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MgZnCdSe/BeZnTe II-VI light emitting diodes (LEDs) with ZnCdSe/BeZnTe type-II superlattice (SL) active layers have been fabricated by molecular beam epitaxy. Yellow-green emissions around 575 nm were observed from electroluminescence measurements. We have also investigated the degradation behavior of the LEDs. In the simple aging test, the lifetime was drastically improved by optimizing the condition of an InGaAs buffer layer. Under the constant current condition at about 18 A/cm 2 at room temperature, a long life operation over 1500 h was achieved.

Xanthan and Na-hyaluronate (Na-Hy) polysaccharides belong to a class of polyelectrolytes that show a maximum in the reduced viscosity as a function of polyelectrolyte concentration. It is also well documented that xanthan solutions present a polyelectrolyte scattering maximum as a function of the wavevector q. However, despite considerable expanded experimental efforts, no scattering peak was observed in Na-Hy systems when using light or neutron scattering techniques. In this work and for the first time, we report that only the use of high brilliance of synchrotron radiation at rest and under shear enables to highlight the expected small-angle scattering peak in the Na-Hy polyelectrolyte system .A t zero shear rate, the scattering profile reveals a very diffuse and hardly detectable maximum at ideal experimental conditions (i.e., semidilute "salt-free" polyelectrolyte concentrationsor low ionic strengths and momentum transfer q). As the shear rate is increased, this very small maximum is magnified and reveals clearly the expected polyelectrolyte nature of Na-Hy not yet observed using other radiation (light or neutrons). The system undergoes a typical and progressive change from isotropic to anisotropic phase, when increasing the shear, confirming the origin of the peak and the role of the electrostatic interactions on the structural order in polyelectrolyte systems. These results are compared to those obtained under the same conditions on the xanthan polyelectrolyte system where, in addition to the so-called polyelectrolyte scattering peak, a second-order peak in the scattering profile is observed as a consequence of the shear.

The robot arm used in these studies is shown. A DC motor is connected to a joint through a harmonic drive gear as a prime mover actuator. The timing belts are provided between the joints to drive a link along the X axis. In this mechanical system the flexibility of the timing belts produces vibrations. The robot arm with timing belts is modeled with consideration given to this flexibility. The appropriateness of the proposed mechanical model is examined based on computer simulations and experimental results. The model of the robot is derived from the Lagrangian equations and the flexible transmission is approximated as a torsional spring. A positioning servosystem with suppression of vibrations based on this mechanical model is presented. The performance of the proposed control system and the effect of the suppression of vibrations are examined based on the computer simulations and experimental results. >

Transgenic mice carrying familial amyotrophic lateral sclerosis (FALS)-linked mutant Cu/Zn superoxide dismutase (SOD1) genes such as G93A (G93A-mice) and G85R (G85R-mice) genes develop limb paresis. Introduction of human wild type SOD1 (hWT-SOD1) gene, which does not cause motor impairment by itself, into different FALS mice resulted in different effects on their clinical courses, from no effect in G85R-mice to acceleration of disease progression in G93A-mice. However, the molecular mechanism which causes the observed difference, has not been clarified. We hypothesized that the difference might be caused by the stability of mutant SOD1 proteins. Using a combination of mass spectrometry and enzyme-linked immunosorbent assay, we found that the concentration of G93A-SOD1 protein was markedly elevated in tissues of transgenic mice carrying both G93A- and hWT-SOD1 genes (G93A/hWT-mice) compared to that in G93A-mice, and also found that the concentration of G93A-SOD1 protein had a close relation to the disease duration. The concentration of metallothionein-I/II in the spinal cord, reflecting the degree of copper-mediated oxidative stress, was highest in G93A/hWT-mice, second in G93A-mice, and normal in the mice carrying hWT-SOD1 gene. These results indicated that the increase of G93A-SOD1 protein was responsible for the increase of oxidative stress and disease acceleration in G93A/hWT-mice. We speculate that coexpression of hWT-SOD1 protein is deleterious to transgenic mice carrying a stable mutant such as G93A-SOD1, because this mutant protein is stabilized by hWT-SOD1 protein, but not to transgenic mice carrying an unstable mutant such as G85R-SOD1, because this mutant protein is not stabilized by hWT-SOD1.

