65 results match your criteria: "Gh. Asachi Technical University[Affiliation]"

: The aim of this study was to evaluate the influence of acidic beverages on the mechanical properties of various dental resin-based materials. : A total number of 160 samples were prepared using four types of resin-based materials-Group A ( = 40): flowable composite, Group B ( = 40): heavy-flow composite, Group C ( = 40): resin-based sealant and Group D ( = 40): nano-hybrid composite. Then, the samples were distributed into four subgroups according to the submersion solution: ( = 10): artificial saliva, ( = 10): coffee, ( = 10): cola and ( = 10): red wine.

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and Aims We conducted this research motivated by the incomplete knowledge of the changes made by resonance and harmonic filtering processes made by articulatory gestures in the supralar-yngeal level of the vocal tract. Aim of research The goal of the study is to evaluate the adaptive changes taking place at the oropharyngeal isthmus during sustained phonation. Methods We focused on exploring the dynamics of the oropharyngeal pavilion in voice professionals using Cone-Beam Computed Tomogra-phy (CBCT).

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Fibrillinopathies have different phenotypic expression: Marfan-like skeleton features, MLSF; mitral valve prolapse syndrome, MVPS; MASS phenotype, M = mitral valve prolapse, MVP, A = aortic root dilation, S = skeletal features, and the second S = (cutaneous) striae; Marfan Syndrome, MS. The study had the following main objectives: the correlation between disc displacement, DD (a major sign for temporomandibular joint dysfunction, TMDs) on magnetic resonance imaging, MRI, and aortic Z score (a major sign for aortic root dilation) on echocardiography; the predictive value of DD towards aortic Z score. DD had 2 types of severity: DD with reduction (the mild type, DDwR), and DD without reduction (the severe type, DDwoR).

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Point-of-gaze estimation is part of a larger set of tasks aimed at improving user experience, providing business insights, or facilitating interactions with different devices. There has been a growing interest in this task, particularly due to the need for upgrades in e-meeting platforms during the pandemic when on-site activities were no longer possible for educational institutions, corporations, and other organizations. Current research advancements are focusing on more complex methodologies for data collection and task implementation, creating a gap that we intend to address with our contributions.

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Introduction: Polymer nanogels are among the most promising nanoplatforms for use in biomedical applications. The substantial interest for these drug carriers is to enhance the transportation of bioactive substances, reduce the side effects, and achieve optimal action on the curative sites by targeting delivery and triggering the release of the drugs in a controlled and continuous mode.

Area Covered: The review discusses the opportunities, applications, and challenges of synthetic polypeptide nanogels in biomedicine, with an emphasis on the recent progress in cancer therapy.

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Photoluminescence of Argan-Waste-Derived Carbon Nanodots Embedded in Polymer Matrices.

Nanomaterials (Basel)

December 2023

Innovative Materials for Energy and Sustainable Development (IMED-Lab), Faculty of Science and Technology, Cadi Ayyad University, Av. Abdelkrim Khattabi, B.P. 511, Marrakech 40000, Morocco.

In this work, photoluminescent (PL) carbon nano dots (CNDs) prepared from argan waste were embedded in highly optical transparent poly(styrene-co-acrylonitrile) (PSA) and cyclo-olefin copolymer (COC) matrices, which were further processed into thin films. In the first step, the luminescent CNDs were prepared through thermal processing of fine-groundargan waste, followed, in the second step, by direct dispersion in the polymer solutions, obtained by solving PSA and COC in selected solvents. These two polymer matrices were selected due to their high optical transparency, resilience to various environmental factors, and ability to be processed as quality thin films.

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Induced Wettability Switch in Thin Films of Conductive Polymer Coatings Exhibiting Hydrophobic/Hydrophilic Interactions.

Sensors (Basel)

August 2023

Department of Communications, Faculty of Electronics, Telecommunications and Information Technologies, "Politehnica" University of Timisoara, V. Pârvan Blvd., No. 2, 300223 Timisoara, Romania.

The hydrophobic/hydrophilic character of some conductive polymer (CP) coatings can be switched in the function of the working conditions of these adaptive materials. We studied the influence of electrical stimuli and intrinsic physical characteristics (nature of the polymerizable core, dopants, the droplet dimension and physical properties, surface roughness, etc.) on the CP wettability.

