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Sample records for dye system degenerate

  1. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  2. Quantum degenerate systems

    SciTech Connect

    Micheli, Fiorenza de; Zanelli, Jorge

    2012-10-15

    A degenerate dynamical system is characterized by a symplectic structure whose rank is not constant throughout phase space. Its phase space is divided into causally disconnected, nonoverlapping regions in each of which the rank of the symplectic matrix is constant, and there are no classical orbits connecting two different regions. Here the question of whether this classical disconnectedness survives quantization is addressed. Our conclusion is that in irreducible degenerate systems-in which the degeneracy cannot be eliminated by redefining variables in the action-the disconnectedness is maintained in the quantum theory: there is no quantum tunnelling across degeneracy surfaces. This shows that the degeneracy surfaces are boundaries separating distinct physical systems, not only classically, but in the quantum realm as well. The relevance of this feature for gravitation and Chern-Simons theories in higher dimensions cannot be overstated.

  3. Non-degenerate two photon absorption enhancement for laser dyes by precise lock-in detection

    SciTech Connect

    Xue, B.; Katan, C.; Bjorgaard, J. A.; Kobayashi, T.

    2015-12-15

    This study demonstrates a measurement system for a non-degenerate two-photon absorption (NDTPA) spectrum. The NDTPA light sources are a white light super continuum beam (WLSC, 500 ∼ 720 nm) and a fundamental beam (798 nm) from a Ti:Sapphire laser. A reliable broadband NDTPA spectrum is acquired in a single-shot detection procedure using a 128-channel lock-in amplifier. The NDTPA spectra for several common laser dyes are measured. Two photon absorption cross section enhancements are found in the experiment and validated by theoretical calculation for all of the chromophores.

  4. Dye system for dye laser applications

    DOEpatents

    Hammond, Peter R.

    1991-01-01

    A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

  5. Hamiltonian structure for degenerate AKNS systems

    NASA Astrophysics Data System (ADS)

    Corona-Corona, Gulmaro

    1997-01-01

    There is a family of degenerate AKNS systems for which the full theory of generic AKNS systems does not directly extend. The linear space of potentials still has a natural Poisson structure, but the scattering method used by Beals and Sattinger to show complete integrability for the generic AKNS systems fails for the degenerate case. A Poisson structure is not induced on the scattering side as in the generic case. As a consequence, the problem of complete integrability for degenerate AKNS systems still is an open question. In addition, contrary to the generic case, the Lax pair gives flows for degenerate integrable systems that are nonlocal. In general, they do not exist, and they are no longer linear on the scattering side. Necessary conditions for their existence and for linear evolution in the scattering side are found.

  6. Hamiltonian Structure for Degenerate Akns Systems

    NASA Astrophysics Data System (ADS)

    Corona-Corona, Gulmaro

    1995-01-01

    There is a family of degenerate AKNS systems for which the full theory of generic AKNS systems does not directly extend. The linear space of potentials still has a natural Poisson structure. This is studied by the scattering method used by Richard Beals and D.H. Sattinger (Commun. Math. Phys. 138, 409-436, 1991) to show complete integrability for the generic AKNS systems. This method fails for the degenerate case since a Poisson structure is not induced on the scattering side as in the generic case. As a consequence, the problem of complete integrability for degenerate AKNS systems still is an open question. In addition, contrary to the generic case, the Lax pair gives flows for degenerate integrable systems that are nonlocal. In general they do not exist, and they are no longer linear on the scattering side. Necessary conditions for their existence and for linear evolution of the scattering side are found.

  7. Visual system degeneration induced by blast overpressure.

    PubMed

    Petras, J M; Bauman, R A; Elsayed, N M

    1997-07-25

    The effect of blast overpressure on visual system pathology was studied in 14 male Sprague-Dawley rats weighing 360-432 g. Blast overpressure was simulated using a compressed-air driven shock tube, with the aim of studying a range of overpressures causing sublethal injury. Neither control (unexposed) rats nor rats exposed to 83 kiloPascals (kPa) overpressure showed evidence of visual system pathology. Neurological injury to brain visual pathways was observed in male rats surviving blast overpressure exposures of 104-110 kPa and 129-173 kPa. Optic nerve fiber degeneration was ipsilateral to the blast pressure wave. The optic chiasm contained small numbers of degenerated fibers. Optic tract fiber degeneration was present bilaterally, but was predominantly ipsilateral. Optic tract fiber degeneration was followed to nuclear groups at the level of the midbrain, midbrain-diencephalic junction, and the thalamus where degenerated fibers arborized among the neurons of: (i) the superior colliculus, (ii) pretectal region, and (iii) the lateral geniculate body. The superior colliculus contained fiber degeneration localized principally to two superficial layers (i) the stratum opticum (layer III) and (ii) stratum cinereum (layer II). The pretectal area contained degenerated fibers which were widespread in (i) the nucleus of the optic tract, (ii) olivary pretectal nucleus, (iii) anterior pretectal nucleus, and (iv) the posterior pretectal nucleus. Degenerated fibers in the lateral geniculate body were not universally distributed. They appeared to arborize among neurons of the dorsal and ventral nuclei: the ventral lateral geniculate nucleus (parvocellular and magnocellular parts); and the dorsal lateral geniculate nucleus. The axonopathy observed in the central visual pathways and nuclei of the rat brain are consistent with the presence of blast overpressure induced injury to the retina. The orbital cavities of the human skull contain frontally-directed eyeballs for binocular

  8. Quantitative Pfirrmann Disc Degeneration Grading System to Overcome the Limitation of Pfirrmann Disc Degeneration Grade.

    PubMed

    Rim, Dae Cheol

    2016-03-01

    Pfirrmann disc degeneration grade is one of morphologic disc degeneration grading system and it was reliable on routine T2-weighted magnetic resonance (MR) images. The purpose of this study was to evaluate the agreement of Pfirrmann disc degeneration grade, and check the alternative technique of disc degeneration grading system. Fifteen volunteers (4 medical doctors related to spinal disease, 2 medical doctors not related to spinal disease, 6 nurses in spinal hospital, and 3 para-medicines) were included in this study. Three different digitalized MR images were provided all volunteers, and they checked Pfirrmann disc degeneration grade of each disc levels after careful listening to explanation. Indeed, all volunteers checked the signal intensity of disc degeneration at the points of nucleus pulposus (NP), disc membrane, ligaments, fat, and air to modify the quantitative Pfirrmann disc degeneration grade. Total 225 grade results of Pfirrmann disc degeneration grade and 405 signal intensity results of quantitative Pfirrmann disc degeneration grade were analyzed. Average interobserver agreement was "moderate (mean±standard deviation, 0.575±0.251)" from poor to excellent. Completely agreed levels of Pfirrmann disc degeneration grade were only 4 levels (26.67%), and the disagreement levels were observed in 11 levels; two different grades in 8 levels (53.33%) and three different grades in 3 levels (20%). Quantitative Pfirrmann disc degeneration showed relatively cluster distribution with the interobserver deviations of 0.41-1.56 at the ratio of NP and disc membrane, and it showed relatively good cluster and distribution indicating that the proposed grading system has good discrimination ability. Pfirrmann disc degeneration grade showed the limitation of different interobserver results, but this limitation could be overcome by using quantitative techniques of MR signal intensity. Further evaluation is needed to access its advantage and reliabilities.

  9. Construction of nonregular pointwise degenerate delay-differential systems

    NASA Technical Reports Server (NTRS)

    Choudhury, A. K.

    1978-01-01

    Pointwise degenerate delay-differential systems (degeneracy at t = 2h) are reduced to Popov's construction under the regularity assumption. Necessary and sufficient conditions for the degeneracy are outlined.

  10. Removal of textile dyes from textile dye effluent using TBAB based aqueous biphasic systems.

    PubMed

    Dilip, Meghna; Venkateswaran, P; Palanivelu, K

    2005-07-01

    Aqueous biphasic systems (ABS) are useful for the extraction of dye molecules from aqueous solution. Thus, they can be used in textile dye bath effluent treatment. The partitioning behavior of two commercially used textile dyes-Cibacron Scarlet LS 2G and Astacryl Red 3B were investigated in a TBAB-salt aqueous biphasic systems. It was found that all three salts, namely sodium chloride, sodium sulphate and sodium carbonate, investigated caused partitioning of dye into the upper TBAB rich phase. The efficiency of separation increased in the order NaCl < Na2SO4 < Na2CO. It was found that the cationic dye partitioned better than the anionic dye in the system. A concentration of 5 g/l of dye was extracted into the upper layer. Alteration of solution pH did not cause any significant difference in distribution ratios. Studies were extended to actual dye bath effluent and small scale up studies carried out. Efficiencies of removal obtained in all cases were extremely good with maximum efficiencies above 98 %.

  11. Coherent pulsed excitation of degenerate multistate systems: Exact analytic solutions

    SciTech Connect

    Kyoseva, E. S.; Vitanov, N. V.

    2006-02-15

    We show that the solution of a multistate system composed of N degenerate lower (ground) states and one upper (excited) state can be reduced by using the Morris-Shore transformation to the solution of a two-state system involving only the excited state and a (bright) superposition of ground states. In addition, there are N-1 dark states composed of ground states. We use this decomposition to derive analytical solutions for degenerate extensions of the most popular exactly soluble models: the resonance solution, the Rabi, Landau-Zener, Rosen-Zener, Allen-Eberly, and Demkov-Kunike models. We suggest various applications of the multistate solutions, for example, as tools for creating multistate coherent superpositions by generalized resonant {pi} pulses. We show that such generalized {pi} pulses can occur even when the upper state is far off resonance, at specific detunings, which makes it possible to operate in the degenerate ground-state manifold without populating the (possibly lossy) upper state, even transiently.

  12. Neuronal degeneration in autonomic nervous system of Dystonia musculorum mice

    PubMed Central

    2011-01-01

    Background Dystonia musculorum (dt) is an autosomal recessive hereditary neuropathy with a characteristic uncoordinated movement and is caused by a defect in the bullous pemphigoid antigen 1 (BPAG1) gene. The neural isoform of BPAG1 is expressed in various neurons, including those in the central and peripheral nerve systems of mice. However, most previous studies on neuronal degeneration in BPAG1-deficient mice focused on peripheral sensory neurons and only limited investigation of the autonomic system has been conducted. Methods In this study, patterns of nerve innervation in cutaneous and iridial tissues were examined using general neuronal marker protein gene product 9.5 via immunohistochemistry. To perform quantitative analysis of the autonomic neuronal number, neurons within the lumbar sympathetic and parasympathetic ciliary ganglia were calculated. In addition, autonomic neurons were cultured from embryonic dt/dt mutants to elucidate degenerative patterns in vitro. Distribution patterns of neuronal intermediate filaments in cultured autonomic neurons were thoroughly studied under immunocytochemistry and conventional electron microscopy. Results Our immunohistochemistry results indicate that peripheral sensory nerves and autonomic innervation of sweat glands and irises dominated degeneration in dt/dt mice. Quantitative results confirmed that the number of neurons was significantly decreased in the lumbar sympathetic ganglia as well as in the parasympathetic ciliary ganglia of dt/dt mice compared with those of wild-type mice. We also observed that the neuronal intermediate filaments were aggregated abnormally in cultured autonomic neurons from dt/dt embryos. Conclusions These results suggest that a deficiency in the cytoskeletal linker BPAG1 is responsible for dominant sensory nerve degeneration and severe autonomic degeneration in dt/dt mice. Additionally, abnormally aggregated neuronal intermediate filaments may participate in neuronal death of cultured

  13. Symmetry of quantum phase space in a degenerate Hamiltonian system

    NASA Astrophysics Data System (ADS)

    Berman, G. P.; Demikhovskii, V. Ya.; Kamenev, D. I.

    2000-09-01

    The structure of the global "quantum phase space" is analyzed for the harmonic oscillator perturbed by a monochromatic wave in the limit when the perturbation amplitude is small. Usually, the phenomenon of quantum resonance was studied in nondegenerate [G. M. Zaslavsky, Chaos in Dynamic Systems (Harwood Academic, Chur, 1985)] and degenerate [Demikhovskii, Kamenev, and Luna-Acosta, Phys. Rev. E 52, 3351 (1995)] classically chaotic systems only in the particular regions of the classical phase space, such as the center of the resonance or near the separatrix. The system under consideration is degenerate, and even an infinitely small perturbation generates in the classical phase space an infinite number of the resonant cells which are arranged in the pattern with the axial symmetry of the order 2μ (where μ is the resonance number). We show analytically that the Husimi functions of all Floquet states (the quantum phase space) have the same symmetry as the classical phase space. This correspondence is demonstrated numerically for the Husimi functions of the Floquet states corresponding to the motion near the elliptic stable points (centers of the classical resonance cells). The derived results are valid in the resonance approximation when the perturbation amplitude is small enough, and the stochastic layers in the classical phase space are exponentially thin. The developed approach can be used for studying a global symmetry of more complicated quantum systems with chaotic behavior.

  14. Evaluation of respiratory system in textile-dyeing workers.

    PubMed

    Salmani Nodoushan, Mojahede; Mehrparvar, Amir Houshang; Loukzadeh, Ziba; Rahimian, Masoud; Ghove Nodoushan, Mohamad Ali; Jafari Nodoushan, Reza

    2014-01-01

    Despite the presence of many textile and dyeing plants in Iran, we couldn't find similar studies in this country. Forthermore, considering progress in the dyeing process and engineering controls, assessment of respiratory system is important for these workers. The present study was performed to evaluate the respiratory system in dyeing workers. In a cross-sectional study, 101 dyeing workers (all dyeing workers in yazd) and 90 workers without respiratory exposures (control group), were evaluated. A questionnaire was filled for each participant included Venables questionnaire and some other questions about age, work experience, personal or familial history of asthma or atopy, acute and chronic respiratory symptoms; Then spirometry was performed before and after the shift work Results: The frequency of acute and chronic respiratory symptoms was significantly higher among dyeing workers than controls. According to the Venables questionnaire, 11.9% of the dyeing workers suffered from asthma. Means of FVC and FEV1 of pre-shift spirometry were lower than control (p< 0.001). Across-shift spirometry showed significant reduction of FVC (p< 0.001), FEV1 (p< 0.001), FEF25-75% (p= 0.05) and FEF25% (p= 0.007) in dyeing workers compared to the control group. Evaluation of dyeing workers' respiratory system in this study showed that despite development in dyeing processes and engineering controls, workers in this job show more prevalent acute and chronic symptoms, and across-shift changes in spirometric parameters were significantly higher in this work group than the control group. Therefore it is necessary to pay attention to the control of respiratory exposures in this job.

  15. Evaluation of respiratory system in textile-dyeing workers

    PubMed Central

    Salmani Nodoushan, Mojahede; Mehrparvar, Amir Houshang; Loukzadeh, Ziba; Rahimian, Masoud; Ghove Nodoushan, Mohamad ali; Jafari Nodoushan, Reza

    2014-01-01

    Background: Despite the presence of many textile and dyeing plants in Iran, we couldn’t find similar studies in this country. Forthermore, considering progress in the dyeing process and engineering controls, assessment of respiratory system is important for these workers. The present study was performed to evaluate the respiratory system in dyeing workers. Methods: In a cross-sectional study, 101 dyeing workers (all dyeing workers in yazd) and 90 workers without respiratory exposures (control group), were evaluated. A questionnaire was filled for each participant included Venables questionnaire and some other questions about age, work experience, personal or familial history of asthma or atopy, acute and chronic respiratory symptoms; Then spirometry was performed before and after the shift work Results: The frequency of acute and chronic respiratory symptoms was significantly higher among dyeing workers than controls. According to the Venables questionnaire, 11.9% of the dyeing workers suffered from asthma. Means of FVC and FEV1 of pre-shift spirometry were lower than control (p< 0.001). Across-shift spirometry showed significant reduction of FVC (p< 0.001), FEV1 (p< 0.001), FEF25-75% (p= 0.05) and FEF25% (p= 0.007) in dyeing workers compared to the control group. Conclusion: Evaluation of dyeing workers’ respiratory system in this study showed that despite development in dyeing processes and engineering controls, workers in this job show more prevalent acute and chronic symptoms, and across-shift changes in spirometric parameters were significantly higher in this work group than the control group. Therefore it is necessary to pay attention to the control of respiratory exposures in this job. PMID:25664289

  16. AMO Teledioptric System for age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Chou, Jim-Son; Ting, Albert C.

    1994-05-01

    A 2.5 X magnification system consisting of a two-zone intraocular implant and a spectacle was developed, tested, and clinically tried by fifty patients with cataract ad age-related macular degeneration. Optical bench testing results and clinical data confirmed that the field of view of the system was 2.6 times wider than an equivalent external telescope. The study also demonstrated that the implant itself was clinically equivalent to a standard monofocal intraocular lens for cataract. The clinical study indicated that higher magnification without compromising the compactness and optical quality was needed as the disease progressed. Also, a sound vision rehabilitation process is important to provide patients the full benefits of the system.

  17. Wearable diagnostic system for age-related macular degeneration.

    PubMed

    Mohaghegh, N; Zadeh, E Ghafar; Magierowski, S

    2016-08-01

    This paper presents a novel head-mounted point-of-care diagnostic system for detection and continuous monitoring of Age-related Macular Degeneration (AMD). This wearable embedded open-source platform enables accurate monitoring of AMD by taking advantage of multiple standard graphical interface techniques such as Amsler Grid, Threshold Amsler Grid, Macular Computerized Psychophysical Test and Preferential Hyperacuity Perimeter (PHP). Here, we describe the proposed multi-Grid or so-called NGRID software and elaborate on the hardware prototype. This prototype includes a commercially available Oculus HMD incorporated with a single board computer. As the first step towards a fully integrated wearable system, this paper successfully proves the functionality of head-mounted graphical interface device ready for a live demonstration. Participants can experience this device and take a 10-minute AMD eye-exam. Furthermore, NGRID has been approved and permitted for an in-hospital clinical trial.

  18. Simultaneous adsorption of Remazol brilliant blue and Disperse orange dyes on red mud and isotherms for the mixed dye system.

    PubMed

    Gadigayya Mavinkattimath, Ratnamala; Shetty Kodialbail, Vidya; Govindan, Srinikethan

    2017-06-27

    The paper presents the adsorption of Remazol brilliant blue (RBB) and Disperse orange 25 (DO25) dyes from aqueous solution of the mixture of dyes onto concentrated sulphuric acid-treated red mud (ATRM). First-order derivative spectrophotometric method was developed for the analysis of RBB and DO25 in mixed dye aqueous solution to overcome the limitations arising due to interference in the zero-order spectral method. The optimum conditions to maximize RBB adsorption favoured the adsorption of RBB, and those for DO25 favoured DO25 adsorption from the mixed dye aqueous solutions. Presence of a second dye always inhibited the adsorption of a target dye. The uptake and percentage adsorption of each of the dyes onto ATRM from the aqueous solution of the mixture of dyes decreased considerably with increasing concentrations of the other dye showing the antagonistic effect. Monocomponent Langmuir isotherm fitted the mixed dye adsorption equilibrium data better than the monocomponent Freundlich isotherm. However, monocomponent models are suitable for the fixed concentration of the other dye. Modified Langmuir isotherm model adequately predicted the multi-component adsorption equilibrium data for RBB-DO25-ATRM adsorption system with a good accuracy and is more generic from the application point of view.

  19. Systemic blood plasma CCL5 and CXCL6: Potential biomarkers for human lumbar disc degeneration.

    PubMed

    Grad, S; Bow, C; Karppinen, J; Luk, K D; Cheung, K M; Alini, M; Samartzis, D

    2016-01-05

    Lumbar disc degeneration severity on magnetic resonance imaging (MRI) is associated with low back pain. Pro-inflammatory chemokines CCL5 and CXCL6 are released by induced degenerative discs, and CCL5 has been associated with discogenic back pain. A case-control study was performed, based on the Hong Kong Disc Degeneration Population-Based Cohort of Southern Chinese, to investigate if systemic levels of CCL5 and CXCL6 were elevated in subjects with disc degeneration compared to non-degenerated individuals. Eighty subjects were selected, 40 with no disc degeneration (control group; DDD score 0) and 40 with moderate/severe disc degeneration (disc degeneration group; DDD score ≥5) as noted on MRI. Subjects were matched for age, sex, body mass index and workload. Blood plasma samples were obtained from each individual, and levels of CCL5 and CXCL6 were measured. Secondary phenotypes of lumbar disc displacement and cervical disc changes were also assessed. CCL5 concentrations were significantly increased in the disc degeneration (mean: 19.8 ng/mL) compared to the control group (mean: 12.8 ng/mL) (p = 0.015). The degeneration group demonstrated higher levels of CXCL6 (mean: 56.9 pg/mL) compared to the control group (mean: 43.4 pg/mL) (p = 0.010). There was a trend towards elevated CCL5 levels with disc displacement in the degeneration group (p = 0.073). Cervical disc degeneration was not associated with elevated chemokine levels (p > 0.05). This is the first study to note that elevated systemic CCL5 and CXCL6 were associated with moderate/severe lumbar disc degeneration, further corroborating tissue studies of painful discs. These chemokines may be systemic biomarkers for the diagnosis and monitoring of disc degeneration.

  20. Formation of Degenerate Band Gaps in Layered Systems

    PubMed Central

    Ignatov, Anton I.; Merzlikin, Alexander M.; Levy, Miguel; Vinogradov, Alexey P.

    2012-01-01

    In the review, peculiarities of spectra of one-dimensional photonic crystals made of anisotropic and/or magnetooptic materials are considered. The attention is focused on band gaps of a special type—the so called degenerate band gaps which are degenerate with respect to polarization. Mechanisms of formation and properties of these band gaps are analyzed. Peculiarities of spectra of photonic crystals that arise due to the linkage between band gaps are discussed. Particularly, it is shown that formation of a frozen mode is caused by linkage between Brillouin and degenerate band gaps. Also, existence of the optical Borrmann effect at the boundaries of degenerate band gaps and optical Tamm states at the frequencies of degenerate band gaps are analyzed. PMID:28817024

  1. Conical intersections, charge localization, and photoisomerization pathway selection in a minimal model of a degenerate monomethine dye.

    PubMed

    Olsen, Seth; McKenzie, Ross H

    2009-12-21

    We propose a minimal model Hamiltonian for the electronic structure of a monomethine dye, in order to describe the photoisomerization of such dyes. The model describes interactions between three diabatic electronic states, each of which can be associated with a valence bond structure. Monomethine dyes are characterized by a charge-transfer resonance; the indeterminacy of the single-double bonding structure dictated by the resonance is reflected in a duality of photoisomerization pathways corresponding to the different methine bonds. The possible multiplicity of decay channels complicates mechanistic models of the effect of the environment on fluorescent quantum yields, as well as coherent control strategies. We examine the extent and topology of intersection seams between the electronic states of the dye and how they relate to charge localization and selection between different decay pathways. We find that intersections between the S(1) and S(0) surfaces only occur for large twist angles. In contrast, S(2)/S(1) intersections can occur near the Franck-Condon region. When the molecule has left-right symmetry, all intersections are associated with con- or disrotations and never with single bond twists. For asymmetric molecules (i.e., where the bridge couples more strongly to one end) the S(2) and S(1) surfaces bias torsion about different bonds. Charge localization and torsion pathway biasing are correlated. We relate our observations with several recent experimental and theoretical results, which have been obtained for dyes with similar structure.

  2. Magnetic Resonance Classification System of Cervical Intervertebral Disk Degeneration: Its Validity and Meaning.

    PubMed

    Suzuki, Akinobu; Daubs, Michael D; Hayashi, Tetsuo; Ruangchainikom, Monchai; Xiong, Chenjie; Phan, Kevin; Scott, Trevor P; Wang, Jeffery C

    2017-06-01

    Retrospective analysis of kinetic magnetic resonance images (kMRIs). (1) To analyze the changes seen on MRI related to disk degeneration and to develop a new grading system for cervical disk degeneration. (2) To evaluate the reliability and validity of the grading system. Few have studied the relationship between changes seen on MRI with cervical disk degeneration and the chronological order of disk degeneration. A few grading systems for cervical disk degeneration have been reported; however, there have been problems related to subjectivity and lack of a clear, reliable algorithm. A total of 300 cervical intervertebral disks were graded for nucleus color, structure, disk bulge, and disk height. On the basis of the analysis, a new grading system consisting of 4 grades (grade 0-III) and algorithm were developed. Intraobserver and interobserver reliabilities were assessed. A total of 2802 intervertebral disks were then evaluated using the grading system to correlate disk degeneration grades with patient age and function and to evaluate the validity of the new system. On the basis of cross-table analysis, disk degeneration presents in the following order: (1) decrease and/or change of nucleus intensity; (2) loss of distinction between nucleus and annulus; (3) positive disk bulge; and (4) disk height decrease. The κ-coefficients for intraobserver and interobserver agreements were 0.96 and 0.90, respectively. Severe disk degeneration is most common at C5/C6 followed by C6/C7 and C4/C5, and total disk degeneration grade is correlated with age (R=0.467). There was a decrease of angular motion in grades I-III and an increase in translational motion and decrease of space available for the cord in grades II-III. We developed a new classification system of cervical disk degeneration based on analysis of the changes seen on MRI. Reliability tests indicated high reproducibility of this system, and further analysis confirmed its validity and clinical significance.

  3. Systemic complement activation in age-related macular degeneration.

    PubMed

    Scholl, Hendrik P N; Charbel Issa, Peter; Walier, Maja; Janzer, Stefanie; Pollok-Kopp, Beatrix; Börncke, Florian; Fritsche, Lars G; Chong, Ngaihang V; Fimmers, Rolf; Wienker, Thomas; Holz, Frank G; Weber, Bernhard H F; Oppermann, Martin

    2008-07-02

    Dysregulation of the alternative pathway (AP) of complement cascade has been implicated in the pathogenesis of age-related macular degeneration (AMD), the leading cause of blindness in the elderly. To further test the hypothesis that defective control of complement activation underlies AMD, parameters of complement activation in blood plasma were determined together with disease-associated genetic markers in AMD patients. Plasma concentrations of activation products C3d, Ba, C3a, C5a, SC5b-9, substrate proteins C3, C4, factor B and regulators factor H and factor D were quantified in patients (n = 112) and controls (n = 67). Subjects were analyzed for single nucleotide polymorphisms in factor H (CFH), factor B-C2 (BF-C2) and complement C3 (C3) genes which were previously found to be associated with AMD. All activation products, especially markers of chronic complement activation Ba and C3d (p<0.001), were significantly elevated in AMD patients compared to controls. Similar alterations were observed in factor D, but not in C3, C4 or factor H. Logistic regression analysis revealed better discriminative accuracy of a model that is based only on complement activation markers Ba, C3d and factor D compared to a model based on genetic markers of the complement system within our study population. In both the controls' and AMD patients' group, the protein markers of complement activation were correlated with CFH haplotypes.This study is the first to show systemic complement activation in AMD patients. This suggests that AMD is a systemic disease with local disease manifestation at the ageing macula. Furthermore, the data provide evidence for an association of systemic activation of the alternative complement pathway with genetic variants of CFH that were previously linked to AMD susceptibility.

  4. Kangaroo rats exhibit spongiform degeneration of the central auditory system similar to that found in gerbils.

    PubMed

    McGinn, M D; Faddis, B T

    1997-02-01

    Kangaroo rats develop spongiform degeneration of the central auditory system similar to that seen in the gerbil. Light microscopic and transmission electron microscopic study of the cochlear nucleus and auditory nerve root (ANR) of Dipodomys deserti and D. merriami show that spongiform lesions develop in dendrites and oligodendrocytes of the cochlear nucleus and in oligodendrocytes of the ANR that are morphologically indistinguishable from those extensively described in the Mongolian gerbil, Meriones unguiculatus. As in Mongolian gerbils, the spongiform degeneration in Dipodomys were much more numerous in animals continually exposed to modest levels of low-frequency noise (< 75 dB SPL). The kangaroo rats with extensive spongiform degeneration also show slightly, but significantly, elevated auditory brainstem evoked response (ABR) thresholds to low-frequency stimuli, a result also found in Mongolian gerbils. These results suggest that the elevated ABR thresholds may be the result of spongiform degeneration. Because low-frequency noise-induced spongiform degeneration has now been shown in the cochlear nucleus of animals from separate families of Rodentia (Heteromyidae and Muridae), the possibility should be investigated that similar noise-induced degenerative changes occur in the central auditory system of other mammals with good low-frequency hearing.

  5. Adsorption kinetics and isotherm of anionic dyes onto organo-bentonite from single and multisolute systems.

    PubMed

    Shen, Dazhong; Fan, Jianxin; Zhou, Weizhi; Gao, Baoyu; Yue, Qinyan; Kang, Qi

    2009-12-15

    The performances of polydiallydimethylammonium modified bentonite (PDADMA-bentonite) as an adsorbent to remove anionic dyes, namely Acid Scarlet GR (AS-GR), Acid Turquoise Blue 2G (ATB-2G) and Indigo Carmine (IC), were investigated in single, binary and ternary dye systems. In adsorption from single dye solutions with initial concentration of 100 micromol/L, the dosage of PDADMA-bentonite needed to remove 95% dye was 0.42, 0.68 and 0.75 g/L for AS-GR, ATB-2G and IC, respectively. The adsorption isotherms of the three dyes obeyed the Langmuir isotherm model with the equilibrium constants of 0.372, 0.629 and 4.31 L/micromol, the saturation adsorption amount of 176.3, 149.2 and 228.7 micromol/g for ATB-2G, IC and AS-GR, respectively. In adsorption from mixed dye solutions, the isotherm of each individual dye followed an expanded Langmuir isotherm model and the relationship between the total amount of dyes adsorbed and the total equilibrium dye concentration was interpreted well by Langmuir isotherm model. In the region of insufficient dosage of PDADMA-bentonite, the dye with a larger affinity was preferentially removed by adsorption. Desorption was observed in the kinetic curve of the dye with lower affinity on PDADMA-bentonite surface by the competitive adsorption. The kinetics in single dye solution and the total adsorption of dyes in binary and ternary dye systems nicely followed pseudo-second-order kinetic model.

  6. Classification of nondegenerate equilibria and degenerate 1-dimensional orbits of the Kovalevskaya-Yehia integrable system

    SciTech Connect

    Logacheva, Nina S

    2012-01-31

    The paper is devoted to a topological analysis of the Kovalevskaya-Yehia integrable case in rigid body dynamics. It is proved that the integral has the Bott property on isoenergy surfaces of the system; the topology of the Liouville foliation in a neighbourhood of degenerate 1-dimensional orbits and equilibria (points of rank 0) is also described. In particular, marked loop molecules are constructed for degenerate 1-dimensional orbits, and a representation in the form of an almost direct product is found for nondegenerate singularities of rank 0. Bibliography: 17 titles.

  7. Trans-synaptic Retrograde Degeneration in the Human Visual System: Slow, Silent, and Real.

    PubMed

    Dinkin, Marc

    2017-02-01

    Degeneration of neuron and axons following injury to cells with which they synapse is termed trans-synaptic degeneration. This phenomenon may be seen in postsynaptic neurons (anterograde) or in presynaptic neurons (retrograde). Retrograde trans-synaptic degeneration (RTSD) of the retinal ganglion cells and retinal nerve fiber layer following injury to the occipital lobe has been well documented histologically in animal studies, but its occurrence in the human retina was, for many years, felt to be limited to cases of neonatal injury during a critical period of neuronal development. Over the last decade, imaging techniques such as MRI and optical coherence tomography have allowed us to visualize and quantify RTSD and analyze its time course and relationship to degree of vision loss and age of cortical injury. A deeper understanding of RTSD in the human visual system may allow us to interfere with its occurrence, potentially allowing for greater recovery following visual cortex injury.

  8. Holographic Recordings in Dye/Polymer Systems For Engineering Applications

    NASA Astrophysics Data System (ADS)

    Lessard, Roger A.; Couture, Jean J.

    1990-04-01

    Since Gabor's first demonstration of reconstructed wavefronts, many holographic techniques provided interesting tools and applications. Presently the future of holography is strongly dependent upon new holographic recording thin films. Because of their excellent responses to high spatial frequency grating recordings (up to 6800 cycles/mm), photopolymers and photocrosslinking materials seem to be good candidates to overcome some limitations. Dichromated gelatin films demons-trated excellent properties for permanent recording grating applications like HOE construction but they are humidity sensitive and they need a chemical development. Today's holographic works need real-time like recording material and law cost organic materials as DYE/POLYMER systems offer some possibilities. We present a review of research works done in our holography laboratories of COPL at Universite Laval. Using an automated spatial frequency analyzer designed at COPL, DYE/POLYMER systems are characterized for transmission holography and also for applications involving real-time holography and four-wave mixing techniques. Also, most of our characterization studies consider volume polarization holograms. The second subject is devoted to polarization hologram recordings in thin colored polyvinyl alcohol films. Those AZO/WA solid films are erasable and can be used for many thousands duty cycles for polarization volume holograms. Holographic characterization studies are conducted in order to know best experimental conditions and applications that allow to use those films. Finally, sensitized PVA films will be discussed.

  9. Modal interaction in linear dynamic systems near degenerate modes

    NASA Technical Reports Server (NTRS)

    Afolabi, D.

    1991-01-01

    In various problems in structural dynamics, the eigenvalues of a linear system depend on a characteristic parameter of the system. Under certain conditions, two eigenvalues of the system approach each other as the characteristic parameter is varied, leading to modal interaction. In a system with conservative coupling, the two eigenvalues eventually repel each other, leading to the curve veering effect. In a system with nonconservative coupling, the eigenvalues continue to attract each other, eventually colliding, leading to eigenvalue degeneracy. Modal interaction is studied in linear systems with conservative and nonconservative coupling using singularity theory, sometimes known as catastrophe theory. The main result is this: eigenvalue degeneracy is a cause of instability; in systems with conservative coupling, it induces only geometric instability, whereas in systems with nonconservative coupling, eigenvalue degeneracy induces both geometric and elastic instability. Illustrative examples of mechanical systems are given.

  10. Supramolecular guest-host systems: combining high dye doping level with low aggregation tendency

    NASA Astrophysics Data System (ADS)

    Priimagi, Arri; Cattaneo, Stefano; Ras, Robin H. A.; Valkama, Sami; Ikkala, Olli; Kauranen, Martti

    2006-08-01

    We demonstrate that the aggregation tendency of dye molecules in a host polymer can be significantly reduced by exploiting non-covalent interactions between the host polymer and guest dye molecules. Such interactions occur spontaneously with no need for chemical synthesis, and could thus be utilized to combine the ease of processing of traditional guest-host systems with the high dye concentrations achievable in covalently linked systems. We studied the aggregation properties of the common azo-dye Disperse Red 1 in polymers with different functional groups. Compared to a nonpolar polymer (polystyrene), dye aggregation tendency is substantially reduced in polar polymer matrices containing hydrogen-bond donating [poly(vinylphenol)] or hydrogen-bond accepting [poly(4-vinylpyridine)] functional sites. Furthermore, by forming a polyelectrolyte-dye complex [Disperse Red 1/poly(styrenesulfonic acid)], a dye monomer can be attached to approximately each polymer unit, resulting in dye concentration of 63 wt. %. Complexation through proton transfer was further studied by using a fluorescent dye 5-phenyl-2-(4-pyridyl)oxazole. Our results indicate that polymer-dye complexes could provide a facile route for new type of optical materials, with potential applications in various fields of optics and photonics.

  11. Noncontact evaluation of articular cartilage degeneration using a novel ultrasound water jet indentation system.

    PubMed

    Lu, M-H; Zheng, Y P; Huang, Q-H; Ling, C; Wang, Q; Bridal, L; Qin, L; Mak, A

    2009-01-01

    We previously reported a noncontact ultrasound water jet indentation system for measuring and mapping tissue mechanical properties. The key idea was to utilize a water jet as an indenter as well as the coupling medium for high-frequency ultrasound. In this paper, the system was employed to assess articular cartilage degeneration, using stiffness ratio as an indicator of the mechanical properties of samples. Both the mechanical and acoustical properties of intact and degenerated bovine patellar articular cartilage (n = 8) were obtained in situ. It was found that the stiffness ratio was reduced by 44 +/- 17% after the articular cartilage was treated by 0.25% trypsin at 37 degrees C for 4 h while no significant difference in thickness was observed between the intact and degenerated samples. A significant decrease of 36 +/- 20% in the peak-to-peak amplitude of ultrasound echoes reflected from the cartilage surface was also found for the cartilage samples treated by trypsin. The results also showed that the stiffness obtained with the new method highly correlated with that measured using a standard mechanical testing protocol. A good reproducibility of the measurements was demonstrated. The present results showed that the ultrasound water jet indentation system may provide a potential tool for the non-destructive evaluation of articular cartilage degeneration by simultaneously obtaining mechanical properties, acoustical properties, and thickness data.

  12. Lorentz estimates for degenerate and singular evolutionary systems

    NASA Astrophysics Data System (ADS)

    Baroni, Paolo

    We prove estimates of Calderón-Zygmund type for evolutionary p-Laplacian systems in the setting of Lorentz spaces. We suppose the coefficients of the system to satisfy only a VMO condition with respect to the space variable. Our results hold true, mutatis mutandis, also for stationary p-Laplacian systems.

  13. Fishing for age-related visual system mutants: behavioral screening of retinal degeneration genes in zebrafish.

    PubMed

    Li, Lei; Li, Yuhao; Chen, Dongyan; Shao, Jinping; Li, Xinle; Xu, Chen

    2010-02-01

    The zebrafish (Danio rerio) has recently become a mainstream model system for genetic studies of human diseases, such as neurological degenerative diseases, heart diseases, immuno-system disorders, etc. In this article, we will review some recent findings of the usefulness of zebrafish as a model vertebrate for behavioral screening of mutations in vertebrate visual system, for example, genes involved in age-related retinal degeneration.

  14. Degradability of selected azo dye metabolites in activated sludge systems.

    PubMed

    Ekici, P; Leupold, G; Parlar, H

    2001-08-01

    The stability of eight environmentally relevant azo dye metabolites [o-aminotoluene (2), 4,4'-thiodianiline (4), 4,4'-diaminodiphenylmethane (6), p-chloroaniline (7), 2,4-toluylenediamine (9), p-kresidine (14), 2,4-diaminoanisole (15), and 2-naphthylamine (18)] was investigated in activated sludge systems and compared to their hydrolysis stability. For both studies, test systems of the EC and EPA were used. The results show that degradation under aerobic conditions proceeds via oxidation of the substituents located on the aromatic ring or on the side chain. Under anaerobic conditions, the azo bond is reductively cleaved, which leads to the substituted amines. These are toxic and potentially hazardous to the environment.

  15. Characterization of degeneration process in combustion instability based on dynamical systems theory

    NASA Astrophysics Data System (ADS)

    Gotoda, Hiroshi; Okuno, Yuta; Hayashi, Kenta; Tachibana, Shigeru

    2015-11-01

    We present a detailed study on the characterization of the degeneration process in combustion instability based on dynamical systems theory. We deal with combustion instability in a lean premixed-type gas-turbine model combustor, one of the fundamentally and practically important combustion systems. The dynamic behavior of combustion instability in close proximity to lean blowout is dominated by a stochastic process and transits to periodic oscillations created by thermoacoustic combustion oscillations via chaos with increasing equivalence ratio [Chaos 21, 013124 (2011), 10.1063/1.3563577; Chaos 22, 043128 (2012), 10.1063/1.4766589]. Thermoacoustic combustion oscillations degenerate with a further increase in the equivalence ratio, and the dynamic behavior leads to chaotic fluctuations via quasiperiodic oscillations. The concept of dynamical systems theory presented here allows us to clarify the nonlinear characteristics hidden in complex combustion dynamics.

  16. Characterization of degeneration process in combustion instability based on dynamical systems theory.

    PubMed

    Gotoda, Hiroshi; Okuno, Yuta; Hayashi, Kenta; Tachibana, Shigeru

    2015-11-01

    We present a detailed study on the characterization of the degeneration process in combustion instability based on dynamical systems theory. We deal with combustion instability in a lean premixed-type gas-turbine model combustor, one of the fundamentally and practically important combustion systems. The dynamic behavior of combustion instability in close proximity to lean blowout is dominated by a stochastic process and transits to periodic oscillations created by thermoacoustic combustion oscillations via chaos with increasing equivalence ratio [Chaos 21, 013124 (2011); Chaos 22, 043128 (2012)]. Thermoacoustic combustion oscillations degenerate with a further increase in the equivalence ratio, and the dynamic behavior leads to chaotic fluctuations via quasiperiodic oscillations. The concept of dynamical systems theory presented here allows us to clarify the nonlinear characteristics hidden in complex combustion dynamics.

  17. Duration of classicality in highly degenerate interacting Bosonic system

    NASA Astrophysics Data System (ADS)

    Todarello, Elisa; Sikivie, Pierre

    2017-01-01

    We study sets of oscillators that have high quantum occupancy and that interact by exchanging quanta. It is shown by analytical arguments and numerical simulations that such systems obey classical equations of motion only on timescales of order their relaxation time τ and not longer than that. The results are relevant to the cosmology of axions and axion-like particles. U. S. Department of Energy.

  18. Ionomycin-induced calcium influx induces neurite degeneration in mouse neuroblastoma cells: analysis of a time-lapse live cell imaging system.

    PubMed

    Nakamura, Saki; Nakanishi, Ayumi; Takazawa, Minami; Okihiro, Shunsuke; Urano, Shiro; Fukui, Koji

    2016-01-01

    Reactive oxygen species induce neuronal cell death. However, the detailed mechanisms of cell death have not yet been elucidated. Previously, we reported neurite degeneration before the induction of cell death. Here, we attempted to elucidate the mechanisms of neurite degeneration before the induction of cell death using the neuroblastoma N1E-115 cell line and a time-lapse live cell imaging system. Treatment with the calcium ionophore ionomycin induced cell death and neurite degeneration in a concentration- and time-dependent manner. Treatment with a low concentration of ionomycin immediately produced a significant calcium influx into the intracellular region in N1E-115 cells. After 1-h incubation with ionomycin, the fluorescence emission of MitoSOX(TM) increased significantly compared to the control. Finally, analysis using a new mitochondrial specific fluorescence dye, MitoPeDPP, indicated that treatment with ionomycin significantly increased the mitochondrial lipid hydroperoxide production in N1E-115 cells. The fluorescence emissions of Fluo-4 AM and MitoPeDPP were detected in the cell soma and neurite regions in ionomycin-treated N1E-115 cells. However, the emissions of neurites were much lower than those of the cell soma. TBARS values of ionomycin-treated cells significantly increased compared to the control. These results indicate that ionomycin induces calcium influx into the intracellular region and reactive oxygen species production in N1E-115 cells. Lipid hydroperoxide production was induced in ionomycin-treated N1E-115 cells. Calcium influx into the intracellular region is a possible activator of neurite degeneration.

  19. Pathology and possible mechanisms of nervous system response to disc degeneration.

    PubMed

    Brisby, Helena

    2006-04-01

    Degeneration of the intervertebral disc is clinically considered to be an important source of pain in patients with low-back pain. Disc deterioration and/or degeneration may influence the nervous system by stimulation of nociceptors in the anulus fibrosus, causing nociceptive pain that is often referred to as discogenic pain. The stimulation of the nociceptors may be of mechanical or inflammatory origin. Deterioration of a disc with loss of normal structure and weight-bearing properties may lead to abnormal motions that cause mechanical stimulation. This theory is supported by the fact that patients commonly experience an increase in pain with weight-bearing and certain movements. In addition, an ingrowth of vessels and nerve fibers into deeper layers of the anulus fibrosus has been observed in degenerated discs. A large number of inflammatory and signaling substances, such as tumor necrosis factor and interleukins (interleukin-1beta, interleukin-6, and interleukin-8), may also play a role in the development of back pain. Independent of stimulus of the nociceptors, the pain impulses are conducted through myelinated A delta fibers and unmyelinated C fibers to the dorsal root ganglion and continue by way of the spinothalamic tract to the thalamus and the somatosensory cortex. In response to stimulation of the nociceptors in the disc, the somatosensory system may increase its sensitivity, resulting in a nonfunctional response; that is, normally innocuous stimuli may generate an amplified response (peripheral sensitization). When disc degeneration leads to a disc herniation, the adjacent nervous system structures, such as the nerve roots or the dorsal root ganglion, can be affected, causing neuropathic pain of mechanical or biochemical origin. Disc deterioration also influences other spinal structures, such as facet joints, ligaments, and muscles, which can also become pain generators. Thus, disc degeneration may be responsible for the development of chronic low

  20. Laccase-mediator system in the decolorization of different types of recalcitrant dyes.

    PubMed

    Hu, Mei Rong; Chao, Ya Peng; Zhang, Guo Qing; Xue, Zhi Quan; Qian, Shijun

    2009-01-01

    Phloroglucinol, thymol, and violuric acid (VIO) were selected as laccase mediators after screening 14 different compounds with indigo carmine (indigoid dye) as a substrate. With the presence of these three mediators, a nearly complete decolorization (90-100%) was attained in 1 h. Thus, these three compounds were used as mediators for the decolorization of other four dyes. The results indicated that VIO was effective mediator in decolorization of Remazol brilliant blue R (RBBR, anthraquinoid dye) and Coomassie brilliant blue G-250 (CBB, triphenylmethane dyes), and Acid red (diazo dye). In presence of VIO, the four dyes described above attained 70% decolorization. Thymol was able to mediate decolorization of RBBR and Azure A (heterocyclic dye). Phloroglucinol has no mediating capability in decolorization of the four dyes analyzed. Mediator concentration, pH, and copper ion have an effect on the decolorization of the RBBR. Our data suggested that the decolorization capabilities of laccase/mediator system were related to the types of mediator, the dye structure and decolorization condition.

  1. Spreading fronts in a partially degenerate integro-differential reaction–diffusion system

    NASA Astrophysics Data System (ADS)

    Li, Wan-Tong; Zhao, Meng; Wang, Jie

    2017-10-01

    This paper is concerned with the spreading and vanishing of an epidemic disease, which is described by a partially degenerate reaction-diffusion system with the nonlocal term and double free boundaries. We first consider the sign of the corresponding principal eigenvalue, which is determined by some given conditions. Then, we get the sufficient conditions that ensure the disease spreading or vanishing. At last, when spreading occurs, some rough estimates of the asymptotic spreading speed are given under some conditions.

  2. The Neuroimmunology of Degeneration and Regeneration in the Peripheral Nervous System

    PubMed Central

    Zigmond, R. E.

    2014-01-01

    Peripheral nerves regenerate following injury due to the effective activation of the intrinsic growth capacity of the neurons and the formation of a permissive pathway for outgrowth due to Wallerian degeneration. Wallerian degeneration and subsequent regeneration are significantly influenced by various immune cells and the cytokines they secrete. Although macrophages have long been known to play a vital role in the degenerative process, recent work has pointed to their importance in influencing the regenerative capacity of peripheral neurons. In this review, we focus on the various immune cells, cytokines, and chemokines that make regeneration possible in the peripheral nervous system, with specific attention placed on the role macrophages play in this process. PMID:25242643

  3. Lamb shift of non-degenerate energy level systems placed between two infinite parallel conducting plates

    NASA Astrophysics Data System (ADS)

    Billaud, B.; Truong, T.-T.

    2013-01-01

    In this paper, the Lamb shift in systems with non-degenerate energy levels, put in the electromagnetic environment provided by two infinite parallel conducting plates, is analyzed. An explicit formula giving the relative Lamb shift (as compared to the standard one in a vacuum) is derived for spherical semiconductor quantum dots (QDs), via a careful mathematical treatment of divergences in the calculations using the theory of distributions. This result settles a controversy between two different formulas existing in the current literature. Its sensitive dependence on the plates separation may be viewed as an indirect manifestation of the Lamb shift and may be used for the fine tuning of the QD non-degenerate energy spectrum in some experimental contexts.

  4. Degeneration in central and peripheral nervous systems produced by pure n-hexane: an experimental study.

    PubMed

    Schaumburg, H H; Spencer, P S

    1976-06-01

    Rats intoxicated with pure n-hexane, either by repetitive subcutaneous injection or by continuous inhalation, developed clinical and/or pathological evidence of peripheral neuropathy. Animals intoxicated by inhalation (400-600 ppm) developed clinical signs after forty-five days and displayed giant axonal swellings and fibre degeneration both in the central and peripheral nervous systems. The changes were most strking in tibial nerves supplying calf muscles and in selected areas of the cerebellum, medulla and spinal cord. In contrast to the usual picture associated with dying-back disease, the distal regions of proximal nerve fibres supplying calf muscles degenerated before equivalent regions of longer fibres supplying the hindfeet. The relevance of the central nervous changes to individuals recovering from toxic neuropathies and the need for a reduction of the present Threshold Limit Value (500 ppm) for human exposure are discussed.

  5. Synthesis of Charge Transfer Dyes for Use as Molecular Sensors in Biological Systems

    NASA Technical Reports Server (NTRS)

    Christie, Joseph J.

    2003-01-01

    This is a continuation of last year's project to synthesize tetraaryl substituted benzodifurans for use as molecular probes in biological systems. The project will involve the synthesis and chemical characterization of dyes and precursor molecules.

  6. Synthesis of Charge Transfer Dyes for Use as Molecular Sensors in Biological Systems

    NASA Technical Reports Server (NTRS)

    Christie, Joseph J.

    2003-01-01

    This is a continuation of last year's project to synthesize tetraaryl substituted benzodifurans for use as molecular probes in biological systems. The project will involve the synthesis and chemical characterization of dyes and precursor molecules.

  7. Degenerate mixtures of rubidium and ytterbium for engineering open quantum systems

    NASA Astrophysics Data System (ADS)

    Vaidya, Varun Dilip

    In the last two decades, experimental progress in controlling cold atoms and ions now allows us to manipulate fragile quantum systems with an unprecedented degree of precision. This has been made possible by the ability to isolate small ensembles of atoms and ions from noisy environments, creating truly closed quantum systems which decouple from dissipative channels. However in recent years, several proposals have considered the possibility of harnessing dissipation in open systems, not only to cool degenerate gases to currently unattainable temperatures, but also to engineer a variety of interesting many-body states. This thesis will describe progress made towards building a degenerate gas apparatus that will soon be capable of realizing these proposals. An ultracold gas of ytterbium atoms, trapped by a species-selective lattice will be immersed into a Bose-Einstein condensate (BEC) of rubidium atoms which will act as a bath. Here we describe the challenges encountered in making a degenerate mixture of rubidium and ytterbium atoms and present two experiments performed on the path to creating a controllable open quantum system. The first experiment will describe the measurement of a tune-out wavelength where the light shift of 87Rb vanishes. This wavelength was used to create a species-selective trap for ytterbium atoms. Furthermore, the measurement of this wavelength allowed us to extract the dipole matrix element of the 5s → 6p transition in 87Rb with an extraordinary degree of precision. Our method to extract matrix elements has found use in atomic clocks where precise knowledge of transition strengths is necessary to account for minute blackbody radiation shifts. The second experiment will present the first realization of a degenerate Bose-Fermi mixture of rubidium and ytterbium atoms. Using a three-color optical dipole trap (ODT), we were able to create a highly-tunable, species-selective potential for rubidium and ytterbium atoms which allowed us to use 87

  8. Age-related degeneration of the egg-laying system promotes matricidal hatching in Caenorhabditis elegans.

    PubMed

    Pickett, Christopher L; Kornfeld, Kerry

    2013-08-01

    The identification and characterization of age-related degenerative changes is a critical goal because it can elucidate mechanisms of aging biology and contribute to understanding interventions that promote longevity. Here, we document a novel, age-related degenerative change in C. elegans hermaphrodites, an important model system for the genetic analysis of longevity. Matricidal hatching--intra-uterine hatching of progeny that causes maternal death--displayed an age-related increase in frequency and affected ~70% of mated, wild-type hermaphrodites. The timing and incidence of matricidal hatching were largely independent of the levels of early and total progeny production and the duration of male exposure. Thus, matricidal hatching appears to reflect intrinsic age-related degeneration of the egg-laying system rather than use-dependent damage accumulation. Consistent with this model, mutations that extend longevity by causing dietary restriction significantly delayed matricidal hatching, indicating age-related degeneration of the egg-laying system is controlled by nutrient availability. To identify the underlying tissue defect, we analyzed serotonin signaling that triggers vulval muscle contractions. Mated hermaphrodites displayed an age-related decline in the ability to lay eggs in response to exogenous serotonin, indicating that vulval muscles and/or a further downstream function that is necessary for egg laying degenerate in an age-related manner. By characterizing a new, age-related degenerative event displayed by C. elegans hermaphrodites, these studies contribute to understanding a frequent cause of death in mated hermaphrodites and establish a model of age-related reproductive complications that may be relevant to the birthing process in other animals such as humans.

  9. Extractive biodecolorization of triphenylmethane dyes in cloud point system by Aeromonas hydrophila DN322p.

    PubMed

    Pan, Tao; Ren, Suizhou; Xu, Meiying; Sun, Guoping; Guo, Jun

    2013-07-01

    The biological treatment of triphenylmethane dyes is an important issue. Most microbes have limited practical application because they cannot completely detoxicate these dyes. In this study, the extractive biodecolorization of triphenylmethane dyes by Aeromonas hydrophila DN322p was carried out by introducing the cloud point system. The cloud point system is composed of a mixture of nonionic surfactants (20 g/L) Brij 30 and Tergitol TMN-3 in equal proportions. After the decolorization of crystal violet, a higher wet cell weight was obtained in the cloud point system than that of the control system. Based on the results of thin-layer chromatography, the residual crystal violet and its decolorized product, leuco crystal violet, preferred to partition into the coacervate phase. Therefore, the detoxification of the dilute phase was achieved, which indicated that the dilute phase could be discharged without causing dye pollution. The extractive biodecolorization of three other triphenylmethane dyes was also examined in this system. The decolorization of malachite green and brilliant green was similar to that of crystal violet. Only ethyl violet achieved a poor decolorization rate because DN322p decolorized it via adsorption but did not convert it into its leuco form. This study provides potential application of biological treatment in triphenylmethane dye wastewater.

  10. Systemic administration of a proteasome inhibitor does not cause nigrostriatal dopamine degeneration.

    PubMed

    Mathur, Brian N; Neely, M Diana; Dyllick-Brenzinger, Melanie; Tandon, Anurag; Deutch, Ariel Y

    2007-09-07

    Proteasomal dysfunction has been suggested to contribute to the degeneration of nigrostriatal dopamine neurons in Parkinson's disease. A recent study reported that systemic treatment of rats with the proteasome inhibitor Z-lle-Glu(OtBu)-Ala-Leu-al (PSI) causes a slowly progressive degeneration of nigrostriatal dopamine neurons, the presence of inclusion bodies in dopamine neurons, and motor impairment. We examined in vitro and in vivo the effects of PSI on nigrostriatal dopamine neurons. Mass spectrometric analysis was employed to verify the authenticity of the PSI compound. PSI was non-specifically toxic to neurons in ventral mesencephalic organotypic slice cultures, indicating that impairment of proteasome function in vitro is toxic. Moreover, systemic administration of PSI transiently decreased brain proteasome activity. Systemic treatment of rats with PSI did not, however, result in any biochemical or anatomical evidence of lesions of nigrostriatal dopamine neurons, nor were any changes in locomotor activity observed. These data suggest that systemic administration of proteasome inhibitors to normal adult rats does not reliably cause an animal model of parkinsonism.

  11. Optimization of biosorptive removal of dye from aqueous system by cone shell of Calabrian pine.

    PubMed

    Deniz, Fatih

    2014-01-01

    The biosorption performance of raw cone shell of Calabrian pine for C.I. Basic Red 46 as a model azo dye from aqueous system was optimized using Taguchi experimental design methodology. L9 (3(3)) orthogonal array was used to optimize the dye biosorption by the pine cone shell. The selected factors and their levels were biosorbent particle size, dye concentration, and contact time. The predicted dye biosorption capacity for the pine cone shell from Taguchi design was obtained as 71.770 mg g(-1) under optimized biosorption conditions. This experimental design provided reasonable predictive performance of dye biosorption by the biosorbent (R (2): 0.9961). Langmuir model fitted better to the biosorption equilibrium data than Freundlich model. This displayed the monolayer coverage of dye molecules on the biosorbent surface. Dubinin-Radushkevich model and the standard Gibbs free energy change proposed physical biosorption for predominant mechanism. The logistic function presented the best fit to the data of biosorption kinetics. The kinetic parameters reflecting biosorption performance were also evaluated. The optimization study revealed that the pine cone shell can be an effective and economically feasible biosorbent for the removal of dye.

  12. Optimization of Biosorptive Removal of Dye from Aqueous System by Cone Shell of Calabrian Pine

    PubMed Central

    Deniz, Fatih

    2014-01-01

    The biosorption performance of raw cone shell of Calabrian pine for C.I. Basic Red 46 as a model azo dye from aqueous system was optimized using Taguchi experimental design methodology. L9 (33) orthogonal array was used to optimize the dye biosorption by the pine cone shell. The selected factors and their levels were biosorbent particle size, dye concentration, and contact time. The predicted dye biosorption capacity for the pine cone shell from Taguchi design was obtained as 71.770 mg g−1 under optimized biosorption conditions. This experimental design provided reasonable predictive performance of dye biosorption by the biosorbent (R 2: 0.9961). Langmuir model fitted better to the biosorption equilibrium data than Freundlich model. This displayed the monolayer coverage of dye molecules on the biosorbent surface. Dubinin-Radushkevich model and the standard Gibbs free energy change proposed physical biosorption for predominant mechanism. The logistic function presented the best fit to the data of biosorption kinetics. The kinetic parameters reflecting biosorption performance were also evaluated. The optimization study revealed that the pine cone shell can be an effective and economically feasible biosorbent for the removal of dye. PMID:25405213

  13. Macular degeneration

    MedlinePlus Videos and Cool Tools

    ... at the center of the field of vision. Macular degeneration results from a partial breakdown of the insulating ... choroid layer of blood vessels behind the retina. Macular degeneration results in the loss of central vision only.

  14. DISCOVERY OF A BRIGHT, EXTREMELY LOW MASS WHITE DWARF IN A CLOSE DOUBLE DEGENERATE SYSTEM

    SciTech Connect

    Vennes, S.; Kawka, A.; Nemeth, P.; Thorstensen, J. R.; Skinner, J. N.; Pigulski, A.; Steslicki, M.; Kolaczkowski, Z.; Srodka, P.

    2011-08-10

    We report the discovery of a bright (V {approx} 13.7), extremely low mass white dwarf in a close double degenerate system. We originally selected GALEX J171708.5+675712 for spectroscopic follow-up among a group of white dwarf candidates in an ultraviolet-optical reduced proper-motion diagram. The new white dwarf has a mass of 0.18 M{sub sun} and is the primary component of a close double degenerate system (P = 0.246137 days, K{sub 1} = 288 km s{sup -1}) comprising a fainter white dwarf secondary with M{sub 2} {approx} 0.9 M{sub sun}. Light curves phased with the orbital ephemeris show evidence of relativistic beaming and weaker ellipsoidal variations. The light curves also reveal secondary eclipses (depth {approx}8 mmag) while the primary eclipses appear partially compensated by the secondary gravitational deflection and are below detection limits. Photospheric abundance measurements show a nearly solar composition of Si, Ca, and Fe (0.1-1 sun), while the normal kinematics suggest a relatively recent formation history. Close binary evolutionary scenarios suggest that extremely low mass white dwarfs form via a common-envelope phase and possible Roche lobe overflow.

  15. Functional behavior of bio-electrochemical treatment system with increasing azo dye concentrations: Synergistic interactions of biocatalyst and electrode assembly.

    PubMed

    Sreelatha, S; Velvizhi, G; Naresh Kumar, A; Venkata Mohan, S

    2016-08-01

    Treatment of dye bearing wastewater through biological machinery is particularly challenging due to its recalcitrant and inhibitory nature. In this study, functional behavior and treatment efficiency of bio-electrochemical treatment (BET) system was evaluated with increasing azo dye concentrations (100, 200, 300 and 500mg dye/l). Maximum dye removal was observed at 300mg dye/l (75%) followed by 200mg dye/l (65%), 100mg dye/l (62%) and 500mg dye/l (58%). Concurrent increment in dye load resulted in enhanced azo reductase and dehydrogenase activities respectively (300mg dye/l: 39.6U; 4.96μg/ml). Derivatives of cyclic voltammograms also supported the involvement of various membrane bound redox shuttlers, viz., cytochrome-c, cytochrome-bc1 and flavoproteins during the electron transfer. Bacterial respiration during BET operation utilized various electron acceptors such as electrodes and dye intermediates with simultaneous bioelectricity generation. This study illustrates the synergistic interaction of biocatalyst with electrode assembly for efficient treatment of azo dye wastewater.

  16. Circularly polarized laser emission induced in isotropic and achiral dye systems

    PubMed Central

    Cerdán, Luis; García-Moreno, Sara; Costela, Angel; García-Moreno, Inmaculada; de la Moya, Santiago

    2016-01-01

    The production of efficient, tunable, and switchable circularly polarized laser emission would have far reaching implications in optical communications or biophotonics. In this work, it is demonstrated the direct generation of circularly polarized (CP) laser emission in achiral and isotropic dye laser systems without the use of extracavity polarizing elements, and without resorting to chiral dyes, chiral liquid crystal matrices, or interferometric methods. The origin of this ellipticity arises from the dynamic birefringence induced by the strong and polarized laser pumping and the subsequent orientation anisotropy of the excited molecular dipoles. A complete polarimetric characterization of the polarization state of conventional dye laser oscillators as a function of different experimental parameters is performed and it is shown that the generated light always possesses a certain level of circularity that changes in a distinctive way with pump energy and polarization. These results demonstrate that it is possible to generate and modulate CP laser light from efficient and photostable conventional laser dyes. PMID:27350073

  17. Circularly polarized laser emission induced in isotropic and achiral dye systems

    NASA Astrophysics Data System (ADS)

    Cerdán, Luis; García-Moreno, Sara; Costela, Angel; García-Moreno, Inmaculada; de La Moya, Santiago

    2016-06-01

    The production of efficient, tunable, and switchable circularly polarized laser emission would have far reaching implications in optical communications or biophotonics. In this work, it is demonstrated the direct generation of circularly polarized (CP) laser emission in achiral and isotropic dye laser systems without the use of extracavity polarizing elements, and without resorting to chiral dyes, chiral liquid crystal matrices, or interferometric methods. The origin of this ellipticity arises from the dynamic birefringence induced by the strong and polarized laser pumping and the subsequent orientation anisotropy of the excited molecular dipoles. A complete polarimetric characterization of the polarization state of conventional dye laser oscillators as a function of different experimental parameters is performed and it is shown that the generated light always possesses a certain level of circularity that changes in a distinctive way with pump energy and polarization. These results demonstrate that it is possible to generate and modulate CP laser light from efficient and photostable conventional laser dyes.

  18. Insights into the Mechanism of a Covalently Linked Organic Dye-Cobaloxime Catalyst System for Dye-Sensitized Solar Fuel Devices.

    PubMed

    Pati, Palas Baran; Zhang, Lei; Philippe, Bertrand; Fernández-Terán, Ricardo; Ahmadi, Sareh; Tian, Lei; Rensmo, Håkan; Hammarström, Leif; Tian, Haining

    2017-06-09

    A covalently linked organic dye-cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye-sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time-resolved fluorescence, transient absorption spectroscopy, and photoelectron spectroscopy. The results show that irradiation of the dye-catalyst on NiO leads to ultrafast hole injection into NiO from the excited dye, followed by a fast electron transfer process to reduce the catalyst. Moreover, the dye adopts different structures with different excited state energies, and excitation energy transfer occurs between neighboring molecules on the semiconductor surface. The photoelectrochemical experiments also show hydrogen production by this system. The axial chloride ligands of the catalyst are released during photocatalysis to create the active sites for proton reduction. A working mechanism of the dye-catalyst system on the photocathode is proposed on the basis of this study. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  19. Development of Encapsulated Dye for Surface Impact Damage Indicator System.

    DTIC Science & Technology

    1987-09-01

    GROUP SUB-GROUP Composites Ultrasonics Dye Impact Microcapsules 11 04 NDE polyurethane 11 1 0Encapsulation Paint 19. ABSTRACT (Continue on reverse if...encapsulation, microencapsule incorporation into the USAF polyurethane paint, dnd initial correlation study of impact damage to impact coating indication. It is...project were to: 1. Refine the microcapsule formulation to be compatible with MIL-C-83286 paint. 2. Fabricate composite panels from isotropic graphite

  20. Imaging mass spectrometry of the visual system: Advancing the molecular understanding of retina degenerations.

    PubMed

    Bowrey, Hannah E; Anderson, David M; Pallitto, Patrick; Gutierrez, Danielle B; Fan, Jie; Crouch, Rosalie K; Schey, Kevin L; Ablonczy, Zsolt

    2016-04-01

    Visual sensation is fundamental for quality of life, and loss of vision to retinal degeneration is a debilitating condition. The eye is the only part of the central nervous system that can be noninvasively observed with optical imaging. In the clinics, various spectroscopic methods provide high spatial resolution images of the fundus and the developing degenerative lesions. However, the currently utilized tools are not specific enough to establish the molecular underpinnings of retinal diseases. In contrast, mass spectrometric imaging (MSI) is a powerful tool to identify molecularly specific disease indicators and classification markers. This technique is particularly well suited to the eye, where molecular information can be correlated with clinical data collected via noninvasive diagnostic imaging modalities. Recent studies during the last few recent years have uncovered a plethora of new spatially defined molecular information on several vision-threatening diseases, including age-related macular degeneration, Stargardt disease, glaucoma, cataract, as well as lipid disorders. Even though MS inside the eye cannot be performed noninvasively, by linking diagnostic and molecular information, these studies are the first step toward the development of smart ophthalmic diagnostic and surgical tools. Here, we provide an overview of current approaches applying MSI technology to ocular pathology.

  1. Myeloperoxidase inhibition ameliorates multiple system atrophy-like degeneration in a transgenic mouse model.

    PubMed

    Stefanova, Nadia; Georgievska, Biljana; Eriksson, Håkan; Poewe, Werner; Wenning, Gregor K

    2012-05-01

    Multiple system atrophy (MSA) is a rare and fatal α-synucleinopathy characterized by a distinctive oligodendrogliopathy with glial cytoplasmic inclusions and associated neuronal multisystem degeneration. The majority of patients presents with a rapidly progressive parkinsonian disorder and atypical features such as early autonomic failure and cerebellar ataxia. We have previously reported that complete MSA pathology can be modeled in transgenic mice overexpressing oligodendroglial α-synuclein under conditions of oxidative stress induced by 3-nitropropionic acid (3-NP) including striatonigral degeneration, olivopontocerebellar atrophy, astrogliosis, and microglial activation. Here, we show that myeloperoxidase (MPO), a key enzyme involved in the production of reactive oxygen species by phagocytic cells, is expressed in both human and mouse MSA brains. We also demonstrate that in the MSA mouse model, MPO inhibition reduces motor impairment and rescues vulnerable neurons in striatum, substantia nigra pars compacta, cerebellar cortex, pontine nuclei, and inferior olives. MPO inhibition is associated with suppression of microglial activation but does not affect 3-NP induced astrogliosis in the same regions. Finally, MPO inhibition results in reduced intracellular aggregates of α-synuclein. This study suggests that MPO inhibition may represent a novel candidate treatment strategy against MSA-like neurodegeneration acting through its anti-inflammatory and anti-oxidative properties. © Springer Science+Business Media, LLC 2011

  2. Bioinspired photoelectric conversion system based on carbon-quantum-dot-doped dye-semiconductor complex.

    PubMed

    Ma, Zheng; Zhang, Yong-Lai; Wang, Lei; Ming, Hai; Li, Haitao; Zhang, Xing; Wang, Fang; Liu, Yang; Kang, Zhenhui; Lee, Shuit-Tong

    2013-06-12

    Compared to nature's photoelectric conversion processes, artificial devices are still far inferior in efficiency and stability. Inspired by light absorption and resonance energy transfer processes of chlorophyll, we developed a highly efficient photoelectric conversion system by introducing Carbon quantum dots (CQDs) as an electron transfer intermediary. Compared with conventional dye-sensitized semiconductor systems, the present CQD-doped system showed significantly higher photoelectric conversion efficiency, as much as 7 times that without CQDs. The CQD-doped dye/semiconductor system may provide a powerful approach to the development of highly efficient photoelectric devices.

  3. Interfacial Properties of a Hydrophobic Dye in the Tetrachloroethylene-Water-Glass Systems

    SciTech Connect

    Tuck, D.M.

    1999-02-23

    Interfacial effects play an important role in governing multiphase fluid behavior in porous media. Strongly hydrophobic organic dyes, used in many experimental studies to facilitate visual observation of the phase distributions, have generally been implicitly assumed to have no influence on the interfacial properties of the various phases in porous media. Sudan IV is the most commonly used dye for non-aqueous phase liquids (NAPLs) in laboratory experiments. It has also been used in at least one field experiment. The effects of this dye on the tetrachloroethylene (PCE)-water-glass system were investigated to test the assumption that the dye does not effect the interfacial properties and therefore PCE mobility. The results indicate that the dye does indeed change the interfacial relationships.The effect of the dye on the interfacial relationships is a complex function of the dye concentration, the solid phase composition, and the dynamic rate of new interface formation. The dye caused a slight (<10 percent) increase in interfacial tension at low concentrations (<0.1 g/L) and high rates of new interface formation. The dye reduced interfacial tension between PCE and water at low rates of new interface formation for all dye concentrations tested (0.00508 to 5.08 g/L). At the highest dye concentration, the PCE-water interfacial tension was significantly reduced regardless of the rate of new interface formation. The apparent interfacial tension increase at low dye concentrations is suspected to be an artifact of a low measured IFT value for the undyed PCE caused by leaching of rubber o-rings by the PCE prior to testing in the final drop-volume configuration.In addition to reducing interfacial tension, the dye was found to significantly alter the wetting relationship between PCE and water on a glass surface at and above the range of reported dye concentrations cited in the literature (1.1 to 1.7 g/L). The wetting relationship was rendered neutral from a water-wet initial

  4. Application of a sequential batch reactor system for textile dyes degradation: comparison between azo and phthalocyanine dyes.

    PubMed

    Harrelkas, F; Pons, M N; Zahraa, O; Yaacoubi, A; Lakhal, E K

    2007-01-01

    Photocatalysis on supported TiO2 was combined with aerobic biological treatment in a sequential batch reactor to compare the degradation of two textile dyes: a blue azo dye (DR KBL CDG) and a green phthalocyanine dye (DR K4GN). Three reactors were run in parallel. SBR1 was used as a reference and was fed with urban wastewater only. SBR2 and SBR3 were fed with the same urban wastewater combined with pretreated (for SBR2) and non-pretreated (for SBR3) dye solution. For an azo dye concentration of 12 mg/L decolouration yields of 78 and 27% were achieved, respectively, in SBR2 and SBR3. For the phthalocyanine dye, the decolouration yields decreased to 24 and 15%, respectively. Concerning COD removal it decreases for both dyes with and without pretreatment, when the dye concentration increases. Although a detrimental effect on biomass could be observed, bacteria were able to cope with the inhibitory effect of the dyes.

  5. Asymptotic behaviour of the solution to a singularly perturbed partially dissipative system with a multiple root of the degenerate equation

    NASA Astrophysics Data System (ADS)

    Butuzov, V. F.

    2016-08-01

    Asymptotic formulae for the solution of the initial-boundary value problem for a singularly perturbed partially dissipative system of reaction-diffusion type are constructed and justified. The system consists of a parabolic and an ordinary differential equation in the case when the corresponding degenerate equation has a root of multiplicity two. The behaviour of the boundary layer functions and the algorithm for constructing them are significantly distinct from the case of a simple (multiplicity-one) root of the degenerate equation. Bibliography: 8 titles.

  6. The Neuropsychology (Broadly Conceived) of Multiple System Atrophy, Progressive Supranuclear Palsy, and Corticobasal Degeneration.

