781 research outputs found

    Hydrogen contamination in Ge-doped SiO[sub 2] thin films prepared by helicon activated reactive evaporation

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    Germanium-doped silicon oxidethin films were deposited at low temperature by using an improved helicon plasma assisted reactive evaporation technique. The origins of hydrogen contamination in the film were investigated, and were found to be H incorporation during deposition and postdeposition water absorption. The H incorporation during deposition was avoided by using an effective method to eliminate the residual hydrogen present in the depositionsystem. The microstructure, chemical bonds, chemical etch rate, and optical index of the films were studied as a function of the deposition conditions. Granular microstructures were observed in low-density films, and were found to be the cause of postdeposition water absorption. The granular microstructure was eliminated and the film was densified by increasing the helicon plasma power and substrate bias during deposition. A high-density film was shown to have no postdeposition water absorption and no OH detected by using a Fourier-transform infrared spectrometer

    Identifying the best Pichia pastoris base strain using functional genomics

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    Market sizes for novel breakthrough therapies and growing demand for existing treatments in emerging markets promise to challenge the current capacity for production of biologics. These trends dictate the need for a concomitant paradigm shift in biomanufacturing toward greater productivity for lower cost. Strain engineering is a promising means to realize the greatest returns by increasing the product titer going into downstream processes. Current cellular hosts are approaching saturation of optimal productivity due to lack of deep biological understanding or limitations of the host’s intrinsic secretion capacity. We demonstrate an approach informed by functional genomics to understand key performance differences between interchangeably-used variants of the host, Pichia pastoris. Genomic variant calling on all USDA-banked and commercially-available strains revealed varying numbers of SNPs relative to the WT strain, Y-11430. Combining transcriptomics and traditional phenotypic assays, the functional impact of these SNPs can inform which host strain is best suited for a given application. Taken together, we have identified key, beneficial SNPs that can be introduced into a WT background to create an IP-free host primed for optimal protein production

    Effects of Two Different Cooling Devices for Testicles Transport on Stallion Epididymal Sperm Quality

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    This study evaluates the effects of two cooling devices and temperature for testicles storage on epididymal sperm quality after 24 hours; different levels of seminal plasma (0% and 10%) were evaluated on sperm after recovering. Testicles from six stallions were recovered immediately after castration (2) or at the slaughterhouse (4); of the same animal, one testicle was placed in Equitainer (+8\ub0C), the other in a styrofoam box with ice (+3\ub0C). After 24 hours, the temperature of parenchyma was measured, and testicles and epididymal were weighted. Sperm were flushed from the cauda epididymides with Kenney extender, total sperm number recorded and motility and viability evaluated immediately after flushing (T0) with or without 10% SP (G1 Eq 0%, G2 Eq 10%, G3 Ice 0%, G4 Ice 10%). Motility and viability were evaluated after 24 hours and 48 hours of storage at +4\ub0C. Temperature of the parenchyma was lower in testicles stored in ice compared to Equitainer (3.2 \ub1 0.6\ub0C and 8.6 \ub1 2.5\ub0C, respectively; P < .05). Motility and viability at T0 were similar (P > .05) in G1 and G3, whereas addition of SP after recovery significantly improved motility only in samples stored in Equitainer (G2). Viability was higher (P < .05) in G2 than in G4. At T24 and T48, no differences (P > .05) in sperm quality were found between storage methods or samples with or without SP. In conclusion, equine testicles can be safely stored either at lower (+3\ub0C) or higher (+8\ub0C) temperature than +5\ub0C. This can be useful, especially when testicles are shipped in a hot climate, where devices cannot guarantee optimal refrigeration conditions

    Arteriovenous fistulae complicating cardiac pacemaker lead extraction: Recognition, evaluation, and management

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    AbstractTransvenous pacemaker lead extraction has become a commonly performed procedure that is associated with a small but significant risk. We report two cases where lead extraction was complicated by arteriovenous fistulae between branches of the aortic arch and the left brachiocephalic vein. Presenting signs and symptoms included severe chest or back pain, persistent or copious bleeding from the venous puncture site, unexplained hypotension or anemia, superior vena cava syndrome, and signs of central venous hypertension or acute heart failure. One patient whose injury was not recognized immediately and who did not undergo repair died rapidly, whereas the other patient who was diagnosed quickly underwent successful repair. Immediate diagnosis with arteriography and rapid intervention with surgery or percutaneous techniques are indicated and may prevent mortality. (J Vasc Surg 2000;32:1225-8.

