scholarly journals Vitreous Substitutes: Old and New Materials in Vitreoretinal Surgery

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Camilla Alovisi ◽  
Claudio Panico ◽  
Ugo de Sanctis ◽  
Chiara M. Eandi
Keyword(s):  
Surgical Techniques ◽  
Vitreoretinal Surgery ◽  
Biochemical Properties ◽  
Clinical Use ◽  
New Materials ◽  
Advantages And Disadvantages ◽  
Look Ahead ◽  
Composition And Structure ◽  
Recent Developments ◽  
Vitreous Substitutes

Recent developments in vitreoretinal surgery have increased the need for suitable vitreous substitutes. A successful substitute should maintain all the physical and biochemical properties of the original vitreous, be easy to manipulate, and be long lasting. Substitutes can be gaseous or liquid, both of which have associated advantages and disadvantages related to their physical properties and use. Furthermore, new surgical techniques with smaller vitreoretinal instruments have driven the use of more viscous substitutes. In this review, we analyze and discuss the most frequently used vitreous substitutes and look ahead to future alternatives. We classify these compounds based on their composition and structure, discuss their clinical use with respect to their associated advantages and disadvantages, and analyze how new vitreoretinal surgical techniques have modified their use.

Functionally Graded Material (FGM) Parts: From Design to the Manufacturing Simulation

2012 ◽  
Author(s):  
Pierre Muller ◽  
Pascal Mognol ◽  
Jean-Yves Hascoet
Keyword(s):  
Additive Manufacturing ◽  
Gas Flow ◽  
Biochemical Properties ◽  
Functionally Graded ◽  
Graded Materials ◽  
Composition And Structure ◽  
Recent Developments ◽  
Graded Material ◽  
Metallic Parts ◽  
Complex Parts

Recent developments in additive manufacturing processes add opportunities to manufacture metallic parts. One of major recent evolutions of additive manufacturing is the ability to produce parts with functionally graded materials (FGM). These materials can be characterized by the variation in composition and structure gradually over the volume. The use of these materials is particularly attractive in fields such as aeronautical or biomedical where the multi-material parts allow modifying locally mechanical, chemical, physical or biochemical properties. Today, main of parts with FGM which are manufactured with these processes are not functional, with simple morphology, small dimensions and discrete multi-material repartition. To move from these samples to functional parts it is necessary to have a global control of the process used. It includes the control of all parameters — laser power, powder and gas flow rates, axis motions — and a manufacturing with an optimal strategy. A methodology to manufacture multi-material complex parts is proposed so as to have this global approach.

Material Properties and Design Aspects of Folding Bicycle Frame

2011 ◽  
Vol 264-265 ◽  
pp. 777-782 ◽  
Author(s):  
M.A. Maleque ◽  
M.S. Hossain ◽  
S. Dyuti
Keyword(s):  
Material Properties ◽  
Raw Material ◽  
New Materials ◽  
Materials Properties ◽  
Advantages And Disadvantages ◽  
Bicycle Frame ◽  
Successful Design ◽  
Future Direction ◽  
The Relationship ◽  
Comprehensive Study

successful design of folding bicycle should take into account the function, material properties, and fabrication process. There are some other factors that should be considered in anticipating the behavior of materials for folding bicycle. In order to understand the relationship between material properties and design of a folding bicycle and also for the future direction in new materials with new design, a comprehensive study on the design under different conditions are essential. Therefore, a systematic study on the relationship between material properties and design for folding bicycle has been performed. The advantages and disadvantages matrix between conventional bicycle and folding bicycle is presented for better understanding of the materials properties and design. It was found that the materials properties of the folding bicycle frame such as fatigue and tensile strength are the important properties for the better performance of the frame. The relationship between materials properties and design is not straight forward because the behavior of the material in the finished product could be different from that of the raw material. The swing hinge technique could be a better technique in the design for the folding bicycle frame.

scholarly journals Advances in the automated synthesis of 6-[18F]Fluoro-L-DOPA

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Ângela C. B. Neves ◽  
Ivanna Hrynchak ◽  
Inês Fonseca ◽  
Vítor H. P. Alves ◽  
Mariette M. Pereira ◽  
...  
Keyword(s):  
Large Scale ◽  
Neuroendocrine Tumours ◽  
Radiochemical Yield ◽  
Clinical Applications ◽  
Clinical Use ◽  
Molar Activity ◽  
Neuropsychiatric Diseases ◽  
Recent Developments ◽  
Key Issues ◽  
Improved Methods

