360 research outputs found
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Grain Growth in Thin Films with a Fibre Texture Studied by Phase-Field Simulations and Mean Field Modelling
The evolution of fiber textured structures is simulated in 2 dimensions using a generalized phase field model assuming two forms for the misorientation, a steady-state regime is reached after a finite amount of grain growth, where the numer and length weighted misorientation distribution functions (MDF) are constant in time, and the mean grain area A as a function of time t follows a power growth law A - A0 = kt^n with n close to 1 and A0 the initial mean grain area. The final shape of the MDF and value of the prefactor k in the power growth law clearly correlate with the misorientation dependence of the grain boundary energy. From a quantitative point of view, the fraction of special boundaries obtained in simulations is quite sensitive to the number of possible discrete orientations. Furthermore, a mean field approach is worked out to predict the growth exponent for systems with nonuniform grain boundary energy. The conclusions from the mean field approach are consistent with the simulation results.Physic
Analysis of genetic heterogeneity in the HCAR adenovirus-binding Ig1 domain in a Caucasian Flemish population
BACKGROUND: Polymorphisms in the gene that encodes the human cellular receptor for group B coxsackieviruses and adenoviruses (HCAR) could be responsible for differences in susceptibility to infections with these pathogens. Moreover, adenovirus subgroup C-mediated gene therapy could be influenced by mutations in the coding exons for the aminoterminal immunoglobulin-like 1 (Ig1) domain, which is the essential component for adenovirus fiber knob binding. RESULTS: Using two primersets in the adjacent intron sequences, HCAR exons 2 and 3, which comprise the full-length Ig1 domain, were amplified by polymerase chain reactions in 108 unselected and unrelated healthy Belgian volunteers. After nucleotide sequencing, no polymorphisms could be demonstrated in the adenovirus-binding Ig1 exons 2 and 3 of the HCAR gene. CONCLUSIONS: The adenovirus-binding Ig1 domain seems to be a highly conserved region in the Caucasian population which is a reassuring finding regarding adenovector-based gene therapy
Robert J. Baczuk v. Salt Lake Regional Medical Center and Dr. Brian Moench : Reply Brief
APPEAL FROM A FINAL JUDGMENT OF THE THIRD DISTRICT COURT THE HONORABLE HOMER F. WILKINSO
Critical evaluation of the FeeNi, FeeTi and FeeNieTi alloy systems
The FeeNieTi alloy system has been evaluated, together with FeeNi and FeeTi binary subsystems, to provide reliable information for applications and in view of a thermodynamic modelling of the system. Available literature has been critically evaluated, mainly considering phase constitution and phase equilibria, thermochemical and diffusion data, as well as ab initio atomistic calculations. A discussion of the presently available CALPHAD-type thermodynamic assessments is also presented. Finally, new experimental investigations needed to solve uncertain and contradictory data are suggested
Avian papillomaviruses: the parrot Psittacus erithacus papillomavirus (PePV) genome has a unique organization of the early protein region and is phylogenetically related to the chaffinch papillomavirus
BACKGROUND: An avian papillomavirus genome has been cloned from a cutaneous exophytic papilloma from an African grey parrot (Psittacus erithacus). The nucleotide sequence, genome organization, and phylogenetic position of the Psittacus erithacus papillomavirus (PePV) were determined. This PePV sequence represents the first complete avian papillomavirus genome defined. RESULTS: The PePV genome (7304 basepairs) differs from other papillomaviruses, in that it has a unique organization of the early protein region lacking classical E6 and E7 open reading frames. Phylogenetic comparison of the PePV sequence with partial E1 and L1 sequences of the chaffinch (Fringilla coelebs) papillomavirus (FPV) reveals that these two avian papillomaviruses form a monophyletic cluster with a common branch that originates near the unresolved center of the papillomavirus evolutionary tree. CONCLUSIONS: The PePV genome has a unique layout of the early protein region which represents a novel prototypic genomic organization for avian papillomaviruses. The close relationship between PePV and FPV, and between their Psittaciformes and Passeriformes hosts, supports the hypothesis that papillomaviruses have co-evolved and speciated together with their host species throughout evolution
Evolution, geographic spreading, and demographic distribution of Enterovirus D68.
