Prospects of hydroxyapatite-based nanomaterials application synthesized by layer-by-layer method for pediatric traumatology and orthopedics

The present brief review focuses on the features of the Layer-by-Layer (LbL) synthesis of coatings containing hydroxyapatite nanoparticles and assesses their use in solving several biomedical problems. This work provides the state-of-art of this field. This method is based on the sequential chemical adsorption of reagents on the substrate surface that makes it possible to apply nanolayers of the specified composition on the surface of a wide range of substrates of complex shape, to control the thickness of the synthesized layers accurately at the nanometer level. It also enables the modification of surface characteristics, including roughness, hydrophilicity, and surface charge, and allows artificially constructed multilayers consisting of hybrid organic and inorganic substances to be obtained. The experimental material presented in the review demonstrates the effectiveness of LbL synthesis for creating new 3D scaffolds as bone substitutes, coatings on the surface of metal implants, and drug delivery systems. A promising direction for the development of LbL synthesis is the creation of methods that involve ion-substituted hydroxyapatites as reagents. Success in this area can pave the way for significant advances in biomedicine and open new opportunities for creating a new generation of structures that mimic the structural, compositional, and mechanical properties of the bone mineral phase.

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Relationships between substrate, surface characteristics, and vegetation in an initial ecosystem

Biogeosciences Discussions ◽

10.5194/bgd-10-4733-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 4733-4780

Author(s):

P. Biber ◽

S. Seifert ◽

M. K. Zaplata ◽

W. Schaaf ◽

H. Pretzsch ◽

...

Keyword(s):

Linear Models ◽

Substrate Surface ◽

Surface Characteristics ◽

Vegetation Density ◽

Vegetation Monitoring ◽

Groundwater Levels ◽

Specific Effects ◽

Wide Range ◽

Generalized Additive Mixed Models ◽

Additive Mixed Models

Abstract. Based on a wide range of empirical data we investigated surface and vegetation dynamics in the artificial initial ecosystem "Chicken Creek" (Lusatia, Germany) in the years 2008–2011. We scrutinized three different hypotheses concerning (1) the relations between initial geomorphological and substrate characteristics with surface structure and terrain properties, (2) the effects of the latter on the occurrence of grouped plant species, and (3) vegetation density effects on terrain surface change. Our data comprise annual vegetation monitoring results, terrestrial laser scans twice a year, annual groundwater levels, and initially measured soil characteristics. Using Generalized Linear Models (GLMM) and Generalized Additive Mixed Models (GAMM) we can mostly confirm our hypotheses, revealing statistically significant relations that partly reflect object or period specific effects but also more general processes which mark the transition from a geo-hydro towards a bio-geo-hydro system, where pure geomorphology or substrate feedbacks are changing into vegetation-substrate feedback processes.

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Compact back-scattered electrons' energy analyzer for standard SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170177 ◽

1994 ◽

Vol 52 ◽

pp. 488-489

Author(s):

S. Likharev ◽

A. Kramarenko ◽

V. Vybornov

Keyword(s):

Depth Resolution ◽

High Energy ◽

Primary Beam ◽

Layer By Layer ◽

Energy Analyzer ◽

High Energy Part ◽

Small Window ◽

Energy Part ◽

Wide Range ◽

High Voltage Supply

At present time the interest is growing considerably for theoretical and experimental analysis of back-scattered electrons (BSE) energy spectra. It was discovered that a special angle and energy nitration of BSE flow could be used for increasing a spatial resolution of BSE mode, sample topography investigations and for layer-by layer visualizing of a depth structure. In the last case it was shown theoretically that in order to obtain suitable depth resolution it is necessary to select a part of BSE flow with the directions of velocities close to inverse to the primary beam and energies within a small window in the high-energy part of the whole spectrum.A wide range of such devices has been developed earlier, but all of them have considerable demerit: they can hardly be used with a standard SEM due to the necessity of sufficient SEM modifications like installation of large accessories in or out SEM chamber, mounting of specialized detector systems, input wires for high voltage supply, screening a primary beam from additional electromagnetic field, etc. In this report we present a new scheme of a compact BSE energy analyzer that is free of imperfections mentioned above.

