Influence of head-over-body and body-over-head posture on craniospinal, vascular, and abdominal pressures in an acute ovine in-vivo model

INTRODUCTION Optimal shunt-based hydrocephalus treatments are heavily influenced by dynamic pressure behaviors between proximal and distal ends of shunt catheters. Posture-dependent craniospinal, arterial, venous, and abdominal dynamics thereby play an essential role. METHODS An in-vivo ovine trial (n = 6) was conducted to evaluate communication between craniospinal, arterial, venous, and abdominal dynamics. Tilt-testing was performed between -13° and + 13° at 10-min intervals starting and ending at 0° prone position. Mean pressure, pulse pressure, and Pearson correlation (r) to the respective angle were calculated. Correlations are defined as strong: |r|≥ 0.7, mild: 0.3 <|r|< 0.7, and weak: |r|≤ 0.3. Transfer functions (TFs) between the arterial and adjacent compartments were derived. RESULTS Strong correlations were observed between posture and: mean carotid/femoral arterial (r = - 0.97, r = - 0.87), intracranial, intrathecal (r = - 0.98, r = 0.94), jugular (r = - 0.95), abdominal cranial, dorsal, caudal, and intravesical pressure (r = - 0.83, r = 0.84, r = - 0.73, r = 0.99) while mildly positive correlation exists between tilt and central venous pressure (r = 0.65). Only dorsal abdominal pulse pressure yielded a significant correlation to tilt (r = 0.21). TFs followed general lowpass behaviors with resonant peaks at 4.2 ± 0.4 and 11.5 ± 1.5 Hz followed by a mean roll-off of - 15.9 ± 6.0 dB/decade. CONCLUSIONS Tilt-tests with multi-compartmental recordings help elucidate craniospinal, arterial, venous, and abdominal dynamics, which is essential to optimize shunt-based therapy. Results motivate hydrostatic influences on mean pressure, with all pressures correlating to posture, with little influence on pulse pressure. TF results quantify the craniospinal, arterial, venous, and abdominal compartments as compliant systems and help pave the road for better quantitative models of the interaction between the craniospinal and adjacent spaces

The Sheep as a Comprehensive Animal Model to Investigate Interdependent Physiological Pressure Propagation and Multiparameter Influence on Cerebrospinal Fluid Dynamics

The present study aims to develop a suitable animal model for evaluating the physiological interactions between cerebrospinal fluid (CSF) dynamics, hemodynamics, and abdominal compartment pressures. We seek to contribute to the enhanced recognition of the pathophysiology of CSF-dependent neurological disorders like hydrocephalus and the improvement of available treatment options. To date, no comprehensive animal model of CSF dynamics exists, and establishing an accurate model will advance our understanding of complex CSF physiology. Persisting knowledge gaps surrounding the communication and pressure propagation between the cerebrospinal space and adjacent anatomical compartments exacerbate the development of novel therapies for neurological diseases. Hence, the need for further investigation of the interactions of vascular, craniospinal, and abdominal pressures remains beyond dispute. Moreover, the results of this animal study support the optimization of in vitro test benches for medical device development, e.g., ventriculoperitoneal shunts. Six female white alpine sheep were surgically equipped with pressure sensors to investigate the physiological values of intracranial, intrathecal, arterial, central venous, jugular venous, vesical pressure, and four differently located abdominal pressures. These values were measured simultaneously during the acute animal trial with sheep under general anesthesia. Both carotid and femoral arterial blood pressure indicate a reliable and comparable representation of the systematic blood pressure. However, the jugular venous pressure and the central venous pressure in sheep in dorsal recumbency do not correlate well under general anesthesia. Furthermore, there is a trend for possible comparability of lateral intraventricular and lumbar intrathecal pressure. Nevertheless, animal body position during measurements must be considered since different body constitutions can alter the horizontal line between the cerebral ventricles and the lumbar subarachnoid space. While intra-abdominal pressure measurement in the four different abdominal quadrants yielded greater inter-individual variability, intra-vesical pressure measurements in our setting delivered comparable values for all sheep. We established a novel and comprehensive ovine animal model to investigate interdependent physiologic pressure propagation and multiparameter influences on CSF dynamics. The results of this study will contribute to further in vitro bench testing, the derivation of novel quantitative models, and the development of a pathologic ovine hydrocephalus model

Venous dynamics in anesthetized sheep govern postural-induced changes in cerebrospinal fluid pressure comparable to those in humans

