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Resistance to the electrical tree in the insulating material of mixed addition polymer nanocomposite was studied under ac high-voltage application. The polymer nanocomposite was made by the mixed addition of AI2O3 nanoparticle ('Al') and phthalocyanine compound ('Pc') into LDPE. Any coupling agent to avoid the clusters of 'Al' and 'Pc' was not used in the preparation of the test sample. The experimental results indicated that the tree initiation voltages (TIVs) for the 'Pc' and 'Al' mixed addition and the 'Pc' single addition (LDPE with 'Pc' only) were about 1.8 times higher than that for the base polymer. However, TIV for the 'Al' single addition did not significantly increase. The results suggested that the increase in TIV for the mixed addition composite is due to the existence of 'Pc' in the polymer, the mechanism of which was discussed basing on the effects of large π-electron cloud in the molecule of 'Pc' and the effect of semi conductive characteristics of 'Pc' crystallite. On the other hand, the period of time from the tree initiation to the breakdown for the mixed addition was almost 10 times longer than that for the base polymer. In the cases of the single addition, the period of time to the breakdown for the 'Al' single addition was about 3 times longer than that for the base polymer, and the period of time for the 'Pc' single addition was almost the same as that for the base polymer. AFM observation suggested that the well dispersion of 'Al' (nanoparticle) in the polymer is achieved in the mixed addition composite which leads to the wide area of the interface between 'Al' and LDPE. The wide area of the interface was found to control the propagation of tree and accordingly provides the long period of time to breakdown. Consequently, both the increase in TIV and the long period of time to the breakdown were obtained by the mixed addition polymer nanocomposite.

Tree initiation voltages (TIVs) for LDPEs with additives of the polycyclic compounds were measured to investigate the fundamental role of the compound in the suppression of tree initiation. Five types of polycyclic compounds were used as additives: naphthalene (Np), anthracene (An), 9,10-dibromoanthracene (Br-An), tetracene (Te), and pentacene (Pn). The experimental results indicated that TIV depends on the typed of the compound: TIV for LDPE with "An" is about 3.5 times higher than that for LDPE without an additive; TIVs for "Np", "Te" and "Pn" are not significantly increased. The mechanism for the dependence of TIV on the type of the compound was discussed based on the following experimental investigations: the fundamental electric characteristics for the test materials (conduction current, permittivity and tan delta); the spectra for UV absorption of the test materials due to the excitation of the compound and the spectra for the luminescence emitted from the test materials due to the deexcitation; the shape of the precipitates of the additives in LDPE; and the surface feature for the test materials by AFM. The measurements and observations suggested that the highest TIV for LDPE with "An" is accomplished mainly by two factors: the relaxation of the electric field due to the semi-conductive precipitates of plate-shape crystal, and the shallower depth of micro-spaces located at the interface between LDPE and the electrode. Although the excitation of additive increases TIV, it is not a significant factor in the dependence of TIV, because the spectra indicated that the excitation occurs even in the materials with additive, which is ineffective to the increase in TIV.

The impulse flashover voltage (FOV) in air across a short gap between foil conductors on a printed wiring board was studied to obtain fundamental and remarkable characteristics that will be useful in the design of wiring on the board. Two types of conductor configuration on the test boards were studied. The studied gap distance (d) ranged from 20 mum to 1200 mum. The board thicknesses (t) and the foil thickness (s) were changed from 60 mum to 800 mum and from 6 mum to 18 mum, respectively. The following results were obtained in the two types of the conductor configuration. FOVs for the boards in the studied range are independent of the foil thickness. FOV is almost un-influenced by the board thickness in the gap distance range shorter than 30 mum or 50 mum. In the gap distance longer than this range, FOV characteristics strictly depend on the board thickness; FOV for t=60 mum steeply increases with an increase in the gap distance, and FOV for t=800 mum gradually increases with an increase in the gap distance. These experimental results were discussed basing upon the calculation results of electric field around the HV foil conductor edge.

