Use of extracorporeal life support for adult patients with respiratory failure and sepsis

Na+,K+-ATPase activity is abundant on the basolateral infoldings of the strial marginal cells and contributes to the maintenance of the characteristic electrolyte composition of the endolymph. However, the stria vascularis of the cochlea is known not to be innervated. In order to clarify its humoral regulation by serotonin, the K+-p-nitrophenylphosphatase activity of strial marginal cells was investigated with a cerium-based method in normal guinea pigs and in guinea pigs treated with reserpine, 5-hydroxytryptamine or reserpine plus 5-hydroxytryptamine. K+-p-nitrophenylphosphatase activity was almost completely depressed 3-20 days after reserpine administration. Ten days after reserpinization, followed by repeated 5-hydroxytryptamine treatment, the enzyme activity was detectable. These results suggest that 5-hydroxytryptamine increases the phosphatase activity. Thus, the function of the stria vascularis in producing cochlear endolymph may be regulated by 5-hydroxytryptamine.     

Masking in three-dimensional auditory displays.

The extent to which simultaneous inputs in a three-dimensional (3D) auditory display mask one another was studied in a simulated sonar task. The minimum signal-to-noise ratio (SNR) required to detect an amplitude-modulated 500-Hz tone in a background of broadband noise was measured using a loudspeaker array in a free field. Three aspects of the 3D array were varied: angular separation of the sources, degree of correlation of the background noises, and listener head movement. Masking was substantially reduced when the sources were uncorrelated. The SNR needed for detection decreased with source separation, and the rate of decrease was significantly greater with uncorrelated sources than with partially or fully correlated sources. Head movement had no effect on the SNR required for detection. Implications for the design and application of 3D auditory displays are discussed.     

The induction of cytotoxic T cells and tumor regression by soluble antigen formulation

CTLs specific for tumor antigens play a major role in the immunity against cancer. We have shown that class I-restricted CTLs can be induced by injecting soluble antigens mixed in an antigen formulation (AF) that consists of squalane, Tween 80, and Pluronic L121 (S. Raychaudhuri et al., Proc. Natl. Acad. Sci. USA, 89: 8308-8312, 1992). In this study, using ovalbumin and the ovalbumin-expressing transfectoma (EG7) as a tumor model system, we examined the in vivo antitumor effect of antigen-AF mixture. Vaccination of mice with ovalbumin in AF 2 or 3 days after EG7 tumor challenge showed significant inhibition of tumor growth compared to mice vaccinated with ovalbumin in alum or in saline. Depletion of CD8+ cells at the time of immunization completely abrogated the AF-induced tumor protection, indicating that CD8+ T cells are the major effectors in tumor protection in vivo. Depletion of CD4+ cells led to a marginal loss of tumor protection, which may be the result of inhibition of ovalbumin-specific CTL response due to the lack of T-helper activity. Our results demonstrate that AF can be used in subunit vaccines to stimulate CTLs and tumor regression in vivo.     

Synthesis and application of novel sulpha drugs based on quinoxaline-2-one and/or quinoxaline-2-thione

Some novel azo-Sulpha drugs as 3-methyl-N-azo-(4′-substituted heterocyclo-benzene-sulphamoyl) quinoxaline-2-ones (1-11) and 3-methyl-N-azo-(4′-substituted heterocyclo-benzene-sulphamoyl)-quinoxaline-2-thiones (1′–11′) were synthesized by coupling 4′-substituted heterocyclo-benzene-sulphamoyl diazonium acetates with 3-methyl-N-(1H)-quinoxaline-2-one and/or with 3-methyl-N(1H) quinoxaline-2-thione in acid medium. The corresponding iron (III) (1a-11, 1′a-11′a) copper (II) (1b-1b′-7b′) and mercury (II) (1c-11c, 1c′-11c) chelates were also prepared in a 1:1 metal-to-ligand ratio. The ligands and their chelates were characterized on the basis of microanalysis, UV, IR and H'-NMR spectrometry and were tested in vitro for their antibacterial and antifungal activities.     

An approximate analytical solution for the nonlinear inverse axial dispersion model

An analytical solution for diffusion with homogenous n the order nonlinear chemical reaction in laminar flow of a Newtonian fluid through tubular reactor with unknown boundary conditions is presented. The results of the new solution have been compared with previously published numerical solutions and shown to be accurate.     

