Flash floods and their effects on the development in El-Qaá plain area in South Sinai, Egypt

The arid regions are dominated to a much larger degree than humid regions by major catastrophic events. Although most of Egypt lies within the great hot desert belt; it experiences especially in the north some torrential rainfall, which causes flash floods all over Sinai Peninsula. Flash floods in hot deserts are characterized by high velocity and low duration with a sharp discharge peak. Large sediment loads may be carried by floods threatening fields and settlements in the wadis and even people who are living there. The extreme spottiness of rare heavy rainfall, well known to desert people everywhere, precludes any efficient forecasting. Thus, although the limitation of data still reflects pre-satellite methods, chances of developing a warning system for floods in the desert seem remote. The relatively short flood-to-peak interval, a characteristic of desert floods, presents an additional impediment to the efficient use of warning systems. The present thesis contains introduction and five chapters, chapter one points out the physical settings of the study area. There are the geological settings such as outcrop lithology of the study area and the deposits. The alluvial deposits of Wadi Moreikh had been analyzed using OSL dating to know deposits and palaeoclimatic conditions. The chapter points out as well the stratigraphy and the structure geology containing main faults and folds. In addition, it manifests the pesent climate conditions such as temperature, humidity, wind and evaporation. Besides, it presents type of soils and natural vegetation cover of the study area using unsupervised classification for ETM+ images. Chapter two points out the morphometric analysis of the main basins and their drainage network in the study area. It is divided into three parts: The first part manifests the morphometric analysis of the drainage networks which had been extracted from two main sources, topographic maps and DEM images. Basins and drainage networks are considered as major influencing factors on the flash floods; Most of elements were studied which affect the network such as stream order, bifurcation ratio, stream lengths, stream frequency, drainage density, and drainage patterns. The second part of this chapter shows the morphometric analysis of basins such as area, dimensions, shape and surface. Whereas, the third part points the morphometric analysis of alluvial fans which form most of El-Qaá plain. Chapter three manifests the surface runoff through rainfall and losses analysis. The main subject in this chapter is rainfall which has been studied in detail; it is the main reason for runoff. Therefore, all rainfall characteristics are regarded here such as rainfall types, distribution, rainfall intensity, duration, frequency, and the relationship between rainfall and runoff. While the second part of this chapter concerns with water losses estimation by evaporation and infiltration which are together the main losses with direct effect on the high of runoff. Finally, chapter three points out the factors influencing desert runoff and runoff generation mechanism. Chapter four is concerned with assessment of flood hazard, it is important to estimate runoff and tocreate a map of affected areas. Therefore, the chapter consists of four main parts; first part manifests the runoff estimation, the different methods to estimate runoff and its variables such as runoff coefficient lag time, time of concentration, runoff volume, and frequency analysis of flash flood. While the second part points out the extreme event analysis. The third part shows the map of affected areas for every basin and the flash floods degrees. In this point, it has been depending on the DEM to extract the drainage networks and to determine the main streams which are normally more dangerous than others. Finally, part four presets the risk zone map of total study area which is of high inerest for planning activities. Chapter five as the last chapter concerns with flash flood Hazard mitigation. It consists of three main parts. First flood prediction and the method which can be used to predict and forecast the flood. The second part aims to determine the best methods which can be helpful to mitigate flood hazard in the arid zone and especially the study area. Whereas, the third part points out the development perspective for the study area indicating the suitable places in El-Qaá plain for using in economic activities.

Studies of pure rotational spectra of isolated molecules and molecular adducts using pulsed jet Fourier transform microwave (PJ-FTM) spectroscopy

This thesis focuses on studying molecular structure and internal dynamics by using pulsed jet Fourier transform microwave (PJ-FTMW) spectroscopy combined with theoretical calculations. Several kinds of interesting chemical problems are investigated by analyzing the MW spectra of the corresponding molecular systems. First, the general aspects of rotational spectroscopy are summarized, and then the basic theory on molecular rotation and experimental method are described briefly. ab initio and density function theory (DFT) calculations that used in this thesis to assist the assignment of rotational spectrum are also included. From chapter 3 to chapter 8, several molecular systems concerning different kind of general chemical problems are presented. In chapter 3, the conformation and internal motions of dimethyl sulfate are reported. The internal rotations of the two methyl groups split each rotational transition into several components line, allowing for the determination of accurate values of the V3 barrier height to internal rotation and of the orientation of the methyl groups with respect to the principal axis system. In chapter 4 and 5, the results concerning two kinds of carboxylic acid bi-molecules, formed via two strong hydrogen bonds, are presented. This kind of adduct is interesting also because a double proton transfer can easily take place, connecting either two equivalent or two non-equivalent molecular conformations. Chapter 6 concerns a medium strong hydrogen bonded molecular complex of alcohol with ether. The dimer of ethanol-dimethylether was chosen as the model system for this purpose. Chapter 7 focuses on weak halogen…H hydrogen bond interaction. The nature of O-H…F and C-H…Cl interaction has been discussed through analyzing the rotational spectra of CH3CHClF/H2O. In chapter 8, two molecular complexes concerning the halogen bond interaction are presented.

