Design, synthesis and Chemical-physical characterization of photocatalytic inorganic nanocrystals for technological applications

This work was based on the synthesis and characterization of innovative crystals for biomedical and technological applications. Different types of syntheses were developed in order to obtain crystals with high photocatalytic properties. A hydrothermal synthesis was also processed to correlate the chemical-physical characteristics with synthesis parameters obtaining synthesis of nanoparticles of titanium dioxide with different morphology, size and crystalline phase depending on the variation of the synthesis parameters. Also a synthesis in water at 80 °C temperature and low pressure was developed from which anatase containing a small percentage of brookite nanoparticles were obtained, presenting a high photocatalytic activity. These particles have been used to obtain the microcrystals formed by an inorganic core of hydroxyapatite surface covered by TiO2 nanoparticles. Micrometer material with higher photocatalytic has been produced. The same nanoparticles have been functionalized with resorcinol oxidized in order to increase the photocatalytic efficiency. Photodegradation test results have confirmed this increase. Finally, synthetic nanoparticles with a waterless synthesis using formic acid and octanol, through esterification "in situ" were synthesized. Nanoparticles superficially covered by carboxylic residues able to bind a wide range of molecules to obtain further photocatalytic properties were obtained.

Integrated analysis and design of optimization and up-scaling of inductively coupled plasma synthesis of nanoparticles

This study is focused on radio-frequency inductively coupled thermal plasma (ICP) synthesis of nanoparticles, combining experimental and modelling approaches towards process optimization and industrial scale-up, in the framework of the FP7-NMP SIMBA European project (Scaling-up of ICP technology for continuous production of Metallic nanopowders for Battery Applications). First the state of the art of nanoparticle production through conventional and plasma routes is summarized, then results for the characterization of the plasma source and on the investigation of the nanoparticle synthesis phenomenon, aiming at highlighting fundamental process parameters while adopting a design oriented modelling approach, are presented. In particular, an energy balance of the torch and of the reaction chamber, employing a calorimetric method, is presented, while results for three- and two-dimensional modelling of an ICP system are compared with calorimetric and enthalpy probe measurements to validate the temperature field predicted by the model and used to characterize the ICP system under powder-free conditions. Moreover, results from the modeling of critical phases of ICP synthesis process, such as precursor evaporation, vapour conversion in nanoparticles and nanoparticle growth, are presented, with the aim of providing useful insights both for the design and optimization of the process and on the underlying physical phenomena. Indeed, precursor evaporation, one of the phases holding the highest impact on industrial feasibility of the process, is discussed; by employing models to describe particle trajectories and thermal histories, adapted from the ones originally developed for other plasma technologies or applications, such as DC non-transferred arc torches and powder spherodization, the evaporation of micro-sized Si solid precursor in a laboratory scale ICP system is investigated. Finally, a discussion on the role of thermo-fluid dynamic fields on nano-particle formation is presented, as well as a study on the effect of the reaction chamber geometry on produced nanoparticle characteristics and process yield.

Non-Linear Analysis and Design of Synchronous Bearingless Multiphase Permanent Magnet Machines and Drives

A two-dimensional model to analyze the distribution of magnetic fields in the airgap of a PM electrical machines is studied. A numerical algorithm for non-linear magnetic analysis of multiphase surface-mounted PM machines with semi-closed slots is developed, based on the equivalent magnetic circuit method. By using a modular structure geometry, whose the basic element can be duplicated, it allows to design whatever typology of windings distribution. In comparison to a FEA, permits a reduction in computing time and to directly changing the values of the parameters in a user interface, without re-designing the model. Output torque and radial forces acting on the moving part of the machine can be calculated. In addition, an analytical model for radial forces calculation in multiphase bearingless Surface-Mounted Permanent Magnet Synchronous Motors (SPMSM) is presented. It allows to predict amplitude and direction of the force, depending on the values of torque current, of levitation current and of rotor position. It is based on the space vectors method, letting the analysis of the machine also during transients. The calculations are conducted by developing the analytical functions in Fourier series, taking all the possible interactions between stator and rotor mmf harmonic components into account and allowing to analyze the effects of electrical and geometrical quantities of the machine, being parametrized. The model is implemented in the design of a control system for bearingless machines, as an accurate electromagnetic model integrated in a three-dimensional mechanical model, where one end of the motor shaft is constrained to simulate the presence of a mechanical bearing, while the other is free, only supported by the radial forces developed in the interactions between magnetic fields, to realize a bearingless system with three degrees of freedom. The complete model represents the design of the experimental system to be realized in the laboratory.

