Experimental evaluation of biological effects of 532 nm wave laser in continuous contact mode under exposure on tissues with various optical and mechanical properties

2021 ◽  
Vol 19 (2) ◽  
pp. 50-55
Author(s):  
E. K. Tikhomirova ◽  
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Biological Tissues ◽  
Careful Selection ◽  
Contact Mode ◽  
Continuous Contact ◽  
Optical And Mechanical Properties ◽  
Coagulation Zone ◽  
532 Nm ◽  
Selection Of

The study presents the results of the experimental action of laser radiation with a wavelength of 532 nm in continuous contact mode on biological tissues with different optical properties. The width of the ablation and coagulation zone, the degree of vaporization of various types of tissues were evaluated. Good coagulation properties of the laser are established when exposed to pigmented tissues. However, the pronounced color dependence characteristic of a given wavelength requires careful selection of the biological objects that are suitable for optical properties. Objectives: An experimental evaluation of the effects of a laser with a wavelength of 532 nm in a continuous contact mode on tissues with different optical and mechanical properties. Materials and methods. We carried out an experimental study of the effects of a laser with a wavelength of 532 nm in a continuous contact mode on biological tissues with different optical and mechanical properties. The crater width and side coagulation zone were measured using an operating microscope and a glass slide with a scale value of 0.1 mm. The tissue samples were weighed before and after the application of a point impact. The increase in laser power contributes to an increase in the width of the incision and the coagulation zone. A more pronounced adhesion of the tissue to the fiber end was noted when exposed to the liver tissue of cattle, which causes smaller values of the ablation zone width in comparison with the muscle tissue of the chicken and is reflected in high values of the error of the mean values. The greatest weight loss with a 2 seconds point impact at a power of 5 W was determined on the muscle tissue of the chicken. Conclusions. Good coagulation properties of the laser have been established when exposed to pigmented tissues, however, the pronounced color dependence characteristic of a given wavelength requires careful selection of the biological objects suitable for optical properties.

scholarly journals 3D-printable zwitterionic nano-composite hydrogel system for biomedical applications

2020 ◽  
Vol 11 ◽  
pp. 204173142096729
Author(s):  
Nathalie Sällström ◽  
Andrew Capel ◽  
Mark P Lewis ◽  
Daniel S Engstrøm ◽  
Simon Martin
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Culture Medium ◽  
Careful Selection ◽  
Nano Composite ◽  
Significant Difference ◽  
Nano Clay ◽  
Hydrogel Surface ◽  
Selection Of ◽  
Hydrogel System

Herein, the cytotoxicity of a novel zwitterionic sulfobetaine hydrogel system with a nano-clay crosslinker has been investigated. We demonstrate that careful selection of the composition of the system (monomer to Laponite content) allows the material to be formed into controlled shapes using an extrusion based additive manufacturing technique with the ability to tune the mechanical properties of the product. Moreover, the printed structures can support their own weight without requiring curing during printing which enables the use of a printing-then-curing approach. Cell culture experiments were conducted to evaluate the neural cytotoxicity of the developed hydrogel system. Cytotoxicity evaluations were conducted on three different conditions; a control condition, an indirect condition (where the culture medium used had been in contact with the hydrogel to investigate leaching) and a direct condition (cells growing directly on the hydrogel). The result showed no significant difference in cell viability between the different conditions and cells were also found to be growing on the hydrogel surface with extended neurites present.

Enhancement of optical and mechanical properties of Si nanopillars by ALD TiO2 coating

RSC Advances ◽  
2016 ◽  
Vol 6 (99) ◽  
pp. 97070-97076 ◽  
Author(s):  
M. Pavlenko ◽  
E. L. Coy ◽  
M. Jancelewicz ◽  
K. Załęski ◽  
V. Smyntyna ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Tio2 Coating ◽  
Optical And Mechanical Properties

The mechanical and optical properties of Si and TiO2–Si nanopillars (NPl) were investigated.

Redesign of Carbon Materials for Novel Storage, Mechanical and Optical Properties

2012 ◽  
Vol 1451 ◽  
pp. 9-14
Author(s):  
Stefano Leoni ◽  
Igor A. Baburin ◽  
S. E. Boulfelfel ◽  
D. Selli
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Carbon Nanotube ◽  
Numerical Methods ◽  
Carbon Materials ◽  
Scaling Up ◽  
Ambient Conditions ◽  
Technological Potential ◽  
Optical And Mechanical Properties

ABSTRACTWe revisit the polymorphism of carbon along two directions. First, we discover novel polymorphs in the vicinity of graphite, with outstanding optical and mechanical properties. Using numerical methods and graph-theoretical tools, we find as many as 4 novel superhard and transparent polymorphs, with great technological potential. Second, scaling up a model of rod packing to carbon nanotube (CNT) scaffoldings, we discover that such complex assemblies of CNTs are outstanding adsorbers of hydrogen, capable of reaching the DOE target (~6.0 wt% at ambient conditions). Along this line, we highlight novel paradigms for revisiting carbon, in view of remarkable qualities and superior properties.

