54 research outputs found

    Multi-Color Coronagraph Experiment in a Vacuum Testbed with a Binary Shaped Pupil Mask

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    We conducted a number of multi-band coronagraph experiments using a vacuum chamber and a binary-shaped pupil mask which in principle should work at all wavelengths, in the context of the research and development on a coronagraph to observe extra-solar planets (exoplanets) directly. The aim of this work is to demonstrate that subtraction of Point Spread Function (PSF) and multi-band experiments using a binary-shaped pupil mask coronagraph would help improve the contrast in the observation of exoplanets. A checkerboard mask, a kind of binary-shaped pupil mask, was used. We improved the temperature stability by installing the coronagraph optics in a vacuum chamber, controlling the temperature of the optical bench, and covering the vacuum chamber with thermal insulation layers. We evaluated how much the PSF subtraction contributes to the high contrast observation by subtracting the images obtained through the coronagraph. We also carried out multi- band experiments in order to demonstrate a more realistic observation using Super luminescent Light Emitting Diodes (SLEDs) with center wavelengths of 650nm, 750nm, 800nm and 850nm. A contrast of 2.3x10-7 was obtained for the raw coronagraphic image and a contrast of 1.3x10-9 was achieved after PSF subtraction with a He-Ne laser at 632.8nm wavelength. Thus, the contrast was improved by around two orders of magnitude from the raw contrast by subtracting the PSF. We achieved contrasts of 3.1x10-7, 1.1x10-6, 1.6x10-6 and 2.5x10-6 at the bands of 650nm, 750nm, 800nm and 850nm, respectively, in the multi-band experiments. The results show that contrast within each of the wavelength bands was significantly improved compared with non-coronagraphic optics. We demonstrated PSF subtraction is potentially beneficial for improving contrast of the coronagraph, and this coronagraph produces a significant improvement in contrast with multi-band light sources.Comment: 14 pages, 7 figures, accepted for publication in PAS

    Delphi Method Consensus-Based Identification of Primary Trauma Care Skills Required for General Surgeons in Japan

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    Purpose General surgeons at regional hospitals should have the primary trauma care skills necessary to treat critically ill trauma patients to withstand transfer. This study was conducted to identify a consensus on primary trauma care skills for general surgeons. Methods An initial list of acute care surgical skills was compiled, and revised by six trauma experts (acute care surgeons); 33 skills were nominated for inclusion in the Delphi consensus survey. Participants (councilors of the Japanese Society for Acute Care Surgery) were presented with the list of 33 trauma care skills and were asked (using web-based software) to rate how strongly they agreed or disagreed (using a 5-point Likert scale) with the necessity of each skill for a general surgeon. The reliability of consensus was predefined as Cronbach’s α ≥ 0.8, and trauma care skills were considered as primarily required when rated 4 (agree) or 5 (strongly agree) by ≥ 80% participants. Results There were 117 trauma care specialists contacted to participate in the Delphi consensus survey panel. In the 1st round, 85 specialists participated (response rate: 72.6%). In the 2nd round, 66 specialists participated (response rate: 77.6%). Consensus was achieved after two rounds, reliability using Cronbach’s α was 0.94, and 34 items were identified as primary trauma care skills needed by general surgeons. Conclusion A consensus-based list of trauma care skills required by general surgeons was developed. This list can facilitate the development of a new trauma training course which has been optimized for general surgeons

    Green cocoon-derived sericin reduces cellular damage caused by radiation in human keratinocytes

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    Abstract Radiation therapy used in the treatment of cancer causes skin damage, and no method of care has been established thus far. Recently, it has become clear that sericin derived from silkworm cocoons has moisturizing and antioxidant functions. In addition, green cocoon-derived sericin, which is rich in flavonoids, may have enhanced functions. However, whether this green cocoon-derived sericin can reduce radiotherapy-induced skin damage is unclear. In the present study, we aimed at establishing care methods to reduce skin cell damage caused by X-irradiation using green cocoon-derived sericin. We investigated its effect on human keratinocytes using lactate dehydrogenase activity to indicate damage reduction. Our results showed that green cocoon-derived sericin reduced cell damage caused by X-irradiation. However, this effect was not observed when cells were treated before X-irradiation or with a sericin derived from white cocoons. In addition, green cocoon-derived sericin decreased the levels of reactive oxygen species and lipid peroxidation. Our results suggest that green cocoon sericin mitigates the damaging effect of X-irradiation on cells, hence presenting potential usefulness in reducing skin damage from radiation therapy and opening new avenues in the care of cancer patients

    Clinical significance of cancer specific methylation of the CDO1 gene in small bowel cancer.

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    Although small bowel cancer (SBC) is extremely rare, its prognosis is poor, and molecular mechanism of the SBC development remains unclear. The aim of our study is to elucidate whether DNA methylation of the promoter region of the cancer-specific methylation gene, cysteine dioxygenase 1 (CDO1), contributes to the carcinogenic process in SBC. The study group comprised patients with 53 patients with SBC, 107 colorectal cancer (CRC), and other rare tumors of the small intestine such as 4 malignant lymphomas, 2 leiomyosarcomas, and 9 gastrointestinal stromal tumors. We analyzed the extent of methylation in each tissue using quantitative TaqMan methylation-specific PCR for CDO1. Significantly higher CDO1 methylation was observed in cancer tissues compared with non-cancerous mucosa of the small intestine (ROC = 0.96). Among the various clinicopathological factors, positive correlation of CDO1 methylation with tumor diameter was observed (R = 0.31, p = 0.03), and the CDO1 methylation level was a possible prognostic factor for relapse-free survival (p = 0.09). Compared with CRC, SBC had a significantly poorer prognosis (p = 0.007) and displayed a significantly higher CDO1 methylation level (p < 0.0001). Intriguingly, especially in pStage I/II, there were robust prognostic difference between SBC and CRC (p = 0.08 / p < 0.0001), which may reflect CDO1 methylation status (p = 0.02 / p = 0.001). Among small bowel tumors, CDO1 methylation in SBC was higher in order of malignant lymphoma, cancer, and leiomyosarcoma/GIST (p = 0.002) by ANOVA. The CDO1 gene shows extremely cancer-specific hypermethylation, and it can be a prognostic marker in SBC
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