2,902 research outputs found

    Management of germ cell tumors in children: Approaches to cure

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    The introduction of cisplatinum chemotherapy and current advances in the surgical treatment have resulted in a dramatic improvement of the prognosis of children with malignant germ cell tumors (GCT). Cisplatinum chemotherapy generally results in sufficient systemic tumor control, but local relapses may still occur in patients who did not receive adequate local treatment. Therefore, the therapeutic consideration must take into account age, primary site of the tumor, and its histology. In gonadal tumors, there is a high chance of primary complete resection since these tumors tend to be encapsulated, and particularly testicular GCT are often detected at a low tumor stage. In contrast, a primary complete resection may be impossible in large nongonadal tumors such as sacrococcygeal or mediastinal GCT. In these tumors, a neoadjuvant or pre-operative chemotherapy after clinical diagnosis by imaging and evaluation of tumor markers significantly facilitates complete resection on delayed surgery. In addition, the impact of chemotherapy on local tumor control may be enhanced by locoregional hyperthermia. In most intracranial GCT complete resection is impossible and may be associated with significant morbidity. Nevertheless, biopsy is essential for diagnosis in nonsecreting tumors. In intracranial GCT, radiotherapy significantly contributes to local tumor control, and doses are stratified according to histology. These general considerations have been integrated into national and international cooperative treatment protocols. In most current protocols, treatment is stratified according to an initial risk assessment that includes the parameters age, site, histology, stage, completeness of resection and the tumor markers alpha(1)-fetoprotein (AFP) and human choriogonadotropin (beta-HCG). With such modern protocols overall cure rates above 80% can be achieved. Moreover, the previously high-risk groups may now expect a favorable prognosis with this risk-adapted treatment, whereas an increasing number of low-risk patients are treated expectantly or with significantly reduced chemotherapy. As current biologic studies reveal distinct genetic patterns in childhood GCT, it can be expected that further combined clinical and genetic studies will be valuable for risk assessment of childhood GCT

    Glatiramer acetate does not protect from acute ischemic stroke in mice

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    Background The role of the immune system in the pathophysiology of acute ischemic stroke is increasingly recognized. However, targeted treatment strategies to modulate immunological pathways in stroke are still lacking. Glatiramer acetate is a multifaceted immunomodulator approved for the treatment of relapsing-remitting multiple sclerosis. Experimental studies suggest that glatiramer acetate might also work in other neuroinflammatory or neurodegenerative diseases apart from multiple sclerosis. Findings We evaluated the efficacy of glatiramer acetate in a mouse model of brain ischemia/reperfusion injury. 60 min of transient middle cerebral artery occlusion was induced in male C57Bl/6 mice. Pretreatment with glatiramer acetate (3.5 mg/kg bodyweight) 30 min before the induction of stroke did not reduce lesion volumes or improve functional outcome on day 1. Conclusions Glatiramer acetate failed to protect from acute ischemic stroke in our hands. Further studies are needed to assess the true therapeutic potential of glatiramer acetate and related immunomodulators in brain ischemia

    To relate surface properties and surface elemental composition - Application of XPS in soil science

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    Soil particles always are coated by thin layers (nm to µm) of predominantly organic compounds that form the interface between particle and pore space and govern soil functioning (e.g. liquid transport, sorption, respiration). Chemical modification of the surface layer can change surface properties such as wettability (quantified in terms of contact angle CA) with implications for e.g. liquid distribution and sorption capacity. This points to the importance to specifically analyze the coating's chemical composition in order to better understand soil functioning. The shallow analysis depth (max. 10 nm) indicates X ray photoelectron spectroscopy (XPS) as a suitable tool. Here, all elements with Z ≥ 3 will be identified by the binding energy of the photoelectrons emitted after irradiation of the surface by X rays. In sensu stricto only applicable to flat and smooth surfaces our results so far prove applicability of XPS as well to rough surfaces such as soil particles. For XPS no sample pre-treatment is needed, i.e. the surfaces analyzed are those governing e.g. CA and sorption. The relation between surface elemental composition and CA could be demonstrated within a soil chronosequence where the changes of surface element contents due to an increasing coating of the particles by organic compounds and microorganisms were correlated to increasing CA. The surface O/C ratio could be identified as a general parameter linking surface chemical composition and CA for a wide range of different materials including hydrophobized glass slides while the amount of non-polar C species was indicated to define CA. Artificially induced modifications of surface properties became visible by changes in the surface elemental composition. Gentle crushing of soil microaggregates (SMA) resulted in slightly increased N contents hinting on a preferred location of N compounds within SMA. Exposition to HCl gas to decrease soil pH or cleaning of quartz sand by HCl treatment resulted in addition of Cl and removal of Fe, respectively. However, due to its high surface sensitivity XPS measures the presence of C species on all surfaces exposed to the environment (adventitious carbon AC). AC was found to complicate the verification of sorption of small amounts of organic acids to montmorillonite, pointing on the necessity to estimate the influence of AC in certain cases. On the other hand, detection of AC indicates AC as a factor to be considered when discussing surface properties

