Development of nickel-metal hydride cell: An update

This paper presents in viewgraph format an overview of NASDA's evaluation of commercial nickel metal-hydride (Ni-MH) cells and the development and testing of Ni-MH cells for use in space. The commercial cells are concluded to be feasible and suitable for use in LEO; for GEO, the durability for overcharge is needed because long-term charge retention is required. For the aerospace Ni-MH cell design, two activation procedures are applied to evaluate the effect of the difference in the amount of overcharge protection and precharge. Specific energy of the Ni-MH cell is nearly accomplished at 50 Wh/kg. Initial characteristics indicate the effect derived from precharge. Thirty-five amp-hour class Ni-MH cells have good performance for LEO cycle of 25 and 40 percent DOD up to 3000 cycles as similar to commercial cells. The effect of the difference in the amount of overcharge protection will appear in life test

Performance test results of ETS-6 Ni-Cd cells

The topics covered are presented in viewgraph form and include the following: development schedule; main specification; cell design; production flow; acceptance test (1); acceptance test (2); cell weight; 20 C performance; capacity; overcharge pressure; end of charge voltage; -5 C performance; ETS-VI simulation cycle test; and battery storage

Battery Performance of ADEOS (Advanced Earth Observing Satellite) and Ground Simulation Test Results

The Advanced Earth Observing Satellite (ADEOS) is developed with the aim of establishment of platform technology for future spacecraft and inter-orbit communication technology for the transmission of earth observation data. ADEOS uses 5 batteries, consists of two packs. This paper describes, using graphs and tables, the ground simulation tests and results that are carried to determine the performance of the ADEOS batteries

Defective Morphogenesis and Functional Maturation in Fetal Islet-Like Cell Clusters From OLETF Rat, A Model of NIDDM

A failure in the compensate proliferation of pancreatic β-cells, as the primary pathogenic event, has been reported in OLETF rat, a model of NIDDM. The aim of the present study is to define whether the β-cell defect is attributed to the fetal stage islet development, if so, whether the defect involves down regulation of PDX-1 protein expression. Morphological changes, β-cell function, and the expression of PDX-1 protein were examined in the cultured fetal islet-like cell clusters (ICCs) from OLETF rats along with their diabetes-resistant control counterpart LETO rats in the presence of 5.5 or 11.1mM glucose for 48, 72, 96, and 120-hr, respectively. We have observed four abnormalities in the ICCs of OLETF rats. First, a defective morphogenesis was noted during the 72 to 120-hr ICC culture, a period characterized by a dramatic increase in both β-cell and non-β-cell (α,σ, and PP) populations in control rats. This defective morphogenesis was demonstrated by a growth retardation of epithelial stratification and poor development of both β-cell and non-β-cell masses along with a parallel decline in relevant islet hormone contents. Second, a functional defect was characterized by failure to response to glucose during the 96 to 120- hr-cultured ICCs. Third, the ultrastructural analysis revealed a significant reduction in the number of secretory granules. Four, Western blot analysis showed a significant decrease of PDX-1 protein expression in the OLETF ICCs cultured in 11.1mM glucose for 48 to 72-hr and in 5.5mM glucose for 120-hr. Therefore, we concluded that during the fetal stage of islet development, OLETF rats exhibit both morphological and functional defects

RVB Contribution to Superconductivity in MgB2MgB_2

We view $MgB_2$ as electronically equivalent to (non-staggered) graphite ($B^-$ layer) that has undergone a zero gap semiconductor to a superconductor phase transition by a large c-axis (chemical) pressure due to $Mg^{++}$ layers. Further, like the \ppi bonded planar organic molecules, graphite is an old resonating valence bond (RVB) system. The RVB's are the `preexisting cooper pairs' in the `parental' zero gap semiconducting $B^-$ (graphite) sheets that manifests themselves as a superconducting ground state of the transformed metal. Some consequences are pointed out.Comment: 4 pages, 2 figure, RevTex. Based on a talk given at the Institute Seminar Week, IMSc, Madras (12-16, Feb. 2001

Facilitation of bone resorption activities in synovial lavage fluid patients with mandibular condyle fractures

