Etablierung und Optimierung eines Produktionssystems zur Synthese des alternativen Süßstoffs 5-Ketofruktose in <em>Gluconobacter</em>-Stämmen

Übergewicht, Adipositas und Diabetes sind in der heutigen Gesellschaft längst keine seltenen Krankheiten mehr. In den letzten Jahrzehnten hat die Prävalenz dieser Erkrankungen enorm zugenommen und kann mit einer zuckerreichen und hoch-kalorischen Ernährungsweise in Verbindung gebracht werden. Einer der Hauptgründe für die Aufnahme unverhältnismäßig hoher Mengen an Zuckern stellt der massive Zusatz von Saccharose, Fruktose und Glukose in Konsumgütern dar. Um diesen Problemen entgegenzuwirken, finden vermehrt alternative Süßungsmittel einen Einsatz in der Lebensmittelindustrie. Die vorliegende Arbeit befasste sich daher mit der Entwicklung eines Verfahrens zur Produktion des Zuckerersatzstoffs 5-Ketofruktose (5-KF). Dieses Fruktosederivat stellt aufgrund seiner sensorischen Eigenschaften und seines Nährwerts eine vielversprechende Möglichkeit zum Austausch kalorienreicher Zucker in Lebensmitteln dar. Die Herstellung von 5-KF aus Fruktose erfolgte in dieser Arbeit mit Hilfe bakterieller Expressionssysteme durch die heterologe Produktion der membrangebundenen Fruktose-Dehydrogenase (FDH) in Gluconobacter oxydans. Durch gezielte Genom-Modifikationen und einer doppelten chromosomalen Integrationen des fdh-Operons in G. oxydans Δmgdh::fdh Δsgdh::fdh konnte ein industrielles Produktionsverfahren etabliert werden, das zukünftig eine antibiotikafreie Synthese von 5-KF aus Fruktose ermöglicht. Um ein industriell angepasstes Verfahren zur Synthese von 5-KF auch aus dem alternativen und kostengünstigen Substrat Saccharose zu ermöglichen, wurde in der vorliegenden Arbeit ein Gluconobacter-basiertes Ein-Stamm-System entwickelt. Zur Substraterweiterung war als initialer und notwendiger Schritt eine effiziente Saccharosespaltung erforderlich. Dafür konnte im Rahmen dieser Arbeit eine Invertase aus G. japonicus LMG 1417 (Inv1417) identifiziert werden, die die höchste spezifische Aktivität unter allen bisher beschriebenen Invertasen im mesophilen Temperaturbereich aufwies (Vmax = 2295 ± 243 U/mg Protein). Durch chromosomale Integration des fdh-Operons und Plasmid-vermittelte Produktion der Invertase1417 in G. oxydans Δmgdh::fdh inv konnte das erste Ein-Stamm-System generiert werden, welches eine biotechnologische Herstellung des alternativen Süßstoffs 5-KF aus Saccharose mit Ausbeuten von 84 ± 2 % ermöglicht. Durch den Nachweis eines homologen Enzyms zu Inv1417 und einem chromosomal integrierten fdh-Operon im Wildtyp-Stamm G. japonicus LMG 26773 konnte ein weiteres Ein-Stamm-System zur Produktion von 5-KF aus Saccharose identifiziert werden. Als Nebenprodukt des Herstellprozesses mit G. japonicus LMG 26773 wurde zudem das Präbiotikum Levan nachgewiesen. Als unveränderter Wildtyp stellt G. japonicus LMG 26773 somit eine vielversprechende Möglichkeit für einen Einsatz im Lebensmittelbereich dar. Der Stamm ermöglicht die erste Gentechnik-freie Umwandlung der kalorienreichen Zucker Saccharose und Fruktose zu 5-KF und zusätzlich die Synthese des kostspieligen Präbiotikums Levan

Violência no ambiente escolar

Orientador :Monografia (especialização) - Universidade Federal do Paraná, Setor de ..., Curso de Especialização em ...Inclui referência

Personality traits and virtual reality performance

Background: Surgeons' personalities have been described as different from those of the general population, but this was based on small descriptive studies limited by the choice of evaluation instrument. Furthermore, although the importance of the human factor in team performance has been recognized, the effect of personality traits on technical performance is unknown. This study aimed to compare surgical residents' personality traits with those of the general population and to evaluate whether an association exists between their personality traits and technical performance using a virtual reality (VR) laparoscopy simulator. Methods: In this study, 95 participants (54 residents with basic, 29 with intermediate laparoscopic experience, and 12 students) underwent personality assessment using the NEO-Five Factor Inventory and performed five VR tasks of the Lap Mentor™ basic tasks module. The residents' personality traits were compared with those of the general population, and the association between VR performance and personality traits was investigated. Results: Surgical residents showed personality traits different from those of the general population, demonstrating lower neuroticism, higher extraversion and conscientiousness, and male residents showed greater openness. In the multivariable analysis, adjusted for gender and surgical experience, none of the personality traits was found to be an independent predictor of technical performance. Conclusions: Surgical residents present distinct personality traits that differ from those of the general population. These traits were not found to be associated with technical performance in a virtual environment. The traits may, however, play an important role in team performance, which in turn is highly relevant for optimal surgical performanc

