29 research outputs found
The astrometric Gaia-FUN-SSO observation campaign of 99 942 Apophis
Astrometric observations performed by the Gaia Follow-Up Network for Solar
System Objects (Gaia-FUN-SSO) play a key role in ensuring that moving objects
first detected by ESA's Gaia mission remain recoverable after their discovery.
An observation campaign on the potentially hazardous asteroid (99 942) Apophis
was conducted during the asteroid's latest period of visibility, from
12/21/2012 to 5/2/2013, to test the coordination and evaluate the overall
performance of the Gaia-FUN-SSO . The 2732 high quality astrometric
observations acquired during the Gaia-FUN-SSO campaign were reduced with the
Platform for Reduction of Astronomical Images Automatically (PRAIA), using the
USNO CCD Astrograph Catalogue 4 (UCAC4) as a reference. The astrometric
reduction process and the precision of the newly obtained measurements are
discussed. We compare the residuals of astrometric observations that we
obtained using this reduction process to data sets that were individually
reduced by observers and accepted by the Minor Planet Center. We obtained 2103
previously unpublished astrometric positions and provide these to the
scientific community. Using these data we show that our reduction of this
astrometric campaign with a reliable stellar catalog substantially improves the
quality of the astrometric results. We present evidence that the new data will
help to reduce the orbit uncertainty of Apophis during its close approach in
2029. We show that uncertainties due to geolocations of observing stations, as
well as rounding of astrometric data can introduce an unnecessary degradation
in the quality of the resulting astrometric positions. Finally, we discuss the
impact of our campaign reduction on the recovery process of newly discovered
asteroids.Comment: Accepted for publication in A&
Влияние полиморфизма Pro198Leu гена глутатионпероксидазы 1-го типа на риск развития аллергической бронхиальной астмы у мужчин
The purpose of our pilot study was to investigate the association between Pro198Leu polymorphism in the glutathione peroxidase-1 gene (GPX1) and susceptibility to atopic and non-atopic asthma in Russian residents of the Central region of Russia. Blood samples from 213 asthmatics and 205 healthy controls matched on gender and age were analyzed for P198L polymorphism of the GPX1 gene using PCR-RFLP methods. The association of 198Pro/Leu GPX1 genotype (OR = 1,53; p = 0,05) with susceptibility to atopic BA was found. However, the 198Pro/Leu genotype of the glutathione peroxidase-1 gene was found to be associated with atopic BA in males only (OR = 2,21; p = 0,01).Впервые изучена связь полиморфизма Pro198Leu гена глутатионпероксидазы-1 (GPX1) с развитием аллергической и неаллергической форм бронхиальной астмы (БА). Материалом для исследования послужила популяционная выборка русских жителей ЦентральноЧерноземного региона России (213 больных БА и 205 здоровых добровольцев). Генотипирование полиморфизма Pro198Leu гена GPX1 проводилось методом полимеразной цепной реакции (ПЦР) и посредством анализа полиморфизма длин рестрикционных фрагментов (ПДРФ). Установлено, что частота гетерозигот 198L/P была выше среди больных аллергической БА, чем среди здоровых индивидов (OR = 1,53; p = 0,05). Однако обнаруженная нами впервые ассоциация полиморфизма Pro198Leu гена GPX1 с аллергической БА была характерна только для мужчин (OR = 2,21, p = 0,01)
Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial
IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved
СРАВНЕНИЕ МОРФОЛОГИЧЕСКИХ И ХИМИЧЕСКИХ СВОЙСТВ СФЕРИЧЕСКИХ И ИГОЛЬЧАТЫХ КАЛЬЦИЙ-ФОСФАТНЫХ БИОНОВ
Aim. To compare morphological properties, mineral, and organic profile of spherical calcium phosphate bions (SCPB) and needle calcium phosphate bions (NCPB) for the assessment of the CPB-specific endothelial toxicity in models of mild or severe hypercalcemia/hyperphosphatemia in the further studies.Methods. Both SCPB and NCPB were artificially synthesized employing blood-mimetic medium either moderately or significantly supersaturated of calcium and phosphorus salts. Size and shape of SCPB and NCPB were investigated by scanning and transmission electron microscopy and atomic force microscopy. Elemental analysis was performed utilizing energy-dispersive X-ray spectroscopy, atomic emission spectroscopy, and CHNSO analysis, functional groups were examined using Fourier-transform infrared spectroscopy and Raman spectroscopy while chemical formula was identified by X-ray powder diffraction analysis. Protein profile of SCPB and NCPB was screened employing sodium dodecyl sulfate polyacrylamide gel electrophoresis following silver staining.Results. SCPB were