1,378 research outputs found

    Distribution of the glutamate transporters GLT-1 (SLC1A2) and GLAST (SLC1A3) in peripheral organs

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    The glutamate transporters GLT-1 and GLAST are widely expressed in astrocytes in the brain where they fulfill important functions during glutamatergic neurotransmission. The present study examines their distribution in peripheral organs using in situ hybridization (ISH) and immunocytochemistry. GLAST was found to be more widely distributed than GLT-1. GLAST was expressed primarily in epithelial cells, cells of the macrophage-lineage, lymphocytes, fat cells, interstitial cells, and salivary gland acini. GLT-1 was primarily expressed in glandular tissue, including mammary gland, lacrimal gland, and ducts and acini in salivary glands, but also by perivenous hepatocytes and follicular dendritic cells in spleen and lymph nodes. The findings demonstrate that, although expressed by the same cells in the brain, these two glutamate transporters have different distribution patterns in peripheral tissues and that they fulfill glutamate transport functions apart from glutamatergic neurotransmission in these area

    Stability and isotopic dating of monazite and allanite in partially molten rocks: examples from the Central Alps

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    We investigated the stability of monazite and allanite as a function of bulk rock composition within several types of Tertiary Alpine anatexites, characterized by different compositions and melting reactions, but similar P-T conditions of melting. The investigated rocks consist of: (1) orthogneisses in which the melting reaction was triggered by water infiltration from the Bergell pluton; (2) anatectic tonalites, which were affected by water-assisted melting; and (3) metapelitic migmatites, which underwent muscovite dehydration melting. The studied anatexites cover a large range of Ca contents and water activities during partial melting, and allow an assessment of how much these parameters affect the stability of accessory phases. The different melting reactions that affected these rocks generated different water activities during the melt-present stage; they were highest in the water-saturated, contact metamorphic anatexites, and lowest in the metapelitic anatexites that underwent dehydration melting. These differences go together with different accessory phases within the migmatites. Whereas metapelitic anatexites only contain monazite, anatexites derived from tonalitic and granodioritic protoliths mainly contain allanite. This is consistent with observations made on Tertiary Alpine anatexites, suggesting that the growth of specific accessory phases is determined by the water activity and Ca content during melting. We measured single-grain monazite U/Pb isotope ages. One grain has relics of old cores, which have also been detected in Y-zonation patterns of the monazite. The data of unzoned monazites indicate partial melting in the Southern Steep Belt between 30.78 ± 0.14 and 28.10 ± 0.28M

    Structure Elucidation and Quantification by HPLC Ion-Trap Multiple Mass Spectrometry

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    High-performance liquid chromatography combined with ion-trap mass spectrometry allows now to record mass spectra in the full-scan mode with sample quantities around 1 ng or less. In addition, the on-line generation of multiple daughter-ion spectra has become possible. This has revolutionised organic trace analysis. Small polar and/or thermolabile molecules such as biotoxins can be detected in the trace range and their structure unequivocally identified. In addition, a complete or partial structure elucidation of related structures is possible. This overview demonstrates the possibilities and limitations of HPLC-Msn with ion traps. Examples shown are the structure elucidation of aconitum alkaloids, trichothecenes and photochemically formed carbonyl compounds. This survey discusses also problems caused by system contamination and adsorption effects. Finally, the achievable performance of quantification in the trace range is briefly presented

    Stent implantation and balloon angioplasty for treatment of branch pulmonary artery stenosis in children

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    Objectives: Comparison of the results of branch pulmonary artery stenosis treated with balloon angioplasty (BA) or stent implantation (SI) in children. Background: Branch pulmonary artery stenosis may be treated with BA or SI. Methods: We compared the results of 147 interventions of branch pulmonary artery stenosis in 87 children (median age 3.6 years). Patients were treated during 1989-2000 with BA and during 2001-2004 with SI. Primary endpoints were acute complications and reintervention during follow up. Secondary variables were age, vessel diameter increase, acute success rate, balloon/vessel diameter ratio, pulmonary artery hypoplasia indices, and procedure related factors. Results: The acute vessel diameter increase with BA (4.31 ± 1.98 vs. 7.15 ± 2.31 mm) and SI (3.71 ± 1.58 vs. 6.97 ± 2.68 mm) was significant within both groups (P < 0.001), but not between both groups. The reintervention rate was comparable between both groups, but median time to reintervention was shorter after SI in infants compared to BA. The balloon/vessel diameter ratio was on average higher in BA than the stent/vessel diameter ratio in SI (3.49 ± 2.16 vs. 2.42 ± 0.56; P < 0.05) and was a significant risk factor (P < 0.01) for the higher complication rate after BA (BA: 14.1% vs. SI: 4.8%). No mortality occurred in both groups. Conclusion: BA and SI are safe interventional catheter therapies of branch pulmonary artery stenosis. The immediate results of BA and SI are comparable. The higher complication rate after BA, especially in infants, was associated with a higher balloon/vessel diameter ratio. SI seems to be a safe permanent alternative with foreign material, but requires more reinterventions in infants due to its therapeutic strateg

