Effect of ultra-endurance exercise on left ventricular performance and plasma cytokines in healthy trained men

The purpose of this study was to investigate the effect of ultra-endurance exercise on left ventricular (LV) performance and plasma concentration of interleukin (IL)-6, IL-10, IL-18 and tumour necrosis factor alpha (TNF-α) as well as to examine the relationships between exercise-induced changes in plasma cytokines and those in echocardiographic indices of LV function in ultra-marathon runners. Nine healthy trained men (mean age 30±1.0 years) participated in a 100-km ultra-marathon. Heart rate, blood pressure, ejection fraction (EF), fractional shortening (FS), ratio of early (E) to late (A) mitral inflow peak velocities (E/A), ratio of early (E’) to late (A’) diastolic mitral annulus peak velocities (E’/A’) and E-wave deceleration time (DT) were obtained by echocardiography before, immediately after and in the 90th minute of the recovery period. Blood samples were taken before each echocardiographic evaluation. The ultra-endurance exercise caused significant increases in plasma IL-6, IL-10, IL-18 and TNF-α. Echocardiography revealed significant decreases in both E and the E/A ratio immediately after exercise, without any significant changes in EF, FS, DT or the E/E’ ratio. At the 90th minute of the recovery period, plasma TNF-α and the E/A ratio did not differ significantly from the pre-exercise values, whereas FS was significantly lower than before and immediately after exercise. The increases in plasma TNF-α correlated with changes in FS (r=0.73) and DT (r=-0.73). It is concluded that ultra-endurance exercise causes alterations in LV diastolic function. The present data suggest that TNF-α might be involved in this effect.     

Race‐specific differences in the phase coherence between blood flow and oxygenation: A simultaneous NIRS,white light spectroscopy and LDF study

Race‐specific differences in the level of glycated hemoglobin are well known. However, these differences were detected by invasive measurement of mean oxygenation, and their understanding remains far from complete. Given that oxygen is delivered to the cells by hemoglobin through the cardiovascular system, a possible approach is to investigate the phase coherence between blood flow and oxygen transportation. Here we introduce a noninvasive optical method based on simultaneous recordings using NIRS, white light spectroscopy and LDF, combined with wavelet‐based phase coherence analysis. Signals were recorded simultaneously for individuals in two groups of healthy subjects, 16 from Sub‐Saharan Africa (BA group) and 16 Europeans (CA group). It was found that the power of myogenic oscillations in oxygenated and de‐oxygenated hemoglobin is higher in the BA group, but that the phase coherence between blood flow and oxygen saturation, or blood flow and hemoglobin concentrations is higher in the CA group     

A fully implantable multi-channel biotelemetry system for measurement of blood flow and temperature: a first evaluation in the green sturgeon

The objective of this study was to evaluate a novel fully implantable radio-based blood flow biotelemetry system which allows simultaneously measurement of blood flow on two channels and temperature on one channel, in fish. These are the first recordings of blood flow from free-swimming fish, showing that the system is capable of recording blood flow in the ventral aorta (cardiac output) and celiacomesenteric artery (gastrointestinal blood flow) in green sturgeon Acipenser medirostris exposed to a series of different stimuli for up to 7 days after implantation. The results showed stable base line recordings and blood flow was used to calculated heart rate (f _H) and stroke volume (V _s). It was possible to reproduce the same type of responses as has previously been reported during exposure to hypoxia, temperature, stress and feeding. The mass of our implant was less than 2% of the body mass which is well within the recommended sizes for surgically implanted telemetry transmitters and it fitted easily within the abdominal cavity of the sturgeon. A fully implantable system minimizes the risk of infection/expulsion and maximizes the likelihood that the studied fish will behave naturally and be treated normally by surrounding fish. The use of biotelemetry in basic comparative physiology and applied animal ecology could help scientists to collect information that has previously been challenging to obtain and to open the possibility for new types of physiological and ecophysiological studies. Handling editor: K. Martens     

