Comparison of the dose perturbation arising from conventional and the novel PEEK prosthesis materials during high energy radiotherapy with 15 MV photons

2021 ◽  
pp. 1-7
Author(s):  
Najmeh Mohammadi
Keyword(s):  
High Energy ◽  
Polymer Materials ◽  
Hip Prostheses ◽  
Metal Implants ◽  
Depth Dose ◽  
Before And After ◽  
New Material ◽  
Biomedical Polymer ◽  
Dose Perturbation ◽  
The Impact

Abstract Aim: This study aimed to evaluate the dosimetric effects of the metal prosthesis in radiotherapy by Siemens Primus 15 MV linac accelerator. In addition, it proposed the new material could lead to less dose perturbation. Materials and methods: The depth dose distributions of typical hip prostheses were calculated for 15 MV photons by MCNP-4C code. Five metal prostheses were selected to reveal the correlation between material type, density and dose perturbations of prostheses. Furthermore, the effects of the location and thickness of the prosthesis on the dose perturbation were also discussed and analysed. Results: The results showed that the Co-Cr-Mo alloy as the prosthesis had more influence on the dose at the interface of metal tissue. The dose increased at the entrance of this prosthesis and experienced the reduction when passed through it. Finally, the impact of the new PEEK biomedical polymer materials was also investigated, and the lowest dose perturbations were introduced based on the obtained results. Conclusion: It was found that the mean relative dose before and after of PEEK prosthesis was 99·2 and 97·1%, respectively. Therefore, this new biomedical polymer material was proposed to replace the current metal implants.

scholarly journals Course of Metal Ions after a Revision of Malfunctioning Metal-on-Metal Total Hip Prostheses

Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 115
Author(s):  
Annamaria Nicolli ◽  
Isabella Bortoletti ◽  
Stefano Maso ◽  
Andrea Trevisan
Keyword(s):  
Metal Ions ◽  
Hip Prosthesis ◽  
Biological Fluids ◽  
Hip Revision ◽  
Hip Prostheses ◽  
Total Hip ◽  
Metal Implants ◽  
Metal On Metal ◽  
Before And After ◽  
Prosthesis Revision

The present research evaluated the course of cobalt and chromium in the blood and urine after the revision of metal-on-metal with a ceramic-on-polyethylene total hip arthroplasty. Seven patients were enrolled for hip prosthesis revision owing to ascertained damage of the implant. Metals in the blood and urine were evaluated before and after the hip revision. The double measurement before the total hip revision revealed high levels of metal ions (on average, 88.1 µg/L of cobalt in the blood, 399.0 µg/g of creatinine cobalt in the urine, 46.8 µg/L of chromium in the blood, and 129.6 µg/g of creatinine chromium in the urine at the first measurements), with an increasing trend between the first and second dosage. Within a week after the hip revision, the levels of metal ions significantly decreased by approximately half. Four to six months after the operation, the cobalt levels were found near to the reference values, whereas the chromium levels reached 25% of the values measured before the revision. The revision of malfunctioning metal-on-metal implants produced a dramatic decrease of metal ions in biological fluids, although it did not completely rescue the chromium level.

Impact of Coronavirus Disease-2019 on Orthopedic and Trauma Cases at Sina Hospital, Tehran, Iran: An Experience from High Trauma Center

2020 ◽  
Author(s):  
Seyyed Hossein Shafiei ◽  
Mohammad Hossein Abootalebi ◽  
Yusof Fallah ◽  
Babak Siavash ◽  
Mohammadreza Golbakhsh
Keyword(s):  
Traffic Accidents ◽  
Road Traffic ◽  
Demographic Data ◽  
High Energy ◽  
Limb Injuries ◽  
The World ◽  
Before And After ◽  
Total Data ◽  
Mechanism Of Trauma ◽  
The Impact

Background: The recent outbreak of the coronavirus disease-2019 (COVID-19) in China has rapidly spread throughout the world and significantly affected orthopedic and trauma cases all over the world. This study aims to evaluate the impact of the COVID-19 pandemic on orthopedic and trauma cases at Sina Hospital, Tehran, Iran. Methods: The study was conducted using the database of Orthopedics Department at Sina Hospital. It consisted of data before four and after four months of the COVID-19 outbreak. The demographic data of the patients with orthopedic problems and trauma, including sex, age, and type and mechanism of trauma was studied. Results: In total, data of 1033 patients was studied, including 597 and 436 patients before and after the COVID-19 outbreak, respectively. In this period of time, the potion of patients with laceration and upper limb injuries increased significantly (P = 0.007 and P = 0.002, respectively). Additionally, the proportion of low energy trauma and high energy trauma respectively increased and decreased (P = 0.055). Conclusion: Because of the outbreak and consequent lockdown in many countries, cases of orthopedics and trauma very significantly reduced. This resulted in less workload on orthopedic surgeons and residents during the COVID-19 pandemic. Decreases in trauma cases and road traffic accidents were also reported by most centers around world.

scholarly journals Physical Characterization of Breast Implants Submitted to High Energy X-Rays

