306 research outputs found
ВВОД ПРОБЫ АРОМАТИЧЕСКИХ СОЕДИНЕНИЙ С КОНЦЕНТРАТОРОВ В ПОЛИКАПИЛЛЯРНУЮ КОЛОНКУ МЕТОДОМ ТЕРМИЧЕСКОЙ ДЕСОРБЦИИ
At present, there is an increased interest in geochemical methods of searching for hydrocarbon deposits by detecting on the Earth's surface the scattering halos of hydrocarbons that migrated from those deposits, namely the aromatic hydrocarbons such as benzene, toluene, xylenes. The concentrations of the migrated hydrocarbons on the surface of the Earth are usually low and could only be detected at the threshold level of the gas analyzers. Therefore, for their registration, the preconcentration is applied, in particular, the passive preconcentration. For this purpose, the concentrators are used, which are laid at shallow depths in the explored area. The survey technology that is being developed by the authors uses the reusable concentrators in the form of hollow stainless-steel tubes with SE-30 siloxane-based sorbent applied on their inner surface. The concentrators placed in the analytical containers are laid in the ground for 1-2 days. The analysis of the samples from the concentrators is carried out on a portable multicapillary gas chromatograph in the field conditions. The current article is devoted to the development of a special device for the sample injection from the passive concentrators and the experimental determination of the optimal mode of thermal desorption sample injection from the concentrators into the multicapillary column. The original injection scheme is given, where the gas-dynamic isolation of the injection device camera and the multicapillary column during the concentrator heating and sample analysis is implemented; the optimum concentrator heating time and the optimum sample injection time are determined.Keywords: passive concentrators, thermal desorption sample injection, gas-dynamic isolation of the injection device and columnDOI: http://dx.doi.org/10.15826/analitika.2019.23.3.003(Russian)V.M. Gruznov1,2,3, M.N. Baldin1, A.O. Malysheva1,3 1Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch of Russian Academy of Sciences, Koptug Avenue, 3, Novosibirsk, 630090,Russian Federation2Novosibirsk State University, Pirogova St., 2, Novosibirsk, 630090, Russian Federation3Novosibirsk State Technical University, Prospekt K. Marx Avenue, 20, Novosibirsk, 630073, Russian FederationВ настоящее время возрос интерес к геохимическим методам поиска залежей углеводородов по выявлению на поверхности Земли ореолов углеводородов, мигрирующих из залежей, в частности ароматических углеводородов: бензола, толуола, ксилолов. Концентрации мигрирующих углеводородов на поверхности Земли, как правило низкие, и находятся на уровне пороговых значений для газоаналитических приборов. Поэтому для их регистрации применяют концентрирование, в частности пассивное. Для этого используют концентраторы, закладываемые на небольшие глубины на разведываемой площади. В технологии съёмки, разрабатываемой авторами, используются многоразовые концентраторы в виде полых трубок из нержавеющей стали с сорбентом на основе силоксана SE-30, нанесенного на внутреннюю поверхность. Концентраторы в аналитических контейнерах закладываются в грунт на 1-2 суток. Анализ проб с концентраторов осуществляется на портативном поликапиллярном газовом хроматографе в полевых условиях. Статья посвящена специальному устройству ввода пробы с пассивных концентраторов и экспериментальному определению оптимального режима термодесорбционного ввода пробы с концентраторов в поликапиллярную колонку. Приведена оригинальная схема ввода, в которой реализована газодинамическая изоляция камеры устройства ввода и поликапиллярной колонки во время нагрева концентратора и анализа пробы, определено оптимальное время нагревания концентраторов и время ввода пробы.Ключевые слова: пассивные концентраторы, ввод методом термической десорбции, газодинамическая изоляция устройства ввода и колонкиDOI: http://dx.doi.org/10.15826/analitika.2019.23.3.00
Species recognition in Pluteus and Volvopluteus (Pluteaceae, Agaricales): morphology, geography and phylogeny
ВНЕЛАБОРАТОРНЫЙ ЭКСПРЕССНЫЙ ГАЗОХРОМАТОГРАФИЧЕСКИЙ МЕТОД АНАЛИЗА ВЫДЫХАЕМОГО ЧЕЛОВЕКОМ ВОЗДУХА С АВТОМАТИЗИРОВАННОЙ ГРАДУИРОВКОЙ
