Synthesis of ZnO in aqueous media. Influence of several synthesis parameters on particle size and shape

No abstract availabl

Pigments ceràmics encapsulats

En aquesta comunicació es presenta un panorama actual del món de la investigació en pigments ceràmics, amb les diferents classificacions establertes per a la seua classificació sistemàtica, s'emfatitza la via del encapsulament de colors ceràmics mitjançant rutes de síntesis sol-gel com la més innovadora, prometedora i rendible de totes les vies d'investigació en el camp dels pigments ceràmics, i es presenten alguns resultats aclaridors respecte de repeste de la naturalesa d'aquests pigments

In-situ laser synthesis of rare earth aluminate coatings in the system Ln-Al-O (Ln = Y, Gd)

Laser zone melting (LZM) was employed in this work to prepare Ln-Al-O coatings on polycrystalline Al2O3 substrates, using the corresponding mixtures of powdered rare-earth oxides and Al2O 3 as starting materials. In-situ synthesis of the compounds Ln = Y, Gd was performed using a CO2 laser, emitting at 10.6 μm. Microstructure (SEM) and phase nature (XRD) demonstrated in-situ formation of Al2O3/Y3Al5O12(YAG) and Al2O3/GdAlO3(GAP) eutectic systems. The interaction with the substrate resulted in mechanically stable, well integrated 200-500 μm thick composite coatings, as observed in nanoindentation tests. The phase relations found in these materials are consistent with the crystallographic concepts advanced by Vegas (Ramos-Gallardo & Vegas, J. Solid State Chem. 128 (1997) 69), where cation sub-arrays are proposed to play an important role in governing metal oxide structures. These sub-arrays are suggested as the structural drive behind eutectic oxide formation. LZM proves to be a convenient method to investigate the behaviour of complex oxide systems at high temperature, to apply a rational concept towards the understanding of phase relations and to develop design criteria for oxide coatings. © 2011 Elsevier Masson SAS. All rights reserved.The authors gratefully acknowledge the financial support from the Spanish Government (projects CEN 2007-2014, MAT2010- 18519 and SURFALUX SOL-00030930),Peer Reviewe

Correlation between microstructure and electric properties in SnO(2) rich enamels

No abstract availabl

Drug Use Mediates the Relationship Between Depressive Symptoms and Adherence to ART Among Recently Incarcerated People Living with HIV

Depression is a known risk factor for antiretroviral therapy (ART) non-adherence, but little is known about the mechanisms explaining this relationship. Identifying these mechanisms among people living with HIV (PLHIV) after release from prison is particularly important, as individuals during this critical period are at high risk for both depression and poor ART adherence. 347 PLHIV recently released from prison in North Carolina and Texas were included in analyses to assess mediation of the relationship between depressive symptoms at 2 weeks post-release and ART adherence (assessed by unannounced telephone pill counts) at weeks 9–21 post-release by the hypothesized explanatory mechanisms of alcohol use, drug use, adherence self-efficacy, and adherence motivation (measured at weeks 6 and 14 post-release). Indirect effects were estimated using structural equation models with maximum likelihood estimation and bootstrapped confidence intervals. On average, participants achieved 79% ART adherence. The indirect effect of depression on adherence through drug use was statistically significant; greater symptoms of depression were associated with greater drug use, which was in turn associated with lower adherence. Lower adherence self-efficacy was associated with depressive symptoms, but not with adherence. Depression screening and targeted mental health and substance use services for depressed individuals at risk of substance use constitute important steps to promote adherence to ART after prison release

Biomimetic rehabilitation engineering: the importance of somatosensory feedback for brain-machine interfaces.