Einflüsse von Folienqualität und Blister-Design auf die Funktionalität von Blisterverpackungen

Ziel dieser Arbeit ist die Untersuchung der Einflüsse von Blister-Design und Folienqualität auf die Funktionalität von Blisterverpackungen. Hierzu werden analytische Methoden mittels Interferometrie, IR-Spektroskopie, Betarückstreuverfahren, Wirbelstromverfahren und Impedanzspektroskopie entwickelt, die zur quantitativen Bestimmung von Heißsiegellacken und Laminatbeschichtungen von Aluminium-Blisterfolien geeignet sind. Ein Vergleich der Methoden zeigt, dass sich das Betarückstreuverfahren, die Interferometrie und IR-Messungen für die Heißsiegellackbestimmung, die Interferometrie und das Wirbelstromverfahren für die Bestimmung von Kunststofflaminaten eignen.rnIm zweiten Abschnitt der Arbeit werden Einflüsse des Heißsiegellack-Flächengewichtes von Deckfolien auf die Qualität von Blisterverpackungen untersucht. Mit Zunahme des Flächengewichtes zeigt sich eine Erhöhung der Siegelnahtfestigkeit aber auch der Wasserdampfdurchlässigkeit von Blistern. Die untersuchten Heißsiegellacke zeigen Permeationskoeffizienten vergleichbar mit Polyvinylchlorid. In Untersuchungen zur Siegelprozessvalidität zeigt das Heißsiegellack-Flächengewicht nur geringfügige Auswirkungen auf diese. rnIm dritten Abschnitt der Arbeit werden Einflüsse des Blister-Designs auf die Benutzerfreundlichkeit von Blisterverpackungen durch eine Handlingstudie untersucht. Variationen der Öffnungskräfte von Durchdrück-Blistern wirken sich deutlich auf die Bewertungen der Blister durch die Probanden aus. Während die meisten Probanden alle getesteten Durchdrück-Blister innerhalb der Testdauer von 4 Minuten öffnen können (>84%), treten beim Peel-Blister und Peel-off-push-through-Blister deutlich mehr Handlingprobleme auf. Die Handlingprobleme korrelieren mit dem Alter, der Lebenssituation, der gesundheitlichen Verfassung und der Sehfähigkeit der Probanden. rn

Entwicklung eines Pikoliter-Tropfengenerators für die Massenspektrometrische Spuren- und Speziesanalytik

