Science.gov

Sample records for chromogenic compounds

  1. Formation of indigo and related compounds from indolecarboxylic acids by aromatic acid-degrading bacteria: chromogenic reactions for cloning genes encoding dioxygenases that act on aromatic acids.

    PubMed Central

    Eaton, R W; Chapman, P J

    1995-01-01

    The p-cumate-degrading strain Pseudomonas putida F1 and the m- and p-toluate-degrading strain P. putida mt-2 transform indole-2-carboxylate and indole-3-carboxylate to colored products identified here as indigo, indirubin, and isatin. A mechanism by which these products could be formed spontaneously following dioxygenase-catalyzed dihydroxylation of the indolecarboxylates is proposed. Indolecarboxylates were employed as chromogenic substrates for identifying recombinant bacteria carrying genes encoding p-cumate dioxygenase and toluate dioxygenase. Dioxygenase gene-carrying bacteria could be readily distinguished as dark green-blue colonies among other colorless recombinant Escherichia coli colonies on selective agar plates containing either indole-2-carboxylate or indole-3-carboxylate. PMID:7592495

  2. A chromogenic cephalosporin for β-lactamase inhibitor screening assays.

    PubMed

    Yu, Sophia; Vosbeek, Amy; Corbella, Katherine; Severson, Jonathan; Schesser, Jacob; Sutton, Larry D

    2012-09-15

    Production of β-lactamases is the primary mechanism of antibiotic resistance employed by gram-negative pathogens. Chromogenic β-lactams are important reagents for detection and assay of β-lactamases, but limited commercial availability and exorbitant pricing of these compounds are prohibitive. Here we describe a straightforward synthesis of a chromogenic cephalosporin for β-lactamase assay that gives an overall yield of 74%. On hydrolysis, its λ(max) undergoes a bathochromic shift that is easy to see and measure spectrophotometrically with a Δε(442 nm) of 14,500 cm⁻¹ M⁻¹. This compound was shown to be a substrate for a variety of β-lactamases. PMID:22709853

  3. Michaelis constants of non-chromogenic substrates may be determined using chromogenic substrates

    SciTech Connect

    Blake, D.A.; Vassall, R.F.; Blake, R.C. II

    1987-05-01

    The object of these experiments was to demonstrate a means of determining the Michaelis constants (Km and Vmax) of a non-chromogenic substrate in a three-part experimental system containing a non-chromogenic substrate, the corresponding enzyme, and an appropriate chromogenic substrate. Two experimental systems were examined, one in which the enzyme activity was subject to product inhibition (alkaline phosphatase) and one in which the activity was not (..beta..-lactamase). In both systems, the initial experimental goal was to quantify the area defined by the entire kinetic trace (absorbance versus time) obtained with the chromogenic substrate in the absence or presence of the non-chromogenic substrate. The difference between these two areas was directly proportional to the concentration of the non-chromogenic substrate and inversely proportional to the Vmax of the non-chromogenic substrate. The value of Vmax thus obtained could then be used with the appropriate integrated Michaelis-Menten rate equation to extract the value of the Km for the non-chromogenic substrate. This method yielded values of kinetic constants that were in good agreement with those obtained directly and/or those available from the literature. It is anticipated that this method may be extended to enzymes with more complicated kinetic mechanisms.

  4. New chromogens of the ferroin type-VII Some 3-substituted-1,2,4-triazines, 3,5-disubstituted-1,2,4-triazolines and triazoles, and 2,4- and 2,6-bis triazinyl and triazolinyl substituted pyridines.

    PubMed

    Schilt, A A; Chriswell, C D; Fang, T A

    1974-08-01

    Chelation and chromogenic properties of 39 new ferroin compounds in reactions with iron(II), copper(I), and cobalt(II) have been investigated spectrophotometrically. The results demonstrate that the chromogenic properties of triazole and triazoline heterocycles are inferior to triazine and pyridine when incorporated into the ferroin chromophore grouping. The triazole and triazoline compounds also undergo hydrolytic decomposition, strongly catalysed by iron(II), making them unsuitable as colorimetric reagents. An outstanding chromogen was found from among the triazine derivatives which is superior in sensitivity to all ferroin-type chromogens previously studied. PMID:18961539

  5. A redox-mediated chromogenic reaction and application in immunoassay.

    PubMed

    Yu, Ru-Jia; Ma, Wei; Peng, Mao-Pan; Bai, Zhi-Shan; Long, Yi-Tao

    2016-08-31

    A novel redox-mediated chromogenic reaction was demonstrated based on the reaction between HAuCl4 and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), which generate various color responses from red to green in the resulting solutions. Various redox substance could be used to mediate the reaction and trigger a distinct color response. We established a sensitive hydrogen peroxide colorimetric sensor based on the redox-mediated chromogenic reaction and depicted the application both in detection of enzyme and in an immunoassay. Combining the traditional chromogenic reagent with gold nanoparticles, our assay has the advantage in short response time (within three minutes), high sensitivity (10(-12) g mL(-1) for HBsAg) and stability. PMID:27506364

  6. Staphylococcus chromogenes, a Coagulase-Negative Staphylococcus Species That Can Clot Plasma.

    PubMed

    Dos Santos, Danielle Cabral; Lange, Carla Christine; Avellar-Costa, Pedro; Dos Santos, Katia Regina Netto; Brito, Maria Aparecida Vasconcelos Paiva; Giambiagi-deMarval, Marcia

    2016-05-01

    Staphylococcus chromogenes is one of the main coagulase-negative staphylococci isolated from mastitis of dairy cows. We describe S. chromogenes isolates that can clot plasma. Since the main pathogen causing mastitis is coagulase-positive Staphylococcus aureus, the coagulase-positive phenotype of S. chromogenes described here can easily lead to misidentification. PMID:26912749

  7. Salivary thiol levels and periodontal parameters assessed with a chromogenic strip.

    PubMed

    Khocht, Ahmed; Seyedain, Merriam; Hardan, Samia; Gaughan, John; Suzuki, Jon B

    2013-08-01

    Periodontitis tends to be associated with bacteria that use sulfate as an energy source and produce thiol compounds that contain sulfhydryl (-SH) groups. This study used a chromogenic thiol-detecting strip to investigate whole saliva -SH concentration (SS) in subjects with and without periodontal disease. Ninety-six subjects were enrolled; all underwent periodontal evaluations, including plaque index (PI), gingival index (GI), probing depth measurements (PD), and attachment levels (AL). Subjects were divided into 3 groups: those who were periodontally healthy (n = 17), those with gingivitis (n = 54), and those with periodontitis (n = 25). Of the 96 subjects, 33% (n = 32) were cigarette smokers. A chromogenic strip was used to collect a whole saliva sample from the mouth. Color reaction was scored based on a color chart. Good-to-moderate correlations were found between SS scores and PI (r = 0.47, P = 0.0001), GI (r = 0.45, P = 0.0001), PD (r = 0.42, P = 0.0001), and AL (r = 0.30, P = 0.002). Analysis of variance showed significant differences in SS scores among the 3 study groups (P = 0.0001); post-hoc analysis showed higher SS scores in subjects with periodontitis than in those without (P = 0.05). Logistic regression, adjusting for smoking, showed the odds ratio of periodontitis increased by a factor of 12.76 for each increase of one unit of measure of SS. These results indicate that assessing whole saliva thiol levels with a chromogenic strip could be used as a screening test for periodontal diseases. PMID:23928440

  8. New chromogens of the ferroin type-VIII Some di- and trisubstituted 1,2,4-triazines, 3-substituted-9H-indeno[1,2-e]-1,2,4-triazin-9-ones, and di- and trisubstituted 1,2,4-triazolines.

    PubMed

    Schilt, A A; Yang, T A; Wu, J F; Nitzki, D M

    1977-11-01

    Thirty-six new ferroin compounds have been investigated as possible chelation regents for the calorimetric detection and determination of trace amounts of iron(II), copper(I), and cobalt(II). Spectral data, solution conditions favourable for chelate formation, and other data are reported. The results reveal that incorporation of triazoline heterocycles in ferroin chromophore groupings generally leads to poor chromogenic properties, except with respect to cobalt. Triazine groups, however, can give rise to superior properties. The most sensitive iron(II) chromogen of the ferroin type found to date and a promising new cobalt chromogen are described. PMID:18962176

  9. Sensing of antipyretic carboxylates by simple chromogenic calix[4]pyrroles.

    PubMed

    Nishiyabu, Ryuhei; Anzenbacher, Pavel

    2005-06-15

    We present a simple, two- or three-step method for the synthesis of chromogenic octamethylcalix[4]pyrrole-based (OMCP) sensors for anions. Electrophilic aromatic substitution allows for converting the pyrrole moieties of OMCP into a dye. The formation of a sensor-anion complex results in partial charge transfer and a dramatic change in color. The absorption (UV-vis) and NMR titration experiments show that the chromogenic OMCPs sense anions administered as aqueous solutions, even at high ionic strength ( approximately 0.1 M NaCl), while displaying selectivity for pyrophosphate and carboxylate anions. The experiments with polyurethane sensor films show a strong response for aqueous carboxylates, such as antipyretics naproxen approximately ibuprofen > salicylate, without being biased by bicarbonate or carboxy termini of blood plasma proteins. PMID:15941245

  10. Chromogenic switchable glazing: Towards the development of the smart window

    SciTech Connect

    Lampert, C.M.

    1995-06-01

    The science and technology of chromogenic materials for switchable glazings in building applications is discussed. These glazings can be used for dynamic control of solar and visible energy. Currently many researchers and engineers are involved with the development of products in this field. A summary of activities in Japan, Europe, Australia, USA and Canada is made. The activities of the International Energy Agency are included. Both non-electrically activated and electrically activated glazings are discussed. Technologies covered in the first category are photochromics, and thermochromics and thermotropics. A discussion of electrically activated chromogenic glazings includes dispersed liquid crystals, dispersed particles and electrochromics. A selection of device structures and performance characteristics are compared. A discussion of transparent conductors is presented. Technical issues concerning large-area development of smart windows are discussed.

  11. Recent progress in chromogenic and fluorogenic chemosensors for hypochlorous acid.

    PubMed

    Yue, Yongkang; Huo, Fangjun; Yin, Caixia; Escobedo, Jorge O; Strongin, Robert M

    2016-03-21

    Due to the biological and industrial importance of hypochlorous acid, the development of optical probes for HOCl has been an active research area. Hypochlorous acid and hypochlorite can oxidize electron-rich analytes with accompanying changes in molecular sensor spectroscopic profiles. Probes for such processes may monitor HOCl levels in the environment or in an organism and via bio-labeling or bioimaging techniques. This review summarizes recent developments in the area of chromogenic and fluorogenic chemosensors for HOCl. PMID:26883493

  12. Development of on-fiber optical sensors utilizing chromogenic materials

    NASA Astrophysics Data System (ADS)

    Yuan, Jianming; El-Sherif, Mahmoud A.

    1999-01-01

    On-fiber optical sensors, designed with chromogenic materials used as the fiber modified cladding, were developed for sensing environmental conditions. The design was based on the previously developed on-fiber devices. It is known that the light propagation characteristics in optical fibers are strongly influenced by the refractive index of the cladding materials. Thus, the idea of the on- fiber devices is based on replacing the passive optical fiber cladding with active or sensitive materials. For example, temperature sensors can be developed by replacing the fiber clad material with thermochromic materials. In this paper, segmented polyurethane-diacetylene copolymer (SPU), was selected as the thermochromic material for temperature sensors applications. This material has unique chromogenic properties as well as the required mechanical behaviors. During UV exposure and heat treatment, the color of the SPU copolymer varies with its refractive index. The boundary condition between core and cladding changes due to the change of the refractive index of the modified cladding material. The method used for the sensor development presented involves three steps: (a) removing the fiber jacket and cladding from a small region, (b) coating the chromogenic materials onto the modified region, and (c) integrating the optical fiber sensor components. The experimental set-up was established to detect the changes of the output signal based on the temperature variations. For the sensor evaluation, real-time measurements were performed under different heating-cooling cycles. Abrupt irreversible changes of the sensor output power were detected during the first heating-cooling cycle. At the same time, color changes of the SPU copolymer were observed in the modified region of the optical fiber. For the next heating-cooling cycles, however, the observed changes were almost completely reversible. This result demonstrates that a low-temperature sensor can be built by utilizing the

  13. A Chromogenic Probe for the Selective Recognition of Sarin and Soman Mimic DFP**

    PubMed Central

    El Sayed, Sameh; Pascual, Lluís; Agostini, Alessandro; Martínez-Máñez, Ramón; Sancenón, Félix; Costero, Ana M; Parra, Margarita; Gil, Salvador

    2014-01-01

    The synthesis, characterization and sensing features of a novel probe 1 for the selective chromogenic recognition of diisopropylfluorophosphate (DFP), a sarin and soman mimic, in 99:1 (v/v) water/acetonitrile and in the gas phase is reported. Colour modulation is based on the combined reaction of phosphorylation of 1 and fluoride-induced hydrolysis of a silyl ether moiety. As fluoride is a specific reaction product of the reaction between DFP and the −OH group, the probe shows a selective colour modulation in the presence of this chemical. Other nerve agent simulants, certain anions, oxidant species and other organophosphorous compounds were unable to induce colour changes in 1. This is one of the very few examples of a selective detection, in solution and in the gas phase, of a sarin and soman simulant versus other reactive derivatives such as the tabun mimic diethylcyanophosphate (DCNP). PMID:25478309

  14. A Chromogenic Probe for the Selective Recognition of Sarin and Soman Mimic DFP.

    PubMed

    El Sayed, Sameh; Pascual, Lluís; Agostini, Alessandro; Martínez-Máñez, Ramón; Sancenón, Félix; Costero, Ana M; Parra, Margarita; Gil, Salvador

    2014-08-01

    The synthesis, characterization and sensing features of a novel probe 1 for the selective chromogenic recognition of diisopropylfluorophosphate (DFP), a sarin and soman mimic, in 99:1 (v/v) water/acetonitrile and in the gas phase is reported. Colour modulation is based on the combined reaction of phosphorylation of 1 and fluoride-induced hydrolysis of a silyl ether moiety. As fluoride is a specific reaction product of the reaction between DFP and the -OH group, the probe shows a selective colour modulation in the presence of this chemical. Other nerve agent simulants, certain anions, oxidant species and other organophosphorous compounds were unable to induce colour changes in 1. This is one of the very few examples of a selective detection, in solution and in the gas phase, of a sarin and soman simulant versus other reactive derivatives such as the tabun mimic diethylcyanophosphate (DCNP). PMID:25478309

  15. Computer-aided techniques for chromogenic immunohistochemistry: status and directions.

    PubMed

    Di Cataldo, Santa; Ficarra, Elisa; Macii, Enrico

    2012-10-01

    Although immunohistochemistry (IHC) is a popular imaging technique, the quantitative analysis of IHC images via computer-aided methods is an emerging field that is gaining more and more importance thanks to the new developments in digital high-throughput scanners. In this paper, we discuss the main steps of IHC and review the techniques for computer-aided chromogenic IHC analysis, including methods to determine the location of interest of the antigens and quantify their activations. Moreover, we discuss the issues arising from the standardization of the immunostaining process, that are generally overlooked by the current literature, and finally provide requirements for reliable computer-aided IHC quantification. PMID:22980752

  16. A chromogenic assay for limit dextrinase and pullulanase activity.

    PubMed

    Bøjstrup, Marie; Christensen, Caspar Elo; Windahl, Michael Skovbo; Henriksen, Anette; Hindsgaul, Ole

    2014-03-15

    A new chromogenic substrate to assay the starch debranching enzymes limit dextrinase and pullulanase is described. The 2-chloro-4-nitrophenyl glycoside of a commercially available branched heptasaccharide (Glc-maltotriosyl-maltotriose) was found to be a suitable specific substrate for starch debranching enzymes and allows convenient assays of enzymatic activities in a format suited for high-throughput analysis. The kinetic parameters of these enzymes toward the synthesized substrate are determined, and the selectivity of the substrate in a complex cereal-based extract is established. PMID:24333247

  17. Turn-On Fluorogenic and Chromogenic Detection of Small Aromatic Hydrocarbon Vapors by a Porous Supramolecular Host.

    PubMed

    Hatanaka, Sou; Ono, Toshikazu; Hisaeda, Yoshiio

    2016-07-18

    Benzene, toluene, ethylbenzene, the isomers of xylene, and trimethylbenzene are harmful volatile organic compounds and pose risks to human health and the environment. However, there are currently no effective chemosensors for vapors of these compounds. A porous supramolecular host for turn-on fluorogenic and chromogenic detection of the vapors of small aromatic hydrocarbons is presented. The host was constructed from a naphthalenediimide derivative that was supramolecularly connected to tris(pentafluorophenyl)borane. The amorphous powder form of the host allowed for effective accommodation of vapors of small aromatic hydrocarbons, resulting in a guest-dependent fluorescence emission. Increases in the fluorescence yield of 76-, 46-, and 37-fold were observed with toluene, benzene, and m-xylene, respectively. Negligible responses were obtained with common organic solvents. This simple supramolecular host could be applied as a useful sensor of small aromatic hydrocarbon vapors. PMID:27224939

  18. Chromogenic Detection of Aqueous Formaldehyde Using Functionalized Silica Nanoparticles.

    PubMed

    El Sayed, Sameh; Pascual, Lluı́s; Licchelli, Maurizio; Martínez-Máñez, Ramón; Gil, Salvador; Costero, Ana M; Sancenón, Félix

    2016-06-15

    Silica nanoparticles functionalized with thiol reactive units and bulky polar polyamines were used for the selective colorimetric detection of formaldehyde. The reaction of thiols groups in the nanoparticles surface with a squaraine dye resulted in loss of the π-conjugation of the chromophores, and the subsequent bleaching of the solution. However, when formaldehyde was present in the suspension, the thiol-squaraine reaction was inhibited and a chromogenic response was observed. A selective response to formaldehyde was observed only when the thiol and polyamine groups were anchored to the silica surface. The observed selective response was ascribed to the fact that bulky polyamines generate a highly polar environment around thiols, which were only able to react with the small and polar formaldehyde, but not with other aldehydes. The sensing nanoparticles showed a limit of detection (LOD) for formaldehyde of 36 ppb in water. PMID:27250594

  19. Proof of concept of using chromogenic arrays as a tool to identify blue cheese varieties.

    PubMed

    Zaragozá, Patricia; Ros-Lis, José V; Vivancos, José-Luis; Martínez-Máñez, Ramón

    2015-04-01

    A new chromogenic array for the identification and classification of blue cheeses has been developed. It is based on the response of a chromogenic array composed of five sensing materials prepared by the incorporation of pH indicators to MCM-41 and alumina. Four blue cheeses were tested: Roquefort, Blue Stilton, blue cheese with leaves and blue cheese spread. The colour modulations of the chromogenic array were processed by the principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The statistical PCA analysis showed different responses to each cheese. PLS-DA models were developed by incorporating the data measured at diverse times, and this approach allowed us to obtain a perfect classification of all five cheeses in 5.5h. The results suggest that chromogenic arrays and optoelectronic noses can be a suitable approach to develop simple systems to classify blue cheeses and of potential use for the detection of food fraud. PMID:25442626

  20. Chromogenic and fluorogenic detection of a nerve agent simulant with a rhodamine-deoxylactam based sensor.

    PubMed

    Wu, Xuanjun; Wu, Zhisheng; Han, Shoufa

    2011-11-01

    A chromogenic and fluorogenic detection of a nerve agent simulant was developed based on diethyl chlorophosphate triggered tandem phosphorylation and intramolecular cyclization of N-(rhodamine B)-deoxylactam-2-aminoethanol. PMID:21952323

  1. Local host response following an intramammary challenge with Staphylococcus fleurettii and different strains of Staphylococcus chromogenes in dairy heifers.

    PubMed

    Piccart, Kristine; Verbeke, Joren; De Visscher, Anneleen; Piepers, Sofie; Haesebrouck, Freddy; De Vliegher, Sarne

    2016-01-01

    Coagulase-negative staphylococci (CNS) are a common cause of subclinical mastitis in dairy cattle. The CNS inhabit various ecological habitats, ranging between the environment and the host. In order to obtain a better insight into the host response, an experimental infection was carried out in eight healthy heifers in mid-lactation with three different CNS strains: a Staphylococcus fleurettii strain originating from sawdust bedding, an intramammary Staphylococcus chromogenes strain originating from a persistent intramammary infection (S. chromogenes IM) and a S. chromogenes strain isolated from a heifer's teat apex (S. chromogenes TA). Each heifer was inoculated in the mammary gland with 1.0 × 10(6) colony forming units of each bacterial strain (one strain per udder quarter), whereas the remaining quarter was infused with phosphate-buffered saline. Overall, the CNS evoked a mild local host response. The somatic cell count increased in all S. fleurettii-inoculated quarters, although the strain was eliminated within 12 h. The two S. chromogenes strains were shed in larger numbers for a longer period. Bacterial and somatic cell counts, as well as neutrophil responses, were higher after inoculation with S. chromogenes IM than with S. chromogenes TA. In conclusion, these results suggest that S. chromogenes might be better adapted to the mammary gland than S. fleurettii. Furthermore, not all S. chromogenes strains induce the same local host response. PMID:27176792

  2. Large-area chromogenics: Materials and devices for transmittance control. Volume IS 4

    SciTech Connect

    Lampert, C.M.; Granqvist, C.G.

    1990-12-31

    Chromogenic materials can alter their optical properties in a persistent yet reversible manner when subjected to a change in external conditions such as irradiation intensity, temperature, or electric-field strength. In the future chromogenic materials may be used on large scale to regulate the throughput of radiant energy for windows in buildings and cars, so that comfortable lighting and temperature are maintained without excessive air conditioning. The purpose of this book is to give a broad coverage of large-area chromogenics and to discuss their applications. The book is divided into the following areas: applications; photochromic materials; thermochromic materials; inorganic electrochromic materials; inorganic electrochromic materials; organic electrochromic materials; conductors for ions and electrons in electrochromic devices; electrochromic devices; and liquid crystals materials and devices. Separate abstracts were prepared for 33 papers in this book.

  3. Draft Genome Sequence of Staphylococcus chromogenes Strain MU 970, Isolated from a Case of Chronic Bovine Mastitis.

    PubMed

    Fry, Pamela R; Calcutt, Michael J; Foecking, Mark F; Hsieh, Hsin-Yeh; Suntrup, Douglas G; Perry, Jeanette; Stewart, George C; Middleton, John R

    2014-01-01

    Coagulase-negative staphylococcal species are a common cause of subclinical bovine mastitis, with Staphylococcus chromogenes being one of the most frequently identified species in these cases. The draft genome sequence of an S. chromogenes isolate (MU 970) recovered from the milk of a cow with a chronic intramammary infection is reported here. PMID:25125652

  4. Draft Genome Sequence of Staphylococcus chromogenes Strain MU 970, Isolated from a Case of Chronic Bovine Mastitis

    PubMed Central

    Fry, Pamela R.; Calcutt, Michael J.; Foecking, Mark F.; Hsieh, Hsin-Yeh; Suntrup, Douglas G.; Perry, Jeanette; Stewart, George C.

    2014-01-01

    Coagulase-negative staphylococcal species are a common cause of subclinical bovine mastitis, with Staphylococcus chromogenes being one of the most frequently identified species in these cases. The draft genome sequence of an S. chromogenes isolate (MU 970) recovered from the milk of a cow with a chronic intramammary infection is reported here. PMID:25125652

  5. Chromogenic detection of Sarin by discolouring decomplexation of a metal coordination complex.

    PubMed

    Ordronneau, Lucie; Carella, Alexandre; Pohanka, Miroslav; Simonato, Jean-Pierre

    2013-10-11

    An innovative chromogenic sensing concept based on decomplexation of a tris-(bipyridine)iron(II) coordination complex has been developed for the detection of organophosphorus nerve agents. It was evaluated both on a simulant and real Sarin in vapour and liquid phases. PMID:23963476

  6. Method validation and clinical utility of chromogenic factor VIII assay compared to one-stage assay.

    PubMed

    Gouws, Wilmare; Botha, Elsabie; Visser, Adele

    2014-01-01

    The chromogenic FVIII assay is currently considered the gold standard for quantitation of factor VIII levels in both haemophilia A patients and as part of screening for thrombophilia. A method validation and evaluation of clinical utility within a routine diagnostic laboratory was undertaken by comparing the currently used one-stage assay to a commercially available chromogenic assay (Siemens, Johannesburg, South Africa). In total, 60 samples were included in this study to encompass the whole diagnostic range of the assay. Both low and high values showed very good correlation on linear regression analysis with correlation coeffients of 0.949 and 0.888 respectively. However, the lower detection limit of the Siemens Chromogenic assay was 1.5 IU/dL rendering it impossible to utilize in the setting of classifying a haemophilia A patient in terms of disease severity. Although the Siemens FVIII chromogenic assay shows excellent correlation to the currently used one-stage assay, the relatively high detection limit restrict implementation as a stand-alone assay in a routine diagnostic laboratory. PMID:23504571

  7. The fundamental Fuzzy logic operators and some complex boolean logic circuits implemented by the chromogenism of a spirooxazine.

    PubMed

    Gentili, Pier Luigi

    2011-12-01

    1,3-Dihydro-1,3,3-trimethyl-8'-nitro-spiro[2H-indole-2,3'-[3H]naphth[2,1-b][1,4]oxazine] (SpO) is a photochromic, acidichromic and metallochromic compound. Its chromogenic properties are characterized in acetonitrile, at room temperature. They are exploited to process both boolean and Fuzzy logic. By using HClO(4), AlCl(3) and Cu(ClO(4))(2) as chemical inputs, UV radiation as power supply, and the absorbance at specific wavelengths in the visible as optical output, SpO results in a five-states molecular switch whereby some complex boolean logic circuits are implemented. If the chemical inputs are varied in an analog manner, the solution of SpO assumes an infinite number of colours. Therefore, by choosing the RGB colour coordinates as optical outputs, the fundamental operators of the "infinite-valued" Fuzzy logic are implemented. Particularly, two Fuzzy logic systems are built upon a new defuzzification procedure imitating the way humans perceive colours. PMID:21997229

  8. Evaluation of a chromogenic medium supplemented with glucose for detecting Enterobacter sakazakii.

    PubMed

    Song, Kwang-Young; Hyeon, Ji-Yeon; Shin, Ho-Chul; Park, Chan-Kyu; Choi, In-Soo; Seo, Kun-Ho

    2008-03-01

    A commercial chromogenic agar medium (DFI) was supplemented with glucose (mDFI) to enhance the specificity of Enterobacter sakazakii (E. sakazakii) detection. Escherichia vulneris (E. vulneris), a putative false-positive strain on the DFI medium, produces alpha-glucosidase. The enzyme alpha- glucosidase hydrolyzes a substrate, 5-bromo-4-chloro-3- indolyl-alpha,D-glucopyranoside (XalphaGlc), producing green colonies. E. sakazakii strains produced green colonies on both DFI and mDFI agar, whereas E. vulneris produced green colonies on DFI agar but small white colonies on mDFI agar. E. sakazakii and E. vulneris were also readily differentiated by colony color when the mixed culture of the two strains was plated on mDFI agar and incubated for 24 h at 37 degrees C. The results indicate that the selectivity of the commercial chromogenic agar medium could be improved by a simple supplementation with glucose. PMID:18388480

  9. Chromogenic and fluorogenic detection and discrimination of nerve agents Tabun and Vx.

    PubMed

    Kumar, Vinod; Rana, Hemlata

    2015-11-28

    Our approach uses squaraine (SQ) as the molecular-receptor as well as an indicator for the chromogenic and fluorogenic detection and discrimination of nerve agents Tabun and Vx. To mimic a real-life scenario, the protocols were implemented in spiked water and soil samples, on surfaces, and in the gas phase. The lower detection limit will be useful to protect human health and national security. PMID:26394304

  10. [Determination of the content of serum calcium with methylthymol blue as chromogenic reagent].

    PubMed

    Yang, C; Liu, W; Zhao, Z; Wu, H

    1998-08-01

    It is reported in this paper that calcium can be determined with MTB as chromogenic reagent by isoabsorption dual-wavelength elimination. The measuring wavelength and referential wavelength were 613.7 and 590.0nm, respectively. No masking reagent was necessary in the analysis. The average recovery and RSD of calcium are 98.98% and 0.81%, respectively. Compared with titration, this method is rapid, simple and precise. PMID:15825349

  11. Rapid and highly selective chromogenic detection of nerve agents with a cleft-shaped host.

    PubMed

    Kumar, Vinod; Kaushik, Mahabir Parshad

    2011-12-21

    A new chromogenic protocol has been developed for rapid and selective detection of nerve agents like tabun. The chemsensor displayed a drastic color change from its colorless solution to yellow instantaneously with an 89 nm bathochromic shift. No inference of other chemical warfare agents and its mimics was observed either with the naked-eye or by UV-Vis spectroscopy. The development of a portable chemosensor kit for tabun demonstrates its practical application in real-time monitoring. PMID:22013586

  12. Evaluation of Factor Xa-Specific Chromogenic Substrate Assays and the Determination of Pharmacokinetics of Fondaparinux.

    PubMed

    Yuri, Maiko; Tabe, Yoko; Tsuchiya, Koji; Sadatsuki, Ryo; Aoki, Jun; Horii, Takashi; Iba, Toshiaki; Ohsaka, Akimichi

    2016-07-01

    Fondaparinux (FPX), a synthesized factor Xa inhibitor, is one of the most popular anticoagulants for the prevention of postoperative venous thromboembolism (VTE). Although routine monitoring is not required, the bleeding adverse events cannot be neglected, and the measurement of anti-Xa activity is expected to be monitored. The primary purpose of this study is to evaluate the performances of 2 chromogenic assays for the detection of anti-Xa activity. Furthermore, the pharmacokinetics of FPX was examined using chromogenic assays. Anti-Xa activity was measured using 2 FPX-based chromogenic substrates (S2222 and STA-Liquid Anti-Xa). The reproducibility, detection limits, linearity, and correlations between the substrates were examined using normal plasma doped with low and high concentrations of FPX formulation. In addition, anti-Xa activity in 235 clinical samples from 164 cases treated was measured, and the pharmacokinetics of FPX was evaluated. Both of the tested substrates were capable of accurately measuring the anti-Xa activity of FPX, with a lower limit of 0.05 μg/mL and a coefficient of variation of less than 10%. The repeated administration of FPX induced a gradual but significant increase in the anti-Xa activity, which was negatively correlated with body weight and estimated glomerular filtration rate. No significant correlation between the anti-Xa activity and the occurrence of postoperative VTE or bleeding event was observed. Anti-Xa activity can be successfully determined using 2 chromogenic assays and automated biochemical analyzers. The clinical significance of anti-Xa activity monitoring should be examined in the future study. PMID:26177660

  13. Evaluation of New bioMérieux Chromogenic CPS Media for Detection of Urinary Tract Pathogens

    PubMed Central

    Rigaill, Josselin; Verhoeven, Paul O.; Mahinc, Caroline; Jeraiby, Mohamed; Grattard, Florence; Fonsale, Nathalie; Carricajo, Anne

    2015-01-01

    Four chromogenic media were compared for their ability to detect urinary tract pathogens in 299 urine specimens, of which 175 were found positive, allowing the growth of 279 microorganisms. After 18 to 24 h of incubation, the CPS ID4, CPSE, CPSO (bioMérieux), and UriSelect4 (Bio-Rad) media showed sensitivities of 97.1%, 99.3%, 99.6%, and 99.6%, respectively. PMID:25994162

  14. Dithizone derivatives as sensitive water soluble chromogenic reagents for the ion chromatographic determination of inorganic and organo-mercury in aqueous matrices.

