WorldWideScience

Sample records for dual function ph

  1. Dual effect of organic acids as a function of external pH in Oenococcus oeni.

    Science.gov (United States)

    Augagneur, Yoann; Ritt, Jean-François; Linares, Daniel M; Remize, Fabienne; Tourdot-Maréchal, Raphaëlle; Garmyn, Dominique; Guzzo, Jean

    2007-08-01

    In this study we analyzed under various pH conditions including low pH, the effects of L-malic acid and citric acid, combined or not, on the growth, the proton motive force components and the transcription level of selected genes of the heterolactic bacterium Oenococcus oeni. It is shown here that L-malate enhanced the growth yield at pH equal or below 4.5 while the presence of citrate in media led to a complete and unexpected inhibition of the growth at pH 3.2. Nevertheless, whatever the growth conditions, both L-malate and citrate participated in the enhancement of the transmembrane pH gradient, whereas the membrane potential decreased with the pH. These results suggested that it was not citrate that was directly responsible for the inhibition observed in cultures done at low pH, but probably its end products. This was confirmed since, in media containing L-malate, the addition of acetate substantially impaired the growth rate of the bacterium and slightly the membrane potential and pH gradient. Finally, study of the expression of genes involved in the metabolism of organic acids showed that at pH 4.5 and 3.2 the presence of L-malate led to an increased amount of mRNA of mleP encoding a malate transporter.

  2. Optical dual self functions

    Institute of Scientific and Technical Information of China (English)

    华建文; 刘立人; 王宁

    1997-01-01

    A recipe to construct the exact dual self-Fourier-Fresnel-transform functions is shown, where the Dirac comb function and transformable even periodic function are used. The mathematical proof and examples are given Then this kind of self-transform function is extended to the feasible optical dual self-transform functions.

  3. Mono-functionalized glycosylated platinum(IV) complexes possessed both pH and redox dual-responsive properties: Exhibited enhanced safety and preferentially accumulated in cancer cells in vitro and in vivo.

    Science.gov (United States)

    Ma, Jing; Yang, Xiande; Hao, Wenpei; Huang, Zhonglv; Wang, Xin; Wang, Peng George

    2017-03-10

    A serious of carbohydrate-conjugated platinum(IV) complexes in the form Pt(L2)(A2)(OH)R based on the clinical drug cisplatin and oxaliplatin were designed, synthesized and evaluated as antitumor agents in vitro and in vivo. The conjugates possessing both pH and redox dual-responsive properties exhibited more potent cytotoxicity in seven different human cancer cell lines and lower toxicity to the normal 3T3 cells than cisplatin, oxaliplatin and even the reported bis-functionalized glycosylated platinum(IV) complexes indicating the enhanced safety of the sugar conjugates. Cellular drug uptake and DNA platination were also superior to cisplatin, oxaliplatin and the reported bis-functionalized ones. Peak current of B7 and B8 with the scan rate of 200mv/s at the concentration of 0.08 mM was 5-fold higher at pH 6.4 than the pH 7.4, indicating that carbohydrate-conjugated mono-functionalized platinum(IV) complexes possessed both pH and redox dual-responsive properties in the cancer cells. The in vivo assays demonstrated that the Pt(IV) compounds could inhibit the growth of MCF-7 tumour and exert more safety than oxaliplatin. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Polypeptide micelles with dual pH activatable dyes for sensing cells and cancer imaging.

    Science.gov (United States)

    Gong, Ping; Yang, Yueting; Yi, Huqiang; Fang, Shengtao; Zhang, Pengfei; Sheng, Zonghai; Gao, Guanhui; Gao, Duyang; Cai, Lintao

    2014-05-21

    pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence in an alkaline environment. Hence, DPNs exhibited a dual response signal with strong red fluorescence and weak green fluorescence under acidic conditions; in contrast, they showed strong green fluorescence and almost no red fluorescence under alkaline and neutral conditions. The favorable inverse pH responses of the two fluorescent dyes resulted in ratiometric pH determination for DPNs with an optimized pH-sensitive range of pH 4.5-7.5. Quantitative analysis of the intracellular pH of intact MCF-7 cells has been successfully demonstrated with our nanosensor. Moreover, single acid activatable fluorescent dye doped polypeptide nanoparticles that only contained RBLC can distinguish tumor tissue from normal tissue by monitoring the acidic extracellular environment.

  5. Novel europium (III)-gatifloxacin complex structure with dual functionality for pH sensing and metal recognition in aqueous environment

    Science.gov (United States)

    Chen, Muhua; Zheng, Yuhui; Gao, Jinwei; Wang, Qianming

    2016-10-01

    A new type of Eu(III)-gatifloxacin complex with characteristic red luminescence has been prepared. Due to the presence of ionization effect linked to the organic chromophore, the molecular fluorescent sensor demonstrated variable pH-sensitive absorption and emission curves. The red emission derived from europium ions was strong during pH range 8-10. Between pH = 7 and 4, the europium emission remained relatively stable and fluorescence signals of gatifloxacin has been improved substantially. Under acidic conditions (pH = 1 to 3), the dramatic changes in the emission colors (from red, yellow to green) were clearly observed. Moreover, the excitation wavelength can be extended into the visible light range (Ex = 411 nm) by using the concentration effect experiment. Importantly, it gave turn-off emissions in the presence of Cu2+ or Fe3+ and the detection limits were determined to be 6.5 μM for Cu2+ and 6.2 μM for Fe3+ respectively.

  6. An injectable, dual pH and oxidation-responsive supramolecular hydrogel for controlled dual drug delivery.

    Science.gov (United States)

    Cheng, Xinfeng; Jin, Yong; Sun, Tongbing; Qi, Rui; Li, Hanping; Fan, Wuhou

    2016-05-01

    A novel pH and oxidation dual-responsive and injectable supramolecular hydrogel was developed, which was formed from multi-block copolymer poly(ether urethane) (PEU) and α-cyclodextrin (α-CD) inclusion complexes (ICs). The PEU copolymer was synthesized through a simple one-pot condensation polymerization of poly(ethylene glycol), di(1-hydroxyethylene) diselenide, dimethylolpropionic acid and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate. In aqueous solution, the amphiphilic PEU copolymers could self-assemble into nanoparticles with dual pH and oxidation sensitivities, which can efficiently load and controllably release a hydrophobic drug indomethacin (IND). Then a dual-drug loaded supramolecular hydrogel was obtained by addition of α-CD and hydrophilic model drug (rhodamine B, RB) into the resulting IND-loaded PEU nanoparticle solution. The rheology studies showed that the supramolecular hydrogels with good injectability underwent a pH-induced reversible sol-gel transition and an oxidation-triggered degradation behavior. The in vitro drug release results demonstrated that the hydrogels showed dual drug release behavior and the release rates could be significantly accelerated by addition of an oxidizing agent (H2O2) or increasing the environmental pH. Therefore, this injectable and dual stimuli-responsive supramolecular hydrogel based codelivery systems could potentially be a promising candidate for controlled drug delivery systems.

  7. Unraveling Executive Functioning in Dual Diagnosis

    Science.gov (United States)

    Duijkers, Judith C. L. M.; Vissers, Constance Th. W. M.; Egger, Jos I. M.

    2016-01-01

    In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other’s expression. Forming a threat to health and society, dual-diagnosis is associated with relapses in addiction-related behavior and a destructive lifestyle. This is due to a persistent failure to control impulses and the maintaining of inadequate self-regulatory behavior in daily life. Thus, several aspects of executive functioning like inhibitory, shifting and updating processes seem impaired in dual-diagnosis. Executive (dys-)function is currently even seen as a shared underlying key component of most mental disorders. However, the number of studies on diverse aspects of executive functioning in dual-diagnosis is limited. In the present review, a systematic overview of various aspects of executive functioning in dual-diagnosis is presented, striving for a prototypical profile of patients with dual-diagnosis. Looking at empirical results, inhibitory and shifting processes appear to be impaired for SUD combined with schizophrenia, bipolar disorder or cluster B personality disorders. Studies involving updating process tasks for dual-diagnosis were limited. More research that zooms in to the full diversity of these executive functions is needed in order to strengthen these findings. Detailed insight in the profile of strengths and weaknesses that underlies one’s behavior and is related to diagnostic classifications, can lead to tailor-made assessment and indications for treatment, pointing out which aspects need attention and/or training in one’s self-regulative abilities. PMID:27445939

  8. Unraveling Executive Functioning in Dual Diagnosis.

    Science.gov (United States)

    Duijkers, Judith C L M; Vissers, Constance Th W M; Egger, Jos I M

    2016-01-01

    In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other's expression. Forming a threat to health and society, dual-diagnosis is associated with relapses in addiction-related behavior and a destructive lifestyle. This is due to a persistent failure to control impulses and the maintaining of inadequate self-regulatory behavior in daily life. Thus, several aspects of executive functioning like inhibitory, shifting and updating processes seem impaired in dual-diagnosis. Executive (dys-)function is currently even seen as a shared underlying key component of most mental disorders. However, the number of studies on diverse aspects of executive functioning in dual-diagnosis is limited. In the present review, a systematic overview of various aspects of executive functioning in dual-diagnosis is presented, striving for a prototypical profile of patients with dual-diagnosis. Looking at empirical results, inhibitory and shifting processes appear to be impaired for SUD combined with schizophrenia, bipolar disorder or cluster B personality disorders. Studies involving updating process tasks for dual-diagnosis were limited. More research that zooms in to the full diversity of these executive functions is needed in order to strengthen these findings. Detailed insight in the profile of strengths and weaknesses that underlies one's behavior and is related to diagnostic classifications, can lead to tailor-made assessment and indications for treatment, pointing out which aspects need attention and/or training in one's self-regulative abilities.

  9. Dual wavelength fluorescent ratiometric pH measurement by scanning near-field optical microscopy

    Science.gov (United States)

    Li, Yongbo; Shinohara, Ryosuke; Iwami, Kentaro; Ohta, Yoshihiro; Umeda, Norihiro

    2010-08-01

    A novel method to observe pH distribution by dual wavelength fluorescent ratiometric pH measurement by scanning near-field optical microscopy (SNOM) is developed. In this method, in order to investigate not only the pH of mitochondrial membrane but also its distribution in the vicinity, a pH sensitive fluorescent reagent covers mitochondria instead of injecting it to mitochondria. This method utilizes a dual-emission pH sensitive dye and SNOM with a themally-pulled and metal-coated optical fiber to improve the spatial resolution. Time-dependence of Fluorescent intensity ratio (FIR) under acid addition is investigated. As the distances between the dropped point and the SNOM probe becomes closer, the time when FIR changes becomes earlier. The response of mitochondria under supplement of nutrition is studied by using this method. While the probe is near to mitochondria, the ratio quickly becomes to increase. In conclusion, it was confirmed that the temporal variation of pH can be detected by this method, and pH distribution in the vicinity of mitochondria is able to be measured by this method.

  10. Structural basis of dual Ca(2+)/pH regulation of the endolysosomal TRPML1 channel.

    Science.gov (United States)

    Li, Minghui; Zhang, Wei K; Benvin, Nicole M; Zhou, Xiaoyuan; Su, Deyuan; Li, Huan; Wang, Shu; Michailidis, Ioannis E; Tong, Liang; Li, Xueming; Yang, Jian

    2017-01-23

    The activities of organellar ion channels are often regulated by Ca(2+) and H(+), which are present in high concentrations in many organelles. Here we report a structural element critical for dual Ca(2+)/pH regulation of TRPML1, a Ca(2+)-release channel crucial for endolysosomal function. TRPML1 mutations cause mucolipidosis type IV (MLIV), a severe lysosomal storage disorder characterized by neurodegeneration, mental retardation and blindness. We obtained crystal structures of the 213-residue luminal domain of human TRPML1 containing three missense MLIV-causing mutations. This domain forms a tetramer with a highly electronegative central pore formed by a novel luminal pore loop. Cysteine cross-linking and cryo-EM analyses confirmed that this architecture occurs in the full-length channel. Structure-function studies demonstrated that Ca(2+) and H(+) interact with the luminal pore and exert physiologically important regulation. The MLIV-causing mutations disrupt the luminal-domain structure and cause TRPML1 mislocalization. Our study reveals the structural underpinnings of TRPML1's regulation, assembly and pathogenesis.

  11. Design, syntheses, and properties of tunable, dual-stimuli (temperature and pH) responsive copolymers

    Science.gov (United States)

    Manokruang, Kiattikhun

    Stimuli responsive polymers are of great interest in biorelated applications ranging from actuators, microfluidics, delivery systems and tissue scaffolds. The specifications of an appropriate polymer system that shows a response to one or more external stimuli vary from application to application, depending on desired functionality. In most cases, the response to an environmental change is desired to be sharp and fast, such as for microfluidics and actuators, while the stability of the collapsed structure is also typically required, such as in tissue scaffolds and in stimulated delivery systems. In addition, the onset of the stimulus response varies depending on application. Thus, a general design strategy for polymer systems to meet specific applications' needs can be a big challenge. This dissertation describes the design, syntheses, and aqueous phase behavior of two polymer classes that show a sharp solution phase transition in different manners: The first polymer class is in the form of a segmented/blocky copolymer and its solution phase separation is designed to occur via micellization, while the second polymer class is designed as an alternating copolymer and it exhibits a first order LCST phase behavior. Copolymers of methyl methacrylate (MMA) and methacrylic acid (MAA), poly(MMA-co-MAA)s, were prepared to have a segmented blocky comonomer distribution along the chain backbone, with sequences composed predominantly of MMA or MAA units. Turbidity (cloud point) measurements were employed to investigate the phase behavior of these copolymers in aqueous solution. The solutions showed sharp solubility transitions upon pH change, and the pH-onsets of the copolymers' transition showed a systematic dependence on the copolymers' MAA content and an almost-linear dependence on the polymer concentration. A strong hysteresis was observed when lowering versus increasing pH, indicating a stable collapsed structure. Dynamic light scattering demonstrated almost monodispersed

  12. Affine Riesz bases and the dual function

    Science.gov (United States)

    Terekhin, P. A.

    2016-09-01

    This paper is concerned with systems of functions on the unit interval which are generated by dyadic dilations and integer translations of a given function. Similar systems have a wide range of applications in the theory of wavelets, in nonlinear, and in particular, in greedy approximations, in the representation of functions by series, in problems in numerical analysis, and so on. Conditions, and in some particular cases, criteria for the generating function are given for the system to be Besselian, to form a Riesz basis or to be an orthonormal system, and separately, to be complete. For this purpose, the concept of the dual function of the generating function of a system is introduced and studied. Some of the conditions given below are easy to verify in practice, as is demonstrated by examples. Bibliography: 25 titles.

  13. Dual and Feller-Reuter-Riley transition functions

    Science.gov (United States)

    Li, Yangrong

    2006-01-01

    In this paper, we investigate duality and Feller-Reuter-Riley (FRR) property of continuous-time Markov chains (CTMCs). A criterion of dual q-functions is given in terms of their q-matrices. For a dual q-matrix Q, a necessary and sufficient conditions for the minimal Q-function to be a FRR transition function are also given. Finally, by using dual technique, we give a criterion of FRR Q-functions when Q is monotone.

  14. Pairs of oblique duals in spaces of periodic functions

    DEFF Research Database (Denmark)

    Christensen, Ole; Goh, Say Song

    2010-01-01

    We construct non-tight frames in finite-dimensional spaces consisting of periodic functions. In order for these frames to be useful in practice one needs to calculate a dual frame; while the canonical dual frame might be cumbersome to work with, the setup presented here enables us to obtain...... explicit constructions of some particularly convenient oblique duals. We also provide explicit oblique duals belonging to prescribed spaces different from the space where we obtain the expansion. In particular this leads to oblique duals that are trigonometric polynomials....

  15. Unraveling executive functioning in dual diagnosis

    NARCIS (Netherlands)

    Duijkers, J.C.L.M.; Vissers, C.T.W.M.; Egger, J.I.M.

    2016-01-01

    In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other's expression. Forming a threat to health and society, dual-diagnosis is assoc

  16. Boronate-Phenolic Network Capsules with Dual Response to Acidic pH and cis-Diols.

    Science.gov (United States)

    Guo, Junling; Sun, Huanli; Alt, Karen; Tardy, Blaise L; Richardson, Joseph J; Suma, Tomoya; Ejima, Hirotaka; Cui, Jiwei; Hagemeyer, Christoph E; Caruso, Frank

    2015-08-26

    Dual-responsive boronate-phenolic network (BPN) capsules are fabricated by the complexation of phenylborate and phenolic materials. The BPN capsules are stable in the presence of competing carbohydrates, but dissociate at acidic pH or in the presence of competing cis-diols at physiological pH. This engineered capsule system provides a platform for a wide range of biological and biomedical applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. New dual emission fluorescent sensor for pH and Pb(II) based on bis(napfthalimide) derivative

    Energy Technology Data Exchange (ETDEWEB)

    Pina-Luis, Georgina, E-mail: gpinaluis@yahoo.com [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico); Martinez-Quiroz, Marisela; Ochoa-Teran, Adrian [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico); Santacruz-Ortega, Hisila [Departamento de investigacion en Polimeros y Materiales, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Mendez-Valenzuela, Eduardo [Centro de Graduados e Investigacion en Quimica, Instituto Tecnologico de Tijuana, AP 1166, Tijuana 22500, BC (Mexico)

    2013-02-15

    This paper describes a novel dual emission bis-1,8-naphthalimide sensor for selective determination of pH and Pb{sup 2+} ions. The influence of the variability in the backbone that links the two fluorophores (naphthalimides) as a function of pH and metal ions was studied by UV-visible and fluorescence spectroscopy. Compounds 1(a-d) with different length alkyl linkers (CH{sub 2}){sub n} (n=1, 2, 4 and 6) showed no excimer formation in aqueous solution. Fluorescence emission of these derivatives varied in a narrow range of pH (5-8) and was only slightly influenced by the addition of metal ions in CH{sub 3}CN solutions. However, derivative 1e with amino-containing spacer (CH{sub 2}-NH-CH{sub 2}) showed excimer emission in aqueous solution, a wide response to pH (2.5-9.5) and fluorescence enhancement with selective behavior towards metal ions. The pH sensor based in derivative 1e has a sufficient selectivity for practical pH monitoring in the presence of Li{sup +}, Na{sup +}, K{sup +}, Cs{sup +}, Ca{sup 2+}, Mg{sup 2+}, Ba{sup 2+}, Cu{sup 2+}, Pb{sup 2+}, Ni{sup 2+}, Zn{sup 2+} and Cd{sup 2+}. The coordination chemistry of these complexes was studied by UV-Vis, fluorescence and {sup 1}H NMR. This chemosensor displayed high selectivity fluorescence enhancement toward Pb{sup 2+} ions in the presence of the metals ions mentioned in CH{sub 3}CN solutions. Competitive assays show that a 1-fold of metal cations in each case, compared with Pb{sup 2+} ions, results in less than {+-}5% fluorescence intensity changes. Linear calibration up to 1 Multiplication-Sign 10{sup -5} M for Pb(II) ions (R=0.9968) was obtained and detection limit resulted of 5.0 Multiplication-Sign 10{sup -8} M. - Highlights: Black-Right-Pointing-Pointer A novel dual emission bis-1,8-naphthalimide sensor for pH and Pb{sup 2+} ions is synthetized. Black-Right-Pointing-Pointer The excimer formation depends on the spacer that links the two naphthalimide groups. Black-Right-Pointing-Pointer Bis

  18. Measurement of Autolysosomal pH by Dual-Wavelength Ratio Imaging.

    Science.gov (United States)

    Saric, A; Grinstein, S; Freeman, S A

    2017-01-01

    Cellular components sequestered by autophagosomes during macroautophagy must be degraded and their components recycled in order to maintain homeostasis. To this end cells orchestrate the fusion of autophagosomes with lysosomes, degradative organelles that are rich in hydrolases. Most of the lysosomal enzymes function optimally at low pH, and products of macromolecular catabolism are cotransported with protons across the autolysosomal membrane. These functions are facilitated by the ability of lysosomes to pump protons inward, acidifying their lumen. Clearly, proper homeostasis of the luminal pH is crucial for autolysosomal function. We describe a method for the measurement of the absolute pH of individual autolysosomes in live cells. This technique involves measurement of the fluorescence of a pH-sensitive probe initially delivered to lysosomes and subsequently determined to have reached autolysosomes. By measuring the fluorescence at two separate wavelengths and calculating their ratio, potential artifacts introduced by photobleaching or by changes in autolysosome size, shape, or positioning are minimized. Combining such ratio determinations with an in situ calibration procedure enables absolute measurements of pH, which are superior to the qualitative estimates obtained with fluorescent weak bases such as LysoTracker.

  19. Microfluidic conceived pH sensitive core-shell particles for dual drug delivery.

    Science.gov (United States)

    Khan, Ikram Ullah; Stolch, Lukas; Serra, Christophe A; Anton, Nicolas; Akasov, Roman; Vandamme, Thierry F

    2015-01-15

    In current study, we report on the synthesis of core-shell microparticles for dual drug delivery by means of a two co-axial microfluidic device and online UV assisted free radical polymerization. Before developing pH-sensitive particles, ketoprofen loaded poly(methyl acrylate) core-ranitidine HCl loaded poly(acrylamide) shell particles were produced. Influence of inner and outer phases flow rates on particle size, shape, core diameter, shell thickness, and drug release properties was studied. All the particles were monodispersed with coefficient of variation below 5%. Furthermore, their diameter ranged from 100 to 151 μm by increasing continuous (Qc) to middle (Qm) phase flow rate ratio (Qc/Qm). Core diameter varied from 58 to 115 μm by decreasing middle (Qm) to inner (Qi) phase flow rate ratio (Qm/Qi) at constant continuous phase flow rate as confirmed by SEM images. It was observed that an optimum concentration of acrylamide (30 wt%) and an appropriate combination of surfactants were necessary to get core-shell particles otherwise Janus structure was obtained. FTIR confirmed the complete polymerization of core and shell phases. MTT assay showed variation in viability of cells under non-contact and contact conditions with less cytotoxicity for the former. Under non-contact conditions LD50 was 3.1mg/mL. Release studies in USP phosphate buffer solution showed simultaneously release of ketoprofen and ranitidine HCl for non pH-sensitive particles. However, release rates of ranitidine HCl and ketoprofen were higher at low and high pH respectively. To develop pH-sensitive particles for colon targeting, the previous shell phase was admixed with few weight percentage of pH sensitive carboxyethyl acrylate monomer. Core and shell contained the same hydrophobic and hydrophilic model drugs as in previous case. The pH-sensitive shell prevented the release of the two entrapped molecules at low pH while increasing significantly their release rate at higher pH with a maximum

  20. Unraveling Executive Functioning in Dual Diagnosis

    OpenAIRE

    Duijkers, J.C.L.M.; Vissers, C.T.W.M.; Egger, J. I. M.

    2016-01-01

    In mental health, the term dual-diagnosis is used for the co-occurrence of Substance Use Disorder (SUD) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other's expression. Forming a threat to health and society, dual-diagnosis is associated with relapses in addiction-related behavior and a destructive lifestyle. This is due to a persistent failure to control impulses and the maintaining of inadequate self-regulatory behavior in ...

  1. DUAL INTEGRAL EQUATIONS INVOLVING LEGENDRE FUNCTIONS IN DISTRIBUTION SPACES

    Directory of Open Access Journals (Sweden)

    P. K. BANERJI, DESHNA LOONKER

    2010-11-01

    Full Text Available In this paper we use the Mehler-Fock transformation to obtain thesolution of dual integral equations involving Legendre functions. The solutionso obtained is proved to be distributional because they satisfy properties ofdistribution space.

  2. Integrated process and dual-function catalyst for olefin epoxidation

    Science.gov (United States)

    Zhou, Bing; Rueter, Michael

    2003-01-01

    The invention discloses a dual-functional catalyst composition and an integrated process for production of olefin epoxides including propylene oxide by catalytic reaction of hydrogen peroxide from hydrogen and oxygen with olefin feeds such as propylene. The epoxides and hydrogen peroxide are preferably produced simultaneously in situ. The dual-functional catalyst comprises noble metal crystallites with dimensions on the nanometer scale (on the order of olefin oxides such as propylene oxide without formation of undesired co-products.

  3. Executive functioning in dual-diagnosis

    NARCIS (Netherlands)

    Duijkers, J.C.L.M.; Vissers, C.T.W.M.; Egger, J.I.M.

    2016-01-01

    Objectives: In mental health, the term dual-diagnosis (DD) is used for the co-occurrence of Substance Use Disorder (SUD: alcohol/drugs) with another mental disorder. These co-occurring disorders can have a shared cause, and can cause/intensify each other's expression. Forming a threat to health and

  4. ON MAXIMA OF DUAL FUNCTION OF THE CDTSUBPROBLEM

    Institute of Scientific and Technical Information of China (English)

    Xiong-da Chen; Ya-xiang Yuan

    2001-01-01

    In this paper, we show the geometry meaning of the maxima of theCDT subproblem's dual function. We also studied the continuity of the global solution of the trust region subproblem. Based on an approximation model, we prove that the global solution of the CDT subproblem is given with the Hessian of Lagrangian positive semi-definite by some specially-located dual maxima and by restricting the location region of the multipliers which corresponding a global solution in other cases.

  5. Dual-Functional Hydrazide-Reactive and Anhydride-Containing Oligomeric Hydrogel Building Blocks.

    Science.gov (United States)

    Kascholke, Christian; Loth, Tina; Kohn-Polster, Caroline; Möller, Stephanie; Bellstedt, Peter; Schulz-Siegmund, Michaela; Schnabelrauch, Matthias; Hacker, Michael C

    2017-02-08

    Biomimetic hydrogels are advanced biomaterials that have been developed following different synthetic routes. Covalent postfabrication functionalization is a promising strategy to achieve efficient matrix modification decoupled of general material properties. To this end, dual-functional macromers were synthesized by free radical polymerization of maleic anhydride with diacetone acrylamide (N-(1,1-dimethyl-3-oxobutyl)acrylamide) and pentaerythritol diacrylate monostearate. Amphiphilic oligomers (Mn 40%). Efficient hydrazide/hydrazine immobilization depending on solution pH, hydrogel ketone content as well as ligand concentration for bioconjugation was shown and reversibility of hydrazone formation was indicated by physiologically relevant hydrazide release over 7 days. Proof-of-concept experiments with hydrazido-functionalized hyaluronan demonstrated potential for covalent aECM immobilization. The presented dual-functional macromers have perspective as reactive hydrogel building blocks for various biomedical applications.

  6. Dual Functional Star Polymers for Lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Cosimbescu, Lelia; Robinson, Joshua W.; Zhou, Yan; Qu, Jun

    2016-09-12

    Star-shaped poly(alkyl methacrylate)s (PAMAs) with a 3-arm architecture were designed, prepared and their performance as a dual additive (viscosity index improver and friction modifier) for engine oils was evaluated. Furthermore, the structure-property relationships between macromolecular structure and lubricant performance were studied. Several co-polymers of dodecylmethacrylate with polar methacrylates in various amounts and various topologies, were synthesized as model compounds. Star polymers with a polar content of at least 10% effectively reduced the friction coefficient in both mixed and boundary lubrication regime only in block or tapered block topology. However, a polar content of 20% was efficient in reducing friction in both random and block topologies.

  7. AND logic-like pH- and light-dual controlled drug delivery by surface modified mesoporous silica nanoparticles.

    Science.gov (United States)

    Zhao, Junwei; He, Zhaoshuai; Li, Biao; Cheng, Tanyu; Liu, Guohua

    2017-04-01

    Recently, the controlled drug delivery system has become a potential platform for biomedical application. Herein, we developed a pH and light-dual controlled cargo release system exhibiting AND logic based on MCM-41 mesoporous silica nanoparticles, which was surface modified using β-cyclodextrin (β-CD) with imine bond and azobenzene derivative. The complex of β-CD and azobenzene derivative effectively blocked the cargo delivery in pH=7.0 phosphate buffered saline (PBS) solution without 365nm UV light irradiation. The cargo was fully released when both factors of acidic environment (pH=5.0 PBS) and 365nm UV light irradiation were satisfied, meanwhile only very little cargo was delivered if one factor was satisfied. The result also demonstrates that the opening/closing of the gate and the release of the cargo in small portions can be controlled. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Extracellular pH regulates bone cell function.

    Science.gov (United States)

    Arnett, Timothy R

    2008-02-01

    The skeletons of land vertebrates contain a massive reserve of alkaline mineral (hydroxyapatite), which is ultimately available to buffer metabolic H+ if acid-base balance is not maintained within narrow limits. The negative impact of acidosis on the skeleton has long been known but was thought to result from passive, physicochemical dissolution of bone mineral. This brief, selective review summarizes what is now known of the direct functional responses of bone cells to extracellular pH. We discovered that bone resorption by cultured osteoclasts is stimulated directly by acid. The stimulatory effect is near-maximal at pH 7.0, whereas above pH 7.4, resorption is switched off. In bone organ cultures, H+-stimulated bone mineral release is almost entirely osteoclast-mediated, with a negligible physicochemical component. Acidification is the key requirement for osteoclasts to excavate resorption pits in all species studied to date, and extracellular H+ may thus be regarded as the long-sought osteoclast activation factor. Acid-activated osteoclasts can be stimulated further by agents such as parathyroid hormone, 1,25-dihydroxycholecalciferol, and receptor activator of nuclear factor kappaB ligand. Osteoclasts may respond to pH changes via H+-sensing ion channels such as transient receptor potential vanilloid 1, a nociceptor that is also activated by capsaicin. Acidosis also exerts a powerful, reciprocal inhibitory effect on the mineralization of bone matrix by cultured osteoblasts. This is caused by increased hydroxyapatite solubility at low pH, together with selective inhibition of alkaline phosphatase, which is required for mineralization. Diets or drugs that shift acid-base balance in the alkaline direction may provide useful treatments for bone loss disorders.

  9. On the dual of Ces\\`aro function space

    CERN Document Server

    Kamińska, Anna

    2011-01-01

    The goal of this paper is to present an isometric representation of the dual space to Ces\\`aro function space $C_{p,w}$, $1function $w$ on interval $(0,l)$ where $0function $\\Psi$ on $(0,l)$, the notion of essential $\\Psi$-concave majorant $\\hat f$ of a measurable function $f$ is introduced and investigated. As applications it is shown that every slice of the unit ball of the Ces\\`aro function space has diameter 2. Consequently Ces\\`aro function spaces do not have the Radon-Nikodym property, are not locally uniformly convex and they are not dual spaces.

  10. Dual-Modal Colorimetric/Fluorescence Molecular Probe for Ratiometric Sensing of pH and Its Application.

    Science.gov (United States)

    Wu, Luling; Li, Xiaolin; Huang, Chusen; Jia, Nengqin

    2016-08-16

    As traditional pH meters cannot work well for minute regions (such as subcellular organelles) and in harsh media, molecular pH-sensitive devices for monitoring pH changes in diverse local heterogeneous environments are urgently needed. Here, we report a new dual-modal colorimetric/fluorescence merocyanine-based molecular probe (CPH) for ratiometric sensing of pH. Compared with previously reported pH probes, CPH bearing the benzyl group at the nitrogen position of the indolium group and the phenol, which is used as the acceptor for proton, could respond to pH changes immediately through both the ratiometric fluorescence signal readout and naked-eye colorimetric observation. The sensing process was highly stable and reversible. Most importantly, the suitable pKa value (6.44) allows CPH to presumably accumulate in lysosomes and become a lysosome-target fluorescent probe. By using CPH, the intralysosomal pH fluctuation stimulated by antimalaria drug chloroquine was successfully tracked in live cells through the ratiometric fluorescence images. Additionally, CPH could be immobilized on test papers, which exhibited a rapid and reversible colorimetric response to acid/base vapor through the naked-eye colorimetric analysis. This proof-of-concept study presents the potential application of CPH as a molecular tool for monitoring intralysosomal pH fluctuation in live cells, as well as paves the way for developing the economic, reusable, and fast-response optical pH meters for colorimetric sensing acid/base vapor with direct naked-eye observation.

  11. Balancing the Dual Functions of Portfolio Assessment

    Science.gov (United States)

    Lam, Ricky; Lee, Icy

    2010-01-01

    While research on portfolio assessment (PA) has focused largely on the summative aspects of writing assessment, not much has been done to find out its formative potential. Drawing upon student questionnaires and student and teacher interview data, this paper aims to explore the formative functions of PA and, specifically, how the formative…

  12. Temperature and pH dual-responsive POEGMA-based coatings for protein adsorption.

    Science.gov (United States)

    Stetsyshyn, Yurij; Fornal, Katarzyna; Raczkowska, Joanna; Zemla, Joanna; Kostruba, Andrij; Ohar, Halyna; Ohar, Mariya; Donchak, Volodymyr; Harhay, Khrystyna; Awsiuk, Kamil; Rysz, Jakub; Bernasik, Andrzej; Budkowski, Andrzej

    2013-12-01

    Poly(oligo(ethylene glycol)ethyl ether methacrylate (POEGMA246) coatings were successfully fabricated using novel approach via polymerization from oligoperoxide grafted to premodified glass substrate. Wettability, content and composition of coatings fabricated with different polymerization times were determined using contact angle measurements, ellipsometry and Time of Flight-Secondary Ion Mass Spectrometry (TOF-SIMS). Thermo- and pH-responsive properties of POEGMA246 coatings were found to depend significantly on concentration of the grafted POEGMA246. Coatings fabricated with polymerization time 30 h exhibit not only temperature- but also pH-dependence of wettability. Thermal response of wettability, measured between 20 and 32°C, was prominent at pH 9 and 7 and diminished or was absent at pH 5 and 3, indicating a transition between hydrated loose coils and hydrophobic collapsed chains, blocked at low pH. Protein adsorption, observed by fluorescence microscopy and analyzed semi-quantitatively using integral geometry approach, decreased dramatically for model protein (lentil lectin labeled with fluorescein isothiocyanate) at transition from pH 5 to pH 9, showing only very weak thermal-dependence. Strong protein adsorption response to pH and very weak one to temperature was confirmed by TOF-SIMS and Principal Component Analysis. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Colon-targeted delivery of budesonide using dual pH- and time-dependent polymeric nanoparticles for colitis therapy

    Directory of Open Access Journals (Sweden)

    Naeem M

    2015-07-01

    Full Text Available Muhammad Naeem,1 Moonjeong Choi,1 Jiafu Cao,1 Yujeong Lee,1 Muhammad Ikram,2 Sik Yoon,2 Jaewon Lee,1 Hyung Ryong Moon,1 Min-Soo Kim,1 Yunjin Jung,1 Jin-Wook Yoo11College of Pharmacy, Pusan National University, Busan, 2Pusan National University School of Medicine, Yangsan, South KoreaAbstract: Single pH-dependent drug delivery systems have been widely used for colon-targeted delivery, but their efficiency is often hampered by the variation in gut pH. To overcome the limitation of single pH-dependent delivery systems, in this study, we developed and evaluated the therapeutic potential of budesonide-loaded dual pH/time-dependent nanoparticles (NPs for the treatment of colitis. Eudragit FS30D was used as a pH-dependent polymer, and Eudragit RS100 as a time-dependent controlled release polymer. Single pH-dependent NPs (pH_NPs, single time-dependent NPs (Time_NPs, and dual pH/time-dependent NPs (pH/Time_NPs were prepared using the oil-in-water emulsion method. The physicochemical properties and drug release profiles of these NPs in gastrointestinal (GI tract conditions were investigated. The therapeutic potential and in vivo distribution of the NPs were evaluated in a dextran sulfate sodium (DSS-induced colitis mice model. The pH/Time_NPs prevented a burst drug release in acidic pH conditions and showed sustained release at a colonic pH. The in vivo distribution study in the mice GI tract demonstrated that pH/Time_NPs were more efficiently delivered to the inflamed colon than pH_NPs were. Compared to the single pH_NPs-treated group, the pH/Time_NPs-treated group showed increased body weight and colon length and markedly decreased disease activity index, colon weight/length ratios, histological damage, and inflammatory cell infiltration in colon tissue. Our results demonstrate that the dual pH/time-dependent NPs are an effective oral colon-targeted delivery system for colitis therapy.Keywords: colon-specific delivery, dual-sensitive delivery

  14. The Number of Monotone and Self-Dual Boolean Functions

    Directory of Open Access Journals (Sweden)

    Haviarova L.

    2014-12-01

    Full Text Available In the present paper we study properties of pre-complete class of Boolean functions - monotone Boolean functions. We discuss interval graph, the abbreviated d.n.f., a minimal d.n.f. and a shortest d.n.f. of this function. Then we present a d.n.f. with the highest number of conjunctionsand we determinate the exact number of them. We count the number of monotone Boolean functions with some special properties. In the end we estimate the number of Boolean functionthat are monotone and self-dual at the same time.

  15. Redox and pH dual-responsive PEG and chitosan-conjugated hollow mesoporous silica for controlled drug release

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Jian; Li, Xian; Zhang, Sha; Liu, Jie; Di, Donghua [Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, Liaoning Province 110016 (China); Zhang, Ying [School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, PR China. (China); Zhao, Qinfu, E-mail: zqf021110505@163.com [Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, Liaoning Province 110016 (China); Wang, Siling, E-mail: silingwang@syphu.edu.cn [Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, Liaoning Province 110016 (China)

    2016-10-01

    In this paper, a hollow mesoporous silica nanoparticles (HMSN) was used as the drug vehicle to develop the redox and pH dual stimuli-responsive delivery system, in which the chitosan (CS), a biodegradable cationic polymer, was grafted on the surface of HMSN via the cleavable disulfide bonds. CS was chosen as the gatekeeper mainly due to its appropriate molecular weight as well as possessing abundant amino groups which could be protonated in the acidic condition to achieve pH-responsive drug release. In addition, the PEG was further grafted on the surface of CS to increase the stability and biocompatibility under physiological conditions. The DOX loaded DOX/HMSN-SS-CS@PEG had a relatively high drug loading efficiency up to 32.8%. In vitro release results indicated that DOX was dramatically blocked within the mesopores of HMSN-SS-CS@PEG in pH 7.4 PBS without addition of GSH. However, the release rate of DOX was markedly increased after the addition of 10 mM GSH or in pH 5.0 release medium. Moreover, the release of DOX was further improved in pH 5.0 PBS with 10 mM GSH. The HMSN-SS-CS@PEG could markedly decrease the hemolysis percent and protein adsorption, and increase the biocompatibility and stability of HMSN compared with the HMSN-SS-CS and bare HMSN. This work suggested an exploration about HMSN based stimuli-responsive drug delivery and these results demonstrated that HMSN-SS-CS@PEG exhibited dual-responsive drug release property and could be used as a promising carrier for cancer therapy. - Highlights: • Hollow mesoporous silica nanoparticles (HMSN) were used as a drug carrier. • Chitosan (CS) and PEG were grafted on the surface of HMSN via disulfide bonds. • The DOX loaded DOX/HMSN-SS-CS@PEG had a high drug loading efficiency up to 32.8%. • DOX/HMSN-SS-CS@PEG showed redox/pH dual-responsive drug release property in vitro. • The grafted PEG could increase the biocompatibility and stability of HMSN.

  16. Mesoporous silica nanoparticles combining Au particles as glutathione and pH dual-sensitive nanocarriers for doxorubicin

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shuang; Li, Yan [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Zhenjie; Hou, Cuilan [Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000 (China); Chen, Tong; Xu, Zhigang [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Zhang, Xiaoyu [Institute of Physiology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000 (China); Zhang, Haixia, E-mail: zhanghx@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2016-02-01

    Mesoporous silica nanoparticles (MSNs) combining gold particles (MSNs–Au) were synthesized as nanocarriers for glutathione (GSH) and pH dual-sensitive intracellular controlled release of the anti-cancer drug doxorubicin (DOX). The MSNs were used as an adsorbent for DOX, and the ultra-small gold nanospheres (Au NPs) partly operated as gatekeepers to control the release of DOX from the pores of MSNs and as the driver of drug release in the presence of GSH due to the association between GSH and Au particles. Under different pH conditions, DOX release changed due to different levels of dissociation between the –SH group on the MSNs and the Au particles. The composition, morphology, and properties of the as-prepared composites were characterized by elemental analysis, fluorescence spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, nitrogen adsorption–desorption, thermal gravimetric and UV–visible spectroscopy. The in vitro release experiments showed that these smart nanocarriers effectively avoided drug leakage in the neutral media. Cytotoxicity and imaging studies also indicated that DOX-loaded Au-MSNs (DOX@MSNs–Au) had a significant inhibitory effect on the growth of Tca8113 cells and sustained the release rate of DOX - Highlights: • Dual-sensitive nanocarrier based on pH and glutathione was fabricated. • Ultra small Au NPs acting as gatekeepers to achieve the controlled release • The drug delivery system exhibited less premature release. • The drug delivery system enabled the high growth inhibition toward Tca8113 cells.

  17. Dual-Functional Antifogging/Antimicrobial Polymer Coating.

    Science.gov (United States)

    Zhao, Jie; Ma, Li; Millians, William; Wu, Tiehang; Ming, Weihua

    2016-04-06

    Dual-functional antifogging/antimicrobial polymer coatings were prepared by forming a semi-interpenetrating polymer network (SIPN) of partially quaternized poly(2-(dimethylamino)ethyl methacrylate-co-methyl methacrylate) and polymerized ethylene glycol dimethacrylate network. The excellent antifogging behavior of the smooth coating was mainly attributed to the hydrophilic/hydrophobic balance of the partially quaternized copolymer, while the covalently bonded, hydrophobic quaternary ammonium compound (5 mol % in the copolymer) rendered the coating strongly antimicrobial, as demonstrated by the total kill against both Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli. The antimicrobial action of the SIPN coating was based on contact killing, without leaching of bactericidal species, as revealed by a zone-of-inhibition test. This type of dual-functional coating may find unique applications where both antimicrobial and antifogging properties are desired.

  18. PhD Thesis: Functional Textiles in Hospital Interiors

    DEFF Research Database (Denmark)

    Mogensen, Jeppe Emil

    consists of a collection of 5 peer-reviewed papers, and an extended summary. The project is overall related to the construction of new Danish hospitals, where the design concept healing architecture is intro- duced in a national context, representing the vision of a promoted healing process of hospitalised...... of plastic, vinyl and steel. These materials also dominate the new hospitals, designed and constructed these years, and despite the increased focus on the design concept healing architecture, the rational requirements of ef cient cleaning and maintenance still seems to direct the interior design of hospital...... of this PhD project has been to explore the possibilities and design qualities of using these materials in hospital inte- rior design. Relating to both technical and aesthetic aspects of using functional textiles in hospitals, the project seeks to integrate these aspects, departing from the overall research...

  19. Banach spaces of continuous functions as dual spaces

    CERN Document Server

    Dales, H G; Lau, A T -M; Strauss, D

    2016-01-01

    This book gives a coherent account of the theory of Banach spaces and Banach lattices, using the spaces C_0(K) of continuous functions on a locally compact space K as the main example. The study of C_0(K) has been an important area of functional analysis for many years. It gives several new constructions, some involving Boolean rings, of this space as well as many results on the Stonean space of Boolean rings. The book also discusses when Banach spaces of continuous functions are dual spaces and when they are bidual spaces.

  20. Orbifold E-functions of dual invertible polynomials

    Science.gov (United States)

    Ebeling, Wolfgang; Gusein-Zade, Sabir M.; Takahashi, Atsushi

    2016-08-01

    An invertible polynomial is a weighted homogeneous polynomial with the number of monomials coinciding with the number of variables and such that the weights of the variables and the quasi-degree are well defined. In the framework of the search for mirror symmetric orbifold Landau-Ginzburg models, P. Berglund and M. Henningson considered a pair (f , G) consisting of an invertible polynomial f and an abelian group G of its symmetries together with a dual pair (f ˜ , G ˜) . We consider the so-called orbifold E-function of such a pair (f , G) which is a generating function for the exponents of the monodromy action on an orbifold version of the mixed Hodge structure on the Milnor fibre of f. We prove that the orbifold E-functions of Berglund-Henningson dual pairs coincide up to a sign depending on the number of variables and a simple change of variables. The proof is based on a relation between monomials (say, elements of a monomial basis of the Milnor algebra of an invertible polynomial) and elements of the whole symmetry group of the dual polynomial.

  1. USB Dual-Mode Function IP Core Development

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper describes the specification and implement of a Universal Serial Bus (USB) dual-mode function IP core used for embedded system. Controlled by micro controller/CPU, the novel IP core can function as a USB host controller or USB peripheral controller. When configured as a USB host controller, it supports all USB 1.1 transaction types; supports automatic preamble insertion, and automatic SOF generation and transmission. Otherwise, when it is configured as a USB device by a microprocessor, it operates as a USB peripheral controller compliant with USB2.0 specification.

  2. pH and temperature dual-sensitive liposome gel based on novel cleavable mPEG-Hz-CHEMS polymeric vaginal delivery system

    Science.gov (United States)

    Chen, Daquan; Sun, Kaoxiang; Mu, Hongjie; Tang, Mingtan; Liang, Rongcai; Wang, Aiping; Zhou, Shasha; Sun, Haijun; Zhao, Feng; Yao, Jianwen; Liu, Wanhui

    2012-01-01

    Background In this study, a pH and temperature dual-sensitive liposome gel based on a novel cleavable hydrazone-based pH-sensitive methoxy polyethylene glycol 2000-hydrazone-cholesteryl hemisuccinate (mPEG-Hz-CHEMS) polymer was used for vaginal administration. Methods The pH-sensitive, cleavable mPEG-Hz-CHEMS was designed as a modified pH-sensitive liposome that would selectively degrade under locally acidic vaginal conditions. The novel pH-sensitive liposome was engineered to form a thermogel at body temperature and to degrade in an acidic environment. Results A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The dual-sensitive liposome gel with a sol-gel transition at body temperature was degraded in a pH-dependent manner, and was stable for a long period of time at neutral and basic pH, but cleavable under acidic conditions (pH 5.0). Arctigenin encapsulated in a dual-sensitive liposome gel was more stable and less toxic than arctigenin loaded into pH-sensitive liposomes. In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0. Conclusion This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery. PMID:22679372

  3. Affine dual equivalence and k-Schur functions

    CERN Document Server

    Assaf, Sami

    2012-01-01

    The k-Schur functions were first introduced by Lapointe, Lascoux and Morse (2003) in the hopes of refining the expansion of Macdonald polynomials into Schur functions. Recently, an alternative definition for k-Schur functions was given by Lam, Lapointe, Morse, and Shimozono (2010) as the weighted generating function of starred strong tableaux which correspond with labeled saturated chains in the Bruhat order on the affine symmetric group modulo the symmetric group. This definition has been shown to correspond to the Schubert basis for the affine Grassmannian of type A by Lam (2008), and, at t = 1, it is equivalent to the k-tableaux characterization of Lapointe and Morse (2007). In this paper, we extend Haiman's (1992) dual equivalence relation on standard Young tableaux to all starred strong tableaux. The elementary equivalence relations can be interpreted as labeled edges in a graph which share many of the properties of Assaf's dual equivalence graphs. These graphs display much of the complexity of working w...

  4. The effects of hyperosmosis or high pH on a dual-species biofilm of Enterococcus faecalis and Pseudomonas aeruginosa : an in vitro study

    NARCIS (Netherlands)

    van der Waal, S. V.; van der Sluis, L. W. M.; Ozok, A. R.; Exterkate, R. A. M.; van Marle, J.; Wesselink, P. R.; de Soet, J. J.

    2011-01-01

    van der Waal SV, van der Sluis LWM, Ozok AR, Exterkate RAM, van Marle J, Wesselink PR, de Soet JJ. The effects of hyperosmosis or high pH on a dual-species biofilm of Enterococcus faecalis and Pseudomonas aeruginosa: an in vitro study. International Endodontic Journal, 44, 11101117, 2011. Aim To inv

  5. Enkephalins: Raman spectral analysis and comparison as function of pH 1-13

    DEFF Research Database (Denmark)

    Abdali, Salim; Refstrup, Pia; Nielsen, O.F.

    2003-01-01

    Raman spectral studies are carried out on Leu- and Met-enkephalin as a function of the pH value in the range of 1-13. The molecules are dissolved in KCI solvent and the pH is controlled at each value. Spectral analyses reveal the dependence of the structural conformation on the pH, and a comparis...

  6. Molecular characterization and functional analysis of two petunia PhEILs

    Directory of Open Access Journals (Sweden)

    Feng Liu

    2016-11-01

    Full Text Available Ethylene plays an important role in flower senescence of many plants. Arabidopsis ETHYLENE INSENSITIVE3 (EIN3 and its homolog EIL1 are the downstream component of ethylene signaling transduction. However, the function of EILs during flower senescence remains unknown. Here, a petunia EIL gene, PhEIL2, was isolated. Phylogenetic tree showed that PhEIL1, whose coding gene is previously isolated, and PhEIL2 are the homologs of Arabidopsis AtEIL3 and AtEIL1, respectively. The expression of both PhEIL1 and PhEIL2 is the highest in corollas and increased during corolla senescence. Ethylene treatment increased the mRNA level of PhEIL1 but reduced that of PhEIL2. VIGS-mediated both PhEIL1 and PhEIL2 silencing delayed flower senescence, and significantly reduced ethylene production and the expression of PhERF3 and PhCP2, two senescence-associated genes in petunia flowers. The PhEIL2 protein activating transcription domain is identified in the 353-612-amino acids at C-terminal of PhEIL2 and yeast two-hybrid and BiFC assays show that PhEIL2 interacts with PhEIL1, suggesting that PhEIL1 and PhEIL2 might form heterodimers to recognize their targets. These molecular characterizations of PhEIL1 and PhEIL2 in petunia are different with those of in Vigna radiata and Arabidopsis.

  7. Pseudoproduction, Pseudocost and Profit Functions in Monopoly from the Dual Perspective

    Directory of Open Access Journals (Sweden)

    Vrankić Ilko

    2016-09-01

    Full Text Available Background: Duality in the microeconomic theory enables us to represent consumers’ preferences and production technology with various dual functions satisfying certain regularity conditions.

  8. pH and temperature dual-sensitive liposome gel based on novel cleavable mPEG-Hz-CHEMS polymeric vaginal delivery system

    Directory of Open Access Journals (Sweden)

    Chen D

    2012-05-01

    Full Text Available Daquan Chen,1,2 Kaoxiang Sun,1,2 Hongjie Mu,1 Mingtan Tang,3 Rongcai Liang,1,2 Aiping Wang,1,2 Shasha Zhou,1 Haijun Sun,1 Feng Zhao,1 Jianwen Yao,1 Wanhui Liu1,21School of Pharmacy, Yantai University, 2State Key Laboratory of Longacting and Targeting Drug Delivery Systems, Yantai, 3School of Pharmaceutical Sciences, Shandong University, Jinan, People's Republic of ChinaBackground: In this study, a pH and temperature dual-sensitive liposome gel based on a novel cleavable hydrazone-based pH-sensitive methoxy polyethylene glycol 2000-hydrazone-cholesteryl hemisuccinate (mPEG-Hz-CHEMS polymer was used for vaginal administration.Methods: The pH-sensitive, cleavable mPEG-Hz-CHEMS was designed as a modified pH-sensitive liposome that would selectively degrade under locally acidic vaginal conditions. The novel pH-sensitive liposome was engineered to form a thermogel at body temperature and to degrade in an acidic environment.Results: A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The dual-sensitive liposome gel with a sol-gel transition at body temperature was degraded in a pH-dependent manner, and was stable for a long period of time at neutral and basic pH, but cleavable under acidic conditions (pH 5.0. Arctigenin encapsulated in a dual-sensitive liposome gel was more stable and less toxic than arctigenin loaded into pH-sensitive liposomes. In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0.Conclusion: This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery.Keywords: mPEG-Hz-CHEMS polymer, pH-sensitive liposomes, thermosensitive

  9. Pairs of dual Gabor frames generated by functions of Hilbert-Schmidt type

    DEFF Research Database (Denmark)

    Christiansen, Lasse Hjuler

    2015-01-01

    We show that any two functions which are real-valued, bounded, compactly supported and whose integer translates each form a partition of unity lead to a pair of windows generating dual Gabor frames for (Formula presented.). In particular we show that any such functions have families of dual windo...

  10. A Decomposition of the Dual Space of Some Banach Function Spaces

    Directory of Open Access Journals (Sweden)

    Claudia Capone

    2012-01-01

    Full Text Available We give a decomposition for the dual space of some Banach Function Spaces as the Zygmund space EXP of the exponential integrable functions, the Marcinkiewicz space ,∞, and the Grand Lebesgue Space ,.

  11. Dual-functionalized graphene oxide for enhanced siRNA delivery to breast cancer cells.

    Science.gov (United States)

    Imani, Rana; Shao, Wei; Taherkhani, Samira; Emami, Shahriar Hojjati; Prakash, Satya; Faghihi, Shahab

    2016-11-01

    The aim of this study is to improve hydrocolloid stability and siRNA transfection ability of a reduced graphene oxide (rGO) based nano-carrier using a phospholipid-based amphiphilic polymer (PL-PEG) and cell penetrating peptide (CPPs). The dual functionalized nano-carrier is comprehensively characterized for its chemical structure, size, surface charge and morphology as well as thermal stability. The nano-carrier cytocompatibility, siRNA condensation ability both in the presence and absence of enzyme, endosomal buffering capacity, cellular uptake and intracellular localization are also assessed. The siRNA loaded nano-carrier is used for internalization to MCF-7 cells and its gene silencing ability is compared with AllStars Hs Cell Death siRNA as a model gene. The nano-carrier remains stable in biological solution, exhibits excellent cytocompatibility, retards the siRNA migration and protects it against enzyme degradation. The buffering capacity analysis shows that incorporation of the peptide in nano-carrier structure would increase the resistance to endo/lysosomal like acidic condition (pH 6-4) The functionalized nano-carrier which is loaded with siRNA in an optimal N:P ratio presents superior internalization efficiency (82±5.1% compared to HiPerFect(®)), endosomal escape quality and capable of inducing cell death in MCF-7 cancer cells (51±3.1% compared to non-treated cells). The success of siRNA-based therapy is largely dependent on the safe and efficient delivery system, therefore; the dual functionalized rGO introduced here could have a great potential to be used as a carrier for siRNA delivery with relevancy in therapeutics and clinical applications.

  12. Photoactivity and pH sensitivity of methyl orange functionalized poly(propyleneamine) dendrimers

    NARCIS (Netherlands)

    Dirksen, A.; Zuidema, E.; Williams, R.M.; De Cola, L.; Kauffmann, C.; Vögtle, F.; Roque, A.; Pina, F.

    2002-01-01

    For the first time a pH indicator that responds to two different external stimuli, i.e. pH and light, namely methyl orange, has been implemented in a dendrimer. Six generations (G0-G5) of methyl orange-functionalized poly(propyleneamine) dendrimers ("MO dendrimers") have been synthesized and

  13. Photoactivity and pH sensitivity of methyl orange functionalized poly(propyleneamine) dendrimers

    NARCIS (Netherlands)

    Dirksen, A.; Zuidema, E.; Williams, R.M.; De Cola, L.; Kauffmann, C.; Vögtle, F.; Roque, A.; Pina, F.

    2002-01-01

    For the first time a pH indicator that responds to two different external stimuli, i.e. pH and light, namely methyl orange, has been implemented in a dendrimer. Six generations (G0-G5) of methyl orange-functionalized poly(propyleneamine) dendrimers ("MO dendrimers") have been synthesized and charact

  14. N-Terminal dual protein functionalization by strain-promoted alkyne-nitrone cycloaddition

    NARCIS (Netherlands)

    Temming, R.P.; Eggermont, L.J.; Eldijk, M.B. van; Hest, J.C. van; Delft, F.L. van

    2013-01-01

    Strain-promoted alkyne-nitrone cycloadditon (SPANC) was optimized as a versatile strategy for dual functionalization of peptides and proteins. The usefulness of the dual labeling protocol is first exemplified by the simultaneous introduction of a chloroquine and a stearyl moiety, two endosomal escap

  15. Functional properties of whey proteins microparticulated at low pH.

    Science.gov (United States)

    Dissanayake, M; Liyanaarachchi, S; Vasiljevic, T

    2012-04-01

    The main aim of the study was to assess the effect of microparticulation at low pH on the functionality of heat-denatured whey proteins (WP). Spray-dried, microparticulated WP (MWP) powders were produced from 7% (wt/wt) WP dispersions at pH 3, acidified with citric or lactic acid, and microfluidized with or without heat denaturation. Nonmicroparticulated, spray-dried powders produced at neutral pH or pH 3 served as controls. The powders were examined for their functional and physicochemical properties. Denatured MWP had an approximately 2 orders of magnitude reduction in particle size compared with those produced at neutral pH, with high colloidal stability indicated by substantially improved solubility. The detection of monomeric forms of WP in PAGE also confirmed the particle size reduction. Microparticulated WP exhibited enhanced heat stability, as indicated by thermograms, along with better emulsifying properties compared with those produced at neutral pH. However, MWP powders created weaker heat-induced gels at neutral pH compared with controls. However, they created comparatively strong cold acid-set gels. At low pH, a combination of heat and high hydrodynamic pressure produced WP micro-aggregates with improved colloidal stability that affects other functionalities.

  16. Inhibition of the development of morphine tolerance by a potent dual mu-delta-opioid antagonist, H-Dmt-Tic-Lys-NH-CH2-Ph.

    Science.gov (United States)

    Jinsmaa, Yunden; Marczak, Ewa D; Balboni, Gianfranco; Salvadori, Severo; Lazarus, Lawrence H

    2008-10-01

    Three analogues of the dual mu-/delta-antagonist, H-Dmt-Tic-R-NH-CH2-Ph (R = 1, Lys-Z; 2, Lys-Ac; 3, Lys) were examined in vivo: 1 and 2 exhibited weak bioactivity, while 3 injected intracerebroventricularly was a potent dual antagonist for morphine- and deltorphin C-induced antinociception comparable to naltrindole (delta-antagonist), but 93% as effective as naloxone (nonspecific opioid receptor antagonist) and 4% as active as CTOP, a mu antagonist. Subcutaneous or oral administration of 3 antagonized morphine-induced antinociception indicating passage across epithelial and blood-brain barriers. Mice pretreated with 3 before morphine did not develop morphine tolerance indicative of a potential clinical role to inhibit development of drug tolerance.

  17. Psychological Well-Being of the Dual Career Women as Function of ...

    African Journals Online (AJOL)

    Psychological Well-Being of the Dual Career Women as Function of Work ... The Ex-post-facto research type was employed. ... Data collected were subjected to Pearson product moment correlation, Analysis of variance and t-test analysis.

  18. Associations between physical function, dual-task performance and cognition in patients with mild Alzheimer's disease

    DEFF Research Database (Denmark)

    Sobol, Nanna Aue; Hoffmann, Kristine; Vogel, Asmus

    2016-01-01

    OBJECTIVE: Alzheimer's disease (AD) causes a gradual decline in cognition, limitations of dual-tasking and physical function leading to total dependence. Hence, information about the interaction between physical function, dual-task performance and cognition may lead to new treatment strategies wi......-task performance was associated with better cognitive performance. CONCLUSION: The evidence of the associations between physical function, dual-task performance and cognition is important when creating new rehabilitation interventions to patients with mild AD.......OBJECTIVE: Alzheimer's disease (AD) causes a gradual decline in cognition, limitations of dual-tasking and physical function leading to total dependence. Hence, information about the interaction between physical function, dual-task performance and cognition may lead to new treatment strategies...... with the purpose of preserving function and quality of life. The objective of this study was to investigate the associations between physical function, dual-task performance and cognition in community-dwelling patients with mild AD. METHODS: Baseline results from 185 participants (50-90 years old) in the single...

  19. Computationally efficient double hybrid density functional theory using dual basis methods

    CERN Document Server

    Byrd, Jason N

    2015-01-01

    We examine the application of the recently developed dual basis methods of Head-Gordon and co-workers to double hybrid density functional computations. Using the B2-PLYP, B2GP-PLYP, DSD-BLYP and DSD-PBEP86 density functionals, we assess the performance of dual basis methods for the calculation of conformational energy changes in C$_4$-C$_7$ alkanes and for the S22 set of noncovalent interaction energies. The dual basis methods, combined with resolution-of-the-identity second-order M{\\o}ller-Plesset theory, are shown to give results in excellent agreement with conventional methods at a much reduced computational cost.

  20. Metal toxicity to freshwater organisms as a function of pH: A meta-analysis.

    Science.gov (United States)

    Wang, Zhen; Meador, James P; Leung, Kenneth M Y

    2016-02-01

    Acidification caused by climate change and seasonal fluctuation can have profound implications for chemical toxicity to freshwater organisms. The present study aims to address this challenging issue through a comprehensive meta-analysis by comparing acute median lethal or effect concentration data (LC50 or EC50) for 10 metals and metalloids for various freshwater species obtained at different pH values. Our results revealed that element toxicity generally follows three different models, including Model-I: decreasing toxicity with increasing pH, Model-II: increasing toxicity with increasing pH, and Model-III: minimal toxicity at intermediate (optimal) pH (pH(opt)) with increasing toxicity as pH increases or decreases from pH(opt). We further examined these observations by constructing pH-dependent species sensitivity distributions (SSDs). The results indicated that the 10(th) percentile hazardous concentrations (HC10s) for copper, lead, selenium and silver generally exhibited a positive linear relationship with pH, following the Model-I. The ability to accurately predict toxicity of elements to biota in natural waters as a function of pH may be limited, however, the pH-dependent SSD approach presented in this study facilitates and helps characterize the role of pH in water quality guidelines and ecological risk assessment.

  1. Roles of interstitial fluid pH in diabetes mellitus: Glycolysisand mitochondrial function

    Institute of Scientific and Technical Information of China (English)

    Yoshinori Marunaka

    2015-01-01

    The pH of body fluids is one the most important keyfactors regulating various cell function such as enzymeactivity and protein-protein interaction via modificationof its binding affinity. Therefore, to keep cell functionnormal, the pH of body fluids is maintained constant byvarious systems. Insulin resistance is one of the mostimportant, serious factors making the body conditionworse in diabetes mellitus. I have recently found thatthe pH of body (interstitial) fluids is lower in diabetesmellitus than that in non-diabetic control, and thatthe lowered pH is one of the causes producing insulinresistance. In this review article, I introduce importanceof body (interstitial) fluid pH in regulation of bodyfunction, evidence on abnormal regulation of bodyfluid pH in diabetes mellitus, and relationship betweenthe body fluid pH and insulin resistance. Further, thisreview proposes perspective therapies on the basis ofregulation of body fluid pH including propolis (honeybeeproduct) diet.

  2. High performance flexible pH sensor based on carboxyl-functionalized and DEP aligned SWNTs

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lu; Shao, Jinyou, E-mail: jyshao@mail.xjtu.edu.cn; Li, Xiangming; Zhao, Qiang; Nie, Bangbang; Xu, Chuan; Ding, Haitao

    2016-11-15

    Highlights: • The flexible chemiresistive pH sensor based on two-terminal microsensors eliminating the need for a reference electrode, is simple in structure and can be fabricated on a variety of substrates such as PET, PI and PVC. • SWNTs as an ideal one dimensional material are carboxyl-functionalized to make the pH sensor show high sensitivity and outstanding flexibility for practical applications. • DEP technique is used to manipulate and position SWNTs into appropriate locations and desired formations to improve the metal-nanotube interface and highly rapid detection of pH value, resulting in better overall device performance. • Mechanical bendability of the pH sensor, which arises from the combination of flexible PET substrates and SWNTs, offer a significant improvement for applications that are difficult or impossible to achieve with traditional sensors on rigid substrates. - Abstract: The detection and control of the pH is very important in many biomedical and chemical reaction processes. A miniaturized flexible pH sensor that is light weight, robust, and conformable is very important in many applications, such as multifunctional lab-on-a-chip systems or wearable biomedical devices. In this work, we demonstrate a flexible chemiresistive pH sensor based on dielectrophoresis (DEP) aligned carboxyl-functionalized single-walled carbon nanotubes (SWNTs). Decorated carboxyl groups can react with hydrogen (H{sup +}) and hydroxide (OH{sup −}) ions, enabling the sensor to be capable of sensing the pH. DEP is used to deposit well-organized and highly aligned SWNTs in desired locations, which improves the metal-nanotube interface and highly rapid detection of the pH, resulting in better overall device performance. When pH buffer solutions are dropped onto such SWNTs, the H{sup +} and OH{sup −} ions caninteract with the carboxyl groups and affect the generation of holes and electrons in the SWNTs, leading to resistance variations in the SWNTs. The results

  3. Functionalized magnetic mesoporous silica nanoparticles for U removal from low and high pH groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dien, E-mail: dien.li@srs.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Egodawatte, Shani [Department of Chemistry, University of Iowa, Iowa City, IA 52242 (United States); Kaplan, Daniel I. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Larsen, Sarah C. [Department of Chemistry, University of Iowa, Iowa City, IA 52242 (United States); Serkiz, Steven M. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Seaman, John C. [Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802 (United States)

    2016-11-05

    Highlights: • Magnetic mesoporous silica nanoparticles were functionalized with organic molecules. • The functionalized nanoparticles had high surface areas and consistent pore sizes. • The functionalized nanoparticles were easily separated due to their magnetism. • They exhibited high capacity for uranium removal from low- or high-pH groundwater. - Abstract: U(VI) species display limited adsorption onto sediment minerals and synthetic sorbents in pH <4 or pH >8 groundwater. In this work, magnetic mesoporous silica nanoparticles (MMSNs) with magnetite nanoparticle cores were functionalized with various organic molecules using post-synthetic methods. The functionalized MMSNs were characterized using N{sub 2} adsorption-desorption isotherms, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), {sup 13}C cross polarization and magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy, and powder X-ray diffraction (XRD), which indicated that mesoporous silica (MCM-41) particles of 100–200 nm formed around a core of magnetic iron oxide, and the functional groups were primarily grafted into the mesopores of ∼3.0 nm in size. The functionalized MMSNs were effective for U removal from pH 3.5 and 9.6 artificial groundwater (AGW). Functionalized MMSNs removed U from the pH 3.5 AGW by as much as 6 orders of magnitude more than unfunctionalized nanoparticles or silica and had adsorption capacities as high as 38 mg/g. They removed U from the pH 9.6 AGW as much as 4 orders of magnitude greater than silica and 2 orders of magnitude greater than the unfunctionalized nanoparticles with adsorption capacities as high as 133 mg/g. These results provide an applied solution for treating U contamination that occurs at extreme pH environments and a scientific foundation for solving critical industrial issues related to environmental stewardship and nuclear power production.

  4. A Dual Sensor for pH and Hydrogen Peroxide Using Polymer-Coated Optical Fibre Tips

    Directory of Open Access Journals (Sweden)

    Malcolm S. Purdey

    2015-12-01

    Full Text Available This paper demonstrates the first single optical fibre tip probe for concurrent detection of both hydrogen peroxide (H2O2 concentration and pH of a solution. The sensor is constructed by embedding two fluorophores: carboxyperoxyfluor-1 (CPF1 and seminaphtharhodafluor-2 (SNARF2 within a polymer matrix located on the tip of the optical fibre. The functionalised fibre probe reproducibly measures pH, and is able to accurately detect H2O2 over a biologically relevant concentration range. This sensor offers potential for non-invasive detection of pH and H2O2 in biological environments using a single optical fibre.

  5. Functional mathematical model of dual pathway AV nodal conduction.

    Science.gov (United States)

    Climent, A M; Guillem, M S; Zhang, Y; Millet, J; Mazgalev, T N

    2011-04-01

    Dual atrioventricular (AV) nodal pathway physiology is described as two different wave fronts that propagate from the atria to the His bundle: one with a longer effective refractory period [fast pathway (FP)] and a second with a shorter effective refractory period [slow pathway (SP)]. By using His electrogram alternance, we have developed a mathematical model of AV conduction that incorporates dual AV nodal pathway physiology. Experiments were performed on five rabbit atrial-AV nodal preparations to develop and test the presented model. His electrogram alternances from the inferior margin of the His bundle were used to identify fast and slow wave front propagations. The ability to predict AV conduction time and the interaction between FP and SP wave fronts have been analyzed during regular and irregular atrial rhythms (e.g., atrial fibrillation). In addition, the role of dual AV nodal pathway wave fronts in the generation of Wenckebach periodicities has been illustrated. Finally, AV node ablative modifications have been evaluated. The model accurately reproduced interactions between FP and SP during regular and irregular atrial pacing protocols. In all experiments, specificity and sensitivity higher than 85% were obtained in the prediction of the pathway responsible for conduction. It has been shown that, during atrial fibrillation, the SP ablation significantly increased the mean HH interval (204 ± 39 vs. 274 ± 50 ms, P AV node mechanisms and should be considered as a step forward in the studies of AV nodal conduction.

  6. Dual-lifetime referencing (DLR: a powerful method for on-line measurement of internal pH in carrier-bound immobilized biocatalysts

    Directory of Open Access Journals (Sweden)

    Boniello Caterina

    2012-03-01

    Full Text Available Abstract Background Industrial-scale biocatalytic synthesis of fine chemicals occurs preferentially as continuous processes employing immobilized enzymes on insoluble porous carriers. Diffusional effects in these systems often create substrate and product concentration gradients between bulk liquid and the carrier. Moreover, some widely-used biotransformation processes induce changes in proton concentration. Unlike the bulk pH, which is usually controlled at a suitable value, the intraparticle pH of immobilized enzymes may deviate significantly from its activity and stability optima. The magnitude of the resulting pH gradient depends on the ratio of characteristic times for enzymatic reaction and on mass transfer (the latter is strongly influenced by geometrical features of the porous carrier. Design and selection of optimally performing enzyme immobilizates would therefore benefit largely from experimental studies of the intraparticle pH environment. Here, a simple and non-invasive method based on dual-lifetime referencing (DLR for pH determination in immobilized enzymes is introduced. The technique is applicable to other systems in which particles are kept in suspension by agitation. Results The DLR method employs fluorescein as pH-sensitive luminophore and Ru(II tris(4,7-diphenyl-1,10-phenantroline, abbreviated Ru(dpp, as the reference luminophore. Luminescence intensities of the two luminophores are converted into an overall phase shift suitable for pH determination in the range 5.0-8.0. Sepabeads EC-EP were labeled by physically incorporating lipophilic variants of the two luminophores into their polymeric matrix. These beads were employed as carriers for immobilization of cephalosporin C amidase (a model enzyme of industrial relevance. The luminophores did not interfere with the enzyme immobilization characteristics. Analytical intraparticle pH determination was optimized for sensitivity, reproducibility and signal stability under

  7. Differentiating calcium oxalate and hydroxyapatite stones in vivo using dual-energy CT and urine supersaturation and pH values.

    Science.gov (United States)

    Liu, Yu; Qu, Mingliang; Carter, Rickey E; Leng, Shuai; Ramirez-Giraldo, Juan Carlos; Jaramillo, Giselle; Krambeck, Amy E; Lieske, John C; Vrtiska, Terri J; McCollough, Cynthia H

    2013-12-01

    Knowledge of urinary stone composition can guide therapeutic intervention for patients with calcium oxalate (CaOx) or hydroxyapatite (HA) stones. In this study, we determined the accuracy of noninvasive differentiation of these two stone types using dual-energy CT (DECT) and urine supersaturation (SS) and pH values. Patients who underwent clinically indicated DECT scanning for stone disease and subsequent surgical intervention were enrolled. Stone composition was determined using infrared spectroscopy. DECT images were processed using custom-developed software that evaluated the ratio of CT numbers between low- and high-energy images. Clinical information, including patient age, gender, and urine pH and supersaturation profile, was obtained from electronic medical records. Simple and multiple logistic regressions were used to determine if the ratio of CT numbers could discriminate CaOx from HA stones alone or in conjunction with urine supersaturation and pH. Urinary stones (CaOx n = 43, HA n = 18) from 61 patients were included in this study. In a univariate model, DECT data, urine SS-HA, and urine pH had an area under the receiver operating characteristic curve of 0.78 (95% confidence interval [CI] 0.66-0.91, P = .016), 0.76 (95% CI 0.61-0.91, P = .003), and 0.60 (95% CI 0.44-0.75, P = .20), respectively, for predicting stone composition. The combination of CT data and the urinary SS-HA had an area under the receiver operating characteristic curve of 0.79 (95% CI 0.66-0.92, P = .007) for correctly differentiating these two stone types. DECT differentiated between CaOx and HA stones similarly to SS-HA, whereas pH was a poor discriminator. The combination of DECT and urine SS or pH data did not improve this performance. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

  8. High performance flexible pH sensor based on carboxyl-functionalized and DEP aligned SWNTs

    Science.gov (United States)

    Liu, Lu; Shao, Jinyou; Li, Xiangming; Zhao, Qiang; Nie, Bangbang; Xu, Chuan; Ding, Haitao

    2016-11-01

    The detection and control of the pH is very important in many biomedical and chemical reaction processes. A miniaturized flexible pH sensor that is light weight, robust, and conformable is very important in many applications, such as multifunctional lab-on-a-chip systems or wearable biomedical devices. In this work, we demonstrate a flexible chemiresistive pH sensor based on dielectrophoresis (DEP) aligned carboxyl-functionalized single-walled carbon nanotubes (SWNTs). Decorated carboxyl groups can react with hydrogen (H+) and hydroxide (OH-) ions, enabling the sensor to be capable of sensing the pH. DEP is used to deposit well-organized and highly aligned SWNTs in desired locations, which improves the metal-nanotube interface and highly rapid detection of the pH, resulting in better overall device performance. When pH buffer solutions are dropped onto such SWNTs, the H+ and OH- ions caninteract with the carboxyl groups and affect the generation of holes and electrons in the SWNTs, leading to resistance variations in the SWNTs. The results shows that the relative resistance variations of the sensor increases linearly with increasing the pH values in the range from 5 to 9 and the response time ranges from 0.2 s to 22.6 s. The pH sensor also shows high performance in mechanical bendability, which benefited from the combination of flexible PET substrates and SWNTs. The SWNT-based flexible pH sensor demonstrates great potential in a wide range of areas due to its simple structure, excellent performance, low power consumption, and compatibility with integrated circuits.