Investigation of intraocular pressure fluctuation as a risk factor of glaucoma progression

Purpose: Since the role of short- and long-term intraocular pressure (IOP) fluctuation as a predictor of glaucoma progression is still controversial, the purpose of this study was to investigate the role of IOP fluctuation in a non-selected patient cohort. Materials and methods: Two-hundred and forty eyes of 120 glaucoma patients (51% female) with a mean age of 64.5 years were included. Inclusion criteria were at least a visual field (VF) and a 48-hour diurnal phasing of IOP including nocturnal measurement. Glaucoma Progression was defined as – if available – confirmed progression of reproducible VF defects in at least three VF examinations or increase of cup area on optic nerve imaging (Heidelberg Retina Tomograph [HRT]) with at least two images after baseline. If results were stable or less than previously mentioned VF or HRT examinations were available, it was classified as “no progression”. Results: Glaucoma progression was seen in seven of 240 eyes in the VF analysis and ten of 240 eyes on HRT. Of all 240 eyes, 92 and 41 eyes fulfilled the criteria to be included for progression evaluation on VF and HRT analysis, respectively. Mean time to progression ± standard error was 3.6±0.2 years on VF and 4.5±0.3 years on HRT. Univariate and multivariate Cox regression analyses revealed short-term IOP fluctuation (P,0.0001) and maximum IOP (P,0.001) as risk factors for glaucoma progression on VF. There was no significant influence of demographic characteristics, ocular or general health on glaucoma progression. Conclusion: Short-term IOP fluctuation was associated with the progression of glaucoma in this non-selected cohort of glaucoma patients receiving phasing of IOP. Keywords: glaucoma progression, short-term IOP fluctuation, long-term IOP fluctuation, glaucoma imaging, visual fiel

Investigation of intraocular pressure fluctuation as a risk factor of glaucoma progression

Purpose: Since the role of short- and long-term intraocular pressure (IOP) fluctuation as a predictor of glaucoma progression is still controversial, the purpose of this study was to investigate the role of IOP fluctuation in a non-selected patient cohort. Materials and methods: Two-hundred and forty eyes of 120 glaucoma patients (51% female) with a mean age of 64.5 years were included. Inclusion criteria were at least a visual field (VF) and a 48-hour diurnal phasing of IOP including nocturnal measurement. Glaucoma Progression was defined as – if available – confirmed progression of reproducible VF defects in at least three VF examinations or increase of cup area on optic nerve imaging (Heidelberg Retina Tomograph [HRT]) with at least two images after baseline. If results were stable or less than previously mentioned VF or HRT examinations were available, it was classified as “no progression”. Results: Glaucoma progression was seen in seven of 240 eyes in the VF analysis and ten of 240 eyes on HRT. Of all 240 eyes, 92 and 41 eyes fulfilled the criteria to be included for progression evaluation on VF and HRT analysis, respectively. Mean time to progression ± standard error was 3.6±0.2 years on VF and 4.5±0.3 years on HRT. Univariate and multivariate Cox regression analyses revealed short-term IOP fluctuation (P,0.0001) and maximum IOP (P,0.001) as risk factors for glaucoma progression on VF. There was no significant influence of demographic characteristics, ocular or general health on glaucoma progression. Conclusion: Short-term IOP fluctuation was associated with the progression of glaucoma in this non-selected cohort of glaucoma patients receiving phasing of IOP. Keywords: glaucoma progression, short-term IOP fluctuation, long-term IOP fluctuation, glaucoma imaging, visual fiel

A Reliability Study in a Cohort of 207 Apparently Healthy Participants

The reliability of single time point measurements of the novel adipokines retinol-binding protein 4 and omentin-1 in the blood has not been evaluated in large samples yet. The present study aimed to assess the amount of biological variation of these two adipokines within individuals. The study sample comprised 207 participants (124 women and 83 men) from Potsdam (Germany) and surrounding areas, with an average age of 56.5 years (SD 4.2). Blood samples were collected from each participant twice, approximately four months apart. Using enzyme linked immunosorbent assays, the concentrations of retinol- binding protein 4 and omentin-1 were determined in EDTA plasma. As indicators of reliability, intraclass correlation coefficients (ICCs) were calculated from the repeated biomarker measurements. The ICCs for repeated retinol- binding protein 4 and omentin-1 measurements were 0.77 (95% CI 0.71, 0.82) and 0.83 (95% CI 0.78, 0.87), respectively, indicating for both adipokines excellent reliability. ICCs were stable across strata according to sex, age, BMI, and blood pressure. Thus, for epidemiological studies it seems reasonable to rely on concentrations of retinol-binding protein 4 and omentin-1 in samples from a single time point if repeated measurements are not available