Polycyclic compounds of acene series without radicals were added to the material of LDPE (low density polyethylene) film to investigate the roles of aromatic compounds in an increase in the breakdown strength (BDS) of the film. The additives used were naphthalene, anthracene, tetracene and pentacene (group A). Dc and impulse BDSs of the film with anthracene were the highest among the films with the group A additives. It was estimated from our experiments that dc breakdown of the film in this study is mainly due to the electron avalanche mechanism. Furthermore, the dependence of BDS upon the type of radical connected to anthracene (An) was measured using three kinds of additive (group B), which are 9,10-dibromoanthracene (Br-An), 9-nitroanthracene (NO-An) and 1-aminoanthracene (NH-An). DcBDS of the films with radicals are arranged in the following order: (PE/NO-An)ges(PE/Br-An)>(PE/An)>(PE/NH-An). DcBDS of (PE/NO-An) was approximately 1.65 times higher than that of the film without an additive. The dependence of dcBDS upon the type of radical connected to An was discussed using the experimental results with UV absorbance, DSC and TSC. The dependence of dcBDS on the kind of group B additive corresponds to the dependence of trap depth for electron carriers on the type of connected radical: the electron-accepting or electron-donating, or halogen type. The excitation of the additive at the collision with electron carriers is considered to increase dcBDS for all the films with the additives of group B and An. The modification of the morphology is not observed significantly in the films studied

Polymer insulating materials are required for use in high altitude regions. For the use of polymer insulating materials in such regions, it must be confirmed whether the resistance to tracking at high altitudes is different from that at altitudes near the sea level. In this paper, an artificial atmospheric chamber was set up to investigate the resistance to tracking on a polymer insulating surface at DC voltage application under a reduced pressure. The tests were carried out in accordance with IEC 60112. The test results showed that the dependences of the resistance to tracking for polymer insulating materials upon the decrease in ambient pressure could be classified into three types. One type is for paper-based phenolic laminate and polycarbonate, where the resistance increases with the decreasing ambient pressure; the second is for polybutylene terephthalate where the resistance decreases with the decreasing ambient pressure; the last type is for epoxy resin where the resistance is almost independent of the decrease in the pressure. A Gaussian wavelet analysis was applied to discharge currents to discuss correlations among the resistance to tracking, the discharge energy level and the ambient pressure. It was found that the data of resistance to tracking with some of the materials obtained at altitudes near sea level are inadequate for use in a high-altitude environment. Problems may occur with respect to the safety and reliability of polymer insulating materials when the DC resistance to tracking decreases under low-pressure conditions.

Partial discharges (PD) developing in a crack or delamination were studied using a simulated crack. The configuration was similar to a rod-plane electrode system, with a rectangular block of insulator inserted between rod and plane (backing) electrodes. In order to provide a crack, a second block of insulator was placed a small distance s 50 mum 50 mm. Outside these values of "s" and "g", positive LDs do not appear. Negative LD appeared over the entire ranges of "s" and "g" studied. These characteristics for LDs were observed for all of the materials used and in the applied voltage range up to 95% of the breakdown voltage. Measurements of the charge distribution on the crack wall revealed a remarkably high-density accumulation of negative charges (ap -1.2 times 10 -8C/cm2) for s 50 mm, which also corresponded to the ranges where the positive LDs appear. Positive LDs are considered to be induced by the propagation of a positive streamer extending to the area where the high-density negative charge had accumulated. The accumulation occurs in cracks of width s < 500 mum, because in such cracks there is insufficient space for the neutralization of the negative accumulated charge, which is performed by the drift of positive ions to the area of the accumulated negative charge. It is suggested that high-voltage apparatus where the composite insulation is adopted must be designed such that its structure does not allow delamination to occur at the interface longer than 50mm, and running parallel to backing electrode

In a human melanoma model of tumor antigen (TA)–based immunization, we tested the functional status of TA-specific CD8+ cytotoxic T lymphocytes. A “quiescent” phenotype lacking direct ex vivo cytotoxic and proliferative potential was identified that was further characterized by comparing its transcriptional profile to that of TA-specific T cells sensitized in vitro by exposure to the same TA and the T-cell growth factor interleukin 2 (IL-2). Quiescent circulating tumor-specific CD8+ T cells were deficient in expression of genes associated with T-cell activation, proliferation, and effector function. This quiescent status may explain the observed lack of correlation between the presence of circulating immunization-induced lymphocytes and tumor regression. In addition, the activation of TA-specific T cells by in vitro antigen recall and IL-2 suggests that a complete effector phenotype might be reinstated in vivo to fulfill the potential of anticancer vaccine protocols.