Die Dissertationsschrift beschäftigt sich mit der Entwicklung und Anwendung einer alternativen Probenzuführungstechnik für flüssige Proben in der Massenspektrometrie. Obwohl bereits einige Anstrengungen zur Verbesserung unternommen wurden, weisen konventionelle pneumatische Zerstäuber- und Sprühkammersysteme, die in der Elementspurenanalytik mittels induktiv gekoppeltem Plasma (ICP) standardmäßig verwendet werden, eine geringe Gesamteffizienz auf. Pneumatisch erzeugtes Aerosol ist durch eine breite Tropfengrößenverteilung gekennzeichnet, was den Einsatz einer Sprühkammer bedingt, um die Aerosolcharakteristik an die Betriebsbedingungen des ICPs anzupassen.. Die Erzeugung von Tropfen mit einer sehr engen Tropfengrößenverteilung oder sogar monodispersen Tropfen könnte die Effizienz des Probeneintrags verbessern. Ein Ziel dieser Arbeit ist daher, Tropfen, die mittels des thermischen Tintenstrahldruckverfahrens erzeugt werden, zum Probeneintrag in der Elementmassenspektrometrie einzusetzen. Das thermische Tintenstrahldruckverfahren konnte in der analytischen Chemie im Bereich der Oberflächenanalytik mittels TXRF oder Laserablation bisher zur gezielten, reproduzierbaren Deposition von Tropfen auf Oberflächen eingesetzt werden. Um eine kontinuierliche Tropfenerzeugung zu ermöglichen, wurde ein elektronischer Mikrokontroller entwickelt, der eine Dosiereinheit unabhängig von der Hard- und Software des Druckers steuern kann. Dabei sind alle zur Tropfenerzeugung relevanten Parameter (Frequenz, Heizpulsenergie) unabhängig voneinander einstellbar. Die Dosiereinheit, der "drop-on-demand" Aerosolgenerator (DOD), wurde auf eine Aerosoltransportkammer montiert, welche die erzeugten Tropfen in die Ionisationsquelle befördert. Im Bereich der anorganischen Spurenanalytik konnten durch die Kombination des DOD mit einem automatischen Probengeber 53 Elemente untersucht und die erzielbare Empfindlichkeiten sowie exemplarisch für 15 Elemente die Nachweisgrenzen und die Untergrundäquivalentkonzentrationen ermittelt werden. Damit die Vorteile komfortabel genutzt werden können, wurde eine Kopplung des DOD-Systems mit der miniaturisierten Fließinjektionsanalyse (FIA) sowie miniaturisierten Trenntechniken wie der µHPLC entwickelt. Die Fließinjektionsmethode wurde mit einem zertifizierten Referenzmaterial validiert, wobei für Vanadium und Cadmium die zertifizierten Werte gut reproduziert werden konnten. Transiente Signale konnten bei der Kopplung des Dosiersystems in Verbindung mit der ICP-MS an eine µHPLC abgebildet werden. Die Modifikation der Dosiereinheit zum Ankoppeln an einen kontinuierlichen Probenfluss bedarf noch einer weiteren Reduzierung des verbleibenden Totvolumens. Dazu ist die Unabhängigkeit von den bisher verwendeten, kommerziell erhältlichen Druckerpatronen anzustreben, indem die Dosiereinheit selbst gefertigt wird. Die Vielseitigkeit des Dosiersystems wurde mit der Kopplung an eine kürzlich neu entwickelte Atmosphärendruck-Ionisationsmethode, die "flowing atmospheric-pressure afterglow" Desorptions/Ionisations Ionenquelle (FAPA), aufgezeigt. Ein direkter Eintrag von flüssigen Proben in diese Quelle war bislang nicht möglich, es konnte lediglich eine Desorption von eingetrockneten Rückständen oder direkt von der Flüssigkeitsoberfläche erfolgen. Die Präzision der Analyse ist dabei durch die variable Probenposition eingeschränkt. Mit dem Einsatz des DOD-Systems können flüssige Proben nun direkt in die FAPA eingetragen, was ebenfalls das Kalibrieren bei quantitativen Analysen organischer Verbindungen ermöglicht. Neben illegalen Drogen und deren Metaboliten konnten auch frei verkäufliche Medikamente und ein Sprengstoffanalogon in entsprechend präpariertem reinem Lösungsmittel nachgewiesen werden. Ebenso gelang dies in Urinproben, die mit Drogen und Drogenmetaboliten versetzt wurden. Dabei ist hervorzuheben, dass keinerlei Probenvorbereitung notwendig war und zur Ermittlung der NWG der einzelnen Spezies keine interne oder isotopenmarkierte Standards verwendet wurden. Dennoch sind die ermittelten NWG deutlich niedriger, als die mit der bisherigen Prozedur zur Analyse flüssiger Proben erreichbaren. Um im Vergleich zu der bisher verwendeten "pin-to-plate" Geometrie der FAPA die Lösungsmittelverdampfung zu beschleunigen, wurde eine alternative Elektrodenanordnung entwickelt, bei der die Probe länger in Kontakt mit der "afterglow"-Zone steht. Diese Glimmentladungsquelle ist ringförmig und erlaubt einen Probeneintrag mittels eines zentralen Gasflusses. Wegen der ringförmigen Entladung wird der Name "halo-FAPA" (h-FAPA) für diese Entladungsgeometrie verwendet. Eine grundlegende physikalische und spektroskopische Charakterisierung zeigte, dass es sich tatsächlich um eine FAPA Desorptions/Ionisationsquelle handelt.