    PubMed

    Shaw, Matthew J; Jones, Phil; Haddad, Paul R

    2003-10-01

    Water-soluble sulfonate and the novel carboxylate analogues of dithizone, combined with ion interaction chromatography on a Dionex Acclaim 120 C18 silica column (250 x 4.6 mm id) with an eluent consisting of 10 mM tetrabutylammonium bromide and 60:40 methanol:water, have been developed as highly sensitive chromogenic ligands for the quantitative isocratic determination of inorganic and organo-mercury compounds in aqueous matrices in under 12 min. Using an optimised post column reagent system containing 0.65 mM dye, 0.5% Triton X-100 and 50 mM sodium hydroxide, good linearity (0-7.5 mg L(-1) R2 > 0.999), reproducibility using peak area measurements (RSD 0.69-1.38%, n = 8), and limits of detection (4-12 microg L(-1)) were achieved for methyl mercury, inorganic mercury and phenyl mercury. PMID:14667153

  15. Novel compound for identifying Escherichia coli.

    PubMed Central

    Watkins, W D; Rippey, S R; Clavet, C R; Kelley-Reitz, D J; Burkhardt, W

    1988-01-01

    A new chromogenic compound, 5-bromo-4-chloro-3-indoxyl-beta-D-glucuronide, was found to be useful for the rapid, specific, differential identification of Escherichia coli in the sanitary analysis of shellfish and wastewater. Of 1,025 presumptively positive colonies (blue) and 583 presumptively negative colonies (nonblue), only 1% false-negative and 5% false-positive results were found. PMID:3046494

  16. Novel method based on chromogenic media for discrimination and selective enumeration of lactic acid bacteria in fermented milk products.

    PubMed

    Galat, Anna; Dufresne, Jérôme; Combrisson, Jérôme; Thépaut, Jérôme; Boumghar-Bourtchai, Leyla; Boyer, Mickaël; Fourmestraux, Candice

    2016-05-01

    Microbial analyses of fermented milk products require selective methods to discriminate between close species simultaneously present in high amounts. A culture-based method combining novel chromogenic agar media and appropriate incubation conditions was developed to enumerate lactic acid bacteria (LAB) strains in fermented milk. M1 agar, containing two chromogenic substrates, allowed selective enumeration of Lactobacillus rhamnosus, two strains of Lactobacillus paracasei subsp. paracasei and Streptococcus salivarius subsp. thermophilus based on differential β-galactosidase and β-glucosidase activities. Depending on the presence of some or all of the above strains, M1 agar was supplemented with L-rhamnose or vancomycin and incubations were carried out at 37 °C or 44 °C to increase selectivity. A second agar medium, M2, containing one chromogenic substrates was used to selectively enumerate β-galactosidase producing Lactobacillus delbrueckii subsp. bulgaricus at 47 °C. By contrast with the usual culture media, the chromogenic method allowed unambiguous enumeration of each species, including discrimination between the two L. paracasei, up to 10(9) CFU/g of fermented milk. In addition, the relevance of the method was approved by enumerating reference ATCC strains in pure cultures and fermented milk product. The method could also be used for enumerations on non-Danone commercial fermented milk products containing strains different from those used in this study, showing versatility of the method. To our knowledge, this is the first description of a chromogenic culture method applied to selective enumeration of LAB. PMID:26742619

  17. Evolution and characterization of a new reversibly photoswitching chromogenic protein, Dathail.

    PubMed

    Langan, Patricia S; Close, Devin W; Coates, Leighton; Rocha, Reginaldo C; Ghosh, Koushik; Kiss, Csaba; Waldo, Geoff; Freyer, James; Kovalevsky, Andrey; Bradbury, Andrew R M

    2016-05-01

    We report the engineering of a new reversibly switching chromogenic protein, Dathail. Dathail was evolved from the extremely thermostable fluorescent proteins thermal green protein (TGP) and eCGP123 using directed evolution and ratiometric sorting. Dathail has two spectrally distinct chromogenic states with low quantum yields, corresponding to absorbance in a ground state with a maximum at 389nm, and a photo-induced metastable state with a maximum at 497nm. In contrast to all previously described photoswitchable proteins, both spectral states of Dathail are non-fluorescent. The photo-induced chromogenic state of Dathail has a lifetime of ~50min at 293K and pH7.5 as measured by UV-Vis spectrophotometry, returning to the ground state through thermal relaxation. X-ray crystallography provided structural insights supporting a change in conformation and coordination in the chromophore pocket as being responsible for Dathail's photoswitching. Neutron crystallography, carried out for the first time on a protein from the green fluorescent protein family, showed a distribution of hydrogen atoms revealing protonation of the chromophore 4-hydroxybenzyl group in the ground state. The neutron structure also supports the hypothesis that the photo-induced proton transfer from the chromophore occurs through water-mediated proton relay into the bulk solvent. Beyond its spectroscopic curiosity, Dathail has several characteristics that are improvements for applications, including low background fluorescence, large spectral separation, rapid switching time, and the ability to switch many times. Therefore, Dathail is likely to be extremely useful in the quickly developing fields of imaging and biosensors, including photochromic Förster resonance energy transfer, high-resolution microscopy, and live tracking within the cell. PMID:27000644

  18. Performance of SaSelect, a Chromogenic Medium for Detection of Staphylococci in Clinical Specimens

    PubMed Central

    Kerttula, Anne-Marie; Kaukoranta, Suvi-Sirkku

    2014-01-01

    In a preliminary study, known staphylococcus (n = 86) and other microbial (n = 12) isolates were plated on three chromogenic media, SaSelect (Bio-Rad, Hercules, CA, USA), CHROMagar Staph. aureus (CHROMagar Microbiology, Paris, France), and S. aureus ID (bioMérieux, Marcy l'Etoile, France). The sensitivities of all the media to detect Staphylococcus aureus after 24 h of incubation were high (100.0%). However, their specificities varied at 93.3% (95% confidence interval [CI], 86.0% to 100.0%) (CHROMagar Staph. aureus), 97.8% (95% CI, 93.5% to 100.0%) (S. aureus ID), and 100.0% (SaSelect). SaSelect also showed the highest sensitivity for recovery and differentiation of other staphylococci. As the best performing chromogenic medium, SaSelect was then prospectively compared to conventional culture and identification tests for the detection of staphylococci from 2,780 clinical specimens. A total of 1,589 staphylococcal isolates were recovered. Of these, 912 were S. aureus and 677 were other staphylococci. The sensitivity and specificity of SaSelect to detect S. aureus in clinical specimens after 24 h of incubation were 99.6% and 99.9% (95% CI, 99.2% to 100.0% and 99.8% to 100.0%), respectively, whereas the sensitivity and specificity using conventional plates combined with laboratory identification methods were 96.8% and 99.5% (95% CI, 95.7 to 97.9% and 99.2% to 99.8%). For the recovery and preliminary identification of other staphylococci, the sensitivity and specificity of SaSelect were 94.4% and 99.9%. SaSelect is a well-performing chromogenic medium that significantly improved the detection of staphylococci, especially S. aureus, compared to conventional culture (P < 0.0001). PMID:24430448

  19. CHROMagar Yersinia, a New Chromogenic Agar for Screening of Potentially Pathogenic Yersinia enterocolitica Isolates in Stools

    PubMed Central

    Renaud, Nicolas; Lecci, Laetitia; Courcol, René J.; Simonet, Michel

    2013-01-01

    CHROMagar Yersinia (CAY) is a new chromogenic medium for the presumptive detection of virulent Yersinia enterocolitica in stools. Based on a comparative analysis of 1,494 consecutive stools from hospitalized patients, CAY was found to be just as sensitive as the reference medium (cefsulodin-irgasan-novobiocin agar) but was significantly more specific and had a very low false-positive rate. CAY reduces the workload (and thus costs) for stool analysis and can therefore be recommended for routine laboratory use. PMID:23363840

  20. Selective fluorogenic and chromogenic probe for detection of silver ions and silver nanoparticles in aqueous media.

    PubMed

    Chatterjee, Amrita; Santra, Mithun; Won, Nayoun; Kim, Sungjee; Kim, Jae Kyung; Kim, Seung Bin; Ahn, Kyo Han

    2009-02-18

    A novel rhodamine-based fluorogenic and chromogenic probe for Ag(+) ions in aqueous media is developed, which can be also used for the detection of AgNPs. The sensing mechanism is based on irreversible tandem ring-opening and -forming processes promoted by Ag(+)-coordination to the iodide of the probe, which is accompanied by both color and turn-on type fluorescence changes. The probe shows remarkably high selectivity over other metal ions and detects silver ions up to 14 ppb. PMID:19159289

  1. Evaluation of four chromogenic media for the isolation of Group B Streptococcus from vaginal specimens in pregnant women.

    PubMed

    Salem, Nahim; Anderson, Jeffrey J

    2015-10-01

    Direct culture onto four commercial chromogenic media, selective for the isolation of Group B Streptococcus (GBS), were compared with the conventional pre-enrichment Centers for Disease Control and Prevention (CDC) method for the ability to isolate GBS from 242 pregnant women's self-collected vaginal/perineal swabs. The sensitivities and specificities for direct culture on to chromogenic agar were 92% and 100% for StrepBSelect (Bio-Rad Laboratories), 96% and 100% for Brilliance GBS (Thermo-Fisher Scientific), 94% and 100% for CHROMagar StrepB (CHROMagar, Dutec Diagnostics), 86% and 100% for ChromID Strepto B (bioMerieux). CDC recommended broth pre-enrichment then culture on blood containing selective agar had a sensitivity and specificity of 90.0% and 100% respectively. The chromogenic agar tested produced comparable results to the pre-enrichment CDC method. PMID:26308132

  2. A multi writable thiophene-based selective and reversible chromogenic fluoride probe with dual -NH functionality.

    PubMed

    Vishwakarma, Siddharth; Kumar, Ajit; Pandey, Abha; Upadhyay, K K

    2017-01-01

    A chromogenic fluoride probe bearing bis imine groups having dual -NH functionality (BSB) has been designed, synthesised and structurally characterized by its single crystal X-ray diffraction studies. The BSB could visually and spectroscopically recognise F(-) with high selectivity over other anions by exhibiting intense chromogenic response (from colourless to red) for F(-) in acetonitrile solution. The UV-visible titration and (1)H NMR titration experiments indicated that the observed changes occur via a combined process including hydrogen bonding and deprotonation between the BSB and F(-). Moreover theoretical calculations at the Density Functional Theory (DFT) level shed further light upon probe design strategy and the nature of interactions between BSB and F(-). The limit of detection and binding constant of BSB towards F(-) were found to be 6.9×10(-7)M and 1.42±0.069×10(8)M(-2) respectively. Finally, by using F(-)and H(+) as chemical inputs and the absorbance as output, a INHIBIT logic gate was constructed, which exhibits "Multi-write" ability without obvious degradation in its optical output. PMID:27442291

  3. Performance of chromogenic media for Candida in rapid presumptive identification of Candida species from clinical materials

    PubMed Central

    Pravin Charles, M. V.; Kali, Arunava; Joseph, Noyal Mariya

    2015-01-01

    Background: In perspective of the worldwide increase in a number of immunocompromised patients, the need for identification of Candida species has become a major concern. The development of chromogenic differential media, introduced recently, facilitate rapid speciation. However, it can be employed for routine mycology workup only after an exhaustive evaluation of its benefit and cost effectiveness. This study was undertaken to evaluate the benefit and cost effectiveness of chromogenic media for speciation of Candida clinical isolates. Materials and Methods: Sputum samples of 382 patients were screened for the presence of Candida spp. by Gram stain and culture on sabouraud dextrose agar. Candida species were identified using Gram stain morphology, germ tube formation, cornmeal agar with Tween-80, sugar fermentation tests and morphology on HiCrome Candida differential agar. All the Candida isolates were inoculated on HiCrome Candida agar (HiMedia, Mumbai, India). Results: The sensitivity and specificity of HiCrome agar for identification of Candida albicans were 90% and 96.42%, respectively whereas sensitivity and specificity of carbohydrate fermentation test were 86.67% and 74.07%, respectively. Sensitivity and specificity values of HiCrome agar for detection of C. albicans, Candida parapsilosis and Candida glabrata were above 90%. Conclusions: We found HiCrome agar has high sensitivity and specificity comparable to that of the conventional method. In addition, use of this differential media could significantly cut down the turnaround time as well as cost of sample processing. PMID:26109791

  4. Heteroleptic dipyrrinato complexes containing 5-ferrocenyldipyrromethene and dithiocarbamates as coligands: selective chromogenic and redox probes.

    PubMed

    Gupta, Rakesh Kumar; Pandey, Rampal; Singh, Roopshikha; Srivastava, Nitin; Maiti, Biswajit; Saha, Satyen; Li, Peizhou; Xu, Qiang; Pandey, Daya Shankar

    2012-08-20

    Six heteroleptic dipyrrinato complexes [Ni(fcdpm)(dedtc)] (1), [Ni(fcdpm)(dipdtc)] (2), [Ni(fcdpm)(dbdtc)] (3), [Pd(fcdpm)(dedtc)] (4), [Pd(fcdpm)(dipdtc)] (5), and [Pd(fcdpm)(dbdtc)] (6) (fcdpm = 5-ferrocenyldipyrromethene; dedtc = diethyldithiocarbamate; dipdtc = diisopropyldithiocarbamate; dbdtc = dibutyldithiocarbamate) have been synthesized and characterized by elemental analyses and spectral (ESI-MS, IR, (1)H, (13)C NMR, UV-vis) and electrochemical studies. Crystal structures of 1, 2, 4, and 5 have been authenticated by X-ray single-crystal analyses. Nickel-based complexes 1-3 display selective chromogenic and redox sensing for Hg(2+) and Pb(2+) ions, while palladium complexes 4-6 display selective chromogenic and redox sensing only for Hg(2+). Electronic absorption, ESI-MS, and electrochemical studies indicated that sensing arises from interaction between 1-3 and Hg(2+)/Pb(2+) through sulfur of the coordinated dithiocarbamates, while it arises from the pyrrolic nitrogen of fcdpm and dithiocarbamate sulfur from 4-6 and Hg(2+). Different modes of binding between Ni and Pd complexes have further been supported by theoretical studies. The receptor-cation binding constants (K(a)) and stoichiometry between probes and Hg(2+)/Pb(2+) have been estimated by the Benesi-Hildebrand method and Job's plot analysis. Detection limits for 1-3 toward Hg(2+)/Pb(2+) and 4-6 for Hg(2+) have been found to be reasonably high. PMID:22871172

  5. Evaluation of chromogenic media and seminested PCR in the identification of Candida species

    PubMed Central

    Daef, Enas; Moharram, Ahmed; Eldin, Salwa Seif; Elsherbiny, Nahla; Mohammed, Mona

    2014-01-01

    Identification of Candida cultured from various clinical specimens to the species level is increasingly necessary for clinical laboratories. Although sn PCR identifies the species within hours but its cost-effectiveness is to be considered. So there is always a need for media which help in the isolation and identification at the species level. The study aimed to evaluate the performance of different chromogenic media and to compare the effectiveness of the traditional phenotypic methods vs. seminested polymerase chain reaction (sn PCR) for identification of Candida species. One hundred and twenty seven Candida strains isolated from various clinical specimens were identified by conventional methods, four different chromogenic media and sn PCR. HiCrome Candida Differential and CHROMagar Candida media showed comparably high sensitivities and specificities in the identification of C. albicans, C. tropicalis, C. glabrata and C. krusei. CHROMagar Candida had an extra advantage of identifying all C. parapsilosis isolates. CHROMagar-Pal’s medium identified C. albicans, C. tropicalis and C. krusei with high sensitivities and specificities, but couldn’t identify C. glabrata or C. parapsilosis. It was the only medium that identified C. dubliniensis with a sensitivity and specificity of 100%. Biggy agar showed the least sensitivities and specificities. The overall concordance of the snPCR compared to the conventional tests including CHROMAgar Candida in the identification of Candida species was 97.5%. The use of CHROMAgar Candida medium is an easy and accurate method for presumptive identification of the most commonly encountered Candida spp. PMID:24948942

  6. Evaluation of a Chromogenic Culture Medium for the Detection of Clostridium difficile

    PubMed Central

    Yang, John Jeongseok; Nam, You Sun; Kim, Min Jin; Cho, Sun Young; You, Eunkyung; Soh, Yun Soo

    2014-01-01

    Purpose Clostridium difficile (C. difficile) is an important cause of nosocomial diarrhea. Diagnostic methods for detection of C. difficile infection (CDI) are shifting to molecular techniques, which are faster and more sensitive than conventional methods. Although recent advances in these methods have been made in terms of their cost-benefit, ease of use, and turnaround time, anaerobic culture remains an important method for detection of CDI. Materials and Methods In efforts to evaluate a novel chromogenic medium for the detection of C. difficile (chromID CD agar), 289 fecal specimens were analyzed using two other culture media of blood agar and cycloserine-cefoxitin-fructose-egg yolk agar while enzyme immunosorbent assay and polymerase chain reaction-based assay were used for toxin detection. Results ChromID showed the highest detection rate among the three culture media. Both positive rate and sensitivity were higher from chromID than other culture media. ChromID was better at detecting toxin producing C. difficile at 24 h and showed the highest detection rate at both 24 h and 48 h. Conclusion Simultaneous use of toxin assay and anaerobic culture has been considered as the most accurate and sensitive diagnostic approach of CDI. Utilization of a more rapid and sensitive chromogenic medium will aid in the dianogsis of CDI. PMID:24954329

  7. Hyperspectral imaging for presumptive identification of bacterial colonies on solid chromogenic culture media

    NASA Astrophysics Data System (ADS)

    Guillemot, Mathilde; Midahuen, Rony; Archeny, Delpine; Fulchiron, Corine; Montvernay, Regis; Perrin, Guillaume; Leroux, Denis F.

    2016-04-01

    BioMérieux is automating the microbiology laboratory in order to reduce cost (less manpower and consumables), to improve performance (increased sensitivity, machine algorithms) and to gain traceability through optimization of the clinical laboratory workflow. In this study, we evaluate the potential of Hyperspectral imaging (HSI) as a substitute to human visual observation when performing the task of microbiological culture interpretation. Microbial colonies from 19 strains subcategorized in 6 chromogenic classes were analyzed after a 24h-growth on a chromogenic culture medium (chromID® CPS Elite, bioMérieux, France). The HSI analysis was performed in the VNIR region (400-900 nm) using a linescan configuration. Using algorithms relying on Linear Spectral Unmixing, and using exclusively Diffuse Reflectance Spectra (DRS) as input data, we report interclass classification accuracies of 100% using a fully automatable approach and no use of morphological information. In order to eventually simplify the instrument, the performance of degraded DRS was also evaluated using only the most discriminant 14 spectral channels (a model for a multispectral approach) or 3 channels (model of a RGB image). The overall classification performance remains unchanged for our multispectral model but is degraded for the predicted RGB model, hints that a multispectral solution might bring the answer for an improved colony recognition.

  8. Use of Selective Inhibitors and Chromogenic Substrates to Differentiate Bacteria Based on Toluene Oxygenase Activity

    SciTech Connect

    Keener, William Kelvin; Schaller, Kastli Dianne; Walton, Michelle Rene; Partin, Judy Kaye; Watwood, Mary Elizabeth; Smith, William Aaron; Chingenpeel, S. R.

    2001-09-01

    In whole-cell studies, two alkynes, 1-pentyne and phenylacetylene, were selective, irreversible inhibitors of monooxygenase enzymes in catabolic pathways that permit growth of bacteria on toluene. 1-Pentyne selectively inhibited growth of Burkholderia cepacia G4 (toluene 2-monooxygenase [T2MO] pathway) and B. pickettii PKO1 (toluene 3-monooxygenase [T3MO] pathway) on toluene, but did not inhibit growth of bacteria expressing other pathways. In further studies with strain G4, chromogenic transformation of a,a,a-Trifluoro-m-cresol (TFC) was irreversibly inhibited by 1-pentyne, but the presence of phenol prevented this inhibition. Transformation of catechol by G4 was unaffected by 1-pentyne. With respect to the various pathways and bacteria tested, phenylacetylene selectively inhibited growth of Pseudomonas mendocina KR1 (toluene 4-monooxygenase [T4MO] pathway) on toluene, but not on p-cresol. An Escherichia coli transformant expressing T4MO transformed indole or naphthalene in chromogenic reactions, but not after exposure to phenylacetylene. The naphthalene reaction remained diminished in phenylacetylene-treated cells relative to untreated cells after phenylacetylene was removed, indicating irreversible inhibition. These techniques were used to differentiate toluene-degrading isolates from an aquifer. Based on data generated with these indicators and inhibitors, along with results from Biolog analysis for sole carbon source oxidation, the groundwater isolates were assigned to eight separate groups, some of which apparently differ in their mode of toluene catabolism.

  9. Detection of Oxacillin-Susceptible mecA-Positive Staphylococcus aureus Isolates by Use of Chromogenic Medium MRSA ID

    PubMed Central

    Steffy, Katherin; Chatterjee, Maitrayee; Sugumar, Madhan; Dinesh, Kavitha R.; Manoharan, Anand; Karim, Shamsul; Biswas, Raja

    2013-01-01

    Reports of oxacillin-susceptible mecA-positive Staphylococcus aureus strains are on the rise. Because of their susceptibility to oxacillin and cefoxitin, it is very difficult to detect them by using routine phenotypic methods. We describe two such isolates that were detected by chromogenic medium and confirmed by characterization of the mecA gene element. PMID:23135944

  10. TOPICAL REVIEW: Polydiacetylene films: a review of recent investigations into chromogenic transitions and nanomechanical properties

    NASA Astrophysics Data System (ADS)

    Carpick, Robert W.; Sasaki, Darryl Y.; Marcus, Matthew S.; Eriksson, M. A.; Burns, Alan R.

    2004-06-01

    Polydiacetylenes (PDAs) form a unique class of polymeric materials that couple highly aligned and conjugated backbones with tailorable pendant side-groups and terminal functionalities. They can be structured in the form of bulk materials, multilayer and monolayer films, polymerized vesicles, and even incorporated into inorganic host matrices to form nanocomposites. The resulting materials exhibit an array of spectacular properties, beginning most notably with dramatic chromogenic transitions that can be activated optically, thermally, chemically, and mechanically. Recent studies have shown that these transitions can even be controlled and observed at the nanometre scale. These transitions have been harnessed for the purpose of chemical and biomolecular sensors, and on a more fundamental level have led to new insights regarding chromogenic phenomena in polymers. Other recent studies have explored how the strong structural anisotropy that these materials possess leads to anisotropic nanomechanical behaviour. These recent advances suggest that PDAs could be considered as a potential component in nanostructured devices due to the large number of tunable properties. In this paper, we provide a succinct review of the latest insights and applications involving PDA. We then focus in more detail on our work concerning ultrathin films, specifically structural properties, mechanochromism, thermochromism, and in-plane mechanical anisotropy of PDA monolayers. Atomic force microscopy (AFM) and fluorescence microscopy confirm that films 1-3 monolayers thick can be organized into highly ordered domains, with the conjugated backbones parallel to the substrate. The number of stable layers is controlled by the head-group functionality. Local mechanical stress applied by AFM and near-field optical probes induces the chromogenic transition in the film at the nanometre scale. The transition involves substantial optical and structural changes in a highly compressed form. Thermochromism

  11. Liquid crystal cells with built-in CdSe nanotubes for chromogenic smart emission devices.

    PubMed

    Lin, Tsung Ju; Chen, Chin-Chang; Cheng, Soofin; Chen, Yang Fang

    2008-01-21

    A simple and general approach for controlling optical anisotropy of nanostructured semiconductors is reported. Our design involves the fabrication of liquid crystal devices with built-in semiconductor nanotubes. Quite interestingly, it is found that semiconductor nanotubes can be well aligned along the orientation of liquid crystals molecules automatically, resulting in a very large emission anisotropy with the degree of polarization up to 72%. This intriguing result manifests a way to obtain well aligned semiconductor nanotubes and the emission anisotropy can be easily manipulated by an external bias. The ability to well control the emission anisotropy should open up new opportunities for nanostructured semiconductors, including optical filters, polarized light emitting diodes, flat panel displays, and many other chromogenic smart devices. PMID:18542142

  12. Chromogenic nitrophenolate-based substrates for light-driven hybrid P450 BM3 enzyme assay.

    PubMed

    Lam, Quan; Cortez, Alejandro; Nguyen, Thanh Truc; Kato, Mallory; Cheruzel, Lionel

    2016-05-01

    The incorporation of a p-nitrophenoxy moiety in substrates has enabled the development of colorimetric assays to rapidly screen for O-demethylation activity of P450 enzymes. For the light-driven hybrid P450 BM3 enzymes, where a Ru(II) photosensitizer powers the enzyme upon visible light irradiation, we have investigated a family of p-nitrophenoxy derivatives as useful chromogenic substrates compatible with the light-driven approach. The validation of this assay and its adaptability to a 96-well plate format will enable the screening of the next generation of hybrid P450 BM3 enzymes towards C-H bond functionalization of non-natural substrates. PMID:26712653

  13. Near-Infrared Fluorescence of the NBT/BCIP Chromogenic Stain

    NASA Astrophysics Data System (ADS)

    McCutchen, M. D.; Bumm, L. A.; McCauley, D. W.; Trinh, L. A.; Bonner-Fraser, M.; Fraser, S. E.

    2007-03-01

    We demonstrate the previously unreported near infrared (NIR) fluorescence of the dark purple stain formed from 5-bromo-4-chloro-3-indolyl phosphate (BCIP) and nitro blue tetrazolium (NBT). Although the product is a solid with strong optical absorption, its fluorescence enables high cellular resolution imaging of gene expression. We use spectrofluorometry to identify NBT diformazan as the component of the stain that is the fluorophore exhibiting the strong fluorescence signal. The fluorescence shows an intense emission signal (780-910 nm) that is well separated from excitation (645-685 nm). The NBT diformazan fluorescence is also photostable. Because NBT/BCIP is a widely used chromogenic stain, existing staining protocols can also be applied to fluorescence imaging techniques to increase the resolution of gene expression patterns.

  14. The optical properties of molecules and chromogenic aggregates of xanthene dyes

    NASA Astrophysics Data System (ADS)

    Mikheev, Yu. A.; Guseva, L. N.; Ershov, Yu. A.

    2009-05-01

    The UV absorption spectra of rhodamine B and G molecules isolated from industrial dye samples were obtained. Two procedures were used. In one of them, rhodamine B molecules were displaced with water into a heptane layer from a solution of the dye in an alcohol-heptane mixture. The second procedure involved heating of the dye introduced into cellulose triacetate films. Individual rhodamine molecules (namely, dye cation-chlorine anion ion pairs) prepared by both methods did not absorb visible light. The spectra of individual rhodamine molecules coincided with the spectra of so-called pseudoleucobases of xanthene dyes reported in the literature. The conclusion was drawn that the chromaticity property in the series of xanthene dyes appeared because of the formation of supramolecular dimeric and larger aggregates, as was earlier established for triphenylmethane dyes (TPMDs) and copper phthalocyanine (CuPc). At the same time, individual xanthene dye molecules, like TPMD and CuPc molecules, are not chromogens.

  15. Naked-eye detection of biologically important anions by a new chromogenic azo-azomethine sensor

    NASA Astrophysics Data System (ADS)

    Rezaeian, Khatereh; Khanmohammadi, Hamid

    2014-12-01

    A new chromogenic azo-azomethine sensor, containing active phenolic sites, has been designed and synthesized via condensation reaction of N,N,N‧,N‧-tetrakis(2-aminoethyl)-2,2-dimethyl propane-1,3-diamine with 1-(3-formyl-4-hydroxyphenylazo)-4-nitrobenzene. The anion recognition ability of the synthesized receptor was evaluated using UV-Vis spectroscopy and 1H NMR technique. The anion recognition studies exhibited that the receptor acts as a sensor for biologically important anions such as F-, AcO- and H2PO4- over other anions. The binding stoichiometry between sensor and anions was found to be 1:2. 1H NMR experiment revealed that sensor recognizes anions via H-bonds and subsequent deprotonation to elicit a vivid color change. Interestingly, the sensory system not only let for the naked eye detection without any spectroscopic instrumentation but also helped to discriminate between anions.

  16. A selective spectrophotometric method for determination of rosoxacin antibiotic using sodium nitroprusside as a chromogenic reagent

    NASA Astrophysics Data System (ADS)

    Askal, Hassan F.; Refaat, Ibrahim H.; Darwish, Ibrahim A.; Marzouq, Mostafa A.

    2008-04-01

    A selective spectrophotometric method for the determination of rosoxacin (ROS), a 4-quinolone antimicrobial agent, has been developed and validated. The method was based on the reaction of ROS with alkaline sodium nitroprusside (SNP) reagent at room temperature forming a red colored chromogen measured at 455 nm. The conditions affecting the reaction (SNP concentration, pH, color-developing time, temperature, diluting solvent and chromogen stability time) were optimized. Under the optimum conditions, good linear relationship ( r = 0.9987) was obtained between the absorbance and the concentration of ROS in the range of 20-50 μg ml -1. The assay limits of detection and quantitation were 2.5 and 8.4 μg ml -1, respectively. The method was successfully applied to the analysis of bulk drug and laboratory-prepared tablets; the mean percentage recoveries were 100.1 ± 0.33 and 101.24 ± 1.28%, respectively. The results were compared favourably with those obtained by the reported method; no significant difference in the accuracy and precision as revealed by the accepted values of t- and F-tests, respectively. The robustness and ruggedness of the method was checked and satisfactory results were obtained. The proposed method was found to be highly selective for ROS among the fluoroquinolone antibiotics. The reaction mechanism was proposed and it proceeded in two steps; the formation of nitroferrocyanide by the action of sodium hydroxide alkalinity on SNP and the subsequent formation of the colored nitrosyl-ROS derivative by the attack at position 6 of ROS.

  17. A Chromogenic Assay Suitable for High-Throughput Determination of Limit Dextrinase Activity in Barley Malt Extracts.

    PubMed

    Bøjstrup, Marie; Marri, Lucia; Lok, Finn; Hindsgaul, Ole

    2015-12-23

    Twenty-four malt samples were assayed for limit dextrinase activity using a chromogenic assay developed recently in our group. The assay utilizes a small soluble chromogenic substrate which is hydrolyzed selectively by limit dextrinase in a coupled assay to release the chromophore 2-chloro-4-nitrophenol. The release of the chromophore, corresponding to the activity of limit dextrinase, can be followed by measuring the UV absorption at 405 nm. The 24 malt samples represented a wide variation of limit dextrinase activities, and these activities could be clearly differentiated by the assay. The results obtained were comparable with the results obtained from a commercially available assay, Limit-Dextrizyme from Megazyme International Ireland. Furthermore, the improved assay uses a soluble substrate. That makes it well suited for high-throughput screening as it can be handled in a 96-well plate format. PMID:26615836

  18. Automated measurement of estrogen receptor in breast cancer: a comparison of fluorescent and chromogenic methods of measurement.

