854 research outputs found
Kondo Effect in Defect-bound Quantum Dots Coupled to NbSe
We report the fabrication of a van der Waals tunneling device hosting a
defect-bound quantum dot coupled to NbSe. We find that upon application of
magnetic field, the device exhibits a zero-bias conductance peak. The peak,
which splits at higher fields, is associated with a Kondo effect. At the same
time, the junction retains conventional quasiparticle tunneling features at
finite bias. Such coexistence of a superconducting gap and a Kondo effect are
unusual, and are explained by noting the two-gap nature of the superconducting
state of NbSe, where a magnetic field suppresses the low energy gap
associated with the Se band. Our data shows that van der Waals architectures,
and defect-bound dots in them, can serve as a novel and effective platform for
investigating the interplay of Kondo screening and superconducting pairing in
unconventional superconductors
Budd-chiari-like syndrome associated with a pheochromocytoma invading the right atrium in a dog
An 8 year-old spayed female Jack Russell Terrier dog was presented with severe abdominal distension due
to ascites and discomfort of five days duration. Abdominal ultrasound revealed ascites and a mass invading
the caudal vena cava pointing to Budd-Chiari-like syndrome (BCLS). The peritoneal fluid was a modified
transudate. The BCLS was a result of a left adrenal mass that invaded the caudal vena cava to a length of 14
cm, up to the right atrium. A phaeochromocytoma was highly suspected and due to its aggressiveness and
poor prognosis the dog was euthanized. The diagnosis was confirmed by histopathology after post mortem.
This is a rare case of a 14 cm-long phaeochromocytoma associated with BCLS illustrating the in vivo diagnostic
approach. A phaeochromocytoma should be considered in cases presenting with BCLS.http://www.isrvma.orgmn201
The key project managers’ competences for different types of projects
This paper describes a quantitative research approach for identifying
key project managers’ competences for different types of projects. By
identifying the perceived most valuable project manager competences, as
having the most potential for increased contribution to project management
(PM) performance, practitioners and organizations can select their priorities
when developing their PM practices. The 46 competences (technical,
behavioural and contextual) provided by IPMA (International Project
Management Association) were surveyed through an online questionnaire.
Three dimensions to distinguish project types were used: application area,
innovation and complexity. Completed questionnaires were received from 96
project managers from Portugal. The results showed that 13 key competences
(20%) were common to the majority of the projects. Most of these are
behavioural competences, such as: ethics, reliability, engagement, openness,
and leadership. It was also observed a clear correlation between technical
competences and project complexity
Tribological behavior of shape-specific microplate-enriched synovial fluids on a linear two-axis tribometer
Nano- and micro-particles are being increasingly used to tune interfacial frictional properties in diverse applications, from friction modifiers in industrial lubrication to enhanced biological fluids in human osteoarthritic joints. Here, we assessed the tribological properties of a simulated synovial fluid enriched with non-spherical, poly lactic-co-glycolic acid (PLGA) microparticles (μPL) that have been previously demonstrated for the pharmacological management of osteoarthritis (OA). Three different μPL configurations were fabricated presenting a 20 μm 20 μm square base and a thickness of 5 μm (thin, 5H μPL), 10 μm (10H μPL), and 20 μm (cubical, 20H μPL). After extensive morphological and physicochemical characterizations, the apparent Young’s modulus of the μPL was quantified under compressive loading returning an average value of 6 kPa, independently of the particle morphology. Then, using a linear two-axis tribometer, the static (μs) and dynamic (μd) friction coefficients of the μPL-enriched simulated synovial fluid were determined in terms of particle configuration and concentration, varying from 0 (fluid only) to 6105 μPL/mL. The particle morphology had a modest influence on friction, possibly because the μPL were fully squeezed between two mating surfaces by a 5.8 N normal load realizing boundary-like lubrication conditions. Differently, friction was observed to depend on the dimensionless parameter , defined as the ratio between the total volume of the μPL enriching the simulated synovial fluid and the volume of the fluid itself. Both coefficients of friction were documented to grow with reaching a plateau of μs 0.4 and μd 0.15, already at 210-3. Future investigations will have to systematically analyze the effect of sliding velocity, normal load, and rigidity of the mating surfaces to elucidate in full the tribological behavior of μPL in the context of osteoarthritis
Hypovitaminosis D in dogs with spirocercosis
BACKGROUND : Spirocercosis in dogs is characterized by esophageal nodules that can undergo neoplastic transformation.
