131 research outputs found

    Modulation instability induced by cross-phase modulation in a dual-wavelength dispersion-managed soliton fiber ring laser

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    We report on the observation of modulation instability induced by cross-phase modulation in a dual-wavelength operation dispersion-managed soliton fiber ring laser with net negative cavity dispersion. The passively mode-locked operation is achieved by using nonlinear polarization rotation technique. A new type of dual-wavelength operation, where one is femtosecond pulse and the other is picosecond pulse operation, is obtained by properly rotating the polarization controllers. When the dual-wavelength pulses are simultaneously circulating in the laser ring cavity, a series of stable modulation sidebands appears in the picosecond pulse spectrum at longer wavelength with lower peak power due to modulation instability induced by cross-phase modulation between the two lasing wavelengths. Moreover, the intensities and wavelength shifts of the modulation sidebands can be tuned by varying the power of the femtosecond pulse or the lasing central wavelengths of the dual-wavelength pulses. The theoretical analysis of the modulation instability induced by cross-phase modulation in our fiber laser is also presented.Comment: 26 pages, 10 figure

    The prevalence of mild cognitive impairment in diverse geographical and ethnocultural regions: The COSMIC Collaboration

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    Background Changes in criteria and differences in populations studied and methodology have produced a wide range of prevalence estimates for mild cognitive impairment (MCI). Methods Uniform criteria were applied to harmonized data from 11 studies from USA, Europe, Asia and Australia, and MCI prevalence estimates determined using three separate definitions of cognitive impairment. Results The published range of MCI prevalence estimates was 5.0%-36.7%. This was reduced with all cognitive impairment definitions: performance in the bottom 6.681% (3.2%-10.8%); Clinical Dementia Rating of 0.5 (1.8%-14.9%); Mini-Mental State Examination score of 24-27 (2.1%-20.7%). Prevalences using the first definition were 5.9% overall, and increased with age (P < .001) but were unaffected by sex or the main races/ethnicities investigated (Whites and Chinese). Not completing high school increased the likelihood of MCI (P = .01). Conclusion Applying uniform criteria to harmonized data greatly reduced the variation in MCI prevalence internationally

    Wnt signalling and cancer stem cells

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    [Abstract] Intracellular signalling mediated by secreted Wnt proteins is essential for the establishment of cell fates and proper tissue patterning during embryo development and for the regulation of tissue homeostasis and stem cell function in adult tissues. Aberrant activation of Wnt signalling pathways has been directly linked to the genesis of different tumours. Here, the components and molecular mechanisms implicated in the transduction of Wnt signal, along with important results supporting a central role for this signalling pathway in stem cell function regulation and carcinogenesis will be briefly reviewed.Ministerio de Ciencia e InnovaciĂłn; SAF2008-0060

    Mouse Chromosome 11

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46996/1/335_2004_Article_BF00648429.pd

    The trans-ancestral genomic architecture of glycemic traits

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    Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Diabetes mellitus: pathophysiological changes and therap

    Improvement of the stability of nattokinase using gamma-polyglutamic acid as a coating material for microencapsulation

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    In this study, nattokinase (NK) was microencapsulated in high-molecular-weight Na-gamma-PGA, and the amount of NK added to the Na-gamma-PGA was in the ratio of 1:1 and 2:1 w/w, which was designated as NK-100 and NK-200, respectively. The temperature and pH stability of microencapsulated NK were found to be higher than those of the free form. Free NK lost its overall initial activity after treatment at a temperature above 60 degrees C or at a pH less than 5.0 for 1 h. NK-100 and NK-200 retained 35% and 60% of their activities after exposure to an acidic condition of pH 4.0 and possessed 18% and 25% activity after treatment at 60 degrees C for 1 h, respectively. Furthermore, NK-100 and NK-200 exhibited More protective bioactivity than free NK did in storage stability tests. This simple and versatile approach can be potentially applied to the microencapsulation of various biomolecules for drug-delivery applications. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved

    Kinetics of winter mushrooms (Flammulina velutipes) microstructure and quality changes during thermal processing

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    Winter mushrooms have become a popular traditional foodstuff with high nutritive value. Winter mushrooms (Flammulina vehitipes) were subjected to thermal treatments to 70, 80, 90 and 100 degrees C for 1, 2, 3, 5 and 10 min. Control and treated samples were analyzed for changes in texture and microstructure. Kinetic parameters for textural changes followed the Arrhenius model. SEM showed that heating resulted in the extraction of soluble polysaccharides from winter mushrooms. The degree of heating damage can be determined according to hyphae softening and surface and interior pilei collapse. These results may be used as a reference for the winter mushrooms industry and provide kinetic data for future research to improve the quality of thermally processed winter mushrooms. (c) 2007 Elsevier Ltd. All rights reserved

    Indigowood root extract protects hematopoietic cells, reduces tissue damage and modulates inflammatory cytokines after total-body irradiation: Does Indirubin play a role in radioprotection?

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    Radix of Isatis indigotica (indigowood root, IR) has been used in traditional medicine for its potential anti-inflammatory effect. The purpose of this study is to investigate THE radioprotective effects of radiation caused damages in hematopoietic system and normal tissues in mice. A total of 57 BALB/c mice were randomized into six treatment groups control, IR treatment (0.195, 0 585 and 1170 g/kg, p o. daily), L-glutamine (0.520 g/kg) and sham group. All mice except the sham group were irradiated and then administered for one week. The radioprotective effect on hematopoietic system, serum cytokines. and intestinal toxicity was studied. Protective effects on spleen and thymus are found in IR-treated groups. IR assisted in restoration of leukocytopenia after whole mice irradiation with significant reduction of serum TNF-alpha, IL-1 beta and IL-6 These enhancements of hematopoietic effects are due to an increase in the serum G-CSF concentration in IR treated groups In histopathological assessment, significant improvement of intestine toxicity is observed in high-dose IR and L-glutamine group Evidences show that IR has potentials to be a radioprotector, especially in recovery of hematopoietic system, reduction of inflammatory cytokines and intestinal toxicity. Indirubin may play a crucial role, but the underlying mechanism is not very clear and warrants further studies. (C) 2009 Elsevier GmbH All rights reserve
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