Produktion von Leistung im digital-gestützten Unterricht

Der Beitrag blickt vor dem Hintergrund eines praxistheoretischen Verständnisses von Leistung auf dessen Hervorbringung im Unterricht. Anhand videographischer Daten zum Geschehen in sog. Tabletklassen wird untersucht, ob und in welcher Weise sich die Möglichkeiten der sozialen Konstruktion von Leistung im digital-gestützten Unterricht verändern. Dafür steckt das erste Kapitel (1) zunächst den theoretischen Horizont ab und stellt praxistheoretische Überlegungen zum Leistungsbegriff vor. Pointiert herausgestellt wird dabei auch die Relevanz sozio-medialer Praktiken in der pädagogischen Ordnungsbildung. Das anschließende Kapitel resümiert den bisherigen Forschungsstand zur Konstruktion von Leistung im Kontext der Unterrichtsforschung (2). Darauffolgend werden verschiedene Varianten der potentiellen Leistungsverschiebung im digital-gestützten Unterricht auf der Grundlage videographierten Unterrichts aus dem TabU-Projekt1 vorgestellt und rekonstruiert (3). Der abschließende Abschnitt (4) bündelt die Erkenntnisse und zieht ein Fazit. (DIPF/Orig.

Exposure risk to carbonyl compounds and furfuryl alcohol through the consumption of sparkling wines

The goals of this study were to verify the occurrence of furfuryl alcohol (FA) and carbonyl compounds (acetaldehyde, acrolein, ethyl carbamate (EC), formaldehyde and furfural) in sparkling wines and to evaluate, for the first time, whether the consumption of the samples under study could represent risk to consumers health. These compounds are electrophilic; and therefore, may covalently bind to DNA, which may result in mutagenicity. EC and formaldehyde were present at low levels (<1μg L-1) in all samples. Acetaldehyde, furfural and acrolein were also found in low levels (<1.5, 1.4 and 1.0μg L-1, respectively) in 57, 71 and 76% of samples. In the other samples, levels of acetaldehyde, furfural and acrolein ranged from 5.2 to 54.8, 10.5 to 41.0 and 20.3 to 36.7μg L-1, respectively. Furfuryl alcohol was also reported in all samples in levels from 10.4 to 33.5μg L-1. Acrolein was the only compound reported at levels sufficient to represent risk to health, which occurred in 24% of the samples. A study focused on the origin of acrolein deserves attention, investigating the influence of the concentration of precursors and the role of fermentation in the formation of this aldehyde, besides the evaluation of possible environmental contamination of grapes during cultivation.Os objetivos deste estudo foram verificar a ocorrência de álcool furfurílico (FA) e compostos carbonílicos (acetaldeído, acroleína, carbamato de etila (CE), formaldeído e furfural) em espumantes e avaliar, pela primeira vez, se o consumo das amostras em estudo poderia representar risco para a saúde do consumidor. Esses compostos são eletrofílicos e, portanto, podem se ligar covalentemente ao DNA, o que pode resultar em mutagenicidade. CE e formaldeído foram encontrados em baixos níveis (<1μg/L) em todas as amostras. Acetaldeído, furfural e acroleína também foram encontrados em baixos níveis (<1,5; 1,4 e 1,0μg L-1, respectivamente) em 57, 71 e 76% das amostras. Nas demais amostras, os níveis de acetaldeído, furfural e acroleína variaram de 5,2 a 54,8, 10,5 a 41,0 e 20,3 a 36,7μg L-1, respectivamente. O álcool furfurílico também foi encontrado em todas as amostras em níveis de 10,4 a 33,5μg L-1. A acroleína foi o único composto encontrado em níveis suficientes para representar risco à saúde, que ocorreu em 24% das amostras. Uma avaliação focada na origem da acroleína merece atenção, investigando a influência da concentração dos precursores e o papel da fermentação na formação do aldeído, além da avaliação da possível contaminação ambiental das uvas durante o cultivo

Identification of rhabdoviral sequences in oropharyngeal swabs from German and Danish bats

BACKGROUND: In the frame of active lyssavirus surveillance in bats, oropharyngeal swabs from German (N = 2297) and Danish (N = 134) insectivorous bats were investigated using a newly developed generic pan-lyssavirus real-time reverse transcriptase PCR (RT-qPCR). FINDINGS: In total, 15 RT-qPCR positive swabs were detected. Remarkably, sequencing of positive samples did not confirm the presence of bat associated lyssaviruses but revealed nine distinct novel rhabdovirus-related sequences. CONCLUSIONS: Several novel rhabdovirus-related sequences were detected both in German and Danish insectivorous bats. The results also prove that the novel generic pan-lyssavirus RT-qPCR offers a very broad detection range that allows the collection of further valuable data concerning the broad and complex diversity within the family Rhabdoviridae