Sintering and microstructure of ultrafine yttriazirconia compacts

Sintering behaviour of ultrafine yttria-zirconia solid solution compacts, with yttria contents ranging between 4 and 10 mol % have been investigated and the microstructural developments during sintering were followed. The 4 mol % yttria-zirconia compacts sinter at 1200 ° C to a high density with a relatively fine uniform microstructure. Firing at 1400 ° C produces no improvement in densification and discontinuous grain growth develops. The lowest density values are obtained with the 10 mol % yttria-zirconia compacts, with clustering in the grains and greater porosity in the microstructure. The activation energies were determined for both 4 and 10 mol % Y₂O₃ -containing bodies in the temperature range 800 to 1000 ° C.     

Efficient PFD-Based Networking and Buffering Models for Improving Video Quality over Congested Links

Video traffic over the Internet becomes increasingly popular and is expected to comprise the largest proportion of the traffic carried by wired and wireless networks. On the other hand, videos are usually compressed by exploiting spatial and temporal redundancy for the reason of increasing the number of video streams that can be simultaneously carried over links. Unfortunately, receiving high-quality video streaming over the Internet remains a challenge due to the packet loss encountered in the congested wired and wireless links. In addition, the problem is more apparent in wireless links due to not only employing limited system capacity, but also some of the major drawbacks of wireless networks, out of which the bandwidth limitations and link asymmetry which refers to the situation where the forward and reverse paths of a transmission have different channel capacities. Therefore, the wireless hops may be congested which result in dropping many video frames. Additionally, as a result of compressing videos, dependencies among frames and within a frame arise. Consequently, the overall video quality tends to be degraded dramatically. The main challenge is to support the growth of video traffic while keeping the perceived quality of the delivered videos high. In this paper, we extend our previous work concerning improving video traffic over wireless networks through professionally studying the dependencies between video frames and their implications on the overall network performance. In other words, we propose very efficient network and buffer models proportionately to novel algorithms that aim to minimize the cost of aforementioned possible losses by selectively discarding frames based on their contribution to picture quality, namely, partial and selective partial frame discarding policies considering the dependencies between video frames. The performance metrics that are employed to evaluate the performance of the proposed algorithms include the rate of non-decodable frames, peak signal-to-noise ratio, frameput, average buffer occupancy, average packet delay, as well as jitter. Our results are so promising and show significant improvements in the perceived video quality over what is relevant in the current literature. We do not end up to this extent, but rather the effect of producing different bit-stream rates by the FFMPEG codecs on aforementioned performance metrics has been extensively studied.     

Excess Conductivity Analysis of Bi1.8Pb0.4Sr2Ca2Cu3O10+δ Added with Nano-ZnO and Nano-Fe2O3

Superconductor samples of type Bi_1.8Pb_0.4Sr₂Ca₂Cu₃O_10+δ added with nano ZnO and Fe₂O₃ were synthesized by the conventional solid-state reaction technique. The samples were characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM), differential scanning calorimetry (DSC) and electrical resistivity measurements. Excess conductivity analysis of the investigated samples was carried out as a function of temperature using Aslamazov and Larkin (AL) model. The analysis showed four different fluctuation regions namely critical (cr), three-dimensional (3D), two-dimensional (2D) and short-wave (sw). The zero temperature coherence length along c-axis, effective layer thickness of the two-dimensional system and inter-layer coupling strength were estimated as a function of nano-oxides concentration. In addition, the thermodynamics, lower and upper critical magnetic fields as well as critical current density were calculated from the Ginzburg number N _G . It was found that the low concentration of nano-ZnO addition up to x=0.2 wt.% improved the physical properties of (Bi,Pb)-2223 phase. In contrary, these properties were deteriorated for x>0.2. These results indicated that the addition of a low amount of nano-ZnO during the final processing of (Bi,Pb)-2223 samples can be effectively improved the flux pinning ability, while the addition of a high amount of nano-ZnO decreased the volume fraction and increased the resistance of grain boundaries. Moreover, the addition of nano-Fe₂O₃ had a negative effect on the superconducting parameters of the (Bi,Pb)-2223 phase. This behavior was attributed to the decrease in the volume fraction of (Bi,Pb)-2223 phase with the increasing of nano-Fe₂O₃.