scholarly journals A review on polymer nanocomposite hydrogel preparation, characterization, and applications

2021 ◽  
Vol 12 (3) ◽  
pp. 329-339
Author(s):  
Md. Arif Roman Azady ◽  
Sony Ahmed ◽  
Md. Shafiul Islam
Keyword(s):  
Mechanical Properties ◽  
Preparation Method ◽  
Dye Adsorption ◽  
Polymer Nanocomposite ◽  
Nanocomposite Hydrogel ◽  
Careful Selection ◽  
Nanocomposite Hydrogels ◽  
Hydrogel Matrix ◽  
Matrix Nanocomposite ◽  
Selection Of

Nanocomposite hydrogels, made by incorporating nanoparticles into a hydrogel matrix, have been developed to fulfill the need for materials with enhanced and predictable mechanical properties and functionality. This review breaks down the process of preparing and characterizing nanocomposite hydrogels and looks at the various applications they can be used for. Through careful selection of the nanoparticle and hydrogel types, as well as the preparation method, the degree of crosslinking and the strength of the intermolecular interactions between the nanoparticles and the hydrogel matrix can be controlled. Once the nanomaterial is prepared, the morphology, gel content, thermal stability, and mechanical properties are investigated. By varying the concentrations of nanoparticles within the hydrogel matrix, nanocomposite hydrogels with optimal functionality and mechanical properties are produced. The optimized nanomaterial can then be used for its intended application(s); here the focus is on applications in the biomedical and dye adsorption fields. With further research, it is predicted that nanocomposite hydrogels will fulfill their potential to be used in practical, everyday applications.

Afterword

2020 ◽  
pp. 680-683
Author(s):  
Janice L. Waldron ◽  
Stephanie Horsley ◽  
Kari K. Veblen
Keyword(s):  
Social Media ◽  
Media Use ◽  
Careful Selection ◽  
Social Media Use ◽  
Pedagogical Tools ◽  
The Future ◽  
User Data ◽  
Selection Of ◽  
Data Surface

We all feel the implications of the force of social media—for good and for ill—in our lives and in our professional world. At the time of this writing, Facebook continues with its struggle to “clean up its act” as more revelations surrounding breaches of trust and hacked user data surface in the news and various countries attempt to hold Facebook to account. Despite this, social media use continues to grow exponentially, and the potential for responsible, ethical, and transparent social media to transform the ways in which we interact with and learn from each other increase with it. As we wait to see what the future holds for social media in society, we are reminded once again that it is the careful selection of pedagogical tools such as social media, as well the guided awareness of the challenges and benefits of those tools, that remains constant, even as tools may change, disappear, or fall out of fashion.

Elaboration and Characterization of the Properties of Refractory Cr Base Alloys

2010 ◽  
Vol 72 ◽  
pp. 46-52 ◽  
Author(s):  
Laurent Royer ◽  
Stéphane Mathieu ◽  
Christophe Liebaut ◽  
Pierre Steinmetz
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Molten Glass ◽  
Energy Production ◽  
Creep Properties ◽  
Refractory Alloys ◽  
Industrial Use ◽  
Kinetics Of ◽  
Selection Of

For energy production and also for the glass industry, finding new refractory alloys which could permit to increase the process temperatures to 1200°C or more is a permanent challenge. Chromium base alloys can be good candidates, considering the melting point of Cr itself, and also its low corrosion rate in molten glass. Two families of alloys have been studied for this purpose, Cr-Mo-W and Cr-Ta-X alloys (X= Mo, Si..). A finer selection of compositions has been done, to optimize their chemical and mechanical properties. Kinetics of HT oxidation by air, of corrosion by molten glass and also creep properties of several alloys have been measured up to 1250°C. The results obtained with the best alloys (Cr-Ta base) give positive indications as regards the possibility of their industrial use.

scholarly journals DFT Study of Electronic Structure and Optical Properties of Kaolinite, Muscovite, and Montmorillonite

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 618
Author(s):  
Layla Shafei ◽  
Puja Adhikari ◽  
Wai-Yim Ching
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Electronic Structure ◽  
Hydrogen Bonds ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Bond Order ◽  
Deep Understanding ◽  
Pharmaceutical Applications ◽  
Structure Properties

Clay mineral materials have attracted attention due to their many properties and applications. The applications of clay minerals are closely linked to their structure and composition. In this paper, we studied the electronic structure properties of kaolinite, muscovite, and montmorillonite crystals, which are classified as clay minerals, by using DFT-based ab initio packages VASP and the OLCAO. The aim of this work is to have a deep understanding of clay mineral materials, including electronic structure, bond strength, mechanical properties, and optical properties. It is worth mentioning that understanding these properties may help continually result in new and innovative clay products in several applications, such as in pharmaceutical applications using kaolinite for their potential in cancer treatment, muscovite used as insulators in electrical appliances, and engineering applications that use montmorillonite as a sealant. In addition, our results show that the role played by hydrogen bonds in O-H bonds has an impact on the hydration in these crystals. Based on calculated total bond order density, it is concluded that kaolinite is slightly more cohesive than montmorillonite, which is consistent with the calculated mechanical properties.