    Der «Behaviour Intervention Design»-Prozess : in sechs Schritten zu einer wirksamen Verhaltensintervention

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    Littering auf öffentlichen Plätzen, zu hoher Fleischkonsum in Personalrestaurants, etliche Flugkilometer bei den Mitarbeitenden oder unzählige Kaffees aus dem Einwegpappbecher – dies sind nur einige Beispiele für unerwünschte Verhaltensweisen, die Unternehmen, Städte und Gemeinden oder Organisationen beschäftigen. Wie aber schaffen sie es mit begrenzten personellen und finanziellen Ressourcen, wirksame Massnahmen zu entwickeln, um Konsumentinnen und Konsumenten zu einem ressourcenschonenden Verhalten zu bewegen

    Intubation depth markings allow an improved positioning of endotracheal tubes in children

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    Objectives: To evaluate the position of the new Microcuff® pediatric tracheal tube, based upon intubation depth markings. Methods: With Institutional Ethics Committee approval and informed parental consent, we included patients from birth (≥ 3 kg) to 16 yr undergoing interventional cardiac catheterization requiring general anesthesia with oro-tracheal intubation. The intubation depth mark of the tracheal tube was placed between the vocal cords by direct laryngoscopy. The distance between tube tip and tracheal carina was measured from routinely taken cardiac catheterization posterior-anteriorx-ray computer images with the patient supine and the head in a neutral position. Evaluation was performed for 20 tubes size 3.0 mm internal diameter (ID) and for ten tubes of each size from 3.5 to 7.0 mm ID. Results: 100 patients were studied (47 girls; 53 boys). Tracheal tube tip advancement into the trachea ranged from 40.6% to 68.6% (median 51.4%). The shortest distance from tube tip to the tracheal carina was 15.7 mm using a 3.0 mm ID tube. Using a standard formula for tube insertion in children aged ≥ two years [12 cm + (age/2)], in one patient the tube tip would have been below the carina and in seven patients the tube cuffs would have been placed within the larynx. Conclusion: The intubation depth markings of the new Microcuff® pediatric tracheal tube allow safe placement of the tracheal tube with a cuff-free laryngeal zone without the risk for endobronchial intubation. Placement using the intubation depth markings was superior to predicted insertion using a standard formul

    On the Development of a Computer-Based Tool for Formative Student Assessment: Epistemological, Methodological, and Practical Issues

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    Formative assessments in schools have the potential to improve students’ learning outcomes and self-regulation skills; they make learning visible and provide evidence-based guidelines for setting up and pursuing individual learning goals. With the recent introduction of the computer-based formative assessment systems for the educational contexts, there is much hope that such systems will provide teachers and students with valuable information to guide the learning process without taking much time from teaching and learning to spend on generating, evaluating and interpreting assessments. In this paper, we combine the theoretical and applied perspectives by addressing (a) the epistemological aspects of the formative assessment, with an emphasis on data collection, model building, and interpretation; (b) the methodological challenges of providing feedback in the context of instruction in the classroom; and (c) practical requirements for and related challenges of setting up and delivering the assessment system to a large number of students. In the epistemological section, we develop and explicate the interpretive argument of formative assessment and discuss the challenges of obtaining data with high validity. From the methodological perspective, we argue that computer-based formative assessment systems are generally superior to the traditional methods of providing feedback in the classroom, as they better allow supporting inferences of the interpretive argument. In the section on practical requirements, we first introduce an existing computer-based formative assessment system, as a case in point, for discussing related practical challenges. Topics covered in this section comprise the specifications of assessment content, the calibration and maintenance of the item bank, challenges concerning teachers’ and students’ assessment literacy, as well as ethical and data-protection requirements. We conclude with an outlook on possible future directions for computer-based formative assessment systems and the field in general
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