Localization of laminin to retinal vessels of the rat and mouse using whole mounts

Using a whole mount procedure in adult and neonatal mice and adult rats, we have developed an immunohistochemical method for the localization of laminin-like immunoreactivity (LLIR) to the retinal vessels. LLIR was localized to the vascular basement membrane, permitting a clear three-dimensional view of the retinal vasculature. Positive stain was seen in the inner limiting membrane, in retracted capillaries, encasing pericytes, and in a banding pattern on retinal arterioles. The major findings with the whole mount preparations were confirmed using paraffin-embedded material, with the additional observation of LLIR in the lens capsule. In whole mounts of retinas from neonatal mice, LLIR was present from the earliest stages of capillary growth, indicating that laminin is likely to be secreted by endothelial cells during retinal angiogenesis. LLIR within the retinal nerve fiber layer does not precede capillary ingrowth, so no evidence was found that laminin acts as a tracker signal for retinal angiogenesis

Phase cascade lattice rectifier array: an exactly solvable nonlinear network circuit

An exact analysis of a 2-D lattice network consisting of N × N sites with rectifier and AC source elements with controllable phases reveals a method for generating ripple-free DC power without the use of any filtering circuit elements. A phase cascade configuration is described in which the current ripple in a load resistor goes to zero in the large N limit, enhancing the rectification efficiency without requiring any additional capacitor or inductor based filters. The integrated modular configuration is qualitatively different from conventional rectenna arrays in which the source, rectifier and filter systems are physically disjoint. Nonlinear networks in the large N limit of source-rectifier arrays are potentially of interest to a fast evolving field of distributed power networks.MNacknowledges support from a Graduate Fellowship in the ECE department at Boston University. We thank CMaedler, R Averitt, and members of the Photonics Center staff for assistance. JC acknowledges support from the Boston University RISE summer program. (Graduate Fellowship in the ECE department at Boston University; Boston University RISE summer program)Published versio

Entwicklung neuer Materialien zur chromatographischen Gruppentrennung aromatischer Stickstoffverbindungen in fossilen Brennstoffen

Neuartige stationäre HPLC-Phasen wurden entwickelt und auf ihre Eignung zur Gruppentrennung von stickstoffhaltigen aromatischen Verbindungen (NCACs) überprüft. Neben der Etablierung der Phasen über Standardverbindungen wurden verschiedene petrochemische Realproben analysiert. Dabei werden die NCACs zunächst auf Aluminiumoxid aufkonzentriert und im Anschluss auf einer Hafnium-modifizierten Silica-Phase in neutrale polycyclische aromatische Stickstoffheterocyclen (PANHs), Amino-PAHs und basische PANHs aufgetrennt. Auf einer weiteren stationären Phase, welche aus einer Metall-Organischen Gerüstverbindung (MOF) bestand, konnten aromatische Nitrile ebenfalls abgetrennt werden. Die Fraktionen konnten über GC-MS analysiert werden, wobei eine hohe Anzahl an Verbindungen identifiziert werden konnte. Die Trennung der Verbindungsgruppen ist notwendig, da viele NCACs funktionsisomer sind und somit bei massenspektrometrischen Analysen ohne chromatographische Vortrennung zu Fehlern führen würde

Variation in viscous fingering pattern morphology due to surfactant-mediated interfacial recognition events

The study of the formation of finger-like patterns during displacement of a viscous fluid by a less viscous one is of technological importance. The morphology of the viscous-finger patterns generated is a function of many parameters such as the flow rate, difference in viscosities of the two fluids and the interfacial tension. We demonstrate herein that the morphology of patterns formed during viscous fingering in a Hele-Shaw cell during displacement of paraffin oil by aqueous solutions of the surfactant sodium dodecyl sulphate (SDS), is extremely sensitive to interfacial tension variation brought about by complexation of divalent cations with the surfactant SDS. The variation in morphology of the patterns formed has been quantified by measuring the fractal dimensions of structures formed in a radial Hele-Shaw cell as well as the average finger width in a linear Hele-Shaw cell. This technique shows promise for studying other interfacial phenomena in chemistry such as biorecognition as well as dynamic processes occurring at interfaces

