310 research outputs found
Comprehensive comparative assessment of technological, physical, chemical and environmental properties of glass for the production of E-glass fiber with boron and without boron
The research results of the boron-containing and boron free glasses of the E type for production of continuous glass fiber are presented. It was established that boron-containing glass has technological advantages due to more intensive glass melting processes, and its production process according to environmental indicators is comparable to boron-free glass production indicators
Accurate free and forced rotational motions of rigid Venus
% context :The precise and accurate modelling of a terrestrial planet like
Venus is an exciting and challenging topic, all the more interesting since it
can be compared with that of the Earth for which such a modelling has already
been achieved at the milliarcsecond level % aims: We want to complete a
previous study (Cottereau and Souchay, 2009), by determining at the
milliarcsecond level the polhody, i.e. the torque-free motion of the axis of
angular momentum of a rigid Venus in a body-fixed frame, as well as the
nutation of its third axis of figure in space, which is fundamental from an
observational point of view. results :In a first part we have computed the
polhody, i.e. the respective free rotational motion of the axis of angular
momentum of Venus with respect to a body-fixed frame. We have shown that this
motion is highly elliptical, with a very long period of 525 cy to be compared
with 430 d for the Earth. This is due to the very small dynamical flattening of
Venus in comparison with our planet. In a second part we have computed
precisely the Oppolzer terms which allow to represent the motion in space of
the third Venus figure axis with respect to Venus angular momentum axis, under
the influence of the solar gravitational torque. We have determined the
corresponding tables of coefficients of nutation of the third figure axis both
in longitude and in obliquity due to the Sun, which are of the same order of
amplitude as for the Earth. We have shown that the coefficients of nutation for
the third figure axis are significantly different from those of the angular
momentum axis on the contrary of the Earth. Our analytical results have been
validated by a numerical integration which revealed the indirect planetary
effects.Comment: 14 pages, 11 figures, accepted for publication in section 11.
Celestial mechanics and astrometry of Astronomy and Astrophysics (27/02/2010
Comparison of Postural Recovery Following Short and Long Duration Spaceflights
INTRODUCTION: Post-flight postural ataxia reflects adaptive changes to vestibulo-spinal reflexes and control strategies adopted for movement in weightlessness. Quantitative measures obtained during computerized dynamic posturography (CDP) from US and Russian programs provide insight into the effect of spaceflight duration in terms of both the initial decrements and recovery of postural stability. METHODS: CDP was obtained on 117 crewmembers following Shuttle flights lasting 4-17 days, and on 64 crewmembers following long-duration missions lasting 48-380 days. Although the number and timing of sessions varied, the goal was to characterize postural recovery pooling similar measures from different research and flight medicine programs. This report focuses on eyes closed, head erect conditions with either a fixed or sway-referenced base of support. A smaller subset of subjects repeated the sway-referenced condition while making pitch head movements (+/- 20deg at 0.33Hz). Equilibrium scores were derived from peak-to-peak anterior-posterior sway. Fall probability was modeled using Bayesian statistical methods to estimate parameters of a logit function. RESULTS: The standard Romberg condition was the least sensitive. Longer duration flights led to larger decrements in stability with sway-reference support during the first 1-2 days, although the timecourse of recovery was similar across flight duration with head erect. Head movements led to increased incidence of falls during the first week, with a significantly longer recovery following long duration flights. CONCLUSIONS: The diagnostic assessment of postural instability, and differences in the timecourse of postural recovery between short and long flight durations, are more pronounced during unstable support conditions requiring active head movements
Atypical hemolytic-uremic syndrome as one of the causes of acute kidney injury in pregnant women
