8,956 research outputs found

    X-ray properties of the young open clusters HM1 and IC2944/2948

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    Using XMM data, we study for the first time the X-ray emission of HM1 and IC2944/2948. Low-mass, pre-main-sequence objects with an age of a few Myr are detected, as well as a few background or foreground objects. Most massive stars in both clusters display the usual high-energy properties of that type of objects, though with log(Lx/Lbol) apparently lower in HM1 than in IC2944/2948. Compared with studies of other clusters, it seems that a low signal-to-noise ratio at soft energies, due to the high extinction, may be the main cause of this difference. In HM1, the two Wolf-Rayet stars show contrasting behaviors: WR89 is extremely bright, but much softer than WR87. It remains to be seen whether wind-wind collisions or magnetically confined winds can explain these emissions. In IC2944/2948, the X-ray sources concentrate around HD101205; a group of massive stars to the north of this object is isolated, suggesting that there exist two subclusters in the field-of-view.Comment: 29 pages in total with 10 figures (12 pages paper + supplementary material), accepted by A&

    Diaspirin cross-linked hemoglobin fails to improve left ventricular diastolic function after fluid resuscitation from hemorrhagic shock

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    In severe hemorrhagic shock, left ventricular (LV) diastolic dysfunction is an early sign of cardiac failure due to compromised myocardial oxygenation. Immediate fluid replacement or, in particular, administration of a hemoglobin-based oxygen carrier (diaspirin cross-linked hemoglobin; DCLHb) improves myocardial oxygenation; therefore, positive effects on LV diastolic function could be expected. The effects of fluid resuscitation from severe hemorrhagic shock with DCLHb were investigated in 20 anesthetized domestic pigs. After generation of a critical left anterior descending coronary artery stenosis (narrowing of the artery until disappearance of reactive hyperemia after a 10-second complete vessel occlusion), hemorrhagic shock (mean arterial blood pressure 45 mm Hg) was induced within 15 min by controlled blood withdrawal and maintained for 60 min. Fluid resuscitation consisted of replacement of the plasma volume withdrawn during hemorrhage by infusion of either 10% DCLHb (DCLHb group, n = 10) or 8% human serum albumin (HSA) oncotically matched to DCLHb (HSA group, n = 10). After completion of resuscitation, an observation period of 60 min elapsed. Measurements of central hemodynamics, myocardial oxygenation, and LV Stolic function were performed at baseline, after induction of critical coronary artery stenosis, after 60 min hemorrhagic shock, immediately after resuscitation, and 60 min later. While 5 out of 10 animals treated with died within the first 20 min after fluid resuscitation from acute LV pump failure, all DCLHb-treated animals survived until the end of the protocol (p < 0.05). Despite superior myocardial oxygenation due to augmentation of the arterial O-2 content as well as of coronary perfusion pressure, no beneficial effects on LV diastolic function were observed after infusion of DCLHb. Peak velocity Of LV pressure decrease (dp/dt(min)) did not reveal significant differences between the two groups. Immediately after completion of fluid resuscitation with DCLHb, the time constant of LV diastolic relaxation (tau) was prolonged when compared with HSA-treated animals (p < 0.05), indicating retardation of early LV diastolic relaxation. Our data suggest that DCLHb fails to improve LV diastolic function after fluid resuscitation from severe hemorrhagic shock. However, positive effects on myocardial perfusion. and oxygenation result in a significant reduction of the mortality of severe hemorrhagic shock. Copyright (C) 2001 S.Karger AG, Basel

    Thermally regenerable carbon dioxide absorbent system Final report, 1 May 1964 - 31 Jan. 1966

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    Carbon dioxide absorption by solid state ion exchange resin

    Classical dynamics near the triple collision in a three-body Coulomb problem

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    We investigate the classical motion of three charged particles with both attractive and repulsive interaction.The triple collision is a main source of chaos in such three body Coulomb problems.By employing the McGehee scaling technique, we analyse here for the first time in detail the three-body dynamics near the triple collision in 3 degrees of freedom.We reveal surprisingly simple dynamical patterns in large parts of the chaotic phase space. The underlying degree of order in the form of approximate Markov partitions may help in understanding the global structures observed in quantum spectra of two-electron atoms.Comment: 4 pages, 3 figure

    Evaluation of A Post-Treatment Follow-Up Program in Patients with Oral Squamous Cell Carcinoma