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Biodegradable metallic materials are increasingly gaining ground in medical applications. Zn-based alloys show a degradation rate between those recorded for Mg-based materials with the fastest degradation rate and Fe-based materials with the slowest degradation rate. From the perspective of medical complications, it is essential to understand the size and nature of the degradation products developed from biodegradable materials, as well as the stage at which these residues are eliminated from the body.

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Strategy Based on Michael Addition Reaction for the Development of Bioinspired Multilayered and Multiphasic 3D Constructs.

Polymers (Basel)

March 2023

Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection "Cristofor Simionescu", "Gh. Asachi" Technical University of Iasi, 71A Bd. D. Mangeron, 700050 Iasi, Romania.

The high incidence of osteochondral defects has increased the interest in the development of improved repairing alternatives, with tissue engineering being considered a promising approach. The hierarchical, complex structure of osteochondral tissue requires the design of a biomimetic multilayered scaffold. Here, a multilayered and multiphasic 3D macroporous structure was achieved at subzero temperature by the Michael addition reaction of amino functionalities of collagen with acryloyl groups of a bifunctionalized poly(ε-caprolactone).

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Background: The aim of the study was to assess the protective effect of applying potassium iodide (KI) over silver diamine fluoride (SDF) on demineralized root dentin in the case of a sustained acidogenic attack.

Methods: Forty caries-free third molars were used in the study. A diamond disc was used to separate the roots and the tooth crowns from the roots.

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Photoluminescent Polymer Aerogels with R, G and B Emission.

Int J Mol Sci

December 2022

Faculty of Chemical Engineering and Environmental Protection, Gh. Asachi Technical University, D. Mangeron 73 Ave., 700050 Iasi, Romania.

In this work, three new polymer aerogels based on 2-hydroxy ethyl methacrylate (HEMA) complexes with Eu(III), Tb(III) and La(III) are prepared and investigated. The polymer aerogels present strong photoluminescence with emissions located in the red, green and blue regions of the visible spectrum. Depending on the water content used during the preparation path, the consistency of the photoluminescent aerogels varies from rigid, regularly shaped monoliths to a flexible, fibrous material with very low density.

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The study presents the achievement of a new assembly with antioxidant behaviour based on a copolymacrolactone structure that encapsulates erythritol (Eryt). Poly(ethylene brassylate-co-squaric acid) (PEBSA) was synthesised in environmentally friendly conditions, respectively, through a process in suspension in water by opening the cycle of ethylene brassylate macrolactone, followed by condensation with squaric acid. The compound synthesised in suspension was characterised by comparison with the polymer obtained by polymerisation in solution.

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The physicochemical properties of "smart" or stimuli-sensitive amphiphilic copolymers can be modeled as a function of their environment. In special, pH-sensitive copolymers have practical applications in the biomedical field as drug delivery systems. Interactions between the structural units of any polymer-drug system imply mutual constraints at various scale resolutions and the nonlinearity is accepted as one of the most fundamental properties.

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Drug-Loaded Polymeric Particulated Systems for Ophthalmic Drugs Release.

Molecules

July 2022

Faculty of Medical Bioengineering, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania.

Drug delivery to the anterior or posterior segments of the eye is a major challenge due to the protection barriers and removal mechanisms associated with the unique anatomical and physiological nature of the ocular system. The paper presents the preparation and characterization of drug-loaded polymeric particulated systems based on pre-emulsion coated with biodegradable polymers. Low molecular weight biopolymers (chitosan, sodium hyaluronate and heparin sodium) were selected due to their ability to attach polymer chains to the surface of the growing system.

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Fibrous membranes based on natural polymers obtained by the electrospinning technique are a great choice for wound dressings. In order to promote an efficient wound repair, and to avoid antibiotics, antibacterial plant extracts can be incorporated. In the present work, the new electrospun nanofibre membranes based on monobasic phosphate curdlan (PCurd) and polyvinyl alcohol (PVA) were obtained for the first time.

