Diagnostic reliability of the percutaneous ultrasonic Doppler technique for vertebral arterial occlusive diseases

There is little data on the diagnostic reliability of the ultrasonic Doppler technique for vertebral arterial occlusive lesions. Percutaneous vertebral Doppler examination and the vertebral angiograms were compared to determine the diagnostic reliability of this technique in 64 vertebral arteries of 53 patients with cerebrovascular disease. The percutaneous vertebral Doppler findings were quantitatively analyzed using a sound spectrograph and were classified into three types: no flow signal type, poor flow type and normal flow type. In nine patients with the no flow type the angiograms revealed vertebral occlusion or a missing vertebral artery in six, giving a diagnostic reliability of 67%. In 17 patients with poor flow type the angiograms revealed vertebral occlusion or a missing vertebral artery in five, terminal narrowing of the artery in nine, and hypoplasia in two giving a diagnostic reliability of 94%. For all vertebral arteries examined with this technique, including normal ones, the diagnostic reliability was 92% (59/64). Percutaneous vertebral Doppler examination has clinical usefulness as a screening test for occlusive vertebral arterial diseases.     

Adsorption to or desorption of beer components from a lipid membrane related to sensory evaluation

The relationship between the adsorption to or desorption of beer from a lipid membrane and sensory evaluation was studied using a lipid-coated quartz crystal microbalance connected to a flow injection system. The adsorption and duration of adsorption of commercial beers showed a significant correlation with their body and smoothness in a sensory evaluation, respectively. Isohumulones, tartaric acid, NaCl, glutamic acid, and tannic acid were adsorbed onto the lipid membrane. Di- and trihydroxyoctadecenoic acids increased the duration of adsorption of the beer components onto the lipid membrane but not the extent of adsorption. They decreased the astringent duration of beer and the smoothness in the sensory evaluation but did not affect the intensity of bitterness or astringency or the body. It seems that this system, which modifies the electrostatic and hydrophobic interactions of the beer components with the tongue and throat surfaces, can mainly evaluate bitterness and/or astringency which significantly affect the body and smoothness of beer.     

Adsorption of Tannins on Lipid Membrane in the Presence of Peptides as Related to Astringency

ABSTRACT: stringent reception mechanism of tannins, which has not been fully elucidated, was studied using a lipid-coated quartz-crystal microbalance. We found that the adsorption of astringent tannins on the lipid membrane significantly increased in the presence of peptides, while NaCl, tartaric acid, quinine-sulfite, sucrose, and glutamic acid had no effect. The adsorption of tannin-peptide complexes showed a linear relationship with tannin concentration and had an optimum concentration of peptides. The adsorption of red wines on the lipid membrane in the presence of bovine serum albumin agreed with astringent intensity in sensory evaluation. It seems that adsorption of tannin-peptide complexes on the oral lipid membrane could be important to the astringent sensation.     

Noncariogenic intense natural sweeteners

There is a definite relationship between the dietary consumption of sucrose and the incidence of dental caries. Noncaloric sucrose substitutes for use in the sweetening of foods, beverages, and medicines may be either synthetic compounds or natural products. In the United States, four potently sweet artificial sweeteners are approved, namely, saccharin, aspartame, acesulfame potassium, and sucralose. Highly sweet plant constituents are used in Japan and some other countries, including the diterpene glycoside stevioside and the protein thaumatin. Recent progress in a research project oriented towards the discovery and evaluation of novel potentially noncariogenic sweeteners from plants has focused on substances in the sesquiterpenoid, diterpenoid, triterpenoid, steroidal saponin, and proanthocyanidin structural classes. The feasibility of using Mongolian gerbil electrophysiological and behavioral assays to monitor the sweetness of plant extracts, chromatographic fractions, and pure isolates has been investigated. An in vivo cariogenicity study on the commercially available natural sweeteners stevioside and rebaudioside A has been carried out.     

New noise rejection techniques on pulse-by-pulse basis for on-linepartial discharge measurement of turbine generators

On-line partial discharge tests for turbine generators are useful for recognizing abnormal or deteriorated stator winding insulation without a machine outage. One problem related to such a test is additional installation of sensors. We propose that wires of a resistance temperature detector (RTD) embedded in a stator slot are applied as a partial discharge sensor in the form of an RF coupler. The other problem is electrical noise that is a pulse similar to partial discharge in frequency characteristic and has higher amplitude than partial discharge. The sensors in two steam turbine generators showed enough sensitivity and broad frequency bandwidth to facilitate the elimination of noise from the partial discharge measurement. Two new techniques of noise rejection on a pulse-by-pulse basis are investigated with the multiple sensors. One is founded on the correlation between pulse height in two frequency bands. The other is based on the correlation between pulse height from the two partial discharge sensors. It was found that each noise rejection technique was successful in a trial testing     

The role of anteromedial foraminotomy and the uncovertebral joints in the stability of the cervical spine. A biomechanical study

