556 research outputs found

    The Alvarez and Lohmann refractive lenses revisited

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    15 pages, 10 figures.-- OCIS codes: 080.1510, 080.2740, 330.4460.Alvarez and Lohmann lenses are variable focus optical devices based on lateral shifts of two lenses with cubic-type surfaces. I analyzed the optical performance of these types of lenses computing the first order optical properties (applying wavefront refraction and propagation) without the restriction of the thin lens approximation, and the spot diagram using a ray tracing algorithm. I proposed an analytic and numerical method to select the most optimum coefficients and the specific configuration of these lenses. The results show that Lohmann composite lens is slightly superior to Alvarez one because the overall thickness and optical aberrations are smaller.I benefit from a Spanish Ministry of Science-UPM "Ramón y Cajal" contract.Peer reviewe

    «Diseño para todos» en la investigación social sobre personas con discapacidad

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    [EN] Social studies on disability have increased in number and importance in Spain and other countries over the last few years. Nevertheless, the majority of the available sources and studies do not adequately represent this heterogeneous group, which currently makes up about 9 per cent of the Spanish population. The implementation of social measures requires representative sources and studies containing relevant information. The aim of this paper is to identify the main diffi culties involved in designing and developing social research methods concerning persons with disabilities, and offer proposals and recommendations in order to advance towards a more inclusive social research using the concepts of accessibility and design for all.[ES] Los estudios sociales sobre la discapacidad han aumentado en número e importancia en España y otros países durante los últimos años. Sin embargo, la mayoría de fuentes de información y estudios disponibles no recogen de manera adecuada la realidad de un colectivo muy heterogéneo, que supone en la actualidad aproximadamente el 9 por ciento de la población española. La implementación de medidas sociales requiere de fuentes y estudios representativos que aporten información precisa acerca de estas personas. El objetivo de esta nota es identifi car las principales difi cultades que se plantean a la hora de diseñar y llevar a la práctica metodologías de investigación social adecuadas hacia las personas con discapacidad, así como ofrecer propuestas y recomendaciones para avanzar hacia una investigación social más inclusiva, mediante los conceptos de accesibilidad y diseño para todos.Work carried out as part of the framework of research projects: “Qualitative Tracking with Young Disabled in European States. Quali-TYDES” (European Science Foundation, 09-ECRP-032) and “Hidden Innovation: paradigm shift in innovation studies” (Spanish Ministry of Economy and Competitiveness, FFI2011-25475).Peer reviewe

    Controversial Aspects of Diagnostics and Therapy of Arthritis of the Temporomandibular Joint in Rheumatoid and Juvenile Idiopathic Arthritis: An Analysis of Evidence- and Consensus-Based Recommendations Based on an Interdisciplinary Guideline Project

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    Introduction: Due to potentially severe sequelae (impaired growth, condylar resorption, and ankylosis) early diagnosis of chronic rheumatic arthritis of the temporomandibular joint (TMJ) and timely onset of therapy are essential. Aim: Owing to very limited evidence the aim of the study was to identify and discuss controversial topics in the guideline development to promote further focused research. Methods: Through a systematic literature search, 394 out of 3771 publications were included in a German interdisciplinary guideline draft. Two workgroups (1: oral and maxillofacial surgery, 2: interdisciplinary) voted on 77 recommendations/statements, in 2 independent anonymized and blinded consensus phases (Delphi process). Results: The voting results were relatively homogenous, except for a greater proportion of abstentions amongst the interdisciplinary group (p < 0.001). Eighty four percent of recommendations/statements were approved in the first round, 89% with strong consensus. Fourteen recommendations/statements (18.2%) required a prolonged consensus phase and further discussion. Discussion: Contrast-enhanced MRI was confirmed as the method of choice for the diagnosis of TMJ arthritis. Intraarticular corticosteroid injection is to be limited to therapy refractory cases and single injection only. In adults, alloplastic joint replacement is preferable to autologous replacement. In children/adolescents, autologous reconstruction may be performed lacking viable alternatives. Alloplastic options are currently still considered experimental

    Large Process Models: Business Process Management in the Age of Generative AI

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    The continued success of Large Language Models (LLMs) and other generative artificial intelligence approaches highlights the advantages that large information corpora can have over rigidly defined symbolic models, but also serves as a proof-point of the challenges that purely statistics-based approaches have in terms of safety and trustworthiness. As a framework for contextualizing the potential, as well as the limitations of LLMs and other foundation model-based technologies, we propose the concept of a Large Process Model (LPM) that combines the correlation power of LLMs with the analytical precision and reliability of knowledge-based systems and automated reasoning approaches. LPMs are envisioned to directly utilize the wealth of process management experience that experts have accumulated, as well as process performance data of organizations with diverse characteristics, e.g., regarding size, region, or industry. In this vision, the proposed LPM would allow organizations to receive context-specific (tailored) process and other business models, analytical deep-dives, and improvement recommendations. As such, they would allow to substantially decrease the time and effort required for business transformation, while also allowing for deeper, more impactful, and more actionable insights than previously possible. We argue that implementing an LPM is feasible, but also highlight limitations and research challenges that need to be solved to implement particular aspects of the LPM vision

    The ESTMJS (European Society of Temporomandibular Joint Surgeons) consensus and evidence-based recommendations on management of Condylar dislocation

