Aggregate formation of erythrocytes in postcapillary venules

2005 ◽  
Vol 288 (2) ◽  
pp. H584-H590 ◽  
Author(s):  
Sangho Kim ◽  
Aleksander S. Popel ◽  
Marcos Intaglietta ◽  
Paul C. Johnson
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Erythrocyte Aggregation ◽  
Aggregate Formation ◽  
Fixed Distance ◽  
High Speed Video Camera ◽  
Time Period ◽  
Before And After ◽  
Short Time

The purpose of the present study was to obtain information on erythrocyte aggregate formation in vivo. The movements of erythrocytes in postcapillary venules of the rat spinotrapezius muscle at various flow rates were recorded with a high-speed video camera before and after infusion of dextran 500. To distinguish aggregates, the following criteria were used: 1) a fixed distance (4 μm) between the center points of two adjacent cells, 2) lack of visible separation between the adjacent cells, and 3) movement of the adjacent cells in the same direction. Without dextran 500 infusion, 11 and 5% of erythrocytes formed aggregates in low (33.2 ± 28.3 s) and high pseudoshear (144.2 ± 58.3 s) conditions, respectively, based on the above criteria. After dextran 500 infusion, 53% of erythrocytes satisfied the criteria in the low pseudoshear condition (26.5 ± 17.0 s) and 13% of erythrocytes met the criteria in the high pseudoshear condition (240.0 ± 85.9 s), indicating erythrocyte aggregation is strongly associated with shear rate. Approximately 90% of aggregate formation occurred in a short time period (0.15–0.30 s after entering the venule) in a region 15 to 30 μm from the entrance. The time delay may reflect rheological entrance conditions in the venule.

scholarly journals Effects of temperature alteration on viscosity, polymerization, and in-vivo arterial distribution of N-butyl cyanoacrylate-iodized oil mixtures

2021 ◽  
Author(s):  
Takahiko Mine ◽  
Daisuke Yasui ◽  
Hidemasa Saito ◽  
Tatsuo Ueda ◽  
Taro Yokoyama ◽  
...  
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Polymerization Time ◽  
Iodized Oil ◽  
High Speed Video Camera ◽  
Oil Mixtures ◽  
Potential Factors ◽  
Peripheral Arterial

Abstract Purpose Temperature alteration can modify the polymerization of n-butyl cyanoacrylate (NBCA)-iodized oil mixtures during vascular embolization; its effects on viscosity, polymerization time, and intra-arterial distribution of the NBCA-iodized oil mixture were investigated. Materials and methods In vitro, the viscosities of NBCA, iodized oil, and NBCA-iodized oil mixtures (ratio, 1:1–8) were measured at 4–60 ºC using a rotational rheometer. The polymerization times (from contact with blood plasma to stasis) were recorded at 0–60 ºC using a high-speed video camera. In vivo, the 1:2 mixture was injected into rabbit renal arteries at 0, 20, and 60 ºC; intra-arterial distribution of the mixture was pathologically evaluated. Results The mixtures’ viscosities decreased as temperature increased; those at 60 ºC were almost four to five times lower than those at 4 ºC. The polymerization time of NBCA and the 1:1–4 mixtures increased as temperature decreased in the 0–30 ºC range; the degree of time prolongation increased as the percentage of iodized oil decreased. The 0 ºC group demonstrated distributions of the mixture within more peripheral arterial branches than the 20 and 60 ºC groups. Conclusion Warming reduces the mixture’s viscosity; cooling prolongs polymerization. Both can be potential factors to improve the handling of NBCA-iodized oil mixtures for lesions requiring peripheral delivery. Secondary abstract Temperature alteration influences the polymerization time, viscosity, and intra-arterial distribution of NBCA-iodized oil mixtures. Warming reduces the viscosity of the mixture, while cooling prolongs polymerization.