  9. Universal asynchronous RSFQ gate for realization of Boolean functions of dual-rail binary variables

    Energy Technology Data Exchange (ETDEWEB)

    Dimov, B [University of Technology Ilmenau, Institute for Information Technology, PO Box 100565, D-98684 Ilmenau (Germany); Khabipov, M [Physikalisch-Technische Bundesanstalt, Division 2.42, Bundesallee 100, D-38116 Braunschweig (Germany); Balashov, D [Physikalisch-Technische Bundesanstalt, Division 2.42, Bundesallee 100, D-38116 Braunschweig (Germany); Brandt, C M [Physikalisch-Technische Bundesanstalt, Division 2.42, Bundesallee 100, D-38116 Braunschweig (Germany); Ortlepp, Th [University of Technology Ilmenau, Institute for Information Technology, PO Box 100565, D-98684 Ilmenau (Germany); Hagedorn, D [Physikalisch-Technische Bundesanstalt, Division 2.42, Bundesallee 100, D-38116 Braunschweig (Germany); Buchholz, F-Im [Physikalisch-Technische Bundesanstalt, Division 2.42, Bundesallee 100, D-38116 Braunschweig (Germany); Niemeyer, J [Physikalisch-Technische Bundesanstalt, Division 2.42, Bundesallee 100, D-38116 Braunschweig (Germany); Uhlmann, F H [University of Technology Ilmenau, Institute for Information Technology, PO Box 100565, D-98684 Ilmenau (Germany)

    2006-06-01

    We report on the design, optimization, fabrication, and successful testing of an universal asynchronous RSFQ logic gate based on the dual-rail data coding. Properly connecting its inputs and outputs, one can perform most of the basic Boolean functions over a pair of dual-rail input variables. Therefore, this gate is fundamental component for the development of high-speed complex asynchronous RSFQ digital devices.

  10. Functional genomics of pH homeostasis in Corynebacterium glutamicum revealed novel links between pH response, oxidative stress, iron homeostasis and methionine synthesis

    Directory of Open Access Journals (Sweden)

    Persicke Marcus

    2009-12-01

    Full Text Available Abstract Background The maintenance of internal pH in bacterial cells is challenged by natural stress conditions, during host infection or in biotechnological production processes. Comprehensive transcriptomic and proteomic analyses has been conducted in several bacterial model systems, yet questions remain as to the mechanisms of pH homeostasis. Results Here we present the comprehensive analysis of pH homeostasis in C. glutamicum, a bacterium of industrial importance. At pH values between 6 and 9 effective maintenance of the internal pH at 7.5 ± 0.5 pH units was found. By DNA microarray analyses differential mRNA patterns were identified. The expression profiles were validated and extended by 1D-LC-ESI-MS/MS based quantification of soluble and membrane proteins. Regulators involved were identified and thereby participation of numerous signaling modules in pH response was found. The functional analysis revealed for the first time the occurrence of oxidative stress in C. glutamicum cells at neutral and low pH conditions accompanied by activation of the iron starvation response. Intracellular metabolite pool analysis unraveled inhibition of the TCA and other pathways at low pH. Methionine and cysteine synthesis were found to be activated via the McbR regulator, cysteine accumulation was observed and addition of cysteine was shown to be toxic under acidic conditions. Conclusions Novel limitations for C. glutamicum at non-optimal pH values were identified by a comprehensive analysis on the level of the transcriptome, proteome, and metabolome indicating a functional link between pH acclimatization, oxidative stress, iron homeostasis, and metabolic alterations. The results offer new insights into bacterial stress physiology and new starting points for bacterial strain design or pathogen defense.

  11. pH and Protein Sensing with Functionalized Semiconducting Oxide Nanobelt FETs

    Science.gov (United States)

    Cheng, Yi; Yun, C. S.; Strouse, G. F.; Xiong, P.; Yang, R. S.; Wang, Z. L.

    2008-03-01

    We report solution pH sensing and selective protein detection with high-performance channel-limited field-effect transistors (FETs) based on single semiconducting oxide (ZnO and SnO2) nanobelts^1. The devices were integrated with PDMS microfluidic channels for analyte delivery and the source/drain contacts were passivated for in-solution sensing. pH sensing experiments were performed on FETs with functionalized and unmodified nanobelts. Functionalization of the nanobelts by APTES was found to greatly improve the pH sensitivity. The change in nanobelt conductance as functions of pH values at different gate voltages and ionic strengths showed high sensitivity and consistency. For the protein detection, we achieved highly selective biotinylation of the nanobelt channel with through APTES linkage. The specific binding of fluorescently-tagged streptavidin to the biotinylated nanobelt was verified by fluorescence microscopy; non-specific binding to the substrate was largely eliminated using PEG-silane passivation. The electrical responses of the biotinylated FETs to the streptavidin binding in PBS buffers of different pH values were systematically measured. The results will be presented and discussed. ^1Y. Cheng et al., Appl. Phys. Lett. 89, 093114 (2006). *Supported by NSF NIRT Grant ECS-0210332.

  12. Doxorubicin loaded dual pH- and thermo-responsive magnetic nanocarrier for combined magnetic hyperthermia and targeted controlled drug delivery applications

    Science.gov (United States)

    Hervault, Aziliz; Dunn, Alexander E.; Lim, May; Boyer, Cyrille; Mott, Derrick; Maenosono, Shinya; Thanh, Nguyen T. K.

    2016-06-01

    Magnetic nanocarriers have attracted increasing attention for multimodal cancer therapy due to the possibility to deliver heat and drugs locally. The present study reports the development of magnetic nanocomposites (MNCs) made of an iron oxide core and a pH- and thermo-responsive polymer shell, that can be used as both hyperthermic agent and drug carrier. The conjugation of anticancer drug doxorubicin (DOX) to the pH- and thermo-responsive MNCs via acid-cleavable imine linker provides advanced features for the targeted delivery of DOX molecules via the combination of magnetic targeting, and dual pH- and thermo-responsive behaviour which offers spatial and temporal control over the release of DOX. The iron oxide cores exhibit a superparamagnetic behaviour with a saturation magnetization around 70 emu g-1. The MNCs contained 8.1 wt% of polymer and exhibit good heating properties in an alternating magnetic field. The drug release experiments confirmed that only a small amount of DOX was released at room temperature and physiological pH, while the highest drug release of 85.2% was obtained after 48 h at acidic tumour pH under hyperthermia conditions (50 °C). The drug release kinetic followed Korsmeyer-Peppas model and displayed Fickian diffusion mechanism. From the results obtained it can be concluded that this smart magnetic nanocarrier is promising for applications in multi-modal cancer therapy, to target and efficiently deliver heat and drug specifically to the tumour.Magnetic nanocarriers have attracted increasing attention for multimodal cancer therapy due to the possibility to deliver heat and drugs locally. The present study reports the development of magnetic nanocomposites (MNCs) made of an iron oxide core and a pH- and thermo-responsive polymer shell, that can be used as both hyperthermic agent and drug carrier. The conjugation of anticancer drug doxorubicin (DOX) to the pH- and thermo-responsive MNCs via acid-cleavable imine linker provides advanced

  13. Phylogenetic and functional potential links pH and N2O emissions in pasture soils

    Science.gov (United States)

    Samad, M. D. Sainur; Biswas, Ambarish; Bakken, Lars R.; Clough, Timothy J.; de Klein, Cecile A. M.; Richards, Karl G.; Lanigan, Gary J.; Morales, Sergio E.

    2016-10-01

    Denitrification is mediated by microbial, and physicochemical, processes leading to nitrogen loss via N2O and N2 emissions. Soil pH regulates the reduction of N2O to N2, however, it can also affect microbial community composition and functional potential. Here we simultaneously test the link between pH, community composition, and the N2O emission ratio (N2O/(NO + N2O + N2)) in 13 temperate pasture soils. Physicochemical analysis, gas kinetics, 16S rRNA amplicon sequencing, metagenomic and quantitative PCR (of denitrifier genes: nirS, nirK, nosZI and nosZII) analysis were carried out to characterize each soil. We found strong evidence linking pH to both N2O emission ratio and community changes. Soil pH was negatively associated with N2O emission ratio, while being positively associated with both community diversity and total denitrification gene (nir & nos) abundance. Abundance of nosZII was positively linked to pH, and negatively linked to N2O emissions. Our results confirm that pH imposes a general selective pressure on the entire community and that this results in changes in emission potential. Our data also support the general model that with increased microbial diversity efficiency increases, demonstrated in this study with lowered N2O emission ratio through more efficient conversion of N2O to N2.

  14. Dual effect of local anesthetics on the function of excitable rod outer segment disk membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mashimo, T.; Abe, K.; Yoshiya, I.

    1986-04-01

    The effects of local anesthetics and a divalent cation, Ca2+, on the function of rhodopsin were estimated from the measurements of light-induced proton uptake. The light-induced proton uptake by rhodopsin in the rod outer segment disk membrane was enhanced at lower pH (4) but depressed at higher pHs (6 to 8) by the tertiary amine local anesthetics lidocaine, bupivacaine, tetracaine, and dibucaine. The order of local anesthetic-induced depression of the proton uptake followed that of their clinical anesthetic potencies. The depression of the proton uptake versus the concentration of the uncharged form of local anesthetic nearly describes the same curve for small and large dose of added anesthetic. Furthermore, a neutral local anesthetic, benzocaine, depressed the proton uptake at all pHs between 4 and 7. These results indicate that the depression of the proton uptake is due to the effect of only the uncharged form. It is hypothesized that the uncharged form of local anesthetics interacts hydrophobically with the rhodopsin in the disk membrane. The dual effect of local anesthetics on the proton uptake, on the other hand, suggests that the activation of the function of rhodopsin may be caused by the charged form. There was no significant change in the light-induced proton uptake by rhodopsin when 1 mM of Ca2+ was introduced into the disk membrane at varying pHs in the absence or presence of local anesthetics. This fact indicates that Ca2+ ion does not influence the diprotonating process of metarhodopsin; neither does it interfere with the local anesthetic-induced changes in the rhodopsin molecule.

  15. Generic primal-dual interior point methods based on a new kernel function

    NARCIS (Netherlands)

    EL Ghami, M.; Roos, C.

    2008-01-01

    In this paper we present a generic primal-dual interior point methods (IPMs) for linear optimization in which the search direction depends on a univariate kernel function which is also used as proximity measure in the analysis of the algorithm. The proposed kernel function does not satisfy all the c

  16. Functionalized magnetic mesoporous silica nanoparticles for U removal from low and high pH groundwater.

    Science.gov (United States)

    Li, Dien; Egodawatte, Shani; Kaplan, Daniel I; Larsen, Sarah C; Serkiz, Steven M; Seaman, John C

    2016-11-05

    U(VI) species display limited adsorption onto sediment minerals and synthetic sorbents in pH 8 groundwater. In this work, magnetic mesoporous silica nanoparticles (MMSNs) with magnetite nanoparticle cores were functionalized with various organic molecules using post-synthetic methods. The functionalized MMSNs were characterized using N2 adsorption-desorption isotherms, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), (13)C cross polarization and magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy, and powder X-ray diffraction (XRD), which indicated that mesoporous silica (MCM-41) particles of 100-200nm formed around a core of magnetic iron oxide, and the functional groups were primarily grafted into the mesopores of ∼3.0nm in size. The functionalized MMSNs were effective for U removal from pH 3.5 and 9.6 artificial groundwater (AGW). Functionalized MMSNs removed U from the pH 3.5 AGW by as much as 6 orders of magnitude more than unfunctionalized nanoparticles or silica and had adsorption capacities as high as 38mg/g. They removed U from the pH 9.6 AGW as much as 4 orders of magnitude greater than silica and 2 orders of magnitude greater than the unfunctionalized nanoparticles with adsorption capacities as high as 133mg/g. These results provide an applied solution for treating U contamination that occurs at extreme pH environments and a scientific foundation for solving critical industrial issues related to environmental stewardship and nuclear power production.

  17. Effects of pH on structure and function of single living erythrocyte

    Institute of Scientific and Technical Information of China (English)

    YAO Chengcan; HUANG Yaoxiong; LI Xiaokun; RUAN Ping

    2003-01-01

    The spontaneous changes in cell shape and size, the membrane bending elastic modulus, and the structure and functions of intracellular hemoglobin of single human living erythrocyte incubated in different suspension pH were studied. The non-invasive, in situ, real time measurements on the parameters at the three levels of intracellular molecule, membrane and cell morphology were performedsimultaneously by using a fast micro-image analyzing technology and a multi-channel micro-spectrophotometer system. The result shows that the cell shape and size, the mechanical property of the cell membrane, and the structure and functionof intracellular hemoglobin are correlated and affected by each other with pH.

  18. A detection method for logic functions suitable for dual-logic synthesis

    Institute of Scientific and Technical Information of China (English)

    Yinshui Xia; Fei Sun; Keyi Mao

    2009-01-01

    Logic functions can be implemented in either AND/OR/NOT-based traditional Boolean (TB) logic or AND/XOR-based Reed-Mul-ler (RM) logic. To the majority of logic functions, it will be beneficial to be partially implemented in both TB logic and RM logic, called dual-logic. In this paper, a detection condition favoring dual-logic synthesis is proposed. A corresponding detection algorithm is devel-oped and implemented in C. The algorithm is applied to test a set of MCNC91 benchmarks for verifying the algorithm. The results show that the proposed algorithm is more efficient than published ones.

  19. Self-Dual Vortices in Abelian Higgs Models with Dielectric Function on the Noncommutative Plane

    CERN Document Server

    Fuertes, W García

    2014-01-01

    We show that Abelian Higgs Models with dielectric function defined on the noncommutative plane enjoy self-dual vorticial solutions. By choosing a particular form of the dielectric function, we provide a family of solutions whose Higgs and magnetic fields interpolate between the profiles of the noncommutative Nielsen-Olesen and Chern-Simons vortices. This is done both for the usual $U(1)$ model and for the $SU(2)\\times U(1)$ semilocal model with a doublet of complex scalar fields. The variety of known noncommutative self-dual vortices which display a regular behaviour when the noncommutativity parameter tends to zero results in this way considerably enlarged.

  20. Smart pH- and reduction-dual-responsive folate-PEG-coated polymeric lipid vesicles for tumor-triggered targeted drug delivery

    Science.gov (United States)

    Wang, Sheng; Wang, Hanjie; Liu, Zhongyun; Wang, Liangliang; Wang, Xiaomin; Su, Lin; Chang, Jin

    2014-06-01

    To improve their therapeutic index, designed nanocarriers should preferentially accumulate in tumor tissues and then rapidly enter tumor cells to release the encapsulated drugs in a triggered manner. In this article, a new kind of a smart pH- and reduction-dual-responsive drug delivery system based on folate-PEG-coated polymeric lipid vesicles (FPPLVs) formed from amphiphilic dextran derivatives was designed and prepared successfully. PEG chains with pH-sensitive hydrazone bonds, stearyl alcohol (SA) chains with reduction-sensitive disulfide bonds and folate were connected to a dextran main chain. The newly developed FPPLVs had a nano-sized structure (~50 nm) with a PEG coating. The in vitro DOX release profiles showed that the FPPLVs achieved a triggered drug release in response to acidic pH and reducing environments due to the cleavage of hydrazone bonds and disulfide bonds. It has also been demonstrated by an in vitro cellular uptake study that the FPPLVs lose their PEG coating as well as expose the folate in acidic conditions, which allows them to efficiently enter tumor cells through ligand-receptor interactions. In vitro cytotoxicity measurements also confirmed that FPPLVs exhibited pronounced antitumor activity against HeLa cells. These results suggest that FPPLVs are promising carriers for smart antitumor drug delivery applications.To improve their therapeutic index, designed nanocarriers should preferentially accumulate in tumor tissues and then rapidly enter tumor cells to release the encapsulated drugs in a triggered manner. In this article, a new kind of a smart pH- and reduction-dual-responsive drug delivery system based on folate-PEG-coated polymeric lipid vesicles (FPPLVs) formed from amphiphilic dextran derivatives was designed and prepared successfully. PEG chains with pH-sensitive hydrazone bonds, stearyl alcohol (SA) chains with reduction-sensitive disulfide bonds and folate were connected to a dextran main chain. The newly developed FPPLVs had a

  1. Embedding dual function into molecular motors through collective motion.

    Science.gov (United States)

    Saito, Nen; Kaneko, Kunihiko

    2017-03-10

    Protein motors, such as kinesins and dyneins, bind to a microtubule and travel along it in a specific direction. Previously, it was thought that the directionality for a given motor was constant in the absence of an external force. However, the directionality of the kinesin-5 Cin8 was recently found to change as the number of motors that bind to the same microtubule is increased. Here, we introduce a simple mechanical model of a microtubule-sliding assay in which multiple motors interact with the filament. We show that, due to the collective phenomenon, the directionality of the motor changes (e.g., from minus- to plus- end directionality), depending on the number of motors. This is induced by a large diffusive component in the directional walk and by the subsequent frustrated motor configuration, in which multiple motors pull the filament in opposite directions, similar to a game of tug-of-war. A possible role of the dual-directional motors for the mitotic spindle formation is also discussed. Our framework provides a general mechanism to embed two conflicting tasks into a single molecular machine, which works context-dependently.

  2. The dual pathway to creativity model : Creative ideation as a function of flexibility and persistence

    NARCIS (Netherlands)

    Nijstad, B.A.; De Dreu, C.K.W.; Rietzschel, E.F.; Baas, M.

    2010-01-01

    The dual pathway to creativity model argues that creativity-the generation of original and appropriate ideas-is a function of cognitive flexibility and cognitive persistence, and that dispositional or situational variables may influence creativity either through their effects on flexibility, on pers

  3. 40 CFR 796.3500 - Hydrolysis as a function of pH at 25 °C.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Hydrolysis as a function of pH at 25 Â....3500 Hydrolysis as a function of pH at 25 °C. (a) Introduction—(1) Background and purpose. (i) Water is... to determine rates of hydrolysis at any pH of environmental concern at 25°C. (2) Definitions...

  4. The functional neuroanatomy of multitasking: combining dual tasking with a short term memory task.

    Science.gov (United States)

    Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan

    2013-09-01

    Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.

  5. Surface degradation of dental ceramics as a function of environmental pH.

    Science.gov (United States)

    Esquivel-Upshaw, J F; Dieng, F Y; Clark, A E; Neal, D; Anusavice, K J

    2013-05-01

    We tested the hypotheses that glass-ceramic veneers and overglazes degrade by ion exchange in an acidic environment, and that they degrade by breakdown of the silica network in a basic environment. Disk specimens of glass-ceramic veneer and glaze were fabricated and immersed in pH 2, 7, or 10 buffer solutions, for 1, 3, 5, 10, 15, and 30 days. Each specimen was placed in a shaker bath containing de-ionized distilled water at 80°C. Concentrations of Al(3+), Ca(2+), Zn(2+), Li(2+), and Si(4+) were analyzed by means of inductively coupled plasma atomic emission spectrometry (ICP/AES). Statistical analyses were performed by factorial ANOVA. Significant differences occurred among leached ion concentrations as a function of material type, solution pH, and exposure time. A substantial release of Si occurred at pH 10 over time, leading to a breakdown of the glass phase. At pH 2, dissolution was controlled by an ionic exchange mechanism. We conclude that ceramic veneers and glazes may be susceptible to considerable degradation in low- and high-pH buffer solutions.

  6. Lung function assessment using Xe-133 dynamic SPECT in dual-camera system

    Energy Technology Data Exchange (ETDEWEB)

    Sakaji, Katsuyuki; Akiyama, Masayuki; Nakazawa, Yasuo [Showa Univ., Tokyo (Japan). Hospital; Umeda, Hirotaka; Takenaka, Haruki; Shinozuka, Akira

    2001-09-01

    The purpose of this study was to estimate lung regional function using Xe-133 dynamic SPECT. SPECT equipment with a dual camera was used. Fourteen rotation acquisitions were obtained beginning immediately after Xe-133 gas inhalation. The time activity curve of each pixel was obtained, and T{sub 1/2} of the washout phase was calculated and mapped. Residual radioactivity was evaluated. Adequate images could be obtained at 30 seconds per rotation even with the dual-camera system. Mapping of T{sub 1/2} allowed temporal changes on one image. Three-dimensional evaluation could be made on a SPECT system using our method. (author)

  7. Functional cerebral lateralization and dual-task efficiency-testing the function of human brain lateralization using fTCD

    NARCIS (Netherlands)

    Lust, J. M.; Geuze, R. H.; Groothuis, A. G. G.; Bouma, A.; Bouma, J.M.

    2011-01-01

    It has been hypothesized that functional cerebral lateralization enhances cognitive performance. Evidence was found in birds and fish. Our study aimed to test this hypothesis by analyzing the relationship between cerebral lateralization and both single-task performance and dual-task efficiency in

  8. Dual-energy lung perfusion computed tomography: a novel pulmonary functional imaging method.

    Science.gov (United States)

    Thieme, Sven F; Johnson, Thorsten R C; Reiser, Maximilian F; Nikolaou, Konstantin

    2010-08-01

    Dual-energy computed tomography (DECT) can be used for visualization of pulmonary microvascular contrast material distribution, representing regional perfusion. It is performed as DECT angiography and allows for the reconstruction of morphologic images as well as of "perfusion maps." The authors of previous studies have shown its potential to reliably depict perfusion defects, mainly in the context of pulmonary embolism. Also in the diagnostic work-up of other pulmonary diseases, there might be additional functional information provided by dual-energy acquisition techniques. This review focuses on the physical and technical background and the potential clinical value of pulmonary DECT. Technical improvements of a second-generation dual-source CT system are elucidated.

  9. Dual functions of perirhinal cortex in fear conditioning.

    Science.gov (United States)

    Kent, Brianne A; Brown, Thomas H

    2012-10-01

    The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. In addition, the neuroanatomy and neurophysiology of rat PRC have been described in considerable detail at the cellular and systems levels. The evidence suggests that PRC can serve at least two types of mnemonic functions in Pavlovian fear conditioning. The first function, termed "stimulus unitization," refers to the ability to treat two or more separate items or stimulus elements as a single entity. Supporting evidence for this perceptual function comes from studies of context conditioning as well as delay conditioning to discontinuous auditory cues. In a delay paradigm, the conditional stimulus (CS) and unconditional stimulus (US) overlap temporally and co-terminate. The second PRC function entails a type of "transient memory." Supporting evidence comes from studies of trace cue conditioning, where there is a temporal gap or trace interval between the CS offset and the US onset. For learning to occur, there must be a transient CS representation during the trace interval. We advance a novel neurophysiological mechanism for this transient representation. These two hypothesized functions of PRC are consistent with inferences based on non-aversive forms of learning.

  10. Synthesis of multi-hydroxyl and sulfonyl dual-functionalized room temperature ionic liquids

    Institute of Scientific and Technical Information of China (English)

    Guo Yang Zhu; Rong Wang; Guo Hua Liu; Li Qun Xu; Bei Zhang; Xia Qin Wu

    2007-01-01

    Starting from the hydroxylamine (dimethyl amino ethanol, triethanolamine) and 1,3-propane sultone, a series of hydroxyl and sulfonyl dual-functionalized zwitterionic salts and corresponding acidic room temperature ionic liquids have been synthesized.The hydroxyl groups of the synthesized substances were confirmed by the 1H NMR measurement.These zwitterionic salts and ionic liquids may be used for synthesizing other functionalized ionic liquids or ionic liquid-polymer (polyelectrolyte).

  11. Co-delivery of doxorubicin and arsenite with reduction and pH dual-sensitive vesicle for synergistic cancer therapy

    Science.gov (United States)

    Zhang, Lu; Xiao, Hong; Li, Jingguo; Cheng, Du; Shuai, Xintao

    2016-06-01

    Drug resistance is the underlying cause for therapeutic failure in clinical cancer chemotherapy. A prodrug copolymer mPEG-PAsp(DIP-co-BZA-co-DOX) (PDBD) was synthesized and assembled into a nanoscale vesicle comprising a PEG corona, a reduction and pH dual-sensitive hydrophobic membrane and an aqueous lumen encapsulating doxorubicin hydrochloride (DOX.HCl) and arsenite (As). The dual stimulation-sensitive design of the vesicle gave rise to rapid release of the physically entrapped DOX.HCl and arsenite inside acidic lysosomes, and chemically conjugated DOX inside the cytosol with high glutathione (GSH) concentration. In the optimized concentration range, arsenite previously recognized as a promising anticancer agent from traditional Chinese medicine can down-regulate the expressions of anti-apoptotic and multidrug resistance proteins to sensitize cancer cells to chemotherapy. Consequently, the DOX-As-co-loaded vesicle demonstrated potent anticancer activity. Compared to the only DOX-loaded vesicle, the DOX-As-co-loaded one induced more than twice the apoptotic ratio of MCF-7/ADR breast cancer cells at a low As concentration (0.5 μM), due to the synergistic effects of DOX and As. The drug loading strategy integrating chemical conjugation and physical encapsulation in stimulation-sensitive carriers enabled efficient drug loading in the formulation.Drug resistance is the underlying cause for therapeutic failure in clinical cancer chemotherapy. A prodrug copolymer mPEG-PAsp(DIP-co-BZA-co-DOX) (PDBD) was synthesized and assembled into a nanoscale vesicle comprising a PEG corona, a reduction and pH dual-sensitive hydrophobic membrane and an aqueous lumen encapsulating doxorubicin hydrochloride (DOX.HCl) and arsenite (As). The dual stimulation-sensitive design of the vesicle gave rise to rapid release of the physically entrapped DOX.HCl and arsenite inside acidic lysosomes, and chemically conjugated DOX inside the cytosol with high glutathione (GSH) concentration. In the

  12. Effect of pH and level of concentrate in the diet on the production of biohydrogenation intermediates in a dual-flow continuous culture.

    Science.gov (United States)

    Fuentes, M C; Calsamiglia, S; Cardozo, P W; Vlaeminck, B

    2009-09-01

    Milk fat depression in cows fed high-grain diets has been related to an increase in the concentration of trans-10 C(18:1) and trans-10,cis-12 conjugated linoleic acid (CLA) in milk. These fatty acids (FA) are produced as a result of the alteration in rumen biohydrogenation of dietary unsaturated FA. Because a reduction in ruminal pH is usually observed when high-concentrate diets are fed, the main cause that determines the alteration in the biohydrogenation pathways is not clear. The effect of pH (6.4 vs. 5.6) and dietary forage to concentrate ratios (F:C; 70:30 F:C vs. 30:70 F:C) on rumen microbial fermentation, effluent FA profile, and DNA concentration of bacteria involved in lipolysis and biohydrogenation processes were investigated in a continuous culture trial. The dual-flow continuous culture consisted of 2 periods of 8 d (5 d for adaptation and 3 d for sampling), with a 2 x 2 factorial arrangement of treatments. Samples from solid and liquid mixed effluents were taken for determination of total N, ammonia-N, and volatile fatty acid concentrations, and the remainder of the sample was lyophilized. Dry samples were analyzed for dry matter, ash, neutral and acid detergent fiber, FA, and purine contents. The pH 5.6 reduced organic matter and fiber digestibility, ammonia-N concentration and flow, and crude protein degradation, and increased nonammonia and dietary N flows. The pH 5.6 decreased the flow of C(18:0), trans-11 C(18:1) and cis-9, trans-11 CLA, and increased the flow of trans-10 C(18:1), C(18:2n-6), C(18:3n-3), trans-11,cis-15 C(18:2) and trans-10,cis-12 CLA in the 1 h after feeding effluent. The pH 5.6 reduced Anaerovibrio lipolytica (32.7 vs. 72.1 pg/10 ng of total DNA) and Butyrivibrio fibrisolvens vaccenic acid subgroup (588 vs. 1,394 pg/10 ng of total DNA) DNA concentrations. The high-concentrate diet increased organic matter and fiber digestibility, nonammonia and bacterial N flows, and reduced ammonia-N concentration and flow. The high

  13. Dual function of the selenoprotein PHGPx during sperm maturation.

    Science.gov (United States)

    Ursini, F; Heim, S; Kiess, M; Maiorino, M; Roveri, A; Wissing, J; Flohé, L

    1999-08-27

    The selenoprotein phospholipid hydroperoxide glutathione peroxidase (PHGPx) changes its physical characteristics and biological functions during sperm maturation. PHGPx exists as a soluble peroxidase in spermatids but persists in mature spermatozoa as an enzymatically inactive, oxidatively cross-linked, insoluble protein. In the midpiece of mature spermatozoa, PHGPx protein represents at least 50 percent of the capsule material that embeds the helix of mitochondria. The role of PHGPx as a structural protein may explain the mechanical instability of the mitochondrial midpiece that is observed in selenium deficiency.

  14. Effect of pH on the functional properties of Arthrospira (Spirulina) platensis protein isolate.

    Science.gov (United States)

    Benelhadj, Sonda; Gharsallaoui, Adem; Degraeve, Pascal; Attia, Hamadi; Ghorbel, Dorra

    2016-03-01

    In the present study, a protein isolate extracted from Arthrospira platensis by isoelectric precipitation was evaluated for its functional properties. The maximum nitrogen solubility was 59.6±0.7% (w/w) at pH 10. The A. platensis protein isolate (API) showed relatively high oil (252.7±0.3g oil/100g API) and water (428.8±15.4g of water/100g of API at pH 10) absorption capacities. The protein zeta potential, the emulsifying capacity, the emulsion ageing stability, the emulsion microstructure and the emulsion opacity as well as the foaming capacity and the foam stability were shown to be greatly affected by pH. Especially, emulsifying and foaming capacities were positively correlated to the protein solubility. Moreover, the API was able to form films when sorbitol (30% (w/w)) was used as plasticizer and to form gels when the API concentration exceeded 12% (w/w).

  15. Peptide functionalized gold nanoparticles: the influence of pH on binding efficiency

    Science.gov (United States)

    Harrison, Emma; Hamilton, Jeremy W. J.; Macias-Montero, Manuel; Dixon, Dorian

    2017-07-01

    We report herein on the synthesis of mixed monolayer gold nanoparticles (AuNPs) capped with both polyethylene glycol (PEG) and one of three peptides. Either a receptor-mediated endocytosis peptide, an endosomal escape pathway (H5WYG) peptide or the Nrp-1 targeting RGD peptide (CRGDK) labeled with FITC. All three peptides have a thiol containing cysteine residue which can be used to bind the peptides to the AuNPs. In order to investigate the influence of pH on peptide attachment, PEGylated AuNPs were centrifuged, the supernatant removed, and the nanoparticles were then re-suspended in a range of pH buffer solutions above, below and at the respective isoelectric points of the peptides before co-functionalization. Peptide attachment was investigated using dynamic light scattering, Ultra-violet visible spectroscopy (UV/Vis), FTIR and photo luminescence spectroscopy. UV/Vis analysis coupled with protein assay results and photoluminescence of the FITC tagged RGD peptide concluded that a pH of ∼8 optimized the cysteine binding and stability, irrespective of the peptide used.

  16. pH- and thermosensitive thin lipid layer coated mesoporous magnetic nanoassemblies as a dual drug delivery system towards thermochemotherapy of cancer.

    Science.gov (United States)

    Pradhan, Lina; Srivastava, R; Bahadur, D

    2014-07-01

    A new pH-sensitive and thermosensitive dual drug delivery system consisting of thin lipid layer encapsulated mesoporous magnetite nanoassemblies (MMNA) has been developed which can deliver two anticancer drugs simultaneously. The formulation of lipid layer used is 5:2:2:2 w/w, DPPC:cholesterol:DSPE-PEG2000:MMNA. The structure, morphology and magnetic properties of MMNA and lipid coated MMNA (LMMNA) were thoroughly characterized. This hybrid system was investigated for its ability to carry two anticancer drugs as well as its ability to provide heat under an alternating current magnetic field (ACMF). A very high loading efficiency of up to ∼81% of doxorubicin hydrochloride (DOX) with an ∼0.02 mg mg(-1) loading capacity and ∼60% of paclitaxel (TXL) with an ∼0.03 mg mg(-1) loading capacity are obtained with LMMNA. A sustained release of drug is observed over a period of 172 h, with better release, of ∼88:53% (DOX:TXL), at pH 4.3 compared to the ∼28:26% (DOX:TXL) in physiological conditions (pH 7.4). An enhanced release of ∼72 and ∼68% is recorded for DOX and TXL, respectively, during the first hour with the application of an ACMF (∼43°C). A greater in vitro cytotoxic effect is observed with the two drugs compared to them individually in HeLa, MCF-7 and HepG2 cancer cells. With the application of an ACMF for 10 min, the cell killing efficiency is improved substantially due to simultaneous thermo- and chemotherapy. Confocal microscopy confirms the internalization of drug loaded MMNA and LMMNA by cells and their morphological changes during thermochemotherapy.

  17. Dual Functions of Phospholipase in Plant Response to Drought

    Institute of Scientific and Technical Information of China (English)

    Yueyun Hong; Suqin Zheng; Xuemin Wang

    2008-01-01

    Phospholipase Dα1 (PLDα1) has been shown to mediate the abscisic acid regulation of stomatal movements.Arabidopsis plants deficient in PLDα1 increased,whereas PLDoLl-overexpressing tobacco decreased,transpirational water loss.In the early stage of drought,the decrease in water loss was associated with a rapid stomatal closure caused by a high level of PLD in PLDα1-overexpressing plants.However,in the late stage of drought,the overexpressing plants displayed more susceptibility to drought than control plants.PLDα1 activity in the overexpressing plants was much higher than that of control plants in which drought also induced an increase in PLDα1 activity.The high level of PLDα1 activity was correlated to membrane degradation in late stages of drought,as demonstrated by ionic leakage and lipid peroxidation.These findings indicate that a high level of PLDα1 expression has different effects on plant response to water deficits.It promotes stomatal closure at earlier stages,but disrupts membranes in prolonged drought stress.These findings are discussed in relation to the understanding of PLD functions and potential applications.

  18. Dual-step prospective ECG-triggered 128-slice dual-source CT for evaluation of coronary arteries and cardiac function without heart rate control: a technical note

    Energy Technology Data Exchange (ETDEWEB)

    Feuchtner, Gudrun [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Innsbruck Medical University, Department of Radiology II, Innsbruck (Austria); Goetti, Robert; Marincek, Borut; Alkadhi, Hatem; Leschka, Sebastian [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Plass, Andre; Wieser, Monika [University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland); Baumueller, Stephan; Stolzmann, Paul; Scheffel, Hans [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland)

    2010-09-15

    To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECG{sub dual-step}) for evaluation of coronary arteries and cardiac function. Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECG{sub dual-step}) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65 bpm/70% RR interval <65 bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated. Mean HR was 68 bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p = 0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p < 0.001) and more segments with impaired image quality (p < 0.001 and p = 0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6 mAs (p < 0.001). The average radiation dose was 3.8 mSv (range, 1.7-7.9) in patients in SR. pECG{sub dual-step}128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dose. (orig.)

  19. pH and reduction dual-responsive dipeptide cationic lipids with α-tocopherol hydrophobic tail for efficient gene delivery.

    Science.gov (United States)

    Liu, Qiang; Su, Rong-Chuan; Yi, Wen-Jing; Zheng, Li-Ting; Lu, Shan-Shan; Zhao, Zhi-Gang

    2017-03-31

    A series of tocopherol-based cationic lipid 3a-3f bearing a pH-sensitive imidazole moiety in the dipeptide headgroup and a reduction-responsive disulfide linkage were designed and synthesized. Acid-base titration of these lipids showed good buffering capacities. The liposomes formed from 3 and co-lipid 1, 2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) could efficiently bind and condense DNA into nanoparticles. Gel binding and HPLC assays confirmed the encapsulated DNA could release from lipoplexes 3 upon addition of 10 mM glutathione (GSH). MTT assays in HEK 293 cells demonstrated that lipoplexes 3 had low cytotoxicity. The in vitro gene transfection studies showed cationic dipeptide headgroups clearly affected the transfection efficiency (TE), and arginine-histidine based dipeptide lipid 3f give the best TE, which was 30.4 times higher than Lipofectamine 3000 in the presence of 10% serum. Cell-uptake assays indicated that basic amino acid containing dipeptide cationic lipids exhibited more efficient cell uptake than serine and aromatic amino acids based dipeptide lipids. Confocal laser scanning microscopy (CLSM) studies corroborated that 3 could efficiently deliver and release DNA into the nuclei of HeLa cells. These results suggest that tocopherol-based dipeptide cationic lipids with pH and reduction dual-sensitive characteristics might be promising non-viral gene delivery vectors.

  20. Switching between Anion-Binding Catalysis and Aminocatalysis with a Rotaxane Dual-Function Catalyst.

    Science.gov (United States)

    Eichstaedt, Katarzyna; Jaramillo-Garcia, Javier; Leigh, David A; Marcos, Vanesa; Pisano, Simone; Singleton, Thomas A

    2017-07-12

    The "off" state for aminocatalysis by a switchable [2]rotaxane is shown to correspond to an "on" state for anion-binding catalysis. Conversely, the aminocatalysis "on" state of the dual-function rotaxane is inactive in anion-binding catalysis. Switching between the different states is achieved through the stimuli-induced change of position of the macrocycle on the rotaxane thread. The anion-binding catalysis results from a pair of triazolium groups that act together to CH-hydrogen-bond to halide anions when the macrocycle is located on an alternative (ammonium) binding site, stabilizing the in situ generation of benzhydryl cation and oxonium ion intermediates from activated alkyl halides. The aminocatalysis and anion-binding catalysis sites of the dual-function rotaxane catalyst can be sequentially concealed or revealed, enabling catalysis of both steps of a tandem reaction process.

  1. Dual representation for the generating functional of the Feynman path-integral

    Science.gov (United States)

    Matone, Marco

    2016-09-01

    The generating functional for scalar theories admits a representation which is dual with respect to the one introduced by Schwinger, interchanging the role of the free and interacting terms. It maps ∫ V (δJ) and JΔJ to δϕc Δδϕc and ∫ V (ϕc), respectively, with ϕc = ∫ JΔ and Δ the Feynman propagator. Comparing the Schwinger representation with its dual version one gets a little known relation that we prove to be a particular case of a more general operatorial relation. We then derive a new representation of the generating functional T [ϕc ] = W [ J ] expressed in terms of covariant derivatives acting on 1

  2. Arginine deiminase in Staphylococcus epidermidis functions to augment biofilm maturation through pH homeostasis.

    Science.gov (United States)

    Lindgren, J K; Thomas, V C; Olson, M E; Chaudhari, S S; Nuxoll, A S; Schaeffer, C R; Lindgren, K E; Jones, J; Zimmerman, M C; Dunman, P M; Bayles, K W; Fey, P D

    2014-06-01

    Allelic replacement mutants were constructed within arginine deiminase (arcA1 and arcA2) to assess the function of the arginine deiminase (ADI) pathway in organic acid resistance and biofilm formation of Staphylococcus epidermidis 1457. A growth-dependent acidification assay (pH ∼5.0 to ∼5.2) determined that strain 1457 devoid of arginine deiminase activity (1457 ΔADI) was significantly less viable than the wild type following depletion of glucose and in the presence of arginine. However, no difference in viability was noted for individual 1457 ΔarcA1 (native) or ΔarcA2 (arginine catabolic mobile element [ACME]-derived) mutants, suggesting that the native and ACME-derived ADIs are compensatory in S. epidermidis. Furthermore, flow cytometry and electron paramagnetic resonance spectroscopy results suggested that organic acid stress resulted in oxidative stress that could be partially rescued by the iron chelator dipyridyl. Collectively, these results suggest that formation of hydroxyl radicals is partially responsible for cell death via organic acid stress and that ADI-derived ammonia functions to counteract this acid stress. Finally, static biofilm assays determined that viability, ammonia synthesis, and pH were reduced in strain 1457 ΔADI following 120 h of growth in comparison to strain 1457 and the arcA1 and arcA2 single mutants. It is hypothesized that ammonia synthesis via the ADI pathway is important to reduce pH stress in specific microniches that contain high concentrations of organic acids.

  3. Fast Fabrication of Flexible Functional Circuits Based on Liquid Metal Dual-Trans Printing.

    Science.gov (United States)

    Wang, Qian; Yu, Yang; Yang, Jun; Liu, Jing

    2015-11-25

    A dual-trans method to print the first functional liquid-metal circuit layout on poly(vinyl chloride) film, and then transfer it into a poly(dimethylsiloxane) substrate through freeze phase transition processing for the fabrication of a flexible electronic device. A programmable soft electronic band and a temperature-sensing module wirelessly communicate with a mobile phone, demonstrating the efficiency and capability of the method.

  4. Dual-well potential field function for articulated manipulator trajectory planning

    Directory of Open Access Journals (Sweden)

    Ahmed Badawy

    2016-06-01

    Full Text Available A new attractive potential field function is proposed in this paper for manipulator trajectory planning. Existing attractive potential field constructs a global minimum through which maneuvering objects move down the gradient of the potential field toward this global minimum. The proposed method constructs a potential field with two minima. The purpose of these two minima is to create a dual attraction between links rather than affecting each link by the preceding one through kinematic constraints.

  5. The synthesis of polymeric dual-functional antimicrobial surface based on poly(2-methyl-2-oxazoline

    Directory of Open Access Journals (Sweden)

    Bidhari Pidhatika

    2015-12-01

    Full Text Available There is a high interest in the development of antimicrobial coatings to fi ght bacterial infections.We present the development of dual-functional antimicrobial surface, in which a biopassive platform wasfunctionalized with bioactive compounds on the surface, using a graft copolymer system poly(L-lysine-graftpoly(2-methyl-2-oxazoline-quarternery ammonium compound (PLL-g-PMOXA-QAC. Alkyne functionalitywas introduced to the PMOXA chain at α-terminus by initiating the living cationic polymerization of 2-methyl-2-oxazoline with a propargylic-initiator. The reaction was terminated with carboxy derivative-terminator thatallows grafting of the polymeric chain from the β-terminus to poly(L-lysine (PLL backbone, resulting in graftcopolymer alkynyl PLL-g-PMOXA. The conjugation between alkynyl PLL-g-PMOXA and QAC was thenperformed using click reaction. The chemical structures of the polymers were characterized by MALDI-TOFspectrometry and NMR spectroscopy. The results demonstrate that we have successfully synthesized PLL-g-PMOXA-QAC copolymer with grafting density (number of lysine/number of PMOXA of 0.33. The resultingPLL-g-PMOXA-QAC copolymer was then immobilized onto carboxylated tissue cultured polystyrene (TCPSsurface and exposed to bacteria solution to test its dual-functional properties. Preliminary live-and-deadbacteria study indicates dual-functionality of the PLL-g-PMOXA-QAC-coated surface.

  6. Functionalized gold nanoparticle-polypyrrole nanobiocomposite with high effective surface area for electrochemical/pH dual stimuli-responsive smart release of insulin.

    Science.gov (United States)

    Shamaeli, Ehsan; Alizadeh, Naader

    2015-02-01

    A novel functionalized gold nanoparticle-polypyrrole-nanobiocomposite (PPy-FGNP-NBC) with large effective surface area was fabricated for electrical/pH dual stimuli-responsive local delivery of insulin. The fabrication method involves simple electrodeposition and immobilization processes without use of organic solvents. Release studies based on the nature of insulin-surface binding indicated that release was promoted for PPy-FGNP-NBC. Kinetics analysis showed that release of insulin strongly affected by applying external potential stimuli. Also, the insulin release was under influence of pH and was slowed down under lower pH. This pH-sensitivity was remarkably increased by applying potential. Based on in vitro release study under applied potential condition, insulin release in the artificial gastric juice is significantly slower than that in the artificial intestinal fluid. Circular dichroism analysis showed that insulin retained its original conformation during electrochemically stimulated release. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Preparation of a novel weak cation exchange/hydrophobic interaction chromatography dual-function polymer-based stationary phase for protein separation using "thiol-ene click chemistry".

    Science.gov (United States)

    Yang, Fan; Bai, Quan; Zhao, Kailou; Gao, Dong; Tian, Lei

    2015-02-01

    A novel dual-function mixed-mode stationary phase based on poly(glycidyl methacrylate-co-ethylene dimethacrylate) microspheres was synthesized by thiol-ene click chemistry and characterized by infrared spectroscopy and elemental analysis. The new system displays both hydrophobic interaction chromatography (HIC) character in a high salt concentration mobile phase, and weak cation exchange (WCX) chromatography character in a low salt concentration mobile phase. It can be used to separate proteins in both ion-exchange chromatography (IEC) mode and HIC mode. The resolution and selectivity of the stationary phase were evaluated in both HIC mode and IEC mode using protein standards. In comparison with the conventional WCX and HIC columns, the results were satisfactory and acceptable. Protein mass and bioactivity recoveries of more than 96% can be achieved in both HIC mode and IEC mode using this column. The results indicate that the novel dual-function mixed-mode column in many cases can replace the use of two individual WCX and HIC columns. In addition, the effects on protein separation of different ligand structures in the dual-function stationary phase and the pH of the mobile phase used were also investigated in detail. The results show that electrostatic interaction of the ligand with proteins must match the hydrophobicity of the ligand, which is an important factor to prepare the dual-function stationary phase. On the basis of this dual-function mixed-mode chromatography column, a new two-dimensional liquid chromatography technology with a single column system was also developed in this study, and was used to renature and purify recombinant human interferon-γ from inclusion bodies. The mass recovery, purity, and specific bioactivity obtained for the purified recombinant human interferon-γ were 87.2%, 92.4%, and 2.8 × 10(7) IU/mg, respectively, in IEC mode, and 83.4%, 95.2%, and 4.3 × 10(7) IU/mg, respectively, in HIC mode. The results indicate that the

  8. Dual representation for the generating functional of the Feynman path-integral

    Directory of Open Access Journals (Sweden)

    Marco Matone

    2016-09-01

    Full Text Available The generating functional for scalar theories admits a representation which is dual with respect to the one introduced by Schwinger, interchanging the role of the free and interacting terms. It maps ∫V(δJ and JΔJ to δϕcΔδϕc and ∫V(ϕc, respectively, with ϕc=∫JΔ and Δ the Feynman propagator. Comparing the Schwinger representation with its dual version one gets a little known relation that we prove to be a particular case of a more general operatorial relation. We then derive a new representation of the generating functional T[ϕc]=W[J] expressed in terms of covariant derivatives acting on 1 T[ϕc]=NN0exp⁡(−U0[ϕc]exp⁡(−∫V(Dϕc−⋅1 where Dϕ±(x=∓Δδδϕ(x+ϕ(x. The dual representation, which is deeply related to the Hermite polynomials, is the key to express the generating functional associated to a sum of potentials in terms of factorized generating functionals. This is applied to renormalization, leading to a factorization of the counterterms of the interaction. We investigate the structure of the functional generator for normal ordered potentials and derive an infinite set of relations in the case of the potential λn!:ϕn: . Such relations are explicitly derived by using the Faà di Bruno formula. This also yields the explicit expression of the generating functional of connected Green's functions.

  9. Production Functions for Water Delivery Systems: Analysis and Estimation Using Dual Cost Function and Implicit Price Specifications

    Science.gov (United States)

    Teeples, Ronald; Glyer, David

    1987-05-01

    Both policy and technical analysis of water delivery systems have been based on cost functions that are inconsistent with or are incomplete representations of the neoclassical production functions of economics. We present a full-featured production function model of water delivery which can be estimated from a multiproduct, dual cost function. The model features implicit prices for own-water inputs and is implemented as a jointly estimated system of input share equations and a translog cost function. Likelihood ratio tests are performed showing that a minimally constrained, full-featured production function is a necessary specification of the water delivery operations in our sample. This, plus the model's highly efficient and economically correct parameter estimates, confirms the usefulness of a production function approach to modeling the economic activities of water delivery systems.

  10. On entire functions restricted to intervals, partition of unities, and dual Gabor frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

    2014-01-01

    Partition of unities appears in many places in analysis. Typically it is generated by compactly supported functions with a certain regularity. In this paper we consider partition of unities obtained as integer-translates of entire functions restricted to finite intervals. We characterize the entire...... functions that lead to a partition of unity in this way, and we provide characterizations of the “cut-off” entire functions, considered as functions of a real variable, to have desired regularity. In particular we obtain partition of unities generated by functions with small support and desired regularity....... Applied to Gabor analysis this leads to constructions of dual pairs of Gabor frames with low redundancy, generated by trigonometric polynomials with small support and desired regularity....

  11. High CO2 levels impair alveolar epithelial function independently of pH.

    Directory of Open Access Journals (Sweden)

    Arturo Briva

    Full Text Available BACKGROUND: In patients with acute respiratory failure, gas exchange is impaired due to the accumulation of fluid in the lung airspaces. This life-threatening syndrome is treated with mechanical ventilation, which is adjusted to maintain gas exchange, but can be associated with the accumulation of carbon dioxide in the lung. Carbon dioxide (CO2 is a by-product of cellular energy utilization and its elimination is affected via alveolar epithelial cells. Signaling pathways sensitive to changes in CO2 levels were described in plants and neuronal mammalian cells. However, it has not been fully elucidated whether non-neuronal cells sense and respond to CO2. The Na,K-ATPase consumes approximately 40% of the cellular metabolism to maintain cell homeostasis. Our study examines the effects of increased pCO2 on the epithelial Na,K-ATPase a major contributor to alveolar fluid reabsorption which is a marker of alveolar epithelial function. PRINCIPAL FINDINGS: We found that short-term increases in pCO2 impaired alveolar fluid reabsorption in rats. Also, we provide evidence that non-excitable, alveolar epithelial cells sense and respond to high levels of CO2, independently of extracellular and intracellular pH, by inhibiting Na,K-ATPase function, via activation of PKCzeta which phosphorylates the Na,K-ATPase, causing it to endocytose from the plasma membrane into intracellular pools. CONCLUSIONS: Our data suggest that alveolar epithelial cells, through which CO2 is eliminated in mammals, are highly sensitive to hypercapnia. Elevated CO2 levels impair alveolar epithelial function, independently of pH, which is relevant in patients with lung diseases and altered alveolar gas exchange.

  12. The dividend function in the jump-diffusion dual model with barrier dividend strategy

    Institute of Scientific and Technical Information of China (English)

    LI Bo; WU Rong

    2008-01-01

    A dual model of the perturbed classical compound Poisson risk model is considered under a constant dividend barrier.A new method is used in deriving the boundary condition of the equation for the expectation function by studying the local time of a related process.We obtain the expression for the expected discount dividend function in terms of those in the corresponding perturbed compound Poisson risk model without barriers.A special case in which the gain size is phase-type distributed is illustrated.We also consider the existence of the optimal dividend level.

  13. Integrated rate-dependent and dual pathway AV nodal functions: principles and assessment framework.

    Science.gov (United States)

    Billette, Jacques; Tadros, Rafik

    2014-01-15

    The atrioventricular (AV) node conducts slowly and has a long refractory period. These features sustain the filtering of atrial impulses and hence are often modulated to optimize ventricular rate during supraventricular tachyarrhythmias. The AV node is also the site of a clinically common reentrant arrhythmia. Its function is assessed for a variety of purposes from its responses to a premature protocol (S1S2, test beats introduced at different cycle lengths) repeatedly performed at different basic rates and/or to an incremental pacing protocol (increasingly faster rates). Puzzlingly, resulting data and interpretation differ with protocols as well as with chosen recovery and refractory indexes, and are further complicated by the presence of built-in fast and slow pathways. This problem applies to endocavitary investigations of arrhythmias as well as to many experimental functional studies. This review supports an integrated framework of rate-dependent and dual pathway AV nodal function that can account for these puzzling characteristics. The framework was established from AV nodal responses to S1S2S3 protocols that, compared with standard S1S2 protocols, allow for an orderly quantitative dissociation of the different factors involved in changes in AV nodal conduction and refractory indexes under rate-dependent and dual pathway function. Although largely based on data from experimental studies, the proposed framework may well apply to the human AV node. In conclusion, the rate-dependent and dual pathway properties of the AV node can be integrated within a common functional framework the contribution of which to individual responses can be quantitatively determined with properly designed protocols and analytic tools.

  14. Molecular orbital ab initio and density functional theoretical study on reaction between PH2 and NO

    Institute of Scientific and Technical Information of China (English)

    HU; Zhengfa(胡正发); WANG; Zhenya(王振亚); LI; Haiyang(李海洋); ZHOU; Shikang(周士康)

    2002-01-01

    The theoretical study of reaction between PH2 and NO on the ground state potential energy surface is reported by using molecular orbital ab initio calculation and density function theory (DFT). Equilibrium structural parameters, harmonic vibrational frequencies, total energies and zero point energies of all species during reaction are computed by HF, MP2 (full) and B3LYP theory levels with the medium basis set 6-31G*. Theoretical results indicate that intermediate IM1(H2PNO) is firstly formed by overcoming a small energy barrier TS1, and then two four-membered ring transient states TS2 and TS5, with energy barriers 103.3 and 102.6 kJ/mol respectively,then H-migration and isomerization are completed and the products PN and H2O are formed. The reaction is exothermic one with -189.6 k J/mol released.

  15. Effects of Dual-Channel Functional Electrical Stimulation on Gait Performance in Patients with Hemiparesis

    Directory of Open Access Journals (Sweden)

    Shmuel Springer

    2012-01-01

    Full Text Available The study objective was to assess the effect of functional electrical stimulation (FES applied to the peroneal nerve and thigh muscles on gait performance in subjects with hemiparesis. Participants were 45 subjects (age 57.8 ± 14.8 years with hemiparesis (5.37 ± 5.43 years since diagnosis demonstrating a foot-drop and impaired knee control. Thigh stimulation was applied either to the quadriceps or hamstrings muscles, depending on the dysfunction most affecting gait. Gait was assessed during a two-minute walk test with/without stimulation and with peroneal stimulation alone. A second assessment was conducted after six weeks of daily use. The addition of thigh muscles stimulation to peroneal stimulation significantly enhanced gait velocity measures at the initial and second evaluation. Gait symmetry was enhanced by the dual-channel stimulation only at the initial evaluation, and single-limb stance percentage only at the second assessment. For example, after six weeks, the two-minute gait speed with peroneal stimulation and with the dual channel was 0.66 ± 0.30 m/sec and 0.70 ± 0.31 m/sec, respectively (. In conclusion, dual-channel FES may enhance gait performance in subjects with hemiparesis more than peroneal FES alone.

  16. Siloxane Nanoprobes for Labeling and Dual Modality Functional Imaging of Neural Stem Cells.

    Science.gov (United States)

    Addington, Caroline P; Cusick, Alex; Shankar, Rohini Vidya; Agarwal, Shubhangi; Stabenfeldt, Sarah E; Kodibagkar, Vikram D

    2016-03-01

    Cell therapy represents a promising therapeutic for a myriad of medical conditions, including cancer, traumatic brain injury, and cardiovascular disease among others. A thorough understanding of the efficacy and cellular dynamics of these therapies necessitates the ability to non-invasively track cells in vivo. Magnetic resonance imaging (MRI) provides a platform to track cells as a non-invasive modality with superior resolution and soft tissue contrast. We recently reported a new nanoprobe platform for cell labeling and imaging using fluorophore doped siloxane core nanoemulsions as dual modality ((1)H MRI/Fluorescence), dual-functional (oximetry/detection) nanoprobes. Here, we successfully demonstrate the labeling, dual-modality imaging, and oximetry of neural progenitor/stem cells (NPSCs) in vitro using this platform. Labeling at a concentration of 10 μL/10(4) cells with a 40%v/v polydimethylsiloxane core nanoemulsion, doped with rhodamine, had minimal effect on viability, no effect on migration, proliferation and differentiation of NPSCs and allowed for unambiguous visualization of labeled NPSCs by (1)H MR and fluorescence and local pO2 reporting by labeled NPSCs. This new approach for cell labeling with a positive contrast (1)H MR probe has the potential to improve mechanistic knowledge of current therapies, and guide the design of future cell therapies due to its clinical translatability.

  17. Continuous Dual Resetting of the Immune Repertoire as a Basic Principle of the Immune System Function

    Science.gov (United States)

    2017-01-01

    Idiopathic chronic inflammatory conditions (ICIC) such as allergy, asthma, chronic obstructive pulmonary disease, and various autoimmune conditions are a worldwide health problem. Understanding the pathogenesis of ICIC is essential for their successful therapy and prevention. However, efforts are hindered by the lack of comprehensive understanding of the human immune system function. In line with those efforts, described here is a concept of stochastic continuous dual resetting (CDR) of the immune repertoire as a basic principle that governs the function of immunity. The CDR functions as a consequence of system's thermodynamically determined intrinsic tendency to acquire new states of inner equilibrium and equilibrium against the environment. Consequently, immune repertoire undergoes continuous dual (two-way) resetting: against the physiologic continuous changes of self and against the continuously changing environment. The CDR-based dynamic concept of immunity describes mechanisms of self-regulation, tolerance, and immunosenescence, and emphasizes the significance of immune system's compartmentalization in the pathogenesis of ICIC. The CDR concept's relative simplicity and concomitantly documented congruency with empirical, clinical, and experimental data suggest it may represent a plausible theoretical framework to better understand the human immune system function. PMID:28246613

  18. Continuous Dual Resetting of the Immune Repertoire as a Basic Principle of the Immune System Function

    Directory of Open Access Journals (Sweden)

    Silvana Balzar

    2017-01-01

    Full Text Available Idiopathic chronic inflammatory conditions (ICIC such as allergy, asthma, chronic obstructive pulmonary disease, and various autoimmune conditions are a worldwide health problem. Understanding the pathogenesis of ICIC is essential for their successful therapy and prevention. However, efforts are hindered by the lack of comprehensive understanding of the human immune system function. In line with those efforts, described here is a concept of stochastic continuous dual resetting (CDR of the immune repertoire as a basic principle that governs the function of immunity. The CDR functions as a consequence of system’s thermodynamically determined intrinsic tendency to acquire new states of inner equilibrium and equilibrium against the environment. Consequently, immune repertoire undergoes continuous dual (two-way resetting: against the physiologic continuous changes of self and against the continuously changing environment. The CDR-based dynamic concept of immunity describes mechanisms of self-regulation, tolerance, and immunosenescence, and emphasizes the significance of immune system’s compartmentalization in the pathogenesis of ICIC. The CDR concept’s relative simplicity and concomitantly documented congruency with empirical, clinical, and experimental data suggest it may represent a plausible theoretical framework to better understand the human immune system function.

  19. The importance of pH in regulating the function of the Fasciola hepatica cathepsin L1 cysteine protease.

    Directory of Open Access Journals (Sweden)

    Jonathan Lowther

    Full Text Available The helminth parasite Fasciola hepatica secretes cathepsin L cysteine proteases to invade its host, migrate through tissues and digest haemoglobin, its main source of amino acids. Here we investigated the importance of pH in regulating the activity and functions of the major cathepsin L protease FheCL1. The slightly acidic pH of the parasite gut facilitates the auto-catalytic activation of FheCL1 from its inactive proFheCL1 zymogen; this process was approximately 40-fold faster at pH 4.5 than at pH 7.0. Active mature FheCL1 is very stable at acidic and neutral conditions (the enzyme retained approximately 45% activity when incubated at 37 degrees C and pH 4.5 for 10 days and displayed a broad pH range for activity peptide substrates and the protein ovalbumin, peaking between pH 5.5 and pH 7.0. This pH profile likely reflects the need for FheCL1 to function both in the parasite gut and in the host tissues. FheCL1, however, could not cleave its natural substrate Hb in the pH range pH 5.5 and pH 7.0; digestion occurred only at pHpH of the parasite relaxes the Hb structure, making it susceptible to proteolysis by FheCL1. This process is enhanced by glutathione (GSH, the main reducing agent contained in red blood cells. Using mass spectrometry, we show that FheCL1 can degrade Hb to small peptides, predominantly of 4-14 residues, but cannot release free amino acids. Therefore, we suggest that Hb degradation is not completed in the gut lumen but that the resulting peptides are absorbed by the gut epithelial cells for further processing by intracellular di- and amino-peptidases to free amino acids that are distributed through the parasite tissue for protein anabolism.

  20. Functionalization of carbon nanotubes with a pH-responsive molecule to produce a pH sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Liping; Nakayama, Tomonobu; Tomimoto, Hiroyuki; Shingaya, Yoshitaka [Nano Functionality Integration Group, National Institute for Materials Science, Tsukuba 305-0044 (Japan); Huang Qing, E-mail: zhao.liping@nims.go.j, E-mail: NAKAYAMA.Tomonobu@nims.go.j [Nanoscale Materials Center, National Institute for Materials Science, Tsukuba 305-0044 (Japan)

    2009-08-12

    Carbon nanotubes were functionalized with the ratiometric pH-responsive dye molecule 6,8-dihydroxy-1,3-pyrenedisulfonic acid disodium salt, which enabled them to indicate pH values over the range of pH 5.6-8.3. The nanotubes were coated with a layer of electron-donating ZnPc, which strengthened the CNT-dye interaction. The range of pH response is relevant for biological systems, which makes the nanotubes suitable for a wide range of applications within nanobiotechnology.

  1. Effect of dual modification of sonication and γ- irradiation on physicochemical and functional properties of lentil (Lens culinaris L.) starch.

    Science.gov (United States)

    Majeed, Toiba; Wani, Idrees Ahmed; Hussain, Peerzada Rashid

    2017-03-21

    Starch isolated from lentil was subjected to two treatments namely sonication and, a dual treatment of sonication and irradiation at a dose of 5kGy. Lentil yielded 26.12 ±1.56g starch/100g of lentil. Chemical composition of native starch revealed 7.83±0.28% moisture, 0.23±0.30% protein, 0.35±0.05% fat and 0.10±0.00% ash. The results revealed that pasting properties of lentil starch were not affected upon sonication. However, these decreased significantly (p≤0.05) upon dual treatments. Amylose content of starch was 31.16±1.80g/100g which showed a decrease upon sonication and dual treatments. Sonication and dual treatments (sonication and irradiation) decreased hunter 'L' value while 'a' and 'b' values showed an increase. Syneresis decreased more or less insignificantly upon sonication. However, a significant decrease in syneresis was observed after 120h storage following dual treatments. Sonication did not decrease the functional properties significantly while as dual treatment induced a significant decrease in functional properties. FT-IR analysis revealed a decrease in the intensities of O-H, C-H and OC stretches and CH2 bending upon sonication and dual treatments.

  2. Dual-Function Air Cathode for Metal-Air Batteries with Pulse-Power Capability

    Science.gov (United States)

    2013-01-28

    Rolison , L. F. Nazar , MRS Bull. 2011 , 36 , 486 . [ 2 ] D. Linden , Ed., Handbook of Batteries : Second Edition , McGraw Hill , New...Dual-Function Air Cathode for Metal–Air Batteries with Pulse-Power Capability J. W. Long, C. N. Chervin, N. W. Kucko, E. S . Nelson, D. R. Rolison...Air Cathode for Metal-Air Batteries with Pulse-Power Capability 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d

  3. Wire transfer function analysis for castellated dual-energy x-ray detectors.

    Science.gov (United States)

    Chan, Jer Wang; Evans, James Paul Owain; Yong, Yen San; Monteith, Andrew

    2004-12-10

    An investigation into the spatial resolving power of a castellated linear dual-energy x-ray detector array is reported. The detector was developed for use in aviation security screening applications. Experiments employing different gauges of lead wire are used to plot a wire transfer function. A numerical simulation is developed to predict and underpin the empirical results. The suitable processing of the castellated detector signals helps to maintain spatial resolving power while affording a 50% reduction in x-ray sensing elements. This encouraging result has formed the basis for an ongoing investigation into materials discrimination capability of the castellated detector array.

  4. Confirmation of translatability and functionality certifies the dual endothelin1/VEGFsp receptor (DEspR) protein

    OpenAIRE

    Herrera, Victoria L. M.; Steffen, Martin; Moran, Ann Marie; Tan, Glaiza A.; Khristine A Pasion; Rivera, Keith; Pappin, Darryl J.; Ruiz-Opazo, Nelson

    2016-01-01

    Background In contrast to rat and mouse databases, the NCBI gene database lists the human dual-endothelin1/VEGFsp receptor (DEspR, formerly Dear) as a unitary transcribed pseudogene due to a stop [TGA]-codon at codon#14 in automated DNA and RNA sequences. However, re-analysis is needed given prior single gene studies detected a tryptophan [TGG]-codon#14 by manual Sanger sequencing, demonstrated DEspR translatability and functionality, and since the demonstration of actual non-translatability ...

  5. The Dual Role of Oxygen Functions in Coal Pretreatment and Liquefaction: Crosslinking and Cleavage Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Michael Serio; Erik Kroo; Sylvie Charpenay; Peter Solomon

    1993-09-30

    The overall objective of this project was to elucidate and model the dual role of oxygen functions in thermal pretreatment and liquefaction of low rank coals through the application of analytical techniques and theoretical models. The project was an integrated study of model polymers representative of coal structures, raw coals of primarily low rank, and selectively modified coals in order to provide specific information relevant to the reactions of real coals. The investigations included liquefaction experiments in microautoclave reactors, along with extensive analysis of intermediate solid, liquid and gaseous products. Attempts were made to incorporate the results of experiments on the different systems into a liquefaction model.

  6. MULTIPLIER OPERATORS AND EXTREMAL FUNCTIONS RELATED TO THE DUAL DUNKL-SONINE OPERATOR

    Institute of Scientific and Technical Information of China (English)

    Fethi SOLTANI

    2013-01-01

    We study the dual Dunkl-Sonine operator tSk,e on Rd,and give expression of tSk,e,using Dunkl multiplier operators on Rd.Next,we study the extremal functions f*λ,λ > 0 related to the Dunkl multiplier operators,and more precisely show that {f*λ}λ>0 converges uniformly to tSk,e(f) as λ → 0+.Certain examples based on Dunkl-heat and Dunkl-Poisson kernels are provided to illustrate the results.

  7. The Importance of pH in Regulating the Function of the Fasciola hepatica Cathepsin L1 Cysteine Protease

    Science.gov (United States)

    Lowther, Jonathan; Robinson, Mark W.; Donnelly, Sheila M.; Xu, Weibo; Stack, Colin M.; Matthews, Jacqueline M.; Dalton, John P.

    2009-01-01

    The helminth parasite Fasciola hepatica secretes cathepsin L cysteine proteases to invade its host, migrate through tissues and digest haemoglobin, its main source of amino acids. Here we investigated the importance of pH in regulating the activity and functions of the major cathepsin L protease FheCL1. The slightly acidic pH of the parasite gut facilitates the auto-catalytic activation of FheCL1 from its inactive proFheCL1 zymogen; this process was ∼40-fold faster at pH 4.5 than at pH 7.0. Active mature FheCL1 is very stable at acidic and neutral conditions (the enzyme retained ∼45% activity when incubated at 37°C and pH 4.5 for 10 days) and displayed a broad pH range for activity peptide substrates and the protein ovalbumin, peaking between pH 5.5 and pH 7.0. This pH profile likely reflects the need for FheCL1 to function both in the parasite gut and in the host tissues. FheCL1, however, could not cleave its natural substrate Hb in the pH range pH 5.5 and pH 7.0; digestion occurred only at pH≤4.5, which coincided with pH-induced dissociation of the Hb tetramer. Our studies indicate that the acidic pH of the parasite relaxes the Hb structure, making it susceptible to proteolysis by FheCL1. This process is enhanced by glutathione (GSH), the main reducing agent contained in red blood cells. Using mass spectrometry, we show that FheCL1 can degrade Hb to small peptides, predominantly of 4–14 residues, but cannot release free amino acids. Therefore, we suggest that Hb degradation is not completed in the gut lumen but that the resulting peptides are absorbed by the gut epithelial cells for further processing by intracellular di- and amino-peptidases to free amino acids that are distributed through the parasite tissue for protein anabolism. PMID:19172172

  8. Development of a patch type embedded cardiac function monitoring system using dual microprocessor for arrhythmia detection in heart disease patient.

    Science.gov (United States)

    Jang, Yongwon; Noh, Hyung Wook; Lee, I B; Jung, Ji-Wook; Song, Yoonseon; Lee, Sooyeul; Kim, Seunghwan

    2012-01-01

    A patch type embedded cardiac function monitoring system was developed to detect arrhythmias such as PVC (Premature Ventricular Contraction), pause, ventricular fibrillation, and tachy/bradycardia. The overall system is composed of a main module including a dual processor and a Bluetooth telecommunication module. The dual microprocessor strategy minimizes power consumption and size, and guarantees the resources of embedded software programs. The developed software was verified with standard DB, and showed good performance.

  9. Dual-function vector for protein expression in both mammalian cells and Xenopus laevis oocytes

    DEFF Research Database (Denmark)

    Jespersen, Thomas; Grunnet, M; Angelo, K;

    2002-01-01

    will often engage both oocytes and mammalian cells. Efficient expression of a protein in both systems have thus far only been possible by subcloning the cDNA into two different vectors because several different molecular requirements should be fulfilled to obtain a high protein level in both mammalian cells...... and oocytes. To address this problem, we have constructed a plasmid vector, pXOOM, that can function as a template for expression in both oocytes and mammalian cells. By including all the necessary RNA stability elements for oocyte expression in a standard mammalian expression vector, we have obtained a dual......-function vector capable of supporting protein production in both Xenopus oocytes and CHO-K1 cells at an expression level equivalent to the levels obtained with vectors optimized for either oocyte or mammalian expression. Our functional studies have been performed with hERGI, KCNQ4, and Kv1.3 potassium channels....

  10. Computationally efficient beampattern synthesis for dual-function radar-communications

    Science.gov (United States)

    Hassanien, Aboulnasr; Amin, Moeness G.; Zhang, Yimin D.

    2016-05-01

    The essence of amplitude-modulation based dual-function radar-communications is to modulate the sidelobe of the transmit beampattern while keeping the main beam, where the radar function takes place, unchanged during the entire processing interval. The number of distinct sidelobe levels (SLL) required for information embedding grows exponentially with the number of bits being embedded. We propose a simple and computationally cheap method for transmit beampattern synthesis which requires designing and storing only two beamforming weight vectors. The proposed method first designs a principal transmit beamforming weight vector based on the requirements dictated by the radar function of the DFRC system. Then, a second weight vectors is obtained by enforcing a deep null towards the intended communication directions. Additional SLLs can be realized by simply taking weighted linear combinations of the two available weight vectors. The effectiveness of the proposed method for beampattern synthesis is verified using simulations examples.

  11. Dual-channel functional electrical stimulation improvements in speed-based gait classifications

    Directory of Open Access Journals (Sweden)

    Springer S

    2013-02-01

    Full Text Available Shmuel Springer,1,2 Yocheved Laufer,1 Meni Becher,1,2 Jean-Jacques Vatine3,41Department of Physical Therapy, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, 2Clinical Department, Bioness Neuromodulation, Ra'anana, 3Outpatient and Research Division, Reuth Medical Center, Tel Aviv, 4Department of Rehabilitation Medicine, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, IsraelBackground: Functional electrical stimulation (FES is becoming an accepted treatment method for enhancing gait performance in patients who present with gait difficulties resulting from hemiparesis. The purpose of this study was to test whether individuals with hemiparesis who have varied gait speeds, which place them in different functional categories, benefit to the same extent from the application of FES.Methods: Thirty-six subjects with chronic hemiparesis demonstrating foot-drop and deficits in knee and/or hip control were fitted with a dual-channel FES system activating the dorsiflexors and hamstring muscles. Gait was assessed during a 2-minute walk test with and without stimulation. A second assessment was conducted after 6 weeks of daily use. Analysis was performed with the subjects stratified into three functional ambulation classes according to their initial gait categories.Results: The dual-channel FES improved the gait velocity of all three subgroups. No minimal gait velocity was required in order to gain benefits from FES. For example, subjects with limited household ambulation capabilities improved their gait speed by 63.3% (from 0.30 ± 0.09 m/sec to 0.49 ± 0.20 m/sec; P < 0.01, while subjects with functional community ambulation capabilities improved their gait speed by 25.5% (from 0.90 ± 0.11 m/sec to 1.13 ± 0.22 m/sec; P < 0.01.Conclusion: Dual-channel FES positively affects gait velocity in patients with chronic hemiparesis, regardless of their initial gait velocity. Furthermore, gait velocity gains may be large enough

  12. Dual-Functional Ultrafiltration Membrane for Simultaneous Removal of Multiple Pollutants with High Performance.

    Science.gov (United States)

    Pan, Shunlong; Li, Jiansheng; Noonan, Owen; Fang, Xiaofeng; Wan, Gaojie; Yu, Chengzhong; Wang, Lianjun

    2017-05-02

    Simultaneous removal of multiple pollutants from aqueous solution with less energy consumption is crucial in water purification. Here, a novel concept of dual-functional ultrafiltration (DFUF) membrane is demonstrated by entrapment of nanostructured adsorbents into the finger-like pores of ultrafiltration (UF) membrane rather than in the membrane matrix in previous reports of blend membranes, resulting in an exceptionally high active content and simultaneous removal of multiple pollutants from water due to the dual functions of rejection and adsorption. As a demonstration, hollow porous Zr(OH)x nanospheres (HPZNs) were immobilized in poly(ether sulfone) (PES) UF membranes through polydopamine coating with a high content of 68.9 wt %. The decontamination capacity of DFUF membranes toward multiple model pollutants (colloidal gold, polyethylene glycol (PEG), Pb(II)) was evaluated against a blend membrane. Compared to the blend membrane, the DFUF membranes showed 2.1-fold increase in the effective treatment volume for the treatment of Pb(II) contaminated water from 100 ppb to below 10 ppb (WHO drinking water standard). Simultaneously, the DFUF membranes effectively removed the colloidal gold and PEG below instrument detection limit, however the blend membrane only achieved 97.6% and 96.8% rejection for colloidal gold and PEG, respectively. Moreover, the DFUF membranes showed negligible leakage of nanoadsorbents during testing; and the membrane can be easily regenerated and reused. This study sheds new light on the design of high performance multifunction membranes for drinking water purification.

