Structural phase transitions in the Ag2Nb4O11 – Na2Nb4O11 solid solution

The phase transitions between various structural modifications of the natrotantite-structured system xAg2Nb4O11 – (1-x)Na2Nb4O11 have been investigated and a phase diagram constructed as a function of temperature and composition. This shows three separate phase transition types: (1) paraelectric – ferroelectric, (2) rhombohedral – monoclinic and (3) a phase transition within the ferroelectric rhombohedral zone between space groups R3c and R3. The parent structure for the entire series has space group R-3c. Compositions with x > 0.75 are rhombohedral at all temperatures whereas compositions with x < 0.75 are all monoclinic at room temperature and below. At x = 0.75, rhombohedral and monoclinic phases coexist with the phase boundary below room temperature being virtually temperature-independent. The ferroelectric phase boundary extends into the monoclinic phase field. No evidence was found for the R3–R3c phase boundary extending into the monoclinic phase field and it is concluded that a triple point is formed

Improved extraction of pine bark for wood adhesives

Pine bark tannins must be subjected to sulphonation to have an acceptable solubility in water for the preparation of wood adhesives. In this study, several extraction variables (sodium sulphite and urea concentrations in the extraction white liquor, extraction time, bark/liquor ratio and temperature) were assessed for their effect on extraction yield, and on the phenol, sulphur and ash content of extracts. Temperature had the highest positive effect on extraction yield and on the yield of total phenols in the extract. Sulphur content (i.e., the degree of sulphonation) was influenced mostly by sulphite concentration in white liquor, as was ash content

Mapping behavioral specifications to model parameters in synthetic biology

With recent improvements of protocols for the assembly of transcriptional parts, synthetic biological devices can now more reliably be assembled according to a given design. The standardization of parts open up the way for in silico design tools that improve the construct and optimize devices with respect to given formal design specifications. The simplest such optimization is the selection of kinetic parameters and protein abundances such that the specified design constraints are robustly satisfied. In this work we address the problem of determining parameter values that fulfill specifications expressed in terms of a functional on the trajectories of a dynamical model. We solve this inverse problem by linearizing the forward operator that maps parameter sets to specifications, and then inverting it locally. This approach has two advantages over brute-force random sampling. First, the linearization approach allows us to map back intervals instead of points and second, every obtained value in the parameter region is satisfying the specifications by construction. The method is general and can hence be incorporated in a pipeline for the rational forward design of arbitrary devices in synthetic biology

Self-assembly of endohedral metallofullerenes: A decisive role of cooling gas and metal-carbon bonding

The endohedral metallofullerene (EMF) self-assembly process in Sc/carbon vapor in the presence and absence of an inert cooling gas (helium) is systematically investigated using quantum chemical molecular dynamics simulations. It is revealed that the presence of He atoms accelerates the formation of pentagons and hexagons and reduces the size of the self-assembled carbon cages in comparison with analogous He-free simulations. As a result, the Sc/C/He system simulations produce a larger number of successful trajectories (i.e. leading to Sc-EMFs) with more realistic cage-size distribution than simulations of the Sc/C system. The main Sc encapsulation mechanism involves nucleation of several hexagons and pentagons with Sc atoms already at the early stages of carbon vapor condensation. In such proto-cages, both Sc–C σ-bonds and coordination bonds between Sc atoms and the π-system of the carbon network are present. Sc atoms are thus rather labile and can move along the carbon network, but the overall bonding is sufficiently strong to prevent dissociation even at temperatures around 2000 kelvin. Further growth of the fullerene cage results in the encapsulation of one or two Sc atoms within the fullerene. In agreement with experimental studies, an extension of the simulations to Fe and Ti as the metal component showed that Fe-EMFs are not formed at all, whereas Ti is prone to form Ti-EMFs with small cage sizes, including Ti@C28-Td and Ti@C30-C2v(3)

Formation of buckminsterfullerene (C60) in interstellar space

Buckminsterfullerene (C60) was recently confirmed to be the largest molecule identified in space. However, it remains unclear how, and where this molecule is formed. It is generally believed that C60 is formed from the build up of small carbonaceous compounds, in the hot and dense envelopes of evolved stars. Analyzing infrared observations, obtained by Spitzer and Herschel, we found that C60 is efficiently formed in the tenuous and cold environment of an interstellar cloud illuminated by strong ultraviolet (UV) radiation fields. This implies that another formation pathway, efficient at low densities, must exist. Based on recent laboratory and theoretical studies, we argue that Polycyclic Aromatic Hydrocarbons are converted into graphene, and subsequently C60, under UV irradiation from massive stars. This shows that alternative - top-down - routes are key to understanding the organic inventory in space.Comment: 22 pages, 4 figures, 3 sup. figures, 1 sup. vide

