35 research outputs found

    Lasiodiplodia theobromae keratitis: A rare tropical fungal keratitis in a non-tropical climate

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    PURPOSE: We present the clinical and histopathological findings of a geographically unique fungal keratitis case in North Carolina. . is a rare cause of fungal keratitis, and all but one of the 51 previously reported cases have occurred in patients living in the tropics. OBSERVATIONS: A man in his early 50s developed keratitis after being struck in the left eye by a piece of debris while using a flexible-cord weed trimmer. Intracapsular lensectomy and penetrating keratoplasty were necessary when initial antimicrobial therapy was ineffective. The best-corrected visual acuity was 20/40 four years postoperatively. CONCLUSIONS AND IMPORTANCE: Our patient is only the second example of keratitis in a patient living in a sub-tropical climate and the first case in the U.S.A. outside of Florida. Additional in-vitro antibiotic sensitivity testing and documentation of more clinical cases are needed to define the optimal therapy for keratitis

    Students’ perspectives on computational challenges in physics class

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    High school science classrooms across the United States are answering calls to make computation a part of science learning. The problem is that there is little known about the barriers to learning that computation might bring to a science classroom or about how to help students overcome these challenges. This case study explores these challenges from the perspectives of students in a high school physics classroom with a newly revamped, computation-integrated curriculum. Focusing mainly on interviews to center the perspectives of students, we found that computation is a double-edged sword: It can make science learning more authentic for students who are familiar with it, but it can also generate frustration and an aversion towards physics for students who are not

    Labdane dimers from Xylopia aromatica

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    From the stem bark of Xylopia aromatica (Annonaceae), have been isolated two new labdane dimers as their methyl esters, together with the known compounds ent-labda-8(17),13(16),14-trien-18-oic acid, sitosterol and stigmasterol. The structures of the dimers were elucidated on the basis of detailed spectroscopic analyses. (C) 1999 Elsevier B.V. Ltd. All rights reserved

    Elements of equipment for road surfaces with photoluminescence marking

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    W przestrzeni publicznej stosuje się wiele oznaczeń służących polepszeniu bezpieczeństwa. Wspomniane oznaczenia bazują na komunikacji wizualnej, często są podświetlane. Takie rozwiązania wymagają doprowadzenia instalacji elektrycznej. Interesującym rozwiązaniem eliminującym zastosowanie kosztownej energii elektrycznej jest zastosowanie pigmentów fotoluminescencyjnych zespolonych z elementami nawierzchni drogowej. Artykuł przedstawia ocenę właściwości technicznych i użytkowych elementów wyposażenia nawierzchni drogowej z oznakowaniem fotoluminescencyjnym.In the public space, one can encounter many markings which serve to improve safety. These markings are based on visual communication and they often tend to be illuminated. Such solutions require an electrical installation. An interesting solution eliminating the use of costly electricity is the use of photoluminescent pigments combined with the elements of the road surface. The article presents the assessment of technical and functional properties of elements of road surface equipment with photoluminescent marking

    Constitutive expression of bergaptol O-methyltransferase in Glehnia littoralis cell cultures.

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    We investigated whether exogenously supplied precursors of bergapten, namely umbelliferone, psoralen and bergaptol, could be utilized to produce bergapten without elicitation in Glehnia littoralis cell suspension cultures. The levels of added psoralen and bergaptol in the medium soon decreased, and this was followed by the detection of bergapten in both culture fluid and cells. Umbelliferone was also incorporated but in this case no bergapten was produced; instead, skimmin, umbelliferone monoglucoside, was detected. To determine whether conversion of psoralen to bergapten was due to enzyme induction by precursor feeding, the transcript accumulations and enzyme activities of bergaptol O-methyltransferase (BMT, EC 2.1.1.69), which catalyzes the last step of bergapten synthesis, and of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5), which catalyzes the initial step of the phenylpropanoid biosynthetic pathway and is known as a marker enzyme of elicitation, were examined. The results showed that both the expression and the activity of BMT were always detected in all cells, including control cells. Since PAL was slightly induced in the cells supplied with/without precursors, phenylethyl alcohol (PEA, a competitive inhibitor of PAL) was applied to suspension cells prior to the addition of psoralen. PAL activity was effectively inhibited by PEA at 1-5 mM concentrations. Under these conditions, PEA did not affect bergapten production by cell cultures fed with psoralen at all. These results demonstrate that BMT is constitutively expressed in G. littoralis cell cultures

    Phenylpropanoid glucosides from leaves of Coussarea hydrangeifolia (Rubiaceae)

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    Phenylpropanoid glycosides, 1 '-O-benzyl-alpha-(L)-rhamnopyranosyl-(1 ''-> 6 ')-beta-(D)-glucopyranoside (1) and alpha-(L)-Xylopyranosyl(4 '', 2 ')-(3-O-beta-(D)-glucopyranosyl)-1 '-O-E-caffeoyl-beta-(D)-glucopyranoside (2), together with the known derivatives, 1,6-di-O-caffeoyl- beta-(D)-glucopyrano side (3), 1-O-(E)-caffeoyl-beta-(D)-glucopyranoside (4) and 1-O-(E)-feruloyl-beta-(D)-glucopyranoside (5), were isolated from leaves of Coussarea hydrangeifolia. Their structures were determined by IR, HRESIMS, and I D and 2D NMR experiments, and their antioxidant activities, evaluated by assaying the free radical scavenging capacity using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical as substrate. The antioxidant activities of 3 and 4 (IC50 values of 15.0 and 19.2 mu M, respectively) were comparable to that of the standard positive control caffeic acid, whilst 2 and 5 were only weakly active and 1 was inactive. (c) 2005 Elsevier Ltd. All rights reserved
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