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Oxide semiconductor alloys of x(LiGaO2)1/2-(1− x)ZnO were fabricated by the solid state reaction between β-LiGaO2 and ZnO and rf-magnetron sputtering. For the solid state reaction, the wurtzite-type single phases were obtained in the composition range of x⩽0.38. The formation range of the alloys was wider than that of the (Mg1− x Zn x )O system, because the β-LiGaO2 possesses a wurtzite-derived structure and approximately the same lattice constants with ZnO. The electrical resistivity and energy band gap of the 0.38(LiGaO2)1/2-0.62ZnO alloyed ceramic were 0.45 Ωcm and 3.7 eV, respectively, at room temperature. For the alloying by sputtering, the films consisting of the wurtzite-type single phase were obtained over the entire composition range of x(LiGaO2)1/2-(1− x)ZnO. The energy band gap was controllable in the range from 3.3 to 5.6 eV. For the as-deposited film fabricated using the 0.4(LiGaO2)1/2-0.6ZnO alloyed ceramic target, the energy band gap was 3.74 eV, and the electrical resistivity, carrier density and the Hall mobility at room temperature were 3.6 Ωcm, 3.4×1017 cm−3 and 5.6 cm2 V−1 s−1, respectively. [ABSTRACT FROM AUTHOR]

Deals with a study which tried to obtain the experimental evidence for the existence of the interstitial oxygen in indium tin oxide (ITO). Possible electron-trapping defects in ITO; Preparation of the sintered samples; Lattice parameters; Absorption spectra of ITO.

Summary¶ Objective. The aim of this study is to investigate the usefulness and problems with spinal motor evoked potential (MEP) recording, especially the reasons for failed recording. We report our personal experience over the last 8 years in patients with lesions adjacent to the primary motor cortex. Methods. MEP records of 50 consecutive patients were retrospectively reviewed. MEP was recorded by a catheter electrode inserted in the cervical epidural space. Stimulation electrodes were placed on the cortical surface during surgery. SEP recording was also performed in 29 of 50 patients. Results. MEP was obtained in 40 cases, and SEP was recorded in all 29 cases. The central sulcus was identified in 93% of patients in whom both MEP and SEP were performed, whereas in only 86% of patients who underwent only MEP. The main reason for MEP failure were inadequate exposure of the motor cortex, pre-existing hemiparesis and technical errors. Postoperative deterioration of motor function was closely related to intra-operative MEP changes. Conclusion. MEP is a useful tool to determine the motor cortex and to predict postoperative motor function. However, precise pre-operative craniotomy planning and combination with intra-operative SEP is essential to reduce the MEP failure. [ABSTRACT FROM AUTHOR]

Pre-operative and postoperative oblique sagittal gradient-echo magnetic resonance (MR) imaging was used to evaluate microvascular decompression of the facial nerves in 26 patients with hemifacial spasm. The pre-operative MR images were divided into two groups as follows: 22 images in Group I, clear imaging of a high-intensity line and/or spot at the root exit zone (REZ) of the facial nerve; and 4 in Group II, and unreliable image around the REZ. Surgery found that the causative vessel was the vertebral artery (VA) in 9 cases and the anterior inferior cerebellar artery (AICA) or the posterior inferior cerebellar artery (PICA) in 13 cases in Group I, and the AICA or the PICA in the 4 cases in Group II. Postoperative MR imaging showed clear decompression as the high-intensity line and/or spot completely separated from the REZ by a low- and/or iso- intensity area in 9 cases of VA compression repositioned to the petrous dura mater, in 11 cases of PICA or AICA compression treated by shredded Teflon pledgets in Group I and in 3 cases in Group II. Postoperative MR imaging showed an incomplete separation of any high-intensity line and/or spot in the REZ in 2 cases of PICA or AICA compression in Group I and in one in Group II. The outcome was excellent in 22 of 23 cases with clear decompression, and in 1 of 3 cases of unclear decompression. Hemifacial spasm persisted in 3 cases. Oblique sagittal gradient-echo MR imaging is a useful method for postoperative follow-up which can demonstrate changes around the REZ of the facial nerve if hemifacial spasm recurs. [ABSTRACT FROM AUTHOR]

To discriminate between the various compressing vessels of the facial nerves in patients with hemifacial spasm, pre-operative oblique sagittal gradient-echo MR imaging was performed. Forty-two patients underwent pre-operative MR imaging and microvascular decompression. The MR images were divided according to findings into three groups as follows: Group A, a thick and/or long high-intensity line along the root exit zone (REZ) of the facial nerve; Group B, a thin and/or short high-intensity line along the REZ; and Group C, an unreliable image around the REZ. Fifteen images were classified as Group A, 19 as Group B, and 8 as Group C. In Group A, vertebral artery (VA) compression was confirmed intra-operatively in 12 cases and posterior inferior cerebellar artery (PICA) or anterior inferior cerebellar artery (AICA) compression in 3. In Group B, PICA or AICA compression was confirmed intra-operatively in all cases. In Group C, PICA or AICA compression was confirmed intra-operatively in 7 cases and no compression in one. In all cases of VA compression of the facial nerve, the oblique sagittal gradient-echo images demonstrated a thick and/or long high intensity line along the REZ. Oblique sagittal gradient-echo MR imaging is a useful pre-operative planning aid, which can predict the possibility of VA compression prior to microvascular decompression for hemifacial spasm. [ABSTRACT FROM AUTHOR]

