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We investigated Si-doped GaN epitaxial layers on a (0001)-sapphire substrate using a HCl vapor-phase etching technique, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. Three kinds of distinctive etch pits correspond to three different types of threading dislocations, edge, mixed, and screw types. Photoluminescence intensity increases with the decrease in the number of etch pits corresponding to mixed and screw dislocations. The number of etch pits corresponding to edge dislocations, however, did not change. We concluded, therefore, that threading dislocations having a screw-component burgers vector act as strong nonradiative centers in GaN epitaxial layers, whereas edge dislocations, which are the majority, do not act as nonradiative centers.

A new fluorescent sensor consisting of Cd(II)-cylcen appended aminocoumarin and a substrate peptide for protein kinase A (PKA) has been designed. Upon phosphorylation by PKA, the metal complex moiety binds to a phosphorylated residue, which in turn displaces the coumarin fluorophore, and this event results in ratiometric change of excitation spectrum in neutral aqueous solution.

Purpose To compare the detectability between glaucomatous visual field changes using standard automated perimetry (SAP), frequency doubling technology (FDT), short-wavelength automated perimetry (SWAP), and flicker perimetry and structural changes using optical coherence tomography (OCT). Participants Fifty-nine eyes of fifty-nine patients with open-angle glaucoma, 24 eyes of 24 glaucoma suspects (GSs), and 40 eyes of 40 healthy age-matched subjects. Methods All subjects underwent Humphrey visual field analyzer II 24-2 full threshold (SAP), Swedish interactive threshold algorithm-SWAP, FDT (30-1, 30-5, 24-2-1, 24-2-5), flicker perimetry on Octopus 311 (4-zone probability 38S), and Stratus OCT [fast retinal nerve fiber layer thickness (NFLT) and fast optic disc]. To evaluate the visual field, FDT and flicker used the number of abnormal points, whereas SAP used mean deviation (MD) and SWAP used both the number of abnormal points and MD. The areas under the receiver operating characteristic curves [area under the curve (AUCs)] and sensitivities at fixed specificities were used to assess the detectability of glaucoma. Results The AUC for FDT 30-1, 30-5, 24-2-1, 24-2-5, flicker perimetry, SWAP (MD), and SWAP (number of abnormal points) were 0.95, 0.94, 0.88, 0.89, 0.99, 0.88, and 0.88 in the early glaucoma group and 0.67, 0.69, 0.65, 0.70, 0.80, 0.64, and 0.66 in the GS group, respectively. In the early glaucoma and GS groups, all OCT parameters had an AUC >0.81 except the disc area parameter. Especially, average NFLT had the highest AUC of 0.94 in the OCT parameters. Conclusions FDT, SWAP, flicker perimetry, and OCT are all useful methods for discriminating between healthy eyes and eyes with early glaucoma. Among all 10 OCT parameters, NFLT has the highest sensitivity for detecting early glaucomatous changes in GS patients.

GaN layers were grown on (0001) sapphire substrates by metalorganic chemical vapor deposition with various growth conditions. Some samples were grown with pressures higher than atmospheric. The residual strain in the epitaxial layer was estimated by measuring the lattice constants using x-ray diffraction. The optical quality was evaluated in terms of the threshold power density of stimulated emission. The residual strain perpendicular to C face, ezz, ranged from 0.058% to 0.125%. The strain ratio under biaxial stress (Δc/c)/(Δa/a), is estimated to be −0.46 from the relation between the lattice constants a and c. From the photoluminescence spectra with weak excitation, δEA/δezz for undoped GaN is estimated to be 16.4 eV. The threshold power density decreased from 2.77 to 0.59 MW/cm2 as the strain increased, suggesting that the strain relaxation process is accompanied by a generation of defects which act as nonradiative recombination centers.

We report our new raised-pressure metalorganic chemical vapor deposition (RP-MOCVD) technique and the room-temperature continuous-wave (cw) operation of GaN-based laser diodes grown using this technique. We have found that both the defect density as measured by etch-pit density and optical pumping threshold-powder density decreases as the growth pressure is increased beyond 1 atm. We fabricated GaN-based laser diodes and achieved lasing under cw conditions at 20°C. The threshold current density was 3.5 kA/cm2 and the operation voltage at threshold was 16.8 V.

