Interspecific variation in the relationship between clutch size, laying date and intensity of urbanization in four species of hole-nesting birds.

The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban compared to nearby natural areas.

Electronic properties of embedded graphene: doped amorphous silicon/CVD graphene heterostructures.

Large-area graphene film is of great interest for a wide spectrum of electronic applications, such as field effect devices, displays, and solar cells, among many others. Here, we fabricated heterostructures composed of graphene (Gr) grown by chemical vapor deposition (CVD) on copper substrate and transferred to SiO2/Si substrates, capped by n‑ or p-type doped amorphous silicon (a-Si:H) deposited by plasma-enhanced chemical vapor deposition. Using Raman scattering we show that despite the mechanical strain induced by the a-Si:H deposition, the structural integrity of the graphene is preserved.

Enhancing the Bipolar Redox Cycling Efficiency of Plane-Recessed Microelectrode Arrays by Adding a Chemically Irreversible Interferent.

The individual electrochemical anodic responses of dopamine (DA), epinephrine (EP), and pyrocatechol (CT) were investigated at arrays of recessed gold disk-microelectrodes arrays (MEAs) covered by a gold plane electrode and compared to those of their binary mixture (CT and EP) when the top-plane electrode was operated as a bipolar electrode or as a collector. The interferent species (EP) displays a chemically irreversible wave over the same potential range as the chemically reversible ones of DA or CT. As expected, in the generator-collector (GC) mode, EP did not contribute to the redox cycling amplification that occurred only for DA or CT.

Generation of Silicone Poly-HIPEs with Controlled Pore Sizes via Reactive Emulsion Stabilization.

Macrocellular silicone polymers are obtained after solidification of the continuous phase of a poly(dimethylsiloxane) emulsion, which contains poly(ethylene glycol) drops of sub-millimetric dimensions. Coalescence of the liquid template emulsion is prohibited by a reactive blending approach. The relationship is investigated in detail between the interfacial properties and the emulsion stability, and micro- and millifluidic techniques are used to generate macrocellular polymers with controlled structural properties over a wider range of cell sizes (0.

Lentiviral vector-mediated overexpression of mutant ataxin-7 recapitulates SCA7 pathology and promotes accumulation of the FUS/TLS and MBNL1 RNA-binding proteins.

Background: We used lentiviral vectors (LVs) to generate a new SCA7 animal model overexpressing a truncated mutant ataxin-7 (MUT ATXN7) fragment in the mouse cerebellum, in order to characterize the specific neuropathological and behavioral consequences of the genetic defect in this brain structure.

Results: LV-mediated overexpression of MUT ATXN7 into the cerebellum of C57/BL6 adult mice induced neuropathological features similar to that observed in patients, such as intranuclear aggregates in Purkinje cells (PC), loss of synaptic markers, neuroinflammation, and neuronal death. No neuropathological changes were observed when truncated wild-type ataxin-7 (WT ATXN7) was injected.

New route toward nanosized crystalline metal borides with tuneable stoichiometry and variable morphologies.

Herein we highlight for the first time the ability to tune the stoichiometry of metal boride nanocrystals through nanoparticle synthesis in thermally stable inorganic molten salts. Two metal-boron systems are chosen as case studies: boron-poor nickel borides and boron-rich yttrium borides. We show that NiB, NiB, NiB, NiB, and YB particles can be obtained as crystalline phases with good selectivity.

Induction and differentiation of human induced pluripotent stem cells into functional cardiomyocytes on a compartmented monolayer of gelatin nanofibers.

Extensive efforts have been devoted to develop new substrates for culture and differentiation of human induced pluripotent stem cells (hiPSCs) toward cardiac cell-based assays. A more exciting prospect is the construction of cardiac tissue for robust drug screening and cardiac tissue repairing. Here, we developed a patch method by electrospinning and crosslinking of monolayer gelatin nanofibers on a honeycomb frame made of poly(ethylene glycol) diacrylate (PEGDA).

