Large Bi-2212 single crystal growth by the floating-zone technique

Effects of the growth velocity on the crystal growth behavior of Bi_2Sr_2Ca_1Cu_2O_x (Bi-2212) have been studied by floating zone technique. The results show that a necessary condition for obtaining large single crystals along the c-axis is that the solid-liquid interface of a growing rod maintains a stable planar growth front. The planar liquid-solid growth interface tends to break down into a cellular interface, while the growth velocity is higher than 0.25 mm/h. Single crystals of up to 50x7.2x7 mm3 along the a-, b- and caxes have been cut in a 7.2 mm diameter rod with optimum growth conditions. Tconset is 91 K measured by magnetic properties measurement system (MPMS) for as-grown crystals. Optical polarization microscope and neutron diffraction show that the quality of the single crystals is good.Comment: 5 pages, 4 figure

Biomechanical analysis of the handstand:a systematic review

In gymnastics, the handstand is one of the most important fundamental skills. It provides a progression route for transferable skills on various apparatuses i.e. (rings, beam, uneven-bars and parallel bars) and various floor disciplines (1). The handstand can be characterized as the action of maneuvering the body into a fixed body configuration in an inverted vertical position while balancing on the hands. However, this maneuver can be made extremely difficult as it involves the use ofspecific apparatuses, overall balance influences, and mechanical characteristics (2). Challenging conditions during the handstand become apparent when the distance between the base and the center of gravity is increased as a result of support of extended arms which causes decreased stability (3). The aim of this systematic review was to investigate the performance of the handstand from a biomechanical perspective.<br/

Simple technologies for fabrication of low-loss silica waveguides

A simple and reproducible technology is developed for the fabrication of low-loss silica waveguides on silicon substrates. The guiding layer is formed by changing the Si-O ratio composition of the SiO/sub 2/ layer. The waveguides can be made to have a good match to either optical fibres or guided-wave devices in III-V compound semiconductor

Hairpin DNA functionalized gold nanorods for mRNA detection in homogenous solution

We report a novel fluorescent probe for mRNA detection. It consists of a gold nanorod (GNR) functionalized with fluorophore labeled hairpin oligonucleotides (hpDNA) that are complementary to the mRNA of a target gene. This nanoprobe was found to be sensitive to a complementary oligonucleotide, as indicated by significant changes in both fluorescence intensity and lifetime. The influence of the surface density of hpDNA on the performance of this nanoprobe was investigated, suggesting that high hybridization efficiency could be achieved at a relatively low surface loading density of hpDNA. However, steady-state fluorescence spectroscopy revealed better overall performance, in terms of sensitivity and detection range, for nanoprobes with higher hairpin coverage. Time-resolved fluorescence lifetime spectroscopy revealed significant lifetime changes of the fluorophore upon hybridization of hpDNA with targets, providing further insight on the hybridization kinetics of the probe as well as the quenching efficiency of GNRs

Adaptive online deployment for resource constrained mobile smart clients

Nowadays mobile devices are more and more used as a platform for applications. Contrary to prior generation handheld devices configured with a predefined set of applications, today leading edge devices provide a platform for flexible and customized application deployment. However, these applications have to deal with the limitations (e.g. CPU speed, memory) of these mobile devices and thus cannot handle complex tasks. In order to cope with the handheld limitations and the ever changing device context (e.g. network connections, remaining battery time, etc.) we present a middleware solution that dynamically offloads parts of the software to the most appropriate server. Without a priori knowledge of the application, the optimal deployment is calculated, that lowers the cpu usage at the mobile client, whilst keeping the used bandwidth minimal. The information needed to calculate this optimum is gathered on the fly from runtime information. Experimental results show that the proposed solution enables effective execution of complex applications in a constrained environment. Moreover, we demonstrate that the overhead from the middleware components is below 2%