Elaborazione di un algoritmo di pianificazione di ricostruzioni del cavo orale, dell'orofaringe, della mandibola.

1.Ricostruzione mandibolare La ricostruzione mandibolare è comunemente eseguita utilizzando un lembo libero perone. Il metodo convenzionale (indiretto) di Computer Aided Design e Computer Aided Manifacturing prevede il modellamento manuale preoperatorio di una placca di osteosintesi standard su un modello stereolitografico della mandibola. Un metodo innovativo CAD CAM diretto comprende 3 fasi: 1) pianificazione virtuale 2) computer aided design della dima di taglio mandibolari, della dima di taglio del perone e della placca di osteosintesi e 3) Computer Aided Manufacturing dei 3 dispositivi chirurgici personalizzati. 7 ricostruzioni mandibolari sono state effettuate con il metodo diretto. I risultati raggiunti e le modalità di pianificazione sono descritte e discusse. La progettazione assistita da computer e la tecnica di fabbricazione assistita da computer facilita un'accurata ricostruzione mandibolare ed apporta un miglioramento statisticamente significativo rispetto al metodo convenzionale. 2. Cavità orale e orofaringe Un metodo ricostruttivo standard per la cavità orale e l'orofaringe viene descritto. 163 pazienti affetti da cancro della cavità orale e dell'orofaringe, sono stati trattati dal 1992 al 2012 eseguendo un totale di 175 lembi liberi. La strategia chirurgica è descritta in termini di scelta del lembo, modellamento ed insetting. I modelli bidimensionali sono utilizzati per pianificare una ricostruzione tridimensionale con il miglior risultato funzionale ed estetico. I modelli, la scelta del lembo e l' insetting sono descritti per ogni regione. Complicazioni e risultati funzionali sono stati valutati sistematicamente. I risultati hanno mostrato un buon recupero funzionale con le tecniche ricostruttive descritte. Viene proposto un algoritmo ricostruttivo basato su template standard.

Water-soluble organic compounds in air particulate matter analyzed by HPLC-DAD-MS and HPLC-MS/MS: abundance, sources and transformation of carboxylic acids, nitrophenols and nitrated proteins