One of the current urgent task in medicine, and preventive medicine in particular, is the development of noninvasive (without surgery) methods of diagnosis and determination of the risks of various diseases. Much attention is paid to the possibilities of exhaled breath analysis for the diagnosis of various diseases such as cancer, gastroenterology, diabetes and others. Possibilities of such analyses are determined by a wide range of human exhaled volatile organic compounds. The growing interest in the development of noninvasive methods of diagnosis of diseases by the analysis of exhaled breath initiated the creation of easy-to-use and portable gas analyzers for the mass examination of patients in non-laboratory conditions. The main requirements for such gas analyzers are combinations of portability, speed, sensitivity and stability control. Current article presents a gas chromatographic method of rapid analysis of exhaled breath with an automated calibration of the vapor-phase concentration source that meets all of the above requirements. A portable polycapillary gas chromatography is used, which provides low thresholds for the determination of substances at the time of analysis of a few tens of seconds. The method of obtaining the vapor-phase calibration concentration of acetone vapors at the level of 10-10 g/cm3 is discussed. The calibration unit is integrated into the gas chromatograph (GC), and its software control ensures the automation of GC calibration. The original scheme of the sampling system (SS) provides multiple input samples from a single exhalation of a person and a completely similar input calibration air mixture in GC to reduce the calibration errors. The structure of the software is implemented in convenient terms for the chemist-analyst practice. Original SS, polycapillary gas chromatography, and built-in automated calibration provide real-time analysis of exhaled air in the presence of the patient. The possibility of differentiation of patients by metabolic disorders (metabolism) in the human body by express analysis of exhaled air using the proposed gas chromatographic method of express analysis of exhaled air with automated calibration is illustrated.Key words: automated sample device, express analysis of exhaled air, polycapillary gas chromatography, automated graduation, a head-space source of concentration(Russian) DOI: http://dx.doi.org/10.15826/analitika.2018.22.2.007A.O. Malysheva1, 3, M.N. Baldin1, V.M. Gruznov1, 2, 3, L.V. Blinova11Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch of Russian Academy of Sciences, Koptyug Avenue, 3, Novosibirsk, 630090,Russian Federation 2Novosibirsk State University, Pirogova St., 2, Novosibirsk, 630090, Russian Federation 3Novosibirsk State Technical University, K. Marx Avenue, 20, Novosibirsk, 630073, Russian FederationВ настоящее время актуальной задачей медицины, в частности профилактической, является разработка неинвазивных (бескровных) методик диагностики и определения риска различных заболеваний. Уделяется большое внимание возможностям анализа выдыхаемого воздуха для диагностики различных заболеваний – раковых, гастроэнтерологических, сахарного диабета и других. Возможности такого анализа определены широким набором выдыхаемых человеком летучих органических соединений. Возрастающий интерес к разработке неинвазивных методик диагностики заболеваний по анализу выдыхаемого человеком воздуха инициирует создание простых в обращении и портативных газовых анализаторов для массового обследования пациентов во внелабораторных условиях. Основные требования к газоанализаторам ‒ это сочетание портативности, быстродействия, чувствительности и контроля стабильности отклика. В статье изложен удовлетворяющий этим требованиям газохроматографический метод экспрессного анализа выдыхаемого воздуха с автоматизированной градуировкой парофазным источником концентрации. Использована портативная поликапиллярная газовая хроматография, обеспечивающая низкие пороги определения веществ при времени анализа в несколько десятков секунд. Обсуждается методика получения парофазной градуировочной концентрации паров ацетона на уровне 10–10 г/см3. Блок градуировки встроен в газовый хроматограф (ГХ), его программное управление обеспечивает автоматизацию градуировки ГХ. Оригинальная схема пробоотборного устройства (ПУ) обеспечивает многократный ввод пробы из разового выдоха человека и полностью аналогичный ввод градуировочной воздушной смеси в ГХ для уменьшения погрешностей градуировки. Структура программного обеспечения (ПО) реализована в терминах, удобных для практики химика-аналитика. Оригинальное ПУ, поликапиллярная газовая хроматография, встроенная автоматизированная градуировка обеспечивают анализ выдыхаемого воздуха в режиме реального времени в присутствии пациента. Проиллюстрирована возможность дифференцирования пациентов по нарушению метаболизма (обмену веществ) в организме человека по экспрессному анализу выдыхаемого воздуха предложенным газохроматографическим методом экспрессного анализа выдыхаемого воздуха с автоматизированной градуировкой.