The relationship between gastrointestinal conditions and halitosis is discussed. Few reports have suggested that gastrointestinal diseases may cause halitosis. H. pylori infection, which causes gastric ulcers, is considered as a possible cause for halitosis. Intensity of malodour of mouth air was found to be higher in H. pylori-positive patients than in negative patients. The levels of hydrogen sulphide and dimethyl sulphide in mouth air were also significantly higher in the positive patients than in the negative patients (P

In order to reduce partial discharges (PD) in a void within an organic insulator, the material of the inner wall of the void was modified by additives, i.e. four types of azobenzo materials: azobenzene, p-nitro-azobenzene, p-amino-azobenzene and nitrobenzene-azo-resorcinol. The voids in the insulator specimens have a cylindrical configuration with a diameter of 1 mm diameter and a height of 100 /spl mu/m. The materials of the top and bottom surfaces of the cylindrical void are high-density polyethylene (HDPE) with additive, prepared by the solution casting method. The specimen was placed between plane electrodes. It was found that the PD for the specimen with additive was reduced to as low as /spl sim/20% of that for the specimen without additive when the applied voltage was near the PD inception. The reduction of PD in the voids was observed for all four kinds of additives. The effective additive concentration was between 0.05 and 0.5% wt. The mechanisms for the reduction in PD were discussed, focusing on two factors: prevention against secondary electron emission from the void wall due to the excitation of the additive, and prevention of electron detachment from the void wall due to the charge traps by the additive, which may play significant roles in the reduction of the PD in the voids.

We investigated the effects of low-intensity pulsed ultrasound on distraction osteogenesis in a rabbit model. Callotasis of the right tibia was performed in 70 male Japanese white rabbits using mini-external fixators. In the first part of the study in 64 animals using normal distraction (waiting period seven days; distraction rate 0.5 mm/12 hours; distraction period ten days), we evaluated the distraction site by radiography, measurement of the bone mineral density (BMD), mechanical testing, and histology. In the second part in six rabbits using fast distraction (waiting period 0 days; distraction rate 1.5 mm/12 hours; distraction period seven days) the site was evaluated radiologically. Half of the animals (35) had received ultrasound to their right leg (30mW/cm2) for 20 minutes daily after ceasing distraction (ultrasound group), while rigid fixation only was maintained in the other half (control group). With normal distraction, the hard callus area, as shown by radiography, the BMD, and the findings on mechanical testing, were significantly greater in those receiving ultrasound than in the control group. Histological analysis showed no tissue damage attributable to exposure to ultrasound. With fast distraction, immature bone regeneration was observed radiologically in the control group, while bone maturation was achieved in the ultrasound group. We conclude that ultrasound can accelerate bone maturation in distraction osteogenesis in rabbits, even in states of poor callotasis.

An endurance test for a printed circuit board to ionic migration was carried out for 2000 h in a chamber controlled at 85/spl deg/C and 85%RH. The capacitance C and tan /spl delta/ between the conductors on the board were measured to find their correlation with ionic migration in the board. The measurement frequency of C and tan /spl delta/ ranged from 1 to 1000 Hz. The configuration of the test circuit was designed according to IPC-SM-840. The material of the insulating board was fiberglass-reinforced epoxy resin. The distance between the Cu conductors was 0.165 mm, and 70 V dc was applied continuously. In the low frequency region ( 30 Hz), on the other hand, gradual slight increases are observed from /spl sim/1100 h after voltage application, but no steep increases. The dependence of C and tan /spl delta/ on frequency at the measurement is due to the low mobility of Cu ions in the water film on the insulating board.

