Opheim High School Commencement

Opheim High School Commencemen

Looking for a perfect match: multimodal combinations of Raman spectroscopy for biomedical applications

Raman spectroscopy has shown very promising results in medical diagnostics by providing label-free and highly specific molecular information of pathological tissue ex vivo and in vivo. Nevertheless, the high specificity of Raman spectroscopy comes at a price, i.e., low acquisition rate, no direct access to depth information, and limited sampling areas. However, a similar case regarding advantages and disadvantages can also be made for other highly regarded optical modalities, such as optical coherence tomography, autofluorescence imaging and fluorescence spectroscopy, fluorescence lifetime microscopy, second-harmonic generation, and others. While in these modalities the acquisition speed is significantly higher, they have no or only limited molecular specificity and are only sensitive to a small group of molecules. It can be safely stated that a single modality provides only a limited view on a specific aspect of a biological specimen and cannot assess the entire complexity of a sample. To solve this issue, multimodal optical systems, which combine different optical modalities tailored to a particular need, become more and more common in translational research and will be indispensable diagnostic tools in clinical pathology in the near future. These systems can assess different and partially complementary aspects of a sample and provide a distinct set of independent biomarkers. Here, we want to give an overview on the development of multimodal systems that use RS in combination with other optical modalities to improve the diagnostic performance

Der Albertverein zu Dresden: Internationaler Frauenverein und Hilfsorganisation

In der vorliegenden Arbeit richtet sich der Blick der Untersuchung auf die Rolle des Albertvereins zu Dresden und seine beiden wichtigsten Protagonistinnen: Königin Carola von Sachsen und Marie Simon. Die Geschichte des Albertvereins soll dabei mit Hilfe zeitgenössischer Überlieferungen ebenso untersucht werden wie das Wirken des Albertvereins im Kriegsfall und die Arbeit seiner Angehörigen in Friedenszeiten. Außerdem wird anhand ausgesuchter Quellen ein Blick auf die Ausbildung der Albertinerinnen zwischen 1870 und 1900 geworfen werden. Um den Einstieg in das Thema zu erleichtern, muss zunächst Grundlagenliteratur und der spezifische Forschungsstand zum Albertverein benannt werden. In den abschließenden Schlussbetrachtungen werden alle Untersuchungsergebnisse zusammengefasst und ein Resümee gezogen

Visualisierung der intrazellulären Aufnahme und des Metabolismus von Lipiden und Lipoproteinen mittels Raman-Spektroskopie

Kardiovaskuläre Erkrankungen sind die häufigsten natürlichen Todesursachen weltweit. Der Krankheitsprozess entwickelt sich oft schleichend über Jahrzehnte ohne Symptome und wirkt sich erst im höheren Alter aus. Im schlimmsten Fall kommt es zu einem Herzinfarkt oder Schlaganfall. Eine Früherkennung, zu einem Zeitpunkt an dem sich noch keine Symptome äußern, kann die Prognose und Therapie der Patienten deutlich verbessern. Die vorliegende Dissertation thematisiert die Visualisierung des Lipidmetabolismus von Makrophagen durch Raman-spektroskopische Bildgebungsverfahren. Die Interaktion zwischen Lipiden und Makrophagen spielt eine Schlüsselrolle in der Entstehung der Atherosklerose, die prominenteste unter den kardiovaskulären Erkrankungen und Hauptursache für Schlaganfälle und Herzinfarkte. Um Erkenntnisse über die Mechanismen der Atherogenese auf Einzelzellebene zu gewinnen, wurden Inkubationsstudien mit unterschiedlichen Aufnahmeprozessen sowie verschiedenen Fettsäuren und Triglyceriden durchgeführt. Eine umfangreiche Übersicht über den Albumin- und endozytotischen Lipoproteintransportweg konnte erstellt werden. Zudem wurde der Beitrag von Lipiden zur Schaumzellbildung von Makrophagen untersucht. Die Kombination von Raman-Spektroskopie mit stabiler Isotopenmarkierung durch Deuterium ermöglichte es die Aufnahmekinetik von Lipiden und deren Speicherprozess in intrazellulären Lipidtropfen auf Einzelzellebene zu erforschen. Die durch die Deuterierung nur geringfügigen Änderungen stellen ein leistungsfähiges Pendant zur etablierten Fluoreszenzmikroskopie dar