Ключевые слова: отбор выдыхаемого воздуха, экспрессный анализ выдыхаемого воздуха, поликапиллярная газовая хроматография, автоматизированная градуировка, парофазный источник концентрацииDOI: http://dx.doi.org/10.15826/analitika.2018.22.2.00
On the orbital and physical parameters of the HDE 226868/Cygnus X-1 binary system
In this paper we explore the consequences of the recent determination of the
mass m=(8.7 +/- 0.8)M_Sun of Cygnus X-1, obtained from the Quasi-Periodic
Oscillation (QPO)-photon index correlation scaling, on the orbital and physical
properties of the binary system HDE 226868/Cygnus X-1. By using such a result
and the latest spectroscopic optical data of the HDE 226868 supergiant star we
get M=(24 +/- 5)M_Sun for its mass. It turns out that deviations from the third
Kepler law significant at more than 1-sigma level would occur if the
inclination i of the system's orbital plane to the plane of the sky falls
outside the range 41-56 deg: such deviations cannot be due to the first
post-Newtonian (1PN) correction to the orbital period because of its smallness;
interpreted in the framework of the Newtonian theory of gravitation as due to
the stellar quadrupole mass moment Q, they are unphysical because Q would take
unreasonably large values. By conservatively assuming that the third Kepler law
is an adequate model for the orbital period we obtain i=(48 +/- 7) deg which
yields for the relative semimajor axis a=(42 +/- 9)R_Sun. Our estimate for the
Roche's lobe of HDE 226868 is r_M = (21 +/- 6)R_Sun.Comment: Latex2e, 7 pages, 1 table, 4 figures. To appear in ApSS (Astrophysics
and Space Science
A clinical case of exocrine pancreatic insufficiency in a patient with type 1 diabetes mellitus
The pancreas belongs to the glands of mixed secretion and simultaneously performs both endo- and exocrine functions. Exocrine pancreatic insufficiency (EPI) is the general name for the malabsorption process caused by inadequate production and decreased activation of the enzymes of the pancreas acinar cells, such as amylase, lipase and protease, which are necessary for digestion. The prevalence of EPI in patients with type 1 diabetes, according to many authors, varies from 25 to 59%, which is determine by the data of pancreatic elastase-1. In this work, we present a clinical case of confirmed exocrine pancreatic insufficiency in a patient with a 6-year history of type 1 diabetes, which became the main cause of the development of episodes of hypoglycemia after meals. In the course of further studies, antibodies to lactoferrin and a reduced prostate volume, determined by MRI data, high levels of antibodies to glutamate decarboxylase and zinc co-transporter 8, as well as residual insulin secretion based on the level of C-peptide on an empty stomach detected
Three very young HgMn stars in the Orion OB1 Association
We report the detection of three mercury-manganese stars in the Orion OB1
association. HD 37886 and BD-0 984 are in the approximately 1.7 million year
old Orion OB1b. HD 37492 is in the approximately 4.6 million year old Orion
OB1c. Orion OB1b is now the youngest cluster with known HgMn star members. This
places an observational upper limit on the time scale needed to produce the
chemical peculiarities seen in mercury-manganese stars, which should help in
the search for the cause or causes of the peculiar abundances in HgMn and other
chemically peculiar upper main sequence stars.Comment: 8 pages including 1 figure. To appear in Astrophysical Journal
Letter
The role of neurohumoral factors in the persistence of aseptic bone inflammation in patients with diabetic neuroosteoarthropathy
