148 research outputs found

    Statistical Modelling in Surveys without Neglecting "The Undecided": Multinomial Logistic Regression Models and Imprecise Classification Trees under Ontic Data Imprecision - extended version

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    In surveys, and most notably in election polls, undecided participants frequently constitute subgroups of their own with specific individual characteristics. While traditional survey methods and corresponding statistical models are inherently damned to neglect this valuable information, an ontic random set view provides us with the full power of the whole statistical modelling framework. We elaborate this idea for a multinomial logistic regression model (which can be derived as a discrete choice model for voting behaviour) and an imprecise classification tree, and apply them as a prototypic illustration to the German Longitudinal Election Study 2013. Our results corroborate the importance of a sophisticated, random set-based modelling. Furthermore, by reinterpreting the undecided respondents' answers as disjunctive random sets, general forecasts based on interval-valued point estimators are calculated

    Wet-Chemically Prepared Porphyrin Layers on Rutile TiO2(110)

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    Porphyrins are large organic molecules that are interesting for different applications, such as photovoltaic cells, gas sensors, or in catalysis. For many of these applications, the interactions between adsorbed molecules and surfaces play a crucial role. Studies of porphyrins on surfaces typically fall into one of two groups: (1) evaporation onto well-defined single-crystal surfaces under well-controlled ultrahigh vacuum conditions or (2) more application-oriented wet chemical deposition onto less well-defined high surface area surfaces under ambient conditions. In this study, we will investigate the wet chemical deposition of 5-(monocarboxyphenyl)-10,15,20-triphenylporphyrin (MCTPP) on well-defined rutile TiO2 (110) single crystals under ambient conditions. Prior to deposition, the TiO2(110) crystals were also cleaned wet-chemically under ambient conditions, meaning none of the preparation steps were done in ultrahigh vacuum. However, after each preparation step, the surfaces were characterized in ultrahigh vacuum with X-ray photoelectron spectroscopy (XPS) and the result was compared with porphyrin layers prepared in ultrahigh vacuum (UHV) by evaporation. The differences of both preparations when exposed to zinc ion solutions will also be discussed.Fil: Wechsler, Daniel. Universitat Erlangen-Nuremberg; AlemaniaFil: Fernández, Cynthia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Köbl, Julia. Universitat Erlangen-Nuremberg; AlemaniaFil: Augustin, Lisa Marie. Universitat Erlangen-Nuremberg; AlemaniaFil: Stumm, Corina. Universitat Erlangen-Nuremberg; AlemaniaFil: Norbert Jux. Universitat Erlangen-Nuremberg; AlemaniaFil: Steinruck, Hans Peter. Universitat Erlangen-Nuremberg; AlemaniaFil: Williams, Federico José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Lytken, Ole. Universitat Erlangen-Nuremberg; Alemani

    Inflammatory Myofibroblastic Tumor of the Right Atrium

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    Cardiac inflammatory myofibroblastic tumor (IMT) is a rare entity and is associated with distinct clinical, pathological and molecular features. The clinical behavior, natural history, biological potential, management and prognosis of such tumors are unclear. We present herewith an adolescent girl who presented with similar entity involving the junction of the right atrium and the inferior vena cava (IVC) in association with thrombocytosis and IVC thrombosis leading to obstruction of blood flow. Diagnostic tools included imaging and immuno-histopathology studies. Surgical management included resection of the tumor and thrombo-embolectomy of the IVC under cardiopulmonary bypass. This case is unique due to association of complete obstruction of IVC caused by the strategic location of the tumor, thrombosis of vena cava and association of thrombocytosis. These features have not been reported yet in relation to the cardiac IMT. This report will help in better understanding and management of similar cases in terms of planning cannulation of femoral veins or application of total hypothermic circulatory arrest during cardiopulmonary bypass and prompt us to look for recurrence or metastasis during follow up using echocardiography and laboratory investigations. The possibility of IMT should be kept in the differential diagnosis of cardiac tumors especially in children and adolescents