Design of multifunctional magnetic nanomaterials for biomedical applications

Diese Arbeit ist ein Beitrag zu den schnell wachsenden Forschungsgebieten der Nano-Biotechnologie und Nanomedizin. Sie behandelt die spezifische Gestaltung magnetischer Nanomaterialien für verschiedene biomedizinische Anwendungsgebiete, wie beispielsweise Kontrastmittel für die magnetische Resonanztomographie (MRT) oder "theragnostische" Agenzien für simultane optische/MR Detektion und Behandlung mittels photodynamischer Therapie (PDT).rnEine Vielzahl magnetischer Nanopartikel (NP) mit unterschiedlichsten magnetischen Eigenschaften wurden im Rahmen dieser Arbeit synthetisiert und erschöpfend charakterisiert. Darüber hinaus wurde eine ganze Reihe von Oberflächenmodifizierungsstrategien entwickelt, um sowohl die kolloidale als auch die chemische Stabilität der Partikel zu verbessern, und dadurch den hohen Anforderungen der in vitro und in vivo Applikation gerecht zu werden. Diese Strategien beinhalteten nicht nur die Verwendung bi-funktionaler und multifunktioneller Polymerliganden, sondern auch die Kondensation geeigneter Silanverbindungen, um eine robuste, chemisch inerte und hydrophile Siliziumdioxid- (SiO2) Schale um die magnetischen NP auszubilden.rnGenauer gesagt, der Bildungsmechanismus und die magnetischen Eigenschaften monodisperser MnO NPs wurden ausgiebig untersucht. Aufgrund ihres einzigartigen magnetischen Verhaltens eignen sich diese NPs besonders als (positive) Kontrastmittel zur Verkürzung der longitudinalen Relaxationszeit T1, was zu einer Aufhellung im entsprechenden MRT-Bild führt. Tatsächlich wurde dieses kontrastverbessernde Potential in mehreren Studien mit unterschiedlichen Oberflächenliganden bestätigt. Au@MnO „Nanoblumen“, auf der anderen Seite, sind Vertreter einer weiteren Klasse von Nanomaterialien, die in den vergangenen Jahren erhebliches Interesse in der wissenschaftlichen Welt geweckt hat und oft „Nano-hetero-Materialien“ genannt wird. Solche Nano-hetero-partikel vereinen die individuellen physikalischen und chemischen Eigenschaften der jeweiligen Komponenten in einem nanopartikulärem System und erhöhen dadurch die Vielseitigkeit der möglichen Anwendungen. Sowohl die magnetischen Merkmale von MnO, als auch die optischen Eigenschaften von Au bieten die Möglichkeit, diese „Nanoblumen“ für die kombinierte MRT und optische Bildgebung zu verwenden. Darüber hinaus erlaubt das Vorliegen zweier chemisch unterschiedlicher Oberflächen die gleichzeitige selektive Anbindung von Katecholliganden (auf MnO) und Thiolliganden (auf Au). Außerdem wurde das therapeutische Potential von magnetischen NPs anhand von MnO NPs demonstriert, die mit dem Photosensibilisator Protoporhyrin IX (PP) funktionalisiert waren. Bei Bestrahlung mit sichtbarem Licht initiiert PP die Produktion von zytotoxisch-reaktivem Sauerstoff. Wir zeigen, dass Nierenkrebszellen, die mit PP-funktionalisierten MnO NPs inkubiert wurden nach Bestrahlung mit Laserlicht verenden, während sie ohne Bestrahlung unverändert bleiben. In einem ähnlichen Experiment untersuchten wir die Eigenschaften von SiO2 beschichteten MnO NPs. Dafür wurde eigens eine neuartige SiO2-Beschichtungsmethode entwickelt, die einer nachfolgende weitere Anbindung verschiedenster Liganden und die Einlagerung von Fluoreszenzfarbstoffen durch herkömmliche Silan- Sol-Gel Chemie erlaubt. Die Partikel zeigten eine ausgezeichnete Stabilität in einer ganzen Reihe wässriger Lösungen, darunter auch physiologische Kochsalzlösung, Pufferlösungen und humanes Blutserum, und waren weniger anfällig gegenüber Mn-Ionenauswaschung als einfache PEGylierte MnO NPs. Des Weiteren konnte bewiesen werden, dass die dünne SiO2 Schicht nur einen geringen Einfluss auf das magnetische Verhalten der NPs hatte, so dass sie weiterhin als T1-Kontrastmittel verwendet werden können. Schließlich konnten zusätzlich FePt@MnO NPs hergestellt werden, welche die individuellen magnetischen Merkmale eines ferromagnetischen (FePt) und eines antiferromagnetischen (MnO) Materials vereinen. Wir zeigen, dass wir die jeweiligen Partikelgrößen, und damit das resultierende magnetische Verhalten, durch Veränderung der experimentellen Parameter variieren können. Die magnetische Wechselwirkung zwischen beiden Materialien kann dabei auf Spinkommunikation an der Grenzfläche zwischen beiden NP-Sorten zurückgeführt werden.rn