Wasserlösliche organische Verbindungen (WSOCs) sind Hauptbestandteile atmosphärischer Aerosole, die bis zu ~ 50% und mehr der organischen Aerosolfraktion ausmachen. Sie können die optischen Eigenschaften sowie die Hygroskopizität von Aerosolpartikeln und damit deren Auswirkungen auf das Klima beeinflussen. Darüber hinaus können sie zur Toxizität und Allergenität atmosphärischer Aerosole beitragen.In dieser Studie wurde Hochleistungsflüssigchromatographie gekoppelt mit optischen Diodenarraydetektion und Massenspektrometrie (HPLC-DAD-MS und HPLC-MS/MS) angewandt, um WSOCs zu analysieren, die für verschiedene Aerosolquellen und -prozesse charakteristisch sind. Niedermolekulare Carbonsäuren und Nitrophenole wurden als Indikatoren für die Verbrennung fossiler Brennstoffe und die Entstehung sowie Alterung sekundärer organischer Aerosole (SOA) aus biogenen Vorläufern untersucht. Protein-Makromoleküle wurden mit Blick auf den Einfluss von Luftverschmutzung und Nitrierungsreaktionen auf die Allergenität primärer biologischer Aerosolpartikel – wie Pollen und Pilzsporen – untersucht.rnFilterproben von Grob- und Feinstaubwurden über ein Jahr hinweg gesammelt und auf folgende WSOCs untersucht: die Pinen-Oxidationsprodukte Pinsäure, Pinonsäure und 3-Methyl-1,2,3-Butantricarbonsäure (3-MBTCA) sowie eine Vielzahl anderer Dicarbonsäuren und Nitrophenole. Saisonale Schwankungen und andere charakteristische Merkmale werden mit Blick auf Aerosolquellen und -senken im Vergleich zu Daten anderen Studien und Regionen diskutiert. Die Verhätlnisse von Adipinsäure und Phthalsäure zu Azelainsäure deuten darauf hin, dass die untersuchten Aerosolproben hauptsächlich durch biogene Quellen beeinflusst werden. Eine ausgeprägte Arrhenius-artige Korrelation wurde zwischen der 3-MBTCA-¬Konzentration und der inversen Temperatur beobachtet (R2 = 0.79, Ea = 126±10 kJ mol-1, Temperaturbereich 275–300 K). Modellrechnungen zeigen, dass die Temperaturabhängigkeit auf eine Steigerung der photochemischen Produktionsraten von 3-MBTCA durch erhöhte OH-Radikal-Konzentrationen bei erhöhten Temperaturen zurückgeführt werden kann. Im Vergleich zur chemischen Reaktionskinetik scheint der Einfluss von Gas-Partikel-Partitionierungseffekten nur eine untergeordnete Rolle zu spielen. Die Ergebnisse zeigen, dass die OH-initiierte Oxidation von Pinosäure der geschwindigkeitsbestimmende Schritt der Bildung von 3-MBTCA ist. 3-MBTCA erscheint somit als Indikator für die chemische Alterung von biogener sekundärer organischer Aerosole (SOA) durch OH-Radikale geeignet. Eine Arrhenius-artige Temperaturabhängigkeit wurde auch für Pinäure beobachtet und kann durch die Temperaturabhängigkeit der biogenen Pinen-Emissionen als geschwindigkeitsbestimmender Schritt der Pinsäure-Bildung erklärt werden (R2 = 0.60, Ea = 84±9 kJ mol-1).rn rnFür die Untersuchung von Proteinnitrierungreaktionen wurde nitrierte Protein¬standards durch Flüssigphasenreaktion von Rinderserumalbumin (BSA) und Ovalbumin (OVA) mit Tetranitromethan (TNM) synthetisiert.Proteinnitrierung erfolgt vorrangig an den Resten der aromatischen Aminosäure Tyrosin auf, und mittels UV-Vis-Photometrie wurde der Proteinnnitrierungsgrad (ND) bestimmt. Dieser ist definiert als Verhältnis der mittleren Anzahl von Nitrotyrosinresten zur Tyrosinrest-Gesamtzahl in den Proteinmolekülen. BSA und OVA zeigten verschiedene Relationen zwischen ND und TNM/Tyrosin-Verhältnis im Reaktionsgemisch, was vermutlich auf Unterschiede in den Löslichkeiten und den molekularen Strukturen der beiden Proteine zurück zu führen ist.rnDie Nitrierung von BSA und OVA durch Exposition mit einem Gasgemisch aus Stickstoffdioxid (NO2) und Ozon (O3) wurde mit einer neu entwickelten HPLC-DAD-¬Analysemethode untersucht. Diese einfache und robuste Methode erlaubt die Bestimmung des ND ohne Hydrolyse oder Verdau der untersuchten Proteine und ernöglicht somit eine effiziente Untersuchung der Kinetik von Protein¬nitrierungs-Reaktionen. Für eine detaillierte Produktstudien wurden die nitrierten Proteine enzymatisch verdaut, und die erhaltenen Oligopeptide wurden mittels HPLC-MS/MS und Datenbankabgleich mit hoher Sequenzübereinstimmung analysiert. Die Nitrierungsgrade individueller Nitrotyrosin-Reste (NDY) korrelierten gut mit dem Gesamt-Proteinnitrierungsgrad (ND), und unterschiedliche Verhältnisse von NDY zu ND geben Aufschluss über die Regioselektivität der Reaktion. Die Nitrierungmuster von BSA und OVA nach Beahndlung mit TNM deuten darauf hin, dass die Nachbarschaft eines negativ geladenen Aminosäurerestes die Tyrosinnitrierung fördert. Die Behandlung von BSA durch NO2 und O3 führte zu anderend Nitrierungemustern als die Behandlung mit TNM, was darauf hindeutet, dass die Regioselektivität der Nitrierung vom Nitrierungsmittel abhängt. Es zeigt sich jedoch, dass Tyrosinreste in Loop-Strukturen bevorzugt und unabhängig vom Reagens nitriert werden.Die Methoden und Ergebnisse dieser Studie bilden eine Grundlage für weitere, detaillierte Untersuchungen der Reaktionskinetik sowie der Produkte und Mechanismen von Proteinnitrierungreaktionen. Sie sollen helfen, die Zusammenhänge zwischen verkehrsbedingten Luftschadstoffen wie Stickoxiden und Ozon und der Allergenität von Luftstaub aufzuklären.rn

