Formation of an adherent polyacrylonitrile/carbon nanotubes composite film onto a polyacrylonitrile brush electrografted on copper

An adherent polymer film based on a composite of polyacrylonitrile/multiwall carbon nanotubes (PAN/MWNTs) have been elaborated on a copper substrate. The first layer is an electrografted PAN brush on which of a subsequent layer of PAN/carbon nanotubes composite has been deposited by simple dipping from solution in dimethylformamide (DMF). MWNTs have been previously chemically functionalized with 3-cyanopropyltrichlorosilane to promote de-bundling and homogeneous dispersion of the carbon nanotubes in the composite.     

Multicentric Castleman''s disease with mediastinal involvement in a patient with HIV infection]

Congenital nephrotic syndrome of Finnish type is a rare disease in Taiwan characterized by intrauterine onset of massive urinary loss of protein. We describe a typical baby of congenital nephrotic syndrome with generalized edema occurring at 3 months of age. Renal biopsy at 4 months of age showed a tubular microcystic change in histology. He had a partial response to corticosteroid. We tried persantin, indomethacin, and captopril since 10 months of age without significant improvement. The baby suffered from recurrent infections and respiratory difficulties due to having upper airway edema since 3 months of age. The baby passed away at 1 year and 2 months of age with severe psychomotor retardation. The first try of the combination of persantin, indomethacin, and captopril for congenital nephrotic syndrome is described.     

Brain-Derived Neurotrophic Factor (BDNF) Is Associated with Platelet Activity and Bleeding Tendency in Patients with Gaucher Disease

Bleeding tendency, a prominent feature of patients with Gaucher disease (GD), is associated with abnormal platelet function. Brain-derived neurotrophic factor (BDNF) is a protein with neuroprotective potential stored in alpha granules of circulating platelets. Here we studied BDNF levels in 50 patients with type I GD (GD1) and their correlation with platelet activity and bleeding tendency. Flow cytometry was used to test unstimulated and stimulated measurement of platelet surface-activated expression of αIIbβ3 integrin, P-selectin and lysosomal-associated membrane protein (LAMP3/CD63). Serum and plasma BDNF levels were quantified using ELISA. The bleeding history was recorded by a bleeding questionnaire. Serum BDNF levels were positively correlated with platelet count and moderately correlated with unstimulated and stimulated platelet P-selectin expression. Patients with more than one bleeding manifestation were shown to have lower serum BDNF levels, albeit similar platelet count. Plasma BDNF levels were significantly elevated in splenectomized patients and showed a moderate positive correlation with stimulated platelet CD63 expression. These observations demonstrate the first association between BDNF levels in the peripheral blood with platelet dysfunction and increased bleeding manifestation. The role of measuring serum BDNF for assessing platelet alpha degranulation defects and bleeding risk in patients with GD and the general population needs further study.     

Structural defects as a result of Zn diffusion into CdTe single crystals

The presence of defects in CdZnTe crystals is detrimental for optoelectronic devices fabrication and therefore should be minimized. In this paper we present the characterization of structural defects on the surface and the cross-section of CdTe single crystals that were subjected to high temperature (up to 950 °C) diffusion of Zn. The defects were characterized by various X-ray techniques, optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Quantitative data are obtained, a practical solution for reducing the defects is suggested and some implementations are discussed. Further effort is currently being made to investigate the lattice sites which are involved with the diffused Zn atoms near the surface and in the bulk.     