Accurate quantitative measurements of micromovement immediately after operation would be a reliable indicator of the stability of an individual component. We have therefore developed a system for measuring micromovement of the tibial component using three non-contact displacement transducers attached to the tibial cortex during total knee arthroplasty (TKA). Using this system we measured the initial stability in 31 uncemented TKAs. All the tibial components were fixed by a stem and four screws. The initial stability was defined as the amount of displacement when a load of 20 kg was applied. The mean subsidence was 60.7 μm and the mean lift-off was 103.3 μm. We also studied the migration of the tibial component using roentgen stereophotogrammetric analysis (RSA) for up to two years after operation. Most migration occurred during the first six months, after which all prostheses remained stable. We defined migration as the maximum total point motion (MTPM) at two years after operation. The mean migration was 1.29 mm at two years. Our results show that there was a significant correlation between the initial stability and migration (p < 0.05) and emphasise the importance of the initial stability of the tibial component.

This paper describes charging characteristics on a dielectric surface in vacuum by electron irradiation and field emission by a triple junction under negative and positive DC HV applications. The authors measured the 2-D distribution of electrostatic charging on a dielectric surface in situ. Experimental results revealed that the negative charge distribution caused by the electron beam had a conical shape over the whole surface. On the other hand, for a triple junction, it was an acute distribution around the triple junction. Moreover, they quantitatively investigated the difference of the 2-D charging distribution, using certain shape parameters, between the two charging processes mentioned above. In addition, they examined the time decay characteristics of the surface potential on the dielectric in vacuum.

Surface PD (partial discharge) on an insulator from a TJ (triple junction) are reduced by recessing the TJ at the HV electrode. The insulators have an inner electrode connected to the ground potential. PD pulses whose magnitude is >10 pC are measured. The applied HV (50 Hz) is 1 to 1.5/spl times/ higher than that at the initiation of the PD. The thickness of the insulator is in a range from 2 to 7.5 mm. For insulator thickness of 7.5 mm, the integrated magnitude and number of the PD pulses from the recessed TJ are reduced to /spl sim/20% and 50% of those from TJ without recess, respectively. The reduction in the pD by the recessed TJ is explained by the field conditions on the insulator near the TJ. It is considered that the reduction in the pD by the recessed TJ results mainly from the following three factors: high surface potential (V/sub s/) on the insulator, weak parallel component of electric field on the insulator surface, and strong normal component of the field on the surface. Propagation of the pD is restricted by these three factors. We have designed the improved configuration of recessed TJ in order to further emphasize these three factors. It is experimentally confirmed that the improved one reduces surface pD more efficiently than the recessed TJ before the improvement. At 7.5 mm insulator thickness, the integrated magnitude and number of pD pulses are reduced to /spl sim/5% and 15% of those for TJ without recess, respectively.

PE films with various additives were prepared by the solution-grown method. The thickness of the films ranged from 5 to 25 /spl mu/m. Six different azocompounds were used as additives. The results show that BDS 0 for the film with additives was higher than that for the film without additives in the temperature range from -35 to 30/spl deg/C. The increasing ratio of BDS depended on the composition of the additives used. Our results indicate that the breakdown of the film is induced by an electron avalanche. The conduction current through the film in the high electric field region was reduced by using the additives. The dependence of the conduction current on additives corresponds to that of BDS; a higher BDS is realized for films with additives by which the conductive current is controlled at the lower value. It was considered that the reduction of current by the additive is due to either the trapping effect or the excitation effect of the additive. The trap level for the additive and the excitation energy depend upon the type of radical connected on the benzene ring of the additive: electron-accepting or electron-donating type. The results suggested that high BDS and small current are obtained when the azocompound on which the electron-accepting radical is connected is used as the additive.

To delineate domains essential for Gq protein coupling in the C-terminal region (C-tail) of rat angiotensin II (Ang II) receptor type 1A (AT1A), we modified the putative cytosolic regions of the receptor by truncation or alanine substitution and determined resultant changes in the guanosine 5'-3-O-(thio)triphosphate (GTPgammaS) effect on Ang II binding and inositol trisphosphate production by the agonist. Independently, we studied the effect of synthetic C-tail peptides (P-5) and its alanine substitution analogs on [35S]GTPgammaS binding to Gq. Effects of GTPgammaS on Ang II binding (shift to a low affinity form) and inositol trisphosphate production in the deletional mutant receptor 1-317 AT1A was similar to wild type AT1A, whereas in shorter C-terminal deletion mutants 1-309, 1-311, 1-312, 1-313 AT1A, and substitutional mutants Y312A, F313A, and L314A these activities were markedly reduced. The binding of [35S]GTPgammaS to Gq was promoted by the synthetic C-terminal peptide P-5 but not when mutated at Tyr312, Phe313, or Leu314. Results indicate that Tyr312, Phe313, and Leu314 in cytosolic carboxyl-terminal region of rat AT1A are essential for coupling and activation of Gq.