Automated Analysis Methods for the Assessment of Bicycle Infrastructure and Demand

A first phase of the research activity has been related to the study of the state of art of the infrastructures for cycling, bicycle use and methods for evaluation. In this part, the candidate has studied the "bicycle system" in countries with high bicycle use and in particular in the Netherlands. Has been carried out an evaluation of the questionnaires of the survey conducted within the European project BICY on mobility in general in 13 cities of the participating countries. The questionnaire was designed, tested and implemented, and was later validated by a test in Bologna. The results were corrected with information on demographic situation and compared with official data. The cycling infrastructure analysis was conducted on the basis of information from the OpenStreetMap database. The activity consisted in programming algorithms in Python that allow to extract data from the database infrastructure for a region, to sort and filter cycling infrastructure calculating some attributes, such as the length of the arcs paths. The results obtained were compared with official data where available. The structure of the thesis is as follows: 1. Introduction: description of the state of cycling in several advanced countries, description of methods of analysis and their importance to implement appropriate policies for cycling. Supply and demand of bicycle infrastructures. 2. Survey on mobility: it gives details of the investigation developed and the method of evaluation. The results obtained are presented and compared with official data. 3. Analysis cycling infrastructure based on information from the database of OpenStreetMap: describes the methods and algorithms developed during the PhD. The results obtained by the algorithms are compared with official data. 4. Discussion: The above results are discussed and compared. In particular the cycle demand is compared with the length of cycle networks within a city. 5. Conclusions

A new double laser pulse pumping scheme for transient collisionally excited plasma soft X-ray lasers

Within this thesis a new double laser pulse pumping scheme for plasma-based, transient collisionally excited soft x-ray lasers (SXRL) was developed, characterized and utilized for applications. SXRL operations from ~50 up to ~200 electron volt were demonstrated applying this concept. As a central technical tool, a special Mach-Zehnder interferometer in the chirped pulse amplification (CPA) laser front-end was developed for the generation of fully controllable double-pulses to optimally pump SXRLs.rnThis Mach-Zehnder device is fully controllable and enables the creation of two CPA pulses of different pulse duration and variable energy balance with an adjustable time delay. Besides the SXRL pumping, the double-pulse configuration was applied to determine the B-integral in the CPA laser system by amplifying short pulse replica in the system, followed by an analysis in the time domain. The measurement of B-integral values in the 0.1 to 1.5 radian range, only limited by the reachable laser parameters, proved to be a promising tool to characterize nonlinear effects in the CPA laser systems.rnContributing to the issue of SXRL pumping, the double-pulse was configured to optimally produce the gain medium of the SXRL amplification. The focusing geometry of the two collinear pulses under the same grazing incidence angle on the target, significantly improved the generation of the active plasma medium. On one hand the effect was induced by the intrinsically guaranteed exact overlap of the two pulses on the target, and on the other hand by the grazing incidence pre-pulse plasma generation, which allows for a SXRL operation at higher electron densities, enabling higher gain in longer wavelength SXRLs and higher efficiency at shorter wavelength SXRLs. The observation of gain enhancement was confirmed by plasma hydrodynamic simulations.rnThe first introduction of double short-pulse single-beam grazing incidence pumping for SXRL pumping below 20 nanometer at the laser facility PHELIX in Darmstadt (Germany), resulted in a reliable operation of a nickel-like palladium SXRL at 14.7 nanometer with a pump energy threshold strongly reduced to less than 500 millijoule. With the adaptation of the concept, namely double-pulse single-beam grazing incidence pumping (DGRIP) and the transfer of this technology to the laser facility LASERIX in Palaiseau (France), improved efficiency and stability of table-top high-repetition soft x-ray lasers in the wavelength region below 20 nanometer was demonstrated. With a total pump laser energy below 1 joule the target, 2 mircojoule of nickel-like molybdenum soft x-ray laser emission at 18.9 nanometer was obtained at 10 hertz repetition rate, proving the attractiveness for high average power operation. An easy and rapid alignment procedure fulfilled the requirements for a sophisticated installation, and the highly stable output satisfied the need for a reliable strong SXRL source. The qualities of the DGRIP scheme were confirmed in an irradiation operation on user samples with over 50.000 shots corresponding to a deposited energy of ~ 50 millijoule.rnThe generation of double-pulses with high energies up to ~120 joule enabled the transfer to shorter wavelength SXRL operation at the laser facility PHELIX. The application of DGRIP proved to be a simple and efficient method for the generation of soft x-ray lasers below 10 nanometer. Nickel-like samarium soft x-ray lasing at 7.3 nanometer was achieved at a low total pump energy threshold of 36 joule, which confirmed the suitability of the applied pumping scheme. A reliable and stable SXRL operation was demonstrated, due to the single-beam pumping geometry despite the large optical apertures. The soft x-ray lasing of nickel-like samarium was an important milestone for the feasibility of applying the pumping scheme also for higher pumping pulse energies, which are necessary to obtain soft x-ray laser wavelengths in the water window. The reduction of the total pump energy below 40 joule for 7.3 nanometer short wavelength lasing now fulfilled the requirement for the installation at the high-repetition rate operation laser facility LASERIX.rn