Metal Oxide Heterostructure Array via Spatially Controlled–Growth within Block Copolymer Templates

Nanofabrication is continuously searching for new methodologies to fabricate 3D nanostructures with 3D control over their chemical composition. A new approach for heterostructure nanorod array fabrication through spatially controlled–growth of multiple metal oxides within block copolymer (BCP) templates is presented. Selective growth of metal oxides within the cylindrical polymer domains of polystyrene‐block‐poly methyl methacrylate is performed using sequential infiltration synthesis (SIS). Tuning the diffusion of trimethyl aluminum and diethyl zinc organometallic precursors in the BCP film directs the growth of AlO_x and ZnO to different locations within the cylindrical BCP domains, in a single SIS process. BCP removal yields an AlO_x‐ZnO heterostructure nanorods array, as corroborated by 3D characterization with scanning transmission electron microscopy (STEM) tomography and a combination of STEM and energy‐dispersive X‐ray spectroscopy tomography. The strategy presented here will open up new routes for complex 3D nanostructure fabrication.     

Carbon and Nitrogen Based Nanosheets as Fluorescent Probes with Tunable Emission

2D carbon and nitrogen based semiconductors (CN) have attracted widespread attention for their possible use as low‐cost and environmentally friendly materials for various applications. However, their limited solution‐dispersibility and the difficulty in preparing exfoliated sheets with tunable photophysical properties restrain their exploitation in imaging‐related applications. Here, the synthesis of carbon and nitrogen organic scaffolds with highly tunable optical properties, excellent dispersion in water and DMSO, and good bioimaging properties is reported. Tailored photophysical and chemical properties are acquired by the synthesis of new starting monomers containing different substituent chemical groups with varying electronic properties. Upon monomer condensation at moderate temperature, 350 °C, the starting chemical groups are fully preserved in the final CN. The low condensation temperature and the effective molecular‐level modification of the CN scaffold lead to well‐dispersed photoluminescent CN thin sheets with a wide range of emission wavelengths. The good bioimaging properties and the tunable fluorescence properties are exemplified by in situ visualization of giant unilamellar vesicles in a buffered aqueous solution as a model system. This approach opens the possibility for the design of tailor‐made CN materials with tunable photophysical and chemical properties toward their exploitation in various fields, such as photocatalysis, bioimaging, and sensing.     

Mixed State Hall Resistivity in YBCO c-Axis-Oriented Thin Films

Hall voltage measurements on YBCO c-axis-oriented thin films in the mixed state were carried out. The films were grown on MgO substrates utilising evaporation technique followed by relatively low heating temperature. Hall voltage was measured in low magnetic fields perpendicular to the film surface, in which sign reversal near T _c was observed. Relatively large transverse voltage was found to be insensitive to the magnetic field inversion (even Hall effect). This effect is discussed in terms of the vortices guided motion model which is argued to give a reasonable explanation for the even Hall effect in type II superconductors.     

Correlate measurements at different test sites

A new method for systematic correlation of measurements in semi-anechoic and anechoic chambers is presented. A signal measured in a semi-anechoic chamber is first processed using the matrix-pencil method which is applied sequentially on small frequency intervals. On each interval the measured signal is decomposed into its propagating wave components. The component corresponding to the wave reflected from the ground is identified and removed to fully retrieve the signal measured in an anechoic chamber. Three examples using log-periodic and Vivaldi antennas in different anechoic and semi-anechoic chambers for varying frequency ranges illustrate the method. The proposed decomposition algorithm can be utilized to characterize measurement test site imperfections     

In situ fabrication of high Tc Y---Ba---Cu---O thin film by resistive evaporation

We have recently used a simple conventional oil-pumped vacuum system equipped with a resistively heated boat for in situ fabrication of Y---Ba---Cu---O high T_c superconductivity phase thin films at a relatively low substrate temperature. A well-ground mixture of yttrium, BaF₂ and copper, weighed in the atomic proportion to yield a stoichiometric YBa₂Cu₃O_7−δ film, was evaporated from a resistively heated boat onto MgO substrates. The substrate temperature was then raised to about 700 °C and the oxygen partial pressure was raised to about 8 Pa for 30 min. The oxygen was injected through a nozzle placed close to the substrate surface. The resulting films, with no further heat treatment, were characterized by a four-probe d.c. method and zero resistance was detected at 85 K.