103 research outputs found

    Metallicity Estimates for Old Star Clusters in M33

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    Using the theoretical stellar population synthesis models of BC96, Kong et al. (2003) showed that some BATC colors and color indices could be used to disentangle the age and metallicity effect. They found that there is a very good relation between the flux ratio of L_{8510}/L_{9170} and the metallicity for stellar populations older than 1 Gyr. In this paper, based on the Kong et al. results and on the multicolor spectrophotometry of Ma et al. (2001, 2002a,b,c), we estimate the metallicities of 31 old star clusters in the nearby spiral galaxy M33, 23 of which are ``true'' globular clusters. The results show that most of these old clusters are metal poor. We also find that the ages and metal abundance for these old star clusters of M33 do not vary with deprojected radial position.Comment: Accepted for Publication in A&A, 13 pages, 7 figures (1 figure of jpg

    Tiefengeothermie Sachsen

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    In drei Gebieten Sachsens wurde durch einen Forschungsverbund unter Leitung des LfULG die Nutzung der petrothermalen Geothermie zur Strom- und Wärmegewinnung untersucht. In der Elbezone im Raum Dresden, in Freiberg und Aue-Schneeberg wurden geologische, petrophysikalische und thermische Daten aufgearbeitet und dreidimensionale Modelle bewertet. Die Ergebnisse zeigen, dass eine Stromerzeugung durch Tiefenaufschlüsse bis 5 km Tiefe in allen drei Untersuchungsgebieten möglich ist. Die Temperaturmodelle weisen in 5 km Tiefe Werte zwischen 105 und 190 °C auf. Dabei verfügt das Untersuchungsgebiet Aue-Schneeberg über die besten Voraussetzungen für die Errichtung eines Geothermiekraftwerkes

    A possible new dipping X-ray source in the field of M31

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    We report the discovery of the new dipping X-ray source, XMMU J004308.6+411247, in M31, during a systematic search for periodicities in XMM-Newton archival observations. During the 2002 January 6 observation, the dips recur with a 107 min period and the source count rate is consistent with zero at the dip minimum. Dips with the same modulation and period are also observed during the XMM-Newton observations carried out on 2000 June 25, 2001 June 29 and the Chandra observation of 2001 October 5. The dips of XMMU J004308.6+411247 show no evidence of energy dependence. The average X-ray flux of XMMU J004308.6+411247 is nearly constant across different observations (~1.e37 erg/s for an assumed M31 distance of 780 kpc in the 0.3-10 keV band); the spectrum is well fit by an absorbed power law with a photon index ~0.8 or an absorbed Comptonization model. The photo-electric absorption is consistent with the Galactic value in the source direction. If XMMU J004308.6+411247 is located in M31 its properties are consistent with those of dipping low mass X-ray binaries in the Galaxy. Present observations do not allow to distinguish between dips and eclipses. The possibility that XMMU J004308.6+411247 is a foreground X-ray source cannot be ruled out at present; in this case the source might be a magnetic cataclysmic variable.Comment: Accepted for publication in A&A, 16 pages, 8 postscript figure

    Practical Recommendations for Optimal Thromboprophylaxis in Patients with COVID-19: A Consensus Statement Based on Available Clinical Trials.