    PubMed

    Gerstenecker, Adam

    2017-09-15

    To review the cognitive and behavioral features of the different atypical parkinsonian syndromes in which motor symptoms dominate early clinical symptomology: multiple systems atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). The impact of cognitive and behavioral deficits on quality of life, associations between neuropsychological and neuropsychiatric findings and brain imaging, and cognitive and behavioral symptom management are also discussed. A review of the available MSA, PSP, and CBD literature was conducted, with emphasis given to studies investigating the cognitive and behavioral features of the syndromes. Although the three reviewed atypical parkinsonian syndromes share many similarities to each other and PD from a neuropsychological perspective, differences in prevalence and severity of cognitive impairment and patterns of performance on neuropsychological and neuropsychiatric measures exist in the research literature. Cognitive and behavioral features are early and pervasive aspects of MSA, PSP, and CBD.

  7. Jump bifurcations in some degenerate planar piecewise linear differential systems with three zones

    NASA Astrophysics Data System (ADS)

    Euzébio, Rodrigo; Pazim, Rubens; Ponce, Enrique

    2016-06-01

    We consider continuous piecewise-linear differential systems with three zones where the central one is degenerate, that is, the determinant of its linear part vanishes. By moving one parameter which is associated to the equilibrium position, we detect some new bifurcations exhibiting jump transitions both in the equilibrium location and in the appearance of limit cycles. In particular, we introduce the scabbard bifurcation, characterized by the birth of a limit cycle from a continuum of equilibrium points. Some of the studied bifurcations are detected, after an appropriate choice of parameters, in a piecewise linear Morris-Lecar model for the activity of a single neuron activity, which is usually considered as a reduction of the celebrated Hodgkin-Huxley equations.

  8. Prediction study on the degeneration of lithium-ion battery based on fuzzy inference system

    NASA Astrophysics Data System (ADS)

    Shi, Jian Ping

    2017-07-01

    The degradation degree prediction of lithium-ion battery has been studied through experimental data. Characterization parameters on the degradation degree of lithium-ion battery were deduced under consideration of the internal and external factors. The analysis of discrete degree was proposed to depict the degradation degree for lithium-ion battery. Furthermore, based on fuzzy inference system (FIS), the predicted model of the degradation degree for lithium-ion battery was built and its output was defined as the degenerate coefficient β, β ∈ [0, 1]. Finally, by learning, training and simulating, the FIS model has been validated to be reliable and applicable in prediction on the degradation degree of lithium-ion battery. The simulation results show that the degradation degree of lithium-ion battery is more serious when β is closer to 1, and the degradation degree is lighter when β is closer to 0.

  9. Triphenylmethane dyes, an alternative for mediated electronic transfer systems in glucose oxidase biofuel cells.

    PubMed

    La Rotta H, Camilo E; Ciniciato, Gustavo P M K; González, Ernesto R

    2011-05-06

    The bioelectrochemical behavior of three triphenylmethane (TPM) dyes commonly used as pH indicators, and their application in mediated electron transfer systems for glucose oxidase bioanodes in biofuel cells was investigated. Bromophenol Blue, Bromothymol Blue, Bromocresol Green were compared bioelectrochemically against two widely used mediators, benzoquinone and ferrocene carboxy aldehyde. Biochemical studies were performed in terms of enzymatic oxidation, enzyme affinity, catalytic efficiency and co-factor regeneration. The different features of the TPM dyes as mediators are determined by the characteristics in the oxidation/reduction processes studied electrochemically. The reversibility of the oxidation/reduction processes was also established through the dependence of the voltammetric peaks with the sweep rates. All three dyes showed good performances compared to the FA and BQ when evaluated in a half enzymatic fuel cell. Potentiodynamic and power response experiments showed maxima power densities of 32.8 μW cm(-2) for ferrocene carboxy aldehyde followed by similar values obtained for TPM dyes around 30 μW cm(-2) using glucose and mediator concentrations of 10 mmol L(-1) and 1.0 mmol L(-1), respectively. Since no mediator consumption was observed during the bioelectrochemical process, and also good redox re-cycled processes were achieved, the use of triphenylmethane dyes is considered to be promising compared to other mediated systems used with glucose oxidase bioanodes and/or biofuel cells. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Aromatic amine degradation in a UASB/CSTR sequential system treating Congo Red dye.

    PubMed

    Işik, Mustafa; Sponza, Delia Teresa

    2003-01-01

    In this study an anaerobic (upflow anaerobic sludge blanket reactor)/aerobic (completely stirred tank reactor) sequential system was used to treat a synthetic wastewater with minerals and co-substrate together with 100-4000 mg L(-1) of Congo Red dye (Direct red 28) (CR), which is a banned azo dye in Turkey. The effect of hydraulic retention time (HRT) on the decolorization and the COD removal efficiency was investigated at constant 100 mg L(-1) Congo Red concentration. 77% of COD and 95% of color was removed at a HRT of 0.486 days and a maximum organic loading rate of 6.656 kg COD m(-3) day(-1) in the anaerobic/aerobic stage. In the continuous operations, 88% of COD, 99% of color and 91% of total aromatic amine (TAA) were removed at a HRT of 3.60 days and at a CR concentration of 4000 mg L(-1). This corresponds to an organic loading rate of 1.81 kg COD m(-3) day(-1), and a CR dye loading rate of 46.37 g dye m(-3) h(-1), respectively, in the whole system. The TAA produced under anaerobic conditions was ultimately removed in the aerobic stage, resulting in very low aromatic amine recoveries (5-18%) in the last one. Therefore the aerobic effluents exhibited higher IC50 and specific methanogenic activities (SMA) compared to anaerobic and dye containing samples, indicating the reduced toxicity.

  11. Evaluation of walking smoothness using wearable robotic system curara® for spinocerebellar degeneration patients.

    PubMed

    Tsukahara, Atsushi; Yoshida, Kunihiro; Matsushima, Akira; Ajima, Kumiko; Kuroda, Chika; Mizukami, Noriaki; Hashimoto, Minoru

    2017-07-01

    This paper aimed to verify the effectiveness of the wearable robotic system "curara" for patients with spinocerebellar degeneration (SCD) by evaluating walking smoothness. The curara system supports the wearer's gait using a synchronization control method that uses a neural oscillator based on a central pattern generator network. The system reflects the motional intention by adjusting the synchronization gains. This modifies the degree of interactive coordinated motion between the curara and the wearer. As a feasibility study, we evaluated the waking smoothness of 10 patients with SCD using three gain condition settings. Harmonic ratio (HR), which has been used extensively to quantify the smoothness during walking, was used to assess their walking. The results show that most HRs in the medio-lateral, anterior-posterior, and vertical directions using the three gain conditions were higher than those for patients not wearing the system. In particular, the increasing rates of the HR in all directions during the gait support were 11.1%, 23.4%, and 23.2% compared with unassisted walking, when the gain condition settings of hip and knee joints are set at 0.4 and 0.5, respectively. Consequently, these results verified the effectiveness of the curara system for patients with SCD.

  12. Laser beam control and diagnostic systems for the copper-pumped dye laser system at Lawrence Livermore National Laboratory

    SciTech Connect

    Bliss, E.S.; Peterson, R.L.; Salmon, J.T.; Thomas, R.A.

    1992-11-01

    The laser system described in the previous paper is used for experiments in which success requires tight tolerances on beam position, direction, and wavefront. Indeed, the optimum performance of the laser itself depends on careful delivery of copper laser light to the dye amplifiers, precise propagation of dye laser beams through restricted amplifier apertures, and accurate monitoring of laser power at key locations. This paper describes the alignment systems, wavefront correction systems, and laser diagnostics systems which ensure that the control requirements of both the laser and associated experiments are met. Because laser isotope separation processes utilize more than one wavelength, these systems monitor and control multiple wavelengths simultaneously.

  13. Dye Sensitized Solar Cells for Economically Viable Photovoltaic Systems.

    PubMed

    Jung, Hyun Suk; Lee, Jung-Kun

    2013-05-16

    TiO2 nanoparticle-based dye sensitized solar cells (DSSCs) have attracted a significant level of scientific and technological interest for their potential as economically viable photovoltaic devices. While DSSCs have multiple benefits such as material abundance, a short energy payback period, constant power output, and compatibility with flexible applications, there are still several challenges that hold back large scale commercialization. Critical factors determining the future of DSSCs involve energy conversion efficiency, long-term stability, and production cost. Continuous advancement of their long-term stability suggests that state-of-the-art DSSCs will operate for over 20 years without a significant decrease in performance. Nevertheless, key questions remain in regards to energy conversion efficiency improvements and material cost reduction. In this Perspective, the present state of the field and the ongoing efforts to address the requirements of DSSCs are summarized with views on the future of DSSCs.

  14. [The genetic variability of complement system in pathogenesis of age-related macular degeneration].

    PubMed

    Kubicka-Trząska, Agnieszka; Karska-Basta, Izabella; Dziedzina, Sylwia; Sanak, Marek

    2015-01-01

    Age-related macular degeneration is the leading cause of irreversible central vision impairment in people aged over 50 in developed countries. Age-related macular degeneration is a complex disease derived from environmental, immune and genetic factors. The complement pathway has been implicated in the pathogenesis of many diseases. Recently, variants in several genes, such as complement H (CFH), complement factor B (CFB), complement 2 (C2), and complement 3 (C3), encoding complement pathway proteins, have been identified as associated with age-related macular degeneration. However, the associations between these genes and age-related macular degeneration varied due to genetic variation within populations and various ethnics groups. The strongest association was found between the age-related macular degeneration and SNP Y402H rs 1061170 variant of CFH gene, which is present in 30% to 50% of age-related macular degeneration patients in Caucasian population and which is a risk factor for the development of age-related macular degeneration. Cohort studies showed that polymorphism Arg102Gly (SNP rs 2230199) of C3 protein could serve as a high-risk genetic marker for the development of age-related macular degeneration. Other rare variants of C3 (Lys155Gln, Lys65Gln, Arg735Trp, Ser1619Arg), may also be associated with a high incidence of age-related macular degeneration in some ethnic groups. A protective haplotype of variants E318D and IVS10 in the C2 gene as well as L9H and R320 in the BF were associated with age-related macular degeneration but only in Caucasians. The genetic findings in age-related macular degeneration patients stress the importance of detailed phenotyping to identify age-related macular degeneration subtypes, which may be associated with the presence of different polymorphisms and various environmental risk factors in any population. Further studies may be helpful to improve the effectiveness of prophylaxis and therapeutic options in age

  15. Construction of response solutions for two classes of quasi-periodically forced four-dimensional nonlinear systems with degenerate equilibrium point under small perturbations

    NASA Astrophysics Data System (ADS)

    Si, Wen; Si, Jianguo

    2017-05-01

    By developing two KAM theorems, in this paper, we show that two classes of quasi-periodically forced four-dimensional nonlinear systems with degenerate equilibrium point, a reversible system and a non-conservative system, admit a response solution under small perturbations. For the degenerate reversible system, applying special structure of unperturbed nonlinear term and Herman method, we successfully control the shift of equilibrium point, which is difficult in view of the degenerate linear term. For the degenerate non-conservative system, KAM method is brought into force even in completely degenerate case because of the restrictions on the smallness and average of perturbation. Moreover, arithmetic condition on the frequency is assumed to satisfy the Brjuno-Rüssmann's non-resonant condition. By the Pöschel-Rüssmann KAM method, we prove that these two kinds of perturbed systems can be reduced to a suitable normal form with zero as equilibrium point by a quasi-periodic transformation.

  16. A study of mode-locked argon ion-dye laser systems

    NASA Astrophysics Data System (ADS)

    Selfridge, R. H.

    1984-06-01

    A new argon ion dye laser double mode locking cavity is presented that allows simultaneous pulse period variation in both laser pulse trains. The predicted number of pulses are analyzed and hence the period of pulses for different cavity length adjustments. A novel approach to creating synchronous picosecond pulse trains at two wavelengths is presented. The method uses a synchronously pumped argon ion laser to cause population inversion and lasing in a mixture of rhodamine 6G and cresyl violet dye. This synchronously pumped double mode locking is simpler to implement than other two wavelength methods. The pulses produced are superior to those generated in the widely used commercial synchronously pumped systems.

  17. Development of an activated carbon-packed microbial bioelectrochemical system for azo dye degradation.

    PubMed

    Cardenas-Robles, Arely; Martinez, Eduardo; Rendon-Alcantar, Idelfonso; Frontana, Carlos; Gonzalez-Gutierrez, Linda

    2013-01-01

    A microbial bioelectrochemical reactor (BER) was employed for the degradation of azo dyes without the use of an external electron donor, using activated carbon (GAC) as a redox mediator. Contribution of pH values, open circuit potential (OCP), dye concentration and applied current were individually studied. A batch system and an upflow fixed bed bioreactor were built for analyzing the effect of the applied current on biodegradation of the azo dye Reactive Red 272. The presence of GAC (20% w/v) regulated both pH and OCP values in solution and led to a removal efficiency of 98%. Cyclic voltammetry results indicate a dependence of the electron transfer mechanism with the concentration of the azo compound. With these results, a continuous flow reactor operating with J=0.045 mA cm(-2), led to removal rates of 95% (± 3.5%) in a half-residence time of 1 hour.

  18. Reliable Magnetic Resonance Imaging Based Grading System for Cervical Intervertebral Disc Degeneration

    PubMed Central

    Chen, Antonia F.; Kang, James D.; Lee, Joon Y.

    2016-01-01

    Study Design Observational. Purpose To develop a simple and comprehensive grading system for cervical discs that precisely, consistently and meaningfully presents radiologic and morphologic data. Overview of Literature The Thompson grading system is commonly used to classify the severity of degenerative lumbar discs on magnetic resonance imaging (MRI). Inherent differences in the morphological and physiological characteristics of cervical discs have hindered development of precise classification systems. Other grading systems have been developed for degenerating cervical discs, but their versatility and feasibility in the clinical setting is suboptimal. Methods MRIs of 46 human cervical discs were de-identified and displayed in PowerPoint format. Each slide depicted a single disc with a normal (grade 0) disc displayed in the top right corner for reference. The presentation was given to 25 physicians comprising attending spine surgeons, spine fellows, orthopaedic residents, and two attending musculoskeletal radiologists. The grading system included Grade 0 (normal height compared to C2–3, mid cleft still visible), grade 1 (dark disc, normal height), grade 2 (collapsed disc, few osteophytes), and grade 3 (collapsed disc, many osteophytes). The ease of use of the system was gauged in the participants and the interobserver reliability was calculated. Results The intraclass correlation coefficient for interobserver reliability was 0.87, and 0.94 for intraobserver reliability, indicating excellent reliability. Ninety-five percent and 85 percent of the clinicians judged the grading system to be clinically feasible and useful in daily practice, respectively. Conclusions The grading system is easy to use, has excellent reliability, and can be used for precise and consistent clinician communication. PMID:26949461

  19. Therapeutic targeting of the complement system in age-related macular degeneration: a review.

    PubMed

    Troutbeck, Robyn; Al-Qureshi, Salmaan; Guymer, Robyn H

    2012-01-01

    The last decade has produced pivotal change in our understanding of the molecular mechanisms underlying age-related macular degeneration (AMD), a leading cause of global blindness. In this time, the complement system has featured as a unifying theme for several elements of new evidence: initially, the discovery of complement proteins within drusen and subsequently, the association between AMD and mutations in various complement pathway genes, most notably complement factor H. Increasingly, a wealth of data are pointing towards a role for chronic local inflammation and complement activation in the patho-aetiology of AMD. These findings have paved the way for the exploration of a new paradigm of therapy in AMD management; targeting of specific molecular constituents in the complement pathway thus producing dampening or inhibition of the inflammatory response. Such an approach has the potential to intervene earlier in the disease process and ideally before vision is compromised. In this review we discuss the role of the complement system in AMD, novel therapies in preclinical evaluation and clinical trial, and whether these have a part to play in reducing the burden of disease.

  20. [The age-related macular degeneration as a vascular disease/part of systemic vasculopathy: contributions to its pathogenesis].

    PubMed

    Fischer, Tamás

    2015-03-01

    The wall of blood vessels including those in choroids may be harmed by several repeated and/or prolonged mechanical, physical, chemical, microbiological, immunologic, and genetic impacts (risk factors), which may trigger a protracted response, the so-called host defense response. As a consequence, pathological changes resulting in vascular injury (e. g. atherosclerosis, age-related macular degeneration) may be evolved. Risk factors can also act directly on the endothelium through an increased production of reactive oxygen species promoting an endothelial activation, which leads to endothelial dysfunction, the onset of vascular disease. Thus, endothelial dysfunction is a link between the harmful stimulus and vascular injury; any kind of harmful stimuli may trigger the defensive chain that results in inflammation that may lead to vascular injury. It has been shown that even early age-related macular degeneration is associated with the presence of diffuse arterial disease and patients with early age-related macular degeneration demonstrate signs of systemic and retinal vascular alterations. Chronic inflammation, a feature of AMD, is tightly linked to diseases associated with ED: AMD is accompanied by a general inflammatory response, in the form of complement system activation, similar to that observed in degenerative vascular diseases such as atherosclerosis. All these facts indicate that age-related macular degeneration may be a vascular disease (or part of a systemic vasculopathy). This recognition could have therapeutic implications because restoration of endothelial dysfunction may prevent the development or improve vascular disease resulting in prevention or improvement of age-related macular degeneration as well.

  1. Performance of microbial fuel cell coupled constructed wetland system for decolorization of azo dye and bioelectricity generation.

    PubMed

    Fang, Zhou; Song, Hai-Liang; Cang, Ning; Li, Xian-Ning

    2013-09-01

    A microbial fuel cell coupled constructed wetland (planted with Ipomoea aquatica) system (planted CW-MFC) was used for azo dye decolorization. Electricity was simultaneously produced during the co-metabolism process of glucose and azo dye. A non-planted and an open-circuit system were established as reference to study the roles of plants and electrodes in azo dye decolorization and electricity production processes, respectively. The results indicated that plants grown in cathode enhanced the cathode potential and slightly promoted dye decolorization efficiency. The electrodes promoted the dye decolorization efficiency in the anode. The planted CW-MFC system achieved the highest decolorization rate of about 91.24% and a voltage output of about 610 mV. The connection of external circuit promoted the growth of electrogenic bacteria Geobacter sulfurreducens and Beta Proteobacteria, and inhibited the growth of Archaea in anode. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Cerebellar Degeneration

    MedlinePlus

    ... is a process in which neurons in the cerebellum - the area of the brain that controls coordination ... body, can cause neurons to die in the cerebellum. Neurological diseases that feature cerebellar degeneration include: ischemic ...

  3. Pre-testing in hair dye users: an assessment of the Colourstart system.

    PubMed

    Basketter, David A; English, John

    2009-01-01

    To avoid adverse reactions to allergenic ingredients, manufacturers recommend "sensitivity testing" prior to use of hair dyes. However, there is no standardised method and the recommendation is often not followed. We assessed the ability of a standardised test system from one manufacturer (Colourstart, a small skin surface water-slide transfer containing p-phenylenediamine (PPD)) for its ability to elicit a reaction in those with a previously diagnosed contact allergy to PPD, the main hair dye allergen. Thirty volunteers with diagnosed PPD allergy (10 each of 3+, 2+ and 1+) were assessed with the Colourstart system according to the manufacturer's instructions. Responses were recorded after 48h exposure. Colourstart identified 100% of those with a 3+ reaction to the diagnostic patch test, 80% of the 2+ reactors and just 10% of the 1+ reactors. Thus, Colourstart successfully identified those individuals with the greatest sensitivity to PPD, who might therefore be at risk of a severe reaction if they dyed their hair. It also identified 83% of those who reported a severe/very severe history of hair dye adverse reaction. However, its proper use and interpretation are necessary if those consumers most at risk are to have the information necessary to avoid serious adverse reactions to hair dyes.

  4. Cyclic mechanical stimulation rescues achilles tendon from degeneration in a bioreactor system.

    PubMed

    Wang, Tao; Lin, Zhen; Ni, Ming; Thien, Christine; Day, Robert E; Gardiner, Bruce; Rubenson, Jonas; Kirk, Thomas B; Smith, David W; Wang, Allan; Lloyd, David G; Wang, Yan; Zheng, Qiujian; Zheng, Ming H

    2015-12-01

    Physiotherapy is one of the effective treatments for tendinopathy, whereby symptoms are relieved by changing the biomechanical environment of the pathological tendon. However, the underlying mechanism remains unclear. In this study, we first established a model of progressive tendinopathy-like degeneration in the rabbit Achilles. Following ex vivo loading deprivation culture in a bioreactor system for 6 and 12 days, tendons exhibited progressive degenerative changes, abnormal collagen type III production, increased cell apoptosis, and weakened mechanical properties. When intervention was applied at day 7 for another 6 days by using cyclic tensile mechanical stimulation (6% strain, 0.25 Hz, 8 h/day) in a bioreactor, the pathological changes and mechanical properties were almost restored to levels seen in healthy tendon. Our results indicated that a proper biomechanical environment was able to rescue early-stage pathological changes by increased collagen type I production, decreased collagen degradation and cell apoptosis. The ex vivo model developed in this study allows systematic study on the effect of mechanical stimulation on tendon biology. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. A fast spinning magnetic white dwarf in the double degenerate, super-Chandrasekhar system NLTT 12758

    NASA Astrophysics Data System (ADS)

    Kawka, Adela; Briggs, Gordon P.; Vennes, Stéphane; Ferrario, Lilia; Paunzen, Ernst; Wickramasinghe, Dayal T.

    2017-04-01

    We present an analysis of the close double degenerate NLTT 12758, which is comprised of a magnetic white dwarf with a field of about 3.1 MG and an apparently non-magnetic white dwarf. We measured an orbital period of 1.154 d and found that the magnetic white dwarf is spinning around its axis with a period of 23 min. An analysis of the atmospheric parameters has revealed that the cooling ages of the two white dwarfs are comparable, suggesting that they formed within a short period of time from each other. Our modelling indicates that the non-magnetic white dwarf is more massive (M = 0.83 M⊙) than its magnetic companion (M = 0.69 M⊙) and that the total mass of the system is higher than the Chandrasekhar mass. Although the stars will not come into contact over a Hubble time, when they do come into contact, dynamically unstable mass transfer will take place leading to either an accretion induced collapse into a rapidly spinning neutron star or a Type Ia supernova.

  6. THE CORE COMPOSITION OF A WHITE DWARF IN A CLOSE DOUBLE-DEGENERATE SYSTEM

    SciTech Connect

    Vennes, S.; Kawka, A.

    2012-01-20

    We report the identification of the double-degenerate system NLTT 16249 that comprises a normal, hydrogen-rich (DA) white dwarf and a peculiar, carbon-polluted white dwarf (DQ) showing photospheric traces of nitrogen. We disentangled the observed spectra and constrained the properties of both stellar components. In the evolutionary scenario commonly applied to the sequence of DQ white dwarfs, both carbon and nitrogen would be dredged up from the core. The C/N abundance ratio ( Almost-Equal-To 50) in the atmosphere of this unique DQ white dwarf suggests the presence of unprocessed material ({sup 14}N) in the core or in the envelope. Helium burning in the DQ progenitor may have terminated early on the red giant branch after a mass-ejection event leaving unprocessed material in the core, although current mass estimates do not favor the presence of a low-mass helium core. Alternatively, some nitrogen in the envelope may have survived an abridged helium-core burning phase prior to climbing the asymptotic giant branch. Based on available data, we estimate a relatively short orbital period (P {approx}< 13 hr) and ongoing spectroscopic observations will help determine precise orbital parameters.

  7. System for the pH-dependent release of a dye in model dental restorations.

    PubMed

    Shen, C; Sarrett, D; Batich, C D; Anusavice, K J

    1994-12-01

    We are developing a system for detecting recurrent caries under dental restorations. The controlled release of dyes under conditions of likely demineralization will alert the dentist to potential secondary caries. Production of acidic species is a characteristic of caries activity; hence, the system uses pH-sensitive polymers to release markers when the pH at the cavity wall of the restored tooth is below 6.5. The objectives of this investigation were to test the hypotheses that (1) the proposed system can be designed to release detectable marker continuously for at least six months in a simulated carious environment, and (2) the transient pH changes in the oral cavity caused by simulated dietary intake will not induce premature marker release from the pH-sensitive polymer placed beneath restorations. Two types of dye-loaded microspheres based on styrene, vinylpyridine, and divinylbenzene were prepared and placed on the floor of model cavity preparations made from an acrylic rod. Each model cavity was restored with a hybrid dental composite, placed in a vial with 5 mL of sodium-lactate/lactic-acid base buffer solution, and stored at 37 degrees C. Solutions of three different pH values were used: 2.86, 4.73, and 6.39. The dye release into storage media was monitored periodically with a UV/VIS spectrophotometer. Results showed that the duration could extend beyond six months for pH > 4.73, and that transient oral pH changes are not likely to result in premature dye release. The data indicate that it would take approximately 21 days for the acidic agent external to the restoration to initiate dye release from restored sites.

  8. D-π-A dye system containing cyano-benzoic acid as anchoring group for dye-sensitized solar cells.

    PubMed

    Katono, Masataka; Bessho, Takeru; Meng, Sheng; Humphry-Baker, Robin; Rothenberger, Guido; Zakeeruddin, Shaik M; Kaxiras, Efthimios; Grätzel, Michael

    2011-12-06

    A D-π-A dye (KM-1) incorporating cyano-benzoic acid as a new acceptor/anchoring group has been synthesized for dye-sensitized solar cells (DSCs) with a high molar extinction coefficient of 66,700 M(-1) cm(-1) at 437 nm. Theoretical calculations show that the hydrogen bond between -CN and surface hydroxyl leads to the most stable configuration on the surface of TiO(2). In addition, the adsorption of the dye on TiO(2) follows a Brunauer-Emmett-Teller (BET) isotherm. Multilayer adsorption of KM-1 on TiO(2) seems to take place particularly at higher dye concentrations. DSC device using KM-1 reached a maximum incident photon-to-current conversion efficiency (IPCE) of 84%, with a solar to electric power conversion efficiency (PCE) of 3.3% at AM1.5 G illumination (100 mW cm(-2)). This new type of anchoring group paves a way to design new dyes that combine good visible light harvesting with strong binding to the metal oxide surface.

  9. Azo dye treatment with simultaneous electricity production in an anaerobic-aerobic sequential reactor and microbial fuel cell coupled system.

    PubMed

    Li, Zhongjian; Zhang, Xingwang; Lin, Jun; Han, Song; Lei, Lecheng

    2010-06-01

    A microbial fuel cell and anaerobic-aerobic sequential reactor coupled system was used for azo dye degradation with simultaneous electricity production. Electricity was produced during the co-metabolism process of glucose and azo dye. A microorganism cultured graphite-granular cathode effectively decreased the charge transfer resistance of the cathode and yielded higher power density. Operation parameters including glucose concentration and hydraulic retention time were optimized. The results indicated that recovering electricity during a sequential aerobic-anaerobic azo dye treatment process enhanced chemical oxygen demand removal and did not decrease azo dye removal. Moreover, UV-vis spectra and GC-MS illustrated that the azo bond was cleaved biologically in the anaerobic chamber and abiotically in the aerobic chamber. The toxic intermediates, aromatic amines, were removed by aerobic treatment. Our work demonstrated that the microbial fuel cell and sequential anode-cathode reactor coupled system could be applied to achieve electricity production with simultaneous azo dye degradation.

  10. Degeneration of penicillin production in ethanol-limited chemostat cultivations of Penicillium chrysogenum: A systems biology approach

    PubMed Central

    2011-01-01

    Background In microbial production of non-catabolic products such as antibiotics a loss of production capacity upon long-term cultivation (for example chemostat), a phenomenon called strain degeneration, is often observed. In this study a systems biology approach, monitoring changes from gene to produced flux, was used to study degeneration of penicillin production in a high producing Penicillium chrysogenum strain during prolonged ethanol-limited chemostat cultivations. Results During these cultivations, the biomass specific penicillin production rate decreased more than 10-fold in less than 22 generations. No evidence was obtained for a decrease of the copy number of the penicillin gene cluster, nor a significant down regulation of the expression of the penicillin biosynthesis genes. However, a strong down regulation of the biosynthesis pathway of cysteine, one of the precursors of penicillin, was observed. Furthermore the protein levels of the penicillin pathway enzymes L-α-(δ-aminoadipyl)-L-α-cystenyl-D-α-valine synthetase (ACVS) and isopenicillin-N synthase (IPNS), decreased significantly. Re-cultivation of fully degenerated cells in unlimited batch culture and subsequent C-limited chemostats did only result in a slight recovery of penicillin production. Conclusions Our findings indicate that the observed degeneration is attributed to a significant decrease of the levels of the first two enzymes of the penicillin biosynthesis pathway, ACVS and IPNS. This decrease is not caused by genetic instability of the penicillin amplicon, neither by down regulation of the penicillin biosynthesis pathway. Furthermore no indications were obtained for degradation of these enzymes as a result of autophagy. Possible causes for the decreased enzyme levels could be a decrease of the translation efficiency of ACVS and IPNS during degeneration, or the presence of a culture variant impaired in the biosynthesis of functional proteins of these enzymes, which outcompeted the high

  11. A home-made system for IPCE measurement of standard and dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio; Fraleoni-Morgera, Alessandro

    2015-01-01

    A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

  12. A home-made system for IPCE measurement of standard and dye-sensitized solar cells

    SciTech Connect

    Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio; Fraleoni-Morgera, Alessandro E-mail: afraleoni@units.it

    2015-01-15

    A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

  13. A home-made system for IPCE measurement of standard and dye-sensitized solar cells.

    PubMed

    Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio; Fraleoni-Morgera, Alessandro

    2015-01-01

    A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

  14. Biomechanics of Disc Degeneration

    PubMed Central

    Palepu, V.; Kodigudla, M.; Goel, V. K.

    2012-01-01

    Disc degeneration and associated disorders are among the most debated topics in the orthopedic literature over the past few decades. These may be attributed to interrelated mechanical, biochemical, and environmental factors. The treatment options vary from conservative approaches to surgery, depending on the severity of degeneration and response to conservative therapies. Spinal fusion is considered to be the “gold standard” in surgical methods till date. However, the association of adjacent level degeneration has led to the evolution of motion preservation technologies like spinal arthroplasty and posterior dynamic stabilization systems. These new technologies are aimed to address pain and preserve motion while maintaining a proper load sharing among various spinal elements. This paper provides an elaborative biomechanical review of the technologies aimed to address the disc degeneration and reiterates the point that biomechanical efficacy followed by long-term clinical success will allow these nonfusion technologies as alternatives to fusion, at least in certain patient population. PMID:22745914

  15. Design and synthesis of novel antimicrobial acyclic and heterocyclic dyes and their precursors for dyeing and/or textile finishing based on 2-N-acylamino-4,5,6,7-tetrahydro-benzo[b]thiophene systems.

    PubMed

    Shams, Hoda Zaki; Mohareb, Rafat Milad; Helal, Maher Helmy; Mahmoud, Amira El-Sayed

    2011-07-26

    A series of novel polyfunctionalized acyclic and heterocyclic dye precursors and their respective azo (hydrazone) counterpart dyes and dye precursors based on conjugate enaminones and/or enaminonitrile moieties were synthesized. The dyes and their precursors are based on 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide, 2-ethoxycarbonyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide or 2-phenylcarbamoyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide systems as precursors. The latter compounds were used to synthesize polyfunctional thiophene-, thiazole-, pyrazole, pyridine-, pyrimidine-, oxazine-, as well as acyclic moieties. The dyes and dye precursors were characterized by elemental analysis and spectral methods. All dyes and their precursors were screened in vitro and evaluated for both their antibacterial and antifungal activities. MIC data of the novel dye systems and their respective precursors showed significant antimicrobial activity against most tested organisms. Some compounds exhibited comparable or even higher efficiency than selected standards. Dyes were applied at 5% depth for disperse dyeing of nylon, acetate and polyester fabrics. Their spectral characteristics and fastness properties were measured and evaluated.

  16. Enhancement of azo dye decolourization in a MFC-MEC coupled system.

    PubMed

    Li, Yang; Yang, Hou-Yun; Shen, Jin-You; Mu, Yang; Yu, Han-Qing

    2016-02-01

    Microbial fuel cells (MFCs) have shown the potential for azo dye decolourization. In this study, a MFC-MEC (microbial electrolysis cell) coupled system was established in order to enhance azo dye decolourization, and the influence of several key factors on reactor performance was evaluated. Moreover, a theoretical analysis was conducted to find the essential preconditions for successfully develop this MFC-MEC coupled system. The results indicate that the decolourization rate in the coupled system had a 36.52-75.28% improvement compared to the single MFC. Anodic acetate concentration of both the MFC and the MEC showed a positive effect on azo dye decolourization, while the cathodic pH of both MEC and MFC in the range of 7.0-10.3 had an insignificant impact on reactor performance in the coupled system. The theoretical analysis reveals that the MFC should have higher short-circuit electricity generation than the MEC before connecting together for a successful coupled system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Development of an image processing support system based on fluorescent dye to prevent elderly people with dementia from wandering.

    PubMed

    Nishigaki, Yutaka; Tanaka, Kentaro; Kim, Juhyon; Nakajima, Kazuki

    2013-01-01

    The wandering of elderly people with dementia is a significant behavioral problem and is a heavy burden on caregivers in residential and nursing homes. Thus, warning systems have been developed to prevent elderly people with dementia from leaving the premises. Some of these systems use radio waves. However, systems based on radio waves present several practical problems. For instance, the transmitter must be carried and may become lost; in addition, the battery of the transmitter must be changed. To solve these problems, we developed a support system that prevents elderly people with dementia from wandering. The system employs image processing technology based on fluorescent dye. The composition of the support system can be described as follows: fluorescent dye is painted in a simple shape on the clothes of an elderly person. The fluorescent color becomes visible by irradiation with a long wavelength of ultraviolet light. In the present paper, the relationship between the color of the dye and the cloth was investigated. A 3D video camera was used to acquire a 3D image and detect the simple shape. As a preliminary experiment, 3 colors (red, green and blue) of fluorescent dye were applied to cloths of 9 different colors. All fluorescent colors were detected on 6 of the cloths, but red and blue dye could not be detected on the other 3 cloths. In contrast, green dye was detectable on all 9 of the cloths. Additionally, we determined whether green dye could be detected in an actual environment. A rectangular shaped patch of green fluorescent dye was painted on the shoulder area of a subject, from the scapula to the clavicle. As a result, the green dye was detected on all 9 different colored cloths.

  18. Reductive decolourisation of sulphonated mono and diazo dyes in one- and two-stage anaerobic systems.

    PubMed

    da Silva, Marcos Erick Rodrigues; Firmino, Paulo Igor Milen; dos Santos, André Bezerra

    2013-05-01

    This work assessed the application of one- and two-stage mesophilic anaerobic systems to colour removal of sulphonated mono and diazo dyes with ethanol as electron donor. The dyes Congo Red (CR), Reactive Black 5 (RB5) and Reactive Red 2 (RR2) were selected as model compounds and tested separately in seven different periods. The one-stage system (R(1)) consisted of a single up-flow anaerobic sludge blanket (UASB) reactor, whereas the two-stage system (R(2)) consisted of an acidogenic UASB reactor (R(A)), a settler and a methanogenic UASB reactor (R(M)). For CR and RB5, no remarkable difference was observed between the colour removal performance of both anaerobic systems R(1) and R(2). The experiments with RR2 revealed that R(2) was more efficient on colour removal than R(1), showing efficiencies almost 2-fold (period VI) and 2.5-fold (period VII) higher than those found by R(1). Additionally, R(2) showed a higher stability, giving a good prospect for application to textile wastewaters. Finally, the acidogenic reactor (R(A)) had an important role in the overall decolourisation achieved by R(2) during the experiments with CR and RB5 (>78 %), whereas for RR2, a more recalcitrant dye, R(A) was responsible for up to 38 % of the total colour removal.

  19. Degeneration of cardiac sympathetic nerve can occur in multiple system atrophy.

    PubMed

    Orimo, Satoshi; Kanazawa, Toshiro; Nakamura, Ayako; Uchihara, Toshiki; Mori, Fumiaki; Kakita, Akiyoshi; Wakabayashi, Koichi; Takahashi, Hitoshi

    2007-01-01

    Decreased cardiac uptake of meta-iodobenzylguanidine (MIBG) on [(123)I] MIBG myocardial scintigraphy, a sensitive biological marker for Parkinson's disease (PD), is related to cardiac sympathetic denervation in patients with PD. A slight decrease in cardiac uptake of MIBG has also been reported in some patients with multiple system atrophy (MSA). However, the pathophysiological mechanism accounting for the slight decrease in MIBG uptake in MSA remains to be elucidated. For confirmation, we examined cardiac tissue and sympathetic ganglia from patients with MSA. We immunohistochemically examined each specimen of 15 patients with MSA together with 10 control subjects using antibodies against tyrosine hydroxylase (TH) and neurofilament (NF). The number of TH-immunoreactive nerve fibers in the epicardium was preserved in 8 of 15 patients with MSA as well as in 10 control subjects. The number of TH-immunoreactive, but not of NF-immunoreactive nerve fibers in the epicardium was mildly or moderately decreased in six patients with MSA, of whom four showed a decrease of TH immunoreactivity in the neuronal somata in the sympathetic ganglia. Moreover, TH- and NF-immunoreactive nerve fibers almost entirely disappeared in the heart of one patient with MSA, in whom Lewy body pathology was present in the sympathetic ganglia. These findings suggest that mild degeneration of the cardiac sympathetic nerve can occur in MSA which is closely related to the pathological change of neurons in the sympathetic ganglia, accounting for the slight decrease in cardiac uptake of MIBG. Moreover, concurrent Lewy body pathology in the sympathetic ganglia might accelerate cardiac sympathetic denervation even in MSA.

  20. A RANDOMIZED PILOT STUDY OF SYSTEMIC IMMUNOSUPPRESSION IN THE TREATMENT OF AGE-RELATED MACULAR DEGENERATION WITH CHOROIDAL NEOVASCULARIZATION

    PubMed Central

    Nussenblatt, Robert B.; Byrnes, Gordon; Sen, H. Nida; Yeh, Steven; Faia, Lisa; Meyerle, Catherine; Wroblewski, Keith; Li, Zhuqing; Liu, Baoying; Chew, Emily; Sherry, Patti R.; Friedman, Penelope; Ferris, Frederick

    2011-01-01

    Background Age-related macular degeneration remains the leading cause of irreversible blindness in the United States and the developed world. Intravitreal injections of anti–vascular endothelial growth factor (VEGF) medications have become standard of care for the treatment of the wet form of the disease. Recent reports have demonstrated an association with various immune factors. We aimed to investigate the effect of immunosuppressive therapy in the clinical course of the wet form of the disease. We compared anti-VEGF therapy plus one of three systemic immunosuppressive therapies versus anti-VEGF therapy alone for recurrent choroidal neovascularization associated with age-related macular degeneration. Methods This was a pilot, Phase I/II, prospective, randomized, unmasked, single-center trial. Patients with subretinal exudation secondary to recurrent choroidal neovascularization associated with age-related macular degeneration were included in the study. Patients were randomized to 1 of 3 systemic arms immunosuppressive agents (daclizumab, rapamycin, or infliximab) for 6 months plus intraocular anti-VEGF therapy if indicated, compared with a group who received only anti-VEGF therapy if indicated. Results The number of anti-VEGF injections per group, visual acuity, retinal thickness, and safety measures were assessed in all groups. Thirteen patients were randomized; comparing anti-VEGF injections before and during the study, a decrease in the number of injections from 0.73 injections per month to 0.42 for daclizumab and from 0.67 to 0.34 for sirolimus was seen, while no apparent decrease was seen for either infliximab or observation. Visual acuities were maintained in all groups. Conclusion These preliminary data suggest that some immunosuppressive agents given systemically can alter the clinical course of the wet form of the disease and support the notion that more definitive clinical trials of immune mediation of age-related macular degeneration are indicated

  1. Chronic systemic complex I inhibition induces a hypokinetic multisystem degeneration in rats.

    PubMed

    Höglinger, Günter U; Féger, Jean; Prigent, Annick; Michel, Patrick P; Parain, Karine; Champy, Pierre; Ruberg, Merle; Oertel, Wolfgang H; Hirsch, Etienne C

    2003-02-01

    In Parkinson's disease, nigral dopaminergic neurones degenerate, whereas post-synaptic striatal target neurones are spared. In some atypical parkinsonian syndromes, both nigral and striatal neurones degenerate. Reduced activity of complex I of the mitochondrial respiratory chain has been implicated in both conditions, but it remains unclear if this affects the whole organism or only the degenerating brain structures. We therefore investigated the differential vulnerability of various brain structures to generalized complex I inhibition. Male Lewis rats infused with rotenone, a lipophilic complex I inhibitor [2.5 mg/kg/day intraveneously (i.v.) for 28 days], were compared with vehicle-infused controls. They showed reduced locomotor activity and loss of striatal dopaminergic fibres (54%), nigral dopaminergic neurones (28.5%), striatal serotoninergic fibres (34%), striatal DARPP-32-positive projection neurones (26.5%), striatal cholinergic interneurones (22.1%), cholinergic neurones in the pedunculopontine tegmental nucleus (23.7%) and noradrenergic neurones in the locus ceruleus (26.4%). Silver impregnation revealed pronounced degeneration in basal ganglia and brain stem nuclei, whereas the hippocampus, cerebellum and cerebral cortex were less affected. These data suggest that a generalized mitochondrial failure may be implicated in atypical parkinsonian syndromes but do not support the hypothesis that a generalized complex I inhibition results in the rather selective nigral lesion observed in Parkinson's disease.

  2. Tracer gauge: an automated dye dilution gauging system for ice-affected streams

    USGS Publications Warehouse

    Clow, D.W.; Fleming, A.C.

    2008-01-01

    In-stream flow protection programs require accurate, real-time streamflow data to aid in the protection of aquatic ecosystems during winter base flow periods. In cold regions, however, winter streamflow often can only be estimated because in-channel ice causes variable backwater conditions and alters the stage-discharge relation. In this study, an automated dye dilution gauging system, a tracer gauge, was developed for measuring discharge in ice-affected streams. Rhodamine WT is injected into the stream at a constant rate, and downstream concentrations are measured with a submersible fluorometer. Data loggers control system operations, monitor key variables, and perform discharge calculations. Comparison of discharge from the tracer gauge and from a Cipoletti weir during periods of extensive ice cover indicated that the root-mean-square error of the tracer gauge was 0.029 m3 s−1, or 6.3% of average discharge for the study period. The tracer gauge system can provide much more accurate data than is currently available for streams that are strongly ice affected and, thus, could substantially improve management of in-stream flow protection programs during winter in cold regions. Care must be taken, however, to test for the validity of key assumptions, including complete mixing and conservative behavior of dye, no changes in storage, and no gains or losses of water to or from the stream along the study reach. These assumptions may be tested by measuring flow-weighted dye concentrations across the stream, performing dye mass balance analyses, and evaluating breakthrough curve behavior.

  3. Economic Evaluation of a Home-Based Age-Related Macular Degeneration Monitoring System.

    PubMed

    Wittenborn, John S; Clemons, Traci; Regillo, Carl; Rayess, Nadim; Liffmann Kruger, Danielle; Rein, David

    2017-05-01

    Medicare recently approved coverage of home telemonitoring for early detection of incident choroidal neovascularization (CNV) among patients with age-related macular degeneration (AMD), but no economic evaluation has yet assessed its cost-effectiveness and budgetary impact. To evaluate a home-based daily visual-field monitoring system using simulation methods and to apply the findings of the Home Monitoring of the Eye study to the US population at high risk for wet-form AMD. In this economic analysis, an evaluation of the potential cost, cost-effectiveness, and government budgetary impact of adoption of a home-based daily visual-field monitoring system among eligible Medicare patients was performed. Effectiveness and visual outcomes data from the Age-Related Eye Disease Study 2 Home Monitoring of the Eye study, treatment data from the Wills Eye Hospital Treat & Extend study, and AMD progression data from the Age-Related Eye Disease Study 1 were used to simulate the long-term effects of telemonitoring patients with CNV in one eye or large drusen and/or pigment abnormalities in both eyes. Univariate and probabilistic sensitivity analysis and an alternative scenario using the Treat & Extend study control group outcomes were used to examine uncertainty in these data and assumptions. Home telemonitoring of patients with AMD for early detection of CNV vs usual care. Incremental cost-effectiveness ratio, net present value of lifetime societal costs, and 10-year nominal government expenditures. Telemonitoring of patients with existing unilateral CNV or multiple bilateral risk factors for CNV (large drusen and retinal pigment abnormalities) incurs $907 (95% CI, -$6302 to $2809) in net lifetime societal costs, costs $1312 (95% CI, $222-$2848) per patient during 10 years from the federal government's perspective, and results in an incremental cost-effectiveness ratio of $35 663 (95% CI, cost savings to $235 613) per quality-adjusted life-year gained. Home telemonitoring

  4. Systemic Complement Inhibition with Eculizumab for Geographic Atrophy in Age-Related Macular Degeneration

    PubMed Central

    Yehoshua, Zohar; Filho, Carlos Alexandre de Amorim Garcia; Nunes, Renata Portella; Gregori, Giovanni; Penha, Fernando M.; Moshfeghi, Andrew A.; Zhang, Kang; Sadda, SriniVas; Feuer, William; Rosenfeld, Philip J.

    2014-01-01

    Purpose To evaluate the effect of eculizumab, a systemic inhibitor of complement component (C5), on the growth of geographic atrophy (GA) in patients with age-related macular degeneration (AMD). Design Prospective, double-masked, randomized clinical trial. Participants Patients with GA measuring from 1.25 to 18 mm2 based on spectral-domain optical coherence tomography imaging. Methods Patients were randomized 2:1 to receive intravenous eculizumab or placebo over 6 months. In the eculizumab treatment arm, the first 10 patients received a low-dose regimen of 600 mg weekly for 4 weeks followed by 900 mg every 2 weeks until week 24, and the next 10 patients received a high-dose regimen of 900 mg weekly for 4 weeks followed by 1200 mg every 2 weeks until week 24. The placebo group was infused with saline. Patients were observed off treatment for an additional 26 weeks. Both normal-luminance and lowluminance visual acuities were measured throughout the study, and the low-luminance deficits were calculated as the difference between the letter scores. Main Outcome Measures Change in area of GA at 26 weeks. Results Thirty eyes of 30 patients were enrolled. Eighteen fellow eyes also met inclusion criteria and were analyzed as a secondary endpoint. For the 30 study eyes, mean square root of GA area measurements ± standard deviation at baseline were 2.55±0.94 and 2.02±0.74 mm in the eculizumab and placebo groups,respectively (P = 0.13). At 26 weeks, GA enlarged by a mean of 0.19±0.12 and 0.18±0.15 mm in the eculizumab and placebo groups, respectively (P = 0.96). At 52 weeks of follow-up, GA enlarged by a mean of 0.37±0.22 mm in the eculizumab-treated eyes and by a mean of 0.37±0.21 mm in the placebo group (P = 0.93, 2 sample t test). None of the eyes converted to wet AMD. No drug-related adverse events were identified. Conclusions Systemic complement inhibition with eculizumab was well tolerated through 6 months but did not decrease the growth rate of GA significantly

  5. Discrimination between FRET and non-FRET quenching in a photochromic CdSe quantum dot/dithienylethene dye system

    NASA Astrophysics Data System (ADS)

    Dworak, Lars; Reuss, Andreas J.; Zastrow, Marc; Rück-Braun, Karola; Wachtveitl, Josef

    2014-11-01

    A photochromic Förster resonance energy transfer (FRET) system was employed to disentangle the fluorescence quenching mechanisms in quantum dot/photochromic dye hybrids. In the off-state of the dye the main quenching mechanism is FRET whereas the moderate quenching in the on-state is due to non-FRET pathways opened up upon assembly.A photochromic Förster resonance energy transfer (FRET) system was employed to disentangle the fluorescence quenching mechanisms in quantum dot/photochromic dye hybrids. In the off-state of the dye the main quenching mechanism is FRET whereas the moderate quenching in the on-state is due to non-FRET pathways opened up upon assembly. Electronic supplementary information (ESI) available: QD and DTE synthesis, preparation of the DTE/QD coupled system, TEM image of the nanocrystals and experimental details. See DOI: 10.1039/c4nr05144k

  6. Genotoxicity assessment of reactive and disperse textile dyes using human dermal equivalent (3D cell culture system).

    PubMed

    Leme, Daniela Morais; Primo, Fernando Lucas; Gobo, Graciely Gomides; da Costa, Cleber Rafael Vieira; Tedesco, Antonio Claudio; de Oliveira, Danielle Palma

    2015-01-01

    Thousands of dyes are marketed daily for different purposes, including textile dyeing. However, there are several studies reporting attributing to dyes deleterious human effects such as DNA damage. Humans may be exposed to toxic dyes through either ingestion of contaminated waters or dermal contact with colored garments. With respect to dermal exposure, human skin equivalents are promising tools to assess in vitro genotoxicity of dermally applied chemicals using a three-dimensional (3D) model to mimic tissue behavior. This study investigated the sensitivity of an in-house human dermal equivalent (DE) for detecting genotoxicity of textile dyes. Two azo (reactive green 19 [RG19] and disperse red 1[DR1]) dyes and one anthraquinone (reactive blue 2 [RB2]) dye were analyzed. RG19 was genotoxic for DE in a dose-responsive manner, whereas RB2 and DR1 were nongenotoxic under the conditions tested. These findings are not in agreement with previous genotoxicological assessment of these dyes carried out using two-dimensional (2D) cell cultures, which showed that DR1 was genotoxic in human hepatoma cells (HepG2) and RG19 was nongenotoxic for normal human dermal fibroblasts (NHDF). These discrepant results probably may be due to differences between metabolic activities of each cell type (organ-specific genotoxicity, HepG2 and fibroblasts) and the test setup systems used in each study (fibroblasts cultured at 2D and three-dimensional [3D] culture systems). Genotoxicological assessment of textile dyes in context of organ-specific genotoxicity and using in vitro models that more closely resemble in vivo tissue architecture and physiology may provide more reliable estimates of genotoxic potential of these chemicals.

  7. Adjacent segment degeneration after lumbar dynamic stabilization using pedicle screws and a nitinol spring rod system with 2-year minimum follow-up.

    PubMed

    Heo, Dong Hwa; Cho, Yong Jun; Cho, Sung Min; Choi, Hyun Chul; Kang, Suk Hyung

    2012-12-01

    Prospective study evaluating the adjacent segment degeneration after lumbar dynamic stabilization using pedicle screws and a Nitinol spring rod system. To assess the changes of the adjacent and implantation segments after lumbar dynamic stabilization surgery using magnetic resonance imaging (MRI). Lumbar fusion operations can accelerate the degeneration of adjacent levels. Recently, motion preservation surgery has been attempted for the treatment of lumbar degenerative diseases to prevent degeneration of adjacent levels. However, there is a controversy over whether lumbar dynamic stabilization accelerates degeneration of adjacent levels. We performed the dynamic stabilization procedure in patients with grade 1 degenerative lumbar spondylolisthesis, lumbar spondylotic stenosis with segmental instability, or a herniated lumbar disc with segmental instability. Postoperative MRI scans were taken for >2 years in all enrolled 25 patients. We compared the findings regarding disc degeneration in the cranial, implantation, and caudal segments between the preoperative period and 2-year-plus postoperative period using T2-weighted sagittal MR images. In addition, we investigated the progression of the central and foraminal stenosis of the adjacent cranial and caudal levels. Three of the 25 cranial adjacent discs (12.0%) and 4 of the 25 (16%) caudal adjacent discs demonstrated progression of degeneration after dynamic stabilization. One of the 13 discs in the implantation segment demonstrated progression of degeneration, and 2 of the 13 discs in the implantation segment showed improvement of their disc degeneration (disc rehydration). A total of 5 (10.0%) of the 50 segments (3 cranial and 2 caudal adjacent) showed increased spinal stenosis postoperatively. Among the 5 cases, 3 patients had symptomatic adjacent stenosis. According to our results, lumbar dynamic stabilization using pedicle screws and a Nitinol spring rod system may not prevent adjacent level degeneration

  8. Long-lived laser dye

    SciTech Connect

    Fletcher, A.N.

    1986-07-29

    A method is described of obtaining in a flashlamp pumped laser system, a long-lived flashpumped laser dye having a low threshold of lasing and a moderate output comprising the steps of: placing a dye solution comprising a laser dye, the N-methyl tosylate salt of 2-(4-pyridyl)-5-(4-methoxphenyl)oxazole, and a solvent into a laser dye cavity; screening the dye solution from ultraviolet light with an optical filter; flushing the dye solution with an inert gas; and optically pumping the dye solution with a flashlamp to produce laser emission.

  9. Degeneration of Fraunhofer diffraction on bacterial colonies due to their light focusing properties examined in the digital holographic microscope system.

    PubMed

    Buzalewicz, Igor; Liżewski, Kamil; Kujawińska, Małgorzata; Podbielska, Halina

    2013-11-04

    The degeneration of Fraunhofer diffraction conditions in the optical system with converging spherical wave illumination for bacteria species identification based on diffraction patterns is analyzed by digital holographic methods. The obtained results have shown that the colonies of analyzed bacteria species act as biological lenses with the time-dependent light focusing properties, which are characterized and monitored by means of phase retrieval from sequentially captured digital holograms. This significantly affects the location of Fraunhofer patterns observation plane, which is continuously shifted across optical axis in time.

  10. Development of sustainable dye adsorption system using Nutraceutical Industrial Fennel Seed Spent - Studies with Congo Red dye.

    PubMed

    Taqui, Syed Noeman; Yahya, Rosiyah; Hassan, Aziz; Nayak, Nayan; Syed, Akheel Ahmed

    2017-01-25

    Fennel seed spent (FSS) - an inexpensive nutraceutical industrial spent has been used as an efficient biosorbent for the removal of Congo Red (CR) from aqueous media. Results show that pH of 2 - 4 and temperature of 30°C was ideal for maximum adsorption. Based on regression fitting of the data it was determined that the SIPS isotherm (R(2) = 0.994, χ(2) = 0.5) adequately described the mechanism of adsorption, suggesting that the adsorption occurs in a homogeneous layer by layer with favourable interaction between layers. Thermodynamic analysis showed that the adsorption is favourable (negative values for ΔG°) and endothermic (ΔH° = 12-20 kJ mol(-1)) for an initial dye concentration of 25, 50 and 100 ppm. The low ΔH° value indicates that the adsorption is a physical process involving weak chemical interactions like hydrogen bonds and van der Waals interactions. The kinetics revealed that the adsorption process showed pseudo second order tendencies with the equal influence of intra-particle as well as film diffusion. The SEM images of FSS show a highly fibrous matrix with a hierarchical porous structure. The FTIR analysis of the spent confirmed the presence of cellulosic and ligno-cellulosic matter giving it both hydrophilic and hydrophobic properties. The investigations indicate that FSS is a cost-effective and efficient biosorbent for the remediation of toxic Congo Red dye.

  11. Dynamics at Infinity, Degenerate Hopf and Zero-Hopf Bifurcation for Kingni-Jafari System with Hidden Attractors

    NASA Astrophysics Data System (ADS)

    Wei, Zhouchao; Moroz, Irene; Wang, Zhen; Sprott, Julien Clinton; Kapitaniak, Tomasz

    2016-06-01

    To understand the complex dynamics of Kingni-Jafari system with hidden attractors, the first objective of this paper is to study the global dynamics, and give a complete description of the dynamics of Kingni-Jafari system at infinity by using the Poincaré compactification of a polynomial vector field in ℝ3. The second objective of this paper is to prove the existence of periodic solutions in the Kingni-Jafari system by classical Hopf bifurcation and degenerate Hopf bifurcation. Moreover, based on averaging theory, a small amplitude periodic solution that bifurcates from a zero-Hopf equilibrium was derived in the Kingni-Jafari system. The theoretical analysis and simulations demonstrate the rich dynamics of the system.

  12. Is age-related macular degeneration a manifestation of systemic disease? New prospects for early intervention and treatment.

    PubMed

    Cheung, C M G; Wong, T Y

    2014-08-01

    Age-related macular degeneration (AMD) is a common vision-threatening condition affecting the elderly. AMD shares common risk factors and processes, including vascular and inflammatory pathways, with many systemic disorders. Associations have been reported between AMD and hypertension, cardiovascular disease, cerebrovascular disease, dyslipidaemia, chronic kidney disease and neurodegenerative disorders. An increasing amount of evidence suggests that individuals with AMD are also at risk of systemic diseases such as stroke. In this review, we summarize the latest evidence to support the notion that AMD is an ocular manifestation of systemic disease processes, and discuss the potential systemic side effects of ocular AMD therapy of which general physicians should be aware. Recent genetic discoveries and understanding of the pathogenic pathways in AMD in relation to systemic disorders are also highlighted. © 2014 The Association for the Publication of the Journal of Internal Medicine.

  13. Fatty degeneration of the rotator cuff muscles on pre- and postoperative CT arthrography (CTA): is the Goutallier grading system reliable?

    PubMed

    Lee, Eugene; Choi, Jung-Ah; Oh, Joo Han; Ahn, Soyeon; Hong, Sung Hwan; Chai, Jee Won; Kang, Heung Sik

    2013-09-01

    To retrospectively evaluate fatty degeneration (FD) of rotator cuff muscles on CTA using Goutallier's grading system and quantitative measurements with comparison between pre- and postoperative states. IRB approval was obtained for this study. Two radiologists independently reviewed pre- and postoperative CTAs of 43 patients (24 males and 19 females, mean age, 58.1 years) with 46 shoulders confirmed as full-thickness tears with random distribution. FD of supraspinatus, infraspinatus/teres minor, and subscapularis was assessed using Goutallier's system and by quantitative measurements of Hounsfield units (HUs) on sagittal images. Changes in FD grades and HUs were compared between pre- and postoperative CTAs and analyzed with respect to preoperative tear size and postoperative cuff integrity. The correlations between qualitative grades and quantitative measurements and their inter-observer reliabilities were also assessed. There was statistically significant correlation between FD grades and HU measurements of all muscles on pre- and postoperative CTA (p < 0.05). Inter-observer reliability of fatty degeneration grades were excellent to substantial on both pre- and postoperative CTA in supraspinatus (0.8685 and 0.8535) and subscapularis muscles (0.7777 and 0.7972), but fair in infraspinatus/teres minor muscles (0.5791 and 0.5740); however, quantitative Hounsfield units measurements showed excellent reliability for all muscles (ICC: 0.7950 and 0.9346 for SST, 0.7922 and 0.8492 for SSC, and 0.9254 and 0.9052 for IST/TM). No muscle showed improvement of fatty degeneration after surgical repair on qualitative and quantitative assessments; there was no difference in changes of fatty degeneration after surgical repair according to preoperative tear size and post-operative cuff integrity (p > 0.05). The average dose-length product (DLP, mGy · cm) was 365.2 mGy · cm (range, 323.8-417.2 mGy · cm) and estimated average effective dose was 5.1 mSv. Goutallier

  14. Optimization of a Raman shifted dye laser system for DIAL applications

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Chu, Zhiping; Mahon, Rita; Wilkerson, Thomas D.

    1990-01-01

    An efficient Raman shifted dye laser system that generates tunable radiation at 765 and 940 nm with a bandwidth of 0.03/cm is described. Operating a Raman cell at hydrogen pressure below 14 atm, optimum first Stokes energy conversions of 45 percent and of 37 percent at 765 and 940 nm, respectively, were recorded. Optical depth measurements made at the centers of twenty-five absorption lines in the P branch of the oxygen A band imply a high spectral purity for both the laser and the Raman shifted radiation, and thus indicate the feasibility of using the stimulated Raman scattered radiation for differential absorption lidar (DIAL) measurements.

  15. Striatopallidonigral degeneration

    PubMed Central

    Bell, W. E.; McCormick, W. F.

    1971-01-01

    A 15-year-old girl is described with a sporadic, progressive illness manifested by unilateral limb rigidity and dystonia. Obvious dysarthria and some intellectual decline also were noted. Neuropathological findings included gross discoloration and shrinkage of the pallida and, microscopically, profound neuronal loss and gliosis of the caudata and putamena, with less severe neuronal loss from the pallida and substantia nigra. The disease bears some similarities to striatonigral degeneration, but certain clinical and morphological differences justify its consideration as a separate syndrome. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:5565467

  16. Unconventional High-Performance Laser Protection System Based on Dichroic Dye-Doped Cholesteric Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Zhang, Wanshu; Zhang, Lanying; Liang, Xiao; Le Zhou; Xiao, Jiumei; Yu, Li; Li, Fasheng; Cao, Hui; Li, Kexuan; Yang, Zhou; Yang, Huai

    2017-02-01

    High-performance and cost-effective laser protection system is of crucial importance for the rapid advance of lasers in military and civilian fields leading to severe damages of human eyes and sensitive optical devices. However, it is crucially hindered by the angle-dependent protective effect and the complex preparation process. Here we demonstrate that angle-independence, good processibility, wavelength tunability, high optical density and good visibility can be effectuated simultaneously, by embedding dichroic anthraquinone dyes in a cholesteric liquid crystal matrix. More significantly, unconventional two-dimensional parabolic protection behavior is reported for the first time that in stark contrast to the existing protection systems, the overall parabolic protection behavior enables protective effect to increase with incident angles, hence providing omnibearing high-performance protection. The protective effect is controllable by dye concentration, LC cell thickness and CLC reflection efficiency, and the system can be made flexible enabling applications in flexible and even wearable protection devices. This research creates a promising avenue for the high-performance and cost-effective laser protection, and may foster the development of optical applications such as solar concentrators, car explosion-proof membrane, smart windows and polarizers.

  17. Unconventional High-Performance Laser Protection System Based on Dichroic Dye-Doped Cholesteric Liquid Crystals

    PubMed Central

    Zhang, Wanshu; Zhang, Lanying; Liang, Xiao; Le Zhou; Xiao, Jiumei; Yu, Li; Li, Fasheng; Cao, Hui; Li, Kexuan; Yang, Zhou; Yang, Huai

    2017-01-01

    High-performance and cost-effective laser protection system is of crucial importance for the rapid advance of lasers in military and civilian fields leading to severe damages of human eyes and sensitive optical devices. However, it is crucially hindered by the angle-dependent protective effect and the complex preparation process. Here we demonstrate that angle-independence, good processibility, wavelength tunability, high optical density and good visibility can be effectuated simultaneously, by embedding dichroic anthraquinone dyes in a cholesteric liquid crystal matrix. More significantly, unconventional two-dimensional parabolic protection behavior is reported for the first time that in stark contrast to the existing protection systems, the overall parabolic protection behavior enables protective effect to increase with incident angles, hence providing omnibearing high-performance protection. The protective effect is controllable by dye concentration, LC cell thickness and CLC reflection efficiency, and the system can be made flexible enabling applications in flexible and even wearable protection devices. This research creates a promising avenue for the high-performance and cost-effective laser protection, and may foster the development of optical applications such as solar concentrators, car explosion-proof membrane, smart windows and polarizers. PMID:28230153

  18. The excited states of stilbene and stilbenoid donor-acceptor dye systems. A theoretical study

    NASA Astrophysics Data System (ADS)

    Rettig, Wolfgang; Strehmel, Bernd; Majenz, Wilfried

    1993-07-01

    Semiempirical calculations within the CNDO/S framework are used to characterize the nature of the "phantom-singlet" excited state P * (double-bond twisted geometry) of stilbene and stilbenoid donor-acceptor dye systems including the laser dyes DCM and DASPMI. P * is highly polar (closed shell "hole-pair" nature) for weakly perturbed stilbenes but for larger donor-acceptor strength, the order of ground and excited state is reversed, and P * becomes of small polarity ("dot-dot" nature), fully consistent with the established model of biradicaloid states. For stilbene, a slight geometric symmetry reduction is necessary in order to localize the orbitals on the subunits. Only then are the calculated results consistent with those for methyl-substituted stilbene. The localized orbital description of twisted stilbene shows that P * contains negligible doubly excited character and possesses a very small gap to the ground state contrary to what is stated in the previous literature. The planar systems are also investigated and correlated with Dähne's triad rule of polymethine systems.

  19. Unconventional High-Performance Laser Protection System Based on Dichroic Dye-Doped Cholesteric Liquid Crystals.

    PubMed

    Zhang, Wanshu; Zhang, Lanying; Liang, Xiao; Le Zhou; Xiao, Jiumei; Yu, Li; Li, Fasheng; Cao, Hui; Li, Kexuan; Yang, Zhou; Yang, Huai

    2017-02-23

    High-performance and cost-effective laser protection system is of crucial importance for the rapid advance of lasers in military and civilian fields leading to severe damages of human eyes and sensitive optical devices. However, it is crucially hindered by the angle-dependent protective effect and the complex preparation process. Here we demonstrate that angle-independence, good processibility, wavelength tunability, high optical density and good visibility can be effectuated simultaneously, by embedding dichroic anthraquinone dyes in a cholesteric liquid crystal matrix. More significantly, unconventional two-dimensional parabolic protection behavior is reported for the first time that in stark contrast to the existing protection systems, the overall parabolic protection behavior enables protective effect to increase with incident angles, hence providing omnibearing high-performance protection. The protective effect is controllable by dye concentration, LC cell thickness and CLC reflection efficiency, and the system can be made flexible enabling applications in flexible and even wearable protection devices. This research creates a promising avenue for the high-performance and cost-effective laser protection, and may foster the development of optical applications such as solar concentrators, car explosion-proof membrane, smart windows and polarizers.

  20. Mutagenicity testing of certified food colors and related azo, xanthene and triphenylmethane dyes with the Salmonella/microsome system.

    PubMed

    Brown, J P; Roehm, G W; Brown, R J

    1978-01-01

    Thirty-seven azo, xanthene and triphenylmethane dyes including FD and C colors currently approved for use in the U.S.A. and a number of delisted food colors, were tested in the Salmonella/microsome system. In addition to direct plate tests with five tester strains (TA1535, TA100, TA1537, TA1538, TA98), the azo dyes were also assayed after chemical reduction to their component amines. Also, a selected group of azo dyes was subjected to liquid tests (both aerobic with microsomes and anaerobic) and to plate tests involving initial 16 h anaerobic incubations to facilitate microbial reduction of the azo bond. None of the presently listed FD and C colors was mutagenic in any of the test modifications. Among formerly listed colors only Butter Yellow (p-dimethylaminoazobenzene), a recognized animal carcinogen, was mutagenic in the aerobic liquid test. Several other azo dyes were either directly mutagenic, viz. Acid Alizarin Yellow R and Alizarin Yellow GG; required microsomal activation, viz. Acid Alizarin Red B and Methyl Red; or required chemical reduction and microsomal activation, viz. Acid Alizarin Violet N and Sudan IV. Of the non-azo dyes tested only two xanthene dyes appeared to be mutagenic, viz. 9-(2-sulfophenyl)-6-hydroxy-3-isoxanthenone and its 2,4,5,7-tetrabromo derivative.

  1. Enhanced azo dye removal through anode biofilm acclimation to toxicity in single-chamber biocatalyzed electrolysis system.

    PubMed

    Wang, You-Zhao; Wang, Ai-Jie; Liu, Wen-Zong; Sun, Qian

    2013-08-01

    Azo dye is widely used in printing and dyeing process as one of refractory wastewaters for its high chroma, stable chemical property and toxicity for aquatic organism. Biocatalyzed electrolysis system (BES) is a new developed technology to degrade organic waste in bioanode and recover recalcitrant contaminants in cathode with effective decoloration. The ion exchange membrane (IEM) separate anode and cathode for biofilm formation protection. Azo removal efficiency was up to 60.8%, but decreased to 20.5% when IEM was removed. However, expensive ion exchange membrane (IEM) not suitable for further practical application, bioelectrochemical activity of bioanode is sensitive to the toxicity of azo dye. A gradient increase of azo dye concentration was used to acclimate anode biofilm to pollutant toxicity. The azo removal efficiency can be enhanced to 73.3% in 10h reaction period after acclimation. The highest removal efficiency reached 83.7% and removal rates were increased to 8.37 from 3.04 g/h/L of dual-chamber. That indicated the feasibility for azo dye removal by single-chamber BES. The IEM cancellation not only decreased the internal resistance, but increased the current density and azo dye removal.

  2. Systemic safety of bevacizumab versus ranibizumab for neovascular age-related macular degeneration

    PubMed Central

    Moja, Lorenzo; Lucenteforte, Ersilia; Kwag, Koren H; Bertele, Vittorio; Campomori, Annalisa; Chakravarthy, Usha; D’Amico, Roberto; Dickersin, Kay; Kodjikian, Laurent; Lindsley, Kristina; Loke, Yoon; Maguire, Maureen; Martin, Daniel F; Mugelli, Alessandro; Mühlbauer, Bernd; Püntmann, Isabel; Reeves, Barnaby; Rogers, Chris; Schmucker, Christine; Subramanian, Manju L; Virgili, Gianni

    2014-01-01

    Background Neovascular age-related macular degeneration (AMD) is the leading cause of legal blindness in elderly populations of industrialised countries. Bevacizumab (Avastin®) and ranibizumab (Lucentis®) are targeted biological drugs (a monoclonal antibody) that inhibit vascular endothelial growth factor, an angiogenic cytokine that promotes vascular leakage and growth, thereby preventing its pathological angiogenesis. Ranibizumab is approved for intravitreal use to treat neovascular AMD, while bevacizumab is approved for intravenous use as a cancer therapy. However, due to the biological similarity of the two drugs, bevacizumab is widely used off-label to treat neovascular AMD. Objectives To assess the systemic safety of intravitreal bevacizumab (brand name Avastin®; Genentech/Roche) compared with intravitreal ranibizumab (brand name Lucentis®; Novartis/Genentech) in people with neovascular AMD. Primary outcomes were death and All serious systemic adverse events (All SSAEs), the latter as a composite outcome in accordance with the International Conference on Harmonisation Good Clinical Practice. Secondary outcomes examined specific SSAEs: fatal and non-fatal myocardial infarctions, strokes, arteriothrombotic events, serious infections, and events grouped in some Medical Dictionary for Regulatory Activities System Organ Classes (MedDRA SOC). We assessed the safety at the longest available follow-up to a maximum of two years. Search methods We searched CENTRAL, MEDLINE, EMBASE and other online databases up to 27 March 2014. We also searched abstracts and clinical study presentations at meetings, trial registries, and contacted authors of included studies when we had questions. Selection criteria Randomised controlled trials (RCTs) directly comparing intravitreal bevacizumab (1.25 mg) and ranibizumab (0.5 mg) in people with neovascular AMD, regardless of publication status, drug dose, treatment regimen, or follow-up length, and whether the SSAEs of interest were

  3. Dye tracing techniques used to determine ground-water flow in a carbonate aquifer system near Elizabethtown, Kentucky

    USGS Publications Warehouse

    Mull, D.S.; Smoot, J.L.; Liebermann, T.D.

    1988-01-01

    Because of the vulnerability of karst aquifers to contamination and the need for water managers to know recharge areas and groundwater flow characteristics for springs and wells used for public water supply, qualitative and quantitative dye tracing techniques were used during a groundwater investigation in the Elizabethtown area, Hardin County, in north-central Kentucky. The principal aquifer in the Elizabethtown area is thick, nearly horizontal beds of limestone, and thin beds of shale of Mississippi age. As much as 65% of all water pumped for the city water supply is obtained from two springs and two wells that obtain water from these rocks. Sinkholes were classified according to their ability to funnel runoff directly into the groundwater flow system, based primarily on the nature of the swallet draining the sinkhole. The presence of bedrock in the sinkhole nearly always ensured a well defined swallet leading to the subsurface. Qualitative and quantitative dye tracing techniques and equipment are discussed in detail. Qualitative dye tracing with fluorescein dye and passive dye detectors, consisting of activated coconut charcoal identified point to point connection between representative sinkholes, sinking streams, and karst windows and the city springs and wells. Qualitative tracing confirmed the presence of infiltrated surface water from a perennial stream, Valley Creek, in water from city wells and generally confirmed the direction of groundwater flow as shown by a water level contour map. Quantitative dye tracing with rhodamin WT, automatic samplers, discharge measurements, and fluorometric analyses were used to determine flow characteristics such as traveltime for arrival of the leading edge, peak concentration, trailing edge, and persistence of the dye cloud at the spring resurgence. Analyses of the dye recovery curves for quantitative dye traces completed between the same sinkholes and a city spring, and during different flow conditions showed that the

  4. Use of selective silver impregnation of neuronal degeneration as a biomarker for assessing organophosphorus-induced neuropathy in the central nervous system. A review

    SciTech Connect

    Tanaka, D. Jr.; Bursian, S.J.