Seven mutant forms of the antibacterial peptide apidaecin with increased activity were created by combinatorial mutagenesis targeted to the three N-terminal amino acid residues that had previously been identified as a nonessential region. An in vitro MIC assay revealed that the amino acid substitutions in the functionally variable region were effective in improving differential activity toward the four gram-negative bacteria tested, while a gram-positive bacterium was unaffected.

We achieve 10-microjoule pulse energies directly from a femtosecond laser oscillator. We underline its suitability for high field experiments at multi-megahertz repetition rate by demonstrating the first electron spectroscopy measurements driven by an oscillator.

1. We examined whether alpha 1-adrenoceptors in various blood vessels can be divided into subtypes by antagonist affinity or by susceptibility to chloroethylclonidine or nifedipine. 2. Noradrenaline or phenylephrine produced concentration-dependent contractions in all the tissues tested, which were competitively inhibited by phentolamine, yohimbine, prazosin, WB4101 and HV723. However, there were large differences between the tissues in the pA2 values for all the antagonists except phentolamine. 3. The blood vessels could be classified into three groups (I, II and III) on the basis of their affinity variation. In group I (dog mesenteric artery and vein, saphenous vein), the pA2 values for HV723 were greater than 9, and those for HV723 and WB4101 were approximately 1 log unit higher than for prazosin. This rank order of affinity reversed in group II (dog carotid artery and rat thoracic aorta), where prazosin was more potent (pA2 values greater than 9.5) than HV723 or WB4101. In group III (rabbit mesenteric artery, thoracic aorta and carotid artery and guinea-pig thoracic aorta), on the other hand, prazosin, HV723 and WB4101 inhibited the noradrenaline response with a similar affinity (pA2 values ranging from 8 to 9). 4. Yohimbine inhibited the responses to noradrenaline and phenylephrine with a lower affinity than prazosin, HV723 or WB4101. The pA2 values for yohimbine were similar in groups I and II (the values greater than 6.5), which were greater than those in group III (values less than 6.4). 5. The alpha l-adrenoceptors in group II were selectively affected by chlorethylclonidine, resulting in an irreversible attenuation of noradrenaline responses in the dog carotid artery and a persistent contraction in the rat thoracic aorta. 6. Nifedipine either produced no effect or a slight inhibition of alpha l-adrenoceptor-mediated contractions in all the blood vessels; these effects were not correlated to the above groups. 7. These results suggest that alpha,-adrenoceptors of blood vessels can be divided into three subtypes (designated as alpha 1H, alpha4L and alpha 1N) by antagonist affinity and their susceptibility to chloroethylclonidine but not to nifedipine: the characteristics of each subtype are summarized in Table 3. Subtypes alpha lH, alpha 1L and alpha lN may be predominantly involved in the contractile responses to noradrenaline or phenylephrine of the blood vessels in groups II, III and I, respectively.

Purpose In Program K, a new automated kinetic algorithm that we developed, the frequency distributions of the number of patients' response points were obtained for external angles to distinguish normal and abnormal isopters. We also assessed the agreement between the results of Program K and Goldmann manual kinetic perimetry (MKP). Methods Program K detected abnormalities in isopters by using the external angles of patients' response points. In experiment 1, a normal external angle range and endpoint for the algorithm were determined by using visual field (VF) results of 100 data sets. In experiment 2, the results of Program K and Goldmann MKP were compared in 63 virtual patients. Visual field loss was assessed by using stimuli of V/4e, III/4e, I/4e, I/3e, I/2e, and I/1e at a speed of 3 deg/s. The isopters by Program K and Goldmann MKP were overlapped and the area of intersection was expressed as a percentage of the union area. The intersection percentages and test durations were evaluated. Results A normal external angle range between 150° and 240° and phase 3 as the appropriate endpoint for the algorithm were determined. The intersection percentages for the six isopters were 84% (V/4e), 83% (III/4e), 78% (I/4e), 71% (I/3e), 60% (I/2e), and 50% (I/1e) (average, 71%). The average examination duration for Program K was 16.0 ± 3.2 minutes. The results of Program K and Goldmann MKP were comparable. Conclusions Program K is clinically efficient and useful for detection and evaluation of abnormalities in a kinetic VF.

Bisnetropsin-linked hydroxamic acids (BNHA) were shown to cleave DNA stands at a single residue with a preferred binding orientation in the presence of ferrous ion. In contrast, the corresponding cerium (III) complexes cleaved DNA with low sequence specificity.