visualized as crystalline spherical spongeous particles of 80-200 nm diameter and mean diameter of around 120 nm while NCPB represented needle crystals of a similar diameter. Both SCPB and NCPB had similar crystallinity, surface charge and tended to form clusters of several particles. Furthermore, both SCPB and NCPB were composed of carbon, oxygen, hydrogen, nitrogen, calcium, and phosphorus, contained phosphate (PO4 3-), carbonate (CO3 2-), and hydroxyl (OH- ) functional groups, and consisted of hydroxyapatite (Ca10(PO4 )6 (OH)2 ) and carbonate-hydroxyapatite (Ca10(PO4)3 (CO3)3 (OH)2 ). In addition, protein profile of SCPB and NCPB was similar and notable for the abundant albumin and fetuin A levels.Conclusion. Having similar size, surface charge, extent of crystallinity, and chemical composition, SCPB and NCPB possess a different shape. Цель Сравнить морфологию, минеральный и органический профиль сферических кальций-фосфатных бионов (СКФБ) и игольчатых кальций-фосфатных бионов (ИКФБ), необходимых для оценки эндотелиотоксического действия КФБ при моделировании умеренной и тяжелой гиперкальциемии/гиперфосфатемии в последующих исследованиях. Материалы и методы СКФБ и ИКФБ были искусственно синтезированы посредством умеренного и выраженного перенасыщения имитирующей состав крови среды солями кальция и фосфора. Размерность и форма СКФБ и ИКФБ были изучены при помощи сканирующей и просвечивающей электронной микроскопии и атомно-силовой микроскопии. Элементный анализ проводился посредством энергодисперсионной рентгеновской спектроскопии, атомно-эмиссионной спектроскопии и CHNSO-анализа, функциональные группы идентифицировались при помощи инфракрасной спектроскопии с преобразованием Фурье и спектроскопии комбинационного рассеяния света, формула входящих в состав бионов химических соединений и степень их кристалличности определялась методом рентгеновской порошковой дифрактометрии. Белковый профиль СКФБ и ИКФБ был исследован путем электрофореза в полиакриламидном геле в присутствии додецилсульфата натрия с последующим окрашиванием нитратом серебра. Результаты СКФБ визуализировались как кристаллические сферические частицы губчатой структуры диаметром 80–200 нм и средним диаметром около 120 нм, в то время как ИКФБ представляли собой игольчатые кристаллы такого же диаметра. Как СКФБ, так и ИКФБ имели схожий поверхностный заряд и были склонны к агрегации. СКФБ и ИКФБ состояли из углерода, кислорода, водорода, азота, кальция и фосфора, содержали фосфатные (PO4 3-), карбонатные (CO3 2-) и гидроксильные (OH- ) группы и состояли из гидроксиапатита (Ca10(PO4 ) 6 (OH)2 ) и карбонат-гидроксиапатита (Ca10(PO4 ) 3 (CO3 ) 3 (OH)2 ). Кроме того, СКФБ и ИКФБ обладали идентичной степенью кристалличности и схожим белковым профилем с преобладанием альбумина и фетуина-А над остальными белками. Заключение СКФБ и ИКФБ отличаются лишь формой, имея схожие размерность, поверхностный заряд, степень кристалличности и химический соста
A large topographic feature on the surface of the trans-Neptunian object (307261) 2002 MS measured from stellar occultations
This work aims at constraining the size, shape, and geometric albedo of the
dwarf planet candidate 2002 MS4 through the analysis of nine stellar
occultation events. Using multichord detection, we also studied the object's
topography by analyzing the obtained limb and the residuals between observed
chords and the best-fitted ellipse. We predicted and organized the
observational campaigns of nine stellar occultations by 2002 MS4 between 2019
and 2022, resulting in two single-chord events, four double-chord detections,
and three events with three to up to sixty-one positive chords. Using 13
selected chords from the 8 August 2020 event, we determined the global
elliptical limb of 2002 MS4. The best-fitted ellipse, combined with the
object's rotational information from the literature, constrains the object's
size, shape, and albedo. Additionally, we developed a new method to
characterize topography features on the object's limb. The global limb has a
semi-major axis of 412 10 km, a semi-minor axis of 385 17 km, and
the position angle of the minor axis is 121 16. From
this instantaneous limb, we obtained 2002 MS4's geometric albedo and the
projected area-equivalent diameter. Significant deviations from the fitted
ellipse in the northernmost limb are detected from multiple sites highlighting
three distinct topographic features: one 11 km depth depression followed by a
25 km height elevation next to a crater-like depression with an
extension of 322 39 km and 45.1 1.5 km deep. Our results present an
object that is 138 km smaller in diameter than derived from thermal
data, possibly indicating the presence of a so-far unknown satellite. However,
