- 著者
- Narihiro Orikasa Atsushi Saito Katsuya Yamashita Takuya Tajiri Yuji Zaizen Tzu-Hsien Kuo Wei-Chen Kuo Masataka Murakami
- 出版者
- Meteorological Society of Japan
- 雑誌
- SOLA (ISSN:13496476)
- 巻号頁・発行日
- vol.16, pp.212-219, 2020 (Released:2020-11-05)
- 参考文献数
- 31
- 被引用文献数
- 2
Since March 2012, multi-year ground-based observation of atmospheric aerosol particles has been carried out in Tsukuba, Japan to characterize the aerosol particle number concentrations (NCs), air mass origin relevance, and specifically, their cloud condensation nuclei (CCN) and ice nucleating particle (INP) characteristics. The CCN NCs at any water supersaturation (SS) exhibit strong seasonality, being higher in winter and lower in summer; this pattern is similar in the polluted urban environment in East Asia and contrary to that in the Pacific coastal region. The hygroscopicity (κ) is generally high in early autumn and low in early summer, likely due to the seasonal difference of synoptic-scale systems. In contrast, the INP NCs and ice nucleation active surface site density (ns) at defined temperature (−15 to −35°C) and SS (0%-5%) lack clear seasonal influence. The average INP NCs and ns in this study were comparable at warmer temperatures and approximately one order of magnitude lower at colder temperatures, compared with those in other urban locations under limited dust impact. Moreover, the ns values were one to four orders of magnitude lower and exhibited weaker temperature dependence than previous parameterizations on mineral dust particles.
- 著者
- Narihiro Orikasa Atsushi Saito Katsuya Yamashita Takuya Tajiri Yuji Zaizen Tzu-Hsien Kuo Wei-Chen Kuo Masataka Murakami
- 出版者
- Meteorological Society of Japan
- 雑誌
- SOLA (ISSN:13496476)
- 巻号頁・発行日
- pp.2020-036, (Released:2020-09-23)
- 被引用文献数
- 2
Since March 2012, multi-year ground-based observation of atmospheric aerosol particles has been carried out in Tsukuba, Japan to characterize the aerosol particle number concentrations (NCs), air mass origin relevance, and specifically, their cloud condensation nuclei (CCN) and ice nucleating particle (INP) characteristics. The CCN NCs at any water supersaturation (SS) exhibit strong seasonality, being higher in winter and lower in summer; this pattern is similar in the polluted urban environment in East Asia and contrary to that in the Pacific coastal region. The hygroscopicity (κ) is generally high in early autumn and low in early summer, likely due to the seasonal difference of synoptic-scale systems. In contrast, the INP NCs and ice nucleation active surface site density (ns) at defined temperature (−15 to −35°C) and SS (0%-5%) lack clear seasonal influence. The average INP NCs and ns in this study were comparable at warmer temperatures and approximately one order of magnitude lower at colder temperatures, compared with those in other urban locations under limited dust impact. Moreover, the ns values were one to four orders of magnitude lower and exhibited weaker temperature dependence than previous parameterizations on mineral dust particles.
