Mechanical characteristics and surface elemental composition of a Yasargil titanium aneurysm clip after long-term implantation

2010 ◽  
Vol 112 (6) ◽  
pp. 1260-1262 ◽  
Author(s):  
Yasunari Otawara ◽  
Kuniaki Ogasawara ◽  
Hiroshi Kashimura ◽  
Yoshitaka Kubo ◽  
Akira Ogawa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Mechanical Characteristics ◽  
Bending Test ◽  
Corrosion Resistant ◽  
Aneurysm Clip ◽  
Before And After ◽  
Long Time ◽  
And Control

The mechanical properties of titanium-alloy aneurysm clips after long-term implantation in the human cranium are unclear. The characteristics of a Yasargil titanium aneurysm clip were evaluated after long-term implantation for 12 years in a patient with a cerebral aneurysm. The closing forces of the retrieved clip before and after implantation were approximately equal. The bending test showed no differences between the retrieved and control clips. Titanium oxide and calcium were identified on the surface of the retrieved clip, which indicated the formation of corrosion-resistant layers. Titanium-alloy clips retain their mechanical properties in the human cranium for a long time.

scholarly journals EFFECT OF COMBINATION OF HYPNOBREASTFEEDING AND ACUPRESSURE ON ANXIETY AND WOUND PAIN IN POST-CAESAREAN MOTHERS

2017 ◽  
Vol 3 (5) ◽  
pp. 525-532
Author(s):  
Diah Evawanna Anuhgera ◽  
Tjahjono Kuncoro ◽  
Sri Sumarni ◽  
Mardiyono Mardiyono ◽  
Ari Suwondo
Keyword(s):  
Public Hospital ◽  
Alternative Therapy ◽  
Control Group ◽  
P Value ◽  
Control Group Design ◽  
Group Data ◽  
Before And After ◽  
Wound Pain ◽  
And Control

Background: Post-cesarean mothers often experience anxiety and discomfort due to long-term pain. The combination of hypnobreastfeeding and acupressure is considered to be effective in reducing anxiety and pain levels. Objective: This study aims to examine the effect of combination of hypnobreastfeeding and acupressure on anxiety and pain levels in post-caesarean mothers.Methods: This study was a true experiment with pretest-posttest control group design, conducted in the Ambarawa Public Hospital on 5 November to 9 December 2016. There were 36 participants selected using stratified random sampling, with 18 assigned in the experiment and control group. Data were analyzed using paired t-test and wilcoxon test.Results: There were statistically significant differences of anxiety and pain levels before and after intervention in the experiment and control group with p-value 0.001 (<0.05).Conclusion: The combination of hypnobreastfeeding and acupressure has a significant effect in reducing anxiety and pain levels in post-cesarean mothers. This intervention could be applied as an alternative therapy in treating post-caesarean mothers.

scholarly journals Developing Capabilities From the Scope of Emotional Intelligence as Part of the Soft Skills Needed in the Long-Term Care Sector: Presentation of Pilot Study and Training Methodology

2020 ◽  
Vol 11 ◽  
pp. 215013272090627
Author(s):  
Yasen Dimitrov ◽  
Tanja Vazova
Keyword(s):  
Emotional Intelligence ◽  
Conflict Management ◽  
Long Term Care ◽  
Soft Skills ◽  
Training Design ◽  
Soft Skill ◽  
Term Care ◽  
Before And After ◽  
And Control

The article presents the results of the preliminary survey and pilot application of the methodological toolkit for the improvement of certain competencies, which are part of the soft skills of professionals in the long-term care sector in Bulgaria. Based on the survey the authors define 2 target competencies, namely conflict management and empathic interaction. These skills are considered a part of the scope of emotional intelligence and its constituent dimensions and authors use Daniel Goleman’s ability-based model as a base for their conceptual frame and theoretical explanations. In order to present their thesis, the authors perform a soft skill analysis of the long-term care sector; define the construct emotional intelligence and justify their choice of a theoretical model for the subsequent survey. On this basis, they develop a training design for the development of these skills and present the results achieved through its pilot application. The study includes 62 participants randomly divided into a test and control groups. The level of targeted skills is measured (before and after) and the authors report a significant increase in those skills (empathic interaction, net effect 1.87; conflict management, net effect 1.75). In conclusion, the authors open a discussion on the importance of emotional management as an essential part of any profession related to health care and underline its importance for the quality of caregiving services.

scholarly journals Does long-term storage of clay samples influence their mechanical characteristics?