  13. Dual function seal: visualized digital signature for electronic medical record systems.

    Science.gov (United States)

    Yu, Yao-Chang; Hou, Ting-Wei; Chiang, Tzu-Chiang

    2012-10-01

    Digital signature is an important cryptography technology to be used to provide integrity and non-repudiation in electronic medical record systems (EMRS) and it is required by law. However, digital signatures normally appear in forms unrecognizable to medical staff, this may reduce the trust from medical staff that is used to the handwritten signatures or seals. Therefore, in this paper we propose a dual function seal to extend user trust from a traditional seal to a digital signature. The proposed dual function seal is a prototype that combines the traditional seal and digital seal. With this prototype, medical personnel are not just can put a seal on paper but also generate a visualized digital signature for electronic medical records. Medical Personnel can then look at the visualized digital signature and directly know which medical personnel generated it, just like with a traditional seal. Discrete wavelet transform (DWT) is used as an image processing method to generate a visualized digital signature, and the peak signal to noise ratio (PSNR) is calculated to verify that distortions of all converted images are beyond human recognition, and the results of our converted images are from 70 dB to 80 dB. The signature recoverability is also tested in this proposed paper to ensure that the visualized digital signature is verifiable. A simulated EMRS is implemented to show how the visualized digital signature can be integrity into EMRS.

  14. Hybrid ultrasound and dual-wavelength optoacoustic biomicroscopy for functional neuroimaging

    Science.gov (United States)

    Rebling, Johannes; Estrada, Hector; Zwack, Michael; Sela, Gali; Gottschalk, Sven; Razansky, Daniel

    2017-03-01

    Many neurological disorders are linked to abnormal activation or pathological alterations of the vasculature in the affected brain region. Obtaining simultaneous morphological and physiological information of neurovasculature is very challenging due to the acoustic distortions and intense light scattering by the skull and brain. In addition, the size of cerebral vasculature in murine brains spans an extended range from just a few microns up to about a millimeter, all to be recorded in 3D and over an area of several dozens of mm2. Numerous imaging techniques exist that excel at characterizing certain aspects of this complex network but are only capable of providing information on a limited spatiotemporal scale. We present a hybrid ultrasound and dual-wavelength optoacoustic microscope, capable of rapid imaging of murine neurovasculature in-vivo, with high spatial resolution down to 12 μm over a large field of view exceeding 50mm2. The dual wavelength imaging capability allows for the visualization of functional blood parameters through an intact skull while pulse-echo ultrasound biomicroscopy images are captured simultaneously by the same scan head. The flexible hybrid design in combination with fast high-resolution imaging in 3D holds promise for generating better insights into the architecture and function of the neurovascular system.

  15. pH Dependence of Chlorophyll States, Protein Structures and Function of the PSII Membranes

    Institute of Scientific and Technical Information of China (English)

    李冬海; 阮翔; 许强; 王可玢; 公衍道; 匡廷云; 张秀芳; 赵南明

    2003-01-01

    The effect of varying pH on the photosystem II (PSII) membrane was studied using absorption and steady-state fluorescence spectroscopy, and using a variable fluorescence technique.pH variations induced significant changes in the chlorophyll states of the PSII membrane, but no effect was seen on the chlorophyll fluorescence parameter F′v/F′m.For acidic pH conditions, protein structures of the PSII membrane were slightly altered, whilst at alkaline pH levels, large changes in the protein structure of the PSII membrane were detected.The results indicate that the microenvironment around Cys in the PSII membrane is very susceptible to alkaline pH conditions, and that in the acid (4≤pH7) regions, pH variation has no effect on the protein structures of the PSII reaction center (RC).

  16. A dual physiological character for sexual function: libido and sexual pheromones.

    Science.gov (United States)

    Motofei, Ion G

    2009-12-01

    Human sexual response is a complex function involving many cerebral, spinal and peripheral aspects; the last are relatively known and benefit from good pharmacological control, as in the case of erectile dysfunction. Spinal cord sexual reflexes also have a good theoretical and experimental description. There is minimal understanding of the cerebral sexual processes (libido, sexual arousal, orgasm). The initial perspective was that the cerebral areas implied in sexuality exert descending stimulatory and inhibitory influences on spinal cord sexual centres/reflexes. This was a wrong supposition, which inhibited progress in this subject, with a considerable impact on a subject's individual and social life. A new approach to sexual function arises from the idea that simple neurological structures can support only simple functions, while a more complex function requires correspondingly complex anatomical structures. For this reason the spinal cord would not be able to realise the integration of multiple (spinal and psychosensorial) stimuli into a unique and coherent ejaculation response. Consequently, all mechanisms implied in human sexuality would be cerebral processes, ejaculation reflexes ascending in evolution to the cerebral level. This new evolutionary concept was developed after 2001 in five distinct articles on the cerebral duality of sexual arousal, sexual hormones, ejaculation and serotonergic receptors. During this period other published results suggested a possible cerebral duality for sexual pheromones and libido in humans. All these dual physiological aspects are integrated in this review into one neurophysiological model, thus trying to further develop the new concepts of sexual function and perhaps relational behaviour. In conclusion, ejaculation is a dual cerebral process with arousal sensation (hormonally modulated) and libido perception (pheromonally modulated) as the afferent part. Two neurophysiological axes could exist in both men and women. In this

  17. A dual change model of life satisfaction and functioning for individuals with schizophrenia.

    Science.gov (United States)

    Edmondson, Melissa; Pahwa, Rohini; Lee, Karen Kyeunghae; Hoe, Maanse; Brekke, John S

    2012-08-01

    Despite the notion that increases in functioning should be associated with increases in life satisfaction in schizophrenia, research has often found no association between the two. Dual change models of global and domain-specific life satisfaction and functioning were examined in 145 individuals with schizophrenia receiving community-based services over 12 months. Functioning and satisfaction were measured using the Role Functioning Scale and Satisfaction with Life Scale. Data were analyzed using latent growth curve modeling. Improvement in global life satisfaction was associated with improvement in overall functioning over time. Satisfaction with living situation also improved as independent functioning improved. Work satisfaction did not improve as work functioning improved. Although social functioning improved, satisfaction with social relationships did not. The link between overall functioning and global life satisfaction provides support for a recovery-based orientation to community based psychosocial rehabilitation services. When examining sub-domains, the link between outcomes and subjective experience suggests a more complex picture than previously found. These findings are crucial to interventions and programs aimed at improving functioning and the subjective experiences of consumers recovering from mental illness. Interventions that show improvements in functional outcomes can assume that they will show concurrent improvements in global life satisfaction as well and in satisfaction with independent living. Interventions geared toward improving social functioning will need to consider the complexity of social relationships and how they affect satisfaction associated with personal relationships. Interventions geared towards improving work functioning will need to consider how the quality and level of work affect satisfaction with employment. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. A DUAL-RELAX PENALTY FUNCTION APPROACH FOR SOLVING NONLINEAR BILEVEL PROGRAMMING WITH LINEAR LOWER LEVEL PROBLEM

    Institute of Scientific and Technical Information of China (English)

    Wan Zhongping; Wang Guangrain; Lv Yibing

    2011-01-01

    The penalty function method, presented many years ago, is an important nu- merical method for the mathematical programming problems. In this article, we propose a dual-relax penalty function approach, which is significantly different from penalty func- tion approach existing for solving the bilevel programming, to solve the nonlinear bilevel programming with linear lower level problem. Our algorithm will redound to the error analysis for computing an approximate solution to the bilevel programming. The error estimate is obtained among the optimal objective function value of the dual-relax penalty problem and of the original bilevel programming problem. An example is illustrated to show the feasibility of the proposed approach.

  19. Dual functionalized graphene oxide serves as a carrier for delivering oligohistidine- and biotin-tagged biomolecules into cells.

    Science.gov (United States)

    Jana, Batakrishna; Mondal, Goutam; Biswas, Atanu; Chakraborty, Indrani; Saha, Abhijit; Kurkute, Prashant; Ghosh, Surajit

    2013-11-01

    A versatile method of dual chemical functionalization of graphene oxide (GO) with Tris-[nitrilotris(acetic acid)] (Tris-NTA) and biotin for cellular delivery of oligohistidine- and biotin-tagged biomolecules is reported. Orthogonally functionalized GO surfaces with Tris-NTA and biotin to obtain a dual-functionalized GO (DFGO) are prepared and characterized by various spectroscopic and microscopic techniques. Fluorescence microscopic images reveal that DFGO surfaces are capable of binding oligohistidine-tagged biomolecules/proteins and avidin/biotin-tagged biomolecules/proteins orthogonally. The DFGO nanoparticles are non-cytotoxic in nature and can deliver oligohistidine- and biotin-tagged biomolecules simultaneously into the cell.

  20. Musical training, bilingualism, and executive function: a closer look at task switching and dual-task performance.

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-07-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician) were matched on age and socioeconomic status and administered task switching and dual-task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual-task performance, musicians also outperformed non-musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance.

  1. Interactive effects of pH and metals on mitochondrial functions of intertidal bivalves Crassostrea virginica and Mercenaria mercenaria

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, Anna V.; Sokolova, Inna M., E-mail: isokolov@uncc.edu

    2013-11-15

    Highlights: •Interactive effects of trace metals Cd and Cu and pH were studied in mitochondria of clams and oysters. •Mitochondrial respiration and membrane potential of bivalves were robust to pH variation (6.6–7.8). •Elevated levels of Cd and Cu inhibited mitochondrial respiration in the pH-dependent manner but did not affect the membrane potential. •Negative effects of Cd and Cd on mitochondrial respiration were alleviated at low pH (7.0 and below). •Moderate acidosis may protect molluscan mitochondria from metal toxicity. -- Abstract: Intertidal bivalves experience broad fluctuations of environmental temperature, pH and oxygen content which could change their intracellular pH. They are also exposed to trace metals such as cadmium (Cd) and copper (Cu) that accumulate in their tissues and may negatively affect mitochondrial functions and bioenergetics. We determined the interactive effects of pH and trace metals (25 μM Cd or Cu) on mitochondrial functions (including respiration and membrane potentials in both ADP-stimulated (state 3) and resting (state 4) states) of two common marine bivalves, the hard clams (Mercenaria mercenaria) and eastern oysters (Crassostrea virginica). In the absence of the trace metals, mitochondrial functions of C. virginica and M. mercenaria were insensitive to pH in a broad physiologically relevant range (6.6–7.8). Mitochondrial respiration was generally suppressed by 25 μM Cd or Cu (with the stronger effects observed for ADP-stimulated compared to the resting respiration) while the mitochondrial membrane potential was unaffected. pH modulated the effects of Cu and Cd on mitochondrial respiration of the bivalves. In oysters, Cu suppressed ADP-stimulated mitochondrial respiration at high and low pH values (6.6 and 7.8, respectively), but had no effect in the intermediate pH range (7.0–7.4). In clams, the negative effect of Cu on ADP-stimulated respiration was only observed at extremely high pH (7.8). A decrease in pH

  2. SERRS and visible extinction spectroscopy of copper chlorophyllin on silver colloids as a function of pH.

    Science.gov (United States)

    House, Paul G; Schnitzer, Cheryl S

    2008-02-15

    A study of sodium copper chlorophyllin adsorbed on silver colloids (CuChl/Ag) is conducted using surface-enhanced resonance Raman scattering (SERRS) and visible extinction spectroscopy to examine how the system changes as a function of pH. Initially at basic pH, SERRS signal is not detected even though CuChl is adsorbed onto the silver surface and deprotonated. Upon decreasing the solution pH slightly, colloidal aggregation is induced, evidenced by the broadening of the visible extinction spectra. The larger aggregates possess a surface plasmon that is in resonance with the laser excitation frequency (633-nm) and SERRS signal is detected. As the acid protonates CuChl, the overall negatively-charged surface approaches neutrality which induces more aggregation. Complete protonation of CuChl by pH 4.6 results in colloidal precipitation. However, when aggregation is halted about pH 5, adding NaOH(aq) to the system maintains the extent of aggregation and an intense SERRS signal is detected at basic pH.

  3. Effect of pH and pepsin limited hydrolysis on the structure and functional properties of soybean protein hydrolysates.

    Science.gov (United States)

    Cui, Chun; Zhao, Mouming; Yuan, Boen; Zhang, Yuanhong; Ren, Jiaoyan

    2013-12-01

    Effects of limited enzymatic hydrolysis with pepsin on the functional properties and structure characteristics of soybean proteins were investigated. Hydrolysates with different incubation time (10 to 900 min) were prepared. Results showed that SPI hydrolyzed for 60 min exhibited the best emulsibility and the ability of resisting freezing/thawing. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis proved that pepsin can degrade glycinin but had little effect on the α' subunit of β-conglycinin. The structure unfolding reached the largest extent after incubation for 60 min and the soluble and flexible aggregates were formed. After 120 min, glycinin was degraded totally and β-conglycinin formed insoluble aggregates. Moreover, 2 methods were applied for the deactivation of pepsin to obtain final hydrolysates at pH 2.0 and 7.0, respectively. The structure analysis revealed that the unfolding extent and structure characteristic were different in these 2 conditions. When adjusting the pH value from 2.0 to 7.0, the unfolding protein molecular would reaggregate again at pH 7.0 due to the charge neutralization, and the hydrodynamic diameter and λmax absorbance decreased compared to pH 2.0. Moreover, some of the insoluble aggregates formed at pH 2.0 became soluble at pH 7.0, because of the salt-in phenomenon.

  4. Effects of Dual-Channel Functional Electrical Stimulation on Gait Performance in Patients with Hemiparesis

    Science.gov (United States)

    Springer, Shmuel; Vatine, Jean-Jacques; Lipson, Ronit; Wolf, Alon; Laufer, Yocheved

    2012-01-01

    The study objective was to assess the effect of functional electrical stimulation (FES) applied to the peroneal nerve and thigh muscles on gait performance in subjects with hemiparesis. Participants were 45 subjects (age 57.8 ± 14.8 years) with hemiparesis (5.37 ± 5.43 years since diagnosis) demonstrating a foot-drop and impaired knee control. Thigh stimulation was applied either to the quadriceps or hamstrings muscles, depending on the dysfunction most affecting gait. Gait was assessed during a two-minute walk test with/without stimulation and with peroneal stimulation alone. A second assessment was conducted after six weeks of daily use. The addition of thigh muscles stimulation to peroneal stimulation significantly enhanced gait velocity measures at the initial and second evaluation. Gait symmetry was enhanced by the dual-channel stimulation only at the initial evaluation, and single-limb stance percentage only at the second assessment. For example, after six weeks, the two-minute gait speed with peroneal stimulation and with the dual channel was 0.66 ± 0.30 m/sec and 0.70 ± 0.31 m/sec, respectively (P hemiparesis more than peroneal FES alone. PMID:23097635

  5. Enzyme-guided plasmonic biosensor based on dual-functional nanohybrid for sensitive detection of thrombin.

    Science.gov (United States)

    Yan, Jing; Wang, Lida; Tang, Longhua; Lin, Lei; Liu, Yang; Li, Jinghong

    2015-08-15

    Rapid and sensitive methodologies for the detection of protein are in urgent requirement for clinic diagnostics. Localized surface plasmon resonance (LSPR) of metal nanostructures has the potential to circumvent this problem due to its sensitive optical properties and strong electromagnetic near-field enhancements. In this work, an enzyme mediated plasmonic biosensor on the basis of a dual-functional nanohybrid was developed for the detection of thrombin. By utilizing LSPR-responsive nanohybrid and anaptamer-enzyme conjugated reporting probe, the sensing platform brings enhanced signal, stability as well as simplicity. Enzymatic reaction catalyzed the reduction of Au(3+) to Au° in situ, further leading to the rapid crystal growth of gold nanoparticles (AuNPs). The LSPR absorbance band and color changed company with the nanoparticle generation, which can be real-time monitoring by UV-visible spectrophotometer and naked eye. Nanohybrid constructed by gold and magnetic nanoparticles acts as a dual functional plasmonic unit, which not only plays the role of signal production, but also endows the sensor with the function of magnetic separation. Simultaneously, the introduction of enzyme effectively regulates the programming crystal growth of AuNPs. In addition, enzyme also serves as signal amplifier owing to its high catalysis efficiency. The response of the plasmonic sensor varies linearly with the logarithmic thrombin concentration up to 10nM with a limit of detection of 200 pM. The as-proposed strategy shows good analytical performance for thrombin determination. This simple, disposable method is promising in developing universal platforms for protein monitoring, drug discovery and point-of-care diagnostics.

  6. Controlled surface adsorption of fd filamentous phage by tuning of the pH and the functionalization of the surface

    Science.gov (United States)

    Jeon, Dae-Young; Hwang, Kyung Hoon; Park, So-Jeong; Kim, Yun-Jeong; Joo, Min-Kyu; Ahn, Seung-Eon; Kim, Gyu-Tae; Nam, Chang-Hoon

    2011-03-01

    The surface adsorption of fd filamentous phage (fd phage) dispersed in different solution pHs was investigated with functionalized SiO2/Si substrates. The fd phages at high pH (˜9.0) were well-adsorbed on the SiO2/Si surface that was functionalized by 3-aminopropyltriethoxysilane, whereas those at low pH (˜3.0) were well-adsorbed on the cleaned SiO2/Si surface. The high affinity of the carboxylic acid groups (COO-) at high pH (˜9.0) was attributed to the fact that they give a higher adsorption to the positively charged amine groups (NH3+) on the surface of the substrate, similar to the effect of H3O+ at low pH (˜3.0) in a solution on the surface of the hydroxyl groups on the substrate (OH-). Interestingly, the aligned structures of the fd phage at intermediate pH (˜7.0), caused by the locally positively charged coat protein of the fd phage and the shear forces along the washing and blowing direction, were identified. The effective spring constant of the fd phage bundles was estimated to be 0.672 N/m using a force-distance curve. Our results offer prerequisite information for the bottom-up assembly in SiO2/Si substrates using the fd phage in bionanoelectronics.

  7. The leaching of major and trace elements from MSWI bottom ash as a function of pH and time

    NARCIS (Netherlands)

    Dijkstra, J.J.; Sloot, van der H.A.; Comans, R.N.J.

    2006-01-01

    In this paper, the leaching behaviour of major components (Al, Ca, SO4, Mg, Si, Fe, Na and DOC) and trace elements (Ni, Zn, Cd, Cu, Pb, Mo and Sb) from MSWI bottom ash is studied as a function of time over a wide range of pH, under pH-controlled conditions. Equilibrium geochemical modelling using th

  8. The dual roles of functional groups in the photoluminescence of graphene quantum dots.

    Science.gov (United States)

    Wang, Shujun; Cole, Ivan S; Zhao, Dongyuan; Li, Qin

    2016-04-14

    The photoluminescent properties of graphene nanoparticle (named graphene quantum dots) have attracted significant research attention in recent years owing to their profound application potential. However, the photoluminescence (PL) origin of this class of nanocarbons is still unclear. In this paper, combining direct experimental evidence enabled by a facile size-tunable oxygenated graphene quantum dots (GQDs) synthesis method and theoretical calculations, the roles of the aromatic core, functional groups and disordered structures (i.e. defects and sp(3) carbon) in the PL of oxygenated GQDs are elucidated in detail. In particular, we found that the functional groups on GQDs play dual roles in the overall emission: (1) they enable π* → n and σ* → n transitions, resulting in a molecular type of PL, spectrally invariable with change of particle size or excitation energy; (2) similar to defects and sp(3) carbon, functional groups also induce structural deformation to the aromatic core, leading to mid-gap states or, in other words, energy traps, causing π* → mid-gap states → π transitions. Therefore, functional groups contribute to both the blue edge and the red shoulder of GQDs' PL spectra. The new insights on the role of functional groups in PL of fluorescent nanocarbons will enable better designs of this new class of materials.

  9. [Post-translational ligation and function of dual-vector transferred split CFTR gene].

    Science.gov (United States)

    Zhu, Fu-Xiang; Liu, Ze-Long; Qu, Hui-Ge; Chi, Xiao-Yan

    2010-01-01

    The mutation of cystic fibrosis transmembrane conductance regulator (CFTR) gene leads to an autosomal recessive genetic disorder cystic fibrosis (CF). The gene therapy for CF using adeno-associated virus (AAV) vectors delivering CFTR gene is restricted by the contents limitation of AAV vectors. In this study the split CFTR genes severed at its regulatory domain were delivered by a dual-vector system with an intein-mediated protein trans-splicing as a technique to investigate the post-translational ligation of CFTR half proteins and its function as a chloride ion channel. A pair of eukaryotic expression vectors was constructed by breaking the human CFTR cDNA before Ser712 codon and fusing with Ssp DnaB intein coding sequences. After co-transfection into baby hamster kidney (BHK) cells followed by transient expression, patch clamps were carried out to record the chloride current of whole-cell and the activity of a single channel, and the ligation of two halves of CFTR was observed by Western blotting. The results showed that the intein-fused half genes co-transfected cells displayed a high whole cell chloride current and activity of a single channel indicating the functional recovery of chloride channel, and an intact CFTR protein band was figured out by CFTR-specific antibodies indicating that intein can efficiently ligate the separately expressed half CFTR proteins. The data demonstrated that protein splicing strategy could be used as a strategy in delivering CFTR gene by two vectors, encouraging our ongoing research program on dual AAV vector system based gene transfer in gene therapy for cystic fibrosis.

  10. Evaluation of global left ventricular function assessment by dual-source computed tomography compared with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Vleuten, Pieter A. van der; Tio, Rene A.; Zijlstra, Felix [University Medical Centre Groningen, Thoraxcenter, Department of Cardiology, P.O. Box 30001, Groningen (Netherlands); Jonge, Gonda J. de; Lubbers, Daniel D.; Willems, Tineke P.; Oudkerk, Matthijs [University Medical Centre Groningen, Department of Radiology, Groningen (Netherlands)

    2009-02-15

    Left ventricular (LV) function assessment by dual-source computed tomography (DSCT) was compared with the reference standard method using magnetic resonance imaging (MRI). Accurate assessment of LV function is essential for the prediction of prognosis in cardiac disease. Thirty-four patients undergoing DSCT examination of the heart for various clinical indications underwent MRI after DSCT. Short-axis cine images were reconstructed from the DSCT datasets and were analyzed using a dedicated post-processing software-tool to generate global left ventricular function parameters. Five DSCT datasets were considered to be of insufficient image quality. DSCT showed a small overestimation of end-diastolic and end-systolic volumes of 11.0 ml and 3.5 ml, nrespectively. Myocardial mass assessed by DSCT showed an average underestimation of 0.2 g. DSCT showed a small overestimation of LV ejection fraction (LVEF) of 0.4%-point with a Bland-Altman interval of [-8.67 (0.40) 9.48]. Global LV functional parameters calculated from DSCT datasets acquired in daily clinical practice correlated well with MRI and may be considered interchangeable. However, visual assessment of the image quality of the short-axis cine slices should be performed to detect any artifacts in the DSCT data which could influence accuracy. (orig.)

  11. The Arecibo Dual-Beam Survey The HI Mass Function of Galaxies

    CERN Document Server

    Schneider, S E; Schneider, Jessica L. Rosenberg & Stephen E.

    2002-01-01

    We use the HI-selected galaxy sample from the Arecibo Dual-Beam Survey (Rosenberg & Schneider 2000) to determine the shape of the HI mass function of galaxies in the local universe using both the step-wise maximum likelihood and the 1/V_tot methods. Our survey region spanned all 24 hours of right ascension at selected declinations between 8 and 29 degrees covering ~430 deg^2 of sky in the main beam. The survey is not as deep as some previous Arecibo surveys, but it has a larger total search volume and samples a much larger area of the sky. We conducted extensive tests on all aspects of the galaxy detection process, allowing us to empirically correct for our sensitivity limits, unlike the previous surveys. The mass function for the entire sample is quite steep, with a power-law slope of \\alpha ~ -1.5. We find indications that the slope of the HI mass function is flatter near the Virgo cluster, suggesting that evolutionary effects in high density environments may alter the shape of the HI mass function. The...

  12. Dual compartment neurofluidic system for electrophysiological measurements in physically segregated and functionally connected neuronal cell culture

    Directory of Open Access Journals (Sweden)

    Thirukumaran T eKanagasabapathi

    2011-10-01

    Full Text Available We developed a dual compartment neurofluidic system with inter-connecting microchannels to connect neurons from their respective compartments, placed on a planar microelectrode array (MEA.The design and development of the compartmented microfluidic device for neuronal cell culture, protocol for sustaining long-term cultures and neurite growth through microchannels in such a closed compartment device are presented. Using electrophysiological measurements of spontaneous network activity in the compartments and selective pharmacological manipulation of cells in one compartment, the biological origin of network activity and the fluidic isolation between the compartments are demonstrated. The connectivity between neuronal populations via the microchannels and the crossing-over of neurites are verified using transfection experiments and immunofluorescence staining. In addition to the neurite cross-over to the adjacent compartment, functional connectivity between cells in both the compartments is verified using cross-correlation based techniques. Bidirectional signal propagation between the compartments is demonstrated using functional connectivity maps. Cross-correlation analysis and connectivity maps demonstrate that the two neuronal populations are not only functionally connected within each compartment but also with each other and a well connected functional network was formed between the compartments despite the physical barrier introduced by the microchannels.

  13. Regulation and Functional Significance of Airway Surface Liquid pH

    Directory of Open Access Journals (Sweden)

    Coakley RD

    2001-07-01

    Full Text Available In gastrointestinal tissues, cumulative evidence from both in vivo and in vitro studies suggests a role for the cystic fibrosis transmembrane conductance regulator (CFTR in apical epithelial bicarbonate conductance. Abnormal lumenal acidification is thus hypothesized to play a role in the genesis of cystic fibrosis (CF pancreatic disease. However, consensus regarding CFTR's participation in pH regulation of airway surface liquid (ASL and thus the contribution of ASL pH to the etiology of CF lung disease, is lacking. The absence of data reflects difficulties in both sampling ASL in vivo and modeling ASL biology in vitro. Here we evaluate the evidence in support of a lumenal acidification hypothesis in the CF lung, summarize current knowledge of pH regulation in the normal airway and illustrate how hyper-acidified airway secretions could contribute to the pathogenesis of CF lung disease.

  14. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation: A functional MRI study.

    Science.gov (United States)

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-08-25

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation.

  15. Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

    Science.gov (United States)

    Banducci, Sarah E.; Daugherty, Ana M.; Fanning, Jason; Awick, Elizabeth A.; Porter, Gwenndolyn C.; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F.; McAuley, Edward

    2017-01-01

    Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial). PMID:28255557

  16. Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults.

    Science.gov (United States)

    Ehlers, Diane K; Banducci, Sarah E; Daugherty, Ana M; Fanning, Jason; Awick, Elizabeth A; Porter, Gwenndolyn C; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F; McAuley, Edward

    2017-01-01

    Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60-79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial).

  17. A probability model for enterotoxin production of Bacillus cereus as a function of pH and temperature.

    Science.gov (United States)

    Ding, Tian; Wang, Jun; Park, Myoung-Su; Hwang, Cheng-An; Oh, Deog-Hwan

    2013-02-01

    Bacillus cereus is frequently isolated from a variety of foods, including vegetables, dairy products, meats, and other raw and processed foods. The bacterium is capable of producing an enterotoxin and emetic toxin that can cause severe nausea, vomiting, and diarrhea. The objectives of this study were to assess and model the probability of enterotoxin production of B. cereus in a broth model as affected by the broth pH and storage temperature. A three-strain mixture of B. cereus was inoculated in tryptic soy broth adjusted to pH 5.0, 6.0, 7.2, 8.0, and 8.5, and the samples were stored at 15, 20, 25, 30, and 35°C for 24 h. A total of 25 combinations of pH and temperature, each with 10 samples, were tested. The presence of enterotoxin in broth was assayed using a commercial test kit. The probabilities of positive enterotoxin production in 25 treatments were fitted with a logistic regression to develop a probability model to describe the probability of toxin production as a function of pH and temperature. The resulting model showed that the probabilities of enterotoxin production of B. cereus in broth increased as the temperature increased and/or as the broth pH approached 7.0. The model described the experimental data satisfactorily and identified the boundary of pH and temperature for the production of enterotoxin. The model could provide information for assessing the food poisoning risk associated with enterotoxins of B. cereus and for the selection of product pH and storage temperature for foods to reduce the hazards associated with B. cereus.

  18. Effects of pH on aggregation kinetics of the repeat domain of a functional amyloid, Pmel17

    Science.gov (United States)

    Pfefferkorn, Candace M.; McGlinchey, Ryan P.; Lee, Jennifer C.

    2010-01-01

    Pmel17 is a functional amyloidogenic protein whose fibrils act as scaffolds for pigment deposition in human skin and eyes. We have used the repeat domain (RPT, residues 315–444), an essential luminal polypeptide region of Pmel17, as a model system to study conformational changes from soluble unstructured monomers to β-sheet-containing fibrils. Specifically, we report on the effects of solution pH (4 → 7) mimicking pH conditions of melanosomes, acidic organelles where Pmel17 fibrils are formed. Local, secondary, and fibril structure were monitored via intrinsic Trp fluorescence, circular dichroism spectroscopy, and transmission electron microscopy, respectively. We find that W423 is a highly sensitive probe of amyloid assembly with spectral features reflecting local conformational and fibril morphological changes. A critical pH regime (5 ± 0.5) was identified for fibril formation suggesting the involvement of at least three carboxylic acids in the structural rearrangement necessary for aggregation. Moreover, we demonstrate that RPT fibril morphology can be transformed directly by changing solution pH. Based on these results, we propose that intramelanosomal pH regulates Pmel17 amyloid formation and its subsequent dissolution in vivo. PMID:21106765

  19. Discrete-Trial Functional Analysis of Problem Behavior and Functional Communication Training in Three Adults with a Dual Diagnosis of a Significant Intellectual Disability and a Mental Illness

    Science.gov (United States)

    Chezan, Laura Claudia

    2012-01-01

    I conducted two studies. First, I examined the applicability of discrete-trial functional analysis (DTFA) for identifying the function of problem behavior in three adults with a dual diagnosis of a significant intellectual disability and a mental illness. Results indicated clear patterns of problem behavior for each participant. Second, I used a…

  20. Discrete-Trial Functional Analysis of Problem Behavior and Functional Communication Training in Three Adults with a Dual Diagnosis of a Significant Intellectual Disability and a Mental Illness

    Science.gov (United States)

    Chezan, Laura Claudia

    2012-01-01

    I conducted two studies. First, I examined the applicability of discrete-trial functional analysis (DTFA) for identifying the function of problem behavior in three adults with a dual diagnosis of a significant intellectual disability and a mental illness. Results indicated clear patterns of problem behavior for each participant. Second, I used a…

  1. Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

    Directory of Open Access Journals (Sweden)

    Diane K. Ehlers

    2017-01-01

    Full Text Available Objectives. Despite evidence of self-efficacy and physical function’s influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults’ street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials and conversed on a cell phone (dual-task trials. Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults’ performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial.

  2. Comparator pH study to evaluate the single-dose pharmacodynamics of dual delayed-release dexlansoprazole 60 mg and delayed-release esomeprazole 40 mg

    Directory of Open Access Journals (Sweden)

    Kukulka M

    2011-09-01

    Full Text Available Michael Kukulka1, Corey Eisenberg2, Sai Nudurupati31Clinical Pharmacology, 2Clinical Science, 3Statistics, Takeda Global Research & Development Center Inc, Deerfield, IL, USABackground: This paper describes a Phase 1, single-center, randomized, open-label, two-period crossover study which compared the pharmacodynamic effects of single doses of dexlansoprazole modified-release 60 mg and esomeprazole 40 mg on 24-hour intragastric pH in healthy adult subjects.Methods: Forty-four subjects aged 20–54 years were randomized in a 1:1 ratio to two sequence groups defining the order in which they received dexlansoprazole and esomeprazole in periods 1 and 2. Primary pharmacodynamic end points over 24 hours postdose were percentage of time with intragastric pH > 4 and mean pH, and secondary pharmacodynamic end points were percentage of time intragastric pH > 4, and mean pH at 0–12 hours, and at >12–24 hours postdose. Each drug was given after an overnight fast and one hour before breakfast. Continuous pH recording began immediately before dosing through to 24 hours postdose.Results: At 0–24 hours postdose, the mean percentage of time with pH > 4 for dexlansoprazole and esomeprazole was 58% and 48%, respectively; the difference was statistically significant (P = 0.003. The average of mean pH values at 0–24 hours postdose for dexlansoprazole and esomeprazole were 4.3 and 3.7, respectively; the difference was statistically significant (P < 0.001. At >12–24 hours postdose, mean percentage of time with pH > 4 and average of mean pH were greater for dexlansoprazole (60% and 4.5, respectively compared with esomeprazole (42% and 3.5, respectively; the difference was statistically significant (P < 0.001 for both intervals. At 0–12 hours postdose, the difference in dexlansoprazole and esomeprazole values for the pharmacodynamic end points was not statistically significant.Conclusion: For the entire 24-hour postdose period, predominantly resulting from

  3. Extracellular pH dynamically controls cell surface delivery of functional TRPV5 channels.

    NARCIS (Netherlands)

    Lambers, T.T.; Oancea, E.; Groot, T. de; Topala, C.N.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    Extracellular pH has long been known to affect the rate and magnitude of ion transport processes among others via regulation of ion channel activity. The Ca(2+)-selective transient receptor potential vanilloid 5 (TRPV5) channel constitutes the apical entry gate in Ca(2+)-transporting cells, contribu

  4. Dual-orthogonal radial basis function networks for nonlinear time series prediction.

    Science.gov (United States)

    Hong, X; Billings, Steve A.

    1998-04-01

    A new structure of Radial Basis Function (RBF) neural network called the Dual-orthogonal RBF Network (DRBF) is introduced for nonlinear time series prediction. The hidden nodes of a conventional RBF network compare the Euclidean distance between the network input vector and the centres, and the node responses are radially symmetrical. But in time series prediction where the system input vectors are lagged system outputs, which are usually highly correlated, the Euclidean distance measure may not be appropriate. The DRBF network modifies the distance metric by introducing a classification function which is based on the estimation data set. Training the DRBF networks consists of two stages. Learning the classification related basis functions and the important input nodes, followed by selecting the regressors and learning the weights of the hidden nodes. In both cases, a forward Orthogonal Least Squares (OLS) selection procedure is applied, initially to select the important input nodes and then to select the important centres. Simulation results of single-step and multi-step ahead predictions over a test data set are included to demonstrate the effectiveness of the new approach.

  5. A Dual-Organic-Transistor-Based Tactile-Perception System with Signal-Processing Functionality.

    Science.gov (United States)

    Zang, Yaping; Shen, Hongguang; Huang, Dazhen; Di, Chong-An; Zhu, Daoben

    2017-02-22

    Organic-device-based tactile-perception systems can open up new opportunities for the next generation of intelligent products. To meet the critical requirements of artificial perception systems, the efficient construction of organic smart elements with integrated sensing and signal processing functionalities is highly desired, but remains a challenge. This study presents a dual-organic-transistor-based tactile-perception element (DOT-TPE) with biomimetic functionality by the construction of organic synaptic transistors with integrated sensing transistors. The unique geometry of the DOT-TPE permits instantaneous sensing of pressure stimuli and synapse-like processing of an electric signal in a single element. More importantly, these organic-transistor-based tactile-perception elements can be built into arrays to serve as bionic tactile-perception systems. The combined biomimetic functionality of tactile-perception systems, together with their promising features of flexibility and large-area fabrication, makes this work represent a step forward toward novel e-skin devices for artificial intelligence.

  6. Dual functions of a small regulatory subunit in the mitochondrial calcium uniporter complex.

    Science.gov (United States)

    Tsai, Ming-Feng; Phillips, Charles B; Ranaghan, Matthew; Tsai, Chen-Wei; Wu, Yujiao; Willliams, Carole; Miller, Christopher

    2016-04-21

    Mitochondrial Ca(2+) uptake, a process crucial for bioenergetics and Ca(2+) signaling, is catalyzed by the mitochondrial calcium uniporter. The uniporter is a multi-subunit Ca(2+)-activated Ca(2+) channel, with the Ca(2+) pore formed by the MCU protein and Ca(2+)-dependent activation mediated by MICU subunits. Recently, a mitochondrial inner membrane protein EMRE was identified as a uniporter subunit absolutely required for Ca(2+) permeation. However, the molecular mechanism and regulatory purpose of EMRE remain largely unexplored. Here, we determine the transmembrane orientation of EMRE, and show that its known MCU-activating function is mediated by the interaction of transmembrane helices from both proteins. We also reveal a second function of EMRE: to maintain tight MICU regulation of the MCU pore, a role that requires EMRE to bind MICU1 using its conserved C-terminal polyaspartate tail. This dual functionality of EMRE ensures that all transport-competent uniporters are tightly regulated, responding appropriately to a dynamic intracellular Ca(2+) landscape.

  7. Functional recurrent mutations in the human mitochondrial phylogeny: dual roles in evolution and disease.

    Science.gov (United States)

    Levin, Liron; Zhidkov, Ilia; Gurman, Yotam; Hawlena, Hadas; Mishmar, Dan

    2013-01-01

    Mutations frequently reoccur in the human mitochondrial DNA (mtDNA). However, it is unclear whether recurrent mtDNA nodal mutations (RNMs), that is, recurrent mutations in stems of unrelated phylogenetic nodes, are functional and hence selectively constrained. To answer this question, we performed comprehensive parsimony and maximum likelihood analyses of 9,868 publicly available whole human mtDNAs revealing 1,606 single nodal mutations (SNMs) and 679 RNMs. We then evaluated the potential functionality of synonymous, nonsynonymous and RNA SNMs and RNMs. For synonymous mutations, we have implemented the Codon Adaptation Index. For nonsynonymous mutations, we assessed evolutionary conservation, and employed previously described pathogenicity score assessment tools. For RNA genes' mutations, we designed a bioinformatic tool which compiled evolutionary conservation and potential effect on RNA structure. While comparing the functionality scores of nonsynonymous and RNA SNMs and RNMs with those of disease-causing mtDNA mutations, we found significant difference (P < 0.001). However, 24 RNMs and 67 SNMs had comparable values with disease-causing mutations reflecting their potential function thus being the best candidates to participate in adaptive events of unrelated lineages. Strikingly, some functional RNMs occurred in unrelated mtDNA lineages that independently altered susceptibility to the same diseases, thus suggesting common functionality. To our knowledge, this is the most comprehensive analysis of selective signatures in the mtDNA not only within proteins but also within RNA genes. For the first time, we discover virtually all positively selected RNMs in our phylogeny while emphasizing their dual role in past evolutionary events and in disease today.

  8. Evaluation of pulmonary function using single-breath-hold dual-energy computed tomography with xenon

    Science.gov (United States)

    Kyoyama, Hiroyuki; Hirata, Yusuke; Kikuchi, Satoshi; Sakai, Kosuke; Saito, Yuriko; Mikami, Shintaro; Moriyama, Gaku; Yanagita, Hisami; Watanabe, Wataru; Otani, Katharina; Honda, Norinari; Uematsu, Kazutsugu

    2017-01-01

    Abstract Xenon-enhanced dual-energy computed tomography (xenon-enhanced CT) can provide lung ventilation maps that may be useful for assessing structural and functional abnormalities of the lung. Xenon-enhanced CT has been performed using a multiple-breath-hold technique during xenon washout. We recently developed xenon-enhanced CT using a single-breath-hold technique to assess ventilation. We sought to evaluate whether xenon-enhanced CT using a single-breath-hold technique correlates with pulmonary function testing (PFT) results. Twenty-six patients, including 11 chronic obstructive pulmonary disease (COPD) patients, underwent xenon-enhanced CT and PFT. Three of the COPD patients underwent xenon-enhanced CT before and after bronchodilator treatment. Images from xenon-CT were obtained by dual-source CT during a breath-hold after a single vital-capacity inspiration of a xenon–oxygen gas mixture. Image postprocessing by 3-material decomposition generated conventional CT and xenon-enhanced images. Low-attenuation areas on xenon images matched low-attenuation areas on conventional CT in 21 cases but matched normal-attenuation areas in 5 cases. Volumes of Hounsfield unit (HU) histograms of xenon images correlated moderately and highly with vital capacity (VC) and total lung capacity (TLC), respectively (r = 0.68 and 0.85). Means and modes of histograms weakly correlated with VC (r = 0.39 and 0.38), moderately with forced expiratory volume in 1 second (FEV1) (r = 0.59 and 0.56), weakly with the ratio of FEV1 to FVC (r = 0.46 and 0.42), and moderately with the ratio of FEV1 to its predicted value (r = 0.64 and 0.60). Mode and volume of histograms increased in 2 COPD patients after the improvement of FEV1 with bronchodilators. Inhalation of xenon gas caused no adverse effects. Xenon-enhanced CT using a single-breath-hold technique depicted functional abnormalities not detectable on thin-slice CT. Mode, mean, and volume of HU histograms of xenon images

  9. Characterization of the PH1704 protease from Pyrococcus horikoshii OT3 and the critical functions of Tyr120.

    Science.gov (United States)

    Zhan, Dongling; Bai, Aixi; Yu, Lei; Han, Weiwei; Feng, Yan

    2014-01-01

    The PH1704 protease from hyperthermophilic archaean Pyrococcus horikoshii OT3 is a member of DJ-1/ThiJ/PfpI superfamily with diverse functional subclasses. The recombinant PH1704 was efficiently purified and was systematically characterized by a combination of substrate specificity analysis, steady-state kinetics study and molecular docking research. The homogeneous protease was obtained as a presumed dodecamer with molecular weight of ∼240 kDa. Iodoacetamide strongly inhibited the peptidase activity, confirming that Cys100 is a nucleophilic residue. The recombinant protein was identified as both an aminopeptidase and an endopeptidase. Experimental data showed that L-R-amc was the best substrate of PH1704. Structural interaction fingerprint analysis (SIFt) indicated the binding pose of PH1704 and showed that Tyr120 is important in substrate binding. Kinetic parameters Kcat and Kcat/Km of the Y120P mutant with L-R-amc was about 7 and 7.8 times higher than that of the wild type (WT). For the endopeptidase Y120P with AAFR-amc, Kcat and Kcat/Km is 10- and 21-fold higher than that of WT. Experimental data indicate the important functions of Tyr120: involvement in enzyme activity to form a hydrogen bond with Cys100 and as an entrance gate of the substrate with Lys43. The results of this study can be used to investigate the DJ-1/ThiJ/PfpI superfamily.

  10. Does extending the dual-task functional exercises workout improve postural balance in individuals with ID?

    Science.gov (United States)

    Mikolajczyk, Edyta; Jankowicz-Szymanska, Agnieszka

    2015-03-01

    Maintaining postural balance, overcoming visual and motor coordination disorders and experiencing problems with low general fitness - typical of intellectually disabled individuals - adversely affect the performance quality of their activities of daily living (ADLs). Physical fitness and postural balance can be improved by taking part in special intervention programs. Our study was designed to test whether extending the dual-task intervention program (combining ADLs with balance exercises on unstable surfaces) from 12 to 24 weeks additionally improved postural balance in individuals with intellectual disability (ID). We also attempted to assess whether the effects of the above intervention program were still noticeable after 8 weeks of holidays, in which participants did not take any rehabilitation exercises. A total of 34 adolescents, aged 14-16 years (15.06±0.9), with moderate ID took part in our study. The experimental group (E) consisted of 17 individuals, who continued the intervention program originated 3 months earlier, and the control group (C) comprised the same number of participants. Postural balance was assessed on a stabilometric platform Alfa. Having extended the workout period by another 12 weeks, we noticed that the path length of the center of pressure (COP) covered by participants on tests with their eyes open and closed significantly shortened. After a lapse of 8 weeks from the completion of the program, the experimental group revealed a statistically significant decrease in the velocity along the medio-lateral (M/L) and anterior-posterior (A/P) axes. The remaining variables stayed at the same level and the control group did not demonstrate any statistically significant changes. Dual-task exercises, in which enhancing functional tasks of daily living is combined with a parallel stimulation of balance reactions, may improve static balance in persons with ID.

  11. A Dual-Function All-in-Fiber Device Based on Negative Dielectric Liquid Crystal Photonic Bandgap Fibers

    DEFF Research Database (Denmark)

    Wei, Lei; Eskildsen, Lars; Weirich, Johannes;

    2008-01-01

    A dual-function all-in-fiber device based on negative dielectric liquid crystal photonic bandgap fibers is presented. This device can work both as an electrically tunable waveplate in the range 1520nm-1580nm, and as a polarimeter at 1310nm....

  12. Musical Training, Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual-Task Performance

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-01-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician)…

  13. Economical, green and dual-function pyridyl iodides as electrolyte components for high efficiency dye-sensitized solar cells.

    Science.gov (United States)

    Zhang, Hong; Shi, Yantao; Wang, Liang; Wang, Chaolei; Zhou, Huawei; Guo, Wei; Ma, Tingli

    2013-10-11

    Pyridyl iodides were synthesized to serve as effective, economical, green and dual function additives for high efficiency and stable DSCs. Using commercial P25 as the photoanode, a high PCE of 7.81% was achieved with a pyridyl iodide-containing electrolyte. Meanwhile, DSCs based on our novel electrolytes demonstrated better stability.

  14. The Dual Functionals for the Generalized Ball Basis of Wang-Said Type and Basis Transformation Formulas

    Institute of Scientific and Technical Information of China (English)

    Ping Jiang; Hongyi Wu; Jieqing Tan

    2006-01-01

    The generalized Ball curves of Wang-Said type with a position parameter L not only unify the Wang-Ball curves and the Said-Ball curves, but also include several useful intermediate curves. This paper presents the dual functionals for the generalized Ball basis of Wang-Said type. The relevant basis transformation formulae are also worked out.

  15. Environmental pH and the requirement for the extrinsic proteins of Photosystem II in the function of cyanobacterial photosynthesis

    Directory of Open Access Journals (Sweden)

    Jaz N Morris

    2016-08-01

    Full Text Available In one of the final stages of cyanobacterial Photosystem II (PS II assembly, binding of up to four extrinsic proteins to PS II stabilizes the oxygen-evolving complex (OEC. Growth of cyanobacterial mutants deficient in certain combinations of these thylakoid-lumen-associated polypeptides is sensitive to changes in environmental pH, despite the physical separation of the membrane-embedded PS II complex from the external environment. In this perspective, we discuss the effect of environmental pH on OEC function and photoautotrophic growth in cyanobacteria, with reference to pH-sensitive PS II mutants lacking extrinsic proteins. We consider the possibilities that, compared to pH 10.0, pH 7.5 increases susceptibility to PS II-generated reactive oxygen species (ROS, causing photoinhibition and reducing PS II assembly in some mutants and that perturbations to channels in the lumenal regions of PS II might alter the accessibility of water to the active site, and egress of oxygen and protons to the thylakoid lumen. Reduced levels of PS II in these mutants and reduced OEC activity arising from the disruption of substrate/product channels could reduce the trans-thylakoid pH gradient (ΔpH, leading to the impairement of photosynthesis. Growth of some PS II mutants at pH 7.5 can be rescued by elevating CO2 levels, suggesting that the pH-sensitive phenotype might primarily be an indirect result of back-pressure in the electron transport chain that results in heightened production of ROS by the impaired photosystem.

  16. Lower limb muscle coactivation levels in healthy younger and older adults during functional dual-task gait

    Directory of Open Access Journals (Sweden)

    Camilla Zamfolini Hallal

    2013-09-01

    Full Text Available The purpose of this study was to investigate the influence of daily cognitive task on stiffness of old and young female adults during the gait. The study included 17 physically active younger and 18 older women, with low risk of falls. The volunteers were asked to walk on the treadmill at two different gait conditions: normal gait and functional dual-task gait. The electromyographic signals were collected of the lower limb muscles. The percentage of coactivation for the tibialis anterior/gastrocnemius lateralis and tibialis anterior/soleus were significantly higher in elderly than in younger in the normal gait and dual-task gait. Our results suggest that the elderly have a greater stiffness in the ankle joint during gait normal and daily dual task gait. Thus, we conclude that challenging cognitively situations during the gait may increase the risk of falls in this population.

  17. Maintaining Gait Performance by Cortical Activation during Dual-Task Interference: A Functional Near-Infrared Spectroscopy Study.

    Directory of Open Access Journals (Sweden)

    Chia-Feng Lu

    Full Text Available In daily life, mobility requires walking while performing a cognitive or upper-extremity motor task. Although previous studies have evaluated the effects of dual tasks on gait performance, few studies have evaluated cortical activation and its association with gait disturbance during dual tasks. In this study, we simultaneously assessed gait performance and cerebral oxygenation in the bilateral prefrontal cortices (PFC, premotor cortices (PMC, and supplemental motor areas (SMA, using functional near-infrared spectroscopy, in 17 young adults performing dual tasks. Each participant was evaluated while performing normal-pace walking (NW, walking while performing a cognitive task (WCT, and walking while performing a motor task (WMT. Our results indicated that the left PFC exhibited the strongest and most sustained activation during WCT, and that NW and WMT were associated with minor increases in oxygenation levels during their initial phases. We observed increased activation in channels in the SMA and PMC during WCT and WMT. Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties. WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only. During dual-task activities, increased activation of the PMC and SMA correlated with declines in gait performance, indicating a control mechanism for maintaining gait performance during dual tasks. Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

  18. Maintaining Gait Performance by Cortical Activation during Dual-Task Interference: A Functional Near-Infrared Spectroscopy Study.

    Science.gov (United States)

    Lu, Chia-Feng; Liu, Yan-Ci; Yang, Yea-Ru; Wu, Yu-Te; Wang, Ray-Yau

    2015-01-01

    In daily life, mobility requires walking while performing a cognitive or upper-extremity motor task. Although previous studies have evaluated the effects of dual tasks on gait performance, few studies have evaluated cortical activation and its association with gait disturbance during dual tasks. In this study, we simultaneously assessed gait performance and cerebral oxygenation in the bilateral prefrontal cortices (PFC), premotor cortices (PMC), and supplemental motor areas (SMA), using functional near-infrared spectroscopy, in 17 young adults performing dual tasks. Each participant was evaluated while performing normal-pace walking (NW), walking while performing a cognitive task (WCT), and walking while performing a motor task (WMT). Our results indicated that the left PFC exhibited the strongest and most sustained activation during WCT, and that NW and WMT were associated with minor increases in oxygenation levels during their initial phases. We observed increased activation in channels in the SMA and PMC during WCT and WMT. Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties. WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only. During dual-task activities, increased activation of the PMC and SMA correlated with declines in gait performance, indicating a control mechanism for maintaining gait performance during dual tasks. Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

  19. Effects of dual-task training on balance and executive functions in Parkinson's disease: A pilot study.

    Science.gov (United States)

    Fernandes, Ângela; Rocha, Nuno; Santos, Rubim; Tavares, João Manuel R S

    2015-01-01

    The aim of this study was to analyze the efficacy of cognitive-motor dual-task training compared with single-task training on balance and executive functions in individuals with Parkinson's disease. Fifteen subjects, aged between 39 and 75 years old, were randomly assigned to the dual-task training group (n = 8) and single-task training group (n = 7). The training was run twice a week for 6 weeks. The single-task group received balance training and the dual-task group performed cognitive tasks simultaneously with the balance training. There were no significant differences between the two groups at baseline. After the intervention, the results for mediolateral sway with eyes closed were significantly better for the dual-task group and anteroposterior sway with eyes closed was significantly better for the single-task group. The results suggest superior outcomes for the dual-task training compared to the single-task training for static postural control, except in anteroposterior sway with eyes closed.

  20. Conductimetric study of struvite crystallization in water as a function of pH

    Science.gov (United States)

    Moulessehoul, A.; Gallart-Mateu, D.; Harrache, D.; Djaroud, S.; de la Guardia, M.; Kameche, M.

    2017-08-01

    The main objective of this work was to investigate the best pH for phosphorus removal from synthetic aqueous solutions using chemical precipitation of struvite, at constant temperature. The experimental approach, developed in the present study, consisted to precipitate struvite in synthetic wastewater containing PO43-, NH4+ and Mg2+ ions in an equal molar ratio, using a stirred tank with continuous monitoring by conductimetry, at 25 °C. Different laboratory experiments were used to evaluate the effects of pH in the range of 8.5 till 11.8, on size, shape, and purity of the precipitated crystals. Struvite crystals were characterized by Infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The phosphorus conversion rate was determined by spectrophotometric determination of residual phosphorus. The experimental results showed that pH 8.5 provided the best conditions for struvite crystal growth, being obtained a 98% phosphorus to phosphate conversion rate, for an initial concentration of 474 mg/L.

  1. Structure reveals function of the dual variable domain immunoglobulin (DVD-Ig™) molecule.

    Science.gov (United States)

    Jakob, Clarissa G; Edalji, Rohinton; Judge, Russell A; DiGiammarino, Enrico; Li, Yingchun; Gu, Jijie; Ghayur, Tariq

    2013-01-01

    Several bispecific antibody-based formats have been developed over the past 25 years in an effort to produce a new generation of immunotherapeutics that target two or more disease mechanisms simultaneously. One such format, the dual-variable domain immunoglobulin (DVD-Ig™), combines the target binding domains of two monoclonal antibodies via flexible naturally occurring linkers, which yields a tetravalent IgG - like molecule. We report the structure of an interleukin (IL)12-IL18 DVD-Ig™ Fab (DFab) fragment with IL18 bound to the inner variable domain (VD) that reveals the remarkable flexibility of the DVD-Ig™ molecule and how the DVD-Ig™ format can function to bind four antigens simultaneously. An understanding of how the inner variable domain retains function is of critical importance for designing DVD-Ig™ molecules, and for better understanding of the flexibility of immunoglobulin variable domains and linkers, which may aid in the design of improved bi- and multi-specific biologics in general.

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

    Science.gov (United States)

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

    2017-01-01

    A chromogenic fluoride probe bearing bis imine groups having dual -NH functionality (BSB) has been designed, synthesised and structurally characterized by its single crystal X-ray diffraction studies. The BSB could visually and spectroscopically recognise F- with high selectivity over other anions by exhibiting intense chromogenic response (from colourless to red) for F- in acetonitrile solution. The UV-visible titration and 1H NMR titration experiments indicated that the observed changes occur via a combined process including hydrogen bonding and deprotonation between the BSB and F-. Moreover theoretical calculations at the Density Functional Theory (DFT) level shed further light upon probe design strategy and the nature of interactions between BSB and F-. The limit of detection and binding constant of BSB towards F- were found to be 6.9 × 10- 7 M and 1.42 ± 0.069 × 108 M- 2 respectively. Finally, by using F- and H+ as chemical inputs and the absorbance as output, a INHIBIT logic gate was constructed, which exhibits "Multi-write" ability without obvious degradation in its optical output.

  3. A dual-functional fibrous scaffold enhances P450 activity of cultured primary rat hepatocytes.

    Science.gov (United States)

    Chua, Kian-Ngiap; Tang, Yen-Ni; Quek, Chai-Hoon; Ramakrishna, Seeram; Leong, Kam W; Mao, Hai-Quan

    2007-09-01

    We have designed a novel dual-functional electrospun fibrous scaffold comprising two fiber mesh layers that were modified differently to induce two separate biological responses from hepatocytes. The first fiber layer was galactosylated on the surface to mediate hepatocyte attachment, while the second layer was loaded with 3-methylcholanthrene (3-Mc) to enhance cytochrome P450 activity of hepatocytes. Primary rat hepatocytes cultured on the galactosylated fibrous scaffolds loaded with different concentrations of 3-Mc were compared for their cell attachment efficiency, albumin secretion activity and cytochrome P450-dependent 7-ethoxycoumarin O-deethylase activity. This hybrid fibrous scaffold mediated hepatocyte attachment with slightly lower efficiency (76+/-2.3%) than a single-layer galactosylated fibrous scaffold (84+/-3.5%). More importantly, the cytochrome P450 activity of the hepatocytes cultured on the hybrid scaffold correlated well with the 3-Mc loading level. The results also showed that transfer of 3-Mc to hepatocytes through direct cell-fiber contact was the dominant transport route, with the induced cytochrome P450 activity being 1.9- to 4.8-fold higher than that of transfer of 3-Mc to hepatocytes via dissolution from fibers to medium. This study demonstrates the feasibility of creating multi-functional fibrous scaffolds that serve both as an adhesive substrate and as a delivery vehicle for bioactive molecules.

  4. A trilayer separator with dual function for high performance lithium-sulfur batteries

    Science.gov (United States)

    Song, Rensheng; Fang, Ruopian; Wen, Lei; Shi, Ying; Wang, Shaogang; Li, Feng

    2016-01-01

    In this article, we propose a trilayer graphene/polypropylene/Al2O3 (GPA) separator with dual function for high performance lithium-sulfur (Li-S) batteries. Graphene is coated on one side of polypropylene (PP) separator, which functions as a conductive layer and an electrolyte reservoir that allows for rapid electron and ion transport. Then Al2O3 particles are coated on the other side to further enhance thermal stability and safety of the graphene coated polypropylene (GCP) separator, which are touched with lithium metal anode in the Li-S battery. The GPA separator shows good thermal stability after heating at 157 °C for 10 min while both GCP and PP separators showing an obvious shrinkage about 10%. The initial discharge specific capacity of Li-S coin cell with a GPA separator could reach 1067.7 mAh g-1 at 0.2C. After 100 discharge/charge cycles, it can still deliver a reversible capacity of as high as 804.4 mAh g-1 with 75% capacity retention. The pouch cells further confirm that the trilayer design has great promise towards practical applications.

  5. Designing Dual-functionalized Gels for Self-reconfiguration and Autonomous Motion

    Science.gov (United States)

    Kuksenok, Olga; Balazs, Anna C.

    2015-04-01

    Human motion is enabled by the concerted expansion and contraction of interconnected muscles that are powered by inherent biochemical reactions. One of the challenges in the field of biomimicry is eliciting this form of motion from purely synthetic materials, which typically do not generate internalized reactions to drive mechanical action. Moreover, for practical applications, this bio-inspired motion must be readily controllable. Herein, we develop a computational model to design a new class of polymer gels where structural reconfigurations and internalized reactions are intimately linked to produce autonomous motion, which can be directed with light. These gels contain both spirobenzopyran (SP) chromophores and the ruthenium catalysts that drive the oscillatory Belousov-Zhabotinsky (BZ) reaction. Importantly, both the SP moieties and the BZ reaction are photosensitive. When these dual-functionalized gels are exposed to non-uniform illumination, the localized contraction of the gel (due to the SP moieties) in the presence of traveling chemical waves (due to the BZ reaction) leads to new forms of spontaneous, self-sustained movement, which cannot be achieved by either of the mono-functionalized networks.

  6. The dual-function CD150 receptor subfamily: the viral attraction.

    Science.gov (United States)

    Sidorenko, Svetlana P; Clark, Edward A

    2003-01-01

    The CD150 subfamily within the CD2 family is a growing group of dual-function receptors that have within their cytoplasmic tails a characteristic signaling motif. The ITSM (immunoreceptor tyrosine-based switch motif) enables these receptors to bind to and be regulated by small SH2 domain adaptor proteins, including SH2D1A (SH2-containing adaptor protein SH2 domain protein 1A) and EAT-2 (EWS-activated transcript 2). A major signaling pathway through the prototypic receptor in this subfamily, CD150, leads to the activation of interferon-gamma, a key cytokine for viral immunity. As a result, many viruses have designed strategies to usurp or alter CD150 functions. Measles virus uses CD150 as a receptor and Molluscum contagiosum virus encodes proteins that are homologous to CD150. Thus, viruses use CD150 subfamily receptors to create a favorable environment to elude detection and destruction. Understanding the CD150 subfamily may lead to new strategies for vaccine development and antiviral therapies.

  7. Functional neuroanatomy of the basal ganglia as studied by dual-probe microdialysis

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, William T. E-mail: woconn@iveagh.ucd.ie

    1998-11-01

    Dual probe microdialysis was employed in intact rat brain to investigate the effect of intrastriatal perfusion with selective dopamine D{sub 1} and D{sub 2} receptor agonists and with c-fos antisense oligonucleotide on (a) local GABA release in the striatum; (b) the internal segment of the globus pallidus and the substantia nigra pars reticulata, which is the output site of the strionigral GABA pathway; and (c) the external segment of the globus pallidus, which is the output site of the striopallidal GABA pathway. The data provide functional in vivo evidence for a selective dopamine D{sub 1} receptor-mediated activation of the direct strionigral GABA pathway and a selective dopamine D{sub 2} receptor inhibition of the indirect striopallidal GABA pathway and provides a neuronal substrate for parallel processing in the basal ganglia regulation of motor function. Taken together, these findings offer new therapeutic strategies for the treatment of dopamine-linked disorders such as Parkinson's disease, Huntington's disease, and schizophrenia.

  8. Some Characterization Results based on Conditional Expectation of function of Dual Generalized Order Statistics

    Directory of Open Access Journals (Sweden)

    Md Izhar Khan

    2012-11-01

    Full Text Available  Two families of probability distributions are characterized through the conditional expectations of dual generalized order statistics ( , conditioned on a non-adjacent dual generalized order statistics. Also a result based on the unconditional expectation and a conditional expectation of  is used to characterize family of distributions. Further, some of its deductions are also discussed.

  9. Comparative Evaluation of the Effect of Menstruation, Pregnancy and Menopause on Salivary Flow Rate, pH and Gustatory Function

    OpenAIRE

    2014-01-01

    Objective: There are five situations in a women’s life during which hormone fluctuations make them more susceptible to oral health problems – during puberty, at certain points in the monthly menstrual cycle, when using birth control pills, during pregnancy, and at menopause. The present study aimed at evaluating the effect of menstruation, pregnancy and menopause on salivary flow rate, pH and gustatory function.

  10. Comparative Evaluation of the Effect of Menstruation, Pregnancy and Menopause on Salivary Flow Rate, pH and Gustatory Function

    OpenAIRE

    Saluja, Pulin; Shetty, Vishwaprakash; Dave, Aparna; Arora, Manpreet; Hans, Vibha; Madan, Ajay

    2014-01-01

    Objective: There are five situations in a women’s life during which hormone fluctuations make them more susceptible to oral health problems – during puberty, at certain points in the monthly menstrual cycle, when using birth control pills, during pregnancy, and at menopause. The present study aimed at evaluating the effect of menstruation, pregnancy and menopause on salivary flow rate, pH and gustatory function.

  11. Dual Exchange in PCN-333: A Facile Strategy to Chemically Robust Mesoporous Chromium Metal-Organic Framework with Functional Groups.

    Science.gov (United States)

    Park, Jihye; Feng, Dawei; Zhou, Hong-Cai

    2015-09-16

    A facile preparation of a mesoporous Cr-MOF, PCN-333(Cr) with functional group, has been demonstrated through a dual exchange strategy, involving a sequential ligand exchange and metal metathesis process. After optimization of the exchange system, the functionalized PCN-333(Cr), N3-PCN-333(Cr) shows well maintained crystallinity, porosity, as well as much improved chemical stability. Because of the exceptionally large pores (∼5.5 nm) in PCN-333(Cr), a secondary functional moiety, Zn-TEPP with a size of 18 Å × 18 Å, has been successfully clicked into the framework. In this article, we have also analyzed kinetics and thermodynamics during dual exchange process, showing our attempts to interpret the exchange event in the PCN-333. Our findings not only provide a highly stable mesoporous Cr-MOF platform for expanding MOF-based applications, but also suggest a route to functionalized Cr-MOF which may have not been achievable through conventional approaches.

  12. Transport of bacteriophage PRD1 through saturated clean sand columns as a function of pH and ionic strength

    Science.gov (United States)

    Sadeghi, G.; Schijven, J. F.; Hassanizadeh, S. M.; Behrends, T.; Gerritse, J.

    2010-12-01

    Groundwater is a major source for drinking water, because of its good microbial quality in its natural state as compared with fresh surface water. Nevertheless, it may be contaminated with pathogenic microorganisms, especially viruses, and that may hamper drinking water production. The two most significant processes controlling virus mobility in the subsurface environment are virus attachment and inactivation. Based on previous studies, many factors have been identified that impact these processes, among them, pH and ionic strength (IS) seem to have the largest influence on virus removal. The objective of this work was to investigate the effects of pH and IS on virus removal in saturated porous media. In addition, it was the objective to determine quantitative relations for these effects. In order to do so, a systematic study was conducted in columns with clean sand under saturated conditions at various pH and IS values within the range of field conditions using bacteriophage PRD1 as a model virus. These experiments were conducted in a 50-cm column with clean quartz sand under saturated conditions and various combinations of pH and ionic strength. Values of pH were 5, 6, 7 and 8 and ionic strength values were 1, 10 and 20 mM. Bacteriophage PRD1 was used as a conservative model virus for virus removal. Attachment, detachment and inactivation rate coefficients were determined from fitting the breakthrough curves. Attachment rate coefficients were found to increase with decreasing pH and increasing ionic strength. Results were used to calculate sticking efficiency values and an empirical formula for it as a function of pH and ionic strength was developed. The applicability of this empirical formula at field scale requires further investigation. Effects of pH and ionic strength on the values of the detachment rate coefficients as well as on inactivation rate coefficients of attached virus particles were also determined but required higher certainty to obtain

  13. Functional test of FOOTPRINT pedotransfer functions for the dual-permeability model MACRO

    Science.gov (United States)

    Moeys, J.; Jarvis, N. J.; Stenemo, F.; Hollis, J. M.; Dubus, I. G.; Larsbo, M.; Brown, C. D.; Bromilow, R.; Coquet, Y.; Vachier, P.

    2009-04-01

    Our ability to assess and predict pollution risks for surface waters and groundwater across larger areas (e.g. catchment and regional scales) relies on our capacity to estimate soil physical and hydrological properties and crop characteristics that are generally required as model parameters. ‘Pedotransfer' functions (PTF) can be used to estimate model parameters from more easily available soil survey data. The EU-FP6 European project FOOTPRINT (www.eu-footprint.org) has supported the development of a full set of PTF's to completely parameterise the pesticide fate model MACRO from only easily available site and soil data for a range of European agronomic, climatic and pedological scenarios The work presented here aimed at assessing the performance of the parameterisation procedures developed in the FOOTPRINT project for MACRO, from a functional point of view. We present a comparison of measured and simulated tracer leaching in medium- to long-term (2 months to 2 years) experiments driven by natural-transient rainfall conditions on 41 lysimeters, representing 15 soil types, located in Sweden, UK and France. For each experiment, the only information used to parameterize the model was a soil profile description, in which each horizon is characterized by its thickness, FAO master horizon type, texture class, organic carbon content and bulk density and knowledge of the tillage (till, no-till, harrowed) and cropping practices (crop type, and sowing dates). The average depth of the lysimeters was 1 meter, each profile containing an average of 4.6 horizons. The soil properties covered a large range of textures (1 to 78% clay), organic matter contents (0 to 29%) and bulk densities (550 to 1870 kg.m-3). Simulations were first conducted without any calibration of parameters. In a second step, we conducted simulations where two crop parameters were optimized (root depth and root water uptake efficiency), in order to estimate the impact of errors in the simulated water balance

  14. Dual-peptide-functionalized albumin-based nanoparticles with ph-dependent self-assembly behavior for drug delivery.

    Science.gov (United States)

    Chen, Bin; He, Xiao-Yan; Yi, Xiao-Qing; Zhuo, Ren-Xi; Cheng, Si-Xue

    2015-07-22

    Drug delivery has become an important strategy for improving the chemotherapy efficiency. Here we developed a multifunctionalized nanosized albumin-based drug-delivery system with tumor-targeting, cell-penetrating, and endolysosomal pH-responsive properties. cRGD-BSA/KALA/DOX nanoparticles were fabricated by self-assembly through electrostatic interaction between cell-penetrating peptide KALA and cRGD-BSA, with cRGD as a tumor-targeting ligand. Under endosomal/lysosomal acidic conditions, the changes in the electric charges of cRGD-BSA and KALA led to the disassembly of the nanoparticles to accelerate intracellular drug release. cRGD-BSA/KALA/DOX nanoparticles showed an enhanced inhibitory effect in the growth of αvβ3-integrin-overexpressed tumor cells, indicating promising application in cancer treatments.

  15. Preparation of self-cleaning surfaces with a dual functionality of superhydrophobicity and photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun Ji; Yoon, Hye Soo; Kim, Dae Han [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Kim, Yong Ho, E-mail: yhkim94@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Young Dok, E-mail: ydkim91@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Biorefinery Research Group, Korean Research Institute of Chemical Technology, Daejeon, 306-600 (Korea, Republic of)

    2014-11-15

    Graphical abstract: - Highlights: • Hydrophobic thin film of polydimethylsiloxane was deposited on SiO{sub 2}. • PDMS-coated SiO{sub 2} and TiO{sub 2} photocatalysts were mixed with various ratios. • Both stable superhydrophobicity and photocatalytic activity appeared on a surface. - Abstract: Thin film of polydimethylsiloxane (PDMS) was deposited on SiO{sub 2} nanoparticles by chemical vapor deposition, and SiO{sub 2} became completely hydrophobic after PDMS coating. Mixtures of TiO{sub 2} and PDMS-coated SiO{sub 2} nanoparticles with various relative ratios were prepared, and distributed on glass surfaces, and water contact angles and photocatalytic activities of these surfaces were studied. Samples consisting of TiO{sub 2} and PDMS-coated SiO{sub 2} with a ratio of 7:3 showed a highly stable superhydrophobicity under UV irradiation with a water contact angle of 165° and UV-driven photocatalytic activity for decomposition of methylene blue and phenol in aqueous solution. Our process can be exploited for fabricating self-cleaning surfaces with dual functionality of superhydrophobicity and photocatalytic activity at the same time.

  16. Dual-Functional Energy-Harvesting and Vibration Control: Electromagnetic Resonant Shunt Series Tuned Mass Dampers.

    Science.gov (United States)

    Zuo, Lei; Cui, Wen

    2013-10-01

    This paper proposes a novel retrofittable approach for dual-functional energy-harvesting and robust vibration control by integrating the tuned mass damper (TMD) and electromagnetic shunted resonant damping. The viscous dissipative element between the TMD and primary system is replaced by an electromagnetic transducer shunted with a resonant RLC circuit. An efficient gradient based numeric method is presented for the parameter optimization in the control framework for vibration suppression and energy harvesting. A case study is performed based on the Taipei 101 TMD. It is found that by tuning the TMD resonance and circuit resonance close to that of the primary structure, the electromagnetic resonant-shunt TMD achieves the enhanced effectiveness and robustness of double-mass series TMDs, without suffering from the significantly amplified motion stroke. It is also observed that the parameters and performances optimized for vibration suppression are close to those optimized for energy harvesting, and the performance is not sensitive to the resistance of the charging circuit or electrical load.

  17. Dual Sensory Loss and Depressive Symptoms: The Importance of Hearing, Daily Functioning and Activity Engagement

    Directory of Open Access Journals (Sweden)

    Kim Matthew Kiely

    2013-12-01

    Full Text Available Background: The association between dual sensory loss (DSL and mental health has been well established. However, most studies have relied on self-report data and lacked measures that would enable researchers to examine causal pathways between DSL and depression. This study seeks to extend this research by examining the effects of DSL on mental health, and identify factors that explain the longitudinal associations between sensory loss and depressive symptoms. Methods: Piecewise linear-mixed models were used to analyse 16-years of longitudinal data collected on up to five occasions from 1611 adults (51% men aged between 65 and 103 years. Depressive symptoms were assessed by the Centre for Epidemiological Studies Depression (CES-D. Vision loss (VL was defined by corrected visual acuity greater than 0.3 logMAR in the better eye, blindness or glaucoma. Hearing loss (HL was defined by pure tone average (PTA greater than 25 dB in the better hearing ear. Analyses were adjusted for socio-demographics, medical conditions, lifestyle behaviours, Activities of Daily Living (ADLs, cognitive function, and social engagement. Results: Unadjusted models indicated that higher levels of depressive symptoms were associated with HL (B=1.16, SE=0.33 and DSL (B=2.15, SE=0.39 but not VL. Greater rates of change in depressive symptoms were also evident after the onset of HL (B=0.16, SE=0.06, p

  18. The pheromone frontalin and its dual function in the invasive bark beetle Dendroctonus valens.

    Science.gov (United States)

    Liu, Zhudong; Xu, Bingbing; Miao, Zhenwang; Sun, Jianghua

    2013-07-01

    The red turpentine beetle, Dendroctonus valens LeConte, is one of the most destructive invasive forest pests in China, having killed more than 6 million pines since its first outbreak in 1999. Little is known about D. valens pheromone biology and no aggregation pheromone has yet been identified. Analysis by gas chromatograph/mass spectrometer of volatiles collected from live beetles in China showed that female beetles produce frontalin and males do not. Olfactory assays in the laboratory showed that males were attracted to frontalin at a wide range of concentrations, whereas females were attracted to it at a narrow range of concentrations. In field trials, 3-carene, a monoterpene kairomone from a pine tree selected to host the beetles attracted both sexes, and when frontalin was added, the total number of beetles captured increased by almost 200%. However, increasing concentrations of frontalin significantly decreased the percentage of female beetles trapped. These results suggest a new role of frontalin as an aggregation pheromone in addition to a female-produced sex pheromone, which was previously shown in a North American population. The dual functions of the pheromone frontalin produced by D. valens females, as well as its ecological significance for overcoming host resistance, are discussed.

