650 research outputs found
Similar plasma lipidomic profile in people living with HIV treated with a darunavir-based or an integrase inhibitor-based antiretroviral therapy
Cardiovascular disease is an important cause of morbidity and mortality in people living with HIV (PLWH), who commonly experience lipid disturbances. The aim of this study was to determine whether the plasma lipidomic profile differs between PLWH receiving a darunavir-based ART and those receiving integrase inhibitor-based ART. This was a cross-sectional study of unselected patients for whom metabolomic analysis was performed using ultra-high-performance liquid chromatography coupled to mass spectrometry. Data for the two subgroups were compared by calculating the log2 of the fold change for each metabolite and then grouping these into the main lipid families. Sixty-two PLWH aged 49.3 +/- 8.6 years (82% men) were included: 12 patients (19.4%) had hypertension, 8 (12.9%) had type 2 diabetes, 25 (41.0%) had dyslipidaemia and 9 (14.5%) were taking statins, without significant differences in all these variables between the two groups. Twenty-five (40.3%) received darunavir-based ART and 37 (59.7%) integrase inhibitor-based ART. Although the differences were not statistically significant, patients treated with darunavir-based ART had higher concentrations of total cholesterol (211 mg/dL vs 194 mg/dL), LDL-cholesterol (132 mg/dL vs 117 mg/dL) and triglycerides (155 mg/dL vs 122 mg/dL), and lower HDL-cholesterol concentration (50 mg/dL vs 52 mg/dL). The main lipid families and metabolites differed slightly between groups (log2-fold change; P-value): ceramides (-0.07; 0.49), phosphatidylinositols (-0.05; 0.63), diacylglycerols (0.10; 0.64), phosphatidylethanolamines (0.03; 0.78), triacylglycerols (0.27; 0.18) and lysophosphatidylethanolamines (0.03; 0.83). In the integrase inhibitor-based group, the use of tenofovir alafenamide fumarate significantly increases the majority of lipid fractions, when compared with tenofovir disoproxil fumarate. The lipidomic profile did not differ between PLWH treated with darunavir-based or integrase inhibitor-based ART. This was especially true for ceramides, which are involved in cardiovascular disease. Further studies are needed to study the impact of ART in lipidomic profile
Roughness analysis applied to niobium thin films grown on MgO(001) surfaces for superconducting radio frequency cavity applications
This paper describes surface studies to address roughness issues inherent to thin film coatings deposited onto superconducting radio frequency (SRF) cavities. This is particularly relevant for multilayered thin film coatings that are being considered as a possible scheme to overcome technical issues and to surpass the fundamental limit of similar to 50 MV/m accelerating gradient achievable with bulk niobium. In 2006, a model by Gurevich [Appl. Phys. Lett. 88, 012511 (2006)] was proposed to overcome this limit that involves coating superconducting layers separated by insulating ones onto the inner walls of the cavities. Thus, we have undertaken a systematic effort to understand the dynamic evolution of the Nb surface under specific deposition thin film conditions onto an insulating surface in order to explore the feasibility of the proposed model. We examine and compare the morphology from two distinct Nb/MgO series, each with its own epitaxial registry, at very low growth rates and closely examine the dynamical scaling of the surface features during growth. Further, we apply analysis techniques such as power spectral density to the specific problem of thin film growth and roughness evolution to qualify the set of deposition conditions that lead to successful SRF coatings. DOI: 10.1103/PhysRevSTAB.16.02200
Early assessment of cardiomyopathy in Duchenne patients by means of longitudinal strain echocardiography
Introduction: The diagnosis of Duchenne-linked cardiomyopathy may be challenging. Conventional echocardiographic measurements typically show deterioration beyond the second decade. Global longitudinal strain has been proposed as an earlier marker than left ventricular ejection fraction. Material and methods: A prospective, observational, cross-sectional, case-control study was carried out. Both Duchenne patients and control subjects underwent transthoracic echocardiogram in order to assess left ventricle function. Bayesian linear regression was the main tool for inference. Age effects were parameterised by means of a spline function because of its simplicity to characterise continuous variables and smooth contributions. The posterior distribution of the marginal age effects was used to assess the earliest age of deterioration of each marker. Results: Sixteen Duchenne patients and twenty-two healthy male subjects were enrolled. On overage, cardiac function measures were found for ejection fraction and longitudinal strain among different groups. Age effects on global longitudinal strain are more reliably found at ages of 6 and above, while ejection fraction starts to deteriorate at an older age. Progressive left ventricular dysfunction in Duchenne patients is one of the key issues and starts at an early age with subtle symptoms. Conclusion: This cross-sectional study provides supporting evidence that global longitudinal strain is an earlier marker of disease progression than ejection fraction in Duchenne patients
