Spectrophotometer for atmospheric ozone research – receiver reaction of irradiation with complex spectral composition

One of the basic problems in elaboration of spectro-photometer for atmospheric ozone research at the Space Research and Technologies Institute – Bulgarian Academy of Sciences seems to be the necessity of calculation of output signal of the irradiating receiver by fixed spectral composition and intensity. The calculation wouldn’t be difficult if the intensity values range is situated on the linear part of the irradiating receiver energetic characteristic. To the end, the absolutely spectral characteristic of receiver sensibility and spectral density of the treated receiver intensity has to be known. The paper is dedicated to the elaboration and the obtained results by offering and creating a method for definition of the irradiating receiver output signal by fixed spectral composition and intensity In the paper presents the obtained schemes and equations in the process of elaboration characterizing the reaction of the photo-receiver complex spectral composition with nonlinear energetic characteristic

Subependymal Gian Cell Astrocytoma in An Adult Without Tuberous Sclerosis Complex: A Neuropathologial Case Report of a Tumor Initially Misdiagnosed as Glioblastoma

Subependymal giant cell astrocytomas (SEGA) are WHO CNS grade 1 tumors, predominantly diagnosed in the pediatric and young adult populations and almost always encountered in the context of the tuberous sclerosis complex (TSC). SEGAs develop from subependymal nodular (SEN), which are a component of TSC, while both have similar radiological and histological. Char-acteristically, SEN are small lesions that are growth stable and typically do not produce symptoms, while SEGAs are steadily growing lesions that produce compression-associated symptoms due to their periventricular location. Histologically, SEGAs present with pleomorphic, epitheloid-like, and giant multinucleated cells, with other glial phenotypes such as pyloid, histiocytic, and others also present. Tumors are sharply demarcated from the surrounding parenchyma and, other than the striking cellular appearance, may also show areas of palisading necrosis, making the histopathological diagnosis challenging. In cases of older patients or when a history of TSC is either not present or not known by the neuropathologist, the differential diagnosis can be quite challenging and includes a myriad of either lower-grade neuroglial tumors as well as high-grade astrocytic ones. Herein, we present a neuropathological case report of a 63-year-old female with no known TSC history and a CNS tumor with morpho-logical characteristics of SEGA

FREE SKIN PLASTY IN TRAUMATIC LESIONS OF THE LIMBS

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SPLEEN LYMPHOCYTE BLAST TRANSFORMATION IN THYMECTOMIZED CHICKENS

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An ultra melt-resistant hydrogel from food grade carbohydrates

© 2017 The Royal Society of Chemistry. We report a binary hydrogel system made from two food grade biopolymers, agar and methylcellulose (agar-MC), which does not require addition of salt for gelation to occur and has very unusual rheological and thermal properties. It is found that the storage modulus of the agar-MC hydrogel far exceeds those of hydrogels from the individual components. In addition, the agar-MC hydrogel has enhanced mechanical properties over the temperature range 25-85 °C and a maximum storage modulus at 55 °C when the concentration of methylcellulose was 0.75% w/v or higher. This is explained by a sol-gel phase transition of the methylcellulose upon heating as supported by differential scanning calorimetry (DSC) measurements. Above the melting point of agar, the storage modulus of agar-MC hydrogel decreases but is still an elastic hydrogel with mechanical properties dominated by the MC gelation. By varying the mixing ratio of the two polymers, agar and MC, it was possible to engineer a food grade hydrogel of controlled mechanical properties and thermal response. SEM imaging of flash-frozen and freeze-dried samples revealed that the agar-MC hydrogel contains two different types of heterogeneous regions of distinct microstructures. The latter was also tested for its stability towards heat treatment which showed that upon heating to temperatures above 120 °C its structure was retained without melting. The produced highly thermally stable hydrogel shows melt resistance which may find application in high temperature food processing and materials templating

Scaling properties of step bunches induced by sublimation and related mechanisms: A unified perspective

This work provides a ground for a quantitative interpretation of experiments on step bunching during sublimation of crystals with a pronounced Ehrlich-Schwoebel (ES) barrier in the regime of weak desorption. A strong step bunching instability takes place when the kinetic length is larger than the average distance between the steps on the vicinal surface. In the opposite limit the instability is weak and step bunching can occur only when the magnitude of step-step repulsion is small. The central result are power law relations of the between the width, the height, and the minimum interstep distance of a bunch. These relations are obtained from a continuum evolution equation for the surface profile, which is derived from the discrete step dynamical equations for. The analysis of the continuum equation reveals the existence of two types of stationary bunch profiles with different scaling properties. Through a mathematical equivalence on the level of the discrete step equations as well as on the continuum level, our results carry over to the problems of step bunching induced by growth with a strong inverse ES effect, and by electromigration in the attachment/detachment limited regime. Thus our work provides support for the existence of universality classes of step bunching instabilities [A. Pimpinelli et al., Phys. Rev. Lett. 88, 206103 (2002)], but some aspects of the universality scenario need to be revised.Comment: 21 pages, 8 figure

Simulation and beyond – Principles of effective obstetric training

Simulation training provides a safe, non-judgmental environment where members of the multi-professional team can practice both their technical and non-technical skills. Poor teamwork and communication are recurring contributing factors to adverse maternal and neonatal outcomes. Simulation can improve outcomes and is now a compulsory part of the national training matrix. Components of successful training include involving the multi-professional team, high fidelity models, keeping training on-site, and focussing on human factors training; a key factor in adverse patient outcomes. The future of simulation training is an exciting field, with the advent of augmented reality devices and the use of artificial intelligence