Internet-based guided self-help for glioma patients with depressive symptoms: a randomized controlled trial

Depressive symptoms are common in glioma patients, and can negatively affect health-related quality of life (HRQOL). We performed a nation-wide randomized controlled trial to evaluate the effects of an online guided self-help intervention for depressive symptoms in adult glioma patients. Glioma patients with depressive symptoms were randomized to a 5-week online course based on problem-solving therapy, or a waiting list control group. After having received the intervention, the glioma patient groups combined were compared with patients with cancer outside the central nervous system (non-CNS cancer controls), who also received the intervention. Sample size calculations yielded 63 participants to be recruited per arm. The primary outcome [depressive symptoms (CES-D)] and secondary outcomes [fatigue (Checklist Individual Strength (CIS)) and HRQOL (Short Form-36)], were assessed online at baseline, post-intervention, and 3 and 12 months follow-up. In total, 89 glioma patients (intervention N = 45; waiting list N = 44) and 26 non-CNS cancer controls were included, of whom 35 and 54% completed the intervention, respectively. Recruitment could not be extended beyond 3.5 years due to funding. On depression, no statistically significant differences between the groups were found. Fatigue decreased post-treatment in the glioma intervention group compared with the waiting list group (p = 0.054, d = 0.306). At 12 months, the physical component summary (HRQOL) remained stable in glioma patients, while scores improved in non-CNS cancer controls (p = 0.035, d = 0.883). In this underpowered study, no evidence for the effectiveness of online guided self-help for depression or HRQOL in glioma patients was found, but it may improve fatigue

Resolving the neural circuits of anxiety

Although anxiety disorders represent a major societal problem demanding new therapeutic targets, these efforts have languished in the absence of a mechanistic understanding of this subjective emotional state. While it is impossible to know with certainty the subjective experience of a rodent, rodent models hold promise in dissecting well-conserved limbic circuits. The application of modern approaches in neuroscience has already begun to unmask the neural circuit intricacies underlying anxiety by allowing direct examination of hypotheses drawn from existing psychological concepts. This information points toward an updated conceptual model for what neural circuit perturbations could give rise to pathological anxiety and thereby provides a roadmap for future therapeutic development.National Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (NIH Director’s New Innovator Award DP2-DK-102256-01)National Institute of Mental Health (U.S.) (NIH) R01-MH102441-01)JPB Foundatio

A PERSONALIDADE CIVIL DOS NASCITUROS E OS SEUS REFLEXOS JURÍDICO-PROCESSUAIS

Sempre foi acirrada a discussão sobre a personalidade e capacidade civil dos nascituros. Reconhecer-lhes a titularidade de direitos fez forçosa a análise sobre a capacidade de ser parte em um processo. O que se concluiu é que, mesmo prevalecendo no Brasil a Teoria Natalista, a Teoria da Personalidade Condicional se apresenta mais acertada, tendo em vista a necessidade de o Código Civil ser interpretado sistemática e teleologicamente com o texto constitucional, de modo que a protetividade das normas de direitos humanos estendam seus efeitos também a quem se encontra no ventre materno

Why simulate a sample of recycled wood?

Wood products follow the same cycle as other materials: manufacture, use and disposal. For certain applications, chemical additives are added to wood to increase its durability against biological and physical attack. At the end of life, waste wood is chipped or crushed before being recovered as raw material for new products or as fuel for energy. In recycled wood, there is the potential that some wood particles are contaminated by hazardous substances, such as organic or heavy metal preservatives. Therefore there is a need for a quality control method of assessing recovered wood that is on the one hand sufficiently precise and on the other not too expensive to preclude the use of recycling wood in to new products.This paper covers some preliminary research that is part of a large study that aims to develop a robust analytical method for recovered wood. However the extreme variability of recovered wood makes it difficult to develop such protocols on real recovered wood samples. Consequently, model chip piles with known contamination levels were created to simulate real world recovered wood samples