Obstetric atypical hemolytic uremic syndrome (aHUS) is one of the reasons for the development of acute kidney injury (AKI) and can determine the prognosis of both mother and child. Aim. Analysis of clinical manifestations, course and outcomes of obstetric aHUS. Materials and methods. 45 patients with aHUS development during pregnancy or immediately after childbirth were observed between 2011 and 2017, age from 16 to 42 years. Results and discussion. All patients had AKI (serum creatinine 521,5±388,0 µmol/l, oliguria or anuria that required initiation of hemodialysis). 93.3% pts had extrarenal manifestations of TMA with the development of multiple organ failure (MOF). The mean number of damage organs was 3,7±1,2. In all patients, the development of aHUS was preceded by obstetric complications, surgery, infection, etc. In the outcome: 53.4% women showed complete recovery of renal function, 11.1% developed CKD 4-5 stages, 35.5% had dialysis-dependent end-stage renal failure (ESDR). Maternal mortality was 23.9%. Perinatal mortality was 32.6%. The early start of eculizumab treatment (within 1-2 weeks from the onset of aHUS), compared with therapy start after 3 weeks, increased the chances of favorable outcome for mother in 5.33 times, and the chances for normalization of renal function in 48.7 times. Conclusion. Obstetric aHUS is characterized by the development of AKI in 100% of cases. In most patients, the obstetric aHUS occurs with the development of MOF. Timely diagnosis of aHUS and immediate treatment by eculizumab allows not only to save the life of patients, but also completely restore their health
Atypical Goodpasture’s disease: a clinical case report and literature review
Goodpasture’s disease (anti-GBM disease) is a rare small vessels vasculitis characterized by the presence of autoantibodies directed against the glomerular basement membrane (GBM) and alveolar basement membrane. Common feature of anti-GBM disease is a combination of rapidly progressive glomerulonephritis and alveolar hemorrhage (pulmonary-renal syndrome). We present a case of atypical disease course in a young male patient who developed alveolar hemorrhage without renal failure. The only symptom of renal involvement was isolated hematuria. Plasmapheresis combined with immunosuppression (cyclophosphamide and corticosteroids) was effective. We present a review of state-of-art data on the pathogenesis and disease course of anti-GBM disease
The effect of spaceflight and microgravity on the human brain
peer reviewedMicrogravity, confinement, isolation, and immobilization are just some of the features astronauts have to cope with during space missions. Consequently, long-duration space travel can have detrimental effects on human physiology. Although research has focused on the cardiovascular and musculoskeletal system in particular, the exact impact of spaceflight on the human central nervous system remains to be determined. Previous studies have reported psychological problems, cephalic fluid shifts, neurovestibular problems, and cognitive alterations, but there is paucity in the knowledge of the underlying neural substrates. Previous space analogue studies and preliminary spaceflight studies have shown an involvement of the cerebellum, cortical sensorimotor, and somatosensory areas and the vestibular pathways. Extending this knowledge is crucial, especially in view of long-duration interplanetary missions (e.g., Mars missions) and space tourism. In addition, the acquired insight could be relevant for vestibular patients, patients with neurodegenerative disorders, as well as the elderly population, coping with multisensory deficit syndromes, immobilization, and inactivity
Development of Training Programs to Optimize Planetary Ambulation
Astronauts experience disturbances in functional mobility following their return to Earth due to adaptive responses that occur during exposure to the microgravity conditions of space flight. Despite significant time spent performing in-flight exercise routines, these training programs have not been able to mitigate postflight alterations in postural and locomotor function. Therefore, the goal of our two inter-related projects (NSBRI-ground based and ISS flight study, "Mobility") is to develop and test gait training programs that will serve to optimize functional mobility during the adaptation period immediately following space flight, thereby improving the safety and efficiency of planetary ambulation. The gait training program entails manipulating the sensory conditions of treadmill exercise to systematically challenge the balance and gait control system. This enhances the overall adaptability of locomotor function enabling rapid reorganization of gait control to respond to ambulation in different gravitational environments. To develop the training program, we are conducting a series of ground-based studies evaluating the training efficacy associated with variation in visual flow, body loading, and support surface stability during treadmill walking. We will also determine the optimal method to present training stimuli within and across training sessions to maximize both the efficacy