    Twirling and Whirling: Viscous Dynamics of Rotating Elastica

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    Motivated by diverse phenomena in cellular biophysics, including bacterial flagellar motion and DNA transcription and replication, we study the overdamped nonlinear dynamics of a rotationally forced filament with twist and bend elasticity. Competition between twist injection, twist diffusion, and writhing instabilities is described by a novel pair of coupled PDEs for twist and bend evolution. Analytical and numerical methods elucidate the twist/bend coupling and reveal two dynamical regimes separated by a Hopf bifurcation: (i) diffusion-dominated axial rotation, or twirling, and (ii) steady-state crankshafting motion, or whirling. The consequences of these phenomena for self-propulsion are investigated, and experimental tests proposed.Comment: To be published in Physical Review Letter

    Characterization of a Homozygous Deletion of Steroid Hormone Biosynthesis Genes in Horse Chromosome 29 as a Risk Factor for Disorders of Sex Development and Reproduction

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    Disorders of sex development (DSD) and reproduction are not uncommon among horses, though knowledge about their molecular causes is sparse. Here we characterized a 200 kb homozygous deletion in chromosome 29 at 29.7-29.9 Mb. The region contains AKR1C genes which function as ketosteroid reductases in steroid hormone biosynthesis, including androgens and estrogens. Mutations in AKR1C genes are associated with human DSDs. Deletion boundaries, sequence properties and gene content were studied by PCR and whole genome sequencing of select deletion homozygotes and control animals. Deletion analysis by PCR in 940 horses, including 622 with DSDs and reproductive problems and 318 phenotypically normal controls, detected 67 deletion homozygotes of which 79% were developmentally or reproductively abnormal. Altogether, 8-9% of all abnormal horses were homozygous for the deletion, with the highest incidence (9.4%) among cryptorchids. The deletion was found in 4% of our phenotypically normal cohort, 1% of global warmblood horses and ponies, and 7% of draught breeds of general horse population as retrieved from published data. Based on the abnormal phenotype of the carriers, the functionally relevant gene content, and the low incidence in general population, we consider the deletion in chromosome 29 as a risk factor for equine DSDs and reproductive disorders

    Molecular engineering improves antigen quality and enables integrated manufacturing of a trivalent subunit vaccine candidate for rotavirus

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    Background Vaccines comprising recombinant subunit proteins are well-suited to low-cost and high-volume production for global use. The design of manufacturing processes to produce subunit vaccines depends, however, on the inherent biophysical traits presented by an individual antigen of interest. New candidate antigens typically require developing custom processes for each one and may require unique steps to ensure sufficient yields without product-related variants. Results We describe a holistic approach for the molecular design of recombinant protein antigens—considering both their manufacturability and antigenicity—informed by bioinformatic analyses such as RNA-seq, ribosome profiling, and sequence-based prediction tools. We demonstrate this approach by engineering the product sequences of a trivalent non-replicating rotavirus vaccine (NRRV) candidate to improve titers and mitigate product variants caused by N-terminal truncation, hypermannosylation, and aggregation. The three engineered NRRV antigens retained their original antigenicity and immunogenicity, while their improved manufacturability enabled concomitant production and purification of all three serotypes in a single, end-to-end perfusion-based process using the biotechnical yeast Komagataella phaffii. Conclusions This study demonstrates that molecular engineering of subunit antigens using advanced genomic methods can facilitate their manufacturing in continuous production. Such capabilities have potential to lower the cost and volumetric requirements in manufacturing vaccines based on recombinant protein subunits

    The Vascular Impairment of Cognition Classification Consensus Study

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    H. Jokinen työryhmän jäsenenä.Introduction: Numerous diagnostic criteria have tried to tackle the variability in clinical manifestations and problematic diagnosis of vascular cognitive impairment (VCI) but none have been universally accepted. These criteria have not been readily comparable, impacting on clinical diagnosis rates and in turn prevalence estimates, research, and treatment. Methods: The Vascular Impairment of Cognition Classification Consensus Study (VICCCS) involved participants (81% academic researchers) from 27 countries in an online Delphi consensus study. Participants reviewed previously proposed concepts to develop new guidelines. Results: VICCCS had a mean of 122 (98-153) respondents across the study and a 67% threshold to represent consensus. VICCCS redefined VCI including classification of mild and major forms of VCI and subtypes. It proposes new standardized VCI-associated terminology and future research priorities to address gaps in current knowledge. Discussion: VICCCS proposes a consensus-based updated conceptualization of VCI intended to facilitate standardization in research. (C) 2016 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.Peer reviewe
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