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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 4549-4567 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The extended two-particle model for statistical interactions in particle beams, developed by Jansen [Coulomb Interactions in Particle Beams (Academic, Boston, 1990)], has been refined to improve the accuracy of the predictions of the trajectory displacement effect in particle beam projection systems. The original theory was developed for probe forming systems, such as electron and ion scanning microscopes and Gaussian or shaped beam lithography systems. Fit functions are used within the theory to express part of the numerical output into explicit analytical prescriptions. These functions were found to become inaccurate for the relatively wide beams typically used in the more recently developed projection type lithography systems. New fit functions are presented which extend the applicability of the theory to the wide beams and doublet configurations used in projection systems. The Monte Carlo program MONTEC, used to verify the results of the analytical theory, has been modified as well to account for the first order space charge magnification effect. This effect could be ignored for the relatively small spots of Gaussian and shaped beam systems, but would yield a significant overestimation of the trajectory displacement effect—assumed to be identical to the remaining blur after refocusing—for the wide images used in projection type of systems. The refined analytical theory and the modified MONTEC program have been used to evaluate the impact of statistical interactions on the performance of the SCALPEL electron projection system and a hypothetical ion projection lithography system, representing a simplified model of the IMS ALG-1000 (He+) system. The analytical predictions are in good agreement with the Monte Carlo results. An estimate of the total system resolution, determined by the combined effect of statistical interactions and geometrical aberrations, indicates that maximum attainable beam current for a 0.18 μm design rule is about 25 μA for the SCALPEL and 0.2–0.3 μA for the ion projection system, leading to an ∼10× higher throughput for the former taking the difference in resist sensitivities for electrons and ions into account. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 804 (1996), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-1920
    Keywords: Key words Creutzfeldt-Jakob disease ; Magnetic resonance imaging ; Globus pallidus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a 49-year-old woman with Creutzfeldt-Jakob disease (CJD). In addition to typical high-signal lesions on proton-density and T 2-weighted images there was high signal in the globus pallidus bilaterally on T 1-weighted images. The latter feature has not been described previously and probably due to deposition of prion protein, as found at autopsy.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0843
    Keywords: Key words Membrane folate receptors ; Methotrexate ; Sensitivity/resistance profiles ; Antifolates ; Human breast cancer cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Two methotrexate (MTX)-resistant human breast-cancer cell lines with impaired transport via the reduced folate carrier (RFC), one established in vitro (MTXR-ZR-75-1) and another inherently resistant (MDA-231), were adapted to grow in medium containing 2 nM folic acid. This induced the expression of previously undetectable membrane folate receptors (MFR) to levels of 8.2 and 2.3 pmol/107 cells, respectively. Polymerase chain reaction (PCR) quantitation revealed that MFR messenger-RNA levels of the isoform first described in human nasopharyngeal carcinoma KB cells (MFR-α) were increased in low-folate-adapted MTXR-ZR-75-1 cells, whereas placental transcripts (MFR-β) coincided with MFR-α expression in low-folate (LF)-adapted MDA-231 cells. These cell lines were used to study the role of MFR in the uptake and growth-inhibitory effects of five different antifolates with varying affinities for MFR: N 10-propargyl-5, 8-dideazafolic acid (CB3717) 〉 5,10-dideazatetra-hydrofolic acid (DDATHF) 〉 N-{5- [N-(3,4-di-hydro-2-methyl-4-oxoquinazolin-6-methyl)-N-methyl-amino] -2-theonyl}-glutamic acid (ZD1694) ≫ MTX 〉 edatrexate (EDX). Expression of MFR only slightly decreased the resistant phenotype for MTX, EDX, and ZD1694, suggesting that these drugs are not transported intracellularly to cytotoxic concentrations at these levels of MFR expression. On the other hand, both cell lines became from at least 180- to 400-fold more sensitive to growth inhibition by CB3717 and DDATHF, which may be correlated with their high affinity for MFR. These sensitivity/resistance profiles were largely similar following cell culture in medium containing 1 nM L-leucovorin, a folate with an affinity for MFR 10-fold lower than that of folic acid, the one exception being the increased sensitivity for ZD1694 seen in the LF-adapted cells with the highest level of MFR expression (MTXR-ZR-75-1). These results illustrate that the efficacy of MFR in mediating antifolate transport and cytotoxicity depends on their affinity for the folate antagonist, their degree of expression, and the levels of competing folates.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European radiology 9 (1999), S. 493-507 
