: a samarium target, a tungsten hairpin cathode (filament), a focusing (Wehnelt) electrode, a polyethylene terephthalate x-ray window 0.25 mm in thickness, and a stainless-steel tube body. In the x-ray tube, the positive high voltage is applied to the anode (target) electrode, and the cathode is connected to the tube body (ground potential). In this experiment, the tube voltage applied was from 50 to 70 kV, and the tube current was regulated to within 0.10 mA by the filament temperature. The exposure time is controlled in order to obtain optimum x-ray intensity. The electron beams from the cathode are converged to the target by the focusing electrode, and clean K-series characteristic x-rays are left using a 50-µm-thick tungsten filter. The x-ray intensity was 1.09 µGy/s at 1.0 m from the x-ray source with a tube voltage of 60 kV and a tube current of 0.10 mA, and angiography was performed using a computed radiography system and iodine-based microspheres 15 µm in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 µm with high contrasts.

High-sensitive radiography system utilizing a kilohertz-range stroboscopic x-ray generator and a night-vision CCD camera (MLX) is described. The x-ray generator consists of the following major components: a main controller, a condenser unit with a Cockcroft-Walton circuit, and an x-ray tube unit in conjunction with a grid controller. The main condenser of about 500 nF in the unit is charged up to 100 kV by the circuit, and the electric charges in the condenser are discharged to the triode by the grid control circuit. The maximum tube current and the repetition rate are approximately 0.5 A and 50 kHz, respectively. The x-ray pulse width ranges from 0.01 to 1.0 ms, and the maximum shot number has a value of 32. At a charging voltage of 60 kV and a width of 1.0 ms, the x-ray intensity obtained without filtering was 6.04 μGy at 1.0 m per pulse. In radiography, an object is exposed by the pulse x-ray generator, and a radiogram is taken by an image intensifier. The image is intensified by the CCD camera, and a stop-motion image is stored by a flash memory device using a trigger delay device. The image quality was improved with increases in the x-ray duration, and a single-shot radiography was performed with durations of less than 1.0 ms.

A simple x-ray computed tomography (CT) system utilizing a cadmium telluride detector and its application to enhanced iodine K-edge angiography are described. The CT system is of the first generation type and consists of an x-ray generator, a turn table, a translation unit, a motor drive unit, a cadmium telluride detector, an interface unit for the detector, and a personal computer (PC). Tomography was performed by the repetition of the translation and rotation. Narrow-photon-energy bremsstrahlung x-rays with a peak photon energy of approximately 35 keV is very useful for performing enhanced K-edge angiography because these rays are absorbed effectively by iodine-based contrast media with a K-edge of 33.2 keV. The tube voltage, the tube current, and the aluminum filter thickness were 60 kV, 1.5 mA, and 3.0 mm, respectively. Holes filled with iodine media in phantoms are visible with high contrasts, and the CT system can be applied to photon-counting and fluorescent x-ray CT systems.

A microfocus x-ray tube is useful in order to perform magnification digital radiography including phase-contrast effect. The 100-µm-focus x-ray generator consists of a main controller for regulating the tube voltage and current and a tube unit with a high-voltage circuit and a fixed anode x-ray tube. The maximum tube voltage, current, and electric power were 105 kV, 0.5 mA, and 50 W, respectively. Using a 3.0-mm-thick aluminum filter, the x-ray intensity was 26.0 µGy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 0.50 mA. Because the peak photon energy was approximately 35 keV using the filter with a tube voltage of 60 kV, the bremsstrahlung x-rays were absorbed effectively by iodine-based contrast media with an iodine K-edge of 33.2 keV. Magnification angiography was performed by two-time magnification imaging with a computed radiography system using iodine-based microspheres 15 µm in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 µm with high contrasts.

A microfocus x-ray tube is useful in order to perform magnification digital radiography including phase-contrast effect. The 100-mu m-focus x-ray generator consists of a main controller for regulating the tube voltage and current and a tube unit, with a high-voltage circuit and a fixed anode x-ray tube. The maximum tube voltage, current, and electric power were 105 kV, 0.5 mA, and 50 W, respectively. Using a 3.0-mm-thick aluminum filter, the x-ray intensity was 26.0 mu Gy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 0.50 mA. Because the peak photon energy was approximately 35 keV using the filter with a tube voltage of 60 kV, the bremsstrahlung x-rays were absorbed effectively by iodine-based contrast media with an iodine K-edge of 33.2 keV Real-time magnification radiography was performed by twofold magnification imaging with an image intensifier camera, and angiography was achieved with iodine-based microspheres 15 mu m in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 mu m with high contrasts.

Eggs of the mirror-finned flying fish Hirundichthlys oxycephalus were collected from the drifts near Goto Islands and Yaku Island, from April to August within the years of 1.998 to 2004. To identify species, the eggs were reared and the hatched larvae were observed. The eggs were 1.6-2.0 min in diameter. Three types of filaments were recognized. One was a single filament of 20 mu m, the others were 5-7 filaments of 10 mu m, and 9-14 filaments of 6 mu m. The number of filaments observed in H. oxycephalus was similar to that formerly reported in H.coromandelensis, however, the thinner diameter of H.oxycephalus filaments than that of H.coromandelensis makes it possible to distinguish between the two species. The eggs were collected in Kagoshima from May to July, and in Nagasaki from July to August, and this difference seems to be due to the difference of water temperature between the two localities.

