18 research outputs found
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Examination of universal microhardness of liard reaction layers resulting from reactions of organic polymers with container glass surfaces and their use for low-friction protective layers
Clear, highly alkaline and wear-resistant hard reaction layers are formed by direct alkaline coupling of organic polymers with functional groups, particularly high-molecular polyols, to siliceous glass surfaces having container glass compositions. As compared with untreated glass these are characterized by an increased universal hardness and an excellent scratch resistance. Formation of these layers requires a highly alkahne reaction medium, e.g. 2% NaOH, 85°C, according to the conditions of the alkaline washing process of returnable beverage bottles in the bottling plants. It can be assumed that the formation of the reaction layer is associated with the formation of highly molecular ionic polymers with 5-coordinated silicon. Results of universal microhardness measurements of the hard reaction layers which were formed with aqueous polymer dispersions (epoxy resin microdispersion; low-molecular oxidized polyethylene) are presented. The increase of plastic universal hardness in comparison with untreated glass demonstrates the enhanced wear resistance of these layers. So far layer thicknesses up to 0.3 µm could be achieved. These results suggest new approaches to develop highly efficient low-friction protective layers for returnable bottles, and after increasing the thickness of the hard reaction layer up to several micrometers, they could possibly be applied also to lightweight bottles under enhanced internal pressure as used for carbonated beverages. Universal microhardness measurements are a very useful tool in the development and most effective improvement of such novel low-friction protective coatings for container glass
Development of a patient-oriented navigation model for patients with lung cancer and stroke in Germany
Background: The concept of patient navigation was first established in the USA to support vulnerable patient groups in receiving timely and comprehensive access to cancer care. It has recently gained increasing interest in Germany to support patients with chronic diseases in a fragmented healthcare system. The aim of this paper is to present the development of such a model adapted to the German context based on the results of mixed-methods studies investigating the need for and barriers to patient-oriented care.
Methods: In a process adapted from Delphi rounds, we conducted regular structured workshops with investigators of the project to discuss results of their studies and identify content and structure of the model based on the data. Workshop discussions were structured along seven core components of a navigation model including target patient groups, navigator tasks, occupational background and education of navigators, and patient-navigator interaction mode.
Results: Using an approach based on empirical data of current care practices with special focus on patients' perspectives, we developed a patient-oriented navigation model for patients who have experienced stroke and lung cancer in the German healthcare context. Patients without personal social support were viewed as struggling most with the healthcare system, as well as multimorbid and elderly patients. Navigators should serve as a longer-term contact person with a flexible contact mode and timing based on the individual situation and preferences of patients. Navigator tasks include the provision of administrative and organizational support as well as referral and guidance to available resources and beneficial health programs with special forms of knowledge. Implementation of the navigator should be flexibly located to ensure a reliable outreach to vulnerable patients for first contact in settings like specialized in-patient and out-patient settings, while navigation itself focuses on care coordination in the out-patient setting.
Conclusion: Flexibility of navigator tasks needed to be a core characteristic of a navigation model to be perceived as supportive from patients' perspectives. In a subsequent feasibility study, an intervention based on the model will be evaluated according to its acceptance, demand, and practicality
Entwicklung von Methoden zum Nachweis von ökologisch erzeugten Produkten am Beispiel der Lachszucht
Zur Zeit stehen der Lebensmittelüberwachung keine analytischen Methoden zur Verfügung mit denen Deklarationen wie „Bio-Fisch“, „Bio-Lachs“ oder „Organic Salmon“ am Erzeugnis überprüft werden können. Das Ziel dieses Projektes bestand in der Entwicklung von objektiven, praxistauglichen Analysenverfahren zur Identifizierung von Lachserzeugnissen aus der ökologischen Aquakultur.
Die Verfügbarkeit solcher Verfahren ermöglicht einen verbesserten Verbraucherschutz und eine Stärkung des redlichen Handels. Es kann aber auch der Tierschutz von den Ergebnissen des Projektes profitieren, wenn man berücksichtigt, dass die ökologische Aquakultur eine artgerechte Haltung der Fische besonders fördern soll.
In einem umfangreichen Untersuchungsprogramm wurden biologische und chemische Methoden, sowie ganzheitliche Verfahren eingesetzt. Zum Vergleich wurden auch Wildlachse und einige Lachsfutter analysiert. Probenziehungen fanden in den Jahren 2002 und 2003 statt; der Ökolachs und Wildlachs stammte aus Irland, Farmlachse hoher Qualität wurden aus Irland und Norwegen bezogen. Insgesamt wurden 100 Lachsproben analysiert.
Folgende Methoden kamen u.a. zum Einsatz: Beurteilung des Ausgangsmaterials (Aussehen, Kondition der Lachse), DNA Analyse, Bildverarbeitung (Muskelstruktur), Aromaprofil Bestimmung, Messung der Gehalte an Eiweiß und Fett, Bestimmung von Stoffwechselprodukten und Stressparametern, Stabil-Isotopen-Analyse (15-N, 13-C), Bestimmung der Astaxanthin-Isomere und Canthaxanthingehalte, Bestimmung von organischen und anorganischen Rückständen.