AbstractThe neurotracer 6-[18F] FDOPA has been, for many years, a powerful tool in PET imaging of neuropsychiatric diseases, movement disorders and brain malignancies. More recently, it also demonstrated good results in the diagnosis of other malignancies such as neuroendocrine tumours, pheochromocytoma or pancreatic adenocarcinoma.The multiple clinical applications of this tracer fostered a very strong interest in the development of new and improved methods for its radiosynthesis. The no-carrier-added nucleophilic 18F-fluorination process has gained increasing attention, in recent years, due to the high molar activities obtained, when compared with the other methods although the radiochemical yield remains low (17–30%). This led to the development of several nucleophilic synthetic processes in order to obtain the product with molar activity, radiochemical yield and enantiomeric purity suitable for human PET studies.Automation of the synthetic processes is crucial for routine clinical use and compliance with GMP requirements. Nevertheless, the complexity of the synthesis makes the production challenging, increasing the chance of failure in routine production. Thus, for large-scale clinical application and wider use of this radiopharmaceutical, progress in the automation of this complex radiosynthesis is of critical importance.This review summarizes the most recent developments of 6-[18F]FDOPA radiosynthesis and discusses the key issues regarding its automation for routine clinical use.

Vitreoretinal Surgery in the Treatment of Dislocations of Intraocular Lens and Nucleus-Lens Particules into the Vitreous Cavity

2021 ◽  
pp. 2-6
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Relative Frequency ◽  
Surgical Techniques ◽  
Vitreoretinal Surgery ◽  
Vitreous Cavity ◽  
Intraocular Lenses

Drops of lens nucleus/cortex particles into the vitreous cavity or dislocations of intraocular lenses (IOLs) are one of the serious complications of cataract surgery with an increasing relative frequency with the increase in the number of cataract surgeries. In addition, spontaneous and traumatic dislocations are other common case groups that should be treated. In this article, the vitreous dislocations of nucleus/cortex residues or IOL dislocations are discussed with different vitreoretinal surgical techniques.

scholarly journals A Study Wireless Communication Domain

2011 ◽  
pp. 82-86
Author(s):  
Sangram Routray ◽  
Lalit M. Satapathy ◽  
Sanjib k. Nayak
Keyword(s):  
Wireless Communication ◽  
Embedded Systems ◽  
Short Range ◽  
Remote Access ◽  
Wireless Technologies ◽  
Advantages And Disadvantages ◽  
Recent Developments

Wireless communication seem destined to make a large and continuing impact on our lives. Recent developments in wireless technologies provide a new channel for implementation of embedded systems with remote access for mobile and non-mobile products and services. Several wireless technologies are available with their own advantages and disadvantages. This paper examines several available short-range wireless technologies and evaluates them for embedded systems.

scholarly journals The application of C2 transpedicular screw, C1 laminar hook fixation and bone graft in the atlantoaxial instability

2021 ◽  
Vol 38 (2) ◽  
pp. 94-98
Author(s):  
Şükrü ORAL
Keyword(s):  
Motor Vehicle ◽  
Motor Vehicle Accident ◽  
Surgical Techniques ◽  
Atlantoaxial Instability ◽  
Posterior Arch ◽  
X Rays ◽  
Advantages And Disadvantages ◽  
Transpedicular Screw ◽  
Flexion Extension ◽  
Laminar Hooks

Traumatic atlantoaxial instability usually results from a motor vehicle accident, falls and motorcycle accidents. Atlantoaxial instability can lead to spinal cord compression and neck pain, but, spasticity and radicular symptoms as well. The purpose of surgery is to remove the compression and stabilize the joint permanently. To date, several surgical techniques have been described to remedy C1-C2 instability. In this study, the clinical and radiological outcomes of patients who operated with the C1 (Atlas bone) laminar hooks fixation and bilateral C2 (Axis bone) trans-pedicular screw technique were shown. Also, the advantages and disadvantages of this technique are discussed. From March 2010 to December 2017, 12 patients who have atlantoaxial instability were surgically treated by modified fixation technique which consists C1 laminar hooks fixation and bilateral C2 transpedicular screw. Twelve patients were operated with this procedure from March 2010 to December 2017. All the patients were checked with flexion-extension x-rays at the end of the twelfth week. The posterior bony fusion formation was observed on imaging in all patients. C2 bilateral pedicle screw combined with C1 laminar hook system is a good method for atlantoaxial instability in the conditions which is not convenient for insertion of C1 lateral mass and C2 trans-articular screw. However, this method may not be available in some cases such as traumatic, infection, neoplastic or degenerative pathologies in which the posterior arch of the atlas is damaged.

scholarly journals On the choice of priority approaches towards taxation of the population