Order and phase nucleation in nonequilibrium nanocomposite Fe-Pt thin films with perpendicular magnetic anisotropy
We report on the time evolution of mass transport upon annealing nonequilibrium Fe-Pt nanocomposite films, leading to nucleation of L1(0) chemically ordered phase. The nonequilibrium nanocomposite films were fabricated by applying Fe(+) ion implantation to epitaxial Pt films grown on (001) MgO substrates, yielding Fe nanoclusters embedded in a Pt matrix at a tailored penetration depth. Time-resolved x-ray diffraction studies were carried out using synchrotron radiation, allowing determination of the activation energy for nucleation of the FePt L1(0) phase within the segregated nanoclusters during annealing. The growth of the segregated L1(0) ordered phase was modeled using ideal grain-size law and found to be dominated by strain-driven surface nucleation. The activation energies were found to correlate with the nanocluster size. Magnetic characterization of selected annealed samples indicates perpendicular magnetic anisotropy with high coercive field coincident with high value of the chemical order parameter of the ordered phase within the magnetic nanoclusters
Optimizing the planar structure of (1 1 1) Au/Co/Au trilayers
Au/Co/Au trilayers are interesting for a range of applications which exploit their unusual optical and electronic transport behaviour in a magnetic field. Here we present a comprehensive structural and morphological study of a series of trilayers with 0–7 nm Co layer thickness fabricated on glass by ultrahigh vacuum vapour deposition. We use a combination of in situ electron diffraction, atomic force microscopy and x-ray scattering to determine the optimum deposition conditions for highly textured, flat and continuous layered structures. The 16 nm Au-on-glass buffer layer, deposited at ambient temperature, is found to develop a smooth (1 1 1) texture on annealing at 350 °C for 10 min. Subsequent growth of the Co layer at 150 °C produces a (1 1 1) textured film with lateral grain size of ∼150 nm in the 7 nm-thick Co layer. A simultaneous in-plane and out-of-plane Co lattice expansion is observed for the thinnest Co layers, converging to bulk values for the thickest films. The roughness of the Co layer is similar to that of the Au buffer layer, indicative of conformal growth. The 6 nm Au capping layer smoothens the trilayer surface, resulting in a surface roughness independent of the Co layer thickness.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58140/2/d7_9_003.pd
Control of the perpendicular magnetic anisotropy of FePd films via Pd capping deposition
We have investigated the influence of two capping layers (MgO and Pd) on the magnetic anisotropy of highly anisotropic L10 FePd films. While we mainly found perpendicular magnetic anisotropy in MgO capped films, we observed that the Pd capping layer induces formation of an additional new phase near the FePd/Pd interface that exhibits in-plane magnetic anisotropy. The combined effect of these two anisotropies results in global canted magnetic anisotropy. Thus, our findings illustrate a mechanism to influence the magnetic anisotropy in FePd highly ordered alloys via adequate choice
of capping layer materials.Peer reviewe
Niobium thin film deposition studies on copper surfaces for superconducting radio frequency cavity applications
Thin film coatings have the potential to increase both the thermal efficiency and accelerating gradient in superconducting radio frequency accelerator cavities. However, before this potential can be realized, systematic studies on structure-property correlations in these thin films need to be carried out since the reduced geometry, combined with specific growth parameters, can modify the physical properties of the materials when compared to their bulk form. Here, we present our systematic studies of Nb thin films deposited onto Cu surfaces to clarify possible reasons for the limited success that this process exhibited in previous attempts. We compare these films with Nb grown on other surfaces. In particular, we study the crystal structure and surface morphology and their effect on superconducting properties, such as critical temperature and lower critical field. We found that higher deposition temperature leads to a sharper critical temperature transition, but also to increased roughness indicating that there are competing mechanisms that must be considered for further optimization
Fengycin and the amyloid TasA of Bacillus subtilis stimulates the growth and immunization of plants by targeting the seed storages
Beneficial microbes are known to stimulate the germination of the seeds; however, the exact mechanisms mediating these interactions are only beginning. Bacillus subtilis is a commonly detected member of the plant holobiont and provides multifaceted traits to the plant health. In this work, we demonstrated that B. subtilis triggered genetic and physiological responses in seeds that resulted in changes in the metabolic and developmental status of adult plants.
