207 research outputs found

    Strong group velocity dispersion compensation with phase-engineered sheet metamaterials

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    Resonant metamaterials usually exhibit substantial dispersion, which is considered a shortcoming for many applications. Here we take advantage of the ability to tailor the dispersive response of a metamaterial introducing a new method of group-velocity dispersion compensation in telecommunication systems. The method consists of stacking a number of highly dispersive sheet metamaterials and is capable of compensating the dispersion of optical fibers with either negative or positive group-velocity dispersion coefficients. We demonstrate that the phase-engineered metamaterial can provide strong group-velocity dispersion management without being adversely affected by large transmission loss, while at the same time offering high customizability and small footprint.Comment: 10 pages, 4 figure

    Highly efficient novel recombinant L-asparaginase with no glutaminase activity from a new halo-thermotolerant Bacillus strain

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    Introduction: The bacterial enzyme has gained more attention in therapeutic application because of the higher substrate specificity and longer half-life. L-asparaginase is an important enzyme with known antineoplastic effect against acute lymphoblastic leukemia (ALL). Methods: Novel L-asparaginase genes were identified from a locally isolated halo-thermotolerant Bacillus strain and the recombinant enzymes were overexpressed in modified E. coli strains, OrigamiTM B and BL21. In addition, the biochemical properties of the purified enzymes were characterized, and the enzyme activity was evaluated at different temperatures, pH, and substrate concentrations. Results: The concentration of pure soluble enzyme obtained from Origami strain was ~30 mg/L of bacterial culture, which indicates the significant improvement compared to L-asparaginase produced by E. coli BL21 strain. The catalytic activity assay on the identified L-asparaginases (ansA1 and ansA3 genes) from Bacillus sp. SL-1 demonstrated that only ansA1 gene codes an active and stable homologue (ASPase A1) with high substrate affinity toward L-asparagine. The Kcat and Km values for the purified ASPase A1 enzyme were 23.96s-1 and 10.66 µM, respectively. In addition, the recombinant ASPase A1 enzyme from Bacillus sp. SL-1 possessed higher specificity to L-asparagine than L-glutamine. The ASPase A1 enzyme was highly thermostable and resistant to the wide range of pH 4.5�10. Conclusion: The biochemical properties of the novel ASPase A1 derived from Bacillus sp. SL-l indicated a great potential for the identified enzyme in pharmaceutical and industrial applications. © 2019 The Author(s)

    Lateralization of inferior petrosal sinus sampling in Cushing's disease correlates with cavernous sinus venous drainage patterns, but not tumor lateralization

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    Background: Inferior petrosal sinus sampling (IPSS) is known as the gold standard to distinguish whether excessive adrenocorticotropin hormone (ACTH) production origins from the pituitary gland or an ectopic source. However, due to a number of factors, the value of IPSS for adenoma lateralization may be limited. Aim of this study was to evaluate the influence of parasellar venous drainage (VD) patterns on IPSS findings in predicting lateralization of pituitary microadenomas. Methods: We retrospectively reviewed records of confirmed cases of Cushing's disease which were evaluated by IPSS prior to endoscopic tansnasal trans-sphenoidal surgery (ETSS) to assess the ability of IPSS to predict adenoma laterality. Results: Seventeen patients with pathologically confirmed Cushing's disease were retrospectively reviewed. The median age of the included patients was 37 years. Laterality of parasellar VD perfectly associated with lateralization as measured by IPSS. Symmetrical VD was associated with symmetrical ACTH gradient on IPSS. However, lateralization measured by IPSS did not show any significant correlation with lateralization detected during ETSS. Conclusion: Our study suggests that IPSS lateralization results strongly depend on parasellar VD pattern but show no significant correlation with the adenoma lateralization found during ETSS. Thus, IPSS does not appear to be an appropriate modality to predict adenoma lateralization. © 2020 Anatomy; Neurology; Medical imaging; Endocrinology; Endocrine system; Clinical research; Inferior petrosal sinus sampling; Cushing's disease; Parasellar venous drainage; Lateralization of microadenoma © 202

    Mudanças nos compostos bioativos e atividade antioxidante de pimentas da região amazônica.