  19. First wall fabrication of 1/3 scale china dual functional lithium lead blanket

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Bo, E-mail: bo.huang@fds.org.cn [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Zhai, Yutao [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Zhang, Junyu [University of Science and Technology of China, Hefei, Anhui 230027 (China); Li, Chunjing; Wu, Qingsheng [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Huang, Qunying [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); University of Science and Technology of China, Hefei, Anhui 230027 (China)

    2014-10-15

    Highlights: • RAFM rectangular tubes were fabricated by cold drawing, and the dimensional accuracy and mechanical properties of rectangular tubes were tested. • Rectangular tubes were bent by rotary bending, and milled plates were curved by molding. Its accuracy meets the requirement for TBM assembly. • FW were pre-sealed by electron beam welding, and assembled by hot isostatic pressing–diffusion bonding. • The as-HIPed FW mock-up was tested by optical observation and X-ray detection, it revealed obviously that the tubes and plates were bonded well. - Abstract: The dual functional lithium lead blanket is chosen as one of the candidate blankets for China fusion reactor, for its advantages of tritium breeding and good heat exchange performance. As one of the most important components of the blanket, the first wall (FW) is assembled with China low activation martensitic (CLAM) rectangular tubes and plates by hot isostatic pressing (HIP)–diffusion bonding (DB). In this work, the rectangular tube fabrication and FW assembly were carried out in order to verify the feasibility of the FW fabrication scheme. The mechanical property and dimensional accuracy of CLAM rectangular tubes were tested, the microstructure observation and non-destructive detection revealed the sound of the FW mock-up, and the reliability of the FW mock-ups is under evaluation.

  20. Performance Investigation and Structure Optimization of a Flat Dual-Function Solar Collector

    Directory of Open Access Journals (Sweden)

    Jinwei Ma

    2015-01-01

    Full Text Available The performance of a dual-function solar collector (DFSC that can work as either water heater or air heater depending on seasonal requirement is investigated via both experimental and numerical approaches in this paper. The numerical results are well consistent with the experimental results. Daily efficiency of the thermosiphon system with DFSC is more than 55% in water heating mode and the instantaneous air heating efficiency of the collector reaches 60%. The effects of inner parameters on the thermal efficiency of the collector are analyzed by numerical simulations of the operation of DFSC in two working modes. It is found that the depths of the two air channels in DFSC have an optimal range suitable for both working modes. The thickness of back insulation should be no less than 0.06 m to prevent heat loss via backboard, and the diameter and number of copper tubes show notable effect on the efficiency of DFSC in water heating mode but slight effect in air heating mode.

  1. Chemically modified inulin microparticles serving dual function as a protein antigen delivery vehicle and immunostimulatory adjuvant.

    Science.gov (United States)

    Gallovic, Matthew D; Montjoy, Douglas G; Collier, Michael A; Do, Clement; Wyslouzil, Barbara E; Bachelder, Eric M; Ainslie, Kristy M

    2016-03-01

    To develop a new subunit vaccine adjuvant, we chemically modified a naturally-occurring, immunostimulatory inulin polysaccharide to produce an acid-sensitive biopolymer (acetalated inulin, Ace-IN). Various hydrophobic Ace-IN polymers were formed into microparticles (MPs) by oil-in-water emulsions followed by solvent evaporation These Ace-IN MPs possessed tunable degradation characteristics that, unlike polyesters used in FDA-approved microparticulate formulations, had only pH-neutral hydrolytic byproducts. Macrophages were passively targeted with cytocompatible Ace-IN MPs. TNF-α production by macrophages treated with Ace-IN MPs could be altered by adjusting the polymers' chemistry. Mice immunized with Ace-IN MPs encapsulating a model ovalbumin (OVA) antigen showed higher production of anti-OVA IgG antibody levels relative to soluble antigen. The antibody titers were also comparable to an alum-based formulation. This proof-of-concept establishes the potential for chemically-modified inulin MPs to simultaneously enable dual functionality as a stimuli-controlled antigen delivery vehicle and immunostimulatory adjuvant.

  2. Experimental determination of struvite dissolution and precipitation rates as a function of pH

    Energy Technology Data Exchange (ETDEWEB)

    Roncal-Herrero, T., E-mail: roncal@lmtg.obs-mip.fr [School of Earth and Environment, University of Leeds, LS2 9JT (United Kingdom); Oelkers, E.H. [GET-Universite Paul Sabatier-CNRS-IRD-OMP, 14 av. Edouard Belin, 31400 Toulouse (France)

    2011-05-15

    Highlights: > Struvite was dissolved and precipitated in closed-system reactors. > Experiments were performed at 25 deg. C and 7.76 < pH < 10.65. > Aqueous fluids rapidly equilibrate with struvite. > Struvite solubilities and dissolution and precipitation rates were retrieved. > Results support use of struvite as a renewable fertilizer. - Abstract: Struvite (MgNH{sub 4}PO{sub 4}.6H{sub 2}O) was dissolved and precipitated in closed-system reactors at 25 deg. C and 7.76 < pH < 10.65. Reactive fluid Mg and P concentrations attained a stationary-state after {approx}10 h in all experiments. The temporal variation of these concentrations was evaluated to retrieve struvite solubilities, and dissolution and precipitation rates. Resulting struvite solubilities are consistent with an equilibrium constant for the reaction: MgNH{sub 4}PO{sub 4}.6H{sub 2}O{r_reversible}Mg{sup 2+}+NH{sub 4}{sup +}+PO{sub 4}{sup 3-}+6H{sub 2}O of 10{sup -13.24{+-}0.5}, which is similar to values previously reported in the literature. Measured struvite dissolution and precipitation rates (r) are found to be consistent with r=r{sub +}(1-exp(A/(2RT))) where r{sub +} symbolizes the forward dissolution rate, A refers to the chemical affinity of the dissolution reaction, R designates the gas constant, and T represents absolute temperature. Values of r{sub +} are found to be independent of pH and equal to 10{sup -12.85{+-}0.15} mol/cm{sup 2}/s in initially NH{sub 4}-free reactive fluids. The presence of 0.06 mol/kg NH{sub 4} in the initial reactive fluid led to non-stoichiometric element release interpreted to stem from the precipitation of a NH{sub 4}-rich phosphate phase. Use of measured rates in geochemical modeling calculations indicate that both undersaturated and supersaturated aqueous fluids will rapidly equilibrate with struvite, supporting its potential use as a renewable fertilizer.

  3. Combining bifunctional chelator with (3 + 2)-cycloaddition approaches: synthesis of dual-function technetium complexes.

    Science.gov (United States)

    Braband, Henrik; Imstepf, Sebastian; Benz, Michael; Spingler, Bernhard; Alberto, Roger

    2012-04-02

    A new concept for the synthesis of dual-functionalized technetium (Tc) compounds is presented, on the basis of the reactivity of fac-{Tc(VII)O(3)}(+) complexes. The concept combines the "classical" bifunctional chelator (BFC) approach with the new ligand centered labeling strategy of fac-{TcO(3)}(+) complexes with alkenes ((3 + 2)-cycloaddition approach). To evidence this concept, fac-{(99)TcO(3)}(+) model complexes containing functionalized 1,4,7-triazacyclononane (tacn) derivatives N-benzyl-2-(1,4,7-triazonan-1-yl)acetamide (tacn-ba) and 2,2',2″-(1,4,7-triazonane-1,4,7-triyl)triacetic acid (nota·3H) were synthesized and characterized. Whereas [(99)TcO(3)(tacn-ba)](+) [2](+) can be synthesized following a established oxidation procedure starting from the Tc(V) complex [(99)TcO(glyc)(tacn-ba)](+) [1](+), a new synthetic pathway for the synthesis of [(99)TcO(3)(nota)](2-) [5](2-) had to be developed, starting from [(99)Tc(nota·3H)(CO)(3)](+) [4](+) and using sodium perborate tetrahydrate (NaBO(3)·4H(2)O) as oxidizing reagent. While [(99)TcO(3)(nota)](2-) [5](2-) is a very attractive candidate for the development of trisubstituted novel multifunctional radioprobes, (3 + 2)-cycloaddition reactions of [(99)TcO(3)(tacn-ba)](+) [2](+) with 4-vinylbenzenesulfonate (styrene-SO(3)(-)) demonstrated the suitability of monosubstituted tacn derivatives for the new mixed "BFC-(3 + 2)-cycloaddition" approach. Kinetic studies of this reaction lead to the conclusion that the alteration of the electronic structure of the nitrogen donors by, e.g., alkylation can be used to tune the rate of the (3 + 2)-cycloaddition.

  4. Distinct functions of the dual leucine zipper kinase depending on its subcellular localization.

    Science.gov (United States)

    Wallbach, Manuel; Duque Escobar, Jorge; Babaeikelishomi, Rohollah; Stahnke, Marie-Jeannette; Blume, Roland; Schröder, Sabine; Kruegel, Jenny; Maedler, Kathrin; Kluth, Oliver; Kehlenbach, Ralph H; Miosge, Nicolai; Oetjen, Elke

    2016-04-01

    The dual leucine zipper kinase DLK induces β-cell apoptosis by inhibiting the transcriptional activity conferred by the β-cell protective transcription factor cAMP response element binding protein CREB. This action might contribute to β-cell loss and ultimately diabetes. Within its kinase domain DLK shares high homology with the mixed lineage kinase (MLK) 3, which is activated by tumor necrosis factor (TNF) α and interleukin (IL)-1β, known prediabetic signals. In the present study, the regulation of DLK in β-cells by these cytokines was investigated. Both, TNFα and IL-1β induced the nuclear translocation of DLK. Mutations within a putative nuclear localization signal (NLS) prevented basal and cytokine-induced nuclear localization of DLK and binding to the importin receptor importin α, thereby demonstrating a functional NLS within DLK. DLK NLS mutants were catalytically active as they phosphorylated their down-stream kinase c-Jun N-terminal kinase to the same extent as DLK wild-type but did neither inhibit CREB-dependent gene transcription nor transcription conferred by the promoter of the anti-apoptotic protein BCL-xL. In addition, the β-cell apoptosis-inducing effect of DLK was severely diminished by mutation of its NLS. In a murine model of prediabetes, enhanced nuclear DLK was found. These data demonstrate that DLK exerts distinct functions, depending on its subcellular localization and thus provide a novel level of regulating DLK action. Furthermore, the prevention of the nuclear localization of DLK as induced by prediabetic signals with consecutive suppression of β-cell apoptosis might constitute a novel target in the therapy of diabetes mellitus.

  5. Prostate stem cell antigen-targeted nanoparticles with dual functional properties: in vivo imaging and cancer chemotherapy

    Directory of Open Access Journals (Sweden)

    Gao X

    2012-07-01

    Full Text Available Xin Gao,1,* Yun Luo,1,* Yuanyuan Wang,1,* Jun Pang,1 Chengde Liao,2 Hanlun Lu,3 Youqiang Fang11Department of Urology, The Third Affiliated Hospital, 2Department of Radiology, The Second Affiliated Hospital, Sun Yat-Sen University, 3Materials Science Institute of Zhongshan University, Guangzhou, China*These authors contributed equally to this workBackground: We designed dual-functional nanoparticles for in vivo application using a modified electrostatic and covalent layer-by-layer assembly strategy to address the challenge of assessment and treatment of hormone-refractory prostate cancer.Methods: Core-shell nanoparticles were formulated by integrating three distinct functional components, ie, a core constituted by poly(D,L-lactic-co-glycolic acid, docetaxel, and hydrophobic superparamagnetic iron oxide nanocrystals (SPIONs, a multilayer shell formed by poly(allylamine hydrochloride and two different sized poly(ethylene glycol molecules, and a single-chain prostate stem cell antigen antibody conjugated to the nanoparticle surface for targeted delivery.Results: Drug release profiles indicated that the dual-function nanoparticles had a sustained release pattern over 764 hours, and SPIONs could facilitate the controlled release of the drug in vitro. The nanoparticles showed increased antitumor efficiency and enhanced magnetic resonance imaging in vitro through targeted delivery of docetaxel and SPIONs to PC3M cells. Moreover, in nude mice bearing PC3M xenografts, the nanoparticles provided MRI negative contrast enhancement, as well as halting and even reversing tumor growth during the 76-day study duration, and without significant systemic toxicity. The lifespan of the mice treated with these targeted dual-function nanoparticles was significantly increased (Chi-square = 22.514, P < 0.0001.Conclusion: This dual-function nanomedical platform may be a promising candidate for tumor imaging and targeted delivery of chemotherapeutic agents in vivo

  6. Dual regulation of the native ClC-K2 chloride channel in the distal nephron by voltage and pH.

    Science.gov (United States)

    Pinelli, Laurent; Nissant, Antoine; Edwards, Aurélie; Lourdel, Stéphane; Teulon, Jacques; Paulais, Marc

    2016-09-01

    ClC-K2, a member of the ClC family of Cl(-) channels and transporters, forms the major basolateral Cl(-) conductance in distal nephron epithelial cells and therefore plays a central role in renal Cl(-) absorption. However, its regulation remains largely unknown because of the fact that recombinant ClC-K2 has not yet been studied at the single-channel level. In the present study, we investigate the effects of voltage, pH, Cl(-), and Ca(2+) on native ClC-K2 in the basolateral membrane of intercalated cells from the mouse connecting tubule. The ∼10-pS channel shows a steep voltage dependence such that channel activity increases with membrane depolarization. Intracellular pH (pHi) and extracellular pH (pHo) differentially modulate the voltage dependence curve: alkaline pHi flattens the curve by causing an increase in activity at negative voltages, whereas alkaline pHo shifts the curve toward negative voltages. In addition, pHi, pHo, and extracellular Ca(2+) strongly increase activity, mainly because of an increase in the number of active channels with a comparatively minor effect on channel open probability. Furthermore, voltage alters both the number of active channels and their open probability, whereas intracellular Cl(-) has little influence. We propose that changes in the number of active channels correspond to them entering or leaving an inactivated state, whereas modulation of open probability corresponds to common gating by these channels. We suggest that pH, through the combined effects of pHi and pHo on ClC-K2, might be a key regulator of NaCl absorption and Cl(-)/HCO3 (-) exchange in type B intercalated cells.

  7. Multivariate optimization and simultaneous determination of hydride and non-hydride-forming elements in samples of a wide pH range using dual-mode sample introduction with plasma techniques: application on leachates from cement mortar material.

    Science.gov (United States)

    Mulugeta, Mesay; Wibetoe, Grethe; Engelsen, Christian J; Asfaw, Alemayehu

    2009-02-01

    Analytical methods have been developed for the simultaneous determination of hydride-forming (As, Sb) and non-hydride-forming (Cr, Mo, V) elements in aqueous samples of a wide pH range (pH 3-13). The methods used dual-mode (DM) sample introduction with ICP-AES and ICP-MS instruments. The effect of selected experimental variables, i.e., sample pH and concentrations of HNO(3), thiourea, and NaBH(4), were studied in a multivariate way using face-centered central composite design (FC-CCD). Compromised optimum values of the experimental parameters were identified using a response optimizer. The statistically found optimum values were verified experimentally. The methods provided improved sensitivities for the hydride-forming elements compared with the respective conventional nebulization (Neb) systems by factors of 67 (As) and 64 (Sb) for ICP-AES and 36 (As) and 54 (Sb) for ICP-MS. Slight sensitivity improvements were also observed for the non-hydride-forming elements. The limits of detection (LOD) of As and Sb were lowered, respectively, to 0.8 and 0.9 microg L(-1) with the DM-ICP-AES system and to 0.01 and 0.02 microg L(-1) with the DM-ICP-MS system. The short-term stabilities of both methods were between 2.1 and 5.4%. The methods were applied for the analysis of leachates of a cement mortar material prepared in the pH range 3-13. The elemental concentration of the leachates determined by the two DM methods were statistically compared with the values obtained from Neb-ICP-MS analysis; the values showed good agreement at the 95% confidence level. Quantitative spike recoveries were obtained for the analytes from most of the leachates using both DM methods.

  8. Predicting Thermodynamic Behaviors of Non-Protein Amino Acids as a Function of Temperature and pH.

    Science.gov (United States)

    Kitadai, Norio

    2016-03-01

    Why does life use α-amino acids exclusively as building blocks of proteins? To address that fundamental question from an energetic perspective, this study estimated the standard molal thermodynamic data for three non-α-amino acids (β-alanine, γ-aminobutyric acid, and ε-aminocaproic acid) and α-amino-n-butyric acid in their zwitterionic, negative, and positive ionization states based on the corresponding experimental measurements reported in the literature. Temperature dependences of their heat capacities were described based on the revised Helgeson-Kirkham-Flowers (HKF) equations of state. The obtained dataset was then used to calculate the standard molal Gibbs energies (∆G (o)) of the non-α-amino acids as a function of temperature and pH. Comparison of their ∆G (o) values with those of α-amino acids having the same molecular formula showed that the non-α-amino acids have similar ∆G (o) values to the corresponding α-amino acids in physiologically relevant conditions (neutral pH, acidic and alkaline pH, the non-α-amino acids are thermodynamically more stable than the corresponding α-ones over a broad temperature range. These results suggest that the energetic cost of synthesis is not an important selection pressure to incorporate α-amino acids into biological systems.

  9. Analysis of velocity-coupled response function data from the dual rotating valve. [combustion stability of solid rocket propellants

    Science.gov (United States)

    Brown, R. S.; Waugh, R. C.

    1980-01-01

    The results of a re-evaluation of the propellant combustion data obtained using the dual valve approach for measuring velocity-coupling characteristics of solid propellants are presented. Data analysis and testing procedures are described. The velocity response is compared to pressure-coupled response data within the context of thermal wave response theory. This comparison shows important inconsistencies which cast doubt on inferring the velocity response from pressure-coupled response functions.

  10. Thermo-Mechanical Analyses of the High Heat Flux Component for ITER Dual Functional Lithium Lead Test Blanket Module

    Institute of Scientific and Technical Information of China (English)

    CHEN Hongli; BAI Yunqing

    2009-01-01

    The finite element code ANSYS is used to calculate the temperature and stress distributions for the first wall of DFLL-TBM (dual functional lithium lead-test blanket module),for testing in ITER. Preliminary analyses indicate that not only the low temperature design rules,the well-known 3Sm rules, are satisfied for the first wall, but the additional high temperature structural design criteria for the creep damage limits and creep-ratcheting limits are met as well.

  11. Influence of pH on the Structure and Function of Kiwi Pectin Methylesterase Inhibitor.

    Science.gov (United States)

    Bonavita, Alessandro; Carratore, Vitale; Ciardiello, Maria Antonietta; Giovane, Alfonso; Servillo, Luigi; D'Avino, Rossana

    2016-07-27

    Pectin methylesterase is a pectin modifying enzyme that plays a key role in plant physiology. It is also an important quality-related enzyme in plant-based food products. The pectin methylesterase inhibitor (PMEI) from kiwifruit inhibits this enzyme activity and is widely used as an efficient tool for research purposes and also recommended in the context of fruit and vegetable processing. Using several methodologies of protein biochemistry, including circular dichroism and fluorescence spectroscopy, chemical modifications, direct protein-sequencing, enzyme activity, and bioinformatics analysis of the crystal structure, this study demonstrates that conformational changes occur in kiwi PMEI by the pH rising over 6.0 bringing about structure loosening, exposure, and cleavage of a natively buried disulfide bond, unfolding and aggregation, ultimately determining the loss of ability of kiwi PMEI to bind and inhibit PME. pH-induced structural changes are prevented when PMEI is already engaged in complex or is in a solution of high ionic strength.

  12. Ambulatory measurement of oesophageal function: clinical use of a new pH and motility recording system.

    Science.gov (United States)

    Barham, C P; Gotley, D C; Miller, R; Mills, A; Alderson, D

    1992-10-01

    Conventional oesophageal manometric studies are open to criticism in that they take place on fasted immobile subjects in the artificial setting of a motility laboratory. A new 24-h pH and motility recording system combined with computerized data analysis was used to study patients with gastro-oesophageal reflux disease and oesophageal motor abnormalities under ambulant conditions. Acid reflux episodes were found to be precipitated by a variety of events with recognizable pressure patterns. Acid clearance abnormalities were demonstrated in patients with erosive oesophagitis but were confined to those with abnormal oesophageal motor function. Improved diagnostic accuracy was demonstrated in the recognition of oesophageal motor disorders.

  13. Thermally Cured Dual Functional Viologen-Based All-in-One Electrochromic Devices with Panchromatic Modulation.

    Science.gov (United States)

    Kao, Sheng-Yuan; Lu, Hsin-Che; Kung, Chung-Wei; Chen, Hsin-Wei; Chang, Ting-Hsiang; Ho, Kuo-Chuan

    2016-02-17

    Vinyl benzyl viologen (VBV) was synthesized and utilized to obtain all-in-one thermally cured electrochromic devices (ECDs). The vinyl moiety of VBV monomer could react with methyl methacrylate (MMA) to yield bulky VBV/poly(methyl methacrylate) (PMMA) chains and even cross-linked network without the assistance of additional cross-linker. Both the bulky VBV/PMMA chains and the resulting polymer network can hinder the aggregation of the viologens and reduce the possibility of dimerization, rendering enhanced cycling stability. Large transmittance changes (ΔT) over 60% at both 570 and 615 nm were achieved when the VBV-based ECD was switched from 0 V to a low potential bias of 0.5 V. Ultimately, the dual functional of VBV molecules, serving simultaneously as a promising electrochromic material and a cross-linker, is fully utilized in the proposed electrochromic system, making its fabrication process much easier. Negligible decays in ΔT at both wavelengths were observed for the cured ECD after being subjected to 1000 repetitive cycles, while 17.1% and 22.0% decays were noticed at 570 and 615 nm, respectively, for the noncured ECD. In addition, the low voltage-driven feature of the VBV-based ECD enables it to be incorporated with phenyl viologen (PV), further expanding the absorption range of the ECD. Panchromatic characteristic of the proposed PV/VBV-based ECD was demonstrated while exhibiting ΔT over 60% at both wavelengths. Only 5.3% and 6.9% decays, corresponding at 570 and 615 nm, respectively, were observed in the PV/VBV-based ECD after 10 000 continuous cycles at bleaching/coloring voltages of 0/0.5 V with an interval of 10 s for both bleaching and coloring processes.

  14. Fabrication, characterization, and functionalization of dual carbon electrodes as probes for scanning electrochemical microscopy (SECM).

    Science.gov (United States)

    McKelvey, Kim; Nadappuram, Binoy Paulose; Actis, Paolo; Takahashi, Yasufumi; Korchev, Yuri E; Matsue, Tomokazu; Robinson, Colin; Unwin, Patrick R

    2013-08-01

    Dual carbon electrodes (DCEs) are quickly, easily, and cheaply fabricated by depositing pyrolytic carbon into a quartz theta nanopipet. The size of DCEs can be controlled by adjusting the pulling parameters used to make the nanopipet. When operated in generation/collection (G/C) mode, the small separation between the electrodes leads to reasonable collection efficiencies of ca. 30%. A three-dimensional finite element method (FEM) simulation is developed to predict the current response of these electrodes as a means of estimating the probe geometry. Voltammetric measurements at individual electrodes combined with generation/collection measurements provide a reasonable guide to the electrode size. DCEs are employed in a scanning electrochemical microscopy (SECM) configuration, and their use for both approach curves and imaging is considered. G/C approach curve measurements are shown to be particularly sensitive to the nature of the substrate, with insulating surfaces leading to enhanced collection efficiencies, whereas conducting surfaces lead to a decrease of collection efficiency. As a proof-of-concept, DCEs are further used to locally generate an artificial electron acceptor and to follow the flux of this species and its reduced form during photosynthesis at isolated thylakoid membranes. In addition, 2-dimensional images of a single thylakoid membrane are reported and analyzed to demonstrate the high sensitivity of G/C measurements to localized surface processes. It is finally shown that individual nanometer-size electrodes can be functionalized through the selective deposition of platinum on one of the two electrodes in a DCE while leaving the other one unmodified. This provides an indication of the future versatility of this type of probe for nanoscale measurements and imaging.

  15. Dual functions of polyvinyl alcohol (PVA): fabricating particles and electrospinning nanofibers applied in controlled drug release

    Energy Technology Data Exchange (ETDEWEB)

    Qin Xiaohong, E-mail: xhqin@dhu.edu.cn [Donghua University, College of Textiles (China); Wu Dequn; Chu Chihchang, E-mail: cc62@cornell.edu [Cornell University, Department of Fiber Science and Apparel Design (United States)

    2013-01-15

    The fabrication of submicron size microsphere from 8-Phe-4 poly(ester amide) (PEA) using polyvinyl alcohol (PVA) as the emulsion was reported. The biodegradable microspheres were prepared by an oil-in-water emulsion/solvent evaporation technique, and PVA was used as the emulsion. Furthermore, the emulsion PVA was electrospun into nanofibrous mats, and 8-Phe-4 PEA microspheres were entrapped in the resultant mats. The dual functions of PVA to fabricate ideal nanofibrous mats which can entrap microspheres in them and to obtain 8-Phe-4 microspheres as emulsion in their potential application were demonstrated. The anti-cancer drug doxorubicin (DOX) was encapsulated in the 8-Phe-4 amino acid-based PEA microspheres and the entrapment efficiency is almost 100 %. At the same time, the DOX can be controlled released in PBS solution and in {alpha}-chymotrypsin solution. The cytotoxicity of PVA, PVA mats-entrapped 8-Phe-4 microspheres and PVA mats-entrapped DOX-loaded 8-Phe-4 microspheres, was investigated. Hela cells were used to test the cytotoxicity of the DOX that released from the PVA mats-entrapped DOX-loaded 8-Phe-4 microspheres for 2 days, and the cell viability is below 30 % when the 8-Phe-4 microspheres concentration is 1 mg/mL. It demonstrated that the PVA mats-entrapped DOX-loaded 8-Phe-4 microspheres have a potential biomedical application.Graphical AbstractThe table of contents: DOX-loaded microspheres can be encapsulated in the PVA fibers by electrospinning and the DOX can be controlled released from the PVA fibers-entrapped microspheres. MTT assay indicated that the more than 70 % Hela cells were killed by the DOX released from DOX-loaded microspheres encapsulated in the PVA after 48 h.

  16. Assessment of left ventricular function and mass in dual-source computed tomography coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Christoph J., E-mail: c.jensen@contilia.d [Department of Cardiology and Angiology, Elisabeth Hospital, Essen (Germany); Jochims, Markus [Department of Cardiology and Angiology, Elisabeth Hospital, Essen (Germany); Hunold, Peter; Forsting, Michael; Barkhausen, Joerg [Department of Diagnostic and Interventional Radiology and Neuroradiology, University of Essen (Germany); Sabin, Georg V.; Bruder, Oliver [Department of Cardiology and Angiology, Elisabeth Hospital, Essen (Germany); Schlosser, Thomas [Department of Diagnostic and Interventional Radiology and Neuroradiology, University of Essen (Germany)

    2010-06-15

    Purpose: To quantify left ventricular (LV) function and mass (LVM) derived from dual-source computed tomography (DSCT) and the influence of beta-blocker administration compared to cardiac magnetic resonance imaging (CMR). Methods: Thirty-two patients undergoing cardiac DSCT and CMR were included, where of fifteen received metoprolol intravenously before DSCT. LV parameters were calculated by the disc-summation method (DSM) and by a segmented region-growing algorithm (RGA). All data sets were analyzed by two blinded observers. Interobserver agreement was tested by the intraclass correlation coefficient. Results.: 1. Using DSM LV parameters were not statistically different between DSCT and CMR in all patients (DSCT vs. CMR: EF 63 {+-} 8% vs. 64 {+-} 8%, p = 0.47; EDV 136 {+-} 36 ml vs. 138 {+-} 35 ml, p = 0.66; ESV 52 {+-} 21 ml vs. 52 {+-} 22 ml, p = 0.61; SV 83 {+-} 22 ml vs. 87 {+-} 19 ml, p = 0.22; CO 5.4 {+-} 0.9 l/min vs. 5.7 {+-} 1.2 l/min, p = 0.09, LVM 132 {+-} 33 g vs. 132 {+-} 33 g, p = 0.99). 2. In a subgroup of 15 patients beta-blockade prior to DSCT resulted in a lower ejection fraction (EF), stroke volume (SV), cardiac output (CO) and increase in end systolic volume (ESV) in DSCT (EF 59 {+-} 8% vs. 62 {+-} 9%; SV 73 {+-} 17 ml vs. 81 {+-} 15 ml; CO 5.7 {+-} 1.2 l/min vs. 5.0 {+-} 0.8 l/min; ESV 52 {+-} 27 ml vs. 57 {+-} 24 ml, all p < 0.05). 3. Analyzing the RGA parameters LV volumes were not significantly different compared to DSM, whereas LVM was higher using RGA (177 {+-} 31 g vs. 132 {+-} 33 g, p < 0.05). Interobserver agreement was excellent comparing DSM values with best agreement between RGA calculations. Conclusion: Left ventricular volumes and mass can reliably be assessed by DSCT compared to CMR. However, beta-blocker administration leads to statistically significant reduced EF, SV and CO, whereas ESV significantly increases. DSCT RGA reliably analyzes LV function, whereas LVM is overestimated compared to DSM.

  17. Inhibition of HIV Virus by Neutralizing Vhh Attached to Dual Functional Liposomes Encapsulating Dapivirine

    Science.gov (United States)

    Wang, Scarlet Xiaoyan; Michiels, Johan; Ariën, Kevin K.; New, Roger; Vanham, Guido; Roitt, Ivan

    2016-07-01

    efficacy in reducing viral replication in vitro. Thus, dual function liposomes may lead to a novel strategy for the prophylaxis of HIV/AIDS by combining the neutralizing activity of Vhh with antiviral effects of high drug concentrations.

  18. State of charge modeling of lithium-ion batteries using dual exponential functions

    Science.gov (United States)

    Kuo, Ting-Jung; Lee, Kung-Yen; Huang, Chien-Kang; Chen, Jau-Horng; Chiu, Wei-Li; Huang, Chih-Fang; Wu, Shuen-De

    2016-05-01

    A mathematical model is developed by fitting the discharging curve of LiFePO4 batteries and used to investigate the relationship between the state of charge and the closed-circuit voltage. The proposed mathematical model consists of dual exponential terms and a constant term which can fit the characteristics of dual equivalent RC circuits closely, representing a LiFePO4 battery. One exponential term presents the stable discharging behavior and the other one presents the unstable discharging behavior and the constant term presents the cut-off voltage.

  19. AV interval optimization using pressure volume loops in dual chamber pacemaker patients with maintained systolic left ventricular function.

    Science.gov (United States)

    Eberhardt, Frank; Hanke, Thorsten; Fitschen, Joern; Heringlake, Matthias; Bode, Frank; Schunkert, Heribert; Wiegand, Uwe K H

    2012-08-01

    Atrioventricular (AV) interval optimization is often deemed too time-consuming in dual-chamber pacemaker patients with maintained LV function. Thus the majority of patients are left at their default AV interval. To quantify the magnitude of hemodynamic improvement following AV interval optimization in chronically paced dual chamber pacemaker patients. A pressure volume catheter was placed in the left ventricle of 19 patients with chronic dual chamber pacing and an ejection fraction >45 % undergoing elective coronary angiography. AV interval was varied in 10 ms steps from 80 to 300 ms, and pressure volume loops were recorded during breath hold. The average optimal AV interval was 152 ± 39 ms compared to 155 ± 8 ms for the average default AV interval (range 100-240 ms). The average improvement in stroke work following AV interval optimization was 935 ± 760 mmHg/ml (range 0-2,908; p AV interval changes the average stroke work by 207 ± 162 mmHg/ml. AV interval optimization also leads to improved systolic dyssynchrony indices (17.7 ± 7.0 vs. 19.4 ± 7.1 %; p = 0.01). The overall hemodynamic effect of AV interval optimization in patients with maintained LV function is in the same range as for patients undergoing cardiac resynchronization therapy for several parameters. The positive effect of AV interval optimization also applies to patients who have been chronically paced for years.

  20. On Complex Zeros of the q-Potts Partition Function for a Self-dual Family of Graphs

    Science.gov (United States)

    Billiot, J.-M.; Corset, F.; Fontenas, E.

    2010-06-01

    This paper deals with the location of the complex zeros of q-Potts partition function for a class of self-dual graphs. For this class of graphs, as the form of the eigenvalues is known, the regions of the complex plane can be focused on the sets where there is only one dominant eigenvalue in particular containing the positive half plane. Thus, in these regions, the analyticity of the free energy per site can be derived easily. Next, some examples of graphs with their Tutte polynomial having few eigenvalues are given. The case of the cycle with an edge having a high order of multiplicity is presented in detail. In particular, we show that the well known conjecture of Chen et al. is false in the finite case. Furthermore we obtain a sequence of self-dual graphs for which the unit circle does not belong to the accumulation sets of the zeros.

  1. A pH and Redox Dual Responsive 4-Arm Poly(ethylene glycol-block-poly(disulfide histamine Copolymer for Non-Viral Gene Transfection in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Kangkang An

    2014-05-01

    Full Text Available A novel 4-arm poly(ethylene glycol-b-poly(disulfide histamine copolymer was synthesized by Michael addition reaction of poly(ethylene glycol (PEG vinyl sulfone and amine-capped poly(disulfide histamine oligomer, being denoted as 4-arm PEG-SSPHIS. This copolymer was able to condense DNA into nanoscale polyplexes (<200 nm in average diameter with almost neutral surface charge (+(5–10 mV. Besides, these polyplexes were colloidal stable within 4 h in HEPES buffer saline at pH 7.4 (physiological environment, but rapidly dissociated to liberate DNA in the presence of 10 mM glutathione (intracellular reducing environment. The polyplexes also revealed pH-responsive surface charges which markedly increased with reducing pH values from 7.4–6.3 (tumor microenvironment. In vitro transfection experiments showed that polyplexes of 4-arm PEG-SSPHIS were capable of exerting enhanced transfection efficacy in MCF-7 and HepG2 cancer cells under acidic conditions (pH 6.3–7.0. Moreover, intravenous administration of the polyplexes to nude mice bearing HepG2-tumor yielded high transgene expression largely in tumor rather other normal organs. Importantly, this copolymer and its polyplexes had low cytotoxicity against the cells in vitro and caused no death of the mice. The results of this study indicate that 4-arm PEG-SSPHIS has high potential as a dual responsive gene delivery vector for cancer gene therapy.

  2. Function, Type, and Distribution of Teacher Questions in Dual-Language Preschool Read Alouds

    Science.gov (United States)

    Gort, Mileidis; Pontier, Ryan W.; Sembiante, Sabrina F.

    2012-01-01

    This exploratory study investigated the nature and distribution of dual-language preschool teachers' questions across parallel Spanish- and English-medium read-aloud activities. The notions of comprehensible input (Krashen, 1985) and language output (Swain, 1985), along with a reciprocal interaction model of teaching (Cummins, 2000), guided our…

  3. Evidence for a dual function of monocyte-derived mononuclear phagocytes during chronic intestinal inflammation

    DEFF Research Database (Denmark)

    Rivollier, Aymeric Marie Christian; Pool, Lieneke; Frising, Ulrika

    Mononuclear phagocytes derived from tissue-infiltrating monocytes play diverse roles in immunity, ranging from pathogen killing to immune regulation. We and others showed that, upon recruitment to the intestinal mucosa, the differentiation of Ly6Chi monocytes into phagocytes with anti- versus pro...... suggest a dual and time-restricted contribution of MDP during the development and healing phases of the disease....

  4. A Concise Access to C2-Symmetric Chiral 4-Pyrrolidinopyridine Catalysts with Dual Functional Side Chains.

    Science.gov (United States)

    Mishiro, Kenji; Takeuchi, Hironori; Furuta, Takumi; Kawabata, Takeo

    2016-07-01

    A practical method was developed for the preparation of a diastereomeric library of C2-symmetric chiral 4-pyrrolidinopyridine catalysts with dual amide side chains. Use of a racemic precursor is the key to the concise production of catalysts with diverse stereochemisty.

  5. Enhanced Strain in Functional Nanoporous Gold with a Dual Microscopic Length Scale Structure

    NARCIS (Netherlands)

    Detsi, Eric; Punzhin, Sergey; Rao, Jiancun; Onck, Patrick R.; De Hosson, Jeff Th. M.

    2012-01-01

    We have synthesized nanoporous Au with a dual microscopic length scale by exploiting the crystal structure of the alloy precursor. The synthesized mesoscopic material is characterized by stacked Au layers of submicrometer thickness. In addition, each layer displays nanoporosity through the entire bu

  6. (p-ClPhSe)2 Reduces Hepatotoxicity Induced by Monosodium Glutamate by Improving Mitochondrial Function in Rats.

    Science.gov (United States)

    Quines, Caroline B; Chagas, Pietro M; Hartmann, Diane; Carvalho, Nélson R; Soares, Félix A; Nogueira, Cristina W

    2017-02-18

    It is has been demonstrated that mitochondrial dysfunction, oxidative stress and chronic inflammatory process are associated with progress of morbid obesity in human patients. For this reason, the searching for safe and effective antiobesity drugs has been the subject of intense research. In this context, the organic selenium compounds have attracted much attention due to their pharmacological properties, such as antihyperglycemic, antioxidant and anti-inflammatory. The aim of this study was to evaluate the hepatoprotective action of p-chloro-diphenyl diselenide (p-ClPhSe)2 , an organic selenium compound, in a model of obesity induced by monosodium glutamate (MSG) administration in rats. Wistar rats were treated during the first ten postnatal days with MSG (4 g/kg by subcutaneous injections) and received (p-ClPhSe)2 (10 mg/kg, intragastrically) from 90(th) to 97(th) postnatal day. Mitochondrial function, purine content and the levels of proteins involved in apoptotic (poly (ADP-ribose) polymerase (PARP)) and inflammatory processes (inducible nitric oxide synthases (iNOS) and p38) were determined in the liver of rats. The present study demonstrated that postnatal administration of MSG to male rats induced a mitochondrial dysfunction, accompanied by oxidative stress and an increase in the ADP levels, without altering the efficiency of phosphorylation in the liver of adult rats. Furthermore, the MSG administration also induces hepatotoxicity, through an increase in PARP, iNOS and p38 levels. (p-ClPhSe)2 treatment had beneficial effects against mitochondrial dysfunction, oxidative stress and modulated protein markers of apoptosis and inflammation in the liver of MSG-treated rats. This article is protected by copyright. All rights reserved.

  7. Adhesion of alkane as a functional group on muscovite and quartz: dependence on pH and contact time.

    Science.gov (United States)

    Juhl, K M S; Pedersen, C S; Bovet, N; Dalby, K N; Hassenkam, T; Andersson, M P; Okhrimenko, D; Stipp, S L S

    2014-12-09

    The interactions between mineral surfaces and organic molecules in water control many processes in nature and in the production of modern materials. To improve the understanding of fluid-surface interactions, we investigated the interface behavior of quartz and muscovite, a model for clay minerals, in aqueous solutions where the pH and composition were controlled. We used atomic force microscopy (AFM) in chemical force mapping (CFM) mode to measure adhesion using tips functionalized with alkyl, -CH3. By combining adhesion forces measured as a function of pH, with data from streaming potential experiments and DLVO calculations, we were able to determine the surface charge density. We observed increased adhesion between the mineral surface and the hydrophobic tips as the contact time increased from 7 ms to ∼2 s. The diffusion of dissolved ions takes time, and density functional theory (DFT) calculations did not indicate a strong hydration of the mineral surfaces. Therefore, we interpret that the loss of ions from the confined space between the tip and sample is a likely explanation of the correlation between the dwell time and adhesion. The maximum adhesion increase with dwell time for muscovite, i.e., 400 ± 77 pN, was considerably larger than for quartz, 84 ± 15 pN, which fits with the different surface structure and composition of the two minerals. We propose two mechanisms to explain these results: (1) cations that are structured in the solution and on the surface remain associated at the tip-sample interface initially but diffuse away during extended contact time and (2) adventitious carbon, the organic material that comes spontaneously from air and solution, can diffuse to the tip-sample interface during contact. This material decreases the surface energy by aggregating near the alkyl tip and increases adhesion between the tip and sample.

  8. Highly dispersed palladium nanoparticles anchored on UiO-66(NH2) metal-organic framework as a reusable and dual functional visible-light-driven photocatalyst

    Science.gov (United States)

    Shen, Lijuan; Wu, Weiming; Liang, Ruowen; Lin, Rui; Wu, Ling

    2013-09-01

    high dispersion of Pd nanoparticles and their close contact with the matrix, which lead to the enhanced light harvesting and more efficient separation of photogenerated electron-hole pairs. More significantly, the Pd@UiO-66(NH2) could be used for simultaneous photocatalytic degradation of organic pollutants, like methyl orange (MO) and methylene blue (MB), and reduction of Cr(vi) with even further enhanced activity in the binary system, which could be attributed to the synergetic effect between photocatalytic oxidation and reduction by individually consuming photogenerated holes and electrons. This work represents the first example of using the MOFs-based materials as dual functional photocatalyst to remove different categories of pollutants simultaneously. Our finding not only proves great potential for the design and application of MOFs-based materials but also might bring light to new opportunities in the development of new high-performance photocatalysts. Electronic supplementary information (ESI) available: XRD patterns of Pd@UiO-66(NH2) before and after the photocatalytic reduction of Cr(vi) reaction; XPS patterns of Pd@UiO-66(NH2) before and after the photocatalytic reduction of Cr(vi) reaction; BET adsorption-desorption isotherms of UiO-66(NH2) (a) and Pd@UiO-66(NH2) (b); Mott-Schottky plot of UiO-66(NH2) in 0.2 M Na2SO4 aqueous solution (pH = 6.8); a schematic drawing of the structure of UiO-66(NH2) based on the structure of UiO-66. Zirconium-oxygen clusters (green part); N of the free amino groups (blue dots). See DOI: 10.1039/c3nr03153e

  9. Improved ankle and knee control with a dual-channel functional electrical stimulation system in chronic hemiplegia. A case report.

    Science.gov (United States)

    Springer, S; Khamis, S; Laufer, Y

    2014-04-01

    The aim of tis report is to describe the effects of a dual-channel functional electrical stimulation (FES) system applied daily as an orthotic device to the dorsiflexors and hamstrings muscles in a subject with chronic hemiparesis. Prior to the application of FES, the patient's gait was characterized by a footdrop and knee hyperextension during stance. measurements of gait performance were collected before FES application, after a conditioning period of six weeks, and following ten months of daily use. Outcomes included lower limb kinematics and temporal gait measures. The kinematic assessments indicated significant benefits for gait with the dorsiflexors and hamstrings FES, as compared to no stimulation and peroneal FES alone. In addition ot improved ankle control, knee hyperextension was reduced during stance, and the self-selected comfortable gait velocity increased following ten months of daily use. The results of this report suggest that dual-channel FES for the dorsiflexors and hamstrings muscles may affect ankle and knee control beyond that witch can be attributed to peroneal stimulation alone. The positive effects observed in this case study point to the potential of dual-channel FES as a viable treatment options in the rehabilitation of patients with similar impairments.

  10. Managing Student Behavior in Dual Immersion Classrooms: A Study of Class-Wide Function-Related Intervention Teams.

    Science.gov (United States)

    Hansen, Blake D; Caldarella, Paul; Williams, Leslie; Wills, Howard P

    2017-09-01

    Classroom management in dual immersion classrooms includes unique challenges. The teacher must instruct and correct in the L2 language, in which students are beginning learners, and effective classroom management strategies appropriate to the L2 context. Class-Wide Function-Related Intervention Teams (CW-FIT) is a positive classroom management program that teaches social skills and uses group contingencies to improve behavior. The present study examined the ability of French immersion teachers to implement CW-FIT in the L2, including the effects of CW-FIT on teacher praise and reprimand rates and as well as on students' classroom behavior. Social validity was also assessed. A single-subject multiple baseline design with embedded reversals was used to evaluate impact in second-, third-, and fourth-grade dual immersion classrooms. Results indicated that dual immersion teachers were able to implement CW-FIT in L2 with fidelity. The intervention significantly increased teacher praise and improved classroom on-task behavior. Changes in teacher reprimand rates were inconsistent. Students and teachers reported CW-FIT to be socially valid.

  11. Functional properties of protein from frozen mantle and fin of jumbo squid Dosidicus gigas in function of pH and ionic strength.

    Science.gov (United States)

    Rocha-Estrada, J G; Córdova-Murueta, J H; García-Carreño, F L

    2010-10-01

    Functional properties of protein from mantle and fin of the jumbo squid Dosidicus gigas were explained based on microscopic muscle fiber and protein fractions profiles as observed in SDS-PAGE. Fin has higher content of connective tissue and complex fiber arrangement, and we observed higher hardness of fin gels as expected. Myosin heavy chain (MHC) was found in sarcoplasmic, myofibril and soluble-in-alkali fractions of mantle and only in sarcoplasmic and soluble-in-alkali fractions of fin. An additive effect of salt concentration and pH affected the solubility and foaming properties. Fin and mantle proteins yielded similar results in solubility tests, but significant differences occurred for specific pH and concentrations of salt. Foaming capacity was proportional to solubility; foam stability was also affected by pH and salt concentration. Hardness and fracture strength of fin gels were significantly higher than mantle gels; gels from proteins of both tissues reached the highest level in the folding test. Structural and molecular properties, such as MHC and paramyosin solubility, arrangement of muscle fibers and the content of connective tissue were useful to explain the differences observed in these protein properties. High-strength gels can be formed from squid mantle or fin muscle. Fin displayed similar or better properties than mantle in all tests.

  12. Value of evaluating diastolic function with the single-beat E/(e’ × s) obtained by dual doppler echocardiograph in coronary heart disease patients with preserved left ventricular systolic function

    Institute of Scientific and Technical Information of China (English)

    汪晶晶

    2014-01-01

    Objective To assess the value of E/(e’×s)in estimating left ventricular diastolic dysfunction in patients with coronary heart disease by dual Doppler echocardiograph.Methods Seventy-seven consecutive coronary heart disease patients with preserved systolic function underwent echocardiographic study were included.The E,e’and s were obtained by the dual Doppler echocardio-

  13. mathematical model of thermal explosion, the dual variational formulation of nonlinear problem, alternative functional

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    in its plane, and in the circular cylinder unlimited in length.An approximate numerical solution of the differential equation that is included in a nonlinear mathematical model of the thermal explosion enables us to obtain quantitative estimates of combination of determining parameters at which the limit state occurs in areas of not only canonical form. A capability to study of the thermal explosion state can be extended in the context of development of mathematical modeling methods, including methods of model analysis to describe the thermal state of solids.To analyse a mathematical model of the thermal explosion in a homogeneous solid the paper uses a variational approach based on the dual variational formulation of the appropriate nonlinear stationary problem of heat conduction in such a body. This formulation contains two alternative functional reaching the matching values in their stationary points corresponding to the true temperature distribution. This functional feature allows you to not only get an approximate quantitative estimate of the combination of parameters that determine the thermal explosion state, but also to find the greatest possible error in such estimation.

  14. Preparation of dual-function starch-based flocculants for the simultaneous removal of turbidity and inhibition of Escherichia coli in water.

    Science.gov (United States)

    Huang, Mu; Wang, Yawen; Cai, Jun; Bai, Junfeng; Yang, Hu; Li, Aimin

    2016-07-01

    A dual-function starch-based flocculant, carboxymethyl-starch-graft-aminomethylated-polyacrylamide (CMS-g-APAM), was designed and prepared by a simple method. The structure and solution properties of CMS-g-APAM were characterized by fourier transform infrared spectroscopy, (1)H nuclear magnetic resonance, and zeta-potential measurements. CMS-g-APAM was then applied to flocculate a kaolin suspension and an Escherichia coli suspension as well as a combination thereof. At suitable pH conditions, the starch-based flocculant not only effectively removed turbidity but it also disrupted bacterial cells. Interpretation of the zeta potential and floc properties (floc size and two-dimensional fractal structure) showed that, for the aforementioned three effluents, simple charge neutralization was the dominant mechanism of flocculation in acidic medium whereas an additional contribution from a patching effect was determined under neutral conditions. Three-dimensional excitation-emission matrix spectra and direct surface morphology observation under a scanning electron microscope both illuminated that the antibacterial activity of CMS-g-APAM involved the partial destruction of the cell wall of Escherichia coli. The mechanism can be attributed to the effective interaction between the tertiary amine group of the flocculant and the negatively charged surface of the bacterium.

  15. Effect of glycerol content and pH value of film-forming solution on the functional properties of protein-based edible films

    Directory of Open Access Journals (Sweden)

    Nemet Nevena T.

    2010-01-01

    Full Text Available The work is concerned with the effects of glycerol content and pH value of film forming solution on the functional properties of protein-based films. The films were produced of chicken breast proteins, dissolved under either acidic (pH 3 or alkaline (pH 11 conditions, with different concentrations of glycerol (35%, 50% and 65% w/w of protein content. Glycerol content affected significantly mechanical properties, water vapor permeability, color at pH 3 and film solubility (p<0.05. The pH value had significant influence on light transmission, color, transparency and film solubility (p<0.05. Considering the results of mechanical properties and film solubility, the obtained films are in the acceptable range for the use as a packaging material. It was estimated that water vapor permeability, color, light transmission and transparency need to be improved for the application.

  16. Primal-dual Interior-point Algorithms for Second-order Cone Optimization Based on a New Parametric Kernel Function

    Institute of Scientific and Technical Information of China (English)

    Yan Qin BAI; Guo Qiang WANG

    2007-01-01

    A class of polynomial primal-dual interior-point algorithms for second-order cone optimization based on a new parametric kernel function, with parameters p and q, is presented. Its growth term is between linear and quadratic. Some new tools for the analysis of the algorithms are proposed.The complexity bounds of O(√Nlog N log N/ε) for large-update methods and O(√Nlog N/ε) for smallupdate methods match the best known complexity bounds obtained for these methods. Numerical tests demonstrate the behavior of the algorithms for different results of the parameters p and q.

  17. Determination of liquid's molecular interference function based on X-ray diffraction and dual-energy CT in security screening.

    Science.gov (United States)

    Zhang, Li; YangDai, Tianyi

    2016-08-01

    A method for deriving the molecular interference function (MIF) of an unknown liquid for security screening is presented. Based on the effective atomic number reconstructed from dual-energy computed tomography (CT), equivalent molecular formula of the liquid is estimated. After a series of optimizations, the MIF and a new effective atomic number are finally obtained from the X-ray diffraction (XRD) profile. The proposed method generates more accurate results with less sensitivity to the noise and data deficiency of the XRD profile.

  18. Tailoring electron energy distribution functions through energy confinement in dual radio-frequency driven atmospheric pressure plasmas

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, C.; Waskoenig, J. [Centre for Plasma Physics, School of Maths and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Gans, T. [Centre for Plasma Physics, School of Maths and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom)

    2012-10-08

    A multi-scale numerical model based on hydrodynamic equations with semi-kinetic treatment of electrons is used to investigate the influence of dual frequency excitation on the effective electron energy distribution function (EEDF) in a radio-frequency driven atmospheric pressure plasma. It is found that variations of power density, voltage ratio, and phase relationship provide separate control over the electron density and the mean electron energy. This is exploited to directly influence both the phase dependent and time averaged effective EEDF. This enables tailoring the EEDF for enhanced control of non-equilibrium plasma chemical kinetics at ambient pressure and temperature.

  19. Practice-related optimization and transfer of executive functions: a general review and a specific realization of their mechanisms in dual tasks.

    Science.gov (United States)

    Strobach, Tilo; Salminen, Tiina; Karbach, Julia; Schubert, Torsten

    2014-11-01

    Improvements in performing demanding and complex task situations are typically related to the optimization of executive functions and efficient behavioral control. The present study systematizes and reviews the optimization of different executive function types: Shifting, Inhibition, Updating, and Dual tasking. In particular, we focus on optimisations of these functions with training and on transfer effects of related training skills to non-trained situations. The aim of the study's empirical part (see also Appendix) was to investigate the specific mechanisms of executive functions in the context of Dual tasking, leading to improved dual-task performance after practice. More specifically, we tested the Efficient Task Instantiation (ETI) model that includes specific assumptions regarding practice-related improvements of executive task coordination skills: Dual-task performance is improved with practice because of an efficient and conjoint instantiation of sets of relevant task information in working memory at the onset of a dual task. According to our knowledge, the ETI model is one of the first that allows illustrating the contribution of cognitive mechanisms underlying practice-related improvements in performing dual tasks and the impact of task coordination skills on this performance.

  20. Effect of adjusted pH prior to ultrafiltration of skim milk on membrane performance and physical functionality of milk protein concentrate.

    Science.gov (United States)

    Luo, X; Vasiljevic, T; Ramchandran, L

    2016-02-01

    Processing conditions during ultrafiltration of skim milk influence properties of the casein micelle and thereby the physical properties of milk protein concentrate (MPC). The aim of the study was to establish the effects of pH adjustment of skim milk feed to obtain MPC with desired emulsification properties. The ultrafiltration was conducted using commercially pasteurized skim milk with the pH adjusted to 6.7 (control), 6.3, 5.9, or 5.5 at 15°C until a volume concentration factor of 5 was reached. Effects of pH adjustment on selected physico-chemical properties (Ca content, particle size, ζ-potential) and functionalities (solubility, heat stability, emulsification capacity, and stability) of MPC were determined. Lowering the feed pH solubilized colloidal calcium phosphate that substantially contributed to modifying the properties of casein. This caused a reduction in the particle size while increasing the net negative charge. The structural modifications in proteins were manifested in the Fourier transform infrared spectra. Subsequent concentration did not induce any further protein structural changes. Such modifications to the casein micelles and colloidal calcium phosphate negatively affected the solubility and heat stability of the corresponding MPC powders. However, the emulsion activity index improved only until the pH of the feed was lowered to 5.9 and declined when pH was dropped to 5.5, followed with the loss of stability. Readjusting the pH of MPC powder dispersions to 6.7 restored their surface properties and thereby their functionality. Lowering the feed pH also negatively affected the membrane performance by clogging the membrane pores and lowering the flux, particularly at pH 5.5. Adjusting pH to 5.9 produced MPC with optimum emulsifying properties with minimal influence on membrane performance. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. On the Interpretation of Response Time vs Onset Asynchrony Functions: Application to Dual-Task and Precue-Utilization Paradigms.

    Science.gov (United States)

    Schwarz, Wolfgang; Ischebeck, Anja

    2001-06-01

    The central bottleneck model of dual-task performance (H. Pashler and J. C. Johnston, 1998, Quarterly Journal of Experimental Psychology, 46A, 51-82) and the serial processing model of precue utilization (R. Gottsdanker, 1992, Acta Psychologica, 79, 21-43) are based on a common formal structure: They both represent response time as RT(tau)=max(X-tau, Y)+Z, where X, Y, Z denote the duration of certain processing stages specified by the models and tau denotes the onset asynchrony (SOA) between two stimuli. We consider this model within a stochastic framework in which the stage durations are random variables following an arbitrary joint distribution and derive properties of the function relating E[RT(tau)] to SOA. We present a distribution-free result which relates the slope of this function to the distribution of the random durations of the assumed processing stages. Our results allow for a direct, model-based interpretation of data from related experiments; specifically, they show how the slope of the SOA-function depends on experimental factors which selectively influence individual processing stages. We explain the implications of our results for models of dual-task performance and precue utilization and illustrate their application to data obtained by M. C. Smith (1969, Acta Psychologica, 30, 220-231) and R. Gottsdanker (1992, loc. cit.) Copyright 2001 Academic Press.

  2. Dual-function photonic integrated circuit for frequency octo-tupling or single-side-band modulation.

    Science.gov (United States)

    Hasan, Mehedi; Maldonado-Basilio, Ramón; Hall, Trevor J

    2015-06-01

    A dual-function photonic integrated circuit for microwave photonic applications is proposed. The circuit consists of four linear electro-optic phase modulators connected optically in parallel within a generalized Mach-Zehnder interferometer architecture. The photonic circuit is arranged to have two separate output ports. A first port provides frequency up-conversion of a microwave signal from the electrical to the optical domain; equivalently single-side-band modulation. A second port provides tunable millimeter wave carriers by frequency octo-tupling of an appropriate amplitude RF carrier. The circuit exploits the intrinsic relative phases between the ports of multi-mode interference couplers to provide substantially all the static optical phases needed. The operation of the proposed dual-function photonic integrated circuit is verified by computer simulations. The performance of the frequency octo-tupling and up-conversion functions is analyzed in terms of the electrical signal to harmonic distortion ratio and the optical single side band to unwanted harmonics ratio, respectively.

  3. Comparative study of the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours as affected by pH.

    Science.gov (United States)

    Raikos, Vassilios; Neacsu, Madalina; Russell, Wendy; Duthie, Garry

    2014-11-01

    The demand for products of high nutritional value from sustainable sources is growing rapidly in the global food market. In this study, the effect of pH on the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours was investigated and compared with wheat flour. Functional properties included solubility, emulsifying and foaming properties, gelling ability, and water holding capacity (WHC). All flours had minimal solubility at pH 4 and their corresponding values increased with increasing pH. Emulsifying properties were improved at pH 10 for all samples and emulsion stability showed a similar trend. Increasing pH in the range 4-10 enhanced the foaming properties of the flours, particularly buckwheat and hemp. Wheat, green pea, buckwheat, and fava bean were more capable of forming firm gels compared with lupin and hemp, as indicated by least gelling concentrations (LGCs). The ranking of the water binding properties of the different types of flours were lupin>hemp>fava bean>buckwheat>green pea>wheat. Results indicate that underutilized flours from sustainable plant sources could be exploited by the food industry as functional food ingredients or as replacements of wheat flour for various food applications. Depending on the application, flour functionality may be effectively tailored by pH adjustment.

  4. Manganese (II) Chelate Functionalized Copper Sulfide Nanoparticles for Efficient Magnetic Resonance/Photoacoustic Dual-Modal Imaging Guided Photothermal Therapy.

    Science.gov (United States)

    Liu, Renfa; Jing, Lijia; Peng, Dong; Li, Yong; Tian, Jie; Dai, Zhifei

    2015-01-01

    The integration of diagnostic and therapeutic functionalities into one nanoplatform shows great promise in cancer therapy. In this research, manganese (II) chelate functionalized copper sulfide nanoparticles were successfully prepared using a facile hydrothermal method. The obtained ultrasmall nanoparticles exhibit excellent photothermal effect and photoaoustic activity. Besides, the high loading content of Mn(II) chelates makes the nanoparticles attractive T1 contrast agent in magnetic resonance imaging (MRI). In vivo photoacoustic imaging (PAI) results showed that the nanoparticles could be efficiently accumulated in tumor site in 24 h after systematic administration, which was further validated by MRI tests. The subsequent photothermal therapy of cancer in vivo was achieved without inducing any observed side effects. Therefore, the copper sulfide nanoparticles functionalized with Mn(II) chelate hold great promise as a theranostic nanomedicine for MR/PA dual-modal imaging guided photothermal therapy of cancer.

  5. A dual voltage control strategy for single-phase PWM converters with power decoupling function

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2014-01-01

    on a symmetrical half bridge circuit is proposed to decouple the ripple power so that balanced instantaneous power flow is assured between source and load, and the required dc-link capacitance can be dramatically reduced. For proper closed-loop regulation, the small signal modeling of the proposed system...... is presented, and a dual voltage control strategy is then proposed, which comprises one voltage loop implemented in the synchronous reference frame for active power balancing, and another one implemented in the harmonic reference frame for ripple power compensation. Special attention is given to the bandwidth...

  6. Cognitive Functioning and Quality of Life in Patients with Dual Diagnosis

    OpenAIRE

    Benaiges Fusté, Irina

    2013-01-01

    Se denomina Patología Dual (PD) a la coocurrencia de un Trastorno Mental Severo (TMS), especialmente de la esfera psicótica y/o afectiva y un trastorno por uso de sustancias (TUS). Se trata de un trastorno de elevada prevalencia, con una gran repercusión clínica y asistencial debido a las complicaciones asociadas a la comorbilidad entre ambas patologías. El presente trabajo se propuso dos objetivos, estudiar el rendimiento cognitivo y la calidad de vida Relacionada con la Salud (CVRS) e...

  7. Calcium is the switch in the moonlighting dual function of the ligand-activated receptor kinase phytosulfokine receptor 1

    KAUST Repository

    Muleya, Victor

    2014-09-23

    Background: A number of receptor kinases contain guanylate cyclase (GC) catalytic centres encapsulated in the cytosolic kinase domain. A prototypical example is the phytosulfokine receptor 1 (PSKR1) that is involved in regulating growth responses in plants. PSKR1 contains both kinase and GC activities however the underlying mechanisms regulating the dual functions have remained elusive. Findings: Here, we confirm the dual activity of the cytoplasmic domain of the PSKR1 receptor. We show that mutations within the guanylate cyclase centre modulate the GC activity while not affecting the kinase catalytic activity. Using physiologically relevant Ca2+ levels, we demonstrate that its GC activity is enhanced over two-fold by Ca2+ in a concentration-dependent manner. Conversely, increasing Ca2+ levels inhibits kinase activity up to 500-fold at 100 nM Ca2+. Conclusions: Changes in calcium at physiological levels can regulate the kinase and GC activities of PSKR1. We therefore propose a functional model of how calcium acts as a bimodal switch between kinase and GC activity in PSKR1 that could be relevant to other members of this novel class of ligand-activated receptor kinases.

  8. Functional Results of Intercondylar Fractures of the Humerus Fixed with Dual Y-Plate; A Technical Note

    Directory of Open Access Journals (Sweden)

    Swagat Mahapatra

    2017-01-01

    Full Text Available Objective: To evaluate and report the functional results of surgical management of intercondylar fractures of the humerus in adults using a novel dual plating technique. Methods: A total number of 60 patients with Riseborough and Radin type II, III, and IV intercondylar humerus fractures were operated with open reduction through a Trans-olecranon approach and internal fixation using two plates in inverted-Y configuration. Patients were followed for 3 weeks, 3 and 6 months were evaluated using the Mayo Elbow performance score and Quick-DASH score. Results: There were 50(83.33%men and 10 (16.67%women with mean age of 34.9 ± 12.63 years. 63.3% of the cases were following Motor vehicle accident and rest following fall. The right upper limb was more commonly affected than the left side. Riseborough and Radin type II fractures accounted for 3.33% of cases; type III fractures accounted for 50% of cases and type IV accounted for 46.67%. Excellent to Good results were seen in almost 80% of cases as per the Mayo Elbow performance score at 6-month follow-up. Quick-DASH scores for the series at 6-month follow-up was on average of 15.96 ± 9.92. Conclusion: Dual plating in inverted Y configuration offers a reliable fixation, which permits early mobilization and good functional outcome.

  9. Dual Functional Polymer Interlayer for Facilitating Ion Transport and Reducing Charge Recombination in Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Wang, Ying-Chiao; Li, Shao-Sian; Wen, Cheng-Yen; Chen, Liang-Yih; Ho, Kuo-Chuan; Chen, Chun-Wei

    2016-12-14

    Dye-sensitized solar cells (DSSCs) present low-cost alternatives to conventional wafer-based inorganic solar cells and have remarkable power conversion efficiency. To further enhance performance, we propose a new DSSC architecture with a novel dual-functional polymer interlayer that prevents charge recombination and facilitates ionic conduction, as well as maintaining dye loading and regeneration. Poly(vinylidene fluoride-trifluoroethylene) (p(VDF-TrFE)) was coated on the outside of a dye-sensitized TiO2 photoanode by a simple solution process that did not sacrifice the amount of adsorbed dye molecules in the DSSC device. Light-intensity-modulated photocurrent and photovoltage spectroscopy revealed that the proposed p(VDF-TrFE)-coated anode yielded longer electron lifetime and improved the injection of photogenerated electrons into TiO2, thereby reducing the electron transport time. Comparative cyclic voltammetry and UV-visible absorption spectroscopy based on a ferrocene-ferrocenium external standard material demonstrated that p(VDF-TrFE) enhanced the power conversion efficiency from 7.67% to 9.11%. This dual functional p(VDF-TrFE) interlayer is a promising candidate for improving the performance of DSSCs and can also be employed in other electrochemical devices.

  10. Functional Results of Intercondylar Fractures of the Humerus Fixed with Dual Y-Plate; A Technical Note  

    Science.gov (United States)

    Mahapatra, Swagat; Abraham, Vineet Thomas

    2017-01-01

    Objective: To evaluate and report the functional results of surgical management of intercondylar fractures of the humerus in adults using a novel dual plating technique. Methods: A total number of 60 patients with Riseborough and Radin type II, III, and IV intercondylar humerus fractures were operated with open reduction through a Trans-olecranon approach and internal fixation using two plates in inverted-Y configuration. Patients were followed for 3 weeks, 3 and 6 months were evaluated using the Mayo Elbow performance score and Quick-DASH score. Results: There were 50(83.33%)men and 10 (16.67%)women with mean age of 34.9 ± 12.63 years. 63.3% of the cases were following Motor vehicle accident and rest following fall. The right upper limb was more commonly affected than the left side. Riseborough and Radin type II fractures accounted for 3.33% of cases; type III fractures accounted for 50% of cases and type IV accounted for 46.67%. Excellent to Good results were seen in almost 80% of cases as per the Mayo Elbow performance score at 6-month follow-up. Quick-DASH scores for the series at 6-month follow-up was on average of 15.96 ± 9.92. Conclusion: Dual plating in inverted Y configuration offers a reliable fixation, which permits early mobilization and good functional outcome.

  11. Copper concentration of vineyard soils as a function of pH variation and addition of poultry litter

    Directory of Open Access Journals (Sweden)

    Gilmar Ribeiro Nachtigall

    2007-11-01

    Full Text Available Copper (Cu concentration was evaluated as a function of pH variation and addition of poultry litter to a Dystrophic Lithic Udorthent and a Humic Dystrudept from the state of Rio Grande do Sul, Brazil, cultivated with vines treated with successive applications of Cu-based product. Samples were collected from the surface layer (0 to 10 cm. Soluble Cu concentration was determined using DTPA and Mehlich III as extractants, and exchangeable Cu was determined in CaCl2. The availability of Cu was mainly affected by the soil pH. CaCl2 extractant had the best correlation with Cu concentration in contaminated soils, according to treatments applied. The addition of poultry litter did not reduce Cu availability in these soils. Total soil Cu content varied between 1,300 and 1,400 mg kg-1 in both soils. Copper available fractions, extracted by DTPA, CaCl2 and Mehlich III, averaged 35, 0.2 and 63%, respectively, of the total Cu present in the soil.Avaliaram-se os teores de Cu em função da variação do pH e da adição de cama-de-frango de dois solos com elevados teores deste elemento. Foram coletadas amostras da camada superficial (0 a 10 cm de um typical dystrophic Lithic Udorthent - LU (Neossolo Litólico distrófico típico e de um Humic Dystrudept - HD (Cambissolo Húmico alumínico típico da região da Serra do RS, cultivados com parreirais que receberam aplicações sucessivas de produtos à base de Cu. Foram determinados os teores de Cu solúvel em DTPA e pelo método Mehlich III, além do Cu trocável em CaCl2. A disponibilidade de Cu foi afetada principalmente pelo pH do solo. O extrator CaCl2 foi o que melhor se correlacionou com os teores de Cu em solos contaminados em função dos tratamentos aplicados. A adição de cama-de-frango não diminuiu a disponibilidade de Cu destes solos. Os teores de Cu total variaram entre 1.300 e 1.400 mg kg-1 nos dois solos. Considerando os teores totais de Cu nos solos, as frações "disponíveis", extra

  12. Analysis of Genotoxic and Cytotoxic Responses Induced by Simulated Space Radiation Qualities by Use of Recombinant Bacteria Carrying a Dual-Function Dual-Reporter Construct

    Science.gov (United States)

    Baumstark-Khan, Christa; Hellweg, Christine; Zahoor, Ahmed; Testard, Isabelle; Reitz, Guenther

    Along with the long-term space exploration come various potential health risks due to unique physical factors of the space environment. Space radiation is one of the primary environmental hazards associated with space flight. In order to deal with space-related risk radiation exposure must be properly characterised and quantified, and biological effects of charged particles have to be analysed in ground based research, especially as astronauts are subjected to a differing radiation quality in space than they receive on Earth. For risk assessment, the mutagenic potential of the heavy ion component of the galactic cosmic radiation is of major concern for tumour induction as radiation late effects. The recombinant SWITCH test is based on TA1535 Salmonella typhimurium cells transformed with a dual-function dual-reporter vector harbouring (a) the genes for bioluminescence production from Photobacterium leiognathi under the control of a DNA-damage inducible promoter and (b) the gene for green fluorescent protein from the jellyfish Aequorea victoria under the control of a constitutive promoter. Suchlike genetically modified organism report on the presence of genotoxic conditions by dose dependent increase of bioluminescence induction and on the presence of cytotoxic conditions by dose dependent decrease in GFP fluorescence. By this, it is possible to analyse bacterial inactivation and mutation induction by ionizing radiation in parallel in the same cell within short time. Experiments with heavy ions have been performed with the SWITCH test at GANIL with the following accelerated heavy ions: 35 MeV/u (72 keV/µm) and 75 MeV/u (37 keV/µm) carbon, 95 MeV/u argon (377 keV/µm), 95 MeV/u neon (98 keV/µm), 75 MeV/u nickel (967 keV/µm) and 29 MeV/u lead (10238 keV/µm). The results obtained clearly show that the numbers of hits (particles per cm2 ) necessary to inactivate the bacteria (cytotoxicity) depend on LET. The higher the ionisation capacity of the accelerated ion, the

  13. QCD Dual

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2009-01-01

    We uncover a novel solution of the 't Hooft anomaly matching conditions for QCD. Interestingly in the perturbative regime the new gauge theory, if interpreted as a possible QCD dual, predicts the critical number of flavors above which QCD in the nonperturbative regime, develops an infrared stable...... fixed point. Remarkably this value is identical to the maximum bound predicted in the nonpertubative regime via the all-orders conjectured beta function for nonsupersymmetric gauge theories.......We uncover a novel solution of the 't Hooft anomaly matching conditions for QCD. Interestingly in the perturbative regime the new gauge theory, if interpreted as a possible QCD dual, predicts the critical number of flavors above which QCD in the nonperturbative regime, develops an infrared stable...

  14. Xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans: correlation of xenon and CT density values with pulmonary function test results

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo; Yang, Dong Hyun; Seo, Joon Beom; Chae, Eun Jin; Lee, Jeongjin [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Songpa-gu, Seoul (Korea); Hong, Soo-Jong; Yu, Jinho; Kim, Byoung-Ju [University of Ulsan College of Medicine, Department of Pediatrics, Asan Medical Center, Seoul (Korea); Krauss, Bernhard [Siemens Medical Solutions AG-Computed Tomography, Forchheim (Germany)

    2010-09-15

    Xenon ventilation CT using dual-source and dual-energy technique is a recently introduced, promising functional lung imaging method. To expand its clinical applications evidence of additional diagnostic value of xenon ventilation CT over conventional chest CT is required. To evaluate the usefulness of xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans (BO). Seventeen children (age 7-18 years; 11 boys) with BO underwent xenon ventilation CT using dual-source and dual-energy technique. Xenon and CT density values were measured in normal and hyperlucent lung regions on CT and were compared between the two regions. Volumes of hyperlucent regions and ventilation defects were calculated with thresholds determined by visual and histogram-based analysis. Indexed volumes of hyperlucent lung regions and ventilation defects were correlated with pulmonary function test results. Effective doses of xenon CT were calculated. Xenon (14.6 {+-} 6.4 HU vs 26.1 {+-} 6.5 HU; P < 0.001) and CT density (-892.8 {+-} 25.4 HU vs -812.3 {+-} 38.7 HU; P < 0.001) values were significantly lower in hyperlucent regions than in normal lung regions. Xenon and CT density values showed significant positive correlation for the entire lung in 16 children ({gamma} = 0.55 {+-} 0.17, P < 0.001 or =0.017) and for hyperlucent regions in 13 children ({gamma} = 0.44 {+-} 0.16, P < 0.001 or =0.001-0.019). Indexed volumes and volume percentages of hyperlucent lung regions and ventilation defects showed strong negative correlations with forced expiratory volume [FEV1, ({gamma} = -0.64-0.85, P {<=} 0.006)], FEV1/forced vital capacity [FVC, ({gamma} = -0.63-0.84, P {<=} 0.008)], and forced midexpiratory flow rate [FEF{sub 25-75}, ({gamma} = -0.68-0.88, P {<=} 0.002). Volume percentages of xenon ventilation defects (35.0 {+-} 16.4%)] were not significantly different from those of hyperlucent lung regions (38.2 {+-} 18.6%). However, mismatches between the

  15. Design and Functional Validation of a Mechanism for Dual-Spinning CubeSats

    Science.gov (United States)

    Peters, Eric; Dave, Pratik; Kingsbury, Ryan; Marinan, Anne; Wise, Evan; Pong, Chris; Prinkey, Meghan; Cahoy, Kerri; Miller, David W.; Sklair, Devon

    2014-01-01

    The mission of the Micro-sized Microwave Atmospheric Satellite (MicroMAS) is to collect useful atmospheric images using a miniature passive microwave radiometer payload hosted on a low-cost CubeSat platform. In order to collect this data, the microwave radiometer payload must rotate to scan the ground-track perpendicular to the satellite's direction of travel. A custom motor assembly was developed to facilitate the rotation of the payload while allowing the spacecraft bus to remained fixed in the local-vertical, local-horizontal (LVLH) frame for increased pointing accuracy. This paper describes the mechanism used to enable this dual-spinning operation for CubeSats, and the lessons learned during the design, fabrication, integration, and testing phases of the mechanism's development lifecycle.

  16. Prior Image Guided Undersampled Dual Energy Reconstruction with Piecewise Polynomial Function Constraint

    Directory of Open Access Journals (Sweden)

    Dufan Wu

    2013-01-01

    Full Text Available Dual energy CT has the ability to give more information about the test object by reconstructing the attenuation factors under different energies. These images under different energies share identical structures but different attenuation factors. By referring to the fully sampled low-energy image, we show that it is possible to greatly reduce the sampling rate of the high-energy image in order to lower dose. To compensate the attenuation factor difference between the two modalities, we use piecewise polynomial fitting to fit the low-energy image to the high-energy image. During the reconstruction, the result is constrained by its distance to the fitted image, and the structural information thus can be preserved. An ASD-POCS-based optimization schedule is proposed to solve the problem, and numerical simulations are taken to verify the algorithm.