Design methods and geometric modelling of scaffolds for bone tissue engineering

Every year, thousand of surgical treatments are performed in order to fix up or completely substitute, where possible, organs or tissues affected by degenerative diseases. Patients with these kind of illnesses stay long times waiting for a donor that could replace, in a short time, the damaged organ or the tissue. The lack of biological alternates, related to conventional surgical treatments as autografts, allografts, e xenografts, led the researchers belonging to different areas to collaborate to find out innovative solutions. This research brought to a new discipline able to merge molecular biology, biomaterial, engineering, biomechanics and, recently, design and architecture knowledges. This discipline is named Tissue Engineering (TE) and it represents a step forward towards the substitutive or regenerative medicine. One of the major challenge of the TE is to design and develop, using a biomimetic approach, an artificial 3D anatomy scaffold, suitable for cells adhesion that are able to proliferate and differentiate themselves as consequence of the biological and biophysical stimulus offered by the specific tissue to be replaced. Nowadays, powerful instruments allow to perform analysis day by day more accurateand defined on patients that need more precise diagnosis and treatments.Starting from patient specific information provided by TC (Computed Tomography) microCT and MRI(Magnetic Resonance Imaging), an image-based approach can be performed in order to reconstruct the site to be replaced. With the aid of the recent Additive Manufacturing techniques that allow to print tridimensional objects with sub millimetric precision, it is now possible to practice an almost complete control of the parametrical characteristics of the scaffold: this is the way to achieve a correct cellular regeneration. In this work, we focalize the attention on a branch of TE known as Bone TE, whose the bone is main subject. Bone TE combines osteoconductive and morphological aspects of the scaffold, whose main properties are pore diameter, structure porosity and interconnectivity. The realization of the ideal values of these parameters represents the main goal of this work: here we'll a create simple and interactive biomimetic design process based on 3D CAD modeling and generative algorithmsthat provide a way to control the main properties and to create a structure morphologically similar to the cancellous bone. Two different typologies of scaffold will be compared: the first is based on Triply Periodic MinimalSurface (T.P.M.S.) whose basic crystalline geometries are nowadays used for Bone TE scaffolding; the second is based on using Voronoi's diagrams and they are more often used in the design of decorations and jewellery for their capacity to decompose and tasselate a volumetric space using an heterogeneous spatial distribution (often frequent in nature). In this work, we will show how to manipulate the main properties (pore diameter, structure porosity and interconnectivity) of the design TE oriented scaffolding using the implementation of generative algorithms: "bringing back the nature to the nature".

The role of paved surfaces in the Urban Heat Island phenomenon: Assessment of fundamental thermal parameters and finite element analysis for UHI mitigation