    1998-12-31

    Exposure to selected groups of organophosphorus compounds has been shown to result in neuronal degeneration in both avian and mammalian nervous systems. Previous investigators, using hematoxylin and eosin stains, concluded that the degeneration resulting from exposure to these compounds was restricted to peripheral nerves and to long fiber tracts of the spinal cord and lower brainstem. The authors re-examined the results of exposure to the organophosphorus compounds tri-Q-tolyl phosphate, diisopropylphosphorofluoridate, and triphenyl phosphite using a variant of the Fink-Heimer silver impregnation method. This method selectively stains degenerating axions and axon terminals. Chickens, Japanese quail, rats, and mature and immature ferrets were used in these studies because of their differential clinical susceptibility to organophosphorus compounds. Their results indicate that exposure to each compound may result in a variable amount of degeneration within selected nuclei and tracts in the brain and spinal cord. The amount of degeneration seen in each instance corresponds well with the severity of the resultant clinical signs. In addition, the locus and severity of neuronal degeneration is dependent on the particular compound used, the species of animal exposed, and the age of the animal at the time of exposure.

  5. Process and kinetics of azo dye decolourization in bioelectrochemical systems: effect of several key factors

    PubMed Central

    Yang, Hou-Yun; He, Chuan-Shu; Li, Lei; Zhang, Jie; Shen, Jin-You; Mu, Yang; Yu, Han-Qing

    2016-01-01

    This study explored the influence of several key factors on the process and kinetics of azo dye decolourization in bioelectrochemical systems (BESs), including cathode potential, dissolved oxygen (DO) concentration of catholyte and biofilm formed on the cathode. The results show that azo dye methyl orange (MO) decolourization in the BES could be well described with the pseudo first-order kinetics. The MO decolourization efficiency increased from 0 to 94.90 ± 0.01% and correspondingly the reaction rate constant increased from 0 to 0.503 ± 0.001 h−1 with the decrease in cathodic electrode potential from −0.2 to −0.8 V vs Ag/AgCl. On the contrary, DO concentration of the catholyte had a negative impact on MO decolourization in the BES. When DO concentration increased from zero to 5.80 mg L−1, the MO decolourization efficiency decreased from 87.19 ± 4.73% to 27.77 ± 0.06% and correspondingly the reaction rate constant reduced from 0.207 ± 0.042 to 0.033 ± 0.007 h−1. Additionally, the results suggest that the biofilm formed on the cathode could led to an adverse rather than a positive effect on azo dye decolourization in the BES in terms of efficiency and kinetics. PMID:27270398

  6. Performance of ceramic ultrafiltration membranes and fouling behavior of a dye-polysaccharide binary system.

    PubMed

    Zuriaga-Agustí, E; Alventosa-deLara, E; Barredo-Damas, S; Alcaina-Miranda, M I; Iborra-Clar, M I; Mendoza-Roca, J A

    2014-05-01

    Ultrafiltration membrane processes have become an established technology in the treatment and reuse of secondary effluents. Nevertheless, membrane fouling arises as a major obstacle in the efficient operation of these systems. In the current study, the performance of tubular ultrafiltration ceramic membranes was evaluated according to the roles exerted by membrane pore size, transmembrane pressure and feed concentration on a binary foulant system simulating textile wastewater. For that purpose, carboxymethyl cellulose sodium salt (CMC) and an azo dye were used as colloidal and organic foulants, respectively. Results showed that a larger pore size enabled more solutes to get adsorbed into the pores, producing a sharp permeate flux decline attributed to the rapid pore blockage. Besides, an increase in CMC concentration enhanced severe fouling in the case of the tighter membrane. Concerning separation efficiency, organic matter was almost completely removed with removal efficiency above 98.5%. Regarding the dye, 93% of rejection was achieved. Comparable removal efficiencies were attributed to the dynamic membrane formed by the cake layer, which governed process performance in terms of rejection and selectivity. As a result, none of the evaluated parameters showed significant influence on separation efficiency, supporting the significant role of cake layer on filtration process.

  7. Age-related macular degeneration and the role of the complement system.

    PubMed

    McHarg, Selina; Clark, Simon J; Day, Anthony J; Bishop, Paul N

    2015-09-01

    Age-related macular degeneration (AMD) is a leading cause of visual impairment. It is characterised by damage to a tissue complex composed of the retinal pigment epithelium, Bruch's membrane and choriocapillaris. In early AMD extracellular debris including drusen accumulates in Bruch's membrane and then in late AMD geographic atrophy and/or neovascularisation develop. Variants in genes encoding components of the alternative pathway of the complement cascade have a major influence on AMD risk, especially at the RCA locus on chromosome 1, which contains CFH and the CFHR genes. Immunohistochemical studies have demonstrated complement components in unaffected and AMD macular tissue. Whilst other factors, including oxidative stress, play important roles in AMD pathogenesis, evidence for the central role played by complement dysregulation is discussed in this review.

  8. Group Theoretical Classification of Doubly Degenerate Orbital Systems on a Triangular Lattice

    NASA Astrophysics Data System (ADS)

    Masago, Akira; Suzuki, Naoshi

    2004-09-01

    On the basis of a group theoretical theory we have classified the mean field solutions of an eg degenerate Hubbard model on a two dimensional triangular lattice. For the crystal structure we have assumed a space group R\\bar{3}m, which is associated with NaNiO2, LiNiO2 and so on. As the ordering vector we have assumed two vectors which correspond to M and K points, respectively, in the first Brillouin zone. We have obtained seventeen kinds of broken symmetry states in total. Those include the triangle arrangements of spin or orbital and the novel state related to magnetic octupole states as well as ordinary ferro-magnetic and orbital ordered states.

  9. Interaction between an organic dye in water and sand packs in a flume system.

    PubMed

    Nome, Rene A; Souza, Aloisio J; Nome, Carlos A; Souza, Bruno S; Nome, Faruk; Fiedler, Haidi D

    2010-11-01

    The sorption kinetics of methylene blue (MB), a standard compound in the American Society for Testing and Materials tests, on natural sand in a batch system at a reciprocal shaking speed of 120 rpm is fast, with equilibrium and surface coverage attained in minutes. When the same experiment is carried out in a recirculating flume, adsorption is much slower, with lifetimes increasing up to several months in the flume. Sorption retardation is dependent on the diffusion coefficient of the dye and on the depth of penetration of the MB layer in sand. The experimental results suggest that, in field experiments, formation of thin films dramatically inhibits the sorption kinetics and, in a closed system, such as a lake or reservoir, contaminants will remain in the water column for long periods, with very slow penetration in the sediment layer. In rivers, the contaminant will travel farther with less penetration into the sediment layer, compared to more static systems.

  10. Electrolytes based on TEMPO-Co tandem redox systems outperform single redox systems in dye-sensitized solar cells.

    PubMed

    Cong, Jiayan; Hao, Yan; Boschloo, Gerrit; Kloo, Lars

    2015-01-01

    A new TEMPO-Co tandem redox system with TEMPO and Co(bpy)3 (2+/3+) has been investigated for the use in dye-sensitized solar cells (DSSCs). A large open-circuit voltage (VOC ) increase, from 862 mV to 965 mV, was observed in the tandem redox system, while the short-circuit current density (JSC ) was maintained. The conversion efficiency was observed to increase from 7.1 % for cells containing the single Co(bpy)3 (2+/3+) redox couple, to 8.4 % for cells containing the TEMPO-Co tandem redox system. The reason for the increase in VOC and overall efficiency is ascribed to the involvement of partial regeneration of the sensitizing dye molecules by TEMPO. This assumption can be verified through the observed much faster regeneration dynamics exhibited in the presence of the tandem system. Using the tandem redox system, the faster recombination problem of the single TEMPO redox couple is resolved and the mass-transport of the metal-complex-based electrolyte is also improved. This TEMPO-Co tandem system is so far the most efficient tandem redox electrolyte reported not involving iodine. The current results show a promising future for tandem system as replacements for single redox systems in electrolytes for DSSCs.

  11. Functional-structural degeneration in dorsal and ventral attention systems for Alzheimer's disease, amnestic mild cognitive impairment.

    PubMed

    Qian, Shaowen; Zhang, Zhaoyan; Li, Bo; Sun, Gang

    2015-12-01

    Growing evidence of attention related failures in patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD) has already been proposed by previous studies. However, previous studies lacked of systematic investigation on the functional and structural substrates for attention function for patients with AD and aMCI. In this work, we investigated the functional connectivity and gray matter density in dorsal and ventral attention networks (DAN, VAN) of normal participants (n = 15) and patients with aMCI (n = 12) and AD (n = 16) by applying group independent component analysis (ICA) and voxel-based morphometry (VBM) analysis. Using ICA, we extracted the functional patterns of DAN and VAN which are respectively responsible for the "top-down" attention process and "bottom-up" process. One-way analysis of variance (ANOVA) revealed significant group-differed functional connectivity in bilateral frontal eye fields (FEF) area and intraparietal sulcus (IPS) area, as well as posterior cingulate cortex and precuneus in the dorsal system. With regard to the ventral system, group-effects were significantly focused in right orbital superior/middle frontal gyrus, right inferior parietal lobule, angular gyrus, and supramarginal gyrus around the temporal-parietal junction area. Post hoc cluster-level comparisons revealed totally impaired functional substrates for both attentional networks for patients with AD, whereas selectively impaired attention systems for patients with aMCI with impaired functional patent of DAN but preserved functional pattern of VAN. Correspondingly, VBM analysis revealed gray matter loss in right ventral and dorsal frontal cortex was in the AD group, whereas preserved gray matter density was in aMCI, even a little extent of expansion of gray matter density in several participants. Using multivariate regression analysis we found discrepant couplings of functional-structural degenerations between both patient groups

  12. Sentinel lymph nodes detection with an imaging system using Patent Blue V dye as fluorescent tracer

    NASA Astrophysics Data System (ADS)

    Tellier, F.; Steibel, J.; Chabrier, R.; Rodier, J. F.; Pourroy, G.; Poulet, P.

    2013-03-01

    Sentinel lymph node biopsy is the gold standard to detect metastatic invasion from primary breast cancer. This method can help patients avoid full axillary chain dissection, thereby decreasing the risk of morbidity. We propose an alternative to the traditional isotopic method, to detect and map the sentinel lymph nodes. Indeed, Patent Blue V is the most widely used dye in clinical routine for the visual detection of sentinel lymph nodes. A Recent study has shown the possibility of increasing the fluorescence quantum yield of Patent Blue V, when it is bound to human serum albumin. In this study we present a preclinical fluorescence imaging system to detect sentinel lymph nodes labeled with this fluorescent tracer. The setup is composed of a black and white CCD camera and two laser sources. One excitation source with a laser emitting at 635 nm and a second laser at 785 nm to illuminate the region of interest. The prototype is operated via a laptop. Preliminary experiments permitted to determine the device sensitivity in the μmol.L-1 range as regards the detection of PBV fluorescence signals. We also present a preclinical evaluation performed on Lewis rats, during which the fluorescence imaging setup detected the accumulation and fixation of the fluorescent dye on different nodes through the skin.

  13. Improved azo dye decolorization in a modified sleeve-type bioelectrochemical system.

    PubMed

    Kong, Fanying; Wang, Aijie; Liang, Bin; Liu, Wenzong; Cheng, Haoyi

    2013-09-01

    Bioelectrochemical system (BES) that removes recalcitrant pollutant out of wastewater is of special interest for practice. This study modified the configuration of BES to be a sleeve-type with compact structure. Azo dye (acid orange 7, AO7) in the outer cathode chamber performed a complete decolorization by electrons supplied from acetate oxidized with electricigens in the inner anode chamber. The AO7 decolorization efficiency (DEAO7) was enhanced to be higher than 98% from 0.14 to 2.00 mM. Electrochemical impedance spectroscopy (EIS) analysis showed that the internal resistance of anode, cathode and the whole cell was 26.4, 38.3, and 64.6 Ω, respectively, indicating that the modified configuration with large area and small distance between anode and cathode can result in a lower internal resistance and higher decolorization performance. This is the first study for azo dye decolorization using sleeve-type configuration with highly efficient decolorization by abiotic cathode BES. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Photoactive Nanomaterials Inspired by Nature: LTL Zeolite Doped with Laser Dyes as Artificial Light Harvesting Systems

    PubMed Central

    Gartzia-Rivero, Leire; Bañuelos, Jorge; López-Arbeloa, Iñigo

    2017-01-01

    The herein reported work describes the development of hierarchically-organized fluorescent nanomaterials inspired by plant antenna systems. These hybrid materials are based on nanostructured zeolitic materials (LTL zeolite) doped with laser dyes, which implies a synergism between organic and inorganic moieties. The non-interconnected channeled structure and pore dimensions (7.1 Å) of the inorganic host are ideal to order and align the allocated fluorophores inside, inferring also high thermal and chemical stability. These artificial antennae harvest a broad range of chromatic radiation and convert it into predominant red-edge or alternatively white-light emission, just choosing the right dye combination and concentration ratio to modulate the efficiency of the ongoing energy transfer hops. A further degree of organization can be achieved by functionalizing the channel entrances of LTL zeolite with specific tailor-made (stopcock) molecules via a covalent linkage. These molecules plug the channels to avoid the leakage of the guest molecules absorbed inside, as well as connect the inner space of the zeolite with the outside thanks to energy transfer processes, making the coupling of the material with external devices easier. PMID:28772856

  15. Examining protein-lipid interactions in model systems with a new squarylium fluorescent dye.

    PubMed

    Ioffe, Valeriya M; Gorbenko, Galyna P; Tatarets, Anatoliy L; Patsenker, Leonid D; Terpechnig, Ewald A

    2006-07-01

    The applicability of newly synthesized squarylium dye Sq to probing the changes in physical characteristics of lipid bilayer on the formation of protein-lipid complexes has been evaluated. Lipid vesicles composed of zwitterionic phospholipid phosphatidylcholine (PC) and its mixtures with positively charged detergent cetyltrimethylammonium bromide (CTAB), anionic phospholipid cardiolipin (CL), and cholesterol (Chol) were employed as lipid component of model membrane systems while protein constituent was represented by lysozyme (Lz). Fluorescence intensity of Sq was found to decrease on Lz association with lipid bilayer. This effect was observed in all kinds of model systems suggesting that Sq is sensitive to modification of lipid bilayer physical properties on hydrophobic protein-lipid interactions. It was found that Sq spectral response to variations in Chol content depends on relative contributions of electrostatic and hydrophobic components of Lz-membrane binding.

  16. Dry Macular Degeneration

    MedlinePlus

    ... delay vision loss due to dry macular degeneration. Symptoms Dry macular degeneration symptoms usually develop gradually and without pain. They may ... of printed words Decreased intensity or brightness of ... causes total blindness. Dry macular degeneration is one of two types ...

  17. Macular degeneration (image)

    MedlinePlus

    Macular degeneration is a disease of the retina that affects the macula in the back of the eye. ... see fine details. There are two types of macular degeneration, dry and wet. Dry macular degeneration is more ...

  18. Peptide redesign for inhibition of the complement system: Targeting age-related macular degeneration

    PubMed Central

    Mohan, Rohith R.; Cabrera, Andrea P.; Harrison, Reed E. S.; Gorham, Ronald D.; Johnson, Lincoln V.; Ghosh, Kaustabh

    2016-01-01

    Purpose To redesign a complement-inhibiting peptide with the potential to become a therapeutic for dry and wet age-related macular degeneration (AMD). Methods We present a new potent peptide (Peptide 2) of the compstatin family. The peptide is developed by rational design, based on a mechanistic binding hypothesis, and structural and physicochemical properties derived from molecular dynamics (MD) simulation. The inhibitory activity, efficacy, and solubility of Peptide 2 are evaluated using a hemolytic assay, a human RPE cell–based assay, and ultraviolet (UV) absorption properties, respectively, and compared to the respective properties of its parent peptide (Peptide 1). Results The sequence of Peptide 2 contains an arginine-serine N-terminal extension (a characteristic of parent Peptide 1) and a novel 8-polyethylene glycol (PEG) block C-terminal extension. Peptide 2 has significantly improved aqueous solubility compared to Peptide 1 and comparable complement inhibitory activity. In addition, Peptide 2 is more efficacious in inhibiting complement activation in a cell-based model that mimics the pathobiology of dry AMD. Conclusions We have designed a new peptide analog of compstatin that combines N-terminal polar amino acid extensions and C-terminal PEGylation extensions. This peptide demonstrates significantly improved aqueous solubility and complement inhibitory efficacy, compared to the parent peptide. The new peptide overcomes the aggregation limitation for clinical translation of previous compstatin analogs and is a candidate to become a therapeutic for the treatment of AMD. PMID:27829783

  19. Development of new near-infrared and leuco-dye optical systems for forensic and crime fighting applications

    NASA Astrophysics Data System (ADS)

    Patonay, Gabor; Strekowski, Lucjan; Salon, Jozef; Medou-Ovono, Martial; Krutak, James J.; Leggitt, Jeffrey; Seubert, Heather; Craig, Rhonda

    2004-12-01

    New chemistry for leuco fluorescin and leuco rhodamine for latent bloodstain and fingerprint detection has been developed in our laboratories. The use of these leuco dyes results in excellent contrast for several hours. The FBI's Evidence Response Team and DNA I unit collaborated with Georgia State University to validate the new fluorescin chemistry for use in the field. In addition, several new NIR dyes have been developed in our laboratories that can be used to detect different chemical residues, e.g., pepper spray, latent fingerprint, latent blood, metal ions, or other trace evidence during crime scene investigations. Proof of principle experiments showed that NIR dyes reacting with such residues can be activated with appropriately filtered semiconductor lasers and LEDs to emit NIR fluorescence that can be observed using optimally filtered night vision intensifiers or pocket scopes, digital cameras, CCD and CMOS cameras, or other NIR detection systems. The main advantage of NIR detection is that the color of the background has very little influence on detection and that there are very few materials that would interfere by exhibiting NIR fluorescence. The use of pocket scopes permits sensitive and convenient detection. Once the residues are located, digital images of the fluorescence can be recorded and samples obtained for further analyses. NIR dyes do not interfere with subsequent follow-up or confirmation methods such as DNA or LC/MS analysis. Near-infrared absorbing dyes will be summarized along with detection mechanisms.

  20. Construction of a high efficiency copper adsorption bacterial system via peptide display and its application on copper dye polluted wastewater.

    PubMed

    Maruthamuthu, Murali Kannan; Nadarajan, Saravanan Prabhu; Ganesh, Irisappan; Ravikumar, Sambandam; Yun, Hyungdon; Yoo, Ik-Keun; Hong, Soon Ho

    2015-11-01

    For the construction of an efficient copper waste treatment system, a cell surface display strategy was employed. The copper adsorption ability of recombinant bacterial strains displaying three different copper binding peptides were evaluated in LB Luria-Bertani medium (LB), artificial wastewater, and copper phthalocyanine containing textile dye industry wastewater samples. Structural characteristics of the three peptides were also analyzed by similarity-based structure modeling. The best binding peptide was chosen for the construction of a dimeric peptide display and the adsorption ability of the monomeric and dimeric peptide displayed strains were compared. The dimeric peptide displayed strain showed superior copper adsorption in all three tested conditions (LB, artificial wastewater, and textile dye industry wastewater). When the strains were exposed to copper phthalocyanine dye polluted wastewater, the dimeric peptide display [543.27 µmol/g DCW dry cell weight (DCW)] showed higher adsorption of copper when compared with the monomeric strains (243.53 µmol/g DCW).

  1. An oxygen scavenging system for improvement of dye stability in single-molecule fluorescence experiments.

    PubMed

    Aitken, Colin Echeverría; Marshall, R Andrew; Puglisi, Joseph D

    2008-03-01

    The application of single-molecule fluorescence techniques to complex biological systems places demands on the performance of single fluorophores. We present an enzymatic oxygen scavenging system for improved dye stability in single-molecule experiments. We compared the previously described protocatechuic acid/protocatechuate-3,4-dioxygenase system to the currently employed glucose oxidase/catalase system. Under standardized conditions, we observed lower dissolved oxygen concentrations with the protocatechuic acid/protocatechuate-3,4-dioxygenase system. Furthermore, we observed increased initial lifetimes of single Cy3, Cy5, and Alexa488 fluorophores. We further tested the effects of chemical additives in this system. We found that biological reducing agents increase both the frequency and duration of blinking events of Cy5, an effect that scales with reducing potential. We observed increased stability of Cy3 and Alexa488 in the presence of the antioxidants ascorbic acid and n-propyl gallate. This new O(2)-scavenging system should have wide application for single-molecule fluorescence experiments.

  2. Conjugate systems using delocalized cationic dyes as a carrier of photosensitizers to mitochondria

    NASA Astrophysics Data System (ADS)

    You, Youngjae; Ngen, Ethel J.; Rajaputra, Pallavi

    2009-06-01

    Following Photofrin, the first generation photosensitizer, several second generation photosensitizers have been developed with improved characteristics. More recently, third generation photosensitizers are proposed to achieve higher selectivity toward cancer cells/ tumor tissue. Elevated mitochondrial membrane potential of malignant cells has tested as a tool for preferential uptake of certain photosensitizers to cancer cells. In the same line, we designed new conjugate systems where delocalized cationic moiety delivers a photosensitizer to mitochondria. To prove our concept, two prototype conjugates (TPP-Rh and TPP-AO) were prepared using two cationic dyes (Rhodamine and Acridine Orange) and a photosensitizer (tetraphenylporphyrin, TPP). The two conjugates generated singlet oxygen quite well. Interestingly, the two conjugates showed higher cellular uptake by mover than 8 times than TPP-OH as well as higher phototoxicity. In particular, TPP-Rh showed closer localization pattern to mitochondria than TPP-OH.

  3. Unusual and tunable one-photon nonlinearity in gold-dye plexcitonic Fano systems.

    PubMed

    Nan, Fan; Zhang, Ya-Fang; Li, Xiaoguang; Zhang, Xiao-Tian; Li, Hang; Zhang, Xinhui; Jiang, Ruibin; Wang, Jianfang; Zhang, Wei; Zhou, Li; Wang, Jia-Hong; Wang, Qu-Quan; Zhang, Zhenyu

    2015-04-08

    Recent studies of the coupling between the plasmonic excitations of metallic nanostructures with the excitonic excitations of molecular species have revealed a rich variety of emergent phenomena known as plexcitonics. Here, we use a combined experimental and theoretical approach to demonstrate new and intriguing aspects in the ultrafast nonlinear responses of strongly coupled hybrid Fano systems consisting of gold nanorods decorated with near-infrared dye molecules. We show that the severely suppressed linear absorption around the Fano dip significantly enhances the unidirectional energy transfer from the plasmons to the excitons and further allows one-photon nonlinearity to be drastically and reversibly tuned. These striking observations are interpreted within a microscopic model stressing on two competing processes: saturated plasmonic absorption and weakened destructive Fano interference from the bleached excitonic absorption. The unusually strong one-photon nonlinearity revealed here provides a promising strategy in fabricating nanoplasmonic devices with both pronounced nonlinearities and good figures of merit.

  4. Decolorizing and detoxifying textile wastewater, containing both soluble and insoluble dyes, in a full scale combined anaerobic/aerobic system.

    PubMed

    Frijters, C T M J; Vos, R H; Scheffer, G; Mulder, R

    2006-03-01

    The wastewater originating from the bleaching and dyeing processes in the textile factory Ten Cate Protect in Nijverdal (the Netherlands) was successfully treated in a sequential anaerobic/aerobic system. In the system, a combination of an anaerobic 70-m3 fluidized bed reactor and a 450-m3 aerobic basin with integrated tilted plate settlers, 80-95% of the color was removed. The color was largely removed in the preacidification basin and the anaerobic reactor. Color, deriving from both reactive as well as disperse, was anaerobically removed, indicating that these type of dyes were reduced to colorless products. Interestingly, the vat dyes, the anthraquinones and indigoids, which were thought to be removed mainly aerobically, were largely anaerobically decolorized. Apparently the anaerobic system is capable of effectively removing the color of both soluble as insoluble dyes. The treated effluent of the sequential anaerobic/aerobic treatment showed no toxicity towards the bioluminescent bacterium Vibrio fisheri (EC20 (95%) > 45%). Partially bypassing the anaerobic stage resulted in increased toxicity (EC20 (95%) of 9% and 14%) in the effluent of the aerobic treatment and caused significant decrease of color removal. The results of this study show a main contribution of anaerobic treatment in decolorizing and detoxifying the textile wastewater in the sequential anaerobic/aerobic system.

  5. Complement system dysregulation and inflammation in the retinal pigment epithelium of a mouse model for Stargardt macular degeneration.

    PubMed

    Radu, Roxana A; Hu, Jane; Yuan, Quan; Welch, Darcy L; Makshanoff, Jacob; Lloyd, Marcia; McMullen, Stephen; Travis, Gabriel H; Bok, Dean

    2011-05-27

    Accumulation of vitamin A-derived lipofuscin fluorophores in the retinal pigment epithelium (RPE) is a pathologic feature of recessive Stargardt macular dystrophy, a blinding disease caused by dysfunction or loss of the ABCA4 transporter in rods and cones. Age-related macular degeneration, a prevalent blinding disease of the elderly, is strongly associated with mutations in the genes for complement regulatory proteins (CRP), causing chronic inflammation of the RPE. Here we explore the possible relationship between lipofuscin accumulation and complement activation in vivo. Using the abca4(-/-) mouse model for recessive Stargardt, we investigated the role of lipofuscin fluorophores (A2E-lipofuscin) on oxidative stress and complement activation. We observed higher expression of oxidative-stress genes and elevated products of lipid peroxidation in eyes from abca4(-/-) versus wild-type mice. We also observed higher levels of complement-activation products in abca4(-/-) RPE cells. Unexpectedly, expression of multiple CRPs, which protect cells from attack by the complement system, were lower in abca4(-/-) versus wild-type RPE. To test whether acute exposure of healthy RPE cells to A2E-lipofuscin affects oxidative stress and expression of CRPs, we fed cultured fetal-derived human RPE cells with rod outer segments from wild-type or abca4(-/-) retinas. In contrast to RPE cells in abca4(-/-) mice, human RPE cells exposed to abca4(-/-) rod outer segments adaptively increased expression of both oxidative-stress and CRP genes. These results suggest that A2E accumulation causes oxidative stress, complement activation, and down-regulation of protective CRP in the Stargardt mouse model. Thus, Stargardt disease and age-related macular degeneration may both be caused by chronic inflammation of the RPE.

  6. Degenerate Quantum Gases of Strontium

    NASA Astrophysics Data System (ADS)

    Stellmer, Simon; Schreck, Florian; Killian, Thomas C.

    2014-03-01

    Degenerate quantum gases of alkaline-earth-like elements open new opportunities in research areas ranging from molecular physics to the study of strongly correlated systems. These experiments exploit the rich electronic structure of these elements, which is markedly different from the one of other species for which quantum degeneracy has been attained. Specifically, alkaline-earth-like atoms, such as strontium, feature metastable triplet states, narrow intercombination lines, and a nonmagnetic, closed-shell ground state. This review covers the creation of quantum degenerate gases of strontium and the first experiments performed with this new system. It focuses on laser-cooling and evaporation schemes, which enable the creation of Bose-Einstein condensates and degenerate Fermi gases of all strontium isotopes, and shows how they are used for the investigation of optical Feshbach resonances, the study of degenerate gases loaded into an optical lattice, as well as the coherent creation of Sr2 molecules.

  7. Quantitative measurement of neuronal degeneration in organotypic hippocampal cultures after combined oxygen/glucose deprivation.

    PubMed

    Strasser, U; Fischer, G

    1995-04-01

    Organotypic hippocampal cultures were used to study cell degeneration during the recovery period after defined periods (30 and 60 min) of combined oxygen/glucose deprivation mimicking transient ischemic conditions. Staining with the fluorescent dye propidium iodide allowed detection of damaged cells. Fluorescence intensity was measured by an image analysis system and used to quantify cell damage at different time points during the recovery period (up to 22 h). At 30 min of oxygen/glucose deprivation cells in the CA1 area were relatively more sensitive compared to CA3 and dentate gyrus cells, with respect to the time course of degeneration and the percentage of affected cells. Expanding the oxygen/glucose deprivation period from 30 to 60 min drastically increased the percentage of cells dying in all hippocampal areas. Still, however, cells in CA1 degenerated faster compared to those in the CA3 area and dentate gyrus. A histological analysis of toluidine blue as well as MAP2-immunostained sections revealed that almost all neurons degenerated in all hippocampal areas following the 60-min deprivation period, whereas GFAP-stained astrocytes appeared to be unaffected. Therefore, neuronal degeneration could be quantified by taking the fluorescence intensity values 22 h after 60 min of oxygen/glucose deprivation as 100% neuronal damage. The possibility to quantify neuronal damage in organotypic cultures offers a useful tool for detailed studies on mechanisms of neuronal cell death in a cell culture system which is closer to in situ conditions than monolayer cell cultures.

  8. Dye Painting!

    ERIC Educational Resources Information Center

    Johnston, Ann

    This resource provides practical instructions for applying color and design directly to fabric. Basic information about the dye painting process is given. The guide addresses the technical aspects of fabric dye and color use and offers suggestions for fabric manipulation and dye application in order to achieve various design effects. This…

  9. Dye Painting!

    ERIC Educational Resources Information Center

    Johnston, Ann

    This resource provides practical instructions for applying color and design directly to fabric. Basic information about the dye painting process is given. The guide addresses the technical aspects of fabric dye and color use and offers suggestions for fabric manipulation and dye application in order to achieve various design effects. This…

  10. Kinetics of ozone-initiated oxidation of textile dye, Amaranth in aqueous systems.

    PubMed

    Dachipally, Purnachandar; Jonnalagadda, Sreekanth B

    2011-01-01

    The ozone facilitated oxidation mechanism of water soluble azo anionic dye, amaranth (Am) was investigated monitoring the depletion kinetics of the dye spectrometrically at 521 nm. The oxidation kinetics of the dye by ozone was studied under semi-batch conditions, by bubbling ozone enriched oxygen through the aqueous reaction mixture of dye, as function of flow rate, ionic strength, [O(3)] and pH variations. With excess concentration of ozone and other reagents and low [amaranth], reaction followed pseudo-first-order kinetics with respect to the dye. Added neutral salts had marginal effect on the reaction rate and the variation of pH from 7 to 2 and 7 to 12 exerted only small increases in the reaction rate suggesting molecular ozone possibly is the principle reactive species in oxidation of dye. The reaction order with respect ozone was near unity and it varied slightly with pH and flow rate variations. The overall second-order rate constant for the reaction was (105 ± 4) M(-1) min(-1). The main oxidation products immediately after amaranth decolorization were identified. The reaction mechanism and overall rate law were proposed. After spiking the seawater, river water and wastewaters with Amaranth dye, the reaction rates and trends in BOD and COD under control and natural conditions were investigated. The rate of depletion of the dye in natural waters was relatively lower, but the ozonation process significantly decreased both the BOD and COD levels.

  11. Decoloration and mineralization of reactive dyes using electron beam irradiation, Part I: Effect of the dye structure, concentration and absorbed dose (single, binary and ternary systems)

    NASA Astrophysics Data System (ADS)

    Vahdat, Ali; Bahrami, S. Hajir; Arami, M.; Bahjat, A.; Tabakh, F.; Khairkhah, M.

    2012-07-01

    In this study, three different reactive dyes (C.I. Reactive Red 4, C.I. Reactive Blue 2 and C.I. Reactive Yellow 4) and their blend solutions were irradiated with 10 MeV electron beam. Effect of absorbed dose, dye structure and primary solution concentrations on the pH value changes, degree of decoloration and chemical oxygen demand (COD) removal of solutions were investigated. Results show that this method is effective in decomposition and decoloration of the dyes solutions. This method can be applied in mineralization of wastewater containing different dyes.

  12. Remediation of anionic dye from aqueous system using bio-adsorbent prepared by microwave activation.

    PubMed

    Sharma, Arush; Sharma, Gaurav; Naushad, Mu; Ghfar, Ayman A; Pathania, Deepak

    2017-04-07

    The present study was attempted to ascertain the possible application of activated carbon as cost effective and eco-friendly adsorbent prepared via microwave (MW) assisted chemical activation. The activated carbon was characterized using different techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM). The various adsorption parameters have been optimized to examine the viability of activated carbon as a plausible sorbent for the remediation of Congo red (CR) dye from aquatic system. The adsorption equilibrium was interpreted using Langmuir, Freundlich and Tempkin isotherms. The equilibrium data adequately fitted to Langmuir isotherm with stronger R(2) (0.994). The maximum adsorption capacity (qm) of activated carbon was recorded to be 68.96 mg/g. Additionally, sorptional kinetic data were examined by reaction based and diffusion based models such as pseudo-first-order, pseudo-second-order, Elovich model and intra-particle diffusion, Dumwald-Wagner models, respectively. The experimental results indicated that pseudo-second-order equation and Elovich model better discuss the adsorption kinetics. The computed values of thermodynamic parameters such as free energy change (ΔG(0)), enthalpy change (ΔH(0)) and entropy change (ΔS(0)) were recorded as -3.63 kJ/mol, 42.47 kJ/mol, 152.07 J/mol K, respectively at 30°C, which accounted for favorable, spontaneous and endothermic process. The regeneration study emphasized that percentage uptake declined from 90.35 to 83.45% after 6cycles of testing. So, our findings implied that activated carbon produced from biomass must be cost-effectively used as an adsorbent for detoxifying the CR dye from industrial effluents.

  13. Self-gravito-acoustic shock structures in a self-gravitating, strongly coupled, multi-component, degenerate quantum plasma system

    NASA Astrophysics Data System (ADS)

    Mamun, A. A.

    2017-10-01

    The existence of self-gravito-acoustic (SGA) shock structures (SSs) associated with negative self-gravitational potential in a self-gravitating, strongly coupled, multi-component, degenerate quantum plasma (SGSCMCDQP) system is predicted for the first time. The modified Burgers (MB) equation, which is valid for both planar and non-planar (spherical) geometries, is derived analytically, and solved numerically. It is shown that the longitudinal viscous force acting on inertial plasma species of the plasma system is the source of dissipation and is responsible for the formation of these SGA SSs in the plasma system. The time evolution of these SGA SSs is also shown for different values (viz., 0.5, 1, and 2) of Γ, where Γ is the ratio of the nonlinear coefficient to the dissipative coefficient in the MB equation. The SGSCMCDQP model and the numerical analysis of the MB equation presented here are so general that they can be applied in any type of SGSCMCDQP systems like astrophysical compact objects having planar or non-planar (spherical) shape.

  14. Systemic, Ocular and Genetic Risk Factors for Age-related Macular Degeneration and Polypoidal Choroidal Vasculopathy in Singaporeans

    PubMed Central

    Cheung, Chui Ming Gemmy; Laude, Augustinus; Yeo, Ian; Tan, Shu-Pei; Fan, Qiao; Mathur, Ranjana; Lee, Shu Yen; Chan, Choi Mun; Tan, Gavin; Lim, Tock Han; Cheng, Ching-Yu; Wong, Tien Yin

    2017-01-01

    To examine the association of systemic, ocular and genetic risk factors in neovascular age-related macular degeneration (nAMD) in a large cohort of Asian patients, and to further compare risk factors between those with typical AMD and polypoidal choroidal vasculoapthy (PCV) subtypes. We recruited 456 cases and 1,824 controls matched for age, gender and ethnicity. Data on systemic and ocular risk factors were collected on questionnaires. In a subgroup of subjects, we included genetic data on four AMD-associated single nucleotide polymorphisms (SNPs). Risk factors for nAMD and subtypes were analyzed. Systemic risk factors for nAMD included older age, male gender, higher BMI and higher HDL-cholesterol. Ocular risk factors included pseudophakic and shorter axial length. Risk factors common to both typical AMD and PCV subtypes included age, BMI and HDL-cholesterol. Shorter axial length was only associated with PCV, while male gender and pseudophakia were only associated with typical AMD. In the subgroup with genotype data, ARMS2 rs10490924 and CFH rs800292 were associated with nAMD. None of the risk factors were significantly different between PCV and typical AMD. Systemic, ocular and genetic risk factors were largely similar for typical AMD and PCV subtypes in this Asian population based in Singapore. PMID:28120909

  15. A self-sufficient system for removal of synthetic dye by coupling of spore-displayed triphenylmethane reductase and glucose 1-dehydrogenase.

    PubMed

    Gao, Fen; Ding, Haitao; Xu, Xiaohong; Zhao, Yuhua

    2016-11-01

    Biodegradation of triphenylmethane dyes by microorganisms is hampered by the transport barrier imposed by cell membranes. On the other hand, cell-free systems using enzyme-based biodegradation strategy are costly. Therefore, an efficient and inexpensive approach circumventing these problems is highly desirable. Here, we constructed a self-sufficient system for synthetic dye removal by coupling of spore surface-displayed triphenylmethane reductase (TMR) and glucose 1-dehydrogenase (GDH) for the first time. Display of both TMR and GDH significantly enhanced their stability under conditions of extreme pH and temperature. These engineered spores also exhibited more robust long-term stability than their purified counterparts. Furthermore, we observed that a high ratio of spore-displayed GDH is necessary for high dye degradation efficiency. These results indicate that this continuous dye removal system with cofactor regeneration offers a promising solution for dye biodegradation applications.

  16. Degenerate metric phase boundaries

    NASA Astrophysics Data System (ADS)

    Bengtsson, I.; Jacobson, T.

    1997-11-01

    The structure of boundaries between degenerate and non-degenerate solutions of Ashtekar's canonical reformulation of Einstein's equations is studied. Several examples are given of such `phase boundaries' in which the metric is degenerate on one side of a null hypersurface and non-degenerate on the other side. These include portions of flat space, Schwarzschild and plane-wave solutions joined to degenerate regions. In the last case, the wave collides with a planar phase boundary and continues on with the same curvature but degenerate triad, while the phase boundary continues in the opposite direction. We conjecture that degenerate phase boundaries are always null.

  17. Enhanced degradation of azo dye by a stacked microbial fuel cell-biofilm electrode reactor coupled system.

    PubMed

    Cao, Xian; Wang, Hui; Li, Xiao-Qi; Fang, Zhou; Li, Xian-Ning

    2017-03-01

    In this study, a microbial fuel cell (MFC)-biofilm electrode reactor (BER) coupled system was established for degradation of the azo dye Reactive Brilliant Red X-3B. In this system, electrical energy generated by the MFC degrades the azo dye in the BER without the need for an external power supply, and the effluent from the BER was used as the inflow for the MFC, with further degradation. The results indicated that the X-3B removal efficiency was 29.87% higher using this coupled system than in a control group. Moreover, a method was developed to prevent voltage reversal in stacked MFCs. Current was the key factor influencing removal efficiency in the BER. The X-3B degradation pathway and the types and transfer processes of intermediate products were further explored in our system coupled with gas chromatography-mass spectrometry.

  18. Direct thermal dyes

    NASA Astrophysics Data System (ADS)

    Ehlinger, Edward

    1990-07-01

    Direct thermal dyes are members of a class of compounds referred to in the imaging industry as color formers or leuco dyes. The oldest members of that class have simple triarylmethane structures, and have been employed for years in various dyeing applications. More complex triarylmethane compounds, such as phthalides and fluorans, are now used in various imaging systems to produce color. Color is derived from all of these compounds via the same mechanism, on a molecular level. That is, an event of activation produces a highly resonating cationic system whose interaction with incident light produces reflected light of a specific color. The activation event in the case of a direct thermal system is the creation of a melt on the paper involving dye and an acidic developer. The three major performance parameters in a thermal system are background color, image density, and image stability. The three major dye physical parameters affecting thermal performance are chemical constituency, purity, and particle size. Those dyes having the best combination of characteristics which can also be manufactured economically dominate the marketplace. Manufacturing high performance dyes for the thermal market involves multi-step, convergent reaction sequences performed on large scale. Intermediates must be manufactured at the right time, and at the right quality to be useful.

  19. Frontotemporal Lobar Degeneration

    PubMed Central

    Rabinovici, Gil D.; Miller, Bruce L.

    2010-01-01

    Frontotemporal lobar degeneration (FTLD) is a clinically and pathologically heterogeneous syndrome, characterized by progressive decline in behaviour or language associated with degeneration of the frontal and anterior temporal lobes. While the seminal cases were described at the turn of the 20th century, FTLD has only recently been appreciated as a leading cause of dementia, particularly in patients presenting before the age of 65 years. Three distinct clinical variants of FTLD have been described: (i) behavioural-variant frontotemporal dementia, characterized by changes in behaviour and personality in association with frontal-predominant cortical degeneration; (ii) semantic dementia, a syndrome of progressive loss of knowledge about words and objects associated with anterior temporal neuronal loss; and (iii) progressive nonfluent aphasia, characterized by effortful language output, loss of grammar and motor speech deficits in the setting of left perisylvian cortical atrophy. The majority of pathologies associated with FTLD clinical syndromes include either tau-positive (FTLD-TAU) or TAR DNA-binding protein 43 (TDP-43)-positive (FTLD-TDP) inclusion bodies. FTLD overlaps clinically and pathologically with the atypical parkinsonian disorders corticobasal degeneration and progressive supranuclear palsy, and with amyotrophic lateral sclerosis. The majority of familial FTLD cases are caused by mutations in the genes encoding microtubule-associated protein tau (leading to FTLD-TAU) or progranulin (leading to FTLD-TDP). The clinical and pathologic heterogeneity of FTLD poses a significant diagnostic challenge, and in vivo prediction of underlying histopathology can be significantly improved by supplementing the clinical evaluation with genetic tests and emerging biological markers. Current pharmacotherapy for FTLD focuses on manipulating serotonergic or dopaminergic neurotransmitter systems to ameliorate behavioural or motor symptoms. However, recent advances in FTLD

  20. Systemic Injection of RPE65-Programmed Bone Marrow-Derived Cells Prevents Progression of Chronic Retinal Degeneration.

    PubMed

    Qi, Xiaoping; Pay, S Louise; Yan, Yuanqing; Thomas, James; Lewin, Alfred S; Chang, Lung-Ji; Grant, Maria B; Boulton, Michael E

    2017-04-05

    Bone marrow stem and progenitor cells can differentiate into a range of non-hematopoietic cell types, including retinal pigment epithelium (RPE)-like cells. In this study, we programmed bone marrow-derived cells (BMDCs) ex vivo by inserting a stable RPE65 transgene using a lentiviral vector. We tested the efficacy of systemically administered RPE65-programmed BMDCs to prevent visual loss in the superoxide dismutase 2 knockdown (Sod2 KD) mouse model of age-related macular degeneration. Here, we present evidence that these RPE65-programmed BMDCs are recruited to the subretinal space, where they repopulate the RPE layer, preserve the photoreceptor layer, retain the thickness of the neural retina, reduce lipofuscin granule formation, and suppress microgliosis. Importantly, electroretinography and optokinetic response tests confirmed that visual function was significantly improved. Mice treated with non-modified BMDCs or BMDCs pre-programmed with LacZ did not exhibit significant improvement in visual deficit. RPE65-BMDC administration was most effective in early disease, when visual function and retinal morphology returned to near normal, and less effective in late-stage disease. This experimental paradigm offers a minimally invasive cellular therapy that can be given systemically overcoming the need for invasive ocular surgery and offering the potential to arrest progression in early AMD and other RPE-based diseases.

  1. Striatonigral Degeneration

    MedlinePlus

    ... Disease Association National Parkinson Foundation Parkinson's Action Network (PAN) Parkinson's Disease Foundation (PDF) The Multiple System Atrophy ... Disease Association National Parkinson Foundation Parkinson's Action Network (PAN) Parkinson's Disease Foundation (PDF) The Multiple System Atrophy ...

  2. Does the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study.

    PubMed

    Biswas, Abul Kalam; Barik, Sunirmal; Das, Amitava; Ganguly, Bishwajit

    2016-06-01

    We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as π-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and π-conjugation on solar cell performance. The calculated electron-injection driving force (ΔG inject), electron-regeneration driving force (ΔG regen), light-harvesting efficiency (LHE), dipole moment (μ normal), and number of electrons transferred (∆q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system. Graphical Abstract The locations of the nitrogen atoms in the donor groups in the designed dye molecules have an important influence on DSSC efficiency.

  3. Organic acids enhanced decoloration of azo dye in gas phase surface discharge plasma system.

    PubMed

    Wang, Tiecheng; Qu, Guangzhou; Ren, Jingyu; Sun, Qiuhong; Liang, Dongli; Hu, Shibin

    2016-01-25

    A gas phase surface discharge plasma combined with organic acids system was developed to enhance active species mass transfer and dye-containing wastewater treatment efficacy, with Acid Orange II (AO7) as the model pollutant. The effects of discharge voltage and various organic acid additives (acetic acid, lactic acid and nonoic acid) on AO7 decoloration efficiency were evaluated. The experimental results showed that an AO7 decoloration efficiency of approximately 69.0% was obtained within 4 min of discharge plasma treatment without organic acid addition, which was improved to 82.8%, 83.5% and 88.6% within the same treatment time with the addition of acetic acid, lactic acid and nonoic acid, respectively. The enhancement effects on AO7 decoloration efficiency could be attributed to the decrease in aqueous surface tension, improvement in bubble distribution and shape, and increase in ozone equivalent concentration. The AO7 wastewater was biodegradable after discharge plasma treatment with the addition of organic acid. AO7 decomposition intermediates were analyzed by UV-vis spectrometry and GC-MS; 2-naphthol, 1,4-benzoquinone, phthalic anhydride, coumarin, 1,2-naphthoquinone, and 2-formyl-benzoic acid were detected. A possible pathway for AO7 decomposition in this system was proposed.

  4. Brilliant Blue Dyes in Daily Food: How Could Purinergic System Be Affected?

    PubMed Central

    Ferreira, Leonardo Gomes Braga; Ferreira, Natiele Carla da Silva; Soares-Bezerra, Rômulo José

    2016-01-01

    Dyes were first obtained from the extraction of plant sources in the Neolithic period to produce dyed clothes. At the beginning of the 19th century, synthetic dyes were produced to color clothes on a large scale. Other applications for synthetic dyes include the pharmaceutical and food industries, which are important interference factors in our lives and health. Herein, we analyzed the possible implications of some dyes that are already described as antagonists of purinergic receptors, including special Brilliant Blue G and its derivative FD&C Blue No. 1. Purinergic receptor family is widely expressed in the body and is critical to relate to much cellular homeostasis maintenance as well as inflammation and cell death. In this review, we discuss previous studies and show purinergic signaling as an important issue to be aware of in food additives development and their correlations with the physiological functions. PMID:27833914

  5. Treatability studies with granular activated carbon (GAC) and sequencing batch reactor (SBR) system for textile wastewater containing direct dyes.

    PubMed

    Sirianuntapiboon, Suntud; Sansak, Jutarat

    2008-11-30

    The GAC-SBR efficiency was decreased with the increase of dyestuff concentration or the decrease of bio-sludge concentration. The system showed the highest removal efficiency with synthetic textile wastewater (STWW) containing 40 mg/L direct red 23 or direct blue 201 under MLSS of 3,000 mg/L and hydraulic retention time (HRT) of 7.5 days. But, the effluent NO(3)(-) was higher than that of the influent. Direct red 23 was more effective than direct blue 201 to repress the GAC-SBR system efficiency. The dyes removal efficiency of the system with STWW containing direct red 23 was reduced by 30% with the increase of direct red 23 from 40 mg/L to 160 mg/L. The system with raw textile wastewater (TWW) showed quite low BOD(5) TKN and dye removal efficiencies of only 64.7+/-4.9% and 50.2+/-6.9%, respectively. But its' efficiencies could be increased by adding carbon sources (BOD(5)). The dye removal efficiency with TWW was increased by 30% and 20% by adding glucose (TWW+glucose) or Thai rice noodle wastewater (TWW+TRNWW), respectively. SRT of the systems were 28+/-1 days and 31+/-2 days with TWW+glucose and TWW+TRNWW, respectively.

  6. Systems-level analysis of age-related macular degeneration reveals global biomarkers and phenotype-specific functional networks

    PubMed Central

    2012-01-01

    Background Age-related macular degeneration (AMD) is a leading cause of blindness that affects the central region of the retinal pigmented epithelium (RPE), choroid, and neural retina. Initially characterized by an accumulation of sub-RPE deposits, AMD leads to progressive retinal degeneration, and in advanced cases, irreversible vision loss. Although genetic analysis, animal models, and cell culture systems have yielded important insights into AMD, the molecular pathways underlying AMD's onset and progression remain poorly delineated. We sought to better understand the molecular underpinnings of this devastating disease by performing the first comparative transcriptome analysis of AMD and normal human donor eyes. Methods RPE-choroid and retina tissue samples were obtained from a common cohort of 31 normal, 26 AMD, and 11 potential pre-AMD human donor eyes. Transcriptome profiles were generated for macular and extramacular regions, and statistical and bioinformatic methods were employed to identify disease-associated gene signatures and functionally enriched protein association networks. Selected genes of high significance were validated using an independent donor cohort. Results We identified over 50 annotated genes enriched in cell-mediated immune responses that are globally over-expressed in RPE-choroid AMD phenotypes. Using a machine learning model and a second donor cohort, we show that the top 20 global genes are predictive of AMD clinical diagnosis. We also discovered functionally enriched gene sets in the RPE-choroid that delineate the advanced AMD phenotypes, neovascular AMD and geographic atrophy. Moreover, we identified a graded increase of transcript levels in the retina related to wound response, complement cascade, and neurogenesis that strongly correlates with decreased levels of phototransduction transcripts and increased AMD severity. Based on our findings, we assembled protein-protein interactomes that highlight functional networks likely to be

  7. The pivotal role of the complement system in aging and age-related macular degeneration: hypothesis re-visited.

    PubMed

    Anderson, Don H; Radeke, Monte J; Gallo, Natasha B; Chapin, Ethan A; Johnson, Patrick T; Curletti, Christy R; Hancox, Lisa S; Hu, Jane; Ebright, Jessica N; Malek, Goldis; Hauser, Michael A; Rickman, Catherine Bowes; Bok, Dean; Hageman, Gregory S; Johnson, Lincoln V

    2010-03-01

    During the past ten years, dramatic advances have been made in unraveling the biological bases of age-related macular degeneration (AMD), the most common cause of irreversible blindness in western populations. In that timeframe, two distinct lines of evidence emerged which implicated chronic local inflammation and activation of the complement cascade in AMD pathogenesis. First, a number of complement system proteins, complement activators, and complement regulatory proteins were identified as molecular constituents of drusen, the hallmark extracellular deposits associated with early AMD. Subsequently, genetic studies revealed highly significant statistical associations between AMD and variants of several complement pathway-associated genes including: Complement factor H (CFH), complement factor H-related 1 and 3 (CFHR1 and CFHR3), complement factor B (CFB), complement component 2 (C2), and complement component 3 (C3). In this article, we revisit our original hypothesis that chronic local inflammatory and immune-mediated events at the level of Bruch's membrane play critical roles in drusen biogenesis and, by extension, in the pathobiology of AMD. Secondly, we report the results of a new screening for additional AMD-associated polymorphisms in a battery of 63 complement-related genes. Third, we identify and characterize the local complement system in the RPE-choroid complex - thus adding a new dimension of biological complexity to the role of the complement system in ocular aging and AMD. Finally, we evaluate the most salient, recent evidence that bears directly on the role of complement in AMD pathogenesis and progression. Collectively, these recent findings strongly re-affirm the importance of the complement system in AMD. They lay the groundwork for further studies that may lead to the identification of a transcriptional disease signature of AMD, and hasten the development of new therapeutic approaches that will restore the complement-modulating activity that

  8. The Pivotal Role of the Complement System in Aging and Age-related Macular Degeneration: Hypothesis Re-visited

    PubMed Central

    Anderson, Don H.; Radeke, Monte J.; Gallo, Natasha B.; Chapin, Ethan A.; Johnson, Patrick T.; Curletti, Christy R.; Hancox, Lisa S.; Hu, Jane; Ebright, Jessica N.; Malek, Goldis; Hauser, Michael A.; Rickman, Catherine Bowes; Bok, Dean; Hageman, Gregory S.; Johnson, Lincoln V.

    2009-01-01

    During the past ten years, dramatic advances have been made in unraveling the biological bases of age-related macular degeneration (AMD), the most common cause of irreversible blindness in western populations. In that timeframe, two distinct lines of evidence emerged which implicated chronic local inflammation and activation of the complement cascade in AMD pathogenesis. First, a number of complement system proteins, complement activators, and complement regulatory proteins were identified as molecular constituents of drusen, the hallmark extracellular deposits associated with early AMD. Subsequently, genetic studies revealed highly significant statistical associations between AMD and variants of several complement pathway-associated genes including: Complement factor H (CFH), complement factor H-related 1 and 3 (CFHR1 and CFHR3), complement factor B (CFB), complement component 2 (C2), and complement component 3 (C3). In this article, we revisit our original hypothesis that chronic local inflammatory and immune-mediated events at the level of Bruch’s membrane play critical roles in drusen biogenesis and, by extension, in the pathobiology of AMD. Secondly, we report the results of a new screening for additional AMD-associated polymorphisms in a battery of 63 complement-related genes. Third, we identify and characterize the local complement system in the RPE-choroid complex -- thus adding a new dimension of biological complexity to the role of the complement system in ocular aging and AMD. Finally, we evaluate the most salient, recent evidence that bears directly on the role of complement in AMD pathogenesis and progression. Collectively, these recent findings strongly re-affirm the importance of the complement system in AMD. They lay the groundwork for further studies that may lead to the identification of a transcriptional disease signature of AMD, and hasten the development of new therapeutic approaches that will restore the complement-modulating activity that

  9. Functiogenesis of the embryonic central nervous system revealed by optical recording with a voltage-sensitive dye.

    PubMed

    Sato, Katsushige; Momose-Sato, Yoko

    2017-01-01

    Clarification of the functiogenesis of the embryonic central nervous system (CNS) has long been problematic, because conventional electrophysiological techniques have several limitations. First, early embryonic neurons are small and fragile, and the application of microelectrodes is challenging. Second, the simultaneous monitoring of electrical activity from multiple sites is limited, and as a consequence, spatiotemporal response patterns of neural networks cannot be assessed. We have applied multiple-site optical recording with a voltage-sensitive dye to the embryonic CNS and paved a new way to analyze the functiogenesis of the CNS. In this review, we discuss key points of optical recording in the embryonic CNS and introduce recent progress in optical investigations on the embryonic CNS with special emphasis on the development of the chick olfactory system. The studies clearly demonstrate the usefulness of voltage-sensitive dye recording as a powerful tool for elucidating the functional organization of the vertebrate embryonic CNS.

  10. Cationic cetylpyridinium micelle as a novel electrolyte system for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Thanacharoenchumrut, Sakon; Angboonpong, Natee; Pakawatpanurut, Pasit

    2016-03-01

    The charge transfer process within the electrolyte system is an active area for further improving the conversion efficiency of the dye-sensitized solar cell (DSSC). In this work, micelle formed by cationic surfactant cetylpyridinium (CP) chloride was used in the electrolyte to enhance the ion transport of the redox couple. Using a mixed solvent of ethylene glycol and acetonitrile at 1:9 volume ratio and 0.50 M CP, an 83% improvement in DSSC efficiency was observed. Because of a strong correlation between the efficiency and the current density as a function of the CP concentration, the presence of CP micelle likely caused a favorable shift in the ion transport within the electrolyte. According to the cyclic voltammetry, such improved ion transport can be attributed to a faster diffusion of the redox couple, particularly the I3- diffusion. In addition, the impedance analysis also revealed a short electron lifetime for the diffusion process in the presence of the CP micelle. From these results, it is plausible that the CP micelle in the electrolyte provides an extensive network of positively-charged interfaces, which facilitates the diffusion of the redox couple and enhances the overall performance of the DSSC.

  11. Picosecond Raman Spectroscopy: A Two Dye Laser Synchronously Pumped Raman System

    NASA Astrophysics Data System (ADS)

    Chung, Y. C.; Hopkins, J. B.; Rentzepis, P. M.

    1986-11-01

    Raman spectroscopy is a mature field of science that does not need introduction nor rationalization for its use. The majority of the Raman spectroscopy literature is concerned with C.W. high resolution spectroscopy. The Raman Scattering instruments utilize almost exclusively laser light sources, and lately nanosecond and picosecond data on time resolved spectra have made their entrance into the scientific journals. The difficulty in most of these resonance Raman experiments is that they do not provide any more time dependent information than fluorescence. This is due to the limitation that a single laser, quite often, a dye laser and its second harmonic are the only two frequencies available for excitation and resonance probe of the excited state. In this scenario, a Raman Scattering signal is emitted and detected only during the lifetime of the excited state. As the excited state decays to either the ground state or other transient species which absorb at a different wavelength, the resonance with the probe wavelength disappears at the same rate as the population of the excited state decays. This rate of depopulation is also portrayed in an identical fashion. These systems are therefore drastically limited in their use as means for the measurement of the evolution of a chemical intermediate. An additional interesting aspect is that of the understanding of the process itself which is being studied, namely the majority of the research papers presented do not address the possibility of the data depicting stimulated emission gain rather than Raman Scattering.

  12. Macular Degeneration Partnership

    MedlinePlus

    ... Age Related Macular Degeneration) Partnership Listen AMD Month Public Service Announcement To raise awareness of AMD, the Macular Degeneration Partnership (MDP) is distributing a public service announcement (PSA) nationwide. Seen through the eyes of a ...

  13. A selection guide for the new generation 6-dye DNA profiling systems.

    PubMed

    Lin, Sze-Wah; Li, Christina; Ip, Stephen C Y

    2017-09-01

    The Federal Bureau of Investigation (FBI) has recently expanded the CODIS core loci from the existing 13 to 20 as a new guideline, and laboratories from the US are required to comply with the new regulation before uploading or conducting identity search in the national database. The expanded CODIS format, which shares all the core loci commonly used in the European countries and the US, not only increases international compatibility, but also reduces the number of adventitious matches, and hence facilitates international law enforcement and counterterrorism endeavours. Here, we review the key performance measures of three new STR amplification systems with 6-dye chemistry, namely, the Investigator 24plex QS Kit from QIAGEN, the GlobalFiler™ PCR Amplification Kit from Applied Biosystems™, and the PowerPlex(®) Fusion 6C System from Promega. Our results have demonstrated that GlobalFiler displays the highest sensitivity among the tested kits, whereas Investigator 24plex shows a higher tolerance to common PCR inhibitors including Humic acid and Tannic acid. GlobalFiler and Fusion 6C, on the other hand, yield DNA profiles with better heterozygous peak height and intra-colour signal balance. Both GlobalFiler and Investigator 24plex exhibit slightly higher sensitivity than Fusion 6C in the profiling of minor components in DNA mixture, but the latter displays a higher consistency in the preservation of the mixture ratio. In summary, our work has demonstrated that these three profiling systems have their different performance features, and hence it is recommended that laboratories should select the most suitable kits according to their own requirements and operational needs. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. [Study of the effect of light source stability on the signal to noise ratio in degenerate four wave mixing experiment].

    PubMed

    Wang, Wei-Bo; Chen, De-Ying; Fan, Rong-Wei; Xia, Yuan-Qin

    2010-02-01

    The effects of the stability of dye laser on the signal to noise ratio in degenerate four-wave mixing (DFWM) were first investigated in iodine vapor using forward geometries. Frequency-doubled outputs from a multi-mode Nd : YAG laser pumped dye laser with laser dye PM580 dissolved in ethanol was used. With the help of forward compensated beam-split technique and imaging detecting system, the saturation intensity of DFWM spectrum in the iodine vapor at 5 554.013 nm was first measured to be 290 microJ under the condition of atmospheric pressure and room temperature. The features of the dye laser such as wavelength ranges, beam quality and energy conversion efficiency decreased gradually with increasing pumping service use, pulse number and intensity. Additionally, with the comparison of the stable and unstable dye laser output, it was found that the instability of dye laser output had greatly influenced the DFWM signal and decreased the signal to background noise ratio. Shot to shot jitter and the broadening in the output frequency leads to an effective broadening of the recorded spectrum and loss of the DFWM signal to noise ratio under the same pumping intensity at different time. The study is of importance to the detection of trace atom, molecule and radical in combustion diagnosis.

  15. The Project MACULA Retinal Pigment Epithelium Grading System for Histology and Optical Coherence Tomography in Age-Related Macular Degeneration.

    PubMed

    Zanzottera, Emma C; Messinger, Jeffrey D; Ach, Thomas; Smith, R Theodore; Freund, K Bailey; Curcio, Christine A

    2015-05-01

    To seek pathways of retinal pigment epithelium (RPE) fate in age-related macular degeneration via a morphology grading system; provide nomenclature, visualization targets, and metrics for clinical imaging and model systems. Donor eyes with geographic atrophy (GA) or choroidal neovascularization (CNV) and one GA eye with previous clinical spectral-domain optical coherence tomography (SDOCT) imaging were processed for histology, photodocumented, and annotated at predefined locations. Retinal pigment epithelial cells contained spindle-shaped melanosomes, apposed a basal lamina or basal laminar deposit (BLamD), and exhibited recognizable morphologies. Thicknesses and unbiased estimates of frequencies were obtained. In 13 GA eyes (449 locations), 'Shedding,' 'Sloughed,' and 'Dissociated' morphologies were abundant; 22.2% of atrophic locations had 'Dissociated' RPE. In 39 CNV eyes (1363 locations), 37.3% of locations with fibrovascular/fibrocellular scar had 'Entombed' RPE; 'Sloughed,' 'Dissociated,' and 'Bilaminar' morphologies were abundant. Of abnormal RPE, CNV and GA both had ~35% 'Sloughed'/'Intraretinal,' with more Intraretinal in CNV (9.5% vs. 1.8%). 'Shedding' cells associated with granule aggregations in BLamD. The RPE layer did not thin, and BLamD remained thick, with progression. Granule-containing material consistent with three morphologies correlated to SDOCT hyperreflective foci in the previously examined GA patient. Retinal pigment epithelium morphology indicates multiple pathways in GA and CNV. Atrophic/scarred areas have numerous cells capable of transcribing genes and generating imaging signals. Shed granule aggregates, possibly apoptotic, are visible in SDOCT, as are 'Dissociated' and 'Sloughed' cells. The significance of RPE phenotypes is addressable in longitudinal, high-resolution imaging in clinic populations. Data can motivate future molecular phenotyping studies.

  16. Effects of intravitreal ranibizumab on the untreated eye and systemic gene expression profile in age-related macular degeneration

    PubMed Central

    Michalska-Małecka, Katarzyna; Kabiesz, Adam; Kimsa, Malgorzata W; Strzałka-Mrozik, Barbara; Formińska-Kapuścik, Maria; Nita, Malgorzata; Mazurek, Urszula

    2016-01-01

    The purpose of this study was to evaluate the systemic effects of intravitreal ranibizumab (Lucentis) treatment in patients with neovascular age-related macular degeneration (AMD). The impact of intravitreal ranibizumab injections on central retinal thickness (CRT) of treated and contralateral untreated eyes, and differences in gene expression patterns in the peripheral blood mononuclear cells were analyzed. The study included 29 patients aged 50 years old and over with diagnosed neovascular AMD. The treatment was defined as 0.5 mg of ranibizumab injected intravitreally in the form of one injection every month during the period of 3 months. CRT was measured by optical coherence tomography. The gene expression profile was assigned using oligonucleotide microarrays of Affymetrix HG-U133A. Studies have shown that there was a change of CRT between treated and untreated eyes, and there were differences in CRT at baseline and after 1, 2, and 3 months of ranibizumab treatment. Three months after intravitreal injection, mean CRT was reduced in the treated eyes from 331.97±123.62 to 254.31±58.75 μm, while mean CRT in the untreated fellow eyes reduced from 251.07±40.29 to 235.45±36.21 μm at the same time. Furthermore, the research has shown that among all transcripts, 3,097 expresses change after the ranibizumab treatment in relation to controls. Among these transcripts, 1,339 were up-regulated, whereas 1,758 were down-regulated. Our results show the potential systemic effects of anti-VEGF therapy for AMD. Moreover, our study indicated different gene expression in peripheral blood mononuclear cells before and after intravitreal ranibizumab treatment. PMID:27069359

  17. The Project MACULA Retinal Pigment Epithelium Grading System for Histology and Optical Coherence Tomography in Age-Related Macular Degeneration

    PubMed Central

    Zanzottera, Emma C.; Messinger, Jeffrey D.; Ach, Thomas; Smith, R. Theodore; Freund, K. Bailey; Curcio, Christine A.

    2015-01-01

    Purpose. To seek pathways of retinal pigment epithelium (RPE) fate in age-related macular degeneration via a morphology grading system; provide nomenclature, visualization targets, and metrics for clinical imaging and model systems. Methods. Donor eyes with geographic atrophy (GA) or choroidal neovascularization (CNV) and one GA eye with previous clinical spectral-domain optical coherence tomography (SDOCT) imaging were processed for histology, photodocumented, and annotated at predefined locations. Retinal pigment epithelial cells contained spindle-shaped melanosomes, apposed a basal lamina or basal laminar deposit (BLamD), and exhibited recognizable morphologies. Thicknesses and unbiased estimates of frequencies were obtained. Results. In 13 GA eyes (449 locations), ‘Shedding,’ ‘Sloughed,’ and ‘Dissociated’ morphologies were abundant; 22.2% of atrophic locations had ‘Dissociated’ RPE. In 39 CNV eyes (1363 locations), 37.3% of locations with fibrovascular/fibrocellular scar had ‘Entombed’ RPE; ‘Sloughed,’ ‘Dissociated,’ and ‘Bilaminar’ morphologies were abundant. Of abnormal RPE, CNV and GA both had ∼35% ‘Sloughed’/‘Intraretinal,’ with more Intraretinal in CNV (9.5% vs. 1.8%). ‘Shedding’ cells associated with granule aggregations in BLamD. The RPE layer did not thin, and BLamD remained thick, with progression. Granule-containing material consistent with three morphologies correlated to SDOCT hyperreflective foci in the previously examined GA patient. Conclusions. Retinal pigment epithelium morphology indicates multiple pathways in GA and CNV. Atrophic/scarred areas have numerous cells capable of transcribing genes and generating imaging signals. Shed granule aggregates, possibly apoptotic, are visible in SDOCT, as are ‘Dissociated’ and ‘Sloughed’ cells. The significance of RPE phenotypes is addressable in longitudinal, high-resolution imaging in clinic populations. Data can motivate future molecular phenotyping

  18. Effects of intravitreal ranibizumab on the untreated eye and systemic gene expression profile in age-related macular degeneration.

    PubMed

    Michalska-Małecka, Katarzyna; Kabiesz, Adam; Kimsa, Malgorzata W; Strzałka-Mrozik, Barbara; Formińska-Kapuścik, Maria; Nita, Malgorzata; Mazurek, Urszula

    2016-01-01

    The purpose of this study was to evaluate the systemic effects of intravitreal ranibizumab (Lucentis) treatment in patients with neovascular age-related macular degeneration (AMD). The impact of intravitreal ranibizumab injections on central retinal thickness (CRT) of treated and contralateral untreated eyes, and differences in gene expression patterns in the peripheral blood mononuclear cells were analyzed. The study included 29 patients aged 50 years old and over with diagnosed neovascular AMD. The treatment was defined as 0.5 mg of ranibizumab injected intravitreally in the form of one injection every month during the period of 3 months. CRT was measured by optical coherence tomography. The gene expression profile was assigned using oligonucleotide microarrays of Affymetrix HG-U133A. Studies have shown that there was a change of CRT between treated and untreated eyes, and there were differences in CRT at baseline and after 1, 2, and 3 months of ranibizumab treatment. Three months after intravitreal injection, mean CRT was reduced in the treated eyes from 331.97±123.62 to 254.31±58.75 μm, while mean CRT in the untreated fellow eyes reduced from 251.07±40.29 to 235.45±36.21 μm at the same time. Furthermore, the research has shown that among all transcripts, 3,097 expresses change after the ranibizumab treatment in relation to controls. Among these transcripts, 1,339 were up-regulated, whereas 1,758 were down-regulated. Our results show the potential systemic effects of anti-VEGF therapy for AMD. Moreover, our study indicated different gene expression in peripheral blood mononuclear cells before and after intravitreal ranibizumab treatment.

  19. Differential display system with vertebrate-common degenerate oligonucleotide primers: uncovering genes responsive to dioxin in avian embryonic liver.

    PubMed

    Teraoka, Hiroki; Ito, Shino; Ikeda, Haruki; Kubota, Akira; Abou Elmagd, M M; Kitazawa, Takio; Kim, Eun-Young; Iwata, Hisato; Endoh, Daiji

    2012-01-03

    To assess possible impacts of environmental pollutants on gene expression profiles in a variety of organisms, we developed a novel differential display system with primer sets that are common in seven vertebrate species, based on degenerate oligonucleotide-primed PCR (DOP-PCR). An 8-mer inverse repeat motif was found in most transcripts from the seven vertebrates including fish to primates with detailed transcriptome information; more than 10,000 motifs were recognized in common in the transcripts of the seven species. Among them, we selected 275 common motifs that cover about 40-70% of transcripts throughout these species, and designed 275 DOP-PCR primers that were common to seven vertebrate species (common DOP-PCR primers). To detect genes responsive to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in developing embryos, differential display with common DOP-PCR primers was applied to embryonic liver of two avian species, the chicken (Gallus gallus) and the common cormorant (Phalacrocorax carbo), which were exposed in ovo to TCDD. The cDNA bands that showed differences between the control and TCDD-treated groups were sequenced and the mRNA expression levels were confirmed by real-time RT-PCR. This approach succeeded in isolating novel dioxin-responsive genes that include 10 coding genes in the chicken, and 1 coding gene and 1 unknown transcript in the cormorant, together with cytochrome P450 1As that have already been well established as dioxin markers. These results highlighted the usefulness of systematically designed novel differential display systems to search genes responsive to chemicals in vertebrates, including wild species, for which transcriptome information is not available.

  20. Macular Degeneration: An Overview.

    ERIC Educational Resources Information Center

    Chalifoux, L. M.

    1991-01-01

    This article presents information on macular degeneration for professionals helping persons with this disease adjust to their visual loss. It covers types of macular degeneration, the etiology of the disease, and its treatment. Also considered are psychosocial problems and other difficulties that persons with age-related macular degeneration face.…

  1. Macular Degeneration: An Overview.

    ERIC Educational Resources Information Center

    Chalifoux, L. M.

