Bewertung der Stabilität von Frakturfixationssystemen: Mechanische Vorrichtung zur Untersuchung der 3-D-Steifigkeit in vitro - Assessment of the Stability of Fracture Fixation Systems: Mechanical Device to Investigate the 3-D Stiffness in vitro

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

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An in vitro assessment of the strength of porcelain veneers dependent on tooth preparation

Journal of Oral Rehabilitation ◽

10.1046/j.1365-2842.2000.00640.x ◽

2000 ◽

Vol 27 (12) ◽

pp. 1024-1029 ◽

Cited By ~ 20

Author(s):

P. Hahn ◽

M. Gustav ◽

E. Hellwig

Keyword(s):

In Vitro Assessment ◽

Tooth Preparation

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In vitro assessment of Labisia pumila and its constituents for interactions with CYPs, P-GP and PXR

Planta Medica ◽

10.1055/s-0034-1382759 ◽

2014 ◽

Vol 80 (10) ◽

Author(s):

VK Manda ◽

OR Dale ◽

C Awortwe ◽

Z Ali ◽

IA Khan ◽

...

Keyword(s):

In Vitro Assessment ◽

Labisia Pumila

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Kinetics of α-amylase and α-glucosidase inhibitory potential of Eucalyptus obliqua ethanolic leaf extract: An in vitro assessment

Planta Medica ◽

10.1055/s-0036-1596325 ◽

2016 ◽

Vol 81 (S 01) ◽

pp. S1-S381

Author(s):

S Sabiu ◽

AOT Ashafa

Keyword(s):

Leaf Extract ◽

In Vitro Assessment ◽

Inhibitory Potential ◽

Kinetics Of ◽

Ethanolic Leaf Extract

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Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

Nuklearmedizin ◽

10.1055/s-0037-1620623 ◽

1977 ◽

Vol 16 (04) ◽

pp. 157-162 ◽

Cited By ~ 1

Author(s):

C. Schümichen ◽

B. Mackenbrock ◽

G. Hoffmann

Keyword(s):

Normal Saline ◽

Half Life ◽

Compound A ◽

Short Half Life ◽

Low Concentrations ◽

The Stability ◽

Kinetics Of ◽

In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

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Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-19-00228 ◽

2020 ◽

Author(s):

Arda Ozdiler ◽

suleyman dayan ◽

Burc Gencel ◽

Gulbahar Isık-Ozkol

Keyword(s):

Dynamic Loading ◽

Antibacterial Agent ◽

In Vitro Study ◽

Control Group ◽

Silicone Sealant ◽

Reverse Torque ◽

The Stability ◽

Torque Values ◽

Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

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Using FRET to Measure the Time it Takes for a Cell to Destroy a Virus

10.26434/chemrxiv.10299164.v1 ◽

2019 ◽

Author(s):

Candace E. Benjamin ◽

Zhuo Chen ◽

Olivia Brohlin ◽

Hamilton Lee ◽

Stefanie Boyd ◽

...

Keyword(s):

Cellular Uptake ◽

Rhodamine B ◽

Virus Like Particle ◽

A Cell ◽

Viral Nanoparticles ◽

The Stability ◽

Open Question ◽

Viral Surface ◽

Fret Pair

<div><div><div><p>The emergence of viral nanotechnology over the preceding two decades has created a number of intellectually captivating possible translational applications; however, the in vitro fate of the viral nanoparticles in cells remains an open question. Herein, we investigate the stability and lifetime of virus-like particle (VLP) Qβ - a representative and popular VLP for several applications - following cellular uptake. By exploiting the available functional handles on the viral surface, we have orthogonally installed the known FRET pair, FITC and Rhodamine B, to gain insight of the particle’s behavior in vitro. Based on these data, we believe VLPs undergo aggregation in addition to the anticipated proteolysis within a few hours of cellular uptake.</p></div></div></div>

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Applicability of Instability Index for In vitro Protein Stability Prediction

Protein and Peptide Letters ◽

10.2174/0929866526666190228144219 ◽

2019 ◽

Vol 26 (5) ◽

pp. 339-347 ◽

Cited By ~ 4

Author(s):

Dilani G. Gamage ◽

Ajith Gunaratne ◽

Gopal R. Periyannan ◽

Timothy G. Russell

Keyword(s):

Protein Stability ◽

Caulobacter Crescentus ◽

Effect Of Temperature ◽

Instability Index ◽

Dipeptide Composition ◽

Experimental Conditions ◽

The Stability ◽

Vitro Protein

Background: The dipeptide composition-based Instability Index (II) is one of the protein primary structure-dependent methods available for in vivo protein stability predictions. As per this method, proteins with II value below 40 are stable proteins. Intracellular protein stability principles guided the original development of the II method. However, the use of the II method for in vitro protein stability predictions raises questions about the validity of applying the II method under experimental conditions that are different from the in vivo setting. Objective: The aim of this study is to experimentally test the validity of the use of II as an in vitro protein stability predictor. Methods: A representative protein CCM (CCM - Caulobacter crescentus metalloprotein) that rapidly degrades under in vitro conditions was used to probe the dipeptide sequence-dependent degradation properties of CCM by generating CCM mutants to represent stable and unstable II values. A comparative degradation analysis was carried out under in vitro conditions using wildtype CCM, CCM mutants and two other candidate proteins: metallo-β-lactamase L1 and α -S1- casein representing stable, borderline stable/unstable, and unstable proteins as per the II predictions. The effect of temperature and a protein stabilizing agent on CCM degradation was also tested. Results: Data support the dipeptide composition-dependent protein stability/instability in wt-CCM and mutants as predicted by the II method under in vitro conditions. However, the II failed to accurately represent the stability of other tested proteins. Data indicate the influence of protein environmental factors on the autoproteolysis of proteins. Conclusion: Broader application of the II method for the prediction of protein stability under in vitro conditions is questionable as the stability of the protein may be dependent not only on the intrinsic nature of the protein but also on the conditions of the protein milieu.

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