BACKGROUND: Diabetic neuroosteoarthropathy (DNOAP, Charcot foot) is a relatively rare complication of diabetes mellitus (DM), which can lead not only to impaired support function of the lower limb in such patients, but also to high amputation. DNOAP is characterized by persistent aseptic inflammation of the bone structures of the foot, which creates significant difficulties in planning therapeutic measures. In the medical literature, there are data demonstrating the role of individual cytokines and neurohumoral factors in the prolongation of the inflammatory process in diabetes, however, there are currently very few studies that determine reliable markers of aseptic inflammation in DNOAP.AIM: To study the effect of neurohumoral factors and advanced glycation end products on the activity of aseptic inflammation in the bone structures of the foot in patients with type 2 diabetes mellitus (DM2) and diabetic neuroosteoarthropathy.MATERIALS AND METHODS. The study included 88 patients with type 2 diabetes (45 men, 43 women). Group 1 consisted of patients with DM2 and inactive DNOAP (n= 43), group 2 (n= 45) consisted of patients with DM2 and distal diabetic neuropathy without osteoarticular pathology. The diagnosis of diabetic neuropathy was based on the analysis of the clinical picture and indicators of peripheral sensitivity. Diagnosis of DNOAP and determination of its stage was based on clinical data, the results of infrared thermometry and radiology tests of the foot bones. General clinical assessment was used, radiology tests (X-ray, MRI), evaluation of CRP, calprotectin, copeptin, glutathione peroxidase 1 (GP1).RESULTS. According to the results of examination and palpation of the feet, as well as the analysis of the temperature gradient of the skin of the affected and contralateral limb (infrared thermometry), DNOAP was detected and the stage of this complication was determined. The diagnosis of the chronic stage of DNOAP was confirmed by the results of MRI and the clinical picture (no difference in skin temperature on the symmetrical areas of the feet). According to the results of laboratory analysis, a statistically significant difference in copeptin values was revealed — in group 1 — 0.232 µg/ml [0.147; 0.342], in group 2 — 0.115 µg/ml [0.065; 0.203] (p>0.05) and CRP — in group 1 — 7.113 mg/l [2.453; 16.505], in group 2 — 2.187 mg/l [1.131; 5.567] (p>0.05), leukocyte levels in the groups did not differ significantly: group 1 — 7.86 [6.40; 9.00]*10^9, group 2 — 7.00 [6.00; 8.15] (p>0.05). There was a trend towards an increase in the level of calprotectin and glutathione peroxidase-1 in the DNOAP group, however, the differences were not significant. calprotectin — in group 1 — 1.948 [1.229; 2.969], in group 2 — 1.692 [1.16; 2.514] μg/ml and glutathione peroxidase-1 in group 1 — 24.72 [20.1; 31.82], in group 2 — 22.98 [18.94; 31.2] ng/ml.CONCLUSION. In the study, statistically significant differences were obtained in the levels of copeptin and C-reactive protein: in patients with DNOAP, their values were significantly higher, which indicates the persistence of the aseptic inflammatory process in the bone tissue of patients even in the chronic stage of DNOAP. These data may help in deciding whether to use one or another method of unloading the affected joints, which will affect the clinical prognosis. The study of neurohumoral markers of arthropathy in the blood serum of patients with DM2 is carried out for the first time, and therefore it is difficult to compare with the results of other authors. It can be assumed that copeptin and CRP are significant markers of persistent inflammation of the osteoarticular structures of the foot in DNOAP
Unmanned aerial vehicles: potential for use in the storage systems of industrial companies
In the article, the authors investigate the problem of using unmanned aerial vehicles (drones) in company warehouses and consider their use as one of the ways to optimize the logistics business processes of companies. Technologies are considered, on the basis of which modern unmanned aerial vehicles, drone models of various companies, the main functionality of drone’s work. The authors high-light the strengths and weaknesses of unmanned aerial vehicles, key factors determining the success of the use of drones, and favorable conditions for their use in warehouses. The authors are considering the possibility of sharing drones and RFID technology. Barriers to the active introduction of drones into the logistics business processes of warehousing systems and requirements for warehouse complexes planning the use of unmanned aerial objects have been identified. Promising areas of application of technology in warehouse logistics are also considered: creation of anti-theft and fire protection systems, using drones to read CIS marks. The authors used data from analytical reports and data collected by the authors themselves, as well as empirical research methods
