Simultaneous determination of five macrolide antibiotics in meat by high-performance liquid chromatography

A simple and rapid method using high-performance liquid chromatography (HPLC) for the simultaneous determination of five macrolides (josamycin, kitasamycin, mirosamicin, spiramycin and tylosin) in meat has been developed. The drugs were extracted with 0.3% metaphosphoric acid-methanol (7:3, v/v), and the extracts were cleaned up on a Bond Elut SCX (500 mg) cartridge. The HPLC separation was performed on a Puresil 5C18 column (150 x 4.6 mm I.D.) with a gradient system of 0.025 M phosphate buffer (pH 2.5)-acetonitrile as the mobile phase at a flow-rate of 1.0 ml/min. The drugs were detected at 232 mn for josamycin, kitasamycin, mirosamicin and spiramycin, and 287 mn for tylosin. The calibration graphs were rectilinear from 2.5 to 100 ng for each drug. The recoveries at the level of 1.0 microgram/g were 70.8-90.4%, and detection limits were 0.05 microgram/g for each drug.     

Immunohistochemical localization of peroxisomal enzymes in developing rat kidney tissues

We studied the developmental changes in the localization of peroxisome-specific enzymes in rat kidney tissues from embryonic Day 16 to postnatal Week 10 by immunoblot analysis and immunohistochemistry, using antibodies for the peroxisomal enzymes catalase, d-amino acid oxidase, l-alpha-hydroxyacid oxidase (isozyme B), and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase bifunctional protein. Peroxisomal enzymes were detected in the neonatal kidney by immunoblot analysis and their amount increased with kidney development. By light microscopic immunohistochemistry, they were first localized in a few proximal tubules in the juxtamedullary cortex of 18-day embryos. The distribution of proximal tubules positive for them expanded towards the superficial cortex with development. The full thickness of the cortex became positive for the staining by 14 days after birth. Peroxisomes could be detected by electron microscopy in structurally immature proximal tubules in 18-day embryos. Their size increased and the ultrastructure of subcompartments became clear with continuing development of proximal tubules. These results show that peroxisomal enzymes appear in the immature proximal tubules in the kidney of embryos and that the ultrastructure of the peroxisomes and localization of the peroxisomal enzymes develop along with the maturation of proximal tubules and kidney tissues.     

p53 accumulation and apoptosis in embolized meningiomas

Preoperative embolization of meningiomas is performed to decrease blood loss at surgery. While it is also expected to reduce tumor recurrence by producing necrosis at the site of dural attachment, very little has been described about what happens to the non-necrotic tumor cells. We investigated how the proliferative activities of meningiomas were modified after embolization. In nine meningiomas which were embolized preoperatively, proliferative potentials and expression of cell cycle inhibitors were assessed immunohistochemically using MIB-1, anti-53 (DO-1 and DO-7), and anti-p21 (WAF1/CIP1) monoclonal antibodies. To determine whether a cell underwent apoptotic death besides necrosis, we applied the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling method. Results were compared with control meningiomas without embolization. MIB-1 positive cells often gathered in perinecrotic areas, although the mean MIB-1 staining index of the embolized meningiomas was not significantly different from the control. p53 and its downstream effector p21 accumulated mainly in the perinecrotic areas in eight of the nine embolized meningiomas. Apoptosis was also observed in the concomitant areas. Double staining for both MIB-1 and p21 frequently showed positive cells for both antibodies. The accumulation of MIB-1 positive cells in the embolized meningiomas may not be a sign of fast growth or malignancy, but it may implicate arrest of cell cycle by the p21. This study indicates that embolized meningiomas exhibit not only necrosis but also apoptosis and cell cycle arrest. The latter effects appear to be at least partly p53 dependent.     

