73 research outputs found
A Four Slot Dual Feed and Dual Band Reconfigurable Antenna for Fixed Satellite Service Applications
A dual feed and dual-band reconfigurable antenna is designed, analyzed, and prototyped in this work for fixed satellite service communication applications. The designed model occupies the compact dimension of 24X21X1.2 mm on FR4 substrate and provides an input impedance of 50 ohms at both ports. The proposed model offers additional circular polarization characteristics at both the resonating bands. The PIN diode-based switching conditions, and the frequency reconfigurability analysis in both simulation and measurement are almost match. The combination of dual-band resonance, frequency reconfigurable nature, and compact dimension makes this model an attractive candidate in the specified field with considerable gain (8.5 dB) and efficiency (80%)
Removal of failed crown and bridge
Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices
have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns
and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more
challenging. Removal is often by destructive means. There are a number of circumstances, however, in which
conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are
different mechanisms available to remove a failed crown or bridge. But there is no information published about the
classification of available systems for crown and bridge removal. So it is logical to classify these systems into different
groups which can help a clinician in choosing a particular type of system depending upon the clinical situation.
The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a
number of systems work; and when and why they might be used.
A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal,
Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews,
their cross references as well as articles published in various journals like International Endodontic Journal,
Journal of Endodontics and were manually searched
Assessment of Various Factors for Feasibility of Fixed Cantilever Bridge: A Review Study
Cantilever fixed partial dentures are defined as having one or more abutments at one end of the prosthesis while the other end is unsupported. Much controversy without documentary evidence has surrounded this prosthesis. Despite negative arguments, the cantilever prosthesis has been used extensively by the clinicians. If used nonjudiciously without following proper guidelines these might lead to some complications. Although complications may be an indication that clinical failure has occurred, this is not typically the case. It is also possible that complications may reflect substandard care. Apart from the substandard care, the unique arrangement of the abutments and pontic also accounts for the prime disadvantage: the creation of a class I lever system. When the cantilevered pontic is placed under occlusal function, forces are placed on the abutments. There are various criteria and factors necessary for a successful cantilever fixed partial denture (FPD). The purpose of this paper is to discuss briefly various factors involved in the planning of a cantilever fixed partial denture
Structural and Dielectric Characterization of La Modified PZT (52/48) Nano Ceramic Material for Electronic Applications
The objective of the presented work is to investigate the effects of varying concentration of La as hard dopant on structural, morphological and dielectric properties of lead zirconium titanate (PZT). The base material PZT was prepared by sol-gel technique on lab scale to reduce the injection of sintering defects. After addition of varying weight percentage of La, the different composite materials were analyzed under scanning electron microscope to study the structural modifications taking place. X-Ray diffraction patterns were studied in combination with variation of dielectric constant with temperature and frequency. it is observed that a single phase perovskite structure with tetragonal phase is formed for all compositions of PLZT. The dielectric constant of undoped PZT is found to be 11,300 at a temperature of 500OC and frequency of 100Hz. The results further indicate that the dielectric properties of the pure-phase PZT are better than La doped PZT at higher temperature
Short clinical crowns (SCC) ' treatment considerations and techniques
When the clinical crowns of teeth are dimensionally inadequate, esthetically and biologically acceptable restoration
of these dental units is difficult. Often an acceptable restoration cannot be accomplished without first surgically
increasing the length of the existing clinical crowns; therefore, successful management requires an understanding
of both the dental and periodontal parameters of treatment. The complications presented by teeth with short clinical
crowns demand a comprehensive treatment plan and proper sequencing of therapy to ensure a satisfactory result.
Visualization of the desired result is a prerequisite of successful therapy. This review examines the periodontal and
restorative factors related to restoring teeth with short clinical crowns. Modes of therapy are usually combined to
meet the biologic, restorative, and esthetic requirements imposed by short clinical crowns. In this study various
methods for treating short clinical crowns are reviewed, the role that restoration margin location play in the maintenance
of periodontal and dental symbiosis and the effects of violation of the supracrestal gingivae by improper
full-coverage restorations has also been discussed
History of materials used for recording static and dynamic occlusal contact marks: a literature review
In the discipline of prosthetic dentistry it is important not only to examine the occlusion, but to be able to record,
store, and transfer the information. Over the years many occlusion testing materials have been used. It has been
suggested the clinical recording and transfer of information using waxes and other occlusion recording materials
have disadvantages relating to inaccuracy and problems of manipulation. Therefore, there has been introduction
of many new systems for recording occlusion contacts to overcome such problems. The correct physiological
recovery of occlusion posses as much a challenge as ever for every dentist and technician. Even the smallest high
spots measuring just a few microns can cause dysfunctions like temporo-mandibular pain. Occlusal proportions are
being constantly changed with every procedure. Therefore, an understanding of the synergy of the teeth in static
and dynamic occlusion forms the basis of good dentistry. The purpose of this review article is to give and overview
of the various materials and methods that have been used to record occlusal contact marks
OPTIMIZED WIND ENERGY SYSTEM INTEGRATION WITH VSC HVDC FOR POWER TRANSMISSION
Increased demand in renewable power move towards the balancing conventional dependent energy source lead the increase in technical development in reliable power generation. This model contains the wind speed variation, capacity, uncertainty, and production are considered in system evaluations to bring the wind power to more sustainable energy. More reliable VSC HVDC technology in power transmissions for longer distances is preferred to transmit the renewable generated energy to remote end areas. Authors introduced particle swarm optimization method into the wind integrated HVDC System. The system is developed in MATLAB/Simulink to evaluate the wind power generation performance and Transmission performance. The simulation results are correlated and validated with the existing VSC HVDC link parameters. The supremacy in wind energy with particle swarm optimization performance is validated and more viable to integrate wind energy system with VSC HVDC system to transmit the reliable power to remote areas
Effect of Aspirin Versus Low-Molecular-Weight Heparin Thromboprophylaxis on Medication Satisfaction and Out-of-Pocket Costs: A Secondary Analysis of a Randomized Clinical Trial
BACKGROUND: Current guidelines recommend low-molecular-weight heparin for thromboprophylaxis after orthopaedic trauma. However, recent evidence suggests that aspirin is similar in efficacy and safety. To understand patients\u27 experiences with these medications, we compared patients\u27 satisfaction and out-of-pocket costs after thromboprophylaxis with aspirin versus low-molecular-weight heparin.