Ca-ATPase activity and protein composition of sarcoplasmic reticulum membranes isolated from skeletal muscles of typical hibernator, the ground squirrel Spermophilus undulatus
Ca-ATPase activity in sarcoplasmic reticulum (SR) membranes isolated from skeletal muscles of the typical hibernator, the ground squirrel Spermophilus undulatus, is about 2-fold lower than that in SR membranes of rats and rabbits and is further decreased 2-fold during hibernation. The use of carbocyanine anionic dye Stains-All has revealed that Ca-binding proteins of SR membranes, histidine-rich Ca-binding protein and sarcalumenin, in ground squirrel, rat, and rabbit SR have different electrophoretic mobility corresponding to apparent molecular masses 165, 155, and 170 kDa and 130, 145, and 160 kDa, respectively; the electrophoretic mobility of calsequestrin (63 kDa) is the same in all preparations. The content of these Ca-binding proteins in SR membranes of the ground squirrels is decreased 3–4 fold and the content of 55, 30, and 22 kDa proteins is significantly increased during hibernation
Transforming growth factor β1 (TGF-β1) in patients with endocrine ophthalmopathy and Graves’ disease: A predictor of treatment efficiency
Current therapeutic approaches to the treatment of endocrine ophthalmopathy (EOP) are based on nonspecific immunosuppression with glucocorticosteroids (GCs) and radiation therapy of the eye orbits. However, some patients exhibit resistance to the treatment. In a previous study, we have detected high levels of soluble cytokine receptors: sTNFα-R1, sTNFα-R2, sIL-2R, and the TGF-β1 cytokine in euthyroid patients with long-lasting non-treated EOP and Graves’ disease (GD). TGF-β1 level was significantly higher in the patients with EOP compared to healthy individuals, and increased with prolonged EOP duration, thus suggesting activation of the factors regulating immune system which promote suppression of the autoimmune process. The aim of this work was to study the dynamics of TGF-β1 and cytokine receptors: sTNFα-R1, sTNFα-R2, sIL-2R in the course of immunosuppressive therapy with high doses of GCs, as possible predictors of treatment efficacy. The study included 49 patients (98 eye orbits) with GD of euthyroid state and subclinical thyrotoxicosis, and the persons with EOP in active phase, who had not previously treatment for EOP. Concentrations of TGF-β1 cytokine, sTNFα-RI and sTNFα-R2, sIL-2R, antibodies to the thyroid-stimulating hormone receptor (rTSH), free fractions of thyroxine (fT4) and triiodothyronine (fT3), TSH in blood serum were determined in blood serum. Ultrasound examination of the thyroid gland (ultrasound of the thyroid gland), multi-layer computed tomography (MSCT)/magnetic resonance imaging (MRI) of the orbits were also performed. The patients were administered immunosuppressive therapy with high doses of HCs (methylprednisolone) in the course of pulse therapy, at a standard dosage of 4500-8000 mg, taking into account the severity and activity of the EOP clinical manifestations. The examination was carried out 3, 6, 12 months after starting the treatment. 3 and 6 months after the GC administration, more than 30% of patients remained resistant to treatment. The levels of TGF-β1 did not change significantly in the patients with positive EOP dynamics. In the patients resistant to GC treatment, the level of TGF-β1 was significantly decreased compared with patients who showed positive clinical dynamics. The level of sNFR1 and sNFaR2 did not change significantly. There were no significant differences in the levels of antibodies to rTSH, thyroid hormones in the patients resistant to GC treatment and with positive dynamics.Immunosuppressive therapy with high-dose of methylprednisolone in pulse therapy regimen showed high efficacy and good tolerability, while some patients remain resistant to treatment. Lower levels of TGF-β1 cytokine at initial time and during the treatment allow usage of TGF-β1 levels as a biomarker of the activity of the process, treatment efficiency, and prognosis of the disease. Activation of TGF-β1, a fibroblast growth factor, may contribute to the development of fibrosis, strabismus, and diplopia
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