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Background Postural tachycardia syndrome (POTS), a subset of orthostatic dysregulation, has been reported to be associated with anxiety. POTS can be classified into two forms based on the degree of tachycardia during orthostasis. Reportedly, POTS with decreased orthostatic heart rate increase is associated with suppressed cardiac parasympathetic activity and increased sympathetic activity in the supine position. In this study, the relationship between the two types of POTS and anxiety was evaluated in terms of autonomic function. Methods Fifty-two patients (23 males, aged 10–15 years) who were diagnosed with POTS at the Department of Pediatrics, Osaka Medical and Pharmaceutical University from 2019 to 2021, provided completed the State-Trait Anxiety Scale for Children (STAIC) questionnaire. They then completed a standing test and were accordingly classified into the two groups of POTS, the Su group, with tachycardia from the supine position and a low heart rate increase on standing, and the SI group, with a high heart rate increase during standing. Autonomic function was assessed by frequency analysis (MemCalc method) based on heart rate, blood pressure changes, heart rate, and blood pressure variability during the orthostatic test. Results Patients in the Su group had higher characteristic anxiety, lower cardiac parasympathetic activity (RR-HF) in the supine position, and greater variability in cardiac parasympathetic activity during orthostasis than those of patients in the SI group. The Su group had a greater decrease in cardiac index on standing than that of the SI group. Conclusions The Su group results may be partly attributed to chronically low venous return. We also found that patients in the Su group had low parasympathetic activity in the supine position, which may interact with the anxiety-prone characteristics of these patients. Therefore, it seems necessary to consider both physical and psychosomatic treatment approaches for patients with POTS. Trial registration The clinical trial registry of Osaka Medical and Pharmaceutical University, Clinical Trial Registration No. 2662-2. Registered 5 March 2019. https://ompu.bvits.com/rinri/Common/print_approve.aspx?ID=3479

形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2021-02-22, 資料番号: PA2120007000

BACKGROUND In adolescence, physical symptoms may develop due to psychosocial problems, but such problems are not fully evaluated in school medical checkups. The aim of the study was to compare the characteristics of students with high and low scores on the Questionnaire for Triage and Assessment with 30 items (QTA30) in a school health checkup. METHODS The QTA30 (a self-completed questionnaire) was used in checkups for 3,414 students from the 5th grade of primary schools to the 3rd grade of junior high schools in south Wakayama Prefecture. The students were divided into groups with high (QTA30 ≥ 37) and low (QTA30 < 37) risk for psychosomatic disorder. Eleven items, including gender, grade, lifestyle habits, and life events, were compared between these groups, and in subgroups with and without recent absence from school. RESULTS The QTA30 response rate was 87.9%. The high-risk group had significantly more 3rd grade students (P< 0.001), females (P< 0.001), problems with teachers or friends (P< 0.001), and experience of bullying (P< 0.001), in addition to game playing for ≥2 h (P< 0.001), late bedtime (P< 0.001), and many absences (P< 0.001). Students in the high-risk group with no absences for 1 month regardless of age still had a late bedtime and problems with friends, and 76.4% of the high-risk students had not visited a medical institution. CONCLUSIONS Use of the QTA30 facilitated detection of psychosomatic stress in school medical checkups, with latent risks of truancy detectable at an early phase. The QTA30 may thus be useful in early intervention for psychosomatic stress of adolescents.

形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2020-04-17, 資料番号: PA2120004000

Pulmonary tumor thrombotic microangiopathy (PTTM) is an acute, progressive, and fatal disease. PTTM manifests as subacute respiratory failure with pulmonary hypertension, progressive right-sided heart failure, and sudden death. An antemortem diagnosis of PTTM is very difficult to obtain, and many patients die within several weeks. We herein report a case of PTTM diagnosed based on a transbronchial lung biopsy. In this case, we finally diagnosed PTTM due to gastric cancer because of its histological identity. The patient was administered chemotherapy, including angiogenesis inhibitors, against gastric cancer at an early age and survived for a long time.

