954 research outputs found

    Retrospektive Analyse zur Dosisintensität von Epirubicin beim Mammakarzinom

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    Objective: In breast cancer the efficacy of epirubicin-based chemotherapy is possibly related to the actual dose intensity applied. We retrospectively determined the administered dose intensity and the relative toxicity and efficacy of an epirubicin-containing regimen in patients with primary or metastatic breast cancer. Patients and Methods: Fluorouracil, epirubicin, and cyclophosphamide (FEC) were either given at a standard dose of 500/50/500 mg/m(2) (FE50C) or at an intensified dose of 500/75/500 mg/m(2) (FE75C) every 3 weeks. Of the 66 patients treated, 63 were evaluable; 43 had metastatic breast cancer, and 20 patients with an increased risk of relapse received FEC as an adjuvant treatment. Results: Dose intensity and absolute dose of adjuvant treatment were 81 and 70% for FE50C and 96 and 88% for FE75C In metastatic breast cancer, the dose intensity for FE50C was 94% and for FE75C 92%. In a retrospective comparison, the 4-year overall survival following adjuvant FE50C and FE75C was 40 and 48%, respectively (p = 0.47). The dose intensification led to a higher response rate of 34 vs. 44%. There were no significant differences in response duration and survival time. The toxicity profiles were comparable between FE50C and FE75C Conclusions: In genera I, the doses applied were lower than initially planned. Higher doses of epirubicin did not result in a significant increase of toxicity. Despite the limitations of a retrospective analysis, our observations support the importance of adherence to the planned dose intensity as a prerequisite for optimal treatment of patients suffering from breast cancer. As our results could be related to selection bias, dose-intensified anthracycline-containing regimens should be further evaluated in prospective trials. Copyright (C) 2001 S. Karger AG, Basel

    Integrating Spatial Data Infrastructures (SDIs) with Volunteered Geographic Information (VGI) creating a Global GIS platform

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    Spatial Data Infrastructures (SDIs) are a special category of data hubs that involve technological and human resources and follow well defined legal and technical procedures to collect, store, manage and distribute spatial data. INSPIRE is the EU’s authoritative SDI in which each Member State provides access to their spatial data across a wide spectrum of data themes to support policy-making. In contrast, Volunteered Geographic Information (VGI) is one type of user-generated geographic information (GI) where volunteers use the web and mobile devices to create, assemble and disseminate spatial information. There are similarities and differences between SDIs and VGI, as well as advantages and disadvantages to both. Thus, the integration of these two data sources will enhance what is offered to end users to facilitate decision-making. This idea of integration is in its early stages, because several key issues need to be considered and resolved first. Therefore, this chapter discusses the challenges of integrating VGI with INSPIRE and outlines a generic framework for a global integrated GIS platform, similar in concept to Digital Earth and Virtual Geographic Environments (VGEs), as a realistic scenario for advancements in the short term

    Accurate Relativistic Real-Time TDDFT for Valence and Core Attosecond Transient Absorption Spectroscopy

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    Attosecond pump-probe transient absorption spectroscopy (TAS) has opened the possibility to study pure electron dynamics on its natural time scale. However, due to the out-of-equilibrium nature of the process, first-principle theoretical modelling remains a challenging task, specially for heavy elements and/or core excitations where relativistic corrections become imperative, as the spectra contain significant imprints of both scalar and spin-orbit relativistic effects. To alleviate this problem, we formulated a methodology for computing TAS spectrum within the relativistic real-time time-dependent density functional theory (RT-TDDFT) framework, for both the valence and core energy regime. Even though RT simulations using full four-component (4c) method are feasible, they are still computationally expensive, especially for TAS. Therefore, in addition to the 4c approach, we have introduced the atomic mean-field exact two-component (amfX2C) Hamiltonian for RT-TDDFT, which accounts for one- and two-electron picture-change corrections and preserves the accuracy of the parent 4c method but at a fraction of its computational cost. Finally, we apply the amfX2C approach to study valence and near L 2,3 -edge TAS processes of experimentally relevant systems, providing additional physical insights through the lens of non-equilibrium response theory

    Exact two-component TDDFT with simple two-electron picture-change corrections: X-ray absorption spectra near L- and M-edges of four-component quality at two-component cost