    1991-01-01

    This article presents information on macular degeneration for professionals helping persons with this disease adjust to their visual loss. It covers types of macular degeneration, the etiology of the disease, and its treatment. Also considered are psychosocial problems and other difficulties that persons with age-related macular degeneration face.…

  2. An intraocular drug delivery system using targeted nanocarriers attenuates retinal ganglion cell degeneration.

    PubMed

    Zhao, Lei; Chen, Guojun; Li, Jun; Fu, Yingmei; Mavlyutov, Timur A; Yao, Annie; Nickells, Robert W; Gong, Shaoqin; Guo, Lian-Wang

    2017-02-10

    Glaucoma is a common blinding disease characterized by loss of retinal ganglion cells (RGCs). To date, there is no clinically available treatment directly targeting RGCs. We aim to develop an RGC-targeted intraocular drug delivery system using unimolecular micelle nanoparticles (unimNPs) to prevent RGC loss. The unimNPs were formed by single/individual multi-arm star amphiphilic block copolymer poly(amidoamine)-polyvalerolactone-poly(ethylene glycol) (PAMAM-PVL-PEG). While the hydrophobic PAMAM-PVL core can encapsulate hydrophobic drugs, the hydrophilic PEG shell provides excellent water dispersity. We conjugated unimNPs with the cholera toxin B domain (CTB) for RGC-targeting and with Cy5.5 for unimNP-tracing. To exploit RGC-protective sigma-1 receptor (S1R), we loaded unimNPs with an endogenous S1R agonist dehydroepiandrosterone (DHEA) as an FDA-approved model drug. These unimNPs produced a steady DHEA release in vitro for over two months at pH7.4. We then co-injected (mice, intraocular) unimNPs with the glutamate analog N-methyl-d-aspartate (NMDA), which is excito-toxic and induces RGC death. The CTB-conjugated unimNPs (i.e., targeted NPs) accumulated at the RGC layer and effectively preserved RGCs at least for 14days, whereas the unimNPs without CTB (i.e., non-targeted NPs) showed neither accumulation at nor protection of NMDA-treated RGCs. Consistent with S1R functions, targeted NPs relative to non-targeted NPs showed markedly better inhibitory effects on apoptosis and oxidative/inflammatory stresses in the RGC layer. Hence, the DHEA-loaded, CTB-conjugated unimNPs represent an RGC/S1R dual-targeted nanoplatform that generates an efficacious template for further development of a sustainable intraocular drug delivery system to protect RGCs, which may be applicable to treatments directed at glaucomatous pathology.

  3. Theory of a two-level system interacting with a degenerate electron gas. I. Partition function

    NASA Astrophysics Data System (ADS)

    Vladár, K.; Zawadowski, A.; Zimányi, Gergely T.

    1988-02-01

    The problem of the two-level system (TLS) interacting with a free-electron gas is considered. In a previous work Yu and Anderson treated that problem by taking into account the screening by the conduction electrons described by an arbitrarily large phase shift. The present paper is devoted to a generalization of their result by including weak electron-assisted TLS transition processes. Generalizing the Yuval-Anderson technique, the partition function is derived, which has the form of the partition function of a one-dimensional Coulomb gas with logarithmic interactions. The charges introduced depend on the phase shifts and on the electron spin and orbital quantum numbers corresponding to the incoming and outgoing electrons in the related electron-TLS scattering processes. Additionally charged dipoles are introduced to describe those processes in which the scattered electrons do not change their quantum number. Special care is paid to the formal divergencies occurring in these processes if the long-time asymptotic expressions are used for the conduction-electron Green's functions. In this way, going beyond the charge-charge interaction, charge-dipole and dipole-dipole interactions are introduced. The next paper deals with the derivation of the scaling equations, which are derived by eliminating the short-time behavior.

  4. Spectrophotometric investigation of the interactions between cationic (C.I. Basic Blue 9) and anionic (C.I. Acid Blue 25) dyes in adsorption onto extracted cellulose from Posidonia oceanic in single and binary system.

    PubMed

    Ben Douissa, Najoua; Dridi-Dhaouadi, Sonia; Mhenni, Mohamed Farouk

    2016-01-01

    Extracted cellulose from Posidonia oceanica was used as an adsorbent for removal of a cationic (Basic blue 9, BB) and anionic textile dye (Acid blue 25, AB) from aqueous solution in single dye system. Characterization of the extracted cellulose and extracted cellulose-dye systems were performed using several techniques such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, zeta potential and Boehm acid-base titration method. Adsorption tests showed that the extracted cellulose presented higher adsorption of BB than AB in single dye system, revealing that electrostatic interactions are responsible, in the first instance, for the dye-adsorbent interaction. In single dye systems, the extracted cellulose presented the maximum adsorption capacities of BB and AB at 0.955 mmol.g(-1) and 0.370 mmol.g(-1), respectively. Adsorption experiments of AB dye on extracted cellulose saturated by BB dye exhibited the release of the latter dye from the sorbent which lead to dye-dye interaction in aqueous solution due to electrostatic attraction between both species. Interaction of BB and AB dyes were investigated using spectrophotometric analysis and results demonstrated the formation of a molecular complex detected at wavelengths 510 and 705 nm when anionic (AB) and cationic (BB) dye were taken in equimolar proportions. The adsorption isotherm of AB, taking into account the dye-dye interaction was investigated and showed that BB dye was released proportionately by AB equilibrium concentration. It was also observed that AB adsorption is widely enhanced when the formation of the molecular complex is disadvantaged.

  5. Characteristics of degenerately doped silicon for spectral control in thermophotovoltaic systems

    SciTech Connect

    Ehsani, H.; Bhat, I.; Borrego, J.; Gutmann, R.; Brown, E.; Dzeindziel, R.; Freeman, M.; Choudhury, N.

    1995-07-01

    Heavily doped Si was investigated for use as spectral control filter in thermal photovoltaic (TPV) system. These filters should reflect radiation at 4 {micro}m and above and transmit radiation at 2 {micro}m and below. Two approaches have been used for introducing impurities into Si to achieve high doping concentration. One was the diffusion technique, using spin-on dopants. The plasma wavelength ({lambda}{sub p}) of these filters could be adjusted by controlling the diffusion conditions. The minimum plasma wavelength achieved was 4.8 {micro}m. In addition, a significant amount of absorption was observed for the wavelength 2 {micro}m and below. The second approach was doping by ion implantation followed by thermal annealing with a capped layer of doped glass. Implantation with high dosage of B and As followed by high temperature annealing (> 1,000 C) resulted in a plasma wavelength that could be controlled between 3.5 and 6 {micro}m. The high temperature annealing (> 1,000 C) that was necessary to activate the dopant atoms and to heal the implantation damage, also caused significant absorption at 2 {micro}m. For phosphorus implanted Si, a moderate temperature (800--900 C) was sufficient to activate most of the phosphorus and to heal the implantation damage. The position of the plasma turn-on wavelength for an implantation dose of 2 {times} 10{sup 16} cm{sup {minus}2} of P was at 2.9 {micro}m. The absorption at 2 {micro}m was less than 20% and the reflection at 5 {micro}m was about 70%.

  6. Altered cortical beta‐band oscillations reflect motor system degeneration in amyotrophic lateral sclerosis

    PubMed Central

    Proudfoot, Malcolm; Rohenkohl, Gustavo; Quinn, Andrew; Colclough, Giles L.; Wuu, Joanne; Talbot, Kevin; Woolrich, Mark W.; Benatar, Michael

    2016-01-01

    Abstract Continuous rhythmic neuronal oscillations underpin local and regional cortical communication. The impact of the motor system neurodegenerative syndrome amyotrophic lateral sclerosis (ALS) on the neuronal oscillations subserving movement might therefore serve as a sensitive marker of disease activity. Movement preparation and execution are consistently associated with modulations to neuronal oscillation beta (15–30 Hz) power. Cortical beta‐band oscillations were measured using magnetoencephalography (MEG) during preparation for, execution, and completion of a visually cued, lateralized motor task that included movement inhibition trials. Eleven “classical” ALS patients, 9 with the primary lateral sclerosis (PLS) phenotype, and 12 asymptomatic carriers of ALS‐associated gene mutations were compared with age‐similar healthy control groups. Augmented beta desynchronization was observed in both contra‐ and ipsilateral motor cortices of ALS patients during motor preparation. Movement execution coincided with excess beta desynchronization in asymptomatic mutation carriers. Movement completion was followed by a slowed rebound of beta power in all symptomatic patients, further reflected in delayed hemispheric lateralization for beta rebound in the PLS group. This may correspond to the particular involvement of interhemispheric fibers of the corpus callosum previously demonstrated in diffusion tensor imaging studies. We conclude that the ALS spectrum is characterized by intensified cortical beta desynchronization followed by delayed rebound, concordant with a broader concept of cortical hyperexcitability, possibly through loss of inhibitory interneuronal influences. MEG may potentially detect cortical dysfunction prior to the development of overt symptoms, and thus be able to contribute to the assessment of future neuroprotective strategies. Hum Brain Mapp 38:237–254, 2017. © 2016 Wiley Periodicals, Inc. PMID:27623516

  7. Squeezers and Leaf-cutters: Differential Diversification and Degeneration of the Venom System in Toxicoferan Reptiles*

    PubMed Central

    Fry, Bryan G.; Undheim, Eivind A.B.; Ali, Syed A.; Jackson, Timothy N. W.; Debono, Jordan; Scheib, Holger; Ruder, Tim; Morgenstern, David; Cadwallader, Luke; Whitehead, Darryl; Nabuurs, Rob; van der Weerd, Louise; Vidal, Nicolas; Roelants, Kim; Hendrikx, Iwan; Gonzalez, Sandy Pineda; Koludarov, Ivan; Jones, Alun; King, Glenn F.; Antunes, Agostinho; Sunagar, Kartik

    2013-01-01

    Although it has been established that all toxicoferan squamates share a common venomous ancestor, it has remained unclear whether the maxillary and mandibular venom glands are evolving on separate gene expression trajectories or if they remain under shared genetic control. We show that identical transcripts are simultaneously expressed not only in the mandibular and maxillary glands, but also in the enigmatic snake rictal gland. Toxin molecular frameworks recovered in this study were three-finger toxin (3FTx), CRiSP, crotamine (beta-defensin), cobra venom factor, cystatin, epididymal secretory protein, kunitz, l-amino acid oxidase, lectin, renin aspartate protease, veficolin, and vespryn. We also discovered a novel low-molecular weight disulfide bridged peptide class in pythonid snake glands. In the iguanian lizards, the most highly expressed are potentially antimicrobial in nature (crotamine (beta-defensin) and cystatin), with crotamine (beta-defensin) also the most diverse. However, a number of proteins characterized from anguimorph lizards and caenophidian snakes with hemotoxic or neurotoxic activities were recruited in the common toxicoferan ancestor and remain expressed, albeit in low levels, even in the iguanian lizards. In contrast, the henophidian snakes express 3FTx and lectin toxins as the dominant transcripts. Even in the constricting pythonid and boid snakes, where the glands are predominantly mucous-secreting, low-levels of toxin transcripts can be detected. Venom thus appears to play little role in feeding behavior of most iguanian lizards or the powerful constricting snakes, and the low levels of expression argue against a defensive role. However, clearly the incipient or secondarily atrophied venom systems of these taxa may be a source of novel compounds useful in drug design and discovery. PMID:23547263

  8. Squeezers and leaf-cutters: differential diversification and degeneration of the venom system in toxicoferan reptiles.

    PubMed

    Fry, Bryan G; Undheim, Eivind A B; Ali, Syed A; Jackson, Timothy N W; Debono, Jordan; Scheib, Holger; Ruder, Tim; Morgenstern, David; Cadwallader, Luke; Whitehead, Darryl; Nabuurs, Rob; van der Weerd, Louise; Vidal, Nicolas; Roelants, Kim; Hendrikx, Iwan; Gonzalez, Sandy Pineda; Koludarov, Ivan; Jones, Alun; King, Glenn F; Antunes, Agostinho; Sunagar, Kartik

    2013-07-01

    Although it has been established that all toxicoferan squamates share a common venomous ancestor, it has remained unclear whether the maxillary and mandibular venom glands are evolving on separate gene expression trajectories or if they remain under shared genetic control. We show that identical transcripts are simultaneously expressed not only in the mandibular and maxillary glands, but also in the enigmatic snake rictal gland. Toxin molecular frameworks recovered in this study were three-finger toxin (3FTx), CRiSP, crotamine (beta-defensin), cobra venom factor, cystatin, epididymal secretory protein, kunitz, L-amino acid oxidase, lectin, renin aspartate protease, veficolin, and vespryn. We also discovered a novel low-molecular weight disulfide bridged peptide class in pythonid snake glands. In the iguanian lizards, the most highly expressed are potentially antimicrobial in nature (crotamine (beta-defensin) and cystatin), with crotamine (beta-defensin) also the most diverse. However, a number of proteins characterized from anguimorph lizards and caenophidian snakes with hemotoxic or neurotoxic activities were recruited in the common toxicoferan ancestor and remain expressed, albeit in low levels, even in the iguanian lizards. In contrast, the henophidian snakes express 3FTx and lectin toxins as the dominant transcripts. Even in the constricting pythonid and boid snakes, where the glands are predominantly mucous-secreting, low-levels of toxin transcripts can be detected. Venom thus appears to play little role in feeding behavior of most iguanian lizards or the powerful constricting snakes, and the low levels of expression argue against a defensive role. However, clearly the incipient or secondarily atrophied venom systems of these taxa may be a source of novel compounds useful in drug design and discovery.

  9. Adsorption isotherm models for dye removal by cationized starch-based material in a single component system: error analysis.

    PubMed

    Gimbert, Frédéric; Morin-Crini, Nadia; Renault, François; Badot, Pierre-Marie; Crini, Grégorio

    2008-08-30

    This article describes the adsorption of an anionic dye, namely C.I. Acid Blue 25 (AB 25), from aqueous solutions onto a cationized starch-based adsorbent. Temperature was varied to investigate its effect on the adsorption capacity. Equilibrium adsorption isotherms were measured for the single component system and the experimental data were analyzed by using Langmuir, Freundlich, Tempkin, Generalized, Redlich-Peterson, and Toth isotherm equations. Five error functions were used to determine the alternative single component parameters by non-linear regression due to the bias in using the correlation coefficient resulting from linearization. The error analysis showed that, compared with other models, the Langmuir model described best the dye adsorption data. Both linear regression method and non-linear error functions provided the best-fit to experimental data with the Langmuir model.

  10. Analysis of the phosphorescent dye concentration dependence of triplet-triplet annihilation in organic host-guest systems

    NASA Astrophysics Data System (ADS)

    Zhang, L.; van Eersel, H.; Bobbert, P. A.; Coehoorn, R.

    2016-10-01

    Using a novel method for analyzing transient photoluminescence (PL) experiments, a microscopic description is obtained for the dye concentration dependence of triplet-triplet annihilation (TTA) in phosphorescent host-guest systems. It is demonstrated that the TTA-mechanism, which could be a single-step dominated process or a diffusion-mediated multi-step process, can be deduced for any given dye concentration from a recently proposed PL intensity analysis. A comparison with the results of kinetic Monte Carlo simulations provides the TTA-Förster radius and shows that the TTA enhancement due to triplet diffusion can be well described in a microscopic manner assuming Förster- or Dexter-type energy transfer.

  11. Azo dye decolorization by a laccase/mediator system in a membrane reactor: enzyme and mediator reusability.

    PubMed

    Mendoza, Laura; Jonstrup, Maria; Hatti-Kaul, Rajni; Mattiasson, Bo

    2011-10-10

    This paper presents the use of a membrane-integrated reactor system with recycling of laccase and mediator for azo dye decolorization. From initial screening of different laccases and mediators, Trametes versicolor laccase and syringaldehyde provided the best system for decolorization. Decolorization yields of 98, 88, 80 and 78% were obtained for Red FN-2BL, Red BWS, Remazol Blue RR and Blue 4BL, respectively. The reaction parameters were optimized and a membrane reactor was set up for dye decolorization in batch mode with reuse of the enzyme. Between 10 and 20 batches could be run with decolorization yields from 95 to 52% depending on the dye type. To study the possibility of reusing both enzyme and mediator, the reactor was run using 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) coupled to polyethylene glycol (PEG). Nine batches were run for the treatment of Remazol Blue RR, providing decolorization yields of 96-78%. Cost analysis of the processes showed that the costs of laccase/syringaldehyde or laccase/TEMPO were almost equal when running 20 batches, but the cost for the PEG-TEMPO was higher. However, the advantages associated with reuse of the mediator should motivate further development of the concept. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Human systemic exposure to [¹⁴C]-paraphenylenediamine-containing oxidative hair dyes: Absorption, kinetics, metabolism, excretion and safety assessment.

    PubMed

    Nohynek, Gerhard J; Skare, Julie A; Meuling, Wim J A; Wehmeyer, Kenneth R; de Bie, Albertus Th H J; Vaes, Wouter H J; Dufour, Eric K; Fautz, Rolf; Steiling, Winfried; Bramante, Mario; Toutain, Herve

    2015-07-01

    Systemic exposure was measured in humans after hair dyeing with oxidative hair dyes containing 2.0% (A) or 1.0% (B) [(14)C]-p-phenylenediamine (PPD). Hair was dyed, rinsed, dried, clipped and shaved; blood and urine samples were collected for 48 hours after application. [(14)C] was measured in all materials, rinsing water, hair, plasma, urine and skin strips. Plasma and urine were also analysed by HLPC/MS/MS for PPD and its metabolites (B). Total mean recovery of radioactivity was 94.30% (A) or 96.21% (B). Mean plasma Cmax values were 132.6 or 97.4 ng [(14)C]-PPDeq/mL, mean AUC(0-∞) values 1415 or 966 ng [(14)C]-PPDeq/mL*hr in studies A or B, respectively. Urinary excretion of [(14)C] mainly occurred within 24 hrs after hair colouring with a total excretion of 0.72 or 0.88% of applied radioactivity in studies A or B, respectively. Only N,N'-diacetylated-PPD was detected in plasma and the urine. A TK-based human safety assessment estimated margins of safety of 23.3- or 65-fold relative to respective plasma AUC or Cmax values in rats at the NOAEL of a toxicity study. Overall, hair dyes containing PPD are unlikely to pose a health risk since they are used intermittently and systemic exposure is limited to the detoxified metabolite N,N'-diacetyl-PPD.

  13. Ballistic delivery of dyes for structural and functional studies of the nervous system

    PubMed Central

    Gan, Wen-Biao; Grutzendler, Jaime; Wong, Rachel O.; Lichtman, Jeff W.

    2010-01-01

    This chapter describes a detail protocol for rapid labeling of cells in a variety of preparations by means of particle-mediated ballistic (gene gun) delivery of fluorescent dyes. This method has been used for rapid labeling of cells with either lipid or water-soluble dyes in a variety of preparations. In particular, carbocyanine lipophilic dyes such as DiI have been used to obtain Golgi-like labeling of neurons and glia in fixed and live cell cultures, brain slices, as well as fixed post-mortem human brain. Water-soluble calcium indicators such as calcium green-1 dextran have been used to image calcium dynamics in living brain slices and retinal explants. This ballistic labeling technique is thus useful for studying the structure and function of neurons and glia in both living and fixed specimens. PMID:20147144

  14. Insights from Genetic Model Systems of Retinal Degeneration: Role of Epsins in Retinal Angiogenesis and VEGFR2 Signaling

    PubMed Central

    Wu, Yong; Liu, Yanjun; Deng, Lin; Chen, Hong

    2017-01-01

    The retina is a light sensitive tissue that contains specialized photoreceptor cells called rods and cones which process visual signals. These signals are relayed to the brain through interneurons and the fibers of the optic nerve. The retina is susceptible to a variety of degenerative diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), retinitis pigmentosa (RP) and other inherited retinal degenerations. In order to reveal the mechanism underlying these diseases and to find methods for the prevention/treatment of retinal degeneration, animal models have been generated to mimic human eye diseases. In this paper, several well-characterized and commonly used animal models are reviewed. Of particular interest are the contributions of these models to our understanding of the mechanisms of retinal degeneration and thereby providing novel treatment options including gene therapy, stem cell therapy, nanomedicine, and CRISPR/Cas9 genome editing. Role of newly-identified adaptor protein epsins from our laboratory is discussed in retinal angiogenesis and VEGFR2 signaling. PMID:28191500

  15. Direct demonstration of transsynaptic degeneration in the human visual system: a comparison of retrograde and anterograde changes

    PubMed Central

    Beatty, RM; Sadun, AA; Smith, LEH; Vonsattel, JP; Richardson, EP

    1982-01-01

    Transneuronal degeneration of retinal ganglion cells was directly demonstrated in a patient who had unilateral removal of the striate cortex forty years prior to necropsy. For comparison, another case is presented showing anterograde transneuronal atrophy forty years after enucleation of one eye. Images PMID:7069426

  16. Dye lasers. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. M.

    1980-08-01

    Studies on dye laser theory, design, components, optical systems, and frequency range are presented in approximately 96 citations. Abstracts on lasing dyes, pumping, tuning, excitation, molecular structure, and modulation are included. Studies on dye laser use in spectroscopy are covered.

  17. Photocatalytic decolorization of soluble dyes by a bis-ions coexistence system of NH4(+) and NO3(-) with high photoreduction ability.

    PubMed

    Shifu, Chen; Wei, Liu; Huaye, Zhang; Xiaoling, Yu

    2011-02-28

    In this paper, we found that the acidic and basic dyes were easily decolorized by a bis-ions coexistence system of NH(4)(+) and NO(3)(-) under UV light irradiation. The coexistence of NH(4)(+) and NO(3)(-) is a necessary condition for the photocatalytic decolorization of soluble dyes. The photocatalytic decolorization of methyl orange (MO) and methylene blue (MB) follows the first order rate kinetics. The location of an absorption peak in the visible region is blue-shifted with the increase in the illumination time. It is proposed that the photocatalytic decolorization of soluble dyes in the bis-ions coexistence system of NH(4)(+) and NO(3)(-) is a photoreduction reaction, in which the ammonium nitrate acts as a photocatalyst. The chromophore of acidic and basic dyes reacts with hydrogen and then results in their rapid decolorization.

  18. Feasibility of a novel remote daily monitoring system for age-related macular degeneration using mobile handheld devices: results of a pilot study.

    PubMed

    Kaiser, Peter K; Wang, Yi-Zhong; He, Yu-Guang; Weisberger, Annemarie; Wolf, Stephane; Smith, Craig H

    2013-10-01

    This pilot study evaluated the feasibility of the Health Management Tool (HMT), a novel computing system using mobile handheld devices, to remotely monitor retinal visual function daily in patients with neovascular age-related macular degeneration treated with ranibizumab. Patients with neovascular age-related macular degeneration in at least 1 eye (newly diagnosed or successfully treated < 1 year) and eligible for ranibizumab therapy were enrolled in this 16-week, prospective, open-label, single-arm study. Patients performed a shape discrimination hyperacuity test (myVisionTrack [mVT]) daily on the HMT device (iPhone 3GS) remotely and at all clinic visits. Data entered into HMT devices were collected in the HMT database, which also sent reminders for patients to take mVT. Among 160 patients from 24 U.S. centers enrolled in the study (103 [64%] ≥ 75 years of age), 84.7% on average complied with daily mVT testing and ≈ 98.9% complied with at least weekly mVT testing. The HMT database successfully uploaded more than 17,000 mVT assessment values and sent more than 9,000 reminders. Elderly patients with neovascular age-related macular degeneration were willing and able to comply with daily self-testing of retinal visual function using mobile handheld devices in this novel system of remote vision monitoring.

  19. Age-related macular degeneration.

    PubMed

    Lim, Laurence S; Mitchell, Paul; Seddon, Johanna M; Holz, Frank G; Wong, Tien Y

    2012-05-05

    Age-related macular degeneration is a major cause of blindness worldwide. With ageing populations in many countries, more than 20% might have the disorder. Advanced age-related macular degeneration, including neovascular age-related macular degeneration (wet) and geographic atrophy (late dry), is associated with substantial, progressive visual impairment. Major risk factors include cigarette smoking, nutritional factors, cardiovascular diseases, and genetic markers, including genes regulating complement, lipid, angiogenic, and extracellular matrix pathways. Some studies have suggested a declining prevalence of age-related macular degeneration, perhaps due to reduced exposure to modifiable risk factors. Accurate diagnosis combines clinical examination and investigations, including retinal photography, angiography, and optical coherence tomography. Dietary anti-oxidant supplementation slows progression of the disease. Treatment for neovascular age-related macular degeneration incorporates intraocular injections of anti-VEGF agents, occasionally combined with other modalities. Evidence suggests that two commonly used anti-VEGF therapies, ranibizumab and bevacizumab, have similar efficacy, but possible differences in systemic safety are difficult to assess. Future treatments include inhibition of other angiogenic factors, and regenerative and topical therapies.

  20. Systemic administration of the iron chelator deferiprone protects against light-induced photoreceptor degeneration in the mouse retina

    PubMed Central

    Song, Delu; Song, Ying; Hadziahmetovic, Majda; Zhong, Yong; Dunaief, Joshua L.

    2012-01-01

    Oxidative stress plays a key role in the light damage (LD) model of retinal degeneration as well as in age-related macular degeneration (AMD). Since iron can promote oxidative stress, the iron chelator Deferiprone (DFP) was tested for protection against light-induced retinal degeneration. To accomplish this, A/J mice were treated with or without DFP in drinking water, and then were placed in constant bright white fluorescent light (10,000 lux) for 20 hours. Retinas were evaluated at several time points after light exposure. Photoreceptor apoptosis was assessed using the TUNEL assay. Retinal degeneration was assessed by histology 10 days after exposure to damaging white light. Two genes upregulated by oxidative stress, heme oxygenase 1 (Hmox1) and ceruloplasmin (Cp), as well as complement component 3 (C3) were quantified by RT-qPCR. Cryosections were immunolabeled for oxidative stress marker (nitrotyrosine), a microglial marker (Iba1) as well as both heavy (H) and light (L) ferritin. Light exposure resulted in substantial photoreceptor-specific cell death. Dosing with DFP protected photoreceptors, decreasing the numbers of TUNEL-positive photoreceptors and increasing the number of surviving photoreceptors. The retinal mRNA levels of oxidative stress related genes and C3 were upregulated following light exposure and diminished by DFP treatment. Immunostaining for nitrotyrosine indicated that DFP reduced the nitrative stress caused by light exposure. Robust H/L-ferritin-containing microglial activation and migration to the outer retina occurred after light exposure and DFP treatment reduced microglial invasion. DFP is protective against light-induced retinal degeneration and has the potential to diminish oxidative stress in the retina. PMID:22579919

  1. Improved azo dye decolorization in an advanced integrated system of bioelectrochemical module with surrounding electrode deployment and anaerobic sludge reactor.

    PubMed

    Kong, Fanying; Wang, Aijie; Ren, Hong-Yu

    2015-01-01

    A new integrated system, embedding a modular bioelectrochemical system (BES) with surrounding electrode deployment into an anaerobic sludge reactor (ASR), was developed to improve azo dye decolorization. Results demonstrated that the AO7 decolorization and COD removal can be improved without co-substrate in such system. The kinetic rate of decolorization (0.54h(-1)) in integrated system was 1.4-fold and 54.0-fold higher than that in biocathode BES (0.39h(-1)) and ASR (0.01h(-1)), respectively. COD can be removed after cleavage of azo bond, different from biocathode BES. The combined advantages of this integrated system were achieved by the cooperation of biocathode in modular BES and sludge in ASR. Biocathode was a predominant factor in AO7 decolorization, and anaerobic sludge contributed negligibly to AO7 reduction decolorization but mostly in the COD removal. These results demonstrated the great potential of integrating a BES module with anaerobic treatment process for azo dye treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Developmental Validation of a novel 5 dye Y-STR System comprising the 27 YfilerPlus loci

    PubMed Central

    Bai, Rufeng; Liu, Yaju; Li, Zheng; Jin, Haiying; Tian, Qinghua; Shi, Meisen; Ma, Shuhua

    2016-01-01

    In this study, a new STRtyper-27 system, including the same Yfiler Plus loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, Y-GATA H4, DYS449, DYS460, DYS481, DYS518, DYS533, DYS570, DYS576, DYS627 and DYF387S1a/b), was established using a set of 5 fluorescent dye labels. Primers, internal size standard, allelic ladders and matrix standard set were designed and created in-house for this multiplex system. This paper describes the validation studies conducted with the STRtyper-27Y system using a 3130XL genetic analyzer for fragment length detection that included the analysis of the following parameters and aspects: sensitivity, species specificity, inhibition, haplotype concordance, precision, stutter, DNA mixtures, and stability studies with crime scene samples. The studies demonstrated, that the STRtyper-27Y system provided equivalent overall performance comparable to the latest Yfiler Plus kit, but with enhanced compatibility in terms of instrument platforms and software allowing forensic laboratories to conduct its forensic application and evaluate its performance, all in their own 5 dye Y-STR chemistry system /environment without software or instrument upgrades. PMID:27406339

  3. Developmental Validation of a novel 5 dye Y-STR System comprising the 27 YfilerPlus loci.

    PubMed

    Bai, Rufeng; Liu, Yaju; Li, Zheng; Jin, Haiying; Tian, Qinghua; Shi, Meisen; Ma, Shuhua

    2016-07-13

    In this study, a new STRtyper-27 system, including the same Yfiler Plus loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, Y-GATA H4, DYS449, DYS460, DYS481, DYS518, DYS533, DYS570, DYS576, DYS627 and DYF387S1a/b), was established using a set of 5 fluorescent dye labels. Primers, internal size standard, allelic ladders and matrix standard set were designed and created in-house for this multiplex system. This paper describes the validation studies conducted with the STRtyper-27Y system using a 3130XL genetic analyzer for fragment length detection that included the analysis of the following parameters and aspects: sensitivity, species specificity, inhibition, haplotype concordance, precision, stutter, DNA mixtures, and stability studies with crime scene samples. The studies demonstrated, that the STRtyper-27Y system provided equivalent overall performance comparable to the latest Yfiler Plus kit, but with enhanced compatibility in terms of instrument platforms and software allowing forensic laboratories to conduct its forensic application and evaluate its performance, all in their own 5 dye Y-STR chemistry system /environment without software or instrument upgrades.

  4. Modified gravitational instability of degenerate and non-degenerate dusty plasma

    NASA Astrophysics Data System (ADS)

    Jain, Shweta; Sharma, Prerana

    2016-09-01

    The gravitational instability of strongly coupled dusty plasma (SCDP) is studied considering degenerate and non-degenerate dusty plasma situations. The SCDP system is assumed to be composed of the electrons, ions, neutrals, and strongly coupled dust grains. First, in the high density regime, due to small interparticle distance, the electrons are considered degenerate, whereas the neutrals, dust grains, and ions are treated non-degenerate. In this case, the dynamics of inertialess electrons are managed by Fermi pressure and Bohm potential, while the inertialess ions are by only thermal pressure. Second, in the non-degenerate regime, both the electrons and ions are governed by the thermal pressure. The generalized hydrodynamic model and the normal mode analysis technique are employed to examine the low frequency waves and gravitational instability in both degenerate and non-degenerate cases. The general dispersion relation is discussed for a characteristic timescale which provides two regimes of frequency, i.e., hydrodynamic regime and kinetic regime. Analytical solutions reveal that the collisions reduce the growth rate and have a strong impact on structure formation in both degenerate and non-degenerate circumstances. Numerical estimation on the basis of observed parameters for the degenerate and non-degenerate cases is presented to show the effects of dust-neutral collisions and dust effective velocity in the presence of polarization force. The values of Jeans length and Jeans mass have been estimated for degenerate white dwarfs as Jeans length L J = 1.3 × 10 5 cm and Jeans mass M J = 0.75 × 10 - 3 M⊙ and for non-degenerate laboratory plasma Jeans length L J = 6.86 × 10 16 cm and Jeans mass M J = 0.68 × 10 10 M⊙. The stability of the SCDP system is discussed using the Routh-Hurwitz criterion.

  5. Dye Painting with Fiber Reactive Dyes

    ERIC Educational Resources Information Center

    Benjamin-Murray, Betsy

    1977-01-01

    In her description of how to use dyes directly onto fabrics the author lists materials to be used, directions for mixing dyes, techniques for applying dyes, references for additional reading and sources for dye materials. Preceding the activity with several lessons in design and other textile techniques with the dye process will ensure a…

  6. Development of an intact intervertebral disc organ culture system in which degeneration can be induced as a prelude to studying repair potential.

    PubMed

    Jim, Bernice; Steffen, Thomas; Moir, Janet; Roughley, Peter; Haglund, Lisbet

    2011-08-01

    The present work describes a novel bovine disc organ culture system with long-term maintenance of cell viability, in which degenerative changes can be induced as a prelude to studying repair. Discs were isolated with three different techniques: without endplates (NEP), with bony endplates (BEP) and with intact cartilage endplates (CEP). Swelling, deformation, and cell viability were evaluated in unloaded cultures. Degeneration was induced by a single trypsin injection into the center of the disc and the effect on cell viability and matrix degradation was followed. Trypsin-treated discs were exposed to TGFβ to evaluate the potential to study repair in this system. NEP isolated discs showed >75% maintained cell viability for up to 10 days but were severely deformed, BEP discs on the other hand maintained morphology but failed to retain cell viability having only 27% viable cells after 10 days. In CEP discs, both cell viability and morphology were maintained for at least 4 weeks where >75% of the cells were still viable. To mimic proteoglycan loss during disc degeneration, a single trypsin injection was administered to the center of the disc. This resulted in 60% loss of aggrecan, after 7 days, without affecting cell viability. When TGFβ was injected to validate that the system can be used to study a repair response following injection of a bio-active substance, proteoglycan synthesis nearly doubled compared to baseline synthesis. Trypsin-treated bovine CEP discs therefore provide a model system for studying repair of the degenerate disc, as morphology, cell viability and responsiveness to bio-active substances were maintained.

  7. Deletion of Munc18-1 in 5-HT Neurons Results in Rapid Degeneration of the 5-HT System and Early Postnatal Lethality

    PubMed Central

    Dudok, Jacobus J.; Groffen, Alexander J. A.; Toonen, Ruud F. T.; Verhage, Matthijs

    2011-01-01

    The serotonin (5-HT) system densely innervates many brain areas and is important for proper brain development. To specifically ablate the 5-HT system we generated mutant mice carrying a floxed Munc18-1 gene and Cre recombinase driven by the 5-HT-specific serotonin reuptake transporter (SERT) promoter. The majority of mutant mice died within a few days after birth. Immunohistochemical analysis of brains of these mice showed that initially 5-HT neurons are formed and the cortex is innervated with 5-HT projections. From embryonic day 16 onwards, however, 5-HT neurons started to degenerate and at postnatal day 2 hardly any 5-HT projections were present in the cortex. The 5-HT system of mice heterozygous for the floxed Munc18-1 allele was indistinguishable from control mice. These data show that deletion of Munc18-1 in 5-HT neurons results in rapid degeneration of the 5-HT system and suggests that the 5-HT system is important for postnatal survival. PMID:22140524

  8. Anesthetic management of a patient with spinocerebellar degeneration

    PubMed Central

    Vadhanan, Prasanna; Kumar, Pramod

    2011-01-01

    Spinocerebellar degeneration or olivopontocerebellar degeneration denotes a group of disorders of various etiologies manifesting as degenerative changes of various part of the central nervous system. We describe the anesthetic management of a patient with severe olivopontocerebellar degeneration posted for vaginal hysterectomy. A combined spinal epidural technique was performed at the level of L2-L3. The anesthetic implications of the various aspects of spinocerebellar degeneration are discussed. PMID:21772692

  9. Model system for multifunctional delivery nanoplatforms based on DNA-Polymer complexes containing silver nanoparticles and fluorescent dye.

    PubMed

    Kasyanenko, Nina; Bakulev, Vladimir; Perevyazko, Igor; Nekrasova, Tatiana; Nazarova, Olga; Slita, Alexandr; Zolotova, Yulia; Panarin, Euginii

    2016-10-20

    Creation of multifunctional nanoplatforms is one of the new approaches to complex treatment and diagnosis with the monitoring of the curative process. Inclusion of various components into the drug delivery system may reduce toxicity and enhance or modify the therapeutic effects of medicines. In particular, some properties of metal nanoparticles and nanoclusters provide the ability to create new systems for treatment and diagnosis of diseases, biocatalysis and imaging of objects. For example, the ability of metal nanoparticles to enhance the quantum yield of luminescence can be used in bioimaging and therapy. The aim of the research was to construct and examine a multicomponent system based on DNA-polycation compact structure with the inclusion of silver nanoparticles and luminescent dye as a model system for delivery of genes and drugs with the possibility of modification and enhancement of their action.

  10. Electromagnetically induced absorption and transparency in degenerate two level systems of metastable Kr atoms and measurement of Landé g-factor

    NASA Astrophysics Data System (ADS)

    Kale, Y. B.; Tiwari, V. B.; Mishra, S. R.; Singh, S.; Rawat, H. S.

    2016-12-01

    We report electromagnetically induced absorption (EIA) and transparency (EIT) resonances of sub-natural linewidth in degenerate two level systems (DTLSs) of metastable 84Kr (84Kr*) and 83Kr (83Kr*) atoms. Using the spectrally narrow EIA signals obtained corresponding to the closed hyperfine transition 4p55s[3/2]2(F=13/2) to 4p55p[5/2]3(F‧ = 15 / 2) in 83Kr* atom, we have measured the Landé g-factor (gF) for the lower hyperfine level involved in this transition by application of small values of magnetic field of few Gauss.

  11. Principal molecular axis and transition dipole moment orientations in liquid crystal systems: an assessment based on studies of guest anthraquinone dyes in a nematic host.

    PubMed

    Sims, Mark T; Abbott, Laurence C; Cowling, Stephen J; Goodby, John W; Moore, John N

    2016-12-21

    An assessment of five different definitions of the principal molecular axis along which molecules align in a nematic liquid crystal system has been made by analysing fully atomistic molecular dynamics (MD) simulations of a set of anthraquinone dyes in the cyanobiphenyl-based nematic host mixture E7. Principal molecular axes of the dyes defined by minimum moment of inertia, minimum circumference, minimum area, maximum aspect ratio, and surface tensor models were tested, and the surface tensor model was found to give the best description. Analyses of MD simulations of E7 alone showed that the surface tensor model also gave a good description of the principal molecular axes of the host molecules, suggesting that this model may be applicable more generally. Calculated dichroic order parameters of the guest-host systems were obtained by combining the surface tensor analysis with fixed transition dipole moment (TDM) orientations from time-dependent density functional theory (TD-DFT) calculations on optimised structures of the dyes, and the trend between the dyes generally matched the trend in the experimental values. Additional analyses of the guest-host simulations identified the range of conformers explored by the flexible chromophores within the dyes, and TD-DFT calculations on corresponding model structures showed that this flexibility has a significant effect on the TDM orientations within the molecular frames. Calculated dichroic order parameters that included the effects of this flexibility gave a significantly improved match with the experimental values for the more flexible dyes. Overall, the surface tensor model has been shown to provide a rationale for the experimental alignment trends that is based on molecular shape, and molecular flexibility within the chromophores has been shown to be significant for the guest-host systems: the computational approaches reported here may be used as a general aid in the predictive design of dyes with appropriate molecular

  12. Imaging signatures of altered brain responses in small-fiber neuropathy: reduced functional connectivity of the limbic system after peripheral nerve degeneration.

    PubMed

    Hsieh, Paul-Chen; Tseng, Ming-Tsung; Chao, Chi-Chao; Lin, Yea-Huey; Tseng, Wen-Yih I; Liu, Kuan-Hong; Chiang, Ming-Chang; Hsieh, Sung-Tsang

    2015-05-01

    Small-fiber neuropathy (SFN) is hallmarked by degeneration of small unmyelinated peripheral nerve fibers in the skin. Traditionally, it has been considered as a pure disorder of the peripheral nervous system. Nevertheless, previous work found that dysfunction of skin nerves led to abnormal recruitment of pain-related regions, suggesting that the brain may be affected in SFN. This report combined structural and functional magnetic resonance imaging to identify structural and functional changes in the brain of 19 patients with SFN compared with 17 healthy controls. We applied tensor-based morphometry to detect brain structural alterations in SFN. Greater volume reduction in pain-processing regions, particularly the bilateral anterior cingulate cortices (ACCs), was associated with greater depletion of intraepidermal nerve fibers, a pathological biomarker of skin nerve degeneration. Based on the hypothesis that structural alterations in the pain-processing regions might impair their functional connectivity, we further applied psychophysiological interaction analysis to assess functional connectivity of the ACCs during noxious heat stimulation. There was significant reduction in functional connectivity from the ACCs to the limbic areas (the parahippocampal gyrus and the posterior cingulate cortex), pain-processing area (the insula), and visuospatial areas (the cuneus). Moreover, the degree of reduction in functional connectivity for the ACC to the amygdala and the precuneus was linearly correlated with the severity of intraepidermal nerve fiber depletion. Our findings suggest that SFN is not a pure peripheral nervous system disorder. The pain-related brain networks tend to break into functionally independent components, with severity linked to the degree of skin nerve degeneration.

  13. Dyes in Liquid Crystals: Experimental and Computational Studies of a Guest-Host System Based on a Combined DFT and MD Approach.

    PubMed

    Sims, Mark T; Abbott, Laurence C; Cowling, Stephen J; Goodby, John W; Moore, John N

    2015-07-06

    Practical applications of guest-host liquid crystal systems are critically dependent on the alignment of the guest species within the liquid crystal host. UV/Vis absorption spectroscopy shows that the 1,5-dihydroxy-2,6-bis-(4-propylphenyl)-9,10-anthraquinone dye aligns within the E7 nematic host, giving an experimental dichroic ratio of 9.40 and dye order parameter of 0.74. This alignment was modelled by using a combination of density functional theory (DFT) and molecular dynamics (MD) computational approaches that do not require the input of experimental data. Time-dependent DFT calculations show that the electronic transition dipole moment is highly aligned with the long molecular axis of the dye. Fully atomistic MD simulations show that the long axis of the dye is less highly aligned within the E7 host, indicating that this contribution limits the overall dye alignment and, thereby, the potential practical applications of this particular system. Importantly, this study demonstrates an experimental and combined DFT and MD computational approach that may be applied generally to guest-host systems, providing a potential route to their rational design. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  14. Equilibrium, kinetics and mechanism modeling and simulation of basic and acid dyes sorption onto jute fiber carbon: Eosin yellow, malachite green and crystal violet single component systems.

    PubMed

    Porkodi, K; Vasanth Kumar, K

    2007-05-08

    Batch experiments were carried out for the sorption of eosin yellow, malachite green and crystal violet onto jute fiber carbon (JFC). The operating variables studied are the initial dye concentration, initial solution pH, adsorbent dosage and contact time. Experimental equilibrium data were fitted to Freundlich, Langmuir and Redlich-Peterson isotherm by non-linear regression method. Langmuir isotherm was found to be the optimum isotherm for eosin yellow/JFC system and Freundlich isotherm was found to be the optimum isotherm for malachite green/JFC and crystal violet/JFC system at equilibrium conditions. The sorption capacities of eosin yellow, malachite green and crystal violet onto JFC according to Langmuir isotherm were found to 31.49 mg/g, 136.58 mg/g, 27.99 mg/g, respectively. A single stage batch adsorber was designed for the adsorption of eosin yellow, malachite green and crystal violet onto JFC based on the optimum isotherm. A pseudo second order kinetic model well represented the kinetic uptake of dyes studied onto JFC. The pseudo second order kinetic model successfully simulated the kinetics of dye uptake process. The dye sorption process involves both surface and pore diffusion with predominance of surface diffusion at earlier stages. A Boyd plot confirms the external mass transfer as the rate limiting step in the dye sorption process. The influence of initial dye concentration on the dye sorption process was represented in the form of dimensionless mass transfer numbers (Sh/Sc(0.33)) and was found to be agreeing with the expression:

  15. Dyeing industry effluent system as lipid production medium of Neochloris sp. for biodiesel feedstock preparation.

    PubMed

    Gopalakrishnan, Vidyadharani; Ramamurthy, Dhandapani

    2014-01-01

    Microalgae lipid feedstock preparation cost was an important factor in increasing biodiesel fuel hikes. This study was conducted with the concept of implementing an effluent wastewater as lipid production medium for microalgae cultivation. In our study textile dyeing industry effluent was taken as a lipid production medium for Neochloris sp. cultivation. The changes in physicochemical analysis of effluent before and after Neochloris sp. treatment were recorded using standard procedures and AAS analysis. There was especially a reduction in heavy metal like lead (Pb) concentration from 0.002 ppm to 0.001 ppm after Neochloris sp. treatment. Neochloris sp. cultivated in Bold Basal Medium (BBM) (specific algal medium) produced 41.93% total lipid and 36.69% lipid was produced in effluent based cultivation. Surprisingly Neochloris sp. cultivated in effluent was found with enhanced neutral lipid content, and it was confirmed by Nile red fluorescence assay. Further the particular enrichment in oleic acid content of the cells was confirmed with thin layer chromatography (TLC) with oleic acid pure (98%) control. The overall results suggested that textile dyeing industry effluent could serve as the best lipid productive medium for Neochloris sp. biodiesel feedstock preparation. This study was found to have a significant impact on reducing the biodiesel feedstock preparation cost with simultaneous lipid induction by heavy metal stress to microalgae.

  16. Dyeing Industry Effluent System as Lipid Production Medium of Neochloris sp. for Biodiesel Feedstock Preparation

    PubMed Central

    Ramamurthy, Dhandapani

    2014-01-01

    Microalgae lipid feedstock preparation cost was an important factor in increasing biodiesel fuel hikes. This study was conducted with the concept of implementing an effluent wastewater as lipid production medium for microalgae cultivation. In our study textile dyeing industry effluent was taken as a lipid production medium for Neochloris sp. cultivation. The changes in physicochemical analysis of effluent before and after Neochloris sp. treatment were recorded using standard procedures and AAS analysis. There was especially a reduction in heavy metal like lead (Pb) concentration from 0.002 ppm to 0.001 ppm after Neochloris sp. treatment. Neochloris sp. cultivated in Bold Basal Medium (BBM) (specific algal medium) produced 41.93% total lipid and 36.69% lipid was produced in effluent based cultivation. Surprisingly Neochloris sp. cultivated in effluent was found with enhanced neutral lipid content, and it was confirmed by Nile red fluorescence assay. Further the particular enrichment in oleic acid content of the cells was confirmed with thin layer chromatography (TLC) with oleic acid pure (98%) control. The overall results suggested that textile dyeing industry effluent could serve as the best lipid productive medium for Neochloris sp. biodiesel feedstock preparation. This study was found to have a significant impact on reducing the biodiesel feedstock preparation cost with simultaneous lipid induction by heavy metal stress to microalgae. PMID:25247176

  17. Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

    SciTech Connect

    Manwaring, John; Rothe, Helga; Obringer, Cindy; Foltz, David J.; Baker, Timothy R.; Troutman, John A.; Hewitt, Nicola J.; Goebel, Carsten

    2015-09-01

    Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passage through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human

  18. Current distribution evaluation of dye-sensitized solar cell using HTS-SQUID-based magnetic measurement system

    NASA Astrophysics Data System (ADS)

    Sakai, Kenji; Tanaka, Kohei; Kiwa, Toshihiko; Tsukada, Keiji

    2016-11-01

    The current flowing inside a dye-sensitized solar cell (DSSC) was measured using a high-temperature superconductor superconducting quantum interference device (HTS-SQUID)-based magnetic measurement system. Further, a new evaluation method of the DSSC, which is difficult to measure using the conventional method, was investigated to improve the characteristics of the DSSC. The tangential components of the magnetic field generated from the DSSC were measured using two HTS-SQUIDs, and the intensity and direction related to the electrical current were obtained by the measured magnetic field. The DSSCs prepared with different dyes and catalytic substances showed different current-intensity mapping. The current direction was different for the DSSC with low performance. In addition, the current flowing in the ITO layer of the ITO glass substrate was also measured and the results confirmed that it had uniform distribution. These results show that the current mapping and the direction of the electrical current depend on the internal factors of the DSSC, and the detection of the magnetic field distribution generated from it is expected to lead to its new evaluation method.

  19. Efficient azo dye decolorization in a continuous stirred tank reactor (CSTR) with built-in bioelectrochemical system.

    PubMed

    Cui, Min-Hua; Cui, Dan; Gao, Lei; Cheng, Hao-Yi; Wang, Ai-Jie

    2016-10-01

    A continuous stirred tank reactor with built-in bioelectrochemical system (CSTR-BES) was developed for azo dye Alizarin Yellow R (AYR) containing wastewater treatment. The decolorization efficiency (DE) of the CSTR-BES was 97.04±0.06% for 7h with sludge concentration of 3000mg/L and initial AYR concentration of 100mg/L, which was superior to that of the sole CSTR mode (open circuit: 54.87±4.34%) and the sole BES mode (without sludge addition: 91.37±0.44%). The effects of sludge concentration and sodium acetate (NaAc) concentration on azo dye decolorization were investigated. The highest DE of CSTR-BES for 4h was 87.66±2.93% with sludge concentration of 12,000mg/L, NaAc concentration of 2000mg/L and initial AYR concentration of 100mg/L. The results in this study indicated that CSTR-BES could be a practical strategy for upgrading conventional anaerobic facilities against refractory wastewater treatment.

  20. Optimization studies of bio-hydrogen production in a coupled microbial electrolysis-dye sensitized solar cell system.

    PubMed

    Ajayi, Folusho Francis; Kim, Kyoung-Yeol; Chae, Kyu-Jung; Choi, Mi-Jin; Chang, In Seop; Kim, In S

    2010-03-01

    Bio-hydrogen production in light-assisted microbial electrolysis cell (MEC) with a dye sensitized solar cell (DSSC) was optimized by connecting multiple MECs to a single dye (N719) sensitized solar cell (V(OC) approx. 0.7 V). Hydrogen production occurred simultaneously in all the connected MECs when the solar cell was irradiated with light. The amount of hydrogen produced in each MEC depends on the activity of the microbial catalyst on their anode. Substrate (acetate) to hydrogen conversion efficiencies ranging from 42% to 65% were obtained from the reactors during the experiment. A moderate light intensity of 430 W m(-2) was sufficient for hydrogen production in the coupled MEC-DSSC. A higher light intensity of 915 W m(-2), as well as an increase in substrate concentration, did not show any improvement in the current density due to limitation caused by the rate of microbial oxidation on the anode. A significant reduction in the surface area of the connected DSSC only showed a slight effect on current density in the coupled MEC-DSSC system when irradiated with light.

  1. Power and polarization dependences of ultra-narrow electromagnetically induced absorption (EIA) spectra of 85 Rb atoms in degenerate two-level system

    NASA Astrophysics Data System (ADS)

    Qureshi, Muhammad Mohsin; Rehman, Hafeez Ur; Noh, Heung-Ryoul; Kim, Jin-Tae

    2016-05-01

    We have investigated ultra-narrow EIA spectral features with respect to variations of polarizations and powers of pump laser beam in a degenerate two-level system of the transition of 85 Rb D2 transition line. Polarizations of the probe laser beam in two separate experiments were fixed at right circular and horizontal linear polarizations, respectively while the polarizations of the pump lasers were varied from initial polarizations same as the probe laser beams to orthogonal to probe polarizations. One homemade laser combined with AOMs was used to the pump and probe laser beams instead of two different lasers to overcome broad linewidths of the homemade lasers. Theoretically, probe absorption coefficients have been calculated from optical Bloch equations of the degenerate two level system prepared by a pump laser beam. In the case of the circular polarization, EIA signal was obtained as expected theoretically although both pump and probe beams have same polarization. The EIA signal become smaller as power increases and polarizations of the pump and probe beams were same. When the polarization of the pump beam was linear polarization, maximum EIA signal was obtained theoretically and experimentally. Experimental EIA spectral shapes with respect to variations of the pump beam polarization shows similar trends as the theoretical results.

  2. Pellucid marginal corneal degeneration.

    PubMed

    Krachmer, J H

    1978-07-01

    Pellucid marginal degeneration of the cornea is a bilateral, clear, inferior, peripheral corneal-thinning disorder. Protrusion of the cornea occurs above a band of thinning, which is located 1 to 2 mm from the limbus and measures 1 to 2 mm in width. American ophthalmologists are generally not familiar with the condition because most of the literature concerning pellucid degeneration is European. Four cases are described. This condition is differentiated from other noninflammatory cornel-thinning disorders such as keratoconus, keratoglobus, keratotorus, and posterior keratoconus. It is also differentiated from peripheral corneal disorders associated with inflammation such as Terrien's peripheral corneal degeneration, Mooren's ulcers, and ulcers from connective tissue disease.

  3. Characteristics of a Broadband Dye Laser Using Pyrromethene and Rhodamine Dyes

    NASA Technical Reports Server (NTRS)

    Tedder, Sarah A.; Danehy, Paul M.; Wheeler, Jeffrey L.

    2011-01-01

    A broadband dye laser pumped by a frequency-doubled Nd:YAG laser with a full-width half-maximum (FWHM) from 592 to 610 nm was created for the use in a dual-pump broadband CARS system called WIDECARS. The desired broadband dye laser was generated with a mixture of Pyrromethene dyes as an oscillator gain medium and a spectral selective optic in the oscillator cavity. A mixture of Rhodamine dyes were used in the amplifier dye cell. To create this laser a study was performed to characterize the spectral behavior of broadband dye lasers created with Rhodamine dyes 590, 610, and 640, Pyrromethene dyes 597 and 650 as well as mixture of these dyes.

  4. Influence of operational key parameters on the photocatalytic decolorization of Rhodamine B dye using Fe2+/H2O2/Nb2O5/UV system.

    PubMed

    Hashemzadeh, Fatemeh; Rahimi, Rahmatollah; Gaffarinejad, Ali

    2014-04-01

    The present research deals with the development of a new heterogeneous photocatalysis and Fenton hybrid system for the removal of color from textile dyeing wastewater as Rhodamine B (RhB) solutions by using Fe(2+)/H2O2/Nb2O5 as a photocatalytic system. The application of this photocatalytic system for the decolorization of dye contaminants is not reported in the literature yet. Different parameters like dye concentration, Nb2O5/Fe(2+) catalyst amount, pH, and H2O2 concentration have been studied. The optimum conditions for the decolorization of the dye were initial concentration of 10 mg L(-1) of dye, pH 4, and Nb2O5/Fe(2+) catalyst concentration of 0.5 g L(-1)/50 mg L(-1). The optimum value of H2O2 concentration for the conditions used in this study was 700 mg L(-1). Moreover, the efficiency of the Nb2O5/photo-Fenton hybrid process in comparison to photo-Fenton alone and a dark Fenton process as a control experiment to decolorize the RhB solution has been investigated. The combination of photo-Fenton and Nb2O5 catalysts has been proved to be the most effective for the treatment of such type of wastewaters. The results revealed that the RhB dye was decolorized in a higher percent (78 %) by the Nb2O5/photo-Fenton hybrid process (Fe(2+)/H2O2/Nb2O5/UV) than by the photo-Fenton process alone (37 %) and dark Fenton process (14 %) after 120 min of treatment. Moreover, the Nb2O5 catalyst as a heterogeneous part of the photocatalytic system was demonstrated to have good stability and reusability.

  5. Charge transfer in graphene oxide-dye system for photonic applications

    SciTech Connect

    Bongu, Sudhakara Reddy Bisht, Prem B.; Thu, Tran V.; Sandhu, Adarsh

    2014-02-20

    The fluorescence of a standard dye Rhodamine 6G (R6G) in solution decreases on addition of reduced graphene oxide (rGO). The absorption spectra and lifetime measurements confirm that no excited-state but a ground-state complex formation is responsible for this effect. For silver decorated rGO (Ag-rGO), the quenching efficiency and ground state complex formation process is small. Z-scan measurements have been done to study the optical nonlinearity at 532 nm under ps time scale. Remarkable reduction in the saturable absorption (SA) effect of R6G indicates no nonlinear contribution from the ground state complex. The results have been explained with varying charge transfer rates and non-fluorescence nature of the complex.

  6. Wet Macular Degeneration

    MedlinePlus

    ... has a hereditary component. Researchers have identified several genes related to developing the condition. Smoking. Smoking cigarettes or being regularly exposed to smoke significantly increases your risk of macular degeneration. Obesity. Research indicates that being obese increases the chance ...

  7. Lower limits of fluorescein and indocyanine green dye for digital cSLO fluorescence angiography

    PubMed Central

    Bindewald, A; Stuhrmann, O; Roth, F; Schmitz-Valckenberg, S; Helb, H-M; Wegener, A; Eter, N; Holz, F G

    2005-01-01

    Background: With the advent of digital confocal scanning laser ophthalmoscopy it is possible to detect low levels of fluorescence. Here we used a novel confocal scanning laser ophthalmoscope (cSLO) to determine lower limits of dye required for fluorescein (FL) and indocyanine green (ICG) angiography. Methods: A cSLO (Heidelberg retina angiograph 2, Heidelberg Engineering, Dossenheim, Germany) with an optically pumped solid state laser (488 nm) for FL and a diode laser (790 nm) for ICG angiography (FL/ICG-A) was used. 62 FL-As were performed in 53 patients and 45 ICG-As were performed in 39 patients with neovascular age related macular degeneration. The volume and overall dye content of bolus injections was gradually tapered (FL: 500 mg, 250 mg, 200 mg, 166 mg, 100 mg; ICG: 25 mg, 20 mg, 15 mg, 10 mg, 5 mg, 2.5 mg), while dye concentrations were kept constant at 100 mg/ml for FL and at 5 mg/ml for ICG. Images were obtained 1, 5, 15, and 30 minutes after dye injection. Image quality was evaluated by two independent readers using standardised criteria. Results: For amounts down to 166 mg for FL and to 5 mg for ICG, sufficient image quality was achieved during all phases following injection. Only late phase images showed less contrast compared to typically used dye amounts, which was irrelevant for interpretation and clinical management. Conclusions: With the increased sensitivity of this novel cSLO system, amounts of injected dye during FL-A can be reduced to one third for FL and to one fifth for ICG without relevant loss of image quality or information compared to conventionally used dye levels. These amounts can be used for routine angiography and allow relevant savings for units performing FL-A. PMID:16299141

  8. [An autopsy case with peculiar acidophilic bodies in the dentate nucleus and brain stem, associated with degeneration of the pyramidal-extrapyramidal systems].

    PubMed

    Kato, Y; Kashima, H; Tominaga, I; Nojima, T; Yanai, K; Takayama, K; Tamazawa, A; Miura, I; Oyanagi, S

    1985-12-01

    Case S.S. 59 years of age, male. At the age of 25, he had admitted to sanatorium for 7 years because of pulmonary tuberculosis. After his discharge, at the age of 45, he had started complaining of depressive mood or the idea of suicide and admitted to a mental hospital. Psychiatric diagnosis was depression and slight mental retardation. Shortly after, his depressive mood was improved, but his hypochondriac attitude was unchanged. No tendency toward dementia was proven. At the age of 54, he became enable to walk. Neurologically, pyramidal and some sort of extrapyramidal signs, dysarthria, disturbance of swallowing, fecal and urinary incontinence became apparent. Laboratory data showed scarcely any abnormality. At the age of 59, he died of bronchopneumonia. Neuropathologically, moderate degeneration of dentate nucleus, slight degeneration of pyramidal tract from medulla oblongata to spinal cord, striatum, substantia nigra were found. Neither senile plaques nor neurofibrillary changes could be seen throughout central nervous system. The most important finding is the presence of peculiar acidophilic bodies. They are round or oval, 10 approximately 20 mu in diameter and distributed in dentate nucleus, oculomotor nucleus, central grey of midbrain, superior colliculus, putamen, pallidum, subthalamic nucleus, Zona incerta, hypothalamus, Locus coeruleus, reticular formation of midbrain and pons, pontine nucleus, raphe nucleus, vestibular nucleus, inferior olive in order of number of the bodies. These bodies are scattered in so-called ground substance, and have no relations to any cell bodies or cell processes.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Helquat Dyes: Helicene-like Push-Pull Systems with Large Second-Order Nonlinear Optical Responses.

    PubMed

    Coe, Benjamin J; Rusanova, Daniela; Joshi, Vishwas D; Sánchez, Sergio; Vávra, Jan; Khobragade, Dushant; Severa, Lukáš; Císařová, Ivana; Šaman, David; Pohl, Radek; Clays, Koen; Depotter, Griet; Brunschwig, Bruce S; Teplý, Filip

    2016-03-04

    Helquat dyes combine a cationic hemicyanine with a helicene-like motif to form a new blueprint for chiral systems with large and tunable nonlinear optical (NLO) properties. We report a series of such species with characterization, including determination of static first hyperpolarizabilities β0 via hyper-Rayleigh scattering and Stark spectroscopy. The measured β0 values are similar to or substantially larger than that of the commercial chromophore E-4'-(dimethylamino)-N-methyl-4-stilbazolium. Density functional theory (DFT) and time-dependent DFT calculations on two of the new cations are used to probe their molecular electronic structures and optical properties. Related molecules are expected to show bulk second-order NLO effects in even nonpolar media, overcoming a key challenge in developing useful materials.

  10. Towards modeling of random lasing in dye doped bio-organic based systems: ray-tracing and cellular automaton analysis

    NASA Astrophysics Data System (ADS)

    Mitus, A. C.; Stopa, P.; Zaklukiewicz, W.; Pawlik, G.; Mysliwiec, J.; Kajzar, F.; Rau, I.

    2015-08-01

    One of many photonic applications of biopolymers as functional materials is random lasing resulting from an incorporation of highly luminescent dyes into biopolymeric matrix, which leads to a random but coherent light scattering in amplifying medium. In spite of numerous theoretical and experimental studies the origin of the coherence is still not clear and various scenarios are discussed. In particular, inhomogeneity of biopolymeric layers can hypothetically promote the feedback in the scattering of the emitted light resulting in coherent and incoherent random lasing. In this paper we analyze the light scattering in a model system of scattering centers of circular shapes and various dimensions using ray-tracing techniques. In the second part, which has mostly a tutorial character, we present the approach to the study of random lasing using a cellular automaton model of Wiersma et al.

  11. Dye laser amplifier

    DOEpatents

    Moses, Edward I.

    1992-01-01

    An improved dye laser amplifier is disclosed. The efficiency of the dye lr amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant.

  12. Dye laser amplifier

    DOEpatents

    Moses, E.I.

    1992-12-01

    An improved dye laser amplifier is disclosed. The efficiency of the dye laser amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant. 3 figs.

  13. Astrocyte-targeted expression of interleukin-6 protects the central nervous system during neuroglial degeneration induced by 6-aminonicotinamide.

    PubMed

    Penkowa, Milena; Camats, Jordi; Hadberg, Hanne; Quintana, Albert; Rojas, Santiago; Giralt, Mercedes; Molinero, Amalia; Campbell, Iain L; Hidalgo, Juan

    2003-08-15

    6-aminonicotinamide (6-AN) is a niacin antagonist, which leads to degeneration of gray matter astrocytes mainly in the brainstem. We have examined the role of interleukin-6 (IL-6) in this degenerative process by using transgenic mice with astrocyte-targeted IL-6 expression (GFAP-IL6 mice). This study demonstrates that transgenic IL-6 expression significantly increases the 6-AN-induced inflammatory response of reactive astrocytes, microglia/macrophages, and lymphocytes in the brainstem. Also, IL-6 induced significant increases in proinflammatory cytokines IL-1, IL-12, and tumor necrosis factor-alpha as well as growth factors basic fibroblast growth factor (bFGF), transforming growth factor-beta, neurotrophin-3, angiopoietin, vascular endothelial growth factor, and the receptor for bFGF. In accordance, angiogenesis was increased in GFAP-IL6 mice relative to controls after 6-AN. Moreover, oxidative stress and apoptotic cell death were significantly reduced by transgenic IL-6 expression. IL-6 is also a major inducer in the CNS of metallothionein I and II (MT-I+II), which were significantly increased in the GFAP-IL6 mice. MT-I+II are antioxidants and neuroregenerative factors in the CNS, so increased MT-I+II levels in GFAP-IL6 mice could contribute to the reduction of oxidative stress and cell death in these mice.

  14. Photodissociation Dye Laser

    DTIC Science & Technology

    1975-04-01

    Chemical Properties of Free Radicals 5 C. Criteria for the Selection of Photodissociation Dye Laser Molecules 6 III. EXPERIMENTAL EFFORT AND...nanoseconds. In radicl systems, however, there is evidence both theoretical and experimental, that the first doublet-doublet electronic tra-jitions are...Properties, of Free Radicals Recombination is only one of many possible reaction paths that can occur in a radical system. Because they are characterized

  15. Pulsed dye laser therapy for infantile hemangiomas: a systemic review and meta-analysis.

    PubMed

    Shen, L; Zhou, G; Zhao, J; Li, P; Xu, Q; Dong, Y; Zhang, Z

    2015-06-01

    Infantile hemangiomas (IH) are common pediatric tumors. This meta-analysis was performed to review the therapeutic efficacy and safety of pulsed dye laser (PDL) in the treatment of IH. Seven databases were searched, including PubMed, OvidSP, Karger, Elsevier, EMBASE, Web of Science and Wiley Online Library. The review collected the characteristics of year of publication, hemangiomas cases, prior treatment, laser parameters, adverse side, pretreatment symptom, and number of response from all articles. A total of 1580 studies were identified, the first round search retrieved 39 articles met inclusion criteria. Of those, only 13 articles with 1529 hemangiomas were included in the meta-analysis. This meta-analysis demonstrated an overall resolution rate of 89.1% with 6.28% incidence of adverse effect. PDL may be the effective modality to decrease the proliferative phase and accelerate rates of involution and resolution with few adverse events. © The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. "Atypical" atypical parkinsonism: new genetic conditions presenting with features of progressive supranuclear palsy, corticobasal degeneration, or multiple system atrophy-a diagnostic guide.

    PubMed

    Stamelou, Maria; Quinn, Niall P; Bhatia, Kailash P

    2013-08-01

    Recently, a number of genetic parkinsonian conditions have been recognized that share some features with the clinical syndromes of progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and multiple system atrophy (MSA), the classic phenotypic templates of atypical parkinsonism. For example, patients with progranulin, dynactin, or ATP13A gene mutations may have vertical supranuclear gaze palsy. This has made differential diagnosis difficult for practitioners. In this review, our goal is to make clinicians aware of these genetic disorders and provide clinical clues and syndromic associations, as well as investigative features, that may help in diagnosing these disorders. The correct identification of these patients has important clinical, therapeutic, and research implications. © 2013 Movement Disorder Society.

  17. Short Time Exposure (STE) test in conjunction with Bovine Corneal Opacity and Permeability (BCOP) assay including histopathology to evaluate correspondence with the Globally Harmonized System (GHS) eye irritation classification of textile dyes.

    PubMed

    Oliveira, Gisele Augusto Rodrigues; Ducas, Rafael do Nascimento; Teixeira, Gabriel Campos; Batista, Aline Carvalho; Oliveira, Danielle Palma; Valadares, Marize Campos

    2015-09-01

    Eye irritation evaluation is mandatory for predicting health risks in consumers exposed to textile dyes. The two dyes, Reactive Orange 16 (RO16) and Reactive Green 19 (RG19) are classified as Category 2A (irritating to eyes) based on the UN Globally Harmonized System for classification (UN GHS), according to the Draize test. On the other hand, animal welfare considerations and the enforcement of a new regulation in the EU are drawing much attention in reducing or replacing animal experiments with alternative methods. This study evaluated the eye irritation of the two dyes RO16 and RG19 by combining the Short Time Exposure (STE) and the Bovine Corneal Opacity and Permeability (BCOP) assays and then comparing them with in vivo data from the GHS classification. The STE test (first level screening) categorized both dyes as GHS Category 1 (severe irritant). In the BCOP, dye RG19 was also classified as GHS Category 1 while dye RO16 was classified as GHS no prediction can be made. Both dyes caused damage to the corneal tissue as confirmed by histopathological analysis. Our findings demonstrated that the STE test did not contribute to arriving at a better conclusion about the eye irritation potential of the dyes when used in conjunction with the BCOP test. Adding the histopathology to the BCOP test could be an appropriate tool for a more meaningful prediction of the eye irritation potential of dyes.

  18. Connections of the terminal nerve and the olfactory system in two galeomorph sharks: an experimental study using a carbocyanine dye.

    PubMed

    Yáñez, Julián; Folgueira, Mónica; Köhler, Elisabeth; Martínez, Cristina; Anadón, Ramón

    2011-11-01

    In elasmobranchs the terminal nerve courses separately from the olfactory nerve. This characteristic makes elasmobranchs excellent models to study the anatomy and function of these two systems. Here we study the neural connections of the terminal nerve and olfactory system in two sharks by experimental tracing methods using carbocyanine dyes. The main projections from the terminal nerve system (consisting of three ganglia in Scyliorhinus canicula) course ipsilaterally to the medial septal nucleus and bilaterally to the ventromedial telencephalic pallial region. Minor terminal nerve projections were also traced ipsilaterally to diencephalic and mesencephalic levels. With regard to the olfactory connections, our results show that in sharks, unlike ray-finned fishes, the primary olfactory projections are mainly restricted to the olfactory bulb. We also performed tracer application to the olfactory bulb in order to analyze the possible central neuroanatomical relationship between the projections of the terminal nerve and the olfactory bulb. In these experiments labeled neurons and fibers were observed from telencephalic to caudal mesencephalic regions. However, we observe almost no overlap between the two systems at central levels. The afferent and the putatively efferent connections of the dogfish olfactory bulb are compared with those previously reported in other elasmobranchs. The significance of the extratelencephalic secondary olfactory projections is also discussed in a comparative context.

  19. Optimized matching modes of bioelectrochemical module and anaerobic sludge in the integrated system for azo dye treatment.

    PubMed

    Kong, Fanying; Wang, Aijie; Ren, Hong-Yu

    2015-09-01

    In this work, three matching modes (relative positions, catholyte flow sequences, and flow regimes) of bioelectrochemical module and anaerobic sludge were evaluated and optimized for azo dye treatment in the integrated system with embedding modular bioelectrochemical system into anaerobic sludge reactor. Results showed that it was favorable to operate this integrated system under the condition of 1/4 cathode soaking into sludge with spiral distributor in down-flow direction. Current, electrochemical impedance spectroscopy and pH clearly demonstrated the important role of 1/4 soaking in electron/proton transfer. The down-flow direction flowed through electrode zone and then sludge zone could benefit to the efficient use of cathode and improve AO7 treatment. Furthermore, the positive effect of spiral catholyte distributor might be due to its promoting role in mixing and creating a spiral flow channel around the cathode electrode-microbes-solution interface. These results exhibited great potential for matching modular bioelectrochemical system with anaerobic treatment process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Development of injection-seeded optical parametric laser systems with pulsed dye amplifiers for high-spectral-resolution combustion diagnostics

    NASA Astrophysics Data System (ADS)

    Bhuiyan, Aizaz Hossain

    The development and application of optical parametric (OP) systems with pulsed dye amplifiers producing single frequency mode (SFM), narrow linewidth, and tunable laser radiation for high-spectral-resolution laser diagnostics is described. An optical parametric generator (OPG) was developed, consisting of a pair of counter-rotating β barium borate (β-BBO) crystals pumped by third-harmonic output of an injection-seeded Nd:YAG laser. The OPG crystals themselves are injection-seeded using a continuous wave (cw) distributed feedback (DFB) diode laser or external cavity diode laser (ECDL) at idler wavelength. The OPG is converted for some applications into an optical parametric oscillator (OPO) by incorporating a feedback cavity. The signal output from the OP system is amplified using pulsed dye amplifiers. The PDAs are pumped either by second-harmonic or third-harmonic output of the Nd:YAG laser depending on the OP output wavelength and the dye solution used in PDAs. The linewidth of the laser beam produced using OP/PDA systems is 200 MHz and the spatial beam profile is nearly Gaussian. Initial application of OP/PDA system included two-photon laser induced fluorescence (LIF) of atomic oxygen in counter-flow flames, dual pump coherent anti-Stokes Raman spectroscopy (CARS) for N2 and CO2, and nitric oxide (NO) planar laser induced fluorescence (PLIF) in compressible flowfield. A two-photon pump polarization spectroscopy probe (TPP-PSP) laser system has also been developed using two SFM OPG/PDA systems for the detection of atomic hydrogen (H-atom) in flames. In TPP-PSP, a 243-nm pump beam excites the 1S-2S two photon transition and the excited atoms in 2S level are probed by polarization spectroscopy between n=2 and n=3 manifolds using a circularly polarized 656-nm pump and a linearly polarized 656-nm probe laser beam. Using the TPP-PSP scheme, atomic hydrogen was detected at concentrations as low as 11 ppm. The use of injection-seeded OPG/PDAs as SFM sources for the

  1. Evaluation of quantum dot immunofluorescence and a digital CMOS imaging system as an alternative to conventional organic fluorescence dyes and laser scanning for quantifying protein microarrays.