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The recent advancements in pulsed laser deposition (PLD) control via plasma diagnostics techniques have been positive and raised questions on the limitation of some techniques, such as the Langmuir probe (LP). The particularities of laser-produced plasma can lead to incorrect interpretation of collected electrical signal. In this paper, we explored the limitations of LP as a technique for in situ PLD control by performing investigations on several metallic plasmas, expanding in various Ar atmosphere conditions.

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Organic semiconductors are an attractive class of materials with large application in various fields, from optoelectronics to biomedicine. Usually, organic semiconductors have low electrical conductivity, and different routes towards improving said conductivity are being investigated. One such method is to increase their ordering degree, which not only improves electrical conduction but promotes cell growth, adhesion, and proliferation at the polymer-tissue interface.

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Special materials are required in many applications to fulfill specific medical or industrial necessities. Biodegradable metallic materials present many attractive properties, especially mechanical ones correlated with good biocompatibility with vivant bodies. A biodegradable iron-based material was realized through electric arc-melting and induction furnace homogenization.

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Collagen is a key component for devices envisaging biomedical applications; however, current increasing requirements impose the use of multicomponent materials. Here, a series of hybrid collagen-based 3D materials, comprising also poly(ε-caprolactone) (PCL) and different concentrations of hyaluronic acid (HA)-in dense, porous or macroporous form-were characterized in comparison with a commercially available collagen sponge, used as control. Properties, such as water uptake ability, water vapour sorption, drug loading and delivery, were investigated in correlation with the material structural characteristics (composition and morphology).

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Heat-resistant magnetic polymer composites were prepared by incorporating cerium-doped copper-nickel ferrite particles, having the general formula NiCuFeCeO (x: 0.0, 0.3, 0.

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Zinc biodegradable alloys attracted an increased interest in the last few years in the medical field among Mg and Fe-based materials. Knowing that the Mg element has a strengthening influence on Zn alloys, we analyze the effect of the third element, namely, Y with expected results in mechanical properties improvement. Ternary ZnMgY samples were obtained through induction melting in Argon atmosphere from high purity (Zn, Mg, and Y) materials and MgY (70/30 wt%) master alloys with different percentages of Y and keeping the same percentage of Mg (3 wt%).

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The article reviews the possibilities of encapsulating essential oils EOs, due to their multiple benefits, controlled release, and in order to protect them from environmental conditions. Thus, we present the natural polymers and the synthetic macromolecular chains that are commonly used as networks for embedding EOs, owing to their biodegradability and biocompatibility, interdependent encapsulation methods, and potential applicability of bioactive blend structures. The possibilities of using artificial intelligence to evaluate the bioactivity of EOs-in direct correlation with their chemical constitutions and structures, in order to avoid complex laboratory analyses, to save money and time, and to enhance the final consistency of the products-are also presented.

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A Theoretical Model for Release Dynamics of an Antifungal Agent Covalently Bonded to the Chitosan.

Molecules

April 2021

Department of Obstetrics and Gynecology, "Grigore T. Popa" University of Medicine and Pharmacy Iasi, 16 Universitatii Str., 700115 Iasi, Romania.

The aim of the study was to create a mathematical model useful for monitoring the release of bioactive aldehydes covalently bonded to the chitosan by reversible imine linkage, considered as a polymer-drug system. For this purpose, two hydrogels were prepared by the acid condensation reaction of chitosan with the antifungal 2-formyl-phenyl-boronic acid and their particularities; influencing the release of the antifungal aldehyde by shifting the imination equilibrium to the reagents was considered, i.e.

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Since epidemiological arguments favouring self-isolation during the COVID-19 pandemic are widely recommended, the consequences of social isolation/loneliness of older people considered to be at higher risk for severe illness are neglected. We identified and described medical, social, psychological, and religious issues, indirectly generated by the COVID-19 lockdown. Mortality induced by SARS-CoV-2 and death from other "neglected" issues were put in balance.

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Bio-oil produced from biomass pyrolysis has the potential to become an alternative renewable fuel. However due to the high content of oxygenated compounds is unsuitable as transportation fuel. The objective of this work is to evaluate the catalytic activity of CoMo /γ-AlO-HMS in the hydrotreating process of biomass pyrolysis bio-oil.

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