Symmetry breaking in the female germline cyst.

[Figure: see text]

Red Emitting Phosphors Doped with Mn and Eu Ions for pc-WLEDs

A new red emitting phosphors based on oxyfluoride glass and glassceramics doped with europium and manganese ions were synthesized and their optical properties and structure were studied. The transparent ceramic matrices for phosphors were selected because they overcome traditional powder phosphors due to high chemical and thermal stability and low temperature sensitivity. The fluoride based red emitting phosphors combined with green one and blue emitting chip used to fabricate phosphor converted white LEDs with warm color temperature and improved color rendering indexes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3537

Symmetry breaking in the female germline cyst.

In mammals and flies, only one cell in a multicellular female germline cyst becomes an oocyte, but how symmetry is broken to select the oocyte is unknown. Here, we show that the microtubule (MT) minus end-stabilizing protein Patronin/CAMSAP marks the future Drosophila oocyte and is required for oocyte specification. The spectraplakin Shot recruits Patronin to the fusome, a branched structure extending into all cyst cells. Patronin stabilizes more MTs in the cell with the most fusome material. Our data suggest that this weak asymmetry is amplified by Dynein-dependent transport of Patronin-stabilized MTs. This forms a polarized MT network, along which Dynein transports oocyte determinants into the presumptive oocyte. Thus, Patronin amplifies a weak fusome anisotropy to break symmetry and select one cell to become the oocyte

Patronin/Shot Cortical Foci Assemble the Noncentrosomal Microtubule Array that Specifies the Drosophila Anterior-Posterior Axis.

Noncentrosomal microtubules play an important role in polarizing differentiated cells, but little is known about how these microtubules are organized. Here we identify the spectraplakin, Short stop (Shot), as the cortical anchor for noncentrosomal microtubule organizing centers (ncMTOCs) in the Drosophila oocyte. Shot interacts with the cortex through its actin-binding domain and recruits the microtubule minus-end-binding protein, Patronin, to form cortical ncMTOCs. Shot/Patronin foci do not co-localize with γ-tubulin, suggesting that they do not nucleate new microtubules. Instead, they capture and stabilize existing microtubule minus ends, which then template new microtubule growth. Shot/Patronin foci are excluded from the oocyte posterior by the Par-1 polarity kinase to generate the polarized microtubule network that localizes axis determinants. Both proteins also accumulate apically in epithelial cells, where they are required for the formation of apical-basal microtubule arrays. Thus, Shot/Patronin ncMTOCs may provide a general mechanism for organizing noncentrosomal microtubules in differentiated cells.This work was supported by a Wellcome Trust PRF to D. St J. (080007), and by core support from the Wellcome Trust (092096) and Cancer Research UK (A14492). D. N. was supported by a postdoctoral fellowship from the Swedish Research Council. A.R.F. is funded by a University of Cambridge PhD studentship.This is the final version of the article. It first appeared from Cell Press / Elsevier via http://dx.doi.org/10.1016/j.devcel.2016.06.010

Hall helps Ohm: some corrections to negative-U centers approach to transport properties of YBa2_2Cu3_3Ox_x and La2−x_{2-x}Srx_xCuO4_4

For broad oxygen and strontium doping ranges, temperature dependences (T-dependences) of the normal state resistivity \rho(T) of YBa_2Cu_3O_x (YBCO) and La_(2-x)Sr_xCuO_4 (LSCO) are calculated and compared to experiments. Holes transport was taken in the \tau-approximation, where \tau(T,\epsilon) is due to acoustic phonons. Besides, T-dependence of the chemical potential \mu(T) and effective carrier mass m* ~10-100 free electron masses, obtained by negative-U centers modelling the T-dependence of the Hall coefficient, were used to calculate \rho(T). In addition, it is demonstrated that anisotropy of the cuprates does not affect the calculated T-variation of neither Hall coefficient nor \rho, but only rescale their magnitudes by factors depending on combinations of m_ab and m_c.Comment: 4th International Conference Fundamental Problems of High-Temperature Superconductivity, Moscow-Zvenigorod (October 3-7, 2011) Submitted to J. Supercond. Nov. Magn.: after revision. Extension for Supercond. Sci. Technol. 24 075026 (2011), DOI: 10.1088/0953-2048/24/7/075026 Contains: 2 pages, 3 figure

