53 research outputs found

    Similarity between the primary and secondary air-assisted liquid jet breakup mechanism

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    we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide range of air speeds. This finding reveals the intrinsic connections of these two breakup regimes and has deep implications on the unified theoretical approach in treating the breakup mechanism of high speed liquid jet.Comment: 15 pages, 4 figure

    Real-time heart rate variability according to ambulatory glucose profile in patients with diabetes mellitus

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    BackgroundAutonomic neuropathy commonly occurs as a long-term complication of diabetes mellitus (DM) and can be diagnosed based on heart rate variability (HRV), calculated from electrocardiogram (ECG) recordings. There are limited data on HRV using real-time ECG and ambulatory glucose monitoring in patients with DM. The aim of this study was to investigate real-time HRV according to ambulatory glucose levels in patients with DM.MethodsA total of 43 patients (66.3 ± 7.5 years) with DM underwent continuous real-time ECG monitoring (225.7 ± 107.3 h) for HRV and ambulatory glucose monitoring using a remote monitoring system. We compared the HRV according to the ambulatory glucose profile. Data were analyzed according to the target in glucose range (TIR).ResultsThere were no significant differences in the baseline characteristics of the patients according to the TIR. During monitoring, we checked ECG and ambulatory glucose levels (a total of 15,090 times) simultaneously for all patients. Both time- and frequency-domain HRVs were lower when the patients had poorly controlled glucose levels (TIR < 70%) compared with well controlled glucose levels (TIR > 70%). In addition, heart and respiratory rates increased with real-time glucose levels (P < 0.001).ConclusionsPoorly controlled glucose levels were independently associated with lower HRV in patients with DM. This was further substantiated by the independent continuous association between real-time measurements of hyperglycemia and lower HRV. These data strongly suggest that cardiac autonomic dysfunction is caused by elevated blood sugar levels

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

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    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

    Impact of Gender on the Association of Epicardial Fat Thickness, Obesity, and Circadian Blood Pressure Pattern in Hypertensive Patients

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    This study aimed to investigate the effects of gender on the association between epicardial fat thickness (EFT) and circadian blood pressure (BP) changes in patients with recently diagnosed essential hypertension (EH). A total of 441 patients with EH (male/female: 236/205, mean age: 50.7 ± 13.8) and 83 control patients underwent 24-hour ambulatory BP monitoring and echocardiography. Obese EH patients had higher circadian BP profile with BP variability, wall thickness, and left ventricular mass than nonobese EH patients and controls (all p’s <0.05) without gender differences. EFT was higher in female than in male patients (7.0 ± 2.5 versus 5.9 ± 2.2 mm, p<0.001) and higher in the obese female EH group (7.5 ± 2.6 mm) than in the control (6.4 ± 2.8 mm) or nonobese EH group (6.7 ± 2.8 mm) among women, whereas EFT did not vary among males (5.9 ± 1.9 versus 6.0 ± 2.7 versus 5.9 ± 2.4 mm, p=0.937). Multivariate logistic regression analysis demonstrated that the 24-hour mean BP variability was associated with SBP (p=0.018) and EFT (p=0.016) in female patients, but not in male patients. The relationships among circadian BP variability, obesity, and EFT were affected by gender in different manners. EFT may be a more valuable parameter in the evaluation of BP severity and obesity in women than in men

    Heart rate recovery and blood pressure response during exercise testing in patients with microvascular angina

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    Abstract Background Angina pectoris with a normal coronary angiogram, termed microvascular angina (MVA), is an important clinical entity; however, its causes remain unclear. Autonomic dysfunction is one of the possible causes. Therefore, this study aimed to investigate parasympathetic dysfunction assessed by heart rate recovery (HRR) and increased sympathetic activity assessed by exaggerated blood pressure (BP) response (EBPR) to exercise in MVA. Methods The study participants were consecutive patients with anginal chest pain who underwent both coronary angiography with an ergonovine provocation test and a treadmill exercise test between January 2008 and February 2015. Patients with significant coronary artery disease (coronary artery stenosis ≥50%) or significant coronary artery spasm (≥90%) were excluded. Based on the treadmill exercise test, patients were categorized into the microvascular angina (MVA) group (patients with uniform ST depression ≥1 mm) and the control group. HRR was defined as peak heart rate minus heart rate after a 1 min recovery; blunted HRR was defined as ≤12 beats/min. EBPR was defined as a peak exercise systolic BP ≥210 mmHg in men and ≥ 190 mmHg in women. These parameters were compared between patients with MVA and the controls. Results Among the 970 enrolled patients (mean age 53.1 years; female 59.0%), 191 (20.0%) were diagnosed with MVA. In baseline characteristics, the MVA group had older participants, female predominance, and a higher prevalence of hypertension. The MVA group showed significantly lower HRR 1 min (24.9 ± 15.9 vs. 31.3 ± 22.7, p <  0.001) compared with the control group. Moreover, the proportion of EBPR was significantly higher in the MVA group than in the control group (21.5% vs. 11.6%, p <  0.001). Multivariable logistic regression analysis showed that age (odds ratio (OR), 1.045; 95% confidence interval (CI), 1.026–1.064; p <  0.001), HRR 1 min (OR, 0.990; 95% CI, 0.982–0.999; p = 0.022), and EBPR (OR, 1.657; 95% CI, 1.074–2.554; p = 0.022) were independently associated with MVA. Conclusion HRR and EBPR were associated with MVA, which suggests a link between MVA and autonomic dysregulation
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