    ISSN: 1432-1084
    Keywords: Key words: MRI ; Epilepsy ; Surgery
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The contribution of MR imaging in patients with drug-resistant epilepsy considered for surgical therapy is discussed. In this review we focus on: (a) focal abnormalities (mesial temporal sclerosis, focal migration disorders, hamartomatous lesions and low-grade tumours, phakomatosis and vascular malformations) associated with therapy-resistant partial epilepsy, requiring resective surgery; (b) abnormalities leading to generalized seizures that require more drastic surgical procedures, such as callosotomy and functional hemispherectomy; and (c) localisation of implanted depth-electrodes.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1076
    Keywords: Key words Vein of Galen  ;  Arteriovenous malformation   ;  Newborn  ;  Ischaemic brain damage  ;  Leukomalacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Vein of Galen malformation is a rare intracranial disorder in newborns. In recent years the survival rate has improved due to improvement in endovascular treatment of this abnormality. We describe three neonates with a vein of Galen malformation for whom treatment was not attempted because of associated severe cerebral damage, of antenatal origin in two and of perinatal origin in the other. Autopsy was performed in two neonates. Periventricular leukomalacia was present in both cases, associated in one case with cortical infarction, gliosis and atrophy. Conclusion We recommend careful evaluation of asso ciated cerebral damage prior to attempted treatment of the vein of Galen malformation.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für Gerontologie + Geriatrie 31 (1998), S. 271-276 
    ISSN: 0044-281X
    Keywords: Schlüsselwörter Geriatrie – stationäres Leistungsangebot – geriatrisches Konsil – Barthel-Index – Screening nach Lachs ; Key words Geriatric – geriatric consultation – geriatric in-patient offer – Barthel Index – Lachs' Screening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In the past the calculation for an in-patient special offer (quantity of beds needed) was mainly carried out by diagnosis-based statistics of hospital cases. The decision for an in-patient care within a geriatric unit is however influenced by factors as “status of selfhelp abilities”, “social situation” and “co-morbidity”. Those factors are investigated either directly by the help of the patient himself or by questioning the nurses and/or the medical staff. A new way of measuring will be introduced for this questioning. The crucial element is the Barthel-Index (BI). Supporting measures are done by the inclusion of main datas concerning the social situation as well as recording the modified screening according Lachs. From the 6th of September until 14th of December 1997 the three-part measuring technique was used at seven hospitals in Hamburg (amongst them one University hospital and one hospital with a geriatric unit) within the framework of a representative sample survey. These collected datas register 18 admission days of all patients of sixty or over who at the time of questioning stayed for five days in one of those acute hospitals. In some hospitals some additional datas were collected at the third or 6th day after admission. Altogether a whole “virtual day-admission” of the 60 years old or older patients was collected for the City of Hamburg at the 5th day after admission. Out of 425 patients 137 were moved or exmitted before questioning, 4 had already died. Out of the rest of 284 patients two of them refused the questioning, whilst the datas of 6 patients were not feasible for evaluating. Finally 276 patients were questioned. Out of them 231 patients are “not potential candidates for a geriatric hospital or a geriatric day-care unit”, 8 are “candidates for a geriatric day-care unit directly after discharge of primary care” and 37 are “candidates for an in-patient geriatric hospital”. The presented three-part question-sheet shows a sensitivity of 89.2% and a specification of 92.2%. This measuring technique in the hands of a trained examiner appears to be a valid and manageable tool in the framework of geriatric consultation as well as for the investigation of own directly ascertained statistic datas for “potential candidates for an in-patient geriatric hospital”.