2020 ◽  
Vol 57 (2) ◽  
pp. 304-309 ◽  
Author(s):  
Mustapha Abdellaziz ◽  
Mahmoud N. Hussien ◽  
Mohamed Chekired ◽  
Mourad Karray
Keyword(s):  
Mechanical Characteristics ◽  
Long Term Storage ◽  
Temperature And Humidity ◽  
Before And After ◽  
Prime Objective ◽  
Term Storage ◽  
Physical And Mechanical Characteristics

The prime objective of this study is to assess the influence of long-term storage on the physical and mechanical characteristics of clay samples. Samples from two different clays were sealed and stored in a temperature- and humidity-controlled room at the geotechnical laboratory of the Université de Sherbrooke for up to 27 years. The stored clay samples were tested before and after long-term storage and the results compared in this note. The comparison showed that even with long-term storage, the majority of the physical and mechanical characteristics of the samples were preserved.

scholarly journals Early Life Maternal Separation and Maternal Behaviour Modulate Acoustic Characteristics of Rat Pup Ultrasonic Vocalizations

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jasmine H. Kaidbey ◽  
Manon Ranger ◽  
Michael M. Myers ◽  
Muhammad Anwar ◽  
Robert J. Ludwig ◽  
...  
Keyword(s):  
Maternal Separation ◽  
Low Frequency ◽  
Ultrasonic Vocalizations ◽  
Maternal Behaviour ◽  
Long Term Effects ◽  
Acoustic Characteristics ◽  
Rat Pups ◽  
Before And After ◽  
And Control

AbstractEarly separation of preterm infants from their mothers has adverse, long-term neurodevelopmental consequences. We investigated the effects of daily maternal separation (MS) of rat pups from postnatal days 2–10 (PND2–10) on neurobehavioural responses to brief isolation at PND12 compared with pups receiving controlled handling without MS. Ultrasonic vocalizations (USV) were measured at PND12 during two, 3-minute isolations occurring immediately before and after a 3-minute maternal reunion. There were no significant differences in acoustic characteristics between MS and control animals in the first isolation. However, in the second isolation, MS pups produced a greater proportion of high (~60 kHz) vs low (~40 kHz) frequency calls. During this isolation, control pups made longer and louder low frequency calls compared to the first isolation, whereas MS pups did the opposite. Maternal behaviour of control and MS mothers modulated pup acoustic characteristics in opposite directions; higher maternal care was associated with more low frequency calls in control pups but more high frequency calls in MS pups. We hypothesize that MS results in USV emission patterns reflective of a greater stress response to isolation. This translational model can be used to identify mechanisms and interventions that may be exploited to overcome the negative, long-term effects of MS.

Effect of Long-Term Ageing at 600 °C on Microstructure of ZG1Cr10MoWVNbN Martensitic Heat-Resistant Steel

2018 ◽  
Vol 37 (6) ◽  
pp. 539-544
Author(s):  
Chengzhi Zhao ◽  
Ning Li ◽  
Yihan Zhao ◽  
Hexin Zhang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
M23c6 Carbide ◽  
Resistant Steel ◽  
Steam Turbines ◽  
Heat Resistant Steel ◽  
Property Variation ◽  
Heat Resistant ◽  
Before And After

AbstractA new kind of martensitic ZG1Cr10MoWVNbN heat-resistant steel has been attracted more attentions in recent years, which is mainly applied in ultra-supercritical steam turbines. The ageing property for ZG1Cr10MoWVNbN heat-resistant steel is very important because it often serves for long-time at high-temperature environment. Herein, a long-term ageing heat treatment was conducted on ZG1Cr10MoWVNbN steel at 600 °C heat for 17,000 hours. The microstructure evolution and property variation of the ZG1Cr10MoWVNbN steel were analysed before and after ageing, and also the effect of the precipitates on the mechanical properties was studied. The result showed that strength, the plastic index and impact power of the ZG1Cr10MoWVNbN steel were gradually decreased after long-term and high-temperature ageing at 600 °C due to the changes of martensite morphology and the coarsening of M23C6 carbide precipitation phase. Furthermore, fine precipitation of matrix MX carbide can also attribute to the change of mechanical properties at high temperature.