  17. A dual voltage control strategy for single-phase PWM converters with power decoupling function

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2014-01-01

    The inherent double line ripple power in singlephase systems is adverse to the converter performance, e.g. limited lifetime due to the requirement of large electrolytic capacitors and low voltage control bandwidth due to harmonic disturbance. In this paper, an active converter topology based...... on a symmetrical half bridge circuit is proposed to decouple the ripple power so that balanced instantaneous power flow is assured between source and load, and the required dc-link capacitance can be dramatically reduced. For proper closed-loop regulation, the small signal modeling of the proposed system...... is presented, and a dual voltage control strategy is then proposed, which comprises one voltage loop implemented in the synchronous reference frame for active power balancing, and another one implemented in the harmonic reference frame for ripple power compensation. Special attention is given to the bandwidth...

  18. A dual voltage control strategy for single-phase PWM converters with power decoupling function

    DEFF Research Database (Denmark)

    Tang, Yi; Qin, Zian; Blaabjerg, Frede

    2015-01-01

    converter topology based on a symmetrical half bridge circuit is proposed to decouple the ripple power so that balanced instantaneous power flow is assured between source and load, and the required dc-link capacitance can be dramatically reduced. For proper closed-loop regulation, the small signal modeling......The inherent double line ripple power in single-phase systems is adverse to the performance of power electronics converters, e.g. limited lifetime due to the requirement of large electrolytic capacitors and low voltage control bandwidth due to harmonic disturbance. In this paper, an active...... of the proposed system is presented, and a dual voltage control strategy is then proposed, which comprises one voltage loop implemented in the synchronous reference frame for active power balancing, and another one implemented in the stationary reference frame for ripple power compensation. Special attention...

  19. Triple Antibiotic Polymer Nanofibers for Intracanal Drug Delivery: Effects on Dual Species Biofilm and Cell Function.

    Science.gov (United States)

    Pankajakshan, Divya; Albuquerque, Maria T P; Evans, Joshua D; Kamocka, Malgorzata M; Gregory, Richard L; Bottino, Marco C

    2016-10-01

    Root canal disinfection and the establishment of an intracanal microenvironment conducive to the proliferation/differentiation of stem cells play a significant role in regenerative endodontics. This study was designed to (1) investigate the antimicrobial efficacy of triple antibiotic-containing nanofibers against a dual-species biofilm and (2) evaluate the ability of dental pulp stem cells (DPSCs) to adhere to and proliferate on dentin upon nanofiber exposure. Seven-day-old dual-species biofilm established on dentin specimens was exposed for 3 days to the following: saline (control), antibiotic-free nanofibers (control), and triple antibiotic-containing nanofibers or a saturated triple antibiotic paste (TAP) solution (50 mg/mL in phosphate buffer solution). Bacterial viability was assessed using the LIVE/DEAD assay (Molecular Probes, Inc, Eugene, OR) and confocal laser scanning microscopy. For cytocompatibility studies, dentin specimens after nanofiber or TAP (1 g/mL in phosphate buffer solution) exposure were evaluated for cell adhesion and spreading by actin-phalloidin staining. DPSC proliferation was assessed on days 1, 3, and 7. Statistics were performed, and significance was set at the 5% level. Confocal laser scanning microscopy showed significant bacterial death upon antibiotic-containing nanofiber exposure, differing significantly (P antibiotic-free fibers and the control (saline). DPSCs showed enhanced adhesion/spreading on dentin specimens treated with antibiotic-containing nanofibers when compared with its TAP counterparts. The DPSC proliferation rate was similar on days 1 and 3 in antibiotic-free nanofibers, triple antibiotic-containing nanofibers, and TAP-treated dentin. Proliferation was higher (9-fold) on dentin treated with antibiotic-containing nanofibers on day 7 compared with TAP. Triple antibiotic-containing polymer nanofibers led to significant bacterial death, whereas they did not affect DPSC attachment and proliferation on dentin

  20. Dual therapeutic functions of F-5 fragment in burn wounds: preventing wound progression and promoting wound healing in pigs.

    Science.gov (United States)

    Bhatia, Ayesha; O'Brien, Kathryn; Chen, Mei; Wong, Alex; Garner, Warren; Woodley, David T; Li, Wei

    2016-01-01

    Burn injuries are a leading cause of morbidity including prolonged hospitalization, disfigurement, and disability. Currently there is no Food and Drug Administration-approved burn therapeutics. A clinical distinction of burn injuries from other acute wounds is the event of the so-called secondary burn wound progression within the first week of the injury, in which a burn expands horizontally and vertically from its initial boundary to a larger area. Therefore, an effective therapeutics for burns should show dual abilities to prevent the burn wound progression and thereafter promote burn wound healing. Herein we report that topically applied F-5 fragment of heat shock protein-90α is a dual functional agent to promote burn wound healing in pigs. First, F-5 prevents burn wound progression by protecting the surrounding cells from undergoing heat-induced caspase 3 activation and apoptosis with increased Akt activation. Accordingly, F-5-treated burn and excision wounds show a marked decline in inflammation. Thereafter, F-5 accelerates burn wound healing by stimulating the keratinocyte migration-led reepithelialization, leading to wound closure. This study addresses a topical agent that is capable of preventing burn wound progression and accelerating burn wound healing.

  1. Effects of sodium hypochlorite and high pH buffer solution in electrokinetic soil treatment on soil chromium removal and the functional diversity of soil microbial community.

    Science.gov (United States)

    Cang, Long; Zhou, Dong-Mei; Alshawabkeh, Akram N; Chen, Hai-Feng

    2007-04-02

    Effects of sodium hypochlorite (NaClO), applied as an oxidant in catholyte, and high pH buffer solution on soil Cr removal and the functional diversity of soil microbial community during enhanced electrokinetic treatments of a chromium (Cr) contaminated red soil are evaluated. Using pH control system to maintain high alkalinity of soil together with the use of NaClO increased the electrical conductivities of soil pore liquid and electroosmotic flux compared with the control (Exp-01). The pH control and NaClO improved the removal of Cr(VI) and total Cr from the soil. The highest removal percentages of soil Cr(VI) and total Cr were 96 and 72%, respectively, in Exp-04 when the pH value of the anolyte was controlled at 10 and NaClO was added in the catholyte. The alkaline soil environment and introduction of NaClO in the soil enhanced the desorption of Cr(VI) from the soil and promoted Cr(III) oxidation to mobile Cr(VI), respectively. However, the elevated pH and introduction of NaClO in the soil, which are necessary for improving the removal efficiency of soil Cr, resulted in a significantly adverse impact on the functional diversity of soil microbial community. It suggests that to assess the negative impact of extreme conditions for enhancing the extraction efficiencies of Cr on the soil properties and function is necessary.

  2. Effects of sodium hypochlorite and high pH buffer solution in electrokinetic soil treatment on soil chromium removal and the functional diversity of soil microbial community

    Energy Technology Data Exchange (ETDEWEB)

    Cang Long [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Zhou Dongmei [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)]. E-mail: dmzhou@issas.ac.cn; Alshawabkeh, Akram N. [Department of Civil and Environmental Engineering, Northeastern University, Boston, MA (United States); Chen Haifeng [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2007-04-02

    Effects of sodium hypochlorite (NaClO), applied as an oxidant in catholyte, and high pH buffer solution on soil Cr removal and the functional diversity of soil microbial community during enhanced electrokinetic treatments of a chromium (Cr) contaminated red soil are evaluated. Using pH control system to maintain high alkalinity of soil together with the use of NaClO increased the electrical conductivities of soil pore liquid and electroosmotic flux compared with the control (Exp-01). The pH control and NaClO improved the removal of Cr(VI) and total Cr from the soil. The highest removal percentages of soil Cr(VI) and total Cr were 96 and 72%, respectively, in Exp-04 when the pH value of the anolyte was controlled at 10 and NaClO was added in the catholyte. The alkaline soil environment and introduction of NaClO in the soil enhanced the desorption of Cr(VI) from the soil and promoted Cr(III) oxidation to mobile Cr(VI), respectively. However, the elevated pH and introduction of NaClO in the soil, which are necessary for improving the removal efficiency of soil Cr, resulted in a significantly adverse impact on the functional diversity of soil microbial community. It suggests that to assess the negative impact of extreme conditions for enhancing the extraction efficiencies of Cr on the soil properties and function is necessary.

  3. The performance of single- and multi-proxy transfer functions (testate amoebae, bryophytes, vascular plants) for reconstructing mire surface wetness and pH

    Science.gov (United States)

    Mitchell, Edward A. D.; Payne, Richard J.; van der Knaap, Willem O.; Lamentowicz, Łukasz; Gąbka, Maciej; Lamentowicz, Mariusz

    2013-01-01

    Peatlands are widely exploited archives of paleoenvironmental change. We developed and compared multiple transfer functions to infer peatland depth to the water table (DWT) and pH based on testate amoeba (percentages, or presence/absence), bryophyte presence/absence, and vascular plant presence/absence data from sub-alpine peatlands in the SE Swiss Alps in order to 1) compare the performance of single-proxy vs. multi-proxy models and 2) assess the performance of presence/absence models. Bootstrapping cross-validation showing the best performing single-proxy transfer functions for both DWT and pH were those based on bryophytes. The best performing transfer functions overall for DWT were those based on combined testate amoebae percentages, bryophytes and vascular plants; and, for pH, those based on testate amoebae and bryophytes. The comparison of DWT and pH inferred from testate amoeba percentages and presence/absence data showed similar general patterns but differences in the magnitude and timing of some shifts. These results show new directions for paleoenvironmental research, 1) suggesting that it is possible to build good-performing transfer functions using presence/absence data, although with some loss of accuracy, and 2) supporting the idea that multi-proxy inference models may improve paleoecological reconstruction. The performance of multi-proxy and single-proxy transfer functions should be further compared in paleoecological data.

  4. LSD1 dual function in mediating epigenetic corruption of the vitamin D signaling in prostate cancer.

    Science.gov (United States)

    Battaglia, Sebastiano; Karasik, Ellen; Gillard, Bryan; Williams, Jennifer; Winchester, Trisha; Moser, Michael T; Smiraglia, Dominic J; Foster, Barbara A

    2017-01-01

    Lysine-specific demethylase 1A (LSD1) is a key regulator of the androgen (AR) and estrogen receptors (ER), and LSD1 levels correlate with tumor aggressiveness. Here, we demonstrate that LSD1 regulates vitamin D receptor (VDR) activity and is a mediator of 1,25(OH)2-D3 (vitamin D) action in prostate cancer (PCa). Athymic nude mice were xenografted with CWR22 cells and monitored weekly after testosterone pellet removal. Expression of LSD1 and VDR (IHC) were correlated with tumor growth using log-rank test. TRAMP tumors and prostates from wild-type (WT) mice were used to evaluate VDR and LSD1 expression via IHC and western blotting. The presence of VDR and LSD1 in the same transcriptional complex was evaluated via immunoprecipitation (IP) using nuclear cell lysate. The effect of LSD1 and 1,25(OH)2-D3 on cell viability was evaluated in C4-2 and BC1A cells via trypan blue exclusion. The role of LSD1 in VDR-mediated gene transcription was evaluated for Cdkn1a, E2f1, Cyp24a1, and S100g via qRT-PCR-TaqMan and via chromatin immunoprecipitation assay. Methylation of Cdkn1a TSS was measured via bisulfite sequencing, and methylation of a panel of cancer-related genes was quantified using methyl arrays. The Cancer Genome Atlas data were retrieved to identify genes whose status correlates with LSD1 and DNA methyltransferase 1 (DNMT1). Results were correlated with patients' survival data from two separate cohorts of primary and metastatic PCa. LSD1 and VDR protein levels are elevated in PCa tumors and correlate with faster tumor growth in xenograft mouse models. Knockdown of LSD1 reduces PCa cell viability, and gene expression data suggest a dual coregulatory role of LSD1 for VDR, acting as a coactivator and corepressor in a locus-specific manner. LSD1 modulates VDR-dependent transcription by mediating the recruitment of VDR and DNMT1 at the TSS of VDR-targeted genes and modulates the epigenetic status of transcribed genes by altering H3K4me2 and H3K9Ac and DNA methylation

  5. 双功能加氢转化催化剂的应用%Application of dual function hydrogenation catalyst

    Institute of Scientific and Technical Information of China (English)

    冯建国

    2000-01-01

    The properties and application of dual function hydrogenation catalysts,including JT-1G,JT-4, T205A/T205B,were introduced. The catalysts could be used in the production of hydrogen and ammonia from the poor gases in high olefine refinery gases.%介绍了JT-1G型、JT-4型、T205A/T205B型双功能加氢转化催化剂的物理特性及其应用情况,该催化剂可用于以高烯烃炼厂气为原料制取氢气和合成氨生产中。

  6. Modeling intraparticle transports during propylene polymerizations using supported metallocene and dual function metallocene as catalysts: Single particle model

    Directory of Open Access Journals (Sweden)

    Li Hua-Rong

    2014-01-01

    Full Text Available Two improved multigrain models (MGMs for preparing homopolypropylene and long chain branched polypropylene via propylene polymerization using silica-supported metallocene or dual function metallocene as catalysts are presented in this paper. The presented models are used to predict the intraparticle flow fields involved in the polymerizations. The simulation results show that the flow field distributions involve dare basically identical. The results also show that both the two polymerization processes have an initiation stage and the controlling step for them is reaction-diffusion-reaction with the polymerization proceeding. Furthermore, the simulation results show that the intra particle mass transfer resistance has significant effect on the polymerization but the heat transfer resistance can be ignored.

  7. Dual-responsive and Multi-functional Plasmonic Hydrogel Valves and Biomimetic Architectures Formed with Hydrogel and Gold Nanocolloids

    Science.gov (United States)

    Song, Ji Eun; Cho, Eun Chul

    2016-10-01

    We present a straightforward approach with high moldability for producing dual-responsive and multi-functional plasmonic hydrogel valves and biomimetic architectures that reversibly change volumes and colors in response to temperature and ion variations. Heating of a mixture of hybrid colloids (gold nanoparticles assembled on a hydrogel colloid) and hydrogel colloids rapidly induces (within 30 min) the formation of hydrogel architectures resembling mold shapes (cylinder, fish, butterfly). The biomimetic fish and butterfly display reversible changes in volumes and colors with variations of temperature and ionic conditions in aqueous solutions. The cylindrical plasmonic valves installed in flow tubes rapidly control water flow rate in on-off manner by responding to these stimuli. They also report these changes in terms of their colors. Therefore, the approach presented here might be helpful in developing new class of biomimetic and flow control systems where liquid conditions should be visually notified (e.g., glucose or ion concentration changes).

  8. In-silico prediction of dual function of DksA like hypothetical protein in V. cholerae O395 genome.

    Science.gov (United States)

    Dutta, Avirup; Katarkar, Atul; Chaudhuri, Keya

    2017-01-01

    Cholera, an acute infection of the small intestine, is caused by Vibrio cholerae. The present study identified a hypothetical protein in V. cholerae O395, which was predicted to be acquired through horizontal gene transfer the origin of which was found to be from a phage. Its expression was further confirmed by RT-PCR. Homology based 3D model of the hypothetical protein indicated DksA like homologue. Protein binding site of 3D-model revealed a deep cleft which may influence the dimer formation and interaction with ds-DNA molecule. Also, canonical function of direct interaction with RNA polymerase (RNAP) holoenzyme in complex with ppGpp suggests its dual role in the pathogenesis of cholera.

  9. Nanogenerator-based dual-functional and self-powered thin patch loudspeaker or microphone for flexible electronics

    Science.gov (United States)

    Li, Wei; Torres, David; Díaz, Ramón; Wang, Zhengjun; Wu, Changsheng; Wang, Chuan; Lin Wang, Zhong; Sepúlveda, Nelson

    2017-05-01

    Ferroelectret nanogenerators were recently introduced as a promising alternative technology for harvesting kinetic energy. Here we report the device's intrinsic properties that allow for the bidirectional conversion of energy between electrical and mechanical domains; thus extending its potential use in wearable electronics beyond the power generation realm. This electromechanical coupling, combined with their flexibility and thin film-like form, bestows dual-functional transducing capabilities to the device that are used in this work to demonstrate its use as a thin, wearable and self-powered loudspeaker or microphone patch. To determine the device's performance and applicability, sound pressure level is characterized in both space and frequency domains for three different configurations. The confirmed device's high performance is further validated through its integration in three different systems: a music-playing flag, a sound recording film and a flexible microphone for security applications.

  10. Staining-free gel electrophoresis-based multiplex enzyme assay using DNA and peptide dual-functionalized gold nanoparticles.

    Science.gov (United States)

    Zhao, Wenting; Yao, Chunlei; Luo, Xiaoteng; Lin, Li; Hsing, I-Ming

    2012-04-01

    We report a simple staining-free gel electrophoresis method to simultaneously probe protease and nuclease. Utilizing gold nanoparticles (Au-NPs) dual-functionalized with DNA and peptide, the presence and concentration of nuclease and protease are determined concurrently from the relative position and intensity of the bands in the staining-free gel electrophoresis. The use of Au-NPs eliminates the need for staining processes and enables naked eye detection, while a mononucleotide-mediated approach facilitates the synthesis of DNA/peptide conjugated Au-NPs and simplifies the operation procedures. Multiplex detection and quantification of DNase I and trypsin are successfully demonstrated. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Dual-responsive and Multi-functional Plasmonic Hydrogel Valves and Biomimetic Architectures Formed with Hydrogel and Gold Nanocolloids

    Science.gov (United States)

    Song, Ji Eun; Cho, Eun Chul

    2016-01-01

    We present a straightforward approach with high moldability for producing dual-responsive and multi-functional plasmonic hydrogel valves and biomimetic architectures that reversibly change volumes and colors in response to temperature and ion variations. Heating of a mixture of hybrid colloids (gold nanoparticles assembled on a hydrogel colloid) and hydrogel colloids rapidly induces (within 30 min) the formation of hydrogel architectures resembling mold shapes (cylinder, fish, butterfly). The biomimetic fish and butterfly display reversible changes in volumes and colors with variations of temperature and ionic conditions in aqueous solutions. The cylindrical plasmonic valves installed in flow tubes rapidly control water flow rate in on-off manner by responding to these stimuli. They also report these changes in terms of their colors. Therefore, the approach presented here might be helpful in developing new class of biomimetic and flow control systems where liquid conditions should be visually notified (e.g., glucose or ion concentration changes). PMID:27703195

  12. Dual-Function Metal-Organic Framework as a Versatile Catalyst for Detoxifying Chemical Warfare Agent Simulants.

    Science.gov (United States)

    Liu, Yangyang; Moon, Su-Young; Hupp, Joseph T; Farha, Omar K

    2015-12-22

    The nanocrystals of a porphyrin-based zirconium(IV) metal-organic framework (MOF) are used as a dual-function catalyst for the simultaneous detoxification of two chemical warfare agent simulants at room temperature. Simulants of nerve agent (such as GD, VX) and mustard gas, dimethyl 4-nitrophenyl phosphate and 2-chloroethyl ethyl sulfide, have been hydrolyzed and oxidized, respectively, to nontoxic products via a pair of pathways catalyzed by the same MOF. Phosphotriesterase-like activity of the Zr6-containing node combined with photoactivity of the porphyrin linker gives rise to a versatile MOF catalyst. In addition, bringing the MOF crystals down to the nanoregime leads to acceleration of the catalysis.

  13. Role of MCT1 and CAII in skeletal muscle pH homeostasis, energetics, and function: in vivo insights from MCT1 haploinsufficient mice

    KAUST Repository

    Chatel, Benjamin

    2017-03-03

    The purpose of this study was to investigate the effects of a partial suppression of monocarboxylate transporter (MCT)-1 on skeletal muscle pH, energetics, and function (MCT1(+/-) mice). Twenty-four MCT1(+/-) and 13 wild-type (WT) mice were subjected to a rest-exercise-recovery protocol, allowing assessment of muscle energetics (by magnetic resonance spectroscopy) and function. The study included analysis of enzyme activities and content of protein involved in pH regulation. Skeletal muscle of MCT1(+/-) mice had lower MCT1 (-61%; P < 0.05) and carbonic anhydrase (CA)-II (-54%; P < 0.05) contents. Although intramuscular pH was higher in MCT1(+/-) mice at rest (P < 0.001), the mice showed higher acidosis during the first minute of exercise (P < 0.01). Then, the pH time course was similar among groups until exercise completion. MCT1(+/-) mice had higher specific peak (P < 0.05) and maximum tetanic (P < 0.01) forces and lower fatigability (P < 0.001) when compared to WT mice. We conclude that both MCT1 and CAII are involved in the homeostatic control of pH in skeletal muscle, both at rest and at the onset of exercise. The improved muscle function and resistance to fatigue in MCT1(+/-) mice remain unexplained.-Chatel, B., Bendahan, D., Hourdé, C., Pellerin, L., Lengacher, S., Magistretti, P., Fur, Y. L., Vilmen, C., Bernard, M., Messonnier, L. A. Role of MCT1 and CAII in skeletal muscle pH homeostasis, energetics, and function: in vivo insights from MCT1 haploinsufficient mice.

  14. Fabrication of quantum dot/silica core-shell particles immobilizing Au nanoparticles and their dual imaging functions

    Science.gov (United States)

    Kobayashi, Yoshio; Matsudo, Hiromu; Li, Ting-ting; Shibuya, Kyosuke; Kubota, Yohsuke; Oikawa, Takahiro; Nakagawa, Tomohiko; Gonda, Kohsuke

    2016-03-01

    The present work proposes preparation methods for quantum dot/silica (QD/SiO2) core-shell particles that immobilize Au nanoparticles (QD/SiO2/Au). A colloid solution of QD/SiO2 core-shell particles with an average size of 47.0 ± 6.1 nm was prepared by a sol-gel reaction of tetraethyl orthosilicate in the presence of the QDs with an average size of 10.3 ± 2.1 nm. A colloid solution of Au nanoparticles with an average size of 17.9 ± 1.3 nm was prepared by reducing Au3+ ions with sodium citrate in water at 80 °C. Introduction of amino groups to QD/SiO2 particle surfaces was performed using (3-aminopropyl)-triethoxysilane (QD/SiO2-NH2). The QD/SiO2/Au particles were fabricated by mixing the Au particle colloid solution and the QD/SiO2-NH2 particle colloid solution. Values of radiant efficiency and computed tomography for the QD/SiO2/Au particle colloid solution were 2.23 × 107 (p/s/cm2/sr)/(μW/cm2) at a QD concentration of 8 × 10-7 M and 1180 ± 314 Hounsfield units and an Au concentration of 5.4 × 10-2 M. The QD/SiO2/Au particle colloid solution was injected into a mouse chest wall. Fluorescence emitted from the colloid solution could be detected on the skin covering the chest wall. The colloid solution could also be X-ray-imaged in the chest wall. Consequently, the QD/SiO2/Au particle colloid solution was found to have dual functions, i.e., fluorescence emission and X-ray absorption in vivo, which makes the colloid solution suitable to function as a contrast agent for dual imaging processes.

  15. pH值对再制干酪功能特性的影响%Influence of pH on Processed Cheese Functional Properties

    Institute of Scientific and Technical Information of China (English)

    尹长林; 刘佳; 赵征

    2011-01-01

    利用质构仪、流变仪、扫描电镜分析pH值对再制干酪产品功能特性的影响,揭示了pH在再制干酪生产过程中的重要作用.结果表明,pH值影响再制干酪的融化性,但是这种影响没有呈现一定的规律性;随着pH值的升高,再制干酪产品的表观黏度也随之升高;在各质构参数中,硬度和咀嚼性随着pH值的升高而降低,pH值对弹性的影响显著(P<0.05);pH值影响水和乳化的过程,pH值越高,越利于水和乳化.%The experiment studied the influence of pH on the functional properties of processed cheese by using texture analyzer, rheometer and SEM, and it described that pH played an important role in the process of making proeessed cheese. The results indicated: pH influenced the meltability of processed cheese, but the results were not regular. With increasing of pH, the apparent viscosity of processed cheese increased. Among all the parameters of processed cheese's texture, both the hardness and chewiness declined as pH increased in processed cheese, springiness were influenced significantly by pH (P <0.05); pH affected the process of emulsification, emulsification became better at higher pH value.

  16. T7 peptide-functionalized nanoparticles utilizing RNA interference for glioma dual targeting.

    Science.gov (United States)

    Kuang, Yuyang; An, Sai; Guo, Yubo; Huang, Shixian; Shao, Kun; Liu, Yang; Li, Jianfeng; Ma, Haojun; Jiang, Chen

    2013-09-15

    Among all the malignant brain tumors, glioma is the deadliest and most common form with poor prognosis. Gene therapy is regarded as a promising way to halt the progress of the disease or even cure the tumor and RNA interference (RNAi) stands out. However, the existence of the blood-brain barrier (BBB) and blood tumor barrier (BTB) limits the delivery of these therapeutic genes. In this work, the delivery system targeting to the transferrin (Tf) receptor highly expressed on both BBB and glioma was successfully synthesized and would not compete with endogenous Tf. U87 cells stably express luciferase were employed here to simulate tumor and the RNAi experiments in vitro and in vivo validated that the gene silencing activity was 2.17-fold higher with the targeting ligand modification. The dual-targeting gene delivery system exhibits a series of advantages, such as high efficiency, low toxicity, stability and high transaction efficiency, which may provide new opportunities in RNAi therapeutics and nanomedicine of brain tumors.

  17. Synthesis of highly active and dual-functional electrocatalysts for methanol oxidation and oxygen reduction reactions

    Science.gov (United States)

    Zhao, Qi; Zhang, Geng; Xu, Guangran; Li, Yingjun; Liu, Baocang; Gong, Xia; Zheng, Dafang; Zhang, Jun; Wang, Qin

    2016-12-01

    The promising Pt-based ternary catalyst is crucial for polymer electrolyte membrane fuel cells (PEMFCs) due to improving catalytic activity and durability for both methanol oxidation reaction and oxygen reduction reaction. In this work, a facile strategy is used for the synthesis ternary RuMPt (M = Fe, Co, Ni, and Cu) nanodendrities catalysts. The ternary RuMPt alloys exhibit enhanced specific and mass activity, positive half-wave potential, and long-term stability, compared with binary Pt-based alloy and the commercial Pt/C catalyst, which is attributed to the high electron density and upshifting of the d-band center for Pt atoms, and synergistic catalytic effects among Pt, M, and Ru atoms by introducing a transition metal. Impressively, the ternary RuCoPt catalyst exhibits superior mass activity (801.59 mA mg-1) and positive half-wave potential (0.857 V vs. RHE) towards MOR and ORR, respectively. Thus, the RuMPt nanocomposite is a very promising material to be used as dual electrocatalyst in the application of PEMFCs.

  18. Analysis of competition between transformation pathways in the functioning of biotic abstract dual automata.

    Science.gov (United States)

    Popa, Radu; Cimpoiasu, Vily M

    2013-05-01

    Properties of avenues of transformation and their mutualism with forms of organization in dynamic systems are essential for understanding the evolution of prebiotic order. We have analyzed competition between two avenues of transformation in an A↔B system, using the simulation approach called BiADA (Biotic Abstract Dual Automata). We discuss means of avoiding common pitfalls of abstract system modeling and benefits of BiADA-based simulations. We describe the effect of the availability of free energy, energy sink magnitude, and autocatalysis on the evolution of energy flux and order in the system. Results indicate that prebiotic competition between avenues of transformation was more stringent in energy-limited environments. We predict that in such conditions the efficiency of autocatalysis during competition between alternative system states will increase for systems with forms of organization having short half-lives and thus information that is time-sensitive to energy starvation. Our results also offer a potential solution to Manfred Eigen's error catastrophe dilemma. In the conditions discussed above, the exponential growth of quasi species is curbed through the removal of less competitive "genetic" variants via energy starvation. We propose that one of the most important achievements (and selective edges) of a dynamic network during competition in energy-limited or energy-variable environments was the capacity to correlate the internal energy flux and the need for free energy with the availability of free energy in the environment.

  19. Thermodynamic prediction of glycine polymerization as a function of temperature and pH consistent with experimentally obtained results.

    Science.gov (United States)

    Kitadai, Norio

    2014-04-01

    Prediction of the thermodynamic behaviors of biomolecules at high temperature and pressure is fundamental to understanding the role of hydrothermal systems in the origin and evolution of life on the primitive Earth. However, available thermodynamic dataset for amino acids, essential components for life, cannot represent experimentally observed polymerization behaviors of amino acids accurately under hydrothermal conditions. This report presents the thermodynamic data and the revised HKF parameters for the simplest amino acid "Gly" and its polymers (GlyGly, GlyGlyGly and DKP) based on experimental thermodynamic data from the literature. Values for the ionization states of Gly (Gly(+) and Gly(-)) and Gly peptides (GlyGly(+), GlyGly(-), GlyGlyGly(+), and GlyGlyGly(-)) were also retrieved from reported experimental data by combining group additivity algorithms. The obtained dataset enables prediction of the polymerization behavior of Gly as a function of temperature and pH, consistent with experimentally obtained results in the literature. The revised thermodynamic data for zwitterionic Gly, GlyGly, and DKP were also used to estimate the energetics of amino acid polymerization into proteins. Results show that the Gibbs energy necessary to synthesize a mole of peptide bond is more than 10 kJ mol(-1) less than previously estimated over widely various temperatures (e.g., 28.3 kJ mol(-1) → 17.1 kJ mol(-1) at 25 °C and 1 bar). Protein synthesis under abiotic conditions might therefore be more feasible than earlier studies have shown.

  20. Interaction of Human Dopa Decarboxylase with L-Dopa: Spectroscopic and Kinetic Studies as a Function of pH

    Directory of Open Access Journals (Sweden)

    Riccardo Montioli

    2013-01-01

    Full Text Available Human Dopa decarboxylase (hDDC, a pyridoxal 5′-phosphate (PLP enzyme, displays maxima at 420 and 335 nm and emits fluorescence at 384 and 504 nm upon excitation at 335 nm and at 504 nm when excited at 420 nm. Absorbance and fluorescence titrations of hDDC-bound coenzyme identify a single pKspec of ~7.2. This pKspec could not represent the ionization of a functional group on the Schiff base but that of an enzymic residue governing the equilibrium between the low- and the high-pH forms of the internal aldimine. During the reaction of hDDC with L-Dopa, monitored by stopped-flow spectrophotometry, a 420 nm band attributed to the 4′-N-protonated external aldimine first appears, and its decrease parallels the emergence of a 390 nm peak, assigned to the 4′-N-unprotonated external aldimine. The pH profile of the spectral change at 390 nm displays a pK of 6.4, a value similar to that (~6.3 observed in both kcat and kcat/Km profiles. This suggests that this pK represents the ESH+ → ES catalytic step. The assignment of the pKs of 7.9 and 8.3 observed on the basic side of kcat and the PLP binding affinity profiles, respectively, is also analyzed and discussed.

  1. Dual-compartment neurofluidic system for electrophysiological measurements in physically segregated and functionally connected neuronal cell culture.

    Science.gov (United States)

    Kanagasabapathi, Thirukumaran T; Ciliberti, Davide; Martinoia, Sergio; Wadman, Wytse J; Decré, Michel M J

    2011-01-01

    We developed a dual-compartment neurofluidic system with inter-connecting microchannels to connect neurons from their respective compartments, placed on a planar microelectrode arrays. The design and development of the compartmented microfluidic device for neuronal cell culture, protocol for sustaining long-term cultures, and neurite growth through microchannels in such a closed compartment device are presented. Using electrophysiological measurements of spontaneous network activity in the compartments and selective pharmacological manipulation of cells in one compartment, the biological origin of network activity and the fluidic isolation between the compartments are demonstrated. The connectivity between neuronal populations via the microchannels and the crossing-over of neurites are verified using transfection experiments and immunofluorescence staining. In addition to the neurite cross-over to the adjacent compartment, functional connectivity between cells in both the compartments is verified using cross-correlation (CC) based techniques. Bidirectional signal propagation between the compartments is demonstrated using functional connectivity maps. CC analysis and connectivity maps demonstrate that the two neuronal populations are not only functionally connected within each compartment but also with each other and a well connected functional network was formed between the compartments despite the physical barrier introduced by the microchannels.

  2. Partition functions of 3d $\\hat D$-quivers and their mirror duals from 1d free fermions

    CERN Document Server

    Assel, Benjamin; Felix, Jan

    2015-01-01

    We study the matrix models calculating the sphere partition functions of 3d gauge theories with $\\mathcal{N}=4$ supersymmetry and a quiver structure of a $\\hat D$ Dynkin diagram (where each node is a unitary gauge group). As in the case of necklace ($\\hat A $) quivers, we can map the problem to that of free fermion quantum mechanics whose complicated Hamiltonian we find explicitly. Many of these theories are conjectured to be dual under mirror symmetry to certain unitary linear quivers with extra Sp nodes or antisymmetric hypermultiplets. We show that the free fermion formulations of such mirror pairs are related by a linear symplectic transformation. We then study the large N expansion of the partition function, which as in the case of the $\\hat A$-quivers is given to all orders in 1/N by an Airy function. We simplify the algorithm to calculate the numerical coefficients appearing in the Airy function and evaluate them for a wide class of $\\hat D$-quiver theories.

  3. Cross-Linkable and Dual Functional Hybrid Polymeric Electron Transporting Layer for High-Performance Inverted Polymer Solar Cells.

    Science.gov (United States)

    Dong, Sheng; Hu, Zhicheng; Zhang, Kai; Yin, Qingwu; Jiang, Xiaofang; Huang, Fei; Cao, Yong

    2017-06-20

    A cross-linkable dual functional polymer hybrid electron transport layer (ETL) is developed by simply adding an amino-functionalized polymer dopant (PN4N) and a light crosslinker into a commercialized n-type semiconductor (N2200) matrix. It is found that the resulting hybrid ETL not only has a good solvent resistance, facilitating multilayers device fabrication but also exhibits much improved electron transporting/extraction properties due to the doping between PN4N and N2200. As a result, by using PTB7-Th:PC71 BM blend as an active layer, the inverted device based on the hybrid ETL can yield a prominent power conversion efficiency of around 10.07%. More interestingly, photovoltaic property studies of bilayer devices suggest that the absorption of the hybrid ETL contributes to photocurrent and hence the hybrid ETL simultaneously acts as both cathode interlayer material and an electron acceptor. The resulting inverted polymer solar cells function like a novel device architectures with a combination of a bulk heterojunction device and miniature bilayer devices. This work provides new insights on function of ETLs and may be open up a new direction for the design of new ETL materials and novel device architectures to further improve device performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Dual-channel in-situ optical imaging system for quantifying lipid uptake and lymphatic pump function

    Science.gov (United States)

    Kassis, Timothy; Kohan, Alison B.; Weiler, Michael J.; Nipper, Matthew E.; Cornelius, Rachel; Tso, Patrick; Brandon Dixon, J.

    2012-08-01

    Nearly all dietary lipids are transported from the intestine to venous circulation through the lymphatic system, yet the mechanisms that regulate this process remain unclear. Elucidating the mechanisms involved in the functional response of lymphatics to changes in lipid load would provide valuable insight into recent implications of lymphatic dysfunction in lipid related diseases. Therefore, we sought to develop an in situ imaging system to quantify and correlate lymphatic function as it relates to lipid transport. The imaging platform provides the capability of dual-channel imaging of both high-speed bright-field video and fluorescence simultaneously. Utilizing post-acquisition image processing algorithms, we can quantify correlations between vessel pump function, lymph flow, and lipid concentration of mesenteric lymphatic vessels in situ. All image analysis is automated with customized LabVIEW virtual instruments; local flow is measured through lymphocyte velocity tracking, vessel contraction through measurements of the vessel wall displacement, and lipid uptake through fluorescence intensity tracking of an orally administered fluorescently labelled fatty acid analogue, BODIPY FL C16. This system will prove to be an invaluable tool for scientists studying intestinal lymphatic function in health and disease, and those investigating strategies for targeting the lymphatics with orally delivered drugs to avoid first pass metabolism.

  5. Effect of chitosan on the heat stability of whey protein solution as a function of pH.

    Science.gov (United States)

    Zhao, Zhengtao; Xiao, Qian

    2017-03-01

    Chitosan was reported to interact with proteins through electrostatic interactions. Their interaction was influenced by pH, which was not fully characterized. Further research on the interactions between protein and chitosan at different pH and their influence on the thermal denaturation of proteins is necessary. In this research, the effect of chitosan on the heat stability of whey protein solution at pH 4.0-6.0 was studied. At pH 4.0, a small amount chitosan was able to prevent the heat-induced denaturation and aggregation of whey protein molecules. At higher pH values (5.5 and 6.0), whey proteins complexed with chitosan through electrostatic attraction. The formation of chitosan-whey protein complexes at pH 5.5 improved the heat stability of dispersions and no precipitation could be detected up to 20 days. The dispersion with a medium amount of chitosan (chitosan:whey protein 1:5) produced the most stable particles, which had an average radius of 135 ± 14 nm and a zeta potential value of 36 ± 1 mV. In contrast, at pH 6.0 only the dispersion with a high amount of chitosan (chitosan:whey protein 1:2) showed good shelf stability up to 20 days. It was possible to produce heat-stable whey protein beverages by regulating the interaction between chitosan and whey protein molecules. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Chromate (CrO(4)(2-)) and copper (Cu2+) adsorption by dual-functional ion exchange resins made from agricultural by-products.

    Science.gov (United States)

    Marshall, Wayne E; Wartelle, Lynda H

    2006-07-01

    Ion exchange resins commonly have a single functionality for either cations or anions. Resins that have a dual functionality for both cations and anions are uncommon. The objective of this study was to create dual-functional ion exchange resins derived from soybean hulls, sugarcane bagasse and corn stover. Dual-functional resins were prepared by two separate two-step processes. In the first two-step process, by-products were reacted with a solution of citric acid in order to impart additional negative charge, and then reacted with the cross-linking reagent dimethyloldihydroxyethylene urea (DMDHEU) and a quaternary amine (choline chloride) to add positive charge to the lignocellulosic material. In the second two-step process, the order of reaction was reversed, with positive charge added first, followed by the addition of negative charge. These combined reactions added both cationic and anionic character to the by-products as evidenced by the increased removal from solution of copper (Cu(2+)) cation and the chromate (CrO(4)(2-)) anion compared to unmodified by-products. The order of reaction appeared to slightly favor the functionality that was added last. That is, if negative charge was added last, the resulting resin sequestered more copper ion than a comparable resin where the negative charge was added first and vice-versa. Cu(2+) and CrO(4)(2-) were used as marker ions in a solution that contained both competing cations and anions. The dual-functional resins adsorbed as much as or more of the marker ions compared to commercial cation or anion exchange resins used for comparison. None of the commercial resins exhibited dual-functional properties to the same extent as the by-product-based resins.

  7. The dual function of and counter-measures for rural population migration.

    Science.gov (United States)

    Gu, S; Jian, X

    1996-01-01

    The authors posit that migration of the Chinese population from poverty stricken and backward rural areas to economically developed and advanced cities and coastal areas can have a positive effect on economic development and social stability. Policies must eliminate the negative disorderly and ineffective aspects and reinforce the positive, well-organized, orderly, and effective aspects. Population mobility enhances the formation of a national, unified labor market and resource distribution that is responsive to supply and demand. Population mobility allows for the transfer of rural surplus labor, relief of employment pressure in rural areas, and reduced population pressure on land availability. Rural surplus labor that moves into rural township enterprises is a major new source of financial capital for the economic development of rural areas. Population mobility aids in the development of an urban economy and increases farmers' income and living standard. Population mobility increases China's shift to a dual economic mode that includes a modern economy. Adverse effects include a decline in the quality of the rural labor force and diminished capital input into agriculture, a strain on urban resources and social services, and disruption of the socioeconomic order. Population mobility enhances social stability by advancing economic development and standards of living. Population mobility allows for the smooth transfer of surplus labor during periods of economic change to a modern economy. A poor economy and deteriorated living conditions lead to violent social disturbances, social conflicts, and resentment among the public. Adverse effects on social stability include increased crime, housing scarcity and temporary shelters, and social conflicts between urban residents and migrants. Government strategies should include the direction of surplus migrants into multiple channels. Six channels are identified. Rural labor should be encouraged to work in enterprises and to

  8. Beyond Creation of Mesoporosity: The Advantages of Polymer-Based Dual-Function Templates for Fabricating Hierarchical Zeolites

    KAUST Repository

    Tian, Qiwei

    2016-02-05

    Direct synthesis of hierarchical zeolites currently relies on the use of surfactant-based templates to produce mesoporosity by the random stacking of 2D zeolite sheets or the agglomeration of tiny zeolite grains. The benefits of using nonsurfactant polymers as dual-function templates in the fabrication of hierarchical zeolites are demonstrated. First, the minimal intermolecular interactions of nonsurfactant polymers impose little interference on the crystallization of zeolites, favoring the formation of 3D continuous zeolite frameworks with a long-range order. Second, the mutual interpenetration of the polymer and the zeolite networks renders disordered but highly interconnected mesopores in zeolite crystals. These two factors allow for the synthesis of single-crystalline, mesoporous zeolites of varied compositions and framework types. A representative example, hierarchial aluminosilicate (meso-ZSM-5), has been carefully characterized. It has a unique branched fibrous structure, and far outperforms bulk aluminosilicate (ZSM-5) as a catalyst in two model reactions: conversion of methanol to aromatics and catalytic cracking of canola oil. Third, extra functional groups in the polymer template can be utilized to incorporate desired functionalities into hierarchical zeolites. Last and most importantly, polymer-based templates permit heterogeneous nucleation and growth of mesoporous zeolites on existing surfaces, forming a continuous zeolitic layer. In a proof-of-concept experiment, unprecedented core-shell-structured hierarchical zeolites are synthesized by coating mesoporous zeolites on the surfaces of bulk zeolites. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Kub5-Hera, the human Rtt103 homolog, plays dual functional roles in transcription termination and DNA repair.

    Science.gov (United States)

    Morales, Julio C; Richard, Patricia; Rommel, Amy; Fattah, Farjana J; Motea, Edward A; Patidar, Praveen L; Xiao, Ling; Leskov, Konstantin; Wu, Shwu-Yuan; Hittelman, Walter N; Chiang, Cheng-Ming; Manley, James L; Boothman, David A

    2014-04-01

    Functions of Kub5-Hera (In Greek Mythology Hera controlled Artemis) (K-H), the human homolog of the yeast transcription termination factor Rtt103, remain undefined. Here, we show that K-H has functions in both transcription termination and DNA double-strand break (DSB) repair. K-H forms distinct protein complexes with factors that repair DSBs (e.g. Ku70, Ku86, Artemis) and terminate transcription (e.g. RNA polymerase II). K-H loss resulted in increased basal R-loop levels, DSBs, activated DNA-damage responses and enhanced genomic instability. Significantly lowered Artemis protein levels were detected in K-H knockdown cells, which were restored with specific K-H cDNA re-expression. K-H deficient cells were hypersensitive to cytotoxic agents that induce DSBs, unable to reseal complex DSB ends, and showed significantly delayed γ-H2AX and 53BP1 repair-related foci regression. Artemis re-expression in K-H-deficient cells restored DNA-repair function and resistance to DSB-inducing agents. However, R loops persisted consistent with dual roles of K-H in transcription termination and DSB repair.

  10. Assessing language and visuospatial functions with one task: a "dual use" approach to performing fMRI in children.

    Science.gov (United States)

    Ebner, Kathina; Lidzba, Karen; Hauser, Till-Karsten; Wilke, Marko

    2011-10-01

    In order to increase the rate of successful functional MR studies in children it is helpful to shorten the time spent in the scanner. To this effect, assessing two cognitive functions with one task seems to be a promising approach. The hypothesis of this study was that the control condition of an established language task (vowel identification task, VIT) requires visuospatial processing and that the control condition (VIT(CC)) therefore may also be applicable to localize visuospatial functions. As a reference task, a visual search task (VST, previously established for use in children) was employed. To test this hypothesis, 43 children (19 f, 24 m; 12.0±2.6, range 7.9 to 17.8 years) were recruited and scanned using both tasks. Second-level random effects group analyses showed activation of left inferior-frontal cortex in the active condition of the VIT, as in previous studies. Additionally, analysis of the VIT(CC) demonstrated activation in right-dominant superior parietal and high-frontal brain regions, classically associated with visuospatial functions; activation seen in the VST was similar with a substantial overlap. However, lateralization in the parietal lobe was significantly more bilateral in the VST than in the VIT(CC). This suggests that the VIT can not only be applied to assess language functions (using the active>control contrast), but also that the control>active condition is useful for assessing visuospatial functions. Future task design may benefit from such a "dual use" approach to performing fMRI not only, but also particularly in children.

  11. Effect of pH on the structure, function, and stability of human calcium/calmodulin-dependent protein kinase IV: combined spectroscopic and MD simulation studies.

    Science.gov (United States)

    Naz, Huma; Shahbaaz, Mohd; Bisetty, Krishna; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

    2016-06-01

    Human calcium/calmodulin-dependent protein kinase IV (CAMKIV) is a member of Ser/Thr protein kinase family. It is regulated by the calcium-calmodulin dependent signal through a secondary messenger, Ca(2+), which leads to the activation of its autoinhibited form. The over-expression and mutation in CAMKIV as well as change in Ca(2+) concentration is often associated with numerous neurodegenerative diseases and cancers. We have successfully cloned, expressed, and purified a functionally active kinase domain of human CAMKIV. To observe the effect of different pH conditions on the structural and functional properties of CAMKIV, we have used spectroscopic techniques such as circular diachroism (CD) absorbance and fluorescence. We have observed that within the pH range 5.0-11.5, CAMKIV maintained both its secondary and tertiary structures, along with its function, whereas significant aggregation was observed at acidic pH (2.0-4.5). We have also performed ATPase activity assays under different pH conditions and found a significant correlation between the structure and enzymatic activities of CAMKIV. In-silico validations were further carried out by modeling the 3-dimensional structure of CAMKIV and then subjecting it to molecular dynamics (MD) simulations to understand its conformational behavior in explicit water conditions. A strong correlation between spectroscopic observations and the output of molecular dynamics simulation was observed for CAMKIV.

  12. A novel dual kinase function of the RET proto-oncogene negatively regulates activating transcription factor 4-mediated apoptosis.

    Science.gov (United States)

    Bagheri-Yarmand, Rozita; Sinha, Krishna M; Gururaj, Anupama E; Ahmed, Zamal; Rizvi, Yasmeen Q; Huang, Su-Chen; Ladbury, John E; Bogler, Oliver; Williams, Michelle D; Cote, Gilbert J; Gagel, Robert F

    2015-05-01

    The RET proto-oncogene, a tyrosine kinase receptor, is widely known for its essential role in cell survival. Germ line missense mutations, which give rise to constitutively active oncogenic RET, were found to cause multiple endocrine neoplasia type 2, a dominant inherited cancer syndrome that affects neuroendocrine organs. However, the mechanisms by which RET promotes cell survival and prevents cell death remain elusive. We demonstrate that in addition to cytoplasmic localization, RET is localized in the nucleus and functions as a tyrosine-threonine dual specificity kinase. Knockdown of RET by shRNA in medullary thyroid cancer-derived cells stimulated expression of activating transcription factor 4 (ATF4), a master transcription factor for stress-induced apoptosis, through activation of its target proapoptotic genes NOXA and PUMA. RET knockdown also increased sensitivity to cisplatin-induced apoptosis. We observed that RET physically interacted with and phosphorylated ATF4 at tyrosine and threonine residues. Indeed, RET kinase activity was required to inhibit the ATF4-dependent activation of the NOXA gene because the site-specific substitution mutations that block threonine phosphorylation increased ATF4 stability and activated its targets NOXA and PUMA. Moreover, chromatin immunoprecipitation assays revealed that ATF4 occupancy increased at the NOXA promoter in TT cells treated with tyrosine kinase inhibitors or the ATF4 inducer eeyarestatin as well as in RET-depleted TT cells. Together these findings reveal RET as a novel dual kinase with nuclear localization and provide mechanisms by which RET represses the proapoptotic genes through direct interaction with and phosphorylation-dependent inactivation of ATF4 during the pathogenesis of medullary thyroid cancer.

  13. Effect of various surface conditioning methods on the adhesion of dual-cure resin cement with MDP functional monomer to zirconia after thermal aging

    NARCIS (Netherlands)

    Ozcan, Mutlu; Nijhuis, Henk; Felipe Valandro, Luiz

    2008-01-01

    This study evaluated the effect of chairside and laboratory types of surface conditioning methods on the adhesion of dual-cure resin cement with MDP functional monomer to zirconia ceramic after thermocycling. Disk-shaped (diameter: 10 mm, thickness: 2 mm) Y-TZP ceramics (Lava(TM), 3M ESPE) were used

  14. Semi-automatic measurement of left ventricular function on dual source computed tomography using five different software tools in comparison with magnetic resonance imaging

    NARCIS (Netherlands)

    de Jonge, G. J.; van der Vleuten, P. A.; Overbosch, J.; Lubbers, D. D.; Jansen-van der Weide, M. C.; Zijlstra, F.; van Ooijen, P. M. A.; Oudkerk, M.

    2011-01-01

    Purpose: To compare left ventricular (LV) function assessment using five different software tools on the same dual source computed tomography (DSCT) datasets with the results of MRI. Materials and methods: Twenty-six patients, undergoing cardiac contrast-enhanced DSCT were included (20 men, mean age

  15. Comparison of (semi-)automatic and manually adjusted measurements of left ventricular function in dual source computed tomography using three different software tools

    NARCIS (Netherlands)

    de Jonge, G. J.; van Ooijen, P. M. A.; Overbosch, J.; Litcheva Gueorguieva, A.; Janssen-van der Weide, M. C.; Oudkerk, M.

    To assess the accuracy of (semi-)automatic measurements of left ventricular (LV) functional parameters in cardiac dual-source computed tomography (DSCT) compared to manually adjusted measurements in three different workstations. Forty patients, who underwent cardiac DSCT, were included (31 men, mean

  16. Semi-automatic measurement of left ventricular function on dual source computed tomography using five different software tools in comparison with magnetic resonance imaging

    NARCIS (Netherlands)

    de Jonge, G. J.; van der Vleuten, P. A.; Overbosch, J.; Lubbers, D. D.; Jansen-van der Weide, M. C.; Zijlstra, F.; van Ooijen, P. M. A.; Oudkerk, M.

    2011-01-01

    Purpose: To compare left ventricular (LV) function assessment using five different software tools on the same dual source computed tomography (DSCT) datasets with the results of MRI. Materials and methods: Twenty-six patients, undergoing cardiac contrast-enhanced DSCT were included (20 men, mean age

  17. A fluoride-sensing receptor based on 2,2'-bis(indolyl)methane by dual-function of colorimetry and fluorescence.

    Science.gov (United States)

    Wei, Wei; Shao, Shi Jun; Guo, Yong

    2015-10-05

    A compound based on 2,2'-bis(indolyl)methane containing nitro group was studied as a new anion receptor. It could recognize selectively F(-) by an increasing fluorescence signal and a visible color change from colorless to blue. The introduction of nitro group induced the spectral dual-function related to the deprotonation of N-H protons.

  18. Comment on "An approximate transfer function for the dual-resonance nonlinear filter model of auditory frequency selectivity" [J. Acoust. Soc. Am. 114, 2112-21171 (L)

    NARCIS (Netherlands)

    Duifhuis, H

    This letter concerns the paper "An approximate transfer function for the dual-resonance nonlinear filter model of auditory frequency selectivity" [E. A. Lopez-Poveda, J. Acoust. Soc. Am. 114, 2112-2117 (2003)]. It proposes a correction of the historical framework in which the paper is presented.

  19. Protein fouling in carbon nanotubes enhanced ultrafiltration membrane: Fouling mechanism as a function of pH and ionic strength

    KAUST Repository

    Lee, Jieun

    2016-11-04

    The protein fouling behavior was investigated in the filtration of the multiwall carbon nanotube (MWCNT) composite membrane and commercial polyethersulfone ultrafiltration (PES-UF) membrane. The effect of solution chemistry such as pH and ionic strength on the protein fouling mechanism was systematically examined using filtration model such as complete pore blocking, intermediate pore blocking and cake layer formation. The results showed that the initial permeate flux pattern and fouling behavior of the MWCNT composite membrane were significantly influenced by pH and ionic strength while the effect of PES-UF membrane on flux was minimal. In a lysozyme (Lys) filtration, the severe pore blocking in the MWCNT membrane was made by the combined effect of intra-foulant interaction (Lys-Lys) and electrostatic repulsion between the membrane surface and the foulant at pH 4.7 and 10.4, and increasing ionic strength where the foulant-foulant interaction and membrane-fouling interaction were weak. In a bovine serum albumin (BSA) filtration, severe pore blocking was reduced by less deposition via the electrostatic interaction between the membrane and foulant at pH 4.7 and 10.4 and increasing ionic strength, at which the interaction between the membrane and BSA became weak. For binary mixture filtration, the protein fouling mechanism was more dominantly affected by foulant-foulant interaction (Lys-BSA, Lys-Lys, and BSA-BSA) at pH 7.0 and increase in ionic strength. This research demonstrates that MWCNT membrane fouling can be alleviated by changing pH condition and ionic strength based on the foulant-foulant interaction and the electrostatic interaction between the membrane and foulant.

  20. The dissolution of high-FeO olivine rock from the Lovasjaervi intrusion (SE-Finland) at 25 deg. C as a function of pH

    Energy Technology Data Exchange (ETDEWEB)

    Duro, Lara [Enviros-Spain S.L. Passeig de Rubi, 29-31, 08197 Valldoreix (Spain); El Aamrani, Fatima [Departament d' Enginyeria Quimica, ETSEIB-UPC (H4), Av. Diagonal 647, 08028 Barcelona (Spain); Rovira, Miquel [CTM-Centre Technologic, Avda. Bases de Manresa 1, 08240 Manresa (Spain); Gimenez, Javier [Departament d' Enginyeria Quimica, ETSEIB-UPC (H4), Av. Diagonal 647, 08028 Barcelona (Spain)]. E-mail: francisco.javier.gimenez@upc.edu; Casas, Ignasi [Departament d' Enginyeria Quimica, ETSEIB-UPC (H4), Av. Diagonal 647, 08028 Barcelona (Spain); Pablo, Joan de [CTM-Centre Technologic, Avda. Bases de Manresa 1, 08240 Manresa (Spain); Bruno, Jordi [Enviros-Spain S.L. Passeig de Rubi, 29-31, 08197 Valldoreix (Spain)

    2005-07-15

    The high-FeO olivine-rich rock from the Lovasjaervi intrusion (65% olivine, 20% plagioclase, 8% magnetite, 4% pyroxene and 3% serpentine) has been proposed as a potential redox-active backfill-additive in deep high level nuclear waste repositories. In this work, the authors report on kinetic dissolution studies of this solid under different pH and redox conditions performed by using a flow-through methodology. Assuming that silicon is mainly released to solution from the olivine contained in the solid, the experimental results have been adjusted to an empirical rate law as a function of proton concentration. The proton concentration reaction orders agree with results found in the literature for both acidic and alkaline pH ranges. The calculations conducted with the reactive transport code RETRASO show that at alkaline pH, the olivine rock might have a lower redox buffer capacity than expected.

  1. Enhancing functional production of a chaperone-dependent lipase in Escherichia coli using the dual expression cassette plasmid

    Directory of Open Access Journals (Sweden)

    Quyen Thi Dinh

    2012-03-01

    folded in vivo into the functional lipase in soluble form whereas the main fraction was still inactive in the form of inclusion bodies. Another controversial finding was that the dual expression cassette plasmid systems E. coli BL21/pELipAB-LipB1a and E. coli/pELipAB-LipB3a secreted the active lipase into the culture medium of 51 and 29 times as high as the single expression cassette plasmid system E. coli pELipABa did, respectively, which has never been reported before. Another interesting finding was that the lipase form LipA6xHis (mature lipase fused with 6× histidine tag expressed in the dual expression cassette plasmid systems (BL21/pELipA-LipB1a and BL21/pELipA-LipB3a showed no lipase activity although the expression level of the lipase and two chaperone forms LipB1 and LipB3 in these systems remained as high as that in E. coli BL21/pELipABa + pELipB1k, BL21/pELipABa + pELipB3k, BL21/pELipAB-LipB1a, and BL21/pELipAB-LipB3a. The addition of Neptune oil or detergents into the LB medium increased the lipase production and secretion by up to 94%. Conclusions Our findings demonstrated that a dual expression cassette plasmid system E. coli could overproduce and secrete the active chaperone-dependent lipase (subfamilies I.1 and I.2 in vivo and an improved dual expression cassette plasmid system E. coli could be potentially applied for industrial-scale production of subfamily I.1 and I.2 lipases.

  2. Functionalized vertically aligned ZnO nanorods for application in electrolyte-insulator-semiconductor based pH sensors and label-free immuno-sensors

    Science.gov (United States)

    Kumar, Narendra; Senapati, Sujata; Kumar, Satyendra; Kumar, Jitendra; Panda, Siddhartha

    2016-04-01

    Vertically aligned ZnO nanorods were grown on a SiO2/Si surface by optimization of the temperature and atmosphere for annealing of the seed. The seed layer annealed at 500 °C in vacuum provided well separated and uniform seeds which also provided the best condition to get densely packed, uniformly distributed, and vertically aligned nanorods. These nanorods grown on the substrates were used to fabricate electrolyte-insulator-semiconductor (EIS) devices for pH sensing. Etching of ZnO at acidic pH prevents the direct use of nanorods for pH sensing. Therefore, the nanorods functionalised with 3-aminopropyltriethoxysilane (APTES) were utilized for pH sensing and showed the pH sensitivity of 50.1 mV/pH. APTES is also known to be used as a linker to immobilize biomolecules (such as antibodies). The EIS device with APTES functionalized nanorods was used for the label free detection of prostate-specific antigen (PSA). Finally, voltage shifts of 23 mV and 35 mV were observed with PSA concentrations of 1 ng/ml and 100 ng/ml, respectively.

  3. Effects of salt concentration and pH on structural and functional properties of Lactobacillus acidophilus: FT-IR spectroscopic analysis.

    Science.gov (United States)

    Gandhi, Akanksha; Shah, Nagendra P

    2014-03-03

    The effects of sodium chloride concentration and varying pH levels on the structural and functional properties of Lactobacillus acidophilus were investigated. Reconstituted skim milk was inoculated with Lb. acidophilus at varying salt concentrations (0, 1, 2, 5 and 10% NaCl) and pH levels (4.0, 5.0 and 6.0) and ACE-inhibitory activity and proteolytic activity were determined and the viable cell count was enumerated after 24h of fermentation at 37 °C. The degree of proteolysis exhibited an increase with higher salt concentration at pH 5.0 and 6.0. ACE-inhibitory activity was found to be the highest at pH 5.0 at all salt concentrations. Fourier transform infrared spectroscopy results demonstrated significant changes occurring beyond 2% NaCl particularly at low pH (4.0). The findings revealed that significant changes occurred in amide I and amide III regions when Lb. acidophilus was subjected to varying salt concentrations.

  4. Electrochemical immunoassay of benzo[a]pyrene based on dual amplification strategy of electron-accelerated Fe{sub 3}O{sub 4}/polyaniline platform and multi-enzyme-functionalized carbon sphere label

    Energy Technology Data Exchange (ETDEWEB)

    Lin Mouhong [Institute of Biomaterials, College of Sciences, South China Agricultural University, Guangzhou 510642, Guangdong Province (China); Liu Yingju, E-mail: liuyingju@hotmail.com [Institute of Biomaterials, College of Sciences, South China Agricultural University, Guangzhou 510642, Guangdong Province (China); Sun Zihong; Zhang Shenglai; Yang Zhuohong [Institute of Biomaterials, College of Sciences, South China Agricultural University, Guangzhou 510642, Guangdong Province (China); Ni Chunlin, E-mail: niclchem@scau.edu.cn [Institute of Biomaterials, College of Sciences, South China Agricultural University, Guangzhou 510642, Guangdong Province (China)

    2012-04-13

    Graphical abstract: Schematic representation of Fe{sub 3}O{sub 4}/PANI/Nafion-based immunosensor using multi-HRP-HCS-Ab{sub 2} bioconjugates as labels. Highlights: Black-Right-Pointing-Pointer An electrochemical immunosensor for high sensitive detection of BaP. Black-Right-Pointing-Pointer A dual amplification strategy by Fe{sub 3}O{sub 4}/PANI/Nafion film and multi-HRP-HCS-Ab{sub 2} label. Black-Right-Pointing-Pointer An accelerated electron transfer pathway by the Fe{sub 3}O{sub 4}/PANI/Nafion film. - Abstract: An electrochemical immunosensor, basing on a dual amplification strategy by employing a biocompatible Fe{sub 3}O{sub 4}/polyaniline/Nafion (Fe{sub 3}O{sub 4}/PANI/Nafion) layer as sensor platform and multi-enzyme-antibody functionalized highly-carbonized spheres (multi-HRP-HCS-Ab{sub 2}) as label, was constructed for sensitive detection of benzo[a]pyrene (BaP). The stable film, Fe{sub 3}O{sub 4}/PANI/Nafion, can not only immobilize biomolecules, but also catalyze the reduction of hydrogen peroxide, indicating an accelerated electron transfer pathway of the platform. The experimental conditions, including the concentration of Nafion, concentration of Fe{sub 3}O{sub 4}/polyaniline (Fe{sub 3}O{sub 4}/PANI), pH of the detection solution and concentrations of biomolecules, were studied in detail. Basing on a competitive immunoassay, the current change was proportional to the logarithm of BaP concentration in the range of 8 pM and 2 nM with the detection limit of 4 pM. The proposed immunosensor exhibited acceptable reproducibility and stability. This new type of dual amplification strategy may provide potential applications for the detection of environmental pollutants.

  5. Sorption of lead in soil as a function of pH: a study case in México.

    Science.gov (United States)

    Martínez-Villegas, N; Flores-Vélez, L Ma; Domínguez, O

    2004-12-01

    Reactions of lead sorption onto soil are largely affected by properties and composition of soil and its solution. In this study, the lead sorption onto regosol eutric soil from Francisco I. Madero, Zacatecas, Mexico is evaluated at different pH values. Soil samples were suspended in lead solutions of 10, 25, 50, 100, 150, 200, 300, and 400 mg/l (as Pb(NO3)2). The pH was adjusted at 2, 3, 4, and 5.5 with nitric acid for each of the lead solution concentrations. In all the cases the ionic strength was I=0.09 M with calcium nitrate. The solid-liquid-ratios were fixed in 1:100 and 1:200 g/ml. The results show that lead sorption increases when pH increases. Experimental isotherms were adjusted by both Langmuir and Freundlich models. The Langmuir affinity parameter, K, indicates that the lead sorption capacity of Francisco I. Madero soils is largely perceptible to pH changes.

  6. Chemical modification and pH dependence of kinetic parameters to identify functional groups in a glucosyltransferase from Strep. Mutans

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.E.; Leone, A.; Bell, E.T.

    1986-05-01

    A glucosyltransferase, forming a predominantly al-6 linked glucan, was partially purified from the culture filtrate of S. mutans GS-5. The kinetic properties of the enzyme, assessed using the transfer of /sup 14/C glucose from sucrose into total glucan, were studied at pH values from pH 3.5 to 6.5. From the dependence of km on pH, a group with pKa = 5.5 must be protonated to maximize substrate binding. From plots of V/sub max/ vs pH two groups, with pKa's of 4.5 and 5.5 were indicated. The results suggest the involvement of either two carboxyl groups (one protonated, one unprotonated in the native enzyme) or a carboxyl group (unprotonated) and some other protonated group such as histidine, cysteine. Chemical modification studies showed that Diethylyrocarbonate (histidine specific) had no effect on enzyme activity while modification with p-phydroxy-mercuribenzoate or iodoacetic acid (sulfhydryl reactive) and carbodimide reagents (carboxyl specific) resulted in almost complete inactivation. Activity loss was dependent upon time of incubation and reagent concentration. The disaccharide lylose, (shown to be an inhibitor of the enzyme with similar affinity to sucrose) offers no protection against modification by the sulfhydryl reactive reagents.

  7. Functional Assessment of Disease-Associated Regulatory Variants In Vivo Using a Versatile Dual Colour Transgenesis Strategy in Zebrafish

    Science.gov (United States)

    Bhatia, Shipra; Gordon, Christopher T.; Foster, Robert G.; Melin, Lucie; Abadie, Véronique; Baujat, Geneviève; Vazquez, Marie-Paule; Amiel, Jeanne; Lyonnet, Stanislas; van Heyningen, Veronica; Kleinjan, Dirk A.

    2015-01-01

    Disruption of gene regulation by sequence variation in non-coding regions of the genome is now recognised as a significant cause of human disease and disease susceptibility. Sequence variants in cis-regulatory elements (CREs), the primary determinants of spatio-temporal gene regulation, can alter transcription factor binding sites. While technological advances have led to easy identification of disease-associated CRE variants, robust methods for discerning functional CRE variants from background variation are lacking. Here we describe an efficient dual-colour reporter transgenesis approach in zebrafish, simultaneously allowing detailed in vivo comparison of spatio-temporal differences in regulatory activity between putative CRE variants and assessment of altered transcription factor binding potential of the variant. We validate the method on known disease-associated elements regulating SHH, PAX6 and IRF6 and subsequently characterise novel, ultra-long-range SOX9 enhancers implicated in the craniofacial abnormality Pierre Robin Sequence. The method provides a highly cost-effective, fast and robust approach for simultaneously unravelling in a single assay whether, where and when in embryonic development a disease-associated CRE-variant is affecting its regulatory function. PMID:26030420

  8. The Role of Ruthenium in CO2 Capture and Catalytic Conversion to Fuel by Dual Function Materials (DFM

    Directory of Open Access Journals (Sweden)

    Shuoxun Wang

    2017-03-01

    Full Text Available Development of sustainable energy technologies and reduction of carbon dioxide in the atmosphere are the two effective strategies in dealing with current environmental issues. Herein we report a Dual Function Material (DFM consisting of supported sodium carbonate in intimate contact with dispersed Ru as a promising catalytic solution for combining both approaches. The Ru-Na2CO3 DFM deposited on Al2O3 captures CO2 from a flue gas and catalytically converts it to synthetic natural gas (i.e., methane using H2 generated from renewable sources. The Ru in the DFM, in combination with H2, catalytically hydrogenates both adsorbed CO2 and the bulk Na2CO3, forming methane. The depleted sites adsorb CO2 through a carbonate reformation process and in addition adsorb CO2 on its surface. This material functions well in O2- and H2O-containing flue gas where the favorable Ru redox property allows RuOx, formed during flue gas exposure, to be reduced during the hydrogenation cycle. As a combined CO2 capture and utilization scheme, this technology overcomes many of the limitations of the conventional liquid amine-based CO2 sorbent technology.

  9. Hypersensitive dual-function luminescence switching of a silver-chalcogenolate cluster-based metal-organic framework

    Science.gov (United States)

    Huang, Ren-Wu; Wei, Yong-Sheng; Dong, Xi-Yan; Wu, Xiao-Hui; Du, Chen-Xia; Zang, Shuang-Quan; Mak, Thomas C. W.

    2017-07-01

    Silver(I) chalcogenide/chalcogenolate clusters are promising photofunctional materials for sensing, optoelectronics and solar energy harvesting applications. However, their instability and poor room-temperature luminescent quantum yields have hampered more extensive study. Here, we graft such clusters to adaptable bridging ligands, enabling their interconnection and the formation of rigid metal-organic frameworks. By controlling the spatial separation and orientation of the clusters, they then exhibit enhanced stability (over one year) and quantum yield (12.1%). Ultrafast dual-function fluorescence switching (volatile organic compounds. Single-crystal X-ray diffraction of the inclusion materials, obtained by single-crystal-to-single-crystal transformation, enables precise determination of the position of the small molecules within the framework, elucidating the switching mechanism. The work enriches the cluster-based metal-organic framework portfolio, bridges the gap between silver chalcogenide/chalcogenolate clusters and metal-organic frameworks, and provides a foundation for further development of functional silver-cluster-based materials.

  10. Modelling biofilm formation of Salmonella enterica ser. Newport as a function of pH and water activity.

    Science.gov (United States)

    Dimakopoulou-Papazoglou, Dafni; Lianou, Alexandra; Koutsoumanis, Konstantinos P

    2016-02-01

    The effect of pH and water activity (aw) on the formation of biofilm by Salmonella enterica ser. Newport, previously identified as a strong biofilm producer, was assessed. Biofilm formation was evaluated in tryptone soy broth at 37 °C and at different combinations of pH (3.3-7.8) and aw (0.894-0.997). In total, 540 biofilm formation tests in 108 pH and aw combinations were carried out in polystyrene microtiter plates using crystal violet staining and optical density (OD; 580 nm) measurements. Since the individual effects of pH and aw on biofilm formation had a similar pattern to that observed for microbial growth rate, cardinal parameter models (CPMs) were used to describe these effects. CPMs described successfully the effects of these two environmental parameters, with the estimated cardinal values of pHmin, pHopt, pHmax, awmin and awopt being 3.58, 6.02, 9.71, 0.894 and 0.994, respectively. The CPMs assumption of the multiplicative inhibitory effect of environmental factors was validated in the case of biofilm formation using additional independent data (i.e. 430 OD data at 86 different combinations of pH and aw). The validation results showed a good agreement (r(2) = 0.938) between observed and predicted OD with no systematic error. In the second part of this study, a probabilistic model predicting the pathogen's biofilm formation boundaries was developed, and the degree of agreement between predicted probabilities and observations was as high as 99.8%. Hence, the effect of environmental parameters on biofilm formation can be quantitatively expressed using mathematical models, with the latter models, in turn, providing useful information for biofilm control in food industry environments.

  11. A single-point mutation enhances dual functionality of a scorpion toxin.

    Science.gov (United States)

    Wang, Xueli; Gao, Bin; Zhu, Shunyi

    2016-01-01

    Scorpion venom represents a tremendous, hitherto partially explored peptide library that has been proven to be useful not only for understanding ion channels but also for drug design. MeuTXKα3 is a functionally unknown scorpion toxin-like peptide. Here we describe new transcripts of this gene arising from alternative polyadenylation and its biological function as well as a mutant with a single-point substitution at site 30. Native-like MeuTXKα3 and its mutant were produced in Escherichia coli and their toxic function against Drosophila Shaker K(+) channel and its mammalian counterparts (rKv1.1-rKv1.3) were assayed by two-electrode voltage clamp technique. The results show that MeuTXKα3 is a weak toxin with a wide-spectrum of activity on both Drosophila and mammalian K(+) channels. The substitution of a proline at site 30 by an asparagine, an evolutionarily conserved functional residue in the scorpion α-KTx family, led to an increased activity on rKv1.2 and rKv1.3 but a decreased activity on the Shaker channel without changing the potency on rKv1.1, suggesting a key role of this site in species selectivity of scorpion toxins. MeuTXKα3 was also active on a variety of bacteria with lethal concentrations ranging from 4.66 to 52.01μM and the mutant even had stronger activity on some of these bacterial species. To the best of our knowledge, this is the first report on a bi-functional short-chain peptide in the lesser Asian scorpion venom. Further extensive mutations of MeuTXKα3 at site 30 could help improve its K(+) channel-blocking and antibacterial functions.

  12. Semiclassical partition function for strings dual to Wilson loops with small cusps in ABJM

    Science.gov (United States)

    Aguilera-Damia, Jeremías; Correa, Diego H.; Silva, Guillermo A.

    2015-03-01

    We compute the 1-loop partition function for strings in , whose worldsheets end along a line with small cusp angles in the boundary of AdS. We obtain these 1-loop results in terms of the vacuum energy for on-shell modes. Our results verify the proposal by Lewkowycz and Maldacena in arXiv:1312.5682 for the exact Bremsstrahlung function up to the next to leading order in the strong coupling expansion. The agreement is observed for cusps distorting either the 1/2 BPS or the 1/6 BPS Wilson line.

  13. Semiclassical partition function for strings dual to Wilson loops with small cusps in ABJM

    CERN Document Server

    Aguilera-Damia, Jeremias; Silva, Guillermo A

    2014-01-01

    We compute the 1-loop partition function for strings in $AdS_4\\times\\mathbb{CP}^3$, whose worldsheets end along a line with small cusp angles in the boundary of AdS. We obtain these 1-loop results in terms of the vacuum energy for on-shell modes. Our results verify the proposal by Lewkowycz and Maldacena in arXiv:1312.5682 for the exact Bremsstrahlung function up to the next to leading order in the strong coupling expansion. The agreement is observed for cusps distorting either the 1/2 BPS or the 1/6 BPS Wilson line.

  14. Gender differential item functioning on a national field-specific test: The case of PhD entrance exam of TEFL in Iran

    Directory of Open Access Journals (Sweden)

    Alireza Ahmadi

    2016-01-01

    Full Text Available Differential Item Functioning (DIF exists when examinees of equal ability from different groups have different probabilities of successful performance in a certain item. This study examined gender differential item functioning across the PhD Entrance Exam of TEFL (PEET in Iran, using both logistic regression (LR and one-parameter item response theory (1-p IRT models. The PEET is a national test consisting of a centralized written examination designed to provide information on the eligibility of PhD applicants of TEFL to enter PhD programs. The 2013 administration of this test provided score data for a sample of 999 Iranian PhD applicants consisting of 397 males and 602 females. First, the data were subjected to DIF analysis through logistic regression (LR model. Then, to triangulate the findings, a 1-p IRT procedure was applied. The results indicated (1 more items flagged for DIF by LR than by 1-p IRT (2 DIF cancellation (the number of DIF items were equal for both males and females, as revealed through LR, (3 equal number of uniform and non-uniform DIF, as tracked via LR, and (4 female superiority in the test performance, as revealed via IRT analysis. Overall, the findings of the study indicated that PEET suffers from DIF. As such, test developers and policymakers (like NOET & MSRT are recommended to take these findings into serious consideration and exercise care in fair test practice by dedicating effort to more unbiased test development and decision making.