Sheep are popular large animals in which to model human disorders and to study physiological processes such as cerebrospinal fluid dynamics. However, little is known about vascular compensatory mechanisms affecting cerebrospinal fluid pressures during acute postural changes in sheep. Six female white Alpine sheep were anesthetized to investigate the interactions of the vascular and cerebrospinal fluid system by acquiring measurements of intracranial pressure and central and jugular venous pressure during passive postural changes induced by a tilt table. The cross-sectional area of the common jugular vein and venous blood flow velocity was recorded. Anesthetized sheep showed bi-phasic effects of postural changes on intracranial pressure during tilting. A marked collapse of the jugular vein was observed during head-over-body tilting; this is in accordance with findings in humans. Active regulatory effects of the arterial system on maintaining cerebral perfusion pressure were observed independent of tilting direction. Conclusion: Anesthetized sheep show venous dynamics in response to posture-induced changes in intracranial pressure that are comparable with those in humans

Физическая подготовка спасателей экономически развитых стран

Объектом исследования является методики подготовки спасателей в России, Республике Казахстан и других экономически развитых странах. Цель работы – провести сравнительный анализ методик физической подготовки спасателей в различных странах мира. В процессе исследования проводился анализ существующего опыта подготовки спасателей нештатных аварийно-спасательных формирований на базе учебных центров, анализ нормативно-правовой базы, регламентирующей деятельность аварийно-спасательных формирований, требований пожарной безопасности России, Казахстана и ряда других стран (Великобритания, США, Китай). В результате исследования были изучены опыт физической подготовки спасателей в разных странах мира.The object of the study is the methods of training rescuers in Russia, the Republic of Kazakhstan and other economically developed countries. The purpose of the work is to carry out a comparative analysis of the methods of physical training of rescuers in various countries of the world. In the process of the analysis, the analysis of the existing experience of training rescuers of emergency rescue teams for the basis of training centers, the analysis of the regulatory and legal framework regulating the activities of rescue units, fire safety requirements of Russia, Kazakhstan and a number of other countries (Great Britain, USA, China). As a result of the study, the experience of physical training of rescuers in different countries of the world was studied

Sleep Disruption and Daytime Sleepiness Correlating with Disease Severity and Insulin Resistance in Non-Alcoholic Fatty Liver Disease: A Comparison with Healthy Controls

BACKGROUND &amp; AIMS: Sleep disturbance is associated with the development of obesity, diabetes and hepatic steatosis in murine models. Hepatic triglyceride accumulation oscillates in a circadian rhythm regulated by clock genes, light-dark cycle and feeding time in mice. The role of the sleep-wake cycle in the pathogenesis of human non-alcoholic fatty liver disease (NAFLD) is indeterminate. We sought to detail sleep characteristics, daytime sleepiness and meal times in relation to disease severity in patients with NAFLD. METHODS: Basic Sleep duration and latency, daytime sleepiness (Epworth sleepiness scale), Pittsburgh sleep quality index, positive and negative affect scale, Munich Chronotype Questionnaire and an eating habit questionnaire were assessed in 46 patients with biopsy-proven NAFLD and 22 healthy controls, and correlated with biochemical and histological parameters. RESULTS: In NAFLD compared to healthy controls, time to fall asleep was vastly prolonged (26.9 vs. 9.8 min., p = 0.0176) and sleep duration was shortened (6.3 vs. 7.2 hours, p = 0.0149). Sleep quality was poor (Pittsburgh sleep quality index 8.2 vs. 4.7, p = 0.0074) and correlated with changes in affect. Meal frequency was shifted towards night-times (p = 0.001). In NAFLD but not controls, daytime sleepiness significantly correlated with liver enzymes (ALAT [r = 0.44, p = 0.0029], ASAT [r = 0.46, p = 0.0017]) and insulin resistance (HOMA-IR [r = 0.5, p = 0.0009]) independent of cirrhosis. In patients with fibrosis, daytime sleepiness correlated with the degree of fibrosis (r = 0.364, p = 0.019). CONCLUSIONS: In NAFLD sleep duration was shortened, sleep onset was delayed and sleep quality poor. Food-intake was shifted towards the night. Daytime sleepiness was positively linked to biochemical and histologic surrogates of disease severity. The data may indicate a role for sleep-wake cycle regulation and timing of food-intake in the pathogenesis of human NAFLD as suggested from murine models

Геология Егозово-Красноярского каменноугольного месторождения и проект разведки участка Менчерепский Северный (Кузбасс)

