3-D Printed Protective Equipment during COVID-19 Pandemic

While the number of coronavirus cases from 2019 continues to grow, hospitals are reporting shortages of personal protective equipment (PPE) for frontline healthcare workers. Furthermore, PPE for the eyes and mouth, such as face shields, allow for additional protection when working with aerosols. 3-D printing enables the easy and rapid production of lightweight plastic frameworks based on open-source data. The practicality and clinical suitability of four face shields printed using a fused deposition modeling printer were examined. The weight, printing time, and required tools for assembly were evaluated. To assess the clinical suitability, each face shield was worn for one hour by 10 clinicians and rated using a visual analogue scale. The filament weight (21-42 g) and printing time (1:40-3:17 h) differed significantly between the four frames. Likewise, the fit, wearing comfort, space for additional PPE, and protection varied between the designs. For clinical suitability, a chosen design should allow sufficient space for goggles and N95 respirators as well as maximum coverage of the facial area. Consequently, two datasets are recommended. For the final selection of the ideal dataset to be used for printing, scalability and economic efficiency need to be carefully balanced with an acceptable degree of protection

Cheater detection for randomized response-techniques : derivation, analyses and application

Finding out how often an embarrassing characteristic exists in a population is accompanied by numerous problems that are due in particular to false answers as a consequence of social undesirability. The oldest of the techniques developed to compensate for these distortions is the Randomized Response Technique which is currently still the most widely used, evaluated and researched technique in the field of sensitive subjects. Although this technique guarantees complete security for the person being questioned and therefore opens up options for answering even threatening questions honestly, even here "cheating" occurs in terms of not complying with the instructions. This volume describes the mathematical derivation of techniques to detect the extent to which this "cheating" occurs. It also provides analyses on the process characteristics and extends these analyses to include practical advice on how to use this process flexibly. A general solution is developed for various forms of "cheating" for the first time

Smart Textiles Production

The research field of smart textiles is currently witnessing a rapidly growing number of applications integrating intelligent functions in textile substrates. With an increasing amount of new developed product prototypes, the number of materials used and that of specially designed production technologies are also growing. This book is intended to provide an overview of materials, production technologies, and product concepts to different groups concerned with smart textiles. It will help designers to understand the possibilities of smart textile production, so that they are enabled to design this type of products. It will also help textile and electronics manufacturers to understand which production technologies are suitable to meet certain product requirements

Impurities in commercial titanium dental implants – A mass and optical emission spectrometry elemental analysis

Objective: Titanium (Ti) is considered bioinert and is still regarded as the “gold standard” material for dental implants. However, even ‘commercial pure’ Ti will contain minor fractions of elemental impurities. Evidence demonstrating the release of Ti ions and particles from ‘passive’ implant surfaces is increasing and has been attributed to biocorrosion processes which may provoke immunological reactions. However, Ti observed in peri-implant tissues has been shown to be co-located with elements considered impurities in biomedical alloys. Accordingly, this study aimed to quantify the composition of impurities in commercial Ti dental implants. Methods: Fifteen commercial titanium dental implant systems were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). Results: The elemental composition of implants manufactured from commercially pure grades of Ti, Ti-6Al-4V, and the TiZr alloy (Roxolid) conformed to the respective ISO/ASTM standards or manufacturers´ data (TiZr/Roxolid). However, all implants investigated included exogenous metal contaminants including Ni, Cr, Sb, and Nb to a variable extent. Other contaminants detected in a fraction of implants included As and the radionuclides U-238 and Th-232. Significance: Although all Ti implant studies conformed with their standard compositions, potentially allergenic, noxious metals and even radionuclides were detected. Since there are differences in the degree of contamination between the implant systems, a certain impurity fraction seems technically avoidable. The clinical relevance of these findings must be further investigated, and an adaptation of industry standards should be discussed

Herleitung, Analyse und Anwendung

Will man herausfinden, wie häufig eine peinliche Eigenschaft in einer Population auftritt, gehen damit etliche Probleme einher, die vor allem auf verfälschte Antworten in Folge sozialer Erwünschtheit zurückgehen. Die älteste der Techniken, die entwickelt wurden um diese Verzerrungen zu kompensieren ist die Randomized Response-Technik, die auch derzeit noch die am weitesten verbreitete und am meisten evaluierte und erforschte Technik im Feld sensitiver Themen darstellt. Obwohl diese Technik den Befragten vollständige Sicherheit garantiert und damit die Möglichkeit eröffnet, auch auf bedrohliche Fragen ehrlich zu antworten, tritt auch dabei „Cheating“ auf im Sinne der Nicht-Beachtung der Instruktionen. Der vorliegende Band beschreibt die mathematische Herleitung von Techniken zur Erkennung des Ausmaßes, in dem dieses „Cheating“ auftritt. Er stellt darüber hinaus Analysen zu Eigenschaften des Verfahrens dar und erweitert diese Analysen um praktische Hinweise zum flexiblen Einsatz dieser Verfahren. Dabei wird erstmals für unterschiedliche Formen des „Cheatings“ eine allgemeine Lösung entwickelt

Articulatory function in glossectomized patients with immediate reconstruction using a free jejunum flap

Postoperative articulation in 18 glossectomized patients was investigated. The subjects were: 5 cases of tongue tumour, 7 cases of tumour of the anterior part of the floor of the mouth and 6 cases of tumour of the lateral part. A new modification of the Freiburger test for speech audiometry was used as test material. Then the articulatory function was assessed according to an overall score based on 180 monosyllables, the manner of production of 171 initial consonants and the place of production of 85 glossal sounds. The cases of tumour of the tongue and the lateral part of the floor of the mouth had excellent scores in all classes of sounds, which were compatible with the normative data. The subjects of tumour of the anterior part of the floor of the mouth had low overall scores, low scores for plosive and affricative sounds, and very low scores for sounds produced with the rear of the tongue. The relation between the site or amount of resection and subsequent articulation was significantly poor in all categories of sounds for the cases of anterior tumour, particularly in the movement of the posterior portion of the tongue even though it was not involved in the operation. In all groups there was a weak negative relation between the amount of resection and postoperative articulation. In reviewing the literature, reconstruction with a free jejunum flap was considered to lead to better articulation than reconstruction by other techniques. The need to assess postoperative function objectively was stressed, to compare the postoperative functions and to determine the indications for the reconstructive technique