Elschnig pearl formation along the posterior capsulotomy margin after neodymium:YAG capsulotomy

PURPOSE: To determine the incidence of Elschnig pearl formation along the capsulotomy margin (string of pearls) after neodymium:YAG (Nd:YAG) laser posterior capsulotomy and to elucidate its clinical features, predisposing factors, effect on visual function, and association with additional capsulotomy. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: The records of 418 eyes that had had Nd:YAG posterior capsulotomy after cataract surgery were retrospectively reviewed. Of those, 315 were excluded for short follow-up (fewer than 12 months) or insufficient clinical examination data. In the remaining 103 eyes, the incidence of string of pearls was calculated, and its clinical features, predisposing factors, effect on visual function, and correlation with additional capsulotomy were evaluated. RESULTS: String of pearls was identified in 49 eyes (47.6%); 37 (75.5%) developed pearls within 1 year after Nd:YAG capsulotomy. The incidence was significantly higher in patients having intraocular lens implantation and continuous curvilinear capsulorhexis (CCC) than in those without (95.9 versus 61.1% and 97.9 versus 55.6%, respectively). No significant differences were found in patient age and sex, total Nd:YAG energy, and the presence of diabetes mellitus or high myopia. String of pearls caused visual disturbances in 17 eyes (34.7%). The rate of repeat capsulotomy was higher in patients with string of pearls than in those without (36.7 and 9.3%, respectively). CONCLUSIONS: String of pearls formation was a common and significant complication after Nd:YAG posterior capsulotomy. Intraocular lens implantation and CCC may promote its formation.     

Accurate measurement method of the position of a buried line

A conventional method to measure the position of a buried line has been used. This method is based on the measurements of magnetic field around a line which conducts a current. However, the pitfall is that the magnetic field generated by an induced current in a secondary line allows considerable measurement errors. This paper describes a novel method to exclude such errors caused by the induced current. While the magnetic field generated by the current in the primary line is in phase with the current, that generated by the induced current delays more than 90° compared to that of the current in the primary line because of a reluctance component of the secondary line. Hence, the 90° component of the magnetic field results from the induced current. This component is measured by a solenoid coil and a lock-in amplifier; the 0° component is measured also and corrected by using the 90° component. Thus, the net magnetic field generated by the current in the primary line is calculated. It is used to determine the correct position of the primary line. The new method is tested by using two buriéd lines and is proved to be useful.     

Measurement of streamer charge distribution on an insulator in SF6 Gas

The charge density produced by streamers on an insulator surface in SF₆ has been investigated by using a probe method with a high-speed temporal resolution. Concentric circular probes, which also act as a plane electrode, are used in this probe method. Probe signals are observed oscilloscopically and converted into the charge densities through a numerical calculation. This method reveals the charge distribution before a disturbance caused by the “back discharge.” The charge density thus obtained ranges from several nC/cm² up to about 60 nC/cm². The density depends on the pressure, voltage height and the position of the streamer. The electric field on the insulator is analyzed numerically taking into account the surface charge. The internal electric field of the streamer is found to be 40 ～ 50 kV/cm · atm when the streamer ceases its propagation. However, it partly exceeds the critical one (89 kV/cm · atm) during the propagation.     

Development of residential PEFC cogeneration systems: Ru catalyst for CO preferential oxidation in reformed gas

The performance of the novel Ru catalyst in a single-stage CO preferential oxidation removal reactor was investigated for residential polymer electrolyte fuel cell (PEFC) cogeneration systems. The outlet CO concentration of the CO removal reactor was reduced to less than 1 ppm even at [O₂]/[CO]=1.5. The natural gas fuel processor equipped with the CO removal reactor achieved the target thermal efficiency of 77% (LHV). Moreover, the durability of the Ru catalyst has been confirmed for more than 16,000 h at a micro-reactor and for more than 8000 h at an actual CO removal reactor. Because of the low O₂/CO molar ratio, the high CO removal conversion and the long-term durability, the Ru catalyst contributes to the development of residential PEFC cogeneration systems.     

Heterogeneous nucleation and crystallization of polyethylene with gold: Dilatometry

Heterogeneous nucleation and crystallization data for polyethylene at a gold interface are reported. Isothermal crystallization is investigated by dilatometry. Avrami plots of the crystallization data suggest that the gold surface acts as a suitable nucleating agent resulting in heterogeneous nucleation and two-dimensional crystal growth at the polyethylene melt–gold interface. The deviation of measurements from Avrami's equation suggests the presence of intercrystalline links during the final growth stages of isothermal crystallization. A closely packed lamellar model is given for heterogeneous nucleation and two-dimensional crystallization which results in high density and rod-like crystals.     

A splice mutation in the human canalicular multispecific organic anion transporter gene causes Dubin-Johnson syndrome

The induction of the Mitochondrial Permeability Transition (MPT) has recently been associated with the release of apoptogenic cytochrome c, which could come about in a swelling-dependent or swelling-independent manner. We observed that canonical inducers of MPT (Ca2+, t-butyl hydroperoxide, atractyloside) induce a swelling-dependent release of cytochrome c, and that osmotic support of mitochondria with PEG-1000 abolishes mitochondrial swelling, protein release, and cytochrome c release by these inducers. By contrast, it was observed that dATP is a potent inducer that caused release of cytochrome c in a swelling independent manner, i.e. even in the presence of osmotic support by PEG-1000; in addition this release of cytochrome c is inhibitable by cyclosporin A. The dATP-dependent and swelling-independent release of cytochrome c from mitochondria is not inhibitable by the protease inhibitor z-VAD, suggesting that it is not mediated by upstream caspases. This is the first report to our knowledge that a chemical compound may directly cause release of cytochrome c from mitochondria, and could explain the toxicity of dATP in the context of the genetic immunodeficiency diseases Adenosine Deaminase deficiency and Purine Nucleotide Phosphorylase deficiency.     

Development of approximate formula for LDL-chol, LDL-apo B and LDL-chol/LDL-apo B as indices of hyperapobetalipoproteinemia and small dense LDL

The adaptive significance of repeated withinpair copulations is not well understood. We analysed the copulatory behaviour of 16 pairs of solitary-nesting American kestrels, Falco sparverius, in southern Quebec (Canada), and the achieved reproductive success (paternity) of 21 kestrel families determined by DNA fingerprinting, in terms of four hypotheses. (1) The paternity assurance hypothesis, which suggests that males copulate frequently to avoid being cuckolded, was rejected because there were few extrapair copulation attempts (<1% of all copulations observed), withinpair copulations were not timed during the fertile period and mate attendance did not increase as the fertile period approached. (2) The immediate material benefits hypothesis, which suggests that females trade copulations for food, was refuted because copulations most often occurred without food transfers, especially outside the fertile period. (3) The female mate guarding of males hypothesis, which suggests that females distract their mates from other mating opportunities by copulating frequently, was rejected because extrapair copulation attempts were infrequent, male and female solicitation frequencies were similar and females did not differ in the timing or frequency of solicitations. (4) The mate assessment hypothesis, which suggests that assessment of mate quality is mediated via copulation, most closely predicted the behaviour observed since withinpair copulations were frequent outside the fertile period and at pair formation, males and females solicited similar numbers of copulations and pairs did not differ significantly in solicitation or copulation frequency. In line with this hypothesis we found that only one brood was extrapair, probably the result of mate replacement.Copyright 1998 The Association for the Study of Animal Behaviour