183 research outputs found

    Cardiac 123I-MIBG Imaging for Clinical Decision Making: 22-Year Experience in Japan

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    Cardiac neuroimaging with (123)I-metaiodobenzylguanidine ((123)I-MIBG) has been officially used in clinical practice in Japan since 1992. The nuclear cardiology guidelines of the Japanese Circulation Society, revised in 2010, recommended cardiac (123)I-MIBG imaging for the management of heart failure (HF) patients, particularly for the assessment of HF severity and prognosis of HF patients. Consensus in North American and European countries regarding incorporation into clinical practice, however, has not been established yet. This article summarizes 22 y of clinical applications in Japan of (123)I-MIBG imaging in the field of cardiology; these applications are reflected in cardiology guidelines, including recent methodologic advances. A standardized cardiac (123)I-MIBG parameter, the heart-to-mediastinum ratio (HMR), is the basis for clinical decision making and enables common use of parameters beyond differences in institutions and studies. Several clinical studies unanimously demonstrated its potent independent roles in prognosis evaluation and risk stratification irrespective of HF etiologies. An HMR of less than 1.6-1.8 and an accelerated washout rate are recognized as high-risk indicators of pump failure death, sudden cardiac death, and fatal arrhythmias and have independent and incremental prognostic values together with known clinical variables, such as left ventricular ejection fraction and brain natriuretic peptide. Another possible use of this imaging technique is the selection of therapeutic strategy, such as pharmacologic treatment and nonpharmacologic treatment with an implantable cardioverter-defibrillator or cardiac resynchronization device; however, this possibility remains to be investigated. Recent multiple-cohort database analyses definitively demonstrated that patients who were at low risk for lethal events and who were defined by an HMR of greater than 2.0 on (123)I-MIBG studies had a good long-term prognosis. Future investigations of cardiac (123)I-MIBG imaging will contribute to better risk stratification of low-risk and high-risk populations, to the establishment of cost-effective use of this imaging technique for the management of HF patients, and to worldwide acceptance of this imaging technique in clinical cardiology practice. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc

    Взаємний зв'язок властивостей і структури плівкових чутливих елементів сенсорів магнітного поля

