Time Constants of Cardiac Function and Their Calculations

Left ventricular diastolic time constant, Tau, is the most established index to describe left ventricular diastolic function. However, the lack of a practical method for the measurement of Tau has been an uncomfortable reality which formerly kept all but a few researchers from making use of it. Recently, the non invasive calculation of Tau in an echo lab was accomplished through formulas developed by universal mathematical method. Tau was first suggested by the fact that left ventricular diastole is an active process, and we can therefore predict that there must be some other time constants which can be used to describe other active movement of ventricular muscles during isovolumic period. Similar mathematical manipulation was employed to develop formulas for “the other Tau(s)”. Such Tau(s) represent new sets of indexes useful for the description of cardiac function. They are expected to be the most established indices given the fact Tau is revealing the power of ventricular muscles without interference from either preload or afterload

Calculation of Left Ventricular Relaxation Time Constant-Tau in Patients With Aortic Regurgitation by Continuous-Wave Doppler

Left ventricular relaxation time constant, Tau, is the best index to evaluate left ventricular diastolic function. The measurement is only available traditionally in catheter lab. In Echo lab, several methods of non-invasive measurement of Tau have been tried since 1992, however almost all the methods are still utilizing the same formula to calculate Tau as in catheter lab, which makes them inconvenient, time-consuming and sometimes not very accurate. A simple method to calculate Tau in patients with mitral regurgitation has been developed just based on Weiss’ formula and simplified Bernoulli’s equation. Similarly, formulas are developed here by pure mathematical derivative to calculate Tau by continuous-wave Doppler in patients with aortic regurgitation

Analysis of volatile flavor components and characteristics of dough fermented with flavor fermentation liquid

Objective: This study aimed to investigate the varieties and contents of volatile components in fermented dough with flavor fermentation broth at different fermentation time. Methods: Headspace solid phase microextraction-gas chromatography (HS-SPME-GC-MS) was used to determine the volatile flavor substances in the dough of the flavor ferment at 12, 24, 36, 48 and 72 h. Also, sensory evaluation of the odor and determination of pH value, total acidity (TAA) and rheological properties of the dough were measured. Results: The strength of eight odors (frankincense, cheese, flower, fruit sweet, wine, malt, grass and sour) showed different performance, depending on the types and contents of the flavour substances produced during the different fermentation periods. The pH value of the dough gradually decreases with the time of fermentation, while TTA was the opposite. The tensile resistance, stretch ratio and tensile area of dough increased first but decreased with the extension of fermentation time, while the elongation of dough decreased first then increased. These results indicated that moderate fermentation (36 h) was beneficial to the formation and stability of the gluten network. A total of 92 volatile substances were detected in the dough with 5 fermentation times, including 22 alcohols, 27 esters, 12 aldehydes, 14 ketones, 10 alkanes, and 7 acids. A total of 27, 43, 38, 41 and 37 volatile flavor components were detected from the dough fermented for 12, 24, 36, 48 and 72 h, respectively. The contents of acids and esters increased first then decreased with the prolongation of fermentation time and reaching the highest at 48 h (47.31% and 20.96%, respectively). On the other hand, the contents of aldehydes, ketones and acids all gradually decreased. Conclusion: The volatile substances of different fermentation times were alcohols mainly, and the total flavor substances and the relative content of alcohols and esters reached the highest at 48 h, indicating that alcohols and esters might be the major contributors to the flavor of dough during fermentation

Calculation of Left Ventricular Relaxation Time Constant-Tau in Humans by Continuous-Wave Doppler

Left ventricular relaxation time constant, Tau, is the best index to evaluate left ventricular diastolic function, but the measurement is only available traditionally in catheter lab. In Echo lab, several methods of non-invasive measurement of Tau have been tried since 1992, however almost all the methods are still utilizing the same formula to calculate Tau as in catheter lab, which makes them inconvenient, time-consuming and sometimes not very accurate. Based on Weiss’ formula and simplified Bernoulli’s equation, a simple method is developed by pure mathematical derivative to calculate Tau by continuous-wave Doppler in patients with mitral regurgitation

The design of the Ali CMB Polarization Telescope receiver

International audienceAliCPT-1 is the first CMB degree scale polarimeter to be deployed to the Tibetan plateau at 5,250m asl. AliCPT-1 is a 95/150GHz 72cm aperture, two lens refracting telescope cooled down to 4K. Alumina lenses image the CMB on a 636mm wide focal plane. The modularized focal plane consists of dichroic polarization-sensitive Transition-Edge Sensors (TESes). Each module includes 1,704 optically active TESes fabricated on a 6in Silicon wafer. Each TES array is read out with a microwave multiplexing with a multiplexing factor up to 2,000. Such large factor has allowed to consider 10's of thousands of detectors in a practical way, enabling to design a receiver that can operate up to 19 TES arrays for a total of 32,300 TESes. AliCPT-1 leverages the technological advancements of AdvACT and BICEP-3. The cryostat receiver is currently under integration and testing. Here we present the AliCPT-1 receiver, underlying how the optimized design meets the experimental requirements