and efficiency of the training procedure. Results indicate that variations in both visual flow and body unloading during treadmill walking leads to modification in locomotor control and can be used as effective training modalities. Additionally, the composition and timing of sensory challenges experienced during each training session has significant impact on the ability to rapidly reorganize locomotor function when exposed to a novel sensory environment. We have developed the capability of producing support surface variation during gait training by mounting a treadmill on a six-degree-of-freedom motion device. This hardware development will allow us to evaluate the efficacy of this type of training in conjunction with variation in visual flow and body unloading
Эпидермальные структуры листьев некоторых сортов Mentha х piperita L. в связи с их продуктивностью
Relevance. It is known that peppermint (Mentha х piperita L.) is characterized by significant polymorphism, due to both genetic factors and growing conditions. Cultivated varieties and populations are distinguished by their economically significant characteristics, such as yield, winter hardiness, resistance to diseases, the content and composition of essential oil. Identification of new highly productive varieties and populations of Mentha x piperita L., distinguished by high productivity of essential oil in the Non-chernozem zone of the Russian Federation, as well as identification of morphological features characteristic of highly productive varieties, remains relevant.Methods. The object of the study was plants of 8 varieties of 2 year old plants and samples of Mentha x piperita L. from the collection of the SI Botanical Garden Rostovtsev RGAU-Moscow Agricultural Academy named after K.A. Timiryazev and from the collection of the Botanical Garden of All-Russian Institute of Medicinal and Aromatic Plants (VILAR), were used as the object of the study. Peppermint leaves (FS.2.5.0029.15 Peppermint leaves) and essential oil (GOST R 53593-2009) are used as herbal medicinal products. Microscopy used Primo Star Carl Zeiss light microscopes and LOMO MIKMED-1. Quantitative determination of the essential oil was carried out by distillation with water vapor, followed by measuring the volume of the resulting oil (GF RF XIV). The oil content was expressed in volumetric-weight percent in terms of dry raw materials.Results. As a result of a comparative study of the epidermal structures of the leaves of plants of 8 varieties of Mentha х piperita L., the density of stomata, the type of stomatal apparatus, density of location and length of multicellular trichomes, density and diameter of essential oil glands, and content of essential oil were determined. The variety specificity and variation of these indices are noted over a wide range, which is explained by the significant intraspecific variability characteristic of the genus Mint (Mentha L.). The most promising varieties of essential oil content were identified. Актуальность. Известно, что для мяты перечной (Mentha х piperita L.) характерна значительная полиморфность, обусловленная как генетическими факторами, так и условиями произрастания. Выращиваемые в культуре сорта и популяции отличаются по хозяйственно значимым признакам, таким как урожайность, зимостойкость, устойчивость к болезням, содержание и состав эфирного масла. Выявление новых высокопродуктивных сортов и популяций Мentha х piperita L., отличающихся высокой продуктивностью эфирного масла в условиях Нечернозёмной зоны Российской Федерации, а также выявление морфологических признаков, характерных для высокопродуктивных сортов, остается актуальным.Материал и методы. Объектом исследования являлись растения 2-х лет вегетации 8 сортов и образцов Mentha х piperita L. из коллекций Ботанического сада имени С.И. Ростовцева РГАУ-МСХА имени К.А. Тимирязева и Всероссийского института лекарственных и ароматических растений (ВИЛАР). В качестве лекарственного сырья применяются лист мяты перечной (ГФ РФ XIV, ФС.2.5.0029.15 Мяты перечной листья) и эфирное масло (ГОСТ Р 53593-2009), которые используются как лекарственные срества. При микроскопии использовали световые микроскопы Primo Star Carl Zeiss и ЛОМО МИКМЕД-1. Количественное определение эфирного масла проводили по ГФ РФ XIV.Результаты. В результате проведенного сравнительного изучения эпидермальных структур листьев растений 8 сортов Mentha х piperita L. были определены плотность расположения устьиц, тип устьичного аппарата, плотность расположения и длина многоклеточных трихом, плотность и диаметр эфирномасличных желёзок, содержание эфирного масла. Отмечены сортоспецифичность и варьирование этих показаелей в широких пределах, что объясняется значительной внутривидовой изменчивостью, характерной для рода Mentha L. Выявлены наиболее перспективные сорта по содержанию эфирного масла.
