scholarly journals Histological and histochemical assessment of short-term events in peri-implant bone for osteoinductivity evaluation of functional-protective implant coatings

2021 ◽  
Vol 26 (3) ◽  
pp. 4-10
Author(s):  
O.Ye. Loskutov ◽  
I.S. Shponka ◽  
O.O. Bondarenko ◽  
N.S. Bondarenko ◽  
A.G. Bozhko
Keyword(s):  
Surface Treatment ◽  
Mechanical Stability ◽  
Protective Coatings ◽  
Low Cost ◽  
Titanium Implants ◽  
Point Of View ◽  
Simultaneous Application ◽  
Chemical Inertness ◽  
Implant Coatings ◽  
Powdered Titanium

Utilization of functional-protective coatings for implants based on corundum ceramics seems promising from the point of view of stability, bioinertness, and low cost. In order to study the histo­logical criteria for evaluating the osteoinductive properties of functional protective coatings, 6 types of coatings were studied on an experimental animal model: 90 Wistar rats were implanted with 6 test types of implants with various combinations of surface treatment (sand-blasting, surface treatment with a plasma torch with simultaneous application of aluminum oxide, powdered titanium, etc.) with an exposure of 1, 2 and 4 weeks. After euthanasia, a histological exa­mination of decalcified bone with Masson-Goldner trichrome staining and TRAP-histochemical reaction for osteoclasts was performed. The obtained results de­monstrated significantly higher osteoinductive properties of functional protective coatings with a more pronounced roughness (Ra>10 μm) compared to an untreated titanium surface after 2 (p<0.01) and 4 (p<0.05) weeks of implantation. The corundum ceramic coating prevented the formation of implant wear particles, hence contributed to the stabilization of the newly formed bone. Therefore, the use of functional protective implant coatings based on corundum ceramics can increase the survival rate of conventional titanium implants, since the combination of factors such as surface roughness, mechanical stability, and chemical inertness of coatings with corundum ceramics provides better osteoinductive properties of implant materials.

In vitro study of antibacterial and osteogenic activity of titanium metal releasing strontium and silver ions

2020 ◽  
Vol 35 (6) ◽  
pp. 670-680
Author(s):  
Yaichiro Okuzu ◽  
Shunsuke Fujibayashi ◽  
Seiji Yamaguchi ◽  
Kazutaka Masamoto ◽  
Bungo Otsuki ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Cellular Response ◽  
Low Cost ◽  
In Vitro Study ◽  
Silver Ions ◽  
Titanium Implants ◽  
Dental Surgery ◽  
Osteogenic Response

Peri-prosthetic infection and loosening of implants are major problems in orthopaedic and dental surgery. To address these issues, surface treatment methods for titanium implants have been improved by modifying the alkali and heat treatment. We have previously fabricated calcium-treated Ti metal that releases Sr ions (CaSr-Ti), which resulted in a higher in vitro osteogenic response and early in vivo bone bonding. Further, we developed a Ti metal that released both Sr and Ag ions (CaSrAg-Ti). In this study, we evaluated the antibacterial ability and osteogenic cellular response of CaSrAg-Ti and CaSr-Ti in vitro using rat bone marrow stromal cells (BMSCs) cultured on implant samples and extract mediums (EMs) made by immersing the implant samples in the medium. CaSrAg-Ti did not show cytotoxicity and was associated with a slightly higher osteogenic response when compared to CaSr-Ti, without inhibiting the effect of Sr. The osteogenic response was also observed in the cells cultured with the CaSrAg-Ti EM; however, the response was not as high as that of the cells on the CaSrAg-Ti implant sample. Significantly higher antibacterial activity was observed along with an antibacterial efficacy of more than 95% against methicillin-susceptible Staphylococcus aureus and Escherichia coli. The main advantages of our surface treatment are its simplicity and low cost. Therefore, our treatment is promising for clinical applications in orthopaedic or dental Ti-based implants with antibacterial and early bone-bonding abilities.