The influence of ambipolarity on plasma confinement and the performace of ECRIS

International audienceCharge diffusion in an ECRIS discharge is usually characterized by non ambipolar behavior. While the ions are transported to the radial walls, electrons are lost axially from the magnetic trap. Global neutrality is maintained via compensating currents in the conducting walls of the vacuum chamber. It is assumed that this behavior reduces the ion breeding times compared to a truly ambipolar plasma. We have carried out a series of dedicated experiments in which the ambipolarity of the ECRIS plasma was influenced by inserting special metal-dielectric structures (MD layers) into the plasma chamber of the Frankfurt 14GHz ECRIS. The measurements demonstrate the positive influence on the source performance when the ECR plasma is changed towards more ambipolar behavior

Imaging the invisible—Bioorthogonal Raman probes for imaging of cells and tissues

A revolutionary avenue for vibrational imaging with super-multiplexing capability can be seen in the recent development of Raman-active bioortogonal tags or labels. These tags and isotopic labels represent groups of chemically inert and small modifications, which can be introduced to any biomolecule of interest and then supplied to single cells or entire organisms. Recent developments in the field of spontaneous Raman spectroscopy and stimulated Raman spectroscopy in combination with targeted imaging of biomolecules within living systems are the main focus of this review. After having introduced common strategies for bioorthogonal labeling, we present applications thereof for profiling of resistance patterns in bacterial cells, investigations of pharmaceutical drug-cell interactions in eukaryotic cells and cancer diagnosis in whole tissue samples. Ultimately, this approach proves to be a flexible and robust tool for in vivo imaging on several length scales and provides comparable information as fluorescence-based imaging without the need of bulky fluorescent tags. © 2020 The Authors. Journal of Biophotonics published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

New methodology to process shifted excitation Raman difference spectroscopy data : a case study of pollen classification

Shifted excitation Raman difference spectroscopy (SERDS) is a background correction method for Raman spectroscopy. Here, the difference spectra were directly used as input for SERDS-based classification after an optimization procedure to correct for photobleaching of the autofluorescence. Further processing included a principal component analysis to compensate for the reduced signal to noise ratio of the difference spectra and subsequent classification by linear discriminant analysis. As a case study 6,028 Raman spectra of single pollen originating from plants of eight different genera and four different growth habits were automatically recorded at excitation wavelengths 784 and 786 nm using a high-throughput screening Raman system. Different pollen were distinguished according to their growth habit, i.e. tree versus non-tree with an accuracy of 95.9%. Furthermore, all pollen were separated according to their genus, providing also insight into similarities based on their families. Classification results were compared using spectra reconstructed from the differences and raw spectra after state-of-art baseline correction as input. Similar sensitivities, specificities, accuracies and precisions were found for all spectra with moderately background. Advantages of SERDS are expected in scenarios where Raman spectra are affected by variations due to detector etaloning, ambient light, and high background

Metal-dielectric structures for high charge state ion production in ECR plasma

Metal-dielectric (MD) structures of pure (99.999%) aluminum foils were previously studied [1, 2] in the National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest, Romania showing high secondary electron emission properties. Consequently, 26 mm diameter disks of such structures (Al-Al2O3) were tested in the ECR ion source of the Institut fuer Kernphysik (IKF) der J. W. Goethe Universitat, Frankfurt/Main, Germany, allowing to demonstrate their ability to significantly increase the ECRIS performances in what concerns the production of high charge state ions [3]. New experiments carried on in Bucharest on a special facility [2] stressed out the possibility to develop high emissive MD structures starting from lower purity (99%) aluminum foils. This result allowed us to make a special cylinder of 1 mm wall thickness electrolytically treated so that only the inner face had a MD structure layer while the external surface remained metallic. Such a cylinder introduced in the plasma chamber of an ECR ion source provides a high rate of secondary electrons that enhance the ECR plasma electron density while its metallic external surface provides a good electric and thermal contact with the plasma chamber. The tests performed with such a MD aluminum cylinder in the IKF 14 GHz ECR ion source, successfully demonstrated the possibility to shift the ECRIS output toward very high charge states (Ar16+) due to the strong secondary electron emission of the MD inner surface of the cylinder