    PubMed

    Jain, Aarti; Taghavian, Omid; Vallejo, Derek; Dotsey, Emmanuel; Schwartz, Dan; Bell, Florian G; Greef, Chad; Davies, D Huw; Grudzien, Jennipher; Lee, Abraham P; Felgner, Philip L; Liang, Li

    2016-04-01

    Organic fluorescent dyes are widely used for the visualization of bound antibody in a variety of immunofluorescence assays. However, the detection equipment is often expensive, fragile, and hard to deploy widely. Quantum dots (Qdot) are nanocrystals made of semiconductor materials that emit light at different wavelengths according to the size of the crystal, with increased brightness and stability. Here, we have evaluated a small benchtop "personal" optical imager (ArrayCAM) developed for quantification of protein arrays probed by Qdot-based indirect immunofluorescence. The aim was to determine if the Qdot imager system provides equivalent data to the conventional organic dye-labeled antibody/laser scanner system. To do this, duplicate proteome microarrays of Vaccinia virus, Brucella melitensis and Plasmodium falciparum were probed with identical samples of immune sera, and IgG, IgA, and IgM profiles visualized using biotinylated secondary antibodies followed by a tertiary reagent of streptavidin coupled to either P3 (an organic cyanine dye typically used for microarrays) or Q800 (Qdot). The data show excellent correlation for all samples tested (R > 0.8) with no significant change of antibody reactivity profiles. We conclude that Qdot detection provides data equivalent to that obtained using conventional organic dye detection. The portable imager offers an economical, more robust, and deployable alternative to conventional laser array scanners. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Evaluation of Quantum dot immunofluorescence and a digital CMOS imaging system as an alternative to conventional organic fluorescence dyes and laser scanning for quantifying protein microarrays

    PubMed Central

    Jain, Aarti; Taghavian, Omid; Vallejo, Derek; Dotsey, Emmanuel; Schwartz, Dan; Bell, Florian G.; Greef, Chad; Davies, D. Huw; Grudzien, Jennipher; Lee, Abraham P.; Felgner, Philip; Liang, Li

    2016-01-01

    Organic fluorescent dyes are widely used for the visualization of bound antibody in a variety of immunofluorescence assays. However, the detection equipment is often expensive, fragile and hard to deploy widely. Quantum dots (Qdot®) are nanocrystals made of semiconductor materials that emit light at different wavelengths according to the size of the crystal, with increased brightness and stability. Here we have evaluated a small benchtop ‘personal’ optical imager (ArrayCAM™) developed for quantification of protein arrays probed by Qdot -based indirect immunofluorescence. The aim was to determine if the Qdot imager system provides equivalent data to the conventional organic dye-labelled antibody/laser scanner system. To do this, duplicate proteome microarrays of Vaccinia virus, Brucella melitensis and Plasmodium falciparum were probed with identical samples of immune sera, and IgG, IgA and IgM profiles visualized using biotinylated secondary antibodies followed by a tertiary reagent of streptavidin coupled to either P3 (an organic cyanine dye typically used for microarrays) or Q800 (Qdot). The data show excellent correlation for all samples tested (R>0.8) with no significant change of antibody reactivity profiles. We conclude that Qdot detection provides data equivalent to that obtained using conventional organic dye detection. The portable imager offers an economical, more robust and deployable alternative to conventional laser array scanners. PMID:26842269

  3. Striatal degeneration in childhood.

    PubMed Central

    Erdohazi, M; Marshall, P

    1979-01-01

    The clinical features, and the radiological and neuropathological findings of 3 unrelated children with striatal degeneration are presented. In one case the father had recently developed choreiform movements while in the other two the family history was negative for neurological disorders. Two patients had juvenile onset of psychiatric symptoms, seizures, and rigidity. The 3rd child presented with focal seizures at 9 weeks of age. The neuropathological findings are virtually identical in all 3 cases. The classification of striatal degeneration in childhood is discussed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:434899

  4. Just Dyeing to Find Out.

    ERIC Educational Resources Information Center

    Monhardt, Becky Meyer

    1996-01-01

    Presents a multidisciplinary unit on natural dyes designed to take advantage of the natural curiosity of middle school students. Discusses history of dyes, natural dyes, preparation of dyes, and the dyeing process. (JRH)

  5. Just Dyeing to Find Out.

    ERIC Educational Resources Information Center

    Monhardt, Becky Meyer

    1996-01-01

    Presents a multidisciplinary unit on natural dyes designed to take advantage of the natural curiosity of middle school students. Discusses history of dyes, natural dyes, preparation of dyes, and the dyeing process. (JRH)

  6. Dye laser principles, with applications

    SciTech Connect

    Duarte, F.J. . Dept. of Physics); Hillman, L.W. . Dept. of Physics)

    1990-01-01

    This book contains papers which explain dye laser principles. Topics covered include: laser dynamics, femtosecond dye lasers, CW dye lasers, technology of pulsed dye lases, photochemistry of laser dyes, and laser applications.

  7. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

    NASA Astrophysics Data System (ADS)

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-04-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment.

  8. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

    PubMed Central

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-01-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment. PMID:27121278

  9. A simple and accurate analytical method for determination of three commercial dyes in different water systems using partial least squares regression.

    PubMed

    Al-Degs, Yahya S; El-Sheikh, Amjad H; Issa, Ayman A; Al-Ghouti, Mohammad A; Sunjuk, Mahmoud

    2012-01-01

    A simple analytical procedure is proposed for simultaneous determination of three common dyes (Basic Blue 9, Brilliant Blue E-4BA, and Reactive Blue 2) in natural waters without prior separation of the solutes. A popular chemometric method, partial least squares regression PLS-1, was effectively applied for spectral resolution of a highly overlapping system. At the best modeling conditions, mean recoveries and relative standard deviations (RSD) for dyes quantification by PLS-1 were found to be 102.1 (4.4), 95.7 (8.4), and 98.9 (6.2) for Basic Blue, Brilliant Blue, and Reactive Blue, respectively. The estimated limits of detection (LOD) were estimated using net-analyte signal concept and were 0.11, 0.52, 0.49 mg L(-1) for Basic Blue, Brilliant Blue, and Reactive Blue, respectively. The quantitative determination of dyes spiked in real water samples was carried out successfully by PLS-1 with satisfactory recoveries for dyes (90-106%).

  10. Envelope solitons in three-component degenerate relativistic quantum plasmas

    NASA Astrophysics Data System (ADS)

    Islam, S.; Sultana, S.; Mamun, A. A.

    2017-09-01

    The criteria for the formation of envelope solitons and their basic features in a three-component degenerate relativistic quantum plasma (DRQP) system (containing relativistically degenerate electrons, non-degenerate inertial light nuclei, and stationary heavy nuclei) are theoretically investigated. The nonlinear Schrödinger equation is derived by employing the multi-scale perturbation technique. The envelope solitons are found to be associated with the modified ion-acoustic waves in which the inertia (restoring force) is provided by the mass density of light nuclei (degenerate pressure of cold electrons). The basic features of these envelope solitons, which are found to formed in such a DRQP system, and their modulational instability criteria (on the basis of the plasma parameters associated with the degenerate pressure of electrons, number densities of degenerate electrons, inertial light nuclei, and stationary heavy nuclei) are identified. The numerical simulations are also performed to confirm the stability of the envelope solitons predicted here by analytical analysis.

  11. Ultrasound energy to accelerate dye uptake and dye-fiber interaction of reactive dye on knitted cotton fabric at low temperatures.

    PubMed

    Tissera, Nadeeka D; Wijesena, Ruchira N; de Silva, K M Nalin

    2016-03-01

    Acoustic cavitation formed due to propagation of ultrasound wave inside a dye bath was successfully used to dye cotton fabric with a reactive dye at lower temperatures. The energy input to the system during sonication was 0.7 W/cm(2). This was within the energy range that contributes towards forming cavitation during ultra-sonication. The influence of ultrasound treatment on dye particle size and fiber morphology is discussed. Particle size analysis of the dye bath revealed ultra-sonication energy was capable of de-agglomeration of hydrolyzed dye molecules during dyeing. SEM micrograph and AFM topographical image of the fiber surface revealed fiber morphology remains unchanged after the sonication. The study was extended in understanding the contribution of ultrasound method of dyeing towards achieving good color strength on the fabric, compared to the normal heating method of dyeing. Study showed color strength obtained using ultra sound method of dyeing is higher compared to normal heating dyeing. Ultrasound energy was able to achieve the good color strength on cotton fabric at very low temperature such as 30 °C, which was approximately 230% more than the color strength achieved in normal heating method of dyeing. This indicates that energy input to the system using ultrasound was capable of acting as an effective alternative method of dyeing knitted cotton fabrics with reactive dye. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Kraepelin and degeneration theory.

    PubMed

    Hoff, Paul

    2008-06-01

    Emil Kraepelin's contribution to the clinical and scientific field of psychiatry is recognized world-wide. In recent years, however, there have been a number of critical remarks on his acceptance of degeneration theory in particular and on his political opinion in general, which was said to have carried "overtones of proto-fascism" by Michael Shepherd [28]. The present paper discusses the theoretical cornerstones of Kraepelinian psychiatry with regard to their relevance for Kraepelin's attitude towards degeneration theory. This theory had gained wide influence not only in scientific, but also in philosophical and political circles in the last decades of the nineteenth century. There is no doubt that Kraepelin, on the one hand, accepted and implemented degeneration theory into the debate on etiology and pathogenesis of mental disorders. On the other hand, it is not appropriate to draw a simple and direct line from early versions of degeneration theory to the crimes of psychiatrists and politicians during the rule of national socialism. What we need, is a differentiated view, since this will be the only scientific one. Much research needs to be done here in the future, and such research will surely have a significant impact not only on the historical field, but also on the continuous debate about psychiatry, neuroscience and neurophilosophy.

  13. Frontotemporal Lobar Degeneration

    PubMed Central

    Josephs, Keith A.

    2009-01-01

    Synopsis Frontotemporal lobar degeneration (FTLD) is a syndromic diagnosis that encompasses at least three different variants. Imaging modalities are clinically useful in FTLD while pathology remains the gold standard for definitive diagnosis. To date three different genes have been identified that account for FTLD. PMID:17659185

  14. Developmental validation of a 6-dye typing system with 27 loci and application in Han population of China.

    PubMed

    Liu, Yaju; Guo, Lihong; Jin, Haiying; Li, Zheng; Bai, Rufeng; Shi, Meisen; Ma, Shuhua

    2017-07-05

    In this study, a novel 27-locus system (now known as the SureID PanGlobal system), including 24 autosomal STRs (D3S1358, TH01, D21S11, D18S51, Penta E, D12S391, D6S1043, D2S1338, D1S1656, D2S441, D5S818, D13S317, D7S820, D19S433, CSF1PO, Penta D, vWA, D8S1179, TPOX, FGA, D16S539, D22S1045, SE33, D10S1248), two Y-chromosome markers (DYS391 and Y-indel) and the sex determining marker, Amelogenin was developed with six fluorescent dyes labeling. The included STR loci belonged to the core loci in the Combined DNA Index System (CODIS) and the European Standard Set (ESS) as well as some additional loci commonly used in commercial kits and national DNA databases. This paper describes the validation studies conducted with the SureID PanGlobal system using Applied Biosystems 3500 XL Genetic Analyzer for fragment length detection that included the analysis of the following parameters and aspects: PCR conditions, sensitivity, species specificity, inhibition, precision, stutter, DNA mixtures, and stability studies with crime scene samples. The studies demonstrated that the SureID PanGlobal system is reproducible, accurate, sensitive and robust for forensic application and databasing. Additionally, the whole cycling time of the system can finish within 65 minutes, which was developed specifically for rapid and reliable generation of DNA profiles obtained from blood, buccal swabs and forensic stains.

  15. Improvement of N-phthaloylchitosan based gel polymer electrolyte in dye-sensitized solar cells using a binary salt system.

    PubMed

    Yusuf, S N F; Azzahari, A D; Selvanathan, V; Yahya, R; Careem, M A; Arof, A K

    2017-02-10

    A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I2) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, JSC of 17.29mAcm(-2), open circuit voltage, VOC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Integration of dye-sensitized solar cells, thermoelectric modules and electrical storage loop system to constitute a novel photothermoelectric generator.

    PubMed

    Chang, Ho; Yu, Zhi-Rong

    2012-08-01

    This study self-develops a novel type of photothermoelectric power generation modules. Dye-sensitized solar cells (DSSCs) serve as the photoelectric conversion system and a copper (Cu) heat-transfer nanofilm coating on both sides of the thermoelectric generator (TEG) acts as a thermoelectric conversion system. Thus module assembly absorbs light and generates electricity by DSSCs, and also recycles waste heat and generates power by the TEG. In addition, a set of pulsating heat pipes (PHP) filled with Cu nanofluid is placed on the cooling side to increase cooling effects and enhance the power generation efficiency. Results show that when the heat source of thermoelectric modules reaches 90 degrees C, TEG power output is increased by 85.7%. Besides, after thermoelectric modules are heated by additional heat source at 80 degrees C, the electrical energy generated by them can let a NiMH cell (1.25 V) be sufficiently charged in about 30 minutes. When photothermoelectric modules is illumined by simulated light, the temperature difference of two sides of TEG can reach 7 degrees C and the thermoelectric conversion efficiency is 2.17%. Furthermore, the power output of the thermoelectric modules is 11.48 mW/cm2, enhancing 1.4 % compared to merely using DSSCs module.

  17. X-82 to Treat Age-related Macular Degeneration

    ClinicalTrials.gov

    2017-01-12

    Age-Related Macular Degeneration (AMD); Macular Degeneration; Exudative Age-related Macular Degeneration; AMD; Macular Degeneration, Age-related, 10; Eye Diseases; Retinal Degeneration; Retinal Diseases

  18. Development of PVA-alginate as a matrix for enzymatic decolorization of textile dye in bioreactor system

    NASA Astrophysics Data System (ADS)

    Yanto, Dede Heri Yuli; Zahara, Syifa; Laksana, Raden Permana Budi; Anita, Sita Heris; Oktaviani, Maulida; Sari, Fahriya Puspita

    2017-01-01

    An immobilization technique using polyvinyl alcohol (PVA) crosslinked with sodium alginate as a matrix has been developed for textile dyes decolorization. Textiles use dye as an addition to the aesthetic value of the product. Dyes are generally used is a textile dye where the waste will be released directly into the waters around 2-20%. Therefore, it is important to develop an enzyme immobilization method using PVA-Alginate as a matrix. Based on the results of the study showed that the PVA-Alginate beads produced high decolorization percent compared to beads which contains only Ca-alginate alone and formula matrix is optimum at PVA 6% and alginate 1.5%. Encapsulation with boric acid at 7% showed optimum decolorization and reduction for enzyme leakage during decolorization. This study suggested that immobilization of enzymes into PVA-alginate matrix might be used as a biodecolorating agent.

  19. Incorporating multiple energy relay dyes in liquid dye-sensitized solar cells.

    PubMed

    Yum, Jun-Ho; Hardin, Brian E; Hoke, Eric T; Baranoff, Etienne; Zakeeruddin, Shaik M; Nazeeruddin, Mohammad K; Torres, Tomas; McGehee, Michael D; Grätzel, Michael

    2011-02-25

    Panchromatic response is essential to increase the light-harvesting efficiency in solar conversion systems. Herein we show increased light harvesting from using multiple energy relay dyes inside dye-sensitized solar cells. Additional photoresponse from 400-590 nm matching the optical window of the zinc phthalocyanine sensitizer was observed due to Förster resonance energy transfer (FRET) from the two energy relay dyes to the sensitizing dye. The complementary absorption spectra of the energy relay dyes and high excitation transfer efficiencies result in a 35% increase in photovoltaic performance.

  20. Comparing Quantitative Values of Two Generations of Laser-Assisted Indocyanine Green Dye Angiography Systems: Can We Predict Necrosis?

    PubMed Central

    Fourman, Mitchell S.; Rivara, Andrew; Dagum, Alexander B.; Huston, Tara L.; Ganz, Jason C.; Bui, Duc T.; Khan, Sami U.

    2014-01-01

    Objective: Several devices exist today to assist the intraoperative determination of skin flap perfusion. Laser-Assisted Indocyanine Green Dye Angiography (LAICGA) has been shown to accurately predict mastectomy skin flap necrosis using quantitative perfusion values. The laser properties of the latest LAICGA device (SPY Elite) differ significantly from its predecessor system (SPY 2001), preventing direct translation of previous published data. The purpose of this study was to establish a mathematical relationship of perfusion values between these 2 devices. Methods: Breast reconstruction patients were prospectively enrolled into a clinical trial where skin flap evaluation and excision was based on quantitative SPY Q values previously established in the literature. Initial study patients underwent mastectomy skin flap evaluation using both SPY systems simultaneously. Absolute perfusion unit (APU) values at identical locations on the breast were then compared graphically. Results: 210 data points were identified on the same patients (n = 4) using both SPY systems. A linear relationship (y = 2.9883x + 12.726) was identified with a high level or correlation (R2 = 0.744). Previously published values using SPY 2001 (APU 3.7) provided a value of 23.8 APU on the SPY Elite. In addition, postoperative necrosis in these patients correlated to regions of skin identified with the SPY Elite with APU less than 23.8. Conclusion: Intraoperative comparison of LAICGA systems has provided direct correlation of perfusion values predictive of necrosis that were previously established in the literature. An APU value of 3.7 from the SPY 2001 correlates to a SPY Elite APU value of 23.8. PMID:25525483

  1. Comparing quantitative values of two generations of laser-assisted indocyanine green dye angiography systems: can we predict necrosis?

    PubMed

    Phillips, Brett T; Fourman, Mitchell S; Rivara, Andrew; Dagum, Alexander B; Huston, Tara L; Ganz, Jason C; Bui, Duc T; Khan, Sami U

    2014-01-01

    Several devices exist today to assist the intraoperative determination of skin flap perfusion. Laser-Assisted Indocyanine Green Dye Angiography (LAICGA) has been shown to accurately predict mastectomy skin flap necrosis using quantitative perfusion values. The laser properties of the latest LAICGA device (SPY Elite) differ significantly from its predecessor system (SPY 2001), preventing direct translation of previous published data. The purpose of this study was to establish a mathematical relationship of perfusion values between these 2 devices. Breast reconstruction patients were prospectively enrolled into a clinical trial where skin flap evaluation and excision was based on quantitative SPY Q values previously established in the literature. Initial study patients underwent mastectomy skin flap evaluation using both SPY systems simultaneously. Absolute perfusion unit (APU) values at identical locations on the breast were then compared graphically. 210 data points were identified on the same patients (n = 4) using both SPY systems. A linear relationship (y = 2.9883x + 12.726) was identified with a high level or correlation (R(2) = 0.744). Previously published values using SPY 2001 (APU 3.7) provided a value of 23.8 APU on the SPY Elite. In addition, postoperative necrosis in these patients correlated to regions of skin identified with the SPY Elite with APU less than 23.8. Intraoperative comparison of LAICGA systems has provided direct correlation of perfusion values predictive of necrosis that were previously established in the literature. An APU value of 3.7 from the SPY 2001 correlates to a SPY Elite APU value of 23.8.

  2. Unveiling characteristics of a bioelectrochemical system with polarity reversion for simultaneous azo dye treatment and bioelectricity generation.

    PubMed

    Sun, Jian; Zhang, Yaping; Liu, Guoguang; Ning, Xunan; Wang, Yujie; Liu, Jingyong

    2015-09-01

    A novel bioelectrochemical system (BES) operated with polarity reversion was explored for simultaneous anaerobic/aerobic treatment of azo dye and production of bioelectricity under extremely low buffer. The Congo red was first decolorized in anode, with completed color removal in 35 h. The resultant decolorization intermediates were then mineralized after the anode reversed to aerobic biocathode, evidenced by 55 % chemical oxygen demand (COD) removal in 200 h. The mineralization efficiency was further increased to 70 % when the period of the half-cycle was prolonged to 375 h. Meanwhile, the BES produced a continuous stable positive/negative alternate voltage output under 5 mM phosphate buffer because of the self-neutralization of the accumulated protons and hydroxyl ions in electrolyte. The electrode performance was significantly improved, which was indicated by alleviated electrode polarization, due to in situ use of accumulated protons and hydroxyl ions and enhanced electron transfer in the presence of Congo red and its degradation intermediates, which resulted in 1.05-fold increases in maximum power density (67.5 vs. 32.9 mW/m(2)). An analysis of the microbial diversity in the biofilm revealed that the biofilm was dominated by facultative bacteria with functional roles in contaminant degradation and electricity generation.

  3. Decolorization of Solophenyl Red 3BL Polyazo Dye by Laccase-Mediator System: Optimization through Response Surface Methodology

    PubMed Central

    Neifar, Mohamed; Jaouani, Atef; Kamoun, Amel; Ellouze-Ghorbel, Raoudha; Ellouze-Chaabouni, Semia

    2011-01-01

    The decolorization of direct Solophenyl red 3BL (SR), a polyazo dye extensively used in textile industry was studied. The Fomes fomentarius laccase alone did not decolorize SR. The natural redox mediator, acetosyringone (AS), was necessary for decolorization to occur. Box-Behnken design was used to evaluate the effects of three parameters, namely, enzyme concentration (0.5–2.5 U mL−1), redox mediator concentration (3–30 μM), and incubation time (1–24 h), on the SR decolorization yield. The fitted mathematical model allowed us to plot response surfaces as well as isoresponse curves and to determine optimal decolorization conditions. The results clearly indicated that the AS concentration was the main factor influencing the SR decolorization yield. The selected optimal conditions were enzyme concentration 0.8 U mL−1, mediator concentration 33 μM, and time 14 h 30 min. These conditions allowed 79.66% of SR decolorization versus 80.70% for the predicted value. These results showed a promising future of applying laccase-AS system for industrial wastewater bioremediation. PMID:21869923

  4. Telangiectasis in CREST syndrome and systemic sclerosis: correlation of clinical and pathological features with response to pulsed dye laser treatment.

    PubMed

    Halachmi, Shlomit; Gabari, Osama; Cohen, Sarit; Koren, Romelia; Amitai, Dan Ben; Lapidoth, Moshe

    2014-01-01

    Telangiectasia are cardinal features of systemic sclerosis (SS) and calcinosis, Raynaud's syndrome, esophageal motility, sclerodactyly, telangiectasias (CREST) syndrome. The etiology of telangiectasia in these syndromes is unknown, but vascular dysfunction has been proposed. However, the telangiectasia of CREST have anecdotally been considered relatively resistant to pulse dye laser (PDL), the treatment of choice for classic telangiectasia. The study was designed to test whether SS/CREST telangiectasia require more treatments than sporadic telangiectasia and to identify clinical and histological features that could explain such an effect. Nineteen skin biopsies from patients with SS or CREST and 10 control biopsies were examined and compared for features that may predict a differential response to PDL. Sixteen cases of SS or CREST treated with PDL between 1997 and 2007 were evaluated and response to treatment was compared with 20 patients with sporadic telangiectasis. Relative to normal skin, CREST/scleroderma telangiectasia exhibited thickened vessels in 17 out of 19 sections and thickened collagen fibers in the reticular or deep dermis in all sections. The number of treatments required to clear SS/CREST telangiectasia was approximately twofold higher. SS/CREST telangiectasia are more resistant to PDL but can be effectively cleared with more treatments.

  5. Mechanisms of secondary degeneration after partial optic nerve transection

    PubMed Central

    Li, Hong-Ying; Ruan, Yi-Wen; Ren, Chao-Ran; Cui, Qi; So, Kwok-Fai

    2014-01-01

    Secondary degeneration occurs commonly in the central nervous system after traumatic injuries and following acute and chronic diseases, including glaucoma. A constellation of mechanisms have been shown to be associated with secondary degeneration including apoptosis, necrosis, autophagy, oxidative stress, excitotoxicity, derangements in ionic homeostasis and calcium influx. Glial cells, such as microglia, astrocytes and oligodendrocytes, have also been demonstrated to take part in the process of secondary injury. Partial optic nerve transection is a useful model which was established about 13 years ago. The merit of this model compared with other optic nerve injury models used for glaucoma study, including complete optic nerve transection model and optic nerve crush model, is the possibility to separate primary degeneration from secondary degeneration in location. Therefore, it provides a good tool for the study of secondary degeneration. This review will focus on the research progress of the mechanisms of secondary degeneration using partial optic nerve transection model. PMID:25206855

  6. Excited-state dynamics and dye-dye interactions in dye-coated gold nanoparticles with varying alkyl spacer lengths.

    PubMed

    Malicki, Michał; Hales, Joel M; Rumi, Mariacristina; Barlow, Stephen; McClary, Lakeisha; Marder, Seth R; Perry, Joseph W

    2010-06-21

    Gold nanoparticles (ca. 3 nm in diameter) coated with bis(diarylamino)biphenyl-based thiols with two different alkyl spacers (propyl and dodecyl) between the chromophore and the surface-anchoring thiol group have been prepared and characterized with a variety of techniques. The excited-state dynamics of the dyes in close proximity to the nanoparticle surface were studied using the time-correlated single-photon counting technique and near-IR fs transient absorption spectroscopy. The excited states of the dyes in the hybrid metal/organic systems exhibit an ultrafast (<5 ps) deactivation as evidenced by the fs transient absorption measurements. The length of the alkyl spacer between the dye and the thiol group has a profound effect on the ultrafast dynamics of the photoexcited systems. An ultrafast formation (ca. 0.5 ps) of a cation-like species has been recorded for the system incorporating the propyl spacer but not for the dodecyl-linker system. The formation of the cation-like species has been shown to be less efficient in a mixed-ligand system in which the bis(diarylamino)biphenyl-based thiol was diluted on the surface with dodecanethiol. Additionally, the ultrafast formation (ca. 1 ps) of a cation-like species with a similar spectroscopic signature has been observed in the solid state of the dye. A combination of the ultrafast dynamics and (1)H NMR spectroscopic data has been used to discuss the observed behavior in terms of dye-dye interactions in the nanoparticle systems. Due to the surface curvature of the nanoparticle, the propyl spacer imposes a closer dye-dye distance than the dodecyl spacer, thus facilitating dye-dye interactions that lead to the formation of a charge-transfer species involving two or more dye molecules.

  7. Cataracts and macular degeneration.

    PubMed

    Shoch, D

    1979-09-01

    The intraocular lens restores general vision and some degree of independence and mobility to patients with dense cataracts and macular degeneration. The patient, however, must be repeatedly warned that fine central vision, particularly reading, will not be possible after the surgery. An aphakic spectacle leaves such patients a narrow band of vision when superimposed over the macular lesion, and contact lenses are too small for the patient to manage insertion without help.

  8. The Ideal Solvent for Paper Chromatography of Food Dyes.

    ERIC Educational Resources Information Center

    Markow, Peter G.

    1988-01-01

    Uses paper chromatography with food dyes to provide a simple and inexpensive basis for teaching chromatography. Provides experimental methodology and tabled results. Includes a solvent system comparison (Rf) for seven dyes and twenty-two solvents. (MVL)

  9. Coadsorption of Doxorubicin and Selected Dyes on Carbon Nanotubes. Theoretical Investigation of Potential Application as a pH-Controlled Drug Delivery System.

    PubMed

    Panczyk, Tomasz; Wolski, Pawel; Lajtar, Leszek

    2016-05-17

    This work shows results of a theoretical survey, based on molecular dynamics simulation, of potential applicability of doxorubicin coadsorption with various dyes molecules on/in carbon nanotubes as a drug delivery system. The central idea is to take advantage of the dyes charge distribution change upon switching the pH of the environment from neutral (physiological 7.4) to acidic one (∼5.5 which is typical for tumor tissues). This work discusses results obtained for four dye molecules revealing more or less interesting behavior. These were bromothymol blue, methyl red, neutral red, and p-phenylenediamine. All of them reveal pKa in the range 5-7 and thus will undergo protonation in that pH range. We considered coadsorption on external walls of carbon nanotubes and sequential filling of the nanotubes inner hollow space by drug and dyes. The latter approach, with the application of neutral red and p-phenylenediamine as blockers of doxorubicin, led to the most promising results. Closer analysis of these systems allowed us to state that neutral red can be particularly useful as a long-term blocker of doxorubicin encapsulated in the inner cavity of (30,0) carbon nanotube at neutral pH. At acidic pH we observed a spontaneous release of neutral red from the nanotube and unblocking of doxorubicin. We also confirmed, by analysis of free energy profiles, that unblocked doxorubicin can spontaneously leave the nanotube interior at the considered conditions. Thus, that system can realize pH controlled doxorubicin release in acidic environment of tumor tissues.

  10. Dyeing behaviour of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves (Lawsonia inermis)

    NASA Astrophysics Data System (ADS)

    Rehman, Fazal-ur; Adeel, Shahid; Qaiser, Summia; Ahmad Bhatti, Ijaz; Shahid, Muhammad; Zuber, Mohammad

    2012-11-01

    Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash -SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties.

  11. Fluoro-Jade C results in ultra high resolution and contrast labeling of degenerating neurons.

    PubMed

    Schmued, Larry C; Stowers, Chris C; Scallet, Andrew C; Xu, Lulu

    2005-02-21

    The causes and effects of neuronal degeneration are of major interest to a wide variety of neuroscientists. Paralleling this growing interest is an increasing number of methods applicable to the detection of neuronal degeneration. The earliest methods employing aniline dyes were methodologically simple, but difficult to interpret due to a lack of staining specificity. In an attempt to circumvent this problem, numerous suppressed silver methods have been introduced. However, these methods are labor intensive, incompatible with most other histochemical procedures and notoriously capricious. In an attempt to develop a tracer with the methodological simplicity and reliability of conventional stains but with the specificity of an ideal suppressed silver preparation, the Fluoro-Jade dyes were developed. Fluoro-Jade C, like its predecessors, Fluoro-Jade and Fluoro-Jade B, was found to stain all degenerating neurons, regardless of specific insult or mechanism of cell death. Therefore, the patterns of neuronal degeneration seen following exposure to either the glutamate agonist, kainic acid, or the inhibitor of mitochondrial respiration, 3-NPA, were the same for all of the Fluoro-Jade dyes. However, there was a qualitative difference in the staining characteristics of the three fluorochromes. Specifically, Fluoro-Jade C exhibited the greatest signal to background ratio, as well as the highest resolution. This translates to a stain of maximal contrast and affinity for degenerating neurons. This makes it ideal for localizing not only degenerating nerve cell bodies, but also distal dendrites, axons and terminals. The dye is highly resistant to fading and is compatible with virtually all histological processing and staining protocols. Triple labeling was accomplished by staining degenerating neurons with Fluoro-Jade C, cell nuclei with DAPI and activated astrocytes with GFAP immunofluoresence.

  12. Visible-light-driven hydrogen production in a dye sensitized polyoxometalate system without noble metals

    NASA Astrophysics Data System (ADS)

    Liu, Xing; Li, Yuexiang; Peng, Shaoqin; Lai, Hua; Yi, Zhengji

    2016-05-01

    In this work, a noble-metal-free homogeneous system was constructed in one step with Keggin-type polyoxometalate (POM) SiW12O404- as a catalyst, Eosin Y as a photosensitizer, and triethanolamine (TEOA) as a sacrificial electron donor for water splitting to produce hydrogen under visible-light irradiation. A two-electron reduced heteropoly blue SiW12O406- is produced by photosensitization under visible-light irradiation. The effect of various component concentrations and POMs with different central atoms (PW12O403-, GeW12O404-, etc.) on hydrogen production was discussed. This simple system made of earth-abundant elements is expected to contribute toward the development of functional and efficient artificial photosynthetic system.

  13. (Dibenzoylmethanato)boron difluoride derivatives containing triphenylamine moieties: a new type of electron-donor/π-acceptor system for dye-sensitized solar cells.

    PubMed

    Mizuno, Yosuke; Yisilamu, Yilihamu; Yamaguchi, Tomoya; Tomura, Masaaki; Funaki, Takashi; Sugihara, Hideki; Ono, Katsuhiko

    2014-10-06

    (Dibenzoylmethanato)boron difluoride derivatives containing triphenylamine moieties were synthesized as a new type of electron-donor/π-acceptor system. These new compounds exhibited long-wavelength absorptions in the UV/Vis spectra, and reversible oxidation and reduction waves in cyclic voltammetry experiments. Their amphoteric redox properties are based on their resonance hybrid forms, in which a positive charge is delocalized on the triphenylamine moieties and a negative charge is localized on the boron atoms. Molecular orbital (MO) calculations indicate that their HOMO and LUMO energies vary with the number of phenylene rings connected to the difluoroboron-chelating ring. This is useful for optimizing the HOMO and LUMO levels to an iodine redox (I(-)/I3(-)) potential and a titanium dioxide conduction band, respectively. Dye-sensitized solar cells fabricated by using these compounds as dye sensitizers exhibited solar-to-electric power conversion efficiencies of 2.7-4.4 % under AM 1.5 solar light.

  14. Treatment Options for Age-Related Macular Degeneration: A Budget Impact Analysis from the Perspective of the Brazilian Public Health System

    PubMed Central

    Elias, Flávia Tavares Silva; da Silva, Everton Nunes; Belfort, Rubens; Silva, Marcus Tolentino; Atallah, Álvaro Nagib

    2015-01-01

    Background Age-related macular degeneration (AMD) is a disease that causes reduced visual acuity and blindness. The new treatment options for AMD are not provided by the Brazilian public health system. Objective To conduct a budget impact analysis of three scenarios for the introduction of AMD treatments: all the medications (verteporfin, ranibizumab, and bevacizumab–the reference scenario), ranibizumab alone, and bevacizumab alone. Methods The basic assumption was that the Brazilian public health system would treat the entire target population with AMD aged > 70 years between 2008 and 2011. The size of the population of interest was estimated from official population projections and the prevalence of the disease was obtained from a systematic review. Medication prices were estimated by weighting their market values with correction factors to take account of the public procurement policy. The possibility of aliquoting bevacizumab was also considered. A panel of experts was consulted to estimate the market share of the different medications for the reference scenario. The incremental costs of the ranibizumab-alone and bevacizumab-alone scenarios compared to the reference scenario were calculated. Univariate sensitivity analyses were run to check the robustness of the model. Results In four years, the Brazilian public health system would have treated 1,136,349 individuals with AMD. The annual costs of treating one patient would have been US$476.65 for bevacizumab, US$11,469.39 for ranibizumab, and US$4,376.28 for verteporfin. The incremental cost of the ranibizumab-alone scenario would have been US$1,878,318,056.00 in four years, while the incremental cost for the bevacizumab-alone scenario would have been a reduction of US$4,978,326,359.00 (i.e., a cost saving) in the same period. The bevacizumab-alone option was found to represent a cost saving across sensitivity analyses. Conclusion The introduction of bevacizumab for the treatment of AMD is recommended for the

  15. An international classification and grading system for age-related maculopathy and age-related macular degeneration. The International ARM Epidemiological Study Group.

    PubMed

    Bird, A C; Bressler, N M; Bressler, S B; Chisholm, I H; Coscas, G; Davis, M D; de Jong, P T; Klaver, C C; Klein, B E; Klein, R

    1995-01-01

    A common detection and classification system is needed for epidemiologic studies of age-related maculopathy (ARM). Such a grading scheme for ARM is described in this paper. ARM is defined as a degenerative disorder in persons > or = 50 years of age characterized on grading of color fundus transparencies by the presence of the following abnormalities in the macular area: soft drusen > or = 63 microns, hyperpigmentation and/or hypopigmentation of the retinal pigment epithelium (RPE), RPE and associated neurosensory detachment, (peri)retinal hemorrhages, geographic atrophy of the RPE, or (peri)retinal fibrous scarring in the absence of other retinal (vascular) disorders. Visual acuity is not used to define the presence of ARM. Early ARM is defined as the presence of drusen and RPE pigmentary abnormalities described above; late ARM is similar to age-related macular degeneration (AMD) and includes dry AMD (geographic atrophy of the RPE in the absence of neovascular AMD) or neovascular AMD (RPE detachment, hemorrhages, and/or scars as described above). Methods to take and grade fundus transparencies are described.

  16. Investigation of retinal microstructure in healthy eyes and dry age-related macular degeneration using a combined AO-OCT-SLO system

    NASA Astrophysics Data System (ADS)

    Wells-Gray, Elaine M.; Choi, Stacey S.; Ohr, Matthew; Cebulla, Colleen M.; Doble, Nathan

    2017-02-01

    Combined adaptive optics (AO) optical coherence tomography (OCT) scanning laser ophthalmoscopy (SLO) imaging allows simultaneous en face and cross sectional views of the retina. We describe improvements to our AO-OCT-SLO system and highlight its resolution capability and clinical utility by presenting results from 3 control and 4 dry agerelated macular degeneration (AMD) subjects. From a group of subjects with healthy eyes, OCT A-scans were grouped as originating from cones or rods and were averaged. The resulting reflectance profiles were then used to identify the location of cone and rod segments. Results for rods and cones were compared, with the focus on inner segment (IS) and outer segment (OS) structures and where these cells embed into the retinal pigment epithelium (RPE). In the AMD patients, cone IS and OS lengths were measured over and around drusen for two retinal regions (fovea-2° and 2°-4°), and those results were correlated to drusen height. For the fovea-2° region, the drusen height that caused statistically significant shortening of cone ISL and OSL compared to the unaffected adjacent area were 40 μm and 50 μm respectively (p = 0.009, and p < 0.001, respectively). For the 2°-4° region, the equivalent drusen heights that caused significant shortening of segment length were 60 μm for IS (p = 0.017) and 80 μm for OS (p < 0.001)

  17. Retinal degeneration associated with ectopia lentis.

    PubMed

    Simonelli, F; De Crecchio, G; Testa, F; Nunziata, G; Mazzeo, S; Romano, N; Cavaliere, L; Rinaldi, M M; Rinaldi, E

    1999-06-01

    Two brothers had retinal degeneration, lens subluxation, and myopia since early life. There was no evidence of Marfan syndrome, homocystinuria, or other systemic disease. They had nystagmus, myopia, inferior dislocation of the lens, and posterior subcapsular opacities in both eyes. Fundus examination showed attenuated retinal vessels, macular atrophy with occasional pigment accumulation as clumps, and perivascular sleeves. Electroretinography revealed decreased photopic and scotopic responses. The visual fields were constricted. We believe this to be the first report of retinal degeneration with bilateral lens subluxation in a family. It appears to be inherited in an autosomal recessive fashion.

  18. CT of sarcomatous degeneration in neurofibromatosis

    SciTech Connect

    Coleman, B.G.; Arger, P.H.; Dalinka, M.K.; Obringer, A.C.; Raney, B.R.; Meadows, A.T.

    1983-02-01

    Neurofibromatosis is a relatively common disorder that often involves many organ systems. One of the least understood aspects of this malady is a well documented potential for sarcomatous degeneration of neurofibromas. The inability to identify patients at risk and the lack of noninvasive screening methods for symptomatic patients often leads to late diagnosis. In six of seven subsequently proven neurofibrosarcomas, CT demonstrated low-density areas that histopathologically appeared to be due to necrosis, hemorrhage, and/or cystic degeneration. The density differences within these sarcomas were enhanced by the intravenous adminstration of iodinated contrast agents.

  19. Systemic Transplantation of Bone Marrow Mononuclear Cells Promotes Axonal Regeneration and Analgesia in a Model of Wallerian Degeneration.

    PubMed

    Usach, Vanina; Malet, Mariana; López, Margarita; Lavalle, Lucía; Piñero, Gonzalo; Saccoliti, María; Cueto, Alicia; Brumovsky, Pablo; Brusco, Alicia; Setton-Avruj, Patricia

    2017-07-01

    Reinnervation timing after nerve injury is critical for favorable axonal regeneration, remyelination, and clinical improvement. Considering bone marrow mononuclear cells (BMMC) are easily obtained and readily available for transplant, this work analyzed the effect of BMMC systemic administration on nerve repair and pain behavior. Adult rats with sciatic nerve crush were immediately and systemically injected BMMC through the caudal artery. Nontreated, sham and naïve rats were also included. Histological, immunohistochemical, biochemical, functional, and behavioral analyses were performed in nerves harvested from each group at different survival times. Axons in BMMC-treated rats exhibited a more conserved morphological appearance than those in nontreated rats, as observed at different survival times both in semithin sections and ultrastructural analysis. BMMC-treated rats also showed a reduction in major myelin protein immunoreactive clusters 7 and 14 days postinjury, as compared with nontreated rats. Electrophysiological analysis showed BMMC treatment to slightly improve the amplitude of compound muscle action potential starting at 14 days postinjury. Finally, mechanical withdrawal threshold revealed a full preventive action against transient mechanical hypersensitivity in BMMC-treated rats. These data demonstrate the efficiency of BMMC, systemically and noninvasively transplanted, in correcting morphological, functional and behavioral alterations resulting from peripheral nerve injury.

  20. Analysis of Zebrafish Larvae Skeletal Muscle Integrity with Evans Blue Dye

    PubMed Central

    Davidson, Ann E.; Dowling, James

    2015-01-01

    The zebrafish model is an emerging system for the study of neuromuscular disorders. In the study of neuromuscular diseases, the integrity of the muscle membrane is a critical disease determinant. To date, numerous neuromuscular conditions display degenerating muscle fibers with abnormal membrane integrity; this is most commonly observed in muscular dystrophies. Evans Blue Dye (EBD) is a vital, cell permeable dye that is rapidly taken into degenerating, damaged, or apoptotic cells; in contrast, it is not taken up by cells with an intact membrane. EBD injection is commonly employed to ascertain muscle integrity in mouse models of neuromuscular diseases. However, such EBD experiments require muscle dissection and/or sectioning prior to analysis. In contrast, EBD uptake in zebrafish is visualized in live, intact preparations. Here, we demonstrate a simple and straightforward methodology for performing EBD injections and analysis in live zebrafish. In addition, we demonstrate a co-injection strategy to increase efficacy of EBD analysis. Overall, this video article provides an outline to perform EBD injection and characterization in zebrafish models of neuromuscular disease. PMID:26649573

  1. Analysis of Zebrafish Larvae Skeletal Muscle Integrity with Evans Blue Dye.

    PubMed

    Smith, Sarah J; Horstick, Eric J; Davidson, Ann E; Dowling, James

    2015-11-30

    The zebrafish model is an emerging system for the study of neuromuscular disorders. In the study of neuromuscular diseases, the integrity of the muscle membrane is a critical disease determinant. To date, numerous neuromuscular conditions display degenerating muscle fibers with abnormal membrane integrity; this is most commonly observed in muscular dystrophies. Evans Blue Dye (EBD) is a vital, cell permeable dye that is rapidly taken into degenerating, damaged, or apoptotic cells; in contrast, it is not taken up by cells with an intact membrane. EBD injection is commonly employed to ascertain muscle integrity in mouse models of neuromuscular diseases. However, such EBD experiments require muscle dissection and/or sectioning prior to analysis. In contrast, EBD uptake in zebrafish is visualized in live, intact preparations. Here, we demonstrate a simple and straightforward methodology for performing EBD injections and analysis in live zebrafish. In addition, we demonstrate a co-injection strategy to increase efficacy of EBD analysis. Overall, this video article provides an outline to perform EBD injection and characterization in zebrafish models of neuromuscular disease.

  2. Single Degenerate Progenitors of Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Bours, Madelon; Toonen, Silvia; Nelemans, Gijs

    2013-01-01

    There is a general agreement that Type Ia supernovae correspond to the thermonuclear runaway of a white dwarf (WD) in a compact binary. The details of these progenitor systems are still unclear. Using the population synthesis code SeBa and several assumption for the WD retention efficiency, we estimate the delay times and supernova rates for the single degenerate scenario.

  3. Riluzole protects from motor deficits and striatal degeneration produced by systemic 3-nitropropionic acid intoxication in rats.

    PubMed

    Guyot, M C; Palfi, S; Stutzmann, J M; Mazière, M; Hantraye, P; Brouillet, E

    1997-11-01

    The putative neuroprotective effect of riluzole was investigated in a rat model of progressive striatal neurodegeneration induced by prolonged treatment (three weeks, intraperitoneal) with 3-nitropropionic acid, an irreversible inhibitor of succinate dehydrogenase. Quantitative analysis of motor behaviour indicated a significant protective effect (60%) of riluzole (8 mg/kg/day) on 3-nitropropionic acid-induced motor deficits as assessed using two independent motor tests. Furthermore, quantitative analysis of 3-nitropropionic acid-induced lesions indicated a significant 84% decrease in the volume of striatal damage produced by 3-nitropropionic acid, the neuroprotective effect apparently being more pronounced in the posterior striatum and pallidum. In addition, it was checked that this neuroprotective effect of riluzole against systemic 3-nitropropionic acid did not result from a decreased bioavailability of the neurotoxin or a direct action of riluzole on 3-nitropropionic acid-induced inhibition of succinate dehydrogenase. We found that riluzole significantly decreased by 48% the size of striatal lesions produced by stereotaxic intrastriatal injection of malonate, a reversible succinate dehydrogenase inhibitor. Furthermore, the inhibition of cortical and striatal succinate dehydrogenase activity induced by systemic 3-nitropropionic acid was left unchanged by riluzole administration. The present results, consistent with a beneficial effect of riluzole in amyotrophic lateral sclerosis, suggest that this compound may be useful in the treatment of chronic neurodegenerative diseases.

  4. Affinity partitioning of albumin and alpha-fetoprotein in an aqueous two-phase system using poly(ethylene glycol)-bound triazine dyes.

    PubMed

    Birkenmeier, G; Usbeck, E; Kopperschläger, G

    1984-01-01

    Human albumin and alpha-fetoprotein are partitioned in an aqueous two-phase system composed of 10% (w/w) Dextran and 7.5% (w/w) poly(ethylene glycol). When a small amount of poly(ethylene glycol) is replaced by Cibacron Blue F3G-A-liganded poly(ethylene glycol) the partition coefficient, K, of albumin increases by the factor of about 4000 whereas the K value of alpha-fetoprotein undergoes only a small change. The change of the partition coefficient in a logarithmic scale induced by increasing dye-polymer concentrations turned out as a useful measure for the affinity of albumin and alpha-fetoprotein to the dyes. The effect of pH and salt concentration on the affinity partition of albumin and alpha-fetoprotein is demonstrated. The partition of the two proteins in presence of Cibacron Blue F3G-A-liganded poly(ethylene glycol) is compared with seven other triazine dye-poly(ethylene glycol) derivatives.

  5. Genetic algorithm-artificial neural network and adaptive neuro-fuzzy inference system modeling of antibacterial activity of annatto dye on Salmonella enteritidis.

    PubMed

    Yolmeh, Mahmoud; Habibi Najafi, Mohammad B; Salehi, Fakhreddin

    2014-01-01

    Annatto is commonly used as a coloring agent in the food industry and has antimicrobial and antioxidant properties. In this study, genetic algorithm-artificial neural network (GA-ANN) and adaptive neuro-fuzzy inference system (ANFIS) models were used to predict the effect of annatto dye on Salmonella enteritidis in mayonnaise. The GA-ANN and ANFIS were fed with 3 inputs of annatto dye concentration (0, 0.1, 0.2 and 0.4%), storage temperature (4 and 25°C) and storage time (1-20 days) for prediction of S. enteritidis population. Both models were trained with experimental data. The results showed that the annatto dye was able to reduce of S. enteritidis and its effect was stronger at 25°C than 4°C. The developed GA-ANN, which included 8 hidden neurons, could predict S. enteritidis population with correlation coefficient of 0.999. The overall agreement between ANFIS predictions and experimental data was also very good (r=0.998). Sensitivity analysis results showed that storage temperature was the most sensitive factor for prediction of S. enteritidis population.

  6. Systemic T cell large granular lymphocyte lymphoma with multifocal white matter degeneration in the brain of a Japanese domestic cat.

    PubMed

    Tsuboi, Masaya; Uchida, Kazuyuki; Park, Eun Sil; Kotera, Yukiko; Seki, Takahiro; Takahashi, Masashi; Nakayama, Hiroyuki

    2010-06-01

    A 10-year-old spayed female Japanese domestic cat exhibited clinical symptoms suggesting pancreatitis. One month later the cat exhibited Horner's syndrome and was euthanized. At necropsy, multiple neoplastic masses were found in the intestines, spleen, kidneys, urinary bladder, and lungs. On cytology, many neoplastic lymphocytic cells had fine to large cytoplasmic granules, suggesting large granular lymphocyte (LGL) lymphoma. Histopathological examinations revealed infiltrative proliferation of the neoplastic cells in almost organs. Immunohistochemically, the neoplastic cells were intensely positive for CD3 and granzyme B. In the brain, there were multifocal white matter lesions characterized by diffuse myelin loss with mild infiltration of the neoplastic cells. Based on these findings, the cat was diagnosed as LGL lymphoma presumptively of intestinal origin with systemic involvement.

  7. Accurate simulation of optical properties in dyes.

    PubMed

    Jacquemin, Denis; Perpète, Eric A; Ciofini, Ilaria; Adamo, Carlo

    2009-02-17

    Since Antiquity, humans have produced and commercialized dyes. To this day, extraction of natural dyes often requires lengthy and costly procedures. In the 19th century, global markets and new industrial products drove a significant effort to synthesize artificial dyes, characterized by low production costs, huge quantities, and new optical properties (colors). Dyes that encompass classes of molecules absorbing in the UV-visible part of the electromagnetic spectrum now have a wider range of applications, including coloring (textiles, food, paintings), energy production (photovoltaic cells, OLEDs), or pharmaceuticals (diagnostics, drugs). Parallel to the growth in dye applications, researchers have increased their efforts to design and synthesize new dyes to customize absorption and emission properties. In particular, dyes containing one or more metallic centers allow for the construction of fairly sophisticated systems capable of selectively reacting to light of a given wavelength and behaving as molecular devices (photochemical molecular devices, PMDs).Theoretical tools able to predict and interpret the excited-state properties of organic and inorganic dyes allow for an efficient screening of photochemical centers. In this Account, we report recent developments defining a quantitative ab initio protocol (based on time-dependent density functional theory) for modeling dye spectral properties. In particular, we discuss the importance of several parameters, such as the methods used for electronic structure calculations, solvent effects, and statistical treatments. In addition, we illustrate the performance of such simulation tools through case studies. We also comment on current weak points of these methods and ways to improve them.

  8. Thermal damage assessment of blood vessels in a hamster skin flap model by fluorescence measurement of a liposome-dye system

    NASA Astrophysics Data System (ADS)

    Mordon, Serge R.; Desmettre, Thomas; Devoisselle, Jean-Marie; Soulie-Begu, Sylvie

    1997-06-01

    The present study was undertaken to evaluate the feasibility of thermal damage assessment of blood vessels by using laser-induced release of liposome-encapsulated dye. Experiments were performed in a hamster skin flap model. Laser irradiation was achieved with a 300micrometers fiber connected to a 805nm diode laser after potentiation using a specific indocyanine green (ICG) formulation. Liposomes- encapsulated carboxyfluorescein were prepared by the sonication procedure. Carboxyfluorescein was loaded at high concentration in order to quench its fluorescence. The measurements were performed after i.v. injection of DSPC liposomes and lasted 40 minutes. Fluorescence emission was measured with an ultra high sensitivity intensified camera. Three different shapes of fluorescent spots were identified depending on target and energy deposition in tissue: (i) intravascular fluorescence, (ii) transient low fluorescence circular spot and (iii) persistent high intense fluorescence spot. These images are correlated with histological data. The advantages of this liposome-dye system are (1) direct measurements can be obtained, (2) several repeated readings can be made from one injection, (3) continuous monitoring of the fluorescence can be made, (4) temperature-sensitive range can be adapted using different liposomes compositions, (5) circulation times of several hours can be achieved using DSPC liposomes (6) the tissue microcirculation and the vessel macrocirculation can be investigated simultaneously, therefore changes in response to a treatment regimen and/or ICG formulations can be detected. One main constraint exists: the fluorescent dye encapsulated into the liposomes has to be carefully chosen in order to avoid any direct absorption by the dye itself. In conclusion, one of the most significant applications of this experimental technique is the evaluation of various degrees of tissue thermal damage. It could be possible to consider the application of this technique in

  9. Two Ultracool Degenerate Companions

    NASA Astrophysics Data System (ADS)

    Farihi, J.

    2005-07-01

    In the course of an extensive survey for low mass stellar and substellar companions to nearby white dwarfs, two extrememly cool degenerate objects have been discovered. GD 392B is one of only a few known white dwarfs with Teff⪉4000 K and exhibits collision induced absorption in the near infrared tep{far04}. GD 1400B is the second known L dwarf companion to a white dwarf and a possible brown dwarf (Farihi & Christopher 2004). Interested readers should consult the references for a complete description of these two cool objects.

  10. Multi-terrawatt, 100 fsec laser system using flashlamp-pumped, dye- converted Ti:Sapphire as an amplifier

    SciTech Connect

    White, W.E.; Reitize, D.H.; Price, D.F.; Shepherd, R.L.; Bonlie, J.D.; Hunter, J.R.; Patterson, F.G.; Perressini, D.L.

    1993-04-14

    We report on amplification of 100 fsec laser pulses to 250 mJ using flashlamp-pumped, dye converted Ti:Sapphire. The resulting 5 Hz beam is focused to irradiances in excess of 5 {times} 10{sup 18} W/cm{sup 2}.

  11. The Minnesota Grading System Using Fundus Autofluorescence of Eye Bank Eyes: A Correlation To Age-Related Macular Degeneration (An AOS Thesis)

    PubMed Central

    Olsen, Timothy W.

    2008-01-01

    Purpose To establish a grading system of eye bank eyes using fundus autofluorescence (FAF) and identify a methodology that correlates FAF to age-related macular degeneration (AMD) with clinical correlation to the Age-Related Eye Disease Study (AREDS). Methods Two hundred sixty-two eye bank eyes were evaluated using a standardized analysis of FAF. Measurements were taken with the confocal scanning laser ophthalmoscope (cSLO). First, high-resolution, digital, stereoscopic, color images were obtained and graded according to AREDS criteria. With the neurosensory retina removed, mean FAF values were obtained from cSLO images using software analysis that excludes areas of atrophy and other artifact, generating an FAF value from a grading template. Age and AMD grade were compared to FAF values. An internal fluorescence reference standard was tested. Results Standardization of the cSLO machine demonstrated that reliable data could be acquired after a 1-hour warm-up. Images obtained prior to 1 hour had falsely elevated levels of FAF. In this initial analysis, there was no statistical correlation of age to mean FAF. There was a statistically significant decrease in FAF from AREDS grade 1, 2 to 3, 4 (P < .0001). An internal fluorescent standard may serve as a quantitative reference. Conclusions The Minnesota Grading System (MGS) of FAF (MGS-FAF) establishes a standardized methodology for grading eye bank tissue to quantify FAF compounds in the retinal pigment epithelium and correlate these findings to the AREDS. Future studies could then correlate specific FAF to the aging process, histopathology AMD phenotypes, and other maculopathies, as well as to analyze the biochemistry of autofluorescent fluorophores. PMID:19277247

  12. Heterogeneous photo-catalysis system for the degradation of azo dye Reactive Black 5 (RB5).

    PubMed

    Huang, Yao-Hui; Wei, Hau-Cheng; Chen, Hung-Ta

    2012-01-01

    This study investigated a heterogeneous photo-catalysis system by introducing a novel brick supported iron oxide (denoted as B1) for the heterogeneous photoassisted degradation of Reactive Black 5 (RB5) at pH value from 3 to 7 in a three-phase (gas-liquid-solid) fluidized bed reactor (3P-FBR). Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and N(2) adsorption/desorption were used to characterize the B1 catalyst. The in situ formation of hydrogen peroxide and the depletion of oxalic acid by photochemical cycle of Fe(III)-oxalate complex under UVA light (λ = 365 nm) were studied. The effects of the solution pH and the concentration of oxalic acid on the degradation of RB5 are elucidated. About 90% decolourization was measured and 80% of the total organic carbon (TOC) was eliminated at pH 5.0 after 120 min for 20 mg/L RB5 in presence of 10 g/L B1 catalyst, 30 mg/L oxalic acid under 15 W UVA light. A mechanism for the photocatalytic degradation of RB5 over B1 catalyst is proposed.

  13. AGE-RELATED MACULAR DEGENERATION.

    PubMed

    Gheorghe, Andreea; Mahdi, Labib; Musat, Ovidiu

    2015-01-01

    The objective of our study was to review the current knowledge on Age- Related Macular Degeneration, including pathogenesis, ocular manifestations, diagnosis and ancillary testing. Relevant publications on Age-Related Macular Degeneration that were published until 2014. Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterized by the appearance of drusen in the macula, accompanied by choroidal neovascularization (CNV) or geographic atrophy.

  14. Benzidine Dyes Action Plan

    EPA Pesticide Factsheets

    This Action Plan addresses the use of benzidine-based dyes and benzidine congener-based dyes, both metalized and non-metalized, in products that would result in consumer exposure, such as for use to color textiles.

  15. Cloth dye poisoning

    MedlinePlus

    ... The outcome depends on the extent of this damage. Poisoning from dye containing an alkali may result in continuing injury to these tissues for weeks or months. If the person swallowed a nonpoisonous household dye, recovery is likely.

  16. Apoptosis in human retinal degenerations.

    PubMed

    Xu, G Z; Li, W W; Tso, M O

    1996-01-01

    This paper examined the role of apoptosis in human retinal degenerations including pathologic myopia, age-related macular degeneration, serous retinal detachment, retinal lattice, and paving stone degenerations. Thirty-seven enucleated human eyes with 1 of the above-mentioned retinal degenerations were studied by histopathology and by TdT-mediated biotin-dUTP nicked-end labelling (TUNEL) technique. Tunnel labelling characteristic DNA fragmentation of apoptosis was observed in photoreceptor cells in 2 of the 4 eyes with pathologic myopia and in 4 of 16 eyes with age-related macular degeneration, 2 of which were exudative and 2 of which were atrophic. However, only a few scattered photoreceptor cells were labelled in 4 of 8 eyes with serous retinal detachment secondary to malignant melanoma of the choroid. Moreover, none of the photoreceptors cells in the 4 eyes with retinal lattice degeneration and 6 eyes with retinal paving stone degeneration were labelled. Apoptosis is 1 of the important pathways of photoreceptor cell degeneration in pathologic myopia and age-related macular degeneration.

  17. Dye lasers. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Cavagnaro, D. M.

    1980-08-01

    This bibliography covers studies on dye laser theory, design, components, optical systems, and frequency range. Abstracts on lasing dyes, pumping, tuning, excitation, molecular structure, and modulation are included. Studies on dye laser use in spectroscopy are covered. This updated bibliography contains 217 citations, none of which are new entries to the previous edition.

  18. Regularized degenerate multi-solitons

    NASA Astrophysics Data System (ADS)

    Correa, Francisco; Fring, Andreas

    2016-09-01

    We report complex {P}{T} -symmetric multi-soliton solutions to the Korteweg de-Vries equation that asymptotically contain one-soliton solutions, with each of them possessing the same amount of finite real energy. We demonstrate how these solutions originate from degenerate energy solutions of the Schrödinger equation. Technically this is achieved by the application of Darboux-Crum transformations involving Jordan states with suitable regularizing shifts. Alternatively they may be constructed from a limiting process within the context Hirota's direct method or on a nonlinear superposition obtained from multiple Bäcklund transformations. The proposed procedure is completely generic and also applicable to other types of nonlinear integrable systems.

  19. Computational study of diketopyrrolopyrrole-based organic dyes for dye sensitized solar cell applications.

    PubMed

    Fan, Wenjie; Tan, Dazhi; Zhang, Qijian; Wang, Huaxing

    2015-04-01

    Four diketopyrrolopyrrole (DPP)-based organic dyes utilizing the donor-π-acceptor motif were investigated by density functional theory (DFT) and time-dependent DFT (TDDFT) approaches. The four dyes were composed of different donor groups, i.e. indoline, carbazole, triphenylamine, and coumarin. We investigated the effects of the DPP unit and different donors on the spectra and electrochemical properties of the dyes, respectively. In comparison with the model dye which adopts a phenylene unit as the π-spacer, the DPP dyes all display remarkably enhanced spectral responses in the visible region of the solar spectrum. The key to this increase was the incorporation of electron-deficient DPP moieties to the molecular core, which significantly lowers LUMO levels and therefore reduces the band gap. The dye/(TiO2)46 anatase nanoparticle systems were also simulated to show the electronic structures at the interface. We studied some key properties including absorption spectra, light-harvesting efficiency, molecular orbital distributions, and injection time of electrons from the excited state of dye to the conduction band of TiO2. The dye DPP-I with indoline moiety as the electron donor demonstrates desirable energetic, electronic, and spectroscopic parameters for dye sensitized solar cells (DSSCs) applications. Our theoretical study is expected to provide valuable insights into the molecular design of novel DPP-based organic dyes for the optimizations of DSSCs.

  20. Comparative study on ultrasonic assisted adsorption of dyes from single system onto Fe3O4 magnetite nanoparticles loaded on activated carbon: Experimental design methodology.

    PubMed

    Bagheri, Ahmad Reza; Ghaedi, Mehrorang; Asfaram, Arash; Bazrafshan, Ali Akbar; Jannesar, Ramin

    2017-01-01

    The present study the ultrasound assisted adsorption of dyes in single system onto Fe3O4 magnetite nanoparticles loaded on activated carbon (Fe3O4-MNPs-AC) was described following characterization and identification of this adsorbent by conventional techniques likes field emission scanning electron microscopy, transmission electron microscopy, particle-size distribution, X-ray diffraction and Fourier transform infrared spectroscopy. A central composite design in conjunction with a response surface methodology according to f-test and t-test for recognition and judgment about significant term led to construction of quadratic model which represent relation among responses and effective terms. This model has unique ability to predict adsorption data behavior over a large space around central and optimum point. Accordingly Optimum conditions for well and quantitative removal of present dyes was obtained best operation and conditions: initial SY, MB and EB dyes concentration of 15, 15 and 25mgL(-1), 4.0, 6.0 and 5.0 of pH, 360, 360 and 240s sonication time and 0.04, 0.03 and 0.032g of Fe3O4-MNPs-AC. Replication of similar experiment (N=5) guide that average removal percentage of SY, MB and EB were found to be 96.63±2.86%, 98.12±1.67% and 99.65±1.21% respectively. Good agreement and closeness of Predicted and experimental result and high adsorption capacity of dyes in short time strongly confirm high suitability of present method for waste water treatment, while easy separation of present nanoparticle and its good regeneration all support good applicability of Fe3O4-MNPs-AC for waste water treatment. The kinetic study can be represented by combination of pseudo second-order and intraparticle diffusion. The obtained maximum adsorption capacities correspond to Langmuir as best model for representation of experimental data correspond to dyes adsorption onto Fe3O4-MNPs-AC were 76.37, 78.76 and 102.00mgg(-1) for SY, MB and EB, respectively. In addition, the performance

  1. Degenerate Systems of Conservation Laws.

    DTIC Science & Technology

    1985-09-01

    uI, ..., un ) u(x,t) , f " (fl’ "**’ fn) and x c R, t ) 0. Such equations arise in applications of gas dynamics, elasticity, oil reservoir ... simulation and other areas of engineering when diffusion is neglected. In solutions of (1), information travels at speeds Xi given by the eigenvalues of...laws which is not strictly hyperbolic", MRC Technical Summary Report #2184, December 29, 1980. [13] Peaceman, D. W., Fundamentals of Numerical Reservoir

  2. ELECTRON MICROSCOPIC AND HISTOCHEMICAL OBSERVATIONS OF MUSCLE DEGENERATION AFTER TOURNIQUET

    PubMed Central

    Moore, Dan H.; Ruska, Helmut; Copenhaver, Wilfred M.

    1956-01-01

    As an experimental model for the different forms of muscle degeneration, injury caused by 2 hours' ischemia has been studied from 20 minutes to 16 hours after release of the tourniquet. Discoid degeneration developed in stretched fibers by dissolution of the I bands (Z substances and actin). The discs represented the Q bands (A-H-A). In fibers which passively maintained contraction lengths during degeneration, the Z substances were dissolved, but the continuity of the fibrils was preserved, since the filaments are continuous over all sarcomeres under these conditions. Mitochondria and the tubules of the endoplasmic reticulum swelled, ruptured, and disintegrated. Granular degeneration developed in fibers where mitochondria were abundant. Unstretched degenerating fibers with few mitochondria gave a homogeneous or hyaline appearance. The different forms of degeneration therefore were dependent on the status of stretch and the fiber type. The extent of degeneration was not a function of time after ischemia, there being both nearly normal and severely damaged fibers at 20 minutes and 16 hours after the release of tourniquets. When degeneration occurred, however, the basic alterations were the same in all fibers; there was mitochondrial and reticular swelling, dissolution of the Z substances, and finally disintegration of the contractile material. Some damage developed in the sarcolemmas and capillaries. The mitochondrial disintegration was not linked with inactivation of the succinic dehydrogenase system. PMID:13398442

  3. Low-threshold Optical limiting and Nonlinear refraction in Nanocomposite films of Light Green dye-polymer system

    NASA Astrophysics Data System (ADS)

    Sreeja, S.; Louie Frobel, P. G.; Mayadevi, S.; Suresh, S. R.; Muneera, C. I.

    2015-02-01

    Poly(vinyl alcohol) (PVA) /Light Green (LG) dye nanocomposites were fabricated and their structure, microstructure, linear and nonlinear optical properties were investigated. The samples were characterized as nanocomposites with dye molecules encapsulated between the larger molecules (molecular chains) of the polymer host PVA. The nonlinear refraction behaviour was investigated employing the Z-scan technique, using a continuous wave (cw) He- Ne laser operating at 632.8 nm, as the excitation source. The samples displayed negative nonlinear refraction (self-defocusing) under the experimental conditions. Low-threshold optical limiting behaviour exhibited by the PVA based nanocomposites was demonstrated using an aperture limited geometry. The low limiting thresholds (~4 mW and ~2.4 mW) observed for the samples indicate that these low cost and durable nanocomposite films are potential media for optical limiting application under cw laser light excitation.

  4. A fluorescent codetection system for immunoblotting and proteomics through ECL-Plex and CyDye labeling.

    PubMed

    McManus, Ciara A; Donoghue, Pamela M; Dunn, Michael J

    2009-01-01

    The qualitative and quantitative capabilities of 2-D electrophoresis and its use in widespread proteome analysis has been revolutionized over the past decade with the introduction of differential gel electrophoresis commonly known as DIGE. This highly sensitive CyDye protein labeling technique now attempts to advance conventional western blotting by the combination of DIGE labeling with the recently developed ECL-Plex CyDye conjugated secondary antibodies. The ability of this method to simultaneously visualize the total protein expression profile as well as the specific immunodetection of an individual protein species will significantly aid protein validation following 2-D gel separation by confirming the exact location of proteins of interest. This simple, rapid, and reproducible technique is demonstrated by 1-D and 2-D electrophoresis through the detection of the small 27-kDa heat shock protein (hsp 27), a protein known to be expressed in the human heart, from a complex cardiac protein extract.

  5. Mitochondrial function and redox control in the aging eye: Role of MsrA and other repair systems in cataract and macular degenerations

    PubMed Central

    Brennan, Lisa A.; Kantorow, Marc

    2009-01-01

    Oxidative stress occurs when the level of prooxidants exceeds the level of antioxidants in cells resulting in oxidation of cellular components and consequent loss of cellular function. Oxidative stress is implicated in wide range of age related disorders including Alzheimer's disease, Parkinson's disease amyotrophic lateral sclerosis (ALS), Huntington's disease and the aging process itself (Lin and Beal, 2006). In the anterior segment of the eye, oxidative stress has been linked to lens cataract (Truscott, 2005) and glaucoma (Tezel, 2006) while in the posterior segment of the eye oxidative stress has been associated with macular degeneration (Hollyfield et al., 2008). Key to many oxidative stress conditions are alterations in the efficiency of mitochondrial respiration resulting in superoxide (O2-) production. Superoxide production precedes subsequent reactions that form potentially more dangerous reactive oxygen species (ROS) species such as the hydroxyl radical (˙OH), hydrogen peroxide (H2O2) and peroxynitrite (OONO-). The major source of ROS in the mitochondria, and in the cell overall, is leakage of electrons from complexes I and III of the electron transport chain. It is estimated that 0.2-2% of oxygen taken up by cells is converted to ROS, through mitochondrial superoxide generation, by the mitochondria (Hansford et al., 1997). Generation of superoxide at complex I and III has been shown to occur at both the matrix side of the inner mitochondrial membrane and the cytosolic side of the membrane (Kakkar and Singh 2007). While exogenous sources of ROS such as UV light, visible light, ionizing radiation, chemotherapeutics, and environmental toxins may contribute to the oxidative milieu, mitochondria are perhaps the most significant contribution to ROS production affecting the aging process. In addition to producing ROS, mitochondria are also a target for ROS which in turn reduces mitochondrial efficiency and leads to the generation of more ROS in a vicious self

  6. Charge-recombination fluorescence from push-pull electronic systems constructed around amino-substituted styryl-BODIPY dyes.

    PubMed

    Nano, Adela; Ziessel, Raymond; Stachelek, Patrycya; Harriman, Anthony

    2013-09-27

    A small series of donor-acceptor molecular dyads has been synthesized and fully characterized. In each case, the acceptor is a dicyanovinyl unit and the donor is a boron dipyrromethene (BODIPY) dye equipped with a single styryl arm bearing a terminal amino group. In the absence of the acceptor, the BODIPY-based dyes are strongly fluorescent in the far-red region and the relaxed excited-singlet states possess significant charge-transfer character. As such, the emission maxima depend on both the solvent polarity and temperature. With the corresponding push-pull molecules, there is a low-energy charge-transfer state that can be observed by both absorption and emission spectroscopy. Here, charge-recombination fluorescence is weak and decays over a few hundred picoseconds or so to recover the ground state. Overall, these results permit evaluation of the factors affecting the probability of charge-recombination fluorescence in push-pull dyes. The photophysical studies are supported by cyclic voltammetry and DFT calculations. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Determination of effective optical gap in dye/TiO{sub 2} systems inspired by p-n junctions

    SciTech Connect

    Hwang, Kyung-Jun; Jeong, Yonkil E-mail: widipark@gist.ac.kr; Park, Dong-Won E-mail: widipark@gist.ac.kr

    2015-04-06

    The effective optical gap and device current limits of dye-sensitized solar cells (DSCs) were investigated. Optical gap determination was based on an approach that assumes the presence of a nanoscale p-n junction in the DSCs between the bulk TiO{sub 2} semiconductor and the dye-cluster with quantum size effect. On the basis of this approach, the effective optical gap of the dye-absorber was extracted from a relation between external quantum efficiency and photon energy. The short-circuit current density of the fabricated DSCs showed a current loss in the range from 3.7 to 5.1 mA cm{sup −2} compared to the device current limit. This current loss can be mainly attributed to the light reflection of the window layer and the native charge-transfer loss by device imperfections, including subsidiary charge-transfer loss by a nanoscale Schottky junction between TiO{sub 2} and the electrolyte.

  8. Accelerated decolorization of azo dye Congo red in a combined bioanode-biocathode bioelectrochemical system with modified electrodes deployment.

    PubMed

    Kong, Fanying; Wang, Aijie; Cheng, Haoyi; Liang, Bin

    2014-01-01

    In this study, BES with bioanode and biocathode was applied to decolorize an azo dye Congo red (CR). Results showed that the Congo red decolorization efficiency (CR-DE) within 23 h in a combined bioanode-biocathode single chamber BES was 98.3±1.3%, significantly higher than that of mixed solution in a dual chamber BES (67.2±3.5%) (P<0.005). Various electrodes deployments (horizontal, vertical and surrounding) in the combined bioanode-biocathode BES were further compared based on the decolorization performance and electrochemical characterization. Results indicated that CR-DE within 11h improved from 87.4±1.3% to 97.5±2.3%, meanwhile the internal resistance decreased from 236.6 to 42.2Ω as modifying the horizontal deployment to be a surrounding deployment. It proved that the combination of bioanode and biocathode with suitable electrodes deployment could accelerate the decolorization of azo dye Congo red, which would be great potential for the application of bioelectrochemical technology in azo dye wastewater treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Laser dye stability

    NASA Astrophysics Data System (ADS)

    Fletcher, N.