This study investigated the impact of coronavirus disease 2019 pandemic school closures on the mental health of school students with chronic diseases.Questionnaires were distributed to students from 4th-9th grade diagnosed with chronic diseases at Osaka Medical College Hospital and their parents or caregivers. Questionnaires from 286 families were returned by mail after the schools reopened. The students were divided into the "psychosomatic disorder" group (group P, n = 42), the "developmental disorder" group (group D, n = 89), and the "other disease" group (group O, n = 155). Using students' self-reports on the Questionnaire for Triage and Assessment with 30 items, we assessed the proportion of students with a high risk of psychosomatic disorder in three groups. We investigated how the students requiring the support of somatic symptom (SS) felt about school during school closure. Further, using parents' and caregivers' answers, SS scores were calculated before and during school closure and after school reopening.The proportion of students with a high risk of developing psychosomatic disorder increased in all groups. For the students in Group P, the response "I did not want to think about school" indicated an increase in SS scores, and for the students in Group O, "I wanted to get back to school soon" indicated a decrease. Furthermore, especially in Group P students, SS scores decreased transiently during school closure and increased after school reopening.The impact of school closure on mental health differed depending on students' diagnoses and feelings about school during school closures.

The purpose of this study was to evaluate the efficacy of early medical intervention for psychosocial problems detected in adolescents in a school health checkup, with the broader goal of prevention of these problems in adolescents.The Questionnaire for Triage and Assessment with 30 items score and scores for five subscales (physical symptoms, depression symptoms, anxiety symptoms, self-efficacy, and family function), and an investigation of lifestyle were determined in a school health checkup for 5th grade elementary to 3rd grade junior high school students. Forty-three children were found to be at high risk for psychosomatic disorder, of whom 18 then received a medical intervention (early intervention group) and 25 did not (non-intervention group). Fifty-seven children (outpatient group) treated for psychosomatic disorder for ≤3 months were also included in the study. The Questionnaire for Triage and Assessment with 30 items (QTA30) was completed by all participants every 3 months for 1 year and scores were compared among the groups.In the early intervention group, total Questionnaire for Triage and Assessment with 30 items scores; physical, depression, and anxiety symptoms; and unstable relationships with friends and teachers at school all significantly improved after 1 year compared to the first survey. None of these items improved in the non-intervention group, while the outpatient group had gradual improvement in all scores. Family function scores in the early intervention group improved over time, whereas those in the non-intervention group worsened.Early detection of children at high risk for psychosomatic disorder at a school health checkup and early medical intervention were useful for prevention of psychosomatic disorder in adolescents.

The Space Infrared Telescope for Cosmology and Astrophysics (SPICA) mission is to be launched into orbit around the second Lagrangian point (L2) in the Sun-Earth system. Taking advantage of the thermal environment in L2, a 2.5m-class large IR telescope is cooled below 8K in combination with effective radiant cooling and a mechanical cooling system. SPICA adopts a cryogen-free system to prevent the mission operation lifetime being limited by the amount of cryogen as a refrigerant. Currently, the mechanical cooler system with the feasible solution giving a proper margin is proposed. As a baseline design, 4K / 1K-class Joule-Thomson coolers are used to cool the telescope and thermal interface for Focal Plane Instruments (FPIs). Additionally, two sets of double stage stirling coolers (2STs) are used to cool the telescope shield. In this design, nominal operation of FPIs can be kept when one mechanical cooler is in failure. In this paper, current baseline configuration of the mechanical cooler system and current status of mechanical coolers developments which need to satisfy the specific requirements of SPICA cryogenic system are presented.

