Investigating noise reduction in an octave-spanning Ti:sapphire laser

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2004.Includes bibliographical references (p. 32).by Annemarie N. Grandke.S.B

Änderung der körperlichen Aktivität bei Patienten mit obstruktiver Schlafapnoe durch die Therapie mit Continous Positive Airway Pressure

Die obstruktive Schlafapnoe geht in der Regel mit erhöhter Tagesmüdigkeit einher, die den Alltag der Patienten erheblich einschränkt. Aus der gesteigerten Tagesmüdigkeit resultiert neben einer eingeschränkten Konzentrationsfähigkeit auch eine Verminderung der körperlichen Aktivität. Werden die Patienten mit continuous positive airway pressure (CPAP) behandelt, nimmt die Tagesmüdigkeit der Patienten erheblich ab, die Patienten berichten über eine subjektiv empfundene Aktivitätssteigerung. In der vorliegenden Arbeit wurde versucht, mit Hilfe der Aktimetrie die subjektiv empfundene Aktivitätssteigerung zu objektivieren. Des Weiteren wurde untersucht, inwieweit sich die körperliche Aktivität während der Wachphase und während des Schlafes nach der Therapie mit CPAP verändert. Die Studie wurde mit !5 Patienten (12 Männer und 3 Frauen) durchgeführt. Einschlusskriterien waren ein Body Mass Index (BMI) >30, ausgeprägte subjektive Tagesmüdigkeit, sowie ein Apnoe/Hypopnoeindex (AHI) von mindestens 20. Von diesen drei Einschlusskriterien mussten mindestens zwei erfüllt sein. Ausschlusskriterien waren Änderungen der Lebensgewohnheiten während der Messdauer (zum Beispiel Urlaub, Krankschreibung oder Arbeitsverlust), psychische Erkrankungen, mobilitätseinschränkende Erkrankungen, Kiefer- und Rachenanomalien, schwere Herzinsuffizienz sowie Schichtarbeit. Die körperliche Aktivität der Patienten wurde zwei Wochen vor Beginn der CPAP-Therapie und vier Wochen nach Beginn der CPAP-Therapie gemessen. Die Aufzeichnung der Aktivität erfolgte über 24 Stunden. Es konnte nachgewiesen werden, das die Aktivität während des Tages signifikant zunimmt. Die Phasen der Inaktivität während des Schlafes nahm ebenfalls zu, ebenso die Schlafeffizienz. Die nächtliche Aktivität während der Nacht nahm ab, dieses Resultat war jedoch nicht signifikant. Der Punktwert auf der Epworth Sleepiness Scale als Ausdruck der subjektiv empfundenen Tagesmüdigkeit nahm ebenfalls ab. In der vorliegenden Studie konnte erstmalig bei Patienten mit obstruktiver Schlafapnoe mit der Methode der Aktimetrie eine Erhöhung der körperlichen Aktivität aufgrund der CPAP-Therapie nachgewiesen werden. Weitere Studien mit einer höheren Fallzahl stehen noch aus

UrMEL – mehr als ein Institutional Repository

Text zum Vortrag auf dem Bibliothekartag in Leipzi

Quality assurance in immunoassay performance – carbamazepine immunoassay format evaluation and application on surface and waste water

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Carbamazepine (CBZ) is one of the most frequently detected pharmaceuticals in water samples. For the determination of this anthropogenic marker, various immunoassay formats were tested and evaluated in order to identify the most suitable one. For these direct competitive assays, the analyte was labelled with the enzyme horseradish peroxidase (HRP) or alkaline phosphatase (AP), and seven substrates with specific detection properties were used. The quality criteria for the standard curves were fulfilled by all HRP assays and the chemiluminescence AP format. Furthermore, intra- and inter-plate coefficients of variation as a measure of the achievable precision were determined for the samples. The application of the AP assays to surface water was unfeasible due to CBZ concentrations below the quantifiable concentration range. Surface as well as waste water samples could be analyzed with the HRP assays. Here, the HRP assay employing the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine yielded the best results

Advantages of continuous genotype values over genotype classes for GWAS in higher polyploids: a comparative study in hexaploid chrysanthemum

Background: Association studies are an essential part of modern plant breeding, but are limited for polyploid crops. The increased number of possible genotype classes complicates the differentiation between them. Available methods are limited with respect to the ploidy level or data producing technologies. While genotype classification is an established noise reduction step in diploids, it gains complexity with increasing ploidy levels. Eventually, the errors produced by misclassifications exceed the benefits of genotype classes. Alternatively, continuous genotype values can be used for association analysis in higher polyploids. We associated continuous genotypes to three different traits and compared the results to the output of the genotype caller SuperMASSA. Linear, Bayesian and partial least squares regression were applied, to determine if the use of continuous genotypes is limited to a specific method. A disease, a flowering and a growth trait with h(2) of 0.51, 0.78 and 0.91 were associated with a hexaploid chrysanthemum genotypes. The data set consisted of 55,825 probes and 228 samples. Results: We were able to detect associating probes using continuous genotypes for multiple traits, using different regression methods. The identified probe sets were overlapping, but not identical between the methods. Baysian regression was the most restrictive method, resulting in ten probes for one trait and none for the others. Linear and partial least squares regression led to numerous associating probes. Association based on genotype classes resulted in similar values, but missed several significant probes. A simulation study was used to successfully validate the number of associating markers. Conclusions: Association of various phenotypic traits with continuous genotypes is successful with both uni- and multivariate regression methods. Genotype calling does not improve the association and shows no advantages in this study. Instead, use of continuous genotypes simplifies the analysis, saves computational time and results more potential markers

