Friction behaviour of hydrophilic lubricious coatings for medical device applications

The friction behaviour of new chitosan derivative coatings obtained by chemical modification of chitosan with fatty acids (linoleic and dilinoleic acid) has been investigated in order to explore their potential as endovascular catheter coatings and to benchmark them against commercially available coatings used in endovascular catheter applications. An in vitro tribological system was developed that was intended to represent to a limited extent the in vivo tribological conditions of a typical endovascular catheterization procedure. Continuous reciprocating sliding tests were carried out with uncoated and coated polymer specimens. The results showed that all of the coatings tested decreased the coefficient of friction compared to the uncoated polymer. Compared to a neat chitosan coating, the chitosan derivative coatings showed a clear reduction in the coefficient of friction to levels similar to those of the commercially-available coatings. A comparison between the friction results and contact angle measurements carried out on the coatings indicated that a range of contact angle values exists for which the friction coefficient is at a minimum. The reason for this is unclear and further studies are required in order to confirm and investigate the trend, especially within the context of hydrophilic lubricious coating development

Location of the narrowest area of the pharynx regarding body mass index and obstructive sleep apnoea severity

Background: Among authors studying morphological determinants of the obstructive sleep apnoea (OSA) controversies exist on the location of the narrowest area within the pharynx, critical for development of obstruction. Those disagreements primarily revolve around differences between obese and nonobese OSA patients. Determination whether the location and size of the narrowest area within the pharynx differentiates the obese and nonobese OSA patients. Materials and methods: A population of 55 subjects was investigated after being diagnosed with OSA in the Polysomnography Laboratory of the Department and Clinic of Otolaryngology in the Medical University of Warsaw, Poland. Additionally a head computed tomography (CT) was performed in all the subjects. The CT images were used to do several crucial measurements which described the geometry of the facial skeleton as well as soft tissues of the head. The obtained results were correlated with apnoea-hypopnoea index (AHI) and body mass index (BMI) values. The data were statistically analysed. Results: The distance between the hard palate and posterior pharyngeal wall parallel to the horizontal plane as well as the shortest distance between the soft palate and posterior pharyngeal wall significantly differentiated patients in the subgroups by AHI but not by BMI. Conclusions: Pharyngeal obstruction at the level of the hard and soft palate differentiates patients with severe OSA from patients with mild and moderate OSA regardless of BMI

The supreme turbinate and the drainage of the posterior ethmoids: a computed tomographic study

Background: It is generally acknowledged that the posterior ethmoidal cells drain under the superior nasal turbinate (SorNT) or, rarely, under the supreme nasal turbinate (SmeNT), and the sphenoid ostium (SO) opens to the sphenoethmoidal recess. However, detailed relations between these structures are variable, complex and still not clear. There is no reliable data on the prevalence of SmeNT and drainage of the posterior ethmoidal cells under this structure. The aim of this study was to re-evaluate the anatomy of the aforementioned region. Materials and methods: Multiplanar and three-dimensional reconstruction analysis of 100 thin slice paranasal sinus computed tomography scans. Results: SmeNT was identified in 77 subjects (136 sides). It formed the ostium to the posterior ethmoidal cell adjacent to the skull base or orbit in 58 subjects (91 sides). This cell drained independently from the remaining posterior ethmoidal cells. The sphenoethmoidal (Onodi) cell drained to supreme meatus in 41 subjects (54 sides), and to superior meatus in 37 subjects (49 sides). SO was always located medial to the posteroinferior attachment of SmeNT, or SorNT (in absence of SmeNT). Conclusions: Patients with divergent drainage of the posterior ethmoids (with posterior ethmoidal cell draining to the supreme meatus) may require more extensive surgery to avoid persistence or recurrence of inflammatory disease. SmeNT is more common than thought, but due to its posterior and superior location to SorNT, it is rarely seen intraoperatively. If SmeNT is present, SO is always located medial to its posteroinferior attachment. (Folia Morphol 2018; 77, 1: 110–115

Dual-path state reconstruction scheme for propagating quantum microwaves and detector noise tomography

Quantum state reconstruction involves measurement devices that are usually described by idealized models, but not known in full detail in experiments. For weak propagating microwaves, the detection process requires linear amplifiers which obscure the signal with random noise. Here, we introduce a theory which nevertheless allows one to use these devices for measuring all quadrature moments of propagating quantum microwaves based on cross-correlations from a dual-path amplification setup. Simultaneously, the detector noise properties are determined, allowing for tomography. We demonstrate the feasibility of our novel concept by proof-of-principle experiments with classical mixtures of weak coherent microwaves.Comment: 11 pages, 3 figure

Methods of restrictions in the number of cockchafer population in the forestry of Poland and Ukraine

Analysis of intensity of cockchafer distribution in Ukraine and Poland is carried out. Methods and ways of pest control are evaluated. Complex approaches to application of means and methods of forest stands protection are presented. Attention is paid to wider introduction of forestry methods for the restriction of pest distribution.Приведен анализ интенсивности распространения майского хруща в Украине и Польше. Оценены методы и способы борьбы с вредителем. Предложены комплексные подходы к применению средств и методов защиты лесных насаждений. Акцентировано внимание на более широком внедрении биологических и лесоводственных методов ограничения распространения вредителя.Наведено аналіз інтенсивності поширення травневого хруща в Україні та Польщі. Оцінено методи та способи його контролювання. Запропоновані комплексні підходи до застосування засобів і методів захисту лісових насаджень. Акцентовано увагу на ширшому запровадженні біологічних і лісівничих методів обмеження поширення шкідника

Pilot Source Study: An Analysis of Pilot Backgrounds and Subsequent Success in US Regional Airline Training Programs

The 2010 Pilot Source Study, commissioned to research the success of pilots in initial training for Part 121 operations, analyzed the training performance of 2,156 new-hire pilots in the years 2005-2009. Six regional airlines provided data that was mined from human resource and pilot training files. Five university researchers independently analyzed the data and integrated their results. The study expressed success in terms of fewer extra training events and fewer non-completions in regional airline training. Statistically, the best performing pilots were those who had flight instructor certificates, graduated from collegiate accredited flight programs, received advanced (post-Private) pilot training in college, graduated with collegiate aviation degrees (any aviation discipline), and had between 500 and 1,000 pre-employment flight hours. Pilot source characteristics that had no significance in regional airline pilot training success were: having a non-aviation college degree and having prior corporate pilot or airline pilot experience

Progress on Chemistry and Application of Chitin and Its

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