Adaptive intermittent control: A computational model explaining motor intermittency observed in human behavior

It is a fundamental question how our brain performs a given motor task in a real-time fashion with the slow sensorimotor system. Computational theory proposed an influential idea of feed-forward control, but it has mainly treated the case that the movement is ballistic (such as reaching) because the motor commands should be calculated in advance of movement execution. As a possible mechanism for operating feed-forward control in continuous motor tasks (such as target tracking), we propose a control model called "adaptive intermittent control" or "segmented control," that brain adaptively divides the continuous time axis into discrete segments and executes feed-forward control in each segment. The idea of intermittent control has been proposed in the fields of control theory, biological modeling and nonlinear dynamical system. Compared with these previous models, the key of the proposed model is that the system speculatively determines the segmentation based on the future prediction and its uncertainty. The result of computer simulation showed that the proposed model realized faithful visuo-manual tracking with realistic sensorimotor delays and with less computational costs (i.e., with fewer number of segments). Furthermore, it replicated "motor intermittency", that is, intermittent discontinuities commonly observed in human movement trajectories. We discuss that the temporally segmented control is an inevitable strategy for brain which has to achieve a given task with small computational (or cognitive) cost, using a slow control system in an uncertain variable environment, and the motor intermittency is the side-effect of this strategy

Low-Cost High-Speed Imaging System for Observing Vocal Fold Vibration in Voice Disorders

Purpose: The aim of this study was to establish a method to observe vocal fold vibration using a low-cost high-speed laryngeal imaging system. Procedures: We assembled a high-speed imaging system with a consumer digital camera and a rigid laryngeal endoscope. The camera can shoot digital images at a rate of 1,200 frames per second and be purchased for about USD 1,000 in Japan. Results: We examined the normal and pathological vocal folds of 215 subjects with our new system and analyzed the vocal fold vibration in these subjects by playback of a video and kymograph images. Conclusions: Our high-speed laryngeal imaging system is highly cost-effective and can be a useful tool for examining the vocal folds of patients with voice disorders

分子鎖配向制御によるポリ乳酸製骨固定デバイスの力学的特性向上に関する研究

首都大学東京, 2016-03-25, 博士（工学）, 甲第579号首都大学東

Novel Synthesis of Cellulose-Based Diblock Copolymer of Poly(hydroxyethyl methacrylate) by Mechanochemical Reaction

The mechanical fracture of polymer produces polymeric free radical chain-ends, by which liner block copolymers have been synthesized. A diblock copolymer of microcrystalline cellulose (MCC) and poly 2-hydroxyethyl methacrylate (pHEMA) was produced by the mechanochemical polymerization under vacuum and room temperature. The fraction of pHEMA in MCC-blockpHEMA produced by the mechanochemical polymerization increased up to 21 mol% with increasing fracture time (∼6 h). Then, the tacticities of HEMA sequences in MCC-block-pHEMA varied according to the reaction time. In the process of mechanochemical polymerization, cellulose could play the role of a radical polymerization initiator capable of controlling stereoregularity

Acceleration effect of coupled oscillator systems

We have developed a curved isochron clock (CIC) by modifying the radial isochron clock to provide a clean example of the acceleration (deceleration) effect. By analyzing a two-body system of coupled CICs, we determined that an unbalanced mutual interaction caused by curved isochron sets is the minimum mechanism needed for generating the acceleration (deceleration) effect in coupled oscillator systems. From this we can see that the Sakaguchi and Kuramoto (SK) model which is a class of non-frustrated mean feild model has an acceleration (deceleration) effect mechanism. To study frustrated coupled oscillator systems, we extended the SK model to two oscillator associative memory models, one with symmetric and one with asymmetric dilution of coupling, which also have the minimum mechanism of the acceleration (deceleration) effect. We theoretically found that the {\it Onsager reaction term} (ORT), which is unique to frustrated systems, plays an important role in the acceleration (de! celeration) effect. These two models are ideal for evaluating the effect of the ORT because, with the exception of the ORT, they have the same order parameter equations. We found that the two models have identical macroscopic properties, except for the acceleration effect caused by the ORT. By comparing the results of the two models, we can extract the effect of the ORT from only the rotation speeds of the oscillators.Comment: 35 pages, 10 figure

Design and Demonstration of a Neutron Spin Flipper for a New Neutron Reflectometer SHARAKU at J-PARC