  15. Exploring the process-structure-function relationship of horseradish peroxidase through investigation of pH- and heat induced conformational changes

    Science.gov (United States)

    Stănciuc, Nicoleta; Aprodu, Iuliana; Ioniță, Elena; Bahrim, Gabriela; Râpeanu, Gabriela

    2015-08-01

    Given the importance of peroxidase as an indicator for the preservation of vegetables by heat treatment, the present study is focused on enzyme behavior under different pH and temperature conditions, in terms of process-structure-function relationships. Thus, the process-structure-function relationship of peroxidase was investigated by combining fluorescence spectroscopy, in silico prediction methods and inactivation kinetic studies. The fluorescence spectra indicated that at optimum pH value, the Trp117 residue is not located in the hydrophobic core of the protein. Significant blue- and red-shifts were obtained at different pH values, whereas the heat-treatment did not cause significant changes in Trp and Tyr environment. The ANS and quenching experiments demonstrated a more flexible conformation at lower pH and respectively at higher temperature. On the other hand molecular dynamics simulations at different temperatures highlighted that the secondary structure appeared better preserved against temperature, whereas the tertiary structure around the heme was more affected. Temperature dependent changes in the hydrogen bonding and ion paring involving amino acids from the heme-binding region (His170 and Asp247) might trigger miss-coordination of the heme iron atom by His170 residue and further enzyme activity loss.

  16. Fuzzy optimization of primal-dual pair using piecewise linear membership functions

    Directory of Open Access Journals (Sweden)

    Pandey D.

    2012-01-01

    Full Text Available Present paper improves the model of Bector and Chandra [Fuzzy Sets and Systems, 125 (2002 317-325] on duality in fuzzy linear programming by using non-linear membership functions. Numerical problem discussed by these authors has also been worked out through our non-linear model to demonstrate improved optimality of the results.

  17. Dual functions of ASCIZ in the DNA base damage response and pulmonary organogenesis.

    Directory of Open Access Journals (Sweden)

    Sabine Jurado

    2010-10-01

    Full Text Available Zn²(+-finger proteins comprise one of the largest protein superfamilies with diverse biological functions. The ATM substrate Chk2-interacting Zn²(+-finger protein (ASCIZ; also known as ATMIN and ZNF822 was originally linked to functions in the DNA base damage response and has also been proposed to be an essential cofactor of the ATM kinase. Here we show that absence of ASCIZ leads to p53-independent late-embryonic lethality in mice. Asciz-deficient primary fibroblasts exhibit increased sensitivity to DNA base damaging agents MMS and H2O2, but Asciz deletion knock-down does not affect ATM levels and activation in mouse, chicken, or human cells. Unexpectedly, Asciz-deficient embryos also exhibit severe respiratory tract defects with complete pulmonary agenesis and severe tracheal atresia. Nkx2.1-expressing respiratory precursors are still specified in the absence of ASCIZ, but fail to segregate properly within the ventral foregut, and as a consequence lung buds never form and separation of the trachea from the oesophagus stalls early. Comparison of phenotypes suggests that ASCIZ functions between Wnt2-2b/ß-catenin and FGF10/FGF-receptor 2b signaling pathways in the mesodermal/endodermal crosstalk regulating early respiratory development. We also find that ASCIZ can activate expression of reporter genes via its SQ/TQ-cluster domain in vitro, suggesting that it may exert its developmental functions as a transcription factor. Altogether, the data indicate that, in addition to its role in the DNA base damage response, ASCIZ has separate developmental functions as an essential regulator of respiratory organogenesis.

  18. Functional Groups Determine Biochar Properties (pH and EC) as Studied by Two-Dimensional (13)C NMR Correlation Spectroscopy.

    Science.gov (United States)

    Li, Xiaoming; Shen, Qirong; Zhang, Dongqing; Mei, Xinlan; Ran, Wei; Xu, Yangchun; Yu, Guanghui

    2013-01-01

    While the properties of biochar are closely related to its functional groups, it is unclear under what conditions biochar develops its properties. In this study, two-dimensional (2D) (13)C nuclear magnetic resonance (NMR) correlation spectroscopy was for the first time applied to investigate the development of functional groups and establish their relationship with biochar properties. The results showed that the agricultural biomass carbonized to biochars was a dehydroxylation/dehydrogenation and aromatization process, mainly involving the cleavage of O-alkylated carbons and anomeric O-C-O carbons in addition to the production of fused-ring aromatic structures and aromatic C-O groups. With increasing charring temperature, the mass cleavage of O-alkylated groups and anomeric O-C-O carbons occurred prior to the production of fused-ring aromatic structures. The regression analysis between functional groups and biochar properties (pH and electrical conductivity) further demonstrated that the pH and electrical conductivity of rice straw derived biochars were mainly determined by fused-ring aromatic structures and anomeric O-C-O carbons, but the pH of rice bran derived biochars was determined by both fused-ring aromatic structures and aliphatic O-alkylated (HCOH) carbons. In summary, this work suggests a novel tool for characterising the development of functional groups in biochars.

  19. Functional Groups Determine Biochar Properties (pH and EC as Studied by Two-Dimensional (13C NMR Correlation Spectroscopy.

    Directory of Open Access Journals (Sweden)

    Xiaoming Li

    Full Text Available While the properties of biochar are closely related to its functional groups, it is unclear under what conditions biochar develops its properties. In this study, two-dimensional (2D (13C nuclear magnetic resonance (NMR correlation spectroscopy was for the first time applied to investigate the development of functional groups and establish their relationship with biochar properties. The results showed that the agricultural biomass carbonized to biochars was a dehydroxylation/dehydrogenation and aromatization process, mainly involving the cleavage of O-alkylated carbons and anomeric O-C-O carbons in addition to the production of fused-ring aromatic structures and aromatic C-O groups. With increasing charring temperature, the mass cleavage of O-alkylated groups and anomeric O-C-O carbons occurred prior to the production of fused-ring aromatic structures. The regression analysis between functional groups and biochar properties (pH and electrical conductivity further demonstrated that the pH and electrical conductivity of rice straw derived biochars were mainly determined by fused-ring aromatic structures and anomeric O-C-O carbons, but the pH of rice bran derived biochars was determined by both fused-ring aromatic structures and aliphatic O-alkylated (HCOH carbons. In summary, this work suggests a novel tool for characterising the development of functional groups in biochars.

  20. An α-helical core encodes the dual functions of the chlamydial protein IncA.

    Science.gov (United States)

    Ronzone, Erik; Wesolowski, Jordan; Bauler, Laura D; Bhardwaj, Anshul; Hackstadt, Ted; Paumet, Fabienne

    2014-11-28

    Chlamydia is an intracellular bacterium that establishes residence within parasitophorous compartments (inclusions) inside host cells. Chlamydial inclusions are uncoupled from the endolysosomal pathway and undergo fusion with cellular organelles and with each other. To do so, Chlamydia expresses proteins on the surface of the inclusion using a Type III secretion system. These proteins, termed Incs, are located at the interface between host and pathogen and carry out the functions necessary for Chlamydia survival. Among these Incs, IncA plays a critical role in both protecting the inclusion from lysosomal fusion and inducing the homotypic fusion of inclusions. Within IncA are two regions homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) domains referred to as SNARE-like domain 1 (SLD1) and SNARE-like domain 2 (SLD2). Using a multidisciplinary approach, we have discovered the functional core of IncA that retains the ability to both inhibit SNARE-mediated fusion and promote the homotypic fusion of Chlamydia inclusions. Circular dichroism and analytical ultracentrifugation experiments show that this core region is composed almost entirely of α-helices and assembles into stable homodimers in solution. Altogether, we propose that both IncA functions are encoded in a structured core domain that encompasses SLD1 and part of SLD2. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. An α-Helical Core Encodes the Dual Functions of the Chlamydial Protein IncA*

    Science.gov (United States)

    Ronzone, Erik; Wesolowski, Jordan; Bauler, Laura D.; Bhardwaj, Anshul; Hackstadt, Ted; Paumet, Fabienne

    2014-01-01

    Chlamydia is an intracellular bacterium that establishes residence within parasitophorous compartments (inclusions) inside host cells. Chlamydial inclusions are uncoupled from the endolysosomal pathway and undergo fusion with cellular organelles and with each other. To do so, Chlamydia expresses proteins on the surface of the inclusion using a Type III secretion system. These proteins, termed Incs, are located at the interface between host and pathogen and carry out the functions necessary for Chlamydia survival. Among these Incs, IncA plays a critical role in both protecting the inclusion from lysosomal fusion and inducing the homotypic fusion of inclusions. Within IncA are two regions homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) domains referred to as SNARE-like domain 1 (SLD1) and SNARE-like domain 2 (SLD2). Using a multidisciplinary approach, we have discovered the functional core of IncA that retains the ability to both inhibit SNARE-mediated fusion and promote the homotypic fusion of Chlamydia inclusions. Circular dichroism and analytical ultracentrifugation experiments show that this core region is composed almost entirely of α-helices and assembles into stable homodimers in solution. Altogether, we propose that both IncA functions are encoded in a structured core domain that encompasses SLD1 and part of SLD2. PMID:25324548

  2. Nxnl2 splicing results in dual functions in neuronal cell survival and maintenance of cell integrity

    Science.gov (United States)

    Jaillard, Céline; Mouret, Aurélie; Niepon, Marie-Laure; Clérin, Emmanuelle; Yang, Ying; Lee-Rivera, Irene; Aït-Ali, Najate; Millet-Puel, Géraldine; Cronin, Thérèse; Sedmak, Tina; Raffelsberger, Wolfgang; Kinzel, Bernd; Trembleau, Alain; Poch, Olivier; Bennett, Jean; Wolfrum, Uwe; Lledo, Pierre-Marie; Sahel, José-Alain; Léveillard, Thierry

    2012-01-01

    The Rod-derived Cone Viability Factors, RdCVF and RdCVF2, have potential therapeutical interests for the treatment of inherited photoreceptor degenerations. In the mouse lacking Nxnl2, the gene encoding RdCVF2, the progressive decline of the visual performance of the cones in parallel with their degeneration arises due to loss of trophic support from RdCVF2. Contrarily, the progressive loss of rod visual function of the Nxnl2−/− mouse results from a decrease in outer segment length, mediated by a cell-autonomous mechanism involving the putative thioredoxin protein RdCVF2L, the second spliced product of the Nxnl2 gene. This novel signaling mechanism extends to olfaction as shown by the progressive impairment of olfaction in aged Nxnl2−/− mice and the protection of olfactory neurons by RdCVF2. This study shows that Nxnl2 is a bi-functional gene involved in the maintenance of both the function and the viability of sensory neurons. PMID:22343139

  3. Dual bronchodilation in COPD: lung function and patient-reported outcomes – a review

    Directory of Open Access Journals (Sweden)

    Price D

    2016-12-01

    Full Text Available David Price,1,2 Anders Østrem,3 Mike Thomas,4 Tobias Welte5 1Department of Primary Care Respiratory Medicine, Division of Applied Health Sciences, University of Aberdeen, Aberdeen, UK; 2Observational and Pragmatic Research Institute, Singapore; 3Gransdalen Legesenter, Oslo, Norway; 4Department of Primary Care Research, University of Southampton, Southampton, UK; 5Department of Pulmonary Medicine, Hannover Medical School, Hannover, Germany Abstract: Several fixed-dose combinations (FDCs of long-acting bronchodilators (a long-acting muscarinic antagonist [LAMA] plus a long-acting β2-agonist [LABA] are available for the treatment of COPD. Studies of these FDCs have demonstrated substantial improvements in lung function (forced expiratory volume in 1 second in comparison with their respective constituent monocomponents. Improvements in patient-reported outcomes (PROs, such as symptoms and health status, as well as exacerbation rates, have been reported compared with a LABA or LAMA alone, but results are less consistent. The inconsistencies may in part be owing to differences in study design, methods used to assess study end points, and patient populations. Nevertheless, these observations tend to support an association between improvements in forced expiratory volume in 1 second and improvements in symptom-based outcomes. In order to assess the effects of FDCs on PROs and evaluate relationships between PROs and changes in lung function, we performed a systematic literature search of publications reporting randomized controlled trials of FDCs. Results of this literature search were independently assessed by two reviewers, with a third reviewer resolving any conflicting results. In total, 22 Phase III randomized controlled trials of FDC bronchodilators in COPD were identified, with an additional study including a post-literature search (ten for indacaterol–glycopyrronium once daily, eight for umeclidinium–vilanterol once daily, three for

  4. Bovine carbonyl lactoperoxidase structure at 2.0Å resolution and infrared spectra as a function of pH.

    Science.gov (United States)

    Singh, Amit K; Smith, Michael L; Yamini, Shavait; Ohlsson, Per-Ingvar; Sinha, Mau; Kaur, Punit; Sharma, Sujata; Paul, Jan A K; Singh, Tej P; Paul, K-G

    2012-10-01

    Lactoperoxidase (LPO) is a hemeprotein catalyzing the oxidation of thiocyanate and I(-) into antimicrobials and small aromatic organics after being itself oxidized by H(2)O(2). LPO is excreted by the lungs, mammary glands, found in saliva and tears and protects mammals against bacterial, fungal and viral invasion. The Fe(II) form binds CO which inactivates LPO like many other hemeproteins. We present the 3-dimensional structure of CO-LPO at 2.0Å resolution and infrared (IR) spectra of the iron-bound CO stretch from pH 3 to 8.8 at 1 cm(-1) resolution. The observed Fe-C-O bond angle of 132° is more acute than the electronically related Fe(III), CN-LPO with a Fe-C-N angle of 161°. The orientations of the two ligands are different with the oxygen of CO pointing towards the imidazole of distal His109 while the nitrogen of CN points away, the Fe(II) moves towards His109 while the Fe(III) moves away; both movements are consistent with a hydrogen bond between the distal His109 and CO, but not to the nitrogen of CN-LPO. The IR spectra of CO-LPO exhibit two major CO absorbances with pH dependent relative intensities. Both crystallographic and IR data suggest proton donation to the CO oxygen by His109 with a pK ≈ 4; close to the pH of greatest enzyme turnover. The IR absorbance maxima are consistent with a first order correlation between frequency and Fe(III)/Fe(II) reduction potential at pH 7; both band widths at half-height correlate with electron density donation from Fe(II) to CO as gauged by the reduction potential.

  5. Dual Functional Roles of Molecular Beacon as a MicroRNA Detector and Inhibitor.

    Science.gov (United States)

    Li, Wai Ming; Chan, Ching-Man; Miller, Andrew L; Lee, Chow H

    2017-03-03

    MicroRNAs are essential in many cellular processes. The ability to detect microRNAs is important for understanding its function and biogenesis. This study is aimed at using a molecular beacon to detect miR-430 in developing zebrafish embryos as a proof of principle. miR-430 is crucial for the clearance of maternal mRNA during maternal zygotic transition in embryonic development. Despite its known function, the temporal and spatial expression of miR-430 remains unclear. We used various imaging techniques, including laser scanning confocal microscopy, spinning disk, and lightsheet microscopy, to study the localization of miR-430 and any developmental defects possibly caused by the molecular beacon. Our results show that miR-430 is expressed early in development and is localized in distinct cytoplasmic granules where its target mRNA can be detected. We also show that the designed molecular beacon can inhibit the function of miR-430 and cause developmental defect in the brain, notochord, heart, and kidney, depending on the delivery site within the embryo, suggesting that miR-430 plays a diverse role in embryonic morphogenesis. When compared with morpholino, molecular beacon is 2 orders of magnitude more potent in inhibiting miR-430. Thus, our results reveal that in addition to being used as a valuable tool for the detection of microRNAs in vivo, molecular beacons can also be employed to inhibit microRNAs in a specific manner. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Modulation of Enzymatic Activities of Dual Functional Peroxiredoxin by Gamma Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Hyun; Lee, Seung Sik; Park, Chul Hong; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2012-05-15

    Recently, enzymes have frequently been used as catalysts in various bio-industrial, commercial, and pharmaceutical applications, because they are more stable, more efficient, and less toxic than the synthetic catalysts. However, one of their major disadvantages is their low thermostability, which leads the researchers to develop new forms of industrially important enzymes with increased resistance to inactivation and aggregation. This study describes a strategy for modifying the molecular chaperone activity of peroxiredoxin (Prx) by using gamma irradiation. Prxs are a ubiquitous family of antioxidant enzymes. Upon oxidation of their peroxidatic Cys, the molecules undergo a structural conversion from a low-molecular-weight (LMW) species acting as a peroxidase to a high-molecular-weight (HMW) complex functioning as a chaperone. In the present study, we examined the effect of gamma irradiation on PP1084 with respect to its protein structure and enzymatic function. The use of gamma irradiation as a physical treatment can increase the cohesive strength of the protein by forming cross-links. The aims of the present work were (1) to improve the chaperone activity of PP1084 by gamma irradiation, (2) to identify the 'optimal' intensity of gamma irradiation, and (3) to investigate the influence of gamma irradiation on protein hydrophobicity as related to chaperone function. Following PP1084 treatment with 30 kGy gamma irradiation, the PP1084 chaperone activity enhanced by about 3-4-fold compared with nonirradiated PP1084, while the peroxidase activity decreased. Ongoing research efforts are addressing the physical modifications of PP1084 protein by gamma irradiation

  7. Nxnl2 splicing results in dual functions in neuronal cell survival and maintenance of cell integrity.

    OpenAIRE

    Jaillard, Céline; Mouret, Aurélie; Niepon, Marie-Laure; Clérin, Emmanuelle; Yang, Ying; Lee-Rivera, Irene; Aït-Ali, Najate; Millet-Puel, Géraldine; Cronin, Thérèse; Sedmak, Tina; Raffelsberger, Wolfgang; Kinzel, Bernd; Trembleau, Alain; Poch, Olivier; Bennett, Jean

    2012-01-01

    International audience; The rod-derived cone viability factors, RdCVF and RdCVF2, have potential therapeutical interests for the treatment of inherited photoreceptor degenerations. In the mouse lacking Nxnl2, the gene encoding RdCVF2, the progressive decline of the visual performance of the cones in parallel with their degeneration, arises due to the loss of trophic support from RdCVF2. In contrary, the progressive loss of rod visual function of the Nxnl2-/- mouse results from a decrease in o...

  8. Highly mesoporous single-crystalline zeolite beta synthesized using a nonsurfactant cationic polymer as a dual-function template

    KAUST Repository

    Zhu, Jie

    2014-02-12

    Mesoporous zeolites are useful solid catalysts for conversion of bulky molecules because they offer fast mass transfer along with size and shape selectivity. We report here the successful synthesis of mesoporous aluminosilicate zeolite Beta from a commercial cationic polymer that acts as a dual-function template to generate zeolitic micropores and mesopores simultaneously. This is the first demonstration of a single nonsurfactant polymer acting as such a template. Using high-resolution electron microscopy and tomography, we discovered that the resulting material (Beta-MS) has abundant and highly interconnected mesopores. More importantly, we demonstrated using a three-dimensional electron diffraction technique that each Beta-MS particle is a single crystal, whereas most previously reported mesoporous zeolites are comprised of nanosized zeolitic grains with random orientations. The use of nonsurfactant templates is essential to gaining single-crystalline mesoporous zeolites. The single-crystalline nature endows Beta-MS with better hydrothermal stability compared with surfactant-derived mesoporous zeolite Beta. Beta-MS also exhibited remarkably higher catalytic activity than did conventional zeolite Beta in acid-catalyzed reactions involving large molecules. © 2014 American Chemical Society.

  9. Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties

    Science.gov (United States)

    Xi, Peng; Zhao, Tianxiang; Xia, Lei; Shu, Dengkun; Ma, Menjiao; Cheng, Bowen

    2017-01-01

    Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

  10. Silver nanoparticles-containing dual-function hydrogels based on a guar gum-sodium borohydride system

    Science.gov (United States)

    Dai, Lei; Nadeau, Ben; An, Xingye; Cheng, Dong; Long, Zhu; Ni, Yonghao

    2016-01-01

    Dual-function hydrogels, possessing both stimuli-responsive and self-healing properties, have recently attracted attention of both chemists and materials scientists. Here we report a new paradigm using natural polymer (guar gum, GG) and sodium borohydride (NaBH4), for the preparation of silver nanoparticles (AgNPs)-containing smart hydrogels in a simple, fast and economical way. NaBH4 performs as a reducing agent for AgNPs synthesis using silver nitrate (AgNO3) as the precursor. Meanwhile, sodium metaborate (NaBO2) (from NaBH4) behaves as a cross-linking agent between GG molecular chains. The AgNPs/GG hydrogels with excellent viscoelastic properties can be obtained within 3 min at room temperature without the addition of other cross-linkers. The resultant AgNPs/GG hydrogels are flowable and injectable, and they possess excellent pH/thermal responsive properties. Additionally, they exhibit rapid self-healing capacity. This work introduces a facile and scale-up way to prepare a class of hydrogels that can have great potential to biomedical and other industrial applications. PMID:27819289

  11. Fluorescence assay for glycan expression on living cancer cells based on competitive strategy coupled with dual-functionalized nanobiocomposites.

    Science.gov (United States)

    Fu, Ying; Lu, Danqin; Lin, Bin; Sun, Qianqian; Liu, Kai; Xu, Lili; Zhang, Shengping; Hu, Chen; Wang, Chuangui; Xu, Zhiai; Zhang, Wen

    2013-11-21

    Cell surface glycans are a class of sophisticated biomolecules related to cancer development and progression, and their analysis is of great significance for early cancer diagnosis and treatment. In this paper, we proposed a fluorescence assay to evaluate glycan expression on living cancer cells based on a competitive strategy coupled with dual-functionalized nanobiocomposites. The competitive assay was conducted between living cancer cells and thiomannosyl derivatives using concanavalin A (Con A)-modified electrode as the interaction platform. To impart fluorescence signaling ability to competitive derivatives, quantum dots (QDs) were anchored on BSA-protected Au nanoparticles, and thiomannosyl derivatives were further immobilized on the nanoparticle surface through Au-S binding. Due to the spacing between QDs and Au nanoparticles by BSA, the {QDs-Au-BSA-mannose} nanobiocomposites maintained the fluorescence of QDs and showed binding ability with the Con A-modified electrode. Au nanorods (AuNRs)-modified electrode was used as an effective substrate to immobilize Con A. This assay was successfully applied to the analysis of two cancer cells lines (A549 and QGY-7701). The method is simple and shows promise for the study of glycan expression on living cancer cells.

  12. Functional characterization of avidins in amphioxus Branchiostoma japonicum: Evidence for a dual role in biotin-binding and immune response.

    Science.gov (United States)

    Guo, Xiaomin; Xin, Jiajing; Wang, Peng; Du, Xiaoyuan; Ji, Guangdong; Gao, Zhan; Zhang, Shicui

    2017-05-01

    Avidin is well known for its high affinity to biotin and has been found in many egg-laying vertebrate species. However, little is known about avidin in invertebrate species to date. Here we clearly showed the presence of two avidin genes, Bjavidin1 and Bjavidin2, in the amphioxus Branchiostoma japonicum, the first ones in non-vertebrate animals. We also showed that the expression of both Bjavidin1 and Bjavidin2 were inducible by progesterone, LTA and LPS. Moreover, we demonstrated for the first time that in addition to biotin-binding, the recombinant proteins rBjAVIDIN1 and rBjAVIDIN2 were not only able to interact with Gram-positive and negative bacteria as well as their conserved surface components LTA and LPS but also to enhance phagocytosis of bacteria by macrophages, suggesting that BjAVIDIN1 and BjAVIDIN2 both function as pattern recognition receptors and opsonins. It is thus clear that avidin may play a dual role in biotin-binding and immune response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Dual-functional sensor based on switchable plasmonic structure of VO2 nano-crystal films and Ag nanoparticles.

    Science.gov (United States)

    Yi, Mingfang; Lu, Changgui; Gong, Yan; Qi, Zhengqing; Cui, Yiping

    2014-12-01

    Utilizing the insulator-metal phase transition of vanadium dioxide (VO2) crystal films, we develop a dual-functional sensor based on the coupling between VO2 nano-crystal films and Ag nanoparticles, which can probe fluorescence or Raman signals on the same substrate and it is switchable by changing temperature. At room temperature, the VO2 crystal films is insulator phase and the fluorescence signals of probe molecules (R6G) is detectable (Raman is in "off"). At high temperature (such as 85 °C), the VO2 crystal films become metallic phase. Ag nanoparticles interact with the metal phase of VO2 crystal films to produce stronger localized electric field. The stronger electric field can excite the Raman signals of probe molecules (R6G) and the coupled structure can also emit the Raman signals out efficiently (Raman is in "on"). The switchable probe of fluorescence and Raman signals would have potential applications in active photoelectric components, such as intelligent switch and multifunctional active sensor etc.

  14. Dual-Functional Polyethylene Glycol-b-polyhexanide Surface Coating with in Vitro and in Vivo Antimicrobial and Antifouling Activities.

    Science.gov (United States)

    Zhi, Zelun; Su, Yajuan; Xi, Yuewei; Tian, Liang; Xu, Miao; Wang, Qianqian; Padidan, Sara; Li, Peng; Huang, Wei

    2017-03-29

    In recent years, microbial colonization on the surface of biomedical implants/devices has become a severe threat to human health. Herein, surface-immobilized guanidine derivative block copolymers create an antimicrobial and antifouling dual-functional coating. We report the preparation of an antimicrobial and antifouling block copolymer by the conjugation of polyhexanide (PHMB) with either allyl glycidyl ether or allyloxy polyethylene glycol (APEG; MW 1200 and 2400). The allyl glycidyl ether modified PHMB (A-PHMB) and allyloxy polyethylene glycol1200/2400 modified PHMB (APEG1200/2400-PHMB) copolymers were grafted onto a silicone rubber surface as a bottlebrush-like coating, respectively, using a plasma-UV-assisted surface-initiated polymerization. Both A-PHMB and APEG1200/2400-PHMB coatings exhibited excellent broad-spectrum antimicrobial properties against Gram-negative/positive bacteria and fungi. The APEG2400-PHMB coating displayed an improved antibiofilm as well as antifouling properties and a long reusable cycle, compared with two other coatings, due to its abundant PEG blocks among those copolymers. Also, the APEG2400-PHMB-coated silicone coupons were biocompatible toward mammalian cells, as revealed by in vitro hemocompatibile and cytotoxic assays. An in vivo study showed a significant decline of Escherichia coli colonies with a 5-log reduction, indicating the APEG2400-PHMB coating surface worked effectively in the rodent subcutaneous infection model. This PHMB-based block copolymer coating is believed to be an effective strategy to prevent biomaterial-associated infections.

  15. Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties.

    Science.gov (United States)

    Xi, Peng; Zhao, Tianxiang; Xia, Lei; Shu, Dengkun; Ma, Menjiao; Cheng, Bowen

    2017-01-09

    Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

  16. Modeling the growth and death kinetics of Salmonella in poultry litter as a function of pH and water activity.

    Science.gov (United States)

    Payne, J B; Osborne, J A; Jenkins, P K; Sheldon, B W

    2007-01-01

    Contaminated poultry litter, serving as a reservoir for Salmonella, can be linked to both food safety concerns when contaminated birds enter processing plants and environmental concerns when used as a fertilizer. Predictive modeling allows for the estimation of microbial growth or inactivation as a function of controlling environmental growth factors. A study was conducted to observe the combined effects of pH and water activity (A(w)) at a constant temperature on Salmonella populations in used turkey litter to predict microbial response over time. Litter, first pH-adjusted and then inoculated with a 3-strain Salmonella serovar cocktail to an initial concentration of approximately 10(7) cfu/g, was placed into individual sealed plastic containers with saturated salt solutions for controlling A(w). A balanced design including 3 A(w) values (0.84, 0.91, 0.96), 3 pH values (4, 7, 9), and a constant temperature of 30 degrees C was used, with litter samples periodically removed and analyzed for Salmonella populations, pH, and A(w). At each combination of environmental factors, the Churchill or exponential inactivation mathematical models were used to describe the growth and death of Salmonella over time. Salmonella populations exhibited growth (approximately 2 log) with little decline up to 42 d in litter environments of pH 7 and 9 and a A(w) of 0.96. As litter A(w) and pH levels were reduced, populations declined, with the most drastic reductions (approximately 5 log in 9 h) occurring in low-pH (4) and low-A(w) (0.84) environments. Generalized models for bacterial growth and death under grouped pH environments were successfully developed to predict Salmonella behavior in litter over time. These findings suggest that the best management practices and litter treatments that lower litter A(w) to growth and decline of Salmonella populations as a function of pH and A(w) has potential application for use in the development of effective pathogen control strategies at the farm

  17. Structure of dual function iron regulatory protein 1 complexed with ferritin IRE-RNA

    Energy Technology Data Exchange (ETDEWEB)

    Walden, William E.; Selezneva, Anna I.; Dupuy, Jérôme; Volbeda, Anne; Fontecilla-Camps, Juan C.; Theil, Elizabeth C.; Volz1, Karl (IBS); (CHORI); (UIC)

    2011-07-27

    Iron regulatory protein 1 (IRP1) binds iron-responsive elements (IREs) in messenger RNAs (mRNAs), to repress translation or degradation, or binds an iron-sulfur cluster, to become a cytosolic aconitase enzyme. The 2.8 angstrom resolution crystal structure of the IRP1:ferritin H IRE complex shows an open protein conformation compared with that of cytosolic aconitase. The extended, L-shaped IRP1 molecule embraces the IRE stem-loop through interactions at two sites separated by {approx}30 angstroms, each involving about a dozen protein:RNA bonds. Extensive conformational changes related to binding the IRE or an iron-sulfur cluster explain the alternate functions of IRP1 as an mRNA regulator or enzyme.

  18. Dual functions of TiC nanoparticles on tribological performance of Al/graphite composites

    Science.gov (United States)

    Fallahdoost, Hamid; Nouri, Alireza; Azimi, Amin

    2016-06-01

    In this study, the effect of TiC nanoparticles as a reinforcement on the mechanical and tribological properties of Aluminum-based self lubricating composite was investigated. The microstructure, relative density, hardness, and tribological properties of Al/graphite and Al/TiC/graphite composites were examined as a function of graphite content. The tribo-surfaces of the samples were analyzed using SEM and EDS elemental mapping. The results indicated that the addition of TiC nanoparticles not only decreased the wear rate and coefficient of friction of the composites, but also facilitated the formation of a stable graphite layer at longer sliding distances and high sliding velocities by forming a durable graphite/TiC composite on the tribo-surface. Therefore, the stability of graphite layer can be considered as a possible cause for decrease in wear rate of the Al/TiC/graphite composite.

  19. TLE3 Is a Dual-Function Transcriptional Coregulator of Adipogenesis

    DEFF Research Database (Denmark)

    Villanueva, Claudio J; Waki, Hironori; Godio, Cristina

    2011-01-01

    PPARγ and Wnt signaling are central positive and negative regulators of adipogenesis, respectively. Here we identify the groucho family member TLE3 as a transcriptional integrator of the PPARγ and Wnt pathways. TLE3 is a direct target of PPARγ that participates in a feed-forward loop during...... adipocyte differentiation. TLE3 enhances PPARγ activity and functions synergistically with PPARγ on its target promoters to stimulate adipogenesis. At the same time, induction of TLE3 during differentiation provides a mechanism for termination of Wnt signaling. TLE3 antagonizes TCF4 activation by β......-catenin in preadipocytes, thereby inhibiting Wnt target gene expression and reversing β-catenin-dependent repression of adipocyte gene expression. Transgenic expression of TLE3 in adipose tissue in vivo mimics the effects of PPARγ agonist and ameliorates high-fat-diet-induced insulin resistance. Our data suggest that TLE3...

  20. Dual host-defence functions of SPLUNC2/PSP and synthetic peptides derived from the protein.

    Science.gov (United States)

    Gorr, Sven-Ulrik; Abdolhosseini, Mahsa; Shelar, Anuradha; Sotsky, Julie

    2011-08-01

    PSP (parotid secretory protein)/SPLUNC2 (short palate, lung and nasal epithelium clone 2) is expressed in human salivary glands and saliva. The protein exists as an N-glycosylated and non-glycosylated form and both appear to induce agglutination of bacteria, a major antibacterial function for salivary proteins. Both forms of PSP/SPLUNC2 bind LPS (lipopolysaccharide), suggesting that the protein may also play an anti-inflammatory role. Based on the predicted structure of PSP/SPLUNC2 and the location of known antibacterial and anti-inflammatory peptides in BPI (bactericidal/permeability-increasing protein) and LBP (LPS-binding protein), we designed GL13NH2 and GL13K, synthetic peptides that capture these proposed functions of PSP/SPLUNC2. GL13NH3 agglutinates bacteria, leading to increased clearance by macrophages and reduced spread of infection in a plant model. GL13K kills bacteria with a minimal inhibitory concentration of 5-10 μg/ml, kills bacteria in biofilm and retains activity in 150 mM NaCl and 50% saliva. Both peptides block endotoxin action, but only GL13K appears to bind endotoxin. The peptides do not cause haemolysis, haemagglutination in serum, inhibit mammalian cell proliferation or induce an inflammatory response in macrophages. These results suggest that the GL13NH2 and the modified peptide GL13K capture the biological activity of PSP/SPLUNC2 and can serve as lead compounds for the development of novel antimicrobial and anti-inflammatory peptides.

  1. Cation-Specific Conformations in a Dual-Function Ion-Pumping Microbial Rhodopsin.

    Science.gov (United States)

    da Silva, Giordano F Z; Goblirsch, Brandon R; Tsai, Ah-Lim; Spudich, John L

    2015-06-30

    A recently discovered rhodopsin ion pump (DeNaR, also known as KR2) in the marine bacterium Dokdonia eikasta uses light to pump protons or sodium ions from the cell depending on the ionic composition of the medium. In cells suspended in a KCl solution, DeNaR functions as a light-driven proton pump, whereas in a NaCl solution, DeNaR conducts light-driven sodium ion pumping, a novel activity within the rhodopsin family. These two distinct functions raise the questions of whether the conformations of the protein differ in the presence of K(+) or Na(+) and whether the helical movements that result in the canonical E → C conformational change in other microbial rhodopsins are conserved in DeNaR. Visible absorption maxima of DeNaR in its unphotolyzed (dark) state show an 8 nm difference between Na(+) and K(+) in decyl maltopyranoside micelles, indicating an influence of the cations on the retinylidene photoactive site. In addition, electronic paramagnetic resonance (EPR) spectra of the dark states reveal repositioning of helices F and G when K(+) is replaced with Na(+). Furthermore, the conformational changes assessed by EPR spin-spin dipolar coupling show that the light-induced transmembrane helix movements are very similar to those found in bacteriorhodopsin but are altered by the presence of Na(+), resulting in a new feature, the clockwise rotation of helix F. The results establish the first observation of a cation switch controlling the conformations of a microbial rhodopsin and indicate specific interactions of Na(+) with the half-channels of DeNaR to open an appropriate path for ion translocation.

  2. Sulfonic Groups Originated Dual-Functional Interlayer for High Performance Lithium-Sulfur Battery.

    Science.gov (United States)

    Lu, Yang; Gu, Sui; Guo, Jing; Rui, Kun; Chen, Chunhua; Zhang, Sanpei; Jin, Jun; Yang, Jianhua; Wen, Zhaoyin

    2017-05-03

    The lithium-sulfur battery is one of the most prospective chemistries in secondary energy storage field due to its high energy density and high theoretical capacity. However, the dissolution of polysulfides in liquid electrolytes causes the shuttle effect, and the rapid decay of lithium sulfur battery has greatly hindered its practical application. Herein, combination of sulfonated reduced graphene oxide (SRGO) interlayer on the separator is adopted to suppress the shuttle effect. We speculate that this SRGO layer plays two roles: physically blocking the migration of polysulfide as ion selective layer and anchoring lithium polysulfide by the electronegative sulfonic group. Lewis acid-base theory and density functional theory (DFT) calculations indicate that sulfonic groups have a strong tendency to interact with lithium ions in the lithium polysulfide. Hence, the synergic effect involved by the sulfonic group contributes to the enhancement of the battery performance. Furthermore, the uniformly distributed sulfonic groups working as active sites which could induce the uniform distribution of sulfur, alleviating the excessive growth of sulfur and enhancing the utilization of active sulfur. With this interlayer, the prototype battery exhibits a high reversible discharge capacity of more than 1300 mAh g(-1) and good capacity retention of 802 mAh g(-1) after 250 cycles at 0.5 C rate. After 60 cycles at different rates from 0.2 to 4 C, the cell with this functional separator still recovered a high specific capacity of 1100 mAh g(-1) at 0.2 C. The results demonstrate a promising interlayer design toward high performance lithium-sulfur battery with longer cycling life, high specific capacity, and rate capability.

  3. Growth and functional responses of different cultivars of Lotus corniculatus to aluminum and low pH stress.

    Science.gov (United States)

    Pavlovkin, Ján; Pal'ove-Balang, Peter; Kolarovic, Lukás; Zelinová, Veronika

    2009-09-15

    Aluminum toxicity is an important stress factor in acid soils. Growth, respiration and permeability properties of root cells were studied in five cultivars of Lotus corniculatus subjected to aluminum (Al) or low pH stress. The cultivars showed significant differences in root elongation under stress conditions, which correlated with changes in membrane potential (E(M)) of root cortical cells. A pH drop from 5.5 to 4.0 resulted in significant membrane depolarization and root growth inhibition. The strongest inhibition was observed in cv. São Gabriel (33.6%) and least in cv. UFRGS (25.8%). Application of an extremely high Al concentration (2mM) stopped the root growth in cv. INIA Draco, while inhibition in cv. UFRGS reached only 75%. The E(M) values of cortical cells of Lotus roots varied between -115 and -144mV. Treatment with 250microM of AlCl(3) (pH 4) resulted in rapid membrane depolarization. The extent of the membrane depolarization ranged between 51mV (cv. UFGRS) and 16mV (cv. INIA Draco). The membrane depolarization was followed by a loss of K(+) from Al-treated roots (2mM Al) and resulted in a decrease of the diffusion potential (E(D)). The total amount of K(+) in Al-treated roots dropped from 31.4 to 16.8micromolg(-1) FW in sensitive cv. INIA Draco, or from 26.1 to 22.7micromolg(-1) FW in tolerant cv. UFGRS. The rate of root respiration under control conditions as well as under Al treatment was higher in cv. INIA Draco than in cv. UFRGS. Al-induced inhibition of root respiration was 21-34% of the control.

  4. Fluorescence-Magnetism Functional EuS Nanocrystals with Controllable Morphologies for Dual Bioimaging.

    Science.gov (United States)

    Sun, Yuanqing; Wang, Dandan; Zhao, Tianxin; Jiang, Yingnan; Zhao, Yueqi; Wang, Chuanxi; Sun, Hongchen; Yang, Bai; Lin, Quan

    2016-12-14

    Multiple functions incorporated in one single component material offer important applications in biosystems. Here we prepared a divalent state of rare earth EuS nanocrystals (NCs), which provides luminescent and magnetic properties, using both 1-Dodecanethiol (DT) and oleylamine (OLA) as reducing agents. The resultant EuS NCs exhibit controllable shapes, uniform size, and bright luminescence with a quantum yield as high as 3.5%. OLA as a surface ligand plays an important role in tunable morphologies, such as nanowires, nanorods, nanospheres et al. Another attractive nature of the EuS NCs is their paramagnetism at room temperature. In order to expand the biological applications, the resultant EuS NCs were modified with amphiphilic block copolymer F127 and transferred from oil to water phase. The excellent biocompatibility of EuS NCs is demonstrated as well as preservation of their luminescence and paramagnetic properties. The EuS NCs offer multifunction and great advantages of bright luminescence, paramagnetic, controllable morphologies, and good biocompatibility promising applications in the field of simultaneous magnetic resonance and fluorescence bioimaging.

  5. Inhibition of Monocyte Adhesion to Brain-Derived Endothelial Cells by Dual Functional RNA Chimeras

    Directory of Open Access Journals (Sweden)

    Jing Hu

    2014-01-01

    Full Text Available Because adhesion of leukocytes to endothelial cells is the first step of vascular-neuronal inflammation, inhibition of adhesion and recruitment of leukocytes to vascular endothelial cells will have a beneficial effect on neuroinflammatory diseases. In this study, we used the pRNA of bacteriophage phi29 DNA packaging motor to construct a novel RNA nanoparticle for specific targeting to transferrin receptor (TfR on the murine brain-derived endothelial cells (bEND5 to deliver ICAM-1 siRNA. This RNA nanoparticle (FRS-NPs contained a FB4 aptamer targeting to TfR and a siRNA moiety for silencing the intercellular adhesion molecule-1 (ICAM-1. Our data indicated that this RNA nanoparticle was delivered into murine brain-derived endothelial cells. Furthermore, the siRNA was released from the FRS-NPs in the cells and knocked down ICAM-1 expression in the TNF-α–stimulated cells and in the cells under oxygen-glucose deprivation/reoxygenation (OGD/R condition. The functional end points of the study indicated that FRS-NPs significantly inhibited monocyte adhesion to the bEND5 cells induced by TNF-α and OGD/R. In conclusion, our approach using RNA nanotechnology for siRNA delivery could be potentially applied for inhibition of inflammation in ischemic stroke and other neuroinflammatory diseases, or diseases affecting endothelium of vasculature.

  6. Monodisperse Dual-Functional Upconversion Nanoparticles Enabled Near-Infrared Organolead Halide Perovskite Solar Cells.

    Science.gov (United States)

    He, Ming; Pang, Xinchang; Liu, Xueqin; Jiang, Beibei; He, Yanjie; Snaith, Henry; Lin, Zhiqun

    2016-03-18

    Extending the spectral absorption of organolead halide perovskite solar cells from visible into near-infrared (NIR) range renders the minimization of non-absorption loss of solar photons with improved energy alignment. Herein, we report on, for the first time, a viable strategy of capitalizing on judiciously synthesized monodisperse NaYF4 :Yb/Er upconversion nanoparticles (UCNPs) as the mesoporous electrode for CH3 NH3 PbI3 perovskite solar cells and more importantly confer perovskite solar cells to be operative under NIR light. Uniform NaYF4 :Yb/Er UCNPs are first crafted by employing rationally designed double hydrophilic star-like poly(acrylic acid)-block-poly(ethylene oxide) (PAA-b-PEO) diblock copolymer as nanoreactor, imparting the solubility of UCNPs and the tunability of film porosity during the manufacturing process. The subsequent incorporation of NaYF4 :Yb/Er UCNPs as the mesoporous electrode led to a high efficiency of 17.8 %, which was further increased to 18.1 % upon NIR irradiation. The in situ integration of upconversion materials as functional components of perovskite solar cells offers the expanded flexibility for engineering the device architecture and broadening the solar spectral use.

  7. A Novel Dual Expression Platform for High Throughput Functional Screening of Phage Libraries in Product like Format.

    Directory of Open Access Journals (Sweden)

    Xiaodong Xiao

    Full Text Available High throughput screenings of single chain Fv (scFv antibody phage display libraries are currently done as soluble scFvs produced in E.coli. Due to endotoxin contaminations from bacterial cells these preparations cannot be reliably used in mammalian cell based assays. The monovalent nature and lack of Fc in soluble scFvs prevent functional assays that are dependent on target cross linking and/or Fc functions. A convenient approach is to convert scFvs into scFv.Fc fusion proteins and express them in mammalian cell lines for screening. This approach is low throughput and is only taken after primary screening of monovalent scFvs that are expressed in bacteria. There is no platform at present that combines the benefits of both bacterial and mammalian expression system for screening phage library output. We have, therefore, developed a novel dual expression vector, called pSplice, which can be used to express scFv.Fc fusion proteins both in E.coli and mammalian cell lines. The hallmark of the vector is an engineered intron which houses the bacterial promoter and signal peptide for expression and secretion of scFv.Fc in E.coli. When the vector is transfected into a mammalian cell line, the intron is efficiently spliced out resulting in a functional operon for expression and secretion of the scFv.Fc fusion protein into the culture medium. By applying basic knowledge of mammalian introns and splisosome, we designed this vector to enable screening of phage libraries in a product like format. Like IgG, the scFv.Fc fusion protein is bi-valent for the antigen and possesses Fc effector functions. Expression in E.coli maintains the speed of the bacterial expression platform and is used to triage clones based on binding and other assays that are not sensitive to endotoxin. Triaged clones are then expressed in a mammalian cell line without the need for any additional cloning steps. Conditioned media from the mammalian cell line containing the fusion proteins

  8. Amino acid derivative-mediated detoxification and functionalization of dual cure dental restorative material for dental pulp cell mineralization.

    Science.gov (United States)

    Minamikawa, Hajime; Yamada, Masahiro; Iwasa, Fuminori; Ueno, Takeshi; Deyama, Yoshiaki; Suzuki, Kuniaki; Yawaka, Yasutaka; Ogawa, Takahiro

    2010-10-01

    Current dental restorative materials are only used to fill the defect of hard tissues, such as dentin and enamel, because of their cytotoxicity. Therefore, exposed dental pulp tissues in deep cavities must be first covered by a pulp capping material like calcium hydroxide to form a layer of mineralized tissue. However, this tissue mineralization is based on pathological reaction and triggers long-lasting inflammation, often causing clinical problems. This study tested the ability of N-acetyl cysteine (NAC), amino acid derivative, to reduce cytotoxicity and induce mineralized tissue conductivity in resin-modified glass ionomer (RMGI), a widely used dental restorative material having dual cure mechanism. Rat dental pulp cells were cultured on untreated or NAC-supplemented RMGI. NAC supplementation substantially increased the percentage of viable cells from 46.7 to 73.3% after 24-h incubation. Cell attachment, spreading, proliferative activity, and odontoblast-related gene and protein expressions increased significantly on NAC-supplemented RMGI. The mineralization capability of cells, which was nearly suppressed on untreated RMGI, was induced on NAC-supplemented RMGI. These improved behaviors and functions of dental pulp cells on NAC-supplemented RMGI were associated with a considerable reduction in the production of intracellular reactive oxygen species and with the increased level of intracellular glutathione reserves. These results demonstrated that NAC could detoxify and functionalize RMGIs via two different mechanisms involving in situ material detoxification and antioxidant cell protection. We believe that this study provides a new approach for developing dental restorative materials that enables mineralized tissue regeneration.

  9. The use of PIB-PET as a dual pathological and functional biomarker in AD.

    Science.gov (United States)

    Forsberg, Anton; Engler, Henry; Blomquist, Gunnar; Långström, Bengt; Nordberg, Agneta

    2012-03-01

    Amyloid imaging with positron emission tomography (PET) is presently used in Alzheimer's disease (AD) research. In this study we investigated the possibility to use early frames (ePIB) of the PIB scans as a rough index of CBF by comparing normalised early PIB values with cerebral glucose metabolism (rCMRglc). PIB-PET and FDG-PET were performed in 37 AD patients, 21 subjects with mild cognitive impairment (MCI) and 6 healthy controls (HC). The patients were divided based on their PIB retention (amyloid load) as either PIB positive (PIB+) or PIB negative (PIB-). Data of the unidirectional influx K(1) from a subset of the subjects including 7 AD patients and 3 HC was used for correlative analysis. Data was analysed using regions of interest (ROI) analysis. A strong, positive correlation was observed across brain regions between K(1) and ePIB (r=0.70; p≤0.001). The ePIB values were significantly lower in the posterior cingulate (p≤0.001) and the parietal cortices (p=0.002) in PIB+ subjects compared to PIB-, although the group difference were stronger for rCMRglc in cortical areas (p≤0.001). Strong positive correlations between ePIB and rCMRglc were observed in all cortical regions analysed, especially in the posterior cingulate and parietal cortices (p≤0.001). A single dynamic PIB-PET scan may provide information about pathological and functional changes (amyloidosis and impaired blood flow). This might be important for diagnosis of AD, enrichment of patients in clinical trials and evaluation of treatment effects. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease.

  10. Integrating folding kinetics and protein function: biphasic kinetics and dual binding specificity in a WW domain.

    Science.gov (United States)

    Karanicolas, John; Brooks, Charles L

    2004-03-09

    Because of the association of beta-sheet formation with the initiation and propagation of amyloid diseases, model systems have been sought to further our understanding of this process. WW domains have been proposed as one such model system. Whereas the folding of the WW domains from human Yes-associated protein (YAP) and Pin have been shown to obey single-exponential kinetics, the folding of the WW domain from formin-binding protein (FBP) 28 has been shown to proceed via biphasic kinetics. From an analysis of free-energy landscapes from atomic-level molecular dynamics simulations, the biphasic folding kinetics observed in the FBP WW domain may be traced to the ability of this WW domain to adopt two slightly different forms of packing in its hydrophobic core. This conformational change is propagated along the peptide backbone and affects the position of a tryptophan residue shown in other WW domains to play a key role in binding. The WW domains of Pin and YAP do not support more than one type of packing each, leading to monophasic folding kinetics. The ability of the FBP WW domain to assume two different types of packing may, in turn, explain the capacity of this WW domain to bind two classes of ligand, a property that is not shared by other WW domains. These findings lead to the hypothesis that lability with respect to conformations separated by an observable barrier as a requirement for function is incompatible with the ability of a protein to fold via single-exponential kinetics.

  11. Preparation of a weak anion exchange/hydrophobic interaction dual-function mixed-mode chromatography stationary phase for protein separation using click chemistry.

    Science.gov (United States)

    Zhao, Kailou; Yang, Fan; Xia, Hongjun; Wang, Fei; Song, Qingguo; Bai, Quan

    2015-03-01

    In this study, 3-diethylamino-1-propyne was covalently bonded to the azide-silica by a click reaction to obtain a novel dual-function mixed-mode chromatography stationary phase for protein separation with a ligand containing tertiary amine and two ethyl groups capable of electrostatic and hydrophobic interaction functionalities, which can display hydrophobic interaction chromatography character in a high-salt-concentration mobile phase and weak anion exchange character in a low-salt-concentration mobile phase employed for protein separation. As a result, it can be employed to separate proteins with weak anion exchange and hydrophobic interaction modes, respectively. The resolution and selectivity of the stationary phase were evaluated in both hydrophobic interaction and ion exchange modes with standard proteins, respectively, which can be comparable to that of conventional weak anion exchange and hydrophobic interaction chromatography columns. Therefore, the synthesized weak anion exchange/hydrophobic interaction dual-function mixed-mode chromatography column can be used to replace two corresponding conventional weak anion exchange and hydrophobic interaction chromatography columns to separate proteins. Based on this mixed-mode chromatography stationary phase, a new off-line two-dimensional liquid chromatography technology using only a single dual-function mixed-mode chromatography column was developed. Nine kinds of tested proteins can be separated completely using the developed method within 2.0 h.

  12. Executive function deficits in team sport athletes with a history of concussion revealed by a visual-auditory dual task paradigm.

    Science.gov (United States)

    Tapper, Anthony; Gonzalez, Dave; Roy, Eric; Niechwiej-Szwedo, Ewa

    2017-02-01

    The purpose of this study was to examine executive functions in team sport athletes with and without a history of concussion. Executive functions comprise many cognitive processes including, working memory, attention and multi-tasking. Past research has shown that concussions cause difficulties in vestibular-visual and vestibular-auditory dual-tasking, however, visual-auditory tasks have been examined rarely. Twenty-nine intercollegiate varsity ice hockey athletes (age = 19.13, SD = 1.56; 15 females) performed an experimental dual-task paradigm that required simultaneously processing visual and auditory information. A brief interview, event description and self-report questionnaires were used to assign participants to each group (concussion, no-concussion). Eighteen athletes had a history of concussion and 11 had no concussion history. The two tests involved visuospatial working memory (i.e., Corsi block test) and auditory tone discrimination. Participants completed both tasks individually, then simultaneously. Two outcome variables were measured, Corsi block memory span and auditory tone discrimination accuracy. No differences were shown when each task was performed alone; however, athletes with a history of concussion had a significantly worse performance on the tone discrimination task in the dual-task condition. In conclusion, long-term deficits in executive functions were associated with a prior history of concussion when cognitive resources were stressed. Evaluations of executive functions and divided attention appear to be helpful in discriminating participants with and without a history concussion.

  13. Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation

    Science.gov (United States)

    Berman, Marvin D.

    2014-01-01

    Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB. PMID:25359538

  14. Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation.

    Science.gov (United States)

    Berman, Marvin D; Carey, Martin C

    2015-01-01

    Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB.

  15. Lateral Protein-Protein Interactions at Hydrophobic and Charged Surfaces as a Function of pH and Salt Concentration.

    Science.gov (United States)

    Hladílková, Jana; Callisen, Thomas H; Lund, Mikael

    2016-04-07

    Surface adsorption of Thermomyces lanuginosus lipase (TLL)-a widely used industrial biocatalyst-is studied experimentally and theoretically at different pH and salt concentrations. The maximum achievable surface coverage on a hydrophobic surface occurs around the protein isoelectric point and adsorption is reduced when either increasing or decreasing pH, indicating that electrostatic protein-protein interactions in the adsorbed layer play an important role. Using Metropolis Monte Carlo (MC) simulations, where proteins are coarse grained to the amino acid level, we estimate the protein isoelectric point in the vicinity of charged surfaces as well as the lateral osmotic pressure in the adsorbed monolayer. Good agreement with available experimental data is achieved and we further make predictions of the protein orientation at hydrophobic and charged surfaces. Finally, we present a perturbation theory for predicting shifts in the protein isoelectric point due to close proximity to charged surfaces. Although this approximate model requires only single protein properties (mean charge and its variance), excellent agreement is found with MC simulations.

  16. Human tooth enamel dissolution in citric acid as a function of degree of saturation and pH

    CERN Document Server

    Barbour, M E

    2002-01-01

    There is increasing concern among the dental community regarding the damage caused to teeth by the acids in soft drinks. Enamel dissolution in acidic solution can be reduced by addition of calcium and/or phosphate salts to increase the degree of saturation with respect to hydroxyapatite (DS sub H sub A), or by an increase in pH. In soft drinks, however, both of these approaches are associated with a reduced taste quality. The separate effects of each parameter are not known. In the work presented here, enamel dissolution was studied in citric acid solutions with compositions typical of soft drinks. Nanoindentation and atomic force microscopy (AFM) were used to investigate very early stages of enamel dissolution, with typical exposure times of 30-600 s. Preliminary investigations of the application of SIMS, ESEM and XPS to enamel dissolution studies are also reported. The individual effects of DS sub H sub A , pH and calcium and phosphate concentrations on enamel dissolution have been investigated. It was show...

  17. Impactful study of dual work function, underlap and hetero gate dielectric on TFET with different drain doping profile for high frequency performance estimation and optimization

    Science.gov (United States)

    Yadav, Dharmendra Singh; Sharma, Dheeraj; Raad, Bhagwan Ram; Bajaj, Varun

    2016-08-01

    This manuscript presents a comparative study of different combination for the dual workfunction gate material, underlap and hetero gate dielectric tunnel field-effect transistors (TFET's). Their performances have been analyzed in terms of ON-state current, ambipolar behaviour and RF response along with different drain doping profile. For this, the Dual work function of gate provides enhancement in ON-state current by reducing the tunnel barrier width at source/channel interface. Whereas, the underlap of gate is done near to the drain region, helps in reduction of ambipolar conduction by creating deficiency of hole for the conduction, which is major hurdle for TFET. Further, the combinations of the dual workfunction and underlap give combine advantages of both such as improve ON-state current and suppressed ambipolar current. Apart from this, the combination of hetero gate dielectric dual workfunction under lapping leads to superior device performance in terms of ON-state current and ambipolar behaviour. The use of hetero gate dielectric and Gaussian doping profile with gate underlap reduces the gate to drain capacitance that also improves the RF parameters of the device.

  18. Enhanced performance of dye-sensitized solar cells with dual-function coadsorbent: reducing the surface concentration of dye-iodine complexes concomitant with attenuated charge recombination.

    Science.gov (United States)

    Mazloum-Ardakani, Mohammad; Khoshroo, Alireza

    2015-09-21

    In this paper, we have investigated the effects of oleic acid as a dual-function coadsorbent on recombination and iodine binding in dye-sensitized solar cells. Oleic acid as a dual-function coadsorbent effectively shields the back electron transfer from TiO2 to I3(-) ions and also reduces the surface concentration of dye-I2 complexes via iodine binding to the unsaturated double bond on oleic acid. It was found that interaction between iodine and the double bond of oleic acid keeps the iodine molecules away from the surface and reduces the recombination rate between injected electrons in a semiconductor and iodine molecules and also increases open-circuit voltage. Furthermore, the interaction between iodine molecules and unexcited dyes affects the UV-Vis spectrum of them and prevents an unfavorable blue shift. Overall, the results point to an improved performance for DSC operation and development.

  19. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    Science.gov (United States)

    Moeys, J.; Larsbo, M.; Bergström, L.; Brown, C. D.; Coquet, Y.; Jarvis, N. J.

    2012-07-01

    Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedo)transfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved. Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42). Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = -0.26) due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72). Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably more important than the

  20. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    Directory of Open Access Journals (Sweden)

    J. Moeys

    2012-07-01

    Full Text Available Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisations usually rely on a set of lookup tables and (pedotransfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved.

    Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42. Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26 due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72. Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is

  1. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    Directory of Open Access Journals (Sweden)

    J. Moeys

    2012-02-01

    Full Text Available Estimating pesticide leaching risks at the regional scale requires the ability to completely parameterise a pesticide fate model using only survey data, such as soil and land-use maps. Such parameterisation usually rely on a set of lookup tables and (pedotransfer functions, relating elementary soil and site properties to model parameters. The aim of this paper is to describe and test a complete set of parameter estimation algorithms developed for the pesticide fate model MACRO, which accounts for preferential flow in soil macropores. We used tracer monitoring data from 16 lysimeter studies, carried out in three European countries, to evaluate the ability of MACRO and this "blind parameterisation" scheme to reproduce measured solute leaching at the base of each lysimeter. We focused on the prediction of early tracer breakthrough due to preferential flow, because this is critical for pesticide leaching. We then calibrated a selected number of parameters in order to assess to what extent the prediction of water and solute leaching could be improved.

    Our results show that water flow was generally reasonably well predicted (median model efficiency, ME, of 0.42. Although the general pattern of solute leaching was reproduced well by the model, the overall model efficiency was low (median ME = −0.26 due to errors in the timing and magnitude of some peaks. Preferential solute leaching at early pore volumes was also systematically underestimated. Nonetheless, the ranking of soils according to solute loads at early pore volumes was reasonably well estimated (concordance correlation coefficient, CCC, between 0.54 and 0.72. Moreover, we also found that ignoring macropore flow leads to a significant deterioration in the ability of the model to reproduce the observed leaching pattern, and especially the early breakthrough in some soils. Finally, the calibration procedure showed that improving the estimation of solute transport parameters is probably

  2. A randomised study to compare salivary pH, calcium, phosphate and calculus formation after using anticavity dentifrices containing Recaldent(®) and functionalized tri-calcium phosphate.

    Science.gov (United States)

    Sharma, Ena; Vishwanathamurthy, Ramesh Alampalli; Nadella, Manjari; Savitha, A N; Gundannavar, Gayatri; Hussain, M Ahad

    2012-10-01

    The aim of this study was to estimate the pH of saliva, concentration of calcium and inorganic phosphate, and calculus formation before and after usage of Recaldent(®) (GC Tooth Mousse Plus™), Functionalized Tricalcium Phosphate (3M ESPE ClinPro™ Tooth Crème) and standard dentifrice (Colgate dental cream). Randomized double-blind study. A total of 50 subjects were recruited, the subjects were assessed at their first visit, on the 21(st) day and on the 42(nd) day. At the first visit, scaling was carried out and oral hygiene instructions were given. After 21 days, the subjects were given coded dentifrices where the operator and the subjects both were unaware of the type of dentifrice. Clinical parameters assessed were Plaque index, Gingival index, and Calculus index. Salivary samples were obtained to measure calcium, phosphate levels, and pH at 21(st) day and 42(nd) day. ANOVA test, t-test, Mann-Whitney test, Kruskal-Wallis test. The mean salivary calcium level and mean salivary phosphate level were higher in Group III (functionalized tricalcium phosphate (3M ESPE ClinPro™ Tooth Creme) as compared to Group II (Recaldent(®) GC Tooth Mousse Plus™) and Group I (Colgate dental cream) on the 42(nd) day after using dentifrices, which was statistically significant. This showed that the usage of remineralizing dentifrices led to an increase in the salivary calcium, phosphate, and pH but it did not reach the level of super saturation of the ions caused by elevated pH which could lead to calculus formation. Thought here was a statistically significant increase in salivary calcium and phosphate level in all three groups from baseline to 42(nd) day, there was no calculus formation.

  3. Enhanced in vivo antitumor efficacy of dual-functional peptide-modified docetaxel nanoparticles through tumor targeting and Hsp90 inhibition.

    Science.gov (United States)

    Jiang, Yao; Yang, Nan; Zhang, Huifeng; Sun, Bo; Hou, Chunying; Ji, Chao; Zheng, Ji; Liu, Yanyong; Zuo, Pingping

    2016-01-10

    Although conventional anticancer drugs exhibit excellent efficacy, serious adverse effects and/or even toxicity have occurred due to their nonselectivity. Moreover, active targeting approaches have not consistently led to successful outcomes. Ligands that simultaneously possess targeting capability and exert a strong influence on intracellular signaling cascades may be expected to improve the therapeutic efficacy of active targeting nanoparticulate carriers. In this study, we screened a targeting peptide, LPLTPLP, which specifically bound to non-small cell lung cancer (NSCLC) specimens in vitro. Surprisingly, this peptide inhibited the expression of Hsp90 and induced apoptosis by preventing autophagy in A549 cells treated with docetaxel. The results suggested that this peptide might be used as a promising dual-functional ligand for cancer treatment. Based on these findings, we designed and developed a novel active targeting delivery system by modifying docetaxel nanoparticles (DNP) with the dual-functional ligand LPLTPLP. We consistently demonstrated that the cellular uptake of nanoparticles (NPs) was significantly enhanced in vitro. Furthermore, the targeting NPs exhibited significantly improved antitumor efficacy and biodistribution compared with nontargeting nanodrug and free docetaxel. These findings demonstrate the feasibility of dual-functional NPs for efficient anticancer therapy.

  4. Magnetic multiwall carbon nanotubes modified with dual hydroxy functional ionic liquid for the solid-phase extraction of protein.

    Science.gov (United States)

    Chen, Jing; Wang, Yuzhi; Huang, Yanhua; Xu, Kaijia; Li, Na; Wen, Qian; Zhou, Yigang

    2015-05-21

    A novel adsorbent based on silica-coated magnetic multiwall carbon nanotubes (MWCNTs) surface modified by dual hydroxy functional ionic liquid (FIL) ([OH]-FIL-m-MWCNTs@SiO2) has been designed and used for the purification of lysozyme (Lys) by magnetic solid-phase extraction (MSPE). Fourier transform infrared spectroscopy (FTIR), a vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were employed to characterize [OH]-FIL-m-MWCNTs@SiO2. After extraction, the concentration of Lys was determined by a UV-Vis spectrophotometer at 278 nm. A series of single-factor experiments were carried out to identify the optimal conditions of the extraction and the extraction amount could reach up to 94.6 mg g(-1). The RSD of the precision, the repeatability and the stability experiments were 0.37% (n = 3), 0.47% (n = 3) and 0.52% (n = 3), respectively. Comparison of [OH]-FIL-m-MWCNTs@SiO2 with silica-coated magnetic Fe3O4 (Fe3O4@SiO2), silica-coated magnetic multiwall carbon nanotubes (m-MWCNTs@SiO2) and alkyl quaternary ammonium ionic liquid-modified on m-MWCNTs@SiO2 was carried out by extracting Lys. The extraction of bovine serum albumin (BSA), trypsin (Try) and ovalbumin (OVA) was also done by the proposed method. Desorption of Lys was carried out by 0.005 mol L(-1) Na2HPO4-1 mol L(-1) NaCl as the eluent solution and the desorption ratio reached 91.6%. Nearly 97.8% of the [OH]-FIL-m-MWCNTs@SiO2 could be recovered from each run, and the extraction amount decreased less after five runs. The circular dichroism spectral experiment analysis indicated that the secondary structure of Lys was unchanged after extraction.

  5. The low attenuation area on dual-energy perfusion CT: Correlation with the pulmonary function tests and quantitative CT measurements

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine (Japan); Kunihiro, Yoshie; Nakashima, Yoshiteru; Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine (Japan); Sano, Yuichi; Yuasa, Yuuki; Narazaki, Akiko; Kudomi, Shohei; Koike, Masahiro [Department of Radiology, Yamaguchi University Hospital (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University (Japan)

    2012-10-15

    Purpose: To retrospectively investigate the distribution of the low attenuation area (LAA) on dual energy perfusion CT (DEpCT) in comparison with the results of pulmonary function tests (PFTs) and quantitative CT measurements. Materials and methods: Twenty-eight patients (15 male and 13 female; mean age: 62.21 years) underwent DEpCT and PFTs within a 1-month interval. The ranges of the LAA on DEpCT were classified into six groups with attenuation values of 0–3, 0–5, 0–8, 0–10, 0–13 and 0–15 HU and the ratios of LAA in each group were compared with the percentage of forced expiratory volume in the 1st second (%FEV{sub 1.0}), FEV{sub 1.0}/forced vital capacity (FEV{sub 1.0}/FVC) and the relative area of the lung with attenuation coefficients lower than −950 HU (RA{sub −950}). Results: The LAAs on the DEpCT images were significantly correlated with the RA{sub −950}, %FEV{sub 1.0} and FEV{sub 1.0}/FVC, and the regression analysis showed that the best values of LAA on DEpCT were 0–10 HU with RA{sub −950} (r = 0.63), 0–8 HU with %FEV{sub 1.0} (r = −0.52) and 0–8 HU with FEV{sub 1.0}/FVC (r = −0.61) per patient. Conclusion: The iodine disturbance on DEpCT had a moderate correlation with the results of the PFTs and RA{sub −950}, but further examination would be needed for evaluation of iodine distribution.

  6. A dual-channel fluorescent chemosensor for discriminative detection of glutathione based on functionalized carbon quantum dots.

    Science.gov (United States)

    Huang, Yuanyuan; Zhou, Jin; Feng, Hui; Zheng, Jieyu; Ma, Hui-Min; Liu, Weidong; Tang, Cong; Ao, Hang; Zhao, Meizhi; Qian, Zhaosheng

    2016-12-15

    A convenient, fluorescent dual-channel chemosensor on the basis of bis(3-pyridylmethyl)amine-functionalized carbon quantum dots (BPMA-CQDs) nanoprobe was constructed, and it can discriminatively detect glutathione from its analogues cysteine and homocysteine based on two distinctive strategies. Two distinct fluorescence responses of BPMA-CQDs probe to Cu(II) and Ag(I) were identified and further employed to achieve selective detection of Cu(II) and Ag(I) respectively. Based on the BPMA-CQDs/Cu(II) conjugate, discriminative detection of GSH was achieved in terms of correlation between the amounts of GSH and fluorescence recovery. The addition of GSH into BPMA-CQDs/Cu(II) system induces the reduction of Cu(II) to Cu(I), which could efficiently block PET process resulting in the following fluorescence recovery. Based on the BPMA-CQDs/Ag(I) conjugate, GSH assay could also be established on the basis of fluorescence response to GSH. The introduction of GSH into the preceding system triggers the competitive coordination to Ag(I) between BPMA and GSH, and silver ions are finally taken away by GSH from the probe, where the fluorescence is restored to its original weak state. Both of the detection strategies can achieve discriminative detection of GSH from Cys and Hcy. The assays showed good stability and repeatability, and covered a broad linear range of up to 13.3μM with a lowest detection limit of 42.0nM. Moreover, both of them were utilized to monitor GSH level in live cells.

  7. Quantitative assessment of left ventricular function with dual-source CT in comparison to cardiac magnetic resonance imaging: initial findings

    Energy Technology Data Exchange (ETDEWEB)

    Busch, S.; Johnson, T.R.C.; Wintersperger, B.J.; Minaifar, N.; Bhargava, A.; Rist, C.; Reiser, M.F.; Becker, C.; Nikolaou, K. [University of Munich, Department of Clinical Radiology, Munich (Germany)

    2008-03-15

    Cardiac magnetic resonance imaging and echocardiography are currently regarded as standard modalities for the quantification of left ventricular volumes and ejection fraction. With the recent introduction of dual-source computedtomography (DSCT), the increased temporal resolution of 83 ms should also improve the assessment of cardiac function in CT. The aim of this study was to evaluate the accuracy of DSCT in the assessment of left ventricular functional parameters with cardiac magnetic resonance imaging (MRI) as standard of reference. Fifteen patients (two female, 13 male; mean age 50.8 {+-} 19.2 years) underwent CT and MRI examinations on a DSCT (Somatom Definition; Siemens Medical Solutions, Forchheim, Germany) and a 3.0-Tesla MR scanner (Magnetom Trio; Siemens Medical Solutions), respectively. Multiphase axial CT images were analysed with a semiautomatic region growing algorithms (Syngo Circulation; Siemens Medical Solutions) by two independent blinded observers. In MRI, dynamic cine loops of short axis slices were evaluated with semiautomatic contour detection software (ARGUS; Siemens Medical Solutions) independently by two readers. End-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction (EF) and stroke volume (SV) were determined for both modalities, and correlation coefficient, systematic error, limits of agreement and inter-observer variability were assessed. In DSCT, EDV and ESV were 135.8 {+-} 41.9 ml and 54.9 {+-} 29.6 ml, respectively, compared with 132.1 {+-} 40.8 ml EDV and 57.6 {+-} 27.3 ml ESV in MRI. Thus, EDV was overestimated by 3.7 ml (limits of agreement -46.1/+53.6), while ESV was underestimated by 2.6 ml (-36.6/+31.4). Mean EF was 61.6 {+-} 12.4% in DSCT and 57.9 {+-} 9.0% in MRI, resulting in an overestimation of EF by 3.8% with limits of agreement at -14.7 and +22.2%. Rank correlation rho values were 0.81 for EDV (P = 0.0024), 0.79 for ESV (P = 0.0031) and 0.64 for EF (P = 0.0168). The kappa value of inter

  8. Assessment of global left ventricular function with dual-source computed tomography in patients with valvular heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Bak, So Hyeon; Jeon, Hae Jeong (Dept. of Radiology, Konkuk Univ. Hospital, Konkuk Univ. School of Medicine, Seoul (Korea, Republic of)); Ko, Sung Min (Dept. of Radiology, Konkuk Univ. Hospital, Konkuk Univ. School of Medicine, Seoul (Korea, Republic of); Research Inst. of Medical Science, Konkuk Univ. Hospital, Konkuk Univ. School of Medicine, Seoul (Korea, Republic of)), Email: 20070437@kuh.ac.kr; Yang, Hyun Suk; Hwang, Hweung Kon (Dept. of Cardiology, Konkuk Univ. Hospital, Konkuk Univ. School of Medicine, Seoul (Korea, Republic of)); Song, Meong Gun (Dept. of Thoracic Surgery, Konkuk Univ. Hospital, Konkuk Univ. School of Medicine, Seoul (Korea, Republic of))

    2012-04-15

    Background: Left ventricular (LV) function is a vital parameter for prognosis, therapy guidance, and follow-up of cardiovascular disease. Dual-source computed tomography (DSCT) provides an accurate analysis of global LV function. Purpose: To assess the performance of DSCT in the determination of global LV functional parameters in comparison with cardiovascular magnetic resonance (CMR) and two-dimensional transthoracic echocardiography (2D-TTE) in patients with valvular heart disease (VHD). Material and Methods: A total of 111 patients (58 men, mean age 49.9 years) with known VHD and who underwent DSCT, 2D-TTE, and CMR a period of 2 weeks before undergoing valve surgery were included in this study. LV end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF) were calculated by DSCT using the threshold-based technique, by 2D-TTE using a modified Simpson's method, and by CMR using Simpson's method. Agreement for parameters of LV global function was determined with the Pearson's correlation coefficient (r) and Bland-Altman analysis. All the DSCT and CMR data-sets were assessed independently by two readers. Results: Fifty of the total 111 patients had aortic VHD, 29 patients had mitral VHD, and 32 patients had mixed aortic and mitral VHD. An excellent inter-observer agreement was seen for the assessment of global LV function using DSCT (r 0.910-0.983) and CMR (r = 0.854-0.965). An excellent or good correlation (r 0.93, 0.95, 0.87, and 0.71, respectively, P < 0.001) was noted between the DSCT and 2D-TTE values for EDV, ESV, SV, and EF. EDV (33.7 mL, P < 0.001), ESV (12.1 mL, P < 0.001), SV (21.2 mL, P < 0.001), and EF (1.6%, P = 0.019) were significantly overestimated by DSCT when compared with 2D-TTE. An excellent correlation (r = 0.96, 0.97, 0.91, and 0.94, respectively, P < 0.001) between DSCT and CMR was seen in the evaluation of EDV, ESV, SV, and EF. EDV (15.9 mL, P < 0.001), ESV (7.3 mL, P < 0.001), and SV

  9. A spectroscopic study on stability of curcumin as a function of pH in silica nanoformulations, liposome and serum protein

    Science.gov (United States)

    Jain, Beena

    2017-02-01

    The effect of pH on the stability of curcumin formulated with different carriers has been studied spectroscopically. This was investigated by monitoring the absorption and emission kinetics and fluorescence decay time of four different curcumin formulations suspended in buffer with pH varying from 5 to 8.5. The carriers were organically modified silica NP (SiNP) having 3-amino propyl and/or vinyl groups, liposome and serum protein. The results reveal that stability of curcumin formulated with SiNP functionalized with 3-amino propyl group (SiNP-VA) is significantly higher as compared to SiNP with only vinyl group (SiNP-V) and buffer but lower as compared to serum protein and liposome. However, fluorescence quantum yield (QY) is highest in SiNP-VA among all the nano formulations at pH 7.4 and below, which is attributed to the excited state interaction of curcumin with the amino groups of SiNP-VA. Results suggest that SiNP-VA could be an effective carrier for curcumin, which may have applications for imaging and drug delivery.

