scholarly journals Polyurethane Treated in Ar/C2H2/Ar Plasma: Towards Deformable Coating with Improved Albumin Adsorption

2021 ◽  
Vol 11 (21) ◽  
pp. 9793
Author(s):  
Ilya A. Morozov ◽  
Alexander S. Kamenetskikh ◽  
Anton Y. Beliaev ◽  
Roman I. Izumov ◽  
Marina G. Scherban ◽  
...  
Keyword(s):  
Treatment Time ◽  
Complex Structure ◽  
Argon Plasma ◽  
Post Treatment ◽  
Plasma Modification ◽  
Uniaxial Tensile ◽  
Duration Of Treatment ◽  
Two Phase ◽  
Mechanical Loads ◽  
Albumin Adsorption

Plasma modification of soft polymeric surfaces has many prospects in creating biomedical devices. The deformability of the obtained coatings should be studied, as the usage of such materials implies mechanical loads. Polyurethane (a two-phase synthetic polymer) treated in argon/acetylene plasma, with post-treatment in argon plasma, was investigated. A carbon-containing nanocoating (discontinuous mesh-like structures) with structural–mechanical inhomogeneities is formed by the action of Ar/C2H2 plasma. The heterogeneities of the coating are due to the complex structure of the initial substrate and short duration of treatment; as the treatment time increases, the coatings become homogeneous, but their stiffness rises. The treated surfaces in the uniaxial tensile state have micro and/or nanocracks in certain cases of plasma treatment. This is associated with an increased elastic modulus of the coatings. The coatings without cracks have regions with sufficiently alternating stiffness. Post-treatment in argon plasma increases wettability and free surface energy, positively affecting the adsorption of albumin. The stiffness of such coatings increases, becoming more homogeneous, which slightly reduces their crack resistance. Thus, plasma coatings on soft polymers operating under mechanical loads without causing damage should have sufficiently low stiffness, and/or structural-mechanical heterogeneities that provide redistribution of stress.

scholarly journals Effect of Low-Pressure Plasma Treatment Parameters on Wrinkle Features

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3852
Author(s):  
Bongjun Gu ◽  
Dongwook Ko ◽  
Sungjin Jo ◽  
Dong Choon Hyun ◽  
Hyeon-Ju Oh ◽  
...  
Keyword(s):  
Power Flow ◽  
Treatment Time ◽  
Argon Plasma ◽  
Negative Ions ◽  
Low Pressure ◽  
Nitrogen Plasma ◽  
Pressure Plasma ◽  
Positive Ions ◽  
Low Pressure Plasma ◽  
Optical Adhesive

Wrinkles attract significant attention due to their ability to enhance the mechanical and optical characteristics of various optoelectronic devices. We report the effect of the plasma gas type, power, flow rate, and treatment time on the wrinkle features. When an optical adhesive was treated using a low-pressure plasma of oxygen, argon, and nitrogen, the oxygen and argon plasma generated wrinkles with the lowest and highest wavelengths, respectively. The increase in the power of the nitrogen and oxygen plasma increased the wavelengths and heights of the wrinkles; however, the increase in the power of the argon plasma increased the wavelengths and decreased the heights of the wrinkles. Argon molecules are heavier and smaller than nitrogen and oxygen molecules that have similar weights and sizes; moreover, the argon plasma comprises positive ions while the oxygen and nitrogen plasma comprise negative ions. This resulted in differences in the wrinkle features. It was concluded that a combination of different plasma gases could achieve exclusive control over either the wavelength or the height and allow a thorough analysis of the correlation between the wrinkle features and the characteristics of the electronic devices.

scholarly journals Biomechanical-Structural Correlation of Chordae tendineae in Animal Models: A Pilot Study

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1678
Author(s):  
Justyn Gach ◽  
Izabela Janus ◽  
Agnieszka Mackiewicz ◽  
Tomasz Klekiel ◽  
Agnieszka Noszczyk-Nowak
Keyword(s):  
Mitral Valve ◽  
Complex Structure ◽  
Future Research ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Histopathological Analysis ◽  
Papillary Muscles ◽  
Chordae Tendineae ◽  
Structural Correlation ◽  
Ring Valve

The mitral valve apparatus is a complex structure consisting of the mitral ring, valve leaflets, papillary muscles and chordae tendineae (CT). The latter are mainly responsible for the mechanical functions of the valve. Our study included investigations of the biomechanical and structural properties of CT collected from canine and porcine hearts, as there are no studies about these properties of canine CT. We performed a static uniaxial tensile test on CT samples and a histopathological analysis in order to examine their microstructure. The results were analyzed to clarify whether the changes in mechanical persistence of chordae tendineae are combined with the alterations in their structure. This study offers clinical insight for future research, allowing for an understanding of the process of chordae tendineae rupture that happens during degenerative mitral valve disease—the most common heart disease in dogs.

