TRAUMATIC INJURY OF ASTROCYTES: AN IN VITRO STUDY

2018 ◽  
Vol 18 (04) ◽  
pp. 1850040
Author(s):  
YI HUA ◽  
CHRISTINA L. WILSON ◽  
SHENGMAO LIN ◽  
DIGANTA DUTTA ◽  
SRIVATSAN KIDAMBI ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Traumatic Injury ◽  
High Speed Imaging ◽  
Response Curves ◽  
Cortical Astrocytes ◽  
Strain And Strain Rate ◽  
Wide Range ◽  
Membrane Strain

The objective of this work is to determine the injury criterion for primary rat cortical astrocytes through an in vitro traumatic injury model. The compressed air pressure was used to reproduce typical blast pressure profile, which could induce biaxial strain up to 100% in millisecond for cells cultured on flexible membrane utilizing a controlled cellular injury (CCI) device. The nominal pressure and time settings could be adjusted to accommodate a wide range of membrane strain and strain rate, which was estimated from finite element models. The relationship between the peak membrane displacement/strain and the nominal settings of the CCI device was then established. The model was calibrated using both high-speed imaging system and a theoretical model. The viability and morphology of the astrocytes were characterized and correlated with the strain level. Three different regimes were identified in the stretch-induced dose-response curves of the primary cortical astrocytes, with a sharp decline from live to dead in a narrow range of membrane strain (18%–35%). The level of actin organization of the astrocytes decreased as the membrane strain increased. This work could facilitate the understanding of cellar behaviors subjected to mild blast loadings and the potential tissue engineering therapeutics.

scholarly journals Experimental study of the dynamic behaviour of High Performance Concrete (HPC) under tensile loading

2018 ◽  
Vol 183 ◽  
pp. 02043 ◽  
Author(s):  
Bratislav Lukić ◽  
Dominique Saletti ◽  
Pascal Forquin
Keyword(s):  
High Speed ◽  
High Performance ◽  
High Performance Concrete ◽  
Imaging System ◽  
Spall Strength ◽  
High Speed Imaging ◽  
Dynamic Tensile Strength ◽  
Full Field ◽  
Local Point ◽  
Measurement Results

This paper presents the measurement results of the dynamic tensile strength of a High Performance Concrete (HPC) obtained using full-field identification method. An ultra-high speed imaging system and the virtual fields method were used to obtain this information. Furthermore the measurement results were compared with the local point-wise measurement to validate the data pressing. The obtained spall strength was found to be consistently 20% lower than the one obtained when the Novikov formula is used.

scholarly journals Coherent Raman Scattering Microscopy in Oncology Pharmacokinetic Research

2021 ◽  
Vol 12 ◽  
Author(s):  
Junjie Zeng ◽  
Wenying Zhao ◽  
Shuhua Yue
Keyword(s):  
Raman Scattering ◽  
High Speed ◽  
Cancer Drug ◽  
Cancer Drugs ◽  
High Speed Imaging ◽  
Coherent Raman Scattering ◽  
Anti Cancer ◽  
Coherent Raman

The high attrition rates of anti-cancer drugs during clinical development remains a bottleneck problem in pharmaceutical industry. This is partially due to the lack of quantitative, selective, and rapid readouts of anti-cancer drug activity in situ with high resolution. Although fluorescence microscopy has been commonly used in oncology pharmacological research, fluorescent labels are often too large in size for small drug molecules, and thus may disturb the function or metabolism of these molecules. Such challenge can be overcome by coherent Raman scattering microscopy, which is capable of chemically selective, highly sensitive, high spatial resolution, and high-speed imaging, without the need of any labeling. Coherent Raman scattering microscopy has tremendously improved the understanding of pharmaceutical materials in the solid state, pharmacokinetics of anti-cancer drugs and nanocarriers in vitro and in vivo. This review focuses on the latest applications of coherent Raman scattering microscopy as a new emerging platform to facilitate oncology pharmacokinetic research.

Preliminary Results on the Influence of Engineered Artificial Mucus Layer on Phonation

2014 ◽  
Vol 57 (2) ◽  
Author(s):  
Michael Döllinger ◽  
Franziska Gröhn ◽  
David A. Berry ◽  
Ulrich Eysholdt ◽  
Georg Luegmair
Keyword(s):  
High Speed ◽  
Polymer Concentration ◽  
Physiological Saline ◽  
Vocal Folds ◽  
Oscillatory Behavior ◽  
Linear Polymers ◽  
High Speed Imaging ◽  
Pass Filter ◽  
Low Pass Filter

Purpose Previous studies have confirmed the influence of dehydration and an altered mucus (e.g., due to pathologies) on phonation. However, the underlying reasons for these influences are not fully understood. This study was a preliminary inquiry into the influences of mucus architecture and concentration on vocal fold oscillation. Method Two excised human larynges were investigated in an in vitro setup. The oscillations of the vocal folds at various airflow volume rates were recorded through the use of high-speed imaging. Engineered mucus containing polymers (interconnected polymers and linear polymers) was applied to the vocal folds. From the high-speed footage, glottal parameters were extracted through the use of objective methods and were compared to a gold standard (physiological saline solution). Results Variations were found for all applications of mucus. Fundamental frequency dropped and the oscillatory behavior (speed quotient [SQ], closing quotient [CQ]) changed for both larynges. The 2 applied mucus architectures displayed different effects on the larynges. The interconnected polymer displayed clear low-pass filter characteristics not found for the linear polymer. Increase of polymer concentration affected parameters to a certain point. Conclusion The data confirm results found in previous studies. Furthermore, the different effects—comparing architecture and concentration—suggest that, in the future, synthetic mucus can be designed to improve phonation.