Intriguing electronic, optical and mechanical properties of the vertical and lateral heterostructures on the boron phosphide and GaN monolayers

2021 ◽  
Vol 56 (12) ◽  
pp. 7451-7463
Author(s):  
Yusheng Wang ◽  
Xiaowei Wu ◽  
Nahong Song ◽  
Xiaohui Yang ◽  
Yafeng Zheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Phosphide ◽  
Optical And Mechanical Properties

scholarly journals Advances in Fabricating the Electrospun Biopolymer-Based Biomaterials

2021 ◽  
Vol 12 (2) ◽  
pp. 26
Author(s):  
Sebastian Wilk ◽  
Aleksandra Benko
Keyword(s):  
Mechanical Properties ◽  
Whey Protein ◽  
Antimicrobial Properties ◽  
Protein Isolate ◽  
Review Article ◽  
Animal Tissues ◽  
Green Material ◽  
Good Potential ◽  
Fibrous Morphology ◽  
Selection Of

Biopolymers formed into a fibrous morphology through electrospinning are of increasing interest in the field of biomedicine due to their intrinsic biocompatibility and biodegradability and their ability to be biomimetic to various fibrous structures present in animal tissues. However, their mechanical properties are often unsatisfactory and their processing may be troublesome. Thus, extensive research interest is focused on improving these qualities. This review article presents the selection of the recent advances in techniques aimed to improve the electrospinnability of various biopolymers (polysaccharides, polynucleotides, peptides, and phospholipids). The electrospinning of single materials, and the variety of co-polymers, with and without additives, is covered. Additionally, various crosslinking strategies are presented. Examples of cytocompatibility, biocompatibility, and antimicrobial properties are analyzed. Special attention is given to whey protein isolate as an example of a novel, promising, green material with good potential in the field of biomedicine. This review ends with a brief summary and outlook for the biomedical applicability of electrospinnable biopolymers.

scholarly journals Structural and physical properties of 99 complex bulk chalcogenides crystals using first-principles calculations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sahib Hasan ◽  
Khagendra Baral ◽  
Neng Li ◽  
Wai-Yim Ching
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
First Principles ◽  
Experimental Studies ◽  
First Principles Calculations ◽  
Chalcogenide Semiconductors ◽  
Optical And Mechanical Properties ◽  
Very Large Database ◽  
Unique Composition ◽  
Fundamental Physical

AbstractChalcogenide semiconductors and glasses have many applications in the civil and military fields, especially in relation to their electronic, optical and mechanical properties for energy conversion and in enviormental materials. However, they are much less systemically studied and their fundamental physical properties for a large class chalcogenide semiconductors are rather scattered and incomplete. Here, we present a detailed study using well defined first-principles calculations on the electronic structure, interatomic bonding, optical, and mechanical properties for 99 bulk chalcogenides including thirteen of these crytals which have never been calculated. Due to their unique composition and structures, these 99 bulk chalcogenides are divided into two main groups. The first group contains 54 quaternary crystals with the structure composition (A2BCQ4) (A = Ag, Cu; B = Zn, Cd, Hg, Mg, Sr, Ba; C = Si, Ge, Sn; Q = S, Se, Te), while the second group contains scattered ternary and quaternary chalcogenide crystals with a more diverse composition (AxByCzQn) (A = Ag, Cu, Ba, Cs, Li, Tl, K, Lu, Sr; B = Zn, Cd, Hg, Al, Ga, In, P, As, La, Lu, Pb, Cu, Ag; C = Si, Ge, Sn, As, Sb, Bi, Zr, Hf, Ga, In; Q = S, Se, Te; $$\hbox {x} = 1$$ x = 1 , 2, 3; $$\hbox {y} = 0$$ y = 0 , 1, 2, 5; $$\hbox {z} = 0$$ z = 0 , 1, 2 and $$\hbox {n} = 3$$ n = 3 , 4, 5, 6, 9). Moreover, the total bond order density (TBOD) is used as a single quantum mechanical metric to characterize the internal cohesion of these crystals enabling us to correlate them with the calculated properties, especially their mechanical properties. This work provides a very large database for bulk chalcogenides crucial for the future theoretical and experimental studies, opening opportunities for study the properties and potential application of a wide variety of chalcogenides.

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