    Kinematical analysis of emotionally induced facial expressions in patients with obsessive–compulsive disorder

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    Background: Motor function is deficient in many patients with obsessive–compulsive disorder (OCD), especially in the face. To investigate subtle motor dysfunction, kinematical analysis of emotional facial expressions can be used. Our aim was to investigate facial movements in response to humorous film stimuli in OCD patients.; Method: Kinematical analysis of facial movements was performed. Ultrasound markers at defined points of the face provided exact measurement of facial movements, while subjects watched a humorous movie (‘Mr Bean’). Thirty-four OCD patients (19 male, 15 female; mean (S.D.) age: 35·8 (11·5) years; mean (S.D.) total Y-BOCS score: 25·5 (5·9)) were studied in unmedicated state and after a 10-week treatment with the SSRI sertraline. Thirty-four healthy controls (19 male, 15 female; mean (S.D.) age: 37·5 (13·1) years) were also investigated.; Results: At baseline, OCD patients showed significantly slower velocity at the beginning of laughing than healthy controls and a reduced laughing frequency. There was a significant negative correlation between laughing frequency and severity of OCD symptoms. Ten weeks later a significant increase of laughing frequency and initial velocity during laughing was found.; Conclusions: Execution of adequate facial reactions to humour is abnormally slow in OCD patients. Susceptibility of OCD patients with regard to emotional stimuli is less pronounced than in healthy subjects. This phenomenon is closely correlated to OCD symptoms and is state-dependent.Peer Reviewe

    Circularly Polarized Luminescence of [6]Helicenes through Excited-State Intramolecular Proton Transfer

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    We present the concept of combining circularly polarized luminescence (CPL) and excited-state intramolecular proton transfer (ESIPT) features into a single molecule as a strategy to generate high-performance ESIPT-based CPL materials. For this purpose, a [6]helicene bearing two ESIPT structural units was synthesized using a double Suzuki–Miyaura reaction and a double C(sp2)−H hydroxylation approach. The photophysical properties of the doubly hydroxylated [6]helicene were studied in parallel with a non-hydroxylated [6]helicene control compound, revealing that the presence of a chiral [6]helicene unit results in a strong CPL response and the presence of the ESIPT units in a considerable red shift. The red-shifted emission along with the outstanding glum (≈10−2) and a large Stokes shift makes the doubly hydroxylated [6]helicene a promising candidate for use in optoelectronics

    The 63^{63}Ni(n,γ\gamma) cross section measured with DANCE

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    The neutron capture cross section of the s-process branch nucleus 63^{63}Ni affects the abundances of other nuclei in its region, especially 63^{63}Cu and 64^{64}Zn. In order to determine the energy dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4π\pi BaF2_2 array DANCE. The (n,γ\gamma) cross section of 63^{63}Ni has been determined relative to the well known 197^{197}Au standard with uncertainties below 15%. Various 63^{63}Ni resonances have been identified based on the Q-value. Furthermore, the s-process sensitivity of the new values was analyzed with the new network calculation tool NETZ.Comment: 11 pages, 13 page

    A procedure to identify natural arsenic sources, applied in an affected area in North Rhine-Westphalia, Germany

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    The aim of the study was to identify the geogenic source for elevated arsenic (As) concentrations recently discovered in soils of the Heubach plain, North Rhine-Westphalia, Germany. Therefore, a catalogue of conditions that an As source has to fulfil in order to be considered as geogenic was formulated, including the source’s linkage to the sink, its mineralogy, As total content, As mobilization potential, groundwater redox conditions and As output. Accordingly, mineralogical, geo- and hydrochemical investigations were carried out, including X-ray diffractometry, microscopy, ICP-OES and AAS analysis and a sequential extraction procedure. Paleo bog iron ores (PBIOs) of Tertiary age, occurring within unconsolidated sands (Haltern-layers, Santonian–Lower Campanian), and glauconitic marlstones (Dülmen-layers, Lower Campanian) were examined. Results indicate that output from the PBIOs is responsible for the elevated As levels. Accounting their diverse mineralogy, five types of PBIOs were defined. Type-dependent, they at least partly fulfil all of the formulated requirements. The relations and behaviour of As sources and sinks in space and time could be clarified for the area of interest. The approach presented in this paper may offer a tool for identifying natural As sources worldwide
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