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    Дисертацію присвячено комплексним експериментальним дослідженням особливостей структурно-фазового стану та магнітних і магніторезистивних властивостей багатошарових плівкових систем на основі Co і Cu, Co і Cr, Fe і Cr та Fe і Cu як можливих матеріалів чутливих елементів сенсорів різного призначення. У роботі встановлено взаємозв’язок між товщиною магнітних шарів і немагнітних прошарків, орієнтацією зразка у зовнішньому магнітному полі, температурою термообробки та магнітними, магніторезистивними і магнітооптичними властивостями багатошарових плівкових систем із можливим спін-залежним розсіюванням електронів. Визначені величини магнітоопору, коерцитивної сили, коефіцієнта прямокутності й чутливості плівкової системи до магнітного поля досліджуваних плівкових систем як приладових структур для формування первинних перетворювачів. Установлена кореляція між структурно-фазовим станом, магнітними та магнітооптичними властивостями тришарових плівкових систем з різним типом розчинності компонент як функціональних елементів датчиків. Запропонована схематична конструкція АМР-датчика магнітного поля для тришарових плівкових систем із спін-залежним розсіюванням електронів. У результаті проведених досліджень впливу геометрії вимірювання, температури термообробки та загальної концентрації феромагнітної компоненти в системі на магнітні й магніторезистивні властивості визначені можливі області застосування плівкових систем на основі Co і Cu або Cr та Fe і Cu або Cr.Диссертация посвящена комплексным экспериментальным исследованиям особенностей структурно-фазового состояния, магнитных магниторезистивных свойств многослойных пленочных систем на основе Co и Cu, Co и Cr, Fe и Cr и Fe и Cu в качестве возможных материалов чувствительных элементов сенсоров различного назначения. В работе установлена взаимосвязь между толщиной магнитных слоев и немагнитных прослоек, ориентацией образца во внешнем магнитном поле, температурой термообработки и магнитными, магниторезистивными и магнитооптическими свойствами многослойных пленочных систем с возможным спин-зависимым рассеянием электронов. При исследовании магнитных свойств пленочных систем на основе Fe, Co, Cu или Cr получено, что для пленочных систем на основе Fe и Cu в форме кривых гистерезиса наблюдается определенный перегиб, свидетельствующий о послойном перемагничивании слоев Fe, в то время как для систем на основе Fe и Cr петля гистерезиса имеет форму, подобную однослойным пленкам Fe, что говорит о преобладании ферромагнитной связи в системе. В пленочных структурах на основе Co и Cr или Cu магнитные свойства системы главным образом определяются состоянием слоев Со, поэтому форма кривых гистерезиса для обеих систем схожа с формой кривых для однослойных пленок Со, а небольшие значения коэрцитивной силы свидетельствуют о реализации ферромагнитной связи в системе. Все четыре системы характеризуются достаточно высоким значением коэффициента прямоугольности, которое при смене ориентации образца от 0 до 90° несколько уменьшается для систем Fe/Cu/Fe и Fe/Cr/Fe и, наоборот, растет в системах на основе Co и Cr. Определены величины магнитосопротивления, коэрцитивной силы, коэффициента прямоугольности и чувствительности пленочной системы к магнитному полю исследуемых пленочных систем как приборных структур для формирования первичных преобразователей. Установлена корреляция между структурно-фазовым состоянием, магнитными и магнитооптическими свойствами трехслойных пленочных систем с разным типом растворимости компонент в качестве функциональных элементов датчиков. Предложена схематическая конструкция АМР-датчика магнитного поля для трехслойных пленочных систем со спин-зависимым рассеянием электронов. В результате проведенных исследований влияния геометрии измерения, температуры термообработки и общей концентрации ферромагнитной компоненты в системе на магниторезистивные свойства определены возможные области применения пленочных систем на основе Co и Cu или Cr и Fe и Cu или Cr.The thesіs іs dedіcаted to the complex experіmentаl reseаrch between the structurаl-phаse stаte, magnetic and magnetoresistance propertіes of multіlаyer fіlm systems bаsed on the Co аnd Cu, Co аnd Cr, Fe аnd Cr, аnd Fe аnd Cu, аs the potential mаterіаls for sensіtіve elements of sensors for dіfferent purposes. Іn thіs thesis wаs found the correlаtіon between the thіckness of the mаgnetіc аnd nonmаgnetіc lаyers, the orіentаtіon of the sаmple іn аn externаl mаgnetіc fіeld, temperаture of heаt treаtment аnd mаgnetіc, mаgnetoresіstіve аnd mаgneto-optіcаl propertіes іn multіlаyer fіlm systems wіth possіble spіn-dependent scаtterіng of electrons. The vаlues of mаgnetoresіstаnce, coercіvіty, squаreness fаctor аnd sensіtіvіty of fіlm system to a mаgnetіc fіeld in the studіed fіlm systems аs devіce structures for the formаtіon of prіmаry converters were defined. The correlаtіon between the structurаl-phаse stаte, mаgnetіc аnd mаgneto-optіcаl propertіes of three-lаyer fіlm systems wіth dіfferent types of component solubіlіty аs functіonаl elements sensors was established. The schemаtіc sturucture of АMR sensor for three-lаyer fіlm systems wіth spіn-dependent scаtterіng of electrons was purposed. The possіble аreаs of аpplіcаtіons wаs іdentіfіed on the bаsіs of studіes of the effect of geometry meаsurement temperаture heаt treаtment аnd the totаl concentrаtіon of ferromаgnetіc components іn the system on the magnetic and mаgnetoresіstіve propertіes of fіlm-systems bаsed on Co аnd Cu, or Cr аnd Fe, аnd Cu or Cr

    Distortion of Magnetic Fields in a Starless Core V: Near-infrared and Submillimeter Polarization in FeSt 1-457

