Simple arthroscopic technique to perform retrograde drilling for osteonecrosis of the femoral condyles with the use of ACL guide

A simple arthroscopic technique was introduced without the need for further staff during the operation. A 2.4 mm pin is positioned through the sleeve of an ACL tibial guide and it is marked with a steri-strip at its body, aiming at 5-10 mm distance between the tips of guide and the pin. The steri-strip serves as a mark and as a stop for inadvertent violation of the cartilage. The tip of the ACL is positioned just over the bone lesion, while the marked 2.4 mm pin is inserted through the ACL tibial guide from anterior surface of the femur. A stab incision is made and without advancing the sleeve to the bone, the pin is drilled to the marked position while cartilage integrity is confirmed arthroscopically. Our arthroscopic technique is simple, fast and effective and it is performed without the need of a special equipment. Keywords: Avascular necrosis; Osteonecrosis; Knee joint; Arthroscopic; Decompression

Enhanced Design of Narrowband Filters Based on The Extraordinary Transmission Through Single Fishnet Structures

A systematic method for the efficient design of narrowband filters founded on the extraordinary transmission via single fishnet structures (SFSs) is presented in this paper. Essentially, due to its strong resonant behavior, this phenomenon is proven suitable for the implementation of high-Q devices. The new design formulas are derived through the combination of full-wave numerical simulations and curve fitting algorithms. Also, adequate mathematical criteria are defined for the evaluation of the filters\u27 linear performance, indicating that the transmitted electromagnetic waves remain practically undistorted in the frequency band of interest. Then, by exploiting the previously developed relations, proper correction factors are introduced in the existing SFS equivalent circuit expressions, which hardly increase the overall computational complexity. This quantitative modification leads to an enhanced characterization of SFSs, as key components for diverse applications. Finally, several limitations as well as possible ways of extending the featured algorithm to more complicated structures and higher frequency bands are briefly discussed

Developing mathematical giftedness within primary schools : a study of strategies for educating children who are gifted in mathematics

This thesis explores the range of strategies used for educational provision for gifted children in mathematics in a group of schools in England. A review of literature relating to international theory and existing research in gifted education and empirical work into the teaching of gifted mathematicians were carried out. The literature review examined the dominant theories of intelligence and giftedness in general, including the historical background of definitions of giftedness and methods for its measurement, before specifically focusing on the concept of mathematical giftedness. The study was located in primary schools within Greater London, where schools are required to implement the ‘Gifted and Talented’ policy of the UK government. The research was conducted in two stages during the school years 2007-2008 and 2008-2009. The first stage involved a questionnaire survey sent to primary schools within five Local Educational Authorities. For the second stage of the research, which constituted the main study, a case study approach was used. The main methods of data collection employed within the case study were observations of mathematics lessons, semi-structured interviews with children nominated as able or gifted mathematicians and their teachers, as well as analysing documentary evidence (i.e., school policy, teacher’s planning, children’s assessment records and children’s written work). It was found that schools were responding to the policy in pragmatic terms, although no specific training was provided for practising teachers or school co-ordinators as part of the national training programme in making provision for mathematically gifted children. In practice, in classrooms, it was found that teachers’ level of confidence and expertise, the level of focused attention given to gifted children, the level of support and extension through higher-order questioning, as well as the size of the class and the nature of the work set were factors which affected the progress, perceptions and attitudes of children who were nominated to be able mathematicians. There is a paucity of research which has investigated aspects of provision for gifted and talented children, particularly in mathematics, in the UK. By specifically addressing this topic, this study makes a distinct contribution to current literature in both understanding aspects of mathematical giftedness and the range of provision used. This study makes a particular contribution to finding out how practising teachers in England are responding to a government initiative, which should be of interest to both policy-makers and practitioners. This thesis also presents examples for organising and teaching mathematics to gifted children at higher cognitive levels, within regular classrooms; this may be of interest to audiences internationally, including countries where there are no policies of provision for mathematically gifted children.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A new medication-based prediction score for postoperative delirium in surgical patients: development and proof of feasibility in a retrospective patient cohort

