379 research outputs found

    The value of left atrial strain and strain rate in predicting left atrial appendage stasis in patients with nonvalvular atrial fibrillation

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      Background: This study aimed to investigate the value of left atrial (LA) strain and strain rate (S/SR) by transthoracic echocardiography (TTE) in predicting left atrial appendage (LAA) stasis, in order to find a way for LAA stasis screening which is easily performed in patients with nonvalvular atrial fibrillation (NVAF). Methods: One hundred and thirty NVAF patients prepared for AF ablation were enrolled. TTE and transesophageal echocardiography (TEE) were performed in all patients. LA S/SR in each phase was analyzed off-line. LAA blood flow state and LAA function were assessed by using TEE. Results: LA S/SRs during atrial reservoir phase (LA Sres/SRres) were significantly negatively cor­related with LAA spontaneous echo contrast (SEC) grade (r = −0.567 and −0.520, respectively; all p < 0.01), and positively correlated with LAA emptying fraction (r = 0.602 and 0.619, respectively; all p < 0.01) and with LAA peak emptying flow velocity (r = 0.623 and 0.642, respectively; all p < 0.01). The multivariate logistic regression analysis showed LA Sres to be the strongest independent predictor of LAA stasis, followed by LA volume index. LA Sres < 13% was recommended to predict LAA stasis with sensitivity of 90% and specificity of 74%. Conclusions: LA Sres by TTE can noninvasively predict LAA stasis and may be used as a screening tool to assist in the detection of LAA stasis in patients with NVAF. (Cardiol J 2018; 25, 1: 87–96

    On the Origin of Galactic Diffuse TeV-PeV Emission: Insight from LHAASO and IceCube

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    The high-energy diffuse gamma-ray emission and neutrino emission are expected from the Galactic plane, generated by hadronuclear interactions between cosmic rays (CR) and interstellar medium (ISM). Therefore, measurements of these diffuse emissions will provide important clues on the origin and nature of Galactic CRs. Comparing the latest observations of LHAASO and IceCube on the diffuse Galactic gamma-ray and neutrino emissions respectively, we suggest that the diffuse gamma-ray emission at multi-TeV energies contains a considerable contribution of a leptonic component. By modelling the gamma-ray halos powered by middle-aged pulsars in our Galaxy with taking into account the magnetic field configuration and the interstellar radiation field in the Galaxy, we demonstrate that the collective contribution of pulsar halos can account for the excess in the measured diffuse gamma-ray emission with respect to the predicted flux from CR-ISM interactions. The resulting one-dimensional profile along the Galactic longitude is also consistent with the observation.Comment: 24 pages, 11 figures; Comments are Welcom

    Tuning the Framework Formation of Silver(I) Coordination Architectures with Heterocyclic Thioethers

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    The reactions of a series of nitrogen-containing heterocyclic thioether ligands, 2,2Ј-[methylenebis (thio) , with silver() nitrate or silver() perchlorate salt led to the formation of five new metal-organic supramolecular architectures from dinuclear to threedimensional structures. All the structures were determined by single-crystal X-ray diffraction analysis. In the crystal structures of the five complexes, a variety of coordination modes of Ag I have been observed, probably due to the variation of the chain length of the linker unit or the terminal groups as well as the counter anions, which indicates that the nature of the ligands is a determining factor in controlling the structural topologies of such metal-organic supramolecular architectures. Geometrical effects seem to be more important than electronic effects in these systems, leading the Ag I centre to prefer to coordinate to N donors first rather than S donors despite Ag I being a 'soft' metal

    The efficacy of mitochondrial targeting antiresistant epirubicin liposomes in treating resistant leukemia in animals

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    Ying Men*, Xiao-Xing Wang*, Ruo-Jing Li, Yan Zhang, Wei Tian, Hong-Juan Yao, Rui-Jun Ju, Xue Ying, Jia Zhou, Nan Li, Liang Zhang, Yang Yu, Wan-Liang LuState Key Laboratory of Natural and Biomimetic Drugs, and School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of China*These authors contributed equally to this manuscriptBackground: Multidrug resistance (MDR) of cancers can be circumvented by inducing programmed cell death, which is known as apoptosis. Mitochondria play a crucial role in apoptosis. Mitochondria-specific therapy would provide an efficient strategy for treating resistant cancers.Design and methods: A strategy was proposed here to overcome MDR by designing cancer mitochondria-specific drug-loaded liposomes, namely, antiresistant epirubicin mitosomes, aimed at treating resistant leukemia by targeting mitochondria. Evaluations were performed on human chronic leukemia K562, MDR K562/ADR cells, and female BALB/c nude mice xenografted with MDR K562/ADR cells. The liposomes were characterized through assays of cytotoxicity, mitochondrial targeting, caspase-9 and caspase-3, antitumor activities, and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) analysis.Results: The average size of antiresistant epirubicin mitosomes was in the range of 105–115 nm. Antiresistant epirubicin mitosomes were effective in inhibiting proliferation of MDR K562/ADR cells in vitro and selectively accumulated into the mitochondria. Caspase-9 and caspase-3 activity was increased after applying antiresistant epirubicin mitosomes. In xenografted resistant MDR K562/ADR tumor in nude mice, antiresistant tumor effect of antiresistant epirubicin mitosomes was evidently observed. Apoptotic inducing effects by antiresistant epirubicin mitosomes were noticeably evidenced via mitochondrial pathway.Conclusions: Antiresistant epirubicin mitosomes had significant inhibitory effect against resistant leukemia in vitro and in vivo, hence providing a promising strategy for improving therapeutic efficacy in resistant human leukemia.Keywords: mitosomes, mitochondria signaling pathway, nude mic