Vacuum Arc Motion Characteristics on CuWCr Composites

2011 ◽  
Vol 346 ◽  
pp. 161-165
Author(s):  
Peng Xiao ◽  
Jun Ru Liu ◽  
Xian Hui Wang ◽  
Shu Hua Liang ◽  
Han Yang Liu
Keyword(s):  
High Speed ◽  
Erosion Resistance ◽  
Video Camera ◽  
Vacuum Arc ◽  
Arc Erosion ◽  
Electrical Arc ◽  
High Speed Video Camera ◽  
Before And After ◽  
Chopping Current ◽  
Motion Characteristics

The CuWCr composites were respectively fabricated by the mixture of W and Cr and WCr alloyed powders, followed by sintering and infiltration. Vacuum arcs on CuWCr composites were observed by a digital high-speed video camera. The morphologies of the composites before and after arc erosion were characterized by a scanning electron microscope. The results show that the microstructure CuWCr composites prepared by WCr alloyed powders becomes finer and more uniform, and, thus, has good characteristics of diffusive arcs and arc erosion resistance. In addition, the composite prepared by WCr alloyed powders has excellent electrical properties such as high breakdown voltage, low chopping current and long arc life. Arc erosion zones of the CuWCr composite fabricated by WCr alloyed powders become more dispersive and uniform on the surfaces with some shallow erosion pits. During the course of arc evolution, the dispersed arcs are caused by the split of electrical arc.

scholarly journals The Effect of Q-Switched Nd:YAG 1064 nm/532 nm Laser in the Treatment of Onychomycosis In Vivo

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Kostas Kalokasidis ◽  
Meltem Onder ◽  
Myrto-Georgia Trakatelli ◽  
Bertrand Richert ◽  
Klaus Fritz
Keyword(s):  
Clinical Study ◽  
Treatment Time ◽  
Prospective Clinical Study ◽  
Self Evaluation ◽  
Time Period ◽  
Level Of Satisfaction ◽  
Before And After ◽  
532 Nm

In this prospective clinical study, the Q-Switched Nd:YAG 1064 nm/532 nm laser (Light Age, Inc., Somerset, NJ, USA) was used on 131 onychomycosis subjects (94 females, 37 males; ages 18 to 68 years). Mycotic cultures were taken and fungus types were detected. The laser protocol included two sessions with a one-month interval. Treatment duration was approximately 15 minutes per session and patients were observed over a 3-month time period. Laser fluencies of 14 J/cm2were applied at 9 billionths of a second pulse duration and at 5 Hz frequency. Follow-up was performed at 3 months with mycological cultures. Before and after digital photographs were taken. Adverse effects were recorded and all participants completed “self-evaluation questionnaires” rating their level of satisfaction. All subjects were well satisfied with the treatments, there were no noticeable side effects, and no significant differences were found treating men versus women. At the 3-month follow-up 95.42% of the patients were laboratory mycologically cured of fungal infection. This clinical study demonstrates that fungal nail infections can be effectively and safely treated with Q-Switched Nd:YAG 1064 nm/532 nm laser. It can also be combined with systemic oral antifungals providing more limited treatment time.

scholarly journals Detonation effects of shallow buried explosive in sandy soil on target plate acceleration in a small-scale blast test

2018 ◽  
Vol 192 ◽  
pp. 02028
Author(s):  
Hassan Zulkifli Abu ◽  
Ibrahim Aniza ◽  
Mohamad Nor Norazman
Keyword(s):  
Sandy Soil ◽  
High Speed ◽  
Early Stage ◽  
Time History ◽  
Video Camera ◽  
Small Scale ◽  
Target Plate ◽  
Air Blast ◽  
High Speed Video Camera ◽  
The Impact

Small-scale blast tests were carried out to observe and measure the influence of sandy soil towards explosive blast intensity. The tests were to simulate blast impact imparted by anti-vehicular landmine to a lightweight armoured vehicle (LAV). Time of occurrence of the three phases of detonation phase in soil with respect to upward translation time of the test apparatus were recorded using high-speed video camera. At the same time the target plate acceleration was measured using shock accelerometer. It was observed that target plate deformation took place at early stage of the detonation phase before the apparatus moved vertically upwards. Previous data of acceleration-time history and velocity-time history from air blast detonation were compared. It was observed that effects of soil funnelling on blast wave together with the impact from soil ejecta may have contributed to higher blast intensity that characterized detonation in soil, where detonation in soil demonstrated higher plate velocity compared to what occurred in air blast detonation.