    Notes: Zusammenfassung Die Berechnung eines stationären Leistungsangebotes (“Bettenbedarfs”) erfolgte in der Vergangenheit vorwiegend über diagnosebezogene Fallzahlstatistiken (Krankenhausfälle). Die Entscheidung für die stationäre Versorgung in einer geriatrischen Abteilung wird jedoch zusätzlich durch Faktoren wie “Selbsthilfestatus”, “soziales Umfeld” und “Komorbidität” entschieden. Diese können direkt am Patienten ermittelt oder durch die Befragung der Pflege und/oder des ärztlichen Dienstes erfaßt werden. Für diese Befragung wird ein neues Meßinstrument vorgestellt. Das Kernstück bildet der Barthel-Index (BI). Flankierend erfolgt die Aufnahme der Eckdaten zur sozialen Situation sowie die Erfassung des modifizierten Screenings nach Lachs. Das dreiteilige Meßinstrument wurde vom 6. September bis 14. Dezember 1997 an sieben Hamburger Kliniken (darunter eine Universitätsklinik und eine geriatrieführende Klinik) im Rahmen einer repräsentativen Stichprobe eingesetzt. Die gesammelten Daten erfassen 18 Aufnahmetage aller 60jährigen und älteren, welche am Tag der Befragung den fünften Tag im jeweiligen Akutkrankenhaus verbrachten. An einigen Kliniken wurden zusätzlich Daten ab dem dritten bzw. bis zum sechsten Tag nach Aufnahme erfaßt. Insgesamt wurde durch die ermittelten Daten eine ganze “virtuelle Tagesaufnahme” der 60jährigen und älteren am fünften Tag für die Stadt Hamburg erfaßt. Von 425 Patienten waren 137 bereits vor der Befragung verlegt oder entlassen worden, 4 waren verstorben. Von den verbliebenen 284 PatientInnen lehnten 2 die Befragung ab, die Daten von 6 PatientInnen waren nicht auswertbar; somit wurden 276 PatientInnen befragt. Von diesen stellen 231 “keine potentiellen KandidatInnen für eine Geriatrie oder geriatrische Tagesklinik” dar, 8 sind “KandidatInnen für eine geriatrische Tagesklinik direkt nach der Entlassung aus der Primärversorgung”, und 37 sind “KandidatInnen für eine stationäre Geriatrie”. Der vorgestellte dreiteilige Frage- und Befundbogen zeigt eine Sensitivität von 89,2% und eine Spezifität von 92,2%. In den Händen eines geschulten Untersuchers stellt das Meßinstrument sowohl im Rahmen des geriatrischen Konsils als auch für die Ermittlung eigener direkt erhobener statistischer Kenndaten “potentieller Kandidaten für eine stationäre Geriatrie” ein valides und in der Handhabung praktisches “Handwerkszeug” dar.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1439-0973
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Einfluß vonEnterococcus faecalis auf die Morphologie der Bakterienzellen der Darmflora und auf die Bindungsfähigkeit von IgG an die Darmflora wurde bestimmt. Nach 29 Tagen Beobachtungs-Vorphase nahmen 10 freiwillige gesunde Versuchspersonen 21 Tage lang dreimal täglich 107 lebende Zellen vonE. faecalis ein. Die Studie wurde nach einer weiteren Beobachtungszeit von 21 Tagen beendet. Während der gesamten Studienphase von 71 Tagen lieferte jeder der Probanden 11 Stuhlproben in siebentägigen Abständen ab. Vor und nach der Gewinnung der Stuhlprobe wurden von allen Probanden Blutproben entnommen. Der Einfluß der Einnahme vonE. faecalis auf die Morphologie der Mikroflora des Darmes wurde durch Bildanalyse beurteilt. Zusätzlich wurde die Bindungsfähigkeit von Serum-IgG an die Darmbakterien bei allen Stuhlproben der mittleren Studienphase mittels quantitativer Immunfluoreszenz bestimmt. Die orale Applikation vonE. faecalis führte zu einer signifikanten Veränderung der Zusammensetzung der Darmflora gemessen an ihrem morphologischen Erscheinungsbild. Zugleich nahm die Fähigkeit der Darmflora zur Bindung von IgG signifikant ab.
    Notes: Summary The influence ofEnterococcus faecalis on the morphology of the bacterial cells which make up the gut microflora and on the levels of circulating IgG bound to the gut microflora was assessed. After 29 days of pretreatment monitoring, ten healthy human volunteers ingested 107 viable cells ofE. faecalis three times daily, for 21 days. After this treatment another 21 days of follow-up completed the study. Each volunteer delivered eleven faecal samples during the entire study period of 71 days with a 7 day interval. Before and after the faeces sampling period, blood samples were collected from all volunteers. The influence of the ingestion ofE. faecalis on the morphology of the gut microflora was measured by image analysis. In addition, the binding of circulating IgG to intestinal bacteria in all intermediate faecal samples was measured by means of quantitative immunofluorescence. The oral administration ofE. faecalis resulted in a significant change of the morphological composition of the gut microflora and in a significant decrease in IgG-binding capacity of the gut microflora.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inherited metabolic disease 20 (1997), S. 85-94 
    ISSN: 1573-2665
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Although ether-linked phospholipids have been known to be constituents of biological membranes for a long time, their physiological function has remained an enigma through the years. Inspired by the suggestion of Zoeller and coworkers that plasmalogens, which are specific types of ether-linked phospholipids characterized by the occurrence of an α,β-unsaturated ether bond at the sn-1 position, are involved in the protection of cells against reactive oxygen species, we studied reactive oxygen species metabolism in cultured human skin fibroblasts. Menadione was used as intracellular generator of reactive oxygen species and cytochrome c as extracellular indicator for the production of reactive oxygen species. The finding that identical results were obtained in control and plasmalogen-deficient fibroblasts leads us to conclude that plasmalogens do not play a major role in protection against reactive oxygen species.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1573-2665
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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