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    © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Although condylar dislocation is not uncommon, terminology, diagnostics, and treatment concepts vary considerably worldwide. This study aims to present a consensus recommendation based on systematically reviewed literature and approved by the European Society of TMJ Surgeons (ESTMJS). Based on the template of the evidence-based German guideline (register # 007-063) the ESTMJS members voted on 30 draft recommendations regarding terminology, diagnostics, and treatment initially via a blinded modified Delphi procedure. After unblinding, a discussion and voting followed, using a structured consensus process in 2019. An independent moderator documented and evaluated voting results and alterations from the original draft. Although the results of the preliminary voting were very heterogenous and differed significantly from the German S3 guideline (p < 0.0005), a strong consensus was achieved in the final voting on terminology, diagnostics, and treatment. In this voting, multiple alterations, including adding and discarding recommendations, led to 24 final recommendations on assessment and management of TMJ dislocation. To our knowledge, the ESTMJS condylar dislocation recommendations are the first both evidence and consensus-based international recommendations in the field of TMJ surgery. We recommend they form the basis for clinical practice guidelines for the management of dislocations of the mandibular condyle.info:eu-repo/semantics/publishedVersio

    Gender specific quality of life in patients with oral squamous cell carcinomas

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    <p>Abstract</p> <p>Background</p> <p>The goal of this study was to evaluate the somatic and psychological effects by means of QUALITY OF LIFE (QOL) of surgical treatment of patients with oral squamous cell carcinoma. The factors gender, age, nicotine consumption, and tumour stage were taken into consideration.</p> <p>Methods</p> <p>54 patients after surgical resection of oral squamous cell carcinomas (OSCC) were analysed from 01.09.2005 to 31.05.2008. Inclusion criteria for the study were: age at least 18 years, no indication or treatment of synchronous and metachronous tumours.</p> <p>German translations of the EORTC H&N-35 and EORTC QLQ-C-30 questionnaires, as well as a general socioeconomic patient history were used as measuring instruments. The questionnaires were completed independently by the patients. The answers were translated into scale values for statistical evaluation using appropriate algorithms.</p> <p>Results</p> <p>Analysis of the EORTC-QLQ-C-30 questionnaires demonstrated a tendency of more negative assessment of emotional function among the female participants, and a more negative evaluation of social function among the male participants. Greater tumour sizes showed significantly lower bodily function (p = 0.018). While a smaller tumour size was significantly associated with lower cognitive functioning (p = 0.031). Other cofactors such as age, nicotine consumption, and tumour stage only showed a tendency to influence the quality of sleep and daily life.</p> <p>Conclusions</p> <p>The data obtained within this investigation demonstrated that gender had the most significant power on the subjectively perceived postoperative quality of life. This factor is important e.g. in preoperative decision making regarding immediate microvascular reconstruction after e.g. mandibular resection and therefore QOL assessment should become integral component of the care of patients with OSCC.</p

    A new biphasic osteoinductive calcium composite material with a negative Zeta potential for bone augmentation

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    The aim of the present study was to analyze the osteogenic potential of a biphasic calcium composite material (BCC) with a negative surface charge for maxillary sinus floor augmentation. In a 61 year old patient, the BCC material was used in a bilateral sinus floor augmentation procedure. Six months postoperative, a bone sample was taken from the augmented regions before two titanium implants were inserted at each side. We analyzed bone neoformation by histology, bone density by computed tomography, and measured the activity of voltage-activated calcium currents of osteoblasts and surface charge effects. Control orthopantomograms were carried out five months after implant insertion. The BCC was biocompatible and replaced by new mineralized bone after being resorbed completely. The material demonstrated a negative surface charge (negative Zeta potential) which was found to be favorable for bone regeneration and osseointegration of dental implants

    Outcome of crisis intervention for borderline personality disorder and post traumatic stress disorder: a model for modification of the mechanism of disorder in complex post traumatic syndromes

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    <p>Abstract</p> <p>Background</p> <p>This study investigates the outcome of crisis intervention for chronic post traumatic disorders with a model based on the theory that such crises manifest trauma in the present. The sufferer's behavior is in response to the current perception of dependency and entrapment in a mistrusted relationship. The mechanism of disorder is the sufferer's activity, which aims to either prove or disprove the perception of entrapment, but, instead, elicits more semblances of it in a circular manner. Patients have reasons to keep such activity private from therapy and are barely aware of it as the source of their symptoms.</p> <p>Methods</p> <p>The hypothesis is that the experimental intervention will reduce symptoms broadly within 8 to 24 h from initiation of treatment, compared to treatment as usual. The experimental intervention sidesteps other symptoms to engage patients in testing the trustworthiness of the troubled relationship with closure, thus ending the circularity of their own ways. The study compares 32 experimental subjects with 26 controls at similar crisis stabilization units.</p> <p>Results</p> <p>The results of the Brief Psychiatric Rating Scale (BPRS) supported the hypothesis (both in total score and for four of five subscales), as did results with Client Observation, a pilot instrument designed specifically for the circular behavior targeted by the experimental intervention. Results were mostly non-significant from two instruments of patient self-observation, which provided retrospective pretreatment scores.</p> <p>Conclusions</p> <p>The discussion envisions further steps to ascertain that this broad reduction of symptoms ensues from the singular correction that distinguishes the experimental intervention.</p> <p>Trial registration</p> <p>Protocol Registration System NCT00269139. The PRS URL is <url>https://register.clinicaltrials.gov</url></p
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