We evaluated the clinical usefulness of flicker perimetry in glaucoma and glaucoma suspect patients using the new Octopus 311 automated perimeter.A total of 52 eyes of 52 glaucoma patients, 26 eyes of 26 glaucoma suspect patients and 61 eyes of 61 normal subjects were examined using standard automated perimetry (SAP), flicker perimetry and frequency doubling technology (FDT) perimetry. Flicker perimetry was performed using the Octopus 311 and its remote software package. Suprathreshold four-zone probability strategy was used to classify the critical fusion frequency probability level. The classified levels were set at 5% and 1% of probability of normality and 5 Hz. Frequency doubling technology perimetry was performed using 24-2-5, 24-2-1, N-30-5, N-30-1 screening programs using Humphrey Matrix perimetry. Standard automated perimetry was performed using the Humphrey field analyser program 24-2 full threshold. Optical coherence tomography using Stratus OCT was used for evaluating the retinal nerve fibre layer thickness in all glaucoma and glaucoma suspect patients.Receiver operating characteristic (ROC) curves were calculated. In the early stage of glaucoma, the areas under the ROC curve (AUCs) were 0.96 in flicker and 0.90 in Matrix perimetry. In the moderate and advanced stages of glaucoma, the AUCs were almost 1.0 in all tests. In glaucoma suspect patients, the AUC of the 5% probability level in flicker was significantly higher than in Matrix perimetry.The four-zone probability strategy using the Octopus 311 is a useful method for evaluating the flicker field in early glaucoma and glaucoma suspect patients.

PURPOSE Using M-CHARTS (Inami Co., Tokyo, Japan), which were developed by the authors to measure metamorphopsia, and image-analysis software, which was developed to quantify retinal contraction, the authors investigated the relationship between the degree of retinal contraction and the degree of metamorphopsia in eyes with idiopathic epiretinal membrane (ERM). METHODS This study was conducted in 29 eyes with ERM (29 patients, 20 women; mean age, 62.1 +/- 8.6 years) observed for at least 3 years (mean, 3.55 +/- 0.6 years) after diagnosis. Horizontal (MH) and vertical (MV) metamorphopsia scores were obtained with the M-CHARTS. Horizontal and vertical retinal contraction due to ERM was measured by using image-analysis software developed by the authors to calculate horizontal and vertical components of changes in the locations of retinal vessels on sequential fundus images. RESULTS There was a significant (P < 0.01) positive correlation between the degree of retinal contraction and metamorphopsia score. In addition, there were significant positive correlations between horizontal contraction of the retina and the MV score (P < 0.01) and between vertical contraction of the retina and the MH score (P < 0.05). No significant correlations were found between change in the metamorphopsia score and change in visual acuity or mean defect. CONCLUSIONS Metamorphopsia scores correlate well with measurements of retinal contraction due to idiopathic ERM. Using M-CHARTS is a simple and useful method for quantitatively monitoring metamorphopsia in patients with ERM.

Purpose To quantify the degree of metamorphopsia in patients with idiopathic epiretinal membranes (ERMs), by use of a new metamorphopsia chart (M-CHARTS) developed by the authors. Methods These M-CHARTS had 19 dotted lines with dot intervals of between 0.2 degrees (fine) and 2.0 degrees (coarse) visual angles. As the dot intervals were changed from fine to coarse, a decrease in the severity of metamorphopsia was noted. In this study, the minimum visual angle of the dotted lines needed to cause the metamorphopsia to disappear was measured in 51 eyes of 51 patients with ERM. The metamorphopsia scores were compared with the stages of ERM classified by scanning laser ophthalmoscope (SLO) images. Results In patients with ERM, the metamorphopsia score increased depending on the severity of membrane proliferation classified by SLO images. The scores obtained from the horizontal dotted lines were larger than those of the vertical lines in advanced stages of ERM. Conclusions M-CHARTS provide a very simple and useful method for evaluating the severity of metamorphopsia in patients with ERM.

