Nanoscale investigation of polymer cement concretes by small angle neutron scattering

An analysis of dense cements, such as polymer cement concrete, is made to produce original innovative components for different types of constructing materials. These materials present good functional properties (ageing resistance, crack formation resistance, hardness, and stability of mechanical modules) and can be used for various applications. In this paper, experimental tests on Portland cement with added γ-Al 2 O 3 and redispersible dry polymer performed using small angle neutron scattering are reported. The objective of the investigation was to assess the key parameters of the material (e.g., porosity, fractal dimensions, and size distribution) at the nanoscale level as well as to obtain useful structural information for expanding the possibility of applications. The results obtained can contribute to the optimisation of the consistency of the material, the design of operating conditions of elements of structures and facilities, and the design of the procedures that support ecological criteria and enhance quality and safety levels. © 2017 Walter de Gruyter GmbH, Berlin/Boston

Особенности диагностики и лечения спонтанных внеорганных гематом мягких тканей шеи и груди

The possibilities of computed tomography in the diagnosis of spontaneous hematomas (sh) of the soft tissues of the neck and chest and the features of their treatment are shown. Computed tomography with intravenous bolus contrast enhancement is the main method for diagnosing sh, which allows you to specify its exact localization, distribution, determine the structure and volume of the hematoma, the contrast agent exiting the contours of the vessel, and, taking into account the data obtained and the clinic, determines the tactics of treatment.Stable sh does not require surgical treatment. In the case of a large volume of chest hematoma, compression syndrome, hemothorax, drainage is indicated. Unstable sh dictate the need for angiography and, if necessary, endovascular embolization.Показаны возможности компьютерной томографии в диагностике спонтанных гематом (СГ) мягких тканей шеи и груди и особенности их лечения. Компьютерная томография с внутривенным болюсным контрастным усилением является основным методом диагностики СГ, позволяющим указать точную ее локализацию, распространение, определить структуру и объем гематомы, выход контрастного препарата за контуры сосуда и с учетом полученных данных и клиники определяет тактику лечения.Стабильные СГ не требуют хирургического лечения. В случае наличия большого объема гематомы груди, компрессионного синдрома, гемоторакса - показано дренирование. Нестабильные СГ, диктуют необходимость выполнения ангиографии и при необходимости эндоваскулярной эмболизации

Orbital dynamics of "smart dust" devices with solar radiation pressure and drag

This paper investigates how perturbations due to asymmetric solar radiation pressure, in the presence of Earth shadow, and atmospheric drag can be balanced to obtain long-lived Earth centred orbits for swarms of micro-scale 'smart dust' devices, without the use of active control. The secular variation of Keplerian elements is expressed analytically through an averaging technique. Families of solutions are then identified where Sun-synchronous apse-line precession is achieved passively to maintain asymmetric solar radiation pressure. The long-term orbit evolution is characterized by librational motion, progressively decaying due to the non-conservative effect of atmospheric drag. Long-lived orbits can then be designed through the interaction of energy gain from asymmetric solar radiation pressure and energy dissipation due to drag. In this way, the usual short drag lifetime of such high area-to-mass spacecraft can be greatly extended (and indeed selected). In addition, the effect of atmospheric drag can be exploited to ensure the rapid end-of-life decay of such devices, thus preventing long-lived orbit debris

Влияние ранней диагностики травматических повреждений на развитие легочных осложнений у пострадавших с сочетанной травмой

