Developing reference material for validation of hair spectral analysis reliability

Mineral analysis of human hair is increasingly proposed as a estimation method for the human contamination with environmental mineral pollutants and even as a diagnostic tool for related health problems. It offers a good way of investigating long-term variation in trace element concentration. Many minor and trace elements can be determined in hair samples with good precision and sensitivity by a variety of analytical techniques. An important requirement in such work is the application of suitable analytical quality control, for which the availability of a hair reference material is important. In paper the preparation of the human hair reference material and the initial stages which were taken to confirm its certification are described

Неоднородность пластических деформаций оливина в ультрамафитах Байкало-Муйского офиолитового пояса (северо-восточное Прибайкалье)

Актуальность работы. Постоянно устанавливаемые признаки пластического течения в ультрамафитах предопределили подход к их изучению, как к метаморфическим породам, с применением нетрадиционного метода петроструктурного анализа. Использование этого метода позволяет реконструировать хронологическую последовательность процессов формирования и пластического деформирования ультрамафитов на уровнях верхняя мантия - земная кора, выявить общую направленность структурно-вещественной эволюции и решить ряд актуальных проблем их минерагении. Цель работы: по результатам выявленной микроструктурной неоднородности дунитов и гарцбургитов, типизации их микроструктур, оценки температур оливин-хромшпинелиевых равновесий и петроструктурного анализа оливина предложить сценарий структурной эволюции ультрамафитов Парамского и Шаманского массива Байкало-Муйского офиолитового пояса на уровнях верхняя мантия - земная кора. Методы исследования. Детальное петрографическое изучение ультрамафитов проводилось на поляризационном микроскопе AxioScope-40 фирмы Carl Zeiss, что позволило провести микроструктурную типизацию дунитов и гарцбургитов. Их типизация основана на морфологических особенностях оливина и была разработана многими исследователями. Количественная оценка деформационных микроструктур оливина в изученных ультрамафитах проводилась с использованием метода стереометрической металлографии. Микроструктурный анализ оливина является неотъемлемой частью петроструктурного изучения ультрамафитов. Он позволяет установить предпочтительные ориентировки минералов по внутреннему строению, которые, в свою очередь, являются отражением термодинамических условий их пластических деформаций. Вещественный состав оливинов и хромшпинелидов установлен на основании микрорентгеноспектральных определений, выполненных в Институте нефтегазовой геологии и геофизики Сибирского отделения Российской академии наук (г. Новосибирск) на микроанализаторе «Camebax». Расчет температурных равновесий проводился с использованием оливин-хромшпинелиевого геотермометра Фабри по вещественному составу сосуществующих оливина и хромшпинелида. Результаты. Для дунитов и гарцбургитов Парамского и Шаманского массивов Байкало-Муйского офиолитового пояса на оригинальном материале проведена идентификация деформационных микроструктур оливина. Они объединены в шесть типов: протогранулярный, мезогранулярный, порфирокластовый, порфиролейстовый, мозаичный (мозаично-лейстовый) и мозаично-паркетовидный. Пространственное распределение выделенных микроструктур в изученных массивах от центра к периферии характеризуется тенденцией уменьшения размера зерен в породах, показывает возрастание степени их пластического деформирования и отражает динамометаморфическую зональность. Петроструктурный анализ оливина в выделенных микроструктурных типах позволил установить термодинамические условия их реализации. Они фиксируют регрессивную направленность метаморфических преобразований ультрамафитов высокотемпературными пластическими деформациями, синтектонической рекристаллизацией и вторичной рекристаллизацией отжига в процессе формирования, перемещения и консолидации ультрамафитов в верхней мантии и земной коре. Установленная эволюция микроструктур оливина отражает рубежи многократно наложенных пластических деформаций, которые при благоприятных условиях могут быть определяющими в локализации хромита, хризотил-асбеста, нефрита, жадеита среди ультрамафитов из офиолитовых комплексов.Relevance of the research. Permanently identified signs of plastic flow in ultramafic rocks predetermined an approach to their study as metamorphic rocks. This approach uses non-traditional method of the petrofabric analysis. This method allows reconstructing the chronological sequence of formation and plastic deformation of ultramafic rocks in the upper mantle-crust, revealing the general trend of structural and matter evolution, and solving a number of urgent problems of the ultramafic mineral genesis. The aim of the study is to develop a scenario of the structural evolution of the Paramsky and Shamansky ultramafic massifs of Baikal-Muya ophiolite belt at the upper mantle-crust levels through the dunite and harzburgite microstructural heterogeneity, typing their microstructures, calculating olivine-chromospinelide thermal equilibrium, and olivine petrofabric analysis. Methods. The detailed petrographic characteristics of ultramafic rocks were performed by the polarizing microscope AxioScope-40 (Carl Zeiss). This study allowed carrying out microstructural typification of dunites and harzburgites. It was based on the morphological features of olivine and it was developed by many researchers. Quantification of deformation microstructures in olivine of ultramafic rocks was studied using the stereometric metallography. Microstructural analysis of olivine is an integral part of the petrofabric study of the ultramafic rocks. It allows determining the preferred orientation of minerals in the internal structure, which in their turn is a reflection of the thermodynamic conditions of their plastic deformation. The olivine and chromospinelide matter composition was determined using micro X-ray spectrum, obtained by microanalyser «Camebax» in the Institute of Petroleum Geology and Geophysics of Siberian Branch of Russian Academy of Sciences (Novosibirsk). The thermal equilibrium was calculated using olivine-chromospinelide Fabry geothermometer on the matter composition of coexisting olivine and chromospinelide. Results. The research provided the identification of the deformation microstructures of olivine for dunites and harzburgites of the Paramsky and Shamansky ultramafic massifs of the Baikal-Muya ophiolite belt. They are grouped into six types: protogranular, mesogranular porphyroclastic, porphyrolath, mosaic (mosaic-lath), mosaic-parquet-like. The spatial distribution of the allocated microstruct ures in the studied massifs from the сenter to the periphery is characterized by reducing the grain size in the rocks. This feature shows the increase in their plastic deformation degree and reflects the dynamometamorphiс zoning. The petrofabric analysis of the olivine in the identified microstructural types allowed determining thermodynamic conditions of their realization. These microstructures reflect a regressive trend of metamorphic transformations of the ultramafic rocks by high-temperature plastic deformations, syntectonic recrystallization, an d secondary annealing recrystallization in formation, transformation and consolidation in the upper mantle - earthґs crust. The identified evolution of the olivine microstructures reflects the limits of repeatedly overlaid plastic deformations, which can be decisive in l ocalization of chromite, chrysotile asbestos, jade, and jadeite within ultramafic rocks of ophiolite complexes under favorable conditions