2021 ◽  
pp. 19-35
Author(s):  
Anna Vital'evna Tikhonova
Keyword(s):  
Socioeconomic Development ◽  
Integrated Approach ◽  
Income Taxes ◽  
Tax Rates ◽  
Scientific Discussion ◽  
Advantages And Disadvantages ◽  
Correlation And Regression Analysis ◽  
Composition And Structure ◽  
Taxation System

The object of this research is the system of taxation of the population, while the subject is the composition and structure of taxes paid by private entities. The author analyzes the two priority approaches towards building the optimal and utmost fair system of taxation of private entities – through the object of “income” or “consumption”. Detailed analysis is conducted on the advanced Russian and foreign research on the topic. The author outlines the advantages and disadvantages of each approach from the perspective of horizontal and vertical justice, individual utility and its discounting. The scientific discussion on the absolute viability of taxation of income and consumption of the population is allocated into a separate chapter of the research. Based on the qualitative theoretical analysis, the author concludes on the rationality of choosing integrated approach towards creation of taxation system of the population. The cornerstone in this regard is the determination of the optimal ratio of consumption and income taxes. For this purpose, the author develops the original methodology based on the scattering matrix of 87 countries of the world, correlation and regression analysis of the indicators of their economic development and tax rates. The scientific novelty of consists in substantiation of the existence of substantial connection between the ratio of taxes on consumption and income of the population and the level of socioeconomic development of the country.

Cartilage Scales Embedded in Fibrin Gel

2017 ◽  
Vol 33 (02) ◽  
pp. 225-232 ◽  
Author(s):  
Milos Kovacevic ◽  
Frank Riedel ◽  
Jochen Wurm ◽  
Gregor Bran
Keyword(s):  
Regenerative Medicine ◽  
Surgical Techniques ◽  
Fibrin Gel ◽  
Platelet Rich Fibrin ◽  
Preliminary Results ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Dorsal Nasal Augmentation ◽  
Diced Cartilage ◽  
Nasal Augmentation

Multiple techniques have been described for dorsal nasal augmentation in rhinoplasty. In this article, we review common surgical techniques for raising the dorsum or eliminating dorsal irregularities, by highlighting inherent advantages and disadvantages of each method. Within the past few years, the use of diced cartilage grafts has become the workhorse in this field of interest. To overcome drawbacks of methods based on diced cartilage, we present a new concept for autologous augmentation, using regenerative medicine protocols. A mix of cartilage scales with cartilage pâté was embedded in platelet-rich fibrin (PRF). Since December 2015, a total of 48 patients were treated with this technique. Based on our preliminary results, cartilage scales in PRF appear to be a promising and reliable alternative to existing procedures for dorsal nasal augmentation.

Endoscopic Vitreoretinal Surgery; Basic Principles, Indications and New Directions

2021 ◽  
pp. 320-326
Keyword(s):  
Anterior Chamber ◽  
Historical Development ◽  
Surgical Techniques ◽  
Vitreoretinal Surgery ◽  
Basic Principles ◽  
Complementary Method ◽  
New Directions ◽  
Ocular Media ◽  
Media Opacities ◽  
Basic Features

In this review, we aimed to give information about the historical development, basic features, and major indications of microendoscopy in vitreoretinal surgery. Microendoscopy permits vitreoretinal surgery for tissues that are not visible using operating microscopy ophthalmoscopy. Evolving technology may overcome the technical limitations of current endoscopic technology. Endoscopic vitreoretinal surgery is particularly useful when tissue details blurred by ocular media opacities or anterior chamber aberrations in contemporary surgical microscopic ophthalmoscopy. Microendoscopy is a robust platform for vitreoretinal surgery. Ophthalmic microendoscopy as a complementary method to modern vitreoretinal surgical techniques is very useful for safe surgery when an operating a microscope becomes insufficient.

Primary Vitrectomy Surgery in Rhegmatogenous Retinal Detachment; Indications and Techniques

2019 ◽  
pp. 197-200
Keyword(s):  
Retinal Detachment ◽  
Visual Loss ◽  
Rhegmatogenous Retinal Detachment ◽  
Vitreoretinal Surgery ◽  
Scleral Buckling ◽  
Primary Vitrectomy ◽  
Advantages And Disadvantages ◽  
Instruments And Techniques ◽  
Vitrectomy Surgery ◽  
State Of Art

Retinal detachment is one of the most important causes of visual loss. Scleral buckling, pneumatic retinopexy, or primary vitrectomy techniques are the state of art treatment approaches for retinal detachment. Novel improvements in instruments and techniques of vitreoretinal surgery have led primary vitrectomy to be more preferable for retinal detachment surgery. Performing primary vitrectomy in selected patients, considering the advantages and disadvantages has a significant impact in terms of prognosis.

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