Electrochemical characterisation of 3Y-TPZ-Fe2O3 composites

The influence of the addition of ferric oxide to 3Y-TZP on the conductivity and microstructure of sintered Y-stabilised tetragonal zirconia ceramics (3Y-TZP) was investigated. A comparison was made between two different dense 3Y-TZP¿¿-Fe2O3 composites. Compacts were made by pressureless sintering at 1150 °C or by sinterforging at 1000 °C and 100 MPa. The sinterforging process resulted in smaller zirconia and hematite grains and a higher monoclinic zirconia content as compared to the compact that was sintered pressureless. The high monoclinic content led to loss of ionic conductivity. The addition of ferric oxide caused electronic conductivity. The sinterforging resulted in a high concentration of metastable defects in the zirconia¿hematite composite, leading to a relatively high electronic conductivity. Heating above 380 °C caused irreversible loss of these defects and a large decrease in electronic conductivity

Synthesis and Magnetic Properties of Cobalt Ferrite (CoFe2O4) Nanoparticles Prepared by Wet Chemical Route

Magnetic nanoparticles of cobalt ferrite have been synthesized by wet chemical method using stable ferric and cobalt salts with oleic acid as the surfactant. X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) confirmed the formation of single phase cobalt ferrite nanoparticles in the range 15-48nm depending on the annealing temperature and time. The size of the particles increases with annealing temperature and time while the coercivity goes through a maximum, peaking at around 28nm. A very large coercivity (10.5kOe) is observed on cooling down to 77K while typical blocking effects are observed below about 260K. The high field moment is observed to be small for smaller particles and approaches the bulk value for large particles.Comment: 18 pages, accepted in JMMM, (May, 2006

A novel brain receptor is expressed in a distinct population of olfactory sensory neurons

Three novel G-protein-coupled receptor genes related to the previously described RA1c gene have been isolated from the mouse genome. Expression of these genes has been detected in distinct areas of the brain and also in the olfactory epithelium of the nose. Developmental studies revealed a differential onset of expression: in the brain at embryonic stage 17, in the olfactory system at stage E12. In order to determine which cell type in the olfactory epithelium expresses this unique receptor type, a transgenic approach was employed which allowed a coexpression of histological markers together with the receptor and thus visualization of the appropriate cell population. It was found that the receptor-expressing cells were located very close to the basal membrane of the epithelium; however, the cells extended a dendritic process to the epithelial surface and their axons projected into the main olfactory bulb where they converged onto two or three glomeruli in the dorsal and posterior region of the bulb. Thus, these data provide evidence that this unique type of receptor is expressed in mature olfactory neurons and suggests that it may be involved in the detection of special odour molecules

The synthesis of nano-nano dual phase ceramic composites

Nano-nano dual-phase composites in which both phases are present as grains with typical dimensions <100 nm are expected to exhibit physical properties, deviating from those of coarser-grained composites. If one phase is electron conducting and the other electrically isolating, special properties can be expected due to Schottky-barrier space-charge formation in the isolator phase near dual-phase boundaries. The extent of the Schottky-barrier (Debije length) can be of the same order as the total grain dimension resulting in special electrical and optical properties. These expectations are the base of this research

TRPC6 in Human Peripheral Nerves—An Investigation Using Immunohistochemistry

Since its discovery, TRPC6 has been associated with a variety of physiological and pathophysiological processes in different tissues. It functions as a non-selective cation channel and belongs to the group of TRP channels. Its importance in the development of pain hypersensitivity is becoming increasingly apparent. This condition has already been associated with increased expression of TRPC6 in dorsal root ganglia. Apart from the fact that most of the evidence has been obtained from samples of animal origin, it remains unclear whether the channel is also expressed in peripheral nerves outside the dorsal root ganglia. The aim of this work was therefore to examine peripheral nerves from human samples for TRPC6. For this purpose, samples of both the sciatic and ulnar nerves were taken from a total of eight body donors and analyzed by immunohistochemistry. Both longitudinal and transverse sections were obtained from the samples and stained. In total, 43 of 48 histological sections showed a positive immunosignal. There were no major differences between the sciatic and ulnar nerves with regard to staining. There was a slight difference in the staining intensity of transverse and longitudinal sections. The longitudinal sections of both nerves were consistently colored slightly more intensely. However, the inter-individual differences between the donors were more pronounced. Interestingly, the samples of a donor who suffered from chronic pain syndrome during his lifetime were particularly strongly stained. This is consistent with the knowledge gained to date, largely from animal experiments, that the channel shows increased expression in pain conditions in dorsal root ganglia. In the future, TRPC6 could therefore be a target in pain therapy

Die Bedeutung eines neonatalen Nephronverlustes während aktiver Nephrogenese für die renale Organogenese und strukturelle Integrität