Glass-metal nanocomposites with planar waveguides for biosensor applications

Abstract At the present time, optical properties of media containing nanoparticles (NPs) of noble metals is a subject of large number of studies [1]. The possibility of light excitation of localized surface plasmon resonance (LSPR) in metal NPs radically changes properties of dielectric media, due to optical absorption of visible range. The spectral position of LSPR can be controlled by modifying parameters of nanocomposite, giving a possibility to use this kind of media in device applications. Considerable attention is also drawn to nonlinear properties of such composites, particularly due to its high-speed nonlinear response Presented paper concerns the development of biosensor platform based on silver nanoparticles, synthesized in glasses of two types: in UV irradiated photo-thermo-refractive glasses and in sodium-borosilicate glasses treated in water atmosphere. Glasses with silver nanoparticles are good candidates for creation of biosensors employing the phenomenon of LSPR effect with planar waveguides circuits for excitation and for detection of plasmon resonance shift Two methods of creation of optical waveguides are examined such as thermal diffusion and ionexchange. The exploitation of planar waveguides in subsurface region allows inputting the light into the sensible part of the glass and facilitates the registration of the optical response of the glass. Two methods of optical waveguide creation are examined: by thermal diffusion and ionexchange. The configuration of localized surface plasmon resonance based biosensor is presented and discussed. The immobilization scheme of D-galactose/D-glucose binding protein on the glass is also presented

Localised dynactin protects growing microtubules to deliver oskar mRNA to the posterior cortex of the Drosophila oocyte.

The localisation of oskar mRNA to the posterior of the Drosophila oocyte defines where the abdomen and germ cells form in the embryo. Kinesin 1 transports oskar mRNA to the oocyte posterior along a polarised microtubule cytoskeleton that grows from non-centrosomal microtubule organising centres (ncMTOCs) along the anterior/lateral cortex. Here, we show that the formation of this polarised microtubule network also requires the posterior regulation of microtubule growth. A missense mutation in the dynactin Arp1 subunit causes most oskar mRNA to localise in the posterior cytoplasm rather than cortically. oskar mRNA transport and anchoring are normal in this mutant, but the microtubules fail to reach the posterior pole. Thus, dynactin acts as an anti-catastrophe factor that extends microtubule growth posteriorly. Kinesin 1 transports dynactin to the oocyte posterior, creating a positive feedback loop that increases the length and persistence of the posterior microtubules that deliver oskar mRNA to the cortex

bicoid mRNA localises to the Drosophila oocyte anterior by random Dynein-mediated transport and anchoring.

bicoid mRNA localises to the Drosophila oocyte anterior from stage 9 of oogenesis onwards to provide a local source for Bicoid protein for embryonic patterning. Live imaging at stage 9 reveals that bicoid mRNA particles undergo rapid Dynein-dependent movements near the oocyte anterior, but with no directional bias. Furthermore, bicoid mRNA localises normally in shot2A2, which abolishes the polarised microtubule organisation. FRAP and photo-conversion experiments demonstrate that the RNA is stably anchored at the anterior, independently of microtubules. Thus, bicoid mRNA is localised by random active transport and anterior anchoring. Super-resolution imaging reveals that bicoid mRNA forms 110-120 nm particles with variable RNA content, but constant size. These particles appear to be well-defined structures that package the RNA for transport and anchoring

Surface Modification of Electrospun Bioresorbable and Biostable Scaffolds by Pulsed DC Magnetron Sputtering of Titanium for Gingival Tissue Regeneration

In this study, polymer scaffolds were fabricated from biodegradable poly(lactide-co-glycolide) (PLGA) and from non-biodegradable vinylidene fluoride-tetrafluoroethylene (VDF-TeFE) by electrospinning. These polymer scaffolds were subsequently surface-modified by sputtering titanium targets in an argon atmosphere. Direct current pulsed magnetron sputtering was applied to prevent a significant influence of discharge plasma on the morphology and mechanical properties of the nonwoven polymer scaffolds. The scaffolds with initially hydrophobic properties show higher hydrophilicity and absorbing properties after surface modification with titanium. The surface modification by titanium significantly increases the cell adhesion of both the biodegradable and the non-biodegradable scaffolds. Immunocytochemistry investigations of human gingival fibroblast cells on the surface-modified scaffolds indicate that a PLGA scaffold exhibits higher cell adhesion than a VDF-TeFE scaffold

Role of RNA helicases in HIV-1 replication

Viruses are replication competent genomes which are relatively gene-poor. Even the largest viruses (i.e. Herpesviruses) encode only slightly >200 open reading frames (ORFs). However, because viruses replicate obligatorily inside cells, and considering that evolution may be driven by a principle of economy of scale, it is reasonable to surmise that many viruses have evolved the ability to co-opt cell-encoded proteins to provide needed surrogate functions. An in silico survey of viral sequence databases reveals that most positive-strand and double-stranded RNA viruses have ORFs for RNA helicases. On the other hand, the genomes of retroviruses are devoid of virally-encoded helicase. Here, we review in brief the notion that the human immunodeficiency virus (HIV-1) has adopted the ability to use one or more cellular RNA helicases for its replicative life cycle