Nanostructural insights into the dissolution behavior of Sr-doped hydroxyapatite

In this study, high-resolution transmission electron microscopy (HRTEM) was employed to characterize the nanostructure of strontium-substituted hydroxyapatite (Sr-HA) and its evolution following in vitro immersion in physiological solutions. HRTEM images showed that the substitution of Sr induced local distortions in the hydroxyapatite (HA) lattice: minor levels of edge dislocations were detected at low doping contents of Sr ions (1 at%); when the Sr content exceeded 10 at%, the density of grain boundaries increased notably and triple junctions were clearly observed. The dissolution of undoped HA was initiated at crystallite surfaces, whereas the dissolution of Sr-HA started around grain boundaries. Acicular nanocrystal reprecipitation was observed on grain surfaces immersed in simulated body fluid (SBF), while not in dilute hydrochloric acid (HCl). These ?ndings suggest appropriate levels of Sr incorporation can introduce imperfections in the crystal structure of apatite and thus enhance its dissolution rate towards enhanced physicochemical performance in biomedical applications.     

Migration and the Multi-Dimensional Well-Being of Elderly Persons in Georgia

High rates of migration coupled with low formal social protection provisions may place many members of the elderly Georgian population in precarious living conditions that promote vulnerability and limit well-being achievement. This potential connection has been poorly explored in past literature, however, suggesting a need to better assess how the migration of an adult child may influence the multidimensional well-being of the elderly in Georgia. Using a novel dataset comprising 2202 elderly individuals across all regions of Georgia (excepting the territories of Abkhazia and South Ossetia), this paper proposes a multidimensional well-being index that has been specifically designed to encompass the unique resources and constraints faced by elderly individuals in different age cohorts. Following the construction of a multidimensional well-being index—comprised of domains including physical health and independence, housing well-being, social well-being, and emotional well-being—the outcomes of elderly individuals are compared by age and the presence/absence of adult children due to migration. Findings suggest that the migration status of an elderly person’s adult children is related to the attainment of well-being. Elderly individuals with a migrant child are more likely to attain well-being in physical health as well as in the overall multidimensional well-being index.     

Evaluation of Bioelectromethanogenesis Part I: Energy Calculations

Bioelectromethanogenesis, a technology to convert electrical energy into CH₄, is on the transition from lab-scale to industrial application. But the question arises if it is really a sustainable technology or just another scientific artifact. Especially the energy efficiency is a crucial aspect to allow conclusions about the applicability. In this paper, the basics of energy calculations are applied to literature data to model the energy efficiency. Different scenarios were calculated, showing that further research has to be conducted to turn bioelectromethanogenesis into a feasible technology.     

The effect of gel structure on the kinetics of simulated gastrointestinal digestion of bovine β-lactoglobulin

The structure and properties of protein gels depend on the conditions under which they are formed. Here, we assessed the susceptibility of protein to simulated gastro-duodenal digestion of weak gels with contrasting structures, produced from either purified bovine β-lactoglobulin (β-Lg) or whey protein isolate (WPI) at pH ranging from 2.5 to 6.5 and using different heating regimes. Gels formed close to the isoelectric point proved to be very resistant to simulated gastric digestion, with more than 85% of β-Lg remaining and in the simulated duodenal phase of digestion. The sample heated to 85 °C was most resistant with over 40% remaining. In the WPI sample heated to 85 °C, more than 20% of the original β-Lg content remained undigested after simulated gastro-duodenal proteolysis. These results suggest that firm particulate gels can persist longer in the GI tract and may be useful in inducing satiety and thus provide another weapon in the fight against obesity.     

Modulation of Endocannabinoids by Caloric Restriction Is Conserved in Mice but Is Not Required for Protection from Acute Kidney Injury

Acute kidney injury (AKI) is a frequent and critical complication in the clinical setting. In rodents, AKI can be effectively prevented through caloric restriction (CR), which has also been shown to increase lifespan in many species. In Caenorhabditis elegans (C. elegans), longevity studies revealed that a marked CR-induced reduction of endocannabinoids may be a key mechanism. Thus, we hypothesized that regulation of endocannabinoids, particularly arachidonoyl ethanolamide (AEA), might also play a role in CR-mediated protection from renal ischemia-reperfusion injury (IRI) in mammals including humans. In male C57Bl6J mice, CR significantly reduced renal IRI and led to a significant decrease of AEA. Supplementation of AEA to near-normal serum concentrations by repetitive intraperitoneal administration in CR mice, however, did not abrogate the protective effect of CR. We also analyzed serum samples taken before and after CR from patients of three different pilot trials of dietary interventions. In contrast to mice and C. elegans, we detected an increase of AEA. We conclude that endocannabinoid levels in mice are modulated by CR, but CR-mediated renal protection does not depend on this effect. Moreover, our results indicate that modulation of endocannabinoids by CR in humans may differ fundamentally from the effects in animal models.     

Neuartige Goldkatalysatoren auf Alumophosphat‐Basis für die direkte Propen‐Epoxidierung

Propene oxide is an important intermediate in chemical industry. Amongst others it is needed for the production of various plastics. As currently applied processes for the production of propene oxide either generate large amounts of undesired by‐products or are highly expensive regarding the reactants introduced to the process, it is desirable to epoxidate propene directly by aerial oxygen. It has been shown that this is possible by the use of supported gold catalysts. This contribution engages in the question to which extent titanium substituted alumophosphates are suitable as support for this kind of catalysts.     

Two tetraplex real-time PCR for the detection and quantification of DNA from eight allergens in food

According to the EU and Swiss legislation, food has to be labelled for allergens to enable allergic consumers to avoid such food and its products. To provide efficient and reliable methods, two novel quantitative multiplex real-time polymerase chain reaction systems were developed and validated. They simultaneously determine DNA of peanut, hazelnut, celery, soy, egg, milk, almond and sesame, respectively. The tests exhibit good specificity and sensitivity in the range of 0.01%. Due to low DNA amounts, lower sensitivities for egg and milk were obtained. First comparisons of ELISA results with PCR results suggest a qualitative accordance, but a low correlation of quantitative results.     

S-Palmitoylation of Synaptic Proteins as a Novel Mechanism Underlying Sex-Dependent Differences in Neuronal Plasticity

Although sex differences in the brain are prevalent, the knowledge about mechanisms underlying sex-related effects on normal and pathological brain functioning is rather poor. It is known that female and male brains differ in size and connectivity. Moreover, those differences are related to neuronal morphology, synaptic plasticity, and molecular signaling pathways. Among different processes assuring proper synapse functions are posttranslational modifications, and among them, S-palmitoylation (S-PALM) emerges as a crucial mechanism regulating synaptic integrity. Protein S-PALM is governed by a family of palmitoyl acyltransferases, also known as DHHC proteins. Here we focused on the sex-related functional importance of DHHC7 acyltransferase because of its S-PALM action over different synaptic proteins as well as sex steroid receptors. Using the mass spectrometry-based PANIMoni method, we identified sex-dependent differences in the S-PALM of synaptic proteins potentially involved in the regulation of membrane excitability and synaptic transmission as well as in the signaling of proteins involved in the structural plasticity of dendritic spines. To determine a mechanistic source for obtained sex-dependent changes in protein S-PALM, we analyzed synaptoneurosomes isolated from DHHC7-/- (DHHC7KO) female and male mice. Our data showed sex-dependent action of DHHC7 acyltransferase. Furthermore, we revealed that different S-PALM proteins control the same biological processes in male and female synapses.