Summary The authors performed Hallux valgus operations on ten patients in 20 feet using Ilizarov external fixator, which is a useful apparatus for treating severe foot deformities. This fixator consists of a half-ring which is made of carbon, six male or female posts, six wire-fixing bolts, and three olive wires 1.5 mm in diameter. The total weight of the instrument is only about 200 g. Instrument fixation lasted around 5–6 weeks. The method of osteotomy comprised 20 distal soft tissue procedures, and the basal metatarsal osteotomy was fixed by two Kirschner (K)-wires 1.8 mm in diameter. The deformity of the Hallux valgus was successfully corrected in all 20 feet. The authors found that all patients were able to walk without crutches immediately after the operation, and the forefoot transverse arch was reconstructed.

The purpose of this study is to decrease PD at a triple junction by addition of a dye to an insulating material. PD is produced on a test specimen subjected to ac voltage under a sphere-plane electrode configuration. The specimen is composed of two layers: a PMMA film with additive, which is 100 /spl mu/m thick; the lower layer a PMMA board 3 mm thick. The film with the additive was prepared by the solution-grown casting method. Five kinds of dye were used as the additive; p-aminoazobenzene (Ab), p-nitrobenzeneazoresorcinol (Nb), methyl yellow (My), methylene blue (Mb) and methyl red (Mr). In the case of the films with Ab and Mb at 0.05% wt, the magnitude and number of PD pulses were reduced to /spl sim/50% less than those in the case of the films without the additive. The decrease in PD was effective under an electric field strength slightly higher than the PD inception. In the case of the other dyes, decrease in PD was not observed. The surface voltage distribution due to the charge by PD depended on the kind of dye additive. The decrease in PD for the Ab and Mb films was explained from the dependence of the surface voltage distribution on the dye. It was concluded that ionization of the dye molecules in the film changes the distribution of surface voltage.

Models of scaphoid non-union with static dorsi-flexed intercalated segment instability were produced in five frozen arms from cadavers or subjects following accidents by repetitive mechanical loading of the wrist joints longitudinally after a bone defect has been made at the mid-portion of the scaphoid. We designed four models of reduction: anatomical reduction; reduction with a shortened scaphoid; anatomical reduction but with the radio-lunate ligament sectioned, and a shortened scaphoid with the radio-lunate ligament sectioned. Results suggested that anatomical reduction with rigid fixation with a Herbert screw was most effective for correction of malalignment with DISI. Preservation of the radio-lunate ligament during the palmar approach to the scaphoid seemed to be important to prevent ligamentous carpal instability.

Breakdown in air through a crack between two insulating plane walls was investigated, using a knife edge, plane electrode configuration. A crack of width s was formed by two plane walls of PE blocks. The minimum crack width studied was 15 /spl mu/m. The maximum electrode distance studied was 80 mm. The experiments were performed in air controlled at 20 to 25/spl deg/C and 40 to 50%RH. In the region of the crack width 15>s>100 /spl mu/m (A region), ac breakdown voltage (BDV) decreased with the decrease in s. In the region 0.1>s>1 mm (B region), BDV slightly increased with a decrease in the width. BDV decreased at the width of the crack where the magnitude of positive charge due to ac partial discharges (PD) was large. The magnitude of the negative charge due to PD was almost unchanged in the B region, but it increased in the A region. The surface voltage distribution on the wall suggested that positive charge accumulation on the wall and its neutralization play an important role of charge quantity of PD on the crack width. >