著者人数: 35名, 形態: カラー図版あり, Number of authors: 35, Physical characteristics: Original contains color illustrations, Accepted: 2018-01-22, 資料番号: PA1810022000

著者人数: 12名, Accepted: 2017-10-01, 資料番号: SA1170240000

The Soft X-ray Spectrometer (SXS) instrument that flew on the Astro-H observatory was designed to perform imaging and spectroscopy of x-rays in the energy range of 0.2 to 13 keV with a resolution requirement of 7 eV or better. This was accomplished using a 6x6 array of x-ray microcalorimeters cooled to an operating temperature of 50 mK by an adiabatic demagnetization refrigerator (ADR). The ADR consisted of three stages in order to operate using either a 1.2 K superfluid helium bath or a 4.5 K Joule-Thomson (JT) cryocooler as its heat sink. The design was based on the following operating strategy. After launch, while liquid helium was present (cryogen mode), two of the ADR’s stages would be used to single-shot cool the detectors, using the helium as a heat sink. When the helium was eventually depleted (cryogen-free mode), all three ADR stages would be used to continuously cool the helium tank to about 1.5 K, and to single-shot cool the detectors (to 50 mK), using the JT cryocooler as a heat sink. The Astro-H observatory, renamed Hitomi after its successful launch in February 2016, carried approximately 36 liters of helium into orbit. Based on measurements during ground testing, the average heat load on the helium was projected to be 0.66 mW, giving a lifetime of more than 4 years. On day 5, the helium had cooled to

Following increasing awareness of aircraft emissions and demand for technologies to reduce NOx emissions, experimental research has been conducted to develop a combustor for a small aircraft engine in the TechCLEAN of Japan Aerospace Exploration Agency project. The combustor was tuned to produce rich–lean combustion behavior through combustion tests, including full annular combustion experiments, under atmospheric and actual operating conditions of the target engine. Excellent combustion performance was observed. The final, optimized full annular combustor achieved a reduction of NOx emissions below 40% of the standard regulated by Committee on Aviation Environmental Protection/4 of International Civil Aviation Organization while maintaining low CO and total hydrocarbon emissions and showing superior exit temperature profiles and lean blow-out performance. Through the combustor development process, the dependence of combustion characteristics on combustor configuration was also clarified.

Large-eddy simulation is performed to simulate high-frequency combustion instability in a single-element atmospheric combustor. Simulations are conducted for corresponding combustion-instability experiments, and the self-excited combustion instability is successfully captured. The first tangential mode of the combustion chamber is excited in the large-eddy simulation, and the amplitude and frequency of the pressure fluctuations are consistent with the experimental observations. The first tangential mode in the large-eddy simulation was observed at 1 kHz, and the peak-to-peak amplitude was approximately 4% of time-averaged pressure. The higher-order modes were also observed in the large-eddy simulation at frequencies ranging from 2 to 4 kHz, although those amplitudes were approximately one-fourth of the first tangential mode. The coupling mechanism between the flame and acoustic mode is explored based on the large-eddy-simulation results. The periodic ignition of the unburnt H2/O2 mixture exhibits lifted combustion in a pulsating motion, and the frequency is similar to the first-tangential-mode frequency. This unsteady pulsating-flame behavior is caused by the coupling between the fuel injection and the first-tangential-mode oscillation. The Rayleigh index indicates that a primary driving factor for the instability is the acoustically coupled pulsating-flame motion. The present results demonstrate that large-eddy simulation can accurately capture the unsteady heat release and its coupling with pressure oscillations. The large-eddy-simulation results clarify details of flame structures that are not completely understood from the experimental measurements. These results are also valuable for understanding the coupling mechanism of the flame and acoustic mode in a combustion chamber., 形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: PA1620032000

形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2020-04-24, 資料番号: PA2120002000