    1980-06-01

    Lasing characteristics and bleaching of four Eastman Kodak ir dyes have been examined in dimethyl sulfoxide. These ir dyes are shown to improve in performance in the absence of oxygen. Their photochemical stability was found to be comparable to the quinolone laser dyes when exposed to flashlamp excitation. Photodecomposition of the ir dyes under lasing conditions was found to vary between 1.6 and 6×10-10 moles of dye for each joule (electrical) of input energy; in comparison, the photodecomposition values for the better coumarin dyes was 0.2 to 1.0×10-10 moles/J at a concentration of 1.0×10-4 M in ethanol. It was also found that increasing the concentration of these tricarbocyanine dyes gives a marked improvement in the useful lifetime of these solutions as lasing media in the absence of oxygen.

  10. Ultrasonic dyeing of cellulose nanofibers.

    PubMed

    Khatri, Muzamil; Ahmed, Farooq; Jatoi, Abdul Wahab; Mahar, Rasool Bux; Khatri, Zeeshan; Kim, Ick Soo

    2016-07-01

    Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing.

  11. Ecological transition predictably associated with gene degeneration.

    PubMed

    Wessinger, Carolyn A; Rausher, Mark D

    2015-02-01

    Gene degeneration or loss can significantly contribute to phenotypic diversification, but may generate genetic constraints on future evolutionary trajectories, potentially restricting phenotypic reversal. Such constraints may manifest as directional evolutionary trends when parallel phenotypic shifts consistently involve gene degeneration or loss. Here, we demonstrate that widespread parallel evolution in Penstemon from blue to red flowers predictably involves the functional inactivation and degeneration of the enzyme flavonoid 3',5'-hydroxylase (F3'5'H), an anthocyanin pathway enzyme required for the production of blue floral pigments. Other types of genetic mutations do not consistently accompany this phenotypic shift. This pattern may be driven by the relatively large mutational target size of degenerative mutations to this locus and the apparent lack of associated pleiotropic effects. The consistent degeneration of F3'5'H may provide a mechanistic explanation for the observed asymmetry in the direction of flower color evolution in Penstemon: Blue to red transitions are common, but reverse transitions have not been observed. Although phenotypic shifts in this system are likely driven by natural selection, internal constraints may generate predictable genetic outcomes and may restrict future evolutionary trajectories.

  12. Retinal remodeling in inherited photoreceptor degenerations.

    PubMed

    Marc, Robert E; Jones, Bryan W

    2003-10-01

    Photoreceptor degenerations initiated in rods or the retinal pigmented epithelium usually evoke secondary cone death and sensory deafferentation of the surviving neural retina. In the mature central nervous system, deafferentation evokes atrophy and connective re-patterning. It has been assumed that the neural retina does not remodel, and that it is a passive survivor. Screening of advanced stages of human and rodent retinal degenerations with computational molecular phenotyping has exposed a prolonged period of aggressive negative remodeling in which neurons migrate along aberrant glial columns and seals, restructuring the adult neural retina (1). Many neurons die, but survivors rewire the remnant inner plexiform layer (IPL), forming thousands of novel ectopic microneuromas in the remnant inner nuclear layer (INL). Bipolar and amacrine cells engage in new circuits that are most likely corruptive. Remodeling in human and rodent retinas emerges regardless of the molecular defects that initially trigger retinal degenerations. Although remodeling may constrain therapeutic intervals for molecular, cellular, or bionic rescue, the exposure of intrinsic retinal remodeling by the removal of sensory control in retinal degenerations suggests that neuronal organization in the normal retina may be more plastic than previously believed.

  13. Genetics Home Reference: Stargardt macular degeneration

    MedlinePlus

    ... Genetics Home Health Conditions Stargardt macular degeneration Stargardt macular degeneration Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Stargardt macular degeneration is a genetic eye disorder that causes progressive ...

  14. Application of novel DNA-based dye tracers to determine the subglacial drainage system structure and morphology of Storglaciären, Sweden

    NASA Astrophysics Data System (ADS)

    Williamson, Andrew; Dahlke, Helen; Arnold, Neil

    2014-05-01

    Storglaciären, Sweden, is a 3.22km2 polythermal valley glacier. Its extensive datasets provide a unique prospect for assessing cryospheric response to climate change over recent years and into the future. Storglaciären has predominantly temperate thermal regime (~85% temperate ice) with a cold surface layer of mostly ~20m thickness, but ~60m thickness at the terminus and margins (Gusmeroli et al., 2012, Journal of Glaciology). Subglacial hydrology exerts important controls on a glacier. Modelling future ice-mass dynamics needs sound understanding of glaciers' subglacial drainage systems, especially the variety of potential structures and morphologies adopted over time and space. Proglacial-runoff changes may result from shifts in subglacial drainage systems over time; these changes have important implications for glacierised catchments' populations. Moreover, knowledge acquired from valley glaciers can be applied to ice sheets. In most studies, subglacial water pressure (Pw) is assumed to equal ice-overburden pressure, yet recent studies suggest a lower long-term value may be more appropriate (e.g. Willis et al., 2008, 2012, Hydrological Processes). Research to date using Shreve's (1972, Journal of Glaciology) hydraulic-potential theory and comparing modelled drainage systems with empirical observations ascertained that Storglaciären's steady-state subglacial Pw is likely adjusted to 70-80% of ice-overburden pressure (Williamson, unpublished undergraduate thesis). Further work using an alternative modelling approach is necessary to determine Storglaciären's spatiotemporal Pw variations. Dye tracing is widely employed to determine subglacial drainage systems' structure and morphology through analysing breakthrough curves and through delimiting the extent of proglacial streams' watersheds. 25 dye-tracing experiments using conventional synthetic tracers (Rhodamine WT and Uranine) were conducted from 12 injection sites during summer 2012. As with all present dye

  15. UK Age-Related Macular Degeneration Electronic Medical Record System (AMD EMR) Users Group Report IV: Incidence of Blindness and Sight Impairment in Ranibizumab-Treated Patients.

    PubMed

    Johnston, Robert L; Lee, Aaron Y; Buckle, Miranda; Antcliff, Richard; Bailey, Clare; McKibbin, Martin; Chakravarthy, Usha; Tufail, Adnan

    2016-11-01

    To study the incidence of blindness and sight impairment in treatment-naive patients receiving ranibizumab (Lucentis) for neovascular age-related macular degeneration (nAMD) in the United Kingdom (UK) National Health Service. Multicenter nAMD database study. A total of 11 135 patients who collectively received 92 976 treatment episodes to 12 951 eyes. Data were extracted from 14 UK centers using the same electronic medical record system (EMR). The EMR-mandated collection of a data set (defined before first data entry) including: age, Early Treatment Diabetic Retinopathy Study visual acuity letter score (VA) for both eyes at all visits, and injection episodes. Participating centers used overwhelmingly a pro re nata re-treatment posology at intended monthly follow-up visits following a loading phase of 3 monthly injections. Incidence of blindness and sight impairment (VA in the better-seeing eye <38 letters [≤20/200 Snellen, approximately], and <68 letters [≤20/50 Snellen, approximately] at 2 consecutive visits, or 1 visit if no further follow-up data) in each year after initiating treatment. Information from >300 000 clinic visits (2.8 million data points) collected over 5 years was collated from 14 centers. Mean age at first treatment was 79.7 years (standard deviation = 9.19 years), with a female preponderance (63%). The mean (median) VA at baseline in the better-seeing eye was 67.2 (72.0) letters, 20/40- (20/40+) approximate Snellen conversion. The cumulative incidence of new blindness and sight impairment in patients with treated nAMD in at least 1 eye at years 1 to 4 after first injection were 5.1%, 8.6%, 12% and 15.6% for new blindness and 29.6%, 41.0%, 48.7%, and 53.7% for new sight impairment, but with significant reductions in the rates between year cohorts initiating treatment (blindness [P = 4.72 × 10(-08)], sight impaired [P = 3.27 × 10(-06)]). To the best of our knowledge, this is the first multicenter real-world study on the

  16. Cr(VI) and azo dye removal using a hollow-fibre membrane system functionalized with a biogenic Pd-magnetite catalyst.

    PubMed

    Coker, V S; Garrity, A; Wennekes, W B; Roesink, H D W; Cutting, R S; Lloyd, J R

    2014-01-01

    This study investigates the application of a hybrid system combining hollow-fibre membrane technology with the reductive abilities of magnetic nanoparticles for the remediation of toxic Cr(VI) and the azo dye, Remazol Black B. Nano-scale biogenic magnetite (Fe3O4), formed by microbial reduction of the mineral ferrihydrite, has a high reductive capacity due to the presence of Fe(II) in the mineral structure. The magnetic nanoparticles (approximately 20 nm) can be arrayed with Pd0 nanoparticles (approximately 5 nm) making a catalytically active nanomaterial. Membrane units, with and without nanoparticles, were challenged with either Cr(VI) or azo dye and some were supplemented with sodium formate, as an electron donor for contaminant reduction promoted by the Pd. The combination of Pd-magnetite with formate resulted in the most effective remediation strategy for both contaminants and the lifetime of the membrane unit was also increased, with 55% (19 days) and 70% (23 days) removal of the azo dye and Cr(VI), respectively. Low flow rates of 0.1 ml/min resulted in improved efficiencies due to increased contact time with the membrane/nanoparticle unit, with 70-75% removal of each contaminant. Chemical analyses of the nanoparticles post-exposure to Cr(VI) in the membrane modules indicated Pd to be more oxidized when Cr removal was maximized, and that the Cr was partially reduced to Cr(III) at the surface of the magnetite. These results have demonstrated that hollow-fibre membrane units can be enhanced for the removal of soluble, redox sensitive contaminants by incorporation of a layer of palladized biogenic nanoparticulate magnetite.

  17. Potentiometric Dye Imaging for Pheochromocytoma and Cortical Neurons with a Novel Measurement System Using an Integrated Complementary Metal-Oxide-Semiconductor Imaging Device

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takuma; Tagawa, Ayato; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Hatanaka, Yumiko; Tamura, Hideki; Ishikawa, Yasuyuki; Shiosaka, Sadao; Ohta, Jun

    2010-11-01

    The combination of optical imaging with voltage-sensitive dyes is a powerful tool for studying the spatiotemporal patterns of neural activity and understanding the neural networks of the brain. To visualize the potential status of multiple neurons simultaneously using a compact instrument with high density and a wide range, we present a novel measurement system using an implantable biomedical photonic LSI device with a red absorptive light filter for voltage-sensitive dye imaging (BpLSI-red). The BpLSI-red was developed for sensing fluorescence by the on-chip LSI, which was designed by using complementary metal-oxide-semiconductor (CMOS) technology. A micro-electro-mechanical system (MEMS) microfabrication technique was used to postprocess the CMOS sensor chip; light-emitting diodes (LEDs) were integrated for illumination and to enable long-term cell culture. Using the device, we succeeded in visualizing the membrane potential of 2000-3000 cells and the process of depolarization of pheochromocytoma cells (PC12 cells) and mouse cerebral cortical neurons in a primary culture with cellular resolution. Therefore, our measurement application enables the detection of multiple neural activities simultaneously.

  18. Voltage-sensitive dye imaging during functional development of the embryonic nervous system: a brief review with special thanks to Professor Larry Cohen.

    PubMed

    Momose-Sato, Yoko; Sato, Katsushige

    2015-04-01

    Investigating the developmental organization of the embryonic nervous system is one of the major challenges in the field of neuroscience. Despite their significance, functional studies on the vertebrate embryonic central nervous system (CNS) have been hampered by the technical limitations associated with conventional electrophysiological methods. The advent of optical techniques using voltage-sensitive dyes, which were developed by Dr. Cohen and his colleagues, has enabled electrical activity in living cells to be monitored noninvasively and also facilitated the simultaneous recording of neural responses from multiple regions. Using optical recording techniques, it is now possible to follow the functional organization of the embryonic CNS and image the spatiotemporal dynamics involved in the formation of this neural network. We herein briefly reviewed optical studies on the embryonic CNS with a special emphasis on methodological considerations and the study of neuronal circuit formation, which demonstrates the utility of fast voltage-sensitive dye imaging as a powerful tool for elucidating the functional organization of the embryonic CNS.

  19. Acridine dyes and other DNA-intercalating agents induce the luminescence system of luminous bacteria and their dark variants.

    PubMed Central

    Ulitzur, S; Weiser, I

    1981-01-01

    Acridine dyes and other DNA-intercalating agents such as ethidium bromide, theophylline, and caffeine induce luminescence in dark variants (K variants) different luminous species of bacteria, as well as in their wild-type luminous cells, prior to induction. The increase in luminescence appears 10-20 min after addition of these agents and is inhibited by chloramphenicol or rifampicin. Addition of these agents affects the synthesis of both luciferase and aldehyde-synthesizing enzymes. It is hypothesized that these agents, through their intercalation into DNA, cause configurational changes resulting in derepressed transcription of the luminescence operon. PMID:6943543

  20. Imaging frontotemporal lobar degeneration.

    PubMed

    Diehl-Schmid, Janine; Onur, Oezguer A; Kuhn, Jens; Gruppe, Traugott; Drzezga, Alexander

    2014-10-01

    The term frontotemporal lobar degeneration (FTLD) refers to a group of neurodegenerative disorders that target the frontal and temporal lobes. It accounts for approximately 10 % of pathologically confirmed dementias but has been demonstrated to be as prevalent as Alzheimer's disease in patients below the age of 65. The 3 major clinical syndromes associated with FTLD include behavioral variant frontotemporal dementia, semantic and nonfluent variants of primary progressive aphasia. The more recently introduced term logopenic variant appears to represent an atypical form of Alzheimer's disease in the majority of cases. The neuropathology underlying these clinical syndromes is very heterogeneous and does not correlate well with the clinical phenotype. This causes great difficulties in early and reliable diagnosis and treatment of FTLD. However, significant advances have been made in recent years via the application of magnetic resonance imaging and positron emission tomography imaging methods as biomarkers. The current review aims to provide a synopsis on the value of magnetic resonance imaging-based and molecular imaging procedures in FTLD.

  1. [Age related macular degeneration].

    PubMed

    Sayen, Alexandra; Hubert, Isabelle; Berrod, Jean-Paul

    2011-02-01

    Age-related macular degeneration (ARMD) is a multifactorial disease caused by a combination of genetic and environmental factors. It is the first cause of blindness in patients over 50 in the western world. The disease has been traditionally classified into early and late stages with dry (atrophic) and wet (neovascular) forms: neovascular form is characterized by new blood vessels development under the macula (choroidal neovascularisation) which lead to a rapid decline of vision associated with metamorphopsia and requiring an urgent ophtalmological examination. Optical coherence tomography is now one of the most important part of the examination for diagnosis and treatment. Patient with age related maculopathy should consider taking a dietary supplement such that used in AREDS. The treatment of the wet ARMD has largely beneficied since year 2006 of anti-VEGF (vascular endothelial growth factor) molecules such as ranibizumab or bevacizumab given as repeated intravitreal injections. A systematic follow up each 4 to 8 week in required for several years. There is no effective treatment at the moment for dry AMD. For patients with binocular visual acuity under 60/200 rehabilitation includes low vision specialist, vision aids and psychological support.

  2. Age-Related Macular Degeneration

    MedlinePlus

    ... version of this page please turn Javascript on. Age-related Macular Degeneration About AMD Click for more ... a leading cause of vision loss among people age 60 and older. It causes damage to the ...

  3. Synthesis of Laser Dyes

    DTIC Science & Technology

    1988-11-09

    block number) This report describes the progress made in attempts to prepare seven laser dyes. These dyes all have a 2-(L-pyridy.)-1,3- oxazole ...structure one dye, The synthesis of one dye, 2-(Ni-met.hyl-4-pyridiniiumi)pherianthroL9,10-dJ-1,3- oxazole tosylate (I) has been com-pleted. Preliminary...1,3- oxazoles . I~ 20 [IISTRI:’UTIGTJi/AVAILABILITY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION 0UNITILA-,SIFIEDI.JNLiITED 0 SAME AS RPT El DTIC

  4. Formation of a leuco spirolactone from 4-(2-carboxyphenyl)-7-diethylamino-4'-dimethylamino-1-benzopyrylium: design of a phase-change thermochromic system based on a flavylium dye.

    PubMed

    Gavara, Raquel; Laia, César A T; Parola, A Jorge; Pina, Fernando

    2010-07-12

    A phase-change thermochromic system was designed through the reversible transformation of the 4-substituted flavylium dye 4-(2-carboxyphenyl)-7-diethylamino-4'-dimethylamino-1-benzopyrylium into its leuco form, in the presence of a developer (ethyldiisopropylamine) and a suitable solvent (e.g., acetonitrile, n-pentadecanonitrile). The leuco form of the flavylium-based dye is a spirolactone species whose ring opens at low temperature (below the solvent melting point) to form the blue flavylium cation. Decarboxylation of the lactone to give 4-phenyl-7-diethylamino-4'-dimethylamino-1-benzopyrylium was observed upon irradiation of the system with UV light, erasing the thermochromic effect.

  5. Contributions of the electrostatic and the dispersion interaction to the solvent shift in a dye-polymer system, as investigated by hole-burning spectroscopy

    NASA Astrophysics Data System (ADS)

    Kador, L.; Jahn, S.; Haarer, D.; Silbey, R.

    1990-06-01

    Persistent spectral holes burned in the system octaethylporphin in poly(styrene) exhibit a symmetrical broadening varying in a linear fashion upon application of a static electric field. This effect is due to permanent electric-dipole moments induced in the dye molecules by the electric ``matrix field.'' The average value of the dipole-moment difference μ between the excited and the ground state of the guest molecules, which can be deduced from the broadening, shows a distinct increase from the blue to the red edge of the inhomogeneous absorption band, thus reflecting the varying dye-matrix interaction for centers with different solvent shift. A detailed analysis of this variation in the framework of a microscopic theory, based on a recent publication by Laird and Skinner [J. Chem. Phys. 90, 3274 (1989)], leads to the conclusion that the solvent shift of the absorption lines and also the μ variation across the inhomogeneous band is largely dominated by the dispersion interaction. The electrostatic contribution to the line shift is smaller by about 2 orders of magnitude.

  6. Stepped light-induced transient measurements of photocurrent and voltage in dye-sensitized solar cells: application for highly viscous electrolyte systems.

    PubMed

    Nakade, Shogo; Kanzaki, Taisuke; Wada, Yuji; Yanagida, Shozo

    2005-11-08

    To measure electron diffusion coefficients (D) and electron lifetimes (tau) of dye-sensitized solar cells (DSC), we introduced stepped light-induced transient measurements of photocurrent and voltage (SLIM-PCV), which can simplify the optical setup and reduce measurement time in comparison to conventional time-of-flight and frequency-modulated measurements. The method was applied to investigate the influence of the viscosity of a thermally stable high-boiling-point solvent on the energy conversion efficiency of DSCs. By systematic study of the influence of the viscosity, the species of cations as the counter charge of I(-)/I(3)(-), and the concentrations of electrolytes, we concluded that a lower dye cation reduction rate due to slower iodine diffusion is a limiting factor for a highly viscous electrolyte system. On the other hand, comparable values of D and increased values of tau were observed in a highly viscous electrolyte. By employing 0.5 M TBAI and 0.05 M I(2) in propylene carbonate, the efficiency of the DSC became comparable to that of a DSC using conventional electrolytes consisting of LiI, imidazolium iodide, and 4-tert-butylpyridine in methoxyacetonitrile. The simultaneous evaluation of D and tau through the appropriately simple measurement realizes fast optimization of the efficient and reliable DSC composed of thermally stable but often viscous electrolytes.

  7. Adsorption of basic dyes from single and binary component systems onto bentonite: simultaneous analysis of Basic Red 46 and Basic Yellow 28 by first order derivative spectrophotometric analysis method.

    PubMed

    Turabik, Meral

    2008-10-01

    The present study deals with the simultaneous analysis and adsorption of Basic Yellow 28 and Basic Red 46 dyes in binary mixture onto bentonite. First order derivative spectrophotometric method was used for simultaneous analysis of BY28 and BR46 in binary mixtures. The adsorption experiments were carried out in a batch system. The mono- and multi-component Langmuir and Freundlich isotherm models were applied to experimental data and the isotherm constants were calculated for BY28 and BR46 dyes. The monolayer coverage capacities of bentonite for BY28 and BR46 dyes in single solution system were found as 256.4 mg/g and 333.3mg/g, respectively. It was observed that the equilibrium uptake amounts of BY28 and BR46 dyes in binary mixture onto bentonite decreased considerably with increasing concentrations of the other dye resulting in their antagonistic effect. The adsorption equilibrium data fitted more adequately to mono-component Langmuir isotherm model than mono-component Freundlich isotherm model, while the extended Freundlich isotherm model adequately predicted the multi-component adsorption equilibrium data at moderate ranges of concentration. Thermodynamic parameters showed that adsorption of BR46 and BY28 was endothermic and spontaneous in nature.

  8. Magnetic diatomite(Kieselguhr)/Fe2O3/TiO2 composite as an efficient photo-Fenton system for dye degradation

    NASA Astrophysics Data System (ADS)

    Barbosa, Isaltino A.; Zanatta, Lucas D.; Espimpolo, Daniela M.; da Silva, Douglas L.; Nascimento, Leandro F.; Zanardi, Fabrício B.; de Sousa Filho, Paulo C.; Serra, Osvaldo A.; Iamamoto, Yassuko

    2017-10-01

    We explored the potential use of diatomite/Fe2O3/TiO2 composites as catalysts for heterogeneous photo-Fenton degradation of methylene blue under neutral pH. Such system consists in magnetic solids synthesized by co-precipitation with Fe2+/Fe3+ in the presence of diatomite, followed by impregnation of TiO2. The results showed that the optimal amount of the catalyst was 2.0 g L-1, since aggregation phenomena become significant above this concentration, which decreases the photodegradation activity. The catalyst is highly efficient in the degradation of methylene blue and shows an easy recovery by an external magnetic field. This allows for an effective catalyst reuse without significant loss of activity in catalytic cycles, which is a highly interesting prospect for recyclable dye degradation systems.

  9. Universal low-temperature MWCNT-COOH-based counter electrode and a new thiolate/disulfide electrolyte system for dye-sensitized solar cells.

    PubMed

    Hilmi, Abdulla; Shoker, Tharallah A; Ghaddar, Tarek H

    2014-06-11

    A new thiolate/disulfide organic-based electrolyte system composed of the tetrabutylammonium salt of 2-methyl-5-trifluoromethyl-2H-[1,2,4]triazole-3-thiol (S(-)) and its oxidized form 3,3'-dithiobis(2-methyl-5-trifluoromethyl-2H-[1,2,4]triazole) (DS) has been formulated and used in dye-sensitized solar cells (DSSCs). The electrocatalytic activity of different counter electrodes (CEs) has been evaluated by means of measuring J-V curves, cyclic voltammetry, Tafel plots, and electrochemical impedance spectroscopy. A stable and low-temperature CE based on acid-functionalized multiwalled carbon nanotubes (MWCNT-COOH) was investigated with our S(-)/DS, I(-)/I3(-), T(-)/T2, and Co(II/III)-based electrolyte systems. The proposed CE showed superb electrocatalytic activity toward the regeneration of the different electrolytes. In addition, good stability of solar cell devices based on the reported electrolyte and CE was shown.

  10. [A noninstrumental Immunoassay based on colloidal dyes].

    PubMed

    Liubavina, I A; Salomatina, I S; Zinchenko, A A; Zherdeev, A V; Dzantiev, B B

    2000-03-01

    Detecting labels based on water dispersions of colloidal textile dyes were developed that are useful in various analytical and diagnostic test systems for a simple visual assessment of the assay. Colored water-insoluble particles of dyes were used for the sorptional immobilization of streptavidin on their surface. The resulting streptavidin-dye (STR-DYE) complexes possessed a high visualizing capacity and were used for the combined detection of pesticides (simazine and 2,4-dichlorophenoxyacetic acid) by noninstrumental immunoassay (DYE-comb-assay, competitive dot-immunoassay in the comb format). The detection limits and the duration of our DYE-comb-assay (4 ng/ml, 20-25 min), HRP-comb-assay (competitive dot-immunoassay in the comb format using the enzymic conjugate of STR with horseradish peroxidase) (16 ng/ml), and the traditional competitive ELISA (12-16 ng/ml, 1.5 h) were compared. This DYE-comb-assay is simple enough and can be used under field conditions.

  11. Over-expression of alpha-synuclein in the nervous system enhances axonal degeneration after peripheral nerve lesion in a transgenic mouse strain.

    PubMed

    Siebert, Heike; Kahle, Philipp J; Kramer, Michael L; Isik, Thomas; Schlüter, Oliver M; Schulz-Schaeffer, Walter J; Brück, Wolfgang

    2010-08-01

    Wallerian degeneration in peripheral nerves occurs after a traumatic insult when the distal nerve part degenerates while peripheral macrophages enter the nerve stump and remove the accruing debris by phagozytosis. We used an experimental model to investigate the effect of either the absence or over-expression of alpha-synuclein (alpha-syn) after transecting the sciatic nerves of mice. alpha-Synuclein is a major component of Lewy bodies and its aggregation results in a premature destruction of nerve cells. It has also been found present in different peripheral nerves but its role in the axon remains still unclear. Following sciatic nerve transection in different mouse strains, we investigated the numbers of invading macrophages, the amounts of remaining myelin and axons 6 days after injury. All mice showed clear signs of Wallerian degeneration, but transgenic mice expressing human wild-type alpha-syn showed lower numbers of invading macrophages, less preserved myelin and significantly lower numbers of preserved axons in comparison with either knockout mice or a mouse strain with a spontaneous deletion of alpha-syn. The use of protein aggregation filtration blots and paraffin-embedded tissue blots displayed depositions of alpha-syn aggregates within sciatic nerve axons of transgenic mice. Thicker myelin sheaths and higher numbers of mitochondria were detected in old alpha-syn transgenic mice. In a human sural nerve, alpha-syn could also be identified within axons. Thus, alpha-syn and its aggregates are not only a component of Lewy bodies and synapses but also of axons and these aggregates might interfere with axonal transport. alpha-Synuclein transgenic mice represent an appropriate model for investigations on axonal transport in neurodegenerative diseases.

  12. Optical properties of natural dyes on the dye-sensitized solar cells (DSSC) performance

    NASA Astrophysics Data System (ADS)

    Pratiwi, D. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

    2016-11-01

    This study reported several natural dyes for application in dye-sensitized solar cells (DSSC). This study aims was to determine the effect of optical absorption properties of natural dyes on efficiency of DSSC. The sandwich structure of DSSC consist of TiO2 as working electrode, carbon layer as counter electrode, natural dyes as photosensitizer, and electrolyte as electron transfer media. The natural dyes used in this experiment were extracted from dragon fruit anthocyanin, mangosteen peels anthocyanin, and red cabbage anthocyanin. The absorbance of dyes solutions and the adsorption of the dye on the surface of TiO2 were characterized using UV-Vis spectrophotometer, the quantum efficiency versus wavelength was characterized using incident photon-to-current efficiency (IPCE) measurement system, and the efficiency of DSSC was calculated using I-V meter. UV-Vis characteristic curves showed that wavelength absorption of anthocyanin dye of red cabbage was 450 - 580 nm, anthocyanin of mangosteen peels was 400 - 480 nm, and anthocyanin of dragon fruit was 400 - 650 nm. Absorption spectra of the dye adsorption on the surface of TiO2 which was resulted in the highest absorbance of red cabbage anthocyanin. IPCE characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted quantum efficiency of 0.058%; 0.047%; and 0.043%, respectively at wavelength maximum about 430 nm. I-V characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted efficiency of 0.054%; 0.042%; and 0.024%, respectively.

  13. Power input effects on degeneration in prolonged penicillin chemostat cultures: A systems analysis at flux, residual glucose, metabolite, and transcript levels.

    PubMed

    Wang, Guan; Wu, Baofeng; Zhao, Junfei; Haringa, Cees; Xia, Jianye; Chu, Ju; Zhuang, Yingping; Zhang, Siliang; Heijnen, Joseph J; van Gulik, Walter; Deshmukh, Amit T; Noorman, Henk J

    2017-09-02

    In the present work, by performing chemostat experiments at 400 and 600 RPM, two typical power inputs representative of industrial penicillin fermentation (P/V, 1.00 kW/m(3) in more remote zones and 3.83 kW/m(3) in the vicinity of the impellers, respectively) were scaled-down to bench-scale bioreactors. It was found that at 400 RPM applied in prolonged glucose-limited chemostat cultures, the previously reported degeneration of penicillin production using an industrial Penicillium chrysogenum strain was virtually absent. To investigate this, the cellular response was studied at flux (stoichiometry), residual glucose, intracellular metabolite and transcript levels. At 600 RPM, 20% more cell lysis was observed and the increased degeneration of penicillin production was accompanied by a 22% larger ATP gap and an unexpected 20-fold decrease in the residual glucose concentration (Cs,out ). At the same time, the biomass specific glucose consumption rate (qs ) did not change but the intracellular glucose concentration was about sixfold higher, which indicates a change to a higher affinity glucose transporter at 600 RPM. In addition, power input differences cause differences in the diffusion rates of glucose and the calculated Batchelor diffusion length scale suggests the presence of a glucose diffusion layer at the glucose transporting parts of the hyphae, which was further substantiated by a simple proposed glucose diffusion-uptake model. By analysis of calculated mass action ratios (MARs) and energy consumption, it indicated that at 600 RPM glucose sensing and signal transduction in response to the low Cs,out appear to trigger a gluconeogenic type of metabolic flux rearrangement, a futile cycle through the pentose phosphate pathway (PPP) and a declining redox state of the cytosol. In support of the change in glucose transport and degeneration of penicillin production at 600 RPM, the transcript levels of the putative high-affinity glucose/hexose transporter genes Pc12

  14. Effect of mercerization and gamma irradiation on the dyeing behaviour of cotton using stilbene based direct dye

    NASA Astrophysics Data System (ADS)

    Bhatti, Ijaz Ahmad; Adeel, Shahid; Fazal-ur-Rehman; Irshad, Misbah; Abbas, Muhammad

    2012-07-01

    The dyeing behaviour of mercerized and gamma irradiated cotton fabric using stilbene based direct dye has been investigated. The fabric was treated with different concentrations of alkali to optimize the mercerization. The optimum mercerized cotton fabric was irradiated to absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. Dyeing was performed using irradiated and un-irradiated cotton with dye solutions. The dyeing parameters such as temperature, time of dyeing, pH of dyeing solutions and salt concentration were optimized. The colour strength values of dyed fabrics were evaluated by comparing irradiated and un-irradiated cotton in CIE Lab system using Spectra flash SF650. Methods suggested by International Standard Organization (ISO) were employed to study the effect of gamma irradiation on the colourfastness properties of dyed fabric. It was found that mercerized and irradiated cotton have not only improved the colour strength but enhanced the rating of fastness properties also.

  15. Dye-Doped Polymer Dispersed Liquid Crystal Films for Flexible Displays

    NASA Astrophysics Data System (ADS)

    Kee-Jeong Yang,; Seung-Chul Lee,; Byeong-Dae Choi,

    2010-05-01

    Red, green, and blue dyes were doped to polymer dispersed liquid crystal (PDLC) films for flexible display applications. Dichroic dye-doped liquid crystal droplets had a bipolar configuration. The E7-DG6071-dye composition showed better chromaticity data than other compositions. The small-particle-size red-dye-doped PDLC film showed good color differences. To improve the color difference, the dye particle size has to be small, and the bead milling process can make dye particles small. In this system, the bigger the liquid crystal droplet size, the higher the PDLC film driving voltage (Von), except in the LC-DG6071-red dye composition. This is the reason that the splay deformation increase is greater than the droplet size increase. In the electro-optic characteristics of dye-doped PDLC film, the TL205-DG6071-red dye composition had the lowest Von and the TL205-DG7052-red dye had the highest contrast ratio.

  16. Efficient degradation of methylene blue dye over tungsten trioxide/multi-walled carbon nanotube system as a novel photocatalyst

    NASA Astrophysics Data System (ADS)

    Dinari, Mohammad; Momeni, Mohamad Mohsen; Ahangarpour, Marzieh

    2016-10-01

    Combination of acid-functionalized multi-walled carbon nanotube/tungsten trioxide (MWCNT/WO3) with different MWCNT's weight percentages as visible light-induced photocatalysts for photodegradation of methylene blue (MB) dye was synthesized. These photocatalysts were characterized by Fourier transform infrared, X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy and transmission electron microscopy techniques. Their photocatalytic activities were tested by using MB as a model compound. The results show that the MWCNT/WO3 hybrid nanostructures exhibit higher photocatalytic activity than pure WO3 or MWCNTs due to their higher absorption enhancement in visible light region and effective separation of electrons and holes. The stability of the hybrid was characterized through cyclic photocatalytic test.

  17. Oxazine laser dyes

    DOEpatents

    Hammond, Peter R.; Field, George F.

    1992-01-01

    New oxazine compounds useful as dye laser media in solution, are superiior to prior art materials. The oxazine dyes useful when pumped by the 578.2 nm copper line to operate in the 700-800 nm range are described by formula I ##STR1##

  18. Microencapsulated Fluorescent Dye Penetrant.

    DTIC Science & Technology

    1979-07-01

    Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

  19. [Neurophysiology of corticobasal degeneration].

    PubMed

    Tyvaert, L; Cassim, F; Derambure, P; Defebvre, L

    2007-09-01

    Corticobasal degeneration (CBD) is a neurodegenerative disorder of mid- to late-adult life. From a clinical standpoint, CBD is characterized by (i) an insidious onset and a slowly progressing, unilateral, levodopa-unresponsive parkinsonian syndrome with dystonia or myoclonus and (ii) cerebral features such as apraxia, alien limb phenomena and cortical sensory loss. Decisive clinical diagnostic criteria are not available and thus a neuropathological study remains essential for accurate CBD diagnosis. Consequently, additional non-clinical criteria must be identified in order to improve diagnosis while patients are still alive. Electrophysiological exploration can yield functional information on a number of brain structures (both cortical and sub-cortical) involved in CBD. The disorder features a specific cortical (frontoparietal) alteration which could help with differential diagnoses for other extrapyramidal syndromes. Hence, exploration of a patient's myoclonus can provide some specific arguments for CBD. Indeed, myoclonus displays a number of clinical and electromyographical characteristics which are consistent with a cortical origin (a shorter latency of the cortical C response, for example). However, some typical cortical features are missing (giant somesthesic evoked potentials, and cortical potentials preceding myoclonus in jerk-locked back-averaging studies). Some authors explain these abnormalities in terms of a sub-cortical origin for the myoclonus. The frontoparietal alteration in CBD has also been explored in studies of oculomotor movement. Indeed, asymmetric lengthening of the lateral ocular saccade latency argues more in favour of CBD than progressive supranuclear palsy. Moreover, cognitive function is also compromised in the early stages of CBD, although it is sometimes difficult to distinguish between CBD, PSP and frontotemporal dementia. Studying cognitive potentials enables one to confirm subcorticofrontal abnormalities and to dissociate CBD

  20. Monolithic dye laser amplifier

    DOEpatents

    Kuklo, Thomas C.

    1993-01-01

    A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

  1. Monolithic dye laser amplifier

    DOEpatents

    Kuklo, T.C.

    1993-03-30

    A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

  2. Rapid double-dye-layer coating for dye-sensitized solar cells using a new method.

    PubMed

    Jung, Cho-long; Han, Chi-Hwan; Moon, Doo Kyung; Jun, Yongseok

    2014-10-01

    Intensive research with the specific aim of developing inexpensive renewable energy sources is currently being undertaken. In dye-sensitized solar cell (DSSC) production, the most time-consuming process is coating the dye on working electrodes: absorption of ruthenium-based dyes [e.g., N719=bis(trtrabutylammonium)-cis-di(thiocyanato)-N,N'-bis(4-carboxylato-4'-carboxylic acid-2,2'-bipyridine) ruthenium(II)] on a photoanode takes a long time. We report a simple dye-coating method using a mixed solvent of ethylene glycol (EG) and glycerol (Gly). According to our experiments, dye-coating time can be reduced to 5 min from several hours. Maximum performance was obtained with an EG/Gly ratio of 1:1. This mixture of solvents gave a performance of 9.1%. Furthermore, the viscous solvent system could control coating depth; positioning dye coatings to a specific depth was rapid and facile. A cell containing two different dyes (N719+black dye) had an efficiency of 9.4%.

  3. Study of the release of a microencapsulated acid dye in polyamide dyeing using mixed cationic liposomes.

    PubMed

    de Sousa, Isabel S C; Castanheira, Elisabete M S; Rocha Gomes, Jaime I N; Real Oliveira, M Elisabete C D

    2011-06-01

    The main objective of this work was to increase the retarding effect of the acid dye Telon(®) Blue RR (C.I. Acid Blue 62; DyStar, Frankfurt, Germany) release on polyamide fibres dyeing by encapsulation of the dye in liposomes as an alternative to synthetic auxiliaries, in order to reduce effluent pollution. The retarding effect achieved with the use of mixed cationic liposomes of dioctadecyldimethylammonium bromide (DODAB)/soybean lecithin (containing a 10% molar fraction of DODAB) was better in comparison with either pure soybean lecithin liposomes or synthetic auxiliaries. The retarding effect of liposomes on the dye release was analysed through changes in the absorption and fluorescence spectra of the acid dye at different conditions. The effect of temperature (in the range of 25 °C - 70 °C) on the spectroscopic behaviour of the dye in the absence and in presence of polyamide was also studied, in order to simulate the dyeing conditions. Exhaustion curves obtained in dyeing experiments showed that, below 45 °C, the retarding effect of the mixed liposomes (lecithin/DODAB (9:1)) was similar to that of the auxiliaries, but better than the one of pure lecithin liposomes. At higher temperatures (above 45 °C), the system lecithin/DODAB presents a better performance, achieving a higher final exhaustion level when compared with the commercial leveling agent without losing the smoothing effect of lecithin.

  4. [The system of control over the use of dyes in the manufacture of food products in Russia. The order of selecting objects of research].

    PubMed

    Bessonov, V V

    2010-01-01

    This review is carried out information in order to assess food dyes, used in the manufacture of food products in Russia. Based on electronic registries, an analysis of the major sources of dyes in food. The author carried out a frequency analysis of various types of dyes. Based on the research, concluded that the relevance of studying the content of carotenoids in the consumer basket of Russia population, as well as create recommendations for the principles of food fortification in the substance. The author identified the most relevant factors control the safe use of food dyes in the study of food.

  5. Photoablating neuronal groups using an intracellularly aggregating dye.

    PubMed

    Garber, S; Camhi, J M

    1991-04-01

    We report here on a new method to kill several selected neurons, using a modified fluorescence photoablation technique that does not require impaling any cells. Rather, we injected extracellularly the dye rhodamine 6-G, which is taken up by the cells. We made our injections into one side of a cockroach ganglion, after which the nearby cell bodies of individually known giant interneurons (GIs), as well as other cell bodies and many axons, became highly fluorescent. After this dye accumulation, we irradiated either the entire ganglionic region of the accumulated dye, or specifically the cell bodies of two identified GIs. After allowing over one week for axonal degeneration, both histological and behavioral tests confirmed that specifically the axons of the targeted illuminated cells had been killed.

  6. Arbitrary electron acoustic waves in degenerate dense plasmas

    NASA Astrophysics Data System (ADS)

    Rahman, Ata-ur; Mushtaq, A.; Qamar, A.; Neelam, S.

    2017-05-01

    A theoretical investigation is carried out of the nonlinear dynamics of electron-acoustic waves in a collisionless and unmagnetized plasma whose constituents are non-degenerate cold electrons, ultra-relativistic degenerate electrons, and stationary ions. A dispersion relation is derived for linear EAWs. An energy integral equation involving the Sagdeev potential is derived, and basic properties of the large amplitude solitary structures are investigated in such a degenerate dense plasma. It is shown that only negative large amplitude EA solitary waves can exist in such a plasma system. The present analysis may be important to understand the collective interactions in degenerate dense plasmas, occurring in dense astrophysical environments as well as in laser-solid density plasma interaction experiments.

  7. Arbitrary electron acoustic waves in degenerate dense plasmas

    NASA Astrophysics Data System (ADS)

    Rahman, Ata-ur; Mushtaq, A.; Qamar, A.; Neelam, S.

    2016-12-01

    A theoretical investigation is carried out of the nonlinear dynamics of electron-acoustic waves in a collisionless and unmagnetized plasma whose constituents are non-degenerate cold electrons, ultra-relativistic degenerate electrons, and stationary ions. A dispersion relation is derived for linear EAWs. An energy integral equation involving the Sagdeev potential is derived, and basic properties of the large amplitude solitary structures are investigated in such a degenerate dense plasma. It is shown that only negative large amplitude EA solitary waves can exist in such a plasma system. The present analysis may be important to understand the collective interactions in degenerate dense plasmas, occurring in dense astrophysical environments as well as in laser-solid density plasma interaction experiments.

  8. A method for dye extraction using an aqueous two-phase system: Effect of co-occurrence of contaminants in textile industry wastewater.

    PubMed

    Borges, Gabriella Alexandre; Silva, Luciana Pereira; Penido, Jussara Alves; de Lemos, Leandro Rodrigues; Mageste, Aparecida Barbosa; Rodrigues, Guilherme Dias

    2016-12-01

    This paper reports a green and efficient procedure for extraction of the dyes Malachite Green (MG), Methylene Blue (MB), and Reactive Red 195 (RR) using an aqueous two-phase system (ATPS). An ATPS consists mainly of water, together with polymer and salt, and does not employ any organic solvent. The extraction efficiency was evaluated by means of the partition coefficients (K) and residual percentages (%R) of the dyes, under different experimental conditions, varying the tie-line length (TLL) of the system, the pH, the type of ATPS-forming electrolyte, and the type of ATPS-forming polymer. For MG, the best removal (K = 4.10 × 10(4), %R = 0.0069%) was obtained with the ATPS: PEO 1500 + Na2C4H4O6 (TLL = 50.21% (w/w), pH = 6.00). For MB, the maximum extraction (K = 559.9, %R = 0.258%) was achieved with the ATPS: PEO 400 + Na2SO4 (TLL = 50.31% (w/w), pH = 1.00). Finally for RR, the method that presented the best results (K = 3.75 × 10(4), %R = 0.237%) was the ATPS: PEO 400 + Na2SO4 (TLL = 50.31% (w/w), pH = 6.00). The method was applied to the recovery of these dyes from a textile effluent sample, resulting in values of K of 1.17 × 10(4), 724.1, and 3.98 × 10(4) for MG, MB, and RR, respectively, while the corresponding %R values were 0.0038, 0.154, and 0.023%, respectively. In addition, the ATPS methodology provided a high degree of color removal (96.5-97.95%) from the textile effluent. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Qualitative and quantitative assessment of degeneration of cervical intervertebral discs and facet joints.

    PubMed

    Walraevens, Joris; Liu, Baoge; Meersschaert, Joke; Demaerel, Philippe; Delye, Hans; Depreitere, Bart; Vander Sloten, Jos; Goffin, Jan

    2009-03-01

    Degeneration of intervertebral discs and facet joints is one of the most frequently encountered spinal disorders. In order to describe and quantify degeneration and evaluate a possible relationship between degeneration and biomechanical parameters, e.g., the intervertebral range of motion and intradiscal pressure, a scoring system for degeneration is mandatory. However, few scoring systems for the assessment of degeneration of the cervical spine exist. Therefore, two separate objective scoring systems to qualitatively and quantitatively assess the degree of cervical intervertebral disc and facet joint degeneration were developed and validated. The scoring system for cervical disc degeneration consists of three variables which are individually scored on neutral lateral radiographs: "height loss" (0-4 points), "anterior osteophytes" (0-3 points) and "endplate sclerosis" (0-2 points). The scoring system for facet joint degeneration consists of four variables which are individually scored on neutral computed tomography scans: "hypertrophy" (0-2 points), "osteophytes" (0-1 point), "irregularity" on the articular surface (0-1 point) and "joint space narrowing" (0-1 point). Each variable contributes with varying importance to the overall degeneration score (max 9 points for the scoring system of cervical disc degeneration and max 5 points for facet joint degeneration). Degeneration of 20 discs and facet joints of 20 patients was blindly assessed by four raters: two neurosurgeons (one senior and one junior) and two radiologists (one senior and one junior), firstly based on first subjective impression and secondly using the scoring systems. Measurement errors and inter- and intra-rater agreement were determined. The measurement error of the scoring system for cervical disc degeneration was 11.1 versus 17.9% of the subjective impression results. This scoring system showed excellent intra-rater agreement (ICC = 0.86, 0.75-0.93) and excellent inter-rater agreement (ICC = 0

  10. Axonal Degeneration Is Mediated by the Mitochondrial Permeability Transition Pore

    PubMed Central

    Barrientos, Sebastian A.; Martinez, Nicolas W.; Yoo, Soonmoon; Jara, Juan S.; Zamorano, Sebastian; Hetz, Claudio; Twiss, Jeffery L.; Alvarez, Jaime; Court, Felipe A.

    2011-01-01

    Axonal degeneration is an active process that has been associated with neurodegenerative conditions triggered by mechanical, metabolic, infectious, toxic, hereditary and inflammatory stimuli. This degenerative process can cause permanent loss of function, so it represents a focus for neuroprotective strategies. Several signaling pathways are implicated in axonal degeneration, but identification of an integrative mechanism for this self-destructive process has remained elusive. Here, we show that rapid axonal degeneration triggered by distinct mechanical and toxic insults is dependent on the activation of the mitochondrial permeability transition pore (mPTP). Both pharmacological and genetic targeting of cyclophilin D, a functional component of the mPTP, protects severed axons and vincristine-treated neurons from axonal degeneration in ex vivo and in vitro mouse and rat model systems. These effects were observed in axons from both the peripheral and central nervous system. Our results suggest that the mPTP is a key effector of axonal degeneration, upon which several independent signaling pathways converge. Since axonal and synapse degeneration are increasingly considered early pathological events in neurodegeneration, our work identifies a potential target for therapeutic intervention in a wide variety of conditions that lead to loss of axons and subsequent functional impairment. PMID:21248121

  11. Age-related macular degeneration

    PubMed Central

    Coleman, Hanna R; Chan, Chi-Chao; Ferris, Frederick L; Chew, Emily Y

    2008-01-01

    Age-related macular degeneration is the leading cause of blindness in elderly populations of European descent. The most consistent risk factors associated with this ocular condition are increasing age and cigarette smoking. Genetic investigations have shown that complement factor H, a regulator of the alternative complement pathway, and LOC387715/HtrA1 are the most consistent genetic risk factors for age-related macular degeneration. Although the pathogenesis of this disease is unknown, oxidative stress might have an important role. Treatment with antioxidant vitamins and zinc can reduce the risk of developing advanced age-related macular degeneration by about a quarter in those at least at moderate risk. Intravitreal injections of ranibizumab, a monoclonal antibody that inhibits all forms of vascular endothelial growth factor, have been shown to stabilise loss of vision and, in some cases, improve vision in individuals with neovascular age-related macular degeneration. These findings, combined with assessments of possible environmental and genetic interactions and new approaches to modulate inflammatory pathways, will hopefully further expand our ability to understand and treat age-related macular degeneration. PMID:19027484

  12. Adaptation for improving lifetime of dye laser using coumarin dyes

    SciTech Connect

    Fletcher, A.N.

    1984-10-23

    The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of absorbing electromagnetic radiation of about 300 nanometers or shorter wavelength.

  13. Cyanine dyes as intercalating agents: kinetic and thermodynamic studies on the DNA/Cyan40 and DNA/CCyan2 systems.

    PubMed

    Biver, Tarita; De Biasi, Angela; Secco, Fernando; Venturini, Marcella; Yarmoluk, Sergiy

    2005-07-01

    The interaction of cyanines with nucleic acids is accompanied by intense changes of their optical properties. Consequently these molecules find numerous applications in biology and medicine. Since no detailed information on the binding mechanism of DNA/cyanine systems is available, a T-jump investigation of the kinetics and equilibria of binding of the cyanines Cyan40 [3-methyl-2-(1,2,6-trimethyl-4(1H)pyridinylidenmethyl)-benzothiazolium ion] and CCyan2 [3-methyl-2-[2-methyl-3-(3-methyl-2(3H)-benzothiazolylidene)-1-propenyl]-benzothiazolium ion] with CT-DNA is performed at 25 degrees C, pH 7 and various ionic strengths. Bathochromic shifts of the dye absorption band upon DNA addition, polymer melting point displacement (DeltaT = 8-10 degrees C), site size determination (n = 2), and stepwise kinetics concur in suggesting that the investigated cyanines bind to CT-DNA primary by intercalation. Measurements with poly(dA-dT).poly(dA-dT) and poly(dG-dC).poly(dG-dC) reveal fair selectivity of CCyan2 toward G-C basepairs. T-jump experiments show two kinetic effects for both systems. The binding process is discussed in terms of the sequence D + S left arrow over right arrow D,S left arrow over right arrow DS(I) left arrow over right arrow DS(II), which leads first to fast formation of an external complex D,S and then to a partially intercalated complex DS(I) which, in turn, converts to DS(II), a more stable intercalate. Absorption spectra reveal that both dyes tend to self-aggregate; the kinetics of CCyan2 self-aggregation is studied by T-jump relaxation and the results are interpreted in terms of dimer formation.

  14. Cyanine Dyes as Intercalating Agents: Kinetic and Thermodynamic Studies on the DNA/Cyan40 and DNA/CCyan2 Systems

    PubMed Central

    Biver, Tarita; De Biasi, Angela; Secco, Fernando; Venturini, Marcella; Yarmoluk, Sergiy

    2005-01-01

    The interaction of cyanines with nucleic acids is accompanied by intense changes of their optical properties. Consequently these molecules find numerous applications in biology and medicine. Since no detailed information on the binding mechanism of DNA/cyanine systems is available, a T-jump investigation of the kinetics and equilibria of binding of the cyanines Cyan40 [3-methyl-2-(1,2,6-trimethyl-4(1H)pyridinylidenmethyl)-benzothiazolium ion] and CCyan2 [3-methyl-2-[2-methyl-3-(3-methyl-2(3H)-benzothiazolylidene)-1-propenyl]-benzothiazolium ion] with CT-DNA is performed at 25°C, pH 7 and various ionic strengths. Bathochromic shifts of the dye absorption band upon DNA addition, polymer melting point displacement (ΔT = 8–10°C), site size determination (n = 2), and stepwise kinetics concur in suggesting that the investigated cyanines bind to CT-DNA primary by intercalation. Measurements with poly(dA-dT)·poly(dA-dT) and poly(dG-dC)·poly(dG-dC) reveal fair selectivity of CCyan2 toward G-C basepairs. T-jump experiments show two kinetic effects for both systems. The binding process is discussed in terms of the sequence D + S ⇆ D,S ⇆ DSI ⇆ DSII, which leads first to fast formation of an external complex D,S and then to a partially intercalated complex DSI which, in turn, converts to DSII, a more stable intercalate. Absorption spectra reveal that both dyes tend to self-aggregate; the kinetics of CCyan2 self-aggregation is studied by T-jump relaxation and the results are interpreted in terms of dimer formation. PMID:15863482

  15. The design of contact lens based ocular drug delivery systems for single-day use: Part (I) Structural factors, surrogate ophthalmic dyes and passive diffusion studies.

    PubMed

    Mahomed, Anisa; Tighe, Brian J

    2014-09-01

    The poor retention and efficacy of instilled drops as a means of delivering drugs to the ophthalmic environment is well-recognised. The potential value of contact lenses as a means of ophthalmic drug delivery, and consequent improvement of pre-corneal retention is one obvious route to the development of a more effective ocular delivery system. Furthermore, the increasing availability and clinical use of daily disposable contact lenses provides the platform for the development of viable single-day use drug delivery devices based on existing materials and lenses. In order to provide a basis for the effective design of such devices, a systematic understanding of the factors affecting the interaction of individual drugs with the lens matrix is required. Because a large number of potential structural variables are involved, it is necessary to achieve some rationalisation of the parameters and physicochemical properties (such as molecular weight, charge, partition coefficients) that influence drug interactions. Ophthalmic dyes and structurally related compounds based on the same core structure were used to investigate these various factors and the way in which they can be used in concert to design effective release systems for structurally different drugs. Initial studies of passive diffusional release form a necessary precursor to the investigation of the features of the ocular environment that over-ride this simple behaviour. Commercially available contact lenses of differing structural classifications were used to study factors affecting the uptake of the surrogate actives and their release under 'passive' conditions. The interaction between active and lens material shows considerable and complex structure dependence, which is not simply related to equilibrium water content. The structure of the polymer matrix itself was found to have the dominant controlling influence on active uptake; hydrophobic interaction with the ophthalmic dye playing a major role. © The

  16. Evaluation of anaerobic sludge volume for improving azo dye decolorization in a hybrid anaerobic reactor with built-in bioelectrochemical system.

    PubMed

    Cui, Min-Hua; Cui, Dan; Gao, Lei; Wang, Ai-Jie; Cheng, Hao-Yi

    2017-02-01

    A hybrid anaerobic reactor with built-in bioelectrochemical system (BES) has been verified for efficiently treating mixed azo dye wastewater, yet still facing many challenges, such as uncertain reactor construction and insufficient electron donors. In this study, an up-flow hybrid anaerobic reactor with built-in BES was developed for acid orange 7 (AO7) containing wastewater treatment. Cathode and real domestic wastewater both served as electron donor for driving azo dye decolorization. The decolorization efficiency (DE) of AO7 (200 mg/L) in the hybrid reactor was 80.34 ± 2.11% with volume ratio between anaerobic sludge and cathode (VRslu:cat) of 0.5:1 and hydraulic retention time (HRT) of 6 h, which was 15.79% higher than that in BES without sludge zone. DE was improved to 86.02 ± 1.49% with VRslu:cat increased to 1:1. Further increase in the VRslu:cat to 1.5:1 and 2:1, chemical oxygen demand (COD) removal efficiency was continuously improved to 28.78 ± 1.96 and 32.19 ± 0.62%, but there was no obvious DE elevation (slightly increased to 87.62 ± 2.50 and 90.13 ± 3.10%). BES presented efficient electron utilization, the electron usage ratios (EURs) in which fluctuated between 11.02 and 13.06 mol e(-)/mol AO7. It was less than half of that in sludge zone of 24.73-32.06 mol e(-)/mol AO7. The present work optimized the volume ratio between anaerobic sludge and cathode that would be meaningful for the practical application of this hybrid system.

  17. Solvatochromic dyes detect the presence of homeopathic potencies.

    PubMed

    Cartwright, Steven J

    2016-02-01

    A systematic approach to the design of simple, chemical systems for investigating the nature of homeopathic medicines has led to the development of an experimental protocol in which solvatochromic dyes are used as molecular probes of serially diluted and agitated solutions. Electronic spectroscopy has been used to follow changes in the absorbance of this class of dyes across the visible spectrum in the presence of homeopathic potencies. Evidence is presented using six different solvatochromic dyes in three different solvent systems. In all cases homeopathic potencies produce consistent and reproducible changes in the spectra of the dyes. Results suggest that potencies influence the supramolecular chemistry of solvatochromic dyes, enhancing either dye aggregation or disaggregation, depending upon dye structure. Comparable dyes lacking the intramolecular charge transfer feature of solvatochromic dyes are unaffected by homeopathic potencies, suggesting potencies require the oscillating dipole of solvatochromic dyes for effective interaction. The implications of the results presented, both for an eventual understanding of the nature of homeopathic medicines and their mode of action, together with future directions for research in this area, are discussed. Copyright © 2015 The Author. Published by Elsevier Ltd.. All rights reserved.

  18. Thermal treatment of dyes from military munitions

    SciTech Connect

    1996-09-01

    Los Alamos National Laboratory has developed thermal treatment equipment to treat Navy smoke and dye compounds. Navy smokes were burned in the Los Alamos Controlled Air Incinerator (CAI) in the early 1980s. These test results were used in the development of a portable system consisting of a Thermal Treatment Unit (TTU), feed preparation and pumping skid, utility skid, and control trailer. This equipment was started up at Navy facilities at China Lake, CA where several destruction removal efficiency tests were completed in 1993 burning smoke compositions. The equipment was set up at the Nevada Test Site (NTS) in 1996 where tests were completed burning green Navy spotting dyes. Operating and test results from the NTS efforts resulted in clearer understanding of equipment deficiencies, dye characteristics and composition, and secondary wastes generated. Future tests, scheduled for July, 1996 will demonstrate higher bum rates, better pH measurement and control, and stack emission test results for other colored dyes.

  19. On-chip tunable optofluidic dye laser

    NASA Astrophysics Data System (ADS)

    Cai, Zengyan; Shen, Zhenhua; Liu, Haigang; Yue, Huan; Zou, Yun; Chen, Xianfeng

    2016-11-01

    We demonstrate a chip-scale tunable optofluidic dye laser with Au-coated fibers as microcavity. The chip is fabricated by soft lithography. When the active region is pumped, a relatively low threshold of 6.7 μJ/mm2 is realized with multimode emission due to good confinement of the cavity mirrors, long active region, as well as total reflectivity. It is easy to tune the lasing emission wavelength by changing the solvent of laser dye. In addition, the various intensity ratios of multicolor lasing can be achieved by controlling flow rates of two fluid streams carried with different dye molecules. Furthermore, the convenience in fabrication and directional lasing emission outcoupled by the fiber make the tunable optofluidic dye laser a promising underlying coherent light source in the integrated optofluidic systems.

  20. Solid state dye laser for medical applications

    NASA Astrophysics Data System (ADS)

    Aldag, Henry R.

    1994-06-01

    The development of solid state dye lasers could lead to a major breakthrough in the cost and compactness of a medical device. Advantages include: elimination of the flow system for the gain medium; ease with which to implement wavelength agility or the replacement of a degraded rod or sheet; and toxicity and flammability become a non-issue. Dye lasers have played a role in cardiology, dermatology, and urology. Of these cardiology is of interest to Palomar. The Palomar Model 3010 flashlamp-pumped dye laser medical device was used during phase 1 FDA clinical trials to break-up blood clots that cause heart attacks, a process known as coronary laser thrombolysis. It is the objective of this research and development effort to produce solid matrix lasers that will replace liquid dye lasers in these medical specialties.

  1. Ballistic labeling with fluorescent dyes and indicators.

    PubMed

    Morgan, Joshua L; Wong, Rachel O L

    2008-04-01

    Neuronal cell labeling is fundamental to investigations of the nervous system. Labeling of cells in live or fixed tissue with dyes or ion indicators using ballistic approaches has recently been developed for the study of neuronal architecture and function. In this approach, dye-coated particles are propelled into cells by a pulse of pressurized helium. This unit provides step-by-step protocols for coating tungsten particles with fluorescent or indicator dyes and for delivering these particles into cells and tissue. The major advantage of the ballistic method of dye delivery is that large populations of neurons can be rapidly labeled within a piece of live or fixed tissue. Advantages and limitations of the approach are discussed and technical advice is provided. (c) 2008 by John Wiley & Sons, Inc.

  2. Quantum Degenerate Gases of Strontium

    NASA Astrophysics Data System (ADS)

    Desalvo, Brian; Martinez de Escobar, Natali; Mickelson, Pacal; Yan, Mi; Killian, Thomas

    2010-03-01

    We have produced quantum degenerate gases of three of the four stable isotopes of strontium. Using two-stage laser trapping and cooling followed by direct evaporative cooling in a far-off- resonance optical dipole trap (ODT), a stable Bose-Einstein Condensate (BEC) of ^84Sr is formed. Via dual species trapping and sympathetic cooling in an ODT, an attractive BEC of ^88Sr is created, as well as a degenerate Fermi gas of ^87Sr. Differences in the evaporation scheme used to reach degeneracy for each isotope will be presented as well as the varied dynamics of the gases.

  3. Adsorption Capability of Cationic Dyes (Methylene Blue and Crystal Violet) onto Poly-γ-glutamic Acid.

    PubMed

    Ogata, Fumihiko; Nagai, Noriaki; Kawasaki, Naohito

    2017-01-01

    In this study, the adsorption capability of cationic dyes, which were methylene blue and crystal violet, by poly-γ-glutamic acid (PGA) in a single or binary solution system was investigated. The effect of the molecular weight of PGA, initial dye concentration, solution pH, and temperature on the adsorption of dyes was evaluated. The adsorption mechanism of dyes onto PGA was the interaction between -COOH group on the PGA surface and the polarity groups of dyes. These results indicated that PGA is useful for removal of dyes and cationic organic compounds from a single or binary solution system.

  4. Photocatalytic property of a keggin-type polyoxometalates-containing bilayer system for degradation organic dye model.

    PubMed

    Li, Taohai; Gao, Shuiying; Li, Feng; Cao, Rong

    2009-10-15

    The photocatalytic activity composite films incorporating the Keggin-type polyoxometalates (POM) K6CoW12O40.-16H2O and K3PW12O40.-nH2O (MW12 (M=P, Co)) and [Cu(II)(1,8-dimethyl-1, 3, 6, 8, 10, 13-hexaazacycloteradecane)](2+)(L) have been prepared by the layer-by-layer (LbL) self-assembly method. The experimental results show that the deposition process is linear and highly reproducible from layer to layer. Atomic force microscopy (AFM) images of the L/MW12 composite films indicate that the film surface is relatively uniform and smooth. In addition, the films show high photocatalytic activity to the degradation of organic dye model (methyl orange (MO)), attributed to the formation of an O-->W charge-transfer excited state at W-O-W bridge bond, resulting in generating highly reactive holes and electrons; The photocatalytic efficiency of the films have little change after several times of photocatalytic cycle, indicating that the composite films are stable, reused and recovered.

  5. Spatially coordinated kinase signaling regulates local axon degeneration.

    PubMed

    Chen, Mark; Maloney, Janice A; Kallop, Dara Y; Atwal, Jasvinder K; Tam, Stephen J; Baer, Kristin; Kissel, Holger; Kaminker, Joshua S; Lewcock, Joseph W; Weimer, Robby M; Watts, Ryan J

    2012-09-26

    In addition to being a hallmark of neurodegenerative disease, axon degeneration is used during development of the nervous system to prune unwanted connections. In development, axon degeneration is tightly regulated both temporally and spatially. Here, we provide evidence that degeneration cues are transduced through various kinase pathways functioning in spatially distinct compartments to regulate axon degeneration. Intriguingly, glycogen synthase kinase-3 (GSK3) acts centrally, likely modulating gene expression in the cell body to regulate distally restricted axon degeneration. Through a combination of genetic and pharmacological manipulations, including the generation of an analog-sensitive kinase allele mutant mouse for GSK3β, we show that the β isoform of GSK3, not the α isoform, is essential for developmental axon pruning in vitro and in vivo. Additionally, we identify the dleu2/mir15a/16-1 cluster, previously characterized as a regulator of B-cell proliferation, and the transcription factor tbx6, as likely downstream effectors of GSK3β in axon degeneration.

  6. The influence of the push-pull effect and a π-conjugated system in conversion efficiency of bis-chalcone compounds in a dye sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Teo, Kien Yung; Tiong, Mee Hing; Wee, Hung Yee; Jasin, Nornadia; Liu, Zhi-Qiang; Shiu, Ming Yang; Tang, Jyun Yang; Tsai, Jenn-Kai; Rahamathullah, Rafizah; Khairul, Wan M.; Tay, Meng Guan

    2017-09-01

    Chalcone and its related compounds are known to be π-conjugated compounds, which can be potentially used in different electronic areas include dye sensitized solar cell (DSSC). A total of six bis-chalcone compounds (1-6) have been synthesized using a Claisen-Schmidt condensation method under basic conditions. The compounds were used as the dye in DSSC to test their solar conversion efficiency. In the process of solar cell fabrication, titanium(II) oxide (TiO2) coated glass was used as the working electrode, whereas the mixture of iodine (I2), lithium iodide (LiI), 4-tertbutylpyridine (4-TBP) and 1,2-dimethyl-3-propylimidazolium (DMPII) in 3-methoxypropionitrile were used as the electrolyte. The DSSC was fabricated by immersing the TiO2 glass into the respective bis-chalcone compound solution and dried into the oven at 45 °C for 120 min. Lastly, the working electrode and counter electrode were sealed using surlyn of 60 μm thickness. The efficiency test was conducted under AM 1.5G illumination with the incident light intensity of 100 mW/cm2. Among the six bis-chalcone derivatives, compound 2, namely 1,4-bis-2-hydroxychalcone, was recorded with the highest efficiency (0.054%) compared to the others (0.022-0.035%). The presence of a π-conjugated system and the push-pull effect in the molecule were found to enhance the conversion efficiency of DSSC. Details of the results are discussed in the present paper.

  7. Organic photosensitizers with a heteroleptic dual donor for dye-sensitized solar cells.

    PubMed

    Kim, Joo Young; Kim, Young Sik

    2012-04-01

    Using DFT and TDDFT calculations, we investigated the substitution effect in the electronic and optical properties of dye sensitizers with a dual donor composed of triphenylamine and/or indoline moieties. Due to replacement with the dual donor moieties, the HOMO levels were split into HOMO and HOMO - 1 levels, and the bandgaps between the HOMO and LUMO levels decreased, leading to the creation of bathochromically extended absorption spectra. Nearly degenerated splitting of the HOMO levels resulted from the similarity of the electronic structure between the HOMO and the HOMO - 1 levels, delocalized over both dual-donor moieties, when replacing the dual donors. It was shown that the additional electron-donating group creates an additional absorption band and causes a cascading two-electron process aiding the charge separation process. Owing to a more panchromatic attribute, easier energy transfer and feasible retardation of the recombination between the injected electrons and the electrolyte, it is expected that dyeTI will show better performance than the other dyes (dyeT dyeTT and dyeIT) as denoted here in terms of the conversion efficiency of dye-sensitized solar cells (DSSCs). This work presents the probable benefits of dye sensitizers with dual-donor moieties and provides insight into the development of more efficient dye sensitizers for DSSCs through modification of the Frontier molecular orbitals.

  8. Age-related macular degeneration.

    PubMed

    Cheung, Lily K; Eaton, Angie

    2013-08-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, and the prevalence of the disease increases exponentially with every decade after age 50 years. It is a multifactorial disease involving a complex interplay of genetic, environmental, metabolic, and functional factors. Besides smoking, hypertension, obesity, and certain dietary habits, a growing body of evidence indicates that inflammation and the immune system may play a key role in the development of the disease. AMD may progress from the early form to the intermediate form and then to the advanced form, where two subtypes exist: the nonneovascular (dry) type and the neovascular (wet) type. The results from the Age-Related Eye Disease Study have shown that for the nonneovascular type of AMD, supplementation with high-dose antioxidants (vitamin C, vitamin E, and β-carotene) and zinc is recommended for those with the intermediate form of AMD in one or both eyes or with advanced AMD or vision loss due to AMD in one eye. As for the neovascular type of the advanced AMD, the current standard of therapy is intravitreal injections of vascular endothelial growth factor inhibitors. In addition, lifestyle and dietary modifications including improved physical activity, reduced daily sodium intake, and reduced intake of solid fats, added sugars, cholesterol, and refined grain foods are recommended. To date, no study has demonstrated that AMD can be cured or effectively prevented. Clearly, more research is needed to fully understand the pathophysiology as well as to develop prevention and treatment strategies for this devastating disease.

  9. Degradation of textile dyes by cyanobacteria.

    PubMed

    Dellamatrice, Priscila Maria; Silva-Stenico, Maria Estela; Moraes, Luiz Alberto Beraldo de; Fiore, Marli Fátima; Monteiro, Regina Teresa Rosim

    Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  10. Energy transfer versus charge separation in hybrid systems of semiconductor quantum dots and Ru-dyes as potential co-sensitizers of TiO2-based solar cells

    NASA Astrophysics Data System (ADS)

    Giménez, Sixto; Rogach, Andrey L.; Lutich, Andrey A.; Gross, Dieter; Poeschl, Andreas; Susha, Andrei S.; Mora-Seró, Ivan; Lana-Villarreal, Teresa; Bisquert, Juan

    2011-07-01

    Hybrid structures of colloidal quantum dots (QDs) with Ru-dyes have been studied as candidates for panchromatic sensitizers for TiO2-based solar cells. Steady-state and time resolved photoluminescence spectroscopy and photocurrent measurements have been employed to identify the prevailing transfer mechanisms for photogenerated excitons between CdSe QDs capped with a traditional bulky organic ligand trioctylphosphine and Ru-dyes (N3 or Ru505) deposited onto inert glass or mesoporous TiO2 substrates. The type II energy level alignment between the QDs and both N3 and Ru505 offers a possibility for the directional charge separation, with electrons transferred to the QDs and holes to the dye. This scenario is indeed valid for the QD/Ru505 and TiO2/QD/Ru505 hybrid systems, with the negligible spectral overlap between the emission of the QDs and the absorption of the Ru505 dye. For the QD/N3 and TiO2/QD/N3 hybrid systems, the spectral overlap favors the longer range energy transfer from the QDs to N3, independently of the presence of the electron acceptor TiO2.

  11. Age-Related Macular Degeneration.

    PubMed

    Mehta, Sonia

    2015-09-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly. AMD is diagnosed based on characteristic retinal findings in individuals older than 50. Early detection and treatment are critical in increasing the likelihood of retaining good and functional vision. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Design of hybrid nanoheterostructure systems for enhanced quantum and solar conversion efficiencies in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Kılıç, Bayram; Telli, Hakan; Tüzemen, Sebahattin; Başaran, Ali; Pirge, Gursev

    2015-04-01

    Dye sensitized solar cells (DSSCs) with an innovative design involving controlled-morphology vertically aligned (VA) ZnO nanowires within mesoporous TiO2 structures with ultrahigh surface area for implementation as photoanodes are herein reported. Although TiO2 nanostructures exhibit excellent power conversion efficiency, the electron transport rate is low owing to low electron mobility. To overcome this, ZnO nanowires with high electron mobility have been investigated as potential candidates for photoanodes. However, the power conversion efficiency of ZnO nanowires is still lower than that of TiO2 owing to their low internal surface area. Consequently, in this work, vertical growth of ZnO nanowires within mesoporous TiO2 structures is carried out to increase their solar power conversion efficiency. The photovoltaic performance of solar cells using ZnO nanowires, mesoporous TiO2, and TiO2/ZnO hybrid structures are compared. The VA TiO2/ZnO hybrid structures are found to provide direct electron transfer compared with the tortuous pathway of zero-dimensional nanostructures, resulting in an increased conversion efficiency. It is demonstrated that the light scattering of the photoanode film is increased and electron recombination is decreased when an appropriate amount of mesoporous TiO2 is used as a substrate for ZnO nanowires. The DSSC fabricated with the TiO2/ZnO hybrid photoanode prepared with 15.8 wt. % TiO2 showed the highest conversion efficiency of 7.30%, approximately 5%, 18%, and 40% higher than that of DSSCs fabricated with 3.99 wt. % TiO2, pure TiO2, and pure ZnO photoanodes, respectively.