Проблемы формирования государственной экологической политики в условиях ограниченности ресурсов

Проблема ограниченности ресурсов является основой развития экономики. Однако также ограниченность оказывает влияние и на экологическую политику в стране. В статье рассмотрены ключевые механизмы формирования государственной экологической политики, экологического менеджмента; предложены пути повышения эффективности экологической политики.The problem of limited resources is the basis for economic development. However, the limited nature also influences the environmental policy in the country. The article considers the key mechanisms for the formation of state environmental policy, environmental management; ways to improve the effectiveness of environmental policy

Maintained right ventricular pressure overload induces ventricular-arterial decoupling in mice.

Assessment of right ventricular (RV) function in rodents is a challenge due to the complex RV anatomy and structure. Subsequently, the best characterization of RV function is achieved by accurate cardiovascular phenotyping, involving a combination of non-invasive imaging and intra-cardiac pressure-volume measurements. We sought to investigate the feasibility of two complementary phenotyping techniques for the evaluation of RV function in an experimental mouse model of sustained RV pressure overload. Mice underwent either Sham surgery (n = 5) or pulmonary artery banding (PAB) (n = 8) to induce isolated RV pressure overload. After three weeks indices of RV function were assessed by echocardiography (Vevo2100) and closed chest-derived invasive pressure-volume measurements (PVR-1030). PAB resulted in RV hypertrophy and dilatation accompanied by systolic and diastolic dysfunction. Invasive RV hemodynamic measurements demonstrate an increased end-systolic as well as arterial elastance after PAB as compared to sham, resulting in ventricular-arterial decoupling. Regression analysis revealed that TAPSE is rather correlated with ventricular-arterial coupling (r² = 0.77, P = 0.002) than RV contractility (r² = -0.61, P = 0.07). Furthermore, IVRT/RR and E/E' correlate well with RV end-diastolic pressure (r² = 0.87, P = 0.0001 and r² = 0.82, P = 0.0009; respectively). Commonly used indices of systolic RV function are associated with RV-arterial coupling rather than contractility, while diastolic indices are interrelated with end-diastolic pressure where there is maintained pressure overload. This article is protected by copyright. All rights reserved

Accuracy of cardiac output measurements with pulse contour analysis (PulseCO (TM)) and Doppler echocardiography during off-pump coronary artery bypass grafting

Background and objective: During off-pump coronary bypass grafting, surgical manipulation and dislocation of the heart may cause cardiovascular instability. Monitoring of cardiac output facilitates intraoperative haemodynamic management but pulmonary artery catheters are often considered too invasive. Pulse contour analysis and transoesophageal echocardiography could serve as alternatives, but there is controversy about their accuracies. We validated pulse contour analysis using a standard radial arterial catheter (PulseCO(TM)) and aortic Doppler flowmetry with transoesophageal echocardiography in patients undergoing off-pump coronary bypass surgery. Pulmonary arterial thermodilution served as the reference technique. Methods: In 20 patients undergoing off-pump coronary bypass, cardiac output was measured with bolus thermodilution (COTD), pulse contour analysis (COPC), and transoesophageal echocardiography (COecho) at fixed time intervals during the procedure. Data were compared using linear regression and Bland-Altman analysis. At the end of the procedure, dobutamine was infused at a rate of 2.5 mu g kg(-1) min(-1) in six patients to study the agreement between methods in quantifying changes in cardiac output. Results: Comparison between COPC and COTD showed a bias +/- limits of agreement of -0.03 +/- 1.30 Lmin(-1) (mean error 29%). Doppler echocardiography was not always feasible when the heart was displaced from the oesophagus and had lower accuracy: bias +/- limits of agreement vs. COTD was 0.45 +/- 1.93 (mean error 43%. Increases in cardiac output induced by dobutamine were well quantified both by pulse contour analysis (COPC = 0.76 X COTD + 0.58; r(2) = 0.65) and Doppler although the latter tended to overestimate these changes (COecho = 1.5 8 X COTD -0.13; r(2) = 0.53). Conclusions: Calibrated pulse contour analysis using the PulseCO system is an acceptable technique to measure cardiac output non-invasively in off-pump coronary bypass patients. Doppler echocardiography performs less well and is not always feasible with transoesophageal echocardiography when the heart is displaced