Science.gov

Sample records for dual functional lithium-lead

  1. Dual function conducting polymer diodes

    DOEpatents

    Heeger, Alan J.; Yu, Gang

    1996-01-01

    Dual function diodes based on conjugated organic polymer active layers are disclosed. When positively biased the diodes function as light emitters. When negatively biased they are highly efficient photodiodes. Methods of preparation and use of these diodes in displays and input/output devices are also disclosed.

  2. Dual-Functionalized Theranostic Nanocarriers.

    PubMed

    Mo, Alexander H; Zhang, Chen; Landon, Preston B; Janetanakit, Woraphong; Hwang, Michael T; Santacruz Gomez, Karla; Colburn, David A; Dossou, Samuel M; Lu, Tianyi; Cao, Yue; Sant, Vrinda; Sud, Paul L; Akkiraju, Siddhartha; Shubayev, Veronica I; Glinsky, Gennadi; Lal, Ratnesh

    2016-06-15

    Nanocarriers with the ability to spatially organize chemically distinct multiple bioactive moieties will have wide combinatory therapeutic and diagnostic (theranostic) applications. We have designed dual-functionalized, 100 nm to 1 μm sized scalable nanocarriers comprising a silica golf ball with amine or quaternary ammonium functional groups located in its pits and hydroxyl groups located on its nonpit surface. These functionalized golf balls selectively captured 10-40 nm charged gold nanoparticles (GNPs) into their pits. The selective capture of GNPs in the golf ball pits is visualized by scanning electron microscopy. ζ potential measurements and analytical modeling indicate that the GNP capture involves its proximity to and the electric charge on the surface of the golf balls. Potential applications of these dual-functionalized carriers include distinct attachment of multiple agents for multifunctional theranostic applications, selective scavenging, and clearance of harmful substances. PMID:27144808

  3. Unraveling Executive Functioning in Dual Diagnosis

    PubMed Central

    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

  4. Unraveling Executive Functioning in Dual Diagnosis.

    PubMed

    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

  5. The Dual Gap Function for Variational Inequalities

    SciTech Connect

    Zhang Jianzhong Wan Changyu; Xiu Naihua

    2003-08-15

    In this paper we further study the dual gap function G, which was introduced by Marcotte and Zhu, for the variational inequality problem (VIP). We characterize the directional derivative and subdifferential of G. Based on these, we get a better understanding of the concepts of a global error bound, weak sharpness, and minimum principle sufficiency property for the pseudo-monotone.

  6. Externally triggered dual function of complex microcapsules.

    PubMed

    Yi, Qiangying; Sukhorukov, Gleb B

    2013-10-22

    By introducing UV-sensitive chemical groups causing different potential response as building blocks, fabricated LbL capsules can be endowed with dual UV-responsive properties in specific layers. One block is responsible for fast capsule sealing and the other for longer term capsule swelling and rupture. Therefore, the multifunction of these capsules could be activated selectively when exposed to external UV light with suitable wavelengths. In this work, dual-functional complex microcapsules (PDADMAC/PAZO)4-(DAR/Nafion)2 containing both diazonium and aozbenzene groups were proposed as clear examples to realize a time-dependent UV response for successive encapsulation and release. Upon exposure to UV light, the DAR/Nafion layers underwent a rapid in situ cross-linking and hence to seal the capsule shells through diazonium-related photolysis. Then further gradual shell swelling was followed by realignment of azobenzene molecules in PDADMAC/PAZO layers. Fluorescent polymers were consequently studied as cargo substances. Results indicated that continuous UV light triggered rapid cargo encapsulation over minutes time scale and gradual release with continuous irradiation over hours. PMID:24083649

  7. Dual functional selenium-substituted hydroxyapatite.

    PubMed

    Wang, Yanhua; Ma, Jun; Zhou, Lei; Chen, Jin; Liu, Yonghui; Qiu, Zhiye; Zhang, Shengmin

    2012-06-01

    Hydroxyapatite (HA) doped with trace elements has attracted much attention recently owing to its excellent biological functions. Herein, we use a facile co-precipitation method to incorporate selenium into HA by adding sodium selenite during synthesis. The obtained selenium-substituted HA products are needle-like nanoparticles which have  size and crystallinity that are similar to those of the pure HA nanoparticles (HANs) when the selenium content is low. HANs are found to have the ability to induce the apoptosis of osteosarcoma cells, and the anti-tumour effects are enhanced after incorporation of selenium. Meanwhile, the nanoparticles can also support the growth of bone marrow stem cells. Furthermore, the flow cytometric results indicate that the apoptosis induction of osteosarcoma cells is caused by the increased reactive oxygen species and decreased mitochondrial membrane potential. These results show that the selenium-substituted HANs are potentially promising bone graft materials in osteosarcoma treatment due to their dual functions of supporting normal cell growth and inducing tumour cell apoptosis. PMID:23741613

  8. Dual Function Positions: A View from the Trenches.

    ERIC Educational Resources Information Center

    Paster, Amy L.