AbstractA new neutron reflectometer SHARAKU with vertical sample-plane geometry was installed on the beam line 17 (BL17) at Materials and Life science experiment Facility (MLF) at J-PARC. Magnetism in a thin magnetic film is one of the main targets on SHARAKU and polarizing devices and neutron spin flippers are required. Since polarized neutrons of wavelength from 0.24nm to 0.64nm can be used on SHARAKU, a neutron spin flipper has to control white neutron beam. A two-coil neutron spin flipper (Drabkin spin flipper) is one of the powerful devices to control neutron spin with white beam. In this study, the two-coil flipper was designed and installed in SHARAKU. Demonstration of the two-coil flipper was also performed and polarization of more than 0.95 with wavelengths ranging from 0.24nm to 0.64nm was obtained

Japanese subpopulation analysis of MONARCH 2: phase 3 study of abemaciclib plus fulvestrant for treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer that progressed on endocrine therapy

BACKGROUND: This was a Japanese subpopulation analysis of MONARCH 2, a double-blind, randomized, placebo-controlled, phase 3 study of abemaciclib plus fulvestrant in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (ABC). METHODS: Eligible women had progressed on (neo)adjuvant endocrine therapy (ET),  ≤ 12 months from end of adjuvant ET, or on first-line ET for ABC, and had not received chemotherapy for ABC. Patients were randomized 2:1 to receive abemaciclib or placebo plus fulvestrant. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), pharmacokinetics (PK), health-related quality of life (HRQoL), and safety. RESULTS: In Japan, 95 patients were randomized (abemaciclib, n = 64; placebo, n = 31). At final PFS analysis (February 14, 2017), median PFS was 21.2 and 14.3 months, respectively, in the abemaciclib and placebo groups (hazard ratio: 0.672; 95% confidence interval: 0.380-1.189). Abemaciclib had a higher objective response rate (37.5%) than placebo (12.9%). PK and safety profiles for Japanese patients were consistent with those of the overall population, without clinically meaningful differences across most HRQoL dimensions evaluated. The most frequent adverse events in the abemaciclib versus placebo groups were diarrhea (95.2 versus 25.8%), neutropenia (79.4 versus 0%), and leukopenia (66.7 versus 0%). At a second data cutoff (June 20, 2019), median OS was not reached with abemaciclib and 47.3 months with placebo (hazard ratio: 0.755; 95% confidence interval: 0.390-1.463). CONCLUSIONS: Results of the Japanese subpopulation were consistent with the improved clinical outcomes and manageable safety profile observed in the overall population. CLINICAL TRIAL REGISTRATION: NCT02107703; U.S. National Library of Medicine: https://clinicaltrials.gov/ct2/show/NCT02107703

Comparative Outcomes of Laparoscopic Gastrectomy and Open Gastrectomy for Scirrhous Gastric Cancer: A Multicenter Retrospective Cohort Study

Objective: A multicenter retrospective cohort study was performed to compare the outcomes of laparoscopic gastrectomy (LG) versus open gastrectomy (OG) for scirrhous gastric cancer (GC) as a unique subtype also known as type 4 gastric cancer or linitis plastica. Background: Although data on the efficacy and safety of LG as an alternative to OG are emerging, the applicability of LG to scirrhous GC remains unclear. Methods: Patients with clinical type 4 GC undergoing gastrectomy at 13 hospitals from 2005 to 2015 were retrospectively reviewed. As the primary endpoint, we compared overall survival (OS) between the LG and OG groups. To adjust for confounding factors, we used multivariate Cox regression analysis for the main analyses and propensity-score matching for sensitivity analysis. Short-term outcomes and recurrence-free survival were also compared. Results: A total of 288 patients (LG, 62; OG, 226) were included in the main analysis. Postoperative complications occurred in 25.8% and 30.1%, respectively (P = 0.44). No significant difference in recurrence-free survival was observed (P = 0.72). The 5-year OS rates were 32.4% and 31.6% in the LG and OG groups, respectively (P = 0.60). The hazard ratio (LG/OG) for OS was 0.98 (95% confidence interval [CI], 0.65–1.43) in the multivariate regression analysis. In the sensitivity analyses after propensity-score matching, the hazard ratio for OS was 0.92 (95% CI, 0.58–1.45). Conclusions: Considering the hazard ratios and 95% CIs for OS, LG for scirrhous GC was not associated with worse survival than that for OG