  13. Design of hybrid nanoheterostructure systems for enhanced quantum and solar conversion efficiencies in dye-sensitized solar cells

    SciTech Connect

    Kılıç, Bayram E-mail: kbayramkilic@gmail.com; Telli, Hakan; Başaran, Ali; Pirge, Gursev; Tüzemen, Sebahattin

    2015-04-07

    Dye sensitized solar cells (DSSCs) with an innovative design involving controlled-morphology vertically aligned (VA) ZnO nanowires within mesoporous TiO{sub 2} structures with ultrahigh surface area for implementation as photoanodes are herein reported. Although TiO{sub 2} nanostructures exhibit excellent power conversion efficiency, the electron transport rate is low owing to low electron mobility. To overcome this, ZnO nanowires with high electron mobility have been investigated as potential candidates for photoanodes. However, the power conversion efficiency of ZnO nanowires is still lower than that of TiO{sub 2} owing to their low internal surface area. Consequently, in this work, vertical growth of ZnO nanowires within mesoporous TiO{sub 2} structures is carried out to increase their solar power conversion efficiency. The photovoltaic performance of solar cells using ZnO nanowires, mesoporous TiO{sub 2}, and TiO{sub 2}/ZnO hybrid structures are compared. The VA TiO{sub 2}/ZnO hybrid structures are found to provide direct electron transfer compared with the tortuous pathway of zero-dimensional nanostructures, resulting in an increased conversion efficiency. It is demonstrated that the light scattering of the photoanode film is increased and electron recombination is decreased when an appropriate amount of mesoporous TiO{sub 2} is used as a substrate for ZnO nanowires. The DSSC fabricated with the TiO{sub 2}/ZnO hybrid photoanode prepared with 15.8 wt. % TiO{sub 2} showed the highest conversion efficiency of 7.30%, approximately 5%, 18%, and 40% higher than that of DSSCs fabricated with 3.99 wt. % TiO{sub 2}, pure TiO{sub 2}, and pure ZnO photoanodes, respectively.

  14. Modified triphenylamine-dicyanovinyl-based donor-acceptor dyes with enhanced power conversion efficiency of p-type dye-sensitized solar cells.

    PubMed

    Zhu, Linna; Yang, Hongbin; Zhong, Cheng; Li, Chang Ming

    2012-12-01

    To dye for: Two new dyes are synthesized by structural modifications of one of the best dyes for NiO p-type dye-sensitized solar cells, which is based on a triphenylamine-dicyanovinyl donor-acceptor system. An additional thiophene unit near the anchoring group can greatly retard charge recombination while enhancing the absorption coefficient to significantly improve the photoconversion efficiency by 50%.

  15. Ataxias and Cerebellar or Spinocerebellar Degeneration

    MedlinePlus

    ... underlying cause of the degeneration. Many ataxias are hereditary and are classified by chromosomal location and pattern ... underlying cause of the degeneration. Many ataxias are hereditary and are classified by chromosomal location and pattern ...

  16. Effect of some process parameters in enzymatic dyeing of wool.

    PubMed

    Tzanov, Tzanko; Silva, Carla Joana; Zille, Andrea; Oliveira, Jovita; Cavaco-Paulo, Artur

    2003-10-01

    This article reports on the dyeing of wool using an enzymatic system comprising laccase; dye precursor, 2,5-diaminobenzenesulfonic acid; and dye modifiers, catechol and resorcinol. Enzymatic dyeing was performed as a batchwise process at the temperature and pH of maximum enzyme activity. The effects of the process variables reaction time, enzyme, and modifier concentration on fabric color were studied, according to an appropriate experimental design. Different hues and depths of shades could be achieved by varying the concentration of the modifiers and the time of laccase treatment. The duration of the enzymatic reaction appeared to be the most important factor in the dyeing process. Thus, the dyeing process, performed at low temperature and mild pH, was advantageous in terms of reduced enzyme and chemical dosage.

  17. A Simplified, Light Emitting Diode (LED) Based, Modular System to be Used for the Rapid Evaluation of Fruit and Vegetable Quality: Development and Validation on Dye Solutions

    PubMed Central

    Civelli, Raffaele; Giovenzana, Valentina; Beghi, Roberto; Naldi, Ezio; Guidetti, Riccardo; Oberti, Roberto

    2015-01-01

    NIR spectroscopy has proven to be one of the most efficient and ready to transfer tools to monitor product’s quality. Portable VIS/NIR instruments are particularly versatile and suitable for field use to monitor the ripening process or quality parameters. The aim of this work is to develop and evaluate a new simplified optoelectronic system for potential measurements on fruit and vegetables directly in the field. The development, characterization and validation of an operative prototype is discussed. LED technology was chosen for the design, and spectral acquisition at four specific wavelengths (630, 690, 750 and 850 nm) was proposed. Nevertheless, attention was given to the modularity and versatility of the system. Indeed, the possibility to change the light sources module with other wavelengths allows one to adapt the use of the same device for different foreseeable applications and objectives, e.g., ripeness evaluation, detection of particular diseases and disorders, chemical and physical property prediction, shelf life analysis, as well as for different natures of products (berry, leaf or liquid). Validation tests on blue dye water solutions have shown the capability of the system of discriminating low levels of reflectance, with a repeatability characterized by a standard deviation proportional to the measured intensity and in general limited to 2%–4%. PMID:26371002

  18. Local delivery of fluorescent dye for fiber-optics confocal microscopy of the living heart

    PubMed Central

    Huang, Chao; Kaza, Aditya K.; Hitchcock, Robert W.; Sachse, Frank B.

    2014-01-01

    Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption, and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio (SNR) of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release vs. foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5–9 lines, which is comparable to 4–8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery. PMID:25309455

  19. Local delivery of fluorescent dye for fiber-optics confocal microscopy of the living heart.

    PubMed

    Huang, Chao; Kaza, Aditya K; Hitchcock, Robert W; Sachse, Frank B

    2014-01-01

    Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption, and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio (SNR) of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release vs. foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5-9 lines, which is comparable to 4-8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery.

  20. Energy transfer between a biological labelling dye and gold nanorods

    NASA Astrophysics Data System (ADS)

    Racknor, Chris; Singh, Mahi R.; Zhang, Yinan; Birch, David J. S.; Chen, Yu

    2014-03-01

    We have demonstrated energy transfer between a biological labelling dye (Alexa Fluor 405) and gold nanorods experimentally and theoretically. The fluorescence lifetime imaging microscopy and density matrix method are used to study a hybrid system of dye and nanorods under one- and two-photon excitations. Energy transfer between dye and nanorods via the dipole-dipole interaction is found to cause a decrease in the fluorescence lifetime change. Enhanced energy transfer from dye to nanorods is measured in the presence of an increased density of nanorods. This study has potential applications in fluorescence lifetime-based intra-cellular sensing of bio-analytes as well as nuclear targeting cancer therapy.

  1. Multimodal scanning laser ophthalmoscopy for image guided treatment of age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Ferguson, R. D.; Patel, Ankit H.; Iftimia, Nicusor V.; Mujat, Mircea; Husain, Deeba

    2009-02-01

    Subretinal neovascular membranes (SRNM) are a deleterious complication of laser eye injury and retinal diseases such as age-related macular degeneration (AMD), choroiditis, and myopic retinopathy. Photodynamic therapy (PDT) and anti-vascular endothelial growth factor (VEGF) drugs are approved treatment methods. PDT acts by selective dye accumulation, activation by laser light, and disruption and clotting of the new leaky vessels. However, PDT surgery is currently not image-guided, nor does it proceed in an efficient or automated manner. This may contribute to the high rate of re-treatment. We have developed a multimodal scanning laser ophthalmoscope (SLO) for automated diagnosis and image-guided treatment of SRNMs associated with AMD. The system combines line scanning laser ophthalmoscopy (LSLO), fluorescein angiography (FA), indocyanine green angiography (ICGA), PDT laser delivery, and retinal tracking in a compact, efficient platform. This paper describes the system hardware and software design, performance characterization, and automated patient imaging and treatment session procedures and algorithms. Also, we present initial imaging and tracking measurements on normal subjects and automated lesion demarcation and sizing analysis of previously acquired angiograms. Future pre-clinical testing includes line scanning angiography and PDT treatment of AMD subjects. The automated acquisition procedure, enhanced and expedited data post-processing, and innovative image visualization and interpretation tools provided by the multimodal retinal imager may eventually aid in the diagnosis, treatment, and prognosis of AMD and other retinal diseases.

  2. Wallerian degeneration demonstrated by magnetic resonance: spectroscopic measurements on peripheral nerve. [Rats

    SciTech Connect

    Jolesz, F.A.; Polak, J.F.; Ruenzel, P.W.; Adams, D.F.

    1984-07-01

    Wallerian degeneration of rat sciatic nerves was induced by nerve section. Fifteen days later the degenerated nerves were compared with the intact contralteral nerves from the same animal. Histological sections showed the changes typical of wallerian degeneration: axonal degeneration and secondary demyelination. The freshly dissected nerves were analyzed by magnetic resonance (MR) spectroscopy at 10 MHz, and the water content was determined by dehydration. In the degenerated nerves there was a marked prolongation of both T1 and T2 relaxation times, accompanied by an increase of water content. These results suggest that it should be possible to detect wallerian degeneration in MR images; this will have an important impact on neuropathological diagnosis of central and peripheral nervous system lesions.

  3. The role of microglia in synaptic stripping and synaptic degeneration: a revised perspective

    PubMed Central

    Hugh Perry, V; O'Connor, Vincent

    2010-01-01

    Chronic neurodegenerative diseases of the CNS (central nervous system) are characterized by the loss of neurons. There is, however, growing evidence to show that an early stage of this process involves degeneration of presynaptic terminals prior to the loss of the cell body. Synaptic plasticity in CNS pathology has been associated with microglia and the phenomenon of synaptic stripping. We review here the evidence for the involvement of microglia in synaptic stripping and synapse degeneration and we conclude that this is a case of guilt by association. In disease models of chronic neurodegeneration, there is no evidence that microglia play an active role in either synaptic stripping or synapse degeneration, but the degeneration of the synapse and the envelopment of a degenerating terminal appears to be a neuron autonomous event. We highlight here some of the gaps in our understanding of synapse degeneration in chronic neurodegenerative disease. PMID:20967131

  4. Complete degradation of the azo dye Acid Orange-7 and bioelectricity generation in an integrated microbial fuel cell, aerobic two-stage bioreactor system in continuous flow mode at ambient temperature.

    PubMed

    Fernando, Eustace; Keshavarz, Taj; Kyazze, Godfrey

    2014-03-01

    In this study, the commercially used model azo dye Acid Orange-7 (AO-7) was fully degraded into less toxic intermediates using an integrated microbial fuel cell (MFC) and aerobic bioreactor system. The integrated bioreactor system was operated at ambient temperature and continuous-flow mode. AO-7 loading rate was varied during experiments from 70gm(-3)day(-1) to 210gm(-3)day(-1). Colour and soluble COD removal rates reached>90% under all AO-7 loading rates. The MFC treatment stage prompted AO-7 to undergo reductive degradation into its constituent aromatic amines. HPLC-MS analysis of metabolite extracts from the aerobic stage of the bioreactor system indicated further oxidative degradation of the resulting aromatic amines into simpler compounds. Bioluminescence based Vibrio fischeri ecotoxicity testing demonstrated that aerobic stage effluent exhibited toxicity reductions of approximately fivefold and ten-fold respectively compared to the dye wastewater influent and MFC-stage effluent.

  5. Morphology transformations in tetrabutyl titanate-acetic acid system and sub-micron/micron hierarchical TiO2 for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Huang, Niu; Xie, Yanan; Sebo, Bobby; Liu, Yumin; Sun, Xiaohua; Peng, Tao; Sun, Weiwei; Bu, Chenghao; Guo, Shishang; Zhao, Xingzhong

    2013-11-01

    The concentration of tetrabutyl titanate (TBT) and H2O influence on the reaction kinetics of TBT and acetic acid (AcOH) solvothermal system are systematically studied. It is found that TBT and H2O have greatly accelerated the hydrolysis-condensation process of the TBT-AcOH system. By adjusting those concentrations with reaction time, we prepare five kinds of sub-micron/micron precursors, which are hierarchical structures consisting of different primary building blocks. The morphology of these precursors varies from noninterlaced structures composed of flower-like microsphere and ellipsoid sphere to interlaced structures composed of flower-like microsphere interlaced nanofibers, ellipsoid spheres interlaced flower-like microsphere and nanoparticles interlaced flower-like microsphere. These interlaced structures are synthesized for the first time and are not ordinary mixtures of the noninterlaced structures. After heat treatment, these precursors are transformed to anatase TiO2. Shape-dependent photovoltaic performances of dye-sensitized solar cells (DSSCs) are also discussed. DSSCs based on these hierarchical sub-micron/micron TiO2 show 7.3%-7.9% energy conversion efficiencies, and the devices based on interlaced structures have higher efficiencies (7.4%-7.9%) than those of the devices based on noninterlaced structures (7.3%-7.6%).

  6. Liquid-phase non-thermal plasma-prepared N-doped TiO(2) for azo dye degradation with the catalyst separation system by ceramic membranes.

    PubMed

    Cheng, Hsu-Hui; Chen, Shiao-Shing; Cheng, Yi-Wen; Tseng, Wei-Lun; Wang, Yi-Hui

    2010-01-01

    This study strived to improve the photocatalytic activity by using liquid-phase non-thermal plasma (LPNTP) technology for preparing N-doping TiO(2) as well as to separate/recover the N-dope TiO(2) particles by using ceramic ultrafiltration membrane process. The yellow color N-doped TiO(2) photocatalysts, obtained through the LPNTP process, were characterized with UV-Vis spectroscopy, X-ray diffraction (XRD), and electron spectroscopy for chemical analysis (ESCA). The UV-Vis spectrum of N-doped TiO(2) showed that the absorption band was shifted to 439 nm and the band gap was reduced to 2.82 eV. The structure analysis of XRD spectra showed that the peak positions and the crystal structure remained unchanged as anatase after plasma-treating at 13.5 W for 40 min. The photocatalytic activity of N-doped TiO(2) was evaluated by azo dyes under visible light, and 63% of them was degraded after 16 hours in a continuous-flow photocatalytic system. For membrane separation/recover system, the recovery efficiency reached 99.5% after the ultrafiltration had been carried out for 90 min, and the result indicated that the photocatalyst was able to be separated/recovered completely.

  7. Fluorescence correlation spectroscopy experiments to quantify free diffusion coefficients in reaction-diffusion systems: The case of Ca^{2+} and its dyes.

    PubMed

    Sigaut, Lorena; Villarruel, Cecilia; Ponce, María Laura; Ponce Dawson, Silvina

    2017-06-01

    Many cell signaling pathways involve the diffusion of messengers that bind and unbind to and from intracellular components. Quantifying their net transport rate under different conditions then requires having separate estimates of their free diffusion coefficient and binding or unbinding rates. In this paper, we show how performing sets of fluorescence correlation spectroscopy (FCS) experiments under different conditions, it is possible to quantify free diffusion coefficients and on and off rates of reaction-diffusion systems. We develop the theory and present a practical implementation for the case of the universal second messenger, calcium (Ca^{2+}) and single-wavelength dyes that increase their fluorescence upon Ca^{2+} binding. We validate the approach with experiments performed in aqueous solutions containing Ca^{2+} and Fluo4 dextran (both in its high and low affinity versions). Performing FCS experiments with tetramethylrhodamine-dextran in Xenopus laevis oocytes, we infer the corresponding free diffusion coefficients in the cytosol of these cells. Our approach can be extended to other physiologically relevant reaction-diffusion systems to quantify biophysical parameters that determine the dynamics of various variables of interest.

  8. Fluorescence correlation spectroscopy experiments to quantify free diffusion coefficients in reaction-diffusion systems: The case of Ca2 + and its dyes

    NASA Astrophysics Data System (ADS)

    Sigaut, Lorena; Villarruel, Cecilia; Ponce, María Laura; Ponce Dawson, Silvina

    2017-06-01

    Many cell signaling pathways involve the diffusion of messengers that bind and unbind to and from intracellular components. Quantifying their net transport rate under different conditions then requires having separate estimates of their free diffusion coefficient and binding or unbinding rates. In this paper, we show how performing sets of fluorescence correlation spectroscopy (FCS) experiments under different conditions, it is possible to quantify free diffusion coefficients and on and off rates of reaction-diffusion systems. We develop the theory and present a practical implementation for the case of the universal second messenger, calcium (Ca2 +) and single-wavelength dyes that increase their fluorescence upon Ca2 + binding. We validate the approach with experiments performed in aqueous solutions containing Ca2 + and Fluo4 dextran (both in its high and low affinity versions). Performing FCS experiments with tetramethylrhodamine-dextran in Xenopus laevis oocytes, we infer the corresponding free diffusion coefficients in the cytosol of these cells. Our approach can be extended to other physiologically relevant reaction-diffusion systems to quantify biophysical parameters that determine the dynamics of various variables of interest.

  9. From Homogeneous to Heterogenized Solar Fuels Assemblies: Observation of Electron Transfer Events in Systems Containing Dye-Sensitized Semiconductors and Molecular Catalysts

    NASA Astrophysics Data System (ADS)

    Kamire, Rebecca Joy

    The conversion of solar energy into chemical energy by simultaneously oxidizing water and reducing protons to hydrogen could provide a much-needed fuel source within a more sustainable energy economy. Dye-sensitized photoelectrochemical cells (DSPECs) are capable of forming fuels using sunlight if photoexcited chromophores transfer charges to semiconductor electrodes and catalysts, and catalysis occurs, at rates exceeding those of charge recombination. The rational design of efficient DSPECs will require an understanding of the catalytic mechanisms and rate-limiting steps of the oxidative and reductive reactions. Here, we focus on how molecular and electrode design can be used to favor the desired charge transfer events from photoexcited perylene-3,4-dicarboximide (PMI) chromophores into semiconductor films and to molecular catalysts. Previous efforts with related chromophores have focused on charge transfer between dyes and catalysts in homogeneous covalent systems without the presence of a supporting electrode. In this work, femtosecond to millisecond transient absorption spectroscopies are utilized to identify a PMI derivative capable of injecting electrons into nanostructured semiconductor films with favorable rates and yields. The identified derivative is further used to oxidize covalently attached homogeneous water oxidation catalyst (WOC) precursor Cp*Ir III(ppy)Cl, where ppy = 2-phenylpyridine, on TiO2 and then incorporated into several photoelectrodes for photodriven water oxidation and hydrogen production. Atomic layer deposition of Al2O3 following chromophore adsorption is employed to improve the chemical stability of the chromophores and to prevent rapid electron-hole recombination. The TiO2-based photoanodes contain a coadsorbed WOC [(Ir IV(pyalc)(H2O)R)2(micro-O)] +2, where pyalc = 2-(2'pyridyl)-2-propanolate, or its mononuclear precursor functionalized with a siloxane binding group. NiO-based photocathodes include molecular cobaloxime- or [Ni(P2N2) 2

  10. Retinal degeneration mutants in the mouse.

    PubMed

    Chang, B; Hawes, N L; Hurd, R E; Davisson, M T; Nusinowitz, S; Heckenlively, J R

    2002-02-01

    The Jackson Laboratory, having the world's largest collection of mouse mutant stocks and genetically diverse inbred strains, is an ideal place to look for genetically determined eye variations and disorders. Through ophthalmoscopy, electroretinography and histology, we have discovered disorders affecting all aspects of the eye including the lid, cornea, iris, lens and retina, resulting in corneal disorders, cataracts, glaucoma and retinal degenerations. Mouse models of retinal degeneration have been investigated for many years in the hope of understanding the causes of photoreceptor cell death. Sixteen naturally occurring mouse mutants that manifest degeneration of photoreceptors in the retina with preservation of all other retinal cell types have been found: retinal degeneration (formerly rd, identical with rodless retina, r, now Pde6b(rd1)); Purkinje cell degeneration (pcd); nervous (nr); retinal degeneration slow (rds, now Prph(Rd2)); retinal degeneration 3 (rd3); motor neuron degeneration (mnd); retinal degeneration 4 (Rd4); retinal degeneration 5 (rd5, now tub); vitiligo (vit, now Mitf(mi-vit)); retinal degeneration 6 (rd6); retinal degeneration 7 (rd7, now Nr2e3(rd7)); neuronal ceroid lipofuscinosis (nclf); retinal degeneration 8 (rd8); retinal degeneration 9 (Rd9); retinal degeneration 10 (rd10, now Pde6b(rd10)); and cone photoreceptor function loss (cpfl1). In this report, we first review the genotypes and phenotypes of these mutants and second, list the mouse strains that carry each mutation. We will also provide detailed information about the cpfl1 mutation. The phenotypic characteristics of cpfl1 mice are similar to those observed in patients with complete achromatopsia (ACHM2, OMIM 216900) and the cpfl1 mutation is the first naturally-arising mutation in mice to cause cone-specific photoreceptor function loss. cpfl1 mice may provide a model for congenital achromatopsia in humans.

  11. Development of a low-cost, phyto-tunnel system using Portulaca grandiflora and its application for the treatment of dye-containing wastewaters.

    PubMed

    Khandare, Rahul V; Watharkar, Anuprita D; Kabra, Akhil N; Kachole, Manvendra S; Govindwar, Sanjay P

    2013-09-28

    A phyto-tunnel was developed using a drilled PVC pipe. It was planted with Portulaca grandiflora and used for the treatment of a textile effluent and a dye mixture. COD, BOD, TOC, conductivity, turbidity, total suspended solids and total dissolved solids of the textile effluent, and dye mixture were decreased by 57, 45, 43, 52, 76, 77 and 24 % within 96 h, and 49, 62, 41, 63, 58, 71 and 33 %, within 60 h, respectively, after treatment. The effluent and dye mixture were decolorized up to 87 and 90 % within 96 and 60 h, respectively. Significant induction in activities of lignin peroxidase, tyrosinase and DCIP reductase was observed in root tissues of the plants. FTIR, HPLC and HPTLC of untreated and treated samples showed the formation of new metabolites and preferential dye removal. Phytotoxicity studies revealed the non-toxic nature of the metabolites.

  12. Electromagnetic wave equations for relativistically degenerate quantum magnetoplasmas.

    PubMed

    Masood, Waqas; Eliasson, Bengt; Shukla, Padma K

    2010-06-01

    A generalized set of nonlinear electromagnetic quantum hydrodynamic (QHD) equations is derived for a magnetized quantum plasma, including collisional, electron spin- 1/2, and relativistically degenerate electron pressure effects that are relevant for dense astrophysical systems, such as white dwarfs. For illustrative purposes, linear dispersion relations are derived for one-dimensional magnetoacoustic waves for a collisionless nonrelativistic degenerate gas in the presence of the electron spin- 1/2 contribution and for magnetoacoustic waves in a plasma containing relativistically degenerate electrons. It is found that both the spin and relativistic degeneracy at high densities tend to slow down the magnetoacoustic wave due to the Pauli paramagnetic effect and relativistic electron mass increase. The present study outlines the theoretical framework for the investigation of linear and nonlinear behaviors of electromagnetic waves in dense astrophysical systems. The results are applied to calculate the magnetoacoustic speeds for both the nonrelativistic and relativistic electron degeneracy cases typical for white dwarf stars.

  13. Electromagnetic wave equations for relativistically degenerate quantum magnetoplasmas

    SciTech Connect

    Masood, Waqas; Eliasson, Bengt; Shukla, Padma K.

    2010-06-15

    A generalized set of nonlinear electromagnetic quantum hydrodynamic (QHD) equations is derived for a magnetized quantum plasma, including collisional, electron spin-(1/2), and relativistically degenerate electron pressure effects that are relevant for dense astrophysical systems, such as white dwarfs. For illustrative purposes, linear dispersion relations are derived for one-dimensional magnetoacoustic waves for a collisionless nonrelativistic degenerate gas in the presence of the electron spin-(1/2) contribution and for magnetoacoustic waves in a plasma containing relativistically degenerate electrons. It is found that both the spin and relativistic degeneracy at high densities tend to slow down the magnetoacoustic wave due to the Pauli paramagnetic effect and relativistic electron mass increase. The present study outlines the theoretical framework for the investigation of linear and nonlinear behaviors of electromagnetic waves in dense astrophysical systems. The results are applied to calculate the magnetoacoustic speeds for both the nonrelativistic and relativistic electron degeneracy cases typical for white dwarf stars.

  14. Degenerate gases of strontium for studies of quantum magnetism

    NASA Astrophysics Data System (ADS)

    Barker, Daniel Schaeder

    We describe the construction and characterization of a new apparatus that can produce degenerate quantum gases of strontium. The realization of degenerate gases is an important first step toward future studies of quantum magnetism. Three of the four stable isotopes of strontium have been cooled into the degenerate regime. The experiment can make nearly pure Bose-Einstein condensates containing approximately 1x104 atoms, for strontium-86, and approximately 4x105 atoms, for strontium-84. We have also created degenerate Fermi gases of strontium-87 with a reduced temperature, T/TF of approximately 0.2. The apparatus will be able to produce Bose-Einstein condensates of strontium-88 with straightforward modifications. We also report the first experimental and theoretical results from the strontium project. We have developed a technique to accelerate the continuous loading of strontium atoms into a magnetic trap. By applying a laser addressing the 3P1 to 3 S1 transition in our magneto-optical trap, the rate at which atoms populate the magnetically-trapped 3P 2 state can be increased by up to 65%. Quantum degenerate gases of atoms in the metastable 3P0 and 3P2 states are a promising platform for quantum simulation of systems with long-range interactions. We have performed an initial numerical study of a method to transfer the ground state degenerate gases that we can currently produce into one of the metastable states via a three-photon transition. Numerical simulations of the Optical Bloch equations governing the three-photon transition indicate that >90% of a ground state degenerate gas can be transferred into a metastable state.

  15. Efficient dye regeneration at low driving force achieved in triphenylamine dye LEG4 and TEMPO redox mediator based dye-sensitized solar cells.

    PubMed

    Yang, Wenxing; Vlachopoulos, Nick; Hao, Yan; Hagfeldt, Anders; Boschloo, Gerrit

    2015-06-28

    Minimizing the driving force required for the regeneration of oxidized dyes using redox mediators in an electrolyte is essential to further improve the open-circuit voltage and efficiency of dye-sensitized solar cells (DSSCs). Appropriate combinations of redox mediators and dye molecules should be explored to achieve this goal. Herein, we present a triphenylamine dye, LEG4, in combination with a TEMPO-based electrolyte in acetonitrile (E(0) = 0.89 V vs. NHE), reaching an efficiency of up to 5.4% under one sun illumination and 40% performance improvement compared to the previously and widely used indoline dye D149. The origin of this improvement was found to be the increased dye regeneration efficiency of LEG4 using the TEMPO redox mediator, which regenerated more than 80% of the oxidized dye with a driving force of only ∼0.2 eV. Detailed mechanistic studies further revealed that in addition to electron recombination to oxidized dyes, recombination of electrons from the conducting substrate and the mesoporous TiO2 film to the TEMPO(+) redox species in the electrolyte accounts for the reduced short circuit current, compared to the state-of-the-art cobalt tris(bipyridine) electrolyte system. The diffusion length of the TEMPO-electrolyte based DSSCs was determined to be ∼0.5 μm, which is smaller than the ∼2.8 μm found for cobalt-electrolyte based DSSCs. These results show the advantages of using LEG4 as a sensitizer, compared to previously record indoline dyes, in combination with a TEMPO-based electrolyte. The low driving force for efficient dye regeneration presented by these results shows the potential to further improve the power conversion efficiency (PCE) of DSSCs by utilizing redox couples and dyes with a minimal need of driving force for high regeneration yields.

  16. Suppression of cucurbit scab on cucumber leaves by photodynamic dyes

    USDA-ARS?s Scientific Manuscript database

    The goal of this study was to test the ability of the photodynamic dyes bengal rose, toluidine blue, and methylene blue, to protect systemically cucumber plants from cucurbit scab. At the stage of one true leaf, water or aqueous solutions of the dyes were applied to the leaf as droplets. When the se...

  17. Rejection of wild-type and genetically engineered major histocompatibility complex-deficient glial cell xenografts in the central nervous system results in bystander demyelination and Wallerian degeneration.

    PubMed

    O'Leary, M T; Bujdoso, R; Blakemore, W F

    1998-07-01

    Mixed glial cell cultures prepared from neonatal wild type and mutant male mice lacking either major histocompatibility complex class I, class II or both class I and II molecules (major histocompatibility complex class I(o/o)II(o/o)), and from syngeneic male rats were transplanted into female rat spinal cord white matter. Graft survival was monitored using DNA probes specific to the Y chromosome. Survival of major histocompatibility complex class-deficient grafts was not prolonged compared to wild-type grafts and in most cases grafts could not be detected at 28 days post-transplantation, at which time syngeneic grafts were still present. However, rejection of xenografts resulted in significant bystander damage to host tissue. In recipients of wild-type and major histocompatibility complex class I(o/o) xenografts the predominant pathology was demyelination. Demyelination was also observed in recipients of major histocompatibility complex class II(o/o) and major histocompatibility complex class I(o/o)II(o/o) xenografts, however in addition there was marked collagen deposition and meningeal cell invasion. Significantly more axons had undergone Wallerian degeneration in recipients of major histocompatibility complex class II(o/o) and major histocompatibility complex class I(o/o)II(o/o) xenografts than recipients of wild-type and major histocompatibility complex class I(o/o) xenografts. These findings were interpreted as evidence of a more destructive immune response associated with rejection of grafts lacking major histocompatibility complex class II molecules. It was proposed that the difference in the severity of bystander damage may be related to the previously demonstrated ability of xenogeneic major histocompatibility complex class II molecules to activate host T cells directly, whereas xenografts lacking major histocompatibility complex class II molecules were capable of activating host T cells only by the indirect pathway.

  18. Light scattering of degenerate fermions

    NASA Astrophysics Data System (ADS)

    Aubin, S.; Leblanc, L. J.; Myrskog, S.; Extavour, M. H. T.; McKay, D.; Stummer, A.; Thywissen, J. H.

    2006-05-01

    We report on progress in measuring the suppression of resonant light scattering in a gas of degenerate fermions. A gas of trapped degenerate fermions is expected to exhibit narrower optical linewidths and longer excited state lifetimes than single atoms when the Fermi energy is larger than the photon recoil energy [1-3]. In this case, the number of available states into which a scattered atom can recoil is significantly reduced due to the filling of the Fermi sea. We produce a degenerate gas of 4x10^4 ultra-cold fermionic ^40K atoms by sympathetic cooling with bosonic ^87Rb in a micro-magnetic chip trap. The atoms can then be loaded into a tight dipole trap just above the surface of the chip and probed with a near resonance laser pulse. [1] Th. Busch, J. R. Anglin, J. I. Cirac, and P. Zoller, Europhys. Lett. 44, 1 (1998). [2] B. DeMarco and D. S. Jin, Phys. Rev. A 58, R4267 (1998). [3] J. Javanainen and J. Ruostekosky, Phys. Rev. A 52, 3033 (1995). Work supported by NSERC, CFI, OIT, Research Corporation, and PRO.

  19. General Pathophysiology in Retinal Degeneration

    PubMed Central

    Wert, Katherine J.; Lin, Jonathan H.; Tsang, Stephen H.

    2015-01-01

    Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/ or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6β) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade. PMID:24732759

  20. Radial keratotomy associated endothelial degeneration

    PubMed Central

    Moshirfar, Majid; Ollerton, Andrew; Semnani, Rodmehr T; Hsu, Maylon

    2012-01-01

    Purpose To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK) and varying degrees of endothelial degeneration. Methods Retrospective case series were used. Results Thirteen eyes (seven patients) were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years (range: 38–72 years), averaging 18.7 years (range: 11–33 years) after RK. The presentation of guttata varied in degree from moderate to severe. Best corrected visual acuity (BCVA) ranged from 20/25 to 20/80. All patients had a history of bilateral RK, except one patient who did not develop any guttata in the eye without prior RK. No patients reported a family history of Fuch’s Dystrophy. One patient underwent a penetrating keratoplasty in one eye and a Descemet’s stripping automated endothelial keratoplasty (DSAEK) in the other eye. Conclusions RK may induce a spectrum of endothelial degeneration. In elderly patients, the findings of guttata may signify comorbid Fuch’s dystrophy in which RK incisions could potentially hasten endothelial decomposition. In these select patients with stable cornea topography and prior RK, DSAEK may successfully treat RK endothelial degeneration. PMID:22347792

  1. Radial keratotomy associated endothelial degeneration.

    PubMed

    Moshirfar, Majid; Ollerton, Andrew; Semnani, Rodmehr T; Hsu, Maylon

    2012-01-01

    To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK) and varying degrees of endothelial degeneration. Retrospective case series were used. Thirteen eyes (seven patients) were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years (range: 38-72 years), averaging 18.7 years (range: 11-33 years) after RK. The presentation of guttata varied in degree from moderate to severe. Best corrected visual acuity (BCVA) ranged from 20/25 to 20/80. All patients had a history of bilateral RK, except one patient who did not develop any guttata in the eye without prior RK. No patients reported a family history of Fuch's Dystrophy. One patient underwent a penetrating keratoplasty in one eye and a Descemet's stripping automated endothelial keratoplasty (DSAEK) in the other eye. RK may induce a spectrum of endothelial degeneration. In elderly patients, the findings of guttata may signify comorbid Fuch's dystrophy in which RK incisions could potentially hasten endothelial decomposition. In these select patients with stable cornea topography and prior RK, DSAEK may successfully treat RK endothelial degeneration.

  2. Laser dye technology

    SciTech Connect

    Hammond, P R

    1999-09-01

    The author has worked with laser dyes for a number of years. A first interest was in the Navy blue-green program where a flashlamp pumped dye laser was used as an underwater communication and detection device. It made use of the optical window of sea-water--blue for deep ocean, green for coastal water. A major activity however has been with the Atomic Vapor Laser Isotope Separation Program (AVLIS) at the Lawrence Livermore National Laboratory. The aim here has been enriching isotopes for the nuclear fuel cycle. The tunability of the dye laser is utilized to selectively excite one isotope in uranium vapor, and this isotope is collected electrostatically as shown in Figure 1. The interests in the AVLIS program have been in the near ultra-violet, violet, red and deep-red.

  3. Hair cosmetics: dyes.

    PubMed

    Guerra-Tapia, A; Gonzalez-Guerra, E

    2014-11-01

    Hair plays a significant role in body image, and its appearance can be changed relatively easily without resort to surgical procedures. Cosmetics and techniques have therefore been used to change hair appearance since time immemorial. The cosmetics industry has developed efficient products that can be used on healthy hair or act on concomitant diseases of the hair and scalp. Dyes embellish the hair by bleaching or coloring it briefly, for temporary periods of longer duration, or permanently, depending on the composition of a dye (oxidative or nonoxidative) and its degree of penetration of the hair shaft. The dermatologist's knowledge of dyes, their use, and their possible side effects (contact eczema, cancer, increased porosity, brittleness) can extend to an understanding of cosmetic resources that also treat hair and scalp conditions. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

  4. Water soluble laser dyes

    DOEpatents

    Hammond, Peter R.; Feeman, James F.; Field, George F.

    1998-01-01

    Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6; X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

  5. Water soluble laser dyes

    DOEpatents

    Hammond, P.R.; Feeman, J.F.; Field, G.F.

    1998-08-11

    Novel water soluble dyes of the formula 1 are provided by the formula described in the paper wherein R{sup 1} and R{sup 4} are alkyl of 1 to 4 carbon atoms or hydrogen; or R{sup 1}--R{sup 2} or R{sup 2}--R{sup 4} form part of aliphatic heterocyclic rings; R{sup 2} is hydrogen or joined with R{sup 1} or R{sup 4} as described above; R{sup 3} is --(CH{sub 2}){sub m}--SO{sub 3}{sup {minus}}, where m is 1 to 6; X is N, CH or formula 2 given in paper where Y is 2 --SO{sub 3}{sup {minus}} ; Z is 3, 4, 5 or 6 --SO{sub 3}{sup {minus}}. The novel dyes are particularly useful as the active media in water solution dye lasers.

  6. Aerobic biodegradation of Azo dye by Bacillus cohnii MTCC 3616; an obligately alkaliphilic bacterium and toxicity evaluation of metabolites by different bioassay systems.

    PubMed

    Prasad, A S Arun; Rao, K V Bhaskara

    2013-08-01

    An obligate alkaliphilic bacterium Bacillus cohnii MTCC 3616 aerobically decolorized a textile azo dye Direct Red-22 (5,000 mg l⁻¹) with 95 % efficiency at 37 °C and pH 9 in 4 h under static conditions. The decolorization of Direct Red-22 (DR-22) was possible through a broad pH (7-11), temperature (10-45 °C), salinity (1-7 %), and dye concentration (5-10 g l⁻¹) range. Decolorization of dye was assessed by UV-vis spectrophotometer with reduction of peak intensity at 549 nm (λ(max)). Biodegradation of dye was analyzed by Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC). The FTIR spectrum revealed that B. cohnii specifically targeted azo bond (N=N) at 1,614.42 cm⁻¹ to break down Direct Red-22. Formation of metabolites with different retention times in HPLC analysis further confirmed the degradation of dye. The phytotoxicity test with 5,000 mg l⁻¹ of untreated dye showed 80 % germination inhibition in Vigna mungo, 70 % in Sorghum bicolor and 80 % in Vigna radiata. No germination inhibition was noticed in all three plants by DR-22 metabolites at 5,000 mg l⁻¹. Biotoxicity test with Artemia salina proved the lethality of the azo dye at LC₅₀ of 4 and 8 % for degraded metabolites by causing death of its nauplii compared to its less toxic-degraded metabolites. Bioaccumulation of dye was observed in the mid-gut of A. salina. The cytogenotoxicity assay on the meristematic root tip cells of Allium cepa further confirmed the cytotoxic nature of azo dye (DR-22) with decrease in mitotic index (0.5 % at 500 ppm) and increase in aberrant index (4.56 %) over 4-h exposure period. Genotoxic damages (lagging chromosome, metaphase cluster, chromosome bridges, and dye accumulation in cytoplasm) were noticed at different stages of cell cycle. The degraded metabolites had negligible cytotoxic and genotoxic effects.

  7. Optimization of working cathode position in sleeve-type bioelectrochemical system with inner chamber/outer chamber for azo dye treatment.

    PubMed

    Kong, Fanying; Wang, Aijie; Ren, Hong-Yu

    2015-12-01

    In this study, the optimization of working cathode position in sleeve-type bioelectrochemical system (BES) was evaluated with inner/outer chamber for azo dye decolorization. Results showed that the working position in outer chamber performed better with decolorization efficiencies of 97.8 ± 2.1% (7h) and 94.0 ± 2.3% (16 h) than that in inner chamber as the volume ratio Vcathode:Vanode=1:1 and 3:1, respectively. The current and electrochemical impedance spectroscopy (EIS) analysis indicated that the proton/electron transfer and anolyte diffusion could be improved using outer chamber as working position. The decolorization with increased volume ratio could be further improved through the strategy of increasing substrate concentration, which would provide enough electrons and decrease diffusion resistance, further improving the whole performance with increased outer cathode volume. It has the great potential in sleeve-type configuration application and would create more challenges for process optimization and maintenance.

  8. Induction of chromosome aberrations in the Allium cepa test system caused by the exposure of seeds to industrial effluents contaminated with azo dyes.

    PubMed

    Caritá, R; Marin-Morales, M A

    2008-06-01

    Numerous potentially mutagenic chemicals have been studied mainly because they can cause damaging and inheritable changes in the genetic material. Several tests are commonly used for biomonitoring pollution levels and to evaluate the effects of toxic and mutagenic agents present in the natural environment. This study aimed at assessing the potential of a textile effluent contaminated with azo dyes to induce chromosomal and nuclear aberrations in Allium cepa test systems. A continuous exposure of seeds in samples of the textile effluent in different concentrations was carried out (0.3%, 3%, 10%, and 100%). Cells in interphase and undergoing division were examined to assess the presence of chromosome aberrations, nuclear changes, and micronuclei. Our results revealed a mutagenic effect of the effluent at concentrations of 10% and 100%. At lower concentrations, the effluent (3% and 0.3%) did not induce mutagenic alterations in the test organism A. cepa. These findings are of concern, since cell damage may be transmitted to subsequent generations, possibly affecting the organism as a whole, as well as the local biota exposed to the effluent discharge. If the damage results in cell death, the development of the organism may be affected, which could also lead to its death.

  9. Fabrication of dye-sensitized solar cell (DSSC) using different particle sizes of TiO2 deposited via nano-particle deposition system (NPDS).

    PubMed

    Kim, Yang-Hee; Kim, Kwang-Su; Lee, Jin-Woong; Kim, Min-Saeng; Choi, Jung-Oh; Ahn, Sung-Hoon; Lee, Caroline Sunyong

    2012-04-01

    TiO2 layers were fabricated using a nano-particle deposition system (NPDS) on transparent conductive oxide (TCO) glass for dye sensitized solar cells (DSSCs). Conventionally, TiO2 paste for working electrodes has been fabricated using paste type methods. The fabricated paste composed of a mixture of nano-sized TiO2 powders, binders and solutions is then painted on TCO glass. After drying, the TiO2 layer on TCO glass is sintered to make a path for electron transfer. TiO2 layers formed by this paste type method require numerous steps, which can be time consuming. In this study, TiO2 powders were sprayed directly on TCO glass using NPDS in order to simplify the fabrication steps. To improve porosity and produce scattering layers, commercial nanocrystalline TiO, powders with different sizes were alternately deposited. Moreover, powders with different sizes were mixed and deposited on the TCO glass. The results indicate that the DSSCs with a TiO2 layer composed of different particle sizes had better cell performance than the cells assembled with single-sized TiO2 particles. Therefore, this study shows that a dry TiO2 coating process is possible for DSSC fabrication to improve its cell efficiencies, and this method can easily be applied on flexible substrates since NPDS is a room-temperature deposition process.

  10. Flashlamp-excited dye laser therapy for treatment of cutaneous vascular lesions

    NASA Astrophysics Data System (ADS)

    Goldberg, David J.

    1990-06-01

    Flashlamp excited dye laser therapy represents an exciting new advance in the treatment of a variety of cutaneous vascular lesions. Portwine stains, angiomas and telangiectases can be treated in all age groups with this laser system. This paper will review the physics of flashlamp dye laser photothermolysis. The differences between argon laser photocoagulation and flashlamp excited dye laser therapy will be reviewed.

  11. A new technology for harnessing the dye polluted water and dye collection in a chemical factory.

    PubMed

    Pu, J P; Pu, P M; Hu, C H; Qian, J L; Pu, J X; Hua, J K

    2001-04-01

    A new technology for harnessing the dye polluted water and dye collection was developed. It is based on the enhanced evaporation by using solar, wind and air temperature energy and additional heat-electric energy. It consists of four parts: (1) evaporation carrier system (evaporation carrier and frame for evaporation carrier) for polluted water; (2) polluted water circulating system (pumping-spraying-collecting); (3) heating system; (4) workshop with polluted water reservoir-tanks and rainfall prevention roof. The polluted water was (heated in case necessary) sprayed to the evaporation carrier system and the water was evaporated when it moved in the space and downward along the carrier mainly by using natural (solar, wind and air temperature energy). In case, when there is no roof for the carrier system, the polluted water can be stored in the reservoirs (storage volume for about 20 days). The first 10-25 mm rainfall also need to be stored in the reservoirs to meet the state standard for discharging wastewater. The dye may be collected at the surface in the reservoir-tanks and the crystallized salt may be collected at the bottom plate. The black-color wastewater released by the factory is no more discharged to the surface water system of Taihu Lake Basin. About 2 kg dye and 200 kg industrial salt may be collected from each tone of the polluted water. The non-pollution production of dye may be realized by using this technology with environmental, economical and social benefits.

  12. Dye filled security seal

    DOEpatents

    Wilson, Dennis C. W.

    1982-04-27

    A security seal for providing an indication of unauthorized access to a sealed object includes an elongate member to be entwined in the object such that access is denied unless the member is removed. The elongate member has a hollow, pressurizable chamber extending throughout its length that is filled with a permanent dye under greater than atmospheric pressure. Attempts to cut the member and weld it together are revealed when dye flows through a rupture in the chamber wall and stains the outside surface of the member.

  13. A geometrical approach to degenerate scalar-tensor theories

    NASA Astrophysics Data System (ADS)

    Chagoya, Javier; Tasinato, Gianmassimo

    2017-02-01

    Degenerate scalar-tensor theories are recently proposed covariant theories of gravity coupled with a scalar field. Despite being characterised by higher order equations of motion, they do not propagate more than three degrees of freedom, thanks to the existence of constraints. We discuss a geometrical approach to degenerate scalar-tensor systems, and analyse its consequences. We show that some of these theories emerge as a certain limit of DBI Galileons. In absence of dynamical gravity, these systems correspond to scalar theories enjoying a symmetry which is different from Galileon invariance. The scalar theories have however problems concerning the propagation of fluctuations around a time dependent background. These issues can be tamed by breaking the symmetry by hand, or by minimally coupling the scalar with dynamical gravity in a way that leads to degenerate scalar-tensor systems. We show that distinct theories can be connected by a relation which generalizes Galileon duality, in certain cases also when gravity is dynamical. We discuss some implications of our results in concrete examples. Our findings can be helpful for assessing stability properties and understanding the non-perturbative structure of systems based on degenerate scalar-tensor systems.

  14. Passive apparatus for stabilizing a flashlamp-pumped dye laser

    SciTech Connect

    De Wilde, M.A.; Decker, L.J.

    1986-04-29

    A flash lamp pumped, dye laser apparatus is described which consists of a flash lamp and a liquid dye solution in a transparent compartment proximate to the flash lamp. The compartment is also connected to a tubular circulatory system for moving the liquid dye. The dye solution is activated by flashing of the lamp for lasing to emit light, the lamp and compartment enclosed in a cooling first water jacket, the jacket enclosing deionized water for cooling, an improved cooling system wherein the temperature of the deionized water and the liquid dye solution are maintained within 0.5/sup 0/C of one another, enabling the laser for pulsing at a stabilized 10 pulses per second rate.

  15. Mouse models for studies of retinal degeneration and diseases

    PubMed Central

    Chang, Bo

    2013-01-01

    Summary Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human retinal degeneration. Mutant mice also provide reproducible, experimental systems for elucidating pathways of normal development and function. Here, I describe the tools used in the discoveries of many retinal degeneration models, including indirect ophthalmoscopy (to look at the fundus appearance), fundus photography and fluorescein angiography (to document the fundus appearance), electroretinography (to check retinal function) as well as the heritability test (for genetic characterization). PMID:23150358

  16. Breather structures in degenerate relativistic non-extensive plasma

    NASA Astrophysics Data System (ADS)

    Shahmansouri, M.; Alinejad, H.; Tribeche, M.

    2017-06-01

    We examine the excitation of breather structures in a degenerate relativistic plasma consisting of non-extensive electrons and cold ions. For this purpose, the multiple time scale perturbation technique is used to obtain a nonlinear Schrödinger equation (NLSE). We then consider different localized solutions regarding analytical breather solutions of the NLSE, and examine their properties in the frame of the present plasma system, i.e. a degenerate relativistic non-extensive plasma. The results of the present investigation may be useful for the understanding of the basic features of the nonlinear excitations that may occur in dense astrophysical plasmas.

  17. Laser dye structures and synonyms

    SciTech Connect

    Kauffman, J.M.

    1980-10-15

    Laser dyes are organic chemicals whose systematic names are lengthy and confusing. Other names: some jargon, some trade: have come into everyday use, but there is no consistency, and sometimes reserch workers will have dyes from different suppliers that are identical in structure although different in name. This paper tabulates laser dyes by a characteristic identification number.

  18. Degenerate parametric oscillation in quantum membrane optomechanics

    NASA Astrophysics Data System (ADS)

    Benito, Mónica; Sánchez Muñoz, Carlos; Navarrete-Benlloch, Carlos

    2016-02-01

    The promise of innovative applications has triggered the development of many modern technologies capable of exploiting quantum effects. But in addition to future applications, such quantum technologies have already provided us with the possibility of accessing quantum-mechanical scenarios that seemed unreachable just a few decades ago. With this spirit, in this work we show that modern optomechanical setups are mature enough to implement one of the most elusive models in the field of open system dynamics: degenerate parametric oscillation. Introduced in the eighties and motivated by its alleged implementability in nonlinear optical resonators, it rapidly became a paradigm for the study of dissipative phase transitions whose corresponding spontaneously broken symmetry is discrete. However, it was found that the intrinsic multimode nature of optical cavities makes it impossible to experimentally study the model all the way through its phase transition. In contrast, here we show that this long-awaited model can be implemented in the motion of a mechanical object dispersively coupled to the light contained in a cavity, when the latter is properly driven with multichromatic laser light. We focus on membranes as the mechanical element, showing that the main signatures of the degenerate parametric oscillation model can be studied in state-of-the-art setups, thus opening the possibility of analyzing spontaneous symmetry breaking and enhanced metrology in one of the cleanest dissipative phase transitions. In addition, the ideas put forward in this work would allow for the dissipative preparation of squeezed mechanical states.

  19. Wallerian degeneration in ICAM-1-deficient mice.

    PubMed Central

    Vougioukas, V. I.; Roeske, S.; Michel, U.; Brück, W.

    1998-01-01

    Wallerian degeneration of the peripheral nervous system was studied in ICAM-1-deficient mice and compared with the phenomena observed in C57BL wild-type animals. There was a decrease in myelin density in both mice strains 4 and 6 days after transection of the sciatic nerve. The degenerating nerves were invaded by Mac-1-, LFA-1-, and F4/80-positive macrophages; significantly lower numbers of macrophages were present in ICAM-1-deficient nerves. Myelin loss decreased after nerve transection with a more prominent loss in ICAM-1-deficient animals. Schwann cells revealed a much higher myelin load in these animals when compared with wild-type nerves, and there was an increased proliferation of endoneurial cells in ICAM-1-deficient mice. These data indicate that ICAM-1 is involved in macrophage recruitment to injured peripheral nerves as well as in the proliferative and phagocytic response of Schwann cells after peripheral nerve transection. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:9422541

  20. Photoactive dye-enhanced tissue ablation for endoscopic laser prostatectomy.

    PubMed

    Ahn, Minwoo; Hau, Nguyen Trung; Van Phuc, Nguyen; Oh, Junghwan; Kang, Hyun Wook

    2014-11-01

    Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia (BPH) over 20 years. Recently, application of high laser power up to 200 W was often reported to swiftly remove a large amount of prostatic tissue. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue vaporization with low laser power. Chicken breast tissue was selected as a target tissue due to minimal optical absorption at the visible wavelength. Four biocompatible photoactive dyes, including amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532 nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm(2) . Light absorbance and ablation threshold were measured with UV-Vis spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with radiant exposure, dye concentration, and number of injection. Among the dyes, AR created the highest ablation rate of 44.2 ± 0.2 µm/pulse due to higher absorbance and lower ablation threshold. High aspect ratios up to 7.1 ± 0.4 entailed saturation behavior in the tissue ablation injected with AR and BD, possibly resulting from plume shielding and increased scattering due to coagulation. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33% reduced laser power with almost equivalent performance. Due to

  1. Global existence for a degenerate haptotaxis model of cancer invasion

    NASA Astrophysics Data System (ADS)

    Zhigun, Anna; Surulescu, Christina; Uatay, Aydar

    2016-12-01

    We propose and study a strongly coupled PDE-ODE system with tissue-dependent degenerate diffusion and haptotaxis that can serve as a model prototype for cancer cell invasion through the extracellular matrix. We prove the global existence of weak solutions and illustrate the model behavior by numerical simulations for a two-dimensional setting.

  2. Partially purified bitter gourd (Momordica charantia) peroxidase catalyzed decolorization of textile and other industrially important dyes.

    PubMed

    Akhtar, Suhail; Ali Khan, Amjad; Husain, Qayyum

    2005-11-01

    The aim of this study was to evaluate the enzymatic action of partially purified bitter gourd peroxidase for the degradation/decolorization of complex aromatic structures. Twenty-one dyes, with a wide spectrum of chemical groups, currently being used by the textile and other important industries have been selected for the study. Here, for the first time we have shown peroxidases from Momordica charantia (300 EU/gm of vegetable) to be highly effective in decolorizing industrially important dyes. Dye solutions, containing 50-200 mg dye/l, were used for the treatment with bitter gourd peroxidase (specific activity of 99.0 EU/mg protein). M. charantia peroxidases were able to decolorize most of the textile dyes by forming insoluble precipitate. When the textile dyes were treated with increasing concentration of enzyme, it was observed that greater fraction of the color was removed but four out of eight reactive dyes were recalcitrant to decolorization by bitter gourd peroxidase. Step-wise addition of enzyme to the decolorizing reaction mixture at the interval of 1h further enhanced the dye decolorization. The rate of decolorization was enhanced when the dyes were incubated with fixed quantity of enzyme for increasing times. Decolorization of non-textile dyes resulted in the degradation and removal of dyes from the solution without any precipitate formation. Decolorization rate was drastically increased when the textile and other industrially important non-textile dyes were treated with bitter gourd peroxidase in presence of 1.0 mM 1-hydroxybenzotriazole. Complex mixtures of dyes were prepared by taking three to four reactive textile and non-textile dyes in equal proportions. Each mixture was decolorized by more than 80% when treated with the enzyme in presence of 1.0 mM 1-hydroxybenzotriazole. Our data suggest that the peroxidase/mediator system is an effective biocatalyst for the treatment of effluents containing recalcitrant dyes from textile, dye manufacturing

  3. Salicylic Acid-Based Organic Dyes Acting as the Photosensitizer for Solar Cells.

    PubMed

    Hong, Sungjun; Park, Jae-Hyeong; Han, Ah-Reum; Ko, Kwan-Woo; Eom, Jin Hee; Namgoong, Sung Keon; Lo, Alvie S V; Gordon, Keith C; Yoon, Sungho; Han, Chi-Hwan

    2016-05-01

    A D-π-A metal-free organic dye, featuring salicylic acid as a novel acceptor/anchoring unit, has been designed, synthesized and applied to dye-sensitized solar cell. The detailed photophysical, electrochemical, photovoltaic and sensitizing properties of the organic dye were investigated, in addition to the computational studies of the dye and dye-(TiO2)6 system. A solar cell device using this new organic dye as a sensitizer produced a solar to electric power conversion efficiency (PCE) of 3.49% (J(sc) = 6.69 mAcm-2, V(oc) = 0.74 V and ff = 0.70) under 100 mWcm(-2) simulated AM 1.5 G solar irradiation, demonstrating that the salicylic acid-based organic dye is a suitable alternative to currently used organometallic dyes.

  4. Effect of dyeing on antibacterial efficiency of silver coated cotton fabrics

    NASA Astrophysics Data System (ADS)

    Shahidi, Sheila; Rezaee, Sahar; Hezavehi, Emadaldin

    2014-04-01

    Despite numerous investigations during recent decades in the field of antimicrobial treating textile fibers using silver, many obscurities remain regarding the durability and dyeing ability and the influences of dyeing on the antimicrobial effectiveness of silver-treated fibers. In this research work, the cotton fabrics were sputtered using DC magnetron sputtering system for different times of exposure by silver. Then the silver coated samples were dyed by different classes of synthetic and natural dyes. The dye ability of coated samples was compared with untreated cotton. The reflective spectrophotometer was used for this purpose. The morphology of the cotton fabrics before and after dyeing was observed using a scanning electron microscope (SEM). The antibacterial activity of samples before and after dyeing, were investigated and compared. For antibacterial investigation, the antibacterial counting tests were used. It was concluded that, dyeing does not have any negative effect on antibacterial activity of coated samples and very good antibacterial activity was achieved after dyeing.

  5. Alzheimer's Dye Test?

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Massachusetts Institute of Technology (MIT) scientists have developed a new dye that could offer noninvasive early diagnosis of Alzheimer's disease, a discovery that could aid in monitoring the progression of the disease and in studying the efficacy of new treatments to stop it. The work is published in Angewandte Chemie. Today, doctors can only…

  6. [Vital dyes in chromovitrectomy].

    PubMed

    Dib, Eduardo; Rodrigues, Eduardo Büchelle; Maia, Maurício; Meyer, Carsten H; Penha, Fernando Marcondes; Furlani, Bruno de Albuquerque; Costa, Elaine de Paula Fiod; Farah, Michel Eid

    2009-01-01

    The aim of this article is to present the current data with regard to the application of vital dyes during vitreoretinal surgery, 'chromovitrectomy', as well as to overview the current literature regarding the properties of dyes, techniques of application, indications and complications in chromovitrectomy. A large body of published research has recently addressed the toxicity profile of indocyanine green for chromovitrectomy. Experimental data demonstrate dose-dependent toxicity of indocyanine green to various retinal cells. Newer generation vital dyes for chromovitrectomy include trypan blue, patent blue, triamcinolone acetonide, infracyanine green, sodium fluorescein, bromophenol blue, fluorometholone acetate and brilliant blue. Novel instruments may enable a selective painting of preretinal tissues during chromovitrectomy. This review suggests that the field of chromovitrectomy represents an expanding area of research. The first line agents for internal limiting membrane staining in chromovitrectomy are indocyanine green, infracyanine green, and brilliant blue. Patent blue, bromophenol blue and trypan blue arose as outstanding biostains for visualization of epiretinal membranes. Novel dyes available for chromovitrectomy deserve further investigation.

  7. Vital dyes for chromovitrectomy.

    PubMed

    Rodrigues, Eduardo B; Maia, Maurício; Meyer, Carsten H; Penha, Fernando M; Dib, Eduardo; Farah, Michel E

    2007-05-01

    The aim of this article is to present the current state-of-the-art in regard to the application of vital dyes during vitreoretinal surgery, 'chromovitrectomy', as well as to overview the current literature regarding the properties of dyes, techniques of application, indications, and complications in chromovitrectomy. A large body of published research has recently addressed the toxicity profile of indocyanine green for chromovitrectomy. Experimental data demonstrate dose-dependent toxicity of indocyanine green to various retinal cells. Newer generation vital dyes for chromovitrectomy include trypan blue, patent blue, triamcinolone acetonide, infracyanine green, sodium fluorescein, bromophenol blue, fluorometholone acetate and brilliant blue. Novel instruments may enable a selective painting of preretinal tissues during chromovitrectomy. This review suggests that the field of chromovitrectomy represents an expanding area of research. The first line agents for internal limiting membrane staining in chromovitrectomy are indocyanine green, infracyanine green, and brilliant blue. Patent blue, bromophenol blue and trypan blue arose as outstanding biostains for visualization of epiretinal membranes. Novel dyes available for chromovitrectomy deserve further investigation.

  8. Alzheimer's Dye Test?

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Massachusetts Institute of Technology (MIT) scientists have developed a new dye that could offer noninvasive early diagnosis of Alzheimer's disease, a discovery that could aid in monitoring the progression of the disease and in studying the efficacy of new treatments to stop it. The work is published in Angewandte Chemie. Today, doctors can only…

  9. Estimation of Fluorescent Dye Amount in Tracer Dye Test

    NASA Astrophysics Data System (ADS)

    Pekkan, Emrah; Balkan, Erman; Balkan, Emir

    2015-04-01

    Karstic groundwater is more influenced by human than the groundwater that disperse in pores. On the other hand karstic groundwater resources, in addition to providing agricultural needs, livestock breeding, drinking and domestic water in most of the months of the year, they also supply drinking water to the wild life at high altitudes. Therefore sustainability and hydrogeological investigation of karstic resources is critical. Tracing techniques are widely used in hydrologic and hydrogeologic studies to determine water storage, flow rate, direction and protection area of groundwater resources. Karanfil Mountain (2800 m), located in Adana, Turkey, is one of the karstic recharge areas of the natural springs spread around its periphery. During explorations of the caves of Karanfil mountain, a 600 m deep cave was found by the Turkish and Polish cavers. At the bottom of the cave there is an underground river with a flow rate of approximately 0.5 m3/s during August 2014. The main spring is located 8 km far from the cave's entrance and its mean flow rate changes between 3.4 m3/s and 0.21 m3/s in March and September respectively according to a flowrate observation station of Directorate of Water Works of Turkey. As such frequent storms, snowmelt and normal seasonal variations in rainfall have a significant and rapid effect on the volume of this main spring resource. The objective of our research is to determine and estimate dye amount before its application on the field inspired from the previously literature on the subject. This estimation is intended to provide a preliminary application of a tracer test of a karstic system. In this study dye injection, inlet point will be an underground river located inside the cave and the observation station will be the spring that is approximately 8 km far from the cave entrance. On the other hand there is 600 meter elevation difference between cave entrance and outlet spring. In this test Rodamin-WT will be used as tracer and the

  10. Near Infrared Heptamethine Cyanine Dye-Mediated Cancer Imaging*

    PubMed Central

    Yang, Xiaojian; Shi, Chunmeng; Tong, Rong; Qian, Weiping; Zhau, Haiyen E.; Wang, Ruoxiang; Zhu, Guodong; Cheng, Jianjun; Yang, Vincent W.; Cheng, Tianmin; Henary, Maged; Strekowski, Lucjan; Chung, Leland W.K.

    2010-01-01

    Purpose Near-infrared (NIR) fluorescence imaging has great potential for noninvasive in vivo imaging of tumors. In this study, we demonstrate the preferential uptake and retention of two hepatamethine cyanine dyes, IR-783 and MHI-148, in tumor cells and tissues. Experimental Design IR-783 and MHI-148 were investigated for their ability to accumulate in human cancer cells, tumor xenografts and spontaneous mouse tumors in transgenic animals. Time- and concentration-dependent dye uptake and retention in normal and cancer cells and tissues were compared, and subcellular localization of the dyes and mechanisms of the dye uptake and retention in tumor cells were evaluated using organelle-specific tracking dyes and bromosulfophthalein (BSP), a competitive inhibitor of organic anion transporting peptides (OATPs). These dyes were used to detect human cancer metastases in a mouse model and differentiate cancer cells from normal cells in blood. Results These NIR hepatamethine cyanine dyes were retained in cancer cells but not normal cells, in tumor xenografts, and in spontaneous tumors in transgenic mice. They can be used to detect cancer metastasis and cancer cells in blood with a high degree of sensitivity. The dyes were found to concentrate in the mitochondria and lysosomes of cancer cells, probably through OATPs since the dye uptake and retention in cancer cells can be blocked completely by BSP. These dyes, when injected to mice, did not cause systemic toxicity. Conclusions These two heptamethine cyanine dyes are promising imaging agents for human cancers and can be further exploited to improve cancer detection, prognosis and treatment. PMID:20410058

  11. Retrograde Axonal Degeneration in Parkinson Disease

    PubMed Central

    Tagliaferro, Patricia; Burke, Robert E.

    2016-01-01

    In spite of tremendous research efforts we have not yet achieved two of our principal therapeutic goals in the treatment of Parkinson’s disease (PD), to prevent its onward progression and to provide restoration of systems that have already been damaged by the time of diagnosis. There are many possible reasons for our inability to make progress. One possibility is that our efforts thus far may not have been directed towards the appropriate cellular compartments. Up until now research has been largely focused on the loss of neurons in the disease. Thus, neuroprotection approaches have been largely aimed at blocking mechanisms that lead to destruction of the neuronal cell body. Attempts to provide neurorestoration have been almost entirely focused on replacement of neurons. We herein review the evidence that the axonal component of diseased neuronal systems merit more of our attention. Evidence from imaging studies, from postmortem neurochemical studies, and from genetic animal models suggests that the axons of the dopaminergic system are involved predominantly and early in PD. Since the mechanisms of axonal destruction are distinct from those of neuron cell body degeneration, a focus on axonal neurobiology will offer new opportunities for preventing their degeneration. At present these mechanisms remain largely obscure. However, defining them is likely to offer new opportunities for neuroprotection. In relation to neurorestoration, while it has been classically believed that neurons of the adult central nervous system are incapable of new axon growth, recent evidence shows that this is not true for the dopaminergic projection. In conclusion, the neurobiology of axons is likely to offer many new approaches to protective and restorative therapeutics. PMID:27003783

  12. Oxidative degradation of azo dyes using tourmaline.

    PubMed

    Wang, Cuiping; Zhang, Yanwei; Yu, Li; Zhang, Zhiyuan; Sun, Hongwen

    2013-09-15

    This study aimed to investigate the catalyzed degradation ability of tourmaline on the dyes methylene blue (MB), rhodamine B (RhB), and congo red (CR) at different pH values. Interestingly, tourmaline strongly adsorbed anionic dyes, but it did not adsorb cationic dyes. When H₂O₂ was introduced into the tourmaline-dye systems, the degradation percentage for CR catalysis by tourmaline was lower than the percentage of adsorption, whereas the opposite was true for MB and RhB systems. Notably, the catalyzed degradation decreased from 100% to 45% for MB, 100% to 15% for RhB and 100% to 25% for CR as the pH increased from 3.0 to 10.0, respectively, which was much greater than the degradation obtained for previously reported materials at pH values ranging from 4.0 to 10.0. Tourmaline catalytically degraded the dyes over a broad range of pH values, which was attributed to tourmaline automatically adjusting the pH of the dye solutions to approximately 5.5 from an initial range of 4.2-10.0. An electron paramagnetic resonance spin trapping technique observed peroxyl (ROO·) and alkoxy (RO·) or alkyl (R·) radicals originated from the attack of ·OH radicals and O₂(·-) radicals, indicating that these radicals were involved in the catalyzed degradation of MB. Importantly, four intermediate products of MB at m/z 383, 316, 203 and 181 were observed by LC/MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Dye-sensitized composite semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Tennakone, K.; Bandaranayake, P. K. M.; Jayaweera, P. V. V.; Konno, A.; Kumara, G. R. R. A.

    2002-04-01

    Understanding of the charge transport and recombination mechanisms of dye-sensitized solar cells based on semiconductor nanostructures is essential for the improvement of their performance. A great deal of information on these systems have been obtained from studies on a single material (mostly TiO 2 and to a lesser extent ZnO and SnO 2). We have conducted extensive measurements on composite dye-sensitized nanosturctures and found that the composite systems possess unusual properties. Dye-sensitized photoelectrochemical cells made from nanocrystalline films of some materials (e.g., SnO 2) yield comparatively small open-circuit voltages and energy and quantum conversion efficiencies, despite excellent dye-semiconductor interaction. However, on deposition of ultra-thin shells of insulators or high band gap semiconductors on the crystallites, a dramatic increase in the above parameters is observed. Outer shells were found to have insignificant or in most cases a negative effect on TiO 2 films. We explain the above findings on the basis of vast differences in the leakage rates of trapped electrons in different materials which is sensitive to the effective electron mass. Electrons injected to the conduction band in dye-sensitization enter into shallow traps from which they get thermally reemitted to the conduction band. The building up of the electron quasi-fermi level and transport depends on this process. The spread of the hydrogenic wave function of a trapped electron increases inverse exponentially with the effective mass so that the electron leakage and their recombination with acceptors ‘outside’ become severe when the crystallite size is comparable to the Bohr radius of the trapped electron. Such recombinations are effectively suppressed by deposition of thin films on the crystallites. Excited dye molecules anchored to the outer shell injects electrons to the conduction band via tunneling.

  14. Systems biology-based analysis implicates a novel role for vitamin D metabolism in the pathogenesis of age-related macular degeneration.

    PubMed

    Morrison, Margaux A; Silveira, Alexandra C; Huynh, Nancy; Jun, Gyungah; Smith, Silvia E; Zacharaki, Fani; Sato, Hajime; Loomis, Stephanie; Andreoli, Michael T; Adams, Scott M; Radeke, Monte J; Jelcick, Austin S; Yuan, Yang; Tsiloulis, Aristoteles N; Chatzoulis, Dimitrios Z; Silvestri, Giuliana; Kotoula, Maria G; Tsironi, Evangelia E; Hollis, Bruce W; Chen, Rui; Haider, Neena B; Miller, Joan W; Farrer, Lindsay A; Hageman, Gregory S; Kim, Ivana K; Schaumberg, Debra A; DeAngelis, Margaret M

    2011-10-01

    Vitamin D has been shown to have anti-angiogenic properties and to play a protective role in several types of cancer, including breast, prostate and cutaneous melanoma. Similarly, vitamin D levels have been shown to be protective for risk of a number of conditions, including cardiovascular disease and chronic kidney disease, as well as numerous autoimmune disorders such as multiple sclerosis, inflammatory bowel diseases and type 1 diabetes mellitus. A study performed by Parekh et al. was the first to suggest a role for vitamin D in age-related macular degeneration (AMD) and showed a correlation between reduced serum vitamin D levels and risk for early AMD. Based on this study and the protective role of vitamin D in diseases with similar pathophysiology to AMD, we examined the role of vitamin D in a family-based cohort of 481 sibling pairs. Using extremely phenotypically discordant sibling pairs, initially we evaluated the association of neovascular AMD and vitamin D/sunlight-related epidemiological factors. After controlling for established AMD risk factors, including polymorphisms of the genes encoding complement factor H (CFH) and age-related maculopathy susceptibility 2/HtrA serine peptidase (ARMS2/HTRA1), and smoking history, we found that ultraviolet irradiance was protective for the development of neovascular AMD (p = 0.001). Although evaluation of serum vitamin D levels (25-hydroxyvitamin D [25(OH)D]) was higher in unaffected individuals than in their affected siblings, this finding did not reach statistical significance. Based on the relationship between ultraviolet irradiance and vitamin D production, we employed a candidate gene approach for evaluating common variation in key vitamin D pathway genes (the genes encoding the vitamin D receptor [VDR]; cytochrome P450, family 27, subfamily B, polypeptide 1 [CYP27B1]; cytochrome P450, family 24, subfamily A, polypeptide 1 [CYP24A1]; and CYP27A1) in this same family-based cohort. Initial findings were then

  15. Systems biology-based analysis implicates a novel role for vitamin D metabolism in the pathogenesis of age-related macular degeneration

    PubMed Central

    2011-01-01

    Vitamin D has been shown to have anti-angiogenic properties and to play a protective role in several types of cancer, including breast, prostate and cutaneous melanoma. Similarly, vitamin D levels have been shown to be protective for risk of a number of conditions, including cardiovascular disease and chronic kidney disease, as well as numerous autoimmune disorders such as multiple sclerosis, inflammatory bowel diseases and type 1 diabetes mellitus. A study performed by Parekh et al. was the first to suggest a role for vitamin D in age-related macular degeneration (AMD) and showed a correlation between reduced serum vitamin D levels and risk for early AMD. Based on this study and the protective role of vitamin D in diseases with similar pathophysiology to AMD, we examined the role of vitamin D in a family-based cohort of 481 sibling pairs. Using extremely phenotypically discordant sibling pairs, initially we evaluated the association of neovascular AMD and vitamin D/sunlight-related epidemiological factors. After controlling for established AMD risk factors, including polymorphisms of the genes encoding complement factor H (CFH) and age-related maculopathy susceptibility 2/HtrA serine peptidase (ARMS2/HTRA1), and smoking history, we found that ultraviolet irradiance was protective for the development of neovascular AMD (p = 0.001). Although evaluation of serum vitamin D levels (25-hydroxyvitamin D [25(OH)D]) was higher in unaffected individuals than in their affected siblings, this finding did not reach statistical significance. Based on the relationship between ultraviolet irradiance and vitamin D production, we employed a candidate gene approach for evaluating common variation in key vitamin D pathway genes (the genes encoding the vitamin D receptor [VDR]; cytochrome P450, family 27, subfamily B, polypeptide 1 [CYP27B1]; cytochrome P450, family 24, subfamily A, polypeptide 1 [CYP24A1]; and CYP27A1) in this same family-based cohort. Initial findings were then

  16. Age-related macular degeneration

    PubMed Central

    Querques, Giuseppe; Avellis, Fernando Onofrio; Querques, Lea; Bandello, Francesco; Souied, Eric H

    2011-01-01

    Clinical question: Is there any new knowledge about the pathogenesis and treatment of age-related macular degeneration (AMD)? Results: We now understand better the biochemical and pathological pathways involved in the genesis of AMD. Treatment of exudative AMD is based on intravitreal injection of new antivascular endothelial growth factor drugs for which there does not yet exist a unique recognized strategy of administration. No therapies are actually available for atrophic AMD, despite some experimental new pharmacological approaches. Implementation: strategy of administration, safety of intravitreal injection PMID:21654887

  17. [Age-related macular degeneration].

    PubMed

    Budzinskaia, M V

    2014-01-01

    The review provides an update on the pathogenesis and new treatment modalities for neovascular age-related macular degeneration (AMD). The impact of polymorphism in particular genes, including complement factor H (CFH), age-related maculopathy susceptibility 2 (ARMS2/LOC387715), and serine peptidase (HTRA1), on AMD development is discussed. Clinical presentations of different forms of exudative AMD, that is classic, occult, or more often mixed choroidal neovascularization, retinal angiomatous proliferation, and choroidal polypoidal vasculopathy, are described. Particular attention is paid to the results of recent clinical trials and safety issues around the therapy.

