scholarly journals Robot-Assisted Distal Locking of Long Bone Intramedullary Nails: Localization, Registration, and In Vitro Experiments

2004 ◽  
pp. 58-65 ◽  
Author(s):  
Ziv Yaniv ◽  
Leo Joskowicz
Keyword(s):  
Long Bone ◽  
In Vitro Experiments ◽  
Robot Assisted ◽  
Intramedullary Nails ◽  
Distal Locking

A robot-assisted system for long bone intramedullary distal locking: concept and preliminary results

2003 ◽  
Vol 1256 ◽  
pp. 485-491 ◽  
Author(s):  
L Joskowicz ◽  
C Milgrom ◽  
M Shoham ◽  
Z Yaniv ◽  
A Simkin
Keyword(s):  
Long Bone ◽  
Robot Assisted ◽  
Preliminary Results ◽  
Distal Locking

scholarly journals C-Arm Image-Based Surgical Path Planning Method for Distal Locking of Intramedullary Nails

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Wei-En Hsu ◽  
Ching-Hsiao Yu ◽  
Chih-Ju Chang ◽  
Hung-Kang Wu ◽  
Tsong-Han Yu ◽  
...  
Keyword(s):  
Axial Direction ◽  
Experimental Results ◽  
Long Bone ◽  
Average Error ◽  
Intramedullary Nails ◽  
Marrow Cavity ◽  
Distal Locking ◽  
Long Bone Fracture ◽  
Bone Marrow Cavity ◽  
Test Sets

Due to the curvature of the bone marrow cavity, the intramedullary nail used in long bone fracture fixation can be deformed, causing displacement of the locking holes. In this study, an algorithm using only one C-arm image to determine the center positions and axial directions of locking holes was developed for drilling guidance. Based on conventional method that the axial direction of locking hole would be identified when locking hole contour is presented as a circle, the proposed method can locate the circle contour centroid by using one C-arm image including two elliptical contours. Then the two distal locking holes’ axial direction and centers would be determined. Three experiments were conducted to verify the performance of the proposed algorithm, which are (1) computer simulation, (2) use of real intramedullary nails, and (3) actual drilling test with the bone model. The experimental results showed that the average error of the axial direction and center position were 0.62 ± 0.6°, 0.73 ± 0.53 mm (simulation) and 3.16 ± 1.36°, 1.10 ± 0.50 mm (actual nail), respectively. The last ten drilling test sets were completed successfully (with an average duration of 48 seconds). Based on the experimental results, the proposed algorithm was feasible for clinic applications.

Neurofilaments and Paired Helical Filaments

1985 ◽  
Vol 43 ◽  
pp. 740-743
Author(s):  
J. Metuzals
Keyword(s):  
Animal Model ◽  
Posttranslational Modifications ◽  
Posttranslational Modification ◽  
Giant Axon ◽  
Paired Helical Filaments ◽  
Squid Giant Axon ◽  
In Vitro Experiments ◽  
Thin Sections ◽  
Structural Relationships

It has been demonstrated that the neurofibrillary tangles in biopsies of Alzheimer patients, composed of typical paired helical filaments (PHF), consist also of typical neurofilaments (NF) and 15nm wide filaments. Close structural relationships, and even continuity between NF and PHF, have been observed. In this paper, such relationships are investigated from the standpoint that the PHF are formed through posttranslational modifications of NF. To investigate the validity of the posttranslational modification hypothesis of PHF formation, we have identified in thin sections from frontal lobe biopsies of Alzheimer patients all existing conformations of NF and PHF and ordered these conformations in a hypothetical sequence. However, only experiments with animal model preparations will prove or disprove the validity of the interpretations of static structural observations made on patients. For this purpose, the results of in vitro experiments with the squid giant axon preparations are compared with those obtained from human patients. This approach is essential in discovering etiological factors of Alzheimer's disease and its early diagnosis.

Different Dosage Effects of Ozone on Oxygen Transport in Blood during in vitro Experiments

BIOPHYSICS ◽  
2020 ◽  
Vol 65 (5) ◽  
pp. 779-783
Author(s):  
V. V. Zinchuk ◽  
E. S. Biletskaya
Keyword(s):  
Oxygen Transport ◽  
In Vitro Experiments ◽  
Dosage Effects

scholarly journals Effects of Substituents on Photophysical and CO-Photoreleasing Properties of 2,6-Substituted meso-Carboxy BODIPY Derivatives

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 238-255
Author(s):  
Esther M. Sánchez-Carnerero ◽  
Marina Russo ◽  
Andreas Jakob ◽  
Lucie Muchová ◽  
Libor Vítek ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Absorption Spectra ◽  
Wavelength Range ◽  
Toxic Effects ◽  
Biological Research ◽  
In Vitro Experiments ◽  
Vast Array ◽  
Physiological Processes ◽  
Photochemical Properties

