Early experience of minimally invasive valve surgery

Gene therapy has been proposed for a wide variety of human conditions including monogenic disorders, such as the haemoglobinopathies and immunodeficiency syndromes, cancer and many other diseases. Prerequisites for the success of this approach include the ability to deliver the therapeutic gene intact to the target cell, persistent levels of transgene expression sufficient to correct the disease phenotype, lack of unwanted side-effects associated with vector exposure or gene transfer and relative simplicity allowing the widespread use of this methodology. Although substantial progress has been made in animal models since the inception of genetic therapy in the early 1980s, significant obstacles remain for human therapy, most notably in the area of vector development. The first generation of gene therapy vectors has failed to overcome many of the biological hurdles cited above necessitating the development of alternate means of gene delivery and expression.     

Ultra high frequency electromagnetic wave detector for diagnosticof metal clad switchgear insulation

This paper describes a newly developed ultra high frequency electromagnetic wave (UHF wave) detector for tracking discharges in metal clad switchgear (MCS) and its performance. The tracking discharges included waves with frequencies of more than a few hundred megahertz and the attenuation of the UHF waves transmitted through a MCS enclosure was about 10 dBμV. On the other hand, noise in the ultra high frequency range was relatively low. The simple UHF wave detector was tested in the laboratory and field     

Degradation of azo dyes by cell-free extract from Pseudomonas stutzeri

The degradation of several azo dyes by the cell-free extract from Pseudomonas stutzeri has been studied. The compounds 2-carboxy-4′-dimethylaminoazobenzene, 4-carboxy-4′-dimethylaminoazobenzene, 2-carboxy 4′-die thy lam inoazobenzene, 2-met hoxycarbonyl-4′-dime t h y lam inoazobenzene, 4-dime t h y lam inoazobenzene sulphonic acid, and 2-hydroxy-1 -naphthaleneazobenzenesulphonic acid were appreciably degraded by the cell- f ree extract. The cell- f ree extract was quite specific for 2-ca rboxy-4 ′-diet h y lam inoazo benzen e, 2 met hoxyca rbonyI4′-dime t h y lam inoazo benzene, and 2-ca rboxy4′-dime t h y lam inoazo benzene, which a reequal in their redox potential. Thus, it is suggested that the substrate specificity is characterised by a log Pdependence. The presence of azo reductase in the cell-free extract was alsoconfirmed by electrophoresis.     

Intraparticle mass transfer in bidispersed porous ion exchanger part I: Isotopic ion exchange

A simple theoretical equation of intraparticle effective diffusivity ??_e, in a bidispersed porous ion exchanger was derived under the assumption of parallel diffusion in the solid phase and the macropore. ??_e of Na⁺, CO²⁺, Zn²⁺ and Ce³⁺ in several MR-type resins and other type of porous resins (P-type resin) were measured by isotopic ion exchange. In MR-type resin, ??_g was affected by the concentration of the bulk solution C_o and was separated into a solid phase diffusivity ??_g and a macropore diffusivity ??_p by using the derived equation. Equations for estimating ??_g were obtained. The diffusivity ratio of ??_p to diffusivity in infinitely dilute aqueous solution for a monovalent ion agreed with the Neale and Neder's theoretical equation for tortuosity factor within 10%. In P-type resin, it became clear that the effect of macropore diffusion is negligible. ??_e was little affected by C_o. Separated ??_p was little larger than ??_g, and ??_g was nearly equal to ??_e. The equations for estimating ??_g of a P-type resin were quite similar to those for gel-type resins.     

Comparison of ELISA and HPLC for the determination of desmosine or isodesmosine in aortic tissue elastin

We developed a rapid and simple method for estimating tissue elastin content by measuring desmosine (D) in tissue hydrolysates by competitive ELISA. We compared the ELISA previously reported HPLC methods. When D or isodesmosine (ID) in hydrolysate of the same elastin preparation were measured by the two different methods, a good linear relationship was obtained (r = 0.854 for human aorta or r = 0.938 for rabbit aorta, respectively). The ELISA method can detect as little as 6 pmol/ml and it may be useful in monitoring elastin metabolism in patients with various connective tissue diseases.     

A Simple Method for Monitoring Fire-Resistant Fluids Used in Electro-Hydraulic Governing Systems

ABSTRACT

Intact triaryl phosphate is essential for the reliable functioning of hydraulic controllers. In this study, a simple approach for monitoring the condition of triaryl phosphate using acid–base indicators was developed. The analytical determination of the products from the degradation of triaryl phosphate revealed acidic components (e.g., diaryl phosphoric acid) that permitted a clear visual test of degradation and digitization using acid–base indicators and spectrophotometry. Methyl red serves as a promising indicator for a wide range of degradation products from triaryl phosphate and was used to demonstrate that the measured lightness value decreased with increasing acid number. This rapid method requires minimal sample preparation and can assess early-stage degradation, thereby making on-site monitoring possible for optimising operational function.     

Investigation of a new extinguishing principle for a gas circuit breaker

A self-extinguishing principle of a gas circuit breaker (GCB) without puffer action (autopuffer GCB) using an external magnetic field was investigated to improve the interrupting capability in the small current region (several kA). Properties of the rotating speed of an arc, the arc voltage, and the gas pressure rise in an expansion space under the external magnetic field were studied experimentally. The relation between the interrupting capability and the radial magnetic flux density in the autopuffer GCB with a permanent magnet (magnet-assisted autopuffer GCB) was obtained experimentally and also analyzed numerically. The results are summarized as follows.

• 1 The arc column is driven in the azimuthal direction by the radial component of the external magnetic field.
• 2 The rotating speed of the arc driven by the radial magnetic field of a permanent magnet remains constant in the arc current range below several kA, and it decreases with an increasing current in the current above several kA.
• 3 Since the arc rotation raises the arc voltage and gas pressure in the expansion space, the gas flow from the expansion space to the arc increases in the vicinity of current zero. The interrupting capability is then improved in the small current region.
• 4 It is confirmed that the magnet-assisted auto-puffer GCB has a good interrupting capability not only for the large current region but also for the small current region.

     

侧链型液晶高分子的合成

讨论了4′甲氧基苯基—4(6″-丙烯酰氧已基)苯甲酸酯(MPAHA)和对氯甲基苯乙烯(CMS)共聚物以及CMS相应的肉桂酸酯衍生物乙烯基苯甲基肉桂酸酯(VBC)共聚物的合成。DSC和偏光显微镜分析表明:该共聚物具有热致变高分子的行为,并根据分子链中MPAHB链节含量的高低,其T_(?)和T_1值发生相应的变化。