Brain-machine interfaces (BMIs) re-establish communication channels between the nervous system and an external device. The use of BMI technology has generated significant developments in rehabilitative medicine, promising new ways to restore lost sensory-motor functions. However and despite high-caliber basic research, only a few prototypes have successfully left the laboratory and are currently home-deployed. The failure of this laboratory-to-user transfer likely relates to the absence of BMI solutions for providing naturalistic feedback about the consequences of the BMI's actions. To overcome this limitation, nowadays cutting-edge BMI advances are guided by the principle of biomimicry; i.e. the artificial reproduction of normal neural mechanisms. Here, we focus on the importance of somatosensory feedback in BMIs devoted to reproducing movements with the goal of serving as a reference framework for future research on innovative rehabilitation procedures. First, we address the correspondence between users' needs and BMI solutions. Then, we describe the main features of invasive and non-invasive BMIs, including their degree of biomimicry and respective advantages and drawbacks. Furthermore, we explore the prevalent approaches for providing quasi-natural sensory feedback in BMI settings. Finally, we cover special situations that can promote biomimicry and we present the future directions in basic research and clinical applications. The continued incorporation of biomimetic features into the design of BMIs will surely serve to further ameliorate the realism of BMIs, as well as tremendously improve their actuation, acceptance, and use

Fluid Mechanics in Dentinal Microtubules Provides Mechanistic Insights into the Difference between Hot and Cold Dental Pain

Dental thermal pain is a significant health problem in daily life and dentistry. There is a long-standing question regarding the phenomenon that cold stimulation evokes sharper and more shooting pain sensations than hot stimulation. This phenomenon, however, outlives the well-known hydrodynamic theory used to explain dental thermal pain mechanism. Here, we present a mathematical model based on the hypothesis that hot or cold stimulation-induced different directions of dentinal fluid flow and the corresponding odontoblast movements in dentinal microtubules contribute to different dental pain responses. We coupled a computational fluid dynamics model, describing the fluid mechanics in dentinal microtubules, with a modified Hodgkin-Huxley model, describing the discharge behavior of intradental neuron. The simulated results agreed well with existing experimental measurements. We thence demonstrated theoretically that intradental mechano-sensitive nociceptors are not “equally sensitive” to inward (into the pulp) and outward (away from the pulp) fluid flows, providing mechanistic insights into the difference between hot and cold dental pain. The model developed here could enable better diagnosis in endodontics which requires an understanding of pulpal histology, neurology and physiology, as well as their dynamic response to the thermal stimulation used in dental practices

Elevated plasma levels of cardiac troponin-I predict left ventricular systolic dysfunction in patients with myotonic dystrophy type 1:A multicentre cohort follow-up study

Objective: High sensitivity plasma cardiac troponin-I (cTnI) is emerging as a strong predictor of cardiac events in a variety of settings. We have explored its utility in patients with myotonic dystrophy type 1 (DM1). Methods: 117 patients with DM1 were recruited from routine outpatient clinics across three health boards. A single measurement of cTnI was made using the ARCHITECT STAT Troponin I assay. Demographic, ECG, echocardiographic and other clinical data were obtained from electronic medical records. Follow up was for a mean of 23 months. Results: Fifty five females and 62 males (mean age 47.7 years) were included. Complete data were available for ECG in 107, echocardiography in 53. Muscle Impairment Rating Scale score was recorded for all patients. A highly significant excess (p = 0.0007) of DM1 patients presented with cTnI levels greater than the 99th centile of the range usually observed in the general population (9 patients; 7.6%). Three patients with elevated troponin were found to have left ventricular systolic dysfunction (LVSD), compared with four of those with normal range cTnI (33.3% versus 3.7%; p = 0.001). Sixty two patients had a cTnI level < 5ng/L, of whom only one had documented evidence of LVSD. Elevated cTnI was not predictive of severe conduction abnormalities on ECG, or presence of a cardiac device, nor did cTnI level correlate with muscle strength expressed by Muscle Impairment Rating Scale score. Conclusions: Plasma cTnI is highly elevated in some ambulatory patients with DM1 and shows promise as a tool to aid cardiac risk stratification, possibly by detecting myocardial involvement. Further studies with larger patient numbers are warranted to assess its utility in this setting