276 research outputs found

    Hydrogel Nanocomposites with Silver Nanoparticles

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    Copolymer hydrogels based on acrylic monomers (primarily acrylamide and acrylonitrile) are synthesized and their physicochemical properties are investigated. Methods of incorporation of nanoparticles of gold and silver into hydrogel pores and methods of their stabilization using reagents of different nature are developed. Our studies showed pronounced bactericidal properties of the nanocomposites regarding gram-positive and gram-negative bacteria and, at the same time, their biocompatibility to stem cells

    ВНЕЛАБОРАТОРНЫЙ ЭКСПРЕССНЫЙ ГАЗОХРОМАТОГРАФИЧЕСКИЙ МЕТОД АНАЛИЗА ВЫДЫХАЕМОГО ЧЕЛОВЕКОМ ВОЗДУХА С АВТОМАТИЗИРОВАННОЙ ГРАДУИРОВКОЙ

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    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

    Three very young HgMn stars in the Orion OB1 Association

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    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

    On the orbital and physical parameters of the HDE 226868/Cygnus X-1 binary system

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    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

    Diaquabis­[3-(hydroxy­imino)­butanoato]nickel(II)

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    In the neutral, mononuclear title complex, [Ni(C4H6NO3)2(H2O)2], the Ni atom lies on a crystallographic inversion centre within a distorted octa­hedral N2O4 environment. Two trans-disposed anions of 3-hydroxy­imino­butanoic acid occupy four equatorial sites, coordinated by the deprotonated carboxyl­ate and protonated oxime groups and forming six-membered chelate rings, while the two axial positions are occupied by the water O atoms. The O atom of the oxime group forms an intra­molecular hydrogen bond with the coordinated carboxyl­ate O atom. The complex mol­ecules are linked into chains along b by hydrogen bonds between the water O atom and the carboxyl­ate O of a neighbouring mol­ecule. The chains are linked by further hydrogen bonds into a layer structure

    The role of neurohumoral factors in the persistence of aseptic bone inflammation in patients with diabetic neuroosteoarthropathy

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    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

    Diaquabis­[3-(hydroxy­imino­)butanoato]nickel(II): a triclinic polymorph

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    The title centrosymmetric mononuclear complex, [Ni(C4H6NO3)2(H2O)2], is a polymorph of the previously reported complex [Dudarenko et al. (2010 ▶). Acta Cryst. E66, m277–m278]. The NiII atom, lying on an inversion center, is six-coordinated by two carboxyl­ate O atoms and two oxime N atoms from two trans-disposed chelating 3-hydroxy­imino­butanoate ligands and two axial water mol­ecules in a distorted octa­hedral geometry. The hydr­oxy group forms an intra­molecular hydrogen bond with the coordinated carboxyl­ate O atom. The complex mol­ecules are linked in stacks along [010] by a hydrogen bond between the water O atom and the carboxyl­ate O atom of a neighboring mol­ecule. The stacks are further linked by O—H⋯O hydrogen bonds into a layer parallel to (001)

    High dietary folate in pregnant mice leads to pseudo-MTHFR deficiency and altered methyl metabolism, with embryonic growth delay and short-term memory impairment in offspring

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    Methylenetetrahydrofolate reductase (MTHFR) generates methyltetrahydrofolate for methylation reactions. Severe MTHFR deficiency results in homocystinuria and neurologic impairment. Mild MTHFR deficiency (677C > T polymorphism) increases risk for complex traits, including neuropsychiatric disorders. Although low dietary folate impacts brain development, recent concerns have focused on high folate intake following food fortification and increased vitamin use. Our goal was to determine whether high dietary folate during pregnancy affects brain development in murine offspring. Female mice were placed on control diet (CD) or folic acid-supplemented diet (FASD) throughout mating, pregnancy and lactation. Three-week-old male pups were evaluated for motor and cognitive function. Tissues from E17.5 embryos, pups and dams were collected for choline/methyl metabolite measurements, immunoblotting or gene expression of relevant enzymes. Brains were examined for morphology of hippocampus and cortex. Pups of FASD mothers displayed short-term memory impairment, decreased hippocampal size and decreased thickness of the dentate gyrus. MTHFR protein levels were reduced in FASD pup livers, with lower concentrations of phosphocholine and glycerophosphocholine in liver and hippocampus, respectively. FASD pup brains showed evidence of altered acetylcholine availability and Dnmt3a mRNA was reduced in cortex and hippocampus. E17.5 embryos and placentas from FASD dams were smaller. MTHFR protein and mRNA were reduced in embryonic liver, with lower concentrations of choline, betaine and phosphocholine. Embryonic brain displayed altered development of cortical layers. In summary, high folate intake during pregnancy leads to pseudo-MTHFR deficiency, disturbed choline/methyl metabolism, embryonic growth delay and memory impairment in offspring. These findings highlight the unintended negative consequences of supplemental folic acid

    DICER and DROSHA gene expression in peripheral mononuclear blood cells from rheumatoid arthritis patients under methotrexate therapy

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    The aim of this research was studying the level of DROSHA and DICER genes expression in peripheral mononuclear blood cells (PBMC) in rheumatoid arthritis (RA) patients under methotrexate therapy. Materials and methods. 82 people (from 45 to 70 years) enrolled in this study were divided into 3 groups (the first one - healthy donors (n=33 median age 49.93±1.87); the second group - rheumatoid arthritis patients without any therapy (n=15; median age 57.28±15.18) and the third group (n=34; median age 60.88±9.02) - rheumatoid arthritis patients who treated at least 4 weeks with methotrexate therapy (10-20 mg/week). The DICER and DROSHA genes expression level was determined by real-time PCR. Results. The number of DICER gene transcripts in PBMC in rheumatoid arthritis patients without therapy as in RA patients treated with methotrexate was reduced in comparison with the healthy donors (p0.05 respectively). The level of DROSHA gene expression in PBMC was not significantly different in all groups enrolled in this study (p>0.05). Conclusion. Our findings suggest that that the DICER gene expression level in perifheral mononuclear blood cells decreased with the development of rheumatoid arthritis. Methotrexate doesn’t influence on the mRNA level of this gene
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