This generator consists of the following components: a constant high-voltage power supply, a filament power supply, a turbomolecular pump, and an x-ray tube. The x-ray tube is a demountable diode which is connected to the turbomolecular pump and consists of the following major devices: a tungsten hairpin cathode (filament), a focusing (Wehnelt) electrode, a polyethylene terephthalate x-ray window 0.25 mm in thickness, a stainless-steel tube body, a pipe target, and a rod target. The pipe and rod targets are useful for forming linear and cone beams, respectively. In the x-ray tube, the positive high voltage is applied to the anode (target) electrode, and the cathode is connected to the tube body (ground potential). In this experiment, the tube voltage applied was from12 to 20 kV, and the tube current was regulated to within 0.10 mA by the filament temperature. The exposure time is controlled in order to obtain optimum x-ray intensity. The electron beams from the cathode are converged to the target by the focusing electrode, and clean K-series characteristic x-rays are produced through the focusing electrode without using a filter. The x-ray intensities of the pipe and rod targets were 1.29 and 4.28 μGy/s at 1.0 m from the x-ray source with a tube voltage of 15 kV and a tube current of 0.10 mA, and quasi-monochromatic radiography was performed using a computed radiography system.

The purpose of this study was to determine the growth and reproductive characteristics of round scad Decapterus maruadsi in the East China Sea. The characteristics regarding growth and reproduction of round scad based on otolith reading and gonad histology, respectively, were estimated. The von Bertalanffy’s growth model for round scad was estimated as follows: FL t =342[1−exp{−0.55( t +0.58)}], (1< t <7) where FL, is fork length (mm) at age in years t . The maturation stage of the ovary was observed by histological techniques. June was the main spawning period; the maturation and migratory nucleus stage of the oocyte was observed when the gonad somatic index value was approximately greater than 4.

A microfocus x-ray tube is useful in order to perform magnification digital radiography including phase-contrast effect. The 100-μm-focus x-ray generator consists of a main controller for regulating the tube voltage and current and a tube unit with a high-voltage circuit and a fixed anode x-ray tube. The maximum tube voltage, current, and electric power were 105 kV, 0.5 mA, and 50 W, respectively. Using a 3-mm-thick aluminum filter, the x-ray intensity was 26.0 μGy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 0.50 mA. Because the peak photon energy was approximately 38 keV using the filter with a tube voltage of 60 kV, the bremsstrahlung x-rays were absorbed effectively by iodine-based contrast media with an iodine K-edge of 33.2 keV. Magnification angiography including phase-contrast effect was performed by three-time magnification imaging with a computed radiography system using iodine-based microspheres 15 μm in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 μm with high contrasts.

In the plasma flash x-ray generator, a 200 nF condenser is charged up to 50 kV by a power supply, and flash x rays are produced by the discharging. The x-ray tube is a demountable triode with a trigger electrode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Target evaporation leads to the formation of weakly ionized linear plasma, consisting of molybdenum ions and electrons, around the fine target, and intense characteristic x rays are produced. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 16 kA. When the charging voltage was increased, the linear plasma formed, and the K-series characteristic x-ray intensities increased. The K lines were quite sharp and intense. The x-ray pulse widths were approximately 600 ns, and the time-integrated x-ray intensity had a value of approximately 65 μC/kg at 1.0 m from the x-ray source with a charging voltage of 50 kV.

The exacerbation of asthma during viral infections is mainly explained by neutrophils infiltrating into the airways. However, enhanced functions of eosinophils are also observed. The aim of this study was to reveal the mechanism of how eosinophils are activated during and after viral infection of the airways, using a model of viral infection. A synthetic double-stranded RNA, poly inosinic-cytidyric acid (poly(IC)), was transfected to a human airway epithelial cell line (BEAS-2B) and the primary bronchial epithelial cells, to mimic a viral infection. The production of chemokines from the cells was investigated. The transfection of poly(IC), alone, marginally affected the eotaxin-3 production of the cells. However, the transfection of poly(IC) prior to interleukin (IL)-4 stimulation enhanced eotaxin-3 production. Poly(IC) transfection increased mRNA and protein expressions of IL-4 receptor (R)α and IL-2Rγ, components of the IL-4R. In BEAS-2B cells, IL-4-mediated phosphorylation of signal transducer and activator of transcription six was enhanced in poly(IC) transfected cells. This was reversed by the addition of anti-IL-4Rα antibody, suggesting the role of an increased number of IL-4 receptors in enhanced IL-4-induced eotaxin-3 production. Poly(IC)-induced upregulation of IL-4Rα was inhibited by treatment with cycloheximide or dexamethasone. In conclusion, these results suggest that viral airway infection may enhance interleukin-4-induced eotaxin-3 production through upregulation of the interleukin-4 receptor in airway epithelial cells.