On the Absorption of X-rays in the Interstellar Medium

We present an improved model for the absorption of X-rays in the ISM intended for use with data from future X-ray missions with larger effective areas and increased energy resolution such as Chandra and XMM, in the energy range above 100eV. Compared to previous work, our formalism includes recent updates to the photoionization cross section and revised abundances of the interstellar medium, as well as a treatment of interstellar grains and the H2molecule. We review the theoretical and observational motivations behind these updates and provide a subroutine for the X-ray spectral analysis program XSPEC that incorporates our model.Comment: ApJ, in press, for associated software see http://astro.uni-tuebingen.de/nh

Surface temperature and synthetic spectral energy distributions for rotationally deformed stars

The spectral energy distribution (SED) of a non-spherical star could differ significantly from the SED of a spherical star with the same average temperature and luminosity. Calculation of the SED of a deformed star is often approximated as a composite of several spectra, each produced by a plane parallel model of given effective temperature and gravity. The weighting of these spectra over the stellar surface, and hence the inferred effective temperature and luminosity, will be dependent on the inclination of the rotation axis of the star with respect to the observer, as well as the temperature and gravity distribution on the stellar surface. Here we calculate the surface conditions of rapidly rotating stars with a 2D stellar structure and evolution code and compare the effective temperature distribution to that predicted by von Zeipel's law. We calculate the composite spectrum for a deformed star by interpolating within a grid of intensity spectra of plane parallel model atmospheres and integrating over the surface of the star. Using this method, we find that the deduced variation of effective temperature with inclination can be as much as 3000 K for an early B star, depending on the details of the underlying model.Comment: 38 pages, 9 figures (AAStex preprint format). Accepted for publication in the Ap

Permitted Oxygen Abundances and the Temperature Scale of Metal-Poor Turn-Off Stars

We use high quality VLT/UVES published data of the permitted OI triplet and FeII lines to determine oxygen and iron abundances in unevolved (dwarfs, turn-off, subgiants) metal-poor halo stars. The calculations have been performed both in LTE and NLTE, employing effective temperatures obtained with the new infrared flux method (IRFM) temperature scale by Ramirez & Melendez, and surface gravities from Hipparcos parallaxes and theoretical isochrones. A new list of accurate transition probabilities for FeII lines, tied to the absolute scale defined by laboratory measurements, has been used. We find a plateau in the oxygen-to-iron ratio over more than two orders of magnitude in iron abundance (-3.2 < [Fe/H] < -0.7), with a mean [O/Fe] = 0.5 dex (sigma = 0.1 dex), independent of metallicity, temperature and surface gravity. According to the new IRFM Teff scale, the temperatures of turn-off halo stars strongly depend on metallicity, a result that is in excellent qualitative and quantitative agreement with stellar evolution calculations, which predict that the Teff of the turn-off at [Fe/H] = -3 is about 600-700 K higher than that at [Fe/H] = -1.Comment: In press, Ap

Differences sustained between diffuse and limited forms of juvenile systemic sclerosis in expanded international cohort. www.juvenile-scleroderma.com

OBJECTIVES: To evaluate the baseline clinical characteristics of juvenile systemic sclerosis (jSSc) patients in the international Juvenile SSc Inception Cohort (jSScC), compare these characteristics between the classically defined diffuse (dcjSSc) and limited cutaneous (lcjSSc) subtypes, and among those with overlap features. METHODS: A cross-sectional study was performed using baseline visit data. Demographic, organ system evaluation, treatment, and patient and physician reported outcomes were extracted and summary statistics applied. Comparisons between dcjSSc and lcSSc subtypes and patients with and without overlap features were performed using Chi-square and Mann Whitney U-tests. RESULTS: At data extraction 150 jSSc patients were enrolled across 42 centers, 83% were Caucasian, 80% female, dcjSSc predominated (72%), and 17% of the cohort had overlap features. Significant differences were found between dcjSSc and lcjSSc regarding the modified Rodnan Skin Score, presence of Gottron's papules, digital tip ulceration, 6 Minute walk test, composite pulmonary and cardiac involvement. All more frequent in dcSSc except for cardiac involvement. DcjSSc patients had significantly worse scores for physician rated disease activity and damage. A significantly higher occurrence of Gottron's papules, musculoskeletal involvement and composite pulmonary involvement, and significantly lower frequency of Raynaud's phenomenon, were seen in those with overlap features. CONCLUSION: Results from a large international jSSc cohort demonstrate significant differences between dcjSSc and lcjSSc patients including more globally severe disease and increased frequency of ILD in dcjSSc patients, while those with lcSSc have more frequent cardiac involvement. Those with overlap features had an unexpected higher frequency of interstitial lung disease

