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Technique Able (technique + able)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Volume Organization of Polymer and Hybrid Solar Cells as Revealed by Electron Tomography

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Svetlana S. van Bavel
Abstract Polymer and hybrid solar cells have the potential to become the leading technology of the 21st century in conversion of sun light to electrical energy because their ease processing from solution producing printable devices in a roll-to-roll fashion with high speed and low cost. The performance of such devices critically depends on the nanoscale organization of the photoactive layer, which is composed of at least two functional materials: the electron donor and the electron acceptor forming a so-called bulk heterojunction; however, control of its volume morphology still is a challenge. In this context, advanced analytical tools are required that are able to provide information on the local volume morphology of the photoactive layer with nanometer resolution. In this report electron tomography is introduced as the technique able to explore the 3D morphology of polymer and hybrid solar cells and the first results achieved are critically discussed. [source]

Cutaneous vascular patterns in psoriasis

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2010
Giuseppe Micali MD
Microvascular abnormalities are a characteristic feature of psoriasis and play a crucial role in its pathogenesis. Investigational studies have shown that activated keratinocytes in lesional skin undergo an accelerated epidermal cell turnover and are a major source of pro-angiogenic cytokines, like as VEGF, ESAF, PDECGE/TP, TNF-,, TGF-, and PDGF, suggesting that the epidermis is capable of inducing vascular proliferation. On the other hand, microvascular alterations are essential for the development and persistence of the psoriatic lesions as they provide cellular and tissue nutrition to hyperplastic keratinocytes and promote inflammatory cell migration. Also, dilated and slightly tortuous blood vessels within dermal papillae represent one of the earliest detectable histological changes for all stages of lesional development. Videodermatoscopy is a new non invasive imaging technique able to identify modifications of microvascular architecture in vivo and such evaluation will be useful for the dermatologist both for diagnostic and prognostic evaluation, as well as for post-therapeutic follow-up. In this review, the role of microvascular abnormalities in the pathogenesis of psoriasis as well as the mechanisms underlying vascular changes and their primary therapeutic implications will be reviewed and discussed. [source]

Simultaneous genotyping to detect myostatin gene polymorphism in beef cattle breeds

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 6 2002
M. E. Miranda
Summary The myostatin gene codes for a growth factor involved in muscle development, and polymorphism in this gene can have important economic consequences. Nine mutations affecting the amino-acidic sequence have already been described, six of which are disruptive, inactivating the protein and causing bovine muscular hypertrophy. As the number of known mutations grows, it is necessary to develop a simple, routinely usable technique able to screen individuals in all populations. The oligonucleotide ligation assay (OLA) is proposed here for the rapid genotyping of the nine mutations known affecting the coding sequence in the main breeds of beef cattle. This technique showed its ability to reveal the genotype of individuals being a good tool to determine the frequency of each mutation in a population. The procedure is very flexible as new mutations can be added and removed at any time. Depending on the genotype of each individual, the technique allows breeders to make quick decisions on matings and general selection tendencies. Zusammenfassung Simultane Genotypisierung von Polymorphismen im Myostatin-Gen in Fleischrinderrassen Das Myostatin-Gen kodiert für einen Wachstumsfaktor, der in die Muskelentwicklung eingebunden ist und Polymorphismen in diesem Gen können daher wichtige ökonomische Konsequenzen haben. Bisher wurden neun Mutationen, die Auswirkungen auf die Aminosäuresequenz haben, beschrieben. Sechs davon inaktivieren das Protein und verursachen bovine muskuläre Hypertrophie. Da die Anzahl der bekannten Mutationen in diesem Gen steigt, ist es notwendig, eine einfache, in der Routine einsetzbare Methode zu entwickeln, um Individuen in allen Populationen untersuchen zu können. Zur schnellen Genotypisierung der neun bekannten Mutationen, welche die kodierende Sequenz in den Hauptfleischrinderrassen betreffen, wird hier der Oligo-Ligationsassay (OLA) vorgeschlagen. Durch diese Technik ist es möglich, den Genotyp jedes Individuums und die Frequenz jeder einzelnen Mutation in der Population festzustellen. Die Prozedur ist sehr flexibel, da zu jedem Zeitpunkt neue Mutationen hinzugefügt bzw. weggelassen werden können. Diese Methode erlaubt dem Züchter, in Abhängigkeit vom Genotyp jedes Individiums schnelle Entscheidungen über die Anpaarung und die allgemeine Selektionsrichtung zu treffen. [source]

Most readily usable methods to measure ocular blood flow

ACTA OPHTHALMOLOGICA, Issue 2009
K GUGLETA
Purpose SIS Lecture. Methods Literature search. Results Ocular Blood Flow Research Association (OBFRA, recently merged with another organization - ISOCO, into one single Association for Ocular CDirculation - AOC) made a significant contribution to standardization of the blood flow measuring techniques in the field of ophthalmology. A consens was reached on the number of OBF measurements techniques that occured in the past decades. Particular emphasis was placed on the basic technology, specific parameters and interpretation, accuracy and reproducibility, field of clinical applications. Open questions were extensively discussed, limits of each technique clearly postulated. and a consensus statement put together for each of the technique involved. It encompassed techniques like color Doppler imaging, laser Doppler flowmetry (continuous as well as scanning LDF), laser Doppler velocimetry, Retinal Vessel Analyzer, combination of the vessel diameter measurement and the LDV, laser interferometry of the fundus pulsations amplitude, retinal oxymetry, measurements of the pulsatile component of the blood flow, blue field entoptic method and the newest - Doppler OCT. Conclusion There is no overwhelming measuring technique able to cover all the aspects of the research and the daily clinical routine. Various parameters and various vascular beds are involved, which makes the interpretation of the obtained results strenuous. Of particular importance is the capability of OBF measuring techniques to capture one dynamic feature of ocular circulation - its ability to regulate and to response to various challenges. It is widely believed that not the constantly reduced blood flow, but rather the lack of regulation thereof, leads to prevalent ocular diseases. [source]