TECCIENCIA ◽  
2019 ◽  
Vol 14 (26) ◽  
pp. 65-71
Author(s):  
Sandra Johana Patiño Leiva ◽  
María Cristina Plazas ◽  
Lisette Barreto
Keyword(s):  
Breast Implants ◽  
High Energy ◽  
Mechanical Tests ◽  
Prosthetic Material ◽  
X Rays ◽  
X Ray ◽  
Before And After ◽  
The Impact ◽  
Radiotherapy Treatment

Based on clinical experience and various studies, it has been found that breast prostheses present failures that are related to a radiotherapy treatment. However, there are currently few studies that analyze the impact of radiotherapy on the material of the prosthesis. Accordingly, the aim of this paper is to characterize the material of silicone breast implants with high cohesiveness. In order to carry out the research a characterization based on mechanical tests, rheology, and spectrophotometry and scanning electron microscopy. This was done with the objective of identifying changes in the prosthesis before and after being irradiated with high energy x-ray photons. To perform the study, 4 breast implants were used. These implants were subjected to the aforementioned tests. The researcher repeated the observation in the second and the third month. Finally, when comparing the results, the mechanical changes are shown in the coating. In the internal material small changes were generated in the elastic and viscous modules. To conclude, effective changes were observed after radiotherapy treatment in the prosthetic material.

scholarly journals High-energy chemistry of formamide: A unified mechanism of nucleobase formation

2014 ◽  
Vol 112 (3) ◽  
pp. 657-662 ◽  
Author(s):  
Martin Ferus ◽  
David Nesvorný ◽  
Jiří Šponer ◽  
Petr Kubelík ◽  
Regina Michalčíková ◽  
...  
Keyword(s):  
Dielectric Breakdown ◽  
Theoretical Calculations ◽  
Mechanistic Model ◽  
Building Blocks ◽  
Life Forms ◽  
High Energy ◽  
Before And After ◽  
Terrestrial Life ◽  
Order Of Magnitude ◽  
The Impact

The coincidence of the Late Heavy Bombardment (LHB) period and the emergence of terrestrial life about 4 billion years ago suggest that extraterrestrial impacts could contribute to the synthesis of the building blocks of the first life-giving molecules. We simulated the high-energy synthesis of nucleobases from formamide during the impact of an extraterrestrial body. A high-power laser has been used to induce the dielectric breakdown of the plasma produced by the impact. The results demonstrate that the initial dissociation of the formamide molecule could produce a large amount of highly reactive CN and NH radicals, which could further react with formamide to produce adenine, guanine, cytosine, and uracil. Based on GC-MS, high-resolution FTIR spectroscopic results, as well as theoretical calculations, we present a comprehensive mechanistic model, which accounts for all steps taking place in the studied impact chemistry. Our findings thus demonstrate that extraterrestrial impacts, which were one order of magnitude more abundant during the LHB period than before and after, could not only destroy the existing ancient life forms, but could also contribute to the creation of biogenic molecules.

The Added Value of Infrared Thermography to Assess the Impact Performance of Composites

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Simone Boccardi ◽  
Natalino D. Boffa ◽  
Giovanni M. Carlomagno ◽  
Carosena Meola ◽  
Fabrizio Ricci ◽  
...  
Keyword(s):  
Composite Materials ◽  
Nondestructive Evaluation ◽  
Infrared Thermography ◽  
Added Value ◽  
Manufacturing Defects ◽  
Impact Performance ◽  
Before And After ◽  
New Material ◽  
Lock In ◽  
The Impact

Composite materials are becoming ever more popular in an increasing number of applications. This because of their many advantages, amongst others the possibility to create a new material of given characteristics in a quite simple way by changing either the type of matrix, or reinforcement, and/or rearranging the reinforcement in a different way. Of course, once a new material is created, it is necessary to characterize it to verify its suitability for a specific exploitation. In this context, infrared thermography (IRT) represents a viable means since it is noncontact, nonintrusive, and can be used either for nondestructive evaluation to detect manufacturing defects, or fatigue-induced degradation, or else for monitoring the inline response to applied loads. In this work, IRT is used to investigate different types of composite materials, which involve carbon fibers embedded in a thermoset matrix and either glass or jute fibers embedded in a thermoplastic matrix, which may be neat, or modified by the addition of a percentage of a specific compatibilizing agent. IRT is used with a twofold function. First, for nondestructive evaluation, with the lock-in technique, before and after loading to either assure absence of manufacturing defects, or discover the damage caused by the loads. Second, for visualization of thermal effects, which develop when the material is subjected to impact. The obtained results show that it is possible to follow inline what happens to the material (bending, delamination, and eventual failure) under impact and get information, which may be valuable to deepen the complex impact damaging mechanisms of composites.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

ANALISIS PENGARUH PEMBANGUNAN JALAN LAYANG JANTI TERHADAP PERKEMBANGAN TATA RUANG KAWASAN JANTI STUDI KASUS : KAWASAN JANTI, DESA CATURTUNGGAL, KABUPATEN SLEMAN, D. I. YOGYAKARTA

