Volumetric Lattice Boltzmann Method for Wall Stresses of Image-Based Pulsatile Flows

Image-based computational fluid dynamics (CFD) has become a new capability for determining wall stresses of pulsatile flows. However, a computational platform that directly connects image information to pulsatile wall stresses is lacking. Prevailing methods rely on manual crafting of a hodgepodge of multidisciplinary software packages, which is usually laborious and error-prone. We present a new computational platform, to compute wall stresses in image-based pulsatile flows using the volumetric lattice Boltzmann method (VLBM). The novelty includes: (1) a unique image processing to extract flow domain and local wall normality, (2) a seamless connection between image extraction and VLBM, (3) an en-route calculation of strain-rate tensor, and (4) GPU acceleration (not included here). We first generalize the streaming operation in the VLBM and then conduct application studies to demonstrate its reliability and applicability. A benchmark study is for laminar and turbulent pulsatile flows in an image-based pipe (Reynolds number: 10 to 5000). The computed pulsatile velocity and shear stress are in good agreements with Womersley\u27s analytical solutions for laminar pulsatile flows and concurrent laboratory measurements for turbulent pulsatile flows. An application study is to quantify the pulsatile hemodynamics in image-based human vertebral and carotid arteries including velocity vector, pressure, and wall-shear stress. The computed velocity vector fields are in reasonably well agreement with MRA (magnetic resonance angiography) measured ones. This computational platform is good for image-based CFD with medical applications and pore-scale porous media flows in various natural and engineering systems

Integrated Assessment of Heavy Metal Contamination in Sediments from a Coastal Industrial Basin, NE China

The purpose of this study is to investigate the current status of metal pollution of the sediments from urban-stream, estuary and Jinzhou Bay of the coastal industrial city, NE China. Forty surface sediment samples from river, estuary and bay and one sediment core from Jinzhou bay were collected and analyzed for heavy metal concentrations of Cu, Zn, Pb, Cd, Ni and Mn. The data reveals that there was a remarkable change in the contents of heavy metals among the sampling sediments, and all the mean values of heavy metal concentration were higher than the national guideline values of marine sediment quality of China (GB 18668-2002). This is one of the most polluted of the world’s impacted coastal systems. Both the correlation analyses and geostatistical analyses showed that Cu, Zn, Pb and Cd have a very similar spatial pattern and come from the industrial activities, and the concentration of Mn mainly caused by natural factors. The estuary is the most polluted area with extremely high potential ecological risk; however the contamination decreased with distance seaward of the river estuary. This study clearly highlights the urgent need to make great efforts to control the industrial emission and the exceptionally severe heavy metal pollution in the coastal area, and the immediate measures should be carried out to minimize the rate of contamination, and extent of future pollution problems

Synthesis and Photophysical Properties of Quinoxaline-Based Blue Aggregation-Induced Emission Molecules

A series of quinoxaline-based compounds 1–4 have been synthesized by Palladium-Catalyzed cross-coupling reaction and their photophysical properties have been extensively studied. Compounds 1–4 show deep blue light emission both in solution (λem ≤ 425 nm, CIEy≤0.03) and in solid-state. Moreover, compounds 1–3 show a non-typical aggregation-induced enhanced emission (AIEE), which would be effective deep blue light-emitting materials. The DFT calculation indicated that the HOMO energy levels of compounds 1–3 are distributed throughout the molecule, and the LUMO energy levels are mainly concentrated on the quinoxaline group. while the HOMO of compound 4 is mainly on the benzene ring at 2,3-position, and the LUMO is distributed both of the quinoxaline and the benzaldehyde group at the 6,7-position.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Epileptic Negative Myoclonus as the First and Only Symptom in a Challenging Diagnosis of Benign Epilepsy With Centrotemporal Spikes

Objective: To investigate the clinical and neurophysiological characteristics of epileptic negative myoclonus as the first and only ictal symptom of benign epilepsy with centrotemporal spikes. Methods: Electrophysiological evaluations included polygraphic recordings with simultaneous video electroencephalogram monitoring and tests performed with patient’s upper limb outstretched in standing posture. Epileptic negative myoclonus manifestations, electrophysiological features, and responses to antiepileptic drugs were analyzed. Results: The authors report 2 patients with benign epilepsy with centrotemporal spikes, who had epileptic negative myoclonus as the first and only seizure type. Video electroencephalogram monitoring results showed that their negative myoclonus seizures were emanating from the contralateral central and the parietal regions. Epileptic negative myoclonus was controlled by administration of valproate and levetiracetam. Conclusion: Epileptic negative myoclonus can be the first and only seizure type of benign epilepsy with centrotemporal spikes, and long-term follow-up monitoring should be the care for the recurrence and/or presence of other types of seizures

Combined Effect of Dynapenia and Abdominal Obesity on the Prevalence of Peripheral Artery Disease in Older Adults Over 75 Years Old in China

The objective is to examine the separate and joint effects of dynapenia and abdominal obesity on the prevalence of peripheral artery disease (PAD) in older adults of different ages (60-74 and over 75 years old). This study comprised 1293 community-dwelling Chinese participants recruited from Shanghai, China, who were aged at least 60 years (753 women; mean age: 72.0 ± 5.9 years). Dynapenia was defined as low-grip strength (<28.0 kg for males and <18.0 kg for females) but normal skeletal muscle index (≥7.0 kg/m 2 for males and ≥5.7 kg/m 2 for females). Abdominal obesity was determined according to waist circumference (≥90 cm for males and ≥85 cm for females), and PAD was diagnosed by an ankle-brachial index  ≤ 0.9. Binary logistic regression models were performed to determine associations between dynapenia, abdominal obesity, and the combination of dynapenia and abdominal obesity and PAD. According to dynapenia and abdominal obesity status stratified by age (60-74 or over 75), the patients were divided into 4 groups: normal, dynapenia alone, abdominal obesity alone, and co-occurring groups. A logistic regression showed that the co-occurring groups (odds ratio = 4.63, 95% confidence interval = 1.41-15.21) had a higher prevalence of PAD than the normal group after adjusting for the covariates in older adults over 75 years of age. The combination of dynapenia and abdominal obesity increase the prevalence of PAD in older adults over 75 years. The present findings have important implications for the early identification of older adults with PAD and appropriate interventions should be implemented