scholarly journals Antibacterial Properties of Plasma-Activated Perfluorinated Substrates with Silver Nanoclusters Deposition

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 182
Author(s):  
Petr Slepička ◽  
Silvie Rimpelová ◽  
Nikola Slepičková Kasálková ◽  
Dominik Fajstavr ◽  
Petr Sajdl ◽  
...  
Keyword(s):  
Surface Properties ◽  
Antibacterial Properties ◽  
Argon Plasma ◽  
Antimicrobial Effect ◽  
Silver Nanoclusters ◽  
Plasma Modification ◽  
Material Surface ◽  
Silver Deposition ◽  
Force Microscopy ◽  
Atomic Force

This article is focused on the evaluation of surface properties of polytetrafluoroethylene (PTFE) nanotextile and a tetrafluoroethylene-perfluoro(alkoxy vinyl ether) (PFA) film and their surface activation with argon plasma treatment followed with silver nanoclusters deposition. Samples were subjected to plasma modification for a different time exposure, silver deposition for different time periods, or their combination. As an alternative approach, the foils were coated with poly-L-lactic acid (PLLA) and silver. The following methods were used to study the surface properties of the polymers: goniometry, atomic force microscopy, and X-ray photoelectron microscopy. By combining the aforementioned methods for material surface modification, substrates with antibacterial properties eliminating the growth of Gram-positive and Gram-negative bacteria were prepared. Studies of antimicrobial activity showed that PTFE plasma-modified samples coated with PLLA and deposited with a thin layer of Ag had a strong antimicrobial effect, which was also observed for the PFA material against the bacterial strain of S. aureus. Significant antibacterial effect against S. aureus, Proteus sp. and E. coli has been demonstrated on PTFE nanotextile plasma-treated for 240 s, coated with PLLA, and subsequently sputtered with thin Ag layer.

Surface Properties of UHMWPE Fiber after Low Temperature Argon-Plasma Treatment

2012 ◽  
Vol 499 ◽  
pp. 90-94 ◽  
Author(s):  
Jin Yun Xu ◽  
Wen Yu Wang ◽  
Xin Jin
Keyword(s):  
Molecular Weight ◽  
Low Temperature ◽  
Plasma Treatment ◽  
Treatment Time ◽  
Argon Plasma ◽  
Uhmwpe Fiber ◽  
Wetting Ability ◽  
Plasma Treatment Time ◽  
Uhmwpe Fibers ◽  
Ultra High Molecular Weight

To improve the adhesion between ultra-high-molecular-weight polyethylene (UHMWPE) fibers and matrix, the UHMWPE fibers were treated by low temperature argon-plasma. The effects of argon-plasma treatment on the properties of UHMWPE have been investigated. The roughness and wetting ability were all found to increase significantly after modifications. The tensile strength of UHMWE fibers were decreased with the plasma treatment time. The optimum plasma treatment is 2min.The increasing of roughness and wetting ability of UHMWPE fiber are beneficial to the improvement the adhesion between UHMWPE fiber and matrix.

scholarly journals Nanohydroxyapatite Application to Osteoporosis Management

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Zairin Noor
Keyword(s):  
Complex Structure ◽  
Bone Matrix ◽  
Bone Cell ◽  
Osteoporotic Bone ◽  
Chemical Formula ◽  
Duration Of Treatment ◽  
Sodium Calcium ◽  
Hydrogen Carbonate ◽  
Close Distance ◽  
Hydroxyapatite Crystals

Hydroxyapatite is chemically related to the inorganic component of bone matrix as a complex structure with the formula of Ca10(OH)2(PO4)6. Previous studies have reported the application of microsized hydroxyapatite to bone regeneration, but the result is not satisfied. The limitation comes from the size of hydroxyapatite. In addition, the duration of treatment is very long. The advantages of hydroxyapatite nanocrystal are the osteoconduction, bioresorption, and contact in close distance. Crystal in osteoporotic bone is calcium phosphate hydroxide with the chemical formula of Ca10(OH)2(PO4)6. Crystal of normal bone issodium calcium hydrogen carbonate phosphate hydratewith the chemical formula of Ca8H2(PO4)6·H2O–NaHCO3–H2O. The recent development is applying nanobiology approach to hydroxyapatite. This is based on the concept that the mineral atoms arranged in a crystal structure of hydroxyapatite can be substituted or incorporated by the other mineral atoms. In conclusion, the basic elements of hydroxyapatite crystals, composed of atomic minerals in a certain geometric pattern, and their relationship to the bone cell biological activity have opened opportunities for hydroxyapatite crystals supplement application on osteoporosis. Understanding of the characteristics of bone hydroxyapatite crystals as well as the behavior of mineral atom in the substitution will have a better impact on the management of osteoporosis.

