Unperturbed dimension of poly(4-acetoxystyrene) measured in good and theta solvents

In order to obtain the additional data concerning the unperturbed dimension of poly-4-substituted styrene, light scattering measurements are performed on the twenty-two fractions with molecular weight of (0.91–352)·10⁴ of poly(4-acetoxystyrene) in dioxan at 25°C, from which the molecular weight obtained was found easily to be evaluated with the gel permeation chromatography using THF. Phase separation experiments for this polymer indicate that the theta state is attained in isopropyl acetate at 19.7°C and butyl acetate at 26.8°C. By making viscosity measurements at that state, the value of K_Θ is directly evaluated as 5.4·10^?4 dl g^?1. The limiting viscosity number is also obtained in good solvents, THF and dioxan, at 25°C and constants of the Mark-Houwink-Sakurada equation in each solvent are determined. Further, approximately the same K_Θ as above is obtained from these data with the Stockmayer-Fixman plot. The calculated value of steric factor, 2.37, on this polymer may be plausible, compared with those of polyvinylaromatic derivatives.     

Functional differentiation of human naive helper T cells

Here we report a case of a 56-year-old male with post-poliomyelitis muscular atrophy (PPMA), who presented with cranial nerve signs and widespread atrophy of the extremities. He had suffered from poliomyelitis at the age of 2 years. After recovery from the acute stage, the paralysis remained in his left arm. He noticed muscle weakness of the right upper and lower extremities at the age of 45 years and the muscle atrophy progressed to his arms, hip and thigh at the age of 55 years. Neurological examination revealed muscle atrophy of the neck and disturbance of left V, VIII, IX, X and bilateral XI cranial nerves. We diagnosed this case as PPMA from his history and electromyographic and muscle biopsy findings which suggested chronic denervation. Among the 21 PPMA cases in the past in which the acute poliomyelitis had resulted in paralysis of the only one limb, ours was the only case that had muscle atrophy of all the limbs. Cranial nerve involvement is known to occur in acute poliomyelitis; therefore, there is a possibility that the involvement of the cranial nerves in our case might be a delayed progressive symptoms.     

Effect of Forming Pressure on the Internal Structure of Alumina Green Bodies Examined with Immersion Liquid Technique

Green bodies prepared by compaction of alumina granules were made transparent by an immersion liquid technique, and the internal structure was characterized with an optical microscope to study the effect of forming pressure on the internal structure. Clear images obtained by the technique provide more detailed information than other existing methods for structures ranging from one to tens of micrometers. Intergranular pores were present between unfractured granules. Their sizes and concentration tended to decrease with increasing forming pressure. However, pores were clearly present even in the green body prepared at 600 MPa. A rod- and needlelike feature was also found and was concluded to correspond to a high-density region. The significance of large pores and high-density regions on processing as well as the details of the technique is discussed.     

GABA and glutamate levels in the substantia nigra reticulata following repetitive cerebral ischemia in gerbils

Repetitive cerebral ischemia produces more severe damage than a similar single duration insult. We have previously shown that, in gerbils, damage in the substantia nigra reticulata (SNr) is seen with repetitive insults rather than a single insult. We have also shown that there is a progressive decrease in the extracellular GABA in the striatum in the days preceding such damage, speculating that a loss of GABA may be in part responsible for this damage. This study evaluates the GABA levels in the SNr in animals exposed to repetitive ischemic insults. Each animal received a total of three ischemic insults of 3-min duration at hourly intervals. In vivo microdialysis was carried out to analyze the GABA and glutamate dialysate levels on Days 1, 3, 5, 7, and 14 following the ischemic insult. In the control and treated (ischemic) animals, there was a significant increase in the GABA levels with the introduction of nipecotic acid on Days 1, 3, 5, and 14. However, on Day 7 there was a significant attenuation in the GABA response to nipecotic acid in the treated animals in comparison to the controls. The glutamate levels in the treated animals were similar to the control animals on Days 1, 3, 5, and 7. However, on Day 14 the glutamate levels were significantly lower than on previous days. Our experiments for the first time measure extracellular glutamate and GABA responses in the SNr in animals exposed to repetitive ischemic insults. Our experiments show that there is a significant decrease in the GABA concentrations at a time when ischemic damage is developing in this region. This confirms our hypothesis that a decrease in GABA may be one factor contributing to neuronal damage during the period following repetitive ischemic insults. Further, the rebound increase in GABA levels on Day 14 with a concomitant fall in glutamate levels would indicate that reparative processes are still active in the 2 weeks following the insult.     