Complementary DNAs for angiotensin II type 1 receptor isoforms AT1A and AT1B were cloned by expression cloning from bovine adrenal and rat vascular smooth muscles. Human AT1 receptor was also cloned. Seven transmembrane structures emerged. The AT1 type receptor interacted with more than one type of G-proteins. The ligand binding site of AT1 involving Arg167, Lys199, and Asp263 has been identified by site directed mutagenesis. The regulation of the receptors occur at many stages. The isoform, AT2, was also expression cloned from rat pheochromocytoma cells. Although its ligand binding is not affected by stable GTP analogs, it is a seven transmembrane domain receptor. It mediates the modulations of phosphotyrosine phosphatase by angiotensin II and AT2 specific CGP42112A. The modulation was abolished by pertussis toxin. Thus, AT2 belongs to a new class of angiotensin receptors with unique signalling and regulatory mechanisms. AT1 mediates cellular growth. Interestingly, AT2 expression is inversely related to the mitogenic activity of cells.

Role of carboxyl tail of the rat angiotensin II type 1A receptor in agonist-induced internalization of the receptor. Binding of angiotensin II (Ang II) to its receptor type 1A (AT 1A ) is known to trigger its internalization. We studied the role of cytosolic segments of AT 1A in the internalization, and obtained results indicating a functional role of the cytosolic carboxyl terminal tail of AT 1A in the internalization. Deletion of 50 amino acids from the carboxyl terminus abolished the receptor internalization. Deletion mutants lacking 13 and 32 amino acid residues in the carboxyl terminal cytosolic region were internalized to the same extent as wild type AT 1A ; however, internalization of a mutant lacking the last 42 residues was partially suppressed. Thus, residues 310 through 327 were shown to be essential for the internalization. We propose that a short domain in the cytoplasmic tail (residues 310 to 327) may play a dominant role in the agonist-induced receptor internalization of AT 1A . Our results also suggest that the molecular determinants of the AT 1A receptor involved in receptor internalization are distinct from those participating in the desensitization process. IMPORTANT: Please read the Note Added in Proof at the end of the article (p. 1495) for important information!

Polymer nano-composite was prepared by mixed addition of azobenzoic compound and Al 2 O 3 nano-particle into LDPE to improve the electrical treeing resistance under ac voltage application. Three kinds of azobenzoic compound were tested: azobenzen (Az), nitro-azobenzen (Ni_Az) and aminoazobenzen (Am_Az). Any dispersant was not used. The test materials of the mixed addition were processed in our laboratory by the solution casting method. The experimental result showed that tree initiation voltage (TIV) was increased by the mixed addition. The increasing ratio of TIV for the mixed addition depends on the kind of azobenzoic compound. The highest increasing ratio of 300% was obtained in the mixed addition of Az and Al 2 O 3 at the concentrations of 2.0 wt% and 3.0 wt%, respectively. The mixed addition was also effective in restriction of tree development. The control effect depended significantly on the concentration of the azobenzoic compound. When the concentrations of Az and Al 2 O 3 were 1.0 wt% and 3 wt%, respectively and PD was induced by 5s of over voltage application, PD due to the treeing from the electrode tip was restricted to undetectable level, which continued more than 2000 min under the constant voltage application. However, in the case of 30s of the over-voltage application, the period of time to the breakdown for the mixed addition of above concentrations was almost the same as that for the single addition of the particle. The restriction of PD to the undetectable level was achieved by increasing the Az concentration to 2.0 wt% in the case of the overvoltage application of 30s.

The knowledge on the dose-response relationships between cumulative phthalate exposure and reproductive hormones in human are lacking. To assess the characteristics of the associations between hazard index (HI) of cumulative di-n-butylphthalate (DBP) and di-2-ethylhexylphthalate (DEHP) exposures and serum concentrations of free testosterone (fT), estradiol, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), we used restricted cubic spline function to characterize the dose-response curves between the HI values and reproductive hormones for 74 male workers occupationally exposed to high levels of DBP and DEHP, and 63 male construction workers as comparison group matched for age and smoking status. The median of HI value was 5.30 for exposed workers, 53.0-fold that of unexposed workers (0.10). 89.2% of exposed workers and 1.6% of unexposed workers have HI over 1.00. We observed a borderline significantly negative association between HI and fT in exposed workers (r=-0.195, p=0.096), but not in unexposed workers. The exposed workers showed inverted long-tailed J-shaped fT and FSH curves, and small changes in the LH curve, whereas unexposed workers had inverted and flattened-S-shaped fT and mirror-S-shaped LH and FSH curves. Both T production and hypothalamo-pituitary-testis (HPT) axis function were damaged in workers with high HI of phthalate exposures. HPT feedback function was activated in workers with both high and low HI, and plays an important role in preventing fT level from further decreasing with a rise in HI.