High power GaN-based laser diodes (LDs) are very desirable for various applications such as optical storage systems. We have obtained GaN films of low dislocation density using epitaxial lateral overgrowth technique and the raised- pressure metalorganic chemical vapor deposition technique. Dislocation density of the improved GaN is about 107 cm-2. Optimized GaN-based LDs fabricated on the improved GaN films have operated up to 35 mW without any kink. The lifetime is more than 500 hours with a constant power of 20 mW at 25 degree(s)C under continuous wave conditions. Furthermore, we have introduced buried-ridge laser diode structure in order to control the optical transverse mode. The features of the far field patterns of LDs with AlGaN burying layers indicate their controllability.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The longer lifetime is desired for high power AlGaInN based violet lasers. We found that lifetime is strongly dependent on both the initial operating consumption power and the dislocation densities in the laser stripe. Pd/Pt/Au as a metal and AlGaN/GaN superlattice as a p-type cladding layer were incorporated to reduce the operating voltage. The optimization of device parameters as well as the stripe width and the RIE etching device depth led to the lower threshold current of 3.4 kA/cm 2 . We used the Pendeo epitaxy technique to get lower dislocation density approximately 10 7 cm -2 . The LDs with these technologies showed an output power as high as 35 mW under room temperature CW condition without kink. The lifetime is more than 500 hours under CW operation with a constant power of 20 mW at 25 degree(s)C.

The underlying GaN layers on which laser diodes are fabricated have been improved through two steps. In the first step, GaN single layer on sapphire was investigated. The residual strain and etch pit density were measured. We found that they reflect the optical quality. We found that the threading dislocation can be reduced to 4 × 108 cm−2. The optical quality depends on the residual strain and dislocation density. In the next step, we have utilized epitaxial lateral overgrowth ELO) technique. The optimized GaN layer on sapphire with the smallest dislocation density was used as seed layer. In the wing region of ELO-GaN, the threading dislocation density was reduced to 1 × 106 cm−2. On the other hand, in the seed region, dislocation density remained 4 × 108 cm−2. Photoluminescence intensity in the wing region was three times as large as that in the seed. The laser diodes were fabricated on the ELO-GaN layer, so that the ridge stripe was fabricated over the wing region, and its properties were compared with those of laser diodes on sapphire. It was found that the lifetime can be increased by using the ELO-GaN layer as the underlying layer.

The chemically modified thanatins with the methyl group (CH(3)), ethyl group (C(2)H(5)), and normal-octyl group (C(8)H(17)) at the side-chain of cysteine residues were synthesized. The octyl group modified form exhibited 8-fold higher antimicrobial activity against Micrococcus luteus than wild type thanatin. It was found that there was an equilateral correlation between antimicrobial activity and side-chain hydrophobicity at the cysteine residues in thanatin.

Nobel hydroxamic acids containing bis-netropsin units coupled by polymethylenetether (BNHA) have been synthesized. BNHA-ferrous complexes sequence-specifically cleaved pBR322 DNA fragment whereas corresponding cerium complexes showed low-sequence specific cleavage pattern.

We examined the effects of inaperisone hydrochloride (inaperisone), a new centrally acting muscle relaxant, on bladder function in anesthetized rats and isolated rat tissues. We also investigated its mechanism of action. When a balloon inserted into the bladder was expanded, rhythmic bladder contractions were observed; inaperisone (4 mg/kg i.v.) abolished these contractions, in both normal and decerebrated rats. The bladder tonus or bladder contraction induced by peripheral stimulation of the pelvic nerve was barely inhibited by inaperisone (4 mg/kg i.v.), but this dose of inaperisone abolished the efferent discharge from the pelvic nerve that accompanied the rhythmic bladder contractions. The doses of intracerebroventricularly (i.c.v.) and intrathecally injected inaperisone which abolished the rhythmic bladder contractions were 10 and 100 micrograms, respectively. The inhibitory effects of inaperisone (4 mg/kg i.v.) were not diminished by naloxone (1 mg/kg i.v.) or by bicuculline (0.5 mg/kg i.v.), but were diminished by phaclofen (30 mg/kg i.v. or 300 micrograms i.c.v.). The specific binding of [3H]baclofen to rat brain synaptosomal membranes was barely inhibited by inaperisone (up to 1 mM). From these results, it is speculated that, among other possible mechanisms, inaperisone inhibits the micturition reflex by acting indirectly on GABAB receptors in the brainstem.

