211 research outputs found
Bethe Ansatz solutions for Temperley-Lieb Quantum Spin Chains
We solve the spectrum of quantum spin chains based on representations of the
Temperley-Lieb algebra associated with the quantum groups for and . The tool is a
modified version of the coordinate Bethe Ansatz through a suitable choice of
the Bethe states which give to all models the same status relative to their
diagonalization. All these models have equivalent spectra up to degeneracies
and the spectra of the lower dimensional representations are contained in the
higher-dimensional ones. Periodic boundary conditions, free boundary conditions
and closed non-local boundary conditions are considered. Periodic boundary
conditions, unlike free boundary conditions, break quantum group invariance.
For closed non-local cases the models are quantum group invariant as well as
periodic in a certain sense.Comment: 28 pages, plain LaTex, no figures, to appear in Int. J. Mod. Phys.
Die Bedeutung von Rhamnolipiden in der Pathogenese epithelialer Pseudomonas aeruginosa Infektionen
Pseudomonas aeruginosa (P. aeruginosa) ist ein ubiquitär vorkommendes, gramnegatives, monotrich begeißeltes, aerob lebendes Stäbchenbakterium. Das opportunistisches Pathogen befällt Menschen, Tiere, Insekten, Nematoden und Pflanzen und ist unter anderem aufgrund seiner Toleranz gegenüber einer Vielzahl von Desinfektionsmitteln und Antibiotika einer der wichtigsten Verursacher von nosokomialen Infektionen.
Die Ergebnisse dieser Arbeit geben einen Hinweis darauf, dass P. aeruginosa das angeborene Immunsystem mit Hilfe von Rhamnolipid, einem vom Bakterium selbst produzierten Surfactant, umgeht.
In der vorliegenden Arbeit konnte nachgewiesen werden, dass die Flagellin-induzierte hBD2-Expression in humanen Keratinozyten durch bakterielle Überstände von P. aeruginosa, die in der stationären Phase generiert wurden, supprimiert wird. Der supprimierende Faktor konnte in Versuchen als hitzestabil und durch Säure ausfällbar identifiziert werden. Außerdem blieb er bei Behandlung mit Proteinase K unbeeinflusst, es handelt sich deshalb nicht um ein Protein. Weitere Untersuchungen konnten den Faktor als Rhamnolipid identifizieren.
Eine Kostimulation von Keratinozyten mit aufgereinigtem Rhamnolipid in Mengen unterhalb der zytotoxischen Konzentration zusammen mit Flagellin zeigte ebenfalls eine Supprimierung der induzierten hBD2-Expression. Ähnliche Effekte konnten bei Kostimulation der Keratinozyten mit Flagellin und BAPTA-AM, einem intrazellulären Calciumchelator, erreicht werden. Neben Flagellin als Induktor ließ sich auch die PMA-induzierte hBD2-Expression supprimieren. Dies lässt vermuten, dass Rhamnolipide mit Calcium-abhängigen Signalkaskaden, wie der PKC-Signalkaskade, interferieren.
Die Versuche dieser Arbeit zeigen damit einen Weg, über den es P. aeruginosa möglich ist, sich auf der Haut zu etablieren, ohne seinen Hauptpathogenitätsfaktor, das Flagellin, verstecken zu müssen
Type 1 diabetes, diabetic nephropathy, and pregnancy: a systematic review and meta-study
BACKGROUND: In the last decade, significant improvements have been achieved in maternal-fetal and diabetic care which make pregnancy possible in an increasing number of type 1 diabetic women with end-organ damage. Optimal counseling is important to make the advancements available to the relevant patients and to ensure the safety of mother and child. A systematic review will help to provide a survey of the available methods and to promote optimal counseling. OBJECTIVES: To review the literature on diabetic nephropathy and pregnancy in type 1 diabetes. METHODS: Medline, Embase, and the Cochrane Library were scanned in November 2012 (MESH, Emtree, and free terms on pregnancy and diabetic nephropathy). Studies were selected that report on pregnancy outcomes in type 1 diabetic patients with diabetic nephropathy in 1980-2012 (i.e. since the detection of microalbuminuria). Case reports with less than 5 cases and reports on kidney grafts were excluded. Paper selection and data extraction were performed in duplicate and matched for consistency. As the relevant reports were highly heterogeneous, we decided to perform a narrative review, with discussions oriented towards the period of publication. RESULTS: Of the 1058 references considered, 34 fulfilled the selection criteria, and one was added from reference lists. The number of cases considered in the reports, which generally involved single-center studies, ranged from 5 to 311. The following issues were significant: (i) the evidence is scattered over many reports of differing format and involving small series (only 2 included over 100 patients), (ii) definitions are non-homogeneous, (iii) risks for pregnancy-related adverse events are increased (preterm delivery, caesarean section, perinatal death, and stillbirth) and do not substantially change over time, except for stillbirth (from over 10% to about 5%), (iv) the increase in risks with nephropathy progression needs confirmation in large homogeneous series, (v) the newly reported increase in malformations in diabetic nephropathy underlines the need for further studies. CONCLUSIONS: The heterogeneous evidence from studies on diabetic nephropathy in pregnancy emphasizes the need for further perspective studies on this issue
Ecological importance of lepidopteran defoliators on eucalyptus plantations based in faunistic and natural enemy analyses
Abstract Areas planted with Eucalyptus urophylla S.T. Blake variety platyphylla F. Muell. (Myrtaceae) expand annually in most regions of Brazil. Many lepidopteran species defoliate this plant, but with damage varying per species. The objective of this study was to identify the pest status of lepidopteran defoliators based in the faunistic analysis of these insects and of their natural enemies on E. urophylla variety platyphylla plantations in a representative producing region of Brazil. Adult moths of lepidopterans and of their natural enemies were captured using a light trap, installed every two weeks, from September 2016 to August 2018. A total of 183, 10, three and 139 lepidopteran species was captured and classified as primary, secondary, without defined importance to eucalypt plants and non-identified with 1,419, seven, 465 and 876 individuals, respectively. Two primary pest species were constants, two accessories and six accidentals and all secondary ones were accidentals. Six primary pest species were common and dominant and four non-dominants. Faunistic indices indicated the main lepidopteran species that should be monitored in pest management programs. Seven hymenopteran species (65 individuals), three dipterans (49 individuals) and two hemipterans (four individuals) were the natural enemies collected using light traps. The monitoring of lepidopteran pests with light traps can contribute to the management and to reduce damage and control costs for these species, besides identifying natural enemies for biological control programs in Eucalyptus plantations
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