METHODS: This study was a secondary analysis of the PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT) trial, conducted at 21 trauma centers in the U.S. and Canada. We included adult patients with an operatively treated extremity fracture or a pelvic or acetabular fracture. Patients were randomly assigned to receive 30 mg of low-molecular-weight heparin (enoxaparin) twice daily or 81 mg of aspirin twice daily for thromboprophylaxis. The duration of the thromboprophylaxis, including post-discharge prescription, was based on hospital protocols. The study outcomes included patient satisfaction with and out-of-pocket costs for their thromboprophylactic medication measured on ordinal scales.
RESULTS: The trial enrolled 12,211 patients (mean age and standard deviation [SD], 45 ± 18 years; 62% male), 9725 of whom completed the question regarding their satisfaction with the medication and 6723 of whom reported their out-of-pocket costs. The odds of greater satisfaction were 2.6 times higher for patients assigned to aspirin than those assigned to low-molecular-weight heparin (odds ratio [OR]: 2.59; 95% confidence interval [CI]: 2.39 to 2.80; p \u3c 0.001). Overall, the odds of incurring any out-of-pocket costs for thromboprophylaxis medication were 51% higher for patients assigned to aspirin compared with low-molecular-weight heparin (OR: 1.51; 95% CI: 1.37 to 1.66; p \u3c 0.001). However, patients assigned to aspirin had substantially lower odds of out-of-pocket costs of at least 25, potentially improving health equity for thromboprophylaxis.
LEVEL OF EVIDENCE: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence
Post-Fasciotomy Classification System for Acute Compartment Syndrome of the Leg
Objective: Acute compartment syndrome (ACS) is a true emergency. Even with urgent fasciotomy there is often muscle damage and need for further surgery. Although ACS is not uncommon, no validated classification system exists to aid in efficient and clear communication. The aim of this study was to establish and validate a classification system for the consequences of ACS treated with fasciotomy. Methods: Using a modified Delphi method, an international panel of ACS experts was assembled to both establish a grading scheme for the disease and then validate the classification system. The goal was to articulate discrete grades of ACS related to fasciotomy findings and associated costs. A pilot analysis was used to determine questions that were clear to the respondents. Discussion of this analysis resulted in another round of cases used for 24 other raters. The twenty-four individuals implemented the classification system two separate times to compare outcomes for 32 clinical cases. The accuracy and reproducibility of the classification system were subsequently calculated based on the providers' responses. Results: The Fleiss’ Kappa of all raters was at 0.711 showing a strong agreement between the 24 raters. Secondary validation was performed for paired 276 raters and correlation was tested using the Kendall coefficient. The median correlation coefficient was 0.855. All 276 pairs had statistically significant correlation. Correlation coefficient between the first and second rating sessions was strong with the median pair scoring at 0.867. All surgeons had statistically significant internal consistency. Conclusion: This new ACS classification system may be applied to better understand the impact of ACS on patient outcomes and economic costs for leg ACS. Level of Evidence: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved
The PE-PPE Domain in Mycobacterium Reveals a Serine α/β Hydrolase Fold and Function: An In-Silico Analysis
The PE and PPE proteins first reported in the genome sequence of Mycobacterium tuberculosis strain H37Rv are now identified in all mycobacterial species. The PE-PPE domain (Pfam ID: PF08237) is a 225 amino acid residue conserved region located towards the C-terminus of some PE and PPE proteins and hypothetical proteins. Our in-silico sequence analysis revealed that this domain is present in all Mycobacteria, some Rhodococcus and Nocardia farcinica genomes. This domain comprises a pentapeptide sequence motif GxSxG/S at the N-terminus and conserved amino acid residues Ser, Asp and His that constitute a catalytic triad characteristic of lipase, esterase and cutinase activity. The fold prediction and comparative modeling of the 3-D structure of the PE-PPE domain revealed a “serine α/β hydrolase” structure with a central β-sheet flanked by α-helices on either side. The structure comprises a lid insertion with a closed structure conformation and has a solvent inaccessible active site. The oxyanion hole that stabilizes the negative charge on the tetrahedral intermediate has been identified. Our findings add to the growing list of serine hydrolases in mycobacterium, which are essential for the maintenance of their impermeable cell wall and virulence. These results provide the directions for the design of experiments to establish the function of PE and PPE proteins
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