T細胞活性化によるアセチルコリン受容体の発現抑制機構の検討

T細胞にはムスカリン性およびニコチン性アセチルコリン受容体（mAChRおよびnAChR）が発現している。T細胞のAChRは、細胞傷害性の増強、細胞分裂の促進、細胞内cGMP濃度の上昇などの生理的役割を担っている。本研究では、T細胞の活性化がAChRの遺伝子発現に及ぼす影響および発現調節メカニズムを検討した。マウス脾臓細胞あるいは脾臓細胞から単離したCD4陽性T細胞において、2 日間の抗CD3/CD28抗体刺激は、M1-M5 mAChR mRNAおよびα4、α7、β2 nAChR mRNAの発現を減少させた。この減少作用には、nuclear factor-κBが関与していることが明らかとなった。さらに、2 日間の抗CD3/CD28抗体刺激は、mAChRあるいはnAChRの活性化による細胞内Ca2＋濃度上昇を抑制した。以上の結果より、T細胞の活性化は受容体発現を減少させることによりAChに対する反応性を低下させることが明らかとなった。すなわち、T細胞の活性化は、mAChRおよびnAChRを介した細胞障害性の増強や細胞分裂促進などの生理作用を低下させる可能性が示唆された。Muscarinic and nicotinic acetylcholine receptors（mAChR and nAChR）are expressed in immune cells including T cells. AChR of T cells plays physiological roles such as the enhancement of cytotoxicity, the promotion of cell division, the elevation of intracellular cGMP concentration. In this study, the effect of T cell activation on the expression of AChR and the mechanism of its expression were examined. In CD4-positive T cells or CD4-negative cells isolated from mouse spleen cells, anti-CD3/CD28 antibody stimulation for 2 days reduced the expression of M1-M5 mAChR mRNAs and α4, α7, β 2 nAChR mRNAs. It was revealed that nuclear factor-κB is involved in this decreasing action. Furthermore,stimulation of intracellular Ca2＋ concentration by activation of mAChR or nAChR was suppressed by stimulation with anti-CD3/CD28 antibody for 2 days. From the above results, it was revealed that activation of T cells reduces the reactivity to ACh by decreasing AChR expression. That is, it was suggested that differentiation of T cells may decrease physiological effects such as enhancement of cytotoxicity and promotion of cell division via mAChR and nAChR.論

合併症を有するB型大動脈解離に対するステントグラフト内挿術における腎動脈に対する治療戦略 : 多施設共同研究

Background: Management of abdominal branches associated with Stanford type B aortic dissection is controversial without definite criteria for therapy after thoracic endovascular aortic repair (TEVAR). This is in part due to lack of data on natural history related to branch vessels and their relationship with the dissection flap, true lumen, and false lumen. Purpose: To investigate the natural history of abdominal branches after TEVAR for type B aortic dissection and the relationship between renal artery anatomy and renal volume as a surrogate measure of perfusion. Materials and Methods: This study included patients who underwent TEVAR for complicated type B dissection from January 2012 to March 2017 at 20 centers. Abdominal aortic branches were classified with following features: patency, branch vessel origin, and presence of extension of the aortic dissection into a branch (pattern 1, supplied by the true lumen without branch dissection; pattern 2, supplied by the true lumen with branch dissection, etc). The branch artery patterns before TEVAR were compared with those of the last follow-up CT (mean interval, 19.7 months) for spontaneous healing. Patients with one kidney supplied by pattern 1 and the other kidney by a different pattern were identified, and kidney volumes over the course were compared by using a simple linear regression model. Results: Two hundred nine patients (mean age ± standard deviation, 66 years ± 13; 165 men and 44 women; median follow-up, 18 months) were included. Four hundred fifty-nine abdominal branches at the last follow-up were evaluable. Spontaneous healing of the dissected branch occurred in 63% (64 of 102) of pattern 2 branches. Regarding the other patterns, 6.5% (six of 93) of branches achieved spontaneous healing. In 79 patients, renal volumes decreased in kidneys with pattern 2 branches with more than 50% stenosis and branches supplied by the aortic false lumen (patterns 3 and 4) compared with contralateral kidneys supplied by pattern 1 (pattern 2 vs pattern 1: −16% ± 16 vs 0.10% ± 11, P = .002; patterns 3 and 4 vs pattern 1: −13% ± 14 vs 8.5% ± 14, P = .004). Conclusion: Spontaneous healing occurs more frequently in dissected branches arising from the true lumen than in other branch patterns. Renal artery branches supplied by the aortic false lumen or a persistently dissected artery with greater than 50% stenosis are associated with significantly greater kidney volume loss.博士（医学）・乙第1461号・令和2年6月30日Copyright © 2019 by authors and RSNA. This work is licensed under the Creative Commons Attribution International License (CC BY-NC-ND 4.0). https://creativecommons.org/licenses/by-nc-nd/4.0/