Oxygen in the Very Early Galaxy

Oxygen abundances in a sample of ultra-metal-poor subdwarfs have been derived from measurements of the oxygen triplet at 7771--5 A and OH lines in the near UV performed in high-resolution and high signal-to-noise spectra obtained with WHT/UES, KeckI/HIRES, and VLT/UVES. Our Fe abundances were derived in LTE and then corrected for NLTE effects following Thevenin and Idiart (1999). The new oxygen abundances confirm previous findings for a progressive linear rise in the oxygen-to-iron ratio with a slope -0.33+-0.02 from solar metallicity to [Fe/H] -3. A slightly higher slope would be obtained if the Fe NLTE corrections were not considered. Below [Fe/H]= -2.5 our stars show [O/Fe] ratios as high as ~ 1.17 (G64-12), which can be interpreted as evidence for oxygen overproduction in the very early epoch of the formation of the halo, possibly associated with supernova events with very massive progenitor stars. We show that the arguments against this linear trend given by Fulbright and Kraft (1999), based on the LTE Fe analysis of two metal-poor stars cannot be sustained when an NLTE analysis is performed. Using 1-D models our analysis of three oxygen indicators available for BD +23 3130 gives consistent abundances within 0.16 dex and average [O/Fe] ratio of 0.91.Comment: 45 pages, 11 figures, accepted for publication in The Astrophysical Journa

Опыт диагностики и лечения болезни Кавасаки в клинике Санкт-Петербургского государственного педиатрического медицинского университета и Д етской городской больнице №1 Санкт-Петербурга

Kawasaki disease (KD) is acute systemic vasculitis of unknown etiology. Approximately 20–25% of untreated patients develop coronary artery changes with a range of severity from asymptomatic coronary artery dilatation to giant coronary artery aneurysms with thrombosis, myocardial infarction, and sudden death. To date there is no official data on the incidence of KD in Russia. In Russia, the disease is not enough known now to a wide circle of physicians and often masks other more common diseases. Since 2010, the detection rate of KD has dramatically increased in Saint-Petersburg.Objective: to analyze the experience in diagnosing and treating KD in two largest hospitals of Saint Petersburg.Patients and methods. The retrospective study included data on 30 children (18 boys, 12 girls) who were hospitalized with a diagnosis of KD in the Saint-Petersburg State Pediatric Medical University Clinic and Children’s Hospital One (Saint Petersburg) between January 2011 and September 2016. Data are represented by median and extreme values. The age of the children was 2.8 (0.2; 4.6) years; of them 5 (16.7%) patients were under the age of 1 year. The children were hospitalized on 5 (1; 14) days of disease onset; KD was diagnosed on 9 (3; 52) day of the disease.Results. Immediately after diagnosis, 27 (90%) children received aspirin. In early stages (before 10 days of the disease), intravenous immunoglobulin (IVIG) therapy was performed in 15 (50%) children, one of them received IVIG before disease day 5 (on day 3), but without effect. On disease days 11-20 (immediately after diagnosis), 10 (33.3%) children were prescribed with IVIG; thereafter fever was abolished in all the patients. Their body temperature became normal on day 11 (6; 23). Ultrasonography revealed coronary artery lesions in 13 (43.3%) patients. Out of the 30 children followed up, one baby who fell ill at the age of 3 months and received IVIG died on day 30 of the disease.Conclusion. Currently, there continues to be a delayed diagnosis of KD. IVIG therapy was effective, especially in cases of timely diagnosis. It is necessary to increase awareness of KD among clinicians and ultrasound diagnosticians.Болезнь Кавасаки (БК) – остро протекающий системный васкулит неизвестной этиологии. Примерно у 20–25% не получивших лечения больных развиваются изменения коронарных артерий различной степени тяжести – от бессимптомной дилатации до гигантских аневризм, тромбоза, инфаркта миокарда и внезапной смерти. До настоящего времени официальных данных о заболеваемости БК в России нет. В нашей стране БК недостаточно известна широкому кругу врачей и часто проходит под маской других более распространенных заболеваний. В Санкт-Петербурге после 2010 г. резко возросла выявляемость БК.Цель исследования – проанализировать опыт диагностики и лечения БК в двух крупных стационарах Санкт-Петербурга.Пациенты и методы. В ретроспективное исследование были включены данные о 30 детях (18 мальчиков, 12 девочек), находившихся на стационарном лечении с диагнозом БК в клинике Санкт-Петербургского государственного педиатрического медицинского университета и Детской городской больнице №1 Санкт-Петербурга с января 2011 г. по сентябрь 2016 г. Данные представлены медианой и крайними значениями. Возраст детей составил 2,8 [0,2; 4,6] года, из них 5 (16,7%) пациентов были в возрасте до 1 года. Дети были госпитализированы на 5-е [1; 14] сутки болезни, диагноз БК установлен на 9-й [3; 52] день болезни.Результаты. Сразу после установления диагноза получили аспирин 27 детей (90%). В ранние сроки (до 10-го дня болезни) терапия внутривенным иммуноглобулином (ВВИГ) проводилась у 15 (50%) пациентов, из них 1 получил ВВИГ ранее 5-го дня болезни (на 3-й день), однако без эффекта. На 11–20-й день болезни (сразу после установления диагноза) ВВИГ назначен 10 (33,3%) детям, после чего лихорадка была купирована у всех пациентов. Температура тела нормализовалась на 11-й [6; 23] день. Поражение коронарных артерий при УЗИ выявлено у 13 (43,3%) пациентов. Из 30 находившихся под наблюдением детей у 1 ребенка, заболевшего в возрасте 3 мес и получившего ВВИГ на 30-й день болезни, зафиксирован летальный исход.Выводы. В настоящее время БК продолжает диагностироваться с опозданием. Терапия ВВИГ была эффективной, особенно в случаях своевременного установления диагноза. Необходимо повышение осведомленности клиницистов и врачей ультразвуковой диагностики о БК