Structured risk screening for postoperative delirium (POD) considering prehospital medication is not established. We aimed to develop a POD-risk prediction score based on known risk factors and delirium-risk increasing drugs to be used by pharmacists during medication reconciliation at hospital admission, and to test for feasibility in a retrospective cohort of surgical patients. Therefore, established POD-risk factors and drugs were extracted from the literature and a score was generated. Following this, the score was tested for feasibility in a retrospective 3-month-cohort of surgical patients. For patients with higher scores suggesting higher probability of POD, patient charts were screened for documentation of POD. For development of the score, the following POD-risk factors were defined and points assigned for score calculation: age (≥65 years=1 point/≥75 years=2), male sex (1), renal insufficiency (RI; 1), hepatic impairment (HI; Model-of-endstage-liver-disease (MELD) 10-14=1/≥15=2), delirium-risk increasing drugs (1 point per drug class), anticholinergic drug burden (ACB; ≥3=1). In the retrospective test cohort of 1174 surgical patients these factors concerned: age ≥65 years 567 patients (48%)/≥75 years 303 (26%), male 652 (55%), RI 238 (20%), MELD 10-14 106 (9%)/≥15 65 (5%), ≥ 1 delirium-risk increasing drug 418 (36%), ACB ≥3 106 (9%). The median POD-risk prediction score was 2 (range 0-9). Of 146 patients (12%) with a score ≥ 5, POD was documented for 43 (30%), no evidence for POD for 91 (62%) and data inconclusive for 12 (8%). For scores of ≥ 7, POD was documented for 50% of the patients with sufficient POD documentation. Overall, POD documentation was poor. To summarize, we developed and successfully tested the feasibility of a POD-prediction-score assessable by pharmacists at medication reconciliation at hospital admission

Polarizability Matrix Extraction of a Bianisotropic Metamaterial from the Scattering Parameters of Normally Incident Plane Waves

In this paper, a polarizability matrix retrieval method for bianisotropic metamaterials is presented. Assuming that scatterers can be modeled by electric and magnetic pointdipoles located at their centers, the induced dipole moments are analytically related to the normally incident fields, while the scattered fields are also analytically obtained for two individual cases of normal wave incidence. The latter can be combined with the incident fields, to express the desired polarizabilities, with regard to the measured or simulated scattering parameters. In this way, the polarizability matrix can be extracted by solving the resulting non-linear system of equations. The proposed technique is applied to two different split-ring resonator structures and reveals very good agreement with previously reported techniques

DGP Cosmology with a Non-Minimally Coupled Scalar Field on the Brane

We construct a DGP inspired braneworld scenario where a scalar field non-minimally coupled to the induced Ricci curvature is present on the brane. First we investigate the status of gravitational potential with non-minimal coupling and observational constraints on this non-minimal model. Then we further deepen the idea of embedding of FRW cosmology in this non-minimal setup. Cosmological implications of this scenario are examined with details and the quintessence and late-time expansion of the universe within this framework are examined. Some observational constraints imposed on this non-minimal scenario are studied and relation of this model with dark radiation formalism is determined with details.Comment: 26 pages, 3 eps figure

Brane Cosmology with a Non-Minimally Coupled Bulk-Scalar Field

We consider the cosmological evolution of a brane in the presence of a bulk scalar field coupled to the Ricci scalar through a term f(\phi)R. We derive the generalized Friedmann equation on the brane in the presence of arbitrary brane and bulk-matter, as well as the scalar field equation, allowing for a general scalar potential V(phi). We focus on a quadratic form of the above non-minimal coupling and obtain a class of late-time solutions for the scale factor and the scalar field on the brane that exhibit accelerated expansion for a range of the non-minimal coupling parameter.Comment: 15 page