  10. Distribution and function of carbamate hydrolase genes cehA and mcd in soils: the distinct role of soil pH.

    Science.gov (United States)

    Rousidou, Constantina; Karaiskos, Dionysis; Myti, Despoina; Karanasios, Evangelos; Karas, Panagiotis A; Tourna, Maria; Tzortzakakis, Emmanuel A; Karpouzas, Dimitrios G

    2017-01-01

    Synthetic carbamates constitute a significant pesticide group with oxamyl being a leading compound in the nematicide market. Oxamyl degradation in soil is mainly microbially mediated. However, the distribution and function of carbamate hydrolase genes (cehA, mcd, cahA) associated with the soil biodegradation of carbamates is not yet clear. We studied oxamyl degradation in 16 soils from a potato monoculture area in Greece where oxamyl is regularly used. Oxamyl showed low persistence (DT50 2.4-26.7 days). q-PCR detected the cehA and mcd genes in 10 and three soils, respectively. The abundance of the cehA gene was positively correlated with pH, while both cehA abundance and pH were negatively correlated with oxamyl DT50. Amongst the carbamates used in the study region, oxamyl stimulated the abundance and expression only of the cehA gene, while carbofuran stimulated the abundance and expression of both genes. The cehA gene was also detected in pristine soils upon repeated treatments with oxamyl and carbofuran and only in soils with pH ≥7.2, where the most rapid degradation of oxamyl was observed. These results have major implications regarding the maintenance of carbamate hydrolase genes in soils, have practical implications regarding the agricultural use of carbamates, and provide insights into the evolution of cehA. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. A Putative Chloroplast-Localized Ca(2+)/H(+) Antiporter CCHA1 Is Involved in Calcium and pH Homeostasis and Required for PSII Function in Arabidopsis.

    Science.gov (United States)

    Wang, Chao; Xu, Weitao; Jin, Honglei; Zhang, Taijie; Lai, Jianbin; Zhou, Xuan; Zhang, Shengchun; Liu, Shengjie; Duan, Xuewu; Wang, Hongbin; Peng, Changlian; Yang, Chengwei

    2016-08-01

    Calcium is important for chloroplast, not only in its photosynthetic but also nonphotosynthetic functions. Multiple Ca(2+)/H(+) transporters and channels have been described and studied in the plasma membrane and organelle membranes of plant cells; however, the molecular identity and physiological roles of chloroplast Ca(2+)/H(+) antiporters have remained unknown. Here we report the identification and characterization of a member of the UPF0016 family, CCHA1 (a chloroplast-localized potential Ca(2+)/H(+) antiporter), in Arabidopsis thaliana. We observed that the ccha1 mutant plants developed pale green leaves and showed severely stunted growth along with impaired photosystem II (PSII) function. CCHA1 localizes to the chloroplasts, and the levels of the PSII core subunits and the oxygen-evolving complex were significantly decreased in the ccha1 mutants compared with the wild type. In high Ca(2+) concentrations, Arabidopsis CCHA1 partially rescued the growth defect of yeast gdt1Δ null mutant, which is defective in a Ca(2+)/H(+) antiporter. The ccha1 mutant plants also showed significant sensitivity to high concentrations of CaCl2 and MnCl2, as well as variation in pH. Taken these results together, we propose that CCHA1 might encode a putative chloroplast-localized Ca(2+)/H(+) antiporter with critical functions in the regulation of PSII and in chloroplast Ca(2+) and pH homeostasis in Arabidopsis.

  12. Alexander Duals of Multipermutohedron Ideals

    Indian Academy of Sciences (India)

    Ajay Kumar; Chanchal Kumar

    2014-02-01

    An Alexander dual of a multipermutohedron ideal has many combinatorial properties. The standard monomials of an Artinian quotient of such a dual correspond bijectively to some -parking functions, and many interesting properties of these Artinian quotients are obtained by Postnikov and Shapiro (Trans. Am. Math. Soc. 356 (2004) 3109–3142). Using the multigraded Hilbert series of an Artinian quotient of an Alexander dual of multipermutohedron ideals, we obtained a simple proof of Steck determinant formula for enumeration of -parking functions. A combinatorial formula for all the multigraded Betti numbers of an Alexander dual of multipermutohedron ideals are also obtained.

  13. An Electrochemical Biosensor with Dual Signal Outputs: Toward Simultaneous Quantification of pH and O2 in the Brain upon Ischemia and in a Tumor during Cancer Starvation Therapy.

    Science.gov (United States)

    Liu, Li; Zhao, Fan; Liu, Wei; Zhu, Tong; Zhang, John Z H; Chen, Chen; Dai, Zhihui; Peng, Huisheng; Huang, Jun-Long; Hu, Qin; Bu, Wenbo; Tian, Yang

    2017-08-21

    Herein, we develop a novel method for designing electrochemical biosensors with both current and potential signal outputs for the simultaneous determination of two species in a living system. Oxygen (O2 ) and pH, simple and very important species, are employed as model molecules. By designing and synthesizing a new molecule, Hemin-aminoferrocene (Hemin-Fc), we create a single electrochemical biosensor for simultaneous detection and ratiometric quantification of O2 and pH in the brain. The reduction peak current of the hemin group increases with the concentration of O2 from 1.3 to 200.6 μm. Meanwhile, the peak potential positively shifts with decreasing pH from 8.0 to 5.5, resulting in the simultaneous determination of O2 and pH. The Fc group can serve as an internal reference for ratiometric biosensing because its current and potential signals remain almost constant with variations of O2 and pH. The developed biosensor has high temporal and spatial resolutions, as well as remarkable selectivity and accuracy, and is successfully applied in the real-time quantification of O2 and pH in the brain upon ischemia, as well as in tumor during cancer therapy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Pyrene-based dual-mode fluorescence switches and logic gates that function in solution and film.

    Science.gov (United States)

    Zhou, Weidong; Li, Yongjun; Li, Yuliang; Liu, Huibiao; Wang, Shu; Li, Cuihong; Yuan, Mingjian; Liu, Xiaofeng; Zhu, Daoben

    2006-07-17

    A dual-mode fluorescence switch controlled by external inputs such as protons and metal ions is described, and each state corresponds to a specific fluorescent emission peak. Based on the reversible changes of the fluorescence emission of the switch responding to different external stimuli, the corresponding integrated logic gates and communication networks have been constructed in solid film or in solution.

  15. Dual-compartment neurofluidic system for electrophysiological measurements in physically segregated and functionally connected neuronal cell culture

    NARCIS (Netherlands)

    Kanagasabapathi, T.T.; Ciliberti, D.; Martinoia, S.; Wadman, W.J.; Decré, M.M.J.

    2011-01-01

    We developed a dual-compartment neurofluidic system with inter-connecting microchannels to connect neurons from their respective compartments, placed on a planar microelectrode arrays. The design and development of the compartmented microfluidic device for neuronal cell culture, protocol for

  16. High (≥6.5) Spontaneous and Persistent Urinary pH Is Protective of Renal Function at Baseline and during Disease Course in Idiopathic Membranous Nephropathy.

    Science.gov (United States)

    Bazzi, Claudio; Tagliabue, Elena; Raimondi, Sara; Rizza, Virginia; Casellato, Daniela; Nangaku, Masaomi

    2015-01-01

    Metabolic acidosis correction in advanced renal failure slows renal function decline attributed to tubulointerstitial damage (TID) reduction. No study evaluated if spontaneous baseline high urinary pH (UpH) is renoprotective in patients with normal renal function and without metabolic acidosis. The study tested this hypothesis in idiopathic membranous nephropathy (IMN). Eighty-five patients (follow-up 81 ± 54 months) measured UpH, serum creatinine, eGFR, protein/creatinine ratio, fractional excretion of albumin, IgG, α1-microglobulin, and urinary N-acetyl-β-D-glucosaminidase (β-NAG)/creatinine ratio. Twenty-eight patients (33%) had UpH ≥ 6.5 and 57 (67%) pH UpH patients had significantly lower values of the tubulointerstitial damage (TID) markers FE α1m and β-NAG and significantly better baseline renal function. These differences persisted over time in a subset of 38 patients with 5 measurements along 53 ± 26 months. In 29 patients with nephrotic syndrome (NS) treated with supportive therapy (follow-up: 80 ± 52 months) renal function was stable in 10 high and significantly worse in 19 low UpH patients. Steroids + cyclophosphamide treatment in 35 NS patients masks the renoprotection of high UpH. Conclusions. In IMN high and persistent UpH is associated with reduction of the proteinuric markers of tubulointerstitial damage and baseline better renal function in all patients and in NS patients treated only with supportive therapy during disease course. The factors associated with high pH-dependent renoprotection were lower values of TID markers, eGFR ≥ 60 mL/min, BP < 140/90 mmHg, and age < 55 years.

  17. High (≥6.5 Spontaneous and Persistent Urinary pH Is Protective of Renal Function at Baseline and during Disease Course in Idiopathic Membranous Nephropathy

    Directory of Open Access Journals (Sweden)

    Claudio Bazzi

    2015-01-01

    Full Text Available Metabolic acidosis correction in advanced renal failure slows renal function decline attributed to tubulointerstitial damage (TID reduction. No study evaluated if spontaneous baseline high urinary pH (UpH is renoprotective in patients with normal renal function and without metabolic acidosis. The study tested this hypothesis in idiopathic membranous nephropathy (IMN. Eighty-five patients (follow-up 81 ± 54 months measured UpH, serum creatinine, eGFR, protein/creatinine ratio, fractional excretion of albumin, IgG, α1-microglobulin, and urinary N-acetyl-β-D-glucosaminidase (β-NAG/creatinine ratio. Twenty-eight patients (33% had UpH ≥ 6.5 and 57 (67% pH < 6.5; high versus low UpH patients had significantly lower values of the tubulointerstitial damage (TID markers FE α1m and β-NAG and significantly better baseline renal function. These differences persisted over time in a subset of 38 patients with 5 measurements along 53 ± 26 months. In 29 patients with nephrotic syndrome (NS treated with supportive therapy (follow-up: 80 ± 52 months renal function was stable in 10 high and significantly worse in 19 low UpH patients. Steroids + cyclophosphamide treatment in 35 NS patients masks the renoprotection of high UpH. Conclusions. In IMN high and persistent UpH is associated with reduction of the proteinuric markers of tubulointerstitial damage and baseline better renal function in all patients and in NS patients treated only with supportive therapy during disease course. The factors associated with high pH-dependent renoprotection were lower values of TID markers, eGFR ≥ 60 mL/min, BP < 140/90 mmHg, and age < 55 years.

  18. Effects of Physical-Cognitive Dual Task Training on Executive Function and Gait Performance in Older Adults: A Randomized Controlled Trial.

    Science.gov (United States)

    Falbo, S; Condello, G; Capranica, L; Forte, R; Pesce, C

    2016-01-01

    Physical and cognitive training seem to counteract age-related decline in physical and mental function. Recently, the possibility of integrating cognitive demands into physical training has attracted attention. The purpose of this study was to evaluate the effects of twelve weeks of designed physical-cognitive training on executive cognitive function and gait performance in older adults. Thirty-six healthy, active individuals aged 72.30 ± 5.84 years were assigned to two types of physical training with major focus on physical single task (ST) training (n = 16) and physical-cognitive dual task (DT) training (n = 20), respectively. They were tested before and after the intervention for executive function (inhibition, working memory) through Random Number Generation and for gait (walking with/without negotiating hurdles) under both single and dual task (ST, DT) conditions. Gait performance improved in both groups, while inhibitory performance decreased after exercise training with ST focus but tended to increase after training with physical-cognitive DT focus. Changes in inhibition performance were correlated with changes in DT walking performance with group differences as a function of motor task complexity (with/without hurdling). The study supports the effectiveness of group exercise classes for older individuals to improve gait performance, with physical-cognitive DT training selectively counteracting the age-related decline in a core executive function essential for daily living.

  19. Circuit modeling on polyaniline functionalized nanowire-templated micro-interdigital capacitors for pH sensing

    DEFF Research Database (Denmark)

    Antohe, V.A.; Radu, A.; Mátéfi-Tempfli, Stefan

    2011-01-01

    This study presents an improved alternative current (ac) circuit modeling of a highly sensitive capacitive pH-sensing element based on polyaniline (PANI) functionalized nanowire-templated micro-interdigited electrodes (NWs μIDEs). While electrical resonance measurements deal with a total equivalent...

  20. Organellar Na+/H+ Exchangers : Novel Players in Organelle pH Regulation and Their Emerging Functions

    NARCIS (Netherlands)

    Ohgaki, Ryuichi; van Ijzendoorn, Sven C. D.; Matsushita, Masafumi; Hoekstra, Dick; Kanazawa, Hiroshi

    2011-01-01

    Mammalian Na+/H+ exchangers (NHEs) play a fundamental role in cellular ion homeostasis. NHEs exhibit an appreciable variation in expression, regulation, and physiological function, dictated by their dynamics in subcellular localization and/or interaction with regulatory proteins. In recent years, a

  1. Functional magnetic porous silica for T 1-T 2 dual-modal magnetic resonance imaging and pH-responsive drug delivery of basic drugs

    Science.gov (United States)

    Li, Ling; Zhang, Run; Guo, Yi; Zhang, Cheng; Zhao, Wei; Xu, Zhiping; Whittaker, Andrew K.

    2016-12-01

    A smart magnetic-targeting drug carrier γ-Fe2O3@p-silica comprising a γ-Fe2O3 core and porous shell has been prepared and characterized. The particles have a uniform size of about 60 nm, and a porous shell of thickness 3 nm. Abundant hydroxyl groups and a large surface area enabled the γ-Fe2O3@p-silica to be readily loaded with a large payload of the basic model drug rhodamine B (RB) (up to 73 mg g-1). Cytotoxicity assays of the γ-Fe2O3@p-silica particles indicated that the particles were biocompatible and suitable for carrying drugs. It was found that the RB was released rapidly at pH 5.5 but at pH 7.4 the rate and extent of release was greatly attenuated. The particles therefore demonstrate an excellent pH-triggered drug release. In addition, the γ-Fe2O3@p-silica particles could be tracked by magnetic resonance imaging (MRI). A clear dose-dependent contrast enhancement in both T 1-weighted and T 2-weighted MR images indicated the potential of the γ-Fe2O3@p-silica particles to act as dual-mode T 1 and T 2 MRI contrast agents.

  2. Modeling the Nanophase Structural Dynamics of Phenylated Sulfonated Poly Ether Ether Ketone Ketone (Ph-SPEEKK) Membranes as a Function of Hydration

    Energy Technology Data Exchange (ETDEWEB)

    Lins, Roberto D.; Devanathan, Ramaswami; Dupuis, Michel

    2011-03-03

    Solvated phenylated sulfonated poly ether ether ketone ketone (Ph-SPEEKK) membranes in the presence of hydronium ions were modeled by classical molecular dynamics simulations. The characterization of the nanophase structure and dynamics of such membranes was carried out as a function of the water content lambda, where lambda is the number of water molecules per sulfonate group, for lambda values of 3.5, 6, 11, 25, and 40. Analysis of pair correlation functions supports the experimental observation of membrane swelling upon hydration as well the increase in water and hydronium ion diffusion with increasing lambda. While the average number of hydrogen bonds between hydronium ions and sulfonate groups is dramatically affected by the hydration level, the average lifetime of the hydrogen bonds remains essentially constant. The membrane is found to be relatively rigid and its overall flexibility shows little dependence on water content. Compared to Nafion, water and ion diffusion coefficients are considerably smaller at lower hydration levels and room temperature. However, at higher lambda values of 25 and 40 these coefficients are comparable to those in Nafion at a lambda value of 16. This study also shows that water diffusion in Ph-SPEEKK membranes at low hydration levels can be significantly improved by raising the temperature with important implications for proton conductivity.

  3. Dual-energy micro-CT functional imaging of primary lung cancer in mice using gold and iodine nanoparticle contrast agents: a validation study.

    Directory of Open Access Journals (Sweden)

    Jeffrey R Ashton

    Full Text Available To provide additional functional information for tumor characterization, we investigated the use of dual-energy computed tomography for imaging murine lung tumors. Tumor blood volume and vascular permeability were quantified using gold and iodine nanoparticles. This approach was compared with a single contrast agent/single-energy CT method. Ex vivo validation studies were performed to demonstrate the accuracy of in vivo contrast agent quantification by CT.Primary lung tumors were generated in LSL-Kras(G12D; p53(FL/FL mice. Gold nanoparticles were injected, followed by iodine nanoparticles two days later. The gold accumulated in tumors, while the iodine provided intravascular contrast. Three dual-energy CT scans were performed-two for the single contrast agent method and one for the dual contrast agent method. Gold and iodine concentrations in each scan were calculated using a dual-energy decomposition. For each method, the tumor fractional blood volume was calculated based on iodine concentration, and tumor vascular permeability was estimated based on accumulated gold concentration. For validation, the CT-derived measurements were compared with histology and inductively-coupled plasma optical emission spectroscopy measurements of gold concentrations in tissues.Dual-energy CT enabled in vivo separation of gold and iodine contrast agents and showed uptake of gold nanoparticles in the spleen, liver, and tumors. The tumor fractional blood volume measurements determined from the two imaging methods were in agreement, and a high correlation (R(2 = 0.81 was found between measured fractional blood volume and histology-derived microvascular density. Vascular permeability measurements obtained from the two imaging methods agreed well with ex vivo measurements.Dual-energy CT using two types of nanoparticles is equivalent to the single nanoparticle method, but allows for measurement of fractional blood volume and permeability with a single scan. As

  4. Lanthanide ion (III) complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminophosphonate for dual biosensing of pH with chemical exchange saturation transfer (CEST) and biosensor imaging of redundant deviation in shifts (BIRDS).

    Science.gov (United States)

    Huang, Yuegao; Coman, Daniel; Ali, Meser M; Hyder, Fahmeed

    2015-01-01

    Relaxivity-based magnetic resonance of phosphonated ligands chelated with gadolinium (Gd(3+)) shows promise for pH imaging. However instead of monitoring the paramagnetic effect of lanthanide complexes on the relaxivity of water protons, biosensor (or molecular) imaging with magnetic resonance is also possible by detecting either the nonexchangeable or the exchangeable protons on the lanthanide complexes themselves. The nonexchangeable protons (e.g. -CHx, where 3 ≥ x ≥ 1) are detected using a three-dimensional chemical shift imaging method called biosensor imaging of redundant deviation in shifts (BIRDS), whereas the exchangeable protons (e.g. -OH or -NHy , where 2 ≥ y ≥ 1) are measured with chemical exchange saturation transfer (CEST) contrast. Here we tested the feasibility of BIRDS and CEST for pH imaging of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminophosphonate (DOTA-4AmP(8-)) chelated with thulium (Tm(3+) ) and ytterbium (Yb(3+)). BIRDS and CEST experiments show that both complexes are responsive to pH and temperature changes. Higher pH and temperature sensitivities are obtained with BIRDS for either complex when using the chemical shift difference between two proton resonances vs using the chemical shift of a single proton resonance, thereby eliminating the need to use water resonance as reference. While CEST contrast for both agents is linearly dependent on pH within a relatively large range (i.e. 6.3-7.9), much stronger CEST contrast is obtained with YbDOTA-4AmP(5-) than with TmDOTA-4AmP(5-). In addition, we demonstrate the prospect of using BIRDS to calibrate CEST as new platform for quantitative pH imaging.

  5. Gadolinium-functionalized aggregation-induced emission dots as dual-modality probes for cancer metastasis study.

    Science.gov (United States)

    Li, Kai; Ding, Dan; Prashant, Chandrasekharan; Qin, Wei; Yang, Chang-Tong; Tang, Ben Zhong; Liu, Bin

    2013-12-01

    Understanding the localization and engraftment of tumor cells at postintravasation stage of metastasis is of high importance in cancer diagnosis and treatment. Advanced fluorescent probes and facile methodologies for cell tracing play a key role in metastasis studies. In this work, we design and synthesize a dual-modality imaging dots with both optical and magnetic contrast through integration of a magnetic resonance imaging reagent, gadolinium(III), into a novel long-term cell tracing probe with aggregation-induced emission (AIE) in far-red/near-infrared region. The obtained fluorescent-magnetic AIE dots have both high fluorescence quantum yield (25%) and T1 relaxivity (7.91 mM(-1) s(-1) ) in aqueous suspension. After further conjugation with a cell membrane penetrating peptide, the dual-modality dots can be efficiently internalized into living cells. The gadolinium(III) allows accurate quantification of biodistribution of cancer cells via intraveneous injection, while the high fluorescence provides engraftment information of cells at single cellular level. The dual-modality AIE dots show obvious synergistic advantages over either single imaging modality and hold great promises in advanced biomedical studies.

  6. Dual-Function Au@Y2O3:Eu(3+) Smart Film for Enhanced Power Conversion Efficiency and Long-Term Stability of Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Chang Woo; Eom, Tae Young; Yang, In Seok; Kim, Byung Su; Lee, Wan In; Kang, Yong Soo; Kang, Young Soo

    2017-07-28

    In the present study, a dual-functional smart film combining the effects of wavelength conversion and amplification of the converted wave by the localized surface plasmon resonance has been investigated for a perovskite solar cell. This dual-functional film, composed of Au nanoparticles coated on the surface of Y2O3:Eu(3+) phosphor (Au@Y2O3:Eu(3+)) nanoparticle monolayer, enhances the solar energy conversion efficiency to electrical energy and long-term stability of photovoltaic cells. Coupling between the Y2O3:Eu(3+) phosphor monolayer and ultraviolet solar light induces the latter to be converted into visible light with a quantum yield above 80%. Concurrently, the Au nanoparticle monolayer on the phosphor nanoparticle monolayer amplifies the converted visible light by up to 170%. This synergy leads to an increased solar light energy conversion efficiency of perovskite solar cells. Simultaneously, the dual-function film suppresses the photodegradation of perovskite by UV light, resulting in long-term stability. Introducing the hybrid smart Au@Y2O3:Eu(3+) film in perovskite solar cells increases their overall solar-to-electrical energy conversion efficiency to 16.1% and enhances long-term stability, as compared to the value of 15.2% for standard perovskite solar cells. The synergism between the wavelength conversion effect of the phosphor nanoparticle monolayer and the wave amplification by the localized surface plasmon resonance of the Au nanoparticle monolayer in a perovskite solar cell is comparatively investigated, providing a viable strategy of broadening the solar spectrum utilization.

  7. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland

    2014-12-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene and the selective layer with isopores was formed by micelle assembly of polystyrene-. b-poly-4-vinyl pyridine. The dual layers had an excellent interfacial adhesion and pore interconnectivity. The dual membranes showed pH response behavior like single layer block copolymer membranes with a low flux for pH values less than 3, a fast increase between pH4 and pH6 and a constant high flux level for pH values above 7. The dry/wet spinning process was optimized to produce dual layer hollow fiber membranes with polystyrene internal support layer and a shell block copolymer selective layer.

  8. Dual neural endopeptidase/endothelin-converting [corrected] enzyme inhibition improves endothelial function in mesenteric resistance arteries of young spontaneously hypertensive rats

    DEFF Research Database (Denmark)

    Lemkens, Pieter; Nelissen, Jelly; Meens, Merlijn J P M T;

    2012-01-01

    through cleavage of big ET1 by endothelin-converting enzyme (ECE) and neutral endopeptidase (NEP). METHOD: We investigated whether the dual NEP/ECE inhibitor SOL1 improves resistance artery function and structure in 12 weeks old spontaneously hypertensive rats (SHRs) and whether arterial structural...... responses to decreased (-90%) or increased (+100%) blood flow are impaired in young SHRs. To this end two groups of SHRs received chronic 4-week treatment at two different time points (4-8 and 8-12 weeks) prior to the experiment. We compared in-vitro effects of cyclo-oxygenase inhibition (1 μmol...

  9. Brown adipose tissue in humans: detection and functional analysis using PET (positron emission tomography), MRI (magnetic resonance imaging), and DECT (dual energy computed tomography).

    Science.gov (United States)

    Borga, Magnus; Virtanen, Kirsi A; Romu, Thobias; Leinhard, Olof Dahlqvist; Persson, Anders; Nuutila, Pirjo; Enerbäck, Sven

    2014-01-01

    If the beneficial effects of brown adipose tissue (BAT) on whole body metabolism, as observed in nonhuman experimental models, are to be translated to humans, tools that accurately measure how BAT influences human metabolism will be required. This chapter discusses such techniques, how they can be used, what they can measure and also some of their limitations. The focus is on detection and functional analysis of human BAT and how this can be facilitated by applying advanced imaging technology such as positron emission tomography, magnetic resonance imaging, and dual energy computed tomography. © 2014 Elsevier Inc. All rights reserved.

  10. The dual role of oxygen functions in coal pretreatment and liquefaction: Crosslinking and cleavage reactions. First annual report, April 1, 1991--March 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Serio, M.A.; Kroo, E.; Teng, H.; Charpenay, S.; Solomon, P.R.

    1992-08-01

    The overall objective of this project is elucidate and model the dual role of oxygen functions in thermal pretreatment and liquefaction of low rank coals through the application of analytical techniques and theoretical models. The project will be an integrated study of model polymers representative of coal structures, raw coals of primarily low rank, and selectivity modified coals in order to provide specific information relevant to the reactions of real coals. The investigations will include liquefaction experiments in microautoclave reactors along with extensive analysis of intermediate solid, liquid and gaseous products. Attempts will be made to incorporate the results of experiments on the different systems into a liquefaction model.

  11. Cell wall composition of Bacillus subtilis changes as a function of pH and Zn²⁺ exposure: insights from cryo-XPS measurements.

    Science.gov (United States)

    Ramstedt, Madeleine; Leone, Laura; Persson, Per; Shchukarev, Andrey

    2014-04-22

    Bacteria play an important role in the biogeochemical cycling of metals in the environment. Consequently, there is an interest to understand how the bacterial surfaces interact with metals in solution and how this affects the bacterial surface. In this work we have used a surface-sensitive analysis technique, cryogenic X-ray photoelectron spectroscopy (cryo-XPS), to monitor the surface of Bacillus subtilis cells as a function of pH and Zn(2+) content in saline solution. The objective of the study was twofold: (1) to investigate the agreement between two data treatment methods for XPS, as well as investigate to what extent sample pretreatment may influence XPS data of bacterial samples, and (2) to characterize how the surface chemistry of bacterial cells is influenced by different external conditions. (1) It was found that the two data treatment methods gave rise to comparable results. However, identical samples analyzed fast-frozen or dry exhibited larger differences in surface chemistry, indicating that sample pretreatment can to large extents influence the obtained surface composition of bacterial samples. (2) The bacterial cell wall (in fast-frozen samples) undergoes dramatic compositional changes with pH and with Zn(2+) exposure. The compositional changes are interpreted as an adaptive metal resistance response changing the biochemical composition of the bacterial cell wall. These results have implications for how adsorption processes at the surface of bacterial cells are analyzed, understood, modeled, and predicted.

  12. Probabilistic model for the spoilage wine yeast Dekkera bruxellensis as a function of pH, ethanol and free SO2 using time as a dummy variable.

    Science.gov (United States)

    Sturm, M E; Arroyo-López, F N; Garrido-Fernández, A; Querol, A; Mercado, L A; Ramirez, M L; Combina, M

    2014-01-17

    The present study uses a probabilistic model to determine the growth/no growth interfaces of the spoilage wine yeast Dekkera bruxellensis CH29 as a function of ethanol (10-15%, v/v), pH (3.4-4.0) and free SO2 (0-50 mg/l) using time (7, 14, 21 and 30 days) as a dummy variable. The model, built with a total of 756 growth/no growth data obtained in a simile wine medium, could have application in the winery industry to determine the wine conditions needed to inhibit the growth of this species. Thereby, at 12.5% of ethanol and pH 3.7 for a growth probability of 0.01, it is necessary to add 30 mg/l of free SO2 to inhibit yeast growth for 7 days. However, the concentration of free SO2 should be raised to 48 mg/l to achieve a probability of no growth of 0.99 for 30 days under the same wine conditions. Other combinations of environmental variables can also be determined using the mathematical model depending on the needs of the industry. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Effects of carbon dioxide and pH variations in vitro on blood respiratory functions, red blood cell volume, transmembrane pH gradients, and sickling in sickle cell anemia

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Y.; Bookchin, R.M.

    1984-08-01

    An examination was made of the O/sub 2/ affinity, Bohr effect, transmembrane pH gradient, mean cell hemoglobin concentration, and red blood cell sickling at half O/sub 2/ saturation in whole sickle cell (SS) and normal (AA) blood during CO/sub 2/ titration and acid-base titration at three Pco/sub 2/ levels, 10, 40, and 80 mm Hg. The CO/sub 2/-induced Bohr effect of SS blood was considerably larger than normal (maximum, 0.91, referred to cell pH) and similar to that found with acid-base titration at Pco/sub 2/ of 40. In contrast to AA blood, SS blood showed an increased O/sub 2/ affinity when Pco/sub 2/ was raised from 40 to 80, and at half O/sub 2/ saturation showed biphasic or sigmoid Bohr curves, a fall in transmembrane pH gradient with rising Pco/sub 2/, and an absence of the normal cell volume increase at low pH and Pco/sub 2/. Sickling of SS cells at half O/sub 2/ saturation was partly inhibited by increasing Pc/sub 2/, particularly in the higher pH ranges. These complex differences in the behavior of SS blood are interpreted in terms of the balancing of several effects: the lowering of hemoglobin O/sub 2/-affinity by polymerization, low pH and increased CO/sub 2/ binding, inhibition of hemoglobin S polymerization by CO/sub 2/ binding to ..beta../sup s/-chain amino termini, differences between hemoglobin S and A in competitive binding of CO/sub 2/ and 2,3-diphosphoglycerate at different pH levels, and an increased net negative charge exhibited by intracellular deoxyhemoglobin S polymers. From a clinical standpoint, in the absence of hypoxia or acidosis, an increased blood Pco/sub 2/ might have a beneficial effect by inhibiting red blood cell sickling, whereas a metabolic acidosis, with low blood pH and Pco/sub 2/, would be very hazardous.

  14. DESIGN OF A DUAL KEYBOARD

    OpenAIRE

    V. Ragavi; G. Geetha

    2013-01-01

    The design of a computer keyboard with dual function is proposed. This computer keyboard called Dual Keyboard can function both as a normal keyboard and as a pressure sensitive keyboard. The proposed device has a switch that decides the function. The keyboard makes use of sensors placed beneath the keys to measure the pressure applied on the key by the user. This device has many applications. In this study, it is applied to mitigate Denial of Service (DoS) attack.

  15. A functional study of EGFR and Notch signaling in brain cancer stem-like cells from glioblastoma multiforme (Ph.d.)

    DEFF Research Database (Denmark)

    Kristoffersen, Karina

    2013-01-01

    on their resemblance to normal neural stem cells (NSC) and their tumorigenic potential. Like for NSC, the epidermal growth factor receptor (EGFR) and Notch receptor signaling pathways are believed to be important for the maintenance of bCSC. These pathways as such present promising targets in a future anti-bCSC GBM...... treatment. The overall aim of the present PhD project has been to study the functional role of EGFR and Notch activity in bCSCs stem cell-like features and tumorigenic potential with the purpose of deepen our knowledge about the significance of these pathways in the bCSC population in GBM. By establishing...... and culturing human derived GBM xenograft cells under NSC conditions we obtained neurosphere cultures that contained cells with stem cell-like and tumorigenic properties. We moreover characterized the different cultures based on their expression level of the EGFR and Notch receptor as well as the expression...

  16. Dual blockade of HER2 in HER2-overexpressing tumor cells does not completely eliminate HER3 function

    Science.gov (United States)

    Garrett, Joan T.; Sutton, Cammie R.; Kuba, María Gabriela; Cook, Rebecca S .; Arteaga, Carlos L.

    2012-01-01

    Purpose Dual blockade of HER2 with trastuzumab with lapatinib or with pertuzumab is a superior treatment approach compared to single agent HER2 inhibitors. However, many HER2-overexpressing breast cancers still escape from this combinatorial approach. Inhibition of HER2 and downstream phosphatidylinositol-3 kinase (PI3K)/AKT causes a transcriptional and post-translational upregulation of HER3 which, in turn, counteracts the antitumor action of the HER2-directed therapies. We hypothesized that suppression of HER3 would synergize with dual blockade of HER2 in breast cancer cells sensitive and refractory to HER2 antagonists. Experimental Design Inhibition of HER2/HER3 in HER2+ breast cancer cell lines was evaluated by western blot. We analyzed drug-induced apoptosis and 2- and 3-dimensional growth in vitro. Growth inhibition of PI3K was examined in vivo in xenografts treated with combinations of trastuzumab, lapatinib, and the HER3 neutralizing monoclonal antibody U3-1287. Results Treatment with U3-1287 blocked the upregulation of total and phosphorylated HER3 that followed treatment with lapatinib and trastuzumab and, in turn, enhanced the anti-tumor action of the combination against trastuzumab-sensitive and -resistant cells. Mice bearing HER2+ xenografts treated with lapatinib, trastuzumab, and U3-1287 exhibited fewer recurrences and better survival compared to mice treated with lapatinib and trastuzumab. Conclusions Dual blockade of HER2 with trastuzumab and lapatinib does not eliminate the compensatory upregulation of HER3. Therapeutic inhibitors of HER3 should be considered as part of multi-drug combinations aimed at completely and rapidly disabling the HER2 network in HER2-overexpressing breast cancers. PMID:23224399

  17. 高校会计科目体系的双重功能%Dual Function of Accounting System in Colleges and Universities

    Institute of Scientific and Technical Information of China (English)

    燕廷淼

    2015-01-01

    在健全完善政府会计制度过程中,有关“会计科目的设置要实现预算会计和财务会计双重功能”的提法,尚有基本理论方面的问题需要进一步澄清。高校作为基层预算单位,是政府财政预算管理的重要部分。分析高校会计科目体系,探讨其双重功能的实现途径,可为政府会计改革提供有益的借鉴。%In the process of perfecting the government accounting system,as to the statement "the setting of accounting subject should realize the dual function of budget accounting and financial accounting",there are still some problems in fundamental theory that need to be further clarified. As the basic unit of the budget,the colleges and universities are an important part of the government financial budget management. Analysis on the accounting subject system in colleges and universities and the exploration on the way to realize the dual function can provide useful reference for the reform of government accounting.

  18. Differential gene expression along the animal-vegetal axis in the ascidian embryo is maintained by a dual functional protein Foxd.

    Science.gov (United States)

    Tokuhiro, Shin-Ichi; Tokuoka, Miki; Kobayashi, Kenji; Kubo, Atsushi; Oda-Ishii, Izumi; Satou, Yutaka

    2017-05-01

    In many animal embryos, a specific gene expression pattern is established along the animal-vegetal axis soon after zygotic transcription begins. In the embryo of the ascidian Ciona intestinalis, soon after the division that separates animal and vegetal hemispheres into distinct blastomeres, maternal Gata.a and β-catenin activate specific genes in the animal and vegetal blastomeres, respectively. On the basis of these initial distinct gene expression patterns, gene regulatory networks promote animal cells to become ectodermal tissues and vegetal cells to become endomesodermal tissues and a part of the nerve cord. In the vegetal hemisphere, β-catenin directly activates Foxd, an essential transcription factor gene for specifying endomesodermal fates. In the present study, we found that Foxd also represses the expression of genes that are activated specifically in the animal hemisphere, including Dmrt1, Prdm1-r.a (Bz1), Prdm1-r.b (Bz2), and Otx. A reporter assay showed that Dmrt1 expression was directly repressed by Foxd, and a chromatin immunoprecipitation assay showed that Foxd was bound to the upstream regions of Dmrt1, Prdm1-r.a, Prdm1-r.b, and Otx. Thus, Foxd has a dual function of activating specific gene expression in the vegetal hemisphere and of repressing the expression of genes that are normally expressed in the animal hemisphere. This dual function stabilizes the initial patterning along the animal-vegetal axis by β-catenin and Gata.a.

  19. Examining the role of endogenous orexins in hypothalamus-pituitary-adrenal axis endocrine function using transient dual orexin receptor antagonism in the rat.

    Science.gov (United States)

    Steiner, Michel A; Sciarretta, Carla; Brisbare-Roch, Catherine; Strasser, Daniel S; Studer, Rolf; Jenck, Francois

    2013-04-01

    The orexin neuropeptide system regulates wakefulness and contributes to physiological and behavioral stress responses. Moreover, a role for orexins in modulating hypothalamus-pituitary-adrenal (HPA) axis activity has been proposed. Brain penetrating dual orexin receptor (OXR) antagonists such as almorexant decrease vigilance and have emerged as a novel therapeutic class for the treatment of insomnia. Almorexant was used here as a pharmacological tool to examine the role of endogenous orexin signaling in HPA axis endocrine function under natural conditions. After confirming the expression of prepro-orexin and OXR-1 and OXR-2 mRNA in hypothalamus, pituitary and adrenal glands, the effects of systemic almorexant were investigated on peripheral HPA axis hormone release in the rat under baseline, stress and pharmacological challenge conditions. Almorexant did not alter basal or stress-induced corticosterone release despite affecting wake and sleep stages (detected by radiotelemetric electroencephalography/electromyography) during the stress exposure. Moreover, almorexant did not affect the release of adrenocorticotropin (ACTH) and corticosterone at different time points along the diurnal rhythm, nor corticotrophin-releasing hormone (CRH)- and ACTH-stimulated neuroendocrine responses, measured in vivo under stress-free conditions. These results illustrate that dual OXR antagonists, despite modulating stress-induced wakefulness, do not interfere with endocrine HPA axis function in the rat. They converge to suggest that endogenous orexin signaling plays a minor role in stress hormone release under basal conditions and under challenge.

  20. Conformational changes in human serum albumin studied by fluorescence and absorption spectroscopy. Distance measurements as a function of pH and fatty acids

    DEFF Research Database (Denmark)

    Honoré, B; Pedersen, A O

    1989-01-01

    pH- and fatty acid-induced conformational changes in human serum albumin were investigated by fluorescence-energy transfer, determining the distance between Trp-214 and bound bilirubin at 25 degrees C. This distance changes significantly with the pH, being 2.52 +/- 0.01 nm at pH 6, 2.31 +/- 0.04 ...... chromophores. The contraction of the protein carrying long-chain saturated fatty acids is even more pronounced at pH 9. Udgivelsesdato: 1989-Feb-15......pH- and fatty acid-induced conformational changes in human serum albumin were investigated by fluorescence-energy transfer, determining the distance between Trp-214 and bound bilirubin at 25 degrees C. This distance changes significantly with the pH, being 2.52 +/- 0.01 nm at pH 6, 2.31 +/- 0.04 nm...... at pH 9, 2.13 +/- 0.07 nm at pH 11.0 and 2.77 nm at pH 11.9. The influence of different fatty acids on the distance was also determined. At pH 7.4 medium-chain fatty acids seem to increase this distance, whereas long-chain fatty acids, at low concentrations, decrease the distance between the two...

  1. Adsorción de cadmio, cromo y mercurio en suelos del Valle del Cauca a varios valores de pH Cadmium, chromium and mercury adsorption on Cauca Valley soils as a function of pH

    Directory of Open Access Journals (Sweden)

    García O. Álvaro

    1991-12-01

    Full Text Available Con el fin de observar el proceso de adsorción de Cd, Cr y Hg y determinar el efecto del pH sobre la adsorción de los metales indicados, se seleccionaron tres suelos de los órdenes predominantes en el Valle del Cauca que, por su ubicación, están siendo regados con aguas contaminadas o pueden llegar a serlo en un futuro. El pH de los suelos se ajustó con ácido acético al 1, 4 y 12% o con NaOH 0.01 N para obtener valores lo más próximo posible a 5.7, 6.5 Y 7.8. Se prepararon soluciones de equilibrio con cada metal (0.0, 0.28, 0.56, 1.12 Y 2.25 mg/L y se adicionaron a 0.25 g de suelo seco al aire y tamizado para pasar una malla de 2 mm. La extracción de los metales se realizó con HCI 001 N y se determinaron por espectrofotometría de absorción atómica. La diferencia entre la concentración inicial y la final se consideró como la cantidad adsorbida por el suelo y la diferencia entre la cantidad adsorbida y la cantidad extraída con H Cl 0.01 N se consideró como la cantidad retenida por el suelo. En general el Cd se adsorbe más a valores de pH neutro o alcalino en todos los suelos, debido a que su forma predominante es la divalente y tiende más a formar complejos solubles e insolubles con los aniones encontrados en el suelo por encima de pH 7.0. La adsorción de Cr y Hg es mayor a valores de pH ácido debido a que forman complejos con la materia orgánica del suelo y/o los óxidos e hidróxidos de Fe, Al y Mn cuyas reacciones se ven favorecidas a estos valores de pH. La menor extracción (mayor retención en todos los suelos se dio a valores de pH entre 6.4 y 6.6, indicando que en este pH los metales quedan fuertemente retenidos por el complejo de cambio y su disponibilidad hacia las plantas es mínima.Soils irrigated with heavy metals contamined water are common in Cauca Valley and there is not available information about of soil behavior and soil processes affected by Cd, Cr and Hg. Three soils of the main orders of Cauca Valley

  2. Dual-beam ELF wave generation as a function of power, frequency, modulation waveform, and receiver location

    Science.gov (United States)

    Agrawal, D.; Moore, R. C.

    2012-12-01

    Dual-beam ELF wave generation experiments performed at the High-frequency Active Auroral Research Program (HAARP) HF transmitter are used to investigate the dependence of the generated ELF wave magnitude on HF power, HF frequency, modulation waveform, and receiver location. During the experiments, two HF beams transmit simultaneously: one amplitude modulated (AM) HF beam modulates the conductivity of the lower ionosphere at ELF frequencies while a second HF beam broadcasts a continuous waveform (CW) signal, modifying the efficiency of ELF conductivity modulation and thereby the efficiency of ELF wave generation. We report experimental results for different ambient ionospheric conditions, and we interpret the observations in the context of a newly developed dual-beam HF heating model. A comparison between model predictions and experimental observations indicates that the theoretical model includes the essential physics involved in multifrequency HF heating of the lower ionosphere. In addition to the HF transmission parameters mentioned above, the model is used to predict the dependence of ELF wave magnitude on the polarization of the CW beam and on the modulation frequency of the modulated beam. We consider how these effects vary with ambientD-region electron density and electron temperature.

  3. Sensitive Immunosensor for Cancer Biomarker Based on Dual Signal Amplification Strategy of Graphene Sheets and Multi-Enzyme Functionalized Carbon Nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Du, Dan; Zou, Zhexiang; Shin, Yongsoon; Wang, Jun; Wu, Hong; Engelhard, Mark H.; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2010-03-30

    A novel electrochemical immunosensor for sensitive detection of cancer biomarker α fetoprotein (AFP) is described that uses a graphene sheet sensor platform and functionalized carbon nanospheres (CNSs) labeling with horseradish peroxidase-secondary antibodies (HRP-Ab2). Greatly enhanced sensitivity for the cancer biomarker is based on a dual signal amplification strategy: first, the synthesized CNSs yielded a homogeneous and narrow size distribution, which allowed several binding events of HRP-Ab2 on each nanosphere. Enhanced sensitivity was achieved by introducing the multi-bioconjugates of HRP-Ab2-CNSs onto the electrode surface through sandwich immunoreactions. Secondly, functionalized graphene sheets used for the biosensor platform increased the surface area to capture a large amount of primary antibodies (Ab1), thus amplifying the detection response. This amplification strategy is a promising platform for clinical screening of cancer biomarkers and point-of-care diagnostics.

  4. Effect of 3 T MRI on the function of shunt valves-Evaluation of Paedi GAV, Dual Switch and proGAV

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, D. [Department of Neurosurgery, University of Leipzig, Liebigstrasse 20, 04103 Leipzig (Germany)]. E-mail: dlind@medizin.uni-leipzig.de; Preul, C. [Max-Planck-Institut for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig (Germany); Trantakis, C. [Department of Neurosurgery, University of Leipzig, Liebigstrasse 20, 04103 Leipzig (Germany); Moeller, H. [Max-Planck-Institut for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig (Germany); Meixensberger, J. [Department of Neurosurgery, University of Leipzig, Liebigstrasse 20, 04103 Leipzig (Germany)

    2005-10-01

    The MR-compatibility of medical implants and devices becomes more and more important with the increasing number of high-field MR-scanners employed. Until the end of 2004, about twenty 3 T MR in Germany will be in clinical practice. Patients with hydrocephalus need frequent follow-up MR-examinations to assure correct functioning of a shunt. We tested three types of gravitational valves: the Paedi GAV, the Dual Switch and as a new programmable valve the proGAV (Miethke Company, Berlin), that have not been evaluated at 3 T, yet. In sum, there is strong evidence for maintenance of function of these valves after exposure to 3 T. This also implies the programmable valve, as long as the brake mechanism is properly adjusted during MR-examination.

  5. Stability and mutual conversion of enamel apatite and brushite at 20 degrees C as a function of pH of the aqueous phase.

    Science.gov (United States)

    Larsen, M J; Jensen, S J

    1989-01-01

    By calculation, apatite is more soluble than brushite at low pH and less soluble at high pH. Apatite, therefore should be able to transform spontaneously to brushite at low pH and brushite to apatite at high pH. The aim was to describe this mutual conversion as related to the aqueous phase composition. Powdered enamel, brushite or 1:1 mixtures of the two salts were suspended in distilled water for up to 12 weeks at 20 degrees C, pH was adjusted to 4, 5, 6, 7, 8, 9 or 10 by drops of perchloric acid or potassium hydroxide. The calcium and the phosphate concentrations and pH were determined, and the nature of the calcium phosphate powder was examined by X-ray diffraction. At pH 8 and above, brushite was invariably converted to apatite, whilst it was transformed to octacalcium phosphate at pH 7. In the pH range 6-4 brushite was not converted to apatite and enamel apatite was not transformed to brushite spontaneously within 2 months. In the enamel apatite suspensions, the apatite ion product altered with pH, which explained why apatite did not transform to brushite at pH 5-4. At pH 3.7, however, the enamel apatite was converted to brushite. No transformation of apatite to brushite was identified in apatite-brushite mixtures at pH 6-4. Supplementary experiments showed that ethanol, used as an agent for removal of water, salted out the water-free dicalcium phosphate, monetite.

  6. Photodegradation of ibuprofen by TiO2 co-doping with urea and functionalized CNT irradiated with visible light - Effect of doping content and pH.

    Science.gov (United States)

    Yuan, Ching; Hung, Chung-Hsuang; Li, Huei-Wen; Chang, Wei-Hsian

    2016-07-01

    Ibuprofen (IBP) is one kind of non-steroidal anti-inflammatory drugs (NSAIDs), which are classified as Pharmaceuticals and Personal Care Products (PPCPs). IBP possesses bioactive property and the substantial use of IBP results in a harmful impact on bioreceptors even in small concentrations. Accordingly, the treatment of these wastewaters is important before discharging them into the ecosystem. The photodegradation of IBP with TiO2 co-doped with functionalized CNTs (CNT-COOH and CNT-COCl) and urea, named as N-doping CNT/TiO2, irradiated with visible light of 410 nm was investigated in this study. The titanium tetrachloride was used as the precursor of Ti. The N-doping CNT-COCl/TiO2 photocatalysts exhibited a better crystalline structure and smaller crystal size than the N-doping CNT-COOH/TiO2 photocatalyst. It might largely ascribe to strong binding between acyl chloride functional group and TiO2. About 85.0%-86.0% of IBP was degraded with N-doping CNT/TiO2 within 120 min at natural condition, which obeyed the pseudo first order reaction and the rate constant was 4.45 × 10(-3)-1.22 × 10(-2) min(-1) and 5.03 × 10(-3)-1.47 × 10(-2) min(-1) for N-doping CNT-COOH/TiO2 and N-doping CNT-COCl/TiO2, respectively. The best IBP degradation of 87.9%-89.0% was found at pH 5, which indicated superoxide radicals (O2(-)) played a key role. The optimal pH was majorly dominated by the nature of IBP and N-doping CNT/TiO2. A successful synergy effect of TiO2 and dopants was exhibited and this mainly attributed to the strong binding strength by functional group of acyl chloride (COCl) and carboxylic acid (COOH). In summary, IBP could be effectively photodegraded by the fabricated N-doping CNT/TiO2 photocatalysts.

  7. A facile one-pot synthesis of starch functionalized graphene as nano-carrier for pH sensitive and starch-mediated drug delivery.

    Science.gov (United States)

    Liu, Kunping; Wang, Yimin; Li, Huiming; Duan, Yixiang

    2015-04-01

    A fast, green and facile method was developed to prepare starch functionalized graphene nanosheets (starch-GNS) via the reduction of exfoliated graphene oxides by soluble starch, which acted both as a reductant and as a functionalization reagent for capping graphene nanosheets to prevent aggregation. The as-prepared starch-GNS exhibited good biocompatibility, which was deemed crucial for the biomedical application of graphene. Cellular toxicity tests suggested that the starch-GNS was nontoxic to SW-620 cells even at the relatively concentration of 200 μg mL(-1). After the loading of the commonly used anticancer drug hydroxycamptothecin (HCPT) via physisorption on starch-GNS, the HCPT@starch-GNS composite exhibited a high drug loading capacity and was therefore used for cellular imaging and drug delivery studies. Through the nonspecific endocytosis effect, the HCPT@starch-GNS composite was encapsulated into cytoplasm by SW-620 cancer cells. With the double action of an acid microenvironment and the diastase in SW-620 cells, the HCPT@starch-GNS composite showed high toxicity to the SW-620 cells and experienced a pH sensitive as well as a starch-mediated in vitro sustained release process, which had the potential advantage of improving therapeutic efficacy. Therefore, the starch-GNS composite could be used as an ideal nano-carrier for drug delivery and offered a new avenue for broadening the application of graphene in biomedicine. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Differential effects of controlled hypotension on gastric intramucosal pH and post-operational gastrointestinal functional under two different anesthesia methods

    Institute of Scientific and Technical Information of China (English)

    Guanglei Wang; Junli Cao; Gongjian Liu

    2008-01-01

    Objective: To observe the effects of controlled hypotension on gastric intramucosal pH and post-operational gastrointestinal functions using two specific anesthesia methods. Methods: Thirty patients(ASA Ⅱ)scheduled for ectomy of hepatocarcinoma, were randomly assigned to two groups: epidural block combined with intravenous anesthesia group(E group) and inhalation anesthesia group(G group). Gastric PgCO2 and pHi were monitored at different time points, before theintravenous induction of controlled hypotension, after 1 h and 2 h, and 1 h after the termination of controlled hypotension. In the meanwhile, the artery blood gas was analyzed. Results: There was no significant difference in blood gas indexes between E group and G group. However, pHi decreased significantly after 1 h and 2 h of controlled hypotension(P<0.05), and during the same periods PgCO2 increased significantly(P<0.05 or P<0.01), the time of bowel movement and defecating deferred significantly shorter in G group patients, when compared with E group patients. Conclusion: Epidural block in combination with general anesthesia can improve gastrointestinal blood flow during controlled hypotension and facilitates post-operational recovery of gastrointestinal functions.

  9. Multifunctional uranyl hybrid materials: structural diversities as a function of pH, luminescence with potential nitrobenzene sensing, and photoelectric behavior as p-type semiconductors.

    Science.gov (United States)

    Song, Jian; Gao, Xue; Wang, Zhi-Nan; Li, Cheng-Ren; Xu, Qi; Bai, Feng-Ying; Shi, Zhong-Feng; Xing, Yong-Heng

    2015-09-21

    A series of uranyl-organic frameworks (UOFs), {[(UO2)2(H2TTHA)(H2O)]·4,4'-bipy·2H2O}n (1), {[(UO2)3(TTHA)(H2O)3]}n (2), and {[(UO2)5(TTHA) (HTTHA)(H2O)3]·H3O}n (3), have been obtained by the hydrothermal reaction of uranyl acetate with a flexible hexapodal ligand (1,3,5-triazine-2,4,6-triamine hexaacetic acid, H6TTHA). These compounds exhibited three distinct 3D self-assembly architectures as a function of pH by single-crystal structural analysis, although the used ligand was the same in each reaction. Surprisingly, all of the coordination modes of the H6TTHA ligand in this work are first discovered. Furthermore, the photoluminescent results showed that these compounds displayed high-sensitivity luminescent sensing functions for nitrobenzene. Additionally, the surface photovoltage spectroscopy and electric-field-induced surface photovoltage spectroscopy showed that compounds 1-3 could behave as p-type semiconductors.

  10. Effectiveness of dual-task functional power training for preventing falls in older people: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Daly, Robin M; Duckham, Rachel L; Tait, Jamie L; Rantalainen, Timo; Nowson, Caryl A; Taaffe, Dennis R; Sanders, Kerrie; Hill, Keith D; Kidgell, Dawson J; Busija, Lucy

    2015-03-27

    Falls are a major public health concern with at least one third of people aged 65 years and over falling at least once per year, and half of these will fall repeatedly, which can lead to injury, pain, loss of function and independence, reduced quality of life and even death. Although the causes of falls are varied and complex, the age-related loss in muscle power has emerged as a useful predictor of disability and falls in older people. In this population, the requirements to produce explosive and rapid movements often occurs whilst simultaneously performing other attention-demanding cognitive or motor tasks, such as walking while talking or carrying an object. The primary aim of this study is to determine whether dual-task functional power training (DT-FPT) can reduce the rate of falls in community-dwelling older people. The study design is an 18-month cluster randomised controlled trial in which 280 adults aged ≥65 years residing in retirement villages, who are at increased risk of falling, will be randomly allocated to: 1) an exercise programme involving DT-FPT, or 2) a usual care control group. The intervention is divided into 3 distinct phases: 6 months of supervised DT-FPT, a 6-month 'step down' maintenance programme, and a 6-month follow-up. The primary outcome will be the number of falls after 6, 12 and 18 months. Secondary outcomes will include: lower extremity muscle power and strength, grip strength, functional assessments of gait, reaction time and dynamic balance under single- and dual-task conditions, activities of daily living, quality of life, cognitive function and falls-related self-efficacy. We will also evaluate the cost-effectiveness of the programme for preventing falls. The study offers a novel approach that may guide the development and implementation of future community-based falls prevention programmes that specifically focus on optimising muscle power and dual-task performance to reduce falls risk under 'real life' conditions in older

  11. Chemiluminescence immunoassay based on dual signal amplification strategy of Au/mesoporous silica and multienzyme functionalized mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Lin Jiehua, E-mail: linjiehua@qust.edu.cn [Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhao Yue; Wei Zhijing; Wang Wei [Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2011-11-15

    Highlights: > The increased amount of monoclonal antibody in Au/SiO{sub 2} led to a wider linear range. > Due to the increased HRP tags in HRP-Ab{sub 2}/SiO{sub 2}, signal amplification achieved. > A simple dual amplification immunoassay achieved with flow injection analysis. - Abstract: A chemiluminescent dual signal amplification strategy for the determination of {alpha}-fetoprotein (AFP) was proposed based on a sandwich immunoassay format. Monoclonal antibody of AFP immobilized on the gold nanoparticles doped mesoporous SiO{sub 2} (Au/SiO{sub 2}) were prepared and used as a primary antibody. Horseradish peroxidase (HRP) and HRP-labeled secondary antibody (Ab{sub 2}) co-immobilized into the mesoporous SiO{sub 2} nanoparticles (HRP-Ab{sub 2}/SiO{sub 2}) were used as the labeled immunological probe. Due to the high ratio surface areas and pore volumes of the mesoporous SiO{sub 2}, not only the amount of AFP monoclonal antibody but also the amount of the modified HRP and Ab{sub 2} in HRP-Ab{sub 2}/SiO{sub 2} were largely increased. Thus the chemiluminescent signal was amplified by using the system of luminol and H{sub 2}O{sub 2} under the catalysis of HRP. Under the optimal conditions, two linear ranges for AFP were obtained from 0.01 to 0.5 ng mL{sup -1} and 0.5 to 100 ng mL{sup -1} with a detection limit of 0.005 ng mL{sup -1} (3{sigma}). The fabricated signal amplification strategy showed an excellent promise for sensitive detection of AFP and other tumor markers.

  12. Dual diagnosis

    OpenAIRE

    2013-01-01

    Dual diagnosis denotes intertwining of intellectual disabilities with mental disorders. With the help of systematic examination of literature, intellectual disabilities are determined (they are characterized by subaverage intellectual activity and difficulties in adaptive skills), along side mental disorders. Their influence is seen in changes of thinking, perception, emotionality, behaviour and cognition. Mental disorders often occur with people with intellectual disabilities (data differs f...

  13. OFF-ON-OFF Dual Emission at Visible and UV Wavelengths from Carbazole Functionalized β-Diketonate Europium(III) Complex.

    Science.gov (United States)

    Imai, Yuki; Kawai, Tsuyoshi; Yuasa, Junpei

    2016-06-23

    This work demonstrates dual emission "OFF-ON-OFF" switching at visible and UV wavelengths of a carbazole functionalized β-diketone (LH) by a simple change of a europium(III) ion (Eu(3+)) concentration in the submicromolar concentration range. In the presence of 0.25 equiv of Eu(3+) (5 μM), LH forms a luminescent 4:1 complex ([Eu(3+)(L(-))4](-)) exhibiting dual emission at 357 and 613 nm resulting from the local excitation of the carbazole ring and ligand-sensitized luminescence from the Eu(3+)-β-diketonate unit, respectively. The 4:1 complex begins to convert into a 2:1 complex ([Eu(3+)(L(-))2](+)) via a 3:1 complex [Eu(3+)(L(-))3] above a molar ratio ([Eu(3+)]/[LH]) of 0.25, which provides the opportunity for binding of solvent methanol molecules to the vacant site of the Eu(3+) ion in the complex ([Eu(3+)(L(-))2(MeOH)n](+)). The OH oscillators of coordinated methanol molecules facilitate the nonradiative pathway of the Eu(3+) emission; hence the emission at 613 nm almost disappears above the 0.50 equivalent of Eu(3+) (11 μM), while the UV emission at 357 nm remains mostly constant over the whole concentration range.

  14. Sensor Fusion Based on an Integrated Neural Network and Probability Density Function (PDF) Dual Kalman Filter for On-Line Estimation of Vehicle Parameters and States.

    Science.gov (United States)

    Vargas-Melendez, Leandro; Boada, Beatriz L; Boada, Maria Jesus L; Gauchia, Antonio; Diaz, Vicente

    2017-04-29

    Vehicles with a high center of gravity (COG), such as light trucks and heavy vehicles, are prone to rollover. This kind of accident causes nearly 33 % of all deaths from passenger vehicle crashes. Nowadays, these vehicles are incorporating roll stability control (RSC) systems to improve their safety. Most of the RSC systems require the vehicle roll angle as a known input variable to predict the lateral load transfer. The vehicle roll angle can be directly measured by a dual antenna global positioning system (GPS), but it is expensive. For this reason, it is important to estimate the vehicle roll angle from sensors installed onboard in current vehicles. On the other hand, the knowledge of the vehicle's parameters values is essential to obtain an accurate vehicle response. Some of vehicle parameters cannot be easily obtained and they can vary over time. In this paper, an algorithm for the simultaneous on-line estimation of vehicle's roll angle and parameters is proposed. This algorithm uses a probability density function (PDF)-based truncation method in combination with a dual Kalman filter (DKF), to guarantee that both vehicle's states and parameters are within bounds that have a physical meaning, using the information obtained from sensors mounted on vehicles. Experimental results show the effectiveness of the proposed algorithm.

  15. Dual-source computed tomography. Effect on regional and global left ventricular function assessment compared to magnetic resonance imaging; Untersuchung der regionalen und globalen linksventrikulaeren Funktion mit der Dual-Source-Computertomografie im Vergleich zur Magnetresonanztomografie

    Energy Technology Data Exchange (ETDEWEB)

    Lueders, F.; Seifarth, H.; Wessling, J.; Heindel, W.; Juergens, Kai Uwe [Inst. fuer Klinische Radiologie, Universitaetsklinikum Muenster (Germany); Fischbach, R. [Klinik fuer Radiologie, Nuklearmedizin und Neuroradiologie, Asklepios Klinik Altona (Germany)

    2009-10-15

    Purpose: to determine regional and global left ventricular (LV) functional parameters and to perform segmental wall thickness (SWT) and motion (WM) analysis of dual source CT (DSCT) with optimized temporal resolution versus MRI. Materials and Methods: 30 patients with known or suspected CAD, non-obstructive HCM, DCM, ARVCM, Fallot Tetralogy, cardiac sarcoidosis and cardiac metastasis underwent DSCT and MRI. The DSCT and MR images were evaluated: end-systolic (ESV), end-diastolic LV (EDV) volumes, stroke volume (SV), ejection fraction (EF), and myocardial mass (MM) as well as LV wall thickening and segmental WM applying the AHA model were obtained and statistically analyzed. Results: The mean LV-EDV (r = 0.96) and ESV (r = 0.98) as well as LV-EF (r = 0.97), SV (r = 0.83), and MM (r = 0.95) correlated well. Bland Altman analysis revealed little systematic underestimation of LV-EF (-1.1 {+-} 7.8%), EDV (-0.3 {+-} 18.2 ml), SV (-1.3 {+-} 16.7 ml) and little overestimation of ESV (1.1 {+-} 7.8 ml) and MM (12.8 {+-} 14.4 g) determined by DSCT. Systolic reconstruction time points correlated well (DSCT 32.2 {+-} 6.7 vs. MRI 35.6 {+-} 4.4% RR-interval). The LV wall thickness obtained by DSCT and MRI showed close correlation in all segments (diameter diff 0.42 {+-} 1 mm). In 413 segments (89%) WM abnormalities were equally rated, whereas DSCT tended to underestimate the degree of wall motion impairment. Conclusion: DSCT with optimized temporal resolution enables regional and global LV function analysis as well as segmental WM analysis in good correlation with MRI. However, the degree of WM impairment is slightly underestimated by DSCT. (orig.)

  16. Nanostructural modification of a model homogalacturonan with a novel pectin methylesterase: Effects of pH on nanostructure, enzyme mode of action and substrate functionality

    Science.gov (United States)

    A pectin methylesterase (CpL-PME) present in a commercial papain preparation was used to modify the amount and distribution of charge in a model pectic homogalacturonan (HG) at pH 4.5 and pH 7.5. Introduced negatively charged demethylesterified blocks (DMB) were excised as oligomers with a limited e...

  17. Mechanism of pH Dependent Decomposition of Monoalkylamine Diazeniumdiolates to Form HNO and NO, Deduced from the Model Compound Methylamine Diazeniumdiolate, Density Functional Theory and CBS-QB3 Calculations

    Science.gov (United States)

    Dutton, Andrew S.; Suhrada, Christopher P.; Miranda, Katrina M.; Wink, David A.; Fukuto, Jon M.; Houk, K. N.

    2011-01-01

    Isopropylamine diazeniumdiolate, IPA/NO, the product of the reaction of isopropylamine and nitric oxide, NO, decomposes in a pH dependent manner to afford nitroxyl, HNO, in the pH range of 13 to above 5 and NO below pH 7. Theoretical studies using B3LYP/6-311+G(d) density functional theory, the PCM and CPCM solvation models and the high accuracy CBS-QB3 method on the simplified model compound, methylamine diazeniumdiolate, predict a mechanism involving HNO production via decomposition of the unstable tautomer MeNN+(O−)NHO−. The production of NO at lower pH is predicted to result from fragmentation of the amide/NO adduct upon protonation of the amine nitrogen. PMID:16529464

  18. Long-term effect of pH on B-cell function in isolated islets of Langerhans in tissue culture

    DEFF Research Database (Denmark)

    Brunstedt, J; Nielsen, Jens Høiriis

    1978-01-01

    Collagenase isolated mouse pancreatic islets were maintained in tissue culture for up to 5 months in a culture medium buffered with Hepes and the pH varying between 6.8 and 7.6. The amount of insulin released into the medium and the insulin response to glucose and glucose plus theophylline were...... measured during the culture period. It was found that islets cultured at pH 7.2 maintained the ability to release insulin into the medium for at least 5 months, which was longer than islets cultured at the other pH values. During the first weeks, the islets cultured at pH 7.6 had a higher response to both...... glucose and glucose plus theophylline than islets cultured at the other pH values, but later they lost their insulin releasing ability....

  19. Characterization of functionally graded ZrO2 thermal barrier coatings sprayed by supersonic plasma spray with dual powder feed ports

    Institute of Scientific and Technical Information of China (English)

    HAN Zhi-hai; WANG Hai-jun; ZHOU Shi-kui; XU Bing-shi

    2005-01-01

    The functionally graded thermal barrier coatings (FG-TBCs) with 80 % ZrO2-13 % CeO2-7 % Y2 Os ( CYSZ)/NiCoCrAlY were prepared using a recently developed supersonic plasma spraying(S-PS) with dual powder feed ports system. The thermal shock experiment of FG-TBCs specimens was carried out by means of the automatic thermal cycle device, in which the samples were heated to 1 200 ℃ by oxygen-acetylene flame jet then waterquenched to ambient temperature. The temperature-time curves of specimens and photographs can be watched online and recorded by a computer during the test. The results show that the totally 1 mm-thick FG-TBCs have excellent thermal shock resistance due to the fact that the coatings have no any peeling-off after 200 thermal cycles. The microstructures and morphologies of FG-TBCs were characterized and analyzed by SEM.

  20. An integrated dual functional recognition/amplification bio-label for the one-step impedimetric detection of Micro-RNA-21.

    Science.gov (United States)

    Azzouzi, Sawsen; Mak, Wing Cheung; Kor, Kamalodin; Turner, Anthony P F; Ali, Mounir Ben; Beni, Valerio

    2017-06-15

    Alteration in expression of miRNAs has been correlated with different cancer types, tumour stage and response to treatments. In this context, a structurally responsive oligonucleotide-based electrochemical impedimetric biosensor has been developed for the simple and sensitive detection of miRNA-21. A highly specific biotinylated DNA/LNA molecular beacon (MB) probe was conjugated with gold nanoparticles (AuNPs) to create an integrated, dual function bio-label (biotin-MB-AuNPs) for both biorecognition and signal generation. In the presence of target miRNA-21, hybridisation takes place resulting in the "activation" of the biotin-MB; this event makes the biotin group, which was previously "protected" by the steric hindrance of the MB stem-loop structure, accessible. The activated biotin-MB-AuNPs/miRNA complexes become available for capture, via supramolecular interaction, onto a nentravidin-modified electrode for electrochemical transduction. The binding event results in a decrease of the charge transfer resistance at the working electrode/electrolyte interface. The biosensor responded linearly in the range 1-1000 pM of miRNA-21, with a limit of detection of 0.3 pM, good reproducibility (Relative Standard deviation (RSD) =3.3%) and high selectivity over other miRNAs (i.e. miRNA-221 and miRNA-205) sequences. Detection of miRNA-21 in spiked serum samples at clinically relevant levels (low pM range) was also demonstrated, thus illustrating the potential of the biosensor for point-of-care clinical applications. The proposed biosensor design, based on the combination of a neutravidin transducing surface and the dual-function biotin-MB-AuNPs bio-label, provides a simple and robust approach for detection of short-length nucleic acid targets, such as miRNAs.

  1. Estimating Age Distributions of Base Flow in Watersheds Underlain by Single and Dual Porosity Formations Using Groundwater Transport Simulation and Weighted Weibull Functions

    Science.gov (United States)

    Sanford, W. E.

    2015-12-01

    Age distributions of base flow to streams are important to estimate for predicting the timing of water-quality responses to changes in distributed inputs of nutrients or pollutants at the land surface. Simple models of shallow aquifers will predict exponential age distributions, but more realistic 3-D stream-aquifer geometries will cause deviations from an exponential curve. In addition, in fractured rock terrains the dual nature of the effective and total porosity of the system complicates the age distribution further. In this study shallow groundwater flow and advective transport were simulated in two regions in the Eastern United States—the Delmarva Peninsula and the upper Potomac River basin. The former is underlain by layers of unconsolidated sediment, while the latter consists of folded and fractured sedimentary rocks. Transport of groundwater to streams was simulated using the USGS code MODPATH within 175 and 275 watersheds, respectively. For the fractured rock terrain, calculations were also performed along flow pathlines to account for exchange between mobile and immobile flow zones. Porosities at both sites were calibrated using environmental tracer data (3H, 3He, CFCs and SF6) in wells and springs, and with a 30-year tritium record from the Potomac River. Carbonate and siliciclastic rocks were calibrated to have mobile porosity values of one and six percent, and immobile porosity values of 18 and 12 percent, respectively. The age distributions were fitted to Weibull functions. Whereas an exponential function has one parameter that controls the median age of the distribution, a Weibull function has an extra parameter that controls the slope of the curve. A weighted Weibull function was also developed that potentially allows for four parameters, two that control the median age and two that control the slope, one of each weighted toward early or late arrival times. For both systems the two-parameter Weibull function nearly always produced a substantially

  2. Density functional investigation of the adsorption effects of PH3 and SH2 on the structure stability of the Au55 and Pt55 nanoclusters

    Science.gov (United States)

    Guedes-Sobrinho, Diego; Chaves, Anderson S.; Piotrowski, Maurício J.; Da Silva, Juarez L. F.

    2017-04-01

    Although several studies have been reported for Pt55 and Au55 nanoclusters, our atomistic understanding of the interplay between the adsorbate-surface interactions and the mechanisms that lead to the formation of the distorted reduced core (DRC) structures, instead of the icosahedron (ICO) structure in gas phase, is still far from satisfactory. Here, we report a density functional theory (DFT) investigation of the role of the adsorption effects of PH3 (one lone pair of electrons) and SH2 (two lone pairs) on the relative stability of the Pt55 and Au55 nanoclusters. In gas phase, we found that the DRC structures with 7 and 9 atoms in the core region are about 5.34 eV (Pt55) and 2.20 eV (Au55) lower in energy than the ICO model with Ih symmetry and 13 atoms in the core region. However, the stability of the ICO structure increases by increasing the number of adsorbed molecules from 1 to 18, in which both DRC and ICO structures are nearly degenerate in energy at the limit of 18 ligands, which can be explained as follows. In gas phase, there is a strong compression of the cationic core region by the anionic surface atoms induced by the attractive Coulomb interactions (core+-surface-), and hence, the strain release is obtained by reducing the number of atoms in the cationic core region, which leads to the 55 atoms distorted reduced core structures. Thus, the Coulomb interactions between the core+ and surface- contribute to break the symmetry in the ICO55 structure. On the other hand, the addition of ligands on the anionic surface reduces the charge transfer between the core and surface, which contributes to decrease the Coulomb interactions and the strain on the core region of the ICO structure, and hence, it stabilizes a compact ICO structure. The same conclusion is obtained by adding van der Waals corrections to the plain DFT calculations. Similar results are obtained by the addition of steric effects, which are considered through the adsorption of triphenylphosphine

  3. Acute Exposure to a Precursor of Advanced Glycation End Products Induces a Dual Effect on the Rat Pancreatic Islet Function

    Directory of Open Access Journals (Sweden)

    Ghada Elmhiri

    2014-01-01

    Full Text Available Aim. Chronic diseases are the leading cause of death worldwide. Advanced glycation end products, known as AGEs, are a major risk factor for diabetes onset and maintenance. Methylglyoxal (MG, a highly reactive metabolite of glucose, is a precursor for the generation of endogenous AGEs. Methods. In this current study we incubated in vitro pancreatic islets from adult rats in absence or presence of MG (10 μmol/l with different concentrations of glucose and different metabolic components (acetylcholine, epinephrine, potassium, forskolin, and leucine. Results. Different effects of MG on insulin secretion were evidenced. In basal glucose stimulation (5.6 mM, MG induced a significant (P<0.05 increase of insulin secretion. By contrast, in higher glucose concentrations (8.3 mM and 16.7 mM, MG significantly inhibited insulin secretion (P<0.05. In the presence of potassium, forskolin, and epinephrine, MG enhanced insulin secretion (P<0.05, while when it was incubated with acetylcholine and leucine, MG resulted in a decrease of insulin secretion (P<0.05. Conclusion. We suggest that MG modulates the secretion activity of beta-cell depending on its level of stimulation by other metabolic factors. These results provide insights on a dual acute effect of MG on the pancreatic cells.

  4. Catechol derivatives as fluorescent chemosensors for wide-range pH detection.

    Science.gov (United States)

    Evangelio, Emilia; Hernando, Jordi; Imaz, Inhar; Bardají, Gisela G; Alibés, Ramon; Busqué, Félix; Ruiz-Molina, Daniel

    2008-01-01

    The synthesis and characterization of a new family of catechol derivatives designed to behave as fluorescent chemosensors for wide-range pH detection has been described. These compounds were prepared by covalently coupling a catechol unit with other aromatic rings, thus obtaining pi-delocalized systems with both pH-responsive groups and fluorescent behavior. In the case of a pyridine-catechol derivative, this leads to up to three different protonation states with distinct optical properties in organic media, as corroborated by density functional theory calculations. By applying dual-wavelength detection techniques, this compound shows complementary "off-on-off" and "on-off-on" emission profiles upon pH variation, a behavior that can be exploited to perform acidity detection over a broad pH range.

  5. Characterization of glutamate decarboxylase from Lactobacillus plantarum and its C-terminal function for the pH dependence of activity.

