The genome of the non-cardiovirulent coxsackievirus B3 (CVB3) strain CVB3/0 was cloned and sequenced to aid in the elucidation of the viral genetic basis for the CVB3 cardiovirulent phenotype. ...Reverse-transcribed sub-genomic complementary DNA (cDNA) fragments were enzymatically amplified using generic oligonucleotide primers and were assembled as a complete infectious genomic copy (pCVB3-0) downstream of the T7 RNA polymerase promoter. Positive-strand viral RNA transcribed from pCVB3-0 using T7 RNA polymerase and transfected into HeLa cells produced infectious virus (CVB3/0c). No differences in phenotype were observed comparing growth of CVB3/0c to the parental CVB3/0 in HeLa single-step growth curves, virus yields, or plaque size. When inoculated into C3H/HeJ mice, CVB3/0c achieved cardiac titers equivalent to the parental CVB3/0 and like the parental virus, demonstrated a non-cardiovirulent phenotype. The nucleotide sequence of the cloned CVB3/0 genome was determined and compared to the genomes of infectious cDNA clones of cardiovirulent CVB3 strains. Two consistent differences among nucleotides in non-translated regions and 8 amino acid differences relative to two well-characterized infectious cDNA copies of genomes from cardiovirulent CVB3 strains were identified.
Pyruvate carboxylase Wallace, J.C.; Jitrapakdee, S.; Chapman-Smith, A.
The international journal of biochemistry & cell biology,
01/1998, Letnik:
30, Številka:
1
Journal Article
Recenzirano
Pyruvate carboxylase EC 6.4.1.1 is a member of the family of biotin-dependent carboxylases and is found widely among eukaryotic tissues and in many prokaryotic species. It catalyses the ATP-dependent ...carboxylation of pyruvate to form oxaloacetate which may be utilised in the synthesis of glucose, fat, some amino acids or their derivatives and several neurotransmitters. Diabetes and hyperthyroidism increase the level of expression of pyruvate carboxylase in the long term, while its activity in the short term is controlled by the intramitochondrial concentrations of acetyl-CoA and pyruvate. Many details of this enzyme's regulation are yet to be described in molecular terms. However, progress towards this goal and towards understanding the relationship of pyruvate carboxylase structure to its catalytic reaction mechanism, has been enormously enhanced recently by the cloning and sequencing of genes and cDNAs encoding the ∼130
kDa subunit of this homotetramer. Defects in the expression or biotinylation of pyruvate carboxylase in humans almost invariably results in early death or at best a severely debilitating psychomotor retardation, clearly reflecting the vital role it plays in intermediary metabolism in many tissues including the brain.
The energies of the excited states in very neutron-rich (42)Si and (41,43)P have been measured using in-beam gamma-ray spectroscopy from the fragmentation of secondary beams of (42,44)S at 39A MeV. ...The low 2(+) energy of (42)Si, 770(19) keV, together with the level schemes of (41,43)P, provides evidence for the disappearance of the Z=14 and N=28 spherical shell closures, which is ascribed mainly to the action of proton-neutron tensor forces. New shell model calculations indicate that (42)Si is best described as a well-deformed oblate rotor.
We present a detailed overview of the science goals and predictions for the Prime-Cam direct detection camera/spectrometer being constructed by the CCAT-prime collaboration for dedicated use on the ...Fred Young Submillimeter Telescope (FYST). The FYST is a wide-field, 6-m aperture submillimeter telescope being built (first light in mid-2024) by an international consortium of institutions led by Cornell University and sited at more than 5600 meters on Cerro Chajnantor in northern Chile. Prime-Cam is one of two instruments planned for FYST and will provide unprecedented spectroscopic and broadband measurement capabilities to address important astrophysical questions ranging from Big Bang cosmology through reionization and the formation of the first galaxies to star formation within our own Milky Way galaxy. Prime-Cam on the FYST will have a mapping speed that is over ten times greater than existing and near-term facilities for high-redshift science and broadband polarimetric imaging at frequencies above 300 GHz. We describe details of the science program enabled by this system and our preliminary survey strategies.