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    Coronavirus disease 2019 (COVID-19) has been shown to be strongly associated with increased risk for venous thromboembolism events (VTE) mainly in the inpatient but also in the outpatient setting. Pharmacologic thromboprophylaxis has been shown to offer significant benefits in terms of reducing not only VTE events but also mortality, especially in acutely ill patients with COVID-19. Although the main source of evidence is derived from observational studies with several limitations, thromboprophylaxis is currently recommended for all hospitalized patients with acceptable bleeding risk by all national and international guidelines. Recently, high quality data from randomized controlled trials (RCTs) further support the role of thromboprophylaxis and provide insights into the optimal thromboprophylaxis strategy. The aim of this statement is to systematically review all the available evidence derived from RCTs regarding thromboprophylaxis strategies in patients with COVID-19 in different settings (either inpatient or outpatient) and provide evidence-based guidance to practical questions in everyday clinical practice. Clinical questions accompanied by practical recommendations are provided based on data derived from 20 RCTs that were identified and included in the present study. Overall, the main conclusions are: (i) thromboprophylaxis should be administered in all hospitalized patients with COVID-19, (ii) an optimal dose of inpatient thromboprophylaxis is dependent upon the severity of COVID-19, (iii) thromboprophylaxis should be administered on an individualized basis in post-discharge patients with COVID-19 with high thrombotic risk, and (iv) thromboprophylaxis should not be routinely administered in outpatients. Changes regarding the dominant SARS-CoV-2 variants, the wide immunization status (increasing rates of vaccination and reinfections), and the availability of antiviral therapies and monoclonal antibodies might affect the characteristics of patients with COVID-19; thus, future studies will inform us about the thrombotic risk and the optimal therapeutic strategies for these patients

    Decreased Th1-Type Inflammatory Cytokine Expression in the Skin Is Associated with Persisting Symptoms after Treatment of Erythema Migrans

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    Background: Despite the good prognosis of erythema migrans (EM), some patients have persisting symptoms of various character and duration post-treatment. Several factors may affect the clinical outcome of EM, e. g. the early interaction between Borrelia (B.) burgdorferi and the host immune response, the B. burgdorferi genotype, antibiotic treatment as well as other clinical circumstances. Our study was designed to determine whether early cytokine expression in the skin and in peripheral blood in patients with EM is associated with the clinical outcome. Methods: A prospective follow-up study of 109 patients with EM was conducted at the A land Islands, Finland. Symptoms were evaluated at 3, 6, 12 and 24 months post-treatment. Skin biopsies from the EM and healthy skin were immunohistochemically analysed for expression of interleukin (IL)-4, IL-10, IL-12p70 and interferon (IFN)-gamma, as well as for B. burgdorferi DNA. Blood samples were analysed for B. burgdorferi antibodies, allergic predisposition and levels of systemic cytokines. Findings: None of the patients developed late manifestations of Lyme borreliosis. However, at the 6-month follow-up, 7 of 88 patients reported persisting symptoms of diverse character. Compared to asymptomatic patients, these 7 patients showed decreased expression of the Th1-associated cytokine IFN-gamma in the EM biopsies (p = 0.003). B. afzelii DNA was found in 48%, B. garinii in 15% and B. burgdorferi sensu stricto in 1% of the EM biopsies, and species distribution was the same in patients with and without post-treatment symptoms. The two groups did not differ regarding baseline patient characteristics, B. burgdorferi antibodies, allergic predisposition or systemic cytokine levels. Conclusion: Patients with persisting symptoms following an EM show a decreased Th1-type inflammatory response in infected skin early during the infection, which might reflect a dysregulation of the early immune response. This finding supports the importance of an early, local Th1-type response for optimal resolution of LB.Original Publication: Johanna Sjöwall, Linda Fryland, Marika Nordberg, Florence Sjögren, Ulf Garpmo, Christian Jansson, Sten-Anders Carlsson, Sven Bergstrom, Jan Ernerudh, Dag Nyman, Pia Forsberg and Christina Ekerfelt, Decreased Th1-Type Inflammatory Cytokine Expression in the Skin Is Associated with Persisting Symptoms after Treatment of Erythema Migrans, 2011, PLOS ONE, (6), 3, 0018220. http://dx.doi.org/10.1371/journal.pone.0018220 Copyright: Public Library of Science (PLoS) http://www.plos.org

    Overlapping SETBP1 gain-of-function mutations in Schinzel-Giedion syndrome and hematologic malignancies