  18. Degeneration of a Nonrecombining Chromosome

    NASA Astrophysics Data System (ADS)

    Rice, William R.

    1994-01-01

    Comparative studies suggest that sex chromosomes begin as ordinary autosomes that happen to carry a major sex determining locus. Over evolutionary time the Y chromosome is selected to stop recombining with the X chromosome, perhaps in response to accumulation of alleles beneficial to the heterogametic but harmful to the homogametic sex. Population genetic theory predicts that a nonrecombining Y chromosome should degenerate. Here this prediction is tested by application of specific selection pressures to Drosophila melanogaster populations. Results demonstrate the decay of a nonrecombining, nascent Y chromosome and the capacity for recombination to ameliorate such decay.

  19. New mouse primary retinal degeneration (rd-3)

    SciTech Connect

    Chang, B.; Hawes, N.L.; Roderick, T.H. ); Heckenlively, J.R. )

    1993-04-01

    A new mouse retinal degeneration that appears to be an excellent candidate for modeling human retinitis pigmentosa is reported. In this degeneration, called rd-3, differentiation proceeds postnatally through 2 weeks, and photoreceptor degeneration starts by 3 weeks. The rod photoreceptor loss is essentially complete by 5 weeks, whereas remnant cone cells are seen through 7 weeks. This is the only mouse homozygous retinal degeneration reported to date in which photoreceptors are initially normal. Crosses with known mouse retinal degenerations rd, Rds, nr, and pcd are negative for retinal degeneration in offspring, and linkage analysis places rd-3 on mouse chromosome 1 at 10 [+-]2.5 cM distal to Akp-1. Homology mapping suggests that the homologous human locus should be on chromosome 1q. 32 refs., 3 figs., 3 tabs.

  20. Mathematical glimpse on the Y chromosome degeneration

    NASA Astrophysics Data System (ADS)

    Lobo, M. P.

    2006-04-01

    The Y chromosomes are genetically degenerate and do not recombine with their matching partners X. Non-recombination of XY pairs has been pointed out as the key factor for the degeneration of the Y chromosome. The aim here is to show that there is a mathematical asymmetry in sex chromosomes which leads to the degeneration of Y chromosomes even in the absence of XX and XY recombination. A model for sex-chromosome evolution in a stationary regime is proposed. The consequences of their asymmetry are analyzed and lead us to a couple of conclusions. First, Y chromosome degeneration shows up sqrt{2} more often than X chromosome degeneration. Second, if nature prohibits female mortalities from beeing exactly 50%, then Y chromosome degeneration is inevitable.

  1. Photochemistry of coumarin laser dyes

    SciTech Connect

    von Trebra, R.J.

    1984-01-01

    Coumarin laser dyes are widely used in dye lasers for the generation of tunable laser light in the blue-green spectral region. As in the case with most laser dyes, coumarin dyes undergo photochemical reactions that interfere with simulated emission and result in loss of laser power output. This thesis describes the photochemistry of coumarin laser dyes under both anaerobic and aerobic conditions and some attempts to extend the useful lifetime of several dyes in dye lasers. Irradiation of Coumarin 311, 7-dimethylamino-4-methyl-coumarin (15), in oxygen-free ethanol solution results in the inefficient dye destruction. Products formed absorb light at the lasing wavelength of the dye, interfere with stimulated emission, and decrease the power output of the dye laser. Addition of the sulfur free radical chain transfer agents ethanethiol and ethyl disulfide retard the rate of formation of photoproducts absorbing at the lasing wavelengths. Deuterium incorporation, from the irradiation of Coumarin 311 in the presence of ethanethiol-S-d and ethyl disulfide, indicates that photoproducts most likely result from the reactions of free radicals which are generated in a bimolecular reaction between excited Coumarin 311 and ground state Coumarin 311. Ethanethiol and ethyl disulfide are shown to decrease the rate of power loss from a Coumarin 1 (3) dye laser. The naturally occurring amino acid cysteine acts similarly.

  2. Parainflammation, chronic inflammation, and age-related macular degeneration.

    PubMed

    Chen, Mei; Xu, Heping

    2015-11-01

    Inflammation is an adaptive response of the immune system to noxious insults to maintain homeostasis and restore functionality. The retina is considered an immune-privileged tissue as a result of its unique anatomic and physiologic properties. During aging, the retina suffers from a low-grade chronic oxidative insult, which sustains for decades and increases in level with advancing age. As a result, the retinal innate-immune system, particularly microglia and the complement system, undergoes low levels of activation (parainflammation). In many cases, this parainflammatory response can maintain homeostasis in the healthy aging eye. However, in patients with age-related macular degeneration, this parainflammatory response becomes dysregulated and contributes to macular damage. Factors contributing to the dysregulation of age-related retinal parainflammation include genetic predisposition, environmental risk factors, and old age. Dysregulated parainflammation (chronic inflammation) in age-related macular degeneration damages the blood retina barrier, resulting in the breach of retinal-immune privilege, leading to the development of retinal lesions. This review discusses the basic principles of retinal innate-immune responses to endogenous chronic insults in normal aging and in age-related macular degeneration and explores the difference between beneficial parainflammation and the detrimental chronic inflammation in the context of age-related macular degeneration. © Society for Leukocyte Biology.

  3. Moments distributions of single dye molecule spectra in a low-temperature polymer: Analysis of system ergodicity

    NASA Astrophysics Data System (ADS)

    Anikushina, T. A.; Naumov, A. V.

    2013-12-01

    This article demonstrates the principal advantages of the technique for analysis of the long-term spectral evolution of single molecules (SM) in the study of the microscopic nature of the dynamic processes in low-temperature polymers. We performed the detailed analysis of the spectral trail of single tetra-tert-butylterrylene (TBT) molecule in an amorphous polyisobutylene matrix, measured over 5 hours at T = 7K. It has been shown that the slow temporal dynamics is in qualitative agreement with the standard model of two-level systems and stochastic sudden-jump model. At the same time the distributions of the first four moments (cumulants) of the spectra of the selected SM measured at different time points were found not consistent with the standard theory prediction. It was considered as evidence that in a given time interval the system is not ergodic

  4. Optical parameters of TN display with dichroic dye

    NASA Astrophysics Data System (ADS)

    Olifierczuk, Marek; Zielinski, Jerzy; Perkowski, Pawel

    2000-05-01

    The present work contain the studies on optical parameters (contrast ratio, viewing angle, birefringence and brightness) of twisted nematic display with black dichroic dye which is designed for an application in large-area information and advertising systems. The numerical optimization of display with a dye has been done. The absorption characteristic of the dye has been obtained. Birefringence of doped mixtures (Delta) n has been measured. The contrast ratio of doped mixtures has been measured in wide temperature range from -25 degree(s)C to +70 degree(s)C. The angle characteristics of contrast ratio for +20 degree(s)C have been obtained. In the work the detailed results describing the effect of a dye on temperature dependence of birefringence and contrast ratio, moreover, the effect of dye on the viewing angle for the first and second transmission minimum will be presented. Additionally, the dielectric characteristics of different mixtures will be shown.

  5. Magnetic modification of microporous carbon for dye adsorption.

    PubMed

    Kyzas, George Z; Deliyanni, Eleni A; Lazaridis, Nikolaos K

    2014-09-15

    In this study, impregnation of microporous activated carbon with magnetite was achieved by co-precipitation of iron salts onto activated carbon. The evaluation of the adsorption ability of this material was examined using the anionic dye Reactive Black 5 as model dye pollutant (adsorbate). The effect of pH, ionic strength, contact time and initial dye concentration were also studied. It was found that high pH and high ionic strength favor the adsorption of Reactive Black 5. The adsorption kinetics and isotherms were well fitted by the fractal BS model and Langmuir model, respectively. The impregnation with magnetite decreases the adsorption capacity of activated carbon. Thermal re-activation of dye-loaded activated carbons was also succeeded. The characterization of the magnetic carbons was investigated by various techniques (SEM/EDAX, VSM, BET, FTIR, XRD, DTG) revealing many possible interactions in the carbon-dye system.

  6. Dye removal using modified copper ferrite nanoparticle and RSM analysis.

    PubMed

    Mahmoodi, Niyaz Mohammad; Soltani-Gordefaramarzi, Sajjad; Sadeghi-Kiakhani, Moosa

    2013-12-01

    In this paper, copper ferrite nanoparticle (CFN) was synthesized, modified by cetyl trimethylammonium bromide, and characterized. Dye removal ability of the surface modified copper ferrite nanoparticle (SMCFN) from single system was investigated. The physical characteristics of SMCFN were studied using Fourier transform infrared, scanning electron microscopy, and X-ray diffraction. Acid Blue 92, Direct Green 6, Direct Red 23, and Direct Red 80 were used as model compounds. The effect of operational parameters (surfactant concentration, adsorbent dosage, dye concentration, and pH) on dye removal was evaluated. Response surface methodology (RSM) was used for the analysis of the dye removal data. The experimental checking in these optimal conditions confirms good agreements with RSM results. The results showed that the SMCFN being a magnetic adsorbent might be a suitable alternative to remove dyes from colored aqueous solutions.

  7. Screening of freshwater fungi for decolorizing multiple synthetic dyes.

    PubMed

    Yang, Panpan; Shi, Wenxiao; Wang, Hongkai; Liu, Hongmei

    The biodegradation of synthetic dyes by fungi is emerging as an effective and promising approach. In the present study, freshwater fungal strains isolated from submerged woods were screened for the decolorization of 7 synthetic dyes. Subsequently, 13 isolates with high decolorization capability were assessed in a liquid system; they belonged to 9 different fungal species. Several strains exhibited a highly effective decolorization of multiple types of dyes. New absorbance peaks appeared after the treatment with 3 fungal strains, which suggests that a biotransformation process occurred through fungal biodegradation. These results showed the unexploited and valuable capability of freshwater fungi for the treatment of dye-containing effluents. The ability of certain fungi to decolorize dyes is reported here for the first time. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  8. Biological decolorization of dye solution containing malachite green by Pandoraea pulmonicola YC32 using a batch and continuous system.

    PubMed

    Chen, Chih-Yu; Kuo, Jong-Tar; Cheng, Chiu-Yu; Huang, Yu-Tang; Ho, I-Hsin; Chung, Ying-Chien

    2009-12-30

    In our study, we have isolated a relatively newly identified bacteria species, Pandoraea pulmonicola YC32, and first assessed its capability to treat malachite green (MG). The effects of various factors on decolorization efficiency were investigated in a batch system. The decolorization efficiency was found to be optimal within a pH of 7-10 and it increased, with increasing initial MG concentration up to 100 mg/l. The relationship between the decolorization rate and MG concentration agreed with Lineweaver-Burk equation. The apparent kinetic parameters, R(MG,max) and K(m), were 6.23 mg-MG/g-cell/h and 153.4 mg/l, respectively. The initial step in the biodegradation pathway of MG by P. pulmonicola YC32 was a reduction or N-demethylation reaction. We achieved a decolorization efficiency of 85.2% with 50mg/l MG in the immobilized P. pulmonicola YC32 continuous column system. This is the first report on the application of a continuous column system to decolorize MG using a microorganism.

  9. [Pathogenesis of age-related macular degeneration].

    PubMed

    Kaarniranta, Kai; Seitsonen, Sanna; Paimela, Tuomas; Meri, Seppo; Immonen, Ilkka

    2009-01-01

    Age-related macular degeneration is a multiform disease of the macula, the region responsible for detailed central vision. In recent years, plenty of new knowledge of the pathogenesis of this disease has been obtained, and the treatment of exudative macular degeneration has greatly progressed. The number of patients with age-related macular degeneration will multiply in the following decades, because knowledge of mechanisms of development of macular degeneration that could be subject to therapeutic measures is insufficient. Central underlying factors are genetic inheritance, exposure of the retina to chronic oxidative stress and accumulation of inflammation-inducing harmful proteins into or outside of retinal cells.

  10. Activation of Bone Marrow-Derived Microglia Promotes Photoreceptor Survival in Inherited Retinal Degeneration

    PubMed Central

    Sasahara, Manabu; Otani, Atsushi; Oishi, Akio; Kojima, Hiroshi; Yodoi, Yuko; Kameda, Takanori; Nakamura, Hajime; Yoshimura, Nagahisa

    2008-01-01

    The role of microglia in neurodegeneration is controversial, although microglial activation in the retina has been shown to provide an early response against infection, injury, ischemia, and degeneration. Here we show that endogenous bone marrow (BM)-derived microglia play a protective role in vascular and neural degeneration in the retinitis pigmentosa model of inherited retinal degeneration. BM-derived cells were recruited to the degenerating retina where they differentiated into microglia and subsequently localized to the degenerating vessels and neurons. Inhibition of stromal-derived factor-1 in the retina reduced the number of BM-derived microglia and accelerated the rate of neurovascular degeneration. Systemic depletion of myeloid progenitors also accelerated the degenerative process. Conversely, activation of BM-derived myeloid progenitors by systemic administration of both granulocyte colony-stimulating factor and erythropoietin resulted in the deceleration of retinal degeneration and the promotion of cone cell survival. These data indicate that BM-derived microglia may play a protective role in retinitis pigmentosa. Functional activation of BM-derived myeloid progenitors by cytokine therapy may provide a novel strategy for the treatment of inherited retinal degeneration and other neurodegenerative diseases, regardless of the underlying genetic defect. PMID:18483210

  11. A study of dyes sorption on biobased cryogels

    NASA Astrophysics Data System (ADS)

    Dobritoiu, Rodica; Patachia, Silvia

    2013-11-01

    Three types of biopolymers based materials were synthesized and tested as adsorbents for the dyes from aqueous solutions. Blends based on poly (vinyl alcohol) [PVA] and scleroglucan [Scl], cellulose micro-fibres [cel] and zein, respectively, have been prepared by repeated freezing-thawing cycles. Methylene blue [MB] was selected as a model dye in order to evaluate the capacity of the prepared materials to remove the dyes from aqueous solutions. The effects of the initial dye concentration, contact time and the composition of materials on the kinetic and thermodynamic parameters of sorption were discussed. The pseudo-second-order kinetics was found to better fit the experimental data thus being able to consistently predict the amount of dye adsorbed over the entire sorption period. The sorption equilibrium data obey Freundlich isotherm. Sorption capacity was evaluated both by dye solution and cryogel analysis by using VIS spectrometry and image analysis with CIELAB system. The sorption of monomer or aggregated dye molecules was identified and correlated with the type and morphology of the gel. The highest efficiency in MB removal was obtained for Scl/PVA cryogels in 1:9 weight ratio (9.5279 mg/g MB for an initial concentration by 8 × 10-5 mol/L in MB). These materials are suitable as sorbents for the advanced removal of dyes from waste water.

  12. Vegetable-based dye-sensitized solar cells.

    PubMed

    Calogero, Giuseppe; Bartolotta, Antonino; Di Marco, Gaetano; Di Carlo, Aldo; Bonaccorso, Francesco

    2015-05-21

    There is currently a large effort to improve the performance of low cost renewable energy devices. Dye-sensitized solar cells (DSSCs) are emerging as one of the most promising low cost photovoltaic technologies, addressing "secure, clean and efficient solar energy conversion". Vegetable dyes, extracted from algae, flowers, fruit and leaves, can be used as sensitizers in DSSCs. Thus far, anthocyanin and betalain extracts together with selected chlorophyll derivatives are the most successful vegetable sensitizers. This review analyses recent progress in the exploitation of vegetable dyes for solar energy conversion and compares them to the properties of synthetic dyes. We provide an in-depth discussion on the main limitation of cell performance e.g. dye degradation, effective electron injection from the dye into the conduction band of semiconducting nanoparticles, such as titanium dioxide and zinc oxide, outlining future developments for the use of vegetable sensitizers in DSSCs. We also discuss the cost of vegetable dyes and how their versatility can boost the advancement of new power management solutions, especially for their integration in living environments, making the practical application of such systems economically viable. Finally, we present our view on future prospects in the development of synthetic analogues of vegetable dyes as sensitizers in DSSCs.

  13. Reuse of reactive dyes for dyeing of jute fabric.

    PubMed

    Chattopadhyay, S N; Pan, N C; Day, A

    2006-01-01

    The aim of the work was to find out suitable method of dyeing so that costly reactive dye can be reused without draining them. The bleached jute fabric was dyed with four different class of reactive dyes namely, cold brand, hot brand, vinyl sulphone and high exhaustion (HE) brand. It is found that the two-step two-bath method of reactive dyeing, where exhaustion and fixation step is separated, is most ideal for reuse of dye bath. Separate original samples produced K/S value same as that of original sample and the K/S value of separate reuse sample varied from 50% to 80% of the original sample depending on the class of dye. In case of same bath method, colour yield of original reuse samples varies from only 10% to maximum 30% of the original samples depending on the class of dyes. Reuse of reactive dyes following separate bath method is particularly suitable for higher depth of shade (4% and above). This process not only utilises costly reactive dyes to the maximum extent but it also produces low water pollution as the effluent contain minimum amount of dye. So the process is economic and eco-friendly as well.

  14. Are allergenic disperse dyes used for dyeing textiles?

    PubMed

    Malinauskiene, Laura; Zimerson, Erik; Bruze, Magnus; Ryberg, Kristina; Isaksson, Marléne

    2012-09-01

    There are no data showing that disperse dyes, used to patch test patients, are currently being used for dyeing synthetic garments. It is unknown whether disperse dyes, which are currently routinely patch tested, are in fact present in synthetic textiles on the market. To determine whether eight disperse dyes, hitherto most widely cited as allergenic, are still used in textiles that are sold in various countries. Textiles from 13 countries in Europe, Asia and the United States were analysed. The procedure used for dye identification was thin-layer chromatography. When there were matching spots from the textile extract and reference dye, high-performance liquid chromatography was performed. Of 121 analysed items, three showed positive results for some of the investigated disperse dyes. Four dyes in these items could be detected and confirmed by the use of high-performance liquid chromatography. A pair of light brown ladies' tights manufactured and purchased in Italy contained Disperse Yellow 3, Disperse Blue 124, and Disperse Blue 106, and a set of black bra and panties purchased in India contained Disperse Orange 1. The eight disperse dyes that are most frequently incriminated in textile dye dermatitis are very rarely used in textiles nowadays. © 2012 John Wiley & Sons A/S.

  15. FY 1980 Report on Dye Laser Materials

    DTIC Science & Technology

    1981-02-01

    by block number) Dye Lasers Laser Dyes Tunable Lasers Photodegradation Rhodamine Dyes 20. ABSTRACT (Continue n resld* it necesiry and Identify by block...limited usefulness as a portable military device because of the photodegradation of the dye solution. Although there have been state-of-the-art reviews...on laser dyes , 1𔃼 the photodegradation of laser dyes ,3 and dye lasers, 4- 6 only authors from, or funded by, military organizations have given strict

  16. Population control in nearly degenerate N-state atoms

    NASA Astrophysics Data System (ADS)

    Shakov, Khazhgery Kh

    2004-12-01

    An analytic description is presented for the dynamics of electronic population in nearly degenerate N-state atoms. The time-dependent Schrodinger equation, written in terms of the probability amplitudes, becomes analytically solvable in the degenerate limit, when all the states accessible by the system have the same energy. Two-state and three-state atoms, as well as possible generalizations on the arbitrary number of states, are considered in detail. The degenerate state approximation allows one to gain additional control over the system by adjusting the parameters of a control field, including the field's frequency, intensity and the shape. The limitations on the frequency of the control field are much less restrictive than in other quantum control schemes, and based on the following conditions. To justify the use of N-state model, the frequency of the control field should be less than the resonant frequency of the transition from any of the active states to the nearest state outside the N-state manifold. At the same time, it should be much higher than the resonant frequency of the transitions between the active states (this enables the use of degenerate model for nearly degenerate states). These conditions define the structure of the electronic states of systems to which the degenerate states approximation can be applied: N states with approximately the same energy (active states), well isolated from all other states. We have identified some of the systems that have this kind of electronic structure, and used them to illustrate the method, as well as to estimate its accuracy and robustness. Our overall goal is to generally determine conditions on both the external field and the transition matrix elements that lead to complete control of a population in a nearly degenerate N-state atom. The effects of the field parameters on the duration of the transferred state and the population leakage due to non-degeneracy are discussed. Additional requirements on the

  17. Dry-spray deposition of TiO2 for a flexible dye-sensitized solar cell (DSSC) using a nanoparticle deposition system (NPDS).

    PubMed

    Kim, Min-Saeng; Chun, Doo-Man; Choi, Jung-Oh; Lee, Jong-Cheon; Kim, Yang Hee; Kim, Kwang-Su; Lee, Caroline Sunyong; Ahn, Sung-Hoon

    2012-04-01

    TiO2 powders were deposited on indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates for application to the photoelectrode of a dye-sensitized solar cell (DSSC). In the conventional DSSC manufacturing process, a semiconductor oxide such as TiO2 powder requires a sintering process at higher temperature than the glass transition temperature (T(g)) of polymers, and thus utilization of flexible polymer substrates in DSSC research has been constrained. To overcome this restriction related to sintering, we used a nanoparticle deposition system (NPDS) that could produce a thin coating layer through a dry-spray method under atmospheric pressure at room temperature. The powder was sprayed through a slit-type nozzle having a 0.4 x 10 mm2 rectangular outlet. In order to determine the deposited TiO2 thickness, five kinds of TiO2 layered specimens were prepared, where the specimens have single and double layer structures. Deposited powders on the ITO coated PET substrates were observed using FE-SEM and a scan profiler The thicker TiO2 photoelectrode with a DSSC having a double layer structure showed higher energy efficiency than the single layer case. The highest fabricated flexible DSSC displayed a short circuit current density J(sc) = 1.99 mA cm(-2), open circuit voltage V(oc) = 0.71 V, and energy efficiency eta = 0.94%. These results demonstrate the possibility of utilizing the dry-spray method to fabricate a TiO2 layer on flexible polymer substrates at room temperature under atmospheric pressure.

  18. Wide-band tunable photonic bandgap device and laser in dye-doped liquid crystal refilled cholesteric liquid crystal polymer template system

    NASA Astrophysics Data System (ADS)

    Lin, Jia-De; Lin, Hong-Lin; Lin, Hsin-Yu; Wei, Guan-Jhong; Lee, Chia-Rong

    2017-02-01

    The scientists in the field of liquid crystal (LC) have paid significant attention in the exploration of novel cholesteric LC (CLC) polymer template (simply called template) in recent years. The self-assembling nanostructural template with chirality can effectively overcome the limitation in the optical features of traditional CLCs, such as enhancement of reflectivity over 50%, multiple photonic bandgaps (PBGs), and changeable optical characteristics by flexibly replacing the refilling LC materials, and so on. This work fabricates two gradient-pitched CLC templates with two opposite handednesses, which are then merged as a spatially tunable and highly reflective CLC template sample. This sample can simultaneously reflect right- and left-circularly polarized lights and the tunable spectral range includes the entire visible region. By increasing the temperature of the template sample exceeding the clearing point of the refilling LC, the light scattering significantly decreases and the reflectance effectively increase to exceed 50% in the entire visible region. This device has a maximum reflectance over 85% and a wide-band spatial tunability in PBG between 400 nm and 800 nm which covers the entire visible region. Not only the sample can be employed as a wide-band spatially tunable filter, but also the system doping with two suitable laser dyes which emitted fluorescence can cover entire visible region can develop a low-threshold, mirror-less laser with a spatial tunability at spectral regions including blue to red region (from 484 nm to 634 nm) and simultaneous lasing emission of left- and right-circular polarizations.

  19. Photoactive dye enhanced tissue ablation for endoscopic laser prostatectomy

    NASA Astrophysics Data System (ADS)

    Ahn, Minwoo; Nguyen, Trung Hau; Nguyen, Van Phuc; Oh, Junghwan; Kang, Hyun Wook

    2015-02-01

    Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia with high laser power. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue ablation with low laser power. The experiment was implemented on chicken breast due to minimal optical absorption Amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532-nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm2. Light absorbance and ablation threshold were measured with UV-VIS spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with input parameter. Among the dyes, AR created the highest ablation rate of 44.2+/-0.2 μm/pulse due to higher absorbance and lower ablation threshold. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33 % reduced laser power with almost equivalent performance. In-depth comprehension on photoactive dye-enhanced tissue ablation can help accomplish efficient and safe laser treatment for BPH with low power application.

  20. Chalcogenopyrylium Dyes with Anchors to Nanoparticle and Semiconductor Surfaces

    NASA Astrophysics Data System (ADS)

    Bedics, Matthew Allen

    Surface enhanced Raman scattering (SERS) has gained widespread attention as a biomedical imaging technique due to its multiplexing capabilities and the low limits of detection (LODs) of SERS-nanoprobes. The library of available reporter molecules, which are used to generate unique SERS spectra, was previously limited to commercially available dyes or a small group of cyanine reporters. Herein, the design and synthesis of a novel group of chalcogenopyrylium SERS reporters is described. These dyes have a high affinity for Au and absorption maxima that range into the NIR region. These reporter molecules enabled the use of the 1280 nm laser, which was previously incompatible with SERS imaging. Also, nanoprobe LODs using these dyes as reporters are lower than any previously documented systems, with a 100 aM LOD using a 785 nm excitation and multiple examples of fM to pM LODs using a 1064 nm or 1280 nm excitation source. Nanoprobes functionalized with these compounds have also been successfully utilized in vivo, and produce more intense SERS spectra as compared to a commonly used cyanine reporter. Dye sensitized solar cells (DSSCs) have produced considerable interest as an alternative to conventionally used Si-based solar cells. Specifically, DSSCs that use metal-free organic dyes as sensitizers are important due to the lower cost and the use of earth abundant materials as starting materials. Herein, a group of chalcogenopyrylium dyes were appended with an anchoring group to TiO2, which enables the use of these dyes as sensitizers. Structural modifications were used to extend absorption maxima into the near-infrared region of the light spectrum and to evaluate the effect that dye aggregation has on device performance. The monomethine dyes successfully produced a photocurrent, with incident photon to current efficiency values as high as 20%. Aggregation was found to benefit these systems due to the spectral broadening of aggregated dyes, and consequent increased range of

  1. Metal-free organic dyes for dye-sensitized solar cells: from structure: property relationships to design rules.

    PubMed

    Mishra, Amaresh; Fischer, Markus K R; Bäuerle, Peter

    2009-01-01

    Dye-sensitized solar cells (DSSC) have attracted considerable attention in recent years as they offer the possibility of low-cost conversion of photovoltaic energy. This Review focuses on recent advances in molecular design and technological aspects of metal-free organic dyes for applications in dye-sensitized solar cells. Special attention has been paid to the design principles of these dyes and on the effect of various electrolyte systems. Cosensitization, an emerging technique to extend the absorption range, is also discussed as a way to improve the performance of the device. In addition, we report on inverted dyes for photocathodes, which constitutes a relatively new approach for the production of tandem cells. Special consideration has been paid to the correlation between the molecular structure and physical properties to their performance in DSSCs.

  2. Triphenylamine-based organic dyes with julolidine as the secondary electron donor for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Guohua; Kong, Fantai; Li, Jingzhe; Fang, Xiaqin; Li, Yi; Dai, Songyuan; Chen, Qianqian; Zhang, Xianxi

    2013-12-01

    Two novel donor-donor-π-conjugated-acceptor (D-D-π-A) metal-free organic dyes (JTPA1 and JTPA2) with a julolidine moiety as the secondary electron donor for dye-sensitized solar cells (DSSCs) are synthesized. Their absorption spectra, electrochemical and photovoltaic properties are extensively investigated and compared with TPA2 dye. Transient absorption measurements show that both sensitizers are quickly regenerated and the dye cations are efficiently intercepted by the redox mediator. Both dyes show good performance as DSSC photosensitizers. In particular, a DSSC using JTPA2 with rhodanine-3-acetic acid shows better photovoltaic performance with a short-circuit photocurrent density (Jsc) of 9.30 mA cm-2, an open-circuit photovoltage (Voc) of 509 mV and a fill factor (FF) of 0.68, corresponding to an overall conversion efficiency (η) of 3.2% under AM 1.5 irradiation (100 mW cm-2). Under similar test conditions, ruthenium-based N719 dye gives an efficiency of 6.7%. Compared to TPA2, the dye regeneration rate, the short-circuit photocurrent density and the conversion efficiency of JTPA2 are doubled by introducing a julolidine unit. Our findings show that the julolidine unit may be an excellent electron donor system for organic dyes harvesting solar irradiation.

  3. Preparation of highly selective solid-phase extractants for Cibacron reactive dyes using molecularly imprinted polymers.

    PubMed

    Al-Degs, Yahya S; Abu-Surrah, Adnan S; Ibrahim, Khalid A

    2009-02-01

    Selective polymeric extractants were prepared for preconcentration of Cibacron reactive red dye, a dye that is often applied with Cibacron reactive blue and Cibacron reactive yellow for dyeing of fabrics. The best extractant was fabricated (in chloroform) using methacrylic acid (as monomer), ethylene glycol dimethacrylate (as crosslinker), AIBN (as initiator for polymerization), and red dye as template molecule, with a molar stoichiometric ratio of 8.0:40.0:2.5:0.63, respectively. The structure of the molecularly imprinted polymer (MIP) was robust, and resisted dissolution up to 260 degrees C. Compared with the un-imprinted polymer, the imprinted product has a large specific surface area which improved its adsorption capacity. The effect of imprinting was obvious from the adsorption capacity measured at pH 4 for red dye (the imprinted molecule), which was increased from 24.0 to 79.3 mg g(-1) after imprinting. Equilibrium adsorption studies revealed that the dye-imprinted-polymer enables efficient extraction of red dye even in the presence of blue and yellow dyes which have similar chemical natures to the red dye. The selectivity coefficients S (red dye/dye), were 13.9 and 17.1 relative to the yellow and blue dyes, respectively. The MIP was found to be effective for red dye preconcentration, with a preconcentration factor of 100, from tap water and treated textile wastewater. The factors affecting extraction of red dye by the MIP were studied and optimized. Under the optimized extraction conditions, red dye was selectively quantified in the presence of other competing dyes at a concentration of 20 microg L(-1) from different water systems with satisfactory recoveries (91-95%) and RSD values (approximately 5.0%).

  4. Efficiency enhancement of dye-sensitized solar cells (DSSC) by addition of synthetic dye into natural dye (anthocyanin)

    NASA Astrophysics Data System (ADS)

    Pratiwi, D. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

    2017-02-01

    This article reported combination of anthocyanin and synthetic dyes in dye-sensitized solar cells (DSSC) applications. This study aims was to improve the performance of DSSC by addition of synthetic dye into anthocyanin dye. Anthocyanin dye was extracted from red cabbage and synthetic dye was obtained from N719. We prepared anthocyanin and synthetic dyes at 2 different volume, anthocyanin dye at volume of 10 ml and combination dyes with anthocyanin and synthetic dyes at volume of 8 mL : 2 mL. The DSSCs were designed into sandwich structure on the fluorine-doped tin oxide (FTO) substrates using TiO2 electrode, carbon electrode, anthocyanin and synthetic dyes, and redox electrolyte. The absorption wavelength of anthocyanin dye of red cabbage was 450 nm – 580 nm, the combination of anthocyanin and synthetic dyes can increase the absorbance peak only. The IPCE characteristic with anthocyanin dye of red cabbage and combination dyes resulted quantum efficiency of 0.081% and 0.092% at wavelength maximum about 430 nm. The DSSC by anthocyanin dye of red cabbage achieved a conversion efficiency of 0.024%, while the DSSC by combination dyes achieved a conversion efficiency of 0.054%, combination dyes by addition synthetic dye into anthocyanin dye enhanced the conversion efficiency up to 125%.

  5. Inflammatory profiles in canine intervertebral disc degeneration.

    PubMed

    Willems, Nicole; Tellegen, Anna R; Bergknut, Niklas; Creemers, Laura B; Wolfswinkel, Jeannette; Freudigmann, Christian; Benz, Karin; Grinwis, Guy C M; Tryfonidou, Marianna A; Meij, Björn P

    2016-01-13

    Intervertebral disc (IVD) disease is a common spinal disorder in dogs and degeneration and inflammation are significant components of the pathological cascade. Only limited studies have studied the cytokine and chemokine profiles in IVD degeneration in dogs, and mainly focused on gene expression. A better understanding is needed in order to develop biological therapies that address both pain and degeneration in IVD disease. Therefore, in this study, we determined the levels of prostaglandin E2 (PGE2), cytokines, chemokines, and matrix components in IVDs from chondrodystrophic (CD) and non-chondrodystrophic (NCD) dogs with and without clinical signs of IVD disease, and correlated these to degeneration grade (according to Pfirrmann), or herniation type (according to Hansen). In addition, we investigated cyclooxygenase 2 (COX-2) expression and signs of inflammation in histological IVD samples of CD and NCD dogs. PGE2 levels were significantly higher in the nucleus pulposus (NP) of degenerated IVDs compared with non-degenerated IVDs, and in herniated IVDs from NCD dogs compared with non-herniated IVDs of NCD dogs. COX-2 expression in the NP and annulus fibrosus (AF), and proliferation of fibroblasts and numbers of macrophages in the AF significantly increased with increased degeneration grade. GAG content did not significantly change with degeneration grade or herniation type. Cytokines interleukin (IL)-2, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, immune protein (IP)-10, tumor necrosis factor (TNF)-α, and granulocyte macrophage colony-stimulating factor (GM-CSF) were not detectable in the samples. Chemokine (C-C) motif ligand (CCL)2 levels in the NP from extruded samples were significantly higher compared with the AF of these samples and the NP from protrusion samples. PGE2 levels and CCL2 levels in degenerated and herniated IVDs were significantly higher compared with non-degenerated and non-herniated IVDs. COX-2 expression in the NP and AF and reactive changes in the

  6. Selection of indicator bacteria based on screening of 16S rDNA metagenomic library from a two-stage anoxic-oxic bioreactor system degrading azo dyes.

    PubMed

    Dafale, Nishant; Agrawal, Leena; Kapley, Atya; Meshram, Sudhir; Purohit, Hemant; Wate, Satish

    2010-01-01

    Dye degradation has gained attention of late due to indiscriminate disposal from user industries. Enhancing efficiency of biological treatment provides a cheaper alternative vis-à-vis other advanced technologies. Dye molecules are metabolized biologically via anoxic and oxic treatments. In this study, bacterial community surviving on dye effluent working in anoxic-oxic bioreactor was analyzed using 16S rDNA approach. Azo-dye decolorizing and degrading bacterial community was enriched in lab-scale two-stage anoxic-oxic bioreactor. 16S rDNA metagenomic libraries of enriched population were constructed, screened and phylogenetically analyzed separately. Removal of approximately 35% COD with complete decolorization was observed in anoxic bioreactor. Process was carried out by uncultured gamma proteobacterium constituting 48% of the total population and 12% clones having homology to Klebsiella. Aromatic amines generated during partial treatment under anoxic bioreactor were treated by aerobic population having 72% unculturable unidentified bacterium and rest of the population consisting of Thauera sp., Pseudoxanthomonas sp., Desulfomicrobium sp., Ottowia sp., Acidovorax sp., and Bacteriodetes bacterium sp.

  7. Azaquinolone dye lasers

    DOEpatents

    Hammond, Peter R.; Atkins, Ronald L.; Henry, Ronald A.; Fletcher, Aaron N.

    1978-01-01

    A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue to near ultraviolet region.

  8. Azacoumarin dye lasers

    DOEpatents

    Hammond, Peter R.; Atkins, Ronald L.; Henry, Ronald A.; Fletcher, Aaron N.

    1978-01-01

    A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue-green to near ultraviolet region.

  9. Fiberized fluorescent dye microtubes

    NASA Astrophysics Data System (ADS)

    Vladev, Veselin; Eftimov, Tinko

    2013-03-01

    In the present work we study the effect of the length of fluorescent dye-filled micro-capillaries on the fluorescence spectra. Two types of micro-capillaries have been studied: a 100 μm inner diameter fused silica capillary with a transparent coating and one of the holes of a fiber optic glass ferrule with 125 μm inner diameter. The tubes were filled with solutions of Rhodamine 6G dissolved in ethanol and then in glycerin. Experimental data show that the maximum fluorescence and the largest spectral widths are observed for a sample length of about 0.25 mm for the used concentration. This results show that miniature tunable fiberized dye lasers can be developed using available standard micro-and fibre-optic components.

  10. Hydration of cyanin dyes

    NASA Astrophysics Data System (ADS)

    Calzolari, Arrigo; Monti, Susanna; Ruini, Alice; Catellani, Alessandra

    2010-03-01

    We investigated the hydration properties of the cyanin dye molecule in the ionic flavylium configuration, through massive classical (force field) and ab initio (Car-Parrinello) molecular dynamics simulations at room temperature. Classical and quantum mechanical results coherently describe the structure of the first solvation shell. We discuss the hydrophobicity/hydrophilicity of the molecule in terms of attractive lateral hydroxyl-water and repulsive carbon π-water interactions. The analysis of the electronic structure shows a net polarization and a molecular orbital redistribution induced by the polar solvent on the intrinsic (gas phase) properties of the dye. Changing the properties of the molecule, the hydration effects should be carefully taken into account in the further interactions of cyanin with the external environment.

  11. [Different manifestations of tapetoretinal degeneration in the same family (author's transl)].

    PubMed

    Fiore, C

    1981-01-01

    A family with two siblings with six cases of tapetoretinal degeneration is reported. In the first case one individual present a degeneration of both scotopic and photopic visual systems, whereas another patient had macular degeneration of the Stargardt type. In the second, there was one case of photopic and stotopic degeneration, one case of fundus flavimaculatus, one case of Stargardt disease, and one case of retinitis pigmentosa inversa. The study of this family suggests on the one hand that Stargardt disease and fundus flavimaculatus are expressions of the same disease. On the other hand, the simultaneous presence of central and diffuse alterations of the fundus raises the question as to whether these various forms of hereditary degeneration may be included in a single class of disease.

  12. Dyeing fabrics with metals

    NASA Astrophysics Data System (ADS)

    Kalivas, Georgia

    2002-06-01

    Traditionally, in textile dyeing, metals have been used as mordants or to improve the color produced by a natural or synthetic dye. In biomedical research and clinical diagnostics gold colloids are used as sensitive signals to detect the presence of pathogens. It has been observed that when metals are finely divided, a distinct color may result that is different from the color of the metal in bulk. For example, when gold is finely divided it may appear black, ruby or purple. This can be seen in biomedical research when gold colloids are reduced to micro-particles. Bright color signals are produced by few nanometer-sized particles. Dr. William Todd, a researcher in the Department of Veterinary Science at the Louisiana State University, developed a method of dyeing fabrics with metals. By using a reagent to bond the metal particles deep into the textile fibers and actually making the metal a part of the chemistry of the fiber. The chemicals of the fabric influence the resulting color. The combination of the element itself, the size of the particle, the chemical nature of the particle and the interaction of the metal with the chemistry of the fabric determine the actual hue. By using different elements, reagents, textiles and solvents a broad range of reproducible colors and tones can be created. Metals can also be combined into alloys, which will produce a variety of colors. The students of the ISCC chapter at the Fashion Institute of Technology dyed fabric using Dr. Todd's method and created a presentation of the results. They also did a demonstration of dyeing fabrics with metals.

  13. [Experimental study of immune reactivity in Swiss mice due to topical administration of three textile dyes].

    PubMed

    Gavăt, C C; Lupuşoru, R V; Ghiciuc, Cristina Mihaela; Lupuşoru, Cătălina Elena

    2010-01-01

    Reactive Red 183, Reactive Red 2 and Reactive Blue 204 (red dye, green dye and blue dye) are three reactive dyes frequently used in textile industry. In some atmospheric conditions ( high temperature, perspiration, pH values, UV/IR radiations), some quantities of these hydrolyzed dyes, could pass from textile clothes directly into the human skin. There were used 4 groups of white Swiss mice (with similar weight and number of both sexes), control group and 3 groups, treated once daily with a retro-auricular application of different reactive dyes. After 14 days of treatment, blood samples were taken from retro-orbitary plexus to assess leukocyte count, phagocytic capacity of peripheral neutrophils, serum opsonic capacity, phagocyte capacity and bactericidal capacity of peritoneal macrophages, splenic T lymphocytes with rossetting capacity and spleen cells forming Jerne plaques. The retro-acuricular and latero-cervical nodes were weighted. Red dye did not influence the weight of the studied nodes, but determined statistically significant modifications on non-specific immune system parameters. Blue and grena dyes determined modifications of weight especially of retroauricular nodes. Grena dye determined important effects of non-specific immune system parameters (serum opsonic capacity, phagocyte capacity and bactericidal capacity of peritoneal macrophages). The blue dye did not determine a biological response. Red and green dye determined important effects on non-specific immune system parameters.

  14. Photoreceptor Cells Influence Retinal Vascular Degeneration in Mouse Models of Retinal Degeneration and Diabetes

    PubMed Central

    Liu, Haitao; Tang, Jie; Du, Yunpeng; Saadane, Aicha; Tonade, Deoye; Samuels, Ivy; Veenstra, Alex; Palczewski, Krzysztof; Kern, Timothy S.

    2016-01-01

    Purpose Loss of photoreceptor cells is associated with retinal vascular degeneration in retinitis pigmentosa, whereas the presence of photoreceptor cells is implicated in vascular degeneration in diabetic retinopathy. To investigate how both the absence and presence of photoreceptors could damage the retinal vasculature, we compared two mouse models of photoreceptor degeneration (opsin−/− and RhoP23H/P23H ) and control C57Bl/5J mice, each with and without diabetes. Methods Retinal thickness, superoxide, expression of inflammatory proteins, ERG and optokinetic responses, leukocyte cytotoxicity, and capillary degeneration were evaluated at 1 to 10 months of age using published methods. Results Retinal photoreceptor cells degenerated completely in the opsin mutants by 2 to 4 months of age, and visual function subsided correspondingly. Retinal capillary degeneration was substantial while photoreceptors were still present, but slowed after the photoreceptors degenerated. Diabetes did not further exacerbate capillary degeneration in these models of photoreceptor degeneration, but did cause capillary degeneration in wild-type animals. Photoreceptor cells, however, did not degenerate in wild-type diabetic mice, presumably because the stress responses in these cells were less than in the opsin mutants. Retinal superoxide and leukocyte damage to retinal endothelium contributed to the degeneration of retinal capillaries in diabetes, and leukocyte-mediated damage was increased in both opsin mutants during photoreceptor cell degeneration. Conclusions Photoreceptor cells affect the integrity of the retinal microvasculature. Deterioration of retinal capillaries in opsin mutants was appreciable while photoreceptor cells were present and stressed, but was less after photoreceptors degenerated. This finding proves relevant to diabetes, where persistent stress in photoreceptors likewise contributes to capillary degeneration. PMID:27548901

  15. Use of the ultrasonic cavitation in wool dyeing process: Effect of the dye-bath temperature.

    PubMed

    Actis Grande, G; Giansetti, M; Pezzin, A; Rovero, G; Sicardi, S

    2017-03-01

    The present work aims to study the effect of the liquid temperature on the performance of ultrasounds (US) in a dyeing process. The approach was both theoretical and experimental. In the theoretical part the simplified model of a single bubble implosion is used to demonstrate that the "maximum implosion pressure" calculated with the well known Rayleigh-Plesset equation for a single bubble can be correlated with the cavitation intensity experimentally measured with an Ultrasonic Energy Meter (by PPB Megasonics). In particular the model was used to study the influence of the fluid temperature on the cavitation intensity. The "relative" theoretical data calculated from the implosion pressure were satisfactorily correlated with the experimental ones and evidence a zone, between 50 and 60°C, were the cavitation intensity is almost constant and still sufficiently high. Hence an experimental part of wool dyeing was carried out both to validate the previous results and to verify the dyeing quality at low temperatures (40-70°C) in presence of US. A prototype dyeing equipment able to treat textile samples with US system of 600W power, was used. The dyeing performances in the presence and absence of US were verified by measuring ΔE (colour variation), Re,% (reflectance percentage), K/S (colour strength) and colour fastness. The US tests performed in the temperature range of 40-70°C were compared with the conventional wool dyeing at 98°C. The obtained results show that a temperature close to 60°C should be chosen as the recommended US dyeing condition, being a compromise between the cavitation intensity and the kinetics which rules the dyestuff diffusion within the fibres.

  16. Depression and the causal role of specific memory system degenerations: link may be supported by reported therapeutic benefits of Omega 3 fatty acids.

    PubMed

    Frais, Anthony T

    2007-01-01

    It is well documented that depressed patients, as a result of their illness, often experience some difficulties with their memory. This hypothesis suggests a vice-versa; that it is a gradual impairment and ultimate failure of specific memory systems that may underpin the onset and continuation of a depressive illness. So particular memory systems of the brain may have a greater role to play in clinical depression and associated anxiety than is generally recognised. A common feature of electroconvulsive therapy (ECT) is that it affects patients' short-term memory adversely. However, in line with the hypothesis, it is suggested that the mechanism of action of successful ECT treatment is that it facilitates the repair and reactivation of particular memory systems. One link that has some bearing on this hypothesis is that of Omega 3 fish oil. It has in some cases been observed to aid recovery of depression and possibly prevent relapse. It has been shown to improve memory.

  17. Photobleaching effect in azo-dye containing epoxy resin films: the potentiality of carbon nanotubes as azo-dye dispensers

    NASA Astrophysics Data System (ADS)

    Díaz Costanzo, Guadalupe; Goyanes, Silvia; Ledesma, Silvia

    2015-04-01

    Azo-dye molecules may suffer from bleaching under certain illumination conditions. When this photoinduced process occurs, it generates an irreversible effect that is characterized by the loss of absorption of the dye molecule. Moreover, the well-known isomerization of azodye molecules does not occur anymore. In this work it is shown how the addition of a small amount of multi-walled carbon nanotubes (MWCNTs) helps to decrease the bleaching effect in a photosensitive guest-host azo-polymer film. Two different systems were fabricated using an epoxy resin as polymer matrix. An azo-dye, Disperse Orange 3, was used as photosensitive material in both systems and MWCNTs were added into one of them. The optical response of the polymeric systems was studied considering the degree of photoinduced birefringence. Photobleaching of the azo-dye was observed in all cases however, the effect is lower for the composite material containing 0.2 wt % MWCNTs. The weak interaction between MWCNTs and dye molecules is less favorable when the material is heated. The optical behavior of the heated composite material suggests that carbon nanotubes can be potentially used as azo dye dispensers. The results are interpreted in terms of the non-covalent interaction between azo-dye molecules and MWCNTs.

  18. Anaerobic/aerobic treatment of selected azo dyes in wastewater

    SciTech Connect

    Seshadri, S.; Bishop, P.L. . Dept. of Civil and Environmental Engineering); Agha, A.M. . Faculty of Civil Engineering)

    1994-01-01

    Azo dyes represent the largest class of dyes in use today. Current environmental concern with these dyes revolves around the potential carcinogenic health risk presented by these dyes or their intermediate biodegradation products when exposed to microflora in the human digestive tract. These dyes may build up in the environment, since many wastewater treatment plants allow these dyes to pass through the system virtually untreated. The initial step in the degradation of these dyes is the cleavage of the Azo bond. This cleavage is often impossible under aerobic conditions, but has been readily demonstrated under anaerobic conditions. The focus of the study was to determine the feasibility of using an anaerobic fluidized-bed reactor to accomplish this cleavage. The effects of typical process variables such as hydraulic retention time (HRT), influent dye concentration levels, and degree of bed fluidization on removal efficiencies were also studied. The four dyes selected for this study were Acid-Orange 7, Acid-Orange 8, Acid-Orange 10, and Acid-Red 14. The effectiveness of using a bench-scale-activated sludge reactor as a sequenced second stage was also examined. Results indicate that nearly complete cleavage of the Azo bond is easily accomplished for each of the four dyes under hydraulic retention times of either 12 or 24 h. Initial results indicate, though, that aromatic amine by-products remain. The sequenced second stage was able to remove the remaining Chemical Oxygen Demand (COD) load to acceptable levels. Work is presently underway to determine the face of the anaerobic by-products in the aerobic second stage.

  19. Exact propagators for some degenerate hyperbolic operators

    NASA Astrophysics Data System (ADS)

    Beals, Richard; Kannai, Yakar

    2006-10-01

    Exact propagators are obtained for the degenerate second order hyperbolic operators ∂2 t - t 2 l Δ x , l=1,2,..., by analytic continuation from the degenerate elliptic operators ∂2 t + t 2 l Δ x . The partial Fourier transforms are also obtained in closed form, leading to integral transform formulas for certain combinations of Bessel functions and modified Bessel functions.

  20. The molecular basis of intervertebral disc degeneration.

    PubMed

    Kepler, Christopher K; Ponnappan, Ravi K; Tannoury, Chadi A; Risbud, Marakand V; Anderson, David G

    2013-03-01

    Intervertebral disc (IVD) degeneration remains a clinically important condition for which treatment is costly and relatively ineffective. The molecular basis of degenerative disc disease has been an intense focus of research recently, which has greatly increased our understanding of the biology underlying this process. To review the current understanding of the molecular basis of disc degeneration. Review article. A literature review was performed to identify recent investigations and current knowledge regarding the molecular basis of IVD degeneration. The unique structural requirements and biochemical properties of the disc contribute to its propensity toward degeneration. Mounting evidence suggests that genetic factors account for up to 75% of individual susceptibility to IVD degeneration, far more than the environmental factors such as occupational exposure or smoking that were previously suspected to figure prominently in this process. Decreased extracellular matrix production, increased production of degradative enzymes, and increased expression of inflammatory cytokines contribute to the loss of structural integrity and accelerate IVD degeneration. Neurovascular ingrowth occurs, in part, because of the changing degenerative phenotype. A detailed understanding of the biology of IVD degeneration is essential to the design of therapeutic solutions to treat degenerative discs. Although significant advances have been made in explaining the biologic mediators of disc degeneration, the inhospitable biochemical environment of the IVD remains a challenging environment for biological therapies. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. What Is Age-Related Macular Degeneration?

    MedlinePlus

    ... To Protect Against Macular Degeneration Jan 27, 2016 Eye Exercises May Improve Vision Around Blind Spot Sep 29, 2015 Could Stem Cells Cure Blindness Caused by Macular Degeneration? Sep 29, 2015 Fighting the Signs of Aging? Don’t Forget the Eyes Sep 11, ... Follow The Academy Professionals: Education ...

  2. Kinetics of degenerate atomic gases

    NASA Astrophysics Data System (ADS)

    Geist, W.; You, L.; Kennedy, T. A. B.

    1998-05-01

    Using the Uehling-Uhlenbeck, or quantum Boltzmann equation, we discuss the kinetics and evaporative cooling of quantum degenerate gases confined in magnetic traps with cylindrical symmetry. We study the full nonergodic time evolution and compare with results obtained by making the ergodic or continuum energy approximation(C. W. Gardiner, P. Zoller, R. J. Ballagh, M. J. Davis, ``Quantum kinetic theory. Simulation of the quantum Boltzmann master equation'', Phys. Rev. A 56), 575 (1997).. We report evidence of strongly non-ergodic distribution functions, whose relaxation times do not coincide with other characteristic timescales, but depend on trap anisotropy. We also report our study of condensate growth which exhibits the same qualitative behaviour as observed in a recent experiment(H. J. Miesner, D. M. Stamper, M. R. Andrews, D. S. Durfee, S. Inouve, W. Ketterle, ``Bosonic stimulation in the formation of a Bose-Einstein condensate'', (preprint).). Preliminary results for sympathetic cooling of fermions by bosons will also be presented.

  3. Degenerate doping of metallic anodes

    DOEpatents

    Friesen, Cody A; Zeller, Robert A; Johnson, Paul B; Switzer, Elise E

    2015-05-12

    Embodiments of the invention relate to an electrochemical cell comprising: (i) a fuel electrode comprising a metal fuel, (ii) a positive electrode, (iii) an ionically conductive medium, and (iv) a dopant; the electrodes being operable in a discharge mode wherein the metal fuel is oxidized at the fuel electrode and the dopant increases the conductivity of the metal fuel oxidation product. In an embodiment, the oxidation product comprises an oxide of the metal fuel which is doped degenerately. In an embodiment, the positive electrode is an air electrode that absorbs gaseous oxygen, wherein during discharge mode, oxygen is reduced at the air electrode. Embodiments of the invention also relate to methods of producing an electrode comprising a metal and a doped metal oxidation product.

  4. Quantal Density Functional Theory(Q-DFT) of Degenerate Ground and Excited States

    NASA Astrophysics Data System (ADS)

    Sahni, Viraht; Pan, Xiaoyin

    2002-03-01

    We present here Q-DFT (V.Sahni et al, PRL 87), 113002 (2001), and references therein. of degenerate states with degeneracy g. We describe : (a) The transformation from a degenerate ground or excited pure state of the interacting system to an S (single Slater determinant) system of noninteracting Fermions with equivalent density, total energy, and ionization potential; (b) The construction of g S systems to reproduce a subspace ensemble density and energy. The density and energy are defined via the ensemble density matrix formed from the degenerate ground or excited pure states of the interacting system; (c) The construction of an S system with a g-fold degenerate highest occupied level, (which leads to g Slater determinants (C.A. Ullrich and W. Kohn, PRL 87), 093001(2001).), to reproduce the ground or excited state ensemble density and energy.

  5. Neural reprogramming in retinal degenerations

    PubMed Central

    Marc, Robert E.; Jones, Bryan W.; Anderson, James R.; Kinard, Krista; Marshak, David W.; Wilson, John H.; Wensel, Theodore; Lucas, Robert J.

    2008-01-01

    Purpose Early visual defects in degenerative diseases such as retinitis pigmentosa (RP) may arise from phased remodeling of the neural retina. We sought to explore the functional expression of ionotropic (iGluR) and group III, type 6 metabotropic (mGluR6) glutamate receptors in late-stage photoreceptor degenerations. Methods Excitation mapping with organic cations and computational molecular phenotyping were used to determine whether retinal neurons displayed functional glutamate receptor signaling in rodent models of retinal degenerations and a sample of human RP. Results After photoreceptor loss in rodent models of RP, bipolar cells lose mGluR6 and iGluR glutamate-activated currents, while amacrine and ganglion cells retain iGluR-mediated responsivity. Paradoxically, amacrine and ganglion cells show spontaneous iGluR signals in vivo even though bipolar cells lack glutamate-coupled depolarization mechanisms. Cone survival can rescue iGluR expression by OFF bipolar cells. In a case of human RP with cone sparing, iGluR signaling appeared intact, but the numbers of bipolar cells expressing functional iGluRs was double that of normal retina. Conclusions RP triggers permanent loss of bipolar cell glutamate receptor expression, though spontaneous iGluR-mediated signaling by amacrine and ganglion cells implies that such truncated bipolar cells still release glutamate in response to some non-glutamatergic depolarization. Focal cone-sparing can preserve iGluR display by nearby bipolar cells, which may facilitate late-RP photoreceptor transplant attempts. An instance of human RP provides evidence that rod bipolar cell dendrite switching likely triggers new gene expression patterns and may impair cone pathway function. PMID:17591910

  6. Clinicopathological correlations in corticobasal degeneration.

    PubMed

    Lee, Suzee E; Rabinovici, Gil D; Mayo, Mary Catherine; Wilson, Stephen M; Seeley, William W; DeArmond, Stephen J; Huang, Eric J; Trojanowski, John Q; Growdon, Matthew E; Jang, Jung Y; Sidhu, Manu; See, Tricia M; Karydas, Anna M; Gorno-Tempini, Maria-Luisa; Boxer, Adam L; Weiner, Michael W; Geschwind, Michael D; Rankin, Katherine P; Miller, Bruce L

    2011-08-01

    To characterize cognitive and behavioral features, physical findings, and brain atrophy patterns in pathology-proven corticobasal degeneration (CBD) and corticobasal syndrome (CBS) with known histopathology. We reviewed clinical and magnetic resonance imaging data in all patients evaluated at our center with either an autopsy diagnosis of CBD (n = 18) or clinical CBS at first presentation with known histopathology (n = 40). Atrophy patterns were compared using voxel-based morphometry. CBD was associated with 4 clinical syndromes: progressive nonfluent aphasia (n = 5), behavioral variant frontotemporal dementia (n = 5), executive-motor (n = 7), and posterior cortical atrophy (n = 1). Behavioral or cognitive problems were the initial symptoms in 15 of 18 patients; less than half exhibited early motor findings. Compared to controls, CBD patients showed atrophy in dorsal prefrontal and perirolandic cortex, striatum, and brainstem (p < 0.001 uncorrected). The most common pathologic substrates for clinical CBS were CBD (35%), Alzheimer disease (AD, 23%), progressive supranuclear palsy (13%), and frontotemporal lobar degeneration (FTLD) with TDP inclusions (13%). CBS was associated with perirolandic atrophy irrespective of underlying pathology. In CBS due to FTLD (tau or TDP), atrophy extended into prefrontal cortex, striatum, and brainstem, whereas in CBS due to AD, atrophy extended into temporoparietal cortex and precuneus (p < 0.001 uncorrected). Frontal lobe involvement is characteristic of CBD, and in many patients frontal, not parietal or basal ganglia, symptoms dominate early stage disease. CBS is driven by medial perirolandic dysfunction, but this anatomy is not specific to a single underlying histopathology. Antemortem prediction of CBD will remain challenging until clinical features of CBD are redefined, and sensitive, specific biomarkers are identified. Copyright © 2011 American Neurological Association.

  7. Clinicopathological correlations in corticobasal degeneration

    PubMed Central

    Lee, Suzee E.; Rabinovici, Gil D.; Mayo, Mary Catherine; Wilson, Stephen M.; Seeley, William W.; DeArmond, Stephen J.; Huang, Eric J.; Trojanowski, John Q.; Growdon, Matthew E.; Jang, Jung Y.; Sidhu, Manu; See, Tricia M.; Karydas, Anna M.; Gorno-Tempini, Maria-Luisa; Boxer, Adam L.; Weiner, Michael W.; Geschwind, Michael D.; Rankin, Katherine P.; Miller, Bruce L.

    2011-01-01

    Objective To characterize cognitive and behavioral features, physical findings and brain atrophy patterns in pathology-proven corticobasal degeneration (CBD) and corticobasal syndrome (CBS) with known histopathology. Methods We reviewed clinical and MRI data in all patients evaluated at our center with either an autopsy diagnosis of CBD (n=18) or clinical CBS at first presentation with known histopathology (n=40). Atrophy patterns were compared using voxel-based morphometry. Results CBD was associated with four clinical syndromes: progressive nonfluent aphasia (5), behavioral variant frontotemporal dementia (5), executive-motor (7), and posterior cortical atrophy (1). Behavioral or cognitive problems were the initial symptoms in 15/18 patients; less than half exhibited early motor findings. Compared to controls, CBD patients showed atrophy in dorsal prefrontal and peri-rolandic cortex, striatum and brainstem (p<0.001 uncorrected). The most common pathologic substrates for clinical CBS were CBD (35%), Alzheimer’s disease (AD, 23%), progressive supranuclear palsy (13%), and frontotemporal lobar degeneration (FTLD) with TDP inclusions (13%). CBS was associated with perirolandic atrophy irrespective of underlying pathology. In CBS due to FTLD (tau or TDP), atrophy extended into prefrontal cortex, striatum and brainstem, while in CBS due to AD, atrophy extended into temporoparietal cortex and precuneus (p<0.001 uncorrected). Interpretation Frontal lobe involvement is characteristic of CBD, and in many patients frontal, not parietal or basal ganglia symptoms, dominate early-stage disease. CBS is driven by medial peri-rolandic dysfunction, but this anatomy is not specific to one single underlying histopathology. Antemortem prediction of CBD will remain challenging until clinical features of CBD are redefined, and sensitive, specific biomarkers are identified. PMID:21823158

  8. Wastewater treatment: Dye and pigment industry. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-03-01

    The bibliography contains citations concerning treatment of wastewater containing dyes and pigments. The citations discuss the of dyes and pigments in wastewater treatment systems, biodegradation of dyes, absorption and adsorption processes to remove dyes from wastewater, environmental effects from the disposal of dye-containing wastes, and methods of analysis for dyes in waste streams. Treatment methods such as ozonation, reverse osmosis, activated charcoal filtration, activated sludge, electrochemical treatments, thermal treatments, simple filtration, and absorption media are included. (Contains a minimum of 112 citations and includes a subject term index and title list.)

  9. Cold Pad-Batch dyeing method for cotton fabric dyeing with reactive dyes using ultrasonic energy.

    PubMed

    Khatri, Zeeshan; Memon, Muhammad Hanif; Khatri, Awais; Tanwari, Anwaruddin

    2011-11-01

    Reactive dyes are vastly used in dyeing and printing of cotton fibre. These dyes have a distinctive reactive nature due to active groups which form covalent bonds with -OH groups of cotton through substitution and/or addition mechanism. Among many methods used for dyeing cotton with reactive dyes, the Cold Pad Batch (CPB) method is relatively more environment friendly due to high dye fixation and non requirement of thermal energy. The dyed fabric production rate is low due to requirement of at least twelve hours batching time for dye fixation. The proposed CPB method for dyeing cotton involves ultrasonic energy resulting into a one third decrease in batching time. The dyeing of cotton fibre was carried out with CI reactive red 195 and CI reactive black 5 by conventional and ultrasonic (US) method. The study showed that the use of ultrasonic energy not only shortens the batching time but the alkalis concentrations can considerably be reduced. In this case, the colour strength (K/S) and dye fixation (%F) also enhances without any adverse effect on colour fastness of the dyed fabric. The appearance of dyed fibre surface using scanning electron microscope (SEM) showed relative straightening of fibre convolutions and significant swelling of the fibre upon ultrasonic application. The total colour difference values ΔE (CMC) for the proposed method, were found within close proximity to the conventionally dyed sample.

  10. Dye-coated europium monosulfide

    SciTech Connect

    Kar, Srotoswini; Dollahon, Norman R.; Stoll, Sarah L.

    2011-05-15

    Nanoparticles of EuS were synthesized using europium dithiocarbamate complexes. The resulting nanoparticles were coated with the dye, 1-pyrene carboxylic acid and the resulting material was characterized using X-ray powder diffraction, TEM, and UV-visible spectroscopy. Fluorescence spectroscopy was used to determine the relative energy of the conduction band edge to the excited state energy of the dye. -- Graphical abstract: Dye sensitized magnetic semiconductor materials were prepared by synthesizing EuS nanoparticles using single source precursors and coating with the dye, 1-pyrene carboxylic acid. Display Omitted highlights: > Synthesized EuS nanoparticles, 11{+-}2.4 nm characterized using XRD, TEM, and UV-vis. spect. > Grafted a dye to the surface and characterized the product using XRD, FTIR, UV-vis., and TEM. > Studied the photophysical properties using fluorescence spectroscopy. > Determined the relative dye excited state to the conduction band of the semiconductor.

  11. Genetics Home Reference: age-related macular degeneration

    MedlinePlus

    ... Health Conditions age-related macular degeneration age-related macular degeneration Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Age-related macular degeneration is an eye disease that is a leading ...

  12. Paclitaxel causes degeneration of both central and peripheral axon branches of dorsal root ganglia in mice.

    PubMed

    Tasnim, Aniqa; Rammelkamp, Zoe; Slusher, Amy B; Wozniak, Krystyna; Slusher, Barbara S; Farah, Mohamed H

    2016-07-11

    Peripheral neuropathy is a common and dose-limiting side effect of many cancer chemotherapies. The taxane agents, including paclitaxel (Taxol(®)), are effective chemotherapeutic drugs but cause degeneration of predominantly large myelinated afferent sensory fibers of the peripheral nervous system in humans and animal models. Dorsal root ganglia (DRG) neurons are sensory neurons that have unipolar axons each with two branches: peripheral and central. While taxane agents induce degeneration of peripheral axons, whether they also cause degeneration of central nervous system axons is not clear. Using a mouse model of paclitaxel-induced neuropathy, we investigated the effects of paclitaxel on the central branches of sensory axons. We observed that in the spinal cords of paclitaxel-intoxicated mice, degenerated axons were present in the dorsal columns, where the central branches of DRG axons ascend rostrally. In the peripheral nerves, degenerated myelinated fibers were present in significantly greater numbers in distal segments than in proximal segments indicating that this model exhibits the distal-to-proximal degeneration pattern generally observed in human peripheral nerve disorders. We conclude that paclitaxel causes degeneration of both the peripheral and central branches of DRG axons, a finding that has implications for the site and mode of action of chemotherapy agents on the nervous system.

  13. Structure formation through self-gravitational instability in degenerate and non-degenerate anisotropic magnetized plasma

    NASA Astrophysics Data System (ADS)

    Sharma, Prerana

    2017-04-01

    The self-gravitational instability is examined for non-degenerate and degenerate magnetized plasma. In the case of non-degenerate collisionless magnetized plasma the pressure is considered as anisotropic while in the case of degenerate situations it is taken as isotropic. The effect of finite Larmor radius correction of non-degenerate ions and viscous dissipation is taken into account in both the cases. Firstly in non-degenerate anisotropic plasma the conventional magnetohydrodynamic model is used to construct basic set of equations within the framework of modified Chew-Goldberger and Low theory. Secondly, in the case of degenerate isotropic plasma, which is considered to be composed of degenerate electrons and non-degenerate ions, the model equations are constructed using quantum magneto hydrodynamic model. The dynamics of degenerate particles are governed by Bohm and exchange potentials. The general dispersion relations are derived for both degenerate and non-degenerate situations separately using linearized perturbation equations. The results are discussed analytically and numerically for various modes of propagation. In case of non degenerate strongly magnetized plasma the effects of stress tensor anisotropy dominate over the influence of FLR effects while the FLR effects prevail in the weak magnetic field region. In case of isotropic degenerate plasma the implications of exchange parameter on the Jeans mass have been estimated and it is found that the increase in exchange parameter increases the limit of Jeans mass. The Jeans length and Jeans mass have been estimated for the white dwarf stars as LJ ≈ 2.1 × 10^{11} m and MJ ≈ 5 × 10^{39} kg respectively assist the existence of super Chandrasekhar white dwarfs.

  14. Treatment of retinal hemangiomas with dye yellow laser.

    PubMed

    Tokumaru, G K

    1993-02-01

    Retinal capillary hemangioma (angiomatosis retinae; von Hippel's disease) is a relatively uncommon vascular tumor. When seen in association with systemic angiomas, it is known as von Hippel-Lindau disease. Untreated, these tumors can cause numerous sight threatening sequelae, including exudative and tractional retinal detachment. Recently, the dye yellow laser has been demonstrated to be a safe and effective method of ablating retinal hemangiomas. This paper discusses the case of a retinal hemangioma that was successfully treated with the dye yellow laser. The current treatment modalities of retinal hemangiomas are reviewed, as well as recent literature on the tunable organic dye laser and its utilization in the treatment of retinal vascular disorders.

  15. High-mobility hydrogen-terminated Si(111) transistors for measurement of six-fold valley degenerate two-dimensional electron systems in fractional quantum Hall regime

    NASA Astrophysics Data System (ADS)

    Hu, Binhui; Yazdanpanah, Mohamad Meqdad; Kane, Bruce E.

    2015-03-01

    The quality of hydrogen-terminated Si(111) (H-Si(111)) transistors has improved significantly. Peak electron mobility of 325,000 cm2/Vs was achieved at 90 mK, and the fractional quantum Hall effect (FQHE) at 1 < ν < 2 was studied extensively. We have further improved the device by solving gate leakage and contact problems with an updated design, in which a Si piece with thermal oxide acts as a gate through a vacuum cavity, and PN junctions are used to define a hexagonal two-dimensional (2D) region on a H-Si(111) piece. The device operates as an ambipolar transistor, in which a 2D electron system (2DES) and a 2D hole system can be induced at the same H-Si(111) surface. Peak electron mobility of more than 200,000 cm2/Vs is routinely achieved at 300 mK. The Si(111) surface has a six-fold valley degeneracy. The hexagonal device is designed to investigate the symmetry of the 2DES. Preliminary data show that the transport anisotropy at ν < 6 can be explained by the valley occupancy. The details of the valley occupancy can be caused by several mechanisms, such as miscut, magnetic field, pseudospin quantum Hall ferromagnetism (QHFM), and nematic valley polarization phases. The FQHE is investigated in magnetic fields up to 35T, and the properties of composite fermions will be discussed.

  16. An Interferometric Harvest of Double Degenerates

    NASA Astrophysics Data System (ADS)

    Nelan, Edmund

    2001-07-01

    The white dwarf {WD} mass and age distributions hold clues to the star formation history of our Galaxy and the age of the disk. To extract this information we need to carefully calibrate the WD mass-radius relation and the WD cooling curve. But to do so, we must directly determine the masses for a variety of WDs of different sub-types. The only direct method is through the orbital analysis of resolved WDs in non- interacting binary systems. Sadly, this has been done, with varying quality, for only 4 WDs {40 Eri B, Sirius B, Procyon B, and Stien 2051B}, mainly because it is extremely difficult to resolve WDs in binary systems with periods less than 50 years. We propose a high angular resolution Snapshot survey with FGS1r to observe cool WDs with the objective of discovering {resolving} double degenerate systems with modest separations and periods as short as 25 years, ideal binaries for follow up mass determinations. By carefully selecting our targets, about 10 such systems should be revealed. This will dramatically increase the number of WDs available for dynamical mass measurements {its 2 for 1.}, enabling a better calibration the WD mass-radius relation.

  17. The Chemistry of Plant and Animal Dyes.

    ERIC Educational Resources Information Center

    Sequin-Frey, Margareta

    1981-01-01

    Provides a brief history of natural dyes. Chemical formulas are provided for flavonoids, luteolin, genistein, brazilin, tannins, terpenes, naphthoquinone, anthraquinone, and dyes with an alkaloid structure. Also discusses chemical background of different dye processes. (CS)

  18. The Chemistry of Plant and Animal Dyes.

    ERIC Educational Resources Information Center

    Sequin-Frey, Margareta

    1981-01-01

    Provides a brief history of natural dyes. Chemical formulas are provided for flavonoids, luteolin, genistein, brazilin, tannins, terpenes, naphthoquinone, anthraquinone, and dyes with an alkaloid structure. Also discusses chemical background of different dye processes. (CS)

  19. Density functional theory study on dye-sensitized solar cells using oxadiazole-based dyes

    NASA Astrophysics Data System (ADS)

    Mehmood, Umer; Hussein, Ibnelwaleed A.; Harrabi, Khalil; Reddy, Belum V. S.

    2015-01-01

    Density functional theory (DFT) and time-dependent DFT(TD-DFT) modeling techniques are used to conduct a computational study of the geometry and electronic structure of oxadiazole-based organic sensitizers. A DFT study on the thermodynamic aspects of the charge transport processes associated with dye-sensitized solar cells (DSSCs) suggests that the system with 1,2,4-oxadiazole has a balance among the different crucial factors and may result in the highest incident photon to charge carrier efficiency. The dye/) anatase clusters were also simulated to illustrate the electron injection efficiency at the interface. This study provides basic understanding of the impact of molecular design on the performance of oxadiazole dyes in DSSCs.

  20. Investigation of lasing from dye doped plastics using flash lamp and Nd:YAG excitation.

    NASA Astrophysics Data System (ADS)

    Masters, Mark; de Armond, Mike; Reynolds, Clint; Suedhoff, Hans

    2006-05-01

    We present an investigation of organic dye doped plastics as a lasing medium. The host materials examined are poly(methyl methacrylate) [acrylic], epoxy, polyester and polyurethane. Various solvents are used to improve dye dispersion within the material. Two forms of excitation (flash lamp and frequency doubled Nd:YAG) are used. For the Nd:YAG pumped dye lasers, a disk of dye doped plastic is mounted in a housing to provide random orbital motion. The disk is within a Littmann configuration cavity. Each dye disk is tested for threshold, durability, power output, bandwidth, and tuning range. An end pumped cylinder is also explored. For the flash lamp pumped dye lasers two configurations are used: a traditional dye cylinder within an elliptical reflector and a hollow cylinder with the flash lamp within the hollow. A monolithic cavity for the flash lamp pumped system is investigated.