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Pulmonary vein (PV) isolation (PVI) including the left atrial posterior wall (LAPW) (Box-PVI) is proposed as an additional strategy for non-paroxysmal atrial fibrillation (NPAF), however, the efficacy remains controversial. The more reliable and durable the Box-PVI we can create, the better the rhythm outcomes might be than with a conventional PVI alone. This study focused on the potential exit conduction of the box lesion and investigated whether the conventional Box-PVI would be sufficient.We enrolled 350 consecutive patients with NPAF that underwent a conventional encircling Box-PVI and examined whether latent exit conduction and dormant "exit" conduction independently remained on the LAPW and in the PVs using high frequency stimulation (HFS) and an adenosine triphosphate (ATP) injection. All electrograms inside the box lesion were eliminated in all cases, however, HFS inside the box propagated outward in 23 cases (6.6%) without any exit conduction by conventional burst stimulation, and 24 cases (6.9%) exhibited only dormant "exit" conduction of the LAPW. Additional ablation where positive HFSs were observed created a complete bidirectional Box-PVI in 43 (41.3%) of the cases without a first pass Box-PVI. The recurrence rates depended on the groups classified according to the HFS response.HFS delivered with an ATP injection on the LAPW and in the PVs following a Box-PVI could not only elucidate true exit block but also identified possible incomplete lesions or connections outside the ablation line, whose elimination could achieve a complete Box-PVI leading to a better rhythm outcome.

A quench detection method using a low-temperature superconducting quench detector (QD) has been proposed to protect rare-earth barium copper oxide (REBCO) coils at temperatures below 20 K in magnetic fields. In this study, we first conducted an experiment at 4.2 K in 0–9 T using a locally- degraded REBCO tape and Nb–Ti QDs (Nb–Ti/Cu, Nb–Ti/Cu–Ni). Quick quench detection before thermal runaway of the REBCO tape was demonstrated by the Nb–Ti/Cu–Ni QD in 0–9 T, whereas Nb–Ti/Cu QD exhibited quick quench detection only at 9 T. Furthermore, we numerically evaluated the quench detection time of Nb–Ti QDs attached to a REBCO tape with local degradation at 4.2 K in 0–9 T. The simulation reproduced the experimental results. Moreover, the contact resistance between the REBCO tape and QD should be lower than 1.0 × 10−3 m2K/W for quick quench detection.

【目的】アンギオ装置は多くの病院で導入され検査や治療のために利用されているが、散乱線による術者への被曝が懸念されている。以前より防護教育の取組みとして、ヘッドマウントディスプレイ（HMD）を用いた空間線量を可視化する試みを行っており、一定の有用性があることを確認できた一方で、空間線量の表現方法の改善点が指摘された。このため、可視化だけではなく、空中の任意の場所に振動を発生させるハプティクスデバイス（HD）を組合せ、視覚と振動による空間線量のフィードバックにより改善できないかと考えた。本研究ではHMDとHDを組合せたシステムを開発し、技術的な実現性および有用性の検証を行った。 【方法】現在開発中の可視化ソフトウェアはHMDにアンギオ室を模した３Dモデルを投影することができる。これに空中HDを組合せ、HMDに投影された直接線に手指が触れた際、手に振動を伝えるプログラムを開発した。これを可視化ソフトウェアと組合せ、放射線技師を始めとする16名に使用してもらい、有用性についてアンケート形式で調査を行った。 【結果】HMDで可視化された直接線に手指が触れた時に手指に振動を与えることが確認でき、直接線の範囲をフィードバックできることを確認できた。また使用者に有用性に関するアンケートを１から３の３段階評価で行い、防護教育ソフトウェアとしての一定の有用性があることを確認できたが、可視化のみと比べると若干の減少が認められた。 【結論】空中HDを用いた空間線量のフィードバックは、術者への放射線防護への意識付けに一定の効果があることを確認することができた。しかし、振動が小さいことや振動を与える範囲が広くないなどといったデバイスに依存する改善すべき点も挙げられた。今後は、直接線のみならず散乱線による空間線量への応用、またさらに効果的な意識付けにするための方法の模索を行い、教育ツールの開発を継続して行っていく。, 第49回日本放射線技術学会秋季学術大会参加

