A semi-analytical approach for the characterization of ordered 3D nano structures using grazing-incidence X-ray fluorescence

Following the recent demonstration of grazing-incidence X-ray fluorescence (GIXRF) based characterization of the 3D atomic distribution of different elements and dimensional parameters of periodic nanoscale structures, this work presents a new computational scheme for the simulation of the angular dependent fluorescence intensities from such periodic 2D and 3D nanoscale structures. The computational scheme is based on the dynamical diffraction theory in many-beam approximation, which allows to derive a semi-analytical solution to the Sherman equation in a linear-algebraic form. The computational scheme has been used to analyze recently published GIXRF data measured on 2D Si3N4 lamellar gratings, as well as on periodically structured 3D Cr nano pillars. Both the dimensional and structural parameters of these nanostructures have been reconstructed by fitting numeric simulations to the experimental GIXRF data. Obtained results show good agreement with nominal parameters used in the manufacturing of the structures, as well as with reconstructed parameters based on the previously published finite element method simulations, in case of the Si3N4 grating

Danger Invariants

Static analysers search for overapproximating proofs of safety commonly known as safety invariants. Conversely, static bug finders (e.g. Bounded Model Checking) give evidence for the failure of an assertion in the form of a counterexample trace. As opposed to safety invariants, the size of a counterexample is dependent on the depth of the bug, i.e., the length of the execution trace prior to the error state, which also determines the computational effort required to find them. We propose a way of expressing danger proofs that is independent of the depth of bugs. Essentially, such danger proofs constitute a compact representation of a counterexample trace, which we call a danger invariant. Danger invariants summarise sets of traces that are guaranteed to be able to reach an error state. Our conjecture is that such danger proofs will enable the design of bug finding analyses for which the computational effort is independent of the depth of bugs, and thus find deep bugs more efficiently. As an exemplar of an analysis that uses danger invariants, we design a bug finding technique based on a synthesis engine. We implemented this technique and compute danger invariants for intricate programs taken from SV-COMP 2016

Membrane Potential Controls Adipogenic and Osteogenic Differentiation of Mesenchymal Stem Cells

Background: Control of stem cell behavior is a crucial aspect of developmental biology and regenerative medicine. While the functional role of electrophysiology in stem cell biology is poorly understood, it has become clear that endogenous ion flows represent a powerful set of signals by means of which cell proliferation, differentiation, and migration can be controlled in regeneration and embryonic morphogenesis. Methodology/Principal Findings: We examined the membrane potential (Vmem) changes exhibited by human mesenchymal stem cells (hMSCs) undergoing adipogenic (AD) and osteogenic (OS) differentiation, and uncovered a characteristic hyperpolarization of differentiated cells versus undifferentiated cells. Reversal of the progressive polarization via pharmacological modulation of transmembrane potential revealed that depolarization of hMSCs prevents differentiation. In contrast, treatment with hyperpolarizing reagents upregulated osteogenic markers. Conclusions/Significance: Taken together, these data suggest that the endogenous hyperpolarization is a functiona

Inside and out: the activities of senescence in cancer.

The core aspect of the senescent phenotype is a stable state of cell cycle arrest. However, this is a disguise that conceals a highly active metabolic cell state with diverse functionality. Both the cell-autonomous and the non-cell-autonomous activities of senescent cells create spatiotemporally dynamic and context-dependent tissue reactions. For example, the senescence-associated secretory phenotype (SASP) provokes not only tumour-suppressive but also tumour-promoting responses. Senescence is now increasingly considered to be an integrated and widespread component that is potentially important for tumour development, tumour suppression and the response to therapy.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nrc377

Iscador Qu inhibits doxorubicin-induced senescence of MCF7 cells

Chemotherapy in patients with inoperable or advanced breast cancer inevitably results in low-dose exposure of tumor-cell subset and senescence. Metabolically active senescent cells secrete multiple tumor promoting factors making their elimination a therapeutic priority. Viscum album is one of the most widely used alternative anti-cancer medicines facilitating chemotherapy tolerance of breast cancer patients. The aim of this study was to model and investigate how Viscum album extracts execute additive anti-tumor activity with low-dose Dox using ER + MCF7 breast cancer cells. We report that cotreatment of MCF7 with Viscum album and Dox abrogates G2/M cycle arrest replacing senescence with intrinsic apoptotic program. Mechanistically, this switch was associated with down-regulation of p21, p53/p73 as well as Erk1/2 and p38 activation. Our findings, therefore, identify a novel mechanistic axis of additive antitumor activity of Viscum album and low dose-Dox. In conclusion, ER + breast cancer patients may benefit from addition of Viscum album to low-dose Dox chemotherapy due to suppression of cancer cell senescence and induction of apoptosis

A new \u3ci\u3ePotamobates\u3c/i\u3e Champion species (Heteroptera: Gerridae) from Ecuador with new distribution records for \u3ci\u3eP. williamsi \u3c/i\u3eHungerford

Abstract: Potamobates sumaco new species is described from the Ecuadorian Amazon. Male and female genitalia differentiate P. sumaco from a similar parapatric species, P. williamsi Hungerford. Phylogenetic analysis indicates P. sumaco is closely related to the species of the P. tridentatus group which includes P. williamsi. A distribution map and revised key to Potamobates species are provided. Resumen: Se describe Potamobates sumaco nueva especies del Amazonas Ecuatoriano. Los genitales del macho y la hembra distinguen P. sumaco de la especie mas cercana P. williamsi Hungerford. El analisis filogenetico indica que P. sumaco partenece a1 grupo P. tridentatus. Se incluye un mapa de la distribucion y una clave modificada para la identificacion de las especies de Potamobates

Evaluation of the Results from an Inter-laboratory Comparison Study for the Determination of Acrylamide in Crispbread and Butter Cookies.

Abstract not availableJRC.D-Institute for Reference Materials and Measurements (Geel