Морфологическая внутривидовая изменчивость некоторых сортов Thymus vulgaris L. в связи с их продуктивностью
Relevance. Common thyme or garden thyme Thymus vulgaris L. (Lamiaceae L.) is the medicinal and aromatic plant containing essential oil which is the source of thymol and other phenol derivatives. This species is characterized by significant morphological and chemical polymorphism. Thymus vulgaris L. has numerous varieties and subspecies which are complicates for the identification of raw materials and makes its quality unstable. The study of intraspecific variability, not only by phenotype but also by biochemical parameters, is an urgent task in the search for varieties and samples of Thýmus vulgáris L. that are promising for the medical industry.Materials and methods. The research material was obtained from botanical institutions and firms in Russia, the Czech Republic and Germany and introduced on the experimental field of Vegetable Growing Department of The Russian State Agricultural University – Moscow Timiryazev Agricultural Academy. Studies were conducted from 2014 to 2019. Sowing the seeds was carried out in the 3rd decade of March in cassettes in a winter greenhouse. Seedlings planted in the field at the end of MayField experiments were laid at the «Vegetable Experimental Station named V.I. Edelstein » in accordance with generally accepted methods of field experiments. A comprehensive comparative assessment of the studied samples was carried out according to a number of criteria, in accordance with the recommendations of the State Register of Selection Achievements and the matrix of the morphological description of plants of the Lamiaceae family developed at the Leibniz-Institut for Pflanzengenetik und Kulturpflanzenforschung (IPK, Germany). Harvesting of raw materials and crop yield was carried out in the phase of mass flowering. Laboratory studies were carried out in the laboratories of the Vegetable Growing Department, Department of Botany, Selection and Seed Production of Garden Plants, Russian State Autonomous University – Moscow Agricultural Academy named after K.A. Timiryazev. The quantitative determination of essential oil was carried out according to the GF RF XIV. Statistical analysis was performed using Microsoft Excel.Results. The possibility of growing samples of Thymus vulgaris L. of different geographical origin under the conditions of introduction in the Moscow region is shown. A comparative study of the main morphological characteristics of plant samples of Thymus vulgaris L. revealed significant variability in the form of inflorescence, leaf index, the presence or absence of pubescence, anthocyanin staining, torsion of the leaf, color of corollas and leaves, plant height, yield, quantitative content of essential oil and flavonoids. At the same time, the height of the plants was relatively stable every year and between varieties. According to a set of indicators, the most productive and stable samples was “Di Roma”, which is characterized by a high yield of aerial mass (104 g / plant), a consistently high content of essential oil (1.04-1.8%) with a predominant thymol component (39-80%), high flavonoid content (1,47-2,26%). Varieties "Medoc" and "Deutsche Winter", which at a lower yield are characterized by a high content of essential oil and flavonoids.Актуальность. Среди пряно-ароматических и лекарственных растений тимьян обыкновенный – Thymus vulgaris L. (семейство Яснотковые – Lamiaceae L.), является одним из наиболее высокопродуктивных источников тимолосодержащего эфирного масла и фенольных соединений. Этот вид характеризуются значительным морфологическим и химическим внутривидовым полиморфизмом. Thymus vulgaris L. имеет большое число сортов, что осложняет идентификацию сырья, и делает нестабильным его качество. Выявление внутривидовой изменчивости как по фенотипу, так и биохимическим показателям является актуальной задачей при поиске перспективных для медицинской промышленности сортов и образцов тимьяна обыкновенного.Материалы и методы. Материалом для исследований служили интродуцированные образцы Thymus vulgaris L. из коллекции кафедры овощеводства РГАУ-МСХА имени К.А. Тимирязева. Исследования проводились с 2014 по 2019 гг. Посев семян на рассаду проводился в 3-ей декаде марта в кассеты в зимней теплице. Полевые опыты закладывали на УНПЦ «Овощная опытная станция им. В.И. Эдельштейна» в соответствии с общепринятыми методиками полевых опытов. Комплексную сравнительную оценку изучаемых образцов проводили по ряду критериев, в соответствии с рекомендациями Государственного Реестра Селекционных достижений и матрицы морфологического описания растений семейства Яснотковые, разработанной в Институте Лейбница (Leibniz-Institut for Pflanzengenetik und Kulturpflanzenforschung (IPK), Германия). Уборку сырья и учёт урожайности проводили в фазе массового цветения. Лабораторные исследования проводили в лабораториях кафедры овощеводства, кафедры ботаники, селекции и семеноводства садовых растений РГАУ − МСХА имени К.А. Тимирязева. Количественное определение эфирного масла проводили по ГФ РФ XIV. Для статистической обработки использовали программу Microsoft Excel.Результаты. 1. Показана возможность выращивания образцов Thymus vulgaris L. разного географического происхождения в условиях интродукции в Московской области. 2. При сравнительном изучении основных морфологических признаков растений образцов Thymus vulgaris L. выявлена значительная вариабельность по форме соцветия, индексу листа, наличию или отсутствию опушения, антоцианового окрашивания, скрученности листа, окраске венчиков и листьев, высоте растений, урожайности, количественному содержанию эфирного масла и флавоноидов. Вместе с тем, относительно стабильной была высота растений как по годам, так и между сортами. По комплексу показателей, следует выделить наиболее продуктивные и устойчивые образцы: сорт «Di Roma», который характеризуется высоким урожаем надземной массы (104 г/куст), стабильно высоким содержанием эфирного масла (1,04-1,8%) с преобладающим компонентом тимолом (39-80%), высоким содержанием флавоноидов (1,47-2,26%); а также сорта «Медок» и «Deutsche Winter», которые при более низкой урожайности характеризуются высоким содержанием эфирного масла и флавоноидов