Nowadays the environmental issues and the climatic change play fundamental roles in the design of urban spaces. Our cities are growing in size, many times only following immediate needs without a long-term vision. Consequently, the sustainable development has become not only an ethical but also a strategic need: we can no longer afford an uncontrolled urban expansion. One serious effect of the territory industrialisation process is the increase of urban air and surfaces temperatures compared to the outlying rural surroundings. This difference in temperature is what constitutes an urban heat island (UHI). The purpose of this study is to provide a clarification on the role of urban surfacing materials in the thermal dynamics of an urban space, resulting in useful indications and advices in mitigating UHI. With this aim, 4 coloured concrete bricks were tested, measuring their emissivity and building up their heat release curves using infrared thermography. Two emissivity evaluation procedures were carried out and subsequently put in comparison. Samples performances were assessed, and the influence of the colour on the thermal behaviour was investigated. In addition, some external pavements were analysed. Albedo and emissivity parameters were evaluated in order to understand their thermal behaviour in different conditions. Surfaces temperatures were recorded in a one-day measurements campaign. ENVI-met software was used to simulate how the tested materials would behave in two typical urban scenarios: a urban canyon and a urban heat basin. Improvements they can carry to the urban microclimate were investigated. Emissivities obtained for the bricks ranged between 0.92 and 0.97, suggesting a limited influence of the colour on this parameter. Nonetheless, white concrete brick showed the best thermal performance, whilst the black one the worst; red and yellow ones performed pretty identical intermediate trends. De facto, colours affected the overall thermal behaviour. Emissivity parameter was measured in the outdoor work, getting (as expected) high values for the asphalts. Albedo measurements, conducted with a sunshine pyranometer, proved the improving effect given by the yellow paint in terms of solar reflection, and the bad influence of haze on the measurement accuracy. ENVI-met simulations gave a demonstration on the effectiveness in thermal improving of some tested materials. In particular, results showed good performances for white bricks and granite in the heat basin scenario, and painted concrete and macadam in the urban canyon scenario. These materials can be considered valuable solutions in UHI mitigation.

Impact of irrigation in the Po valley (Italy) on meteorological parameters through numerical simulation

Recent studies found that soil-atmosphere coupling features, through soil moisture, have been crucial to simulate well heat waves amplitude, duration and intensity. Moreover, it was found that soil moisture depletion both in Winter and Spring anticipates strong heat waves during the Summer. Irrigation in geophysical studies can be intended as an anthropogenic forcing to the soil-moisture, besides changes in land proprieties. In this study, the irrigation was add to a LAM hydrostatic model (BOLAM) and coupled with the soil. The response of the model to irrigation perturbation is analyzed during a dry Summer season. To identify a dry Summer, with overall positive temperature anomalies, an extensive climatological characterization of 2015 was done. The method included a statistical validation on the reference period distribution used to calculate the anomalies. Drought conditions were observed during Summer 2015 and previous seasons, both on the analyzed region and the Alps. Moreover July was characterized as an extreme event for the referred distribution. The numerical simulation consisted on the summer season of 2015 and two run: a control run (CTR), with the soil coupling and a perturbed run (IPR). The perturbation consists on a mask of land use created from the Cropland FAO dataset, where an irrigation water flux of 3 mm/day was applied from 6 A.M. to 9 A.M. every day. The results show that differences between CTR and IPR has a strong daily cycle. The main modifications are on the air masses proprieties, not on to the dynamics. However, changes in the circulation at the boundaries of the Po Valley are observed, and a diagnostic spatial correlation of variable differences shows that soil moisture perturbation explains well the variation observed in the 2 meters height temperature and in the latent heat fluxes.On the other hand, does not explain the spatial shift up and downslope observed during different periods of the day. Given the results, irrigation process affects the atmospheric proprieties on a larger scale than the irrigation, therefore it is important in daily forecast, particularly during hot and dry periods.

Mining tissue microarray data to uncover combinations of biomarker expression patterns that improve intermediate staging and grading of clear cell renal cell cancer

PURPOSE: Tumor stage and nuclear grade are the most important prognostic parameters of clear cell renal cell carcinoma (ccRCC). The progression risk of ccRCC remains difficult to predict particularly for tumors with organ-confined stage and intermediate differentiation grade. Elucidating molecular pathways deregulated in ccRCC may point to novel prognostic parameters that facilitate planning of therapeutic approaches. EXPERIMENTAL DESIGN: Using tissue microarrays, expression patterns of 15 different proteins were evaluated in over 800 ccRCC patients to analyze pathways reported to be physiologically controlled by the tumor suppressors von Hippel-Lindau protein and phosphatase and tensin homologue (PTEN). Tumor staging and grading were improved by performing variable selection using Cox regression and a recursive bootstrap elimination scheme. RESULTS: Patients with pT2 and pT3 tumors that were p27 and CAIX positive had a better outcome than those with all remaining marker combinations. A prolonged survival among patients with intermediate grade (grade 2) correlated with both nuclear p27 and cytoplasmic PTEN expression, as well as with inactive, nonphosphorylated ribosomal protein S6. By applying graphical log-linear modeling for over 700 ccRCC for which the molecular parameters were available, only a weak conditional dependence existed between the expression of p27, PTEN, CAIX, and p-S6, suggesting that the dysregulation of several independent pathways are crucial for tumor progression. CONCLUSIONS: The use of recursive bootstrap elimination, as well as graphical log-linear modeling for comprehensive tissue microarray (TMA) data analysis allows the unraveling of complex molecular contexts and may improve predictive evaluations for patients with advanced renal cancer.