The gp43 glycoprotein is an immune-dominant antigen in patients with paracoccidioidomycosis (PCM). It is protective against murine PCM and is a putative virulence factor. The gp43 gene of Paracoccidioides brasiliensis B-339 is located in a 1,329-bp DNA fragment that includes two exons, a 78-bp intron, and a leader peptide-coding region of 105 bp. Polymorphism in gp43 has been suggested by the occurrence, in the same isolate or among different fungal samples, of isoforms with distinct isoelectric points. In the present study we aligned and compared with a consensus sequence the gp43 precursor genes of 17 P. brasiliensis isolates after sequencing two PCR products from each fungal sample. The genotypic types detected showed 1 to 4 or 14 to 15 informative substitution sites, preferentially localized between 578 and 1166 bp. Some nucleotide differences within individual isolates (noninformative sites) resulted in a second isoelectric point for the deduced protein. The most polymorphic sequences were also phylogenetically distant from the others and encoded basic gp43 isoforms. The three isolates in this group were from patients with chronic PCM, and their DNA restriction patterns were distinct in Southern blots. The nucleotides encoding the inner core of the murine T-cell-protective epitope of gp43 were conserved, offering hope for the development of a universal vaccine.

A 22-year-old man had choreatic movements in upper limbs, neck and trunk for over twelve years which were associated with dystonia in lower limbs upon initiating voluntary movements. The choreatic movement lasted for a few seconds and the dystonia lasted for a few minutes. He also had high serum CK levels and hypertrophic calf muscles. His muscle strength and deep tendon reflexes were normal. His choreatic movements fulfill the criteria for paroxysmal kinesigenic choreoathetosis (PKC). However, it was unclear what the symptom of dystonia was due to. From a muscle biopsy and DNA analysis, he was diagnosed as having Becker muscular dystrophy. Administration of anticonvulsant improved the dystonia as well as the choreatic movement, which showed that the dystonia was a symptom of PKC. Coincidence of choreatic movements and dystonias which had different lasting time in a patient of PKC was atypical and had not previously reported.

Using a video game format, this study examined the effects of time pressure (TP) on behavioral and electrocortical indices. The behavioral results were consistent with previous time pressure research in that TP reduced time to perform a task and increases behavioral errors. In addition, electroencephalogram (EEG) measures showed distinctive patterns associated with TP in the theta, mu, and gamma bands along the midline. Site specific changes in the success vs. failure trials were also seen in midline theta at Fz, gamma at Fz, and mu at Cz. Right parietal alpha also differentiated TP and success vs. failure trials. In specific TP (1) increased frontal midline theta activity and (2) increased gamma at midline (frontal, central, and partietal) and in right frontal areas. The results of these findings are discussed in terms of the formation of specific neurocognitive strategies as evidenced by the topographic distribution of task-related modulation of the EEG within certain frequency bands. It is suggested that the effect of TP on visuomotor performance is mediated by adopting either task-relevant or task-irrelevant neurocognitive strategies as evidenced by successful or failed trials, respectively. Whether these strategies are formulated prior to performance or appear spontaneously during task performance remains unclear and is awaiting further experimentation.