Comparing Presenting Clinical Features in 48 Children With Microscopic Polyangiitis to 183 Children Who Have Granulomatosis With Polyangiitis (Wegener&apos;s) : an ARChiVe Cohort Study

OBJECTIVE: To uniquely classify children with microscopic polyangiitis (MPA), to describe their demographic characteristics, presenting clinical features, and initial treatments in comparison to patients with granulomatosis with polyangiitis (Wegener's) (GPA). METHODS: The European Medicines Agency (EMA) classification algorithm was applied by computation to categorical data from patients recruited to the ARChiVe (A Registry for Childhood Vasculitis: e-entry) cohort, with the data censored to November 2015. The EMA algorithm was used to uniquely distinguish children with MPA from children with GPA, whose diagnoses had been classified according to both adult- and pediatric-specific criteria. Descriptive statistics were used for comparisons. RESULTS: In total, 231 of 440 patients (64% female) fulfilled the classification criteria for either MPA (n\u2009=\u200948) or GPA (n\u2009=\u2009183). The median time to diagnosis was 1.6 months in the MPA group and 2.1 months in the GPA group (ranging to 39 and 73 months, respectively). Patients with MPA were significantly younger than those with GPA (median age 11 years versus 14 years). Constitutional features were equally common between the groups. In patients with MPA compared to those with GPA, pulmonary manifestations were less frequent (44% versus 74%) and less severe (primarily, hemorrhage, requirement for supplemental oxygen, and pulmonary failure). Renal pathologic features were frequently found in both groups (75% of patients with MPA versus 83% of patients with GPA) but tended toward greater severity in those with MPA (primarily, nephrotic-range proteinuria, requirement for dialysis, and end-stage renal disease). Airway/eye involvement was absent among patients with MPA, because these GPA-defining features preclude a diagnosis of MPA within the EMA algorithm. Similar proportions of patients with MPA and those with GPA received combination therapy with corticosteroids plus cyclophosphamide (69% and 78%, respectively) or both drugs in combination with plasmapheresis (19% and 22%, respectively). Other treatments administered, ranging in decreasing frequency from 13% to 3%, were rituximab, methotrexate, azathioprine, and mycophenolate mofetil. CONCLUSION: Younger age at disease onset and, perhaps, both gastrointestinal manifestations and more severe kidney disease seem to characterize the clinical profile in children with MPA compared to those with GPA. Delay in diagnosis suggests that recognition of these systemic vasculitides is suboptimal. Compared with adults, initial treatment regimens in children were comparable, but the complete reversal of female-to-male disease prevalence ratios is a provocative finding