Study on Mechanical Properties Aging of Spray Pure Polyurea for Hydraulic Concrete Protection

2011 ◽  
Vol 374-377 ◽  
pp. 1325-1329 ◽  
Author(s):  
Wei Bo Huang ◽  
Jia Yu Xiang ◽  
Ping Lv ◽  
Xin Mao Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Development Trend ◽  
Elongation At Break ◽  
Tear Strength ◽  
Hydraulic Concrete ◽  
Before And After ◽  
Ultraviolet Ray ◽  
Resistance Performance

Researches of spray pure polyurea technology for hydraulic concrete protection in water conservancy facilities to ensure long term security operation has a great significance. With an emphasis upon mechanical properties and surface morphology of spray pure polyurea coatings comparing before and after aging by means of the artificial accelerated xenon arc lamp(AAXAL) and scanning electron microscope(SEM) in this paper. Besides, the dry-wet circulation resistance performance of coatings wre analyzed through experiment. It is shown that tensile strength, elongation at break and tear strength of coatings increased by 0.2%, 0.5% and 1.7% respectively after AAXAL aging 720h. By contrast, after aging 3000h the results were 22.6%, 3.8% and 17.4% respectively, the tendency of increasing at first and then reducing can be obtained. The mechanical properties reduced slightly for adding defects of coating surface after aging, however, the resistance performance of ultraviolet ray was excellent. The similar development trend of mechanical properties were gained from dry-wet circulation experiment. After aging 200 cycles, the tensile strength and tear strength descended by 4.1% and 1.7% severally but the elongation at break ascended by 5.0%. In a word, it is suggested that the aging of coatings were negligible in dry-wet circulation in short term.

The Effects of Retesting on the Mechanical Properties of Brain Tissue

2013 ◽  
Author(s):  
A. Rezaei ◽  
M. Salimi Jazi ◽  
G. Karami ◽  
M. Ziejewski
Keyword(s):  
Mechanical Properties ◽  
Brain Tissue ◽  
Relaxation Times ◽  
Human Brain Tissue ◽  
Relaxation Functions ◽  
Before And After ◽  
Short And Long Term ◽  
Tissue Characteristics ◽  
Testing Protocols

Traumatic brain injury (TBI) is one of the most important problems in biomechanical engineering, and there have been many experiments conducted in order to characterize the mechanical properties of brain tissue. However, obtaining fresh human brain tissue is difficult, if not impossible. Also, the sample preparation and testing protocols must be carried out with great delicacy because brain tissue is very soft and vulnerable to being deformed under a very small amount of load. Most importantly, according to several researchers, each sample must be tested only one time as the tissue may be damaged and its characteristics subsequently changed. This paper is intended to examine the amount of decay that can happen in material characteristics due to retesting. A stress relaxation test is conducted on the same samples of the swine brain tissue multiple times in small and large deformations. The mechanical properties of the substance are calculated before and after retesting, and the constants of the tissue, as mechanical characteristics, are determined and compared. Short- and long-term moduli, relaxation times and relaxation functions are calculated and compared to understand how much they decay after repeating the experiments. The results show that retesting does not significantly change the elastic part of the tissue characteristics, but the viscous behavior shows a relatively sizeable change. The ability to account for the material decay of the samples due to repetition of the experiments results in the need for fewer samples and less preparation time and effort.

scholarly journals An Update on Nickel-Titanium Rotary Instruments in Endodontics: Mechanical Characteristics, Testing and Future Perspective—An Overview

2021 ◽  
Vol 8 (12) ◽  
pp. 218
Author(s):  
Alessio Zanza ◽  
Maurilio D’Angelo ◽  
Rodolfo Reda ◽  
Gianluca Gambarini ◽  
Luca Testarelli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Mechanical Characteristics ◽  
State Of The Art ◽  
Cyclic Fatigue ◽  
Nickel Titanium ◽  
Future Perspective ◽  
Current State ◽  
Rotary Instruments ◽  
Torsional Loads

Since the introduction of Nickel-Titanium alloy as the material of choice for the manufacturing of endodontic rotary instruments, the success rate of the root canal therapies has been significantly increased. This success mainly arises from the properties of the Nickel-Titanium alloy: the biocompatibility, the superelasticity and the shape memory effect. Those characteristics have led to a reduction in time of endodontic treatments, a simplification of instrumentation procedures and an increase of predictability and effectiveness of endodontic treatments. Nevertheless, the intracanal separation of Nickel-Titanium rotary instruments is still a major concern of endodontists, with a consequent possible reduction in the outcome rate. As thoroughly demonstrated, the two main causes of intracanal separation of endodontic instruments are the cyclic fatigue and the torsional loads. As results, in order to reduce the percentage of intracanal separation research and manufacturers have been focused on the parameters that directly or indirectly influence mechanical properties of endodontic rotary instruments. This review describes the current state of the art regarding the Nickel-Titanium alloy in endodontics, the mechanical behavior of endodontic rotary instruments and the relative stresses acting on them during intracanal instrumentation, highlighting the limitation of the current literature.