Hypovitaminosis D has been associated with neoplasia formation. We hypothesized hypovitaminosis D in neoplastic
spirocercosis and that it could be a risk factor for neoplastic transformation.
OBJECTIVE : To measure and compare vitamin D status, assessed by serum 25-hydroxyvitamin D [25(OH)D] concentrations
in non-neoplastic (n = 25) and neoplastic (n = 26) spirocercosis client-owned dogs and healthy dogs (n = 24).
ANIMALS : Twenty-five non-neoplastic dogs, 26 neoplastic dogs, and 24 healthy dogs.
METHODS : Fifty-one dogs were randomly selected from 119 dogs diagnosed with spirocercosis presenting to our hospital,
and further divided into non-neoplastic or neoplastic groups. Exclusion criteria included dogs less than 1 year old, with
concurrent diseases, received corticosteroids, or treated prophylactically for spirocercosis. Serum 25(OH)D concentration
was measured by high-performance liquid chromatography. Spirocercosis dogs’ appetites were graded and compared.
RESULTS : Serum 25(OH)D concentrations were significantly different among all groups (P < .001). 25-Hydroxyvitamin
D concentrations were significantly lower in neoplastic group (median 30.7 nmol/L [range 14.7–62.2]) compared to nonneoplastic
(median 52.7 nmol/L [range 19.1–129.7, P < .05]) and healthy groups (median 74.6 nmol/L [range 37.4–130.5,
P < .005]). 25-hydroxyvitamin D concentrations were significantly lower in non-neoplastic spirocercosis dogs compared
to healthy ones (P < .05). Neoplastic and non-neoplastic spirocercosis dogs had similar appetite scores (P = 1.0). 25-
Hydroxyvitamin D concentrations were not significantly different between dogs with normal (P = .087) and abnormal
(P = .125) appetites within neoplastic and non-neoplastic spirocercosis groups.
CONCLUSIONS AND CLINICAL IMPORTANCE : Further studies are warranted to determine potential use of vitamin D treatment
in spirocercosis and explore role of hypovitaminosis D in pathogenesis of malignant transformation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1939-1676hb2014mn201
Vitamin D status in dogs with babesiosis
Canine babesiosis is a virulent infection of dogs in South Africa caused principally by Babesia
rossi. Hypovitaminosis D has been reported in a wide range of infectious diseases in humans
and dogs, and low vitamin D status has been associated with poor clinical outcomes.
However, the relationship between vitamin D status and canine babesiosis has not been
investigated. The objective of this study was to examine the relationship between the
presence and severity of B. rossi infection and vitamin D status of infected dogs. Owners
with dogs with a confirmed diagnosis of B. rossi infection and of healthy control dogs
were invited to enrol onto the study. Vitamin D status was assessed by measurement of
serum concentrations of the major circulating vitamin D metabolite, 25-hydroxyvitamin
D (25[OH]D). Dogs with babesiosis (n = 34) had significantly lower mean serum 25(OH)D
concentrations than healthy dogs (n = 24) (37.76 ± 21.25 vs. 74.2 ± 20.28 nmol/L). The effect
of babesiosis on serum 25(OH)D concentrations was still significant after adjusting for any
effect of age, body weight and sex. There was a negative relationship between serum 25(OH)
D concentrations and disease severity in dogs with babesiosis. Serum concentrations of
creatinine and alanine aminotransferase and time to last meal were not associated with
serum 25(OH)D concentrations in dogs with babesiosis. In conclusion, dogs with Babesia
rossi infections had lower serum 25(OH)D concentrations than healthy dogs. The inverse
correlation between 25(OH)D concentrations and the clinical severity score indicate that
hypovitaminosis D might be a helpful additional indicator of disease severity.http://www.ojvr.orgam2019Companion Animal Clinical Studie
Tunneling spectroscopy of few-monolayer NbSe in high magnetic field: Ising protection and triplet superconductivity
In conventional Bardeen-Cooper-Scrieffer (BCS) superconductors, Cooper pairs
of electrons of opposite spin (i.e. singlet structure) form the ground state.