Development of new molecular methods for the diagnosis and the study of viral diseases of fish

The increase in aquaculture operations worldwide has provided new opportunities for the transmission of aquatic viruses. The occurrence of viral diseases remains a significant limiting factor in aquaculture production and for the sustainability. The ability to identify quickly the presence/absence of a pathogenic organism in fish would have significant advantages for the aquaculture systems. Several molecular methods have found successful application in fish pathology both for confirmatory diagnosis of overt diseases and for detection of asymptomatic infections. However, a lot of different variants occur among fish host species and virus strains and consequently specific methods need to be developed and optimized for each pathogen and often also for each host species. The first chapter of this PhD thesis presents a complete description of the major viruses that infect fish and provides a relevant information regarding the most common methods and emerging technologies for the molecular diagnosis of viral diseases of fish. The development and application of a real time PCR assay for the detection and quantification of lymphocystivirus was described in the second chapter. It showed to be highly sensitive, specific, reproducible and versatile for the detection and quantitation of lymphocystivirus. The use of this technique can find multiple application such as asymptomatic carrier detection or pathogenesis studies of different LCDV strains. The third chapter, a multiplex RT-PCR (mRT-PCR) assay was developed for the simultaneous detection of viral haemorrhagic septicaemia (VHS), infectious haematopoietic necrosis (IHN), infectious pancreatic necrosis (IPN) and sleeping disease (SD) in a single assay. This method was able to efficiently detect the viral RNA in tissue samples, showing the presence of single infections and co-infections in rainbow trout samples. The mRT-PCR method was revealed to be an accurate and fast method to support traditional diagnostic techniques in the diagnosis of major viral diseases of rainbow trout.

Accretion of Mass and Angular Momentum onto The Discs of Spiral Galaxies

In this Thesis, we study the accretion of mass and angular momentum onto the disc of spiral galaxies from a global and a local perspective and comparing theory predictions with several observational data. First, we propose a method to measure the specific mass and radial growth rates of stellar discs, based on their star formation rate density profiles and we apply it to a sample of nearby spiral galaxies. We find a positive radial growth rate for almost all galaxies in our sample. Our galaxies grow in size, on average, at one third of the rate at which they grow in mass. Our results are in agreement with theoretical expectations if known scaling relations of disc galaxies are not evolving with time. We also propose a novel method to reconstruct accretion profiles and the local angular momentum of the accreting material from the observed structural and chemical properties of spiral galaxies. Applied to the Milky Way and to one external galaxy, our analysis indicates that accretion occurs at relatively large radii and has a local deficit of angular momentum with respect to the disc. Finally, we show how structure and kinematics of hot gaseous coronae, which are believed to be the source of mass and angular momentum of massive spiral galaxies, can be reconstructed from their angular momentum and entropy distributions. We find that isothermal models with cosmologically motivated angular momentum distributions are compatible with several independent observational constraints. We also consider more complex baroclinic equilibria: we describe a new parametrization for these states, a new self-similar family of solution and a method for reconstructing structure and kinematics from the joint angular momentum/entropy distribution.