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    Schinzel-Giedion syndrome (SGS) is a rare developmental disorder characterized by multiple malformations, severe neurological alterations and increased risk of malignancy. SGS is caused by de novo germline mutations clustering to a 12bp hotspot in exon 4 of SETBP1. Mutations in this hotspot disrupt a degron, a signal for the regulation of protein degradation, and lead to the accumulation of SETBP1 protein. Overlapping SETBP1 hotspot mutations have been observed recurrently as somatic events in leukemia. We collected clinical information of 47 SGS patients (including 26 novel cases) with germline SETBP1 mutations and of four individuals with a milder phenotype caused by de novo germline mutations adjacent to the SETBP1 hotspot. Different mutations within and around the SETBP1 hotspot have varying effects on SETBP1 stability and protein levels in vitro and in in silico modeling. Substitutions in SETBP1 residue I871 result in a weak increase in protein levels and mutations affecting this residue are significantly more frequent in SGS than in leukemia. On the other hand, substitutions in residue D868 lead to the largest increase in protein levels. Individuals with germline mutations affecting D868 have enhanced cell proliferation in vitro and higher incidence of cancer compared to patients with other germline SETBP1 mutations. Our findings substantiate that, despite their overlap, somatic SETBP1 mutations driving malignancy are more disruptive to the degron than germline SETBP1 mutations causing SGS. Additionally, this suggests that the functional threshold for the development of cancer driven by the disruption of the SETBP1 degron is higher than for the alteration in prenatal development in SGS. Drawing on previous studies of somatic SETBP1 mutations in leukemia, our results reveal a genotype-phenotype correlation in germline SETBP1 mutations spanning a molecular, cellular and clinical phenotype

    Thromboembolic Disease in Patients With Cancer and COVID-19: Risk Factors, Prevention and Practical Thromboprophylaxis Recommendations–State-of-the-Art.

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    Cancer and COVID-19 are both well-established risk factors predisposing to thrombosis. Both disease entities are correlated with increased incidence of venous thrombotic events through multifaceted pathogenic mechanisms involving the interaction of cancer cells or SARS-CoV2 on the one hand and the coagulation system and endothelial cells on the other hand. Thromboprophylaxis is recommended for hospitalized patients with active cancer and high-risk outpatients with cancer receiving anticancer treatment. Universal thromboprophylaxis with a high prophylactic dose of low molecular weight heparins (LMWH) or therapeutic dose in select patients, is currentlyindicated for hospitalized patients with COVID-19. Also, prophylactic anticoagulation is recommended for outpatients with COVID-19 at high risk for thrombosis or disease worsening. However, whether there is an additive risk of thrombosis when a patient with cancer is infected with SARS-CoV2 remains unclear In the current review, we summarize and critically discuss the literature regarding the epidemiology of thrombotic events in patients with cancer and concomitant COVID-19, the thrombotic risk assessment, and the recommendations on thromboprophylaxis for this subgroup of patients. Current data do not support an additive thrombotic risk for patients with cancer and COVID-19. Of note, patients with cancer have less access to intensive care unit care, a setting associated with high thrombotic risk. Based on current evidence, patients with cancer and COVID-19 should be assessed with well-established risk assessment models for medically ill patients and receive thromboprophylaxis, preferentially with LMWH, according to existing recommendations. Prospective trials on well-characterized populations do not exist

    Genomic epidemiology reveals multiple introductions of Zika virus into the United States

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    Zika virus (ZIKV) is causing an unprecedented epidemic linked to severe congenital abnormalities. In July 2016, mosquito-borne ZIKV transmission was reported in the continental United States; since then, hundreds of locally acquired infections have been reported in Florida. To gain insights into the timing, source, and likely route(s) of ZIKV introduction, we tracked the virus from its first detection in Florida by sequencing ZIKV genomes from infected patients and Aedes aegypti mosquitoes. We show that at least 4 introductions, but potentially as many as 40, contributed to the outbreak in Florida and that local transmission is likely to have started in the spring of 2016-several months before its initial detection. By analysing surveillance and genetic data, we show that ZIKV moved among transmission zones in Miami. Our analyses show that most introductions were linked to the Caribbean, a finding corroborated by the high incidence rates and traffic volumes from the region into the Miami area. Our study provides an understanding of how ZIKV initiates transmission in new regions
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