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    The relationship between submillimeter (submm) dust emission polarization and near-infrared (NIR) HH-band polarization produced by dust dichroic extinction was studied for the cold starless dense core FeSt 1-457. The distribution of polarization angles (9090^{\circ}-rotated for submm) and degrees were found to be very different between at submm and NIR wavelengths. The mean polarization angles for FeSt 1-457 at submm and NIR wavelengths are 132.1±22.0132.1^{\circ} \pm 22.0^{\circ} and 2.7±16.22.7^{\circ} \pm 16.2^{\circ}, respectively. The correlation between PHP_H and AVA_V was found to be linear from outermost regions to relatively dense line of sight of AV25A_V \approx 25 mag, indicating that NIR polarization reflects overall polarization (magnetic field) structure of the core at least in this density range. The flat PH/AVP_H/A_V versus AVA_V correlations were confirmed, and the polarization efficiency was found to be comparable to the observational upper limit (Jones 1989). On the other hand, as reported by Alves et al., submm polarization degrees show clear linearly decreasing trend against AVA_V from AV20A_V \approx 20 mag to the densest center (AV41A_V \approx 41 mag), appearing as "polarization hole" structure. The power law index for the PsubmmP_{\rm submm} versus AVA_V relationship was obtained to be 1\approx -1, indicating that the alignment for the submm sensitive dust is lost. These very different polarization distributions at submm and NIR wavelengths suggest that (1) there is different radiation environment at these wavelengths or (2) submm-sensitive dust is localized or the combination of them.Comment: Accepted to the Astrophysical Journal (ApJ

    Grafting of iPS cell-derived tenocytes promotes motor function recovery after Achilles tendon rupture

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    ヒトのiPS細胞から腱の細胞を作製する --アキレス腱断裂のラットに移植し、機能回復を確認--. 京都大学プレスリリース. 2021-08-31.Repairing tendon injuries with stem cells. 京都大学プレスリリース. 2021-08-31.Tendon self-renewal is a rare occurrence because of the poor vascularization of this tissue; therefore, reconstructive surgery using autologous tendon is often performed in severe injury cases. However, the post-surgery re-injury rate is relatively high, and the collection of autologous tendons leads to muscle weakness, resulting in prolonged rehabilitation. Here, we introduce an induced pluripotent stem cell (iPSC)-based technology to develop a therapeutic option for tendon injury. First, we derived tenocytes from human iPSCs by recapitulating the normal progression of step-wise narrowing fate decisions in vertebrate embryos. We used single-cell RNA sequencing to analyze the developmental trajectory of iPSC-derived tenocytes. We demonstrated that iPSC-tenocyte grafting contributed to motor function recovery after Achilles tendon injury in rats via engraftment and paracrine effects. The biomechanical strength of regenerated tendons was comparable to that of healthy tendons. We suggest that iPSC-tenocytes will provide a therapeutic option for tendon injury

    Evaluation of Cloud Microphysics in JMA-NHM Simulations Using Bin or Bulk Microphysical Schemes through Comparison with Cloud Radar Observations

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    Numerical weather prediction (NWP) simulations using the Japan Meteorological Agency NonhydrostaticModel (JMA-NHM) are conducted for three precipitation events observed by shipborne or spaceborneW-band cloud radars. Spectral bin and single-moment bulk cloud microphysics schemes are employed separatelyfor an intercomparative study. A radar product simulator that is compatible with both microphysicsschemes is developed to enable a direct comparison between simulation and observation with respect to theequivalent radar reflectivity factor Ze, Doppler velocity (DV), and path-integrated attenuation (PIA). Ingeneral, the bin model simulation shows better agreement with the observed data than the bulk modelsimulation. The correction of the terminal fall velocities of snowflakes using those of hail further improves theresult of the bin model simulation. The results indicate that there are substantial uncertainties in the masssizeand sizeterminal fall velocity relations of snowflakes or in the calculation of terminal fall velocity of snowaloft. For the bulk microphysics, the overestimation of Ze is observed as a result of a significant predominanceof snow over cloud ice due to substantial deposition growth directly to snow. The DV comparison shows thata correction for the fall velocity of hydrometeors considering a change of particle size should be introducedeven in single-moment bulk cloud microphysics