产前超声诊断结果与胎儿先天性心脏病结局的相关性及危险因素分析

摘要 目的：对比先天性心脏病胎儿与正常胎儿的产前超声差异，分析产前超声诊断结果与胎儿先天性心脏病的相关性及危险因素。方法：选取我院2018年12月到2020年12月共收治的80例有先天性心脏病胎儿的孕妇作为研究对象，将其分为观察组，另选取健康胎儿的80例孕妇进行对比研究，将其分为对照组，对所有孕妇进行彩色多普勒超声进行诊断，分析观察组超声诊断与最终结果，对比两组胎儿的超声诊断情况，并对孕期胎儿先天性心脏病的风险因素进行单因素与多因素logistic回归分析。结果：通过尸检和出生后随访最终确定结果与超声诊断结果对比无显著差异（P＞0.05），超声诊断中有3例漏诊；由于卵圆孔直径大于6 mm、心内膜垫缺损（Endocardial cushion defect, ECD）和单心房胎儿没有正常的四腔心结构，因此无法进行腔室内径的测量，对其他观察组患儿进行测量之后发现，观察组患儿左心发育不全综合征（hypoplastic left heart syndrome, HLHS）的左心房与左心室、法洛氏四联症（Tetralogy of Fallot, TOF）右心室、室间隔缺损（Ventricular Septal Defect, VSD）右心室内径明显低于对照组（P＜0.05）；对可能造成胎儿先天性心脏病的高风险因素进行分析发现，两组孕妇的孕期早期服药、高龄产妇以及家族心脏病史情况对比差异显著，观察组明显更高（P＜0.05）；对所有因素进行赋值，其中"是"或"有"为1，"否"或"无"为0。通过logistic回归分析发现只有孕期早期服药和家族心脏病史为胎儿先天性心脏病的独立危险因素（P＜0.05）。结论：对孕妇进行综合产前超声诊断胎儿先天性心脏病的准确率较高，与最终结果无明显区别；虽然高龄孕妇与胎儿先天性心脏病具有一定关系，但是只有孕期早期服药和家族心脏病史是胎儿先天性心脏病的独立危险因素。     

Research and Development of High-performance Explosives

Developmental testing of high explosives for military applications involves small-scale formulation, safety testing, and finally detonation performance tests to verify theoretical calculations. small-scale For newly developed formulations, the process begins with small-scale mixes, thermal testing, and impact and friction sensitivity. Only then do subsequent larger scale formulations proceed to detonation testing, which will be covered in this paper. Recent advances in characterization techniques have led to unparalleled precision in the characterization of early-time evolution of detonations. The new technique of photo-Doppler velocimetry (PDV) for the measurement of detonation pressure and velocity will be shared and compared with traditional fiber-optic detonation velocity and plate-dent calculation of detonation pressure. In particular, the role of aluminum in explosive formulations will be discussed. Recent developments led to the development of explosive formulations that result in reaction of aluminum very early in the detonation product expansion. This enhanced reaction leads to changes in the detonation velocity and pressure due to reaction of the aluminum with oxygen in the expanding gas products.     

Fast scan magnetic resonance imaging and Doppler ultrasonography of uteroplacental hemodynamics in the rhesus monkey (Macaca mulatta)

Fast scan magnetic resonance imaging, color Doppler ultrasonography, and magnetic resonance angiography were used to demonstrate the uteroplacental hemodynamics in rhesus monkeys. “Jets” of maternal blood spurting into the placenta were observed with, or without, the use of a contrast medium from 114 days to the term of pregnancy. Cumulative intravenous doses of cocaine hydrochloride brought about changes in the sequences of imaging of the maternal blood inflow to the placenta. These methods appear suitable for non-invasive monitoring of the effects of drugs on placental function.     

Effect of xylazine,isoxsuprine, and lidocaine on Doppler sonographic uterine and umbilical blood flow measurements in cows during the last month of pregnancy