The aim of this study was to investigate the bone resorption effect of the mediators delivered in joint cavity of patients with mandibular condyle fractures by detecting osteoclast markers using cellular biochemistry methods, and by analysing bone resorption activities via inducing osteoclast differentiation of the infiltrated cells from arthrocentesis. Sixteen joints in 10 patients with mandibular condyle fractures were evaluated. The control group consisted of synovial fluid (SF) samples from seven joints of four volunteers who had no clinical signs or symptoms involving the temporomandibular joint (TMJ) or disc displacement. We collected SF cells from all patients during therapeutic arthrocentesis. The infiltrating cells from TMJ SF were cultured, differentiated into tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells and examined bone resorption activities. We also investigated factors related to osteoclast induction of SF, using ELISA procedures. Osteoclast-like cells were induced from the SF cells obtained from all patients with condylar fractures. These multinucleated giant cells were positive for TRAP and actin, and had the ability to absorb dentin slices. The levels of macrophage colony-stimulating factor (M-CSF), prostaglandin E2 (PGE2), soluble form of receptor activator of nuclear factor kappa-B ligand (sRANKL) and osteoprotegerin (OPG), in SF samples from the patients, were significantly higher than in the controls. These findings indicate that bone resorption activities in SF from patients with mandibular condyle fractures were upregulated and may participate in the pathogenesis and wound healing

Protein dynamics with off-lattice Monte Carlo moves

A Monte Carlo method for dynamics simulation of all-atom protein models is introduced, to reach long times not accessible to conventional molecular dynamics. The considered degrees of freedom are the dihedrals at C$_\alpha$-atoms. Two Monte Carlo moves are used: single rotations about torsion axes, and cooperative rotations in windows of amide planes, changing the conformation globally and locally, respectively. For local moves Jacobians are used to obtain an unbiased distribution of dihedrals. A molecular dynamics energy function adapted to the protein model is employed. A polypeptide is folded into native-like structures by local but not by global moves.Comment: 10 pages, 4 Postscript figures, uses epsf.sty and a4.sty; scheduled tentatively for Phys.Rev.E issue of 1 March 199

Insights into Protein Aggregation by NMR Characterization of Insoluble SH3 Mutants Solubilized in Salt-Free Water

Protein aggregation in vivo has been extensively associated with a large spectrum of human diseases. On the other hand, mechanistic insights into protein aggregation in vitro were incomplete due to the inability in solubilizing insoluble proteins for high-resolution biophysical investigations. However, a new avenue may be opened up by our recent discovery that previously-thought insoluble proteins can in fact be solubilized in salt-free water. Here we use this approach to study the NMR structural and dynamic properties of an insoluble SH3 mutant with a naturally-occurring insertion of Val22 at the tip of the diverging turn. The obtained results reveal: 1) regardless of whether the residue is Val, Ala, Asp or Arg, the insertion will render the first hNck2 SH3 domain to be insoluble in buffers. Nevertheless, all four mutants could be solubilized in salt-free water and appear to be largely unfolded as evident from their CD and NMR HSQC spectra. 2) Comparison of the chemical shift deviations reveals that while in V22-SH3 the second helical region is similarly populated as in the wild-type SH3 at pH 2.0, the first helical region is largely unformed. 3) In V22-SH3, many non-native medium-range NOEs manifest to define non-native helical conformations. In the meanwhile a small group of native-like long-range NOEs still persists, indicating the existence of a rudimentary native-like tertiary topology. 4) Although overall, V22-SH3 has significantly increased backbone motions on the ps-ns time scale, some regions still own restricted backbone motions as revealed by analyzing 15N relaxation data. Our study not only leads to the establishment of the first high-resolution structural and dynamic picture for an insoluble protein, but also shed more light on the molecular events for the nonhierarchical folding mechanism. Furthermore, a general mechanism is also proposed for in vivo protein aggregation triggered by the genetic mutation and posttranslational modification

Polymorphism Located between CPT1B and CHKB, and HLA-DRB1*1501-DQB1*0602 Haplotype Confer Susceptibility to CNS Hypersomnias (Essential Hypersomnia)

Background: SNP rs5770917 located between CPT1B and CHKB, and HLA-DRB1*1501-DQB1*0602 haplotype were previously identified as susceptibility loci for narcolepsy with cataplexy. This study was conducted in order to investigate whether these genetic markers are associated with Japanese CNS hypersomnias (essential hypersomnia: EHS) other than narcolepsy with cataplexy. Principal Findings: EHS was significantly associated with SNP rs5770917 (Pallele = 3.6610 23; OR = 1.56; 95 % c.i.: 1.12–2.15) and HLA-DRB1*1501-DQB1*0602 haplotype (Ppositivity = 9.2610 211; OR = 3.97; 95 % c.i.: 2.55–6.19). No interaction between the two markers (SNP rs5770917 and HLA-DRB1*1501-DQB1*0602 haplotype) was observed in EHS. Conclusion: CPT1B, CHKB and HLA are candidates for susceptibility to CNS hypersomnias (EHS), as well as narcolepsy with cataplexy