- 著者
- Tatsuya SASAKI Kensuke MURAKAMI Atsushi SAITO Shinya HARYU Masayuki KAMEYAMA Yoshiharu TAKAHASHI Satoru TAKAMURO Nana KATO Toshiki ENDO
- 出版者
- The Japan Neurosurgical Society
- 雑誌
- Neurologia medico-chirurgica (ISSN:04708105)
- 巻号頁・発行日
- pp.2023-0007, (Released:2023-06-28)
- 参考文献数
- 24
The usefulness of transcranial motor evoked potentials (Tc-MEPs) in clipping surgery has been reported. However, numerous false positive and false negative cases were reported. We report the usefulness of a new protocol compared with direct cortical MEP (Dc-MEP).Materials were 351 patients who underwent aneurysmal clipping under simultaneous monitoring of Tc- and Dc-MEPs. A total of 337 patients without hemiparesis and 14 with hemiparesis were separately analyzed. Intraoperative changes of Tc-MEP thresholds were examined in the first 50 patients without hemiparesis. The stimulation strength of Tc-MEP was set at +20% of the stimulation threshold. As thresholds changed intraoperatively, thresholds were examined every 10 min and changed stimulation strength.Stimulation thresholds of Tc-MEP were significantly decreased after craniotomy and significantly increased after CSF aspiration. The recording ratios of Tc- and Dc-MEPs were 98.8% and 90.5%, respectively. Out of 304 patients without MEP change, 5 patients developed transient or mild hemiparesis with infarction of the territory of the perforating artery arising from the posterior communicating artery. Out of 31 patients whose MEP transiently disappeared, 3 patients developed transient or mild hemiparesis. The other two patients without MEP recovery manifested persistent hemiparesis. In 14 patients with preoperative hemiparesis, 3 patients whose healthy/affected ratio of Tc-MEP was large developed severe persistent hemiparesis.We clarified the intraoperative changes of Tc-MEP thresholds for the first time. A new protocol of Tc-MEP that followed thresholds and changed stimulation strength to +20% of thresholds is useful for stable monitoring. The usefulness of Tc-MEP is the same as that or better than that of Dc-MEP.
- 著者
- Keiji Wada Yukihisa Suzuki Akira Ushiyama Shin Ohtani Kenji Hattori Atsushi Saito Satoshi Nakasono Satoshi Miyawaki Takashi Yanagisawa Yoshiya Ohnuma
- 出版者
- The Institute of Electronics, Information and Communication Engineers
- 雑誌
- IEICE Communications Express (ISSN:21870136)
- 巻号頁・発行日
- vol.11, no.10, pp.661-666, 2022-10-01 (Released:2022-10-01)
- 参考文献数
- 7
This letter presents development of a magnetic field generator to evaluation of biological effects. The magnetic field generator has a frequency bandwidth of 85 kHz because it is intended for wireless power supply for electric vehicles. Furthermore, the generator is designed to operate for only one second, and can produce the induced magnetic field of 10 times compared to basic restrictions of the ICNIRP. By applying the magnetic field generator, it is possible to conduct a evaluation and verification of biological effect depending on electromagnetic fields for WPT systems of electric vehicles.
- 著者
- Atsushi SAITO Takashi INOUE Shinsuke SUZUKI Masayuki EZURA Hiroshi UENOHARA Teiji TOMINAGA
- 出版者
- The Japan Neurosurgical Society
- 雑誌
- Neurologia medico-chirurgica (ISSN:04708105)
- 巻号頁・発行日
- pp.oa.2020-0131, (Released:2021-01-28)
- 参考文献数
- 20
- 被引用文献数
- 5
Few studies have reviewed the roles of perfusion magnetic resonance (MR) imaging in the histopathological examination of meningiomas. We analyzed the relationships between radiological findings on perfusion MR imaging and pathological characteristics such as origin of the tumor, mitotic activity, pathological subtype, and perifocal edema formation. The subjects were 21 surgical cases of meningioma preoperatively evaluated by perfusion MR imaging. A region of interest (ROI) was set inside of the tumor, and perifocal edema of the same size, cerebral blood volume (CBV), and cerebral blood flow (CBF) on perfusion MR and diffusion-weighted (DW) imaging were analyzed. These radiological data were evaluated in comparison with histopathological characteristics. On perfusion MR imaging, the average ratio of CBV against the contralateral side was 6.43 (1.13–20.0) and that of CBF was 7.73 (1.34–11.3). There was no significant relationship with perfusion MR imaging data, tumor volume, or perifocal edema volume. However, the large peritumoral edema group often had a higher CBV and CBF than the non-large peritumoral edema group. The skull base group had a significantly higher CBV and lower signal intensity on DW images than the non-skull base group. Signal intensity on DW images was higher in grade II or III than in grade I. Perfusion MR imaging data revealed that the higher ratio of peritumoral edema against tumor size was associated with higher blood flow and blood volume under intratumoral circulatory conditions, and that skull base meningioma had a higher blood volume than non-skull base meningioma.
