47 research outputs found

    Measurement of Doppler effects in a cryogenic buffer-gas cell

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    Buffer-gas cooling is a universal cooling technique for molecules and used for various purposes. One of its ap- plications is using molecules inside a buffer-gas cell for low-temperature spectroscopy. Although a high-intensity signal is expected in the cell, complex molecular dynamics is a drawback for precise spectroscopy. In this study, we performed high-resolution absorption spectroscopy of low -J transitions in the òΠ(0, 0, 0)-˜X²Î£+(0, 0, 0) band of calcium monohydroxide (CaOH). CaOH molecules were produced by laser ablation in a copper cell and cooled to ∼5 K using helium buffer gas. We probed the Doppler effects in a buffer-gas cell by injecting counterpropagating lasers inside the cell. The time evolutions of the Doppler width and shift were simulated using a dedicated Monte Carlo simulation and compared with data

    Low-J Transitions in A˜2Π(0,0,0)−X˜2Σ+(0,0,0) Band of Buffer-gas-cooled CaOH

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    Calcium monohydroxide radical (CaOH) is receiving an increasing amount of attention from the astrophysics community as it is expected to be present in the atmospheres of hot rocky super-Earth exoplanets as well as interstellar and circumstellar environments. Here, we report the high-resolution laboratory absorption spectroscopy on low-J transitions in A ˜ 2 Π ( 0 , 0 , 0 ) − X ˜ 2 Σ + ( 0 , 0 , 0 ) band of buffer-gas-cooled CaOH. In total, 40 transitions out of the low-J states were assigned, including 27 transitions that have not been reported in previous literature. The determined rotational constants for both ground and excited states are in excellent agreement with previous literature, and the measurement uncertainty for the absolute transition frequencies was improved by more than a factor of 3. This will aid future interstellar, circumstellar, and atmospheric identifications of CaOH. The buffer-gas-cooling method employed here is a particularly powerful method to probe low-J transitions and is easily applicable to other astrophysical molecules.</jats:p

    High-resolution spectroscopy of buffer-gas-cooled phthalocyanine

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    For over five decades, studies in the field of chemical physics and physical chemistry have primarily aimed to understand the quantum properties of molecules. However, high-resolution rovibronic spectroscopy has been limited to relatively small and simple systems because translationally and rotationally cold samples have not been prepared in sufficiently large quantities for large and complex systems. In this study, we present high-resolution rovibronic spectroscopy results for large gas-phase molecules, namely, free-base phthalocyanine (FBPc). The findings suggest that buffer-gas cooling may be effective for large molecules introduced via laser ablation. High-resolution electronic spectroscopy, combined with other experimental and theoretical studies, will be useful in understanding the quantum properties of molecules. These findings also serve as a guide for quantum chemical calculations of large molecules

    High-resolution spectroscopy of buffer-gas-cooled phthalocyanine

    Get PDF
    For over five decades, studies in the field of chemical physics and physical chemistry have primarily aimed to understand the quantum properties of molecules. However, high-resolution rovibronic spectroscopy has been limited to relatively small and simple systems because translationally and rotationally cold samples have not been prepared in sufficiently large quantities for large and complex systems. In this study, we present high-resolution rovibronic spectroscopy results for large gas-phase molecules, namely, free-base phthalocya-nine (FBPc). The findings suggest that buffer-gas cooling may be effective for large molecules introduced via laser ablation. High-resolution electronic spectroscopy, combined with other experimental and theoretical studies, will be useful in understanding the quantum properties of molecules. These findings also serve as a guide for quantum chemical calculations of large molecules

    High-resolution spectroscopy of buffer-gas-cooled phthalocyanine

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    High-resolution molecular spectroscopy provides invaluable insight into the quantum properties of molecules, but high-resolution rovibronic spectroscopy has largely been limited to relatively small systems owing to the difficulty in preparing translationally and rotationally cold samples for large and complex systems. Here, the authors demonstrate that buffer-gas cooling may be an effective strategy to obtain high-resolution rovibronic spectroscopy results for large gas-phase molecules

    小児がん患者の退院後の口腔の健康状態と歯科保健行動の実態

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    退院後の小児がん患者の口腔の健康状態と歯科保健行動の問題点を明らかにし,小児がん患者の歯科保健指導のあり方を検討することを目的とした.A市内の総合病院2施設で小児がん治療を受けて退院した小児と保護者66名を対象に,構造化面接法による口腔の健康状態と歯科保健行動に関する質問紙調査を実施した.口腔の健康状態では,「う蝕歯あり」は47名(71.2%),「う蝕5本以上」17名(25.8%)であった.治療内容別に比較した結果,造血幹細胞移植実施群(p <0.05)と放射線療法実施群(p <0.01)において「う蝕5本以上」の割合が高かった.造血幹細胞移植群では化学療法開始年齢が3歳未満において「う蝕5本以上」の割合が高かった(p <0.05).形成障害については,造血幹細胞移植実施群,放射線療法実施群での割合が高かった(p <0.01).造血幹細胞移植実施群では,化学療法開始年齢3歳未満が「矮小歯・先天性欠如あり」の割合が高かった(p <0.05).歯科保健行動については,9割以上が1日2回以上歯磨きを実施していたが,歯科定期受診しているものは3割以下であった.退院後の小児がん患者の口腔の健康状態は,う蝕や形成障害などの問題が多いが歯科の定期受診の割合が低いことから,歯科の晩期合併症に対する情報を提供し,定期的な歯科受診の必要性について指導する必要がある.This study aimed to clarify the state of oral cavity health and the dental health behavior among pediatric cancer patients after they are discharged from a hospital environment. We obtained consent to participate from 66 subjects comprising children who had been treated for pediatric cancer at and discharged from two general hospitals in City A and their parents, and structured interviews. Among the respondents, 47 (71.2%) reported that the children had dental caries and 17 (25.8%) reported that the dental caries affected five or more teeth. The incidence was high among those who had undergone hematopoietic stem cell transplantation (p<0.05) and those who had undergone radiation therapy (p<0.01). Among children who had undergone hematopoietic stem cell transplantation, the incidence was high in children who were younger than 3 years old when they began undergoing treatment (p<0.05). For dysplasia, the incidence was high for children who had undergone hematopoietic stem cell transplantation and those who had undergone radiation therapy (p<0.01). Among children who had undergone hematopoietic stem cell transplantation, there was a high incidence of microdontia or congenital lack of teeth for children who were younger than 3 years old when they began chemotherapy (p<0.05). Over 90% of the children were currently brushing their teeth twice a day. Approximately 70% of the children had been told the name of their illness, and fewer than 30% were receiving regular dental checkups. It is important to ensure that patients and parents are provided with information about late dental complications and emphasize the necessity for regular dental checkups. It is necessary to provide guidance on the need for dentist consultation for about late effects
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