量子センシング・イメージング実現に向けて、ダイヤモンド中NVセンターの基礎的物性から高濃度・高輝度発光NVセンターの形成についてナノダイヤモンド(ND)材料を用いた研究を進めている。ND中のNVセンターは、単一細胞レベルから動物レベルまでの幅広い生体に導入することができ、それらの生命現象により誘起される微小温度変化、細胞活性に伴う磁気・電気的変化の検出を活用した体内のイメージング材料として期待されている。NVセンターの量子性を利用した量子センシング・イメージングのためには、より効率的にNVセンターを導入することに加え、量子性の優れたND中NVセンター形成技術が求められている。今日までにNDに電子線照射と熱処理により高輝度なNVセンター形成技術の最適化を図ってきており、そのようにして作製した高輝度NV-NDの表面に対して、生体導入に適した化学処理を施す必要があり、それらNDの表面化学修飾についても最適化を進めている。 本研究では、50 nm NDについて電子線照射量と熱処理条件を実施し、種々の条件とNVセンター形成への影響を調べ、更に生体系へ導入するための高発光蛍光ND(Fluorescence Nano-Diamond: FND)の表面に化学修飾についても報告する。, 量子生命科学会第3回大会

Multi-vital signs detection; respiration, heart rate, and body temperature from respiration airflow at the mouth was proposed, and three sensors patterns (flow-rate, - direction, and -temperature sensors) were formed on a single MEMS sensor. The small-sized tube type flow sensor was designed and fabricated to apply it the animal experiment, and its detection characteristics were experimentally evaluated. The flow rate sensor output followed the King's equation, and the response time of 50 ms was obtained to confirm the following oscillating breathing airflow measurement. Then, we confirmed that the fabricated sensor can measure the airflow whose temperature changes periodically. Finally, we conducted an animal experiment using rats, and confirmed that the fabricated sensor can measure three vital signs of respiration, heart rate, and body temperature from respiration.

Background Ethanol injections into the vein of Marshall (VOM) (EIM) are considered to be a good therapeutic option for atrial tachyarrhythmias, however, the safety remains to be determined. To elucidate what would affect the safety and potential complications of an EIM, we investigated the anatomical features of the VOM and patient background. Methods We performed the EIM before the conventional pulmonary vein isolation for drug‐resistant atrial fibrillation in 88 patients and evaluated the anatomical features of the VOM and their background. Results All procedures were completed, however, other than myocardial staining, trivial contrast medium leaked out of the VOM into the pericardial space, that is, extravasation of contrast medium with capillary rupture, during the EIM in 20 patients (22.7%) regardless of the features of the VOM. No pericardial effusions requiring further intervention developed after the extravasation, which resolved by the next day on echocardiography in 18 of those patients. However, two patients who had extravasation other than during the initial contrast injection required additional therapeutic intervention for nonnegligible pericardial effusions. Their body weights were significantly lower and the latter two patients were also small lean women with heart failure and a preserved ejection fraction. Conclusions The physical constitution, regardless of the characteristics of the VOM, could be strongly associated with adverse events during the EIM. We must take extreme care in smaller patients with poor compliant hearts during the EIM.

Quench detection in a rare-earth barium copper oxide (REBCO) coil is difficult due to the slow normal zone propagation in it. To address this issue, we have proposed a quench detection method using a low temperature superconducting (LTS) wire as a quench detector. A demonstration experiment in our previous research using a REBCO tape showed that the quench detector was able to detect quench in the tape before it burned out. Therefore, to verify the applicability of this method to a real magnet system, we first numerically evaluated the quench detectability of Nb-Ti and Nb 3 Al detectors attached on stacked REBCO tapes at 4.2 K under magnetic fields up to 20 T assuming the coil excitation process. The results indicated that the detectors were not needed to be placed in each layer of the REBCO coil. Furthermore, we have conducted an experiment using a REBCO single pancake coil with the Nb-Ti quench detector at 4.2 K and self-field. As the results of the experiment, we demonstrated that one Nb-Ti detector was able to detect the quench in the REBCO coil even if there were at least three REBCO tapes and the polyimide tapes between the detector and the hot-spot in the REBCO coil.

