425 research outputs found

    Analysis of the generation of photon pairs in periodically poled lithium niobate

    Full text link
    The process of spontaneous parametric down-conversion (SPDC) in nonlinear crystals makes it fairly easy to generate entangled photon states. It has been known for some time that the conversion efficiency can be improved by employing quasi-phase-matching in periodically poled crystals. Using two single-photon detectors, we have analyzed the photon pairs generated by SPDC in a periodically poled lithium niobate crystal pumped by a femtosecond laser. Several parameters could be varied in our setup, allowing us to obtain data in close agreement with both thermal and Poissonian photon-pair distributions.Comment: 4 pages, 4 figures, uses ws-procs10x7.cls; v2: Sign in equation (5) correcte

    AA amyloidosis-resistant CE/J mice have Saa1 and Saa2 genes that encode an identical SAA isoform

    Get PDF
    The CE/J mouse strain is resistant to amyloid A protein (AA) amyloidosis. In contrast to AA amyloidosis-susceptible mouse strains that concomitantly express serum amyloid A precursor protein (SAA) types 1 and 2 isoforms encoded by the Saa1 and Saa2 genes, respectively, in response to inflammatory stimulation from the liver, CE/J mice express only a single SAA isoform named SAA2.2. In addition, CE/J mice uniquely possess a Q30L amino acid substitution in SAA2.2 that inhibits amyloidogenesis. To elucidate the genetic basis underlying the expression of only a single SAA isoform in this strain, we conducted PCR cloning and nucleotide sequencing of the Saa1 and Saa2 genes from the CE/J genome. We revealed that CE/J mice possess functional Saa1 and Saa2 genes. Intriguingly, the two genes were identical with respect to amino acid sequence, each encoding the SAA2.2 isoform. RT-PCR analysis of inflamed liver tissue from CE/J mice demonstrated that both genes are expressed at equivalent levels. Reporter assays revealed that promoter/enhancer sequences of Saa1 and Saa2 genes in CE/J are also functional. These results indicate that the SAA2.2 isoform in CE/J is a mixture of Saa1 and Saa2 gene products.ArticleAMYLOID-JOURNAL OF PROTEIN FOLDING DISORDERS. 21(1):1-8 (2014)journal articl

    Hereditary cataract of the Nakano mouse: Involvement of a hypomorphic mutation in the coproporphyrinogen oxidase gene

    Get PDF
    The Nakano cataract (NCT) is a recessive disorder in the mouse linked to the nct locus on chromosome 16. In this study, we positionally cloned the critical gene in the nct locus. Herein, we report that cataracts in the BALB/c-nct/nct mouse are caused by a hypomorphic mutation in the coproporphyrin oxidase gene (Cpox), encoding the enzyme responsible for catalyzing oxidative decarboxylation of the heme precursor, coproporphyrinogen III, in the heme biosynthetic pathway. BALB/c-nct/nct mice are homozygous for a G to T nucleotide substitution in the Cpox gene, which results in a p.R380L amino acid substitution in the CPDX protein. The CPDX isoform with the p.R380L substitution retained only 15% of the activity of the wild type isoform. BALB/c-nct/nct mice had excessive accumulation of coproporphyrin HI in the lens. The NCT phenotype was normalized by the introduction of a wild type Cpox transgene. The mechanisms by which impairment of CPDX leads to lens opacity in the NCT are elusive. However, our data illuminate a hitherto unanticipated involvement of the heme biosynthesis pathway in lens physiology.ArticleEXPERIMENTAL EYE RESEARCH. 112:45-50 (2013)journal articl

    Clinical perspectives of Treponema pallidum subsp. Endemicum infection in adults, particularly men who have sex with men in the Kansai area, Japan: A case series