STUDY DESIGN: The biomechanical role of the cervical uncovertebral joint was investigated using human cadaveric spines. Sequential resection of cervical uncovertebral joints, including clinical anteromedial foraminotomy, was conducted, followed by biomechanical testing after each stage of resection. OBJECTIVES: To clarify the biomechanical role of uncovertebral joints and clinical anteromedial foraminotomy in the cervical spine and their effects on interbody bone graft stability. SUMMARY OF BACKGROUND DATA: Although the biomechanical role of the cervical uncovertebral joints has been considered to be that of a guiding mechanism in flexion and extension and a limiting mechanism in posterior translation and lateral bending, there have been no studies quantifying this role. According to results in quantitative anatomic studies, anatomic variations exist in uncovertebral joints, depending on the vertebral level, articular angulation, and relative height of the joints. METHODS: Fourteen human functional spinal units at C3-C4 and C6-C7 underwent sequential uncovertebral joint resection, with each stage of resection followed by biomechanical testing. The uncovertebral joint was divided anatomically into three parts on each side: the posterior foraminal part, the posterior half, and the anterior half. The loading modes included torsion, flexion, extension, and lateral bending. A simulated anterior bone graft construct was also tested after each uncovertebral joint resection procedure. RESULTS: Significant changes in stability were observed after sequential uncovertebral joint resection in all loading modes (P < 0.05). The biomechanical contribution of uncovertebral joints decreased in the following order: the posterior foraminal part, the posterior half, and the anterior half. Unilateral and bilateral foraminotomy most affected the stability of the functional spinal unit during extension, causing a 30% and 36% decrease in stiffness of the functional spinal unit, respectively. The effect was less in torsion and lateral bending. After sequential resection, there was a statistically significant difference between decreases in torsional stiffness at C3-C4 and C6-C7 (P < 0.05). The stiffness of the simulated bone graft construct decreased progressively during flexion and lateral bending after each foraminotomy (P < 0.05). Increased bone graft height of 79% returned stability to the preforaminotomy level. CONCLUSIONS: This is the first study to quantitate the biomechanical role of uncovertebral joints in cervical segmental stability and the effect at each intervertebral level. The effect differs because of anatomic variations in uncovertebral joints. The major biomechanical function of uncovertebral joints includes the regulation of extension and lateral bending motion, followed by torsion, which is mainly provided by the posterior uncovertebral joints. This study highlights the clinical assessment of additional segmental instability attributed to destruction of the uncovertebral joints during surgical procedures or by neoplastic lesions.     

Modeling accuracy of a fiber-optics test bed using MGF method

The absolute accuracy of modeling a high bit rate optical transmitter-receiver test-bed by using moment generating functions is investigated with extensive system measurements and component characterizations. We achieved a 0.5-dB average optical signal-to-noise ratio accuracy for a 10-Gb/s return-to-zero fiber-optics test bed. The methodology shown here can be very useful for both efficient and accurate component or system engineering.     

Tribological properties of Fe7Mo6-based alloy under two ionic liquid lubrications

The tribological properties of Fe₇Mo₆-based alloy, Mo, Fe and ASTM class no. 45 cast iron disk specimens were investigated against ASTM 52100 steel balls under the lubrication of two different kinds of hydrophobic ionic liquid: N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13-TFSI) and N-N-N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide (TMPA-TFSI). When lubricated with PP13-TFSI or TMPA-TFSI, the Fe₇Mo₆-based alloy disk specimens exhibited lower friction coefficients and lower wear rates than the Mo, Fe and ASTM class no. 45 cast iron disk specimens. The low friction coefficients and low wear rates of the Fe₇Mo₆-based alloy were considered to be caused by the formation of low friction materials such as MoO₃ and FeSO₄ on the worn surface.     

Ex situ and in situ characterization studies of spin-coated TiO2 film electrodes for the electrochemical ozone production process

An electrode composed of silicon/titanium oxide/platinum/titanium dioxide (Si/TiO_X/Pt/TiO₂) was fabricated by spin-coating TiO₂ multilayers on a Si/TiO_X/Pt substrate and was used in electrochemical ozone production (EOP). EOP was realized when the Si/TiO_X/Pt substrate was completely covered with the TiO₂ film and a current efficiency of 7% was achieved at a low current density of 26.7 mA cm⁻² in 0.01 M HClO₄ at 15 °C. The TiO₂ film was found to be of an anatase-type TiO₂ and that to comprise aperture structures from the X-ray diffraction (XRD) and transmission electron microscopy (TEM) observations. Moreover, the fabricated TiO₂ film was found to be an n-type semiconductor by photoelectrochemical measurements. The high efficiency at a low current density of EOP on the TiO₂ n-type semiconductor was explained to result from the electron transfer through the TiO₂/HClO₄ interface as tunneling current. When the tunneling current passes through a depletion layer of TiO₂, the electrode potential is necessarily high enough to facilitate EOP.