    PubMed

    Zarrella, Elizabeth R; Coulter, Madeline; Welsh, Allison W; Carvajal, Daniel E; Schalper, Kurt A; Harigopal, Malini; L Rimm, David; M Neumeister, Veronique

    2016-09-01

    Whereas FDA-approved methods of assessment of estrogen receptor (ER) are 'fit for purpose', they represent a 30-year-old technology. New quantitative methods, both chromogenic and fluorescent, have been developed and studies have shown that these methods increase the accuracy of assessment of ER. Here, we compare three methods of ER detection and assessment on two retrospective tissue microarray (TMA) cohorts of breast cancer patients: estimates of percent nuclei positive by pathologists and by Aperio's nuclear algorithm (standard chromogenic immunostaining), and immunofluorescence as quantified with the automated quantitative analysis (AQUA) method of quantitative immunofluorescence (QIF). Reproducibility was excellent (R(2)>0.95) between users for both automated analysis methods, and the Aperio and QIF scoring results were also highly correlated, despite the different detection systems. The subjective readings show lower levels of reproducibility and a discontinuous, bimodal distribution of scores not seen by either mechanized method. Kaplan-Meier analysis of 10-year disease-free survival was significant for each method (Pathologist, P=0.0019; Aperio, P=0.0053, AQUA, P=0.0026); however, there were discrepancies in patient classification in 19 out of 233 cases analyzed. Out of these, 11 were visually positive by both chromogenic and fluorescent detection. In 10 cases, the Aperio nuclear algorithm labeled the nuclei as negative; in 1 case, the AQUA score was just under the cutoff for positivity (determined by an Index TMA). In contrast, 8 out of 19 discrepant cases had clear nuclear positivity by fluorescence that was unable to be visualized by chromogenic detection, perhaps because of low positivity masked by the hematoxylin counterstain. These results demonstrate that automated systems enable objective, precise quantification of ER. Furthermore, immunofluorescence detection offers the additional advantage of a signal that cannot be masked by a counterstaining

  19. Gene numerical imbalances in cytological specimens based on fluorescence/chromogenic in situ hybridization analysis.

    PubMed

    Tsiambas, E; Karameris, A; Lygeros, M; Athanasiou, A E; Salemis, N S; Gourgiotis, S; Ragkos, V; Metaxas, G E; Vilaras, G; Patsouris, E

    2012-01-01

    Design and development of novel targeted therapeutic strategies is an innovation in handling patients with solid malignancies including breast, colon, lung, head & neck or even pancreatic and hepatocellular carcinoma. For a long time, immunohistocytochemistry (IHC/ICC) has been performed as a routine method in almost all labs for evaluating protein expression. Modern molecular approaches show that identification of specific structural and numerical imbalances regarding genes involved in signal transduction pathways provide important data to the oncologists. Alterations in molecules such as epidermal growth factor receptor (EGFR), HER2/neu, PTEN or Topoisomerase IIa affect the response rates to specific chemotherapeutic agents modifying also patients' prognostic rates. In situ hybridization (ISH) techniques based on fluorescence and chromogenic variants (FISH/CISH) or silver in situ hybridization (SISH) are applicable in both tissue and cell substrates. Concerning cytological specimens, FISH/CISH analysis appears to be a fast and very accurate method in estimating gene/chromosome ratios. In this paper, we sought to evaluate the usefulness of FISH/ CISH analysis in cytological specimens, describing also the advantages and disadvantages of these methods from the technical point of view. PMID:23033306

  20. An evaluation of chromogenic substrates for characterization of serine protease produced by pathogenic Vibrio alginolyticus.

    PubMed

    Chen, F R; Liu, P C; Lee, K K

    1999-01-01

    Four chromogenic substrates for characterizing serine protease of Vibrio alginolyticus were evaluated. The protease activity of bacterial extracellular products, or the fractions of 33 kD protease purified by the AKTA purifier system with various columns, was completely inhibited by ethylenediamine tetra-acetic acid, ethylene glycol-bis(beta-amino-ethyl ether) N,N,N',N'-tetraacetic acid (EGTA), antipain and phenylmethylsulphonyl fluoride (PMSF) using water-soluble substrates (azoalbumin and azocasein). It was only completely inhibited by antipain and PMSF using water-insoluble substrates (azocoll and hide powder azure). The protease activity was not, or only partially, inhibited by 1,10-phenanthroline and sodium dodecyl sulphate (SDS) using all four substrates. Since chelating agents and 1,10-phenanthroline are commonly employed as inhibitors to identify metalloprotease, the two water-soluble substrates may not be appropriate for this purpose, except for using 1,10-phenanthroline as an inhibitor. Chelating agents may be still applicable as inhibitors using water-insoluble substrates and 1,10-phenanthroline is highly recommended in the characterization for metalloprotease to avoid confusion. In the present study, the 33 kD protease was further confirmed as an SDS-resistant serine protease and not a metalloprotease. PMID:10413876

  1. Recombinant to modified factor VIII and factor IX - chromogenic and one-stage assays issues.

    PubMed

    Kitchen, S; Kershaw, G; Tiefenbacher, S

    2016-07-01

    The recent development of modified recombinant factor VIII (FVIII) and factor IX (FIX) therapeutic products with extended half-lives will create challenges for the haemostasis laboratory in obtaining recovery estimates of these products in clinical samples using existing assays. The new long-acting therapeutic concentrates contain molecular modifications of Fc fusion, site-specific of polyethylene glycol or albumin fusion. The optimum methods for monitoring each new product will need to be assessed individually and laboratories should select an assay which gives similar results to the assay used to assign potency to the product in question. For some extended half-life FVIII and FIX products some one stage assays are entirely unsuitable for monitoring purposes. For most products and assay reagents studied so far, and reviewed in this manuscript, chromogenic FVIII or FIX assays can be safely used with conventional plasma standards. If one stage assays are used then they should be performed using carefully selected reagents/methods which have been shown to recover activity close to the labelled potency for the specific product being monitored. PMID:27405680

  2. Novel chromogenic aminopeptidase substrates for the detection and identification of clinically important microorganisms.

    PubMed

    Cellier, Marie; James, Arthur L; Orenga, Sylvain; Perry, John D; Rasul, Ari K; Robinson, Shaun N; Stanforth, Stephen P

    2014-10-01

    A series of amino acid derivatives 8-10, 42 and 43 have been prepared as chromogenic enzyme substrates in order to detect aminopeptidase activity in clinically important Gram-negative and Gram-positive bacteria. Enzymatic hydrolysis liberates the amino acid moiety and either a 4-aminophenol or a 4-dialkylaminoaniline derivative which undergoes oxidative coupling with 1-naphthol or a substituted 1-naphthol giving an indophenol dye. Substrates and 1-naphthols were incorporated into an agar-based culture medium and this allowed growth of intensely coloured bacterial colonies based on hydrolysis by specific enzymes. Red/pink coloured colonies were produced by the substrates 8-10 and blue coloured colonies were formed by the substrates 42 and 43. The L-alanyl aminopeptidase substrates 8 targeted L-alanyl aminopeptidase activity and gave coloured colonies with a range of Gram-negative bacteria. Substrates 9 targeted β-alanyl aminopeptidase activity and generated coloured colonies with selected Gram-negative species including Pseudomonas aeruginosa. Three substrates for L-pyroglutamyl acid aminopeptidase (10a, 10c and 43) were hydrolysed by enterococci and Streptococcus pyogenes to generate coloured colonies. Two yeasts were also included in the study, but they did not produce coloured colonies with any of the substrates examined. PMID:25172150

  3. Application of p-toluidine in chromogenic detection of catechol and protocatechuate, diphenolic intermediates in catabolism of aromatic compounds

    SciTech Connect

    Parke, D. )

    1992-08-01

    In the presence of p-toluidine and iron, protocatechuate and catechols yield color. Inclusion of p-toluidine in media facilities the screening of microbial strains for alterations affecting aromatic catabolism. Such strains include mutants affected in the expression of oxygenases and Escherichia coli colonies carrying cloned or subcloned aromatic catabolic genes which encode enzymes giving rise to protocatechuate or catechol. The diphenolic detection system can also be applied to the creation of vectors relying on insertion of cloned DNA into one of the latter marker genes.

  4. Direct Isolation of Candida spp. from Blood Cultures on the Chromogenic Medium CHROMagar Candida

    PubMed Central

    Horvath, Lynn L.; Hospenthal, Duane R.; Murray, Clinton K.; Dooley, David P.

    2003-01-01

    CHROMagar Candida is a selective and differential chromogenic medium that has been shown to be useful for identification of Candida albicans, Candida krusei, Candida tropicalis, and perhaps Candida glabrata. Colony morphology and color have been well defined when CHROMagar Candida has been used to isolate yeast directly from clinical specimens, including stool, urine, respiratory, vaginal, oropharyngeal, and esophageal sources. Direct isolation of yeast on CHROMagar Candida from blood cultures has not been evaluated. We evaluated whether the color and colony characteristics produced by Candida spp. on CHROMagar Candida were altered when yeasts were isolated directly from blood cultures. Fifty clinical isolates of Candida were inoculated into aerobic and anaerobic blood culture bottles and incubated at 35°C in an automated blood culture system. When growth was detected, an aliquot was removed and plated onto CHROMagar Candida. As a control, CHROMagar Candida plates were inoculated with the same isolate of yeast grown on Sabouraud dextrose agar simultaneously. No significant difference was detected in color or colony morphology between the blood and control isolates in any of the tested organisms. All C. albicans (n = 12), C. tropicalis (n = 12), C. glabrata (n = 9), and C. krusei (n = 5) isolates exhibited the expected species-specific colony characteristics and color, whether isolated directly from blood or from control cultures. CHROMagar Candida can be reliably used for direct isolation of yeast from blood cultures. Direct isolation could allow mycology laboratories to more rapidly identify Candida spp., enable clinicians to more quickly make antifungal agent selections, and potentially decrease patient morbidity and mortality. PMID:12791890

  5. Development of a Novel Chromogenic Medium for Improved Campylobacter Detection from Poultry Samples.

    PubMed

    Teramura, Hajime; Iwasaki, Mihoko; Ogihara, Hirokazu

    2015-09-01

    The presence of expanded-spectrum β-lactamase (ESBL)-producing Escherichia coli is a common problem in the isolation of Campylobacter from poultry samples using conventional cefoperazone-based selective media. A novel chromogenic medium (CM-HT), based on modified charcoal cefoperazone deoxycholate agar (mCCDA), has been developed as a solution for improved Campylobacter detection from poultry samples. Although the basic components of CM-HT are the same as mCCDA, CM-HT uses both granular charcoal and sodium cefoxitin to enhance viewability and inhibit ESBL-producing bacteria. All tested Campylobacter jejuni (n = 31) and Campylobacter coli (n = 6) strains grew and formed purple-colored colonies on CM-HT. In contrast, the growth of all other tested microorganisms, including ESBL-producing E. coli strains, was suppressed by this medium. Additionally, 84 poultry samples were examined for the presence of Campylobacter using the ISO 10272-1 method (enrichment with Bolton broth) and the NIHSJ-02 method (enrichment with Preston broth) with mCCDA and CM-HT media for the isolation. The numbers of samples from which Camplylobacter was detected on CM-HT using Preston and Bolton broth were 22 and 18, whereas the numbers on mCCDA were 22 and 13, respectively. Only Campylobacter was detected on CM-HT using both enrichment broths; however, there were 5 and 19 samples from which ESBL-producing E. coli was detected on mCCDA using Preston and Bolton broth, respectively. Thus, there was a significant difference between CM-HT and mCCDA in selectivity for ESBL-producing E. coli regardless of which enrichment broth was used. The results obtained demonstrated that CM-HT is a possible solution for the improved isolation of Campylobacter from poultry samples. PMID:26319731

  6. Evaluation of use of a new chromogenic agar in detection of urinary tract pathogens.

    PubMed

    Samra, Z; Heifetz, M; Talmor, J; Bain, E; Bahar, J

    1998-04-01

    CHROMagar Orientation, a new chromogenic medium, was evaluated for the detection and differentiation of gram-positive and gram-negative pathogenic microorganisms in 900 urine samples from hospitalized patients. Performance characteristics of the medium were evaluated in comparison to those of 5% sheep blood and MacConkey agars by direct inoculation of the urine samples on the three media. Four gram-negative and two gram-positive strains as well as one yeast control strain from the American Type Culture Collection were used to ensure quality control. CHROMagar Orientation succeeded in detecting all the urine pathogens that were detected by the reference media, including gram-negative bacilli, staphylococci, streptococci, and yeasts. Colony color and morphology on CHROMagar Orientation accurately differentiated Escherichia coli, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Acinetobacter spp. Owing to the similarity in the pigmentation produced by Klebsiella, Enterobacter, and Citrobacter isolates, the medium failed to distinguish among them; however, these isolates were easily recognized as coliforms because of their metallic blue coloration. Staphylococci were clearly perceptible: S. aureus and S. epidermidis grow in regular-size colonies that range from opaque white to yellowish, and S. saprophyticus produces opaque pink colonies. All streptococcus strains, including those from groups B and C, were detected. They grow as undifferentiated flat dry diffused colonies, and additional tests were required for identification. Enterococci were easily discriminated by their strong turquoise pigmentation and their typical growth on the agar's surface. Yeast grow in typical creamy wet convex colonies. The accuracy of antibiotic susceptibility determinations according to standard methods was also tested by picking isolates directly from CHROMagar Orientation. The results showed excellent correlation with those obtained with microorganisms picked from

  7. Automated Scoring of Chromogenic Media for Detection of Methicillin-Resistant Staphylococcus aureus by Use of WASPLab Image Analysis Software

    PubMed Central

    Faron, Matthew L.; Vismara, Chiara; Lacchini, Carla; Bielli, Alessandra; Gesu, Giovanni; Liebregts, Theo; van Bree, Anita; Jansz, Arjan; Soucy, Genevieve; Korver, John

    2015-01-01

    Recently, systems have been developed to create total laboratory automation for clinical microbiology. These systems allow for the automation of specimen processing, specimen incubation, and imaging of bacterial growth. In this study, we used the WASPLab to validate software that discriminates and segregates positive and negative chromogenic methicillin-resistant Staphylococcus aureus (MRSA) plates by recognition of pigmented colonies. A total of 57,690 swabs submitted for MRSA screening were enrolled in the study. Four sites enrolled specimens following their standard of care. Chromogenic agar used at these sites included MRSASelect (Bio-Rad Laboratories, Redmond, WA), chromID MRSA (bioMérieux, Marcy l'Etoile, France), and CHROMagar MRSA (BD Diagnostics, Sparks, MD). Specimens were plated and incubated using the WASPLab. The digital camera took images at 0 and 16 to 24 h and the WASPLab software determined the presence of positive colonies based on a hue, saturation, and value (HSV) score. If the HSV score fell within a defined threshold, the plate was called positive. The performance of the digital analysis was compared to manual reading. Overall, the digital software had a sensitivity of 100% and a specificity of 90.7% with the specificity ranging between 90.0 and 96.0 across all sites. The results were similar using the three different agars with a sensitivity of 100% and specificity ranging between 90.7 and 92.4%. These data demonstrate that automated digital analysis can be used to accurately sort positive from negative chromogenic agar cultures regardless of the pigmentation produced. PMID:26719443

  8. Automated Scoring of Chromogenic Media for Detection of Methicillin-Resistant Staphylococcus aureus by Use of WASPLab Image Analysis Software.

    PubMed

    Faron, Matthew L; Buchan, Blake W; Vismara, Chiara; Lacchini, Carla; Bielli, Alessandra; Gesu, Giovanni; Liebregts, Theo; van Bree, Anita; Jansz, Arjan; Soucy, Genevieve; Korver, John; Ledeboer, Nathan A

    2016-03-01

    Recently, systems have been developed to create total laboratory automation for clinical microbiology. These systems allow for the automation of specimen processing, specimen incubation, and imaging of bacterial growth. In this study, we used the WASPLab to validate software that discriminates and segregates positive and negative chromogenic methicillin-resistant Staphylococcus aureus (MRSA) plates by recognition of pigmented colonies. A total of 57,690 swabs submitted for MRSA screening were enrolled in the study. Four sites enrolled specimens following their standard of care. Chromogenic agar used at these sites included MRSASelect (Bio-Rad Laboratories, Redmond, WA), chromID MRSA (bioMérieux, Marcy l'Etoile, France), and CHROMagar MRSA (BD Diagnostics, Sparks, MD). Specimens were plated and incubated using the WASPLab. The digital camera took images at 0 and 16 to 24 h and the WASPLab software determined the presence of positive colonies based on a hue, saturation, and value (HSV) score. If the HSV score fell within a defined threshold, the plate was called positive. The performance of the digital analysis was compared to manual reading. Overall, the digital software had a sensitivity of 100% and a specificity of 90.7% with the specificity ranging between 90.0 and 96.0 across all sites. The results were similar using the three different agars with a sensitivity of 100% and specificity ranging between 90.7 and 92.4%. These data demonstrate that automated digital analysis can be used to accurately sort positive from negative chromogenic agar cultures regardless of the pigmentation produced. PMID:26719443

  9. Chromogenic assay for the prothrombin activator ecarin from the venom of the saw-scaled viper (Echis carinatus).

    PubMed

    Stocker, K; Fischer, H; Brogli, M

    1986-01-01

    Ecarin, by limited proteolysis and subsequent autocatalytic reactions, causes the conversion of prothrombin into three products with amidolytic activity: meizothrombin, meizothrombin 1 and lpha-thrombin. Ecarin action may be abolished by ethylenediaminetetraacetic acid and the activity of alpha-thrombin can, with a high degree of selectivity, be inhibited by heparin. Thus, ecarin potency may be assayed by measuring the meizothrombin activity generated by ecarin action on human plasma in the presence of heparin. The chromogenic substrate Tosyl-glycyl-L-prolyl-L-arginine-p-nitroanilide (Chromozym TH) is used in this assay. PMID:3082039

  10. Performance of a New Chromogenic Medium, BBL CHROMagar MRSA II (BD), for Detection of Methicillin-Resistant Staphylococcus aureus in Screening Samples ▿

    PubMed Central

    Van Vaerenbergh, Kristien; Cartuyvels, Reinoud; Coppens, Guy; Frans, Johan; Van den Abeele, Anne-Marie; De Beenhouwer, Hans

    2010-01-01

    Two chromogenic media for the detection of MRSA were compared: BBL CHROMagar MRSA II (BD) and MRSA ID agar (bioMérieux). Following overnight nonselective enrichment, 1,919 screening samples were inoculated on both chromogenic agars. After 24 h, the sensitivities of both media were high and comparable. Both media showed an important decrease in specificity after 48 h of incubation (decreases of 8% for MRSA II and 10% for MRSA ID), but MRSA II was significantly more specific at both time points. PMID:20181915

  11. [THE APPLICATION OF SELECTIVE CHROMOGENIC AGAR FOR DETECTING ENTEROBACTERIA WITH PRODUCTION OF BETA-LACTAMASES].

    PubMed

    Korobova, A G; Frolova, L N; Kliasova, G A

    2015-11-01

    The detection of enterobacteria with production of beta-lactamases of extended spectrum in selective chromogenic agar was analyzed The results ofdetection of beta-lactamases of extended spectrum was compared with "double disc" technique. The smears from mucous membrane of guttur and rectum from patients were analyzed in parallel on solid growth agar (Endo or Mac Conkey) and on selective agar CHROMagartm ESBL (CHROMagar France). The production of beta-lactamases of extended spectrum was confirmed using "double discs" technique. To exclude hyper-production of ampC beta-lactamases E-test was applied containing cefotetan and cefotetan with cloxacillin. The sampling consisted of 1552 samples from patients. The study permitted to isolate 1243 strains of enterobacteria on agar Endo or Mac Conkey and 409 strains of enterobacteria on selective agar CHROMagartm ESBL (Escherichia coli n = 226, Klebsiella pneumoniae n = 105, enterobacter spp. n = 35, Citrobacter spp. n = 21, others n = 22). The application of "double discs" technique confirmed production of beta-lactamases of extended spectrum in 386 (94%) out of 409 strains isolated on agar CHROMagartm ESBL. In 23 (6%) of strains no confirmation was established and hyper-production of ampC of beta-lactamases was established 15 out of total. Additionally, 8 were sensitive to cephalosporin of third generation. All enterobacteria isolated on agar Endo or Mac Conkey also were tested by "double discs" technique. Overall, 394 strains of enterobacteria with production of beta-lactamases of extended spectrum were obtained. On all agars (agar Endo or Mac Conkey and CHROMagartm ESBL)--263 (67%) strains; only on CHROMagartm ESBL--123 (31%) and only on agar Endo or Mac Conkey--8 (2%) (p < 0.0001). The sensitivity of selective agar CHROMagartm ESBL made up to 98% and specificity--97%. The resolution about detection of enterobacteria producing beta-lactamases of extended spectrum were submitted to clinic in 18-24 hours after arrival

  12. The Anopheles punctulatus complex: DNA probes for identifying the Australian species using isotopic, chromogenic, and chemiluminescence detection systems

    SciTech Connect

    Cooper, L.; Cooper, R.D.; Burkot, T.R. )

    1991-07-01

    Isotopic and enzyme-labeled species-specific DNA probes were made for the three known members of the Anopheles punctulatus complex of mosquitoes in Australia (Anopheles farauti Nos. 1, 2, and 3). Species-specific probes were selected by screening total genomic libraries made from the DNA of individual species with 32P-labeled DNA of homologous and heterologous mosquito species. The 32P-labeled probes for A. farauti Nos. 1 and 2 can detect less than 0.2 ng of DNA while the 32P-labeled probe for A. farauti No. 3 has a sensitivity of 1.25 ng of DNA. Probes were then enzyme labeled for chromogenic and chemiluminescence detection and compared to isotopic detection using 32P-labeled probes. Sequences of the probe repeat regions are presented. Species identifications can be made from dot blots or squashes of freshly killed mosquitoes or mosquitoes stored frozen, dried, and held at room temperature or fixed in isopropanol or ethanol with isotopic, chromogenic, or chemiluminescence detection systems. The use of nonisotopic detection systems will enable laboratories with minimal facilities to identify important regional vectors.

  13. Dithizone as novel and efficient chromogenic probe for cyanide detection in aqueous media through nucleophilic addition into diazenylthione moiety.

    PubMed

    Tavallali, Hossein; Deilamy-Rad, Gohar; Parhami, Abolfath; Kiyani, Sajede

    2014-01-01

    A new selective chemodosimeter probe was developed by the introduction of dithizone (DTZ) as a simple and available dye for detection of cyanide in aqueous media which enables recognition of cyanide over other competing anions such as acetate, dihydrogen phosphate, fluoride and benzoate through covalent bonding. The sensing properties of DTZ were investigated in DMSO/H2O (1:9) and have demonstrated a very high selectivity toward the cyanide anions. A reasonable recognition mechanism was suggested using UV-Vis, (1)H NMR and FTIR spectroscopy techniques. Time dependent density function theory (TDDFT) computations of UV-Vis excitation for DTZ2-CN adduct agreed well with our experimental findings. The detection limit of the new chromogenic probe was measured to be 0.48 μmol L(-1) which is much lower than most recently reported chromogenic probes for cyanide determination. The analytical utility of the method for the analysis of cyanide ions in electroplating wastewater (EPWW), human serum, tap and mineral water samples was demonstrated and the results were compared successfully with the conventional reference method. The short time response and the detection by the naked eye make the method available for the detection and quantitative determination of cyanide in a variety of real samples. PMID:24231750

  14. Dithizone as novel and efficient chromogenic probe for cyanide detection in aqueous media through nucleophilic addition into diazenylthione moiety

    NASA Astrophysics Data System (ADS)

    Tavallali, Hossein; Deilamy-Rad, Gohar; Parhami, Abolfath; Kiyani, Sajede

    2014-03-01

    A new selective chemodosimeter probe was developed by the introduction of dithizone (DTZ) as a simple and available dye for detection of cyanide in aqueous media which enables recognition of cyanide over other competing anions such as acetate, dihydrogen phosphate, fluoride and benzoate through covalent bonding. The sensing properties of DTZ were investigated in DMSO/H2O (1:9) and have demonstrated a very high selectivity toward the cyanide anions. A reasonable recognition mechanism was suggested using UV-Vis, 1H NMR and FTIR spectroscopy techniques. Time dependent density function theory (TDDFT) computations of UV-Vis excitation for DTZ2-CN adduct agreed well with our experimental findings. The detection limit of the new chromogenic probe was measured to be 0.48 μmol L-1 which is much lower than most recently reported chromogenic probes for cyanide determination. The analytical utility of the method for the analysis of cyanide ions in electroplating wastewater (EPWW), human serum, tap and mineral water samples was demonstrated and the results were compared successfully with the conventional reference method. The short time response and the detection by the naked eye make the method available for the detection and quantitative determination of cyanide in a variety of real samples.

  15. A new chromogenic medium for isolation of Bacteroides fragilis suitable for screening for strains with antimicrobial resistance.

    PubMed

    Tierney, Daniel; Copsey, Sarah D; Morris, Trefor; Perry, John D

    2016-06-01

    There have been an increasing number of reports describing the acquisition of antimicrobial resistance by Bacteroides fragilis including the occurrence of strains with resistance to multiple antimicrobials that are relied upon for treatment of infections. The aim of this study was to design a chromogenic selective medium for isolation of B. fragilis that could be adapted for specific isolation of antimicrobial-resistant strains. Bacteroides chromogenic agar (BCA) was the result of this endeavour and allowed growth of Bacteroides spp. as black colonies and the efficient inhibition of almost all other genera tested. The medium also allowed some differentiation of B. fragilis from other members of the B. fragilis group. When compared with an adaptation of Bacteroides bile-esculin agar (BBE) for the isolation of B. fragilis from 100 stool samples, 30 isolates of B. fragilis were recovered on BCA compared with 19 isolates recovered on BBE (P = 0.022). When supplemented with meropenem (4 μg/ml) or metronidazole (2 μg/ml), BCA could be used to select for the growth of B. fragilis isolates with resistance to these agents. We conclude that BCA is a useful research tool for surveillance studies to assess the prevalence of B. fragilis and, in particular, the occurrence of antimicrobial-resistant strains. PMID:27060277

  16. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae

    PubMed Central

    El-Jade, Mohamed Ramadan; Parcina, Marijo; Schmithausen, Ricarda Maria; Stein, Christoph; Meilaender, Alina; Hoerauf, Achim; Molitor, Ernst

    2016-01-01

    Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen. PMID:27494134

  17. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae.

    PubMed

    El-Jade, Mohamed Ramadan; Parcina, Marijo; Schmithausen, Ricarda Maria; Stein, Christoph; Meilaender, Alina; Hoerauf, Achim; Molitor, Ernst; Bekeredjian-Ding, Isabelle

    2016-01-01

    Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen. PMID:27494134

  18. The past and the future of chromogenic colour photographs: lifetime modelling using near-infrared spectroscopy & enhancement using hypoxia

    NASA Astrophysics Data System (ADS)

    Fenech, Ann; Strlič, Matija; Cassar, May

    2012-02-01

    Chromogenic colour prints are amongst the most unstable materials found in heritage collections as the information-carrying dyes fade appreciably even in the dark. However, image stability is just one of the numerous properties that photographic companies aspire for in their products, along with constant improvements in colour balance and image development. It is shown that these continuous changes can be exploited to model the date a print was developed, as well as dye stability. As a non-destructive analytical technique, near-infrared spectroscopy in conjunction with multivariate data analysis was used to derive models to predict the year of development of a photographic print (Root Mean Square Error of Cross-Validation, RMSECV = 5.4 years) and dye stability (RMSECV = 1.4 Δ E T , i.e. normalised annual colour change). To examine the possibility to extend the lifetime of the valuable objects during storage, the use of oxygen-depleted environments (hypoxia) was also investigated. The results obtained show that hypoxia should not be used as a blanket approach for all chromogenic prints, as some degraded faster in hypoxic conditions than the control samples degraded in air. However, for most samples hypoxic storage turned out to be beneficial.

  19. Comparison of two chromogenic media and evaluation of two molecular based identification systems for Enterobacter sakazakii detection

    PubMed Central

    Lehner, Angelika; Nitzsche, Sabine; Breeuwer, Pieter; Diep, Benjamin; Thelen, Karin; Stephan, Roger

    2006-01-01

    Background Enterobacter sakazakii is a foodborne pathogen that has been associated with sporadic cases and outbreaks causing meningitis, necrotizing enterocolitis and sepsis especially in neonates. The current FDA detection method includes two enrichment steps, the subculturing of the second enrichment broth on a selective agar (VRBG), a further subculturing of selected grown colonies on TSA and the subsequent biochemical identification of yellow-pigmented colonies by API20E. However, there is a strong need for simplified methods for isolation and identification of E. sakazakii. In this study, two chromogenic media, which allow to indicate presumptive E. sakazakii colonies by the alpha glucosidase activity, as well as a newly developed 1,6-alpha-glucosidase based conventional PCR assay and a rRNA oligonucleotide probe based commercial test system for identification of presumptive E. sakazakii were evaluated on 98 target and non-target strains. The methods were compared with respect to specificity aspects. Results A total of 75 presumptive E. sakazakii and 23 non-target strains were analysed by using chromogenic media, alpha-glucosidase based PCR assay, and the VIT assay. For most presumptive E. sakazakii strains on the chromogenic media, the PCR and VIT assay confirmed the identification. However, for a number of presumptive E. sakazakii isolates from fruit powder, the alpha-glucosidase PCR and VIT assay did not correspond to the typical E. sakazakii colonies on DFI and ESIA. Further characterization by API32E identification, phylogenetic analysis of partial 16S rRNA sequences and ribotyping strongly suggested, that these strains did not belong to the species E. sakazakii. The newly developed alpha-glucosidase based PCR assay as well as the commercially available VIT Enterobacter sakazakii identification test showed an excellent correlation with the 16S rRNA data, and are thus well suited for identification of E. sakazakii. Conclusion The results indicate that

  20. Mitochondria-Targeting Chromogenic and Fluorescence Turn-On Probe for the Selective Detection of Cysteine by Caged Oxazolidinoindocyanine.

    PubMed

    Kim, Chae Yeong; Kang, Hyo Jin; Chung, Sang J; Kim, Hyun-Kyung; Na, Sang-Yun; Kim, Hae-Jo

    2016-07-19

    We report a chromogenic and fluorescence turn-on probe based on crotonoyl ester-functionalized oxazolidinoindole for the selective detection of cysteine in neutral buffer. The probe rapidly formed indocyanophenolate through the Michael addition and a subsequent cyclization reaction of cysteine, inducing both a dramatic bathochromic shift (>130 nm) and a large fluorescence turn-on response (F/F0 12) in the UV-vis and fluorescence spectra and affording a micromolar limit of detection (LOD = 5.0 μM) of cysteine in HEPES buffer. When cysteine was added, the probe exhibited a dual optical change with strong green fluorescence and dramatic red color by the oxazolidinoindole-to-hydroxyethylindolium transformation. Further cellular application of the probe was successfully performed for the mitochondrial imaging of HeLa cells. PMID:27367584

  1. A comparison of standard cultural methods for the detection of foodborne Salmonella species including three new chromogenic plating media.

    PubMed

    Schönenbrücher, Vanessa; Mallinson, Edward T; Bülte, Michael

    2008-03-31

    In this study the draft of the horizontal method for the detection of Salmonella species from human food and animal feed (ISO 6579:2002) was compared to the European gold standard (DIN EN 12824:1998), including the three new chromogenic plating media AES Salmonella Agar Plate (ASAP), Oxoid Salmonella Chromogen Media (OSCM) and Miller-Mallinson agar (MM). First the growth and appearance of 36 bacterial type strains (Salmonella and other 21 species) on ASAP, OSCM and MM were compared to those on the three traditional agars Brilliant Green Agar according to Edel and Kampelmacher (BGA), Xylose Lysine Deoxycholate Agar (XLD) and Xylose Lysine Tergitol 4 Agar (XLT4). Only on MM agar, did all of 36 tested type strains produce typical colonies, especially strains of S. Senftenberg, Salmonella arizonae, S. Dublin and S. Derby. Artificial inoculation experiments using raw pork ground meat (n=92) were subsequently conducted. A shortened incubation time of 24 h in RVS broth yielded a Salmonella species recovery of 100% from spiked meat samples. Finally, 286 naturally contaminated raw porcine and bovine minced meat samples and raw poultry meat samples were investigated. Forty-three strains from a total of 39 Salmonella-positive samples were found. S. Typhimurium (n=21), with DT 104 L, DT 012 and RDNC being the most prevalent subtypes isolated. D-tartrate-positive S. Paratyphi B (n=2) and S. Saint-Paul (n=3) were also recovered. They were cultured from poultry meat and were multi-resistant against antibiotics including nalidixic acid. Rappaport Vassiliadis broth with soypeptone (RVS) yielded the highest recovery of Salmonella spp. (97,4%) compared to Tetrathionate broth with Novobiocin according to Muller and Kauffman (MKTTn, 94,9%) and Selenite Cystine broth (SC, 38,5%). However, no significant difference was obtained by comparing the ISO 6579:2002 draft to the gold standard. PMID:18192050

  2. Improved method of detecting the ERG gene rearrangement in prostate cancer using combined dual-color chromogenic and silver in situ hybridization.