Efficient treatment of breast cancer xenografts with multifunctionalized iron oxide nanoparticles combining magnetic hyperthermia and anti-cancer drug delivery

Introduction: Tumor cells can effectively be killed by heat, e.g. by using magnetic hyperthermia. The main challenge in the field, however, is the generation of therapeutic temperatures selectively in the whole tumor region. We aimed to improve magnetic hyperthermia of breast cancer by using innovative nanoparticles which display a high heating potential and are functionalized with a cell internalization and a chemotherapeutic agent to increase cell death. Methods: The superparamagnetic iron oxide nanoparticles (MF66) were electrostatically functionalized with either Nucant multivalent pseudopeptide (N6L; MF66-N6L), doxorubicin (DOX; MF66-DOX) or both (MF66-N6LDOX). Their cytotoxic potential was assessed in a breast adenocarcinoma cell line MDA-MB-231. Therapeutic efficacy was analyzed on subcutaneous MDA-MB-231 tumor bearing female athymic nude mice. Results: All nanoparticle variants showed an excellent heating potential around 500 W/g Fe in the alternating magnetic field (AMF, conditions: H = 15.4 kA/m, f = 435 kHz). We could show a gradual inter- and intracellular release of the ligands, and nanoparticle uptake in cells was increased by the N6L functionalization. MF66-DOX and MF66-N6LDOX in combination with hyperthermia were more cytotoxic to breast cancer cells than the respective free ligands. We observed a substantial tumor growth inhibition (to 40% of the initial tumor volume, complete tumor regression in many cases) after intratumoral injection of the nanoparticles in vivo. The proliferative activity of the remaining tumor tissue was distinctly reduced. Conclusion: The therapeutic effects of breast cancer magnetic hyperthermia could be strongly enhanced by the combination of MF66 functionalized with N6L and DOX and magnetic hyperthermia. Our approach combines two ways of tumor cell killing (magnetic hyperthermia and chemotherapy) and represents a straightforward strategy for translation into the clinical practice when injecting nanoparticles intratumorallyThe described work was carried out within the project, Multifunctional Nanoparticles for the Selective Detection and Treatment of Cancer (Multifun), which is funded by the European Seventh Framework Program (FP7/2007-2013) under grant agreement number 262943. We thank Dr Vijay Patel and Liquids Research Ltd (Mentec, Deiniol Road, Bangor, Gwynedd, North Wales, UK,) for the supply of MF66 MNP. We gratefully acknowledge Julia Göring and Susann Burgold for technical assistance in carrying out in vivo experiments and Yvonne Ozegowski for animal handling. We thank Francisco J. Teran (Unidad Asociada de Nanobiotecnología CNB-CSIC & IMDEA Nanociencia, Madrid) for helpful discussions. AS and ALC acknowledge financial support from Ministerio de Economia y Competitividad (grants: SAF-15440 and BIO2012-34835) and IMDEA Nanociencia. This work was partially founded by the Comunidad de Madrid NANOFRONTMAG-CM project (S2013/MIT-2850) (IMDEA-Nanociencia)

Genetic variants associated with the root system architecture of oilseed rape (Brassica napus L.) under contrasting phosphate supply

Breeding crops with ideal root system architecture for efficient absorption of phosphorus is an important strategy to reduce the use of phosphate fertilizers. To investigate genetic variants leading to changes in root system architecture, 405 oilseed rape cultivars were genotyped with a 60K Brassica Infinium SNP array in low and high P environments. A total of 285 single-nucleotide polymorphisms were associated with root system architecture traits at varying phosphorus levels. Nine single-nucleotide polymorphisms corroborate a previous linkage analysis of root system architecture quantitative trait loci in the BnaTNDH population. One peak single-nucleotide polymorphism region on A3 was associated with all root system architecture traits and co-localized with a quantitative trait locus for primary root length at low phosphorus. Two more single-nucleotide polymorphism peaks on A5 for root dry weight at low phosphorus were detected in both growth systems and co-localized with a quantitative trait locus for the same trait. The candidate genes identified on A3 form a haplotype ‘BnA3Hap’, that will be important for understanding the phosphorus/root system interaction and for the incorporation into Brassica napus breeding programs

PERGOLA: fast and deterministic linkage mapping of polyploids

Background: A large share of agriculturally and horticulturally important plant species are polyploid. Linkage maps are used to locate associations between genes and traits by breeders and geneticists. Linkage map creation for polyploid species is not supported by standard tools. We want to overcome this limitation and validate our results with simulation studies. Results: We developed PERGOLA, a deterministic and heuristic method that addresses this problem. We show that it creates correct linkage groups, marker orders and distances for simulated and real datasets. We compare it to existing tools and demonstrate that it overcomes limitations in ploidy and outperforms them in computational time and mapping accuracy. We represent linkage maps as dendrograms and show that this has advantages in the comparison of different maps. Conclusions: PERGOLA can be used successfully to calculate linkage maps for diploid and polyploid species and outperforms existing tools