Tensile Behaviour and Temperature Stability of Modified HDPE by Radiation Cross-Linking after Temperature Load

2015 ◽  
Vol 752-753 ◽  
pp. 337-341
Author(s):  
Ales Mizera ◽  
Miroslav Manas ◽  
David Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Temperature Stability ◽  
Point Of View ◽  
Tensile Behaviour ◽  
Cross Linking ◽  
Radiation Processing ◽  
Temperature Load ◽  
Before And After ◽  
Commercial Method ◽  
3D Scans ◽  
New Applications

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers, especially temperature stability. The tensile behaviour of modified HDPE samples by radiation cross-linking were measured at the ambient and after temperature load. Sample 3D scans were made and investigated before and after temperature load. The tested samples showed significant changes of temperature stability. From this point of view, new applications could also be seen in areas with service temperatures higher than their former melting point.

Thermo-Mechanical Properties and Tensile Behaviour of Modified LDPE by Radiation Cross-Linking after Temperature Load

2015 ◽  
Vol 752-753 ◽  
pp. 373-377
Author(s):  
Ales Mizera ◽  
Miroslav Manas ◽  
David Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Point Of View ◽  
Tensile Behaviour ◽  
Cross Linking ◽  
Radiation Processing ◽  
Temperature Load ◽  
Before And After ◽  
Commercial Method ◽  
New Applications

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers, especially thermo-mechanical properties. The thermo-mechanical properties and the tensile behaviour of modified LDPE samples by radiation cross-linking were measured at the ambient temperature and after temperature load. The tested samples showed significant changes of tensile behaviour before and after temperature load. From this point of view, new applications could also be seen in areas with service temperatures higher than their former melting point.

Thermo-Mechanical Properties and Tensile Behaviour of Modified HDPE by Beta Rays after Temperature Load at 220 °C

2015 ◽  
Vol 1120-1121 ◽  
pp. 1183-1186
Author(s):  
Ales Mizera ◽  
Miroslav Manas ◽  
David Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Ambient Temperature ◽  
Point Of View ◽  
Tensile Behaviour ◽  
Cross Linking ◽  
Radiation Processing ◽  
Temperature Load ◽  
Commercial Method ◽  
New Applications

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers, especially thermo-mechanical properties. The tensile behaviour of modified HDPE samples by radiation cross-linking was measured at the ambient temperature and after temperature load at 220 °C. The tested samples showed significant changes of thermo-mechanical properties and tensile behaviour after 220 °C. From this point of view, new applications could also be seen in areas with service temperatures higher than their former melting point.

Physical Properties of Polyamide 11 after Radiation Cross-Linking by Accelerated Electrons

2017 ◽  
Vol 756 ◽  
pp. 19-26
Author(s):  
Ales Mizera ◽  
Pavel Stoklasek ◽  
Martin Bednarik
Keyword(s):  
Elevated Temperature ◽  
Physical Properties ◽  
Automotive Industry ◽  
Point Of View ◽  
Cross Linking ◽  
Radiation Processing ◽  
Polyamide 11 ◽  
Accelerated Electrons ◽  
Commercial Method ◽  
New Applications

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers, especially physical properties. The physical properties of modified polyamide 11 samples by beta rays were measured at the ambient and elevated temperature. The tested samples showed significant changes of physical properties between ambient (23°C) and elevated (80°C) temperature. From this point of view, new applications could also be seen in areas where more expensive materials are used, especially for application in automotive industry.

Temperature Stability of Modified PBT by Radiation Cross-Linking

2014 ◽  
Vol 1025-1026 ◽  
pp. 256-260 ◽  
Author(s):  
Ales Mizera ◽  
Miroslav Manas ◽  
David Manas ◽  
Zdenek Holik ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Temperature Stability ◽  
High Energy ◽  
Industrial Applications ◽  
Cross Linking ◽  
Radiation Processing ◽  
Polybutylene Terephthalate ◽  
High Energy Radiation ◽  
Commercial Method ◽  
New Applications

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers. The principle of radiation processing is the ability of high energy radiation to produce reactive cations, anions and free radicals in materials. The industrial applications of the radiation processing of plastics and composites include polymerization, cross-linking, degradation and grafting. Radiation processing mainly involves the use of either electron beams from electron accelerators or gamma radiation from Cobalt-60 sources. The PBT Polybutylene terephthalate tested showed significant changes of temperature stability and mechanical properties after irradiation. From this point view, new applications could also be seen in areas with service temperatures higher than their former melting point. The comparison of the temperature stability and mechanical properties of irradiated and non-irradiated PBT is presented in this paper.