    PubMed

    Braun, Martin; Stomper, Julia; Boehm, Diana; Vogel, Wenzel; Scheble, Veit J; Wernert, Nicolas; Shaikhibrahim, Zaki; Fend, Falko; Kristiansen, Glen; Perner, Sven

    2012-07-01

    The recently detected TMPRSS2-ERG fusion gene was revealed as a recurrent and prevalent prostate cancer (PCa)-specific event, potentially qualifying it for clinical use. To detect this alteration, fluorescence in situ hybridization (FISH) is the method of choice. However, FISH has some disadvantages for widespread adoption in clinical practice. Subsequently, chromogenic in situ hybridization, which uses organic chromogens, and enzymatic metallography silver in situ hybridization have emerged as promising bright-field alternatives. Compared with chromogenic in situ hybridization, silver in situ hybridization signals are very distinct and superior with regard to signal clarity and resolution, but the method excludes multicolor protocols. Based on the ERG break-apart FISH assay, we established a dual-color ERG break-apart assay using combined chromogenic in situ hybridization and silver in situ hybridization (CS-ISH) and compared these results with those obtained by FISH. We assessed 178 PCa and 10 benign specimens for their ERG rearrangement status by applying dual-color FISH and CS-ISH ERG break-apart assays to consecutive sections. We observed a highly significant concordance (97.7%) between FISH- and CS-ISH-based results (Pearson's correlation coefficient = 0.955, P < 0.001). Our findings demonstrate that the ERG rearrangement status can reliably be assessed by CS-ISH. Further, the CS-ISH technique combines the accuracy and precision of FISH with the ease of bright-field microscopy. This tool allows a much broader spectrum of applications in which to study the biological role and clinical use of ERG rearrangements in PCa. PMID:22642898

  3. Assessment of a new selective chromogenic Bacillus cereus group plating medium and use of enterobacterial autoinducer of growth for cultural identification of Bacillus species.

    PubMed

    Reissbrodt, R; Rassbach, A; Burghardt, B; Rienäcker, I; Mietke, H; Schleif, J; Tschäpe, H; Lyte, M; Williams, P H

    2004-08-01

    A new chromogenic Bacillus cereus group plating medium permits differentiation of pathogenic Bacillus species by colony morphology and color. Probiotic B. cereus mutants were distinguished from wild-type strains by their susceptibilities to penicillin G or cefazolin. The enterobacterial autoinducer increased the sensitivity and the speed of enrichment of B. cereus and B. anthracis spores in serum-supplemented minimal salts medium (based on the standard American Petroleum Institute medium) and buffered peptone water. PMID:15297532

  4. Spectrophotometric determination of copper in alkaline solutions and evaluation of some hydroxy-substituted 1,10-phenanthrolines as chromogenic reagents.

    PubMed

    Dunbar, W E; Schilt, A A

    1972-09-01

    Seven new hydroxy-substituted 1,10-phenanthroline derivatives have been evaluated as chromogenic reagents for the determination of copper in strongly alkaline solution. The most sensitive of these, 2,9-dimethyl-4,7-dihydroxy-1,10-phenanthroline, has proven to be highly effective in a simple, rapid procedure for determining trace amounts of copper in sodium hydroxide, potassium carbonate, sodium phosphate or ammonium hydroxide. PMID:18961151

  5. High concentration of human lactoferrin in milk of rhLf-transgenic cows relieves signs of bovine experimental Staphylococcus chromogenes intramammary infection.

    PubMed

    Simojoki, Heli; Hyvönen, Paula; Orro, Toomas; Pyörälä, Satu

    2010-08-15

    Six transgenic cows producing recombinant human lactoferrin (rhLf) in their milk and five normal cows at the same lactation stage were experimentally infected with Staphylococcus chromogenes to study the effect of a high concentration of lactoferrin in milk. Coagulase-negative staphylococci such as S. chromogenes have become very common as agents causing mild or subclinical mastitis. All transgenic cows became infected but showed no clinical signs, unlike the control cows, which developed mild clinical mastitis. Transgenic cows eliminated bacteria faster from the quarters than did the controls. Local clinical signs were milder, and the inflammatory reaction assessed by NAGase activity in the milk and by the concentration of milk amyloid A was lower in the transgenic cows. The mild response probably reflected the rapid elimination of bacteria. The milk concentration of rhLf remained constant throughout the study period, but the total concentration of bovine lactoferrin in the milk peaked in both groups at 46h post-challenge. Three cows, all in the control group, exhibited systemic acute phase response as increased concentrations of serum amyloid A in the blood circulation. Transgenic cows with a high concentration of human lactoferrin in their milk seemed to be protected from clinical disease and from prolonged inflammatory reaction, but not from experimental intramammary infection induced by S. chromogenes. PMID:20400186

  6. Antibody-Free Colorimetric Detection of Total Aflatoxins in Rice Based on a Simple Two-Step Chromogenic Reaction.

    PubMed

    Du, Bibai; Su, Xiaoou; Yang, Kunhao; Pan, Long; Liu, Qingju; Gong, Lingling; Wang, Peilong; Yang, Jingkui; He, Yujian

    2016-04-01

    The prevalently used immunoassays for fast screening of aftatoxins (AFs) usually cannot meet the requirement for simultaneous determination of total AFs (aflatoxin B1 + aflatoxin B2 + aflatoxin G1 + aflatoxin G2) due to the deficiency of highly group-specific antibodies. This paper describes a two-step chromogenic reaction based method to quantitatively detect total AFs in rice using colorimetric measurement without antibody. In the method, colorless AFs transform into green-colored indophenol products through the reaction with sodium hydroxide and 2,6-dibromoquinone-4-chloroimide (DBQC) successively, allowing selectively determining total AFs up to 3.9 μg/kg over other competitive mycotoxins under optimal conditions by a UV-vis spectrophotometer. In addition, the colorimetric measurement results of the rice samples agree well with that of a standard HPLC method, demonstrating the good reliability and applicability of the method. Uniquely, the method has potential for on-site detection of total AFs in rice when using a nylon membrane-based device. PMID:26938207

  7. Comparison of two chromogenic media for the detection of vancomycin-resistant enterococcal carriage by nursing home residents.

    PubMed

    Gouliouris, Theodore; Blane, Beth; Brodrick, Hayley J; Raven, Kathy E; Ambridge, Kirsty E; Kidney, Angela D; Hadjirin, Nazreen F; Török, M Estée; Limmathurotsakul, Direk; Peacock, Sharon J

    2016-08-01

    We compared ChromID VRE and Brilliance VRE media for the detection of vancomycin-resistant enterococci (VRE). Using a panel of 28 enterococcal isolates, 10 vanA Enterococcus faecium and three vanA Enterococcus faecalis isolates grew as per manufacturers' instructions whilst growth of two vanC and eight vancomycin-susceptible enterococci was inhibited on both media. Important differences were noted in the selectivity and chromogenic properties of the two media for vanA Enterococcus raffinosus and vanB E. faecium. The two media were further evaluated using 295 stool samples from nursing home residents, 34 of which grew VRE (11.5%). ChromID and Brilliance had comparable sensitivity, which was increased markedly by prolonging incubation to 48 hours (from 29% to 82%, and from 41% to 85%, respectively) and by a pre-enrichment step (to 97% and 100%, respectively). Brilliance VRE agar had higher selectivity at 48 hours, and after pre-enrichment. PMID:27312688

  8. Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package.

    PubMed

    Rosen, Hannah; Gilly, William; Bell, Lauren; Abernathy, Kyler; Marshall, Greg

    2015-01-15

    Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behaviors in free-swimming D. gigas in the Gulf of California with a focus on color-generating (chromogenic) behaviors. We documented two dynamic displays without artificial lighting at depths of up to 70 m. One dynamic pattern, termed 'flashing' is characterized by a global oscillation (2-4 Hz) of body color between white and red. Flashing was almost always observed when other squid were visible in the video frame, and this behavior presumably represents intraspecific signaling. Amplitude and frequency of flashing can be modulated, and the phase relationship with another squid can also be rapidly altered. Another dynamic display termed 'flickering' was observed whenever flashing was not occurring. This behavior is characterized by irregular wave-like activity in neighboring patches of chromatophores, and the resulting patterns mimic reflections of down-welled light in the water column, suggesting that this behavior may provide a dynamic type of camouflage. Rapid and global pauses in flickering, often before a flashing episode, indicate that flickering is under inhibitory neural control. Although flashing and flickering have not been described in other squid, functional similarities are evident with other species. PMID:25609785

  9. Presumptive identification of Candida species other than C. albicans, C. krusei, and C. tropicalis with the chromogenic medium CHROMagar Candida

    PubMed Central

    Hospenthal, Duane R; Beckius, Miriam L; Floyd, Karon L; Horvath, Lynn L; Murray, Clinton K

    2006-01-01

    Background CHROMagar Candida (CaC) is increasingly being reported as a medium used to differentiate Candida albicans from non-albicans Candida (NAC) species. Rapid identification of NAC can assist the clinician in selecting appropriate antifungal therapy. CaC is a differential chromogenic medium designed to identify C. albicans, C. krusei, and C. tropicalis based on colony color and morphology. Some reports have proposed that CaC can also reliably identify C. dubliniensis and C. glabrata. Methods We evaluated the usefulness of CaC in the identification of C. dubliniensis, C. famata, C. firmetaria, C. glabrata, C. guilliermondii, C. inconspicua, C. kefyr, C. lipolytica, C. lusitaniae, C. norvegensis, C. parapsilosis, and C. rugosa. Results Most NAC produced colonies that were shades of pink, lavender, or ivory. Several isolates of C. firmetaria and all C. inconspicua produced colonies difficult to differentiate from C. krusei. Most C. rugosa isolates produced unique colonies with morphology like C. krusei except in a light blue-green color. C. glabrata isolates produced small dark violet colonies that could be differentiated from the pink and lavender colors produced by other species. All seventeen isolates of C. dubliniensis produced green colonies similar to those produced by C. albicans. Conclusion C. glabrata and C. rugosa appear distinguishable from other species using CaC. Some NAC, including C. firmetaria and C. inconspicua, could be confused with C. krusei using this medium. PMID:16390552

  10. Multi-target Chromogenic Whole-mount In Situ Hybridization for Comparing Gene Expression Domains in Drosophila Embryos

    PubMed Central

    Hauptmann, Giselbert; Söll, Iris; Krautz, Robert; Theopold, Ulrich

    2016-01-01

    To analyze gene regulatory networks active during embryonic development and organogenesis it is essential to precisely define how the different genes are expressed in spatial relation to each other in situ. Multi-target chromogenic whole-mount in situ hybridization (MC-WISH) greatly facilitates the instant comparison of gene expression patterns, as it allows distinctive visualization of different mRNA species in contrasting colors in the same sample specimen. This provides the possibility to relate gene expression domains topographically to each other with high accuracy and to define unique and overlapping expression sites. In the presented protocol, we describe a MC-WISH procedure for comparing mRNA expression patterns of different genes in Drosophila embryos. Up to three RNA probes, each specific for another gene and labeled by a different hapten, are simultaneously hybridized to the embryo samples and subsequently detected by alkaline phosphatase-based colorimetric immunohistochemistry. The described procedure is detailed here for Drosophila, but works equally well with zebrafish embryos. PMID:26862978

  11. Selective chromogenic and fluorogenic peptide substrates for the assay of cysteine peptidases in complex mixtures.

    PubMed

    Semashko, Tatiana A; Vorotnikova, Elena A; Sharikova, Valeriya F; Vinokurov, Konstantin S; Smirnova, Yulia A; Dunaevsky, Yakov E; Belozersky, Mikhail A; Oppert, Brenda; Elpidina, Elena N; Filippova, Irina Y

    2014-03-15

    This study describes the design, synthesis, and use of selective peptide substrates for cysteine peptidases of the C1 papain family, important in many biological processes. The structure of the newly synthesized substrates is Glp-Xaa-Ala-Y (where Glp=pyroglutamyl; Xaa=Phe or Val; and Y=pNA [p-nitroanilide], AMC [4-amino-7-methylcoumaride], or AFC [4-amino-7-trifluoromethyl-coumaride]). Substrates were synthesized enzymatically to guarantee selectivity of the reaction and optical purity of the target compounds, simplifying the scheme of synthesis and isolation of products. The hydrolysis of the synthesized substrates was evaluated by C1 cysteine peptidases from different organisms and with different functions, including plant enzymes papain, bromelain, ficin, and mammalian lysosomal cathepsins B and L. The new substrates were selective for C1 cysteine peptidases and were not hydrolyzed by serine, aspartic, or metallo peptidases. We demonstrated an application of the selectivity of the synthesized substrates during the chromatographic separation of a multicomponent set of digestive peptidases from a beetle, Tenebrio molitor. Used in combination with the cysteine peptidase inhibitor E-64, these substrates were able to differentiate cysteine peptidases from peptidases of other classes in midgut extracts from T. molitor larvae and larvae of the genus Tribolium; thus, they are useful in the analysis of complex mixtures containing peptidases from different classes. PMID:24388866

  12. [Spectrophotometric determination of aromatic amino compounds with J-acid].

    PubMed

    Yin, Xiao-hang; Shi, Wen-jian; Shen, Xin; Ma, Jun-tao; Li, Liang

    2015-01-01

    The problems such as chromogenic reaction selectivity, reaction rate, sensitivity and water-solubility of azo compounds were considered. The molecular structures of coupling components were theoretically designed and screened in the present research The reaction conditions and methods of chromogenic reaction were investigated. J-Acid (2-amino-5-naphthol-7-sulfonic acid) as a coupling reagent to determine aromatic amino compounds was established. In the presence of potassium bromide, at room temperature, nitrite reacted with aromatic amino compounds in the medium of thin hydrochloric acid. Then diazonium salt reacted with J-Acid in the aqueous solution of sodium carbonate, forming coloured azo dye, which had a maximum adsorption at 480 nm. The molar adsorption coeffcients of aniline, 4-aminobenzene sulfonic acid and 1-naphthylamine were 3. 95 X 10(4), 3. 24 X 10(4) and 3. 91 X 10(4) L . mol-1 . cm-1 , respectively. Experimental results showed that common coexisting ions on the surface water did not affect the results of determination. J-Acid of spectrophotometry was used to determine the samples of Shanghai Fu Xing Dao canal. Meanwhile, recovery experiments by standard addition method were done. Experiment results showed that the recoveries of aniline were in the range of 98. 5%-102. 1%, and RSD was 2. 08%. J-Acid is a common organic reagent. It is soluble in water and low volatile, and its toxicity is much lower than N-ethylenediamine. spectrophotometric determination of aromatic amino compounds by J-Acid has the advantage of high sensitivity, good selectivity, simple rapid operation and accurate results, and thus it can be used for the determination of trace aromatic amino compounds in the environmental water. PMID:25993847

  13. Evaluation of the Q analyzer, a new cap-piercing fully automated coagulometer with clotting, chromogenic, and immunoturbidometric capability.

    PubMed

    Kitchen, Steve; Woolley, Anita

    2013-01-01

    The Q analyzer is a recently launched fully automated photo-optical analyzer equipped with primary tube cap-piercing and capable of clotting, chromogenic, and immunoturbidometric tests. The purpose of the present study was to evaluate the performance characteristics of the Q analyzer with reagents from the instrument manufacturer. We assessed precision and throughput when performing coagulation screening tests, prothrombin time (PT)/international normalized ratio (INR), activated partial thromboplastin time (APTT), and fibrinogen assay by Clauss assay. We compared results with established reagent instrument combinations in widespread use. Precision of PT/INR and APTT was acceptable as indicated by total precision of around 3%. The time to first result was 3  min for an INR and 5  min for PT/APTT. The system produced 115 completed samples per hour when processing only INRs and 60 samples (120 results) per hour for PT/APTT combined. The sensitivity of the DG-APTT Synth/Q method to mild deficiency of factor VIII (FVIII), IX, and XI was excellent (as indicated by APTTs being prolonged above the upper limit of the reference range). The Q analyzer was associated with high precision, acceptable throughput, and good reliability. When used in combination with DG-PT reagent and manufacturer's instrument-specific international sensitivity index, the INRs obtained were accurate. The Q analyzer with DG-APTT Synth reagent demonstrated good sensitivity to isolated mild deficiency of FVIII, IX, and XI and had the advantage of relative insensitivity to mild FXII deficiency. Taken together, our data indicate that the Q hemostasis analyzer was suitable for routine use in combination with the reagents evaluated. PMID:23249565

  14. Detection of Tritrichomonas foetus and Pentatrichomonas hominis in intestinal tissue specimens of cats by chromogenic in situ hybridization

    PubMed Central

    Mostegl, Meike M.; Wetscher, Andreas; Richter, Barbara; Nedorost, Nora; Dinhopl, Nora; Weissenböck, Herbert

    2012-01-01

    In this retrospective study 102 cats were analyzed for the presence of trichomonads in intestinal tissue sections using chromogenic in situ hybridization (CISH). Two intestinal trichomonad species are described in cats: Pentatrichomonas hominis and Tritrichomonas foetus. While P. hominis is considered a mere commensal, T. foetus has been found to be the causative agent of feline large-bowel diarrhea. For the detection of both agents within intestinal tissue CISH assays using three different probes were performed. In the first CISH run a probe specific for all relevant members of the order Trichomonadida (OT probe) was used. In a second CISH run all positive samples were further examined on three consecutive tissue sections using the OT probe, a probe specific for the family of Tritrichomonadidae (Tritri probe) and a newly designed probe specifically detecting P. hominis (Penta hom probe). In total, four of the 102 cats were found to be positive with the OT probe. Thereof, one cat gave a positive reaction with the P. hominis probe and three cats were positive with the T. foetus probe. All Trichomonas-positive cats were pure-bred and between 8 and 32 weeks of age. In one cat positive for T. foetus large amounts of parasites were found in the gut lumen and invading the intestinal mucosa. The species of the detected trichomonads were confirmed by polymerase chain reaction and nucleotide sequencing of a part of the 18S ribosomal RNA gene. In this study, the usefulness of CISH to detect intestinal trichomonads within feline tissue samples was shown. Additionally, the specific detection of P. hominis using CISH was established. Generally, it was shown that CISH is well suited for detection and differentiation of trichomonosis in retrospective studies using tissue samples. PMID:21856079

  15. Tubular and endothelial chimerism in renal allografts using fluorescence and chromogenic in situ hybridization (FISH, CISH) technology.

    PubMed

    Varga, Zsuzsanna; Gaspert, Ariana; Behnke, Silvia; von Teichman, Adriana; Fritzsche, Florian; Fehr, Thomas

    2012-04-01

    The role of endothelial and tubular chimerism in renal allograft adaptation and rejection varies in different studies. We addressed the correlation between different clinico-pathological settings and sex-chromosomal endothelial and/or tubular chimerism in renal allografts. We examined the presence or absence of the X and Y chromosomes by fluorescence and chromogenic in situ hybridization (FISH, CISH) methodology on paraffin embedded kidney biopsies in 16 gender mismatched renal transplants (1 to 12 years post-transplantation). Twelve patients were male, four female. Four groups were selected: (i) Vascular calcineurin inhibitor toxicity without rejection; (ii) T-cell mediated vascular rejection; (iii) antibody mediated rejection; and (iv) C4d-positivity in AB0-incompatible transplants with or without rejection. Twelve non-transplant kidney biopsies (8 female, 4 male) were used as controls. Tubular chimerism was detected more frequently (69%) than endothelial chimerism (12%) in renal transplants. One of 12 control patients had tubular and endothelial chimeric cells (8%). The Y chromosome occurred in 8/12 male recipients (67%) in tubular epithelial cells and in 5/12 male recipients (42%) in endothelial cells. Double X chromosomes were detected in 3/4 female recipients in tubular epithelium. Tubular chimerism occurred more often with endothelial chimerism and capillaritis without correlation with other parameters, such as rejection. Combined Y chromosomal tubular and lymphatic endothelial chimerism correlated with T-cell mediated vascular rejection in two out of three patients (66%). Combined Y chromosomal tubular and peritubular capillary chimerism correlated with antibody mediated C4d+ rejection in one out of two patients (50%). Tubular and/or endothelial chimerism occur frequently in gender mismatched renal allografts and, when combined, this is associated with T-cell mediated rejection. PMID:22449229

  16. Microfluidic paper-based multiplex colorimetric immunodevice based on the catalytic effect of Pd/Fe₃O₄@C peroxidase mimetics on multiple chromogenic reactions.

    PubMed

    Liang, Linlin; Ge, Shenguang; Li, Li; Liu, Fang; Yu, Jinghua

    2015-03-01

    In this report, a non-toxic method was proposed for the simple synthesis of palladium nanoparticles (Pd)/Fe3O4@C peroxidase mimetics by virtue of in situ growth of Pd nanoparticles on Fe3O4@C magnetic nanoparticles. And a microfluidic paper-based multiplex colorimetric immunodevice (named α-sheet) was developed by site-selectively immobilizing multiple antigens owing to its intrinsic high-efficiency catalytic activity of peroxidase mimetics to multiple chromogenic reactions. The immunosensor platform was prepared by growing a layer of flower-like gold nanoparticles which could entrap the primary antibodies onto paper sensing zones, and the as-prepared Pd/Fe3O4@C peroxidase mimetics was used to label secondary antibodies. In the presence of 3,3',5,5'-tetramethylbenzidine and o-phenylenediamine chromogenic substrates, Pd/Fe3O4@C peroxidase mimetics catalyzed chromogenic reactions and showed different colors with respective intensity. To precisely identify the intensity, a piece of black wax printed chromatographic paper with three observing windows (named β-sheet) was flatted on α-sheet. Under the optimal condition, the proposed multiplex colorimetric immunodevice displayed wide linear ranges from 0.005 to 30 ng mL(-1) with low detection limits of 1.7 pg mL(-1) for carcinoembryonic antigen (CEA) and α-fetoprotein (α-AFP). Meanwhile, the proposed method provided provided a non-toxic, low-cost and promising tool for point-of-care diagnosis. PMID:25682430

  17. Coagulase-negative staphylococci from non-mastitic bovine mammary gland: characterization of Staphylococcus chromogenes and Staphylococcus haemolyticus by antibiotic susceptibility testing and pulsed-field gel electrophoresis.

    PubMed

    Pate, Mateja; Zdovc, Irena; Avberšek, Jana; Ocepek, Matjaž; Pengov, Andrej; Podpečan, Ožbalt

    2012-05-01

    During routine microbiological examination of milk samples from dairy cows without clinical signs of mastitis, quarter milk samples of 231 dairy cows from 12 herds were investigated for the presence of coagulase-negative staphylococci (CNS). The isolates were identified on the basis of colony morphology, Gram staining, catalase and coagulase test and the commercial kit, API Staph. CNS was detected in 29% (67/231) of the cows. A total of seven CNS species were identified with the most prevalent being Staphylococcus (Staph.) chromogenes (30%) and Staph. haemolyticus (28·8%), followed by Staph. simulans (11·2%), Staph. xylosus (11·2%), Staph. epidermidis (7·5%), Staph. hyicus (6·3%) and Staph. sciuri (5%). The predominant species, Staph. chromogenes and Staph. haemolyticus, were further characterized by antibiotic susceptibility testing using the agar disc diffusion method (Kirby-Bauer) and by pulsed-field gel electrophoresis (PFGE). Considerable resistance to ampicillin and penicillin was observed in both species. Isolates with identical or highly similar PFGE profiles were detected at the herd level despite a marked heterogeneity seen for both species. On the basis of somatic cell count, absence of clinical signs of inflammation and heterogeneity of genotypes, we assume that CNS isolated in this study could not be considered as important causative agents of the bovine mammary gland inflammation. PMID:22067091

  18. Some new chromogens for iron, cobalt, and copper Substituted hydrazidines and 1,2,4-triazines containing the ferroin group.

    PubMed

    Schilt, A A

    1966-07-01

    The spectral characteristics and solution conditions requisite for formation of the iron(II), cobalt(II), and copper(I) complexes of some newly synthesised compounds containing the ferroin functional grouping have been determined. These properties are useful for evaluation of the possible analytical effectiveness of the compounds as spectrophotometric reagents for the determination of iron, cobalt, and copper. PMID:18959951

  19. Evaluation of chromogenic medium and direct latex agglutination test for detection of group B streptococcus in vaginal specimens from pregnant women in Lebanon and Kuwait.

    PubMed

    Ghaddar, Nahed; Alfouzan, Wadha; Anastasiadis, Elie; Al Jiser, Tamima; Itani, Saad Eddine; Dernaika, Racha; Eid, Toufic; Ghaddar, Ali; Charafeddine, Adib; Dhar, Rita; El Hajj, Hiba

    2014-10-01

    This study was undertaken to evaluate chromogenic medium and a direct latex agglutination test (DLA) for detection of Group B Streptococcus (GBS) in the vaginal specimens of pregnant women, and to ascertain the prevalence of GBS in this population in Kuwait and Lebanon. Vaginal swabs, collected from women at 35-37 weeks of gestation, were cultured on 5 % sheep blood agar (SBA), colistin nalidixic acid agar (CNA), Strept B Select chromogenic agar (SBS) as well as Lim enrichment broth in 168 cases in Lebanon while only SBA was used for 1391 samples in Kuwait. In addition, vaginal samples from 102 GBS-positive and 20 GBS-negative women near the time of delivery were collected in Kuwait for evaluation of the DLA test. During the study period, the prevalence of GBS colonization was determined to be 20.7 % (288/1391) in Kuwait while 18.4 % (31) of 168 pregnant women in Lebanon had vaginal cultures positive for GBS. By direct plating of vaginal swabs on the three media used, the isolation rates of GBS were 51.6, 64.5 and 77.4 % on SBA, CNA and SBS, respectively, which increased to 90.35, 93.1 and 96.8 %, respectively, following subculture in Lim broth after 18 h of incubation. The sensitivity of the DLA test was found to be dependent on the density of GBS colonization, resulting in 100 % sensitivity and 100 % specificity for heavy (>10(2) c.f.u. per swab) and moderately heavy (50-100 c.f.u. per swab) growth of GBS. However, for vaginal specimens yielding <50 c.f.u. per swab, the sensitivity, specificity, positive and negative predictive values of the DLA test were 100, 55.5, 63.6 and 100 %, respectively. In conclusion, a chromogenic agar, such as SBS, and a DLA test can be used for rapid detection of GBS in pregnant women. The DLA test, in particular, could prove to be a useful tool for immediate detection of GBS in women near delivery so that intrapartum antibiotic prophylaxis can be initiated. PMID:25082944

  20. Evaluation of Five Chromogenic Agar Media and the Rosco Rapid Carb Screen Kit for Detection and Confirmation of Carbapenemase Production in Gram-Negative Bacilli

    PubMed Central

    Gilmour, Matthew W.; DeGagne, Pat; Nichol, Kim; Karlowsky, James A.

    2014-01-01

    An efficient workflow to screen for and confirm the presence of carbapenemase-producing Gram-negative bacilli was developed by evaluating five chromogenic screening agar media and two confirmatory assays, the Rapid Carb screen test (Rosco Diagnostica A/S, Taastrup, Denmark) and the modified Hodge test. A panel of 150 isolates was used, including 49 carbapenemase-producing isolates representing a variety of β-lactamase enzyme classes. An evaluation of analytical performance, assay cost, and turnaround time indicated that the preferred workflow (screening test followed by confirmatory testing) was the chromID Carba agar medium (bioMérieux, Marcy l'Étoile, France), followed by the Rapid Carb screen test, yielding a combined sensitivity of 89.8% and a specificity of 100%. As an optional component of the workflow, a determination of carbapenemase gene class via molecular means could be performed subsequent to confirmatory testing. PMID:25355764

  1. Development of a chromogenic in situ hybridization for Giardia duodenalis and its application in canine, feline, and porcine intestinal tissues samples.

    PubMed

    Weissenböck, Herbert; Ondrovics, Martina; Gurtner, Susanne; Schiessl, Peter; Mostegl, Meike M; Richter, Barbara

    2011-05-01

    In the present study, a chromogenic in situ hybridization for the identification of Giardia duodenalis in paraffin-embedded tissue samples was developed. The sensitivity and specificity of the probe was validated by testing it on cultured reference samples of different assemblages of G. duodenalis as well as culture and tissue samples containing other protozoa and infectious agents. The probe gave a positive reaction with the Giardia samples and a negative reaction with all other samples. Further, the probe was used for screening of histological slides of intestine from different animal species (99 canine samples, 85 feline samples, and 202 porcine samples) for the presence of G. duodenalis trophozoites. With this assay, the parasites were detected in samples from 8 dogs (8.08%), 6 cats (7.06%), and zero pigs. The results clearly indicate that the described method is useful for detection of Giardia trophozoites in routinely processed intestinal tissue of different animal species. PMID:21908276

  2. Prospective evaluation of the chromogenic medium CandiSelect 4 for differentiation and presumptive identification of non-Candida albicans Candida species.

    PubMed

    Zhao, Liang; de Hoog, G Sybren; Cornelissen, Akke; Lyu, Qian; Mou, Lili; Liu, Taohua; Cao, Yu; Vatanshenassan, Mansoureh; Kang, Yingqian

    2016-02-01

    Rapid identification of pathogenic yeasts is a crucial step in timely and appropriate antifungal therapy. For diagnostics in the clinical laboratory, simplified alternatives to barcoding are needed. CandiSelect 4 (CS4) medium, a chromogenic medium for isolation of clinical yeasts, allows routine recognition of Candida albicans and presumptive identification of Candida tropicalis, Candida glabrata, and Candida krusei. We evaluated an extension of this method with 46 non-Candida albicans Candida (NCAC) and 7 Malassezia species. The medium supported growth of all species tested and a wide diversity of cultural types were observed. Colony colours were in violet, turquoise (including green and blue), or white tinges. Eight NCAC species produced violet pigmentation similar to that of C. albicans. Most NCAC species, including C. glabrata and C. tropicalis were distributed in the turquoise group. Malassezia species were invariably blue. PMID:26781374

  3. Comparison of chromogenic Biolog Rainbow agar Shigella/Aeromonas with xylose lysine desoxycholate agar for isolation and detection of Shigella spp. from foods.