scholarly journals Insights into Biodegradable Polymer-Supported Titanium Dioxide Photocatalysts for Environmental Remediation

Macromol ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 201-233
Author(s):  
Nina Maria Ainali ◽  
Dimitrios Kalaronis ◽  
Eleni Evgenidou ◽  
Dimitrios N. Bikiaris ◽  
Dimitra A. Lambropoulou
Keyword(s):  
Titanium Dioxide ◽  
Biodegradable Polymers ◽  
Biodegradable Polymer ◽  
Environmental Remediation ◽  
Mechanical Stability ◽  
Dip Coating ◽  
Tio2 Photocatalysts ◽  
Chemical Inertness ◽  
Polymeric Substrates ◽  
Published Research

During the past two decades, immobilization of titanium dioxide (TiO2), a well-known photocatalyst, on several polymeric substrates has extensively gained ground since it limits the need of post-treatment separation stages. Taking into account the numerous substrates tested for supporting TiO2 photocatalysts, the use of biodegradable polymer seems a hopeful option owing to its considerable merits, including the flexible nature, low price, chemical inertness, mechanical stability and wide feasibility. The present review places its emphasis on recently published research articles (2011–2021) and exhibits the most innovative studies facilitating the eco-friendly biodegradable polymers to fabricate polymer-based photocatalysts, while the preparation details, photocatalytic performance and reuse of the TiO2/polymer photocatalysts is also debated. The biodegradable polymers examined herein comprise of chitosan (CS), cellulose, alginate, starch, poly(lactid acid) (PLA), polycaprolactone (PCL) and poly(lactide-co-glycolide) (PLGA), while an emphasis on the synthetical pathway (dip-coating, electrospinning, etc.) of the photocatalysts is provided.

scholarly journals Innovative Polymeric Hybrid Nanocomposites for Application in Photocatalysis

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1184
Author(s):  
Maria Cantarella ◽  
Giuliana Impellizzeri ◽  
Alessandro Di Mauro ◽  
Vittorio Privitera ◽  
Sabrina Carola Carroccio
Keyword(s):  
Hybrid Systems ◽  
Hybrid Materials ◽  
Large Scale ◽  
Mechanical Stability ◽  
Low Cost ◽  
Atomic Layer ◽  
Hybrid Nanocomposites ◽  
Polymeric Nanocomposites ◽  
Wastewater Remediation ◽  
Antibacterial Performance

The immobilization of inorganic nanomaterials on polymeric substrates has been drawing a lot of attention in recent years owing to the extraordinary properties of the as-obtained materials. The hybrid materials, indeed, combine the benefits of the plastic matter such as flexibility, low-cost, mechanical stability and high durability, with them deriving from their inorganic counterparts. In particular, if the inorganic fillers are nanostructured photocatalysts, the originated hybrid systems will be able to utilize the energy delivered by light, catalysing chemical reactions in a sustainable pathway. Most importantly, since the nanofillers can be ad-hoc anchored to the macromolecular structure, their release in the environment will be prevented, thus overcoming one of the main restrictions that impedes their applications on a large scale. In this review, several typologies of hybrid photocatalytic nanomaterials, obtained by using both organic and inorganic semiconductors and realized with different synthetic protocols, were reported and discussed. In the first part of the manuscript, nanocomposites realized by simply blending the TiO2 or ZnO nanomaterials in thermoplastic polymeric matrices are illustrated. Subsequently, the atomic layer deposition (ALD) technique is presented as an excellent method to formulate polymeric nanocomposites. Successively, some examples of polyporphyrins hybrid systems containing graphene, acting as photocatalysts under visible light irradiation, are discussed. Lastly, photocatalytic polymeric nanosponges, with extraordinary adsorption properties, are shown. All the described materials were deeply characterized and their photocatalytic abilities were evaluated by the degradation of several organic water pollutants such as dyes, phenol, pesticides, drugs, and personal care products. The antibacterial performance was also evaluated for selected systems. The relevance of the obtained results is widely overviewed, opening the route for the application of such multifunctional photocatalytic hybrid materials in wastewater remediation.