The X-ray Imaging and Spectroscopy Mission (XRISM) is a recovery mission of ASTRO-H (Hitomi) launched in 2016. The Resolve instrument on the XRISM is an 6 × 6 array of silicon-thermistor microcalorimeters cooled down to 50 mK combined with a 5.6 m focal length X-ray telescope. Its design inherits that of the Soft X-ray Spectrometer (SXS) onboard ASTRO-H that demonstrated high resolution spectroscopy of the X-ray microcalorimeters by observing astronomical objects and providing superb resolution spectra. The cooling chain of the Resolve consists of a 3-stage adiabatic demagnetization refrigerator (ADR), a Joule-Thomson cooler, ~ 30 L superfluid helium, four Stirling coolers and a vacuum vessel or a dewar. Design of the Resolve cooling system is basically the same as that in the SXS but several changes are adopted based on lessons learned. This paper describes mainly the cooling system from room temperature to about 1 K providing the ADR heat sink. Major changes include an aperture baffle for micrometeoroid and orbital debris protection and optical light reduction, an eddy current damper to slow a gate valve opening, a new vibration isolation system with launch-locks.

In this experimental study, the combined effect of spatial and temporal variations of fuel-air mixture on self-excited combustion instabilities in a gas-turbine model combustor (approximately 60 kW) with a low-swirl injector is reported. Detailed measurements were performed in 4 fuel split (to upstream/downstream injections) conditions while keeping the total equivalence ratio constant. The combustion stability was found to be very sensitive to the fuel split parameter which determined the local equivalence ratio distribution. The majority of the heat-release oscillations was generated in the flame-to-wall impingement region in a manner that satisfied the Rayleigh criterion. The driving force of the instability was considered the periodic interaction between the traveling vortex filled with fresh mixtures and the flame in the near-wall region as reported in the previous study on homogeneous mixture flame. However, the strength of the instability was sensitively modified by the change in the local equivalence ratio distribution. In the strongest oscillation case with inhomogeneous mixture, temporal variations of equivalence ratio exhibited a positive contribution to the thermoacoustic coupling. This suggested that temporal variations in equivalence ratio were enhancing the driving factor of the thermoacoustic instability in addition to the vortex-flame interaction mechanism., 資料番号: PA1520022000

Background Postural tachycardia syndrome (POTS) manifests as marked tachycardia while standing. We noticed two forms of circulatory response to orthostatic stress in POTS. We investigated cardiovascular and autonomic nervous response to orthostatic stress in the two forms. Methods We studied 79 patients with POTS and 38 healthy control subjects (Ct). Beat-to-beat blood pressure (BP) and heart rate (HR) were non-invasively and continuously measured in the supine and standing positions. Autonomic nervous function was evaluated on power spectral analysis of HR variability and diastolic BP variability. We divided the subjects into two groups: standing-induced tachycardia (SI group; increase in HR ≥35 beats/min) and supine tachycardia (Su group; standing HR ≥115 beats/min with standing-induced HR increase

Accepted: 2019-09-16, 資料番号: SA1190202000

Background Migraine is a common and disabling neurological disorder. Studies attempting to determine a relationship between migraine and the autonomic nervous system (ANS) have been inconclusive. Moreover, pediatric studies are extremely limited. Therefore, the present study investigated interictal ANS function in adolescent migraineurs. Methods We studied 21 patients with migraine and 26 healthy controls. Beat-to-beat blood pressure (BP) and heart rate (HR) were noninvasively and continuously measured in the supine and standing positions. ANS function was evaluated by power spectral analysis of HR variability and diastolic BP (DBP) variability. Results HR and systolic BP were not different between the two groups in either the supine or standing position. DBP did not differ between groups in the standing position, but was significantly higher in migraineurs in the supine position. The vasoconstrictor index was significantly higher in migraineurs. High-frequency (HF) RR interval variability (RR-HF) and the ratio of the low-frequency (LF) to HF component of RR interval variability (RR-LF/HF) were not different between the two groups in both position. The LF component of DBP variability (DBP-LF) in the supine position was significantly lower in migraineurs, while DBP- LF during standing in migraineurs was significantly higher than that in controls. Conclusion We found that migraineurs have significantly lower sympathetic vasomotor activity in the supine position and sympathetic vasomotor activity was hyperresponsive during standing. This article is protected by copyright. All rights reserved.