    PubMed

    Zhang, Guodong; Lampel, Keith A

    2010-08-01

    Shigella outbreaks are widely reported throughout the world. However, it remains a challenge to isolate Shigella spp. from foods by using conventional microbiological media. The main objective of this study was to determine the effectiveness of a novel chromogenic medium, Rainbow agar Shigella/Aeromonas (Rainbow agar), for the isolation and detection of Shigella spp. in foods. All four Shigella species, S. sonnei, S. flexneri, S. dysenteriae, and S. boydii, were studied. Rainbow agar was compared with tryptic soy agar, xylose lysine desoxycholate agar (XLD), and Salmonella Shigella agar (SSA) for enumeration of Shigella spp. in pure culture. This chromogenic agar and XLD were also used to isolate Shigella spp. in artificially contaminated foods (4.8 log CFU/g of food), including lettuce, parsley, cilantro, spinach, potato salad, and shrimp. The inhibitory effect on Shigella growth by Rainbow agar was between that of XLD and SSA. All vegetables studied showed a moderately high background microflora on XLD and Rainbow agar. With artificially inoculated produce, Rainbow agar recovered about 1 to 2 log CFU more S. sonnei, S. dysenteriae, and S. boydii per g of food than did XLD. For potato salad and shrimp, which had low background microflora on Rainbow agar, Rainbow agar was slightly better in recovering Shigella spp. than XLD was in most cases. However, we found that the addition of streptomycin (6.25 mg/liter) to Rainbow agar could facilitate the isolation of Shigella in vegetables tested. In conclusion, Rainbow agar was a much more effective medium than was XLD for the isolation of Shigella spp. from foods. PMID:20819355

  4. Comparison of three chromogenic media and evaluation of two molecular-based identification systems for the detection of Enterobacter sakazakii from environmental samples from infant formulae factories.

    PubMed

    Derzelle, Sylviane; Dilasser, Françoise; Maladen, Véronique; Soudrie, Nicole; Leclercq, Alexandre; Lombard, Bertrand; Lafarge, Veŕonique

    2007-07-01

    Enterobacter sakazakii is an occasional contaminant of powdered infant formula that can cause rare but severe foodborne infections in infants. To determine optimal methods for the detection and identification of E. sakazakii, 38 naturally contaminated samples from infant formulae factories were analyzed by two PCR-based methods and by a method (TS 22964/RM 210) developed by the International Organization for Standardization and the International Dairy Federation (ISO-IDF) using three different commercial chromogenic agars. The ISO-IDF method includes two enrichment steps, plating of the second enrichment broth on E. sakazakii isolation agar (a chromogenic selective agar), picking of five typical colonies for transfer onto tryptone soy agar, and subsequent confirmation of yellow-pigmented colonies by biochemical characterization. Twenty-two of the 38 samples were positive by the culture method. E. sakazakii isolation agar (ESIA; AES Laboratoires), COMPASS agar (Biokar Diagnostics), and Druggan-Forsythe-Iversen agar (Oxoid) compared favorably with violet red bile glucose agar (VRBG, a selective medium for Enterobacteriaceae), with positive predictive values of 86.96, 88, and 74.07%, respectively, in contrast to 47.83% for VRBG. One additional positive sample was detected using the nonpatented real-time PCR method evaluated, and those results were in 97.3% concordance with the ISO-IDF results. Some discrepancies between the results of the DuPont Qualicon BAX system and those of the ISO-IDF method could be explained by heterogeneity of contamination and sampling. Thus, both PCR-based systems were suitable for detecting and specifically identifying E. sakazakii within 1 to 2 days, and COMPASS agar and ESIA could be used interchangeably as a first-step medium to isolate presumptive E. sakazakii colonies. PMID:17685342

  5. Monitoring the apple polyphenol oxidase-modulated adduct formation of phenolic and amino compounds.

    PubMed

    Reinkensmeier, Annika; Steinbrenner, Katrin; Homann, Thomas; Bußler, Sara; Rohn, Sascha; Rawel, Hashadrai M

    2016-03-01

    Minimally processed fruit products such as smoothies are increasingly coming into demand. However, they are often combined with dairy ingredients. In this combination, phenolic compounds, polyphenoloxidases, and amino compounds could interact. In this work, a model approach is presented where apple serves as a source for a high polyphenoloxidase activity for modulating the reactions. The polyphenoloxidase activity ranged from 128 to 333nakt/mL in different apple varieties. From these, 'Braeburn' was found to provide the highest enzymatic activity. The formation and stability of resulting chromogenic conjugates was investigated. The results show that such adducts are not stable and possible degradation mechanisms leading to follow-up products formed are proposed. Finally, apple extracts were used to modify proteins and their functional properties characterized. There were retaining antioxidant properties inherent to phenolic compounds after adduct formation. Consequently, such interactions may also be utilized to improve the textural quality of food products. PMID:26471529

  6. Compound matrices

    NASA Astrophysics Data System (ADS)

    Kravvaritis, Christos; Mitrouli, Marilena

    2009-02-01

    This paper studies the possibility to calculate efficiently compounds of real matrices which have a special form or structure. The usefulness of such an effort lies in the fact that the computation of compound matrices, which is generally noneffective due to its high complexity, is encountered in several applications. A new approach for computing the Singular Value Decompositions (SVD's) of the compounds of a matrix is proposed by establishing the equality (up to a permutation) between the compounds of the SVD of a matrix and the SVD's of the compounds of the matrix. The superiority of the new idea over the standard method is demonstrated. Similar approaches with some limitations can be adopted for other matrix factorizations, too. Furthermore, formulas for the n - 1 compounds of Hadamard matrices are derived, which dodge the strenuous computations of the respective numerous large determinants. Finally, a combinatorial counting technique for finding the compounds of diagonal matrices is illustrated.

  7. Polybenzimidazole compounds

    DOEpatents

    Klaehn, John R.; Peterson, Eric S.; Wertsching, Alan K.; Orme, Christopher J.; Luther, Thomas A.; Jones, Michael G.

    2010-08-10

    A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

  8. Performance of the Chromogenic Medium CHROMagar Staph Aureus and the Staphychrom Coagulase Test in the Detection and Identification of Staphylococcus aureus in Clinical Specimens

    PubMed Central

    Carricajo, Anne; Treny, Axel; Fonsale, Nathalie; Bes, Michele; Reverdy, Marie Elisabeth; Gille, Yves; Aubert, Gerald; Freydiere, Anne Marie

    2001-01-01

    CHROMagar Staph aureus (CSAM) (CHROMagar Microbiology, Paris, France) is a new chromogenic medium designed to enable detection of colonies of Staphylococcus aureus by their pink color. A total of 775 specimens were cultured in parallel on CHROMagar Staph aureus and conventional media. Among the 267 S. aureus strains recovered on at least one medium, 263 were isolated on CSAM medium (sensitivity, 98.5%), and 245 (sensitivity, 91.8%) were isolated on conventional media. The specificity of presumptive identification of S. aureus on the basis of pink colony color on CSAM medium was 97% (493 of 508). This specificity increased to 100% when coagulase detection with the Staphychrom coagulase test was added and to 98.8% when S. aureus surface components were detected by agglutination in the Pastorex Staph Plus test. Susceptibility testing of 67 S. aureus strains, performed in parallel on pink CSAM colonies and on colonies grown on blood agar, gave similar results. Thus, rapid and accurate recognition and identification of S. aureus isolates were achieved with CSAM as the primary isolation medium, followed by the staphylocoagulase Staphychrom test. Antimicrobial susceptibility testing (disk-diffusion method or ATB STAPH System) can be performed directly on pink CSAM colonies. PMID:11427572

  9. Selective sensing of submicromolar iron(III) with 3,3‧,5,5‧-tetramethylbenzidine as a chromogenic probe

    NASA Astrophysics Data System (ADS)

    Zhang, Lufeng; Du, Jianxiu

    2016-04-01

    The development of highly selective and sensitive method for iron(III) detection is of great importance both from human health as well as environmental point of view. We herein reported a simple, selective and sensitive colorimetric method for the detection of Fe(III) at submicromolar level with 3,3,‧5,5‧-tetramethylbenzidine (TMB) as a chromogenic probe. It was observed that Fe(III) could directly oxidize TMB to form a blue solution without adding any extra oxidants. The reaction has a stoichiometric ratio of 1:1 (Fe(III)/TMB) as determined by a molar ratio method. The resultant color change can be perceived by the naked eye or monitored the absorbance change at 652 nm. The method allowed the measurement of Fe(III) in the range 1.0 × 10- 7-1.5 × 10- 4 mol L- 1 with a detection limit of 5.5 × 10- 8 mol L- 1. The relative standard deviation was 0.9% for eleven replicate measurements of 2.5 × 10- 5 mol L- 1 Fe(III) solution. The chemistry showed high selectivity for Fe(III) in contrast to other common cation ions. The practically of the method was evaluated by the determination of Fe in milk samples; good consistency was obtained between the results of this method and atomic absorption spectrophotometry as indicated by statistical analysis.

  10. Assessment of commercial chromogenic solid media for the detection of non-O157 Shiga toxin-producing Escherichia coli (STEC).

    PubMed

    Zelyas, Nathan; Poon, Alan; Patterson-Fortin, Laura; Johnson, Roger P; Lee, Winki; Chui, Linda

    2016-07-01

    Detection of Shiga toxin-producing Escherichia coli (STEC) has evolved significantly since the introduction of sorbitol-MacConkey agar. This study compares four chromogenic media (CHROMagar™ STEC, Rainbow® O157 agar, CHROMagar™ O157, and Colorex® O157) in their identification of non-O157 STEC. When 161 non-O157 STEC were directly inoculated onto each medium, detection rates on CHROMagar™ STEC, Rainbow® O157 agar, CHROMagar™ O157 and Colorex® O157 were 90%, 70%, 3.7% and 6.8%, respectively. Tellurite minimal inhibitory concentrations (MICs) correlated with growth on CHROMagar™ STEC as 20 of 22 isolates with poor or no growth had MICs ≤1μg/mL. Stool spiking experiments revealed that CHROMagar™ STEC had the highest recovery of the six most common non-O157 STEC, ranging from 30% (in mucoid stool) to 98% (in watery stool). When using clinical stool samples, CHROMagar™ STEC had a sensitivity, specificity, positive predictive value, and negative predictive value of 84.6%, 87%, 13.9%, and 99.6%, respectively. PMID:27157987

  11. Somatic cell count and milk neutrophil viability of dairy heifers with specific CXCR1 genotypes following experimental intramammary infection with Staphylococcus chromogenes originating from milk.

    PubMed

    Verbeke, Joren; Piccart, Kristine; Piepers, Sofie; Van Poucke, Mario; Peelman, Luc; De Visscher, Anneleen; De Vliegher, Sarne

    2015-06-01

    Previous observational studies suggest an association between polymorphism c.980A>G in the CXCR1 gene, encoding the chemokine (C-X-C motif) receptor 1, and the innate immunity and infection status of the mammary gland. Mammary glands of eight Holstein heifers were experimentally infected with a Staphylococcus chromogenes isolate originating from a chronic intramammary infection (IMI) to study differences between CXCR1 genotypes c.980AG and c.980GG. Quarters from heifers with genotypes c.980AG and c.980GG developed subclinical mastitis but showed differences in the early response at 6-18 h post challenge. Bacterial count at 18 h post challenge tended to be higher in quarters from c.980AG heifers compared to c.980GG heifers. Somatic cell count (SCC) was higher at 6 h post challenge and tended to be higher at 9 h post challenge in c.980AG heifers compared to c.980GG heifers. Milk production decreased similarly. Milk neutrophils of c.980AG heifers showed more apoptosis at 9 h post challenge and tended to show more necrosis at 6, 9 and 12 h post challenge than c.980GG heifers. Differences were less pronounced in the later stage (>18 h) of infection. The results demonstrate that CXCR1 polymorphism can influence SCC and milk neutrophil viability following experimental IMI. PMID:25933826

  12. Multipurpose Compound

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

  13. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2001-01-01

    Seawater and natural brines accounted for about 63% of US magnesium compounds production during 2000. Premier Services in Florida, Dow Chemical in Michigan, Martin Marietta Magnesia Specialties, and Rohm & Haas recovered dead-burned and caustic-calcined magnesias from seawater. And Premier Services' recoveries, in Nevada, were from magnasite.

  14. Spectrophotometric determination of dapsone in pharmaceutical products using sodium 1,2-naphthoquinone-4-sulfonic as the chromogenic reagent

    NASA Astrophysics Data System (ADS)

    Wang, Huai You; Xu, Li Xiao; Xiao, Yan; Han, Juan

    2004-10-01

    Spectrophotometric determination of dapsone is described. The dapsone reacts with sodium 1,2-naphthoquinone-4-sulfonic in pH 6.98 buffer solution to form a salmon pink compound, and its maximum absorption wavelength is at 525 nm, ɛ525=3.68×10 4 l mol -1 cm -1. The absorbance of dapsone from 0.40 to 10 μg ml -1 obeys Beer's law. The linear regression equation of the calibration graph is C=0.2334 A+0.01288, with a linear regression correlation coefficient of 0.9998, the detection limit is 0.24 μg ml -1, and recovery is from 99.2 to 102.4%. Effects of pH, surfactant, organic solvents, foreign ions, and standing time on the determination of dapsone have been examined. This method is simple and can be used for the determination of dapsone in injection solution of dapsone. The results obtained by this method agreed with those by the official method (dead-stop titration method [The Chinese Pharmacopoeia, Pharmacopoeia Commission, Ministry of Health, vol. 2, fifth ed., PRC Chemical Industry Press, Beijing, 2000, p.720]).

  15. Analysis of Epstein Barr Virus Encoded RNA Expression in Nasopharyngeal Carcinoma in North-Eastern India: A Chromogenic in Situ Hybridization Based Study

    PubMed Central

    Saikia, Anjan; Raphael, Vandana; Shunyu, N-Brian; Khonglah, Yookarin; Mishra, Jaya; Jitani, Ankit-Kumar; Medhi, Jayanta

    2016-01-01

    Introduction: Nasopharyngeal carcinoma (NPC) is a common cancer in the North-East region of India. Though the role of environmental contributors of NPC in the North-Eastern part of India is firmly established, EBV as an etiological agent in the region remains unexplored. Material and Methods: Fifty-one patients, who presented at the department of ENT, NEIGRIHMS and were confirmed as NPC upon histopathological examination, were included in the study. Chromogenic in-situ hybridization (CISH) was used for the evaluation of EBER (Epstein Barr Virus Encoded RNA). Presence of nuclear signals was taken as positive for EBER expression. EBER status was correlated with various clinicopathological parameters like age, sex, dietary habits, histological types of NPC, and ethnicity of the patients. Results: The age range of the study group was 25 to 70 years with a mean age of 44.64 years and a male:female ratio of 3:2. Non-keratinizing undifferentiated type of NPC was the most common histological type. EBV was positive in 59% (30/51) of our cases. It showed a statistically significant correlation with the Naga community (P=0.01), with consumption of smoked food (P=0.02), and cigarette smoking (P=0.02). There was no correlation of EBV with age, sex, lymph node metastasis, stage, and histology. Conclusion: Our result indicates that EBV may be an additional risk factor in the pathogenesis of NPC in this region of India. So apart from lifestyle modification, a future study for a screening test for EBV viral load even in asymptomatic patients may be considered, for determination of disease susceptibility, early diagnosis, and proper management. PMID:27602338

  16. Evaluation of CHROMagar Staph. aureus, a New Chromogenic Medium, for Isolation and Presumptive Identification of Staphylococcus aureus from Human Clinical Specimens

    PubMed Central

    Gaillot, Olivier; Wetsch, Muriel; Fortineau, Nicolas; Berche, Patrick

    2000-01-01

    CHROMagar Staph. aureus (CSA) is a new chromogenic medium for presumptive identification of Staphylococcus aureus as mauve colonies after 24 h of incubation. We conducted a preliminary study with 100 S. aureus and 45 coagulase-negative Staphylococcus (CoNS) stock isolates plated on CSA. All S. aureus isolates yielded mauve colonies after 24 h of incubation at 37°C, while CoNS isolates grew as blue, white, or beige colonies. Culture on CSA was then prospectively compared to a conventional laboratory method, i.e., culture on 5% horse blood agar (HBA), catalase test, and latex agglutination test (HBA-catalase-latex), for isolation and presumptive identification of S. aureus from 2,000 consecutive clinical samples. Among the 310 S. aureus isolates recovered by at least one of the two methods, 296 grew as typical mauve colonies on CSA, while only 254 yielded catalase-positive, latex-positive colonies on HBA. The sensitivity of CSA was significantly higher than that of the conventional method (95.5 and 81.9%, respectively; P < 0.001) and allowed the recovery of important clinical isolates that were undetected on blood agar. The specificities of the two methods were not significantly different, although that of CSA was slightly higher (99.4% versus 98.9% for HBA-catalase-latex; P = 0.08). On the basis of its excellent sensitivity and specificity, ease of identification of positive colonies, and absence of complementary testing, CSA can be recommended as a routine plating medium for presumptive identification of S. aureus in clinical specimens. PMID:10747148

  17. Ruthenium(II) and osmium(II) vinyl complexes as highly sensitive and selective chromogenic and fluorogenic probes for the sensing of carbon monoxide in air.

    PubMed

    Toscani, Anita; Marín-Hernández, Cristina; Moragues, María E; Sancenón, Félix; Dingwall, Paul; Brown, Neil J; Martínez-Máñez, Ramón; White, Andrew J P; Wilton-Ely, James D E T

    2015-10-01

    The detection of carbon monoxide in solution and air has been achieved using simple, inexpensive systems based on the vinyl complexes [M(CHCHR)Cl(CO)(BTD)(PPh3 )2 ] (R=aryl, BTD=2,1,3-benzothiadiazole). Depending on the nature of the vinyl group, chromogenic and fluorogenic responses signalled the presence of this odourless, tasteless, invisible, and toxic gas. Solutions of the complexes in CHCl3 underwent rapid change between easily differentiated colours when exposed to air samples containing CO. More significantly, the adsorption of the complexes on silica produced colorimetric probes for the naked-eye detection of CO in the gas phase. Structural data for key species before and after the addition of CO were obtained by means of single X-ray diffraction studies. In all cases, the ruthenium and osmium vinyl complexes studied showed a highly selective response to CO with exceptionally low detection limits. Naked-eye detection of CO at concentrations as low as 5 ppb in air was achieved with the onset of toxic levels (i.e., 100 ppm), thus resulting in a remarkably clear colour change. Moreover, complexes bearing pyrenyl, naphthyl, and phenanthrenyl moieties were fluorescent, and greater sensitivities were achieved (through turn-on emission fluorescence) in the presence of CO both in solution and air. This behaviour was explored computationally using time-dependent density functional theory (TDDFT) experiments. In addition, the systems were shown to be selective for CO over all other gases tested, including water vapour and common organic solvents. Supporting the metal complexes on cellulose strips for use in an existing optoelectronic device allows numerical readings for the CO concentration to be obtained and provision of an alarm system. PMID:26270512

  18. Rapid, synergistic extractive spectrophotometric determination of copper(II) by using sensitive chromogenic reagent N″,N″‧-bis[(E)-(4-fluorophenyl) methylidene]thiocarbonohydrazide

    NASA Astrophysics Data System (ADS)

    Nalawade, Rekha A.; Nalawade, Avinash M.; Kamble, Ganesh S.; Anuse, Mansing A.

    2015-07-01

    A rapid and simple spectrophotometric method was developed for the determination of copper(II) by using newly synthesized chromogenic reagent, N″,N″‧-bis[(E)-(4-fluorophenyl)methylidene]thiocarbonohydrazide [bis(4-fluoroPM)TCH]. The reagent is highly sensitive and it forms yellow colored ternary complex with copper(II) in presence pyridine having composition 1:1:2 (M:L:Py) in the acidic pH range. Absorption of colored complex in amyl acetate is measured with reagent as a blank at λmax 375 nm. The synergistic effect is observed due to pyridine forming adduct with reagent in the organic phase. Beer's law was obeyed in the concentration range from 2.0 to 14 μg mL-1 for copper(II)-[bis(4-fluoroPM)TCH]-Py complex. Molar absorptivity and Sandell's sensitivity values for Cu(II)-bis(4-fluoroPM)TCH]-Py complex are 0.42545 × 105 and 0.0014 μg/cm2, respectively. The selectivity of the developed method was checked in the presence of various foreign ions. The developed method showed relative standard deviation (R.S.D.) of 0.13% for n = 10. The composition of Cu(II)-[bis(4-fluoroPM)TCH]-Py complex was determined by known methods such as Job's method of continuous variation, mole ratio method and slope ratio method. It is found that the ternary complex is stable for more than 24 h. Various factors influencing on the degree of complexation, such as, effect of pH, reagent concentration, synergent concentration, solvent etc. were studied. The accuracy and reliability of method was verified by AAS. This method is found to be simple, rapid and reproducible.

  19. Evaluation of the new chromogenic medium Candida ID 2 for isolation and identification of Candida albicans and other medically important Candida species.

    PubMed

    Eraso, Elena; Moragues, María D; Villar-Vidal, María; Sahand, Ismail H; González-Gómez, Nagore; Pontón, José; Quindós, Guillermo

    2006-09-01

    The usefulness of Candida ID 2 (CAID2) reformulated medium (bioMérieux, France) has been compared with that of the former Candida ID (CAID; bioMérieux), Albicans ID 2 (ALB2; bioMérieux), and CHROMagar Candida (CAC; Chromagar, France) chromogenic media for the isolation and presumptive identification of clinically relevant yeasts. Three hundred forty-five stock strains from culture collections, and 103 fresh isolates from different clinical specimens were evaluated. CAID2 permitted differentiation based on colony color between Candida albicans (cobalt blue; sensitivity, 91.7%; specificity, 97.2%) and Candida dubliniensis (turquoise blue; sensitivity, 97.9%; specificity, 96.6%). Candida tropicalis gave distinguishable pink-bluish colonies in 97.4% of the strains in CAID2 (sensitivity, 97.4%; specificity, 100%); the same proportion was reached in CAC, where colonies were blue-gray (sensitivity, 97.4%; specificity, 98.7%). CAC and CAID2 showed 100% sensitivity values for the identification of Candida krusei. However, with CAID2, experience is required to differentiate the downy aspect of the white colonies of C. krusei from other white-colony-forming species. The new CAID2 medium is a good candidate to replace CAID and ALB2, and it compares well to CAC for culture and presumptive identification of clinically relevant Candida species. CAID2 showed better results than CAC in some aspects, such as quicker growth and color development of colonies from clinical specimens, detection of mixed cultures, and presumptive differentiation between C. albicans and C. dubliniensis. PMID:16954270

  20. Quantitative real-time RT-PCR and chromogenic in situ hybridization: precise methods to detect HER-2 status in breast carcinoma

    PubMed Central

    2009-01-01

    Background HER-2 gene testing has become an integral part of breast cancer patient diagnosis. The most commonly used assay in the clinical setting for evaluating HER-2 status is immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). These procedures permit correlation between HER-2 expression and morphological features. However, FISH signals are labile and fade over time, making post-revision of the tumor difficult. CISH (chromogenic in situ hybridization) is an alternative procedure, with certain advantages, although still limited as a diagnostic tool in breast carcinomas. Methods To elucidate the molecular profile of HER-2 status, mRNA and protein expression in 75 invasive breast carcinomas were analyzed by real time quantitative RT-PCR (qRT-PCR) and IHC, respectively. Amplifications were evaluated in 43 of these cases by CISH and in 11 by FISH. Results The concordance rate between IHC and qRT-PCR results was 78.9%, and 94.6% for qRT-PCR and CISH. Intratumoral heterogeneity of HER-2 status was identified in three cases by CISH. The results of the three procedures were compared and showed a concordance rate of 83.8%; higher discordances were observed in 0 or 1+ immunostaining cases, which showed high-level amplification (15.4%) and HER-2 transcript overexpression (20%). Moreover, 2+ immunostaining cases presented nonamplified status (50%) by CISH and HER-2 downexpression (38.5%) by qRT-PCR. In general, concordance occurred between qRT-PCR and CISH results. A high concordance was observed between CISH/qRT-PCR and FISH. Comparisons with clinicopathological data revealed a significant association between HER-2 downexpression and the involvement of less than four lymph nodes (P = 0.0350). Conclusion Based on these findings, qRT-PCR was more precise and reproducible than IHC. Furthermore, CISH was revealed as an alternative and useful procedure for investigating amplifications involving the HER-2 gene. PMID:19309522

  1. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2003-01-01

    Seawater and natural brines accounted for about 60 percent of U.S. magnesium compounds production during 2002. Dead-burned and caustic-calcined magnesias were recovered from seawater by Premier Chemicals in Florida. They were also recovered from well brines in Michigan by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And they were recovered from magnesite in Nevada by Premier Chemicals.

  2. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2006-01-01

    In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

  3. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2010-01-01

    Seawater and natural brines accounted for about 40 percent of U.S. magnesium compounds production in 2009. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Chemicals in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover, and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta from its operation mentioned above.

  4. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2002-01-01

    Seawater and natural brines accounted for about 60% of US magnesium compounds production in 2001. Dead-burned and caustic-calcined magnesias were recovered from seawater in Florida by Premier Chemicals. They were also recovered from Michigan well brines by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And Premier Chemicals recovered dead-burned and caustic-calcined magnesias from magnesite in Nevada. Reilly Industries and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.

  5. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2011-01-01

    Seawater and natural brines accounted for about 54 percent of U.S. magnesium compounds production in 2010. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash-Wendover and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its operation mentioned above.

  6. Intermetallic Compounds

    NASA Astrophysics Data System (ADS)

    Takagiwa, Y.; Matsuura, Y.; Kimura, K.

    2014-06-01

    We have focused on the binary narrow-bandgap intermetallic compounds FeGa3 and RuGa3 as thermoelectric materials. Their crystal structure is FeGa3-type (tetragonal, P42/ mnm) with 16 atoms per unit cell. Despite their simple crystal structure, their room temperature thermal conductivity is in the range 4-5-W-m-1-K-1. Both compounds have narrow-bandgaps of approximately 0.3-eV near the Fermi level. Because their Seebeck coefficients are quite large negative values in the range 350-<-| S 373K|-<-550- μV-K-1 for undoped samples, it should be possible to obtain highly efficient thermoelectric materials both by adjusting the carrier concentration and by reducing the thermal conductivity. Here, we report the effects of doping on the thermoelectric properties of FeGa3 and RuGa3 as n and p-type materials. The dimensionless figure of merit, ZT, was significantly improved by substitution of Sn for Ga in FeGa3 (electron-doping) and by substitution of Zn for Ga in RuGa3 (hole-doping), mainly as a result of optimization of the electronic part, S 2 σ.

  7. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2007-01-01

    Seawater and natural brines accounted for about 52 percent of U.S. magnesium compounds production in 2006. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from sea-water by Premier Chemicals in Florida; from well brines in Michigan by Martin Marietta and Rohm and Haas; and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from brucite by Applied Chemical Magnesias in Texas, from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta and Rohm and Haas from their operations mentioned above. About 59 percent of the magnesium compounds consumed in the United States was used for refractories that are used mainly to line steelmaking furnaces. The remaining 41 percent was consumed in agricultural, chemical, construction, environmental and industrial applications.

  8. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2012-01-01

    Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

  9. Bismaleimide compounds

    DOEpatents

    Adams, Johnnie E.; Jamieson, Donald R.

    1986-01-14

    Bismaleimides of the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, C1 or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the alkylene bridging group, optionally, is substituted by 1-3 methyl groups or by fluorine, form polybismaleimide resins which have valuable physical properties. Uniquely, these compounds permit extended cure times, i.e., they remain fluid for a time sufficient to permit the formation of a homogeneous melt prior to curing.

  10. Bismaleimide compounds

    DOEpatents

    Adams, J.E.; Jamieson, D.R.

    1986-01-14

    Bismaleimides of the formula shown in the diagram wherein R[sub 1] and R[sub 2] each independently is H, C[sub 1-4]-alkyl, C[sub 1-4]-alkoxy, Cl or Br, or R[sub 1] and R[sub 2] together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R[sub 1] and R[sub 2] are not t-butyl or t-butoxy; X is O, S or Se; n is 1--3; and the alkylene bridging group, optionally, is substituted by 1--3 methyl groups or by fluorine, form polybismaleimide resins which have valuable physical properties. Uniquely, these compounds permit extended cure times, i.e., they remain fluid for a time sufficient to permit the formation of a homogeneous melt prior to curing.

  11. Magnetic bead-based enzyme-chromogenic substrate system for ultrasensitive colorimetric immunoassay accompanying cascade reaction for enzymatic formation of squaric acid-iron(III) chelate.

    PubMed

    Lai, Wenqiang; Tang, Dianping; Zhuang, Junyang; Chen, Guonan; Yang, Huanghao

    2014-05-20

    This work reports on a simple and feasible colorimetric immunoassay with signal amplification for sensitive determination of prostate-specific antigen (PSA, used as a model) at an ultralow concentration by using a new enzyme-chromogenic substrate system. We discovered that glucose oxidase (GOx), the enzyme broadly used in enzyme-linked immunosorbent assay (ELISA), has the ability to stimulate in situ formation of squaric acid (SQA)-iron(III) chelate. GOx-catalyzed oxidization of glucose leads to the formation of gluconic acid and hydrogen peroxide (H2O2). The latter can catalytically oxidize iron(II) to iron(III), which can rapidly (<1 min) coordinate with the SQA. Formation of the iron-squarate complex causes the color of the solution to change from bluish purple to bluish red accompanying the increasing absorbance with the increment of iron(III) concentration. On the basis of the SQA-iron(III) system, a new immunoassay protocol with GOx-labeled anti-PSA detection antibody can be designed for the detection of target PSA on capture antibody-functionalized magnetic immunosensing probe, monitored by recording the color or absorbance (λ = 468 nm) of the generated SQA-iron(III) chelate. The absorbance intensity shows to be dependent on the concentration of target PSA. A linear dependence between the absorbance and target PSA concentration is obtained under optimal conditions in the range from 1.0 pg mL(-1) to 30 ng mL(-1) with a detection limit (LOD) of 0.5 pg mL(-1) (0.5 ppt) estimated at the 3Sblank level. The sensitivity displays to be 3-5 orders of magnitude better than those of most commercialized human PSA ELISA kits. In addition, the developed colorimetric immunoassay was validated by assaying 12 human serum samples, receiving in good accordance with those obtained by the commercialized PSA ELISA kit. Importantly, the SQA-based immunosensing system can be further extended for the detection of other low-abundance proteins or biomarkers by controlling the target

  12. Combined Use of Pastorex Staph-Plus and Either of Two New Chromogenic Agars, MRSA ID and CHROMagar MRSA, for Detection of Methicillin-Resistant Staphylococcus aureus▿

    PubMed Central

    Compernolle, Veerle; Verschraegen, Gerda; Claeys, Geert

    2007-01-01

    We describe the search toward a fast and reliable strategy to detect and confirm the presence of methicillin-resistant Staphylococcus aureus (MRSA) in screening samples. First, we evaluated the sensitivities and specificities of oxacillin resistance screening agar (ORSA) with enrichment (tryptic soy broth [TSB] and ORSA [TSB-ORSA]) and without enrichment (ORSA), MRSA ID (MRSA_ID) plates, and CHROMagar MRSA (C_MRSA) plates, all of which were inoculated with equal volumes of a suspension made by emulsifying screening swabs. Whereas the sensitivities after 48 h were similar for all media tested (77% for MRSA_ID and ORSA; 73% for C_MRSA and ORSA after enrichment [TSB-ORSA]), the specificities of MRSA_ID (98% after 24 h and 94% after 48 h) and C_MRSA (98% after 24 h and 90% after 48 h) were superior to the specificities of ORSAs (92% after 24 h and 83% after 48 h) and TSB-ORSA (86% after 24 h and 81% after 48 h). Subsequently, the performance of the Pastorex Staph-Plus agglutination test with presumptive MRSA isolates taken directly from chromogenic agars (direct_Pastorex agglutination) was compared to that of the Pastorex Staph-Plus agglutination test with isolates from blood agar subcultures (conventional_Pastorex agglutination). When the direct_Pastorex agglutination test on MRSA_ID plates was combined with Gram staining, the direct_Pastorex agglutination test with samples from MRSA_ID plates was as reliable as the conventional_Pastorex agglutination test with samples from blood agar subcultures from MRSA_ID plates. In contrast, the direct_Pastorex agglutination test with samples from C_MRSA plates gave false-negative results. Finally, we calculated the processing times of the four different strategies, namely, (i) enrichment in TSB supplemented with NaCl, subsequent culture on ORSA, and the conventional_Pastorex agglutination test; (ii) direct inoculation of ORSA combined with conventional_Pastorex agglutination test; (iii) direct inoculation of MRSA_ID plates

  13. Development of an reliable analytical method for synergistic extractive spectrophotometric determination of cobalt(II) from alloys and nano composite samples by using chromogenic chelating ligand.

