scholarly journals Determination of sodium hypochlorite concentrations in the activation of the irrigant by passive technique with ultrasonic, during the ex vivo endodontic protocol.

2020 ◽  
Vol 13 (3) ◽  
pp. 132-134
Author(s):  
Carmen María Pirela ◽  
Silvana Maggiolo ◽  
Ismael Yévenes
Keyword(s):  
Sodium Hypochlorite ◽  
Ex Vivo ◽  
Passive Technique

scholarly journals Insight into Glutamatergic Involvement in Rewarding Effects of Mephedrone in Rats: In Vivo and Ex Vivo Study

2021 ◽  
Author(s):  
Olga Wronikowska ◽  
Maria Zykubek ◽  
Agnieszka Michalak ◽  
Anna Pankowska ◽  
Paulina Kozioł ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Interdisciplinary Approach ◽  
Nmda Antagonist ◽  
Exchange Chromatography ◽  
Resonance Spectroscopy ◽  
Monoamine Transporters ◽  
Ex Vivo Study ◽  
Insight Into

AbstractMephedrone is a widely used drug of abuse, exerting its effects by interacting with monoamine transporters. Although this mechanism has been widely studied heretofore, little is known about the involvement of glutamatergic transmission in mephedrone effects. In this study, we comprehensively evaluated glutamatergic involvement in rewarding effects of mephedrone using an interdisciplinary approach including (1) behavioural study on effects of memantine (non-selective NMDA antagonist) on expression of mephedrone-induced conditioned place preference (CPP) in rats; (2) evaluation of glutamate concentrations in the hippocampus of rats following 6 days of mephedrone administration, using in vivo magnetic resonance spectroscopy (MRS); and (3) determination of glutamate levels in the hippocampus of rats treated with mephedrone and subjected to MRS, using ion-exchange chromatography. In the presented research, we confirmed priorly reported mephedrone-induced rewarding effects in the CPP paradigm and showed that memantine (5 mg/kg) was able to reverse the expression of this effect. MRS study showed that subchronic mephedrone administration increased glutamate level in the hippocampus when measured in vivo 24 h (5 mg/kg, 10 mg/kg and 20 mg/kg) and 2 weeks (5 mg/kg and 20 mg/kg) after last injection. Ex vivo chromatographic analysis did not show significant changes in hippocampal glutamate concentrations; however, it showed similar results as obtained in the MRS study proving its validity. Taken together, the presented study provides new insight into glutamatergic involvement in rewarding properties of mephedrone.

scholarly journals Comparison of the Resistance to Bending Forces of the 4.5 LCP Plate-rod Construct and of 4.5 LCP Alone Applied to Segmental Femoral Defects in Miniature Pigs

2010 ◽  
Vol 79 (4) ◽  
pp. 613-620 ◽  
Author(s):  
Lucie Urbanová ◽  
Robert Srnec ◽  
Pavel Proks ◽  
Ladislav Stehlík ◽  
Zdeněk Florian ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Femoral Diaphysis ◽  
Miniature Pig ◽  
Femoral Bone ◽  
Bone Implant ◽  
Miniature Pigs ◽  
Bone Defect Healing ◽  
Considerable Strain

The study deals with the determination of mechanical properties, namely resistance to bending forces, of flexible buttress osteosynthesis using two different bone-implant constructs stabilizing experimental segmental femoral bone defects (segmental ostectomy) in a miniature pig ex vivo model using 4.5 mm titanium LCP and a 3 mm intramedullary pin (“plate and rod” construct) (PR-LCP), versus the 4.5 mm titanium LCP alone (A-LCP). The “plate and rod” fixation (PR-LCP) of the segmental femoral defect is significantly more resistant (p < 0.05) to bending forces (200 N, 300 N, and 500 N) than LCP alone (A-LCP). Stabilisation of experimental segmental lesions of the femoral diaphysis in miniature pigs by flexible bridging osteosynthesis 4.5 mm LCP in combination with the “plate and rod” construct appears to be a suitable fixation of non-reducible fractures where considerable strain of the implants by bending forces can be assumed. These findings will be used in upcoming in vivo experiments in the miniature pig to investigate bone defect healing after transplantation of mesenchymal stem cells in combination with biocompatible scaffolds.

scholarly journals Root Canal Penetration of a Sodium Hypochlorite Mixture Using Sonic or Ultrasonic Activation

