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BACKGROUND: Conventional approach to myocardial strain analysis relies on a software designed for the left ventricle (LV) which is complex and time-consuming and is not specific for right ventricular (RV) and left atrial (LA) assessment. This study compared this conventional manual approach to strain evaluation with a novel semi-automatic analysis of myocardial strain, which is also chamber-specific. METHODS: Two experienced observers used the AutoStrain software and manual QLab analysis to measure the LV, RV and LA strains in 152 healthy volunteers. Fifty cases were randomly selected for timing evaluation. RESULTS: No significant differences in LV global longitudinal strain (LVGLS) were observed between the two methods (-21.0% ± 2.5% vs. -20.8% ± 2.4%, p = 0.230). Conversely, RV longitudinal free wall strain (RVFWS) and LA longitudinal strain during the reservoir phase (LASr) measured by the semi-automatic software differed from the manual analysis (RVFWS: -26.4% ± 4.8% vs. -31.3% ± 5.8%, p < 0.001; LAS: 48.0% ± 10.0% vs. 37.6% ± 9.9%, p < 0.001). Bland-Altman analysis showed a mean error of 0.1%, 4.9%, and 10.5% for LVGLS, RVFWS, and LASr, respectively, with limits of agreement of -2.9,2.6%, -8.1,17.9%, and -12.3,33.3%, respectively. The semi-automatic method had a significantly shorter strain analysis time compared with the manual method. CONCLUSIONS: The novel semi-automatic strain analysis has the potential to improve efficiency in measurement of longitudinal myocardial strain. It shows good agreement with manual analysis for LV strain measurement.
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Ventrículos do Coração , Software , Humanos , Reprodutibilidade dos Testes , Estudos de Viabilidade , Ventrículos do Coração/diagnóstico por imagem , Átrios do Coração , Função Ventricular EsquerdaRESUMO
Saliva is essential for oral health. The molecular mechanisms leading to physiological fluid secretion are largely established, but factors that underlie secretory hypofunction, specifically related to the autoimmune disease Sjögren's syndrome (SS) are not fully understood. A major conundrum is the lack of association between the severity of inflammatory immune cell infiltration within the salivary glands and glandular hypofunction. In this study, we investigated in a mouse model system, mechanisms of glandular hypofunction caused by the activation of the stimulator of interferon genes (STING) pathway. Glandular hypofunction and SS-like disease were induced by treatment with 5,6-Dimethyl-9-oxo-9H-xanthene-4-acetic acid (DMXAA), a small molecule agonist of murine STING. Contrary to our expectations, despite a significant reduction in fluid secretion in DMXAA-treated mice, in vivo imaging demonstrated that neural stimulation resulted in greatly enhanced spatially averaged cytosolic Ca2+ levels. Notably, however, the spatiotemporal characteristics of the Ca2+ signals were altered to signals that propagated throughout the entire cytoplasm as opposed to largely apically confined Ca2+ rises observed without treatment. Despite the augmented Ca2+ signals, muscarinic stimulation resulted in reduced activation of TMEM16a, although there were no changes in channel abundance or absolute sensitivity to Ca2+. However, super-resolution microscopy revealed a disruption in the intimate colocalization of Inositol 1,4,5-trisphosphate receptor Ca2+ release channels in relation to TMEM16a. TMEM16a channel activation was also reduced when intracellular Ca2+ buffering was increased. These data are consistent with altered local coupling between the channels contributing to the reduced activation of TMEM16a. Appropriate Ca2+ signaling is also pivotal for mitochondrial morphology and bioenergetics and secretion is an energetically expensive process. Disrupted mitochondrial morphology, a depolarized mitochondrial membrane potential, and reduced oxygen consumption rate were observed in DMXAA-treated animals compared to control animals. We report that early in SS disease, dysregulated Ca2+ signals lead to decreased fluid secretion and disrupted mitochondrial function contributing to salivary gland hypofunction and likely the progression of SS disease.
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Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson et al. [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fanlike electron outflow region including three well-collimated electron jets appears. The (>1 MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS.
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Crohn's disease (CD) is a chronic and relapsing-remitting inflammatory disorder of the gastrointestinal tract. Approximately 70% of patients inevitably develop fibrosis-associated intestinal stricture after 10 years of CD diagnosis, which seriously affects their quality of life. Current therapies play limited role in preventing or reversing the process of fibrosis and no specific anti-fibrotic therapy is yet available. Nearly half of patients thus have no alternative but to receive surgery. The potential mechanisms of intestinal fibrosis remain poorly understood; extracellular matrix remodeling, aberrant immune response, intestinal microbiome imbalance and creeping fat might exert fundamental influences on the multiple physiological and pathophysiological processes. Recently, the emerging new diagnostic techniques have markedly promoted an accurate assessment of intestinal stricture by distinguishing fibrosis from inflammation, which is crucial for guiding treatment and predicting prognosis. In this review, we concisely summarized the key studies published in the year 2020 covering pathogenesis, diagnostic modalities, and therapeutic strategy of intestinal stricture. A comprehensive and timely review of the updated researches in intestinal stricture could provide insight to further elucidate its pathogenesis and identify novel drug targets with anti-fibrotic potentiality.
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Constrição Patológica , Doença de Crohn , Animais , Constrição Patológica/diagnóstico , Constrição Patológica/etiologia , Constrição Patológica/patologia , Constrição Patológica/terapia , Doença de Crohn/complicações , Doença de Crohn/patologia , Doença de Crohn/terapia , Modelos Animais de Doenças , Fibrose/patologia , Humanos , Obstrução Intestinal/diagnóstico , Obstrução Intestinal/etiologia , Obstrução Intestinal/patologia , Obstrução Intestinal/terapia , Intestinos/patologia , Intestinos/cirurgia , Qualidade de VidaRESUMO
K-shell x-ray at about 3 keV emitted from Ar clusters irradiated by 110 mJ 55 fs intense laser pulses is studied. The x-ray flux is optimized by moving the nozzle away from the focus of the laser pulse. The total flux of K-shell x-ray photons in 4pi reaches a maximum of 4.5x10(9) photons/shot with a conversion efficiency of 2.5x10(-5) when the nozzle displacement is 2 mm and a long plasma channel is observed by a probe beam.