Nucleate Boiling From Micro-Machined Surfaces

2003 ◽  
Author(s):  
Adrian M. Holland ◽  
Colin P. Garner
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Imaging System ◽  
Laser System ◽  
Ccd Camera ◽  
Nucleate Boiling ◽  
Heat Fluxes ◽  
Frame Rate ◽  
High Speed Imaging ◽  
Machined Surfaces

This paper discusses the production and use of laser-machined surfaces that provide enhanced nucleate boiling and heat transfer characteristics. The surface features of heated plates are known to have a significant effect on nucleate boiling heat transfer and bubble growth dynamics. Nucleate boiling starts from discrete bubbles that form on surface imperfections, such as cavities or scratches. The gas or vapours trapped in these imperfections serve as nuclei for the bubbles. After inception, the bubbles grow to a certain size and depart from the surface. In this work, special heated surfaces were manufactured by laser machining cavities into polished aluminium plates. This was accomplished with a Nd:YAG laser system, which allowed drilling of cavities of a known diameter. The size range of cavities was 20 to 250 micrometers. The resulting nucleate pool boiling was analysed using a novel high-speed imaging system comprising an infrared laser and high resolution CCD camera. This system was operated up to a 2 kHz frame rate and digital image processing allowed bubbles to be analysed statistically in terms of departure diameter, departure frequency, growth rate, shape and velocity. Data was obtained for heat fluxes up to 60 kW.m−2. Bubble measurements were obtained working with water at atmospheric pressure. The surface cavity diameters were selected to control the temperature at which vapour bubbles started to grow on the surface. The selected size and spacing of the cavities was also explored to provide optimal heat transfer.

scholarly journals Low-Cost High-Speed Imaging System for Observing Vocal Fold Vibration in Voice Disorders

ORL ◽  
2012 ◽  
Vol 74 (4) ◽  
pp. 208-210 ◽  
Author(s):  
Kenichi Kaneko ◽  
Koichi Sakaguchi ◽  
Masato Inoue ◽  
Haruo Takahashi
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Imaging System ◽  
Low Cost ◽  
Voice Disorders ◽  
High Speed Imaging ◽  
Vocal Fold Vibration

Velocity Measurements Using High-Speed Imaging System for Impact Test

2014 ◽  
Vol 903 ◽  
pp. 187-193 ◽  
Author(s):  
Abdul Aziz Jaafar ◽  
Anwar P.P. Abdul Majeed ◽  
S.M. Sapuan ◽  
Shahnor Basri
Keyword(s):  
High Speed ◽  
Impact Test ◽  
Imaging System ◽  
Velocity Measurements ◽  
Glass Composite ◽  
Free Flight ◽  
High Speed Imaging ◽  
Fibre Glass ◽  
System A ◽  
Kinematic Properties

This paper presents the velocity measurements for an impact test on a laminated fibre-glass composite plate. The free flight kinematic properties of a blunt-nosed cylindrical projectile on the upstream and downstream of a test coupon were measured using a high-speed camera imaging system. A visual geometric detection technique is discussed and it is shown that the uncertainties of velocity measurements are associated with an imposed constraint on the camera viewing area and shutter speed.

Visualization of Oil Droplets Distribution in a Rotary Compressor

2019 ◽  
Author(s):  
Puyuan Wu ◽  
Jun Chen ◽  
Paul E. Sojka
Keyword(s):  
Multiphase Flow ◽  
High Speed ◽  
Imaging System ◽  
Discharge Rate ◽  
Current Phase ◽  
Rotary Compressor ◽  
Cfd Analysis ◽  
High Speed Imaging ◽  
Oil Droplets ◽  
Rolling Piston

Abstract A rotary compressor relies on an eccentric rolling piston, which rotates at high speed, to compress gas in the compression chamber. The oil in the rotary compressor is used for lubricating the bearing and sealing the clearance of sliding parts. However, the oil can exhaust from the rotary compressor by the refrigerant flow and reduce the reliability of the compressor as a result. Thus, studying the behavior of oil droplets distribution in a rotary compressor is a major challenge for manufacturers who rely on CFD tools to predict the multiphase flow. By modifying a rotary compressor, the oil behavior inside the cylinder is observed and recorded by a high-speed imaging system. In the current phase, multiple targeted locations, including the space between the bearing housing and the stator, and the space above the stator are measured in different conditions. The number, size, velocity, and morphology of oil droplets are analyzed based on multiple snapshots. The result can assist designers in improving the CFD analysis of compressors and ultimately reducing the oil discharge rate (ODR).

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