Improvements in production and storage of HP-129 Xe

Seit seiner Entdeckung im Jahre 1978 wurden für hyperpolarisiertes (HP) 129Xe zahlreiche Anwendungen gefunden. Aufgrund seiner hohen Verstärkung von NMR-Signalen wird es dabei typischerweise für Tracer- und Oberflächenstudien verwendet. Im gasförmigen Zustand ist es ein interessantes, klinisches Kontrastmittel, welches für dynamische Lungen MRT genutzt oder auch in Blut oder lipophilen Flüssigkeiten gelöst werden kann. Weiterhin findet HP-Xe auch in der Grundlagenphysik in He-Xe Co-Magnetometern Verwendung, mit welchen z. B. das elektrische Dipolmoment von Xe bestimmt werden soll, oder es dient zur Überprüfung auf Lorentz-Invarianzen. Alle diese Anwendungen profitieren von einem hohen Polarisationsgrad (PXe), um hohe Signalstärken und lange Lagerzeiten zu erreichen. rnIn dieser Arbeit wurden zwei mobile Xe-Polarisatoren konstruiert: einer für Experimente in der Grundlagenphysik mit einer Produktionsrate von 400 mbar·l/h mit PXe ≈ 5%. Der zweite Xe-Polarisator wurde für medizinische Anwendungen entwickelt und soll 1 bar l/h mit PXe > 20% erzeugen. Der letztere wurde noch nicht getestet. Die Arbeitsbedingungen des Xe-Polarisators für Grundlagenphysik (Strömung des Gasgemischs, Temperatur, Druck und Konzentration von Xe) wurden variiert, um einen höchstmöglichen Polarisationsgrad zu erzielen. Die maximale Polarisation von 5,6 % wurde bei Verwendung eine Gasmischung von 1% Xe bei einem Durchfluss von 200 ml/min, einer Temperatur von 150°C und einem Gesamtdruck von 4 bar erreicht. rnWeiterhin muss HP-Xe auch effizient gelagert werden, um Polarisationsverluste zu minimieren. Das ist besonders für solche Anwendungen notwendig, welche an einem entfernten Standort durchgeführt werden sollen oder auch wenn lange Spinkohärenzeiten gefordert sind, z.B. bei He-Xe Co-Magnetometern. rnHierbei bestand bisher die größte Schwierigkeit darin, die Reproduzierbarkeit der gemessenen Lagerzeiten sicherzustellen. In dieser Arbeit konnte die Spin-Gitter-Relaxationszeit (T1) von HP-129Xe in unbeschichteten, Rb-freien, sphärischen Zellen aus Aluminiumsilikatglas (GE-180) signifikant verbessert werden. Die T1–Zeit wurde in einem selbstgebauten Niederfeld-NMR-System (2 mT) sowohl für reines HP-Xe als auch für HP-Xe in Mischungen mit N2, SF6 und CO2 bestimmt. Bei diesen Experimenten wurde die maximale Relaxationszeit für reines Xe (85% 129 Xe) bei (4,6 ± 0,1) h festgestellt. Dabei lagen die typischen Wand-Relaxationszeiten bei ca. 18 h für Glaszellen mit einem Durchmesser von 10 cm. Des Weiteren wurde herausgefunden, dass CO2 eine unerwartet hohe Effizienz bei der Verkürzung der Lebensdauer der Xe-Xe Moleküle zeigte und somit zu einer deutlichen Verlängerung der gesamten T1-Zeit genutzt werden kann. rnIm Verlauf vieler Experimente wurde durch wiederholte Messungen mit der gleichen Zelle, ein "Alterungsprozess“ bei der Wandrelaxation identifiziert und untersucht. Dieser Effekt könnte leicht rückgängig gemacht werden, indem die anfängliche Reinigungsprozedur wiederholt wurde. Auf diese Weise kann eine konstante Wandrelaxation sichergestellt werden, durch die sehr reproduzierbare T1-Messungen möglich werden. rnSchließlich wurde die maximale Relaxationszeit für HP-Xe mit natürlicher Häufigkeit in Mischungen mit SF6 bestimmt. Überraschenderweise war dieser Wert um ca. 75% niedriger als der Wert für Xenon, das zu 85% mit 129Xe angereichert war. Dieser Effekt wurde durch drei unabhängige Experimente bestätigt, da er nicht von der bestehenden Theorie der Xe-Relaxation ableitbar ist. rnDie Polarisation von HP-Xe, PXe, wird normalerweise durch den Vergleich der NMR-Signale des HP-Xe mit einer thermischen polarisierten Probe (z. B. 1H2O oder Xe) bestimmt. Dabei beinhaltet der Vergleich unterschiedlicher Messungen an verschiedenen Proben (unterschiedlicher Druck, Signalintensität und Messverfahren) viele experimentelle Unsicherheiten, welche sich oft nicht leicht bestimmen lassen. Eine einfache, genaue und kostengünstige Methode zur Bestimmung von PXe durch eine direkte Messung der makroskopischen Magnetisierung in einem statischen Magnetfeld vermeidet alle diese Unsicherheiten. Dieses Verfahren kann Polarisationen von > 2 % mit einer Genauigkeit von maximal 10% fast ohne Polarisationsverlust bestimmen. Zusätzlich kann diese Methode ohne weitere Änderungen auch für Bestimmungen des Polarisationsgrades anderer HP-Gase verwendet werden.rn