    ABC3 Consensus: Assessment by a German Group of Experts

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    The Advanced Breast Cancer Third International Consensus Conference on the diagnosis and treatment of advanced breast cancer took place in Lisbon, Portugal, on November 5-7, 2015. This year's conference (ABC3) was focused on the treatment of metastatic breast cancer (stage IV), as it was 4 years ago at the first consensus meeting (ABC1). A matter of particular interest was the patients' perspective. Thus, patient-relevant issues were addressed by the consensus discussions, such as those on treatment goals, quality of life, care of long-term survivors ('survivorship issues'), and coping with disease-related symptoms and the side effects of treatment. Further important issues on the agenda were the use of standardized instruments for the assessment of individual treatment success ('patient-reported outcome measures') and the evaluation of the benefit of novel drugs (e.g. the European Society for Medical Oncology (ESMO) Magnitude of Clinical Benefit Scale). Diagnosis and treatment of inoperable locally advanced breast cancer had already been discussed 2 years earlier at the ABC2 Consensus and were not dealt with in the framework of this year's ABC3 Consensus. With regard to country-specific peculiarities, which unavoidably found their way into the ABC Consensus, a working group of German breast cancer experts commented on the voting results of the ABC panelists. As for the past consensus, the group specially considered the German guidelines for the diagnosis and treatment of breast cancer (AGO (Gyneco-Oncology Working Group), S3, DGHO (German Society of Hematology and Medical Oncology)) in order to adapt the ABC3 consensus for everyday therapy in Germany. (C) 2016 S. Karger GmbH, Freibur

    Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives (Lauraceae)

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    Waleguele CC, Mba’ning BM, Awantu AF, et al. Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives (Lauraceae). Molecules. 2020;25(12): 2862.The MeOH/CH2Cl2 (1:1) extracts of the roots and leaves of Beilschmiedia louisii and B. obscura showed potent antitrypanosomal activity during preliminary screening on Trypanosoma brucei brucei. Phytochemical investigation of these extracts led to the isolation of a mixture of two new endiandric acid derivatives beilschmiedol B (1) and beilschmiedol C (2), and one new phenylalkene obscurene A (3) together with twelve known compounds (4–15). In addition, four new derivatives (11a–11d) were synthesized from compound 11. Their structures were elucidated based on their NMR and MS data. Compounds 5, 6, and 7 were isolated for the first time from the Beilschmiedia genus. Additionally, the NMR data of compound 4 are given here for the first time. The isolates were evaluated for their antitrypanosomal and antimalarial activities against Tb brucei and the Plasmodium falciparum chloroquine-resistant strain Pf3D7 in vitro, respectively. From the tested compounds, the mixture of new compounds 1 and 2 exhibited the most potent antitrypanosomal activity in vitro with IC50 value of 4.91 μM

    Everolimus after failure of one prior VEGF-targeted therapy in metastatic renal cell carcinoma : Final results of the MARC-2 trial

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    MARC-2, a prospective, multicenter phase IV trial, aimed to investigate clinical outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with everolimus after failure of one initial vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) therapy and to identify subgroups benefiting most, based on clinical characteristics and biomarkers. Patients with clear cell mRCC failing one initial VEGFR-TKI received everolimus until progression or unacceptable toxicity. Primary endpoint was 6-month progression-free survival rate (6moPFS). Secondary endpoints were overall response rate (ORR), PFS, overall survival (OS), and safety. Between 2011 and 2015, 63 patients were enrolled. Median age was 65.4 years (range 43.3-81.1). 6moPFS was 39.3% (95% confidence interval [CI], 27.0-51.3) overall, 54.4% (95% CI, 35.2-70.1) vs 23.7% (95% CI, 10.5-39.9) for patients aged ≥65 vs 25 vs ≤25 kg/m2. A Cox proportional hazards model confirmed a longer PFS for patients aged ≥65 years (hazard ratio [HR] 0.46; 95% CI, 0.26-0.80) and a longer OS for patients with BMI >25 kg/m2 (HR 0.36; 95% CI, 0.18-0.71). Median PFS and median OS were 3.8 months (95% CI, 3.2-6.2) and 16.8 months (95% CI, 14.3-24.3). ORR was 7.9% and disease control rate was 60.3%. No new safety signals emerged. Most common adverse events were stomatitis (31.7%), fatigue (31.7%), and anemia (30.2%). One patient died from treatment-related upper gastrointestinal hemorrhage. Everolimus remains a safe and effective treatment option for mRCC patients after one prior VEGFR-TKI therapy. Patients aged ≥65 years and patients with BMI >25 kg/m2 benefited most

