In this paper we study the effect of volumetric fraction and bilayer modulation period (Λ) on mechanical properties of metal/ceramic multilayer coatings. Two sets of Zr/ZrN multilayer systems with ...different modulation period and volumetric fraction were synthesized by DC reactive magnetron sputtering. The crystalline structure of the multilayers films was determined by X-ray diffraction and morphology were analyzed by AFM and TEM, which show that crystalline films are formed in all cases. High resolution TEM analysis revealed well-formed multilayer composites with very smooth layers. Nanoindentation tests were carried out to measure the mechanical properties of the multilayer Zr/ZrN coating. Hardness (H), elastic modulus (E) and elastic recovery (We) were determined by using the Oliver and Pharr method, the values are also discussed in terms of H3/E2 ratio. The results show that mechanical properties varied according to volumetric fraction Zr/ZrN. However, coatings with metallic volume fraction between 10% and 20% showed a significant improvement in hardness of 16–21% in comparison with monolithic ZrN values. Moreover, the best values for elastic recovery and resistance to plastic deformation (H3/E2) also were found in Zr/ZrN multilayer with 10–20% of metallic phase, increasing up to 12% on We and up to 79% on H3/E2. These results allowed further understanding of the mechanical behavior of multilayer systems, demonstrating with this the importance of volumetric fraction in a metal/ceramic system.
Sodium bicarbonate (NaHCO3) is a common treatment for metabolic acidemia; however, little definitive information exists regarding its treatment efficacy and cerebral hemodynamic effects. This pilot ...observational study quantifies relative changes in cerebral blood flow (ΔrCBF) and oxy- and deoxyhemoglobin concentrations (ΔHbO2 and ΔHb) due to bolus administration of NaHCO3 in patients with mild base deficits.
Infants and children with hypoplastic left heart syndrome (HLHS) were enrolled before cardiac surgery. NaHCO3 was given as needed for treatment of base deficit. Diffuse optical spectroscopies were used for 15 min postinjection to noninvasively monitor ΔHb, ΔHbO2, and ΔrCBF relative to baseline before NaHCO3 administration.
Twenty-two anesthetized and mechanically ventilated patients with HLHS (aged 1 d to 4 y) received a median (interquartile range) dose of 1.1 (0.8, 1.8) mEq/kg NaHCO3 administered intravenously over 10-20 s to treat a median (interquartile range) base deficit of -4 (-6, -3) mEq/l. NaHCO3 caused significant dose-dependent increases in ΔrCBF; however, population-averaged ΔHb and ΔHbO2 as compared with those of controls were not significant.
Dose-dependent increases in cerebral blood flow (CBF) caused by bolus administration of NaHCO3 are an important consideration in vulnerable populations wherein risk of rapid CBF fluctuations does not outweigh the benefit of treating a base deficit.
Solving the phase problem in x-ray crystallography has occupied a considerable scientific effort in the 20th century and led to great advances in structural science. Here we use x-ray ptychography to ...demonstrate an interference method which measures the phase of the beam transmitted through a crystal, relative to the incoming beam, when diffraction takes place. The observed phase change of the direct beam through a small gold crystal is found to agree with both a quasikinematical model and full dynamical theories of diffraction. Our discovery of a diffraction contrast mechanism will enhance the interpretation of data obtained from crystalline samples using the ptychography method, which provides some of the most accurate x-ray phase-contrast images.
Growth hormone insensitivity: Mexican case report Castilla-Cortazar, I; De Ita, J R; Aguirre, G A ...
Endocrinology, diabetes & metabolism case reports,
11/2017, Letnik:
2017, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Summary Herein, we present a 14-year-old patient with short stature (134 cm) referred from Paediatrics to our department for complementary evaluation since growth hormone (GH) treatment failed to ...show any improvement. He was born premature and small for gestational age. Genital examination classified the patient as Tanner I–II with small penis and testicular size for his age. Biochemical analyses revealed normal GH levels with low serum insulin-like growth factor-1 (IGF-1). Molecular diagnosis confirmed several mutations in IGF1R and IGFALS, and so he was diagnosed with Laron Syndrome or GH insensibility and treated with IGF-1 substitutive therapy. Learning points: Evaluation of the GH/IGF-1 axis when short stature does not respond to conservative treatment must be included in the ordinary practice. Laron Syndrome real incidence should be calculated once undiagnosed cases arise, as treatment, due to lack of market, is unaffordable. Even when adulthood is reached, and no longitudinal growth can be achieved, still IGF-1 treatment in Laron Syndrome patients should be pursued as metabolic and protective derangements could arise.
This paper presents updated estimates of source parameters for GW150914, a binary black-hole coalescence event detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015 ...Abbott et al. Phys. Rev. Lett. 116, 061102 (2016).. Abbott et al. Phys. Rev. Lett. 116, 241102 (2016). presented parameter estimation of the source using a 13-dimensional, phenomenological precessing-spin model (precessing IMRPhenom) and an 11-dimensional nonprecessing effective-one-body (EOB) model calibrated to numerical-relativity simulations, which forces spin alignment (nonprecessing EOBNR). Here, we present new results that include a 15-dimensional precessing-spin waveform model (precessing EOBNR) developed within the EOB formalism. We find good agreement with the parameters estimated previously Abbott et al. Phys. Rev. Lett. 116, 241102 (2016)., and we quote updated component masses of 35(+5)(-3) solar M; and 30(+3)(-4) solar M; (where errors correspond to 90 symmetric credible intervals). We also present slightly tighter constraints on the dimensionless spin magnitudes of the two black holes, with a primary spin estimate is less than 0.65 and a secondary spin estimate is less than 0.75 at 90% probability. Abbott et al. Phys. Rev. Lett. 116, 241102 (2016). estimated the systematic parameter-extraction errors due to waveform-model uncertainty by combining the posterior probability densities of precessing IMRPhenom and nonprecessing EOBNR. Here, we find that the two precessing-spin models are in closer agreement, suggesting that these systematic errors are smaller than previously quoted.
The human metapneumovirus (hMPV) is a recently described respiratory RNA virus that mainly affects children. To date there has not been a report that describes the detection of this virus in Mexico. ...This study was performed to detect hMPV in hospitalized Mexican children with respiratory infections, and describe their epidemiological and clinical characteristics. Nasal wash samples from 558 children younger than 3 years of age with the admission diagnosis of a respiratory tract infection were evaluated. Respiratory viruses were detected in 221 children respiratory syncytial virus (RSV), 193 (34.6 %); influenza virus, 13 (2.3 %); parainfluenza viruses, 15 (2.7 %). Respiratory secretions of 323 children in whom the presence of these viruses was excluded (131 admitted during the 2002-2003 respiratory season and 192 during the 2003-2004 season) were tested for hMPV infection. The hMPV genome was detected in 34 specimens by amplification using real-time RT-PCR. Sequencing of amplicons and phylogenetic analysis indicated the predominance of genotype A hMPV. The months with the highest number of hMPV detections were February and March. During the 2002-2003 season hMPV activity peaked after the RSV season. During the 2003-2004 season hMPV and RSV epidemics occurred simultaneously. The clinical presentation of an hMPV infection was indistinguishable from other respiratory infections. Except for one death, the outcomes of the hMPV infections were good. In this study, among the viruses routinely tested for, hMPV was the second most common agent, after RSV, in children younger than 3 years of age hospitalized with respiratory tract infections.
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