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The Impact of Initial Conditions in N-Body Simulations of Debris Discs

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2015.41 ◽

2015 ◽

Vol 32 ◽

Cited By ~ 4

Author(s):

E. Thilliez ◽

S. T. Maddison

Keyword(s):

Numerical Simulations ◽

Initial Conditions ◽

Parent Body ◽

Dust Trapping ◽

Physical Context ◽

Disc Width ◽

Wide Range ◽

Belt Width ◽

New Generation ◽

The Impact

AbstractNumerical simulations are a crucial tool to understand the relationship between debris discs and planetary companions. As debris disc observations are now reaching unprecedented levels of precision over a wide range of wavelengths, an appropriate level of accuracy and consistency is required in numerical simulations to confidently interpret this new generation of observations. However, simulations throughout the literature have been conducted with various initial conditions often with little or no justification. In this paper, we aim to study the dependence on the initial conditions of N-body simulations modelling the interaction between a massive and eccentric planet on an exterior debris disc. To achieve this, we first classify three broad approaches used in the literature and provide some physical context for when each category should be used. We then run a series of N-body simulations, that include radiation forces acting on small grains, with varying initial conditions across the three categories. We test the influence of the initial parent body belt width, eccentricity, and alignment with the planet on the resulting debris disc structure and compare the final peak emission location, disc width and offset of synthetic disc images produced with a radiative transfer code. We also track the evolution of the forced eccentricity of the dust grains induced by the planet, as well as resonance dust trapping. We find that an initially broad parent body belt always results in a broader debris disc than an initially narrow parent body belt. While simulations with a parent body belt with low initial eccentricity (e ~ 0) and high initial eccentricity (0 < e < 0.3) resulted in similar broad discs, we find that purely secular forced initial conditions, where the initial disc eccentricity is set to the forced value and the disc is aligned with the planet, always result in a narrower disc. We conclude that broad debris discs can be modelled by using either a dynamically cold or dynamically warm parent belt, while in contrast eccentric narrow debris rings are reproduced using a secularly forced parent body belt.

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Review of Functional Treatments for Modified Wood

Coatings ◽

10.3390/coatings11030327 ◽

2021 ◽

Vol 11 (3) ◽

pp. 327

Author(s):

Morwenna J. Spear ◽

Simon F. Curling ◽

Athanasios Dimitriou ◽

Graham A. Ormondroyd

Keyword(s):

High Performance ◽

Responsive Materials ◽

Wood Modification ◽

Wide Range ◽

Natural Wood ◽

Impregnation Modification ◽

New Applications ◽

New Generation ◽

Dimensional Instability ◽

Modified Wood

Wood modification is now widely recognized as offering enhanced properties of wood and overcoming issues such as dimensional instability and biodegradability which affect natural wood. Typical wood modification systems use chemical modification, impregnation modification or thermal modification, and these vary in the properties achieved. As control and understanding of the wood modification systems has progressed, further opportunities have arisen to add extra functionalities to the modified wood. These include UV stabilisation, fire retardancy, or enhanced suitability for paints and coatings. Thus, wood may become a multi-functional material through a series of modifications, treatments or reactions, to create a high-performance material with previously impossible properties. In this paper we review systems that combine the well-established wood modification procedures with secondary techniques or modifications to deliver emerging technologies with multi-functionality. The new applications targeted using this additional functionality are diverse and range from increased electrical conductivity, creation of sensors or responsive materials, improvement of wellbeing in the built environment, and enhanced fire and flame protection. We identified two parallel and connected themes: (1) the functionalisation of modified timber and (2) the modification of timber to provide (multi)-functionality. A wide range of nanotechnology concepts have been harnessed by this new generation of wood modifications and wood treatments. As this field is rapidly expanding, we also include within the review trends from current research in order to gauge the state of the art, and likely direction of travel of the industry.

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Host-vector systems

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1989.0061 ◽

1989 ◽

Vol 324 (1224) ◽

pp. 477-485 ◽

Cited By ~ 2

Keyword(s):

Genetic Manipulation ◽

Pharmaceutical Products ◽

Host Cells ◽

Animal Cells ◽

Vector Systems ◽

Wide Range ◽

Novel Host ◽

Basic Concepts ◽

Foreign Genes ◽

New Generation

In 1980 it was only possible to express foreign genes in bacteria and a few easily cultured animal cells. During the subsequent eight years specialized vectors have been developed to allow the genetic manipulation of a wide range of both prokaryotes and eukaryotes. One of the major goals of biotechnology in 1980 was to use host cells as ‘factories’ for the production of proteins that were only available in minute quantities from natural sources. This has already lead to a new generation of pharmaceutical products. Advances in our understanding of host-vector systems have defined new goals. The basic concepts of expression vector design will be illustrated. Some of the new goals are discussed with particular reference to the exploitation of novel host-vector systems to develop vaccines and anti-viral agents against AIDS.

