Radiation-damage produced in BaHfO₃ irradiated with thermal and fast-neutrons

Samples of BaHfO₃ were irradiated with fast and thermal neutrons to produce ^181Hf. Attenuations of the gamma-gamma perturbed angular correlations in ^181Ta were observed, and they may have been caused by the interaction between defects (produced during or after neutron irradiation) and oxygen vacancies. Several defect structures were detected. For one of the structures, an excitation energy of 12 meV was measured, which was attributed to an electron state below the conduction band. The values of the dielectric constant and of the effective electron mass were also deduced

La producción de la Universidad española en Física, reflejada en las publicaciones españolas y extranjeras

The scientific productíon of Spanish Universities in the field of Physics for the period 1986-88 is analyzed with data obtaincd from two databases: INSPEC, whích covcrs publications in foreign journals and also, but only in a selective way, those published in a certain numbcr of Spanísh journals; and ICYT, which covcrs comprehcnsively ali original papcrs published in Spanish journals. Comparison of the two series of data Ieads to ccrtain conclusions as rcgards the trends to publish in foreign journals. A further comparison is made betwcen the periods 1982-85 and 1986-88, with thc data obtained from INSPEC.Se analiza la producción científica de la Universidad española en el campo de la Física, y en el período 1986-88, a través de dos bases de datos: INSPEC, que recoge lo publicado en revistas extranjeras y también, aunque de modo selectivo, en cierto número de revistas españolas; e ICYT, que recoge exhaustivamente todos los trabajos originales publicados en revistas españolas. La comparación entre ambas series de datos permite deducir tendencias de publícación en el extranjero. Asimismo se analizan comparativamente los periodos 1982-85 y 1986-88, con los datos obtenidos de INSPEC

Gold Nanoparticles Generated in Ethosome Bilayers, As Revealed by Cryo-Electron-Tomography

Gold nanoparticles have been synthesized inside ethosomes, vesicles composed of phospholipid, ethanol and water, which could be very efficient not only in delivery probes to the skin but also as diagnostic and therapeutic multimodal agents. High efficiency encapsulation of gold nanoparticles is achieved by a simple strategy: the nanoparticles synthesis occurs simultaneously with the ethosomes formation, in the absence of any undesirable reducing agents. A three-dimensional reconstruction of a gold-embedded ethosome generated by cryoelectron tomography reveals that the gold particle is localized inside the lipid bilayer, leaving the ethosome surface and core free for further functionalization. The resulting gold nanoparticles are homogeneous in size and shape and, depending on synthesis temperature, the size ranges from 10 to 20 nm, as revealed by TEM. The ethosome-nanoparticles hybrids size has been investigated by means of dynamic light scattering and has been found to vary with temperature and gold salt concentration from 700 to 400 nm. Gold nanoparticles encapsulated ethosomes offer a versatile platform for the enhancement of pharmacological efficacy in transdermal and dermal delivery systems.Comment: 2 videos of the cryo-electron tomographic reconstruction in Supporting Informatio

Positive psychology of Malaysian students: impacts of engagement, motivation, self-compassion and wellbeing on mental health

Malaysia plays a key role in education of the Asia Pacific, expanding its scholarly output rapidly. However, mental health of Malaysian students is challenging, and their help-seeking is low because of stigma. This study explored the relationships between mental health and positive psychological constructs (academic engagement, motivation, self-compassion, and wellbeing), and evaluated the relative contribution of each positive psychological construct to mental health in Malaysian students. An opportunity sample of 153 students completed the measures regarding these constructs. Correlation, regression, and mediation analyses were conducted. Engagement, amotivation, self-compassion, and wellbeing were associated with, and predicted large variance in mental health. Self-compassion was the strongest independent predictor of mental health among all the positive psychological constructs. Findings can imply the strong links between mental health and positive psychology, especially selfcompassion. Moreover, intervention studies to examine the effects of self-compassion training on mental health of Malaysian students appear to be warranted.N/

Increased circulating ANG II and TNF-α represents important risk factors in obese Saudi adults with hypertension irrespective of diabetic status and BMI

Central adiposity is a significant determinant of obesity-related hypertension risk, which may arise due to the pathogenic inflammatory nature of the abdominal fat depot. However, the influence of pro-inflammatory adipokines on blood pressure in the obese hypertensive phenotype has not been well established in Saudi subjects. As such, our study investigated whether inflammatory factors may represent useful biomarkers to delineate hypertension risk in a Saudi cohort with and without hypertension and/or diabetes mellitus type 2 (DMT2). Subjects were subdivided into four groups: healthy lean controls (age: 47.9±5.1 yr; BMI: 22.9±2.1 Kg/m2), non-hypertensive obese (age: 46.1±5.0 yr; BMI: 33.7±4.2 Kg/m2), hypertensive obese (age: 48.6±6.1 yr; BMI: 36.5±7.7 Kg/m2) and hypertensive obese with DMT2 (age: 50.8±6.0 yr; BMI: 35.3±6.7 Kg/m2). Anthropometric data were collected from all subjects and fasting blood samples were utilized for biochemical analysis. Serum angiotensin II (ANG II) levels were elevated in hypertensive obese (p<0.05) and hypertensive obese with DMT2 (p<0.001) compared with normotensive controls. Systolic blood pressure was positively associated with BMI (p<0.001), glucose (p<0.001), insulin (p<0.05), HOMA-IR (p<0.001), leptin (p<0.01), TNF-α (p<0.001) and ANG II (p<0.05). Associations between ANG II and TNF-α with systolic blood pressure remained significant after controlling for BMI. Additionally CRP (p<0.05), leptin (p<0.001) and leptin/adiponectin ratio (p<0.001) were also significantly associated with the hypertension phenotype. In conclusion our data suggests that circulating pro-inflammatory adipokines, particularly ANG II and, TNF-α, represent important factors associated with a hypertension phenotype and may directly contribute to predicting and exacerbating hypertension risk

Particle interactions in liquid magnetic colloids by zero field cooled measurements: effects on heating efficiency

The influence of magnetic interactions in assemblies formed by either aggregated or disaggregated uniform gamma-Fe_2O_3 particles are investigated as a function of particle size, concentration, and applied field. Hyperthermia and magnetization measurements are performed in the liquid phase of colloids consisting of 8 and 13 nm uniform gamma-Fe_2O_3 particles dispersed in water and hexane. Although hexane allows the disagglomerated obtaining particle system; aggregation is observed in the case of water colloids. The zero field cooled (ZFC) curves show a discontinuity in the magnetization values associated with the melting points of water and hexane. Additionally, for 13 nm gamma-Fe_2O_3 dispersed in hexane, a second magnetization jump is observed that depends on particle concentration and shifts toward lower temperature by increasing applied field. This second jump is related to the strength of the magnetic interactions as it is only present in disagglomerated particle systems with the largest size, i.e., is not observed for 8 nm superparamagnetic particles, and surface effects can be discarded. The specific absorption rate (SAR) decreases with increasing concentration only for the hexane colloid, whereas for aqueous colloids, the SAR is almost independent of particle concentration. Our results suggest that, as a consequence of the magnetic interactions, the dipolar field acting on large particles increases with concentration, leading to a decrease of the SAR