2017 ◽  
Vol 11 (3) ◽  
pp. 255
Author(s):  
Jeky El Boru
Keyword(s):  
Road Network ◽  
Open Space ◽  
Qualitative Description ◽  
Analysis Method ◽  
Open Spaces ◽  
The Road ◽  
Before And After ◽  
Linkage Method ◽  
The Impact ◽  
Parking Place

Abstract: This research aims to analyze the impact of Janti Flyover Construction toward the growth of layout at Janti Urban Area, including structured space, open space, and linkage. Method used for data collecting are observation, air photograph monitoring, and interview, whereas the analysis method is qualitative description, which is the superimposed method of two layers, that are the layout condition before and after flyover construction. The result shows that the impact of Janti Flyover construction can be seen on building mass (solid), the increasing number of open spaces, including the road network, parking place, and park, whereas the relation between spaces, visually and structurally, can be seen on the growth of buildings which have new shapes and styles, therefore the performance of the overall building does not have a proportional shape. Considering Janti Street at the collective relation, its role is getting stronger as the main frame road network.Keywords: Flyover construction, layout changing, Janti AreaAbstrak: Penelitian ini bertujuan untuk menganalisis pengaruh pembangunan Jalan Layang Janti terhadap perkembangan tata ruang Kawasan Janti, meliputi ruang terbangun, ruang terbuka, serta hubungan antar ruang (“linkage”). Metode pengumpulan data dilakukan melalui observasi, pengamatan foto udara, dan wawancara; sedangkan metode analisis melalui deskripsi secara kualitatif yang berupa “superimposed method” dari dua lapisan kondisi lahan, yakni kondisi tata ruang sebelum dan sesudah pembangunan jalan layang. Hasil penelitian menunjukkan bahwa pengaruh pembangunan Jalan Layang Janti terdapat pada massa bangunan (“solid”), pertambahan ruang terbuka yang berupa jaringan jalan, parkir, dan taman; sedangkan pada hubungan antar ruang ̶ secara visual dan struktural ̶ yakni tumbuhnya bangunan dengan bentuk dan gaya baru, sehingga bentuk tampilan bangunan secara keseluruhan tidak proporsional. Pada hubungan kolektif, Jalan Janti semakin kuat perannya sebagai kerangka utama jaringan jalan.Kata kunci : Pembangunan jalan layang, tata ruang, Kawasan Janti

Impact of merger on efficiency and productivity : a case study of commercial banks in Malaysia

1970 ◽  
Vol 5 (1) ◽  
pp. 77
Author(s):  
Mahadzir Ismail ◽  
Saliza Sulaiman ◽  
Hasni Abdul Rahim ◽  
Nordiana Nordin
Keyword(s):  
Efficiency Score ◽  
Malmquist Productivity Index ◽  
Productivity Index ◽  
Data Envelopment ◽  
Master Plan ◽  
Before And After ◽  
Domestic Banks ◽  
The Impact ◽  
Efficiency And Productivity

The Financial Master Plan (2001- 2010) aims to enhance the capacity of banking industry so that higher effic iency and productivity can be reaped in the future. This study seeks to determine the impact of merger on the efficiency and productivity ofcommercial banks in Malaysia for the period 1995 until 2005. The study uses a non-parametric approach, nam ely DEA (data envelopment analysis?) to estimate the efficiency scores and to construct the Malmquist productivity index. To enable this estimation, three bank inputs and outputs are used. Amongst the findings are those banks exhibit higher efficiency score after the merger and thefo reign banks are more efficient than the local banks. Productivity of the banks is calculated in both periods, before and after the merger: The results show that, it is the local banks that have improved the most after the merger. The main source of productivity is technical change or innovation. The findings support the existing policy of having larger domestic banks in term of size.

THE EFFECT OF METACOGNITIVE INSTRUCTION ON MAXIMIZING EFL LEARNERS’ METACOGNITIVE AWARENESS IN LISTENING

2018 ◽  
Vol 7 (1) ◽  
pp. 8-17
Author(s):  
Mahsa Assadi
Keyword(s):  
Experimental Research ◽  
Listening Comprehension ◽  
Intervention Program ◽  
Metacognitive Awareness ◽  
Listening Test ◽  
Efl Learners ◽  
Metacognitive Instruction ◽  
Before And After ◽  
Comprehension Ability ◽  
The Impact

This study reports a pre-experimental research on the impact of metacognitive instruction on EFL learners’ metacognitive awareness and their listening performance. To obtain the goal of the study, a group of 30 Iranian intermediate EFL learners, including 14 males and 16 females, were selected randomly. Their ages range from 20 to 24. The participants took part in 16 weeks’ intervention program based on metacognitive pedagogical sequence consisted of five stages. The metacognitive awareness listening questionnaire (MALQ), and a listening test were also used to find changes in metacognitive awareness and listening performance before and after the treatment. The results of comparing pre and posttests scores revealed that metacognitive instruction raised the learners’ metacognitive awareness and helped them improve their listening comprehension ability.

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