    Neural network emulation of the human ventricular cardiomyocyte action potential for more efficient computations in pharmacological studies

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    Computer models of the human ventricular cardiomyocyte action potential (AP) have reached a level of detail and maturity that has led to an increasing number of applications in the pharmaceutical sector. However, interfacing the models with experimental data can become a significant computational burden. To mitigate the computational burden, the present study introduces a neural network (NN) that emulates the AP for given maximum conductances of selected ion channels, pumps, and exchangers. Its applicability in pharmacological studies was tested on synthetic and experimental data. The NN emulator potentially enables massive speed-ups compared to regular simulations and the forward problem (find drugged AP for pharmacological parameters defined as scaling factors of control maximum conductances) on synthetic data could be solved with average root-mean-square errors (RMSE) of 0.47 mV in normal APs and of 14.5 mV in abnormal APs exhibiting early afterdepolarizations (72.5% of the emulated APs were alining with the abnormality, and the substantial majority of the remaining APs demonstrated pronounced proximity). This demonstrates not only very fast and mostly very accurate AP emulations but also the capability of accounting for discontinuities, a major advantage over existing emulation strategies. Furthermore, the inverse problem (find pharmacological parameters for control and drugged APs through optimization) on synthetic data could be solved with high accuracy shown by a maximum RMSE of 0.22 in the estimated pharmacological parameters. However, notable mismatches were observed between pharmacological parameters estimated from experimental data and distributions obtained from the Comprehensive in vitro Proarrhythmia Assay initiative. This reveals larger inaccuracies which can be attributed particularly to the fact that small tissue preparations were studied while the emulator was trained on single cardiomyocyte data. Overall, our study highlights the potential of NN emulators as powerful tool for an increased efficiency in future quantitative systems pharmacology studies

    Papillary fibroelastoma of the aortic valve - a case report and literature review

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    The prevalence of primary cardiac tumour ranges from 0.0017-0.28% and papillary fibroelastoma is rare but not uncommon benign cardiac neoplasm. Currently, with the advent of higher-resolution imaging technology especially transoesophageal echocardiography such cases being recognized frequently. The clinical presentation of these tumours varies from asymptomatic to severe ischaemic or embolic complications. We herein, present a 50-year-old female patient with a papillary fibroelastoma of the aortic valve arising from the endocardium of the right coronary cusp very close to the commissure between the right and non-coronary cusps. The patient presented with angina-like chest pain and was investigated using echocardiography and CT angiographic modalities in addition to the usual investigations. The differential diagnosis considered was a thrombus, myxoma, Lambl's excrescence and infective vegetation. The surgical management included a prompt resection of the tumour on cardiopulmonary bypass avoiding injury to the aortic valve. The patient recovered well. A review of the literature suggests that the cardiac papillary fibroelastoma is a rare but potentially treatable cause of embolic stroke and other fatal complications, therefore, a strong suspicion; appropriate use of imaging modality, preoperative anticoagulation and urgent surgical resection is warranted. Also, possibility of this diagnosis should be kept in mind while managing cardiac or valvular tumours
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