within the error bars, the geometric albedo in the V-band agrees with the
results published in the literature, even with the radiometric-derived albedo
The astrometric Gaia-FUN-SSO observation campaign of 99942 Apophis
© 2015 ESO. Aims. Astrometric observations performed by the Gaia Follow-Up Network for Solar System Objects (Gaia-FUN-SSO) play a key role in ensuring that moving objects first detected by ESA's Gaia mission remain recoverable after their discovery. An observation campaign on the potentially hazardous asteroid (99 942) Apophis was conducted during the asteroid's latest period of visibility, from 12/21/2012 to 5/2/2013, to test the coordination and evaluate the overall performance of the Gaia-FUN-SSO. Methods. The 2732 high quality astrometric observations acquired during the Gaia-FUN-SSO campaign were reduced with the Platform for Reduction of Astronomical Images Automatically (PRAIA), using the USNO CCD Astrograph Catalogue 4 (UCAC4) as a reference. The astrometric reduction process and the precision of the newly obtained measurements are discussed. We compare the residuals of astrometric observations that we obtained using this reduction process to data sets that were individually reduced by observers and accepted by the Minor Planet Center. Results. We obtained 2103 previously unpublished astrometric positions and provide these to the scientific community. Using these data we show that our reduction of this astrometric campaign with a reliable stellar catalog substantially improves the quality of the astrometric results. We present evidence that the new data will help to reduce the orbit uncertainty of Apophis during its close approach in 2029. We show that uncertainties due to geolocations of observing stations, as well as rounding of astrometric data can introduce an unnecessary degradation in the quality of the resulting astrometric positions. Finally, we discuss the impact of our campaign reduction on the recovery process of newly discovered asteroids
Ion Etching Effects Occurring in Secondary Ion Mass Spectrometry Depth profiling of InGaAs/InP and InGaAs/AlAs/InP MBE Grown Heterostructures
Depth profiling analysis of InGaAs heterolayers grown by MBE on Fe doped InP(100) substrates was performed in the SAJW-02 secondary ion mass spectrometry analyser equipped with 4.5 keV O ion source and a specially designed sample manipulator enabling depth profiling in the standard as well as in so-called Zalar rotation operation modes. The fairly high energy of the primary ion beam required for sputtering in secondary ion mass spectrometry measurements causes changes in surface topography, usually of different origin. Depth resolution parameters and roughness formation monitored by scanning electron microscopy were analysed for a set of samples with composition x changing in the range 0.33 to 0.60. The results were compared with the same data for a layer of x=0.53 (best lattice-matched to InP) grown on the top of a three monolayer thick AlAs film deposited previously on the InP substrate. Improvement in the depth profile resolution was revealed for the structure with an AlAs layer indicating sharper interface transition. Moreover, sample rotation applied for this structure improves further the depth profiling resolution. Thus, we showed for the first time that a very thin AlAs layer grown by MBE between the InP substrate and the InGaAs improves considerably the heterointerface properties and that Zalar rotation applied for depth profiling of the investigated material system diminishes further the negative effects of ion etching on depth resolution in secondary ion mass spectrometry analysis
Cytocompatibility and Osteoinductive Properties of Collagen-Fibronectin Hydrogel Impregnated with siRNA Targeting Glycogen Synthase Kinase 3β: In Vitro Study
In this study, we developed an osteoplastic material based on collagen–fibronectin hydrogel impregnated with siRNA molecules targeting glycogen synthase kinase 3β (GSK3β), which inhibits the osteogenic differentiation of mesenchymal stem cells. The hydrogel impregnated with polyplexes containing siRNA GSK3β and polyethylenimine has been shown to have no cytotoxic effect: there was no statistically significant change in the cell’s viability after 7 days of incubation in its presence compared to the control group. On days 2 and 7, an increase in the level of expression of markers of osteogenic differentiation was observed, which confirms the osteoinductive qualities of the material. It has been demonstrated that the hydrogel maintains cell adhesion. Our results obtained in vitro indicate cytocompatibility and osteoinductive properties of collagen–fibronectin hydrogel impregnated with siRNA GSK3β molecules