Pigment organelles known as melanosomes disperse or aggregate in a melanophore in response to hormones. These movements are mediated by the microtubule motors kinesin-2 and cytoplasmic dynein. However, the force generation mechanism of dynein, unlike that of kinesin, is not well understood. In this study, to address this issue, we investigated the dynein-mediated aggregation of melanosomes in zebrafish melanophores. We applied the fluctuation theorem of non-equilibrium statistical mechanics to estimate forces acting on melanosomes during transport by dynein, given that the energy of a system is related to its fluctuation. Our results demonstrate that multiple force-producing units cooperatively transport a single melanosome. Since the force is generated by dynein, this suggests that multiple dyneins carry a single melanosome. Cooperative transport has been reported for other organelles; thus, multiple-motor transport may be a universal mechanism for moving organelles within the cell.

【目的】アンギオ装置は多くの病院で導入され検査や治療のため利用されている。患者への侵襲性が低く負担が少ないというメリットがあるが、術中に発生する散乱線によって医師や看護師など術者への職業被ばくが懸念されており、ICRPは術者への放射線被ばくの低減のための勧告を行っている。術者の放射線防護は安定した医療の提供ために非常に重要であり、術者への防護に対する意識付けが必要である。そのためには放射線を可視化することが効果的ではないかと考え、空間線量を可視化するためのソフトウェアを開発し、有効性の確認を行った。 【方法】初めに、アンギオ装置で照射されるコーンビームおよび患者や治療室の３Dモデルを作成し、空間線量をシミュレーションした。次に、現実空間に立体的な３Dモデルを描画するヘッドマウントディスプレイ（HMD）にシミュレーションした空間線量を描画するソフトウェアを開発した。空間線量のシミュレーションには粒子・重イオン輸送計算コード（PHITS）を使用した。HMDにはMicrosoft HoloLens 2(R)を使用し、ソフトウェア開発にはUnity(R)を用いた。また、空間の位置を定めるためのArgument Reality（AR）マーカとしてVuforia(C)社が提供するライブラリを使用した。これらを用いてソフトウェアを開発し有効性を確認した。 【結果】PHITSでシミュレーションした結果をHMD上に投影することができ、技術的に空間線量を可視化できることを確認した。また、HMDのハンドトラッキング機能を用いて利用者の両手を３Dモデルとして空間線量と同時に投影することで、線量の高い場所に触れているかどうかを確かめることができ、放射線防護への意識付けに有効であることが確認できた。今後は実際の治療室をモデルにシミュレーションすることや、遮蔽板の有無による空間線量の変化が視覚的に分かるように改良を行い、教育ツールとしての有効性について引き続き検証を行っていく。, 第77回日本放射線技術学会総会学術大会

放射線グラフト重合を利用した機能性高分子膜の作製では、基材の物性・形状を保ちながら新たな機能を付与できるため、耐熱性および機械特性に優れたポリエーテルエーテルケトン(PEEK)等の芳香族炭化水素高分子が有力な基材候補として挙げられる。一方、芳香族炭化水素高分子は、その優れた耐薬品性により、機能性モノマーの拡散が遅く、グラフト重合の進行が困難な場合が多い。これまで、結晶化度11%の低結晶性PEEK（lPEEK）基材へのスチレンスルホン酸エチルエステル（ETSS）モノマーのグラフト重合について、結晶化度25％以下では反応が進行する一方、それ以上の結晶化度では、14 nm周期のラメラ構造の形成により、重合反応が阻害されることを報告してきた。また、l-PEEK基材を2官能性モノマーであるジビニルベンゼン（DVB）のジオキサン（DOX）溶液中で熱処理することで、ETSSのグラフト重合速度が約4倍になることが見出されている。今回、溶媒処理のグラフト重合促進効果について、既に報告した熱処理と同様にPEEK基材の結晶モルフォロジーがその重合性に影響している可能性が高いことから、溶媒処理およびグラフト重合による結晶性やラメラ構造の変化を解析した。, 第69回高分子討論会