    PubMed

    Kamble, Ganesh S; Ghare, Anita A; Kolekar, Sanjay S; Han, Sung H; Anuse, Mansing A

    2011-12-15

    A synergistic simple and selective spectrophotometric method was developed for the determination of cobalt(II) with 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol [2',4'-dinitro APTPT] as a chromogenic reagent. The proposed method has been described on the basis of synergistic effective extraction of cobalt(II) in presence of pyridine at pH range 9.5-10.2, showed orange-red coloured ternary complex having molar ratio 1:2:2 (M:L:Py). The equilibrium time is 10 min for extraction of cobalt(III) from organic phase. The absorbance of coloured organic layer in chloroform is measured spectrophotometrically at 490 nm against reagent blank. The Beer's law was obeyed in the concentration range 2.5-15 μg mL(-1) of cobalt(II) and optimum concentration range was 5-12.5 μg mL(-1) of cobalt(II) and it was evaluated from Ringbom's plot. The molar absorptivity and Sandell's sensitivity of cobalt(II)-2',4'-dinitro APTPT-pyridine complex in chloroform are 1.109×10(3) L mol(-1) cm(-1) and 0.053 μg cm(-2), respectively while molar absorptivity and Sandell's sensitivity of cobalt(II)-2',4'-dinitro APTPT complex in chloroform are 6.22×10(2) L mol(-1) cm(-1) and 0.096 μg cm(-2), respectively. The composition of cobalt(II)-2',4'-dinitro APTPT-pyridine complex (1:2:2) was established by slope ratio method, mole ratio method and Job's method of continuous variation. The ternary complex was stable for more than 48 h. The interfering effects of various cations and anions were also studied, and use of suitable masking agents enhances the selectivity of the method. The method is successfully applied for the determination of cobalt(II) in binary, synthetic mixtures and real samples. A repetition of the method was checked by finding relative standard deviation (R.S.D.) for n=5 which was 0.15%. The reliability of the method is confirmed by comparison of experimental results with atomic absorption spectrophotometer. PMID:21978559

  14. Comparison of Clot-based, Chromogenic, and Fluorescence Assays for Measurement of Factor VIII Inhibitors in the U.S. Hemophilia Inhibitor Research Study

    PubMed Central

    Miller, Connie H.; Rice, Anne S.; Boylan, Brian; Shapiro, Amy D.; Lentz, Steven R.; Wicklund, Brian M.; Kelly, Fiona M.; Soucie, J. Michael

    2015-01-01

    Summary Background Detection and validation of inhibitors (antibodies) to hemophilia treatment products are important for clinical care, evaluation of product safety, and assessment of population trends. Methods Centralized monitoring for factor VIII (FVIII) inhibitors was conducted for patients in the Hemophilia Inhibitor Research Study using a previously reported modified Nijmegen-Bethesda clotting assay (NBA), a chromogenic Bethesda assay (CBA), and a novel fluorescence immunoassay (FLI). Results NBA and CBA were performed on 1005 specimens and FLI on 272 specimens. CBA was negative on 880/883 specimens (99.7%) with Nijmegen-Bethesda units (NBU)<0.5 and positive on 42/42 specimens (100%) with NBU≥2.0 and 43/80 specimens (53.8%) with NBU 0.5–1.9. Among specimens with positive NBA and negative CBA, 58.1% were FLI-negative, 12.9% had evidence of lupus anticoagulant, and 35.5% had non-time-dependent inhibition. CBA and FLI were positive on 72.4% and 100% of 1.0–1.9 NBU specimens and 43.1% and 50.0% of 0.5–0.9 NBU specimens. FLI detected antibodies in 98.0% of CBA-positive and 81.6% of NBA-positive specimens (P=0.004). Among 21 new inhibitors detected by NBA, 5 (23.8%) with 0.7–1.3 NBU did not react in CBA or FLI. Among previously positive patients with 0.5–1.9 NBU, 7/25 (28%) were not CBA or FLI positive. FLI was positive on 36/169 NBU-negative specimens (21.3%). Conclusions FVIII specificity could not be demonstrated by CBA or FLI for 26% of inhibitors of 0.5–1.9 NBU; such results must be interpreted with caution. Low titer inhibitors detected in clot-based assays should always be repeated, with consideration given to evaluating their reactivity with FVIII using more specific assays. PMID:23601690

  15. Development of an reliable analytical method for synergistic extractive spectrophotometric determination of cobalt(II) from alloys and nano composite samples by using chromogenic chelating ligand

    NASA Astrophysics Data System (ADS)

    Kamble, Ganesh S.; Ghare, Anita A.; Kolekar, Sanjay S.; Han, Sung H.; Anuse, Mansing A.

    2011-12-01

    A synergistic simple and selective spectrophotometric method was developed for the determination of cobalt(II) with 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol [2',4'-dinitro APTPT] as a chromogenic reagent. The proposed method has been described on the basis of synergistic effective extraction of cobalt(II) in presence of pyridine at pH range 9.5-10.2, showed orange-red coloured ternary complex having molar ratio 1:2:2 (M:L:Py). The equilibrium time is 10 min for extraction of cobalt(III) from organic phase. The absorbance of coloured organic layer in chloroform is measured spectrophotometrically at 490 nm against reagent blank. The Beer's law was obeyed in the concentration range 2.5-15 μg mL -1 of cobalt(II) and optimum concentration range was 5-12.5 μg mL -1 of cobalt(II) and it was evaluated from Ringbom's plot. The molar absorptivity and Sandell's sensitivity of cobalt(II)-2',4'-dinitro APTPT-pyridine complex in chloroform are 1.109 × 10 3 L mol -1 cm -1 and 0.053 μg cm -2, respectively while molar absorptivity and Sandell's sensitivity of cobalt(II)-2',4'-dinitro APTPT complex in chloroform are 6.22 × 10 2 L mol -1 cm -1 and 0.096 μg cm -2, respectively. The composition of cobalt(II)-2',4'-dinitro APTPT-pyridine complex (1:2:2) was established by slope ratio method, mole ratio method and Job's method of continuous variation. The ternary complex was stable for more than 48 h. The interfering effects of various cations and anions were also studied, and use of suitable masking agents enhances the selectivity of the method. The method is successfully applied for the determination of cobalt(II) in binary, synthetic mixtures and real samples. A repetition of the method was checked by finding relative standard deviation (R.S.D.) for n = 5 which was 0.15%. The reliability of the method is confirmed by comparison of experimental results with atomic absorption spectrophotometer.

  16. Comparative Evaluation of a Prototype Chromogenic Medium (ChromID CARBA) for Detecting Carbapenemase-Producing Enterobacteriaceae in Surveillance Rectal Swabs

    PubMed Central

    Vrioni, Georgia; Daniil, Ioannis; Voulgari, Evangelia; Ranellou, Kyriaki; Koumaki, Vasiliki; Ghirardi, Sandrine; Kimouli, Maria; Zambardi, Gilles

    2012-01-01

    Carbapenemase-producing Enterobacteriaceae (CPE) are an increasing problem worldwide, and rectal swab surveillance is recommended as a component of infection control programs. The performance of a prototype chromogenic medium (chromID CARBA) was evaluated and compared with media tested by four other screening methods: (i) overnight selective enrichment in 5 ml tryptic soy broth with a 10-μg ertapenem disk followed by plating onto MacConkey agar (CDC-TS), (ii) short selective enrichment in 9 ml brain heart infusion broth with a 10-μg ertapenem disk followed by plating onto chromID ESBL medium (ESBL-BH), (iii) direct plating onto chromID ESBL, and (iv) direct plating onto MacConkey agar supplemented with meropenem (1 μg/ml) (MCM). The screening methods were applied to detect CPE in 200 rectal swab specimens taken from different hospitalized patients. Identification and antimicrobial susceptibility were performed by the Vitek 2 system. Carbapenem MICs were checked by Etest. Carbapenemase production was confirmed using the modified Hodge test, combined-disk tests, and PCR assays. In total, 133 presumptive CPE strains were detected. Phenotypic and genotypic assays confirmed 92 strains to be CPE (56 KPC-positive Klebsiella pneumoniae, 29 VIM-positive K. pneumoniae, and 7 KPC-positive Enterobacter aerogenes strains) recovered from 73 patients, while the remaining 41 strains were confirmed to be CPE negative (19 ESBL producers and 22 nonfermenters). chromID CARBA, ESBL-BH, and chromID ESBL exhibited the highest sensitivity (92.4%), followed by CDC-TS and MCM (89.1%) (P = 0.631). The specificity was greater for chromID CARBA (96.9%) and ESBL-BH (93.2%) than for CDC-TS (86.4%), MCM (85.2%), and chromID ESBL (84.7%) (P = 0.014). In conclusion, chromID CARBA was found to be a rapid and accurate culture screening method for active CPE surveillance. PMID:22461675

  17. Determination of HER2 amplification in primary breast cancer using dual-colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens

    PubMed Central

    García-Caballero, Tomás; Grabau, Dorthe; Green, Andrew R; Gregory, John; Schad, Arno; Kohlwes, Elke; Ellis, Ian O; Watts, Sarah; Mollerup, Jens

    2010-01-01

    García-Caballero T, Grabau D, Green A R, Gregory J, Schad A, Kohlwes E, Ellis I O, Watts S & Mollerup J (2010) Histopathology56, 472–480 Determination of HER2 amplification in primary breast cancer using dual-colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens Aims: Fluorescence in situ hybridization (FISH) can be used to reveal several genomic imbalances relevant to proper cancer diagnosis and to the correct treatment regime. However, FISH requires expensive and advanced fluorescence microscopes in addition to expertise in fluorescence microscopy. To determine whether a newly developed dual-colour chromogenic in situ hybridization (CISH) method is a suitable alternative to FISH, we analysed the human epidermal growth factor receptor 2 gene (HER2) amplification level of 168 breast cancer specimens using dual-colour CISH and FISH and compared the results. Methods and results: We found 100% agreement between HER2 status determined by FISH and dual-colour CISH. Furthermore, we observed that the time used to score slides was significantly reduced by 28% in dual-colour CISH compared with the FISH protocol. Concordance between HER2 protein status and dual-colour CISH or FISH was equally good with an overall agreement of 96.8%. Correlation between the HER2/centromere 17 gene ratios obtained with dual-colour CISH and FISH was highly significant with an overall correlation coefficient (ρ) of 0.96. Conclusions: We conclude that dual-colour CISH and bright field microscopy are excellent alternatives to FISH when analysing the HER2 status of primary breast cancer. PMID:20459554

  18. Fluorescent and chromogenic in situ hybridization of CEN17q as a potent useful diagnostic marker for Birt-Hogg-Dubé syndrome-associated chromophobe renal cell carcinomas.

    PubMed

    Kato, Ikuma; Iribe, Yasuhiro; Nagashima, Yoji; Kuroda, Naoto; Tanaka, Reiko; Nakatani, Yukio; Hasumi, Hisashi; Yao, Masahiro; Furuya, Mitsuko

    2016-06-01

    Birt-Hogg-Dubé syndrome (BHD) is a familial disorder associated with a germline mutation of FLCN that is a tumor suppressor gene. Patients with BHD have high risks for developing multiple renal cell carcinomas (RCCs). The frequent histological types are hybrid oncocytic/chromophobe tumors (HOCTs) and chromophobe RCCs. The morphology of HOCTs could alert pathologists to the possibility of BHD. On the other hand, chromophobe RCCs occurring in BHD patients demonstrate positive immunostaining for cytokeratin-7, CD82, and Ksp-cadherin similar to their sporadic counterparts. Highly reliable markers for BHD-associated chromophobe RCCs have not been identified. In the present study, we analyzed the state of chromosome 17 in 18 renal tumors composed of 8 chromophobe RCCs, 7 HOCTs, and 3 papillary RCCs obtained from BHD patients using fluorescent and chromogenic in situ hybridization probes for the centromeric region of chromosome 17 long arm. All chromophobe RCCs and HOCTs were disomic except for 1 chromophobe RCC that showed monosomy. On the other hand, 12 of 14 sporadic chromophobe RCCs were monosomic (P = .0008). The state of chromosomes 2 and 6 were also statistically different (P = .0074 and P = .0007, respectively). Three BHD-associated papillary RCCs demonstrated either trisomy (n = 2) or disomy (n = 1). Three of 5 sporadic papillary RCCs showed trisomy. The results indicate that fluorescent and chromogenic in situ hybridization of the centromeric region of chromosome 17 long arm should be a potent useful marker for chromophobe RCCs in patients who have not been diagnosed with BHD and thereby help to determine whether the cases should be considered for genetic testing. PMID:26980015

  19. Compounding in Ukraine.

    PubMed

    Zdoryk, Oleksandr A; Georgiyants, Victoriya A; Gryzodub, Oleksandr I; Schnatz, Rick

    2013-01-01

    Pharmaceutical compounding in modern Ukraine has a rich history and goes back to ancient times. Today in the Ukraine, there is a revival of compounding practice, the opening of private compounding pharmacies, updating of legislative framework and requirements of the State Pharmacopeia of Ukraine for compounding preparations, and the introduction of Good Pharmaceutical Practice. PMID:23696172

  20. Compounds affecting cholesterol absorption

    NASA Technical Reports Server (NTRS)

    Hua, Duy H. (Inventor); Koo, Sung I. (Inventor); Noh, Sang K. (Inventor)

    2004-01-01

    A class of novel compounds is described for use in affecting lymphatic absorption of cholesterol. Compounds of particular interest are defined by Formula I: ##STR1## or a pharmaceutically acceptable salt thereof.

  1. Dinitroso and polynitroso compounds

    PubMed Central

    Gowenlock, Brian G.; Richter-Addo, George B.

    2005-01-01

    The growing interest in the chemistry of C-nitroso compounds (RN=O; R = alkyl or aryl group) is due in part to the recognition of their participation in various metabolic processes of nitrogen-containing compounds. C-Nitroso compounds have a rich organic chemistry in their own right, displaying interesting intra- and intermolecular dimerization processes and addition reactions with unsaturated compounds. In addition, they have a fascinating coordination chemistry. While most of the attention has been directed towards C-nitroso compounds containing a single –NO moiety, there is an emerging area of research dealing with dinitroso and polynitroso compounds. In this critical review, we present and discuss the synthetic routes and properties of these relatively unexplored dinitroso and polynitroso compounds, and suggest areas of further development involving these compounds. (126 references.) PMID:16100619

  2. Caulking compound poisoning

    MedlinePlus

    Caulking compounds are substances used to seal cracks and holes around windows and other openings. Caulking compound poisoning occurs when someone swallows these substances. This is for information only and not for use in the ...

  3. A new selective chromogenic reagent for the spectrophotometric determination of thallium(I) and (III) and its separation using flotation and the solid-phase extraction on polyurethane foam.

    PubMed

    Abou-El-Sherbini, Khaled S; Mostafa, Gamal A E; Hassanien, Mohamed M

    2003-09-01

    A new sensitive chromogenic reagent, 9,10-phenanthaquinone monoethylthiosemicarbazone (PET), has been synthesized and used in the spectrophotometric determination of Tl(III). In HNO3, H2SO4 or H3PO4 acids, PET can react immediately at room temperature with Tl(III) to form a red 2:1 complex with a maximum absorption at 516 nm. The different analytical parameters affecting the extraction and determination processes have been examined. The calibration curve was found to be linear over the range 0.2-10 microg cm(-3) with a molar absorptivity of 2.2 x 10(4) dm3 mol(-1) cm(-1). Sandell's sensitivity was found to be 0.0093 microg cm(-2). No interference from macroamounts of foreign ions was detected, except for Pd(II). However, Pd(II) does not affect the determination process, because its complex with PET has its lambda(max) at 625 nm. The proposed method has been applied to the determination of Tl(I and III) in synthetic and natural samples after separation by flotation (in oleic acid/kerosene) and solid-phase extraction (on polyurethane foam) techniques. The two methods were found to be accurate and not subject to random error, but solid-phase extraction was preferred because it is cheap, simpler and there is no contamination risk coming from flotation reagents. PMID:14516078

  4. N-ethoxycarbonyl-D-phenylalanyl-L-prolyl-alpha-azalysine p-nitrophenyl ester: a novel, high selective and optimal chromogenic active site titrant for human and bovine alpha-, beta- and gamma-thrombin.

    PubMed

    Balliano, G; Milla, P; Giordano, C; Gallina, C; Coletta, M; Menegatti, E; Rizzi, M; Bolognesi, M; Ascenzi, P

    1996-08-14

    The serine proteinase catalyzed hydrolysis of N-ethoxycarbonyl-D-phenylalanyl-L-prolyl-alpha-azalysine p- nitrophenyl ester (Eoc-D-Phe-Pro-azaLys-ONp) was investigated at pH 6.2 and 21.0 degrees C. The results are consistent with the minimum three-step catalytic mechanism. The acylation step is rate limiting for human (Lys 77 species) and porcine plasmin, and for bovine beta-trypsin, the deacylation rate being limiting, on the other hand, for human and bovine alpha-, beta- and gamma-thrombin. Moreover the M(r) 33,000 species of human urokinase and the neuraminidase-treated porcine pancreatic beta-kallikrein-B do not catalyze the hydrolysis of the tripeptide. According to the specificity properties of the serine proteinases considered. Eoc-D-Phe- Pro-azaLys-ONp shows the characteristics of a novel, high selective and optimal chromogenic active site titrant for human and bovine alpha-, beta- and gamma-thrombin. PMID:8753800

  5. Multiplex PCR and a chromogenic DNA macroarray for the detection of Listeria monocytogens, Staphylococcus aureus, Streptococcus agalactiae, Enterobacter sakazakii, Escherichia coli O157:H7, Vibrio parahaemolyticus, Salmonella spp. and Pseudomonas fluorescens in milk and meat samples.

    PubMed

    Chiang, Yu-Cheng; Tsen, Hau-Yang; Chen, Hsin-Yen; Chang, Yu-Hsin; Lin, Chien-Ku; Chen, Chih-Yuan; Pai, Wan-Yu

    2012-01-01

    Food products, such as milk and meat products including cheese, milk powder, fermented milk, sausage, etc. are susceptible to the contamination by pathogenic and deteriorative bacteria. These bacteria include Listeria monocytogens, Staphylococcus aureus, Enterobacter sakazakii, Escherichia coli O157:H7, Salmonella spp., Vibrio parahaemolyticus, Streptococcus agalactiae and Pseudomonas fluorescens, etc. Traditional methods for the detection of these microorganisms are laborious and time consuming. Therefore, rapid and accurate diagnostic methods are needed. In this study, we designed the DNA probes and PCR primers for the detection of aforementioned microorganisms. By using two sets of multiplex PCR, followed by a chromogenic macroarray system, these organisms in milk or other food products could be simultaneously detected. When the system was used for the inspection of milk or meat homogenate containing 10(0) target cells per milliliter or gram of the sample, all these bacterial species could be identified after an 8h pre-enrichment step. The system consisting of a multiplex PCR step followed by macroarray allowed us to detect multiple target bacterial species simultaneously without the use of agarose gel electrophoresis. Compared to the commonly used multiplex PCR method, this approach has the additional advantage of detecting more bacterial strains because some bacterial strains generate PCR products with the same molecular sizes which can be differentiated by macroarray but not by electrophoresis. PMID:22101309

  6. Production of epoxy compounds from olefinic compounds

    SciTech Connect

    Gelbein, A.P.; Kwon, J.T.

    1985-01-29

    Chlorine and tertiary alkanol dissolved in an inert organic solvent are reacted with aqueous alkali to produce tertiary alkyl hypochlorite which is recovered in the organic solvent and reacted with water and olefinically unsaturated compound to produce chlorohydrin and tertiary alkanol. Chlorohydrin and tertiary alkanol recovered in the organic solvent are contacted with aqueous alkali to produce the epoxy compound, and tertiary alkanol recovered in the organic solvent is recycled to hypochlorite production. The process may be integrated with the electrolytic production of chlorine, with an appropriate treatment of the recycle aqueous stream when required.

  7. XAFS Model Compound Library

    DOE Data Explorer

    Newville, Matthew

    The XAFS Model Compound Library contains XAFS data on model compounds. The term "model" compounds refers to compounds of homogeneous and well-known crystallographic or molecular structure. Each data file in this library has an associated atoms.inp file that can be converted to a feff.inp file using the program ATOMS. (See the related Searchable Atoms.inp Archive at http://cars9.uchicago.edu/~newville/adb/) This Library exists because XAFS data on model compounds is useful for several reasons, including comparing to unknown data for "fingerprinting" and testing calculations and analysis methods. The collection here is currently limited, but is growing. The focus to date has been on inorganic compounds and minerals of interest to the geochemical community. [Copied, with editing, from http://cars9.uchicago.edu/~newville/ModelLib/

  8. Ecotoxicology of organofluorous compounds.

    PubMed

    Murphy, Margaret B; Loi, Eva I H; Kwok, Karen Y; Lam, Paul K S

    2012-01-01

    Organofluorous compounds have been developed for myriad purposes in a variety of fields, including manufacturing, industry, agriculture, and medicine. The widespread use and application of these compounds has led to increasing concern about their potential ecological toxicity, particularly because of the stability of the C-F bond, which can result in chemical persistence in the environment. This chapter reviews the chemical properties and ecotoxicology of four groups of organofluorous compounds: fluorinated refrigerants and propellants, per- and polyfluorinated compounds (PFCs), fluorinated pesticides, and fluoroquinolone antibiotics. These groups vary in their environmental fate and partitioning, but each raises concern in terms of ecological risk on both the regional and global scale, particularly those compounds with long environmental half-lives. Further research on the occurrence and toxicities of many of these compounds is needed for a more comprehensive understanding of their ecological effects. PMID:21952849

  9. Preparation of uranium compounds

    DOEpatents

    Kiplinger, Jaqueline L; Montreal, Marisa J; Thomson, Robert K; Cantat, Thibault; Travia, Nicholas E

    2013-02-19

    UI.sub.3(1,4-dioxane).sub.1.5 and UI.sub.4(1,4-dioxane).sub.2, were synthesized in high yield by reacting turnings of elemental uranium with iodine dissolved in 1,4-dioxane under mild conditions. These molecular compounds of uranium are thermally stable and excellent precursor materials for synthesizing other molecular compounds of uranium including alkoxide, amide, organometallic, and halide compounds.

  10. Nitrodifluoraminoterphenyl compounds and processes

    DOEpatents

    Lerom, M.W.; Peters, H.M.

    1975-07-08

    This patent relates to the nitrodifluoraminoterphenyl compounds: 3,3''-bis (difluoramino)-2,2'' 4,4', 4'',6,6',6''-octanitro-m-terphenyl (DDONT) and 3,3''-bis(difluoramino)-2,2',2''4,4',4'',6,6',6''-nonanitro-m-terphenyl (DDNONA). Procedures are described wherein diamino precursors of the indicated compounds are prepared and the final compounds are obtained by a fluorination operation. The compounds are highly energetic and suitable for use as explosives and particularly in exploding bridge wire (EBW) detonators. (auth)

  11. Chromogenic in situ hybridization to detect EGFR gene copy number in cell blocks from fine-needle aspirates of non small cell lung carcinomas and lung metastases from colo-rectal cancer

    PubMed Central

    2010-01-01

    Background Several studies demonstrated that epidermal growth factor receptor (EGFR) gene copy number (GCN) correlates to the response to tyrosine kinase inhibitors in non small cell lung cancer (NSCLC) and to anti-EGFR monoclonal antibodies (MoAbs) in metastatic colorectal cancer (CRC). In the presence of lung nodules, cytology is often the only possible diagnostic approach. Chromogenic in situ hybridization (CISH) is an alternative technique to fluorescence in situ hybridization (FISH), but its feasibility in detecting EGFR GCN in cell blocks from fine-needle aspiration cytology (FNAC) of lung nodules has not yet been established. Methods We evaluated the feasibility of CISH on 33 FNAC from 20 primary NSCLC (5 squamous carcinomas, 8 large cell carcinomas and 7 adenocarcinomas) and 13 lung metastases from CRC. Results Of the 33 FNAC analyzed by CISH, 27 (82%) presented a balanced increase in EGFR gene and chromosome 7 number: 10 cases (30%) showed a low polysomy, 15 (45%) a high polysomy and 2 (6%) NSCLC were amplified. No significant differences between NSCLC and CRC lung metastases were found in relation to disomic or polysomic status. In addition, no correlation between EGFR GCN and EGFR immunohistochemical overexpression was found. Furthermore, we compared CISH results with those obtained by FISH on the same samples and we found 97% overall agreement between the two assays (k = 0.78, p < 0.0001). Two cases were amplified with both assays, whereas 1 case of NSCLC was amplified by FISH only. CISH sensitivity was 67%, the specificity and positive predictive value (PPV) was 100%, and the negative predictive value (NPV) was 97%. Conclusions Our study shows that CISH is a valid method to detect EGFR GCN in cell blocks from FNAC of primary NSCLC or metastatic CRC to the lung. PMID:20843314

  12. Comparison of Sorbitol MacConkey Agar and a Two-Step Method Which Utilizes Enzyme-Linked Immunosorbent Assay Toxin Testing and a Chromogenic Agar To Detect and Isolate Enterohemorrhagic Escherichia coli

    PubMed Central

    Novicki, Thomas J.; Daly, Judy A.; Mottice, Susan L.; Carroll, Karen C.

    2000-01-01

    Enterohemorrhagic Escherichia coli (EHEC) and specifically serotype O157:H7 are a significant cause of hemorrhagic gastrointestinal disease and the hemolytic uremic syndrome. Methods currently used in clinical microbiology labs, such as sorbitol-MacConkey (SMAC) agar, reliably detect only O157:H7. We have evaluated a two-step method that has the potential to identify and isolate all EHEC serotypes, including serotype O157:H7. This method utilizes a chromogenic selective-differential medium for the isolation of E. coli together with an enzyme-linked immunosorbent assay (ELISA) that detects the Shiga-like toxins Stx1 and Stx2. Both are commercially available and usable in a wide range of clinical microbiology laboratories. Compared to a Vero cell cytotoxic assay, SMAC had sensitivities of 23.5% for the identification of all EHEC serotypes and of 50.0% for the identification of O157:H7 alone. The two-step method had sensitivities of 76.5 and 100%, respectively. The ELISA alone had a sensitivity of 82.4% in the detection of Stx1 and Stx2. The specificity was 100% in all cases. Overall, 14 EHEC isolates were obtained: 8 (58%) O157:H7, 2 (14%) O26, 2 (14%) O111:NM, 1 (7%) O103:H2, and 1 (7%) O121:H19. All but one were isolated during the months of May to September. The two-step method was found to be considerably more expensive than SMAC for both positive and negative samples. PMID:10655343

  13. Anti-Fog Compound

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Tracer Chemical Corporation's TRX Anti-Fog Composition is an inexpensive product which prevents condensation on plastic and glass surfaces. It was the result from a Tech Briefs article detailing a Johnson Space Center compound.

  14. Stabilized Lanthanum Sulphur Compounds

    NASA Technical Reports Server (NTRS)

    Reynolds, George H. (Inventor); Elsner, Norbert B. (Inventor); Shearer, Clyde H. (Inventor)

    1985-01-01

    Lanthanum sulfide is maintained in the stable cubic phase form over a temperature range of from 500 C to 1500 C by adding to it small amounts of calcium, barium. or strontium. This novel compound is an excellent thermoelectric material.

  15. Heart testing compound

    DOEpatents

    Knapp, Jr., Furn F.; Goodman, Mark M.

    1985-01-01

    The compound 15-(p-[.sup.125 I]-iodophenyl)-6-tellurapentadecanoic acid is disclosed as a myocardial imaging agent having rapid and pronounced uptake, prolonged myocardial retention, and low in vivo deiodination.

  16. Heart testing compound

    DOEpatents

    Knapp, F.F. Jr.; Goodman, M.M.

    1983-06-29

    The compound 15-(p-(/sup 125/I)-iodophenyl)-6-tellurapentadecanoic acid is disclosed as a myocardial imaging agent having rapid and pronounced uptake, prolonged myocardial retention, and low in vivo deiodination.

  17. Compounding a Problem?

    PubMed

    Berlin, Joey

    2016-01-01

    Allergist-immunologists say a U.S. Pharmacopeia proposal will mess with an allergy treatment system that's worked for more than a century. The revised standards, if adopted, would remove a key exemption separating allergen extract preparations from the stricter requirements of other compounds. Immunologists say the exemption has allowed them to compound allergen extracts in their own offices, and they've done so safely and effectively millions of times a year. PMID:27175928

  18. Chemistry of peroxide compounds

    NASA Technical Reports Server (NTRS)

    Volnov, I. I.

    1981-01-01

    The history of Soviet research from 1866 to 1967 on peroxide compounds is reviewed. This research dealt mainly with peroxide kinetics, reactivity and characteristics, peroxide production processes, and more recently with superoxides and ozonides and emphasis on the higher oxides of group 1 and 2 elements. Solid state fluidized bed synthesis and production of high purity products based on the relative solubilities of the initial, intermediate, and final compounds and elements in liquid ammonia are discussed.

  19. Compound composite odontoma

    PubMed Central

    Girish, G; Bavle, Radhika M; Singh, Manish Kumar; Prasad, Sahana N

    2016-01-01

    The term odontoma has been used as a descriptor for any tumor of odontogenic origin. It is a growth in which both epithelial and mesenchymal cells exhibits complete differentiation. Odontomas are considered as hamartomas rather than true neoplasm. They are usually discovered on routine radiographic examination. Odontomas, according to the World Health Organization, are classified into complex odontoma and compound odontomas. The present paper reports a case of compound composite odontomas. PMID:27194882

  20. Compound composite odontoma.

    PubMed

    Girish, G; Bavle, Radhika M; Singh, Manish Kumar; Prasad, Sahana N

    2016-01-01

    The term odontoma has been used as a descriptor for any tumor of odontogenic origin. It is a growth in which both epithelial and mesenchymal cells exhibits complete differentiation. Odontomas are considered as hamartomas rather than true neoplasm. They are usually discovered on routine radiographic examination. Odontomas, according to the World Health Organization, are classified into complex odontoma and compound odontomas. The present paper reports a case of compound composite odontomas. PMID:27194882

  1. Phenolic Molding Compounds

    NASA Astrophysics Data System (ADS)

    Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

    Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

  2. Understanding medication compounding issues.

    PubMed

    Hicks, Rodney W

    2014-04-01

    The potential for contamination of compounded products and the resulting infections are a serious threat to patient safety. Immediate use products are used frequently in the perioperative department, and perioperative nurses should be familiar with the guidelines and practices that aim to reduce the contamination that can occur during the sterile compounding process. Four common themes lead to successful compounding: quality (eg, product identification, purity, stability, compatibility, risk level assessment), the environment (eg, using a segregated compounding area with specialized airflow capabilities, reducing particulate matter, practicing proper hand hygiene, performing gloved fingertip sampling, properly cleaning equipment and work areas), personnel activities (eg, familiarity with types of containers used and how often they can be accessed, following expiration dates and the number of times containers can be accessed), and the control process (eg, process monitoring, quality improvement). If a third-party vendor is contracted to handle compounding for a facility, perioperative personnel should be aware of the responsibilities for the facility and the vendor to ensure a quality compounding program. PMID:24674793

  3. Nonpost mold cure compound

    NASA Astrophysics Data System (ADS)

    Hirata, Akihiro

    1997-08-01

    The recent low price trend of electronic products has made IC manufacturing efficiency a top priority in the semiconductor industry. Post mold cure (PMC) process, which generally involves heating the packages in the oven at 175 C for 4 to 8 hours, takes up much longer time than most other assembly processes. If this PMC process can be reduced or eliminated, semiconductor makers will be rewarded with a much higher cost merit. We define the purpose of Non-PMC as 'to get high reliability with suitable physical and electrical properties without PMC'. We compared carious properties of molding compound before and after PMC. We found that curing reaction has almost complete through DSC and C-NMR measurement, but several properties have not stabilized yet, and that not all properties after PMC were better than before PMC. We developed new grade of molding compound considering these facts. And we found that main factors to accomplish non-PMC compound are curability and flowability, and more, increasing of fundamental properties. To accomplish non-PMC, at first, molding compound need to have very high curability. Generally speaking, too high curability causes low flowability, and causes incomplete filing, wire sweep, pad shift, and weak adhesion to inner parts of IC packages. To prevent these failures, various compound properties were studied, and we achieved in adding good flowability to very high curable molding compound. Finally, anti-popcorn property was improved by adding low moisture, high adhesion, high Tg, and high flexural strengths at high temperature. Through this study, we developed new compound grade for various package, especially large QFP using standard ECN resin.