    Get PDF
    Bejel, caused by Treponema pallidum subsp. Endemicum (TEN), is a locally transmitted disease among children and juveniles in hot and dry regions. The number of adult cases of TEN infection outside of endemic areas has recently increased. We clinically examined five cases of TEN infection among adult cases previously reported in Japan. TEN infection mainly developed among young to middle-aged men who have sex with men (MSM). The clinical features of cases of TEN infection were similar to those of primary- and secondary-stage T. pallidum subsp. pallidum (TPA) infection. Genital lesions were common as the primary lesion. The clinical features and laboratory parameters of cases of TEN infection were similar to those of TPA infection. Most of the isolated strains had the A2058G mutation in 23S rDNA, which is responsible for resistance to macrolides. We also performed the systemic literature review of the TEN cases outside the endemic countries. The recent reported cases diagnosed with molecular methods shared the clinical features, occurred in young-to middle-aged sexually active persons in urban areas of developed countries and often accompanied with genital lesions, which were distinct from the classic description of bejel. This case series and the literature review provides important clinical insights and will contribute to the clinical detection of this rarely identified disease in developed countries. The surveillance of treponematoses, including TEN infection, using molecular diagnostic techniques is also warranted in developed countries, for the purpose of grasping the epidemic situation and control the local transmission

    Repair of double-chambered right ventricle using right ventricular outflow chamber ventriculotomy via left intercostal thoracotomy under beating heart in two dogs

    Get PDF
    Double-chambered right ventricle was diagnosed in two dogs, one of them a pup and the other full grown. Both dogs underwent surgery using the novel approach of right ventricular outflow chamber ventriculotomy via left intercostal thoracotomy with moderate hypothermia and moderate pump flow cardiopulmonary bypass under beating heart. No major complication occurred during and after the operation. On continuous wave Doppler echocardiography, the pressure gradient across the stenosis in the right ventricle decreased from 130 mmHg pre-operatively to 40 mmHg post-operatively at 1 year 5 months in the adult dog, and from 209 mmHg pre-operatively to 47 mmHg post-operatively at 1 year in the pup. Both dogs are active without clinical signs

    Clinically Significant Nonperfusion Areas on Widefield OCT Angiography in Diabetic Retinopathy

    Get PDF
    [Purpose] To investigate the distribution of clinically significant nonperfusion areas (NPAs) on widefield OCT angiography (OCTA) images in patients with diabetes. [Design] Prospective, cross-sectional, observational study. [Participants] One hundred and forty-four eyes of 114 patients with diabetes. [Methods] Nominal 20 × 23 mm OCTA images were obtained using a swept-source OCTA device (Xephilio OCT-S1), followed by the creation of en face images 20-mm (1614 pixels) in diameter centering on the fovea. The nonperfusion squares (NPSs) were defined as the 10 × 10 pixel squares without retinal vessels, and the ratio of eyes with the NPSs to all eyes in each square was referred to as the NPS ratio. The areas with probabilistic differences (APD) for proliferative diabetic retinopathy (PDR) and nonproliferative diabetic retinopathy (NPDR) (APD[PDR] and APD[NPDR]) were defined as sets of squares with higher NPS ratios in eyes with PDR and NPDR, respectively. The P ratio (NPSs within APD[PDR] but not APD[NPDR]/all NPSs) was also calculated. [Main Outcome Measures] The probabilistic distribution of the NPSs and the association with diabetic retinopathy (DR) severity. [Results] The NPSs developed randomly in eyes with mild and moderate NPDR and were more prevalent in the extramacular areas and the temporal quadrant in eyes with severe NPDR and PDR. The APD(PDR) was distributed mainly in the extramacular areas, sparing the areas around the vascular arcades and radially peripapillary capillaries. The APD(PDR) contained retinal neovascularization more frequently than the non-APD(PDR) (P = 0.023). The P ratio was higher in eyes with PDR than in those with NPDR (P < 0.001). The multivariate analysis designated the P ratio (odds ratio, 8.293 × 107; 95% confidence interval, 6.529 × 102–1.053 × 1013; P = 0.002) and the total NPSs (odds ratio, 1.002; 95% confidence interval, 1.001–1.003; P < 0.001) as independent risk factors of PDR. Most eyes with NPDR and 4-2-1 rule findings of DR severity had higher P ratios but not necessarily greater NPS numbers. [Conclusions] The APD(PDR) is uniquely distributed on widefield OCTA images, and the NPA location patterns are associated with DR severity, independent of the entire area of NPAs. [Financial Disclosure(s)] Proprietary or commercial disclosure may be found after the references
    corecore