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Water Filtration Membranes Based on Non-Woven Cellulose Fabrics: Effect of Nanopolysaccharide Coatings on Selective Particle Rejection, Antifouling, and Antibacterial Properties

Nanomaterials ◽

10.3390/nano11071752 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1752

Author(s):

Blanca Jalvo ◽

Andrea Aguilar-Sanchez ◽

Maria-Ximena Ruiz-Caldas ◽

Aji P. Mathew

Keyword(s):

Cellulose Nanofibers ◽

Antibacterial Properties ◽

Surface Characteristics ◽

Water Filtration ◽

Separation Performance ◽

Nonwoven Fabrics ◽

Filtration Membranes ◽

Wide Range ◽

Dry Conditions ◽

Cellulose Fabrics

This article presents a comparative study of the surface characteristics and water purification performance of commercially available cellulose nonwoven fabrics modified, via cast coating, with different nano-dimensioned bio-based carbohydrate polymers, viz. cellulose nanocrystals (CNC), TEMPO-oxidized cellulose nanofibers (T-CNF), and chitin nanocrystals (ChNC). The surface-modified nonwoven fabrics showed an improvement in wettability, surface charge modification, and a slight decrease of maximum pore size. The modification improved the water permeance in most of the cases, enhanced the particle separation performance in a wide range of sizes, upgraded the mechanical properties in dry conditions, and showed abiotic antifouling capability against proteins. In addition, T-CNF and ChNC coatings proved to be harmful to the bacteria colonizing on the membranes. This simple surface impregnation approach based on green nanotechnology resulted in highly efficient and fully bio-based high-flux water filtration membranes based on commercially available nonwoven fabrics, with distinct performance for particle rejection, antifouling and antibacterial properties.

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Abstract 120: Surpass Flow Diverter for Endovascular Treatment of Intracranial Aneurysms - A Multicenter Preliminary Clinical and Angiographic Experience in 161 Patients with 186 Aneurysms

Stroke ◽

10.1161/str.45.suppl_1.120 ◽

2014 ◽

Vol 45 (suppl_1) ◽

Author(s):

Ajay K Wakhloo ◽

Pedro Lylyk ◽

Joost de Vries ◽

Matthew J Gounis ◽

Alexandra Biondi ◽

...

Keyword(s):

Intracranial Aneurysms ◽

Experimental Studies ◽

Flow Diverter ◽

Posterior Circulation ◽

Parent Artery ◽

Anterior Circulation ◽

Neck Size ◽

Wide Range ◽

New Generation

Objective: Validated through experimental studies a new generation of flow diverters (Surpass™ FD) was evaluated for treatment of intracranial aneurysms (IA). We present our multicenter preliminary clinical and angiographic experience. METHODS: To achieve the calculated flow disruption between the parent artery and aneurysm for thrombosis, single FDs were placed endovascularly in parent arteries. Implants measured 2.5-5.3mm in diameter with a length of 10-80mm. Patients were enrolled harboring a wide range large and giant wide-neck, fusiform and multiple small and blister-type aneurysm. Clinical and angiographic follow-up were performed at 1-3, 6, and 12 months. RESULTS: A total of 186 consecutive IA in 161 patients (mean age 57.1 years) were treated at 33 centers. Fifty-three aneurysms were smaller than 5 mm, 64 were 5-9.9mm in diameter, 47 were 10-20mm in diameter, and 22 were larger than 20mm (10.4±0.7mm, neck size 6.0±0.5mm [mean±SEM]) . The aneurysms originated in 63.4% from the internal carotid artery; 22% and 14.5% of the lesions were located in the anterior circulation distal to Circle of Willis and posterior circulation respectively. Technical success was achieved in 182 aneurysms (98%); average number of devices used per aneurysm was 1.05. Permanent morbidity and mortality during the follow-up period of mean 8.4months (range 1-24 months) including periprocedural complications for patients with aneurysms of the anterior circulation were encountered in 5 (3.7%) and 2 (1.5 %) patients respectively and 1 (3.7%) and 4 (14.8%) respectively for patients with aneurysms of the posterior circulation location. One-hundred-ten patients (70.5%) harboring 127 (70.2%) were available for clinical and angiographic follow-up and showed a complete or near complete aneurysm occlusion in 63 (81.8%) of the ICA. Aneurysms of the ICA≥10mm that were completely covered by FD and not previously stent-treated with a minimum of 6 months follow-up available in 16 patients showed a complete obliteration in 81.3% (n=13) and >90% occlusion in remaining 3 patients. CONCLUSION: Preliminary data demonstrate high safety and efficacy of a new generation of FD for a wide range of IA of the anterior and posterior circulation with a single implant.