Structure Change from β-Strand and Turn to α-Helix in Histone H2A-H2B Induced by DNA Damage Response.

Using synchrotron radiation-based circular dichroism spectroscopy, we found that the DNA damage response induces an increase of α-helix structure and a decrease of β-strand and turn structures in histone H2A-H2B extracted from x-irradiated human HeLa cells. The structural alterations correspond to the assumption that an average of eight amino acid residues form new α-helix structures at 310 K. We propose the structural transition from β-strand and turn structures to an α-helix structure in H2A-H2B as a novel, to our knowledge, process involved in the DNA damage response.

ERα dimerization: a key factor for the weak estrogenic activity of an ERα modulator unable to compete with estradiol in binding assays.

Estrothiazine (ESTZ) is a weak estrogen sharing structural similarities with coumestrol. ESTZ failed to compete with [H]17β-estradiol ([H]17β-E) for binding to the estrogen receptor α (ERα), questioning its ability to interact with the receptor. However, detection by atomic force spectroscopy (AFS) of an ESTZ-induced ERα dimerization has eliminated any remaining doubts.

Antisense pre-treatment increases gene therapy efficacy in dystrophic muscles.

In preclinical models for Duchenne muscular dystrophy, dystrophin restoration during adeno-associated virus (AAV)-U7-mediated exon-skipping therapy was shown to decrease drastically after six months in treated muscles. This decline in efficacy is strongly correlated with the loss of the therapeutic AAV genomes, probably due to alterations of the dystrophic myofiber membranes. To improve the membrane integrity of the dystrophic myofibers at the time of AAV-U7 injection, mdx muscles were pre-treated with a single dose of the peptide-phosphorodiamidate morpholino (PPMO) antisense oligonucleotides that induced temporary dystrophin expression at the sarcolemma.

Organic photoredox catalysis for the oxidation of silicates: applications in radical synthesis and dual catalysis.

Metal free photooxidation of alkyl bis(catecholato)silicates with the organic dye 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyano-benzene (4CzIPN) allows the smooth formation of alkyl radicals. The latter can be efficiently engaged either with radical acceptors to provide homolytic addition products or in photoredox/nickel dual catalysis reactions to obtain cross-coupling products.

Single molecule studies of helicases with magnetic tweezers.

Helicases are a broad family of enzymes that perform crucial functions in DNA replication and in the maintenance of DNA and RNA integrity. A detailed mechanical study of helicases on DNA and RNA is possible using single molecule manipulation methods. Among those, magnetic tweezers (or traps) present a convenient, moderate throughput assay (tens of enzymes can be monitored simultaneously) that allow for high resolution (single base-pair) studies of these enzymes in various conditions and on various substrates (double and single stranded DNA and RNA).

Dual Photoredox/Gold Catalysis Arylative Cyclization of o-Alkynylphenols with Aryldiazonium Salts: A Flexible Synthesis of Benzofurans.

A new method for the arylative cyclization of o-alkynylphenols with aryldiazonium salts via dual photoredox/gold catalysis is described. The reaction proceeds smoothly at room temperature in the absence of base and/or additives and offers an efficient approach to benzofuran derivatives. The scope of the transformation is wide, and the limitations are discussed.

Modeling the Kinetics of Open Self-Assembly.

In this work, we explore theoretically the kinetics of molecular self-assembly in the presence of constant monomer flux as an input, and a maximal size. The proposed model is supposed to reproduce the dynamics of viral self-assembly for enveloped virus. It turns out that the kinetics of open self-assembly is rather quantitatively different from the kinetics of similar closed assembly.

Simulations of the infrared, Raman, and 2D-IR photon echo spectra of water in nanoscale silica pores.

