scholarly journals Optical verification and in-vitro characterization of two commercially available acoustic bubble counters for cardiopulmonary bypass systems

Perfusion ◽  
2017 ◽  
Vol 33 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Tim Segers ◽  
Marco C. Stehouwer ◽  
Filip M.J.J. de Somer ◽  
Bastian A. de Mol ◽  
Michel Versluis
Keyword(s):  
High Speed ◽  
In Vitro Study ◽  
High Speed Imaging ◽  
In Vitro Characterization ◽  
Quantitative Monitoring ◽  
Order Of Magnitude ◽  
Air Removal ◽  
New Generation ◽  
Relative Change

Introduction: Gaseous microemboli (GME) introduced during cardiac surgery are considered as a potential source of morbidity, which has driven the development of the first bubble counters. Two new generation bubble counters, introduced in the early 2000s, claim correct sizing and counting of GME. This in-vitro study aims to validate the accuracy of two bubble counters using monodisperse bubbles in a highly controlled setting at low GME concentrations. Methods: Monodisperse GME with a radius of 43 µm were produced in a microfluidic chip. Directly after their formation, they were injected one-by-one into the BCC200 and the EDAC sensors. GME size and count, measured with the bubble counters, were optically verified using high-speed imaging. Results: During best-case scenarios or low GME concentrations of GME with a size of 43 µm in radius in an in-vitro setup, the BCC200 overestimates GME size by a factor of 2 to 3 while the EDAC underestimates the average GME size by at least a factor of two. The BCC200 overestimates the GME concentration by approximately 20% while the EDAC overestimates the concentration by nearly one order of magnitude. Nevertheless, the calculated total GME volume is only over-predicted by a factor 2 since the EDAC underestimates the actual GME size. For the BCC200, the total GME volume was over-predicted by 25 times due to the over-estimation of GME size. Conclusions: The measured errors in the absolute sizing/counting of GME do not imply that all results obtained using the bubble counters are insignificant or invalid. A relative change in bubble size or bubble concentration can accurately be measured. However, care must be taken in the interpretation of the results and their absolute values. Moreover, the devices cannot be used interchangeably when reporting GME activity. Nevertheless, both devices can be used to study the relative air removal characteristics of CPB components or for the quantitative monitoring of GME production during CPB interventions.

scholarly journals Drug delivery via tattooing: Effect of needle and fluid properties

2021 ◽  
Author(s):  
Idera Lawal ◽  
Pankaj Rohilla ◽  
Jeremy Marston
Keyword(s):  
Drug Delivery ◽  
High Speed ◽  
In Vitro Study ◽  
Injection Technique ◽  
High Speed Imaging ◽  
Injection Process ◽  
Gelatin Gels ◽  
Fluid Properties

Tattooing is a commonplace practice among the general populace in which ink is deposited within dermal tissue. Typically, an array of needles punctures the skin which facilitates the delivery of a fluid within the dermis. Although, a few studies in the past have investigated the potential of tattooing as an intradermal (ID) drug injection technique, an understanding of the fluid dynamics involved in the delivery of fluid into skin is still lacking. Herein, we sought to provide insight into the process via an in vitro study. We utilize a five needle flat array (5F) with a tattoo machine to inject fluids into gelatin gels. High-speed imaging was used to visualize the injection process and estimate the amount of fluid delive red after each injection upto the 50th injection. We investigate the role of reciprocating frequency (f) of the needle array and the physical properties of the fluids on the volume (Vo) and the percentage delivery (η) after injection. In addition, we illustrate the physical mechanism of fluid infusion during tattooing, which has not been reported. An understanding of the injection process via tattooing can be useful in the development of ID tattoo injectors as drug delivery devices.

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.

In vivo and in vitro trimethadione oxidation activity of the liver from various animal species including mouse, hamster, rat, rabbit, dog, monkey and human

1999 ◽  
Vol 18 (1) ◽  
pp. 12-16 ◽  
Author(s):  
E Tanaka ◽  
A Ishikawa ◽  
T Horie
Keyword(s):  
Animal Species ◽  
In Vitro Study ◽  
Metabolic Clearance ◽  
Oxidation Activity ◽  
In Vitro Characterization ◽  
Demethylase Activity ◽  
Total Body