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Automation and Management of Design Process of the Main Drive for an Innovative Fruits and Vegetables Washer

INFORMACIONNYE TEHNOLOGII ◽

10.17587/it.27.9-17 ◽

2021 ◽

Vol 27 (1) ◽

pp. 9-17

Author(s):

V. P. Bui ◽

◽

S. S. Gavruishin ◽

V. B. Phung ◽

H. M. Dang ◽

...

Keyword(s):

Design Process ◽

Rational Design ◽

Fruits And Vegetables ◽

Rational Solution ◽

Quality Criteria ◽

Pareto Optimal ◽

Optimal Domain ◽

Wide Range ◽

A New Technique ◽

New Generation

A new technique is described, used by the authors to automate the design process of the main drive of a new generation machine intended for industrial washing of fruits and vegetables. To solve the problem of multi-criteria design, the original approach is proposed that uses interconnected mathematical models describing the dynamic behavior, strength reliability and functional characteristics of the machine in a unified information space. The generalized mathematical model includes 12 controlled parameters, 16 functional constraints, and 3 quality criteria. A genetic algorithm was used to find the space of Pareto-optimal solutions. The situational approach was used to select the final rational solution from a set of solutions belonging to the Pareto-optimal domain. The rational design of option the washer found using the proposed approach is compared with the existing ones. The proposed design methodology can be recommended for the design of a wide range of similar mechanical structures.

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The life and works of Domenico Mario Nuti, 1937–2020: An appreciation

Acta Oeconomica ◽

10.1556/032.2021.00009 ◽

2021 ◽

Vol 71 (2) ◽

pp. 181-194

Author(s):

Saul Estrin ◽

Milica Uvalic

Keyword(s):

Economic Theory ◽

Original Work ◽

Policy Advice ◽

Wide Range ◽

New Generation ◽

At Home

AbstractIt is challenging to provide an encompassing portrait of Mario Nuti's life and works: he was an exceptional man, who made significant intellectual contributions across a wide range of fields, as well as inspiring generations of students, colleagues and the profession in general, for more than fifty years. A brilliant debater and controversialist, he was equally at home in economic theory and in giving policy advice, and over the decades he had made significant contributions to many branches of the discipline. In this memorial article, we try to give a flavour of the man and his work, hopefully reminding the conoscenti of Mario's perceptive and original work, while introducing a new generation of scholars to his distinctive take on the field of economics.

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Effect of Different Heat Treatments on Mechanical Properties of Laser Sintered Additive Manufactured Parts

Volume 2: Additive Manufacturing; Materials ◽

10.1115/msec2017-2769 ◽

2017 ◽

Author(s):

Sagar Sarkar ◽

Cheruvu Siva Kumar ◽

Ashish Kumar Nath

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Yield Strength ◽

Tensile Strain ◽

Wear Loss ◽

Layer By Layer ◽

Solution Annealing ◽

Wear Properties ◽

Sem Images ◽

Wide Range

One of the most popular additive manufacturing processes is laser based direct metal laser sintering process which enables us to make complex three dimensional parts directly from CAD models. Due to layer by layer formation, parts built in this process tend to be anisotropic in nature. Suitable heat treatment can reduce this anisotropic behaviour by changing the microstructure. Depending upon the applications, a wide range of mechanical properties can be achieved between 482–621° C temperature for precipitation-hardened stainless steels. In the present study effect of different heat treatment processes, namely solution annealing, ageing and overaging, on tensile strength, hardness and wear properties has been studied in detail. Suitable metallurgical and mechanical characterization techniques have been applied wherever required, to support the experimental observations. Results show H900 condition gives highest yield strength and lowest tensile strain at break whereas solution annealing gives lowest yield strength and as-built condition gives highest tensile strain at break. SEM images show that H900 and H1150 condition produces brittle and ductile morphology respectively which in turn gives highest and lowest hardness value respectively.XRD analysis shows presence of austenite phases which can increase hardness at the cost of ductility. Average wear loss for H900 condition is highest whereas it is lowest for solution annealed condition. Further optical and SEM images have been taken to understand the basic wear mechanism involved.

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