Цель работы – разведка, подсчет и утверждение запасов каменного угля на участке «Менчерепский Северный» в установленном порядке. В дипломном проекте представлены геологическая характеристика и строение Егозово-Красноярского месторождения каменного угля, определена сеть геологоразведочных работ, методика опробования, ожидаемые результаты работ, производственная и экологическая безопасность при проведении геологоразведочных работ, технико-экономическое обоснование работ. В специальной части дипломного проекта проведено исследование "Вещественный состав углей" участка «Менчерепский Северный» Егозово-Краснояркого каменноугольного месторождения.Purpose – Exploration, estimation and approval of reserves of coal in the area, "Mencherepsky North" in the prescribed manner. A Capstone project presented to the geological characteristics and the structure of egozovo-Krasnoyarsk deposits of coal, identified a network of exploration, methods of testing, expected outcomes of work, industrial and ecological safety at carrying out of exploration works, feasibility of works. In the special part of the graduation project research conducted on the Material composition of coals" plot "Mencherepsky North", egozovo-Krasnoyarka coal field

The inter-kingdom volatile signal indole promotes root development by interfering with auxin signalling

Recently, emission of volatile organic compounds (VOCs) has emerged as a mode of communication between bacteria and plants. Although some bacterial VOCs that promote plant growth have been identified, their underlying mechanism of action is unknown. Here we demonstrate that indole, which was identified using a screen for Arabidopsis growth promotion by VOCs from soil-borne bacteria, is a potent plant-growth modulator. Its prominent role in increasing the plant secondary root network is mediated by interfering with the auxin-signalling machinery. Using auxin reporter lines and classic auxin physiological and transport assays we show that the indole signal invades the plant body, reaches zones of auxin activity and acts in a polar auxin transport-dependent bimodal mechanism to trigger differential cellular auxin responses. Our results suggest that indole, beyond its importance as a bacterial signal molecule, can serve as a remote messenger to manipulate plant growth and development

Изучение агрегации наночастиц меди в водных суспензиях для прогнозирования ее влияния на корнеобразование высших растений

Целью выпускной квалификационной работы является определение влияния размера наночастиц меди и состава среды на степень агрегации наночастиц меди в водных суспензиях для прогнозирования их влияния на корнеобразование высших растений. В работе показано влияние размера электровзрывных наночастиц Cu (50, 100 и 200 нм), времени УЗ обработки и состава дисперсионной среды на дисперсионные свойства суспензий с применением методов лазерной дифракции и сканирующей электронной микроскопии. Сделан прогноз влияния суспензий наночастиц на корнеобразование растений. Экономическая значимость работы заключается в прогнозировании влияния наночастиц Cu и Zn на корнеобразование растений и возможности применения этих данных в сельском хозяйстве.The purpose of the final qualification work is to determine the effect of the size of copper nanoparticles and the composition of the medium on the degree of aggregation of copper nanoparticles in aqueous suspensions to predict their effect on the root formation of higher plants. The paper shows the effect of the size of electroexplosive Cu nanoparticles (50, 100, and 200 nm), the time of ultrasonic treatment and the composition of the dispersion medium on the dispersion roperties of suspensions using laser diffraction and scanning electron microscopy. A forecast of the effect of nanoparticle suspensions on plant root formation has been made. The economic significance of the work lies in predicting the impact Cu and Zn nanoparticles on plant root formation and the possibility of using these data in agricultur

A Soft Robotic Actuator System for in vivo Modeling of Normal Pressure Hydrocephalus

OBJECTIVE: The intracranial pressure (ICP) affects the dynamics of cerebrospinal fluid (CSF) and its waveform contains information that is of clinical importance in medical conditions such as hydrocephalus. Active manipulation of the ICP waveform could enable the investigation of pathophysiological processes altering CSF dynamics and driving hydrocephalus. METHODS: A soft robotic actuator system for intracranial pulse pressure amplification was developed to model normal pressure hydrocephalus in vivo. Different end actuators were designed for intraventricular implantation and manufactured by applying cyclic tensile loading on soft rubber tubing. Their mechanical properties were investigated, and the type that achieved the greatest pulse pressure amplification in an in vitro simulator of CSF dynamics was selected for application in vivo. A hydraulic actuation device based on a linear voice coil motor was developed to enable automated and fast operation of the end actuators. The combined system was validated in an acute ovine pilot in vivo study. RESULTS: In vitro results show that variations in the used materials and manufacturing settings altered the end actuator's dynamic properties, such as the pressure-volume characteristics. In the in vivo model, a cardiac-gated actuation volume of 0.125 mL at a heart rate of 62 bpm caused an increase of 205% in mean peak-to-peak amplitude but only an increase of 1.3% in mean ICP. CONCLUSION: The introduced soft robotic actuator system is capable of ICP waveform manipulation. SIGNIFICANCE: Continuous amplification of the intracranial pulse pressure could enable in vivo modeling of normal pressure hydrocephalus and shunt system testing under pathophysiological conditions to improve therapy for hydrocephalus