Apical surgery of a maxillary molar creating a maxillary sinus window using ultrasonics: a clinical case

AIM: To describe a method of carrying out apical surgery of a maxillary molar using ultrasonics to create a lateral sinus window into the maxillary sinus and an endoscope to enhance visibility during surgery. SUMMARY: A 37-year-old female patient presented with tenderness to percussion of the maxillary second right molar. Root canal treatment had been undertaken, and the tooth restored with a metal-ceramic crown. Radiological examination revealed an apical radiolucency in close proximity to the maxillary sinus. Apical surgery of the molar was performed through the maxillary sinus, using ultrasonics for the osteotomy, creating a window in the lateral wall of the maxillary sinus. During surgery, the lining of the sinus was exposed and elevated without perforation. The root-end was resected using a round tungsten carbide drill, and the root-end cavity was prepared with ultrasonic retrotips. Root-end filling was accomplished with MTA(®) . An endoscope was used to examine the cut root face, the prepared cavity and the root-end filling. No intraoperative or postoperative complications were observed. At the 12-month follow-up, the tooth had no clinical signs or symptoms, and the radiograph demonstrated progressing resolution of the radiolucency. KEY LEARNING POINTS: When conventional root canal retreatment cannot be performed or has failed, apical surgery may be considered, even in maxillary molars with roots in close proximity to the maxillary sinus. Ultrasonic sinus window preparation allows more control and can minimize perforation of the sinus membrane when compared with conventional rotary drilling techniques. The endoscope enhances visibility during endodontic surgery, thus improving the quality of the case.

Adopting a family approach to theory and practice: measuring distress in cancer patient-partner dyads with the distress thermometer

Objective: Significant others are central to patients' experience and management of their cancer illness. Building on our validation of the Distress Thermometer (DT) for family members, this investigation examines individual and collective distress in a sample of cancer patients and their matched partners, accounting for the aspects of gender and role. Method: Questionnaires including the DT were completed by a heterogeneous sample of 224 couples taking part in a multisite study. Results: Our investigation showed that male patients (34.2%), female patients (31.9%), and male partners (29.1%) exhibited very similar levels of distress, while female partners (50.5%) exhibited much higher levels of distress according to the DT. At the dyad level just over half the total sample contained at least one individual reporting significant levels of distress. Among dyads with at least one distressed person, the proportion of dyads where both individuals reported distress was greatest (23.6%). Gender and role analyses revealed that males and females were not equally distributed among the four categories of dyads (i.e. dyads with no distress; dyads where solely the patient or dyads where solely the partner is distressed; dyads where both are distressed). Conclusion: A remarkable number of dyads reported distress in one or both partners. Diverse patterns of distress within dyads suggest varying risks of psychosocial strain. Screening patients' partners in addition to patients themselves may enable earlier identification of risk settings. The support offered to either member of such dyads should account for their role- and gender-specific needs. Copyright © 2010 John Wiley ; Sons, Ltd.