Introduction Exit block, which is difficult to strictly confirm and cannot be adopted for adenosine triphosphate (ATP) injections to provoke dormancy, is an essential concept of atrial fibrillation (AF) ablation. We investigated exit conduction using high frequency stimulation (HFS) and evaluated whether dormant “exit” conduction of the pulmonary veins (PVs) and left atrial posterior wall (LAPW) would remain in patients in which an encircling isolation of all PVs and LAPW isolation (Box PVI) were performed. Methods We enrolled 345 consecutive patients with various severities of AF undergoing a Box PVI and defined the procedure endpoint as complete bidirectional block with no dormant “entrance and exit” conduction of all PVs and the LAPW using HFS and ATP. Results Dormant “exit” conduction of the PVs with HFS delivered at the PV carina following an ATP injection remained in 0.9% after additional applications, and that for the LAPW was provoked in 5.5%, which remained in 1.4%. Our definition of a complete bidirectional Box PVI was satisfied in 79.7% and showed the best clinical outcome. In the non-paroxysmal AF group, there were significant differences in the recurrence rates between the groups with and without a complete LAPW isolation, however, the clinical outcome was independent of a complete LAPW isolation in the paroxysmal AF group. Conclusion HFS delivered at the PV carina and LAPW following a Box PVI could clearly elucidate true exit block, and a concomitant ATP injection could define dormant “exit” conduction, suggesting incomplete lesions that had been missed.

Hydrogen-permselective membranes were developed using a radiation-induced grafting method. Styrene (St) and acrylic acid (AAc) monomers were introduced into porous polyvinylidene fluoride (PVDF) membranes to obtain St- and AAc-grafted PVDF membranes with grafting degrees of 82% and 92%, respectively. The porosities of the grafted membranes were controlled in the range 30&ndash, 40% by hot-press compression at 159 &deg, C and 4 MPa. The hydrogen permeability was found to be of the order of 10&minus, 7 mol/m2∙s∙Pa, which was higher than the permeability for water vapor and nitrogen (oxygen model). The St- and AAc-grafted membranes exhibited 9.0 and 34 times higher permeability for H2 than for H2O and N2, respectively.

BACKGROUND Public interest in radiation rose after the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Station accident was caused by an earthquake off the Pacific coast of Tohoku on March 11, 2011. Various reports on the accident and radiation were spread by the mass media, and people displayed their emotional reactions, which were thought to be related to information about the Fukushima accident, on Twitter, Facebook, and other social networking sites. Fears about radiation were spread as well, leading to harmful rumors about Fukushima and the refusal to test children for radiation. It is believed that identifying the process by which people emotionally responded to this information, and hence became gripped by an increased aversion to Fukushima, might be useful in risk communication when similar disasters and accidents occur in the future. There are few studies surveying how people feel about radiation in Fukushima and other regions in an unbiased form. OBJECTIVE The purpose of this study is to identify how the feelings of local residents toward radiation changed according to Twitter. METHODS We used approximately 19 million tweets in Japanese containing the words “radiation” (放射線), “radioactivity” (放射能), and “radioactive substances” (放射性物質) that were posted to Twitter over a 1-year period following the Fukushima nuclear accident. We used regional identifiers contained in tweets (ie, nouns, proper nouns, place names, postal codes, and telephone numbers) to categorize them according to their prefecture, and then analyzed the feelings toward those prefectures from the semantic orientation of the words contained in individual tweets (ie, positive impressions or negative impressions). RESULTS Tweets about radiation increased soon after the earthquake and then decreased, and feelings about radiation trended positively. We determined that, on average, tweets associating Fukushima Prefecture with radiation show more positive feelings than those about other prefectures, but have trended negatively over time. We also found that as other tweets have trended positively, only bots and retweets about Fukushima Prefecture have trended negatively. CONCLUSIONS The number of tweets about radiation has decreased overall, and feelings about radiation have trended positively. However, the fact that tweets about Fukushima Prefecture trended negatively, despite decreasing in percentage, suggests that negative feelings toward Fukushima Prefecture have become more extreme. We found that while the bots and retweets that were not about Fukushima Prefecture gradually trended toward positive feelings, the bots and retweets about Fukushima Prefecture trended toward negative feelings.