Photon probe fault locator for single-mode optical fiber using an acoustooptical light deflector

A new backscattering technique for diagnosing the attenuation characteristics, spatial imperfections with length (fault location), and splice loss in a single-mode optical fiber has been developed by using a TeO2acoustooptical light deflector operating at 120 MHz. Due to the small insertion loss and high extinction ratio of the deflector, the dynamic range of the backscattered signal has been increased by at least 10 dB, which corresponds to the extension of 5 km in measurable length for fiber loss of 1 dB/km, compared with the conventional back-scattering technique in which the beam splitter and polarizer-analyzer combination are utilized. Another advantage of this technique is in that the saturation of the amplifier is avoided by arbitrarily cutting off a large power in the early stage of the Rayleigh scattering signal. A single-mode fiber of 19.2 km in length has been examined, and the distance for fault location up to 18.4 km was obtained.     

A Decomposition Method for Computing System Reliability by a Matrix Expression

A decomposition method using a matrix representation for computing the reliability of a redundant system is proposed. The system is decomposed into two subsystems according to up- and down- states of a keystone element. This is repeated recursively until all subsystems have known reliability. The criterion for choosing the keystone element and an algorithm for decomposing a system are described.     

Marked extension of diagnosis length in optical time domain reflectometry using 1.32 ?m YAG laser

An optical time domain reflectometer was newly constructed by using a high power Nd:YAG laser operating at a wavelength of 1.32 ?m and a TeO2 acousto-optical light deflector. As a result, the maximum detectable fault location length of 34 km for single-mode fibre and that of 60 km for multimode graded-index fibre were successfully attained.     

The effects of parent training on parenting stress and sense of competence.

Examined the effects of behavioral parent training groups on parenting stress and sense of competence. Ss, parents of 91 clinically diagnosed hyperactive preschoolers (aged 3–6 yrs), were randomly assigned to an immediate treatment group (experimental) or a delayed treatment group (control). Results indicate that group parent training yielded benefits beyond changes in parent and child behavior. Compared with controls, experimental Ss reported less parenting stress and increased sense of competence following treatment and 3 mo later. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of microstructural instability on creep behavior of a martensitic 9Cr-2W steel

The microstructural instability during creep and its effect on creep behavior were investigated for a martensitic 9Cr-2W steel. The steel was developed as a low radioactive steel suitable for fusion reactor structure. Creep testing was carried out at 873 K for up to 15,100 ks (4200 hours). The creep curve consisted of transition creep, where creep rate decreased with time, and acceleration creep, where creep rate increased with time. During creep, microstructural instability, such as the recovery of dislocations, the agglomeration of carbides, and the growth of martensite lath subgrains, was observed to occur, which resulted in softening but no hardening. The transition creep was a consequence of the movement and annihilation of excess dislocations, resulting in the decrease in dislocation density and the increase in martensite lath size with time. The acceleration creep was a consequence of a gradual loss of creep strength due to the microstructural instability which occurred from the initial stage of creep.     

The effect of tungsten on creep

The effect of tungsten on creep behavior and microstructural evolution was investigated for tempered martensitic 9Cr steels with various W concentrations from 0 to 4 wt pct. The creep rupture testing was carried out at 823, 873, and 923 K for up to 54 Ms (15,000 hours). The creep and creep rupture strength increased linearly with W concentration up to about 3 wt pct, where the steels consisted of the single constituent of the tempered martensite. It increased only slightly above 3 wt pct, where the matrix consisted of the tempered martensite and δ-ferrite. The minimum creep rate was described by a power law. The apparent activation energy for the minimum creep rate showed a tendency similar to the W concentration dependence of the creep-rupture strength and was larger than the activation energy for self-diffusion at high W concentrations above 1 wt pct. The martensite lath microstructure with fine carbides along lath boundaries was responsible for a high resistance to creep deformation. With increasing W con- centration, the martensite lath microstructure became stabilized, which decreased the minimum creep rate and increased the apparent activation energy for the minimum creep rate.     

Optical soliton communication in a positively and negativelydispersion-allocated optical fibre transmission line

A bright optical soliton described by a nonlinear Schrodinger equation can survive even in a positive dispersion region as long as the average dispersion has a negative value. This allows us to combine fibres with large positive and large negative dispersion, which in turn will enable us to introduce solitons in a commercial system