    Maternal exposure to life events during pregnancy and congenital heart disease in offspring: a case-control study in a Chinese population

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    Background: Previous studies have suggested that maternal stress could increase the risk of some adverse pregnancy outcomes, but evidence on congenital heart disease (CHD) is limited. We aimed to explore the association between maternal exposure to life events during pregnancy and CHD in offspring. Methods: The data was based on an unmatched case-control study about CHD conducted in Shaanxi province of China from 2014 to 2016. We included 2280 subjects, 699 in the case group and 1581 in the control group. The cases were infants or fetuses diagnosed with CHD, and the controls were infants without any birth defects. The life events were assessed by the Life Events Scale for Pregnant Women, and were divided into positive and negative events for synchronous analysis. A directed acyclic graph was drawn to screen the confounders. Logistic regression was employed to estimate the odds ratio and 95% confidence interval for the effects of life events on CHD. Results: After controlling for the potential confounders, the pregnant women experiencing the positive events during pregnancy had lower risk of CHD in offspring than those without positive events (OR = 0.38, 95%CI: 0.30 ~ 0.48). The risk of CHD in offspring could increase by 62% among the pregnant women experiencing the negative events compared to those without (OR = 1.62, 95%CI: 1.29 ~ 2.03). Both effects showed a certain dose-response association. Besides, the positive events could weaken the risk impact of negative events on CHD. Conclusion: It may suggest that maternal exposure to negative life events could increase the risk of CHD in offspring, while experiencing positive events could play a potential protective role

    Exploring noninvasive matrices for assessing long-term exposure to phthalates: a scoping review

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    The phthalic acid esters (PAEs) are one class of the most abundant and frequently studied pseudo-persistent organic pollutants. Noninvasive urine is an effective substrate for evaluating PAE exposure, but repeated sampling is needed to overcome this bias. This adds much work to on-site collection and the cost of detection increases exponentially. Therefore, the aim of this study was to conduct a scope review to describe the detection methods and validity of the use of other noninvasive matrices, such as nails and hair, for assessing long-term exposure to PAEs. The PubMed, Web of Science and China National Knowledge Infrastructure (CNKI), electronic databases were searched from 1 January 2000 to 3 April 2024, and 12 studies were included. Nine and three studies used hair and nails, respectively, as noninvasive matrices for detecting PAE exposure. Five articles compared the results of nail or hair and urine tests for validity of the assessment of PAE exposure. The preprocessing and detection methods for these noninvasive samples are also described. The results of this review suggest that, compared with nails, hair may be more suitable as a noninvasive alternative matrix for assessing long-term exposure to PAEs. However, sample handling procedures such as the extraction and purification of compounds from hair are not uniform in various studies; therefore, further exploration and optimization of this process, and additional research evidence to evaluate its effectiveness, are needed to provide a scientific basis for the promotion and application of hair detection methods for assessing long-term PAE exposure levels

    Characterization of rock thermophysical properties and factors affecting thermal conductivity−A case study of Datong Basin, China

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    Rock thermal physical properties play a crucial role in understanding deep thermal conditions, modeling the thermal structure of the lithosphere, and discovering the evolutionary history of sedimentary basins. Recent advancements in geothermal exploration, particularly the identification of high-temperature geothermal resources in Datong Basin, Shanxi, China, have opened new possibilities. This study aims to characterize the thermal properties of rocks and explore factors influencing thermal conductivity in basins hosting high-temperature geothermal resources. A total of 70 groups of rock samples were collected from outcrops in and around Datong Basin, Shanxi Province. Thermal property tests were carried out to analyze the rock properties, and the influencing factors of thermal conductivity were studied through experiments at different temperature and water-filled states. The results indicate that the thermal conductivity of rocks in Datong, Shanxi Province, typically ranges from 0.690 W/(m·K) to 6.460 W/(m·K), the thermal diffusion coefficient ranges from 0.441 mm2/s to 2.023 mm2/s, and the specific heat capacity of the rocks ranges from 0.569 KJ/(kg·°C) to 1.117 KJ/(kg·°C). Experimental results reveal the impact of temperature and water saturation on the thermal conductivity of the rock. The thermal conductivity decreases with increasing temperature and rises with high water saturation. A temperature correction formula for the thermal conductivity of different lithologies in the area is proposed through linear fitting. The findings from this study provide essential parameters for the assessment and prediction, development, and utilization of geothermal resources in the region and other basins with typical high-temperature geothermal resource
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