Tensile Behaviour of Modified PBT by Radiation Cross-Linking

2014 ◽  
Vol 1025-1026 ◽  
pp. 261-264 ◽  
Author(s):  
Ales Mizera ◽  
Miroslav Manas ◽  
David Manas ◽  
Zdenek Holik ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Irradiation Dose ◽  
Electron Beams ◽  
Industrial Applications ◽  
Tensile Behaviour ◽  
Cross Linking ◽  
Radiation Processing ◽  
Polybutylene Terephthalate ◽  
Elongation At Break ◽  
Electron Accelerators ◽  
Commercial Method

Radiation processing of polymers is a well-established and economical commercial method of precisely modifying the properties of polymers. The industrial applications of the radiation processing of plastics and composites include polymerization, cross-linking, degradation and grafting. Radiation processing mainly involves the use of either electron beams from electron accelerators or gamma radiation from Cobalt-60 sources. The PBT Polybutylene terephthalate was used in this research and the tensile behaviour was investigated at the ambient temperature. Results demonstrate that PBT has higher values of tensile strength and E-modulus with the increased irradiation dose and it has decreased elongation at break. This behaviour leads to the expansion of these materials in the automotive and electrical industry.

Parathyroid gland before and after cisplatin treatment

1987 ◽  
Vol 45 ◽  
pp. 860-861
Author(s):  
S.K. Aggarwal ◽  
J.M. Fadool
Keyword(s):  
Parathyroid Gland ◽  
Wistar Rats ◽  
Antitumor Agent ◽  
The Body ◽  
Cross Linking ◽  
Limiting Factor ◽  
Hormonal Changes ◽  
Primary Mechanism ◽  
Before And After ◽  
Dna Strands

Cisplatin (CDDP) a potent antitumor agent suffers from severe toxic side effects with nephrotoxicity being the major dose-limiting factor, The primary mechanism of its action has been proposed to be through its cross-linking DNA strands. It has also been shown to inactivate various transport enzymes and induce hypocalcemia and hypomagnesemia that may be the underlying cause for some of its toxicities. The present is an effort to study its influence on the parathyroid gland for any hormonal changes that control calcium levels in the body.Male Swiss Wistar rats (Crl: (WI) BR) weighing 200-300 g and of 60 days in age were injected (ip) with cisplatin (7mg/kg in normal saline). The controls received saline injections only. The animals were injected (iv) with calcium (0.5 ml of 10% calcium gluconate/day) and were killed by decapitation on day 1 through 5. Trunk blood was collected in heparinized tubes.

Clinically Meaningful Change

Methodology ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 97-105
Author(s):  
Rodrigo Ferrer ◽  
Antonio Pardo
Keyword(s):  
Effect Size ◽  
False Negative ◽  
False Negative Rate ◽  
Point Of View ◽  
Skewed Distribution ◽  
Effect Sizes ◽  
False Negatives ◽  
Large Size ◽  
Before And After ◽  
Post Test

Abstract. In a recent paper, Ferrer and Pardo (2014) tested several distribution-based methods designed to assess when test scores obtained before and after an intervention reflect a statistically reliable change. However, we still do not know how these methods perform from the point of view of false negatives. For this purpose, we have simulated change scenarios (different effect sizes in a pre-post-test design) with distributions of different shapes and with different sample sizes. For each simulated scenario, we generated 1,000 samples. In each sample, we recorded the false-negative rate of the five distribution-based methods with the best performance from the point of view of the false positives. Our results have revealed unacceptable rates of false negatives even with effects of very large size, starting from 31.8% in an optimistic scenario (effect size of 2.0 and a normal distribution) to 99.9% in the worst scenario (effect size of 0.2 and a highly skewed distribution). Therefore, our results suggest that the widely used distribution-based methods must be applied with caution in a clinical context, because they need huge effect sizes to detect a true change. However, we made some considerations regarding the effect size and the cut-off points commonly used which allow us to be more precise in our estimates.

Diversity of Primary Structures of the Carboxy-terminal Regions of Mammalian Fibrinogen Aα-Chains

1993 ◽  
Vol 69 (04) ◽  
pp. 351-360 ◽  
Author(s):  
Masahiro Murakawa ◽  
Takashi Okamura ◽  
Takumi Kamura ◽  
Tsunefumi Shibuya ◽  
Mine Harada ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rhesus Monkey ◽  
Syrian Hamster ◽  
Tandem Repeats ◽  
Mammalian Species ◽  
Amino Acid Sequences ◽  
Point Of View ◽  
Cross Linking ◽  
Amino Terminal ◽  
Rgd Sequence