A multidisciplinary approach based on microscopy, transcriptomics and metabolomics demonstrated that the chemically diverse extracellular matrix of Bacillus structurally cooperate in bacterial colonization of the seed storage tissues. The amyloid protein TasA and fengycin, two components of the extracellular matrix differentially stimulated levels of ROS inside seeds after imbibition and targeted the oil bodies of the seed endosperm, provoking specific changes in lipid metabolism or accumulation of glutathione-related molecules that resulted in two different plant growth programs: the development of seed radicles or major growth and immunization of adult plants. Our findings prove the versatility of the bacterial ECM in establishing a mutualistic interaction with plants.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
The impact of silent vascular brain burden in cognitive impairment in Parkinson's disease
White matter hyperintensities (WMHs) detected by magnetic
resonance imaging (MRI) of the brain are associated with dementia and cognitive
impairment in the general population and in Alzheimer's disease. Their effect in
cognitive decline and dementia associated with Parkinson's disease (PD) is still
unclear. METHODS: We studied the relationship between WMHs and cognitive state in
111 patients with PD classified as cognitively normal (n = 39), with a mild
cognitive impairment (MCI) (n = 46) or dementia (n = 26), in a cross-sectional
and follow-up study. Cognitive state was evaluated with a comprehensive
neuropsychological battery, and WMHs were identified in FLAIR and T2-weighted
MRI. The burden of WMHs was rated using the Scheltens scale. RESULTS: No
differences in WMHs were found between the three groups in the cross-sectional
study. A negative correlation was observed between semantic fluency and the
subscore for WMHs in the frontal lobe. Of the 36 non-demented patients
re-evaluated after a mean follow-up of 30 months, three patients converted into
MCI and 5 into dementia. Progression of periventricular WMHs was associated with
an increased conversion to dementia. A marginal association between the increase
in total WMHs burden and worsening in the Mini Mental State Examination was
encountered. CONCLUSIONS: White matter hyperintensities do not influence the
cognitive status of patients with PD. Frontal WMHs have a negative impact on
semantic fluency. Brain vascular burden may have an effect on cognitive
impairment in patients with PD as WMHs increase overtime might increase the risk
of conversion to dementia. This finding needs further confirmation in larger
prospective studies
Detection of very high energy gamma-ray emission from the gravitationally-lensed blazar QSO B0218+357 with the MAGIC telescopes
Context. QSO B0218+357 is a gravitationally lensed blazar located at a
redshift of 0.944. The gravitational lensing splits the emitted radiation into
two components, spatially indistinguishable by gamma-ray instruments, but
separated by a 10-12 day delay. In July 2014, QSO B0218+357 experienced a
violent flare observed by the Fermi-LAT and followed by the MAGIC telescopes.
Aims. The spectral energy distribution of QSO B0218+357 can give information on
the energetics of z ~ 1 very high energy gamma- ray sources. Moreover the
gamma-ray emission can also be used as a probe of the extragalactic background
light at z ~ 1. Methods. MAGIC performed observations of QSO B0218+357 during
the expected arrival time of the delayed component of the emission. The MAGIC
and Fermi-LAT observations were accompanied by quasi-simultaneous optical data
from the KVA telescope and X-ray observations by Swift-XRT. We construct a
multiwavelength spectral energy distribution of QSO B0218+357 and use it to
model the source. The GeV and sub-TeV data, obtained by Fermi-LAT and MAGIC,
are used to set constraints on the extragalactic background light. Results.
Very high energy gamma-ray emission was detected from the direction of QSO
B0218+357 by the MAGIC telescopes during the expected time of arrival of the
trailing component of the flare, making it the farthest very high energy
gamma-ray sources detected to date. The observed emission spans the energy
range from 65 to 175 GeV. The combined MAGIC and Fermi-LAT spectral energy
distribution of QSO B0218+357 is consistent with current extragalactic
background light models. The broad band emission can be modeled in the
framework of a two zone external Compton scenario, where the GeV emission comes
from an emission region in the jet, located outside the broad line region.Comment: 11 pages, 6 figures, accepted for publication in A&
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