scholarly journals A Feasibility Study of the Use of Smartwatches in Wearable Fall Detection Systems

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2254
Author(s):  
Francisco Javier González-Cañete ◽  
Eduardo Casilari
Keyword(s):  
Low Cost ◽  
Fall Detection ◽  
The Elderly ◽  
Point Of View ◽  
False Alarms ◽  
Battery Life ◽  
Area Network ◽  
Battery Lifetime ◽  
Detection Systems ◽  
Operational Aspects

Over the last few years, the use of smartwatches in automatic Fall Detection Systems (FDSs) has aroused great interest in the research of new wearable telemonitoring systems for the elderly. In contrast with other approaches to the problem of fall detection, smartwatch-based FDSs can benefit from the widespread acceptance, ergonomics, low cost, networking interfaces, and sensors that these devices provide. However, the scientific literature has shown that, due to the freedom of movement of the arms, the wrist is usually not the most appropriate position to unambiguously characterize the dynamics of the human body during falls, as many conventional activities of daily living that involve a vigorous motion of the hands may be easily misinterpreted as falls. As also stated by the literature, sensor-fusion and multi-point measurements are required to define a robust and reliable method for a wearable FDS. Thus, to avoid false alarms, it may be necessary to combine the analysis of the signals captured by the smartwatch with those collected by some other low-power sensor placed at a point closer to the body’s center of gravity (e.g., on the waist). Under this architecture of Body Area Network (BAN), these external sensing nodes must be wirelessly connected to the smartwatch to transmit their measurements. Nonetheless, the deployment of this networking solution, in which the smartwatch is in charge of processing the sensed data and generating the alarm in case of detecting a fall, may severely impact on the performance of the wearable. Unlike many other works (which often neglect the operational aspects of real fall detectors), this paper analyzes the actual feasibility of putting into effect a BAN intended for fall detection on present commercial smartwatches. In particular, the study is focused on evaluating the reduction of the battery life may cause in the watch that works as the core of the BAN. To this end, we thoroughly assess the energy drain in a prototype of an FDS consisting of a smartwatch and several external Bluetooth-enabled sensing units. In order to identify those scenarios in which the use of the smartwatch could be viable from a practical point of view, the testbed is studied with diverse commercial devices and under different configurations of those elements that may significantly hamper the battery lifetime.

Natural Locomotion Based on Foot-Mounted Inertial Sensors in a Wireless Virtual Reality System

2015 ◽  
Vol 24 (4) ◽  
pp. 298-321 ◽  
Author(s):  
Ernesto de la Rubia ◽  
Antonio Diaz-Estrella
Keyword(s):  
Virtual Reality ◽  
Gait Cycle ◽  
Inertial Sensors ◽  
Low Cost ◽  
Point Of View ◽  
Handheld Devices ◽  
Preliminary Evaluation ◽  
Virtual Reality System ◽  
Object Searching

Virtual reality has become a promising field in recent decades, and its potential now seems clearer than ever. With the development of handheld devices and wireless technologies, interest in virtual reality is also increasing. Therefore, there is an accompanying interest in inertial sensors, which can provide such advantages as small size and low cost. Such sensors can also operate wirelessly and be used in an increasing number of interactive applications. An example related to virtual reality is the ability to move naturally through virtual environments. This is the objective of the real-walking navigation technique, for which a number of advantages have previously been reported in terms of presence, object searching, and collision, among other concerns. In this article, we address the use of foot-mounted inertial sensors to achieve real-walking navigation in a wireless virtual reality system. First, an overall description of the problem is presented. Then, specific difficulties are identified, and a corresponding technique is proposed to overcome each: tracking of foot movements; determination of the user’s position; percentage estimation of the gait cycle, including oscillating movements of the head; stabilization of the velocity of the point of view; and synchronization of head and body yaw angles. Finally, a preliminary evaluation of the system is conducted in which data and comments from participants were collected.