scholarly journals Plasma Treatment Limits Human Melanoma Spheroid Growth and Metastasis Independent of the Ambient Gas Composition

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2570 ◽  
Author(s):  
Sybille Hasse ◽  
Tita Meder ◽  
Eric Freund ◽  
Thomas von Woedtke ◽  
Sander Bekeschus
Keyword(s):  
Plasma Treatment ◽  
Treatment Time ◽  
Argon Plasma ◽  
Ambient Air ◽  
Human Melanoma ◽  
Melanoma Metastasis ◽  
Spheroid Growth ◽  
Tumor Entity ◽  
Melanoma Treatment ◽  
Jet Plasma

Melanoma skin cancer is still a deadly disease despite recent advances in therapy. Previous studies have suggested medical plasma technology as a promising modality for melanoma treatment. However, the efficacy of plasmas operated under different ambient air conditions and the comparison of direct and indirect plasma treatments are mostly unexplored for this tumor entity. Moreover, exactly how plasma treatment affects melanoma metastasis has still not been explained. Using 3D tumor spheroid models and high-content imaging technology, we addressed these questions by utilizing one metastatic and one non-metastatic human melanoma cell line targeted with an argon plasma jet. Plasma treatment was toxic in both cell lines. Modulating the oxygen and nitrogen ambient air composition (100/0, 75/25, 50/50, 25/75, and 0/100) gave similar toxicity and reduced the spheroid growth for all conditions. This was the case for both direct and indirect treatments, with the former showing a treatment time-dependent response while the latter resulted in cytotoxicity with the longest treatment time investigated. Live-cell imaging of in-gel cultured spheroids indicated that plasma treatment did not enhance metastasis, and flow cytometry showed a significant modulation of S100A4 but not in any of the five other metastasis-related markers (β-catenin, E-cadherin, LEF1, SLUG, and ZEB1) investigated.

scholarly journals Estimation of Effective Thermal Conductivity of Two-Phase Material for Hollow Circular Model

2018 ◽  
Vol 172 ◽  
pp. 02004
Author(s):  
Prateek Kumar Sahu ◽  
Nisha Netam ◽  
Lal Chandra Shah
Keyword(s):  
Thermal Conductivity ◽  
Circular Cylinder ◽  
Effective Thermal Conductivity ◽  
Complex Structure ◽  
Fundamental Property ◽  
Percentage Error ◽  
Phase System ◽  
Two Phase ◽  
Hollow Circular Cylinder ◽  
Circular Model

Two-phase materials are commonly used in engineering application because of its various properties like strength, thermal conductivity, durability and toughness etc. Effective thermal conductivity (ETC) of two-phase material is the fundamental property to predict its thermal performance. Various geometry (spheres, cylinders, irregular particles) have been considered by researchers for calculating ETC of two-phase materials. Due to complex structure, hollow circular cylinder geometry is not reported yet. In this paper, two-dimensional periodic two-phase system, with hollow circular cylinder shape is considered for calculating ETC. In present work unit cell approach method is used to derive collocated parameters model for estimation of ETC. Hollow circular cylinder model with Ψ = 0.2 gives good result for estimating ETC with average percentage error of 6.46%.

scholarly journals Barriers and facilitators to recommended physical activity in lower-limb osteoarthritis: protocol for a qualitative study exploring patients and physiotherapist perspectives using the theoretical domains framework and behaviour change taxonomy

BMJ Open ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. e029199
Author(s):  
Matthew James Willett ◽  
Carolyn Greig ◽  
David Rogers ◽  
Sally Fenton ◽  
Joan Duda ◽  
...  
Keyword(s):  
Behaviour Change ◽  
Lower Limb ◽  
Treatment Time ◽  
Change Theory ◽  
Theoretical Domains Framework ◽  
Post Treatment ◽  
Barriers And Facilitators ◽  
Structured Interviews ◽  
Behaviour Change Theory ◽  
Physiotherapy Intervention