BACKGROUND: It has been 10 years since the implementation in Japan of donor blood screening for human T-cell lymphotropic virus type I (HTLV-I). This report reviews the effectiveness of screening in preventing transmission of HTLV-I through blood transfusion and the current status of patients with confirmed seroconversion due to transfusions given before the implementation of screening. STUDY DESIGN AND METHODS: Patients who received blood at Kyushu University Hospital from 1990 to 1997 were followed. Serum samples were collected before transfusion and 60 days or more after transfusion. Seroconversion was determined by a second-generation particle agglutination test. Confirmation tests were an immunofluorescence assay, enzyme-linked immunosorbent assay, and immunoblotting. Confirmed seroconverted patients were followed by a search of hospital records. RESULTS: Seroconversion was found in one of 4672 transfused patients, but the donor was identified and confirmed to be negative for anti-HTLV-I and virus genome by nested polymerase chain reaction. A total of 23,323 red cell concentrates and 17,237 platelet concentrates were transfused to these 4672 patients. Therefore, the anti-HTLV-I prevalence in blood for transfusion after screening was estimated at 1 in 45,560 (0.0022%; the upper 95% CI was 0.0080%). One hundred two seroconverted patients who were transfused before donor screening for HTLV-I were followed. One patient developed HTLV-I-associated myelopathy, diagnosed 18 weeks after seroconversion, and another patient developed uveitis 1 month after seroconversion. No patients developed adult T-cell lymphoma, and the survival rate of seroconverted patients was 92.5 percent 15 years after transfusion. CONCLUSION: This study confirmed that the present donor screening program for HTLV-I by the new particle agglutination test can almost completely prevent virus transmission by transfusion. Complications of HTLV-I transmission were at lower rates than expected.

To prepare poly(lactide-co-glycolide)(PLGA) microspheres containing recombinant hepatitis B core antigen (HBcAg; Mw = 3,600,000) by a w/o/w emulsion/solvent evaporation method and evaluate the possibility of this system as a potent long-acting carrier for hepatitis B core antigen in mice.Various additives had been incorporated in the internal aqueous phase during the process of microencapsulating HBcAg, HBcAg antigenicity in the medium extracted from the prepared microspheres were measured by ELISA. Shape confirmation of the HBcAg antigen was performed by a sucrose gradient velocity centrifugal technique. For in vivo study, prepared microspheres were administered subcutaneously to Balb/C mice, and the serum IgG level was determined by ELISA.The inactivation of HBcAg by methylene chloride was dramatically reduced by the addition of gelatin (4-8% (w/v)) to the internal aqueous phase during the preparation. Further improvement of the loading efficiency to almost 61% resulted with cooling (4 degrees C). The prepared microspheres (4.27 microm+/-1.23 microm) containing 0.15% HBcAg displayed burst release (50-60% within 2 days). In subcutaneous inoculation, the adjuvant effect of PLGA microspheres was almost the same as that of the complete Freund's adjuvant. Whereas oral inoculation using the microspheres was not effective.The pH of the added gelatin seemed to be the key to the stabilization of HBcAg from various stability tests and CD spectrum study. Finally, the possibility of using this system as a potent long-acting hepatitis B vaccine was demonstrated.

Termination mutations in the precore open reading frame of hepatitis B virus (HBV) variants with defective hepatitis B e antigen (HBeAg) production have been demonstrated in both infected patients who have seroconverted to anti-HBe and those with fulminant hepatitis B. A donated plasma sample was found to be positive for the hepatitis B surface antigen, but negative for both HBeAg and anti-HBe. The HBV DNA titer in the plasma was estimated to be 32 pg/ml, and circulating virus-like particles were observed by electron microscopy. The entire nucleotide sequence of the virus was determined and at least 7 nucleotides were found to be unique when compared with previously reported sequences. These nucleotides created no termination codon in the precore/core, pol, preS/S and HBx open reading frames. The deduced amino acid substitutions were 28 Arg--Gln, 94 His--Tyr, 131 Val--Ile and 132 Phe--Tyr of HBx and 715 Met--Val and 789 Asp--Asn of pol. Furthermore, the precore and core/pregenome promoter contained altered 1764 A, 1766 T and 1768 A. Therefore, mutations in regions other than the precore open reading frame can cause defective HBeAg production.