1 0 0 0 OA ストレスと精神障害
- 著者
- 秋山 一文 斉藤 淳 Kazufumi Akiyama Atsushi Saito 獨協医科大学精神神経医学教室 獨協医科大学精神神経医学教室
- 雑誌
- Dokkyo journal of medical sciences (ISSN:03855023)
- 巻号頁・発行日
- vol.33, no.3, pp.207-212, 2006-10-25
脳には視床下部-下垂体-副腎皮質系(hypothalamiic-pituitary-adrenocortical axis, HPA系)とノルアドレナリン系というストレス反応を担う2つの系が存在する.急性のストレス反応を終焉させるためにHPA系全体に負のフィードバックが作動する.しかしストレス反応は長期化すればいわば「両刃の刃」としての性質をもつようになる.その引き金になるのがストレスの反復による海馬神経細胞への障害で,これにはbrain derived neurotrophic factor(BDNF)の減少が関与しているかもしれない.またストレスの反復によって脳内ノルアドレナリンの放出は感作される.精神障害は何らかの意味でストレスの影響を被るが,特にストレス反応を担うHPAの制御の障害が示唆される精神障害としてうつ病.外傷後ストレス障害(posttraumatic stress disorder, PTSD),摂食障害を取り上げた.いずれも遺伝的要因を含む脆弱性を有する個人に何らかのストレス負荷が加わり発症するという図式に共通点がある.しかしデキサメサゾン抑制試験で評価したHPAの制御障害の方向性はうつ病では非抑制,PTSDでは過剰抑制と相反している.MRIによるうつ病の画像研究では海馬の萎縮を認めた報告が多い.これがいつから始まるかという問題はストレスによる海馬神経細胞への障害の時間的経過という点で興味深いが更に今後の検討が必要と考えられる.近年,児童虐待が社会問題化しているが,被虐待児が後年になってうつ病,あるいはPTSDなど深刻な精神障害を高率に発症することが見いだされている.このようにストレスと精神障害との関係は大きな広がりを見せつつある.
- 著者
- Mikio Ota Fumi Seshima Nobuki Okubo Takashi Kinumatsu Sachiyo Tomita Takeshi Okubo Atsushi Saito
- 出版者
- Tokyo Dental College, Japan
- 雑誌
- The Bulletin of Tokyo Dental College (ISSN:00408891)
- 巻号頁・発行日
- vol.54, no.1, pp.51-57, 2013 (Released:2013-04-23)
- 参考文献数
- 22
- 被引用文献数
- 2 1
As periodontal disease and diabetes mellitus (DM) have bidirectional interactions, an effective approach to periodontal treatment for patients with diabetes in the clinical setting is essential. This paper reports an effort in collaborative care for patients with periodontitis and diabetes between dental and medical professionals, and provides a preliminary evaluation regarding the clinical outcomes. We have introduced a clinical pathway program at our institution applicable to patients with periodontitis and DM. Physicians and dentists utilize the clinical pathway to share medical and dental information in order to provide the optimal care for each patient. So far, this clinical pathway has been applied to the treatment of 50 patients. We analyzed clinical outcomes in 10 patients with the chief complaint of periodontal problems who had also been diagnosed with type 2 DM. After initial periodontal therapy and diabetes care, a significant improvement in the mean value of glycated hemoglobin and fasting plasma glucose was observed, accompanied by clinical resolution of periodontal parameters. Within the limitations of the present study, the results suggest that collaborative care between periodontists and physicians based on the clinical pathway is effective in glycemic control of patients with periodontitis and type 2 DM. This indicates the need for closer collaboration between medical and dental professionals in improving the management of these diseases.