The maternal portion of the bovine placenta receives blood mainly from the uterine arteries (AUT) and the fetal portion from the umbilical arteries (AUM). Placental perfusion is crucial for fetal development and undergoes adaptive changes during pregnancy according to the fetal requirements. One goal of this study was to investigate changes in Doppler sonographic measurements of blood vessels that supply blood to the placenta in cows during the last 4 weeks of pregnancy. Another goal was to examine how these measurements are affected by three drugs commonly used in cows at the time of parturition. Nine cows underwent Doppler sonographic examination of the AUT ipsilateral and contralateral to the pregnant horn and one AUM three times per week during the last 4 weeks of gestation. This was followed by the randomized administration of one of the three following experimental drugs per day: isoxsuprine (200 mg/cow, iv), xylazine (2 mg/100 kg, iv), and lidocaine for epidural anesthesia (100 mg/cow). Doppler sonographic examination was repeated 30 minutes after medication. Maternal pulse rate increased during the study period (P < 0.001), and the diameter of the contralateral AUT was smaller in the last week before birth than in the two preceding weeks. The resistance index (RI) of the ipsilateral AUT was smaller in the last week than in the first 2 weeks of the study period. Uterine blood flow volume increased after isoxsuprine by 5% and after epidural anesthesia by 6% (both P ≤ 0.05) and decreased after xylazine by 10% (P < 0.001). Isoxsuprine was the only drug that elevated the blood flow volume in the AUM (P ≤ 0.05). Xylazine increased the RI of both AUT (both P < 0.001) and significantly reduced maternal and fetal pulse frequencies, whereas isoxsuprine significantly reduced the RI of both AUT and the AUM and increased maternal and fetal pulse frequencies. The results reported that Doppler sonographic measurements of uterine and AUM change little in the last month of pregnancy in the cow. Isoxsuprine and epidural anesthesia with lidocaine have the potential to improve uterine perfusion.     

Processing of simple and complex acoustic signals in a tonotopically organized ear

Processing of complex signals in the hearing organ remains poorly understood. This paper aims to contribute to this topic by presenting investigations on the mechanical and neuronal response of the hearing organ of the tropical bushcricket species Mecopoda elongata to simple pure tone signals as well as to the conspecific song as a complex acoustic signal. The high-frequency hearing organ of bushcrickets, the crista acustica (CA), is tonotopically tuned to frequencies between about 4 and 70 kHz. Laser Doppler vibrometer measurements revealed a strong and dominant low-frequency-induced motion of the CA when stimulated with either pure tone or complex stimuli. Consequently, the high-frequency distal area of the CA is more strongly deflected by low-frequency-induced waves than by high-frequency-induced waves. This low-frequency dominance will have strong effects on the processing of complex signals. Therefore, we additionally studied the neuronal response of the CA to native and frequency-manipulated chirps. Again, we found a dominant influence of low-frequency components within the conspecific song, indicating that the mechanical vibration pattern highly determines the neuronal response of the sensory cells. Thus, we conclude that the encoding of communication signals is modulated by ear mechanics.     

Responses in acral and non-acral skin vasomotion and temperature during lowering of ambient temperature

Arteriovenous anastomoses (AVA) in acral skin (palms and soles) have a huge capacity to shunt blood directly from the arteries to the superficial venous plexus of the extremities. We hypothesized that acral skin, which supplies blood to the superficial venous plexus, has a stronger influence on blood flow adjustments during cooling in thermoneutral subjects than does non-acral skin. Thirteen healthy subjects were exposed to stepwise cooling from 32 °C to 25 °C and 17 °C in a climate chamber. Laser Doppler flux and skin temperature were measured simultaneously from the left and right third finger pulp and bilateral upper arm skin. Coherence and correlation analyses were performed of short-term fluctuations at each temperature interval. The flux from finger pulps showed the synchronous spontaneous fluctuations characteristic of skin areas containing AVAs. Fluctuation frequency, amplitude and synchronicity were all higher at 25 °C than at 32 °C and 17 °C (p<0.02). Bilateral flux from the upper arm skin showed an irregular, asynchronous vasomotor pattern with small amplitudes which were independent of ambient temperature. At 32 °C, ipsilateral median flux values from the right arm (95% confidence intervals) were 492 arbitrary units (au) (417, 537) in finger pulp and 43 au (35, 60) in upper arm skin. Flux values gradually decreased in finger pulp to 246 au (109, 363) at 25 °C, before an abrupt fall occurred at a median room temperature of 24 °C, resulting in a flux value of 79 au (31, 116) at 17 °C. In the upper arm skin a gradual fall throughout the cooling period to 21 au (13, 27) at 17 °C was observed. The fact that the response of blood flow to ambient cooling is stronger in acral skin than in non-acral skin suggests that AVAs have a greater capacity to adjust blood flow in thermoneutral zone than arterioles in non-acral skin.