Trimethadione (TMO) has the properties required of a probe drug for the evaluation of hepatic drug-oxidizing capacity and, in this study, we have summarized the in vivo and in vitro metabolism of TMO in various animal species including mouse, hamster, rat, rabbit, dog, monkey and human. In the in vivo study, the plasma TMO level was measured after intravenous or oral (human) administration of TMO at a dose of 4 mg/kg to various animal species. The rate of TMO metabolic clearance in these animal species in vivo was in the order mouse > hamster >rat>rabbit>dog>monkey>human. In the in vitro study, species differences were observed in the cytochrome P450 (P450) content and drug-oxidizing enzyme activity. The content of P450 was monkey> mouse>dog>rabbit>hamster>rat>human. On the other hand, TMO N-demethylation was in the order mouse >hamster >rat >rabbit>dog>monkey>human. There was a good correlation between the mean total body clearance of TMO ( in vivo)andthemeanTMON-demethylase activity ( in vitro) (y=1.7×+0.11, r=0.965, P<0.001). These results show that TMO is a probe agent with metabolic and pharmacokinetic characteristics making it attractive for the in vivo and in vitro characterization of metabolic activity in various animal species.

scholarly journals In vitro angiographic comparison of the flow-diversion performance of five neurovascular stents

2017 ◽  
Vol 24 (2) ◽  
pp. 150-161 ◽  
Author(s):  
Ronak J Dholakia ◽  
Ari D Kappel ◽  
Andrew Pagano ◽  
Henry H Woo ◽  
Baruch B Lieber ◽  
...  
Keyword(s):  
High Speed ◽  
In Vitro Study ◽  
Flow Diverter ◽  
Flow Diversion ◽  
High Porosity ◽  
Bifurcation Aneurysm ◽  
Flow Activity ◽  
Statistical Trends ◽  
Better Than

Background and purpose Data differentiating flow diversion properties of commercially available low- and high-porosity stents are limited. This in vitro study applies angiographic analysis of intra-aneurysmal flow to compare the flow-diversion performance of five neurovascular devices in idealized sidewall and bifurcation aneurysm models. Methods Five commercial devices (Enterprise, Neuroform, LVIS, FRED, and Pipeline) were implanted in silicone sidewall and bifurcation aneurysm models under physiological average flow of blood analog fluid. High-speed angiographic images were acquired pre- and post-device implantation and contrast concentration-time curves within the aneurysm were recorded. The curves were quantified with five parameters to assess changes in contrast transport, and thus aneurysm hemodynamics, due to each device. Results Inter-device flow-diversion performance was more easily distinguished in the sidewall model than the bifurcation model. There were no obvious overall statistical trends in the bifurcation parameters but the Pipeline performed marginally better than the other devices. In the sidewall geometry, overall evidence suggests that the LVIS performed better than the Neuroform and Enterprise. The Pipeline and FRED devices were statistically superior to the three stents and Pipeline was superior to FRED in all sidewall parameters evaluated. Conclusions Based on this specific set of experiments, lower-porosity flow diverters perform significantly better in reducing intra-aneurysmal flow activity than higher-porosity stents in sidewall-type geometries. The LVIS device is potentially a better flow diverter than the Neuroform and Enterprise devices, while the Pipeline is potentially better than the FRED.

scholarly journals Effect of Carisolv Gel on Sound, Demineralized and Carious Dentin: In Vitro Study

2015 ◽  
Vol 62 (1) ◽  
pp. 21-26
Author(s):  
Marina Eftimoska ◽  
Sonja Apostolska ◽  
Vasilka Rendzova ◽  
Sašo Elencevski ◽  
Aleksandra Popovac ◽  
...  
Keyword(s):  
High Speed ◽  
In Vitro Study ◽  
Nickel Titanium ◽  
Mechanical Method ◽  
Dental Visits ◽  
Carious Lesions ◽  
Caries Removal ◽  
Electronic Microscope ◽  
Dental Burs

Summary Intoduction Pain and discomfort during dental interventions caused by high-speed dental burs are the most frequent reasons for avoiding dental visits. Numerous possibilities have been offered in the last decade aiming to replace burs for caries removal, one of them is chemo-mechanical method of caries elimination. The aim of this study was to analyze micromorphological changes caused by Carisolv on sound, demineralized and carious (softened) dentin using SEM. Material and Methods Study included 30 teeth (20 intact and 10 with carious lesions) extracted for orthodontic reasons. Carisolv™ system (MediTeam, Sweden) that contains Carisolv gel and specific nickel-titanium hand instruments was used for chemo-mechanical caries elimination. In our study only Carisolv gel was applied on sound, demineralized and carious dentin for 20 min. Dentin surface was analyzed using scanning electronic microscope (SEM). Results SEM showed that Carisolv gel affected soft carious dentin only with no changes on sound dentin regardless of demineralization status. Conclusion Carisolv did not affect sound and demineralized dentin while it selectively dissolved carious dentin.