Dependence of thin film transistor characteristics on thedeposition conditions of silicon nitride and amorphous silicon

The systematic relation between thin film transistors' (TFT's) characteristics and the deposition conditions of amorphous silicon nitride (a-SiN) films and hydrogenated amorphous silicon (a-Si:H) films is investigated. It is observed that field effect mobility μ_FE and threshold voltage V_th of the TFT's strongly depend on the deposition conditions of these films. The maximum μ_FE of 0.88 cm²/V·s is obtained for the TFT of which a-SiN film is deposited at a pressure of 85 Pa. This phenomenon is due to the variation of the interface states density between a-Si:H film and a-SiN film     

Effects of Particle Size of Bulk Drug and food on the Bioavailability of U-78875 in Dogs

The effects of particle size and food on the absolute bioavailability of U-78875 in dogs after oral administration of either a suspension or tablet dosage form were investigated. A reduction of particle size caused a significant increase in bioavailability along with an increase in dissolution rate. Additionally, both suspension and tablet dosage forms administered after food caused an increase in bioavailability. Thus, to accelerate drug dissolution, a reduction of U-78875 particle size from the unmilled state is important for the optimization of formulation compositions. To increase the bioavailability of U-78875, postprandial dosing should be considered.     

Low-cycle fatigue behavior of Sn-Ag, Sn-Ag-Cu, and Sn-Ag-Cu-Bi lead-free solders

Low-cycle fatigue (LCF) tests on as-cast Sn-3.5Ag, Sn-3Ag-0.5Cu, Sn-3Ag-0.5Cu-1Bi, and Sn-3Ag-0.5Cu-3Bi solders was carried out using a noncontact strain-controlled system at 20°C with a constant frequency of 0.1 Hz. The addition of Cu does not significantly affect the fatigue life of eutectic Sn-Ag solder. However, the fatigue life was significantly reduced with the addition of Bi. The LCF behavior of all solders followed the Coffin-Manson relationship. The fatigue life of the present solders is dominated by the fracture ductility and can be described by the ductility-modified Coffin-Manson’s relationship. Steps at the boundaries of dendrite phases were the initiation sites for microcracks for Sn-3.5Ag, Sn-3Ag-0.5Cu, and Sn-3Ag-0.5Cu-1Bi solders, while for Sn-3Ag-0.5Cu-3Bi solder, cracks initiated along both the dendrite boundaries and subgrain boundaries in the dendrite phases. The linking of these cracks and the propagation of cracks inside the specimen occurred both transgranularly through eutectic phases and intergranularly along dendrite boundaries or subgrain boundaries.     

Stromal CCL5 Promotes Breast Cancer Progression by Interacting with CCR3 in Tumor Cells

Chemokines secreted from stromal cells have important roles for interactions with carcinoma cells and regulating tumor progression. C-C motif chemokine ligand (CCL) 5 is expressed in various types of stromal cells and associated with tumor progression, interacting with C-C chemokine receptor (CCR) 1, 3 and 5 expressed in tumor cells. However, the expression on CCL5 and its receptors have so far not been well-examined in human breast carcinoma tissues. We therefore immunolocalized CCL5, as well as CCR1, 3 and 5, in 111 human breast carcinoma tissues and correlated them with clinicopathological characteristics. Stromal CCL5 immunoreactivity was significantly correlated with the aggressive phenotype of breast carcinomas. Importantly, this tendency was observed especially in the CCR3-positive group. Furthermore, the risk of recurrence was significantly higher in the patients with breast carcinomas positive for CCL5 and CCR3 but negative for CCR1 and CCR5, as compared with other patients. In summary, the CCL5-CCR3 axis might contribute to a worse prognosis in breast cancer patients, and these findings will contribute to a better understanding of the significance of the CCL5/CCRs axis in breast carcinoma microenvironment.     

Direct Observation of Internal Structure in Spray-Dried Alumina Granules

The internal structure of spray-dried alumina granules was characterized by optical microscopy by immersing them in a liquid having a refractive index close to that of alumina. This method provides a unique technique for the detailed analysis of the internal structure of spray-dried granules.