Vibrational spectroscopy is frequently used to characterize nanoconfined liquids and probe the effect of the confining framework on the liquid structure and dynamics relative to the corresponding bulk fluid. However, it is still unclear what molecular-level information can be obtained from such measurements. In this paper, we address this question by using molecular dynamics (MD) simulations to reproduce the linear infrared (IR), Raman, and two-dimensional IR (2D-IR) photon echo spectra for water confined within hydrophilic (hydroxyl-terminated) silica mesopores.

Effective motor neuron differentiation of hiPSCs on a patch made of crosslinked monolayer gelatin nanofibers.

Human induced pluripotent stem cells (hiPSCs) are differentiated into mature motor neurons by using a culture patch made of crosslinked monolayer gelatin nanofibers. Compared to the conventional culture dish method, the patch method is more effective for culture and differentiation of stem cells, because cells are supported by a net-like structure made of crosslinked monolayer nanofibers instead of a planar substrate. The pores of the net-like structure have sizes smaller than those of cells but large enough to minimize the exogenous cell-material contact and to increase the permeability as well as the efficiency of cell-cell interactions.

Involvement of 3D osteoblast migration and bone apatite during in vitro early osteocytogenesis.

The transition from osteoblast to osteocyte is described to occur through passive entrapment mechanism (self-buried, or embedded by neighboring cells). Here, we provide evidence of a new pathway where osteoblasts are "more" active than generally assumed. We demonstrate that osteoblasts possess the ability to migrate and differentiate into early osteocytes inside dense collagen matrices.

Engineering the Charge Transfer in all 2D Graphene-Nanoplatelets Heterostructure Photodetectors.

Two dimensional layered (i.e. van der Waals) heterostructures open up great prospects, especially in photodetector applications.

The physics of lipid droplet nucleation, growth and budding.

Lipid droplets (LDs) are intracellular oil-in-water emulsion droplets, covered by a phospholipid monolayer and mainly present in the cytosol. Despite their important role in cellular metabolism and growing number of newly identified functions, LD formation mechanism from the endoplasmic reticulum remains poorly understood. To form a LD, the oil molecules synthesized in the ER accumulate between the monolayer leaflets and induce deformation of the membrane.

Aggregation of Antibody Drug Conjugates at Room Temperature: SAXS and Light Scattering Evidence for Colloidal Instability of a Specific Subpopulation.

Coupling a hydrophobic drug onto monoclonal antibodies via lysine residues is a common route to prepare antibody-drug conjugates (ADC), a promising class of biotherapeutics. But a few chemical modifications on protein surface often increase aggregation propensity, without a clear understanding of the aggregation mechanisms at stake (loss of colloidal stability, self-assemblies, denaturation, etc.), and the statistical nature of conjugation introduces polydispersity in the ADC population, which raises questions on whether the whole ADC population becomes unstable.

EF-Tu from the enacyloxin producing Frateuria W-315 strain: Structure/activity relationship and antibiotic resistance.

In this report, we have demonstrated that the poly(U)-dependent poly(Phe) synthesis activity of elongator factor Tu (EF-Tu) from the enacyloxin producing strain Frateuria sp. W-315 is inhibited by the antibiotic similarly to that of Escherichia coli EF-Tu. The inhibitory effect of enacyloxin observed in a purified system was the same as that obtained with an S30 extract from E.

Bis-phosphine allene ligand: coordination chemistry and preliminary applications in catalysis.

A 1,3-bis-diphenylphosphine allene can give rise to new coordination complexes with palladium, platinum and gold metals. These complexes were fully characterized by NMR, HRMS and X-ray diffraction analysis. For gold(i), the corresponding dinuclear complex has been used in a series of diagnostic catalytic reactions and gave promising preliminary results in asymmetric catalysis.

Plant sphingolipids: Their importance in cellular organization and adaption.

Sphingolipids and their phosphorylated derivatives are ubiquitous bio-active components of cells. They are structural elements in the lipid bilayer and contribute to the dynamic nature of the membrane. They have been implicated in many cellular processes in yeast and animal cells, including aspects of signaling, apoptosis, and senescence.