A resonant cavity waveguide device structure is reported which incorporates a grating structure to couple the vertical incident light into the waveguide and uses Bragg grating to constitute a resonator. Two types of grating are fabricated simultaneously on a surface of thin Si waveguide to gain high sensor sensitivity for the refractive index change measurement.

1. 1. The HCl-methanol (HCl-MeOH) soluble fraction from the puparial cuticle of yellow, black and ebony of D. melanogaster was hydrolyzed in hydrochloric acid and examined for β-alanine, ketocatechol, and acetic acid. 2. 2. Between β-alanine and ketocatechol and between β-alanine and acetic acid, a quantitatively inverse relationship was found, respectively. The former relationship was further confirmed by the feeding experiment of β-alanine to black . 3. 3. Of total β-alanine in the HCl-MeOH extract, the proportion of those having free amino group was 74.8 per cent. 4. 4. All these results indicate that the HCl-MeOH soluble fraction of the puparial cuticle may be useful for investigating the cross-link structure of the cuticle.

The serum of a woman was found by the Ouchterlony double-diffusion and the hemagglutination inhibition (HAI) methods to have immunoglobulin A (IgA) deficiency. Further investigation using the hemagglutination (HA) test with red cells coated with IgA myeloma proteins of different specificities showed that the serum agglutinated only IgA2-, A2M-1, and A2M 2-coated cells. The patterns of the HAI test with a reference panel confirmed the presence of two specificities. One was anti-IgA2 and the other was a rare antibody against the allotype A2M 2. The anti-A2M 2 was used for population studies. Testing of the Han Chinese population, including family studies, confirms that A2M.1 and A2M.2 have an autosomal dominant mode of inheritance and are controlled by a codominant allele. The distribution of the two Am genetic markers among the Han Chinese population demonstrated A2M.1 with a gene frequency of 0.553 and A2M.2 with a gene frequency of 0.447 (chi 2 = 0.145, 0.80 greater than p greater than 0.70).

To prevent the transmission of human T-lymphotropic virus, type 1 (HTLV-1) during blood transfusion, a program was implemented to screen donors for antibodies to the virus, using a newly developed, passive agglutination (PA) method. During the period April 1986 to March 1987, 675 recipients of donor blood in whom the antibody to HTLV-1 was not present before transfusion were followed for at least 50 days after transfusion. One of these 675 seroconverted despite the transfusion of screened blood, but this seroconversion rate (0.15%) represents a marked decrease from the rate of 8.3 percent prevalent before donor screening began. The rate in the Fukuoka area of donors seropositive for anti-HTLV-1 is 5.34 percent, as detected by the PA method and 1.80 percent, as assessed by the indirect immunofluorescence (IF) technique, with PA-positive but IF-negative blood units thus accounting for 3.5 percent (5.34–1.80) of the total blood donated. The seroconversion rate among recipients transfused with blood screened by IF (at Kyushu University Hospital only) from 1981 to 1985 was 0.41 percent, which was not significantly different from the rate of 0.15 percent observed after PA screening. The discrepancy between PA and IF in the rate of seropositivity was due, in part, to the higher sensitivity of PA in detecting anti-HTLV-1. It is proposed that all donor blood in areas where HTLV-1 is endemic be screened by PA before transfusion. For reasons of expense and equipment unavailability, it is not possible for IF to be used on a general basis, but because of the possibility of false-positive results with PA, PA-positive blood units should be reexamined by IF or Western blot testing to reduce the amount of wasted blood, especially in areas highly endemic for HTLV-1, such as Kyushu, Japan.

The hydrostatic pressure dependence of pseudodirect gaps in ZnGeP 2 has been investigated at room temperature using a diamond anvil cell. The pressure coefficients of pseudodirect gaps between the lowest conduction band Γ 6 c and three valence bands (Γ 6 V , Γ 7 V , Γ 6 V ) were −1.9 × 10 −6 eV/bar. These values are very close to that of the indirect gap (Γ 15 V −X 1 c ) in A III B V semiconductors, as well as those in ZnSiP 2 .