In Situ Observation Method for Quantitative Evaluation of Solidification Phenomena and Solidification Cracks during Welding

2014 ◽  
Vol 782 ◽  
pp. 3-7
Author(s):  
Kenji Shinozaki ◽  
Motomichi Yamamoto ◽  
Kohta Kadoi ◽  
Peng Wen
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Solidification Cracking ◽  
In Situ Observation ◽  
High Speed Video Camera ◽  
Varestraint Test ◽  
Solidification Cracks ◽  
Observation Method ◽  
Solidification Crack

Solidification cracking during welding is very serious problem for practical use. Therefore, there are so many reports concerning solidification cracking. Normally, solidification cracking susceptibility of material is quantitatively evaluated using Trans-Varestraint test. On the other hand, local solidification cracking strain was tried to measure precisely using in-situ observation method, called MISO method about 30 years ago. Recently, digital high-speed video camera develops very fast and its image quality is very high. Therefore, we have started to observe solidification crack using in site observation method. In this paper, the local critical strain of a solidification crack was measured and the high temperature ductility curves of weld metals having different dilution ratios and different grain sizes to evaluate quantitatively the effects of dilution ratio and grain size on solidification cracking susceptibility by using an improved in situ observation method.

Study on Magnetic Barrel Machine Equipped with Three-Dimensional Arrangement of Magnets

2007 ◽  
Vol 329 ◽  
pp. 761-766 ◽  
Author(s):  
Y. Zhang ◽  
Masato Yoshioka ◽  
Shin-Ichiro Hira
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
The Media ◽  
Set Up

At present, a commercially available magnetic barrel machine equipped with permanent magnets has some faults arising from constructional reason. That is, grinding or finishing ability is different from place to place in the machining region, resulting in the limitation on the region we can use in the container of workpieces. Therefore, in this research, authors made the new magnetic barrel machine equipped with three dimensional (3D) magnet arrangement to overcome these faults. The grinding ability of the new 3D magnetic barrel machine converted was experimentally examined, and compared with that of the traditional magnetic barrel machine. As a result, it was shown that we can use much broader region in the new 3D machine. It was also shown that the grinding ability became higher. The distribution of barrel media in action was recorded by means of a high speed video camera. It was clarified that the media rose up higher and were distributed more uniformly in the container by the effect of the magnet block newly set up. It was supposed that this must be the reason for the above-mentioned improvement of grinding ability.

Grease soap particles passing through an elastohydrodynamic contact under side slip conditions

2000 ◽  
Vol 214 (4) ◽  
pp. 317-325 ◽  
Author(s):  
P Eriksson ◽  
V Wikström ◽  
R Larsson
Keyword(s):  
Film Thickness ◽  
High Speed ◽  
Previous Investigation ◽  
Video Camera ◽  
Slip Conditions ◽  
High Speed Video ◽  
Elastohydrodynamic Contact ◽  
High Speed Video Camera ◽  
Pure Rolling ◽  
Minimum Film Thickness

In a previous investigation, grease thickener fibres were tracked as they passed through an elastohydrodynamic (EHD) contact in pure rolling using interferometry in a standard ball-and-disc apparatus. In order to capture single thickener fibres, a high-speed video camera was used. Here, the experiments have been repeated introducing different amounts of side slip for different rolling speeds and a faster video camera capable of capturing 4500 frames/s. The contact was lubricated with a continuous supply of grease. Two greases, based on the same synthetic poly(α-olefin) but thickened with Li-12-OH and lithium complex soap respectively, were studied. It was observed that the thickener fibres were stretched both before entering the contact and as they passed through it. Fibres seem to avoid the minimum film thickness regions and, if they enter, the film is restored immediately after passage.

Biomechanical Analysis of a World Record Javelin Throw: A Case Study

1985 ◽  
Vol 1 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Robert J. Gregor ◽  
Marilyn Pink
Keyword(s):  
High Speed ◽  
Video Camera ◽  
The United States ◽  
Track And Field ◽  
Biomechanical Analysis ◽  
World Record ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Ongoing Project

As part of an ongoing project to evaluate elite track and field throwers in the United States, the javelin competition was filmed during the 1983 Pepsi Invitational Track Meet. A high-speed video camera (Spin Physics SP2000) was positioned orthogonal to the javelin runway to record the release of all throws. During this competition, Tom Petranoff’s world record (99.72 m) was filmed at 200 fields per second. Subsequent frame-by-frame digitization yielded results consistent with reports in the literature. Release velocity was 32.3 m/s and represents one of the highest values ever reported. Angle of release was .57r, javelin attitude at release was .64r» and angle of attack was .07r. While optimum values for these release parameters, in light of published results, remain open to discussion, the results presented here represent unique information on a world record performance and can serve as a basis of comparison for future performances.

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