    A Pooled Analysis of Multicenter Cohort Studies of 123I-mIBG Imaging of Sympathetic Innervation for Assessment of Long-Term Prognosis in Heart Failure

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    ObjectivesThe study objectives were to create a cardiac metaiodobenzylguanidine (mIBG) database using multiple prospective cohort studies and to determine the quantitative iodine-123–labeled mIBG indices for identifying patients with chronic heart failure (HF) at greatest and lowest risk of lethal events.BackgroundAlthough the prognostic value of cardiac mIBG imaging in patients with HF has been shown, clinical use of this procedure has been limited. It is required to define universally accepted quantitative thresholds for high and low risk that could be used as an aid to therapeutic decision-making using a large cohort database.MethodsSix prospective HF cohort studies were updated, and the individual datasets were combined for the present patient-level analysis. The database consisted of 1,322 patients with HF followed up for a mean interval of 78 months. Heart-to-mediastinum ratio (HMR) and washout rate of cardiac mIBG activity were the primary cardiac innervation markers. The primary outcome analyzed was all-cause death.ResultsLethal events were observed in 326 patients, and the population mortality rate was 5.6%, 11.3%, and 19.7% at 1, 2, and 5 years, respectively. Multivariate Cox proportional hazard model analysis for all-cause mortality identified age (p < 0.0001), New York Heart Association (NYHA) functional class (p < 0.0001), late HMR of cardiac mIBG activity (p < 0.0001), and left ventricular ejection fraction (LVEF) (p = 0.0029) as significant independent predictors. Analysis of the 512-patient subpopulation with B-type natriuretic peptide (BNP) results showed BNP (p < 0.0001), greater NYHA functional class (p = 0.0002), and late HMR (p = 0.0011) as significant predictors, but LVEF was not. The receiver-operating characteristic–determined threshold of HMR (1.68) identified patients at significantly increased risk in any LVEF category. Survival rates decreased progressively with decreasing HMR, with 5-year all-cause mortality rates >7% annually for HMR <1.25, and <2% annually for HMR ≥1.95. Addition of HMR to clinical information resulted in a significant net reclassification improvement of 0.175 (p < 0.0001).ConclusionsPooled analyses of independent cohort studies confirmed the long-term prognostic value of cardiac mIBG uptake in patients with HF independently of other markers, such as NYHA functional class, BNP, and LVEF, and demonstrated that categoric assessments could be used to define meaningful thresholds for lethal event risk

    Near-Infrared Imaging Polarimetry of the NGC 2071 Star Forming Region with SIRPOL

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    We have conducted deep JHKs imaging polarimetry of a ~8' x 8' area of the NGC 2071 star forming region. Our polarization data have revealed various infrared reflection nebulae (IRNe) associated with the central IR young star cluster NGC2071IR and identified their illuminating sources. There are at least 4 IRNe in NGC2071IR and several additional IRNe are identified around nearby young stars in the same field-of-view. Each illuminating source coincides with a known near-IR source except for IRS3, which is only a part of IRN2 and is illuminated by the radio source 1c. Aperture polarimetry of each cluster source is used to detect unresolved circumstellar disk/outflow systems. Aperture polarimetry of the other point-like sources within the field is made in this region for the first time. The magnetic field structures (from ~1 pc down to \~0.1 pc) are derived using both aperture polarimetry of the point-like sources and imaging polarimetry of the shocked H2 emission that is seen as the dominant knotty nebulae in the Ks band image; they are both of dichroic origin and the derived field directions are consistent with each other. The magnetic field direction projected on the sky is also consistent with that inferred from the 850 micron thermal continuum emission polarimetry of the central 0.2 pc region, but running roughly perpendicular (~75 degrees) to the direction of the large scale outflow. We argue that the field strength is too weak to align the outflow in the large scale field direction via magnetic braking.Comment: o appear in PASJ, 9 pages, 11 Postscript figure
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