Перспективы некорневой обработки раствором глицина для повышения продуктивности укропа огородного
Relevance. Dill is a popular food and medicinal crop (Anethum graveolens L.) of the Celery family (Apiaceae). Seeds of dill are included in the 14th edition of the State Pharmacopoeia of the Russian Federation. However, this crop is characterized by a relatively low yield, which reduces the efficiency of its production. The use of environmentally friendly growth-regulating compounds can significantly increase the yield and improve its quality. As a growth-regulating, foliar treatment with a solution of the amino acid glycine was tested. The amino acid glycine is environmentally friendly and does not pose a danger to humans and animals. The aim of the work was to increase the productivity of garden dill using foliar treatments with glycine amino acid.Materials and methods. Dill varieties Gribovsky and Symphony were chosen as objects to study the effect of the foliar treatments with glycine. Sowing of seeds was carried out at an early date, which for the conditions of the Lipetsk region corresponds to the first decade of April, with a SZT-3.6 seeder with 15 cm row spacing. The seeding rate was 15 kg/ha, the seeding depth was 1-2 cm. were Treatment with glycine solution was achieved in plants rosette phase. The concentration of glycine was 25, 50 and 100 mg / l. The control plants were sprayed with distilled water. The crop was cut during the period of brown seeds on the central umbrella. The content of essential oil was determined by the 14th edition of the State Pharmacopoeia of the Russian Federation (method 1). The content of the main components was determined by gas chromatography.Results. As a result of the research, a positive effect of foliar treatments with glycine on both yield and the content of essential oil in the raw material of dill varieties Gribovsky and Symphony was revealed. As a result of treatments, regardless of concentration, the seeds yield and the yield of essential oil per unit area increased. The increase in the mass of 1000 pieces of fruits was not unambiguous. Based on the results obtained, the effective concentration of amino acid glycine is determined not only by the characteristics of the variety, but also by weather conditions, when, depending on the conditions during the processing period and prior to harvesting, different aspects of the drug's action appear. According to the results of observations for 2 years and an assessment by the sum of the indicators, the optimal concentration of glycine in most cases was 100 mg / l, at the same time, for the Symphony variety for two years, two-foliar treatment with low concentrations of glycine (10 mg / l rosette + 10 mg / l budding).Актуальность. Укроп огородный является востребованной пищевой и лекарственной культурой (Anethum graveolens L.) из семейства Сельдерейные (Apiaceae). Плоды укропа огородного включены в 14 издание Государственной Фармакопеи РФ. Однако эта культура характеризуются относительно низкой урожайностью, что снижает эффективность его производства. Применение экологически безопасных рострегулирующих соединений позволяет существенно повысить урожай и улучшить его качество. В качестве препарата нами была испытана некорневая обработка раствором аминокислоты глицин, который не представляет опасности для человека и окружающей среды. Целью работы явилось повышение продуктивности укропа огородного с помощью некорневых обработок раствором аминокислоты глицин.Материалы и методы.В качестве объектов для изучения действия препарата были выбраны сорта укропа огородного Грибовский и Симфония. Посев растений проводили в ранние сроки, что для условий Липецкой области соответствует первой декаде апреля, сеялкой СЗТ-3,6 с междурядьями 15 см. Норма высева составляла 15 кг/га, глубина заделки семян – 1-2 см. Обработку растений раствором глицина проводили в фазе розетки. Концентрации препарата – 25, 50 и 100 мг/л. Контроль опрыскивали дистиллированной водой. Срезку проводили в период побурения семян на центральном зонтике. Содержание эфирного масла определяли по ГФ 14 методом 1. Содержание основных компонентов определяли методом газовой хроматографии.Результаты. В результате исследований выявлено положительное влияние внекорневых обработок глицином как на урожайность, так и на содержание эфирного масла в сырье укропа сортов Грибовский и Симфония. В результате обработок независимо от концентрации повышалась урожайность и выход эфирного масла с единицы площади. Увеличение массы 1000 штук плодов было не однозначным. Исходя из полученных результатов, эффективная концентрация препарата определяется не только особенностями сорта, но и погодными условиями, когда в зависимости от условий в период обработки и предшествующий уборке проявляются разные аспекты действия препарата. По результатам наблюдений за двумя сортами укропа огородного в течение 2-х лет и оценке результата по сумме показателей оптимальная концентрация глицина в большинстве случаев составила 100 мг/л, вместе с тем для сорта Симфония в течение двух лет была эффективна двукратная обработка низкими концентрациями глицина (10 мг/л розетка + 10 мг/л бутонизация)
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