ABSTRACT
The drying process of different grades of Angelicae Sinensis Radix under low temperature and resurgence conditions was simulated based on the Weibull distribution function,in order to clarify the low-temperature moisture regain drying characteristics of different grades of Angelicae Sinensis Radix,and explore the effect of grade and drying conditions on the drying process of Angelicae Sinensis Radix. Research results indicated that the Weibull function can be used to simulate different grades of Angelicae Sinensis Radix low-temperature moisture regain drying process,and the lower the drying temperature,the smaller the grade,and the better the simulation effect. The grade and drying temperature showed a significant effect on the low-temperature moisture regain drying process of Angelicae Sinensis Radix,and the effect of temperature on the relative moisture regain rate of Angelicae Sinensis Radix was greater than the grade. The relative moisture regain rate of different grades of Angelicae Sinensis Radix at 40 ℃ was higher than 55 ℃,and the relative moisture regain rate at 40 ℃ was first class > second class > third class. After drying,the moisture ratio at 40 ℃ was lower than that at 55 ℃; the effect of the grade on the effective diffusion coefficient of dry water was greater than the temperature. Under different conditions of 40 ℃ and 55 ℃ moisture regain,the effective diffusion coefficient of water was between 2. 941 6×10-6-7. 991 5×10-6 and3. 093 8×10-6-8. 483 8×10-6 for different grades. Under the same temperature conditions,the effective diffusion coefficient of water was first class > second class > third class. Therefore,Weibull function can be used to study and simulate the drying characteristics of different grades of Angelicae Sinensis Radix under low-temperature moisture regain conditions,providing experimental basis for the improvement of traditional drying technology of Angelicae Sinensis Radix and the optimization of drying process of different specifications or grades of Angelicae Sinensis Radix.
Subject(s)
Angelica sinensis/chemistry , Cold Temperature , Desiccation , Drugs, Chinese Herbal/chemistry , Plant Roots/chemistry , TemperatureABSTRACT
BACKGROUND:Previous studies have demonstrated that tissue Doppler echocardiography and two-dimensional speckle tracking echocardiography are minimally invasive imaging methods used to screen for coronary atherosclerotic heart disease.However,they are not highly sensitive and specific for patients with suspected heart disease presenting with normal ventricular wall motion or for patients with early coronary heart disease.The newly emerging three-dimensional longitudinal strain imaging technology can overcome these shortcomings and has become a relatively mature technique for quantitative assessment of myocardial function.OBJECTIVE:To investigate the early diagnosis value of left ventricular global longitudinal peak strain (LVGLPS)measured by three-dimensional longitudinal strain imaging technology for high-risk coronary atherosclerotic heart disease.METHODS:This is a single-center,open-label,diagnostic trial.Three hundred elderly patients suspected of coronary atherosclerotic heart disease receiving treatment at the Department of Ultrasound Medicine,Taihe Hospital of China from January 2013 to January 2018 are included in this study.These patients will be divided into three groups:low-risk group (n=100;≥ 70％ diameter stenosis in one or two branches of the right main coronary artery and the left circumflex artery),high-risk group (n=100;≥ 50％ diameter stenosis in the left main coronary artery or ≥ 70％ diameter stenosis in the left anterior descending branch),and control group (n=100;＜50％ diameter stenosis in the main coronary arteries and all branches).All patients will undergo conventional echocardiography followed by three-dimensional longitudinal strain imaging to measure the LVGLPS.The LVGLPS will be compared among the three groups.The primary outcome measure is the sensitivity of the LVGLPS for prediction of coronary atherosclerotic heart disease.The secondary outcome measures are:the specificity,positive predictive value,negative predictive value,positive likelihood ratio,negative likelihood ratio,and accuracy rate of the LVGLPS for prediction of coronary atherosclerotic heart disease;change in the LVGLPS;change in conventional echocardiography parameters;and change in the receiver operating characteristic curve for prediction of high-risk coronary atherosclerotic heart disease using the LVGLPS.This study will be performed in accordance with the Declaration of Helsinki.All patients have been informed of the study protocol and procedure and have provided written informed consent.This trial was approved by Taihe Hospital (Affiliated Hospital of Hubei University of Medicine) with the approval No.2013(03) in January 2013.Participant recruitment and data collection began in January 2013 and will continue through December 2017.Outcome measure analysis will be performed and the trial will be completed in January 2018.Results will be disseminated through presentations at scientific meetings and publications in peer-reviewed journals.This trial was registered with ClinicalTrial.gov (identifier:ChiCTR-DDD-17012839).DISCUSSION:The findings from this study will help to confirm that three-dimensional longitudinal strain imaging technology is highly sensitive and specific for patients with abnormal coronary arteries with suspected coronary heart disease but who present with normal ventricular wall motion.The change in the LVGLPS contributes to early diagnosis of high-risk coronary atherosclerotic heart disease in elderly patients.This helps clinicians to diagnose early coronary heart disease and take timely strategies to avoid serious cardiovascular events as much as possible.