Effects of the Inertia Barbell Training on Lumbar Muscle T2 Relaxation Time.

Sun, M-Y, Lu, J-Q, Ma, Z-C, Lü, J-J, Huang, Q, Sun, Y-N, and Liü, Y. Effects of the inertia barbell training on lumbar muscle T2 relaxation time. J Strength Cond Res 34(12): 3454-3462, 2020-The purpose of this study was to investigate variations in T2 relaxation time in normal human lumbar muscles caused by inertia barbell training. Thirty undergraduate healthy men (mean age = 19 ± 1.2 years, body mass = 72 ± 10.0 kg, and height = 1.78 ± 0.1 m) were recruited to participate in this study. Subjects were randomly assigned into 2 groups: an inertia barbell training group (IBTG) (n = 15) and a normal barbell-training group (NBTG) (n = 15). All subjects participated in lumbar flexion and extension muscle strength training for 1 hour per time, 3 times per week for a total of 8 weeks. The lumbar area of each subject was scanned before and after the experiment using a 3.0T superconductive magnetic resonance imaging system. The T2 values measured after intervention were significantly different compared with the T2 values measured before the experiment in both the IBTG and NBTG groups (p < 0.001). After intervention, there was no significant difference in T2 values between the IBTG and NBTG groups (p = 0.17). The ([INCREMENT]T2)/T2 percentage was significantly different in the IBTG group (p < 0.01). This study demonstrated that 8 weeks of strength training led to significant improvements in the values for T2 relaxation time of the lumbar muscles. Furthermore, the ([INCREMENT]T2)/T2 percentage for IBTG was higher than that for NBTG, which suggested that lumbar muscle activity increased more with inertial barbell training.

Rapid and Noninvasive Detection of Skin Cholesterol with Diffuse Reflectance Spectroscopy Technology.

Due to the urgent need for noninvasive detection of skin cholesterol, a portable, intelligent and real-time skin diffuse reflectance spectroscopy measurement system was designed based on a micro-spectrometer. Digitonin-horseradish peroxidase copolymer solution was prepared. According to the properties digitonin binds to the hydroxy of cholesterol molecular specifically and the horseradish peroxidase reacts with TMB color solution (the main component is 3,3',5,5'-tetramethylbenzidine ) a color change was produced, by which the skin cholesterol was identified and instructed with high sensitivity and high specificity, and the concentration of skin cholesterol was quantified by measuring the degree of color change. In order to validate the feasibility of this method, pig skin which is similar to human skin was taken as the experimental subject, and cholesterol samples of gradient concentration were achieved through the extraction. After that the spectroscopy measurement system was adopted to detect the cholesterol concentration. The experiment result showed that, relative diffuse reflectance can distinguish the cholesterol samples with different concentrations, and the diffuse reflectance intensity factor can quantity the concentrations of cholesterol at characteristic wavelengths (442, 450 and 463 nm) and characteristic wavelength band of 442~500 nm. Linear fitting curves were obtained with the determination coefficient R2 were 0.960, 0.959, 0.958 and 0.958, respectively. The study has shown that, using diffuse reflectance spectroscopy technology can realize noninvasive rapid detection of skin cholesterol, and applying it to the risk assessment of atherosclerotic diseases would contribute to the prevention and control of such diseases significantly.

A new tonometric device for radial augmentation index and subendocardial viability ratio: potential use in health screening.

Augmentation index (AIx) and subendocardial viability ratio (SEVR) are widely accepted indices of wave reflection and myocardial oxygen demand relative to supply. This study aimed to validate a new tonometric device (IIM-2010A) for obtaining AIx and SEVR from radial artery. A total of 68 outpatients (32 men and 36 women) aged 20 to 76 years (44.7±16.6 years) recruited from a health screening center participated in the study. AIx was obtained from radial pressure using the HEM-9000AI and IIM-2010A devices, while SEVR was measured from carotid pressure with the tonometric method and from radial pressure by the IIM-2010A device. In a subgroup of 24 patients, the measurements of AIx and SEVR were repeated after an interval of 10 minutes. The correlation of radial AIx between the IIM-2010A and HEM-9000AI devices was highly significant (r=0.956, P<.01). Radial SEVR determined from IIM-2010A was also highly related to carotid SEVR (r=0.864, P<.01), although the value was about 13.1% lower. There was no statistically significant difference between the repeated measurements of both indices. The lower coefficient of variation (2.9% vs 4.3% for AIx, 3.3% vs 4.1% for SEVR) and higher intraclass correlation coefficient (0.96 vs 0.91 for AIx, 0.93 vs 0.86 for SEVR) of IIM-2010A confirmed better short-term reproducibility, compared with the HEM-9000AI device and carotid tonometry. The new tonometric device IIM-2010A is effective and reproducible in calculating radial AIx and SEVR and has potential use in health screening.

Reducing temperature influence on dry quantitative ultrasound bone assessment with constant temperature control.

Nowadays, ultrasonic bone assessment is increasingly being used to assess bone status. Therefore, the purpose of this study was to enhance the precision of ultrasonic bone assessment by reducing the influence of temperature in a dry, gel coupled transducer system. A warm airflow generator was designed to make the measurement temperature constant (35±1°C). Thirty people were recruited for the evaluation of in-vivo performance. The short-term precision was performed 10 times with repositioning during a consecutive measurement session within 20min. It was expressed as root-mean square average of coefficient of variation, which is abbreviated for CV(RMS). The CV(RMS) was 3.84% for broadband ultrasound attenuation, and 0.30% for speed of sound. The Pearson correlations between gel coupled transducer system and dual energy X-ray absorptiometry (DEXA) were 0.808 (p<0.001) for broadband ultrasound attenuation, and 0.586 (p<0.005) for speed of sound. The result showed the high performance of reproducibility and the significant (p<0.005) correlations with DEXA in the dry, gel coupled transducer system.

Radial pulse transit time is an index of arterial stiffness.

Aortic pulse wave velocity, calculated from pulse transit time (PTT), is often used as an indicator of arterial stiffness and suggested to be standardized for heart rate (HR). This study aimed to determine whether PTT obtained directly from radial arterial waveforms could be used to assess arterial stiffness and the effect of HR on it. Measurements of anthropometric parameters, blood pressure (BP) and radial PTT were taken in 266 apparently healthy adults (113 men and 153 women; age 18-78 years). BP and radial PTT were measured in a subgroup of 11 young subjects (seven men and four women, age 24-35 years) in a 3-month follow-up study, which aimed to investigate the effect of HR changes. Radial PTT was significantly higher in men compared with women (0.116 ± 0.022 s compared with 0.103 ± 0.031 s, P < 0.001). It was inversely related to age in men and women (r=-0.838 and r=-0.804, respectively, P < 0.01 for both). Multiple regression analysis showed that HR was a potent predictor of radial PTT in addition to age, sex and systolic BP. There was no significant change in radial PTT when HR ranged from 60 to 75 b.p.m. A significant decrease was found in radial PTT when HR was up to 80 b.p.m. (P < 0.01). These findings indicate that the simple and easily obtainable radial PTT could be a useful index of arterial stiffness, and HR changes should be considered when it is up to 80 b.p.m.