Equal spin triplet pairs (ESTPs), as in superfluid He, are of great
interest for superconducting spintronics and topological superconductivity, yet
remain elusive. Recently, odd-parity ESTPs were predicted to arise in
(few-)monolayer superconducting NbSe, from the non-colinearity between the
out-of-plane Ising spin-orbit field (due to the lack of inversion symmetry in
monolayer NbSe) and an applied in-plane magnetic field. These ESTPs couple
to the singlet order parameter at finite field. Using van der Waals tunnel
junctions, we perform spectroscopy of superconducting NbSe flakes, of 2--25
monolayer thickness, measuring the quasiparticle density of states (DOS) as a
function of applied in-plane magnetic field up to 33T. In flakes 15
monolayers thick the DOS has a single superconducting gap. In these thin
samples, the magnetic field acts primarily on the spin (vs orbital) degree of
freedom of the electrons, and superconductivity is further protected by the
Ising field. The superconducting energy gap, extracted from our tunnelling
spectra, decreases as a function of the applied magnetic field. However, in
bilayer NbSe, close to the critical field (up to 30T, much larger than the
Pauli limit), superconductivity appears to be more robust than expected from
Ising protection alone. Our data can be explained by the above-mentioned ESTPs
Quantitative principles of cis-translational control by general mRNA sequence features in eukaryotes.
BackgroundGeneral translational cis-elements are present in the mRNAs of all genes and affect the recruitment, assembly, and progress of preinitiation complexes and the ribosome under many physiological states. These elements include mRNA folding, upstream open reading frames, specific nucleotides flanking the initiating AUG codon, protein coding sequence length, and codon usage. The quantitative contributions of these sequence features and how and why they coordinate to control translation rates are not well understood.ResultsHere, we show that these sequence features specify 42-81% of the variance in translation rates in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Arabidopsis thaliana, Mus musculus, and Homo sapiens. We establish that control by RNA secondary structure is chiefly mediated by highly folded 25-60 nucleotide segments within mRNA 5' regions, that changes in tri-nucleotide frequencies between highly and poorly translated 5' regions are correlated between all species, and that control by distinct biochemical processes is extensively correlated as is regulation by a single process acting in different parts of the same mRNA.ConclusionsOur work shows that general features control a much larger fraction of the variance in translation rates than previously realized. We provide a more detailed and accurate understanding of the aspects of RNA structure that directs translation in diverse eukaryotes. In addition, we note that the strongly correlated regulation between and within cis-control features will cause more even densities of translational complexes along each mRNA and therefore more efficient use of the translation machinery by the cell
Theileriosis in six dogs in South Africa and its potential clinical significance
Please read abstract in the article.http://www.jsava.co.zaam201
Transcatheter Valve Implantation in Failed Surgically Inserted Bioprosthesis Review and Practical Guide to Echocardiographic Imaging in Valve-in-Valve Procedures
AbstractAn increased use of bioprosthetic heart valves has stimulated an interest in possible transcatheter options for bioprosthetic valve failure given the high operative risk. The encouraging results of transcatheter aortic valve implantation in high-risk surgical candidates with native disease have led to the development of the transcatheter valve-in-valve (VIV) procedures for failed bioprostheses. VIV procedures are unique in many ways, and there is an increased need for multimodality imaging in a team-based approach. The echocardiographic approach to VIV procedures has not previously been described. In this review, we summarize key echocardiographic requirements for optimal patient selection, procedural guidance, and immediate post-procedural assessment for VIV procedures
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