The Soft X-ray Spectrometer (SXS) is the first space-based instrument to implement redundancy in the operation of a sub-Kelvin refrigerator. The SXS cryogenic system consists of a superfluid helium tank and a combination of Stirling and Joule-Thompson (JT) cryocoolers that support the operation of a 3-stage adiabatic demagnetization refrigerator (ADR). When liquid helium is present, the x-ray microcalorimeter detectors are cooled to their 50 mK operating temperature by two ADR stages, which reject their heat directly to the liquid at ~1.1 K. When the helium is depleted, all three ADR stages are used to accomplish detector cooling while rejecting heat to the JT cooler operating at 4.5 K. Compared to the simpler helium mode operation, the cryogen-free mode achieves the same instrument performance by controlling the active cooling devices within the cooling system differently. These include the three ADR stages and four active heat switches, provided by NASA, and five cryocoolers, provided by JAXA. Development and verification details of this capability are presented within this paper and offer valuable insights into the challenges, successes, and lessons that can benefit other missions, particularly those employing cryogen-free cooling systems.

Suppression of super fluid helium flow is critical for the Soft X-ray Spectrometer onboard ASTRO-H (Hitomi). In nominal operation, a small helium gas flow of ~30 μg/s must be safely vented and a super fluid film flow must be sufficiently small

The Soft X-ray Spectrometer (SXS) onboard ASTRO-H (Hitomi) achieved a high energy resolution of ~ 4.9 eV at 6 keV with an X-ray microcalorimeter array kept at 50 mK in the orbit. The cooling system utilizes liquid helium, and a porous plug phase separator is utilized to confine it. Therefore, it is required to keep the helium temperature always lower than the λ point of 2.17 K in the orbit. To clarify the maximum allowable helium temperature at the launch also considering the uncertainties of the initial operation in the orbit, we constructed a thermal mathematical model of the SXS dewar which properly implements the helium mass flow rate through the porous plug, and carried out time-series thermal simulations. Based on the results, the maximum allowable helium temperature at the launch was set at 1.7 K. We also conducted a transient thermal calculation using the actual temperatures at the launch as initial conditions. As a result, the helium mass flow rate when the helium temperature was in equilibrium is estimated to be 34–42 μg/s, and the life time of the helium mode is predicted to be ~ 3.9–4.7 years. The present paper reports model structures, simulation results, and the comparisons with temperatures measured in the orbit.

The Soft X-ray Spectrometer (SXS) is a cryogenic high-resolution X-ray spectrometer onboard the ASTRO-H satellite, that achieves energy resolution better than 7 eV at 6 keV, by operating the detector array at 50 mK using an adiabatic demagnetization refrigerator. The cooling chain from room temperature to the ADR heat sink is composed of 2-stage Stirling cryocoolers, a 4He Joule-Thomson cryocooler, and super uid liquid He, and is installed in a dewar. It is designed to achieve a helium lifetime of more than 3 years with a minimum of 30 liters. The satellite was launched on 2016 February 17, and the SXS worked perfectly in orbit, until March 26 when the satellite lost its function. It was demonstrated that the heat load on the He tank was about 0.7 mW, which would have satisfied the lifetime requirement. This paper describes the design, results of ground performance tests, prelaunch operations, and initial operation and performance in orbit of the flight dewar and cryocoolers.

Soft X-ray Spectrometer (SXS) onboard ASTRO-H (named Hitomi after launch) is a microcalorimeter-type spectrometer, installed in a dewar to be cooled at 50 mK. The energy resolution of the SXS engineering model suffered from micro-vibration from cryocoolers mounted on the dewar. This is mitigated for the flight model by introducing vibration isolation systems between the cryocoolers and the dewar. The detector performance of the flight model was verified before launch of the spacecraft in both ambient condition and thermal-vac condition, showing no detectable degradation in energy resolution. The in-orbit performance was also consistent with that on ground, indicating that the cryocoolers were not damaged by launch environment. The design and performance of the vibration isolation system along with the mechanism of how the micro-vibration could degrade the cryogenic detector is shown.