SummaryThe partial amino acid sequences of fibrinogen Aα-chains from five mammalian species have been inferred by means of the polymerase chain reaction (PCR). From the genomic DNA of the rhesus monkey, pig, dog, mouse and Syrian hamster, the DNA fragments coding for α-C domains in the Aα-chains were amplified and sequenced. In all species examined, four cysteine residues were always conserved at the homologous positions. The carboxy- and amino-terminal portions of the α-C domains showed a considerable homology among the species. However, the sizes of the middle portions, which corresponded to the internal repeat structures, showed an apparent variability because of several insertions and/or deletions. In the rhesus monkey, pig, mouse and Syrian hamster, 13 amino acid tandem repeats fundamentally similar to those in humans and the rat were identified. In the dog, however, tandem repeats were found to consist of 18 amino acids, suggesting an independent multiplication of the canine repeats. The sites of the α-chain cross-linking acceptor and α2-plasmin inhibitor cross-linking donor were not always evolutionally conserved. The arginyl-glycyl-aspartic acid (RGD) sequence was not found in the amplified region of either the rhesus monkey or the pig. In the canine α-C domain, two RGD sequences were identified at the homologous positions to both rat and human RGD S. In the Syrian hamster, a single RGD sequence was found at the same position to that of the rat. Triplication of the RGD sequences was seen in the murine fibrinogen α-C domain around the homologous site to the rat RGDS sequence. These findings are of some interest from the point of view of structure-function and evolutionary relationships in the mammalian fibrinogen Aα-chains.

Arthroscopy in Arthrosis: Is It Worth it? A case Presentation

2018 ◽  
Vol 69 (8) ◽  
pp. 2232-2235
Author(s):  
Marius Moga ◽  
Mark Edward Pogarasteanu ◽  
Antoine Edu
Keyword(s):  
Clinical Status ◽  
Loose Body ◽  
Point Of View ◽  
The Other ◽  
Joint Range Of Motion ◽  
Objective Evidence ◽  
Before And After ◽  
Total Knee ◽  
Joint Range

The role of arthroscopy in incipient and mild arthrosis, even combined with proximal tibial ostetomy, is well known and well documented. On the other hand, its role in the treatment of advanced arthrosis of the large joints, especially the knee, is a subject of controversy. The proponents of the use of arthroscopy in advanced arthrosis claim that meniscectomy, synovectomy, ostophytectomy, chondral lesion stabilization, arthroscopic release, plica and loose body removal greatly improve the quality of life for most patients, especially if followed by the use of viscoelastic injection, by diminishing pain and improving joint range of motion. The opponents claim that, even though the advantages are clear in the cases that refuse arthroplasty, in all the other cases the surgical indication should be total knee arthroplasty, as the clinical relief is temporary, but with all the risks of a surgical intervention. We have conducted an overview of the recent literature, in order to find objective evidence to sustain either point of view. We focused on articles published that included an objective measurement of before and after clinical status through clinical scores and objective measurements. We also focused on the follow-up period and on the evolution of the pathology after arthroscopy.

scholarly journals Systemic Lupus Erythematosus before and after COVID-19 Lockdown: How the Perception of Disease Changes through the Lenses of Narrative Medicine

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 726
Author(s):  
Fulvia Ceccarelli ◽  
Venusia Covelli ◽  
Giulio Olivieri ◽  
Francesco Natalucci ◽  
Fabrizio Conti
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Narrative Medicine ◽  
Good Control ◽  
Final Analysis ◽  
Point Of View ◽  
Systemic Lupus ◽  
Before And After ◽  
Text Content ◽  
Insight Into

Background: The COVID-19 pandemic contributes to the burden of living with different diseases, including Systemic Lupus Erythematosus (SLE). We described, from a narrative point of view, the experiences and perspectives of Italian SLE adults during the COVID-19 emergency, by distinguishing the illness experience before and after the lockdown. Methods: Fifteen patients were invited to participate. Illness narratives were collected between 22 and 29 March 2020 using a written modality to capture patients’ perspectives before and after the COVID-19 lockdown. We performed a two-fold analysis of collected data by distinguishing three narrative types and a qualitative analysis of content to identify the relevant themes and sub-themes reported. Results: Eight narratives included in the final analysis (mean length 436.9 words) have been written by eight females (mean age 43.3 ± 9.9 years, mean disease duration 13.1 ± 7.4 years). Six patients provided a quest narrative, one a chaos and the remaining one a restitution narrative. By text content analysis, we identified specific themes, temporally distinct before and after the lockdown. Before COVID-19, all the patients referred to a good control of disease, however the unexpected arrival of the COVID-19 emergency broke a balance, and patients perceived the loss of health status control, with anxiety and stress. Conclusions: We provided unique insight into the experiences of people with SLE at the time of COVID-19, underlining the perspective of patients in relation to the pandemic.

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