  4. An interlaboratory study on efficient detection of Shiga toxin-producing Escherichia coli O26, O103, O111, O121, O145, and O157 in food using real-time PCR assay and chromogenic agar.

    PubMed

    Hara-Kudo, Yukiko; Konishi, Noriko; Ohtsuka, Kayoko; Iwabuchi, Kaori; Kikuchi, Rie; Isobe, Junko; Yamazaki, Takumiko; Suzuki, Fumie; Nagai, Yuhki; Yamada, Hiroko; Tanouchi, Atsuko; Mori, Tetsuya; Nakagawa, Hiroshi; Ueda, Yasufumi; Terajima, Jun

    2016-08-01

    To establish an efficient detection method for Shiga toxin (Stx)-producing Escherichia coli (STEC) O26, O103, O111, O121, O145, and O157 in food, an interlaboratory study using all the serogroups of detection targets was firstly conducted. We employed a series of tests including enrichment, real-time PCR assays, and concentration by immunomagnetic separation, followed by plating onto selective agar media (IMS-plating methods). This study was particularly focused on the efficiencies of real-time PCR assays in detecting stx and O-antigen genes of the six serogroups and of IMS-plating methods onto selective agar media including chromogenic agar. Ground beef and radish sprouts samples were inoculated with the six STEC serogroups either at 4-6CFU/25g (low levels) or at 22-29CFU/25g (high levels). The sensitivity of stx detection in ground beef at both levels of inoculation with all six STEC serogroups was 100%. The sensitivity of stx detection was also 100% in radish sprouts at high levels of inoculation with all six STEC serogroups, and 66.7%-91.7% at low levels of inoculation. The sensitivity of detection of O-antigen genes was 100% in both ground beef and radish sprouts at high inoculation levels, while at low inoculation levels, it was 95.8%-100% in ground beef and 66.7%-91.7% in radish sprouts. The sensitivity of detection with IMS-plating was either the same or lower than those of the real-time PCR assays targeting stx and O-antigen genes. The relationship between the results of IMS-plating methods and Ct values of real-time PCR assays were firstly analyzed in detail. Ct values in most samples that tested negative in the IMS-plating method were higher than the maximum Ct values in samples that tested positive in the IMS-plating method. This study indicates that all six STEC serogroups in food contaminated with more than 29CFU/25g were detected by real-time PCR assays targeting stx and O-antigen genes and IMS-plating onto selective agar media. Therefore, screening

  5. Sulfur compounds in coal

    NASA Technical Reports Server (NTRS)

    Attar, A.; Corcoran, W. H.

    1977-01-01

    The literature on the chemical structure of the organic sulfur compounds (or functional groups) in coal is reviewed. Four methods were applied in the literature to study the sulfur compounds in coal: direct spectrometric and chemical analysis, depolymerization in drastic conditions, depolymerization in mild conditions, and studies on simulated coal. The data suggest that most of the organic sulfur in coal is in the form of thiophenic structures and aromatic and aliphatic sulfides. The relative abundance of the sulfur groups in bituminous coal is estimated as 50:30:20%, respectively. The ratio changes during processing and during the chemical analysis. The main effects are the transformation during processing of sulfides to the more stable thiophenic compounds and the elimination of hydrogen sulfide.

  6. Compound management beyond efficiency.

    PubMed

    Burr, Ian; Winchester, Toby; Keighley, Wilma; Sewing, Andreas

    2009-06-01

    Codeveloping alongside chemistry and in vitro screening, compound management was one of the first areas in research recognizing the need for efficient processes and workflows. Material management groups have centralized, automated, miniaturized and, importantly, found out what not to do with compounds. While driving down cost and improving quality in storage and processing, researchers still face the challenge of interfacing optimally with changing business processes, in screening groups, and with external vendors and focusing on biologicals in many companies. Here we review our strategy to provide a seamless link between compound acquisition and screening operations and the impact of material management on quality of the downstream processes. Although this is driven in part by new technologies and improved quality control within material management, redefining team structures and roles also drives job satisfaction and motivation in our teams with a subsequent positive impact on cycle times and customer feedback. PMID:19502566

  7. Metalloid compounds as drugs

    PubMed Central

    Sekhon, B. S.

    2013-01-01

    The six elements commonly known as metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium. Metalloid containing compounds have been used as antiprotozoal drugs. Boron-based drugs, the benzoxaboroles have been exploited as potential treatments for neglected tropical diseases. Arsenic has been used as a medicinal agent and arsphenamine was the main drug used to treat syphilis. Arsenic trioxide has been approved for the treatment of acute promyelocytic leukemia. Pentavalent antimonials have been the recommended drug for visceral leishmaniasis and cutaneous leishmaniasis. Tellurium (IV) compounds may have important roles in thiol redox biological activity in the human body, and ammonium trichloro (dioxoethylene-O, O’-)tellurate (AS101) may be a promising agent for the treatment of Parkinson’s disease. Organosilicon compounds have been shown to be effective in vitro multidrug-resistance reverting agents. PMID:24019824

  8. Microoptical compound lens

    DOEpatents

    Sweatt, William C.; Gill, David D.

    2007-10-23

    An apposition microoptical compound lens comprises a plurality of lenslets arrayed around a segment of a hollow, three-dimensional optical shell. The lenslets collect light from an object and focus the light rays onto the concentric, curved front surface of a coherent fiber bundle. The fiber bundle transports the light rays to a planar detector, forming a plurality of sub-images that can be reconstructed as a full image. The microoptical compound lens can have a small size (millimeters), wide field of view (up to 180.degree.), and adequate resolution for object recognition and tracking.

  9. Analyzing cranberry bioactive compounds.

    PubMed

    Côté, J; Caillet, S; Doyon, G; Sylvain, J-F; Lacroix, M

    2010-10-01

    There is a growing public interest for the North American cranberry (Vaccinium macrocarpon) as a functional food because of the potential health benefits linked to phytochemical compounds present in the fruit--the anthocyanin pigments, responsible for its brilliant red color, and other secondary plant metabolites (flavonols, flavan-3-ols, proanthocyanidins, and phenolic acid derivatives). Isolation of these phenolic compounds and flavonoids from a sample matrix is a prerequisite to any comprehensive analysis scheme. By far the most widely employed analytical technique for the characterization of these compounds has been high-performance liquid chromatography(HPLC) coupled with ultraviolet-visible(UV/Vis) and mass spectrometer(MS) detection. This review covers the cranberry major bioactive compounds, the extraction and purification methods, and the analytical conditions for HPLC used to characterize them. Extraction, chromatographic separation and detection strategies, analyte determinations, and applications in HPLC are discussed and the information regarding methods of specific cranberry analyte analyses has been summarized in tabular form to provide a means of rapid access to information pertinent to the reader. PMID:20924868

  10. Aminopropyl thiophene compounds

    DOEpatents

    Goodman, Mark M.; Knapp, Jr., Furn F.

    1990-01-01

    Radiopharmaceuticals useful in brain imaging comprising radiohalogenated thienylethylamine derivatives. The compounds are 5-halo-thiophene-2-isopropyl amines able to cross the blood-brain barrier and be retained for a sufficient length of time to allow the evaluation of regional blood flow by radioimaging of the brain.

  11. PERSISTENT PERFLUORINATED ORGANIC COMPOUNDS

    EPA Science Inventory

    Perfluorinated compounds (PFCs) have gained notoriety in the recent past. Global distribution of PFCs in wildlife, environmental samples and humans has sparked a recent increase in new investigations concerning PFCs. Historically PFCs have been used in a wide variety of consume...

  12. Zinc and Compounds

    Integrated Risk Information System (IRIS)

    Zinc and Compounds ; CASRN 7440 - 66 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  13. Boron and Compounds

    Integrated Risk Information System (IRIS)

    Boron and Compounds ; CASRN 7440 - 42 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  14. Lead and compounds (inorganic)

    Integrated Risk Information System (IRIS)

    Lead and compounds ( inorganic ) ; CASRN 7439 - 92 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for

  15. Barium and Compounds

    Integrated Risk Information System (IRIS)

    Barium and Compounds ; CASRN 7440 - 39 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  16. Beryllium and compounds

    Integrated Risk Information System (IRIS)

    Beryllium and compounds ; CASRN 7440 - 41 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  17. Selenium and Compounds

    Integrated Risk Information System (IRIS)

    Selenium and Compounds ; CASRN 7782 - 49 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  18. 8-fluoropurine compounds

    DOEpatents

    Barrio, Jorge R.; Satyamurthy, Nagichettiar; Namavari, Mohammad; Phelps, Michael E.

    2001-01-01

    An efficient, regiocontrolled approach to the synthesis of 8-fluoropurines by direct fluorination of purines with dilute elemental fluorine, or acetyl hypofluorite, is provided. In a preferred embodiment, a purine compound is dissolved in a polar solvent and reacted with a dilute mixture of F.sub.2 in He or other inert gas.

  19. Urinary Compounds in Autism

    ERIC Educational Resources Information Center

    Alcorn, A.; Berney, T.; Bretherton, K.; Mills, M.; Savery, D.; Shattock, P.

    2004-01-01

    Although earlier claims to identify specific compounds in the urine of people with autism had been discredited, it was subsequently suggested that there might be biochemical characteristics that were specific to early childhood, particularly in those who also did not have a severe degree of intellectual disability This study was to establish…

  20. Aminopropyl thiophene compounds

    SciTech Connect

    Goodman, M.M.; Knapp, F.F.

    1990-04-03

    This patent describes radiopharmaceuticals useful in brain imaging comprising radiohalogenated thienylethylamine derivatives. The compounds are 5-halo-thiophene-2-isopropyl amines able to cross the blood-brain barrier and be retained for a sufficient length of time to allow the evaluation of regional blood flow by radioimaging of the brain.

  1. Fun with Ionic Compounds

    ERIC Educational Resources Information Center

    Logerwell, Mollianne G.; Sterling, Donna R.

    2007-01-01

    Ionic bonding is a fundamental topic in high school chemistry, yet it continues to be a concept that students struggle to understand. Even if they understand atomic structure and ion formation, it can be difficult for students to visualize how ions fit together to form compounds. This article describes several engaging activities that help…

  2. The Onium Compounds

    NASA Astrophysics Data System (ADS)

    Tsarevsky, Nicolay V.; Slaveykova, Vera; Manev, Stefan; Lazarov, Dobri

    1997-06-01

    The onium salts are of a big interest for theoretical and structural chemistry, and for organic synthesis. Some representatives of the group (e.g. ammonium salts) were known from the oldest times. Many onium salts are met the nature: ammonium salts (either as inorganic salts, and organic derivatives, e.g. aminoacids, salts of biogenic amines and alkaloids, etc.); oxonium salts (plant pigments as anthocyans are organic oxonium compounds), etc. In 1894 C. Hartmann and V. Meyer prepared the first iodonium salts - 4-iododiphenyliodonium hydrogensulfate and diphenyliodonium salts, and suggested the ending -onium for all compounds with properties similar to those of ammonium salts. Nowadays onium compounds of almost all nonmetals are synthesised and studied. A great variety of physical methods: diffraction (e.g. XRD) and spectral methods (IR-, NMR-, and UV-spectra), as well as the chemical properties and methods of preparation of onium salts have been used in determination of the structure of these compounds. The application of different onium salts is immense. Ammonium, phosphonium and sulfonium salts are used as phase-transfer catalysts; diazonium salts - for the preparation of dyes, metalochromic and pH-indicators. All the onium salts and especially diazonium and iodonium salts are very useful reagents in organic synthesis.

  3. Noun Compounding in Thai.

    ERIC Educational Resources Information Center

    Fasold, Ralph William August

    The present study, a slightly revised version of the author's 1968 Ph.D. thesis presented to the University of Chicago, investigates compound formation in Thai. Chapter 1 summarizes the transformational generative theory on which the study is based, discusses the concept that Thai is a "simple" language in comparison with English, and briefly…

  4. Compound floating pivot micromechanisms

    DOEpatents

    Garcia, Ernest J.

    2001-04-24

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

  5. Electroactive polymers in large area chromogenics

    SciTech Connect

    Inganaes, O.

    1990-12-31

    The synthesis of highly conducting polyacetylene in the late seventies inaugurated an era of extensive studies of electronic structure and transport in organic polymers. The recent attainment of conductivities in metallic polyacetylene comparable to that of copper is the outcome of major advances in the theoretical understanding and chemical synthesis of these materials. In parallel to this quest for understanding of the electronic properties of one-dimensional organic polymers, there has also been an active search for applications of these materials. A few applications are now reaching extensive use, among which should be mentioned polymer secondary batteries exploiting polymer materials as electrodes. Many new techniques for preparing the conductive polymers in forms suited for practical application have been proposed. For application as conductive coatings, antistatic surface treatments and electromagnetic shielding, practical use can be foreseen in the near future. One of the applications that has received considerable study, electrochromic devices utilizing electroactive polymers as active materials, has not reached that stage of maturity yet. In this short review, the authors present the basic physics of electrochromism in electroactive polymers, also named conductive polymers; point out the requirements for use of electroactive polymers in electrochromic devices (which includes displays, smart windows and electrooptical modulators); and describe some of the materials and processing aspects that are of particular relevance with reference to thin film technology.

  6. Nature of chromogens of protonated azobenzene

    NASA Astrophysics Data System (ADS)

    Mikheev, Yu. A.; Guseva, L. N.; Ershov, Yu. A.

    2015-02-01

    Changes in the absorption spectra of azobenzene in UV-Vis light are studied with respect to its protonation in sulfuric acid solutions and interaction with gaseous HCl in cellulose triacetate films. In both processes, the emergence of an intense orange color is shown to represent the electronic structure of forming monocations where the positive charge of NH+ groups shifts electrons from the o- and p-positions of Nphfragment phenyls. It was found that the charge distribution and color was the same as observed for the cations of the benzyl and phenylaminyl types. The mechanism of azobenzene monocation photocyclization in sulfuric acid is presented, and the origin of the red color of azobenzene dications formed in oleum is explained.

  7. Photofunctions of intercalation compounds

    SciTech Connect

    Ogawa, Makoto; Kuroda, Kazuyuki

    1995-03-01

    In this article, the authors review the studies on the photofunctions of intercalation compounds. (The structures and properties of host materials which have been used for immobilizing photoactive species have been summarized in the following section.) some of these studies are for the purpose of characterizing the properties of host materials and host-guest systems, and others are for the purpose of contributing to future practical applications. The well-defined layered structures as well as the ability to accommodate guest species on the surface of the layers are very useful for organizing photoactive species to evaluate and control the photofunctions. Table 1 summarizes the characteristics of typical host-guest systems studied for immobilizing photoactive species. Attention is mainly focused on the role of layered structure on the organization of photoactive species; the photofunctions of intercalation compounds are discussed only in connection with the microscopic structures. 321 refs.

  8. Arsonium compounds in algae

    PubMed Central

    Benson, A. A.

    1989-01-01

    Search for a precursor of the arsenobetaine discovered in Western Australian rock lobster tail muscle has led to an algal metabolite of radioarsenate having the properties of a trimethylarsoniumriboside derivative of the major arsenicals of aquatic plants, dimethylarsinoylribosylglycerol, its sulfate ester, and the corresponding riboside of phosphatidylglycerol. Such an arsonium compound could serve as metabolic precursor of arsenobetaine, the innocuous arsenical component of many marine food products. The oceanic diatom, Chaetoceros gracilis, cultured in radioarsenate produced a compound whose chemical, chromatographic, and electrophoretic properties are described. It was found to be identical to the trimethylarsonium derivative synthesized from the major algal arsenical, 1-(5′-dimethylarsinoyl-5′-deoxyribosyl)glycerol-3-O -sulfate. PMID:16594059

  9. Organic compounds in meteorites

    NASA Technical Reports Server (NTRS)

    Lawless, J. G.

    1980-01-01

    Recent studies of carbonaceous chondrites provide evidence that certain organic compounds are indigenous and the result of an abiotic, chemical synthesis. The results of several investigators have established the presence of amino acids and precursors, mono- and dicarboxylic acids, N-heterocycles, and hydrocarbons as well as other compounds. For example, studies of the Murchison and Murray meteorites have revealed the presence of at least 40 amino acids with nearly equal abundances of D and L isomers. The population consists of both protein and nonprotein amino acids including a wide variety of linear, cyclic, and polyfunctional types. Results show a trend of decreasing concentration with increasing carbon number, with the most abundant being glycine (41 n Moles/g). These and other results to be reviewed provide persuasive support for the theory of chemical evolution and provide the only natural evidence for the protobiological subset of molecules from which life on earth may have arisen.

  10. Compound cycle engine program

    NASA Technical Reports Server (NTRS)

    Bobula, G. A.; Wintucky, W. T.; Castor, J. G.

    1986-01-01

    The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded power plant which combines the lightweight pressure rise capability of a gas turbine with the high efficiency of a diesel. When optimized for a rotorcraft, the CCE will reduce fuel burned for a typical 2 hr (plus 30 min reserve) mission by 30 to 40 percent when compared to a conventional advanced technology gas turbine. The CCE can provide a 50 percent increase in range-payload product on this mission. A program to establish the technology base for a Compound Cycle Engine is presented. The goal of this program is to research and develop those technologies which are barriers to demonstrating a multicylinder diesel core in the early 1990's. The major activity underway is a three-phased contract with the Garrett Turbine Engine Company to perform: (1) a light helicopter feasibility study, (2) component technology development, and (3) lubricant and material research and development. Other related activities are also presented.

  11. Antifungal Compounds from Cyanobacteria

    PubMed Central

    Shishido, Tânia K.; Humisto, Anu; Jokela, Jouni; Liu, Liwei; Wahlsten, Matti; Tamrakar, Anisha; Fewer, David P.; Permi, Perttu; Andreote, Ana P. D.; Fiore, Marli F.; Sivonen, Kaarina

    2015-01-01

    Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders. PMID:25871291

  12. Compound chondrules fused cold

    NASA Astrophysics Data System (ADS)

    Hubbard, Alexander

    2015-07-01

    About 4-5% of chondrules are compound: two separate chondrules stuck together. This is commonly believed to be the result of the two component chondrules having collided shortly after forming, while still molten. This allows high velocity impacts to result in sticking. However, at T ∼ 1100 K, the temperature below which chondrules collide as solids (and hence usually bounce), coalescence times for droplets of appropriate composition are measured in tens of seconds. Even at 1025 K, at which temperature theory predicts that the chondrules must have collided extremely slowly to have stuck together, the coalescence time scale is still less than an hour. These coalescence time scales are too short for the collision of molten chondrules to explain the observed frequency of compound chondrules. We suggest instead a scenario where chondrules stuck together in slow collisions while fully solid; and the resulting chondrule pair was subsequently briefly heated to a temperature in the range of 900-1025 K. In that temperature window the coalescence time is finite but long, covering a span of hours to a decade. This is particularly interesting because those temperatures are precisely the critical window for thermally ionized MRI activity, so compound chondrules provide a possible probe into that vital regime.

  13. Toxic compounds in honey.

    PubMed

    Islam, Md Nazmul; Khalil, Md Ibrahim; Islam, Md Asiful; Gan, Siew Hua

    2014-07-01

    There is a wealth of information about the nutritional and medicinal properties of honey. However, honey may contain compounds that may lead to toxicity. A compound not naturally present in honey, named 5-hydroxymethylfurfural (HMF), may be formed during the heating or preservation processes of honey. HMF has gained much interest, as it is commonly detected in honey samples, especially samples that have been stored for a long time. HMF is a compound that may be mutagenic, carcinogenic and cytotoxic. It has also been reported that honey can be contaminated with heavy metals such as lead, arsenic, mercury and cadmium. Honey produced from the nectar of Rhododendron ponticum contains alkaloids that can be poisonous to humans, while honey collected from Andromeda flowers contains grayanotoxins, which can cause paralysis of limbs in humans and eventually leads to death. In addition, Melicope ternata and Coriaria arborea from New Zealand produce toxic honey that can be fatal. There are reports that honey is not safe to be consumed when it is collected from Datura plants (from Mexico and Hungary), belladonna flowers and Hyoscamus niger plants (from Hungary), Serjania lethalis (from Brazil), Gelsemium sempervirens (from the American Southwest), Kalmia latifolia, Tripetalia paniculata and Ledum palustre. Although the symptoms of poisoning due to honey consumption may differ depending on the source of toxins, most common symptoms generally include dizziness, nausea, vomiting, convulsions, headache, palpitations or even death. It has been suggested that honey should not be considered a completely safe food. PMID:24214851

  14. Offset Compound Gear Drive

    NASA Technical Reports Server (NTRS)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  15. Special Risks of Pharmacy Compounding

    MedlinePlus

    ... Consumer Updates RSS Feed The Special Risks of Pharmacy Compounding Get Consumer Updates by E-mail Consumer ... page: A Troubling Trend What You Can Do Pharmacy compounding is a practice in which a licensed ...

  16. Immunomodulating compounds in Basidiomycetes

    PubMed Central

    Mizuno, Masashi; Nishitani, Yosuke

    2013-01-01

    Mushrooms are distinguished as important food containing immunomodulating and anticancer agents. These compounds belong mostly to polysaccharides especially β-d-glucans. Among them, β-1,3-glucan with side chain β-1,6-glucose residues have more important roles in immunomodulating and antitumor activities. In this review, we have introduced polysaccharide mainly from Lentinula edodes and Agaricus blazei Murill with immunomodulating and antitumor activities. In addition, the mechanism of activation of immune response and signal cascade are also reviewed. PMID:23704809

  17. Boronated porphyrin compounds

    DOEpatents

    Kahl, Stephen B.; Koo, Myoung-Seo

    1992-01-01

    A compound is described having the structure ##STR1## where R preferably is ##STR2## and most preferably R.sup.3 is a closo-carborane and R.sup.2 is --H, an alkyl or aryl having 1 to about 7 carbon atoms, This invention was made with Government support under NIH Grant No. CA-37961 awarded by the Department of Health and Human Services and under the Associated Universities Inc. Contract No. De-AC02-76CH00016 with the U.S. Department of Energy. The Government has rights in this invention.

  18. Boronated porphyrin compounds

    DOEpatents

    Kahl, S.B.; Koo, M.S.

    1992-09-22

    A compound is described having the structure ##STR1## where R preferably is ##STR2## and most preferably R.sup.3 is a closo-carborane and R.sup.2 is --H, an alkyl or aryl having 1 to about 7 carbon atoms, This invention was made with Government support under NIH Grant No. CA-37961 awarded by the Department of Health and Human Services and under the Associated Universities Inc. Contract No. De-AC02-76CH00016 with the U.S. Department of Energy. The Government has rights in this invention.

  19. Turbo compound engine

    SciTech Connect

    Okada, M.; Sekiyama, S.

    1988-06-07

    A turbo compound engine is described comprising: an engine having an exhaust gas passage and a crankshaft; a power turbine disposed in the exhaust gas passage so as to recover the exhaust gas energy; driving power transmission means for drivingly connecting the power turbine and the crankshaft so as to transmit the driving power; a fluid passage connected to a portion of the exhaust passage which lies between the power turbine and the engine; and fluid passage switching means for closing the exhaust passage upstream of the fluid passage while opening the fluid passage during exhaust braking.

  20. Oligosilanylated Antimony Compounds

    PubMed Central

    2015-01-01

    By reactions of magnesium oligosilanides with SbCl3, a number of oligosilanylated antimony compounds were obtained. When oligosilanyl dianions were used, either the expected cyclic disilylated halostibine was obtained or alternatively the formation of a distibine was observed. Deliberate formation of the distibine from the disilylated halostibine was achieved by reductive coupling with C8K. Computational studies of Sb–Sb bond energies, barriers of pyramidal inversion at Sb, and the conformational behavior of distibines provided insight for the understanding of the spectroscopic properties. PMID:25937691

  1. Titanium alkoxide compound

    DOEpatents

    Boyle, Timothy J.

    2007-08-14

    A titanium alkoxide composition is provided, as represented by the chemical formula (OC.sub.6H.sub.5N).sub.2Ti(OC.sub.6H.sub.5NH.sub.2).sub.2. As prepared, the compound is a crystalline substance with a hexavalent titanium atom bonded to two OC.sub.6H.sub.5NH.sub.2 groups and two OC.sub.6H.sub.5N groups with a theoretical molecular weight of 480.38, comprising 60.01% C, 5.04% H and 11.66% N.

  2. Compound allergy. An overview.

    PubMed

    Bashir, S J; Maibach, H I

    1997-04-01

    This review defines the term "compound allergy" in the context of new findings, and discusses evidence that allergenic reaction products have been identified. Material was gathered by searching Index Medicus and the Science Citation Index, and reviewing several standard texts. Issues regarding the validity of patch test results are addressed and we introduce the term "pseudocompound allergy" to cover cases of false-negative patch tests. We present new theories regarding the mechanisms by which new allergens are formed and a means of classification. PMID:9165199

  3. Thrombostatin FM compounds: direct thrombin inhibitors - mechanism of action in vitro and in vivo

    SciTech Connect

    Nieman, M T; Burke, F; Warnock, M; Zhou, Y; Sweigart, J; Chen, A; Ricketts, D; Lucchesi, B R; Chen, Z; Cera, E Di; Hilfinger, J; Kim, J S; Mosberg, H I; Schmaier, A H

    2008-04-29

    Novel pentapeptides called Thrombostatin FM compounds consisting mostly of D-isomers and unusual amino acids were prepared based upon the stable angiotensin converting enzyme breakdown product of bradykinin - RPPGF. These peptides are direct thrombin inhibitors prolonging the thrombin clotting time, activated partial thromboplastin time, and prothrombin time at ≥0.78, 1.6, and 1.6 μm, respectively. They competitively inhibit α-thrombin-induced cleavage of a chromogenic substrate at 4.4--8.2 μm. They do not significantly inhibit plasma kallikrein, factor (F) XIIa, FXIa, FIXa, FVIIa-TF, FXa, plasmin or cathepsin G. One form, FM19 [rOicPaF(p-Me)], blocks α-thrombin-induced calcium flux in fibroblasts with an IC50 of 6.9 ± 1.2 μm. FM19 achieved 100% inhibition of threshold α- or γ-thrombin-induced platelet aggregation at 8.4 ± 4.7 μm and 16 ± 4 μm, respectively. The crystal structure of thrombin in complex with FM19 shows that the N-terminal D-Arg retrobinds into the S1 pocket, its second residue Oic interacts with His-57, Tyr-60a and Trp-60d, and its C-terminal p-methyl Phe engages thrombin's aryl binding site composed of Ile-174, Trp-215, and Leu-99. When administered intraperitoneal, intraduodenal, or orally to mice, FM19 prolongs thrombin clotting times and delays carotid artery thrombosis. FM19, a low affinity reversible direct thrombin inhibitor, might be useful as an add-on agent to address an unmet need in platelet inhibition in acute coronary syndromes in diabetics and others who with all current antiplatelet therapy still have reactive platelets.

  4. Thrombostatin FM compounds: direct thrombin inhibitors – mechanism of action in vitro and in vivo

    PubMed Central

    Nieman, M. T.; Burke, F.; Warnock, M.; Zhou, Y.; Sweigart, J.; Chen, A.; Ricketts, D.; Lucchesi, B. R.; Chen, Z.; Di Cera, E.; Hilfinger, J.; Kim, J. S.; Mosberg, H. I.; Schmaier, A. H.

    2009-01-01

    Summary Background Novel pentapeptides called Thrombostatin FM compounds consisting mostly of D-isomers and unusual amino acids were prepared based upon the stable angiotensin converting enzyme breakdown product of bradykinin – RPPGF. Methods and Results These peptides are direct thrombin inhibitors prolonging the thrombin clotting time, activated partial thromboplastin time, and prothrombin time at ≥0.78, 1.6, and 1.6 µm, respectively. They competitively inhibit α-thrombin-induced cleavage of a chromogenic substrate at 4.4–8.2 µm. They do not significantly inhibit plasma kallikrein, factor (F) XIIa, FXIa, FIXa, FVIIa-TF, FXa, plasmin or cathepsin G. One form, FM19 [rOicPaF(p-Me)], blocks α-thrombin-induced calcium flux in fibroblasts with an IC50 of 6.9 ± 1.2 µm. FM19 achieved 100% inhibition of threshold α- or γ-thrombin-induced platelet aggregation at 8.4 ± 4.7 µm and 16 ± 4 µm, respectively. The crystal structure of thrombin in complex with FM19 shows that the N-terminal D-Arg retrobinds into the S1 pocket, its second residue Oic interacts with His-57, Tyr-60a and Trp-60d, and its C-terminal p-methyl Phe engages thrombin_s aryl binding site composed of Ile-174, Trp-215, and Leu-99. When administered intraperitoneal, intraduodenal, or orally to mice, FM19 prolongs thrombin clotting times and delays carotid artery thrombosis. Conclusion FM19, a low affinity reversible direct thrombin inhibitor, might be useful as an add-on agent to address an unmet need in platelet inhibition in acute coronary syndromes in diabetics and others who with all current antiplatelet therapy still have reactive platelets. PMID:18315550

  5. Organometallic chemistry of bimetallic compounds

    SciTech Connect

    Casey, C.P.