Despite the existing progress in providing care to patients with severe multisystem chest injury using advanced diagnostic methods, a high mortality rate still reaches 20–30%.Aim of study. To assess the impact of early diagnosis and correction of chest injuries on the development of complications in patients with multisystem trauma.Material and methods. The results of diagnosis and treatment of 89 patients with severe multisystem closed chest injury were studied. According to the time of admission to the Institute, the patients were divided into two groups: Group I, who were admitted to the Institute within the first hours after the injury (51 patients), and Group II, who were transferred from other medical institutions on the 3rd–7th day (38). CT was performed as a standard method of diagnosis and monitoring the dynamics of the process. With the development of purulent-inflammatory pulmonary complications, the bacteriological test of bronchoalveolar lavage was performed. Treatment included complex intensive therapy, drainage of the pleural cavity and emergency surgical interventions, if necessary.Results. In Group I, lung contusion occurred in 43 (84%) patients, and after 7-10 days, the contusion foci partially regressed in 20 (46.5%) patients. In 8 (16%) patients with lung rupture, infiltrative changes in the lung were resolved on the 18th-30th day, while 4 (50%) of them had pneumonia outside the contusion zones. In Group II, patients were put on a ventilator and inflammatory changes in the lungs were revealed in 30 patients (79%). Lung rupture associated with the contusion was revealed in 2 (5.2%). When comparing the groups by the composition of the isolated microflora, it was found that in patients of group II, Acinetobacter spp was more often found (46.7% vs. 17.1% in group I patients, p=0.021) and Enterococcus spp. (30.0% and 8.6%, respectively, p=0.058), as well as Klebsiella pneumoniae (46.7% and 37.1%, p=0.6). At the same time, Staphylococcus aureus was not found in these patients, while it was detected in 14.3% of patients from Group I (p=0.09). Medical care in Group I was carried out according to the principles of the “golden hour”: within the first hour from the moment of admission to the patients with the presence of pneumothorax and hemothorax, the pleural cavity was drained. In Group II, this procedure was performed in other medical institutions and in 5 additional patients at the Institute.Conclusions. Early computed tomography diagnosis of multisystem trauma makes it possible to assess the severity of injuries to the chest organs and other areas of the body and determine the treatment tactics. A comprehensive approach to the management of patients, including early diagnosis of trauma, drainage of the pleural cavity, determination of management tactics, bacterial test of the lower respiratory tract discharge, helps reduce infectious complications by an average of 45.46%. Актуальность. Несмотря на имеющийся прогресс в оказании помощи пострадавшим с тяжелой сочетанной травмой с использованием передовых методов диагностики, сохраняется высокий уровень летальности, достигающий 20–30%.Цель исследования. Оценить влияние ранней диагностики и коррекции повреждений груди на развитие осложнений у пострадавших с сочетанной травмой.Материал и методы. Изучены результаты диагностики и лечения 89 пострадавших с тяжелой сочетанной травмой. В соответствии со временем поступления в институт пациенты разделены на две группы: I группа — поступили в институт в первые 3 часа после травмы (51 больной), II — переведены из других лечебных учреждений на 3-и–7-е сутки (38). Компьютерную томографию выполняли как стандартный метод диагностики и контроля за динамикой процесса. При развитии гнойно-воспалительных легочных осложнений проводили бактериологическое исследование бронхоальвеолярного лаважа. Лечебные мероприятия включали в себя комплексную интенсивную терапию, дренирование плевральной полости и при необходимости проведение неотложных хирургических вмешательств.Результаты. В I группе ушиб легких был у 43 пациентов (84%), через 7–10 дней очаги ушиба частично регрессировали у 20 пострадавших (46,5%). При разрыве легкого у 8 (16%) инфильтративные изменения легкого разрешались на 18–30-е сутки, при этом у 4 (50%) из них было присоединение пневмонии вне зон контузии. Во II группе пострадавшие поступали на искусственной вентиляции легких, и воспалительные изменения в легких были у 30 больных (79%). Разрыв легкого на фоне ушиба был у 2 (5,2%). При сравнении групп по составу выделенной микрофлоры обнаружено, что у пациентов II группы чаще выделяли Acinetobacter spp. (46,7% против 17,1% у пациентов I группы, p=0,021) и Enterococcus spp. (30,0% и 8,6% соответственно, p=0,058), а также Klebsiella pneumoniae (46,7% и 37,1%, p=0,6). При этом Staphylococcus aureus у данных пациентов не встречался, тогда как его обнаруживали у 14,3% больных из I группы (p=0,09). Медицинскую помощь в I группе осуществляли по принципам «золотого часа»: в течение первого часа от момента поступления пострадавшим с наличием пневмо- и гемоторакса выполняли дренирование плевральной полости. Во II группе этот прием проводили в других лечебных учреждениях и у 5 пострадавших дополнительно в институте.Выводы. Ранняя компьютерно-томографическая диагностика сочетанной травмы дает возможность оценить тяжесть повреждений органов груди, других областей тела и определить тактику лечения. Комплексный подход к ведению пострадавших, включающий раннюю диагностику травмы, дренирование плевральной полости, определение тактики ведения, бактериальную оценку отделяемого нижних дыхательных путей, способствует снижению инфекционных осложнений в среднем на 45,46%.