Operator variability using different polishing methods and surface geometry of a nanohybrid composite

This study evaluated the operator variability of different finishing and polishing techniques. After placing 120 composite restorations (Tetric EvoCeram) in plexiglassmolds, the surface of the specimens was roughened in a standardized manner. Twelve operators with different experience levels polished the specimens using the following finishing/polishing procedures: method 1 (40 ?m diamond [40D], 15 ?m diamond [15D], 42 ?m silicon carbide polisher [42S], 6 ?m silicon carbide polisher [6S] and Occlubrush [O]); method 2 (40D, 42S, 6S and O); method 3 (40D, 42S, 6S and PoGo); method 4 (40D, 42S and PoGo) and method 5 (40D, 42S and O). The mean surface roughness (Ra) was measured with a profilometer. Differences between the methods were analyzed with non-parametric ANOVA and pairwise Wilcoxon signed rank tests (?=0.05). All the restorations were qualitatively assessed using SEM. Methods 3 and 4 showed the best polishing results and method 5 demonstrated the poorest. Method 5 was also most dependent on the skills of the operator. Except for method 5, all of the tested procedures reached a clinically acceptable surface polish of Ra?0.2 ?m. Polishing procedures can be simplified without increasing variability between operators and without jeopardizing polishing results.

Paediatric traffic accident and obstructive sleep apnoea by antrochoanal polyps: case report and literature review

Antrochoanal polyps are hyperplasias of the nasal mucosa, which have their origin in the maxillary sinus and extend through the nasal cavity and the choanae into the naso- and oropharynx. In children antrochoanal polyps represent one of the more frequent manifestations of paediatric nasal polyposis. Most studies on antrochoanal polyps in children report only on nasal obstruction, hyponasal speech and snoring, which are also encountered in the most common cause of obstructive sleep apnoea syndrome; i.e. adenoid or tonsillar hyperplasia. Only very few studies report on additional health hazards by antrochoanal polyps ranging from obstructive sleep apnoea syndrome to swallowing disorders and cachexia. We present the case of an 8 year old girl with a bicycle accident caused by excessive daytime sleepiness and obstructive sleep apnoea syndrome due to an extensive antrochoanal polyp. After a transnasal polypectomy and meatotomy type II the obstructive sleep apnoea and day time sleepiness resolved completely. Awareness of this additional health hazard is important and correct evaluation and timely diagnosis of a potential antrochoanal polyp is mandatory because minimally invasive rhinosurgery is highly curative in preventing further impending problems.

Combined bone and soft-tissue augmentation surgery in temporo-orbital contour reconstruction

Temporal hollowing due to temporal muscle atrophy after standard skull base surgery is common. Various techniques have been previously described to correct the disfiguring defect. Most often reconstruction is performed using freehand molded polymethylmethacrylate cement. This method and material are insufficient in terms of aesthetic results and implant characteristics. We herein propose reconstruction of such defects with a polyetheretherketone (PEEK)-based patient-specific implant (PSI) including soft-tissue augmentation to preserve normal facial topography. We describe a patient who presented with a large temporo-orbital hemangioma that had been repaired with polymethylmethacrylate 25 years earlier. Because of a toxic skin atrophy fistula, followed by infection and meningitis, this initial implant had to be removed. The large, disfiguring temporo-orbital defect was reconstructed with a PEEK-based PSI. The lateral orbital wall and the temporal muscle atrophy were augmented with computer-aided design and surface modeling techniques. The operative procedure to implant and adopt the reconstructed PEEK-based PSI was simple, and an excellent cosmetic outcome was achieved. The postoperative clinical course was uneventful over a 5-year follow-up period. Polyetheretherketone-based combined bony and soft contour remodeling is a feasible and effective method for cranioplasty including combined bone and soft-tissue reconstruction of temporo-orbital defects. Manual reconstruction of this cosmetically delicate area carries an exceptional risk of disfiguring results. Augmentation surgery in this anatomic location needs accurate PSIs to achieve satisfactory cosmetic results. The cosmetic outcome achieved in this case is superior compared with previously reported techniques.

Therapy options and long-term results of sinonasal malignancies

Nasal and paranasal sinus malignancies are rare. The most common lesions are located in the nasal cavity and the maxillary sinus, although they also occur in the ethmoid, sphenoid and frontal sinuses. Treatment often combines surgery, radiotherapy and chemotherapy. Endoscopic surgical approaches are increasingly used in order to reduce the morbidity associated with standard open resection. The aim of our study was to analyse the long-term treatment results of sinonasal malignancies (SNM), with a special focus on surgical approaches.