    1991-07-01

    This report consists of six sections: heterobimetallic dihydrides, early-late transition metal heterobimetallic compounds, amphiphilic carbene complexes and hydroxycarbene complexes, diiron compounds with bridging hydrocarbon ligands, diphosphine chelates with natural bite angles near 120 degrees, and synthesis and reactions of M=M compounds. (WET)

  6. Potential risks of pharmacy compounding.

    PubMed

    Gudeman, Jennifer; Jozwiakowski, Michael; Chollet, John; Randell, Michael

    2013-03-01

    Pharmacy compounding involves the preparation of customized medications that are not commercially available for individual patients with specialized medical needs. Traditional pharmacy compounding is appropriate when done on a small scale by pharmacists who prepare the medication based on an individual prescription. However, the regulatory oversight of pharmacy compounding is significantly less rigorous than that required for Food and Drug Administration (FDA)-approved drugs; as such, compounded drugs may pose additional risks to patients. FDA-approved drugs are made and tested in accordance with good manufacturing practice regulations (GMPs), which are federal statutes that govern the production and testing of pharmaceutical products. In contrast, compounded drugs are exempt from GMPs, and testing to assess product quality is inconsistent. Unlike FDA-approved drugs, pharmacy-compounded products are not clinically evaluated for safety or efficacy. In addition, compounded preparations do not have standard product labeling or prescribing information with instructions for safe use. Compounding pharmacies are not required to report adverse events to the FDA, which is mandatory for manufacturers of FDA-regulated medications. Some pharmacies engage in activities that extend beyond the boundaries of traditional pharmacy compounding, such as large-scale production of compounded medications without individual patient prescriptions, compounding drugs that have not been approved for use in the US, and creating copies of FDA-approved drugs. Compounding drugs in the absence of GMPs increases the potential for preparation errors. When compounding is performed on a large scale, such errors may adversely affect many patients. Published reports of independent testing by the FDA, state agencies, and others consistently show that compounded drugs fail to meet specifications at a considerably higher rate than FDA-approved drugs. Compounded sterile preparations pose the additional risk

  7. Turbo compound engine

    SciTech Connect

    Kawamura, H.

    1988-05-24

    A turbo compound engine having a first exhaust turbine coupled to an exhaust pipe of an internal combustion engine and a second exhaust turbine coupled to an exhaust port of the first exhaust turbine is described comprising: a first generator drivable by the first exhaust turbine; a second generator drivable by the second exhaust turbine; a motor operatively coupled to an output shaft of the internal combustion engine; speed detecting means for detecting the speed of rotation of the internal combustion engine; and control means for controlling the frequency of electric power, which is the sum of electric power outputs from the first and second generators and supplied to the motor, based on a signal from the speed detecting means, in order to control operation of the motor.

  8. Microoptical telescope compound eye

    NASA Astrophysics Data System (ADS)

    Duparré, Jacques W.; Schreiber, Peter; Matthes, André; Pshenay–Severin, Ekaterina; Bräuer, Andreas; Tünnermann, Andreas; Völkel, Reinhard; Eisner, Martin; Scharf, Toralf

    2005-02-01

    A new optical concept for compact digital image acquisition devices with large field of view is developed and proofed experimentally. Archetypes for the imaging system are compound eyes of small insects and the Gabor Superlens. A paraxial 3x3 matrix formalism is used to describe the telescope arrangement of three microlens arrays with different pitch to find first order parameters of the imaging system. A 2mm thin imaging system with 21x3 channels, 70ºx10º field of view and 4.5mm x 0.5mm image size is optimized and analyzed using sequential and non sequential raytracing and fabricated by microoptics technology. Anamorphic lenses, where the parameters are a function of the considered optical channel, are used to achieve a homogeneous optical performance over the whole field of view. Captured images are presented and compared to simulation results.

  9. Microoptical telescope compound eye.

    PubMed

    Duparré, Jacques; Schreiber, Peter; Matthes, André; Pshenay-Severin, Ekaterina; Bräuer, Andreas; Tünnermann, Andreas; Völkel, Reinhard; Eisner, Martin; Scharf, Toralf

    2005-02-01

    A new optical concept for compact digital image acquisition devices with large field of view is developed and proofed experimentally. Archetypes for the imaging system are compound eyes of small insects and the Gabor-Superlens. A paraxial 3x3 matrix formalism is used to describe the telescope arrangement of three microlens arrays with different pitch to find first order parameters of the imaging system. A 2mm thin imaging system with 21x3 channels, 70 masculinex10 masculine field of view and 4.5mm x 0.5mm image size is optimized and analyzed using sequential and non-sequential raytracing and fabricated by microoptics technology. Anamorphic lenses, where the parameters are a function of the considered optical channel, are used to achieve a homogeneous optical performance over the whole field of view. Captured images are presented and compared to simulation results. PMID:19494951

  10. Group-IV semiconductor compounds

    SciTech Connect

    Berding, M.A.; Sher, A.; van Schilfgaarde, M.

    1997-08-01

    Properties of ordered group-IV compounds containing carbon, silicon, and germanium are calculated within the local density approximation. Twenty-seven fully relaxed compounds represented by seven different compound structures are compared and, with the exception of SiC, all compounds are found to be metastable. Two trends emerge: carbon-germanium bonds are disfavored, and compounds that have carbon on a common sublattice are the least unbound because of their relatively low strain. When carbon shares a sublattice with silicon or germanium, the large strain results in a narrowing of the band gap, and in some cases the compound is metallic. The most promising structures with the lowest excess energy contain carbon on one sublattice and although they do not lattice match to silicon, they match rather well to silicon carbide. {copyright} {ital 1997} {ital The American Physical Society}

  11. Compound chondrules: an experimental investigation

    NASA Astrophysics Data System (ADS)

    Connolly, H. C., Jr.; Hewins, R. H.; Atre, N.; Lofgren, G. E.

    1994-07-01

    Compound chondrules are considered to be the product of collisions between molten chondrules during chondrule formation Wasson, J. T. et al. (1994) have argued that some compound chondrules are formed when a chondrule with an accretional rim experienced a flash-melting event similar to a chondrule-forming event. We have designed experiments to investigate the formation of compound chondrules by both methods. Experiments were performed on a Deltech vertical muffle tube furnace to form synthetic chondrules to use as accretion rim material. For our experimental conditions, it is clear that compound chondrules can only be made by a collisional event. Our changes maintain their spherical shape and produce distinct boundaries between charges that are similar to natural compound chondrules. Furthermore, collision event(s) between chondrules will cause nucleation if they are molten and undercooled, thus producing chondrule textures. Flash melting chondrules with accretionary rims will not produce compound chondrules but will produce new chondrules with new textures.

  12. Compounding in synthetic aperture imaging.

    PubMed

    Hansen, Jens Munk; Jensen, Jørgen Arendt

    2012-09-01

    A method for obtaining compound images using synthetic aperture data is investigated using a convex array transducer. The new approach allows spatial compounding to be performed for any number of angles without reducing the frame rate or temporal resolution. This important feature is an intrinsic property of how the compound images are constructed using synthetic aperture data and an improvement compared with how spatial compounding is obtained using conventional methods. The synthetic aperture compound images are created by exploiting the linearity of delay-and-sum beamformation for data collected from multiple spherical emissions to synthesize multiple transmit and receive apertures, corresponding to imaging the tissue from multiple directions. The many images are added incoherently, to produce a single compound image. Using a 192-element, 3.5-MHz, λ-pitch transducer, it is demonstrated from tissue-phantom measurements that the speckle is reduced and the contrast resolution improved when applying synthetic aperture compound imaging. At a depth of 4 cm, the size of the synthesized apertures is optimized for lesion detection based on the speckle information density. This is a performance measure for tissue contrast resolution which quantifies the tradeoff between resolution loss and speckle reduction. The speckle information density is improved by 25% when comparing synthetic aperture compounding to a similar setup for compounding using dynamic receive focusing. The cystic resolution and clutter levels are measured using a wire phantom setup and compared with conventional application of the array, as well as to synthetic aperture imaging without compounding. If the full aperture is used for synthetic aperture compounding, the cystic resolution is improved by 41% compared with conventional imaging, and is at least as good as what can be obtained using synthetic aperture imaging without compounding. PMID:23007781

  13. New England Compounding Center Indictment.

    PubMed

    Cabaleiro, Joe

    2015-01-01

    This article is a review of the lapses in compliance with United States Pharmacopeia standards and pharmacy law as alleged by the New England Compounding Center indictment. This indictment was a result of an outbreak of fungal meningitis traced to fungal contamination of compounded methylprednisolone suspension for epidural steroid injections. This article is also intended as a gap analysis for compounders to review compliance at their own facility, and, if necessary, take the appropriate steps to implement best practices. PMID:26685489

  14. Method of producing cyclohexasilane compounds

    SciTech Connect

    Elangovan, Arumugasamy; Anderson, Kenneth; Boudjouk, Philip R; Schulz, Douglas L

    2015-03-10

    A method of preparing a cyclohexasilane compound from trichlorosilane is provided. The method includes contacting trichlorosilane with a reagent composition to produce a compound containing a tetradecahalocyclohexasilane dianion, such as a tetradecachlorocyclohexasilane dianion. The reagent composition typically includes (a) tertiary polyamine ligand; and (b) a deprotonating reagent, such as a tertiary amine having a pKa of at least about 10.5. Methods of converting the tetradecahalocyclohexasilane dianion-containing compound to cyclohexasilane or a dodecaorganocyclohexasilane are also provided.

  15. Method of preparing metallocene compounds

    DOEpatents

    Rosenblum, Myron; Matchett, Stephen A.

    1992-01-01

    This invention describes a novel method of preparing metallocene compounds. The invention is based on synthesis of novel bis cyclopentadienides that, under appropriate conditions, will either encapsulate a transition metal to produce a metallocene such as ferrocene, or ferrocene derivative, or will yield a polymeric metallocene. Compounds produced by this process are useful as catalysts in propulsion systems, or as anti-knock compounds in gasolines.

  16. Compounding with Silicones.

    PubMed

    Allen, Loyd V

    2015-01-01

    Since the 1940s, methylchlorosilanes have been used to treat glassware to prevent blood from clotting. The use of silicones in pharmaceutical and medical applications has grown to where today they are used in many life-saving devices (pacemakers, hydrocephalic shunts) and pharmaceutical applications from tubing, to excipients in topical formulations, to adhesives to affix transdermal drug delivery systems, and are also being used in products as active pharmaceutical ingredients, such as antiflatulents. About 60% of today's skin-care products now contain some type of silicone where they are considered safe and are known to provide a pleasant "silky-touch," non-greasy, and non-staining feel. Silicones exhibit many useful characteristics, and the safety of these agents supports their numerous applications; their biocompatibility is partially due to their low-chemical reactivity displayed by silicones, low-surface energy, and their hydrophobicity. Silicones are used both as active ingredients and as excipients. In addition is their use for "siliconization," or surface treatment, of many parenteral packaging components. Dimethicone and silicone oil are used as lubricants on stoppers to aid machineability, in syringes to aid piston movement, or on syringe needles to reduce pain upon injection. Silicones are also useful in pharmaceutical compounding as is discussed in this artiele included with this article are in developing formulations with silicones. PMID:26714363

  17. Biomedical Compounds from Marine organisms

    PubMed Central

    Jha, Rajeev Kumar; Zi-rong, Xu

    2004-01-01

    The Ocean, which is called the ‘mother of origin of life’, is also the source of structurally unique natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities and are helpful for the invention and discovery of bioactive compounds, primarily for deadly diseases like cancer, acquired immuno-deficiency syndrome (AIDS), arthritis, etc., while other compounds have been developed as analgesics or to treat inflammation, etc. The life-saving drugs are mainly found abundantly in microorganisms, algae and invertebrates, while they are scarce in vertebrates. Modern technologies have opened vast areas of research for the extraction of biomedical compounds from oceans and seas.

  18. Organic Compounds in Carbonaceous Meteorites

    NASA Technical Reports Server (NTRS)

    Cooper, Grorge

    2001-01-01

    Carbonaceous meteorites are relatively enriched in soluble organic compounds. To date, these compounds provide the only record available to study a range of organic chemical processes in the early Solar System chemistry. The Murchison meteorite is the best-characterized carbonaceous meteorite with respect to organic chemistry. The study of its organic compounds has related principally to aqueous meteorite parent body chemistry and compounds of potential importance for the origin of life. Among the classes of organic compounds found in Murchison are amino acids, amides, carboxylic acids, hydroxy acids, sulfonic acids, phosphonic acids, purines and pyrimidines (Table 1). Compounds such as these were quite likely delivered to the early Earth in asteroids and comets. Until now, polyhydroxylated compounds (polyols), including sugars (polyhydroxy aldehydes or ketones), sugar alcohols, sugar acids, etc., had not been identified in Murchison. Ribose and deoxyribose, five-carbon sugars, are central to the role of contemporary nucleic acids, DNA and RNA. Glycerol, a three-carbon sugar alcohol, is a constituent of all known biological membranes. Due to the relative lability of sugars, some researchers have questioned the lifetime of sugars under the presumed conditions on the early Earth and postulated other (more stable) compounds as constituents of the first replicating molecules. The identification of potential sources and/or formation mechanisms of pre-biotic polyols would add to the understanding of what organic compounds were available, and for what length of time, on the ancient Earth.

  19. Antimicrobial Compounds in Tears

    PubMed Central

    McDermott, Alison M.

    2013-01-01

    The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here. PMID:23880529

  20. ATMOSPHERIC FREONS AND HALOGENATED COMPOUNDS

    EPA Science Inventory

    Ambient levels of atmospheric Freons, halogenated hydrocarbons, and SF6 were measured at various locations in the U.S.A. Compounds such as CCl3F, CCl2F2, CH3-CCl3, and CCl4 were ubiquitious and generally measured at sub ppb levels. Tropospherically reactive compounds such as C2Cl...

  1. Antifungal Compounds from Piper Species

    PubMed Central

    Xu, Wen-Hui; Li, Xing-Cong

    2013-01-01

    This review documents chemical structures and antifungal activities of 68 compounds isolated from 22 Piper species of the plant family Piperaceae. These compounds include amides, flavonoids, prenylated benzoic acid derivatives, lignans, phenylpropanoids, butenolides, and cyclopentendiones. Some of them may serve as leads for potential pharmaceutical or agricultural fungicide development. PMID:24307889

  2. Morphological Dynamics in Compound Processing

    ERIC Educational Resources Information Center

    Kuperman, Victor; Bertram, Raymond; Baayen, R. Harald

    2008-01-01

    This paper explores the time-course of morphological processing of trimorphemic Finnish compounds. We find evidence for the parallel access to full-forms and morphological constituents diagnosed by the early effects of compound frequency, as well as early effects of left constituent frequency and family size. We also observe an interaction between…

  3. Bilingual Reading of Compound Words

    ERIC Educational Resources Information Center

    Ko, In Yeong; Wang, Min; Kim, Say Young

    2011-01-01

    The present study investigated whether bilingual readers activate constituents of compound words in one language while processing compound words in the other language via decomposition. Two experiments using a lexical decision task were conducted with adult Korean-English bilingual readers. In Experiment 1, the lexical decision of real English…

  4. METHOD OF REDUCING PLUTONIUM COMPOUNDS

    DOEpatents

    Johns, I.B.

    1958-06-01

    A method is described for reducing plutonium compounds in aqueous solution from a higher to a lower valence state. This reduction of valence is achieved by treating the aqueous solution of higher valence plutonium compounds with hydrogen in contact with an activated platinum catalyst.

  5. Bilayer Effects of Antimalarial Compounds.

    PubMed

    Ramsey, Nicole B; Andersen, Olaf S

    2015-01-01

    Because of the perpetual development of resistance to current therapies for malaria, the Medicines for Malaria Venture developed the Malaria Box to facilitate the drug development process. We tested the 80 most potent compounds from the box for bilayer-mediated effects on membrane protein conformational changes (a measure of likely toxicity) in a gramicidin-based stopped flow fluorescence assay. Among the Malaria Box compounds tested, four compounds altered membrane properties (p< 0.05); MMV007384 stood out as a potent bilayer-perturbing compound that is toxic in many cell-based assays, suggesting that testing for membrane perturbation could help identify toxic compounds. In any case, MMV007384 should be approached with caution, if at all. PMID:26551613

  6. Macrocyclic compounds as corrosion inhibitors

    SciTech Connect

    Quraishi, M.A.; Rawat, J.; Ajmal, M.

    1998-12-01

    The influence of three macrocyclic compounds on corrosion of mild steel (MS) in hydrochloric acid (HCl) was investigated using weight loss, potentiodynamic polarization, alternating current (AC) impedance, and hydrogen permeation techniques. All the investigated compounds showed significant efficiencies and reduced permeation of hydrogen through MS in HCl. Inhibition efficiency (IE) varied with the nature and concentrations of the inhibitors, temperature, and concentrations of the acid solutions. The addition of iodide ions (I{sup {minus}}) increased IE of all the tested compounds as a result of the synergistic effect. Potentiodynamic polarization results revealed that macrocyclic compounds acted as mixed inhibitors in 1 M HCl to 5 M HCl. Adsorption on the metal surface obeyed Temkin`s adsorption isotherm. Auger electron spectroscopy (AES) of the polished MS surface, exposed with tetraphenyldithia-octaazacyclotetradeca-hexaene (PTAT) proved adsorption of this compound on the surface through nitrogen and sulfur atoms.

  7. Bilayer Effects of Antimalarial Compounds

    PubMed Central

    Ramsey, Nicole B.; Andersen, Olaf S.

    2015-01-01

    Because of the perpetual development of resistance to current therapies for malaria, the Medicines for Malaria Venture developed the Malaria Box to facilitate the drug development process. We tested the 80 most potent compounds from the box for bilayer-mediated effects on membrane protein conformational changes (a measure of likely toxicity) in a gramicidin-based stopped flow fluorescence assay. Among the Malaria Box compounds tested, four compounds altered membrane properties (p< 0.05); MMV007384 stood out as a potent bilayer-perturbing compound that is toxic in many cell-based assays, suggesting that testing for membrane perturbation could help identify toxic compounds. In any case, MMV007384 should be approached with caution, if at all. PMID:26551613

  8. Assimilation of Unusual Carbon Compounds

    NASA Astrophysics Data System (ADS)

    Middelhoven, Wouter J.

    Yeast taxa traditionally are distinguished by growth tests on several sugars and organic acids. During the last decades it became apparent that many yeast species assimilate a much greater variety of naturally occurring carbon compounds as sole source of carbon and energy. These abilities are indicative of a greater role of yeasts in the carbon cycle than previously assumed. Especially in acidic soils and other habitats, yeasts may play a role in the degradation of carbon compounds. Such compounds include purines like uric acid and adenine, aliphatic amines, diamines and hydroxyamines, phenolics and other benzene compounds and polysaccharides. Assimilation of purines and amines is a feature of many ascomycetes and basidiomycetes. However, benzene compounds are degraded by only a few ascomycetous yeasts (e.g. the Stephanoascus/ Blastobotrys clade and black yeastlike fungi) but by many basidiomycetes, e.g. Filobasidiales, Trichosporonales, red yeasts producing ballistoconidia and related species, but not by Tremellales. Assimilation of polysaccharides is wide-spread among basidiomycetes

  9. Antiparasitic Compounds That Target DNA

    PubMed Central

    Wilson, W. David; Tanious, Farial A.; Mathis, Amanda; Tevis, Denise; Hall, James Edwin; Boykin, David W.

    2008-01-01

    Designed, synthetic heterocyclic diamidines have excellent activity against eukaryotic parasites that cause diseases such as sleeping sickness and leishmania and adversely affect millions of people each year. The most active compounds bind specifically and strongly in the DNA minor groove at AT sequences. The compounds enter parasite cells rapidly and appear first in the kinetoplast that contains the mitochondrial DNA of the parasite. With time the compounds are also generally seen in the cell nucleus but are not significantly observed in the cytoplasm. The kinetoplast decays over time and disappears from the mitochondria of treated cells. At this point the compounds begin to be observed in other regions of the cell, such as the acidocalcisomes. The cells typically die in 24–48 hours after treatment. Active compounds appear to selectively target extended AT sequences and induce changes in kinetoplast DNA minicircles that cause a synergistic destruction of the catenated kinetoplast DNA network and cell death. PMID:18343228

  10. Devices for collecting chemical compounds

    DOEpatents

    Scott, Jill R; Groenewold, Gary S

    2013-12-24

    A device for sampling chemical compounds from fixed surfaces and related methods are disclosed. The device may include a vacuum source, a chamber and a sorbent material. The device may utilize vacuum extraction to volatilize the chemical compounds from a fixed surface so that they may be sorbed by the sorbent material. The sorbent material may then be analyzed using conventional thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS) instrumentation to determine presence of the chemical compounds. The methods may include detecting release and presence of one or more chemical compounds and determining the efficacy of decontamination. The device may be useful in collection and analysis of a variety of chemical compounds, such as residual chemical warfare agents, chemical attribution signatures and toxic industrial chemicals.

  11. Membrane rejection of nitrogen compounds

    NASA Technical Reports Server (NTRS)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Rejection characteristics of nitrogen compounds were examined for reverse osmosis, nanofiltration, and low-pressure reverse osmosis membranes. The rejection of nitrogen compounds is explained by integrating experimental results with calculations using the extended Nernst-Planck model coupled with a steric hindrance model. The molecular weight and chemical structure of nitrogen compounds appear to be less important in determining rejection than electrostatic properties. The rejection is greatest when the Donnan potential exceeds 0.05 V or when the ratio of the solute radius to the pore radius is greater than 0.8. The transport of solute in the pore is dominated by diffusion, although convective transport is significant for organic nitrogen compounds. Electromigration contributes negligibly to the overall solute transport in the membrane. Urea, a small organic compound, has lower rejection than ionic compounds such as ammonium, nitrate, and nitrite, indicating the critical role of electrostatic interaction in rejection. This suggests that better treatment efficiency for organic nitrogen compounds can be obtained after ammonification of urea.

  12. New syntheses of diazo compounds.

    PubMed

    Maas, Gerhard

    2009-01-01

    Diazo compounds (R1R2C=N2) are known as versatile and useful substrates for an array of chemical transformations and, therefore, diazo chemistry is still far from losing anything of its long-standing fascination. In addition to many studies on the subsequent chemistry of the diazo group, the inventory of methods for the preparation of diazo compounds is continuously supplemented by new methods and novel variations of established procedures. Several of these synthetic approaches take into account the lability and remarkable chemical reactivity of certain classes of diazo compounds, and environmentally more benign procedures also continue to be developed. PMID:19790217

  13. Regulation of Compound Leaf Development

    PubMed Central

    Wang, Yuan; Chen, Rujin

    2013-01-01

    Leaf morphology is one of the most variable, yet inheritable, traits in the plant kingdom. How plants develop a variety of forms and shapes is a major biological question. Here, we discuss some recent progress in understanding the development of compound or dissected leaves in model species, such as tomato (Solanum lycopersicum), Cardamine hirsuta and Medicago truncatula, with an emphasis on recent discoveries in legumes. We also discuss progress in gene regulations and hormonal actions in compound leaf development. These studies facilitate our understanding of the underlying regulatory mechanisms and put forward a prospective in compound leaf studies. PMID:27135488

  14. Polishing compound for plastic surfaces

    DOEpatents

    Stowell, Michael S.

    1995-01-01

    A polishing compound for plastic surfaces. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS.TM., LEXAN.TM., LUCITE.TM., polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  15. Polishing compound for plastic surfaces

    DOEpatents

    Stowell, M.S.

    1995-08-22

    A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains fine particles silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired. 5 figs.

  16. Polishing compound for plastic surfaces

    SciTech Connect

    Stowell, M.S.

    1993-01-01

    A polishing compound for plastic surfaces is disclosed. The compound contains by weight approximately 4 to 17 parts at least one petroleum distillate lubricant, 1 to 6 parts mineral spirits, 2.5 to 15 parts abrasive particles, and 2.5 to 10 parts water. The abrasive is tripoli or a similar material that contains colloidal silica. Preferably, most of the abrasive particles are less than approximately 10 microns, more preferably less than approximately 5 microns in size. The compound is used on PLEXIGLAS{sup TM}, LEXAN{sup TM}, LUCITE{sup TM}, polyvinyl chloride (PVC) and similar plastic materials whenever a smooth, clear polished surface is desired.

  17. Crystallographic properties of fertilizer compounds

    SciTech Connect

    Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.

    1991-02-01

    This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA's fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

  18. Compound cuing in free recall.

    PubMed

    Lohnas, Lynn J; Kahana, Michael J

    2014-01-01

    According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cuing in free recall. Specifically, the temporal contiguity effect should be greater when the 2 most recently recalled items were studied in contiguous list positions. A meta-analysis of published free recall experiments demonstrates evidence for compound cuing in both conditional response probabilities and interresponse times. To help rule out a rehearsal-based account of these compound cuing effects, we conducted an experiment with immediate, delayed, and continual-distractor free recall conditions. Consistent with retrieved context theory but not with a rehearsal-based account, compound cuing was present in all conditions, and was not significantly influenced by the presence of interitem distractors. PMID:23957364

  19. Polishing compound for plastic surfaces

    DOEpatents

    Stowell, M.S.

    1991-01-01

    This invention is comprised of a polishing compound for plastic materials. The compound includes approximately by approximately by weight 25 to 80 parts at least one petroleum distillate lubricant, 1 to 12 parts mineral spirits, 50 to 155 parts abrasive paste, and 15 to 60 parts water. Preferably, the compound includes approximately 37 to 42 parts at least one petroleum distillate lubricant, up to 8 parts mineral spirits, 95 to 110 parts abrasive paste, and 50 to 55 parts water. The proportions of the ingredients are varied in accordance with the particular application. The compound is used on PLEXIGLAS{trademark}, LEXAN{trademark}, LUCITE{trademark}, polyvinyl chloride (PVC), and similar plastic materials whenever a smooth, clear polished surface is desired.

  20. Crystallographic properties of fertilizer compounds

    SciTech Connect

    Frazier, A.W.; Dillard, E.F.; Thrasher, R.D.; Waerstad, K.R.; Hunter, S.R.; Kohler, J.J.; Scheib, R.M.

    1991-02-01

    This bulletin is a compilation of crystallographic data collected at NFERC on 450 fertilizer-related compounds. In TVA`s fertilizer R and D program, petrographic examination, XRD, and infrared spectroscopy are combined with conventional chemical analysis methods in identifying the individual compounds that occur in fertilizer materials. This handbook brings together the results of these characterization studies and supplemental crystallographic data from the literature. It is in one-compound-per-page, loose-leaf format, ordered alphabetically by IUPAC name. Indexes provided include IUPAC name, formula, group, alternate formula, synonyms, x-ray data, optical data. Tables are given for solids, compounds in commercial MAP and DAP, and matrix materials in phosphate rock.

  1. Detection of chlorinated aromatic compounds

    DOEpatents

    Ekechukwu, Amy A.

    1996-01-01

    A method for making a composition for measuring the concentration of chloated aromatic compounds in aqueous fluids, and an optical probe for use with the method. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis.

  2. Detection of chlorinated aromatic compounds

    DOEpatents

    Ekechukwu, A.A.

    1996-02-06

    A method for making a composition for measuring the concentration of chlorinated aromatic compounds in aqueous fluids, and an optical probe for use with the method are disclosed. The composition comprises a hydrophobic polymer matrix, preferably polyamide, with a fluorescent indicator uniformly dispersed therein. The indicator fluoresces in the presence of the chlorinated aromatic compounds with an intensity dependent on the concentration of these compounds in the fluid of interest, such as 8-amino-2-naphthalene sulfonate. The probe includes a hollow cylindrical housing that contains the composition in its distal end. The probe admits an aqueous fluid to the probe interior for exposure to the composition. An optical fiber transmits excitation light from a remote source to the composition while the indicator reacts with chlorinated aromatic compounds present in the fluid. The resulting fluorescence light signal is reflected to a second optical fiber that transmits the light to a spectrophotometer for analysis. 5 figs.

  3. Volatile Organic Compounds in Uremia

    PubMed Central

    Seifert, Luzia; Slodzinski, Rafael; Jankowski, Joachim; Zidek, Walter; Westhoff, Timm H.

    2012-01-01

    Background Although “uremic fetor” has long been felt to be diagnostic of renal failure, the compounds exhaled in uremia remain largely unknown so far. The present work investigates whether breath analysis by ion mobility spectrometry can be used for the identification of volatile organic compounds retained in uremia. Methods Breath analysis was performed in 28 adults with an eGFR ≥60 ml/min per 1.73 m2, 26 adults with chronic renal failure corresponding to an eGFR of 10–59 ml/min per 1.73 m2, and 28 adults with end-stage renal disease (ESRD) before and after a hemodialysis session. Breath analysis was performed by ion mobility spectrometryafter gas-chromatographic preseparation. Identification of the compounds of interest was performed by thermal desorption gas chromatography/mass spectrometry. Results Breath analyses revealed significant differences in the spectra of patients with and without renal failure. Thirteen compounds were chosen for further evaluation. Some compounds including hydroxyacetone, 3-hydroxy-2-butanone and ammonia accumulated with decreasing renal function and were eliminated by dialysis. The concentrations of these compounds allowed a significant differentiation between healthy, chronic renal failure with an eGFR of 10–59 ml/min, and ESRD (p<0.05 each). Other compounds including 4-heptanal, 4-heptanone, and 2-heptanone preferentially or exclusively occurred in patients undergoing hemodialysis. Conclusion Impairment of renal function induces a characteristic fingerprint of volatile compounds in the breath. The technique of ion mobility spectrometry can be used for the identification of lipophilic uremic retention molecules. PMID:23049998

  4. Sulfated compounds from marine organisms.

    PubMed

    Kornprobst, J M; Sallenave, C; Barnathan, G

    1998-01-01

    More than 500 sulfated compounds have been isolated from marine organisms so far but most of them originate from two phyla only, Spongia and Echinodermata. The sulfated compounds are presented according to the phyla they have been identified from and to their chemical structures. Biological activities, when available, are also given. Macromolecules have also been included in this review but without structural details. PMID:9530808

  5. Sensing acetylcholine and anticholinesterase compounds.

    PubMed

    Schena, Alberto; Johnsson, Kai

    2014-01-27

    Acetylcholine is a key neurotransmitter, and anticholinesterase agents are essential compounds used as medical drugs, pesticides, and chemical warfare agents. A semisynthetic fluorescence-based probe for the direct, real-time detection of acetylcholine and anticholinesterase compounds is introduced. The probe possesses good sensitivity, tunable detection range, and can be selectively targeted to cell surfaces, thereby making it an attractive tool for applications in analytical chemistry and quantitative biology. PMID:24339043

  6. Aza compounds as anion receptors

    DOEpatents

    Lee, H.S.; Yang, X.Q.; McBreen, J.

    1998-01-06

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of Li{sup +} ion in alkali metal batteries. 3 figs.

  7. Aza compounds as anion receptors

    DOEpatents

    Lee, Hung Sui; Yang, Xiao-Qing; McBreen, James

    1998-01-06

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of Li.sup.+ ion in alkali metal batteries.

  8. Photochemical dimerization of organic compounds

    SciTech Connect

    Crabtree, R.H.; Brown, S.H.; Muedas, C.A.; Ferguson, R.R.

    1992-04-14

    This patent describes improvement in a Group IIb photosensitized vapor phase dimerization of an organic compound in which a gaseous mixture of a Group IIB metal and the organic compound is irradiated in a reaction zone with a photosensitizing amount of radiant energy. The improvement comprises: a continuous stream of the gaseous mixture is passed as a vapor phase in a single pass through the reaction zone at a temperature at which the thus-produced dimer condenses immediately upon the formation thereof; the starting gaseous mixture comprises hydrogen and two ethylenically unsaturated compounds selected from the group consisting of alkenes of at least six carbon atoms, unsaturated nitriles, unsaturated epoxides, unsaturated silanes, unsaturated amines, unsaturated phosphines, and fluorinated alkenes; the gaseous mixture comprises nitrous oxide and the organic compound is a saturated compound with C-H bond strengths greater than 100 kcal/mol or a mixture of the saturated compound and an alkene; or the starting gaseous comprises an activating amount of hydrogen and the dimerization is a dehydrodimerization or cross-dimerization of a saturated hydrocarbon.

  9. Miniature curved artificial compound eyes

    PubMed Central

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L’Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A.; Franceschini, Nicolas

    2013-01-01

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574

  10. Miniature curved artificial compound eyes.

    PubMed

    Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L'Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A; Franceschini, Nicolas

    2013-06-01

    In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574