Acetone-dried cells of Arthrobacter simplex, whose steroid Δ activity had been previously induced, were entrapped by the use of photo-crosslinkable resin prepolymers. When the hydrophobicity of the cell-entrapping gel was increased by mixing a hydrophobic prepolymer (main chain component; polypropyleneglycol) with a hydrophilic prepolymer (main chain component; polypropyleneglycol) with a hydrophilic prepolymer (main chain component; polyethyleneglycol) (up to 30%), the hydrocortisone to prednisolone conversion rate of the immobilized cells increased significantly, attaining approximately 20% of that of the free cells. A 10% addition of organic solvents, such as methanol, to the aqueous reaction mixture enhanced the solubility of the substrate greatly and to a lesser degree the reaction rate of the immobilized cells. The presence of an electron acceptor, phenazine methosulfate or 2,6-dichlorophenolindophenol, stimulated the steroid conversion of the entrapped as well as the free cells. The stability of the entrapped cells over repeated reactions was improved by immobilization. [ABSTRACT FROM AUTHOR]

After acoustic exposure, in the infranuclear region of the basal turn histochemically the lactate dehydrogenase activity increased more than normal. In the lower half of the second turn of this region, small vesicles, free ribosomes and coated vesicles decreased in number and cytoplasmic matrix become lower in electron density and lactic dehydrogenase activity decreased. Small vesicles were found to be preferentially distributed in the presynaptic side of the afferent nerve endings. Movement of these small vesicles leads to the speculation that small vesicles have close relationship to the afferent nerve endings. [ABSTRACT FROM AUTHOR]

The outer hair cells of the rabbit were electron microscopically and histochemically investigated. The results clearly showed that the outer hair cells of the rabbit have no agglomeration of mitochondria in its infranuclear region. This anatomical fact means that the functional mechanism in the outer hair cells of the rabbit may be substantially different from that of other animals which have agglomeration of mitochondria. From the results of the histochemical study, it is reasonably supposed that the anaerobic energy metabolism may ordinarily play the leading part in sustaining the cellular functions in the infranuclear region of the outer hair cells of the rabbit. [ABSTRACT FROM AUTHOR]

Rabbits were exposed to 100 dB pure-tone sound at 2 kHz for 2 h. Electron microscopy was used to study the relationship between changes in the outer hair cells, afferent nerve endings and efferent nerve endings. There was no relationship found between the degree of changes produced in the afferent nerve endings and that the outer hair cells. However, there was a relationship demonstrable between the degree of changes seen in the efferent nerve endings and the infranuclear region of the outer hair cells. These findings show that acoustic trauma will damage most the infranuclear region of the outer hair cells, while efferent nerve endings are injured next and least affected are afferent nerve endings. [ABSTRACT FROM AUTHOR]

Rabbits were exposed to pure tone (2 kHz, 100 dB for 2 h) and the changes in the nerve endings of the outer hair cells over a period of 1 month were studied using the electron microscope. In the afferent nerve endings mitochondria dilated and small vesicles decreased in number immediately after acoustic exposure. However, the afferent nerve endings recovered during the period of 1 month. In the efferent nerve endings mitochondria dilated and were distributed throughout the nerve endings, and small vesicles decreased in number immediately after acoustic exposure. The efferent nerve endings recovered more slowly than afferent nerve endings. In addition, the changes in the agglomerations of synaptic vesicles along the synaptic membrane and the gap-structures in the synaptic cleft in the efferent nerve endings after acoustic exposure are briefly discussed. [ABSTRACT FROM AUTHOR]

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En bloc resection of superficial tumors in the colon is challenging but beneficial for the precise diagnosis and treatment. We have been using a novel technique of endoscopic submucosal dissection with a viscous substance, sodium hyaluronate, and a needle knife in combination with a small-caliber-tip transparent hood and succeeded in the endoscopic en bloc resection of large superficial tumors in the colon. We endoscopically treated superficial tumors larger than 20 mm in diameter of the colon in 166 patients between June 1998 and March 2005. All the lesions were successfully resected endoscopically and en bloc resection was achieved in 77 % of them. Even large superficial tumors in the colon can be resected in one piece by using this technique. [ABSTRACT FROM AUTHOR]