IntroductionOsteoarthritis (OA) is the leading cause of disability and pain in older adults. Although increasing physical activity (PA) can help reduce symptoms, patients with lower-limb OA are less active than the general public. Although physiotherapists commonly deliver PA programmes, they lack knowledge of key barriers and facilitators to adherence to prescribed PA that patients with lower-limb OA experience while attending physiotherapy appointments (treatment period) and after discharge (post-treatment period). This study aims to explore the perspectives of patients with lower-limb OA of barriers and facilitators to adherence to physiotherapy prescribed PA in the treatment and post-treatment time periods to inform the development of intervention underpinned by behaviour change theory.Methods and analysisA qualitative study, based on phenomenology, will purposively recruit patients with lower-limb OA who have had physiotherapy. In-depth semi-structured interviews will be undertaken following discharge from physiotherapy at a single time point. Participants’ perspectives of physiotherapy interventions, including barriers and facilitators to prescribed PA and techniques that they felt optimised adherence to physiotherapist PA prescription will be explored (phase I). The acceptability and feasibility of delivering a physiotherapy intervention incorporating the techniques identified in the semi-structured interviews will then be explored through focus groups conducted with physiotherapists (phase II). Data will be coded following thematic analysis, with barriers and facilitators mapped to the constructs on the theoretical domains framework, and behaviour change techniques identified following definitions from Michie’s V1 taxonomy.Ethics and disseminationFindings from this study will inform development of a physiotherapy intervention underpinned by behaviour change theory aiming to optimise adherence to PA prescription in patients with lower-limb OA during the treatment and post-treatment time periods. This study has ethical approval (IRAS 247904) and results will be disseminated through publications in peer-reviewed journals and presentations at conferences and to study participants.

Avaliação da Prevalência de Erros de Prescrições Recebidas em Uma Instituição de Utilidade Pública do Vale do Aço – MG

2017 ◽  
Vol 21 (2) ◽  
pp. 70
Author(s):  
Jackeline De Souza Alecrim ◽  
Josiane Marcia de Castro ◽  
Francisco Antônio Fernandes Reinaldo ◽  
Dayane Cristine Andrade Lacerda ◽  
Jéssica Fernandes dos Reis ◽  
...  
Keyword(s):  
Treatment Time ◽  
Cross Sectional Study ◽  
Minas Gerais ◽  
Public Utility ◽  
Measurement Unit ◽  
Sectional Study ◽  
Adherence To Treatment ◽  
Duration Of Treatment ◽  
Cross Sectional ◽  
Drug Errors

Avaliar a prevalência de erros de prescrição de medicamentos em uma instituição de utilidade pública do Vale do Aço/Minas Gerais. Trata-se de um estudo descritivo, transversal, por meio de uma abordagem qualiquantitativa. As informações foram coletadas por meio de uma amostra de 150 prescrições de uma instituição de utilidade pública da região, na qual foram contabilizados os erros, a partir de uma análise quanto a: legibilidade, rasuras, emendas, abreviaturas, nome do medicamento, concentração, unidade de medida, forma farmacêutica, intervalo de administração, dosagem, quantidade, via de administração, tempo de tratamento e orientações sobre administração, no período de março a setembro de 2015. Detectou-se o predomínio de alguns erros, tais como: ilegibilidade, presença de rasuras, presença apenas do nome fantasia, ausência do tempo de tratamento, ausência de concentração e ausência de unidade de medida. Diante desses problemas reforça-se a importância do seguimento de prescrições padronizadas, a fim de aumentar a adesão ao tratamento e, assim, reduzir ocorrências relacionadas aos erros destas, fato que pode ser aprimorado pelo diálogo interdisciplinar.Palavras-chave: Erros de Medicação. Ilegibilidade. Interdisciplinariedade.AbstractTo evaluate the prevalence of prescription drug errors in a public utility institution Valley Steel / Minas Gerais. This was a descriptive cross-sectional study, by means of a quali-quantitative approach. Since the information was collected through a sample of 150 prescriptions of a public utility institution in the region in which the errors were recorded, from an analysis as to: Readability, erasures, amendments, abbreviations, drug name, concentration measured unit dosage form, dosing interval, dosage, quantity, route of administration, duration of treatment and administration of guidelines. We detected the predominance of some errors, such as illegibility, presence of erasures, only the presence of fancy name, absence of treatment time, lack of concentration and lack of measurement unit. In view of these problems reinforces the importance of following standard requirements in order to increase adherence to treatment and thus reduce incidents related to these errors, which can be enhanced by interdisciplinary dialogue.Keywords: Medication Errors. Illegibility. Interdisplinariedade.

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