Continuous interfacial polycondensation of nylon 6-6

Nylon 6-6 has been prepared by continuous interfacial polycondensation from hexamethylene diamine and adipyl chloride in a stirred system. The effect of monomer concentration and stirring on the intrinsic viscosity of polyamide 6-6 solution in formic acid (90%) was determined. As stirring rate and monomer ratio increased, the intrinsic viscosity and polymer yield went through a maximum. Diffusion coefficient (DAB) for hexamethylene diamine was calculated and from that JD and mass transfer coefficient /DAB were calculated. A relation between Reynolds number and JD factor was established by correlation curve

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Application of Visual Analytics For Thermal State Management in Large Data Centers

Today's large data centres are the computational hubs of the next generation of IT services. With the advent of dynamic smart cooling and rack level sensing, the need for visual data exploration is growing. If administrators know the rack level thermal state changes and catch problems in real time, energy consumption can be greatly reduced. In this paper, we apply a cell-based spatio-temporal overall view with high-resolution time series to simultaneously analyze complex thermal state changes over time across hundreds of racks. We employ cell-based visualization techniques for trouble shooting and abnormal state detection. These techniques are based on the detection of sensor temperature relations and events to help identify the root causes of problems. In order to optimize the data centre cooling system performance, we derive new non-overlapped scatter plots to visualize the correlations between the temperatures and chiller utilization. All these techniques have been used successfully to monitor various time-critical thermal states in real-world large-scale production data centres and to derive cooling policies. We are starting to embed these visualization techniques into a handheld device to add mobile monitoring capabilit

Right Coronary Aneurysm with Coronary Arteriovenous Fistula to Right Atrium

<p>A 56-year-old man presented with shortness of breath and palpitations. Workup and evaluation revealed paroxysmal atrial fibrillation, severe tricuspid regurgitation, and a giant right coronary aneurysm with an arteriovenous fistula to the right atrium. An echocardiogram revealed an aneurysm of the proximal right coronary artery. Cardiac catheterization and cardiac magnetic resonance imaging showed the aneurysm coursing between the right pulmonary artery and the ascending aorta. The caliber of the right coronary artery distal to the aneurysm was normal.<br> A median sternotomy was performed and the pericardium was opened to encounter the proximal right coronary aneurysm. The superior vena cava was looped to allow for exclusion of venous return. Direct cannulation of the aorta and percutaneous access of the femoral vein were performed to place the patient on cardiopulmonary bypass. Further dissection revealed the giant aneurysm between the aorta, right pulmonary artery, and superior vena cava, with an apparent arteriovenous fistula between the right coronary aneurysm and the right atrium. The shunted blood flow coursed from the aorta, to the right coronary aneurysm, to the right atrium.<br> After the heart was arrested and the patient placed on cardiopulmonary bypass, the normal right coronary artery distal to the aneurysm was dissected, allowing for a reverse saphenous vein to be grafted. The right coronary artery between the aneurysm and the graft was ligated. The proximal right coronary artery was further identified and ligated at the aorta. Attention was then turned to the right atrium, which was opened to identify the entry of the arteriovenous fistula. Additionally, the proximal right coronary artery aneurysm sac was opened and followed down through the giant aneurysm to the right atrium. A probe was passed to delineate the flow through the fistula. A bovine pericardium patch was sewn from within the right atrium to close the fistula. <br> The severe tricuspid regurgitation discovered during preoperative workup was managed with the placement of a tricuspid annuloplasty ring. A left-sided pulmonary vein maze procedure was performed for the atrial arrhythmia, and was accompanied by the placement of a left atrial appendage clip. The proximal vein graft was then anastomosed to the aorta, and the aortic clamp was released. The right coronary aneurysm sac and giant aneurysm were oversewn. The patient was taken off of cardiopulmonary bypass with restoration of normal anatomic blood flow.<br> In conclusion, this video demonstrates the presentation, diagnosis, and surgical treatment of a large complex right coronary artery aneurysm with an arteriovenous fistula to the right atrium. The surgical treatment was ligation and exclusion of the aneurysm, with coronary artery bypass to the distal right coronary artery, and patch repair of the right atrium. The patient had an uneventful postoperative course with a full recovery.</p