Glucose induced in-situ reduction of chloroaurate ions entrapped in a fatty amine film: formation of gold nanoparticle-lipid composites

The formation of gold nanoparticle-lipid composite films by glucose-induced reduction of chloroaurate ions entrapped in thermally evaporated fatty amine films is described. Simple immersion of films of the salt of octadecylamine and chloroaurate ions (formed by immersion of thermally evaporated fatty amine films in chloroauric acid solution) in glucose solution leads to the facile in-situ reduction of the metal ions to form gold nanoparticles in the fatty amine matrix. The formation of gold nanoparticles is readily detected by the appearance of a violet color in the film and thus forms the basis of a possible new, gold nanoparticle-based colorimetric sensor for glucose. The formation of the fatty amine salt of chloroauric acid and the subsequent reduction of the metal ions by glucose has been followed by quartz crystal microgravimetry, Fourier transform infrared spectroscopy, X-ray photoemission spectroscopy and transmission electron microscopy measurements

Anterior segment mesenchymal dysgenesis in a large Australian family is associated with the recurrent 17 bp duplication in PITX3

Purpose: A recurrent 17 bp duplication (c.657ins17bp) of a segment of the paired-like homeodomain transcription factor 3 (PITX3) gene on human chromosome 10 has been reported in seven families with autosomal dominant posterior polar cataracts with or without anterior segment mesenchymal dysgenesis (ASMD). ASMD can include Peters anomaly with corneal clouding, iridolenticular corneal adhesions, displaced Schwalbe's line, and cataract as described previously in a large Australian family. This study reports the examination of PITX3 in this Australian family. Methods: Clinical examinations of the proband and her relatives were performed as part of routine follow up. A polymerase chain reaction (PCR) based test for the duplication in PITX3 was developed, and DNA from 21 members of the proband's family was tested. Results: All clinically affected members of the family had the same 17 bp duplication of PITX3. There was no difference in the size of the duplication between the severely affected individuals and the more mildly affected individuals. Prenatal diagnosis was performed for two offspring of one affected person. In the first pregnancy, the fetus was shown to carry the duplication while in the second pregnancy, the fetus was shown to be homozygous for the normal allele. Conclusions: The results show that in some individuals within one family, duplication of this segment of PITX3 can result in severe symptoms leading to functional blindness while in other individuals in the same family or in other families, the same duplication leads to treatable cataract with minimal visual impairment

Impacts of urbanisation on the native avifauna of Perth, Western Australia

Urban development either eliminates, or severely fragments, native vegetation, and therefore alters the distribution and abundance of species that depend on it for habitat. We assessed the impact of urban development on bird communities at 121 sites in and around Perth, Western Australia. Based on data from community surveys, at least 83 % of 65 landbirds were found to be dependent, in some way, on the presence of native vegetation. For three groups of species defined by specific patterns of habitat use (bushland birds), there were sufficient data to show that species occurrences declined as the landscape changed from variegated to fragmented to relictual, according to the percentage of vegetation cover remaining. For three other groups (urban birds) species occurrences were either unrelated to the amount of vegetation cover, or increased as vegetation cover declined. In order to maximise the chances of retaining avian diversity when planning for broad-scale changes in land-use (i.e. clearing native vegetation for housing or industrial development), land planners should aim for a mosaic of variegated urban landscapes (\u3e60 % vegetation retention) set amongst the fragmented and relictual urban landscapes (% vegetation retention) that are characteristic of most cities and their suburbs. Management actions for conserving remnant biota within fragmented urban landscapes should concentrate on maintaining the integrity and quality of remnant native vegetation, and aim at building awareness among the general public of the conservation value of remnant native vegetation