The Soft X-ray Spectrometer instrument on the Astro-H observatory contains a 6x6 array of x-ray microcalorimeters, which is cooled to 50 mK by an adiabatic demagnetization refrigerator (ADR). The ADR consists of three stages in order to provide stable detector cooling using either a 1.2 K superfluid helium bath or a 4.5 K Joule-Thomson (JT) cryocooler as its heat sink. When liquid helium is present, two of the ADR’s stages are used to single-shot cool the detectors while rejecting heat to the helium. After the helium is depleted, all three stages are used to cool both the helium tank (to about 1.5 K) and the detectors (to 50 mK) using the JT cryocooler as its heat sink. The Astro-H observatory, renamed Hitomi after its successful launch in February 2016, carried approximately 36 liters of helium into orbit. On day 5, the helium had cooled sufficiently (

The calorimeter array of the JAXA Astro-H (renamed Hitomi) Soft X-ray Spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV. The properties that make the SXS a powerful x-ray spectrometer also make it sensitive to the entire electromagnetic band. If characterized as a bolometer, it would have a noise equivalent power (NEP) of < 4x10(exp -18) W/(Hz)0.5. Thus it was imperative to shield the detector from thermal radiation from the instrument and optical and UV photons from the sky. Additionally, it was necessary to shield the coldest stages of the instrument from the thermal radiation emanating from the warmer stages. These needs are addressed by a series of five thin-film radiation blocking filters that block long-wavelength radiation while minimizing x-ray attenuation. The SXS aperture assembly is a system of barriers, baffles, filter carriers, and filter mounts that supports the filters and inhibits their potential contamination. The three warmer filters also were equipped with thermometers and heaters for decontamination.

International audience; In this paper, experimental results obtained with laser-induced plasma spectroscopy to retrieve local compositions are presented for an ambient pressure up to 5.0 MPa in a still cell. Well-controlled mixtures of gases are introduced and plasma is obtained with the fundamental emission of a pulsed Nd:YAG laser. Simultaneously, plasma shape and spectrally resolved data are taken with a temporal resolution down to 2 ns. First, the temporal evolutions of a high-pressure nitrogen plasma are analyzed as function of spark energy. It is shown that plasma changes orientation from an elongated shape parallel to the laser line to a perpendicular one in a very short time. Results are reported for both spatial and spectral variations. Afterward, the effects of increased carbon concentration are discussed in both shape and spectra. It is seen that strong intensity due to the atomic carbon emissions appear for the high-pressure case. From those experiments, calibration strategies are proposed to get equivalence ratio under high-pressure conditions with a ratio of carbon versus nitrogen and oxygen. The delay between plasma and measurements is set to 2,000 ns and the signal is integrated for 5,000 ns, so as to yield a good signal to noise ratio and a good sensitivity of the technique to changes in mixture fraction. Calibration curves are reported for equivalence ratio up to 1.00 and for pressure from 1.0 to 5.0 MPa. It is shown that typical uncertainties are limited to 7.5% regardless the equivalence ratio in a single shot approach using a spectral fit procedure, whereas it accounts to two times more in a more classical peak ratio approach. Increasing the pressure tends to increase the precision as lower pressure had higher uncertainties.

Intense tangential pressure oscillations due to oscillatory combustion are generated experimentally inside a cylindrical chamber and are analyzed to understand their characteristic features. To generate the tangential mode, a coaxial injector is installed offcenter on the closed side of the chamber. Hydrogen and nitrogen-diluted oxygen are used as working gases under atmospheric conditions. The features of the side-wall pressure in the first tangential mode (1T mode) at high amplitude, whose amplitude is over 30% of the chamber pressure, differ from those of the side-wall pressure in the 1Tmode at low amplitude in the followingmanner: 1) The positive half-wave of the pressure oscillation has twin sharp peaks. 2) The amplitude of the positive half-wave (zero to positive peak) of the pressure oscillations is larger than that of the negative half-wave (negative peak to zero). The acoustical features of the signals are reproduced and investigated by conducting an analysis and anumerical simulation under similar configurations. It is found that the characteristic feature of the intense signal is originated in the nonlinearity due to the large amplitude of the pressure oscillation.