Evaluation of Changes in Temperature of Zirconia Frameworks During Grinding Under Different Chair-Side Conditions: An In Vitro Study

2020 ◽  
pp. 232020682095394
Author(s):  
Özgecan S¸ivet ◽  
Özlem Malkondu ◽  
Sercan Küçükkurt ◽  
Ender Kazazoglu
Keyword(s):  
High Speed ◽  
In Vitro Study ◽  
Water Cooling ◽  
Significance Level ◽  
Mean Temperature ◽  
Significant Difference ◽  
Clinical Conditions ◽  
Rotary Instrument ◽  
Difference Test

Aim: To evaluate the changes in the temperature of zirconia during grinding under different clinical conditions. Materials and Methods: A total of 60 zirconia framework specimens were fabricated and divided into groups of 10 specimens each. Two different handpieces, namely, a high-speed handpiece (HSH) and a low-speed handpiece (LSH), were used for grinding with and without water cooling. Fine- and coarse-grit diamond burrs were used with the HSH, separately. The following six groups were created: (a) HSH fine-grit with water cooling, (b) HSH coarse grit with water cooling, (c) HSH fine grit without water cooling, (d) HSH coarse grit without water cooling, (e) LSH with water cooling, and (f) LSH without water cooling. Each zirconia framework was ground until 1 mm3 of the material was removed. Temperature values corresponding to the grinding techniques were compared and statistically analyzed. One-way analysis of variance was used to compare the group parameters, while the Tukey honest significant difference test was used to detect significant differences between the groups. The significance level was set at P <.05. Results: The highest mean temperature was measured in the case of grinding with the LSH without water cooling (54.7 °C ± 11.6 °C), while the lowest mean temperature was observed in the case of grinding with the HSH using the coarse-grit diamond rotary instrument under water cooling (22.6 °C ± 0.6 °C). Conclusions: The grinding of zirconia must be performed with an HSH under water cooling. Further, when water cooling is used, neither the type of handpiece nor the grain type of the rotary instrument used as it has a significant effect on the temperature.

scholarly journals Bone damage induced by different cutting instruments: an in vitro study

2009 ◽  
Vol 20 (2) ◽  
pp. 162-168 ◽  
Author(s):  
Umberto Romeo ◽  
Alessandro Del Vecchio ◽  
Gaspare Palata ◽  
Gianluca Tenore ◽  
Paolo Visca ◽  
...  
Keyword(s):  
High Speed ◽  
Thermal Damage ◽  
Er:Yag Laser ◽  
In Vitro Study ◽  
Thin Sections ◽  
Bone Damage ◽  
Bone Biopsies ◽  
Bone Fragments ◽  
Tissue Specimens

The aim of this study was to compare the peripheral bone damage induced by different cutting systems. Four devices were tested: Er:YAG laser (2.94 mm), Piezosurgery, high-speed drill and low-speed drill. Forty-five bone sections, divided into 9 groups according to different parameters, were taken from pig mandibles within 1 h post mortem. Specimens were fixed in 10% buffered formalin, decalcified and cut in thin sections. Four different parameters were analyzed: cut precision, depth of incision, peripheral carbonization and presence of bone fragments. For statistical analysis, the Kruskal-Wallis test was applied to assess equality of sample medians among groups. All sections obtained with the Er:YAG laser showed poor peripheral carbonization. The edges of the incisions were always well-shaped and regular, no melting was observed. Piezosurgery specimens revealed superficial incisions without thermal damage but with irregular edges. The sections obtained by traditional drilling showed poor peripheral carbonization, especially if obtained at lower speed. There was statistically significant differences (p<0.01) among the cutting systems for all analyzed parameters. Er:YAG laser, gave poor peripheral carbonization, and may be considered an effective method in oral bone biopsies and permits to obtain clear and readable tissue specimens.

scholarly journals The Energy Balance in Aluminum–Copper High-Speed Collision Welding

2021 ◽  
Vol 5 (2) ◽  
pp. 62
Author(s):  
Peter Groche ◽  
Benedikt Niessen
Keyword(s):  
High Speed ◽  
Bond Formation ◽  
High Strength ◽  
Weld Interface ◽  
High Speed Imaging ◽  
Collision Zone ◽  
High Speed Collision ◽  
New Generation ◽  
Lower Limits

Collision welding is a joining technology that is based on the high-speed collision and the resulting plastic deformation of at least one joining partner. The ability to form a high-strength substance-to-substance bond between joining partners of dissimilar metals allows us to design a new generation of joints. However, the occurrence of process-specific phenomena during the high-speed collision, such as a so-called jet or wave formation in the interface, complicates the prediction of bond formation and the resulting bond properties. In this paper, the collision welding of aluminum and copper was investigated at the lower limits of the process. The experiments were performed on a model test rig and observed by high-speed imaging to determine the welding window, which was compared to the ones of similar material parings from former investigation. This allowed to deepen the understanding of the decisive mechanisms at the welding window boundaries. Furthermore, an optical and a scanning electron microscope with energy dispersive X-ray analysis were used to analyze the weld interface. The results showed the important and to date neglected role of the jet and/or the cloud of particles to extract energy from the collision zone, allowing bond formation without melting and intermetallic phases.

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