The design of artificial nestboxes for the study of secondary hole-nesting birds: a review of methodological inconsistencies and potential biases

The widespread use of artificial nestboxes has led to significant advances in our knowledge of the ecology, behaviour and physiology of cavity nesting birds, especially small passerines Nestboxes have made it easier to perform routine monitoring and experimental manipulation of eggs or nestlings, and also repeatedly to capture, identify and manipulate the parents However, when comparing results across study sites the use of nestboxes may also Introduce a potentially significant confounding variable in the form of differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained However, the use of nestboxes may also introduce an unconsidered and potentially significant confounding variable clue to differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained Here we review to what extent the characteristics of artificial nestboxes (e g size, shape, construction material, colour) are documented in the 'methods' sections of publications involving hole-nesting passerine birds using natural or excavated cavities or artificial nestboxes for reproduction and roosting Despite explicit previous recommendations that authors describe in detail the characteristics of the nestboxes used, we found that the description of nestbox characteristics in most recent publications remains poor and insufficient We therefore list the types of descriptive data that should be included in the methods sections of relevant manuscripts and justify this by discussing how variation in nestbox characteristics can affect or confound conclusions from nestbox studies We also propose several recommendations to improve the reliability and usefulness of research based on long-term studies of any secondary hole-nesting species using artificial nestboxes for breeding or roosting.

Population-Based Design of Mandibular Plates Based on Bone Quality and Morphology

In this paper we present a new population-based implant design methodology, which advances the state-of-the-art approaches by combining shape and bone quality information into the design strategy. The method enhances the mechanical stability of the fixation and reduces the intra-operative in-plane bending which might impede the functionality of the locking mechanism. The method is presented for the case of mandibular locking fixation plates, where the mandibular angle and the bone quality at screw locations are taken into account. Using computational anatomy techniques, the method automatically derives, from a set of computed tomography images, the mandibular angle and the bone thickness and intensity values at the path of every screw. An optimisation strategy is then used to optimise the two parameters of plate angle and screw position. Results for the new design are presented along with a comparison with a commercially available mandibular locking fixation plate. A statistically highly significant improvement was observed. Our experiments allowed us to conclude that an angle of 126° and a screw separation of 8mm is a more suitable design than the standard 120° and 9mm.

Evaluation of respiratory parameters at presentation as clinical indicators of the respiratory localization in dogs and cats with respiratory distress

OBJECTIVE: To describe clinical respiratory parameters in cats and dogs with respiratory distress and identify associations between respiratory signs at presentation and localization of the disease with particular evaluation between the synchrony of abdominal and chest wall movements as a clinical indicators for pleural space disease. Design - Prospective observational clinical study. SETTING: Emergency service in a university veterinary teaching hospital. ANIMALS: Cats and dogs with respiratory distress presented to the emergency service between April 2008 and July 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The following parameters were systematically determined at time of admission: respiratory rate, heart rate, temperature, type of breathing, movement of the thoracic and abdominal wall during inspiration, presence of stridor, presence and type of dyspnea, and results of thoracic auscultation. Abdominal and chest wall movement was categorized as synchronous, asynchronous, or inverse. Diagnostic test results, diagnosis, and outcome were subsequently recorded. Based on the final diagnoses, animals were assigned to 1 or more of the following groups regarding the anatomical localization of the respiratory distress: upper airways, lower airways, lung parenchyma, pleural space, thoracic wall, nonrespiratory causes, and normal animals. One hundred and seventy-six animals (103 cats and 73 dogs) were evaluated. Inspiratory dyspnea was associated with upper airway disease in dogs and expiratory dyspnea with lower airway disease in cats. Respiratory noises were significantly associated and highly sensitive and specific for upper airway disease. An asynchronous or inverse breathing pattern and decreased lung auscultation results were significantly associated with pleural space disease in both dogs and cats (P<0.001). The combination is highly sensitive (99%) but not very specific (45%). Fast and shallow breathing was not associated with pleural space disease. Increased or moist pulmonary auscultation findings were associated with parenchymal lung disease. CONCLUSIONS: Cats and dogs with pleural space disease can be identified by an asynchronous or inverse breathing pattern in combination with decreased lung sounds on auscultation.

