299 research outputs found
Pulmonary function correlates with arterial stiffness in asthmatic patients
SummaryBackgroundAt the population level, asthma has been associated with chronic systemic inflammation as well as adverse cardiovascular outcomes.ObjectivesThe aim of this study was to investigate peripheral vascular hemodynamic variables of arterial stiffness (AS) and their relationship to pulmonary function tests in asthmatic patients.MethodsYoung asthmatic patients from the tertiary center for pulmonary diseases at the Barzilai Medical Center underwent pulmonary function evaluation and non-invasive radial artery hemodynamic profiling, pre- and post-exercise. Results were compared to age matched, non-asthmatic controls.Results23 young asthmatics and 41 controls, completed all evaluation points. Pulmonary flow parameters were significantly reduced in the asthma group at all points. There were no differences between groups in BMI, blood pressure, pulse rate or measurements of AS at baseline or after bronchodilation. The % predicted forced expiratory volume in the first second at baseline (FEV1%) in asthmatics was positively correlated with the small arteries elasticity index (SAEI) and negatively correlated with the systemic vascular resistance (SVR) in these patients. These correlations were not observed in non-asthmatic controls. In multifactorial regression FEV1 remained the major factor associated with measurements of AS in asthmatic patients, while gender was the only significant factor in non-asthmatic controls.ConclusionsSignificant correlations between measurements of AS and FEV1 in young asthmatics, suggest the presence of a common systemic, most likely inflammatory pathway involving both the cardiovascular and respiratory systems
Structural and magnetic properties of amorphous Co-W alloyed nanoparticles
18 páginas, 20 figuras, 4 tablas.-- PACS number(s): 75.75.Fk, 75.50.Kj, 75.30.Gw, 61.46.Df.-- et al.et al.W-capped Co nanoparticles dispersed in an alumina matrix are studied by means of high-resolution transmission electron microscopy, extended x-ray absorption fine structure, SQUID-based magnetic measurements, dc magnetization, ac magnetic susceptibility, and x-ray magnetic circular dichroism. Results show the formation of amorphous Co-W alloy nanoparticles, the magnetic properties of which are modified by the amount of W or Co present in the samples. The average Co magnetic moment depends on the number of W atoms surrounding it. Co-W particles show superparamagnetic behavior and are described as an array of noninteracting particles with random anisotropy axes and an average moment per particle proportional to the particle volume and to the average Co moment for each alloy composition. Values of the magnetic anisotropy constant of the particles are on the order of 106 erg/cm3, higher than that of bulk Co. Evidence of short-range ordering within each amorphous particle is found that provides insight of the origin of their magnetic anisotropy.The financial
support of MICINN-FEDER MAT08/1077 and Aragonese
IMANA project is acknowledged. A.I.F. acknowledges a
CSIC JAE2008-Predoc grant.Peer reviewe
Exciton Footprint of Self-assembled AlGaAs Quantum Dots in Core-Shell Nanowires
Quantum-dot-in-nanowire systems constitute building blocks for advanced
photonics and sensing applications. The electronic symmetry of the emitters
impacts their function capabilities. Here, we study the fine structure of
gallium-rich quantum dots nested in the shell of GaAs-AlGaAs core-shell
nanowires. We used optical spectroscopy to resolve the splitting resulting from
the exchange terms and extract the main parameters of the emitters. Our results
indicate that the quantum dots can host neutral as well as charges excitonic
complexes and that the excitons exhibit a slightly elongated footprint, with
the main axis tilted with respect to the growth axis. GaAs-AlGaAs emitters in a
nanowire are particularly promising for overcoming the limitations set by
strain in other systems, with the benefit of being integrated in a versatile
photonic structure
Chemical solution synthesis and ferromagnetic resonance of epitaxial thin films of yttrium iron garnet
We report the fabrication of epitaxial Y3Fe5O12 (YIG) thin films on Gd3Ga5O12 (111) using a chemical solution method. Cubic YIG is a ferrimagnetic material at room temperature, with excellent magneto-optical properties, high electrical resistivity, and a very narrow ferromagnetic resonance, which makes it particularly suitable for applications in filters and resonators at microwave frequencies. But these properties depend on the precise stoichiometry and distribution of Fe3+ ions among the octahedral/tetrahedral sites of a complex structure, which hampered the production of high-quality YIG thin films by affordable chemical methods. Here we report the chemical solution synthesis of YIG thin films, with excellent chemical, crystalline, and magnetic homogeneity. The films show a very narrow ferromagnetic resonance (long spin relaxation time), comparable to that obtained from high-vacuum physical deposition methods. These results demonstrate that chemical methods can compete to develop nanometer-thick YIG films with the quality required for spintronic devices and other high-frequency applications
Circulating miR-181 is a prognostic biomarker for amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS) is a relentless neurodegenerative disease of the human motor neuron system, where variability in progression rate limits clinical trial efficacy. Therefore, better prognostication will facilitate therapeutic progress. In this study, we investigated the potential of plasma cell-free microRNAs (miRNAs) as ALS prognostication biomarkers in 252 patients with detailed clinical phenotyping. First, we identified, in a longitudinal cohort, miRNAs whose plasma levels remain stable over the course of disease. Next, we showed that high levels of miR-181, a miRNA enriched in neurons, predicts a greater than two-fold risk of death in independent discovery and replication cohorts (126 and 122 patients, respectively). miR-181 performance is similar to neurofilament light chain (NfL), and when combined together, miR-181 + NfL establish a novel RNA–protein biomarker pair with superior prognostication capacity. Therefore, plasma miR-181 alone and a novel miRNA–protein biomarker approach, based on miR-181 + NfL, boost precision of patient stratification. miR-181-based ALS biomarkers encourage additional validation and might enhance the power of clinical trials
Comparative biochemical analysis of wildtype and drug resistant HIV-1 integrase subtypes B and C
Evaluation of Methodologies for Microrna Biomarker Detection by Next Generation Sequencing
In recent years, microRNAs (miRNAs) in tissues and biofluids have emerged as a new class of promising biomarkers for numerous diseases. Blood-based biomarkers are particularly desirable since serum or plasma is easily accessible and can be sampled repeatedly. To comprehensively explore the biomarker potential of miRNAs, sensitive, accurate and cost-efficient miRNA profiling techniques are required. Next generation sequencing (NGS) is emerging as the preferred method for miRNA profiling; offering high sensitivity, single-nucleotide resolution and the possibility to profile a considerable number of samples in parallel. Despite the excitement about miRNA biomarkers, challenges associated with insufficient characterization of the sequencing library preparation efficacy, precision and method-related quantification bias have not been addressed in detail and are generally underappreciated in the wider research community.