    Science.gov (United States)

    Shin, Sun-Mi; Kim, Hana; Joo, Yunhye; Lee, Sang-Jae; Lee, Yong-Jik; Lee, Sang Jun; Lee, Dong-Woo

    2014-12-17

    The gadB gene encoding glutamate decarboxylase (GAD) from Lactobacillus plantarum was cloned and expressed in Escherichia coli. The recombinant enzyme exhibited maximal activity at 40 °C and pH 5.0. The 3D model structure of L. plantarum GAD proposed that its C-terminal region (Ile454-Thr468) may play an important role in the pH dependence of catalysis. Accordingly, C-terminally truncated (Δ3 and Δ11 residues) mutants were generated and their enzyme activities compared with that of the wild-type enzyme at different pH values. Unlike the wild-type GAD, the mutants showed pronounced catalytic activity in a broad pH range of 4.0-8.0, suggesting that the C-terminal region is involved in the pH dependence of GAD activity. Therefore, this study may provide effective target regions for engineering pH dependence of GAD activity, thereby meeting industrial demands for the production of γ-aminobutyrate in a broad range of pH values.

  6. Ph3CCOOSnPh3.Ph3PO AND Ph3CCOOSnPh3.Ph3AsO: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    ABDOU MBAYE

    2014-08-01

    Full Text Available The mixture of ethanolic solutions of Ph3CCOOSnPh3 and Ph3PO or Ph3AsO gives Ph3CCOOSnPh3.Ph3PO and Ph3CCOOSnPh3.Ph3AsO adducts which have been characterized by infrared spectroscopy. A discrete structure is suggested for both, the environment around the tin centre being trigonal bipyramidal, the triphenylacetate anion behaving as a mondentate ligand.

  7. Na+,HCO3--cotransport is functionally upregulated during human breast carcinogenesis and required for the inverted pH gradient across the plasma membrane

    DEFF Research Database (Denmark)

    Lee, Soojung; Mele, Marco; Vahl, Pernille

    2015-01-01

    and promoting cancer cell metabolism, proliferation, migration, and invasion. We investigated the effects of breast carcinogenesis on the mechanisms of cellular pH control using multicellular epithelial organoids freshly isolated from human primary breast carcinomas and matched normal breast tissue...... (~0.3 units of magnitude) in steady-state intracellular pH of human primary breast carcinomas compared to normal breast tissue. Na(+)/H(+)-exchange activity and steady-state intracellular pH in the absence of CO2/HCO3 (-) were practically unaffected by breast carcinogenesis. These effects were evident....... Intracellular pH was measured by fluorescence microscopy, while protein expression was investigated by immunofluorescence imaging and immunoblotting. We found that cellular net acid extrusion increased during human breast carcinogenesis due to enhanced Na(+),HCO3 (-)-cotransport, which created an alkaline shift...

  8. Functional Magnetic Resonance Imaging Clinical Trial of a Dual-Processing Treatment Protocol for Substance-Dependent Adults

    Science.gov (United States)

    Matto, Holly C.; Hadjiyane, Maria C.; Kost, Michelle; Marshall, Jennifer; Wiley, Joseph; Strolin-Goltzman, Jessica; Khatiwada, Manish; VanMeter, John W.

    2014-01-01

    Objectives: Empirical evidence suggests substance dependence creates stress system dysregulation which, in turn, may limit the efficacy of verbal-based treatment interventions, as the recovering brain may not be functionally capable of executive level processing. Treatment models that target implicit functioning are necessary. Methods: An RCT was…

  9. Lp-dual Quermassintegral sums

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper,we first introduce a concept of L_p-dual Quermassintegral sum function of convex bodies and establish the polar projection Minkowski inequality and the polar projection Aleksandrov-Fenchel inequality for L_p-dual Quermassintegral sums.Moreover,by using Lutwak’s width-integral of index i,we establish the L_p-Brunn-Minkowski inequality for the polar mixed projec- tion bodies.As applications,we prove some interrelated results.

  10. Clinical application of dual-source CT in the evaluation of patients with lung cancer: correlation with perfusion scintigraphy and pulmonary function tests.

    Science.gov (United States)

    Fraioli, F; Serra, G; Liberali, S; Fiorelli, A; Liparulo, V; Zaccagna, F; Ciccariello, G; Catalano, C; Passariello, R

    2011-09-01

    This study was done to assess the diagnostic potential of dual-source computed tomography (DSCT) in the functional evaluation of lung cancer patients undergoing surgical resection. The CT data were compared with pulmonary perfusion scintigraphy and pulmonary function tests (PFTs). All patients were evaluated with DSCT, scintigraphy and PFTs. The DSCT scan protocol was as follows: two tubes (80 and 140 kV; Care Dose protocol); 70 cc of contrast material (5 cc/s); 5- to 6-s scan time; 0.6 mm collimation. After the automatic calculation of lung perfusion with DSCT and quantification of air volumes and emphysema with dedicated software applications, the perfusional CT studies were compared with scintigraphy using a visual score for perfusion defects; CT air volumes and emphysema were compared with PFTs. The values of accuracy, sensitivity, specificity and positive (PPV) and negative (NPV) predictive values of DSCT compared with perfusion scintigraphy as the reference standard were: 0.88, 0.84, 0.90, 0.93 and 0.88, respectively. The McNemar test did not identify significant differences either between the two imaging techniques (p=0.07) or between CT and PFTs (p=0.09). DSCT is a robust and promising technique that provides important and accurate information on lung function.

  11. PhEDEx Data Service

    Science.gov (United States)

    Egeland, Ricky; Wildish, Tony; Huang, Chih-Hao

    2010-04-01

    The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the "SiteDB" service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

  12. PhEDEx Data Service

    Energy Technology Data Exchange (ETDEWEB)

    Egeland, Ricky [University of Minnesota, Twin Cities (United States); Wildish, Tony [Princeton University (United States); Huang, Chih-Hao [Fermi National Accelerator Laboratory (United States)

    2010-04-01

    The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the 'SiteDB' service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

  13. Kinetics of polydopamine film deposition as a function of pH and dopamine concentration: insights in the polydopamine deposition mechanism.

    Science.gov (United States)

    Ball, Vincent; Del Frari, Doriane; Toniazzo, Valérie; Ruch, David

    2012-11-15

    The formation of "polydopamine" thin films becomes a popular method to confer multifunctionality to solid-liquid interfaces through the available catechol groups of such films. The mechanism of film formation is, however, not well elucidated, and most investigators use the protocol developed by Messersmith et al. (H. Lee, S.M. Dellatore, W.M. Miller, P.B. Messersmith, Science 318 (2007) 426.) using a dopamine solution at a constant concentration of 2 g L(-1) in the presence of Tris(hydroxymethyl aminomethane) at pH 8.5. A particular finding of this initial study was that the film thickness reaches a constant value (almost substrate independent) of about 40 nm. Herein, we investigate the change in the polydopamine film thickness, morphology, surface energy and electrochemical properties as a function of the concentration of the dopamine solution put in the presence of silicon substrates. As a surprising finding, we observe a constant increase in the maximal film thickness with an increase in the dopamine solution between 0.1 and 5 g L(-1). The surface morphology is also markedly affected by the concentration of the dopamine solution, whereas the different components of the surface energy stay unaffected by the dopamine solution concentration. In addition, electrochemical impedance spectroscopy shows that the higher the initial dopamine concentration, the more rapidly compact and impermeable films are formed. Finally, we propose a model for the deposition of polydopamine films taking all our findings into account. This model relies on a rate equation taking into account both attractive and repulsive interactions between small polydopamine aggregates on the surface and in solution.

  14. Use of a Spreadsheet to Calculate the Net Charge of Peptides and Proteins as a Function of pH: An Alternative to Using "Canned" Programs to Estimate the Isoelectric Point of These Important Biomolecules

    Science.gov (United States)

    Sims, Paul A.

    2010-01-01

    An approach is presented that utilizes a spreadsheet to allow students to explore different means of calculating and visualizing how the charge on peptides and proteins varies as a function of pH. In particular, the concept of isoelectric point is developed to allow students to compare the results of their spreadsheet calculations with those of…

  15. Use of a Spreadsheet to Calculate the Net Charge of Peptides and Proteins as a Function of pH: An Alternative to Using "Canned" Programs to Estimate the Isoelectric Point of These Important Biomolecules

    Science.gov (United States)

    Sims, Paul A.

    2010-01-01

    An approach is presented that utilizes a spreadsheet to allow students to explore different means of calculating and visualizing how the charge on peptides and proteins varies as a function of pH. In particular, the concept of isoelectric point is developed to allow students to compare the results of their spreadsheet calculations with those of…

  16. High-resolution Imaging of pH in Alkaline Sediments and Water Based on a New Rapid Response Fluorescent Planar Optode.

    Science.gov (United States)

    Han, Chao; Yao, Lei; Xu, Di; Xie, Xianchuan; Zhang, Chaosheng

    2016-05-20

    A new dual-lumophore optical sensor combined with a robust RGB referencing method was developed for two-dimensional (2D) pH imaging in alkaline sediments and water. The pH sensor film consisted of a proton-permeable polymer (PVC) in which two dyes with different pH sensitivities and emission colors: (1) chloro phenyl imino propenyl aniline (CPIPA) and (2) the coumarin dye Macrolex(®) fluorescence yellow 10 GN (MFY-10 GN) were entrapped. Calibration experiments revealed the typical sigmoid function and temperature dependencies. This sensor featured high sensitivity and fast response over the alkaline working ranges from pH 7.5 to pH 10.5. Cross-sensitivity towards ionic strength (IS) was found to be negligible for freshwater when IS water associated with the photosynthesis of Vallisneria spiral species was also presented, suggesting that the sensor held great promise for the field applications.

  17. Cognitive function and gait speed under normal and dual-task walking among older adults with mild cognitive impairment

    National Research Council Canada - National Science Library

    Doi, Takehiko; Shimada, Hiroyuki; Makizako, Hyuma; Tsutsumimoto, Kota; Uemura, Kazuki; Anan, Yuya; Suzuki, Takao

    2014-01-01

    .... We classified 389 elderly adults into amnestic MCI (n = 191) and non-amnestic MCI (n = 198), assessed their cognitive functions, and administered gait experiments under NW and DTW conditions...

  18. Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus

    Science.gov (United States)

    Vandecandelaere, Ilse; Van Nieuwerburgh, Filip; Deforce, Dieter

    2017-01-01

    In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other’s behavior, but additional studies are required necessary to elucidate the exact

  19. Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus.

    Science.gov (United States)

    Vandecandelaere, Ilse; Van Nieuwerburgh, Filip; Deforce, Dieter; Coenye, Tom

    2017-01-01

    In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other's behavior, but additional studies are required necessary to elucidate the exact

  20. Dual responsive polymeric nanoparticles prepared by direct functionalization of polylactic acid-based polymers via graft-from ring opening metathesis polymerization.

    Science.gov (United States)

    Veccharelli, Kate M; Tong, Venus K; Young, Jennifer L; Yang, Jerry; Gianneschi, Nathan C

    2016-01-11

    Polylactic acid (PLA) has found widespread use in plastics and in biomedical applications due to its biodegradability into natural benign products. However, PLA-based materials remain limited in usefulness due to difficulty of incorporating functional groups into the polymer backbone. In this paper, we report a strategy for PLA functionalization that establishes the preparation of highly derivatized materials in which ring opening metathesis polymerization (ROMP) is employed as a graft-from polymerization technique utilizing a norbornene-modified handle incorporated into the PLA backbone. As a demonstration of this new synthetic methodology, a PLA-derived nanoparticle bearing imidazole units protected with a photolabile group was prepared. The morphology of this material could be controllably altered in response to exposure of UV light or acidic pH as a stimulus. We anticipate that this graft-from approach to derivatization of PLA could find broad use in the development of modified, biodegradable PLA-based materials.

  1. Semi-automatic measurement of left ventricular function on dual source computed tomography using five different software tools in comparison with magnetic resonance imaging.

    Science.gov (United States)

    de Jonge, G J; van der Vleuten, P A; Overbosch, J; Lubbers, D D; Jansen-van der Weide, M C; Zijlstra, F; van Ooijen, P M A; Oudkerk, M

    2011-12-01

    To compare left ventricular (LV) function assessment using five different software tools on the same dual source computed tomography (DSCT) datasets with the results of MRI. Twenty-six patients, undergoing cardiac contrast-enhanced DSCT were included (20 men, mean age 59±12 years). Reconstructions were made at every 10% of the RR-interval. Function analysis was performed with five different, commercially available workstations. In all software tools, semi-automatic LV function measurements were performed, with manual corrections if necessary. Within 0-22 days, all 26 patients were scanned on a 1.5 T MRI-system. Bland-Altman analysis was performed to calculate limits of agreement between DSCT and MRI. Pearson's correlation coefficient was calculated to assess the correlation between the different DSCT software tools and MRI. Repeated measurements were performed to determine intraobserver and interobserver variability. For all five DSCT workstations, mean LV functional parameters correlated well with measurements on MRI. Bland-Altman analysis of the comparison of DSCT and MRI showed acceptable limits of agreement. Best correlation and limits of agreement were obtained by DSCT software tools with software algorithms comparable to MRI software. The five different DSCT software tools we examined have interchangeable results of LV functional parameters compared to regularly analysed results by MRI. The best correlation and the narrowest limits of agreement were found when the same software algorithm was used for both DSCT and MRI examinations, therefore our advice for clinical practice is to always evaluate images with the same type of post-processing tools in follow-up. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  2. Characterization of functional antibody and memory B-cell responses to pH1N1 monovalent vaccine in HIV-infected children and youth.

    Directory of Open Access Journals (Sweden)

    Donna J Curtis

    Full Text Available We investigated immune determinants of antibody responses and B-cell memory to pH1N1 vaccine in HIV-infected children.Ninety subjects 4 to <25 years of age received two double doses of pH1N1 vaccine. Serum and cells were frozen at baseline, after each vaccination, and at 28 weeks post-immunization. Hemagglutination inhibition (HAI titers, avidity indices (AI, B-cell subsets, and pH1N1 IgG and IgA antigen secreting cells (ASC were measured at baseline and after each vaccination. Neutralizing antibodies and pH1N1-specific Th1, Th2 and Tfh cytokines were measured at baseline and post-dose 1.At entry, 26 (29% subjects had pH1N1 protective HAI titers (≥1:40. pH1N1-specific HAI, neutralizing titers, AI, IgG ASC, IL-2 and IL-4 increased in response to vaccination (p<0.05, but IgA ASC, IL-5, IL-13, IL-21, IFNγ and B-cell subsets did not change. Subjects with baseline HAI ≥1:40 had significantly greater increases in IgG ASC and AI after immunization compared with those with HAI <1:40. Neutralizing titers and AI after vaccination increased with older age. High pH1N1 HAI responses were associated with increased IgG ASC, IFNγ, IL-2, microneutralizion titers, and AI. Microneutralization titers after vaccination increased with high IgG ASC and IL-2 responses. IgG ASC also increased with high IFNγ responses. CD4% and viral load did not predict the immune responses post-vaccination, but the B-cell distribution did. Notably, vaccine immunogenicity increased with high CD19+CD21+CD27+% resting memory, high CD19+CD10+CD27+% immature activated, low CD19+CD21-CD27-CD20-% tissue-like, low CD19+CD21-CD27-CD20-% transitional and low CD19+CD38+HLADR+% activated B-cell subsets.HIV-infected children on HAART mount a broad B-cell memory response to pH1N1 vaccine, which was higher for subjects with baseline HAI≥1:40 and increased with age, presumably due to prior exposure to pH1N1 or to other influenza vaccination/infection. The response to the vaccine was dependent

  3. A red tide alga grown under ocean acidification up-regulates its tolerance to lower pH by increasing its photophysiological functions

    Directory of Open Access Journals (Sweden)

    S.-W. Chen

    2014-05-01

    Full Text Available Phaeocystis globosa, a red tide alga, often forms blooms in or adjacent to coastal waters and experiences changes of pH and seawater carbonate chemistry caused by either diel/periodic fluctuation in biological activity, human activity or, in the longer term, ocean acidification due to atmospheric CO2 rise. We examined the photosynthetic physiology of this species while growing it under different pH levels induced by CO2 enrichment and investigated its acclimation to carbonate chemistry changes under different light levels. Short-term exposure to reduced pHnbs (7.70 decreased the alga's photosynthesis and light use efficiency. However, acclimation to the reduced pH level for 1–19 generations led to recovered photosynthetic activity, being equivalent to that of cells grown under pH 8.07 (control, though such acclimation required a different time span (number of generations under different light regimes. The low-pH grown cells increased their contents of chlorophyll and carotenoids with prolonged acclimation to the acidification, with increased photosynthetic quantum yield and decreased non-photochemical quenching. The specific growth rate of the low-pH grown cells also increased to emulate that grown under the ambient pH level. This study clearly shows that Phaeocystis globosa is able to acclimate to seawater acidification by increasing its energy capture and decreasing its non-photochemcial energy loss.

  4. In silico logistic model for table olive related microorganisms as a function of sodium metabisulphite, cinnamaldehyde, pH, and type of acidifying agent

    Directory of Open Access Journals (Sweden)

    Verónica Romero-Gil

    2016-08-01

    Full Text Available A probabilistic/logistic model, based on binary data (growth/no growth, was used to assess the effects of sodium metabisulphite (SM and cinnamaldehyde (CIN (0-1,000 mg/L against the main microbial groups found in table olive environment (lactic acid bacteria (LAB, yeasts, and Enterobacteriaceae, according to pH (range 3.5-5.0 and type of acidifying agent (HCl or pyruvic acid. The inhibitory effect of SM depended on the pH while that of CIN was scarcely influenced by it (except for LAB. LAB were more sensitive to SM, while yeasts were to CIN. The use of pyruvic acid for correction of pH always produced a reduction (compared to HCl of the inhibitory power of both preservatives. The in silico models for HCl showed that, at pH 4.0 and growth probability 0.01, the LAB population might be inhibited by the presence in the medium of 150 mg/L SM or 1,000 mg/L CIN, while in the case of yeasts, 450 mg/L SM or 150 mg/L CIN are required. No growth of Enterobacteriaceae was observed at this (or lower pH level. The results obtained may contribute to the stabilization of non-thermally treated table olive packaging.

  5. In silico Logistic Model for Table Olive Related Microorganisms As a Function of Sodium Metabisulphite, Cinnamaldehyde, pH, and Type of Acidifying Agent.

    Science.gov (United States)

    Romero-Gil, Verónica; Garrido-Fernández, Antonio; Arroyo-López, Francisco N

    2016-01-01

    A probabilistic/logistic model, based on binary data (growth/no growth), was used to assess the effects of sodium metabisulphite (SM) and cinnamaldehyde (CIN; 0-1000 mg/L) against the main microbial groups found in table olive environment [lactic acid bacteria (LAB), yeasts, and Enterobacteriaceae], according to pH (range 3.5-5.0), and type of acidifying agent (HCl or pyruvic acid). The inhibitory effect of SM depended on the pH while that of CIN was scarcely influenced by it (except for LAB). LAB were more sensitive to SM, while yeasts were to CIN. The use of pyruvic acid for correction of pH always produced a reduction (compared to HCl) of the inhibitory power of both preservatives. The in silico models for HCl showed that, at pH 4.0, and growth probability 0.01, the LAB population might be inhibited by the presence in the medium of 150 mg/L SM or 1000 mg/L CIN, while in the case of yeasts, 450 mg/L SM, or 150 mg/L CIN are required. No growth of Enterobacteriaceae was observed at this (or lower) pH level. The results obtained may contribute to the stabilization of non-thermally treated table olive packaging.

  6. In silico Logistic Model for Table Olive Related Microorganisms As a Function of Sodium Metabisulphite, Cinnamaldehyde, pH, and Type of Acidifying Agent

    Science.gov (United States)

    Romero-Gil, Verónica; Garrido-Fernández, Antonio; Arroyo-López, Francisco N.

    2016-01-01

    A probabilistic/logistic model, based on binary data (growth/no growth), was used to assess the effects of sodium metabisulphite (SM) and cinnamaldehyde (CIN; 0–1000 mg/L) against the main microbial groups found in table olive environment [lactic acid bacteria (LAB), yeasts, and Enterobacteriaceae], according to pH (range 3.5–5.0), and type of acidifying agent (HCl or pyruvic acid). The inhibitory effect of SM depended on the pH while that of CIN was scarcely influenced by it (except for LAB). LAB were more sensitive to SM, while yeasts were to CIN. The use of pyruvic acid for correction of pH always produced a reduction (compared to HCl) of the inhibitory power of both preservatives. The in silico models for HCl showed that, at pH 4.0, and growth probability 0.01, the LAB population might be inhibited by the presence in the medium of 150 mg/L SM or 1000 mg/L CIN, while in the case of yeasts, 450 mg/L SM, or 150 mg/L CIN are required. No growth of Enterobacteriaceae was observed at this (or lower) pH level. The results obtained may contribute to the stabilization of non-thermally treated table olive packaging. PMID:27630627

  7. A red tide alga grown under ocean acidification upregulates its tolerance to lower pH by increasing its photophysiological functions

    Science.gov (United States)

    Chen, S.; Beardall, J.; Gao, K.

    2014-09-01

    Phaeocystis globosa, a red tide alga, often forms blooms in or adjacent to coastal waters and experiences changes in pH and seawater carbonate chemistry caused by either diel/periodic fluctuation in biological activity, human activity or, in the longer term, ocean acidification due to atmospheric CO2 rise. We examined the photosynthetic physiology of this species while growing it under different pH levels induced by CO2 enrichment and investigated its acclimation to carbonate chemistry changes under different light levels. Short-term exposure to reduced pHnbs (7.70) decreased the alga's photosynthesis and light use efficiency. However, acclimation to the reduced pH level for 1-19 generations led to recovered photosynthetic activity, being equivalent to that of cells grown under pH 8.07 (control), though such acclimation required a different time span (number of generations) under different light regimes. The low-pH-grown cells increased their contents of chlorophyll and carotenoids with prolonged acclimation to the acidification, with increased photosynthetic quantum yield and decreased non-photochemical quenching. The specific growth rate of the low-pH-grown cells also increased to emulate that grown under the ambient pH level. This study clearly shows that {Phaeocystis globosa} is able to acclimate to seawater acidification by increasing its energy capture and decreasing its non-photochemical energy loss.

  8. A red tide alga grown under ocean acidification up-regulates its tolerance to lower pH by increasing its photophysiological functions

    Science.gov (United States)

    Chen, S.-W.; Beardall, J.; Gao, K.-S.

    2014-05-01

    Phaeocystis globosa, a red tide alga, often forms blooms in or adjacent to coastal waters and experiences changes of pH and seawater carbonate chemistry caused by either diel/periodic fluctuation in biological activity, human activity or, in the longer term, ocean acidification due to atmospheric CO2 rise. We examined the photosynthetic physiology of this species while growing it under different pH levels induced by CO2 enrichment and investigated its acclimation to carbonate chemistry changes under different light levels. Short-term exposure to reduced pHnbs (7.70) decreased the alga's photosynthesis and light use efficiency. However, acclimation to the reduced pH level for 1-19 generations led to recovered photosynthetic activity, being equivalent to that of cells grown under pH 8.07 (control), though such acclimation required a different time span (number of generations) under different light regimes. The low-pH grown cells increased their contents of chlorophyll and carotenoids with prolonged acclimation to the acidification, with increased photosynthetic quantum yield and decreased non-photochemical quenching. The specific growth rate of the low-pH grown cells also increased to emulate that grown under the ambient pH level. This study clearly shows that Phaeocystis globosa is able to acclimate to seawater acidification by increasing its energy capture and decreasing its non-photochemcial energy loss.

  9. Colletotrichum higginsianum extracellular LysM proteins play dual roles in appressorial function and suppression of chitin-triggered plant immunity.

    Science.gov (United States)

    Takahara, Hiroyuki; Hacquard, Stéphane; Kombrink, Anja; Hughes, H Bleddyn; Halder, Vivek; Robin, Guillaume P; Hiruma, Kei; Neumann, Ulla; Shinya, Tomonori; Kombrink, Erich; Shibuya, Naoto; Thomma, Bart P H J; O'Connell, Richard J

    2016-09-01

    The genome of the hemibiotrophic anthracnose fungus, Colletotrichum higginsianum, encodes a large repertoire of candidate-secreted effectors containing LysM domains, but the role of such proteins in the pathogenicity of any Colletotrichum species is unknown. Here, we characterized the function of two effectors, ChELP1 and ChELP2, which are transcriptionally activated during the initial intracellular biotrophic phase of infection. Using immunocytochemistry, we found that ChELP2 is concentrated on the surface of bulbous biotrophic hyphae at the interface with living host cells but is absent from filamentous necrotrophic hyphae. We show that recombinant ChELP1 and ChELP2 bind chitin and chitin oligomers in vitro with high affinity and specificity and that both proteins suppress the chitin-triggered activation of two immune-related plant mitogen-activated protein kinases in the host Arabidopsis. Using RNAi-mediated gene silencing, we found that ChELP1 and ChELP2 are essential for fungal virulence and appressorium-mediated penetration of both Arabidopsis epidermal cells and cellophane membranes in vitro. The findings suggest a dual role for these LysM proteins as effectors for suppressing chitin-triggered immunity and as proteins required for appressorium function. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  10. Dual function of the nuclear export signal of the Borna disease virus nucleoprotein in nuclear export activity and binding to viral phosphoprotein.

    Science.gov (United States)

    Yanai, Mako; Sakai, Madoka; Makino, Akiko; Tomonaga, Keizo

    2017-07-11

    Borna disease virus (BoDV), which has a negative-sense, single-stranded RNA genome, causes persistent infection in the cell nucleus. The nuclear export signal (NES) of the viral nucleoprotein (N) consisting of leucine at positions 128 and 131 and isoleucine at positions 133 and 136 overlaps with one of two predicted binding sites for the viral phosphoprotein (P). A previous study demonstrated that higher expression of BoDV-P inhibits nuclear export of N; however, the function of N NES in the interaction with P remains unclear. We examined the subcellular localization, viral polymerase activity, and P-binding ability of BoDV-N NES mutants. We also characterized a recombinant BoDV (rBoDV) harboring an NES mutation of N. BoDV-N with four alanine-substitutions in the leucine and isoleucine residues of the NES impaired its cytoplasmic localization and abolished polymerase activity and P-binding ability. Although an alanine-substitution at position 131 markedly enhanced viral polymerase activity as determined by a minigenome assay, rBoDV harboring this mutation showed expression of viral RNAs and proteins relative to that of wild-type rBoDV. Our results demonstrate that BoDV-N NES has a dual function in BoDV replication, i.e., nuclear export of N and an interaction with P, affecting viral polymerase activity in the nucleus.

  11. Dual learning processes underlying human decision-making in reversal learning tasks: Functional significance and evidence from the model fit to human behavior

    Directory of Open Access Journals (Sweden)

    Yu eBai

    2014-08-01

    Full Text Available Humans are capable of correcting their actions based on actions performed in the past, and this ability enables them to adapt to a changing environment. The computational field of reinforcement learning (RL has provided a powerful explanation for understanding such processes. Recently, the dual learning system, modeled as a hybrid model that incorporates value update based on reward-prediction error and learning rate modulation based on the surprise signal, has gained attention as a model for explaining various neural signals. However, the functional significance of the hybrid model has not been established. In the present study, we used computer simulation in a reversal learning task to address functional significance. The hybrid model was found to perform better than the standard RL model in a large parameter setting. These results suggest that the hybrid model is more robust against mistuning of parameters compared to the standard RL model when decision makers continue to learn stimulus-reward contingencies, which make an abrupt changes. The parameter fitting results also indicated that the hybrid model fit better than the standard RL model for more than 50% of the participants, which suggests that the hybrid model has more explanatory power for the behavioral data than the standard RL model.

  12. Dual functions of 2D WS2 and MoS2-WS2 monolayers coupled with a Ag3PO4 photocatalyst

    Science.gov (United States)

    Wei, Zeng-Xi; Huang, Wei-Qing; Xu, Liang; Hu, Wangyu; Peng, P.; Huang, Gui-Fang

    2016-09-01

    The photocatalytic performance of semiconductors can be improved by coupling two-dimensional (2D) layered materials. Understanding the underlying mechanism of this phenomenon at the electronic level is important for the development of photocatalysts with a high efficiency. Here, we first present a theoretical elucidation of the dual functions of 2D layered material as a sensitizer and a co-catalyst by performing density functional theory calculations, taking WS2 and a lateral heterogeneous WS2-MoS2 monolayer as examples to couple with a promising photocatalyst Ag3PO4. The band alignment of a staggered type-II is formed between Ag3PO4 and the 2D monolayer with the latter possessing the higher electron affinity, resulting in the robust separation of photoexcited charge carriers between them, and indicating that the 2D monolayer is an effective sensitizer. Interestingly, the W (Mo) atoms, which are catalytically inert in the isolated 2D monolayer, turn into catalytic active sites, making the 2D monolayer a highly active co-catalyst in hybrids. A better photocatalytic performance in the coupled lateral heterogeneous WS2-MoS2 monolayer and Ag3PO4 can be expected. The calculated results can be rationalized by available experiments. These findings provide theoretical evidence supporting the experimental reports and may be used as a foundation for developing highly efficient 2D layered materials-based photocatalysts.

  13. DESIGN OF A DUAL KEYBOARD

    Directory of Open Access Journals (Sweden)

    V. Ragavi

    2013-01-01

    Full Text Available The design of a computer keyboard with dual function is proposed. This computer keyboard called Dual Keyboard can function both as a normal keyboard and as a pressure sensitive keyboard. The proposed device has a switch that decides the function. The keyboard makes use of sensors placed beneath the keys to measure the pressure applied on the key by the user. This device has many applications. In this study, it is applied to mitigate Denial of Service (DoS attack.

  14. Why there is more to protein evolution than protein function: splicing, nucleosomes and dual-coding sequence.

    Science.gov (United States)

    Warnecke, Tobias; Weber, Claudia C; Hurst, Laurence D

    2009-08-01

    There is considerable variation in the rate at which different proteins evolve. Why is this? Classically, it has been considered that the density of functionally important sites must predict rates of protein evolution. Likewise, amino acid choice is usually assumed to reflect optimal protein function. In the present article, we briefly review evidence suggesting that this protein function-centred view is too simplistic. In particular, we concentrate on how selection acting during the protein's production history can also affect protein evolutionary rates and amino acid choice. Exploring the role of selection at the DNA and RNA level, we specifically address how the need (i) to specify exonic splice enhancer motifs in pre-mRNA, and (ii) to ensure nucleosome positioning on DNA have an impact on amino acid choice and rates of evolution. For both, we review evidence that sequence affected by more than one coding demand is particularly constrained. Strikingly, in mammals, splicing-related constraints are quantitatively as important as expression parameters in predicting rates of protein evolution. These results indicate that there is substantially more to protein evolution than protein functional constraints.

  15. Determination of kidney function with 99mTc-DTPA renography using a dual-head camera

    DEFF Research Database (Denmark)

    Madsen, Claus J; Møller, Michael L; Zerahn, Bo;

    2013-01-01

    Single-head gamma camera renography has been used for decades to estimate kidney function. An estimate of the glomerular filtration rate (GFR) can be obtained using Tc-diethylenetriaminepentaacetic acid (Tc-DTPA). However, because of differing attenuation, an error is introduced when the kidney...

  16. Dual function of Ixr1 in transcriptional regulation and recognition of cisplatin-DNA adducts is caused by differential binding through its two HMG-boxes.

    Science.gov (United States)

    Vizoso-Vázquez, A; Lamas-Maceiras, M; Fernández-Leiro, R; Rico-Díaz, A; Becerra, M; Cerdán, M E

    2017-02-01

    Ixr1 is a transcriptional factor involved in the response to hypoxia, which is also related to DNA repair. It binds to DNA through its two in-tandem high mobility group box (HMG-box) domains. Each function depends on recognition of different DNA structures, B-form DNA at specific consensus sequences for transcriptional regulation, or distorted DNA, like cisplatin-DNA adducts, for DNA repair. However, the contribution of the HMG-box domains in the Ixr1 protein to the formation of different protein-DNA complexes is poorly understood. We have biophysically and biochemically characterized these interactions with specific DNA sequences from the promoters regulated by Ixr1, or with cisplatin-DNA adducts. Both HMG-boxes are necessary for transcriptional regulation, and they are not functionally interchangeable. The in-tandem arrangement of their HMG-boxes is necessary for functional folding and causes sequential cooperative binding to specific DNA sequences, with HMG-box A showing a higher contribution to DNA binding and bending than the HMG-box B. Binding of Ixr1 HMG boxes to specific DNA sequences is entropy driven, whereas binding to platinated DNA is enthalpy driven for HMG-box A and entropy driven for HMG-box B. This is the first proof that HMG-box binding to different DNA structures is associated with predictable thermodynamic differences. Based on our study, we present a model to explain the dual function of Ixr1 in the regulation of gene expression and recognition of distorted DNA structures caused by cisplatin treatment.

  17. Higher Representations Duals

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2010-01-01

    We uncover novel solutions of the 't Hooft anomaly matching conditions for scalarless gauge theories with matter transforming according to higher dimensional representations of the underlying gauge group. We argue that, if the duals exist, they are gauge theories with fermions transforming...... according to the defining representation of the dual gauge group. The resulting conformal windows match the one stemming from the all-orders beta function results when taking the anomalous dimension of the fermion mass to be unity which are also very close to the ones obtained using the Schwinger......-Dyson approximation. We use the solutions to gain useful insight on the conformal window of the associated electric theory. A consistent picture emerges corroborating previous results obtained via different analytic methods and in agreement with first principle lattice explorations....

  18. In silico Logistic Model for Table Olive Related Microorganisms As a Function of Sodium Metabisulphite, Cinnamaldehyde, pH, and Type of Acidifying Agent

    OpenAIRE

    Romero-Gil, Verónica; Garrido-Fernández, Antonio; Arroyo-López, Francisco N.

    2016-01-01

    A probabilistic/logistic model, based on binary data (growth/no growth), was used to assess the effects of sodium metabisulphite (SM) and cinnamaldehyde (CIN; 0–1000 mg/L) against the main microbial groups found in table olive environment [lactic acid bacteria (LAB), yeasts, and Enterobacteriaceae], according to pH (range 3.5–5.0), and type of acidifying agent (HCl or pyruvic acid). The inhibitory effect of SM depended on the pH while that of CIN was scarcely influenced by it (except for LAB)...

  19. A novel dual-function molecularly imprinted polymer on CdTe/ZnS quantum dots for highly selective and sensitive determination of ractopamine

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huilin; Liu, Dongrui; Fang, Guozhen; Liu, Fangfang; Liu, Cuicui; Yang, Yukun [Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457 (China); Wang, Shuo, E-mail: s.wang@tust.edu.cn [Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457 (China)

    2013-01-31

    Highlights: ► We have developed a novel dual-function MIP-coated QDs material. ► The MIP-coated QDs combine the advantage of molecular imprinting and QDs. ► We used MIP-coated QDs as fluorescence sensing material for recognize RAC. ► We used QDs@MIP as sorbent to combine SPE with HPLC for the determination. -- Abstract: A novel dual-function material was synthesized by anchoring a molecularly imprinted polymer (MIP) layer on CdTe/ZnS quantum dots (QDs) using a sol–gel with surface imprinting. The material exhibited highly selective and sensitive determination of ractopamine (RAC) through spectrofluorometry and solid-phase extraction (SPE) coupled with high performance liquid chromatography (HPLC). A series of adsorption experiments revealed that the material showed high selectivity, good adsorption capacity and a fast mass transfer rate. Fluorescence from the MIP-coated QDs was more strongly quenched by RAC than that of the non-imprinted polymer, which indicated that the MIP-coated QDs acted as a fluorescence sensing material could recognize RAC. In addition, the MIP-coated QDs as a sorbent was also shown to be promising for SPE coupled with HPLC for the determination of trace RAC in feeding stuffs and pork samples. Under optimal conditions, the spectrofluorometry and SPE-HPLC methods using the MIP-coated QDs had linear ranges of 5.00 × 10{sup −10}–3.55 × 10{sup −7} and 1.50 × 10{sup −10}–8.90 × 10{sup −8} mol L{sup −1}, respectively, with limits of detection of 1.47 × 10{sup −10} and 8.30 × 10{sup −11} mol L{sup −1}, the relative standard deviations for six repeat experiments of RAC (2.90 × 10{sup −9} mol L{sup −1}) were below 2.83% and 7.11%.

  20. Dual Functional Nanocarrier for Cellular Imaging and Drug Delivery in Cancer Cells Based on π-Conjugated Core and Biodegradable Polymer Arms.

    Science.gov (United States)

    Kulkarni, Bhagyashree; Surnar, Bapurao; Jayakannan, Manickam

    2016-03-14

    Multipurpose polymer nanoscaffolds for cellular imaging and delivery of anticancer drug are urgently required for the cancer therapy. The present investigation reports a new polymer drug delivery concept based on biodegradable polycaprolactone (PCL) and highly luminescent π-conjugated fluorophore as dual functional nanocarrier for cellular imaging and delivery vehicles for anticancer drug to cancer cells. To accomplish this goal, a new substituted caprolactone monomer was designed, and it was subjected to ring opening polymerization using a blue luminescent bishydroxyloligo-phenylenevinylene (OPV) fluorophore as an initiator. A series of A-B-A triblock copolymer building blocks with a fixed OPV π-core and variable chain biodegradable PCL arm length were tailor-made. These triblocks self-assembled in organic solvents to produce well-defined helical nanofibers, whereas in water they produced spherical nanoparticles (size ∼150 nm) with blue luminescence. The hydrophobic pocket of the polymer nanoparticle was found to be an efficient host for loading water insoluble anticancer drug such as doxorubicin (DOX). The photophysical studies revealed that there was no cross-talking between the OPV and DOX chromophores, and their optical purity was retained in the nanoparticle assembly for cellular imaging. In vitro studies revealed that the biodegradable PCL arm was susceptible to enzymatic cleavage at the intracellular lysosomal esterase under physiological conditions to release the loaded drugs. The nascent nanoparticles were found to be nontoxic to cancer cells, whereas the DOX-loaded nanoparticles accomplished more than 80% killing in HeLa cells. Confocal microscopic analysis confirmed the cell penetrating ability of the blue luminescent polymer nanoparticles and their accumulation preferably in the cytoplasm. The DOX loaded red luminescent polymer nanoparticles were also taken up by the cells, and the drug was found to be accumulated at the perinuclear environment

  1. A facile approach to prepare a dual functionalized DNA based material in a bio-deep eutectic solvent.

    Science.gov (United States)

    Mondal, Dibyendu; Bhatt, Jitkumar; Sharma, Mukesh; Chatterjee, Shruti; Prasad, Kamalesh

    2014-04-18

    DNA (Salmon testes) was functionalized by Fe3O4 nanoparticles and protonated layered dititanate sheets (H2·Ti2O5·H2O) in a mixture of choline chloride and ethylene glycol (a deep eutectic solvent) to yield a hybrid material having magnetic and antibacterial properties. Ti sheets were found to interact with the phosphate moieties, while Fe interacted with the base pair of DNA in the hybrid material.

  2. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P. [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Gurinov, Andrey [Research Resources Center for Magnetic Resonance, Saint Petersburg State University, Universitetskij pr. 26, 198504 St. Petersburg (Russian Federation); Ortiz, Genaro Gabriel [Laboratorio Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano de Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Carbajal Arízaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.mx [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico)

    2015-03-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488 nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. - Highlights: • Hydroxyapatite functionalized with glucuronic acid reduced oxidative stress in rats. • Functionalization with folic acid reduced oxidative stress in rats. • Dysprosium doping does not affect the crystalline structure of hydroxyapatite. • Dysprosium doped particles are visible in fluorescent microscope. • Dysprosium doped particles act as MRI contrast agents.

  3. Thermodynamic analysis of (bi)sulphate adsorption on a Pt(1 1 1) electrode as a function of pH

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Araez, Nuria; Climent, Victor; Rodriguez, Paramaconi; Feliu, Juan M. [Instituto de Electroquimica, Universidad de Alicante, Apt. 99, E-03080 Alicante (Spain)

    2008-10-01

    A complete thermodynamic study of (bi)sulphate adsorption on Pt(1 1 1) electrodes from solutions at four different pHs (pH 0.43, 2.1, 3.1 and 4.1) is reported. The effect of pH on the sum of the Gibbs excesses of sulphate and bisulphate species, standard Gibbs energies of adsorption and formal partial charge numbers is analyzed. The results provide relevant information on the nature of species involved in the different voltammetric features. The experiments at pH 0.43 were performed in a higher base electrolyte concentration (0.5 M), that allows the study of (bi)sulphate adsorption in a broader range of concentrations. Under these conditions, two adsorption steps are clearly defined, associated to two different voltammetric features, between 0.30 and 0.60 V and between 0.65 and 0.90 V (standard hydrogen scale, SHE). Once the pH is increased, a marked decrease in absolute value of the (bi)sulphate adsorption Gibbs energy is observed, concomitant with an increasing amount of OH co-adsorption. (author)

  4. Clinical Psychology Ph.D. Program Admissions: Differential Values as a Function of Program Characteristics and the Implications of the Mentor-Model Approach

    Science.gov (United States)

    Metzger, Jesse A.

    2010-01-01

    The aims of this research were to 1) examine the qualities for which applicants are selected for entrance into clinical psychology Ph.D. programs, and 2) investigate the prevalence and impact of the mentor-model approach to admissions on multiple domains of programs and the field at large. Fifty Directors of Clinical Training (DCTs) provided data…

  5. Clinical Psychology Ph.D. Program Admissions: Differential Values as a Function of Program Characteristics and the Implications of the Mentor-Model Approach

    Science.gov (United States)

    Metzger, Jesse A.

    2010-01-01

    The aims of this research were to 1) examine the qualities for which applicants are selected for entrance into clinical psychology Ph.D. programs, and 2) investigate the prevalence and impact of the mentor-model approach to admissions on multiple domains of programs and the field at large. Fifty Directors of Clinical Training (DCTs) provided data…

  6. Functionality of whey proteins covalently modified by allyl isothiocyanate. Part 1 physicochemical and antibacterial properties of native and modified whey proteins at pH 2 to 7

    NARCIS (Netherlands)

    Keppler, Julia Katharina; Martin, Dierk; Garamus, Vasil M.; Berton-Carabin, Claire; Nipoti, Elia; Coenye, Tom; Schwarz, Karin

    2017-01-01

    Whey protein isolate (WPI) (∼75% β-lactoglobulin (β-LG)) is frequently used in foods as a natural emulsifying agent. However, at an acidic pH value, its emulsification capacity is greatly reduced. The covalent attachment of natural electrophilic hydrophobic molecules to WPI proteins is a

  7. Functionality of whey proteins covalently modified by allyl isothiocyanate. Part 1 physicochemical and antibacterial properties of native and modified whey proteins at pH 2 to 7

    NARCIS (Netherlands)

    Keppler, Julia Katharina; Martin, Dierk; Garamus, Vasil M.; Berton-Carabin, Claire; Nipoti, Elia; Coenye, Tom; Schwarz, Karin

    2017-01-01

    Whey protein isolate (WPI) (∼75% β-lactoglobulin (β-LG)) is frequently used in foods as a natural emulsifying agent. However, at an acidic pH value, its emulsification capacity is greatly reduced. The covalent attachment of natural electrophilic hydrophobic molecules to WPI proteins is a promisin

  8. Individualized dual antiplatelet therapy based on platelet function testing in patients undergoing percutaneous coronary intervention: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Zhou, Yijiang; Wang, Yanwei; Wu, Yutao; Huang, Chaoyang; Yan, Hui; Zhu, Weiguo; Xu, Weiwei; Zhang, Li; Zhu, Jianhua

    2017-06-15

    High on-treatment platelet reactivity (HPR) represents a strong risk factor for thrombotic events after PCI. We aim to evaluate the efficacy and safety of individualizing intensified dual antiplatelet therapy (DAPT) in PCI-treated patients with HPR based on platelet function testing (PFT). Electronic databases were searched for randomized control trials that reported the clinical outcomes of using an intensified antiplatelet protocol with P2Y12 receptor inhibitor comparing with standard maintenance dose of clopidogrel on the basis of platelet function testing. Clinical endpoints were assessed. From 2005 to 2016, thirteen clinical studies comprising 7290 patients were included for analysis. Compared with standard antiplatelet therapy with clopidogrel, the intensified protocol based on platelet function testing was associated with a significant reduction in major adverse cardiovascular events (RR:0.55, 95% CI: 0.36-0.84, p = 0.005), cardiovascular death (RR:0.60, 95% CI: 0.38-0.96, p = 0.03), stent thrombosis (RR:0.58, 95% CI: 0.36-0.93, p = 0.02) and target vessel revascularization (RR:0.33, 95% CI: 0.14-0.76, p = 0.009). No significant difference was found in the rate of bleeding events between intensified and standard protocol. Compared with standard clopidogrel therapy, individualized intensified antiplatelet therapy on the basis of platelet reactivity testing reduces the incidence of cardiovascular events in patient undergoing PCI, without increasing the risk of bleeding.

  9. Incorporation of the purified epstein barr virus/C3d receptor (CR2) into liposomes and demonstration of its dual ligand binding functions

    Energy Technology Data Exchange (ETDEWEB)

    Mold, C.; Cooper, N.R.; Nemerow, G.R.

    1986-06-01

    The 145-kDA molecule that has been identified as the C3d receptor CR2 was isolated from lysates of Raji cells by affinity chromatography by using the monoclonal antibody (MoAb)HB-5. The purified protein was incorporated into /sup 14/C-phosphatidylcholine liposomes by deoxycholate dialysis followed by flotation on discontinuous sucrose gradients. Incorporation of the receptor was verified by testing the gradient fractions for CR2 by an enzyme-linked immunosorbent assay. Liposomes were shown to be unilamellar vesicles ranging in diameter from 25 to 100 nm by electron microscopy. The external orientation of CR2 in the membranes was demonstrated by immunoelectron microscopy. The functional activities of liposomes containing CR2 and liposomes without protein were compared. CR2 liposomes bound to EC3d, but not to E, and this binding was inhibited by the anti-CR2 MoAb OKB7 and by a MoAb specific for C3d. Control liposomes failed to bind to either E or EC3D. The ability of CR2 to function as a receptor for Epstein Barr virus (EBV) was tested in two ways. First, CR2 liposomes bound to B95-8, a cell line expressing EBV membrane antigens, but not to B95-8 cells treated with the viral DNA polymerase inhibitor phosphonoformic acid. Second, liposomes containing CR2 were shown by ultracentrifugal analyses to bind directly to purified EBV, and this binding was also inhibited by OKB7. Control liposomes did not bind to B95-8 cells or to EBV. These findings show that CR2 purified from detergent extracts of Raji cells can be reconstituted into lipid membranes with maintenance of its dual functions as a receptor for C3d and EBV.

  10. The structure of bradyzoite-specific enolase from Toxoplasma gondii reveals insights into its dual cytoplasmic and nuclear functions

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, Jiapeng [Northwestern University, 320 E. Superior Street, Morton 7-601, Chicago, IL 60611 (United States); Mouveaux, Thomas [Université Lille Nord de France, (France); Light, Samuel H.; Minasov, George; Anderson, Wayne F. [Northwestern University, 320 E. Superior Street, Morton 7-601, Chicago, IL 60611 (United States); Tomavo, Stanislas [Université Lille Nord de France, (France); Ngô, Huân M., E-mail: h-ngo@northwestern.edu [Northwestern University, 320 E. Superior Street, Morton 7-601, Chicago, IL 60611 (United States); BrainMicro LLC, 21 Pendleton Street, New Haven, CT 06511 (United States)

    2015-03-01

    The second crystal structure of a parasite protein preferentially enriched in the brain cyst of T. gondii has been solved at 2.75 Å resolution. Bradyzoite enolase 1 is reported to have differential functions as a glycolytic enzyme and a transcriptional regulator in bradyzoites. In addition to catalyzing a central step in glycolysis, enolase assumes a remarkably diverse set of secondary functions in different organisms, including transcription regulation as documented for the oncogene c-Myc promoter-binding protein 1. The apicomplexan parasite Toxoplasma gondii differentially expresses two nuclear-localized, plant-like enolases: enolase 1 (TgENO1) in the latent bradyzoite cyst stage and enolase 2 (TgENO2) in the rapidly replicative tachyzoite stage. A 2.75 Å resolution crystal structure of bradyzoite enolase 1, the second structure to be reported of a bradyzoite-specific protein in Toxoplasma, captures an open conformational state and reveals that distinctive plant-like insertions are located on surface loops. The enolase 1 structure reveals that a unique residue, Glu164, in catalytic loop 2 may account for the lower activity of this cyst-stage isozyme. Recombinant TgENO1 specifically binds to a TTTTCT DNA motif present in the cyst matrix antigen 1 (TgMAG1) gene promoter as demonstrated by gel retardation. Furthermore, direct physical interactions of both nuclear TgENO1 and TgENO2 with the TgMAG1 gene promoter are demonstrated in vivo using chromatin immunoprecipitation (ChIP) assays. Structural and biochemical studies reveal that T. gondii enolase functions are multifaceted, including the coordination of gene regulation in parasitic stage development. Enolase 1 provides a potential lead in the design of drugs against Toxoplasma brain cysts.

  11. Dual functions of interferon regulatory factors 7C in Epstein-Barr virus-mediated transformation of human B lymphocytes.

    Directory of Open Access Journals (Sweden)

    Yong Zhao

    Full Text Available Epstein-Barr virus (EBV infection is associated with several human malignancies. Interferon (IFN regulatory factor 7 (IRF-7 has several splicing variants, and at least the major splicing variant (IRF-7A has oncogenic potential and is associated with EBV transformation processes. IRF-7C is an alternative splicing variant with only the DNA-binding domain of IRF-7. Whether IRF-7C is present under physiological conditions and its functions in viral transformation are unknown. In this report, we prove the existence of IRF-7C protein and RNA in certain cells under physiological conditions, and find that high levels of IRF-7C are associated with EBV transformation of human primary B cells in vitro as well as EBV type III latency. EBV latent membrane protein 1 (LMP-1 stimulates IRF-7C expression in B lymphocytes. IRF-7C has oncogenic potential in rodent cells and partially restores the growth properties of EBV-transformed cells under a growth-inhibition condition. A tumor array experiment has identified six primary tumor specimens with high levels of IRF-7C protein--all of them are lymphomas. Furthermore, we show that the expression of IRF-7C is apparently closely associated with other IRF-7 splicing variants. IRF-7C inhibits the function of IRF-7 in transcriptional regulation of IFN genes. These data suggest that EBV may use splicing variants of IRF-7 for its transformation process in two strategies: to use oncogenic properties of various IRF-7 splicing variants, but use one of its splicing variants (IRF-7C to block the IFN-induction function of IRF-7 that is detrimental for viral transformation. The work provides a novel relation of host/virus interactions, and has expanded our knowledge about IRFs in EBV transformation.

  12. MS_RHII-RSD, a dual-function RNase HII-(p)ppGpp synthetase from Mycobacterium smegmatis.

    Science.gov (United States)

    Murdeshwar, Maya S; Chatterji, Dipankar

    2012-08-01

    In the noninfectious soil saprophyte Mycobacterium smegmatis, intracellular levels of the stress alarmones guanosine tetraphosphate and guanosine pentaphosphate, together termed (p)ppGpp, are regulated by the enzyme Rel(Msm). This enzyme consists of a single, bifunctional polypeptide chain that is capable of both synthesizing and hydrolyzing (p)ppGpp. The rel(Msm) knockout strain of M. smegmatis (Δrel(Msm)) is expected to show a (p)ppGpp null [(p)ppGpp(0)] phenotype. Contrary to this expectation, the strain is capable of synthesizing (p)ppGpp in vivo. In this study, we identify and functionally characterize the open reading frame (ORF), MSMEG_5849, that encodes a second functional (p)ppGpp synthetase in M. smegmatis. In addition to (p)ppGpp synthesis, the 567-amino-acid-long protein encoded by this gene is capable of hydrolyzing RNA·DNA hybrids and bears similarity to the conventional RNase HII enzymes. We have classified this protein as actRel(Msm) in accordance with the recent nomenclature proposed and have named it MS_RHII-RSD, indicating the two enzymatic activities present [RHII, RNase HII domain, originally identified as domain of unknown function 429 (DUF429), and RSD, RelA_SpoT nucleotidyl transferase domain, the SYNTH domain responsible for (p)ppGpp synthesis activity]. MS_RHII-RSD is expressed and is constitutively active in vivo and behaves like a monofunctional (p)ppGpp synthetase in vitro. The occurrence of the RNase HII and (p)ppGpp synthetase domains together on the same polypeptide chain is suggestive of an in vivo role for this novel protein as a link connecting the essential life processes of DNA replication, repair, and transcription to the highly conserved stress survival pathway, the stringent response.

  13. Modeling the growth/no growth interface of Alicyclobacillus acidoterrestris CRA 7152 in orange juice as a function of pH, temperature, Brix and nisin concentration

    Directory of Open Access Journals (Sweden)

    Wilmer Luera Peña

    2010-03-01

    Full Text Available The growth probability of Alicyclobacillus acidoterrestris CRA 7152 in orange juice was studied in different product conditions. The microorganism response was monitored until 47 days of storage in different conditions of pH (3 to 5.8, soluble solids (11 to 19°Brix, temperature (20 to 54°C and nisin concentration (0 to 70 IU/ml. Growth/no growth data were modeled by the polynomial logistics regression model. The concordance of the obtained model was 96.3% indicating good fitting of observed data. The results showed fast growth in the conditions 0 IU nisin/ml juice, pH 4.4 and 15ºBrix, at 35ºC. For 70 IU nisin/ml there was no growth, pH 4.4, at 37ºC, up to 47 days of storage. Simple juices (11°Brix with pHs between 3.5 to 3.7 can keep stable and withstand abuse temperatures up to 36°C, since added in 70IU nisin/ml, extending its shelf life. With 0.05 growth probability and using the logistics model, high pH critical values can be obtained when 50 IU nisin/ml, at 25ºC, are present in the juice, however increases in temperature and decreases in soluble solids concentration make the pH critical values decrease. It is then concluded that nisin incorporation is an alternative for controlling A. acidoterrestris growth in orange juice, as well as the logistics regression model proved to be an important tool for determining the microbial response under critical values of the variables, besides predicting growth probabilities for the different studied conditions.

  14. Dual functions of Macpiwi1 in transposon silencing and stem cell maintenance in the flatworm Macrostomum lignano.

    Science.gov (United States)

    Zhou, Xin; Battistoni, Giorgia; El Demerdash, Osama; Gurtowski, James; Wunderer, Julia; Falciatori, Ilaria; Ladurner, Peter; Schatz, Michael C; Hannon, Gregory J; Wasik, Kaja A

    2015-11-01

    PIWI proteins and piRNA pathways are essential for transposon silencing and some aspects of gene regulation during animal germline development. In contrast to most animal species, some flatworms also express PIWIs and piRNAs in somatic stem cells, where they are required for tissue renewal and regeneration. Here, we have identified and characterized piRNAs and PIWI proteins in the emerging model flatworm Macrostomum lignano. We found that M. lignano encodes at least three PIWI proteins. One of these, Macpiwi1, acts as a key component of the canonical piRNA pathway in the germline and in somatic stem cells. Knockdown of Macpiwi1 dramatically reduces piRNA levels, derepresses transposons, and severely impacts stem cell maintenance. Knockdown of the piRNA biogenesis factor Macvasa caused an even greater reduction in piRNA levels with a corresponding increase in transposons. Yet, in Macvasa knockdown animals, we detected no major impact on stem cell self-renewal. These results may suggest stem cell maintenance functions of PIWI proteins in flatworms that are distinguishable from their impact on transposons and that might function independently of what are considered canonical piRNA populations.

  15. Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions

    KAUST Repository

    Huang, Yi-Jen

    2016-04-07

    The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (<±1 V) and self-compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.

  16. Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions

    Science.gov (United States)

    Huang, Yi-Jen; Chao, Shih-Chun; Lien, Der-Hsien; Wen, Cheng-Yen; He-Hau, Jr.; Lee, Si-Chen

    2016-04-01

    The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.

  17. Dual functions of α-ketoglutarate dehydrogenase E2 in the Krebs cycle and mitochondrial DNA inheritance in Trypanosoma brucei.

    Science.gov (United States)

    Sykes, Steven E; Hajduk, Stephen L

    2013-01-01

    The dihydrolipoyl succinyltransferase (E2) of the multisubunit α-ketoglutarate dehydrogenase complex (α-KD) is an essential Krebs cycle enzyme commonly found in the matrices of mitochondria. African trypanosomes developmentally regulate mitochondrial carbohydrate metabolism and lack a functional Krebs cycle in the bloodstream of mammals. We found that despite the absence of a functional α-KD, bloodstream form (BF) trypanosomes express α-KDE2, which localized to the mitochondrial matrix and inner membrane. Furthermore, α-KDE2 fractionated with the mitochondrial genome, the kinetoplast DNA (kDNA), in a complex with the flagellum. A role for α-KDE2 in kDNA maintenance was revealed in α-KDE2 RNA interference (RNAi) knockdowns. Following RNAi induction, bloodstream trypanosomes showed pronounced growth reduction and often failed to equally distribute kDNA to daughter cells, resulting in accumulation of cells devoid of kDNA (dyskinetoplastic) or containing two kinetoplasts. Dyskinetoplastic trypanosomes lacked mitochondrial membrane potential and contained mitochondria of substantially reduced volume. These results indicate that α-KDE2 is bifunctional, both as a metabolic enzyme and as a mitochondrial inheritance factor necessary for the distribution of kDNA networks to daughter cells at cytokinesis.

  18. Hydroxyethyl cellulose doped with copper(II) phthalocyanine-tetrasulfonic acid tetrasodium salt as an effective dual functional hole-blocking layer for polymer light-emitting diodes

    Science.gov (United States)

    Wu, Cheng-Liang; Chen, Yun

    2017-07-01

    We report a doping method to improve the performance of solution-processed polymer light-emitting diodes (PLEDs). Doping 12 wt% copper(II) phthalocyanine-tetrasulfonated acid tetrasodium salt (TS-CuPc) into hydroxyethyl cellulose (HEC) as a dual functional hole-blocking layer (df-HBL) of multilayer PLED (glass/ITO/PEDOT:PSS/HY-PPV/TS-CuPc-doped HEC/LiF/Al) significantly enhanced maximum luminance, maximum current and power efficiency over that without the df-HBL (10,319 cd/m2, 2.98 cd/A and 1.24 lm/W) to (29,205 cd/m2, 13.27 cd/A and 9.56 lm/W). CV measurements reveal that HEC possesses a powerful hole-blocking capability. Topography and conductivity AFM images show that doping TS-CuPc increases the interfacial contact area and interfacial conductivity, which can overcome the insulating nature of HEC and thus further facilitate electron injection. Enhancements in device performance are attributed to the improved carrier balance and recombination in the presence of df-HBL, confirmed in electron-only and hole-only devices. Moreover, apparently raised open-circuit voltages provide further evidence that enhanced electron injection is indeed realized by the df-HBL. This study demonstrates an effective approach to develop highly efficient PLEDs.

  19. An integrative technique based on synergistic coremoval and sequential recovery of copper and tetracycline with dual-functional chelating resin: roles of amine and carboxyl groups.

    Science.gov (United States)

    Ling, Chen; Liu, Fu-Qiang; Xu, Chao; Chen, Tai-Peng; Li, Ai-Min

    2013-11-27

    A novel chelating resin (R-AC) bearing dual-functional groups (amino and carboxyl groups) was self-synthesized and it showed superior properties on synergistic coremoval of Cu(II) and tetracycline (TC) to commercial resins (amine, carboxyl, and hydrophobic types), which was deeply investigated by equilibrium and kinetic tests in binary, preloading, and saline systems. The adsorption of TC on R-AC was markedly enhanced when coexisted with Cu(II), up to 13 times of that in sole system, whereas Cu(II) uptake seldom decreased in the copresence of TC. Decomplexing-bridging, which included [Cu-TC] decomplexing and [R-Cu] bridging for TC, was demonstrated as the leading mechanism for the synergistic coremoval of Cu(II) and TC. Carboxyl groups of R-AC played a dominant role in decomplexing of [Cu-TC] complex and releasing free TC. Cu(II) coordinated with amine groups of R-AC was further proved to participate in bridging interaction with free TC, and the bridging stoichiometric ratio ([NH-Cu]: TC) possibly was 2:1. About 96.9% of TC and 99.3% of Cu could be sequentially recovered with dilute NaOH followed by HCl. Considering stable application for five cycles in simulated and practical wastewater, R-AC shows great potential in green and simple coremoval of antibiotic and heavy metal ions.

  20. Optical and electrochemical dual channel sensing of Cu2 + using functionalized furo[2,3-d]pyrimidines-2,4[1H,3H]-diones

    Science.gov (United States)

    Kumar, Manoj; Kumawat, Lokesh Kumar; Bhatt, Priyanka; Jha, Anjali; Agarwal, Shilpi; Sharma, Anuj; Gupta, Vinod Kumar

    2017-06-01

    Owing to their easy accessibility and high degree of structural and functional diversity, many multicomponent reactions (MCRs) have been a rich source of conjugate π-systems, functionalised chromophores (or fluorophore) and redox active molecules. Despite their high explorative potential and practical benefits, only a few MCR products have been so far investigated for their metal sensing abilities. In the present report, two furopyrimidinones (FPys) based molecular systems have been synthesized by [4 + 1] cycloaddition based MCR sequence. Designed chemosensors displayed optic (absorption spectra) as well as electroanalytical (ion selective electrode) response toward Cu2 + ion in solution and membrane phase respectively (dual channel sensing). Different aspects of both the sensing phenomena such as selectivity, association constants, detection limit, membrane composition etc. were studied in detail using UV-Vis spectroscopy, NMR titration and cell assembly. Both the compounds showed excellent performance characteristics such as high selectivity, acceptable affinity and low detection limits (10- 7 M) in both sensing assays with potential utility in the area of sample monitoring.

  1. Dual Functional Core-Shell Fluorescent Ag2S@Carbon Nanostructure for Selective Assay of E. coli O157:H7 and Bactericidal Treatment.

    Science.gov (United States)

    Wang, Ning; Wei, Xing; Zheng, An-Qi; Yang, Ting; Chen, Ming-Li; Wang, Jian-Hua

    2017-03-24

    A dual functional fluorescent core-shell Ag2S@Carbon nanostructure is prepared by a hydrothermally assisted multi-amino synthesis approach with folic acid (FA), polyethylenimine (PEI), and mannoses (Mans) as carbon and nitrogen sources (FA-PEI-Mans-Ag2S nanocomposite shortly as Ag2S@C). The nanostructure exhibits strong fluorescent emission at λex/λem = 340/450 nm with a quantum yield of 12.57 ± 0.52%. Ag2S@C is bound to E. coli O157:H7 via strong interaction with the Mans moiety in Ag2S@C with FimH proteins on the fimbriae tip in E. coli O157:H7. Fluorescence emission from Ag2S@C/E. coli conjugate is closely related to the content of E. coli O157:H7. Thus, a novel procedure for fluorescence assay of E. coli O157:H7 is developed, offering a detection limit of 330 cfu mL(-1). Meanwhile, the Ag2S@C nanostructure exhibits excellent antibacterial performance against E. coli O157:H7. A 99.9% sterilization rate can be readily achieved for E. coli O157:H7 at a concentration of 10(6)-10(7) cfu mL(-1) with 3.3 or 10 μg mL(-1) of Ag2S@C with an interaction time of 5 or 0.5 min, respectively.

  2. Dual functions of the nucleus-encoded factor TDA1 in trapping and translation activation of atpA transcripts in Chlamydomonas reinhardtii chloroplasts.

    Science.gov (United States)

    Eberhard, Stephan; Loiselay, Christelle; Drapier, Dominique; Bujaldon, Sandrine; Girard-Bascou, Jacqueline; Kuras, Richard; Choquet, Yves; Wollman, Francis-André

    2011-09-01

    After endosymbiosis, organelles lost most of their initial genome. Moreover, expression of the few remaining genes became tightly controlled by the nucleus through trans-acting protein factors that are required for post-transcriptional expression (maturation/stability or translation) of a single (or a few) specific organelle target mRNA(s). Here, we characterize the nucleus-encoded TDA1 factor, which is specifically required for translation of the chloroplast atpA transcript that encodes subunit α of ATP synthase in Chlamydomonas reinhardtii. The sequence of TDA1 contains eight copies of a degenerate 38-residue motif, that we named octotrico peptide repeat (OPR), which has been previously described in a few other trans-acting factors targeted to the C. reinhardtii chloroplast. Interestingly, a proportion of the untranslated atpA transcripts are sequestered into high-density, non-polysomic, ribonucleoprotein complexes. Our results suggest that TDA1 has a dual function: (i) trapping a subset of untranslated atpA transcripts into non-polysomic complexes, and (ii) translational activation of these transcripts. We discuss these results in light of our previous observation that only a proportion of atpA transcripts are translated at any given time in the chloroplast of C. reinhardtii.

  3. Simple fabrication of carbon/TiO2 composite nanotubes showing dual functions with adsorption and photocatalytic decomposition of Rhodamine B

    Science.gov (United States)

    Im, Ji Hyuk; Yang, Seung Jae; Yun, Chang Hun; Park, Chong Rae

    2012-01-01

    Carbon/TiO2 composite nanotubes were fabricated via a very simple electrospinning process and their dual functionalities of adsorptivity and photocatalytic activity were evaluated using Rhodamine B (RhB) as a model organic pollutant. A poly(vinyl alcohol) (PVA) aqueous solution was directly electrospun into a coagulation bath containing titanium (IV) tetraisopropoxide (TTIP) solution so that PVA-core/TiO2-shell composite nanofibers were formed through the in situ sol-gel reaction of TTIP. The carbon/TiO2 composite nanotubes were then fabricated by heat treatment of composite nanofibers under nitrogen atmosphere. By using several characterization methods, we confirmed that the resultant nanotubes consisted of anatase TiO2 nanocrystallites embedded in a carbonaceous matrix. The prepared nanotubes exhibited fast adsorption of RhB with high capacity compared with a commercial porous carbon, and they also showed the photocatalytic decomposition activity for the dye molecules under UV irradiation comparable to the degradation by P-25 and ST-01 (commercial TiO2). Finally, the carbon/TiO2 composite nanotubes exhibited several cycle performances of adsorption-photodegradation for RhB. This indicates that the composite nanotubes can adsorb and photodecompose organic pollutants repeatedly without additional activating processes.

  4. Gold-decorated titania nanotube arrays as dual-functional platform for surface-enhanced Raman spectroscopy and surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Nitta, Syuhei; Yamamoto, Atsushi; Kurita, Masahiro; Arakawa, Ryuichi; Kawasaki, Hideya

    2014-06-11

    In this report, we demonstrate gold-decorated titania nanotube arrays (Au-TNA substrate) as a dual-functional platform for surface-enhanced Raman spectroscopy (SERS) and surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The Au nanoparticles are grown on the substrate using vapor deposition of Au. The resulting substrates perform better than Au colloids in terms of the reproducibility of the SERS measurements, long-term stability of the fabricated structures, and clean surface of the Au. The nanostructure of the Au-TNA substrate was designed to optimize the SALDI-MS and SERS performance. Excellent reproducibility of the SERS measurements using the Au-TNA substrate was obtained, with a standard error less than 6 %. SALDI activity was also demonstrated for the same Au-TNA substrates. Finally, the Au-TNA substrate was used for combined SERS and SALDI-MS analysis (i) to discriminate the structural isomers of pyridine compounds (para-, meta-, and ortho-pyridinecarboxylic acid) and (ii) to detect polycarbamate, a dithiocarbamate fungicide. These results are difficult to obtain using either approach alone.

  5. Effects of Rare-Earth La2O3 Addition on Microstructures and Electrical Properties of SrTiO3 Varistor-Capacitor Dual Functional Ceramics

    Institute of Scientific and Technical Information of China (English)

    Ji Huiming; Li Cuixia; Meng Hui; Gan Guoyou; Yan Jikang

    2005-01-01

    The effects of rare-earth La2O3 addition on microstructures and electrical properties of SrTiO3 ceramics were investigated. Semiconductor SrTiO3-based voltage-sensing and dielectric dual functional ceramics was prepared by a single step sintering technology in this study, and the effects of the content of La2O3 on characteristics of the product were discussed in terms of microstructures and electrical properties of materials. The results show that SrTiO3-based ceramics doped with La2O3 exhibits more homogeneous grain distribution, greater grain size, and excellent voltage sensing and dielectric characteristics than those without La2O3 doping. The samples doped with 1.1% La2O3 were sintered at 1420 ℃ in N2+C weak reducing atmosphere. The average grain size of the samples doped with La2O3 is 40 μm, the breakdown voltage of 19.7 V*mm-1, the nonlinear exponent of 7.2, and dielectric constant of 22500. The results reveal that final products are suitable to use in low operating voltage.

  6. Controlled Architecture of Dual-Functional Block Copolymer Brushes on Thin-Film Composite Membranes for Integrated "Defending" and "Attacking" Strategies against Biofouling.

    Science.gov (United States)

    Ye, Gang; Lee, Jongho; Perreault, François; Elimelech, Menachem

    2015-10-21

    We report a new macromolecular architecture of dual functional block copolymer brushes on commercial thin-film composite (TFC) membranes for integrated "defending" and "attacking" strategies against biofouling. Mussel-inspired catechol chemistry is used for a convenient immobilization of initiator molecules to the membrane surface with the aid of polydopamine (PDA). Zwitterionic polymer brushes with strong hydration capacity and quaternary ammonium salt (QAS) polymer brushes with bactericidal ability are sequentially grafted on TFC membranes via activators regenerated by electron transfer-atom transfer radical polymerization (ARGET-ATRP), an environmentally benign and controlled polymerization method. Measurement of membrane intrinsic transport properties in reverse osmosis experiments shows that the modified TFC membrane maintains the same water permeability and salt selectivity as the pristine TFC membrane. Chemical force microscopy and protein/bacterial adhesion studies are carried out for a comprehensive evaluation of the biofouling resistance and antimicrobial ability, demonstrating low biofouling propensity and excellent bacterial inactivation for the modified TFC membrane. We conclude that this polymer architecture, with complementary "defending" and "attacking" capabilities, can effectively prevent the attachment of biofoulants and formation of biofilms and thereby significantly mitigate biofouling on TFC membranes.

  7. Alanyl-tRNA synthetase genes of Vanderwaltozyma polyspora arose from duplication of a dual-functional predecessor of mitochondrial origin.

    Science.gov (United States)

    Chang, Chia-Pei; Tseng, Yi-Kuan; Ko, Chou-Yuan; Wang, Chien-Chia

    2012-01-01

    In eukaryotes, the cytoplasmic and mitochondrial forms of a given aminoacyl-tRNA synthetase (aaRS) are typically encoded by two orthologous nuclear genes, one of eukaryotic origin and the other of mitochondrial origin. We herein report a novel scenario of aaRS evolution in yeast. While all other yeast species studied possess a single nuclear gene encoding both forms of alanyl-tRNA synthetase (AlaRS), Vanderwaltozyma polyspora, a yeast species descended from the same whole-genome duplication event as Saccharomyces cerevisiae, contains two distinct nuclear AlaRS genes, one specifying the cytoplasmic form and the other its mitochondrial counterpart. The protein sequences of these two isoforms are very similar to each other. The isoforms are actively expressed in vivo and are exclusively localized in their respective cellular compartments. Despite the presence of a promising AUG initiator candidate, the gene encoding the mitochondrial form is actually initiated from upstream non-AUG codons. A phylogenetic analysis further revealed that all yeast AlaRS genes, including those in V. polyspora, are of mitochondrial origin. These findings underscore the possibility that contemporary AlaRS genes in V. polyspora arose relatively recently from duplication of a dual-functional predecessor of mitochondrial origin.

  8. TEMPORAL CHARACTERIZATION OF LASER PULSES FROM JIGUANG-I LASER FACILITY WITH A COMPACT DUAL FUNCTION AUTOCORRELATOR

    Institute of Scientific and Technical Information of China (English)

    夏江帆; 魏志义; 邱阳; 吕铁铮; 腾浩; 王兆华; 张杰

    2001-01-01

    An optical pulse autocorrelator for rapid and slow scanning is described in this paper. Using an audio loudspeaker on one arm, an interferometric rapid-scanning signal of the output from a high-repetition laser oscillator is obtained.However, by adjusting the positions of the mirrors and using a step-motor on another arm, the intensity autocorrelation function of the output from a low-repetition laser amplifier can be easily measured. Using all-reflecting optics and an adequate nonlinear crystal, the whole instrument is very compact and has been used to measure sub-20 fs light pulses in both configurations with excellent agreement. In the slow-scanning configuration, a pulse train as long as 500ps has been determined. Using this autocorrelator, the home-made JIGUANG-I CPA laser facility was characterized for its pulse duration evolution.

  9. Microporous metal-organic framework with dual functionalities for highly efficient removal of acetylene from ethylene/acetylene mixtures

    Science.gov (United States)

    Hu, Tong-Liang; Wang, Hailong; Li, Bin; Krishna, Rajamani; Wu, Hui; Zhou, Wei; Zhao, Yunfeng; Han, Yu; Wang, Xue; Zhu, Weidong; Yao, Zizhu; Xiang, Shengchang; Chen, Banglin

    2015-06-01

    The removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene is a technologically very important, but highly challenging task. Current removal approaches include the partial hydrogenation over a noble metal catalyst and the solvent extraction of cracked olefins, both of which are cost and energy consumptive. Here we report a microporous metal-organic framework in which the suitable pore/cage spaces preferentially take up much more acetylene than ethylene while the functional amine groups on the pore/cage surfaces further enforce their interactions with acetylene molecules, leading to its superior performance for this separation. The single X-ray diffraction studies, temperature dependent gas sorption isotherms, simulated and experimental column breakthrough curves and molecular simulation studies collaboratively support the claim, underlying the potential of this material for the industrial usage of the removal of acetylene from ethylene/acetylene mixtures containing 1% acetylene at room temperature through the cost- and energy-efficient adsorption separation process.

  10. Microporous metal–organic framework with dual functionalities for highly efficient removal of acetylene from ethylene/acetylene mixtures