The relative humidity (RH) and temperature dependence of the conductance and mechanical properties of poly(styrenesulfonic acid) (PSSA)-grafted poly(ethylene-co-tetrafluoroethylene) polymer electrolyte membrane (ETFE-PEM) at a grafting degree (GD) of 36%, corresponding to an ion exchange capacity (IEC) of 2.03 mmol/g with Nafion-212 as a reference, were investigated. The activation energy of ETFE-PEM was 8.2 kJ/mol, which is lower than that of Nafion-212 (13.2 kJ/mol). The tensile strength of ETFE-PEM (12 − 34 MPa) is higher than that of Nafion-212 (10 − 25 MPa) under dry, wet, or humidified conditions (at 0% and 98% RH at 80 °C). The excellent mechanical properties of ETFE-PEM under humidified conditions can be explained by partial or total compensation effects between PSSA grafts containing water and the ETFE backbone and hierarchical crystalline structures of the membrane. The pristine ETFE, grafted-ETFE, and ETFE-PEM exhibited crystallinities of 30.3%, 22.4%, and 14.6% according to X-ray diffraction results. Thus, sulfonation strongly altered the natural crystalline structures of the pristine ETFE film. Additionally, the 112 XRD reflections played an essential role in the crystalline properties, which determined the mechanical strength of the membrane. The results indicate that ETFE-PEM with an IEC of 2.03 mmol/g exhibited promising electrochemical and mechanical properties under moderately severe operating conditions for fuel cell applications.

The polymer electrolyte membrane consisting of poly(styrenesulfonic acid)-grafted poly(ether ether ketone) (PEEK-PEM) was investigated for application to two electrochemical devices; a fuel cell and electrolytic enrichment of tritium. For fuel cells, high temperature operation has been required from the viewpoints of simplification of cooling systems, heat recovery systems and so forth, and durability is one critical issue affecting practical use. We performed a long term durability test for PEEK-PEM (ion exchange capacity = 2.4 mmol/g, conductivity = 0.15 S/cm) under the condition of 110 °C and 50% relative humidity, and achieved a lifetime of 1500 h at a constant current of 0.3 A/cm2. The cell voltage maintained 97% of initial voltage after 1300 h of operation. There have been only a few reports that PEMs exhibit longer lifetime than 1000 h at temperatures above 100 °C. For quantitative evaluation of tritium concentration in low-level tritiated water such as environmental water, the tritium enrichment by a solid polymer electrolysis (SPE) method is required prior to the tritium concentration measurements. The SPE device composed of PEEK-PEMs with IECs of 0.9–1.2 mmol/g showed a tritium enrichment ratio of 1.35 at 30 °C, which is 20% higher than that of Nafion. Higher tritium enrichment ratios in PEEK-PEM are explained by the smaller amount of transported water. The water transport coefficient in PEEK-PEM is ∼1, which is a half value of Nafion. In addition, the water transport coefficient of PEEK-PEM shows less temperature dependence, at least, up to 60 °C. These features have advantages in electrolytic enrichment of tritium for practical use.

