120 research outputs found
Scintillation Counters for the D0 Muon Upgrade
We present the results of an upgrade to the D0 muon system. Scintillating
counters have been added to the existing central D0 muon system to provide
rejection for cosmic ray muons and out-of-time background, and to provide
additional fast timing information for muons in an upgraded Tevatron.
Performance and results from the 1994-1996 Tevatron run are presented.Comment: 30 pages, 25 postscript figure
An electric field cell for performing in situ single-crystal synchrotron X-ray diffraction
With the recent increase in research into ferroelectric, anti-ferroelectric and piezoelectric materials, studying the solid-state properties in situ under applied electric fields is vital in understanding the underlying processes. Where this behaviour is the result of atomic displacements, crystallographic insight has an important role. This work presents a sample environment designed to apply an electric field to single-crystal samples in situ on the small-molecule single-crystal diffraction beamline I19, Diamond Light Source (UK). The configuration and operation of the cell is described as well as its application to studies of a proton-transfer colour-change material
Development and characterization of acellular porcine pulmonary valve scaffolds for tissue engineering.
Currently available replacement heart valves all have limitations. This study aimed to produce and characterize an acellular, biocompatible porcine pulmonary root conduit for reconstruction of the right ventricular outflow tract e.g. during Ross procedure. A process for the decellularization of porcine pulmonary roots was developed incorporating trypsin treatment of the adventitial surface of the scraped pulmonary artery and sequential treatment with: hypotonic Tris buffer (HTB; 10mM Tris pH 8.0, 0.1% (w/v) EDTA, 10KIU aprotinin), 0.1% (w/v) SDS in HTB, two cycles of DNase and RNase, and sterilisation with 0.1% (v/v) peracetic acid. Histology confirmed an absence of cells and retention of the gross histoarchitecture. Immunohistochemistry further confirmed cell removal and partial retention of the extra cellular matrix, but a loss of collagen type IV. DNA levels were reduced by more than 96 % throughout all regions of the acellular tissue and no functional genes were detected using PCR. Total collagen levels were retained but there was a significant loss of glycosaminoglycans following decellularization. The biomechanical, hydrodynamic and leaflet kinematics properties were minimally affected by the process. Both immunohistochemical labelling and antibody absorption assay confirmed a lack of α-gal epitopes in the acellular porcine pulmonary roots and in vitro biocompatibility studies indicated that acellular leaflets and pulmonary arteries were not cytotoxic. Overall the acellular porcine pulmonary roots have excellent potential for development of a tissue substitute for right ventricular out flow tract reconstruction e.g. during the Ross procedure
Progresso da seca da haste (Botrytis cinerea) do hibisco (Hibiscus sabdariffa) em quatro épocas e dois métodos de plantio
Substituição dos parâmetros do modelo de Green-Ampt-Mein-Larson para estimativa da infiltração em alguns solos do Brasil
Condições sanitárias das águas de irrigação de hortas do município de São Paulo: II. Isolamento de vírus entéricos
The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): Illuminating the Functional Diversity of Eukaryotic Life in the Oceans through Transcriptome Sequencing
Microbial ecology is plagued by problems of an abstract nature. Cell sizes are so small and population sizes so large that both are virtually incomprehensible. Niches are so far from our everyday experience as to make their very definition elusive. Organisms that may be abundant and critical to our survival are little understood, seldom described and/or cultured, and sometimes yet to be even seen. One way to confront these problems is to use data of an even more abstract nature: molecular sequence data. Massive environmental nucleic acid sequencing, such as metagenomics or metatranscriptomics, promises functional analysis of microbial communities as a whole, without prior knowledge of which organisms are in the environment or exactly how they are interacting. But sequence-based ecological studies nearly always use a comparative approach, and that requires relevant reference sequences, which are an extremely limited resource when it comes to microbial eukaryotes
Large-scale discovery of novel genetic causes of developmental disorders
Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders1, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach2 to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing3,4,5,6,7,8,9,10,11 and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders
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