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    X-ray absorption spectroscopy (XAS) has gained popularity in recent years as it probes matter with high spatial and elemental sensitivity. However, the theoretical modelling of XAS is a challenging task since XAS spectra feature a fine structure due to scalar (SC) and spin-orbit (SO) relativistic effects, in particular near L and M absorption edges. While full four-component (4c) calculations of XAS are nowadays feasible, there is still interest in developing approximate relativistic methods that enable XAS calculations at the two-component (2c) level while maintaining the accuracy of the parent 4c approach. In this article we present theoretical and numerical insights into two simple yet accurate 2c approaches based on an (extended) atomic mean-field exact two-component Hamiltonian framework, (e)amfX2C, for the calculation of XAS using linear eigenvalue and damped-response time-dependent density functional theory (TDDFT). In contrast to the commonly used one-electron X2C (1eX2C) Hamiltonian, both amfX2C and eamfX2C account for the SC and SO two-electron and exchange-correlation picture-change (PC) effects that arise from the X2C transformation. As we demonstrate on L- and M-edge XAS spectra of transition metal and actinide compounds, the absence of PC corrections in the 1eX2C approximation results in a substantial overestimatation of SO splittings, whereas (e)amfX2C Hamiltonians reproduce all essential spectral features such as shape, position, and SO splitting of the 4c references in excellent agreement, while offering significant computational savings. Therefore, the (e)amfX2C PC correction models presented here constitute reliable relativistic 2c quantum-chemical approaches for modelling XAS

    Complex gunshot injury to the heart as a consequence of suicide attempt in a schizophrenic patient

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    AbstractIntroductionSelf-inflicted gunshot injury to the heart is uncommon in Western Europe countries. However it is considered to have a high mortality through cardiac tamponade or exsanguination and concomitant chest or abdominal cavity injury.Case presentationWe present a 39-year-old schizophrenic woman who attempted suicide with the aid of a 6.35mm caliber handgun, after self-discontinuing of antipsychotic treatment. Lower third of sternum, right heart atrium and ventricle and inferior caval vein were hit by the bullet which consequently got lodged in the right paravertebral muscle mass at the lower thoracic vertebral level. As she was hemodynamically unstable due to hemopericardium and a huge right hemothorax, she underwent emergent surgery. Heart and inferior vena caval injuries were repaired on extracorporeal circulation. The postoperative course was uneventful and she was transferred to a psychiatric facility on the 7th postoperative day. One year after the surgery she is well, compliant to antipsychotic medications and on periodic follow-up by psychiatrists.ConclusionThis case represents management of complex self-inflicted gunshot cardiac injury in a schizophrenic patient who discontinued antipsychotic medication. Liaison between themedical rescue service and high level trauma center essentially reduced injury-to-surgery time. Complex heart injury was successfully repaired on extracorporeal circulation

    Bioadhesive properties of Gantrez nanoparticles

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    Bioadhesive nanoparticles have been proposed as carriers for the oral delivery of poorly available drugs and facilitate the use of this route. This work summarises some experiments describing the bioadhesive potential of Gantrez nanoparticles fluorescently labeled with rhodamine B isothiocyanate. The adhesive potential of Gantrez was found to be stronger when folded as nanoparticles than in the solubilised form. Conventional nanoparticles displayed a tropism for the upper areas of the gastrointestinal tract, with a maximum of adhesion 30 min post-administration and a decrease in the adhered fraction along the time depending on the given dose. The cross-linkage of nanoparticles with increasing amounts of 1,3-diaminopropane stabilised the resulting carriers and prolonged their half-life in an aqueous environment; although, the adhesive capacity of nanoparticles, the intensity and the relative duration of the adhesive interactions within the gut as a function of the cross-linking degree. Finally, nanoparticles were coated with either gelatin or albumin. In the first case, the presence of gelatin dramatically decreased the initial capacity of these carriers to interact with the gut mucosa and the intensity of these phenomenons. In the latter, bovine serum albumin coated nanoparticles (BSA-NP) showed an important tropism for the stomach mucosa without further significant distribution to other parts of the gut mucosa

    The role of electronic correlation in the Si(100) reconstruction: a quantum Monte Carlo study

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    Recent low-temperature scanning tunneling experiments have challenged the generally accepted picture of buckled silicon dimers as the ground state reconstruction of the Si(100) surface. Together with the symmetric dimer model of the surface suggested by quantum chemistry calculations on small clusters, these findings question our general understanding of electronic correlations at surfaces and its proper description within density functional theory. We present quantum Monte Carlo calculations on large cluster models of the symmetric and buckled surface, and conclude that buckling remains energetically more favorable even when the present-day best treatment of electronic correlation is employed.Comment: 5 pages, Revtex, 10 figure
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