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    Objectives The duration and the frequency of follow-up after treatment of oral squamous cell carcinoma are not standardized in the current literature. The purpose of this study was to evaluate our local standard post-treatment and follow-up protocol. Materials and methods Overall, 228 patients treated curatively from 01/2006 to 07/2013 were reviewed. To evaluate the follow-up program, data on the secondary event were used. To determine risk groups, all patients with tumor recurrence were specifically analyzed. Relapse-free rate were estimated by the Kaplan-Meier product limit method. The chi-square test was used to identify independent risk factors for tumor relapse. Results In total, 29.8 % patients had a secondary event. The majority of the relapse cases (88.2 %) were detected within 2 years postoperatively, 61.8 % of them within the first year. Most events were local recurrences (34.7 %). UICC-stage IV was significantly associated with tumor recurrence (p = 0.001). Gender (p = 0.188), age (p = 0.195), localization (p = 0.739), T-stage (p = 0.35), N-stage (p = 0.55), histologic grade (p = 0.162), and tobacco and alcohol use (p = 0.248) were not significantly associated with tumor recurrence. Patients with positive neck nodes relapsed earlier (p = 0.011). The majority of relapses (86.3 %) were found in asymptomatic patients at routine follow-up. Conclusions The results of this study suggest an intensified follow-up within the first 2 years after surgery. Clinical relevance Given the higher relapse rate of patients exhibiting an UICC-stage IV and/or positive neck nodes, it seems to be from special interest to perform in this group a risk-adapted follow-up with monthly examinations also in the second year

    Biologically meaningful coverage indicators for eliminating malaria transmission.

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    Mosquitoes, which evade contact with long-lasting insecticidal nets and indoor residual sprays, by feeding outdoors or upon animals, are primary malaria vectors in many tropical countries. They can also dominate residual transmission where high coverage of these front-line vector control measures is achieved. Complementary strategies, which extend insecticide coverage beyond houses and humans, are required to eliminate malaria transmission in most settings. The overwhelming diversity of the world's malaria transmission systems and optimal strategies for controlling them can be simply conceptualized and mapped across two-dimensional scenario space defined by the proportion of blood meals that vectors obtain from humans and the proportion of human exposure to them which occurs indoors

    Oral Health and Dental Anxiety in a German Practice-based Sample

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    Objective Does dental anxiety have an effect on dental and periodontal health? Methods Survey data was collected from n = 200 adults (53 % females, average age 49 years) in a cross-sectional study. Dental anxiety was measured with the modified dental anxiety scale (MDAS, score 1–5, the greater the score, the greater the anxiety). Clinical parameters including probing depth (PD), clinical attachment level (CAL), plaque index (SLI), and bleeding on probing (BoP) as well as the DMFT index were recorded and statistically analyzed. Results Rating of dental anxiety was higher in women than in men (65 vs 35 %). Subjects with higher MDAS values visited the dentist less frequently (p = 0.001) and had more decay (DT 6.7 ± 4.2 vs 1.7 ± 2.4; p \u3c 0.001) but fewer filled teeth than subjects with lower ratings of dental anxiety (FT 7.1 ± 4.5 vs 9.8 ± 5.7; p = 0.042). There were no differences in PD or CAL between subjects with or without dental anxiety, while patients with higher MDAS value showed significantly more BoP (50 ± 19 vs 34 ± 20 %; p = 0.002) than patients with low MDAS scores (no or low dental anxiety). Conclusions Patients with higher ratings of dental anxiety had significantly more caries experience and gingivitis. Therefore, dental anxiety is associated with negative effect on dental and periodontal health. Clinical relevance Identifying patients with high dental anxiety and helping to manage this anxiety has important implications to improve oral health in adults. The MDAS appears to be an easy and efficient tool that can be used to identify patients with dental anxiety in dental practices

    Climate and socioeconomic influences on interannual variability of cholera in Nigeria

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    AbstractCholera is one of the most important climate sensitive diseases in Nigeria that pose a threat to public health because of its fatality and endemic nature. This study aims to investigate the influences of meteorological and socioeconomic factors on the spatiotemporal variability of cholera morbidity and mortality in Nigeria. Stepwise multiple regression and generalised additive models were fitted for individual states as well as for three groups of the states based on annual precipitation. Different meteorological variables were analysed, taking into account socioeconomic factors that are potentially enhancing vulnerability (e.g. absolute poverty, adult literacy, access to pipe borne water). Results quantify the influence of both climate and socioeconomic variables in explaining the spatial and temporal variability of the disease incidence and mortality. Regional importance of different factors is revealed, which will allow further insight into the disease dynamics. Additionally, cross validated models suggest a strong possibility of disease prediction, which will help authorities to put effective control measures in place which depend on prevention, and or efficient response
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