Prävention und Früherkennung von Erkrankungen sind wesentliche Ziele der Pädiatrie. Das Patientenkollektiv der Frühgeborenen mit seinen zahlreichen perinatalen Komorbiditäten, sowie einer erhöhten Inzidenz von Erkrankungen im fortgeschrittenen Lebensalter, ist für die Kinder- und Jugendmedizin von zentraler Bedeutung. Ziel der vorliegenden Arbeit war es, die renalen Veränderung nach akutem Nephronverlust in der vulnerablen Phase der postnatalen Nephrogenese des Frühgeborenen zu untersuchen. Um einen definierten Nephronverlust beim Frühgeborenen mit einem GA unter 36 SSW zu simulieren, erfolgte im Tiermodell der Wistar-Ratte postnatal an Lebenstag 1 eine Uninephrektomie. Die verbleibende Niere wurde drei Tage nach initialer Uninephrektomie entnommen. Um die kurz- und langfristigen Folgen für die Niere zu ergründen, wurden ausgesuchte Marker mittels RNA-Sequenzierung, in silico Funktionspfadanalyse, Real-time PCR und Immunhistochemie auf Unterschiede zur Kontrollgruppe untersucht. Es konnte gezeigt werden, dass UNX während der Phase der aktiven Nephrogenese einen weitreichenden Einfluss auf die unreife Niere hat. Die Entwicklung des Nierengewichtes und die Anzahl verändert regulierter Gene verdeutlicht den Einschnitt in die Organogenese dieser Tiere. Die in silico Analyse zeigte ebenfalls weitgehende Veränderungen der Expressionsmuster sowie Signalwege spezifischer Gene der Nephrogenese sowie der renalen Homöostase und Regeneration auf. Dies lässt postulieren, dass UNX während der aktiven Nephrogenese nicht nur Mechanismen des Wachstums und der Differenzierung der Niere verändert, sondern zusätzlich auch die renale regenerative Kapazität und Organhomöostase beeinflusst. Dies lässt wiederum ein erhöhtes Risiko für die Entstehung sekundärer renaler Erkrankungen in diesem Patientenkollektiv annehmen. Die in dieser Arbeit nach neonataler UNX verändert exprimierten Kandidatengene sind bereits gut untersuchte molekulare Marker der renalen Organogenese und Regeneration. Ziel zukünftiger Studien sollte es nun sein, ihren prädiktiven Wert bezüglich der Entstehung sekundärer Nephropathien im untersuchten Patientenkollektiv zu prüfen. Hieraus könnte sich ein diagnostisches Setup für eine patientenspezifische Nachsorge erarbeiten lassen. Die funktionelle Bedeutung der Kandidatengene im Hinblick auf Prävention und Therapie renaler Folgeerkrankungen nach neonatalem Nephronverlust sollte zudem Gegenstand weiterführender tierexperimenteller Untersuchungen sein

Natural Cubic Spline Method as a Method in Constructing a Life Table in Gegelang Village West Lombok

This research aims to reconstruct a life table based on real data obtained in Gegelang Village, West Lombok. The data used in this research is the population in 2016, the death rate in 2014-2018 and the birth rate in 2014-2018. The first step taken was to compile a rough life table using the partial data situation and full data situation methods. Both methods are included in the maximum likelihood method. After carrying out calculations, different life expectancy figures are obtained. The respective calculation results were 62.21 years for the partial data situation method and 73.07 years for the full data situation method. Next, a graduation is carried out using the natural cubic spline method on the life table obtained from a rough life table model calculation. The graphic model produced by the rough life table is fluctuating so it is necessary to graduate using the natural cubic spline method to obtain a monotonically decreasing graph. The life table model chosen for graduation is a life table whose life expectancy is close to the life expectancy of West Lombok Regency in 2015, namely 65.1 years. After graduation, the new life expectancy was found to be 66.92 years

Using Orbitrap mass spectrometry to assess the isotopic compositions of individual compounds in mixtures

The isotopic compositions of individual chemical species are routinely used by the geochemical, environmental, forensic, anthropological, chemical, and biomedical communities to elucidate the conditions, sources, and reaction pathways of the molecules in question. Mass spectrometric methods of measuring isotopic compositions of individual compounds generally require that analytes be pure to yield precise, accurate results, yet most applications examine materials that are mixtures of multiple components. Various methods of chemical purification, e.g., chromatography, are used to isolate analytes from mixtures prior to mass spectrometric analysis. However, these techniques take time and specialized instrumentation, both of which could potentially be obviated via the use of ultra-high-resolution mass spectrometry. Here we report on the use of Orbitrap™-based Fourier-transform mass spectrometry to perform isotope ratio measurements of single species within mixtures delivered to the mass spectrometer (MS) without prior chromatographic separation. We demonstrate that instrument biases (attributed here to space charge effects) within the Orbitrap mass analyzer can cause the measured ¹³C/¹²C ratio of a molecular ion in the presence of non-analyte-derived ‘contaminating’ species to spuriously decrease relative to the ¹³C/¹²C ratio measured for the same ion in a pure analyte. We observe that the decrease in ¹³C/¹²C is proportional to the relative concentrations of the additional ‘contaminating’ components. We then recommend several strategies by which this effect can be mediated such that accurate isotope ratios can be obtained