A Study on Mechanical Behavior of Dental Hard Tissues and Dental Restorative Materials by Three-Point Bending Test

2014 ◽  
Author(s):  
K. J. Chun ◽  
C. Y. Kim ◽  
J. Y. Lee
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Gold Alloy ◽  
Bending Test ◽  
Dental Resin ◽  
Three Point Bending ◽  
Bending Force ◽  
Dental Restorative Materials ◽  
Restorative Materials ◽  
Dental Restorative

Dental restorative materials including amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy are used to reconstruct damaged teeth, as well as to recover their function. In this study, the mechanical properties of various dental restorative materials were determined using test specimens of identical shape and dimension under the same three-point bending test condition, and the test results were compared to enamel and dentin. The maximum bending force of enamel and dentin was 6.9 ± 2.1 N and 39.7 ± 8.3 N, and the maximum bending deflection was 0.12 ± 0.02 mm and 0.25 ± 0.03 mm, respectively. The maximum bending force of amalgam, dental ceramic, gold alloy, dental resin, zirconia, and titanium alloy were 1.9 ± 0.4 N, 2.7 ± 0.6 N, 66.9 ± 4.1 N, 2.7 ± 0.3 N, 19.0 ± 2.0 N, and 121.3 ± 6.8 N, respectively, and the maximum bending deflection was 0.20 ± 0.08 mm, 0.28 ± 0.07 mm, 2.53 ± 0.12 mm, 0.37 ± 0.05 mm, 0.39 ± 0.05 m, and 2.80 ± 0.08 mm, respectively. The dental restorative materials that possessed greater maximum bending force than that of enamel were gold alloy, zirconia, and titanium alloy. Gold alloy and titanium alloy had greater maximum bending force than dentin. The dental restorative materials that possessed greater maximum bending deflection than that of enamel were all of the dental restorative materials, and the dental restorative materials that possessed greater maximum bending deflection than that of dentin were all of the dental restorative materials except amalgam. The appropriate dental restorative materials for enamel are gold alloy and zirconia and for dentin is gold alloy concerning the maximum bending force and the maximum bending deflection. These results are expected to aid dentists in their choice of better clinical treatment and to contribute to the development of dental restorative materials that possess properties that are most similar to the mechanical properties of dental hard tissue.

Mechanical Properties of X80 Grade UOE Pipe for Long-Term Exposure at Elevated Temperature

2004 ◽  
Author(s):  
Ryuji Muraoka ◽  
Mitsuhiro Okatsu ◽  
Nobuyuki Ishikawa ◽  
Shigeru Endo ◽  
Shinichi Kakihara ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Mechanical Tests ◽  
Heat Treatments ◽  
Oil Sand ◽  
Operation Condition ◽  
Long Time ◽  
Simulated Condition ◽  
Installation Cost

Recently, X80 grade UOE pipes have been planned to apply to steam injecting oil sand recovery systems to increase the volume of steam to be injected and lowering installation cost. The pipes for systems are subjected to high temperature for a long time, such as 350-C, for 20 years. Before real applications of the pipes, it is important to ensure the reliability of the pipes during and after long-term operations. In this study, in order to establish simulation conditions for 350-C × 20 years of operation, the change in microstructure and resulting mechanical properties of X80 grade pipes after a long-term exposure at elevated temperatures were investigated. Then, mechanical properties of the pipes subjected to the established simulated condition were examined. Change in the microstructure was quite small after exposure of 400-C and lower temperatures. Tensile strengths of the base metal and seam weld after up to 400-C of heat treatment can be arranged with the Larson-Miller parameter composed with temperature and holding time of the heat treatments. Therefore, heat treatments at 400-C for shorter than 20 years can be simulation conditions for the operation condition of the systems. As a result of mechanical tests simulating long-term exposure, satisfied performance of X80 grade pipes can be obtained.

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