Point mutations confer loss of ATP-induced human P2X7 receptor function

AbstractResidues considered essential for ATP binding to the human P2X7 receptor (hP2X7R) were investigated. HEK293 cells or Xenopus oocytes were transfected with wild-type or site-directed mutants of hP2X7R constructs and channel/pore activity measured in the presence of ATP or 2′,3′-O-(4-benzoylbenzoyl)-ATP (BzATP). Barium uptake and ethidium influx into HEK293 cells were abolished in cells expressing K193A and K311A mutants, and were partially reduced in cells expressing mutant P210A. K193A and K311A mutations also completely abolished responses to ATP and BzATP in Xenopus oocytes as measured by electrophysiology. These results indicate that K193 and K311 are essential residues in ATP binding in the hP2X7R

Short-term rhGH increases PIIINP, a biomarker of endothelial dysfunction

Objectives: In arterial hypertension, amino-terminal propeptide of type III procollagen (PIIINP) is elevated in arterial aneurysm tissue and associated with a poor prognosis following acute myocardial infarction (MI). Recombinant human growth hormone (rhGH) administration attenuates endothelial dysfunction but increases PIIINP. This study was conducted to establish if short-term rhGH administration affects PIIINP, endothelial function and selected cardiovascular disease (CVD) risk factors, in healthy males. Design: Method: Male subjects (n=48) were randomly assigned into two groups: (1): control group (C) n=24, mean ± SD, age 32 ± 11 years; height 1.8 ± 0.06 metres; (2): rhGH administration group (rhGH) n=24, mean ± SD, age 32 ± 9 years; height 1.8 ± 0.07 metres. Blood pressure (BP), heart rate (HR), arterial pulse wave velocity (APWV), and biochemical indices were investigated. Results: PIIINP (0.28±0.1 vs. 0.42±0.2, U/ml); Insulin like growth factor-I (159±54 vs. 323±93, ng.mL-1); resting HR (72±14 vs. 78±11, b.p.m.) and rate pressure product (RPP) (90±18 vs. 97±14, bpm x mm.Hg x 10-2) all significantly increased (P<0.05). Total cholesterol (4.7±0.9 vs. 4.4±0.7, mmol.L-1); high sensitivity C-reactive protein (1.77±2.1 vs. 1.29±1.6, mg.L-1); serum homocysteine (13.2±4.0 vs. 11.7±3.1, μmol.L-1) and APWV (9.97±1.38 vs. 9.18±1.6, m.s-1) all significantly decreased (P<0.05). Conclusion: Paradoxically, there was an improvement in CVD inflammatory markers and APWV; but PIIINP and resting RPP increased. Elevated PIIINP may have a confounding adverse effect on the endothelium, but may also provide clinical prognostic information in monitoring arterial hypertension, left ventricular function in the sub-acute phase following MI and endothelial function in aortic aneurysms

Time-dependent photoionization spectroscopy of the Seyfert galaxy NGC 3783

High Energy Astrophysic

10 Yr transformation of the obscuring wind in NGC 5548

GalaxiesHigh Energy Astrophysic

Functional diversity of chemokines and chemokine receptors in response to viral infection of the central nervous system.

Encounters with neurotropic viruses result in varied outcomes ranging from encephalitis, paralytic poliomyelitis or other serious consequences to relatively benign infection. One of the principal factors that control the outcome of infection is the localized tissue response and subsequent immune response directed against the invading toxic agent. It is the role of the immune system to contain and control the spread of virus infection in the central nervous system (CNS), and paradoxically, this response may also be pathologic. Chemokines are potent proinflammatory molecules whose expression within virally infected tissues is often associated with protection and/or pathology which correlates with migration and accumulation of immune cells. Indeed, studies with a neurotropic murine coronavirus, mouse hepatitis virus (MHV), have provided important insight into the functional roles of chemokines and chemokine receptors in participating in various aspects of host defense as well as disease development within the CNS. This chapter will highlight recent discoveries that have provided insight into the diverse biologic roles of chemokines and their receptors in coordinating immune responses following viral infection of the CNS