Quench detection for the high-temperature superconducting tape, especially rare-earth barium copper oxide (REBCO) tape, is difficult due to the small normal zone propagation velocity in it. To address this issue, we have proposed a novel quench detectable REBCO tape with a low-temperature superconducting wire used as a quench detector, “REBCO/LTSd tape.” In this paper, we numerically and experimentally demonstrated the validity of the tape consisting of the yttrium barium copper oxide (YBCO) tape and the Nb–Ti wire used at 4.2 K under no external field. Results of the numerical simulation showed that sufficiently high voltage of 0.1 V can be detected before the maximum temperature of the YBCO tape reaches 50 K with the Nb–Ti wires having high resistance at normal conducting state. Experimental results also demonstrated that the quench in the YBCO was detected with the 1 V scale voltage by using the pure Nb–Ti wire.

Blastic plasmacytoid dendritic cell (pDC) neoplasm (BPDCN) is a relatively rare hematological malignancy with significantly complex clinicopathological features that are still unclear. This study aimed to analyze the clinicopathological data of BPDCN and evaluate immunohistochemical detection of minimal bone marrow (BM) involvement. In this study, we examined skin and BM lesions from 6 patients with BPDCN. Neoplastic cells tested positive for CD303 (polyclonal, 100%; monoclonal, 40%) in the skin lesions and for CD303 (polyclonal, 100%; monoclonal, 67%) in the BM clots. Although immunostaining of CD4, CD56, CD123, CD303, and TCLl detected minimal BM involvement in 3 patients, morphological identification was challenging in the BM clots stained with hematoxylin–eosin. In conclusion, our results demonstrate the significance of observing BM smears to detect neoplastic cells and that immunohistochemical examination, including CD303 antibodies, is useful to detect minimal BM involvement. This study is the first to report the expression of thymic stromal lymphopoietin (TSLP) and its receptor in BPDCN cells. Therefore, the TSLP/TSLP receptor axis may be associated with the proliferation of BPDCN, and consequently, the survival of patients.

A coarse-grained molecular dynamics method is applied to the structural analysis of the amorphous region of a polymer electrolyte membrane (PEM) comprising an ethylene-co-tetrafluoroethylene (ETFE), poly(styrene sulfonic acid) (PSSA), and water. The simulated PEM structures reproduce two phase-separated structures comprising hydrophobic ETFE and hydrophilic PSSA/water. The X-ray scattering intensity calculated from the simulation data is consistent with that in the experiment. Both scattering intensity profiles show Porod's law in the lower-q region and exhibit a shoulder peak in the higher-q region, originating from the interface between the hydrophobic/hydrophilic phases and derived from a correlation between sulfonic acid groups, respectively. From an analysis using structure factors, it is shown that there is a phase-separated structure between polystyrene and water in the hydrophilic region. Radial distribution functions show hydrophobic interaction between the benzene unit in the PSSA and a unit in ETFE and miscibility between a sulfonic acid group and water.

We prepared proton exchange membranes (PEMs) composed of block-type polymers by a combination of radiation-induced graft polymerization (RIGP) and atom-transfer radical polymerization (ATRP). This process involves the following three steps: (i) RIGP of styrene (St) and chloromethylstyrene (CMS) into poly(ethylene-co-tetrafluoroethylene) (ETFE) films; (ii) the ATRP of ethyl styrene sulfonate (EtSS) starting from the grafted CMS units; and (iii) hydrolysis of the EtSS-grafted film, converting poly(EtSS) to poly(styrene sulfonic acid) (PSSA). The ATRP of EtSS (step (ii)), the key process in our preparation method, was successfully performed by controlling the catalyst concentration at a relatively-low temperature (50 oC), under the condition of which undesirable thermal polymerization was suppressed. The grafting degree during ATRP could be controlled and ranged from 24% to 240%, resulting in the preparation of PEMs with ion exchange capacities ranging from 0.96 to 2.9 mmol/g. Thus, we have demonstrated that ATRP reactions can be carried out inside solid polymer films. At 30% relative humidity and 80 oC, the block-type PEMs exhibited higher proton conductivities and water contents than those of the conventional RIGP-PEMs. In the block-type PEMs, the hydrophilic proton-conducting PSSA grafts are separated from the ETFE matrix by the hydrophobic polystyrene grafts. Hence, the PSSA-graft-chain aggregation occurs, creating a well-connected ion channel network, which in turn results in increased proton conduction.