Carbon monoxide (CO) is an endogenously produced signaling molecule involved in the control of a vast array of physiological processes. One of the strategies to administer therapeutic amounts of CO is the precise spatial and temporal control over its release from photoactivatable CO-releasing molecules (photoCORMs). Here we present the synthesis and photophysical and photochemical properties of a small library of meso-carboxy BODIPY derivatives bearing different substituents at positions 2 and 6. We show that the nature of substituents has a major impact on both their photophysics and the efficiency of CO photorelease. CO was found to be efficiently released from π-extended 2,6-arylethynyl BODIPY derivatives possessing absorption spectra shifted to a more biologically desirable wavelength range. Selected photoCORMs were subjected to in vitro experiments that did not reveal any serious toxic effects, suggesting their potential for further biological research.

scholarly journals Native-like membrane models of E. coli polar lipid extract shed light on the importance of lipid composition complexity

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kristyna Pluhackova ◽  
Andreas Horner
Keyword(s):  
Polar Lipid ◽  
Lipid Extract ◽  
Coarse Grained ◽  
In Vitro Experiments ◽  
E Coli ◽  
Water Permeation ◽  
Aquaporin 1 ◽  
Lipid Component ◽  
Membrane Models

Abstract Background Lipid-protein interactions stabilize protein oligomers, shape their structure, and modulate their function. Whereas in vitro experiments already account for the functional importance of lipids by using natural lipid extracts, in silico methods lack behind by embedding proteins in single component lipid bilayers. However, to accurately complement in vitro experiments with molecular details at very high spatio-temporal resolution, molecular dynamics simulations have to be performed in natural(-like) lipid environments. Results To enable more accurate MD simulations, we have prepared four membrane models of E. coli polar lipid extract, a typical model organism, each at all-atom (CHARMM36) and coarse-grained (Martini3) representations. These models contain all main lipid headgroup types of the E. coli inner membrane, i.e., phosphatidylethanolamines, phosphatidylglycerols, and cardiolipins, symmetrically distributed between the membrane leaflets. The lipid tail (un)saturation and propanylation stereochemistry represent the bacterial lipid tail composition of E. coli grown at 37∘C until 3/4 of the log growth phase. The comparison of the Simple three lipid component models to the complex 14-lipid component model Avanti over a broad range of physiologically relevant temperatures revealed that the balance of lipid tail unsaturation and propanylation in different positions and inclusion of lipid tails of various length maintain realistic values for lipid mobility, membrane area compressibility, lipid ordering, lipid volume and area, and the bilayer thickness. The only Simple model that was able to satisfactory reproduce most of the structural properties of the complex Avanti model showed worse agreement of the activation energy of basal water permeation with the here performed measurements. The Martini3 models reflect extremely well both experimental and atomistic behavior of the E. coli polar lipid extract membranes. Aquaporin-1 embedded in our native(-like) membranes causes partial lipid ordering and membrane thinning in its vicinity. Moreover, aquaporin-1 attracts and temporarily binds negatively charged lipids, mainly cardiolipins, with a distinct cardiolipin binding site in the crevice at the contact site between two monomers, most probably stabilizing the tetrameric protein assembly. Conclusions The here prepared and validated membrane models of E. coli polar lipids extract revealed that lipid tail complexity, in terms of double bond and cyclopropane location and varying lipid tail length, is key to stabilize membrane properties over a broad temperature range. In addition, they build a solid basis for manifold future simulation studies on more realistic lipid membranes bridging the gap between simulations and experiments.

scholarly journals Development of a gel dedicated to gel immersion endoscopy

2021 ◽  
Vol 09 (06) ◽  
pp. E918-E924
Author(s):  
Tomonori Yano ◽  
Atsushi Ohata ◽  
Yuji Hiraki ◽  
Makoto Tanaka ◽  
Satoshi Shinozaki ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Porcine Model ◽  
Ex Vivo ◽  
In Vitro Experiments ◽  
Efficacy And Safety ◽  
Coagulative Necrosis ◽  
Novel Technique ◽  
In Vivo Experiments

Abstract Backgrounds and study aims Gel immersion endoscopy is a novel technique to secure the visual field during endoscopy. The aim of this study was to develop a dedicated gel for this technique. Methods To identify appropriate viscoelasticity and electrical conductivity, various gels were examined. Based on these results, the dedicated gel “OPF-203” was developed. Efficacy and safety of OPF-203 were evaluated in a porcine model. Results  In vitro experiments showed that a viscosity of 230 to 1900 mPa·s, loss tangent (tanδ) ≤ 0.6, and hardness of 240 to 540 N/cm2 were suitable. Ex vivo experiments showed electrical conductivity ≤ 220 μS/cm is appropriate. In vivo experiments using gastrointestinal bleeding showed that OPF-203 provided clear visualization compared to water. After electrocoagulation of gastric mucosa in OPF-203, severe coagulative necrosis was not observed in the muscularis but limited to the mucosa. Conclusions OPF-203 is useful for gel immersion endoscopy.

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