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    A Embrapa Amazônia Oriental possui um Banco Ativo de Pimenteira com diferentes genótipos do gênero Capsicum, os quais ainda não foram analisados, quanto às suas características funcionais e capacidade antioxidante. Este estudo objetivou determinar os teores de ácido ascórbico, compostos fenólicos, carotenoides totais e a atividade antioxidante total, em frutos imaturos e maduros de genótipos de pimentas Capsicum spp. As concentrações de vitamina C (100,76-361,65 mg 100 g-1 nos frutos imaturos e 36,70-157,76 mg 100 g-1 nos maduros) decresceram com a maturação dos frutos. Carotenoides totais não foram detectados nos frutos imaturos, porém, nos frutos maduros, observaram-se valores de 73,80-1349,97 mg g-1, em função do genótipo. Os teores de compostos fenólicos aumentaram nos frutos maduros (147,40-718,64 mg GAE 100 g-1), para oito dos nove genótipos avaliados. Os frutos de pimenteira apresentaram significativa atividade antioxidante (55,02-92,03 mM trolox g-1 nos frutos imaturos e 39,60-113,08 mM trolox g- 1 nos maduros). Concluiu-se que o grau de maturação dos frutos influenciou nos teores de compostos bioativos dos genótipos estudados. Destacaram-se, como genótipos promissores com potencial para serem utilizados em programas de melhoramento genético, IAN-186301 e IAN-186324, pelos altos teores de carotenoides totais; IAN-186301, IAN-186311, IAN-186312 e IAN-186313, com relação às altas concentrações de ácido ascórbico; IAN-186304 e IAN-186311, pelos altos teores de compostos fenólicos; e IAN-186311, para atividade antioxidante

    Frequency, mutual exclusivity and clinical associations of myositis autoantibodies in a combined European cohort of idiopathic inflammatory myopathy patients

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    Objectives: To determine prevalence and co-existence of myositis specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs) and associated clinical characteristics in a large cohort of idiopathic inflammatory myopathy (IIM) patients. Methods: Adult patients with confirmed IIM recruited to the EuroMyositis registry (n = 1637) from four centres were investigated for the presence of MSAs/MAAs by radiolabelled-immunoprecipitation, with confirmation of anti-MDA5 and anti-NXP2 by ELISA. Clinical associations for each autoantibody were calculated for 1483 patients with a single or no known autoantibody by global linear regression modelling. Results: MSAs/MAAs were found in 61.5% of patients, with 84.7% of autoantibody positive patients having a sole specificity, and only three cases (0.2%) having more than one MSA. The most frequently detected autoantibody was anti-Jo-1 (18.7%), with a further 21 specificities each found in 0.2–7.9% of patients. Autoantibodies to Mi-2, SAE, TIF1, NXP2, MDA5, PMScl and the non-Jo-1 tRNA-synthetases were strongly associated (p < 0.001) with cutaneous involvement. Anti-TIF1 and anti-Mi-2 positive patients had an increased risk of malignancy (OR 4.67 and 2.50 respectively), and anti-SRP patients had a greater likelihood of cardiac involvement (OR 4.15). Interstitial lung disease was strongly associated with the anti-tRNA synthetases, anti-MDA5, and anti-U1RNP/Sm. Overlap disease was strongly associated with anti-PMScl, anti-Ku, anti-U1RNP/Sm and anti-Ro60. Absence of MSA/MAA was negatively associated with extra-muscular manifestations. Conclusions: Myositis autoantibodies are present in the majority of patients with IIM and identify distinct clinical subsets. Furthermore, MSAs are nearly always mutually exclusive endorsing their credentials as valuable disease biomarkers

    Bioinformatics research in the Asia Pacific: a 2007 update

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    We provide a 2007 update on the bioinformatics research in the Asia-Pacific from the Asia Pacific Bioinformatics Network (APBioNet), Asia's oldest bioinformatics organisation set up in 1998. From 2002, APBioNet has organized the first International Conference on Bioinformatics (InCoB) bringing together scientists working in the field of bioinformatics in the region. This year, the InCoB2007 Conference was organized as the 6th annual conference of the Asia-Pacific Bioinformatics Network, on Aug. 27–30, 2007 at Hong Kong, following a series of successful events in Bangkok (Thailand), Penang (Malaysia), Auckland (New Zealand), Busan (South Korea) and New Delhi (India). Besides a scientific meeting at Hong Kong, satellite events organized are a pre-conference training workshop at Hanoi, Vietnam and a post-conference workshop at Nansha, China. This Introduction provides a brief overview of the peer-reviewed manuscripts accepted for publication in this Supplement. We have organized the papers into thematic areas, highlighting the growing contribution of research excellence from this region, to global bioinformatics endeavours
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