Improving the performance of direct-drive cryogenic targets at the Omega Laser Facility requires the development of a new cryogenic system to (1) field nonpermeable targets with a fill tube and (2) ...provide a clean environment around the target. This capability is to demonstrate that imploding a scaled-down version of the direct-drive ignition target for the National Ignition Facility (NIF) on the OMEGA laser will generate the hot-spot pressure that is needed for ignition; this will justify future cryogenic direct-drive experiments on the NIF cryogenic targets. The paper describes the target, the cryogenic equipment that is being constructed to achieve this goal, and the proposed target delivery process. Thermal calculations, fill tube-based target designs, and structural/vibrational analyses are provided to demonstrate the credibility of the design.
This new design will include capabilities not available (or possible) with the existing OMEGA cryogenic system, with the emphasis being to preserve a pristinely clean environment around the target and to provide upgraded diagnostics to characterize both the ice layer and the target's surface. The conceptual design is complete and testing of prototypes and subcomponents is underway. The rationale and capabilities of the new design are discussed.
Caustics in cylindrical ducts Chapman, C. J.
Proceedings of the Royal Society. A, Mathematical, physical, and engineering sciences,
07/1999, Letnik:
455, Številka:
1987
Journal Article
Recenzirano
of a ray segment, the hyperbolic umbilic region near segment, has length of order, This paper determines the caustic structure of the acoustic field reflected from the end face of a circular ...cylindrical duct
when the incident field from inside the duct is a spinning acoustic mode. The rays of the reflected field are piecewise linear
helices, which begin at the circular rim of the end face of the duct as straight–line diffracted rays lying on one–quarter
of a Keller cone of diffracted rays, and continue by multiple reflection of straight–line ray segments off the circular wall
of the duct. The caustics of the reflected field, which are envelopes of the axisymmetric curved surfaces obtained by rotating
the piecewise linear helices about the duct axis, are infinite in number and have cusps. The paper analyses the resulting
longitudinal chain of infinitely many cusped caustics, and shows that, because each cusp is close to a smooth caustic of the
same family of rays, the reflected field contains a hyperbolic umbilic singularity. In terms of the reflection number, . The paper also determines the orders, as powers of, and width of order, of the length and width of a wall region and an ‘outer region’. The orders are used to construct asymptotic expansions for
the positions of the caustics in all the regions. The expansions satisfy Van Dyke's matching rule, and the leading terms are
shown to be numerically accurate as early as the first reflection. The results are promising for the application of Keller's
geometrical theory of diffraction and Weinstein's exact Wiener–Hopf theory to the study of acoustic fields and resonant interactions
in aeroengine ducts. The mathematical techniques used in the paper, reflection–number asymptotics and a method of dominant
triple balances, apply also to multiple reflections of acoustic fields and of internal waves in shear layers and in ocean
waveguides.
Hepatocellular carcinoma(HCC) is an aggressive tumor that often occurs in the setting of chronic liver disease.Many patients do not initially manifest any symptoms of HCC and present late when cure ...with surgical resection or transplantation is no longer possible.For this reason,patients at high risk for developing HCC are subjected to frequent screening processes.The surgical management of HCC is complex and requires an inter-disciplinary approach.Hepatic resection is the treatment of choice for HCC in patients without cirrhosis and is indicated in some patients with early cirrhosis(Child-Pugh A).Liver transplantation has emerged in the past decade as the standard of care for patients with cirrhosis and HCC meeting Milan criteria and in select patients with HCC beyond Milan criteria.Loco-regional therapy with transarterial chemoembolization,transarterial embolization,radiofrequency ablation and other similar local treatments can be used as neo-adjuvant therapy to downstage HCC to within Milan criteria or as a bridge to transplantation in patients on transplant wait list.
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