Worldwide outbreaks of enterovirus D68 (EV-D68) in 2014 and 2016 have caused serious respiratory and neurological disease. We collected samples from several European countries during the 2018 outbreak and determined 53 near full-length genome ('whole genome') sequences. These sequences were combined with 718 whole genome and 1,987 VP1-gene publicly available sequences. In 2018, circulating strains clustered into multiple subgroups in the B3 and A2 subclades, with different phylogenetic origins. Clusters in subclade B3 emerged from strains circulating primarily in the US and Europe in 2016, though some had deeper roots linking to Asian strains, while clusters in A2 traced back to strains detected in East Asia in 2015-2016. In 2018, all sequences from the USA formed a distinct subgroup, containing only three non-US samples. Alongside the varied origins of seasonal strains, we found that diversification of these variants begins up to 18 months prior to the first diagnostic detection during a EV-D68 season. EV-D68 displays strong signs of continuous antigenic evolution and all 2018 A2 strains had novel patterns in the putative neutralizing epitopes in the BC- and DE-loops. The pattern in the BC-loop of the USA B3 subgroup had not been detected on that continent before. Patients with EV-D68 in subclade A2 were significantly older than patients with a B3 subclade virus. In contrast to other subclades, the age distribution of A2 is distinctly bimodal and was found primarily among children and in the elderly. We hypothesize that EV-D68's rapid evolution of surface proteins, extensive diversity, and high rate of geographic mixing could be explained by substantial reinfection of adults. Better understanding of evolution and immunity across diverse viral pathogens, including EV-D68 and SARS-CoV-2, is critical to pandemic preparedness in the future
A European multicentre evaluation of detection and typing methods for human enteroviruses and parechoviruses using RNA transcripts
Polymerase chain reaction (PCR) detection has become the gold standard for diagnosis and typing of enterovirus (EV) and human parechovirus (HPeV) infections. Its effectiveness depends critically on using the appropriate sample types and high assay sensitivity as viral loads in cerebrospinal fluid samples from meningitis and sepsis clinical presentation can be extremely low. This study evaluated the sensitivity and specificity of currently used commercial and in-house diagnostic and typing assays. Accurately quantified RNA transcript controls were distributed to 27 diagnostic and 12 reference laboratories in 17 European countries for blinded testing. Transcripts represented the four human EV species (EV-A71, echovirus 30, coxsackie A virus 21, and EV-D68), HPeV3, and specificity controls. Reported results from 48 in-house and 15 commercial assays showed 98% detection frequencies of high copy (1000 RNA copies/5 mu L) transcripts. In-house assays showed significantly greater detection frequencies of the low copy (10 copies/5 mu L) EV and HPeV transcripts (81% and 86%, respectively) compared with commercial assays (56%, 50%; P = 7 x 10(-5)). EV-specific PCRs showed low cross-reactivity with human rhinovirus C (3 of 42 tests) and infrequent positivity in the negative control (2 of 63 tests). Most or all high copy EV and HPeV controls were successfully typed (88%, 100%) by reference laboratories, but showed reduced effectiveness for low copy controls (41%, 67%). Stabilized RNA transcripts provide an effective, logistically simple and inexpensive reagent for evaluation of diagnostic assay performance. The study provides reassurance of the performance of the many in-house assay formats used across Europe. However, it identified often substantially reduced sensitivities of commercial assays often used as point-of-care tests.Peer reviewe
An overview of the clinical use of filter paper in the diagnosis of tropical diseases.
Tropical infectious diseases diagnosis and surveillance are often hampered by difficulties of sample collection and transportation. Filter paper potentially provides a useful medium to help overcome such problems. We reviewed the literature on the use of filter paper, focusing on the evaluation of nucleic acid and serological assays for diagnosis of infectious diseases using dried blood spots (DBS) compared with recognized gold standards. We reviewed 296 eligible studies and included 101 studies evaluating DBS and 192 studies on other aspects of filter paper use. We also discuss the use of filter paper with other body fluids and for tropical veterinary medicine. In general, DBS perform with sensitivities and specificities similar or only slightly inferior to gold standard sample types. However, important problems were revealed with the uncritical use of DBS, inappropriate statistical analysis, and lack of standardized methodology. DBS have great potential to empower healthcare workers by making laboratory-based diagnostic tests more readily accessible, but additional and more rigorous research is needed
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