Myo-inositol monophosphatase (IMP) catalyzes the dephosphorylation of myo-inositol 3-phosphate in the last step of myo-inositol biosynthesis. IMP is also important in phosphate metabolism and is required for the biosynthesis of cell wall polysaccharides, phytic acid, and phosphatidylinositol. In Arabidopsis, IMP is encoded by VTC4. There are, however, two additional IMP candidate genes, IMPL1 and IMPL2, which have not yet been elucidated. In our genetic studies of Arabidopsis IMP genes, only the loss-of-function mutant impl2 showed embryonic lethality at the globular stage. All IMP genes were expressed in a similar manner both in the vegetative and reproductive organs. In developing seeds, expression of IMP genes was not coupled with the expression of the genes encoding myo-inositol phosphate synthases, which supply the substrate for IMPs in the de novo synthesis pathway. Instead, expression of IMP genes was correlated with expression of the gene for myo-inositol polyphosphate 1-phosphatase (SAL1), which is involved in the myo-inositol salvage pathway, suggesting a possible salvage pathway role in seed development. Moreover, the partial rescue of the impl2 phenotype by histidine application implies that IMPL2 is also involved in histidine biosynthesis during embryo development.

著者人数：13名, Accepted: 2010-02-22, 資料番号: SA1002676000

形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2018-02-09, 資料番号: PA1820045000

MIRIS is the main payload of the STSAT-3 (Science and Technology Satellite 3) and the first infrared space telescope for astronomical observation in Korea. MIRIS space observation camera (SOC) covers the observation wavelength from to with a wide field of view . The PICNIC HgCdTe detector in a cold box is cooled down below 100K by a micro Stirling cooler of which cooling capacity is 220mW at 77K. MIRIS SOC adopts passive cooling technique to chill the telescope below 200 K by pointing to the deep space (3K). The cooling mechanism employs a radiator, a Winston cone baffle, a thermal shield, MLI (Multi Layer Insulation) of 30 layers, and GFRP (Glass Fiber Reinforced Plastic) pipe support in the system. Optomechanical analysis was made in order to estimate and compensate possible stresses from the thermal contraction of mounting parts at cryogenic temperatures. Finite Element Analysis (FEA) of mechanical structure was also conducted to ensure safety and stability in launching environments and in orbit. MIRIS SOC will mainly perform Galactic plane survey with narrow band filters (Pa and Pa continuum) and CIB (Cosmic Infrared Background) observation with wide band filters (I and H) driven by a cryogenic stepping motor.

Cyclobutane pyrimidine dimers (CPDs) constitute a majority of DNA lesions caused by ultraviolet-B (UVB). CPD photolyase, which rapidly repairs CPDs, is essential for plant survival under sunlight containing UVB. Our earlier results that the transcription of the cucumber CPD photolyase gene (CsPHR) was activated by light have prompted us to propose that this light-driven transcriptional activation would allow plants to meet the need of the photolyase activity upon challenges of UVB from sunlight. However, molecular mechanisms underlying the light-dependent transcriptional activation of CsPHR were unknown. In order to understand spectroscopic aspects of the plant response, we investigated the wavelength-dependence (action spectra) of the light-dependent transcriptional activation of CsPHR. In both cucumber seedlings and transgenic Arabidopsis seedlings expressing reporter genes under the control of the CsPHR promoter, the action spectra exhibited the most predominant peak in the long-wavelength UVB waveband (around 310 nm). In addition, a 95-bp cis-acting region in the CsPHR promoter was identified to be essential for the UVB-driven transcriptional activation of CsPHR. Thus, we concluded that the photoperception of long-wavelength UVB by UVB photoreceptor(s) led to the induction of the CsPHR transcription via a conserved cis-acting element.