Flexural Joints in Mechanisms

2000 ◽  
Author(s):  
M. P. Koster
Keyword(s):  
Consumer Goods ◽  
Design Methodology ◽  
Low Cost ◽  
Point Of View ◽  
Industrial Technology ◽  
Scientific Instruments ◽  
Manufacturing Equipment ◽  
Flexural Fatigue ◽  
Elastic Deflection ◽  
Flexural Joints

Abstract The application of flexural joints in mechanisms has a number of advantages. Extreme repeatability of position is obtained because of the absence of backlash and friction. From a tribological point of view, no lubrication is needed and no wear exists. In many cases their application gives rise to a low cost assembly. Flexural elements have their particular drawbacks as well. Deflections are limited; only oscillating motions can be performed and work has to be done as a consequence of the elastic deflection. Flexural fatigue sets another limit to their application. The paper gives an overview of a design methodology that has been developed at the Philips Center for Industrial Technology by the author and his colleagues over the last several decades. Some aspects of this methodology are well known; other aspects are unique. The methodology is described in detail in a book by the author about design principles (Koster 1998). The methodology has been used to design hundreds of practical mechanisms incorporated in scientific instruments, manufacturing equipment and consumer goods. Many examples are given in (Koster 1998). Several interesting examples are given in this paper.

Evaluating and Exploring Successful Disruptive Innovation in the Aviation Industry From the Perspective of Consumers

2021 ◽  
Vol 13 (4) ◽  
pp. 105-119
Author(s):  
Gang-Hoon Seo
Keyword(s):  
Word Of Mouth ◽  
Low Cost ◽  
Disruptive Innovation ◽  
Point Of View ◽  
Aviation Industry ◽  
Basic Service ◽  
Low Cost Carriers ◽  
Content Analyses ◽  
Southwest Airlines

Since Southwest Airlines' disruptive innovation was introduced, low-cost carriers (LCCs) have had a prominent impact on the aviation industry. Therefore, considerable attention has been paid to the LCC model. However, it is still not clear whether it is a successful disruptive innovation, or what factors and differentiation points for successful LCC service exist from the passengers' perspective. As this study's methodology, quantitative and qualitative content analyses are conducted using the word-of-mouth data of 1,854 passengers of 20 airlines. This study found that the LCC model is perceived as a successful disruptive innovation from the passengers' point of view. For successful LCC service, LC airlines should offer higher quality services than passengers' expectations using basic service elements. Also, good staff characteristics, leaving a professional impression, and providing good optional services could play a role as differentiation tools.

scholarly journals PHOTOGRAMMETRY AS A PARTICIPATORY RECOVERY TOOL AFTER DISASTERS: A GROUNDED FRAMEWORK FOR FUTURE GUIDELINES

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 921-928
Author(s):  
C. Pezzica ◽  
A. Piemonte ◽  
C. Bleil de Souza ◽  
V. Cutini
Keyword(s):  
Low Cost ◽  
Central Italy ◽  
Semantic Content ◽  
Ethnographic Study ◽  
Point Of View ◽  
Humanitarian Response ◽  
Central Italy Earthquake ◽  
Depth Analysis ◽  
Crowdsourced Data ◽  
Fit For Purpose