Population-based design of mandibular fixation plates with bone quality and morphology considerations

In this paper we present a new population-based implant design methodology, which advances the state-of-the-art approaches by combining shape and bone quality information into the design strategy. The method may enhance the mechanical stability of the fixation and reduces the intra-operative in-plane bending which might impede the functionality of the locking mechanism. The computational method is presented for the case of mandibular locking fixation plates, where the mandibular angle and the bone quality at screw locations are taken into account. The method automatically derives the mandibular angle and the bone thickness and intensity values at the path of every screw from a set of computed tomography images. An optimization strategy is then used to optimize the two parameters of plate angle and screw position. The method was applied to two populations of different genders. Results for the new design are presented along with a comparison with a commercially available mandibular locking fixation plate (MODUS(®) TriLock(®) 2.0/2.3/2.5, Medartis AG, Basel, Switzerland). The proposed designs resulted in a statistically significant improvement in the available bone thickness when compared to the standard plate. There is a higher probability that the proposed implants cover areas of thicker cortical bone without compromising the bone mineral density around the screws. The obtained results allowed us to conclude that an angle and screw separation of 129° and 9 mm for females and 121° and 10 mm for males are more suitable designs than the commercially available 120° and 9 mm.

Cardiac transplantation with hearts from donors after circulatory declaration of death: haemodynamic and biochemical parameters at procurement predict recovery following cardioplegic storage in a rat model

OBJECTIVES: Donation after circulatory declaration of death (DCDD) could significantly improve the number of cardiac grafts for transplantation. Graft evaluation is particularly important in the setting of DCDD given that conditions of cardio-circulatory arrest and warm ischaemia differ, leading to variable tissue injury. The aim of this study was to identify, at the time of heart procurement, means to predict contractile recovery following cardioplegic storage and reperfusion using an isolated rat heart model. Identification of reliable approaches to evaluate cardiac grafts is key in the development of protocols for heart transplantation with DCDD. METHODS: Hearts isolated from anaesthetized male Wistar rats (n = 34) were exposed to various perfusion protocols. To simulate DCDD conditions, rats were exsanguinated and maintained at 37°C for 15-25 min (warm ischaemia). Isolated hearts were perfused with modified Krebs-Henseleit buffer for 10 min (unloaded), arrested with cardioplegia, stored for 3 h at 4°C and then reperfused for 120 min (unloaded for 60 min, then loaded for 60 min). Left ventricular (LV) function was assessed using an intraventricular micro-tip pressure catheter. Statistical significance was determined using the non-parametric Spearman rho correlation analysis. RESULTS: After 120 min of reperfusion, recovery of LV work measured as developed pressure (DP)-heart rate (HR) product ranged from 0 to 15 ± 6.1 mmHg beats min(-1) 10(-3) following warm ischaemia of 15-25 min. Several haemodynamic parameters measured during early, unloaded perfusion at the time of heart procurement, including HR and the peak systolic pressure-HR product, correlated significantly with contractile recovery after cardioplegic storage and 120 min of reperfusion (P < 0.001). Coronary flow, oxygen consumption and lactate dehydrogenase release also correlated significantly with contractile recovery following cardioplegic storage and 120 min of reperfusion (P < 0.05). CONCLUSIONS: Haemodynamic and biochemical parameters measured at the time of organ procurement could serve as predictive indicators of contractile recovery. We believe that evaluation of graft suitability is feasible prior to transplantation with DCDD, and may, consequently, increase donor heart availability.