To determine the specific mechanism of ligand binding to angiotensin (Ang II) receptor AT1, mutagenized rat receptor cDNAs were expressed transiently in COS-7 cells and the effect of the mutations on the binding to peptidic and non-peptidic ligands was analyzed by Scatchard plots. Mutation of Lys199 to Gln in the intramembrane domain strongly reduced the affinity to both [125I] Ang II and [125I]-1Sar, 8Ile-Ang II whereas mutation of two other Lys had little effect, indicating involvement of Lys199 in binding ligands. Replacement of each of four Cys in the extracellular domain markedly reduced binding affinity, indicating the importance of two putative disulfide bridges in the formation of active receptor conformation. Substitution of Asp for Asn in N-glycosylation had no effect on ligand binding or expression of the receptor. These studies indicate mutated receptors are expressed in the plasma membrane and are amenable for further detailed studies.

This paper focuses on evaluating the adhesive strength of silver-tin (Ag-Sn) solder-jointed single-crystal silicon (SCS) specimens. The exothermic reaction in aluminum-nickel (Al/Ni) multilayer film was used as a heat source for melting the solder film. The reaction generated heat enough to melt Ag-Sn film [1]. To measure the adhesive strength of solder-jointed SCS specimens, we developed the four-point bending tester for minute specimens. The rectangular-solid SCS specimens having an Ag-Sn/AlNi/Ag-Sn section were prepared by dicing the bonded SCS wafer under various pressure loads in air and vacuum. As a result, fracture strength increased with an increase of pressure load. The strength of specimens bonded in vacuum was higher than that bonded in air.

The influence of addition of polycyclic compounds into LDPE upon electrical tree initiation was investigated to demonstrate the fundamental role of the aromatic compound in the tree initiation process. Five kinds of the polycyclic compounds were used in this study; naphthalene (Np), anthracene (An), 9,10-bromoanthracene (Br-An), tetracene (Te) and pentacene (Pn). The experimental results indicated that the tree initiation voltage (TIV) depend on the kind of polycyclic compounds added to LDPE. TIV for ldquoPE/Anrdquo is the highest, and is about 3.5 times higher than that for ldquoPErdquo (without additive). TIV for ldquoPE/Br-Anrdquo is the secondly highest. However, the scatter for ldquoPE/Br-Anrdquo is much wider than that for ldquoPE/Anrdquo. TIVs for ldquoPE/Terdquo and ldquoPE/Pnrdquo are not significantly higher than that for ldquoPErdquo. The addition of ldquoNprdquo has almost no effect on the increase in TIV. The mechanisms for the increase in TIV are discussed based on the experimental results with the pi-electron effects for absorption of kinetic energy of the hot electron and observations of deposit of the additive in the test materials by AFM and SEM.

Objective: To better differentiate patients with human T lymphotropic virus type I (HTLV-I)–associated myelopathy/tropical spastic paraparesis (HAM/TSP) from patients with multiple sclerosis (MS) who are HTLV-I seropositive, we compared the HTLV-I antibodies and HTLV-I proviral DNA loads in CSF and peripheral blood mononuclear cells (PBMC). Methods: Intrathecal synthesis of HTLV-I antibodies and HTLV-I proviral DNA loads in CSF and PBMC were measured and compared in 39 Brazilian patients: 17 HAM/TSP and 22 HTLV-I-seropositive non-HAM/TSP (7 with other neurologic diseases, 11 asymptomatic carriers, and 4 HTLV-I-seropositive patients with an MS-like phenotype). In addition, we followed immunologic and virologic markers in comparison to the clinical course (by Kurtzke Expanded Disability Status Scale) of seven patients (five with HAM/TSP and two with an MS-like phenotype) for a mean period of 16 (SD ± 5) months. Results: The proviral load in CSF and PBMC was higher in HAM/TSP than in non-HAM/TSP patients, except in the two HTLV-I-seropositive patients with an MS-like phenotype that also fulfilled the criteria for HAM/TSP. Higher HTLV-I proviral DNA load in CSF was associated with the higher proviral DNA load in PBMC and lower intrathecal synthesis of HTLV-I antibodies. These laboratory findings remained stable during follow-up. Conclusion: The high proviral load in peripheral blood mononuclear cells or in CSF or both may be a good marker of human T lymphotropic virus type I (HTLV-I)–associated myelopathy/tropical spastic paraparesis (HAM/TSP) and can differentiate patients with HAM/TSP from patients with multiple sclerosis infected with HTLV-I.