<p><strong>Abstract.</strong> This paper identifies the application domain, context of use, processes and goals of low-cost street-level photogrammetry after urban disasters. The proposal seeks a synergy between top-down and bottom-up initiatives carried out by different actors during the humanitarian response phase in data scarce contexts. By focusing on the self-organisation capacities of local people, this paper suggests using collaborative photogrammetry to empower communities hit by disasters and foster their active participation in recovery and reconstruction planning. It shows that this task may prove technically challenging depending on the specifics of the collected imagery and develops a grounded framework to produce user-centred image acquisition guidelines and fit-for-purpose photogrammetric reconstruction workflows, useful in future post-disaster scenarios. To this end, it presents an in-depth analysis of a collaborative photographic mapping initiative undergone by a group of citizen-scientists after the 2016 Central Italy earthquake, followed by the explorative processing of some sample datasets. Specifically, the paper firstly presents a visual ethnographic study of the photographic material uploaded by participants from September 2016 to November 2018 in the two Italian municipalities of Arquata del Tronto and Norcia. Secondly, it illustrates from a technical point of view issues concerning the processing of crowdsourced data (e.g. image filtering, selection, quality, semantic content and 3D model scaling) and discusses the viability of using it to enrich the pool of geo-information available to stakeholders and decision-makers. Final considerations are discussed as part of a grounded framework for future guidelines tailored to multiple goals and data processing scenarios.</p>

scholarly journals Effect of laser processing parameters on the efficiency of material: a review in industrial application field

2019 ◽  
Vol 8 (4) ◽  
pp. 509
Author(s):  
Muhammed Sabri Sabri Salim ◽  
Naseer Sabri ◽  
T. K. Ibrahim ◽  
Noaman M. Noaman ◽  
Israa N. Akram ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Surface Composition ◽  
Laser Energy ◽  
Low Cost ◽  
Processing Parameters ◽  
Laser Materials ◽  
Initial State ◽  
Higher Power ◽  
The Cost ◽  
Laser Devices

There is considerable interest in reducing the cost of alloy components that are highly resistant to corrosion. Therefore, low-cost laser energy was used compared to other treatments, where this energy was used to enhance surface resistance of the alloy. In this paper, the advantages of surface treatment using laser energy have demonstrated, in addition, analysis of the effect of the treatment parameters on the material properties. Surface treatment methods for laser materials were classified in thermal processes and thermal chemical processes. The chemical thermal process shows a change in the surface composition of the treated material. The initial state of hydration for cement paste can be identified by analyzing the changes resulting from the intensity of the laser processor. Alumina samples in Ceram proved more soluble areas and became more homogenous and smooth with fewer openings and cracks, especially with energy higher than 10 W CO2 and higher power density than Excimer 6.2 J / cm laser devices. The optimum power of the laser used to remove the material is 40-200 W / cm2. 

scholarly journals Interface Engineering for Perovskite Solar Cells Based on 2D-Materials: A Physics Point of View

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5843
Author(s):  
Rosaria Verduci ◽  
Antonio Agresti ◽  
Valentino Romano ◽  
Giovanna D’Angelo
Keyword(s):  
Solar Cells ◽  
Transition Metal ◽  
2D Materials ◽  
Low Cost ◽  
Transition Metal Dichalcogenides ◽  
Perovskite Solar Cells ◽  
Precursor Solution ◽  
Point Of View ◽  
Physical Mechanisms ◽  
Metal Dichalcogenides

The last decade has witnessed the advance of metal halide perovskites as a promising low-cost and efficient class of light harvesters used in solar cells (SCs). Remarkably, the efficiency of lab-scale perovskite solar cells (PSCs) reached a power conversion efficiency of 25.5% in just ~10 years of research, rivalling the current record of 26.1% for Si-based PVs. To further boost the performances of PSCs, the use of 2D materials (such as graphene, transition metal dichalcogenides and transition metal carbides, nitrides and carbonitrides) has been proposed, thanks to their remarkable optoelectronic properties (that can be tuned with proper chemical composition engineering) and chemical stability. In particular, 2D materials have been demonstrated as promising candidates for (i) accelerating hot carrier transfer across the interfaces between the perovskite and the charge extraction layers; (ii) improving the crystallization of the perovskite layers (when used as additives in the precursor solution); (iii) favoring electronic bands alignment through tuning of the work function. In this mini-review, we discuss the physical mechanisms underlying the increased efficiency of 2D material-based PSCs, focusing on the three aforementioned effects.

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