2014 ◽  
Vol 25 (6) ◽  
pp. 489-493 ◽  
Author(s):  
Marta Sáinz-Pardo ◽  
Roberto Estevez ◽  
Óliver Valencia de Pablo ◽  
Giampiero Rossi-Fedele ◽  
Rafael Cisneros
Keyword(s):  
Sodium Hypochlorite ◽  
Root Canal ◽  
Ex Vivo ◽  
Positive Pressure ◽  
Ultrasonic Activation ◽  
Penetration Length ◽  
Working Length ◽  
Closed Systems ◽  
Canal Shaping ◽  
Ex Vivo Study

The purpose of this ex vivo study was to determine, in "open" and "closed" systems, whether the design has an influence on the penetration length of sodium hypochlorite mixed with a radiopaque contrast medium, measured in millimeters, when delivered using positive pressure (PP) and using sonic (SI) or passive ultrasonic (PUI) activation. Sixty single-rooted teeth were divided into two groups: open and closed systems (n=30). Root canal shaping was performed to a working length of 17 mm. The samples were divided into three sub-groups (n=10) according to irrigant delivery and activation: PP, and SI or PUI activation. By using radiographs, penetration length was measured, and vapor lock was assessed. For the closed group, the penetration distance means were: PP 15.715 (±0.898) mm, SI 16.299 (±0.738) mm and PUI 16.813 (±0.465) mm, with vapor lock occurring in 53.3% of the specimens. In the open group, penetration to 17 mm occurred in 97.6% of the samples, and no vapor lock occurred. Irrigant penetration and distribution evaluation using open and closed systems provide significantly different results. For closed systems, PUI is the most effective in delivering the irrigant to working length, followed by SI.

scholarly journals Structure Determination of Microtubules and Pili: Past, Present, and Future Directions

2022 ◽  
Vol 8 ◽  
Author(s):  
James A. Garnett ◽  
Joseph Atherton
Keyword(s):  
Ex Vivo ◽  
Structural Heterogeneity ◽  
Resonance Spectroscopy ◽  
Future Directions ◽  
Computational Approaches ◽  
The Past ◽  
Major Shift ◽  
Technical Innovations

Historically proteins that form highly polymeric and filamentous assemblies have been notoriously difficult to study using high resolution structural techniques. This has been due to several factors that include structural heterogeneity, their large molecular mass, and available yields. However, over the past decade we are now seeing a major shift towards atomic resolution insight and the study of more complex heterogenous samples and in situ/ex vivo examination of multi-subunit complexes. Although supported by developments in solid state nuclear magnetic resonance spectroscopy (ssNMR) and computational approaches, this has primarily been due to advances in cryogenic electron microscopy (cryo-EM). The study of eukaryotic microtubules and bacterial pili are good examples, and in this review, we will give an overview of the technical innovations that have enabled this transition and highlight the advancements that have been made for these two systems. Looking to the future we will also describe systems that remain difficult to study and where further technical breakthroughs are required.

scholarly journals Potentiometric Determination of Chlorate Impurities in Hypochlorite Solutions

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Dmitry V. Girenko ◽  
Al’ona A. Gyrenko ◽  
Nikolai V. Nikolenko
Keyword(s):  
Sodium Hypochlorite ◽  
Sodium Sulfite ◽  
Systematic Errors ◽  
Expanded Uncertainty ◽  
Iodide Ions ◽  
Low Concentrations ◽  
Sophisticated Equipment ◽  
The Matrix ◽  
Fold Excess

The method of iodometric determination of chlorates impurities in sodium hypochlorite solutions for medical and veterinary purposes was developed. This method does not require sophisticated equipment and can be implemented directly where the solutions are used. The method is based on the different rates of interaction of ClO- and ClO3- with iodide ions depending on the acidity of the medium. We have shown that blank titration is advisable to improve the accuracy of the determination of low concentrations of chlorates in the matrix of hypochlorite which is present in excess since in this case possible systematic errors due to the presence of oxidizing impurities in the reagents are prevented. To quantify the low concentrations of chlorates, we proposed to remove 85-95% of hypochlorite ions by means of reducing their excess with sodium sulfite at pH 10.5. The solution of sodium sulfite does not require standardization before each analysis in the proposed procedure. The possibility of quantitative determination of chlorate impurities in the range of 2-50 mg/L in the presence of 50-500–fold excess of sodium hypochlorite with an error of 5% has been proved. The expanded uncertainty of chlorate determination did not exceed 0.6 mg/L.

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