The relation between ac flashover voltage (ACFOV) and an attachment of nylon string on the insulator surface is studied in air by using a PMMA insulator which has a backside electrode. The measurements show that the ACFOV is decreased by the attachment of the string. ACFOV characteristics can be classified into two types with the contact angle between the H.V. electrode and the insulator surface. In a region of the contact angle from 90/spl deg/ to 120/spl deg/, the maximum percentage of the decrease is 15%. In the other region of the angle from 120/spl deg/ to 180/spl deg/, the maximum decrease is 25%.

Flashover along the surface of a solid insulator (surface flashover) prevents minimizing the size of vacuum devices It has been considered that the emission ofelectrons from the cathode hiple junction won is the first step of initiating the surface flashover, subsequent gas desorption from insulator surface stimulated by elechon impact is the second stop and finally the surface flashover occurs in the desorbed gases In addition it has been recognized that conditioning treatment by repetitive surface flashover cleans insulator surface and brings higher flashover voltage. Therefore removal of adsorbed gas= and surface contaminants may improve surface flashover voltage. In this expetiment, vacuum heat treatment (about 465 degrees Celsius) for Alumina samples was employed as a means of removal of adsorbed gases and surface contaminants. AAer heat treatment, repetitive flashover test was conducted in vacuum without the expsure.of sample to atmosphere Flashover voltages with and without heat treatment were compared. As a mull, flashover voltage for the sample with heat treatment was higher than that for without heat treatment In particular, an appreciable improvement of first flashover voltage was confirmed for heat treatment samples significant conditioning eNwt for the sample with heat treatment was obtained as well. In addition the dependence of the flashover voltage on the purity of aluminas with heat treatment was clalified.

This paper deals with the characterization of mechanical properties of impacted morsellized cancellous allograft (IMCA) produced by dynamic compaction of allograft femoral heads ground by commercially available bone mills, i.e. rotating rasp and reciprocating type bone mills. Various ranges and profiles of particle size in the graft aggregates were obtained using these bone mills, and the effect of number of compaction as well as the distribution of particle sizes on the mechanical properties of IMCA under quasistatic compression and shear loading conditions was discussed. The morsellized cancellous allograft prepared by the reciprocating type bone mill showed a broad distribution of particle sizes, and gave IMCA superior mechanical properties to the graft with a more uniform size distribution, or prepared by the rotating rasp type bone mills. The increase of number of compaction also improved the mechanical properties of IMCA in compression.

Interposed fibrous tissue at bone-implant interfaces was quantitatively measured in the presence or absence of polyethylene (PE) or alumina particles. Three different conditions of the interface were designed by implanting a pre-polymerized polymethylmethacrylate (PMMA) plug (plug group), a doughy PMMA (injection group) and a hydroxyapatite (HA) plug (HA group) in the hole drilled at the intercondylar notch of rabbit knees. PE (170+/-18 microm) or alumina particles (88+/-26 microm) were repeatedly administered into the knee joints at one month intervals (six times). All animals were sacrificed seven months after the implantation. The bone-implant interface was histomorphometrically examined using undecalcified ground sections. In the plug group, the PE particles significantly increased the extent of the interposed fibrous tissue (p0.05), while the alumina particles showed no effect. In contrast, both particles showed no significant effects in the injection and the HA groups. These results indicate that both particle characteristics and conditions of the bone-implant interface affected particle-induced fibrous tissue interposition. The loose PMMA plug with PE particles induced the greatest amount of fibrous tissue interposition.