QUALITY CONTROL OF FOREST CHEMICAL PRODUCTS

This article discusses the quality control of forest chemical products. The conducted tests are described with obtaining quantitative and qualitative characteristics.В данной статье рассматривается контроль качества лесохимической продукции. Описываются проводимые испытания с целью получения количественных и качественных характеристик

BETULIN ANALYSIS TECHNIQUE QUALITY INDICATORS

This article discusses the quality indicators of betulin analysis techniques. The betulin production process control is presented. Instrumental methods of analysis are described.В данной статье рассматриваются показатели качества методик анализа бетулина. Представлен контроль процесса получения бетулина. Описаны инструментальные методы анализа

Evidence of Isotopic Fractionation During Vapor Exchange Between the Atmosphere and the Snow Surface in Greenland

Several recent studies from both Greenland and Antarctica have reported significant changes in the water isotopic composition of near‐surface snow between precipitation events. These changes have been linked to isotopic exchange with atmospheric water vapor and sublimation‐induced fractionation, but the processes are poorly constrained by observations. Understanding and quantifying these processes are crucial to both the interpretation of ice core climate proxies and the formulation of isotope‐enabled general circulation models. Here, we present continuous measurements of the water isotopic composition in surface snow and atmospheric vapor together with near‐surface atmospheric turbulence and snow‐air latent and sensible heat fluxes, obtained at the East Greenland Ice‐Core Project drilling site in summer 2016. For two 4‐day‐long time periods, significant diurnal variations in atmospheric water isotopologues are observed. A model is developed to explore the impact of this variability on the surface snow isotopic composition. Our model suggests that the snow isotopic composition in the upper subcentimeter of the snow exhibits a diurnal variation with amplitudes in δ18O and δD of ~2.5‰ and ~13‰, respectively. As comparison, such changes correspond to 10–20% of the magnitude of seasonal changes in interior Greenland snow pack isotopes and of the change across a glacial‐interglacial transition. Importantly, our observation and model results suggest, that sublimation‐induced fractionation needs to be included in simulations of exchanges between the vapor and the snow surface on diurnal timescales during summer cloud‐free conditions in northeast Greenland

РЕЗУЛЬТАТЫ ЛЕЧЕНИЯ БОЛЬНЫХ МЕСТНОРАСПРОСТРАНЕННЫМ И МЕТАСТАТИЧЕСКИМ НЕПЛОСКОКЛЕТОЧНЫМ НЕМЕЛКОКЛЕТОЧНЫМ РАКОМ ЛЕГКОГО ПРЕПАРАТОМ ПЕМЕТРЕКСЕД (СОБСТВЕННЫЙ ОПЫТ)

Lung cancer is one of the most common malignant tumors. As over 70 % of patients at diagnosis have locally advanced or generalized process, the majority of patients receive drug treatment only. We evaluated effectiveness and toxicity of pemetrexed (Alimta) in 24 patients with locally advanced and metastatic non-squamous cell non-small-cell lung carcinoma with the known EGFR mutation status. Pemetrexed 500 mg/m2 was administered as monotherapy (8 patients) or in combination with platinum-based drugs (15 patients). Three (12.5 %) patients showed complete regression, 7 (29.2 %) – partial regression, 10 (41.7 %) – stabilization, 4 (16.6 %) – progression. The median survival was 14.8 months. Non-hematological complications were registered, usually concerning the digestive system. Hematological complications included first-degree leukopenia – 27 (21.3 %), second- and third-degree thrombocytopenia – 1 case of each (0.8%). The complications did not require administration of drugs or were corrected medicamentally. We observed a high effectiveness of pemetrexed in patients with non-squamous NSCLC, as well as a low rate of complications and controlled toxicity

Иммунологические аспекты патогенеза развития стриктуры трахеи

Cicatricial tracheal stenosis is a fairly common complication that occurs after tracheal intubation or tracheostomy. However, critical tracheal stenosis is a rare case, sometimes not associated with trauma, and is probably due to the peculiarities of the patient’s immune response during the development of stenosis. In this regard, the study of the immune mechanisms of the development of inflammation in the upper respiratory tract is a very relevant and promising direction. This review is devoted to the analysis of the immunological mechanisms of tracheal stricture formation, and presents modern data on the immunopathogenesis of the disease.Clarification of some pathogenetic mechanisms of the immune response during the formation of tracheal strictures of various origins can help in identifying laboratory markers as risk factors for tracheal stricture and timely prevention of such complications.Рубцовый стеноз трахеи довольно частое осложнение, возникающее после интубации трахеи или наложения трахеостомы. Однако критический стеноз трахеи наблюдается редко, иногда не связан с травмой и, вероятно, обусловлен особенностями иммунного ответа пациента при развитии стеноза. В связи с этим изучение иммунных механизмов развития процессов воспаления верхних дыхательных путей является весьма актуальным и перспективным направлением. Данный обзор посвящен анализу иммунологических механизмов формирования стриктуры трахеи, в котором представлены современные данные об иммунопатогенезе заболевания. Прояснение некоторых патогенетических механизмов иммунного ответа при формировании стриктуры трахеи различного генеза может помочь в выявлении лабораторных маркеров как факторов риска стриктуры трахеи и своевременно предупреждать подобные осложнения