Electrical transmural stimulation evoked contraction and relaxation in isolated urethral circular muscle of the dog. The responses were abolished by tetrodotoxin, indicating their neurogenic origin. The contractile force in the middle urethra was greater than that in the proximal and distal urethra. The contractions were not affected by atropine and propranolol, but were completely inhibited by phenoxybenzamine, prazosin and guanethidine. In preparations contracted with prostaglandin F2 alpha, electrical stimulation induced frequency-dependent relaxation in all urethral portions. Atropine, phenoxybenzamine, prazosin and guanethidine had no effect on the relaxation, while propranolol slightly attenuated the relaxation induced at the highest frequency used (5 Hz). The non-adrenergic, non-cholinergic relaxation was also not affected by ketanserin, methysergide, diphenhydramine, alpha,beta-methylene ATP or capsaicin. Exogenously applied phenylephrine and clonidine both produced contractions but the maximal response to clonidine was much smaller than that to phenylephrine. Acetylcholine produced no or feeble contractions. In the preparations contracted with prostaglandin F2 alpha, isoproterenol and vasoactive intestinal polypeptide (VIP) produced relaxation. These results suggest that the circular muscle of dog urethra is reciprocally innervated by sympathetic adrenergic and non-adrenergic, non-cholinergic nerves, and that the neurogenic responses are markedly affected by muscle tension and the portion of the urethra examined.

— A high-pixel-rate, high-contrast (30,000:1) wide-color-gamut grating-light-valve laser projector is reported. A new optical engine enabling high-frame-rate (240 Hz) scan projection is employed. Panoramic wide-angle-scan projection with a 64:9 aspect ratio was also developed. Speckle noise is eliminated using a simple but highly efficient technique. The optical throughput efficiency of the grating-light-valve laser projector is reviewed.

We report a high frame rate (240Hz), high contrast (30,000:1), wide color gamut GxL (G-by-L) laser projector. Proposed application areas for GxL are also discussed.

We have grown 1.5 µm-thick GaN layers on (0001) sapphire substrates by metalorganic chemical vapor deposition with various flow rates of trimethylgallium. The lattice constants a and c in the layer were estimated by X-ray diffraction. The threshold power density for stimulated emission was measured by photopumping the layers. It was found that the grown layers were elastically deformed and that the residual strain can be sustained by decreasing the flow rate of trimethylgallium. It was also found that the threshold power density of stimulated emission decreases as the lattice constant a decreases. This tendency indicates that the strain relaxation mechanism is associated with enhancement of nonradiative recombination.

Phenanthridine-linked hydroxamic acids with alkyl chain of variable length (n= 3, 4, 5, 6 and 7) have been newly synthesized. Their DNA cleavage activities have been investigated by Col E1 plasmid relaxation assay in the presence of transition(II)(ferrous and vanadyl) or lanthanide(III)(lutetium) metal ions. Linker length is extremely determinant for lutetium-mediated DNA cleavage. The increase in cleavage activity of the lutetium system with increasing pH suggests the involvement of metal-bound hydroxide as catalytically active species. Middle (samarium and europium) and late (thulium, ytterbium and lutetium) trivalent lanthanide systems are effective for DNA cleavage. For maximal DNA cleavage activity, the lutetium/hydroxamic acid ratio has been found to be 2 whereas that of the transition system has been found to be 1. We propose a hydrolytic mechanism in which two lanthanide ions are acting in concert for effective DNA cleavage.

Phenanthridine-linked hydroxamic acid 1 effectively cleaves ColE1 DNA in the presence of transition (ferrous, ferric and vanadyl) or lanthanide(III)(lutetium, thulium and europium) metal ions; in the presence of the former, the cleavage is inhibited by free radical scavengers, but in the latter case it is not.

The pharmacological profile of a newly synthesized imidazole derivative, DJ-7141, was examined with special reference to alpha-2 adrenoceptors. In the rat vas deferens and dog mesenteric artery, DJ-7141 at concentrations over 10−9 M selectively acted on the presynaptic alpha-2 adrenoceptors on the sympathetic nerve terminals and inhibited the contractions induced by electrical transmural stimulation. The potency of DJ-7141 was almost the same as those of clonidine and guanabenz. DJ-7141 also acted on the postsynaptic alpha-2 adrenoceptors to contract the dog saphenous vein. However, no alpha-1 agonist and antagonist actions were found at concentrations showing presynaptic alpha-2 agonist activity. In contrast to DJ-7141, clonidine produced an apparent contraction in the dog mesenteric artery, and the response was inhibited by prazosin. In urethane-anesthetized rats, clonidine at doses ranging from 0.003 mg/kg to 0.03 mg/kg produced a marked and prolonged hypotension, while DJ-7141 at such doses failed to produce a reduction of blood pressure. From these results, it is suggested that, in contrast to clonidine and other alpha-2 agonists, DJ-7141 is a unique alpha-2 agonist which shows high affinity to peripheral alpha-2 adrenoceptors but only a mild hypotensive activity.