Here, we have tested in parallel four commercially available small RNA sequencing kits against a cohort of samples comprised of human plasma, human serum, murine brain tissue and a reference library containing ~ 950 synthetic miRNAs. We discuss the advantages and limits of these methodologies for massive parallel microRNAs profiling. This work can serve as guideline for choosing an adequate library preparation method, based on sensitivity, specificity and accuracy of miRNA quantification, workflow convenience and potential for automation
Native Speaker Perceptions of Accented Speech: The English Pronunciation of Macedonian EFL Learners
The paper reports on the results of a study that aimed to describe the vocalic and consonantal features of the English pronunciation of Macedonian EFL learners as perceived by native speakers of English and to find out whether native speakers who speak different standard variants of English perceive the same segments as non-native. A specially designed computer web application was employed to gather two types of data: a) quantitative (frequency of segment variables and global foreign accent ratings on a 5-point scale), and b) qualitative (open-ended questions). The result analysis points out to three most frequent markers of foreign accent in the English speech of Macedonian EFL learners: final obstruent devoicing, vowel shortening and substitution of English dental fricatives with Macedonian dental plosives. It also reflects additional phonetic aspects poorly explained in the available reference literature such as allophonic distributional differences between the two languages and intonational mismatch
Suppression of three dimensional twinning for a 100% yield of vertical GaAs nanowires on silicon
Multiple seed formation by three-dimensional twinning at the initial stages of growth explains the manifold of orientations found when self-catalyzed GaAs nanowires grow on silicon. This mechanism can be tuned as a function of the growth conditions by changing the relative size between the GaAs seed and the Ga droplet. We demonstrate how growing under high V/III ratio results in a 100% yield of vertical nanowires on silicon(111). These results open up the avenue towards the efficient integration of III-V nanowire arrays on the silicon platform
Final analysis of the phase III non-inferiority COLUMBA study of subcutaneous versus intravenous daratumumab in patients with relapsed or refractory multiple myeloma
In the primary analysis of the phase III COLUMBA study, daratumumab by subcutaneous administration (DARA SC) demonstrated non-inferiority to intravenous administration (DARA IV) for relapsed or refractory multiple myeloma (RRMM). Here, we report the final analysis of efficacy and safety from COLUMBA after a median of 29.3 months follow-up (additional 21.8 months after the primary analysis). In total, 522 patients were randomized (DARA SC, n=263; DARA IV, n=259). With longer follow-up, DARA SC and DARA IV continued to show consistent efficacy and maximum trough daratumumab concentration as compared with the primary analysis. The overall response rate was 43.7% for DARA SC and 39.8% for DARA IV. The maximum mean (standard deviation [SD]) trough concentration (cycle 3, day 1 pre-dose) of serum DARA was 581 (SD, 315) µg/mL for DARA SC and 496 (SD, 231) µg/mL for DARA IV. Median progression-free survival was 5.6 months for DARA SC and 6.1 months for DARA IV; median overall survival was 28.2 months and 25.6 months, respectively. Grade 3/4 treatment-emergent adverse events occurred in 50.8% of patients in the DARA SC group and 52.7% in the DARA IV group; the most common (≥10%) were thrombocytopenia (DARA SC, 14.2%; DARA IV, 13.6%), anemia (13.8%; 15.1%), and neutropenia (13.1%; 7.8%). The safety profile remained consistent with the primary analysis after longer follow-up. In summary, DARA SC and DARA IV continue to demonstrate similar efficacy and safety, with a low rate of infusion-related reactions (12.7% vs. 34.5%, respectively) and shorter administration time (3-5 minutes vs. 3-7 hours) supporting DARA SC as a preferable therapeutic choice
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