Aus den vielfältigen Ergebnissen ist zu schließen, dass Öko- und Farmlachs sich in Aussehen, Zusammensetzung (z.B. im Fettgehalt) und Schadstoffgehalten generell nicht unterscheiden. Nur mit Hilfe einer Methode, der Bestimmung der Astaxanthin-Isomere, konnte der Ökolachs aus Irland sicher identifiziert werden
Type III restriction endonuclease EcoP15I is a heterotrimeric complex containing one Res subunit with several DNA-binding regions and ATPase activity
For efficient DNA cleavage, the Type III restriction endonuclease EcoP15I communicates with two inversely oriented recognition sites in an ATP-dependent process. EcoP15I consists of methylation (Mod) and restriction (Res) subunits forming a multifunctional enzyme complex able to methylate or to cleave DNA. In this study, we determined by different analytical methods that EcoP15I contains a single Res subunit in a Mod2Res stoichiometry. The Res subunit comprises a translocase (Tr) domain carrying functional motifs of superfamily 2 helicases and an endonuclease domain with a PD..D/EXK motif. We show that the isolated Tr domain retains ATP-hydrolyzing activity and binds single- and double-stranded DNA in a sequence-independent manner. To localize the regions of DNA binding, we screened peptide arrays representing the entire Res sequence for their ability to interact with DNA. We discovered four DNA-binding regions in the Tr domain and two DNA-binding regions in the endonuclease domain. Modelling of the Tr domain shows that these multiple DNA-binding regions are located on the surface, free to interact with DNA. Interestingly, the positions of the DNA-binding regions are conserved among other Type III restriction endonucleases
Overproduction of Inactive Variants of the Murein Synthase PBP1B Causes Lysis in Escherichia coli
Penicillin-binding protein 1B (PBP1B) of Escherichia coli is a bifunctional murein synthase containing both a transpeptidase domain and a transglycosylase domain. The protein is present in three forms (α, β, and γ) which differ in the length of their N-terminal cytoplasmic region. Expression plasmids allowing the production of native PBP1B or of PBP1B variants with an inactive transpeptidase or transglycosylase domain or both were constructed. The inactive domains contained a single amino acid exchange in an essential active-site residue. Overproduction of the inactive PBP1B variants, but not of the active proteins, caused lysis of wild-type cells. The cells became tolerant to lysis by inactive PBP1B at a pH of 5.0, which is similar to the known tolerance for penicillin-induced lysis under acid pH conditions. Lysis was also reduced in mutant strains lacking several murein hydrolases. In particular, a strain devoid of activity of all known lytic transglycosylases was virtually tolerant, indicating that mainly the lytic transglycosylases are responsible for the observed lysis effect. A possible structural interaction between PBP1B and murein hydrolases in vivo by the formation of a multienzyme complex is discussed
Hematopoietic Stem Cell Transplantation in an Infant with Immunodeficiency, Centromeric Instability, and Facial Anomaly Syndrome
Immunodeficiency, centromeric instability, and facial anomaly (ICF) syndrome is a rare autosomal recessive genetic condition with severe immunodeficiency, which leads to lethal infections if not recognized and treated in early childhood. Up-to-date treatment regimens consist of prophylactic and supportive treatment of the recurrent infections. Here, we report the case of a 1-year-old boy of Moroccan consanguineous parents, who was diagnosed at 4 months of age with ICF syndrome with a homozygous missense mutation in the DNMT3B gene. He was initially admitted to the hospital with recurrent pulmonary infections from the opportunistic pathogen Pneumocystis jirovecii (PJ). Further immunological workup revealed agammaglobulinemia in the presence of B cells. After successful recovery from the PJ pneumonia, he underwent hematopoietic stem cell transplantation (HSCT) from the HLA-matched healthy sister using a chemotherapeutic conditioning regimen consisting of treosulfan, fludarabine, and thiotepa. Other than acute chemotherapy-associated side effects, no serious adverse events occurred. Six months after HSCT immune-reconstitution, he had a stable chimerism with 2.9% autologous portion in the peripheral blood and a normal differential blood cell count, including all immunoglobulin subtypes. This is one of the first cases of successful HSCT in ICF syndrome. Early diagnosis and subsequent HSCT can prevent severe opportunistic infections and cure the immunodeficiency. Centromeric instability and facial anomaly remain unaffected. Although the long-term patient outcome and the neurological development remain to be seen, this curative therapy for immunodeficiency improves life expectancy and quality of life. This case is meant to raise physicians awareness for ICF syndrome and highlight the consideration for HSCT in ICF syndrome early on
Next-generation-sequencing-spectratyping reveals public T-cell receptor repertoires in pediatric very severe aplastic anemia and identifies a beta chain CDR3 sequence associated with hepatitis-induced pathogenesis
Krell P, Reuther S, Fischer U, et al. Next-generation-sequencing-spectratyping reveals public T-cell receptor repertoires in pediatric very severe aplastic anemia and identifies a beta chain CDR3 sequence associated with hepatitis-induced pathogenesis. Haematologica. 2013;98(9):1388-1396