    Following an overview of the Pennsylvania State University Libraries, this paper discusses the role of dual function librarians. The duties and responsibilities of a RISD (Reference and Instructional Services Division) cataloger are listed, and problems of terminology, evaluation, divided loyalties, and inflated expectations are addressed.…

  9. Monitoring: a dual-function coping style.

    PubMed

    Shiloh, Shoshana; Orgler-Shoob, Michal

    2006-04-01

    Monitoring (Miller, 1991) is defined as a cognitive coping style characterized by the tendency to seek information about threats. This study found that information seeking in stressful situations is perceived by individuals as related to the emotion-focused more than the problem-focused function of coping and that there is considerable variance among individuals in the perceived functions of information seeking and the relationships among information-seeking reactions and their perceived functions. Information-seeking preferences in a natural stressful situation (a final course examination) were predicted by individual differences in perceived functions of information seeking rather than by generalized behavioral coping styles (monitoring). The results were interpreted in relation to the cognitive-affective system theory (Mischel & Shoda, 1995), and implications for the measurement of coping dispositions were discussed. PMID:16529583

  10. Dual-function fluorescent probe for cancer imaging and therapy.

    PubMed

    Cui, Hongjing; Wang, Ran; Zhou, Ying; Shu, Chang; Song, Fengjuan; Zhong, Wenying

    2016-05-01

    To date, several fluorescent probes modified by a single targeting agent have been explored. However, studies on the preparation of dual-function quantum dot (QD) fluorescent probes with dual-targeting action and a therapeutic effect are rare. Here, a dual-targeting CdTe/CdS QD fluorescent probe with a bovine serum albumin-glycyrrhetinic acid conjugate and arginine-glycine-aspartic acid was successfully prepared that could induce the apoptosis of liver cancer cells and showed enhanced targeting in in vitro cell imaging. Therefore, the as-prepared fluorescent probe in this work is an efficient diagnostic tool for the simultaneous detection of liver cancer and breast cancer cells. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26387677

  11. Colored dual-functional photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Lee, Kyu-Tae; Lee, Jae Yong; Xu, Ting; Park, Hui Joon; Guo, L. Jay

    2016-06-01

    In this article, we review our recent efforts on multi-functional photovoltaic (PV) cells that can produce desired reflective, transmissive, or neutral colors, by controlling light interaction with semiconductors and electrode structures in a desired manner. The PV cells integrated with plasmonic color filtering schemes using subwavelength gratings, and other approaches exploiting photonic resonances in an optical nanocavity consisting of highly absorbing semiconductor media are described. For further enhancement of optical and electrical performance characteristics of the multi-functional PV cells, possible difficulties and the outlook for future work are discussed.

  12. Polymeric blends for sensor and actuation dual functionality

    NASA Technical Reports Server (NTRS)

    St. Clair, Terry L. (Inventor); Harrison, Joycelyn S. (Inventor); Su, Ji (Inventor); Ounaies, Zoubeida (Inventor)

    2004-01-01

    The invention described herein supplies a new class of electroactive polymeric blend materials which offer both sensing and actuation dual functionality. The blend comprises two components, one component having a sensing capability and the other component having an actuating capability. These components should be co-processable and coexisting in a phase separated blend system. Specifically, the materials are blends of a sensing component selected from the group consisting of ferroelectric, piezoelectric, pyroelectric and photoelectric polymers and an actuating component that responds to an electric field in terms of dimensional change. Said actuating component includes, but is not limited to, electrostrictive graft elastomers, dielectric electroactive elastomers, liquid crystal electroactive elastomers and field responsive polymeric gels. The sensor functionality and actuation functionality are designed by tailoring the relative fraction of the two components. The temperature dependence of the piezoelectric response and the mechanical toughness of the dual functional blends are also tailored by the composition adjustment.

  13. Enrichment of orange emission of Er3+ ion with Sn4+ ion as sensitizer in lithium lead phosphate glass system

    NASA Astrophysics Data System (ADS)

    Rajanikanth, P.; Gandhi, Y.; Veeraiah, N.

    2015-10-01

    Lithium lead phosphate glasses doped with 1.0 mol% of Er2O3 and mixed with varying concentrations of SnO2 (from 0 to 7.0 mol%) have been synthesized. Optical absorption and luminescence spectra of the prepared glasses were recorded at ambient temperature. The radiative lifetimes were measured from the luminescence decay profiles recorded at room temperature. Similar studies have also been carried out for the SnO2 singly doped glasses. The absorption and luminescence spectra of Er3+ ions doped glasses were characterized using Judd-Ofelt theory. The radiative parameters viz., transition probability A, branching ratio β and the radiative lifetime τ of principal emission transitions of these glasses have been evaluated. The energy transfer mechanism between Sn4+ and Er3+ in co-doped glasses has been explored as a function of SnO2 concentration with the help of rate equations. The results indicated a significant enhancement in the intensity of orange emission 4G11/2 → 4I11/2 of Er3+ ions due to co-doping with SnO2. The results were further analyzed with IR spectral data and ac conductivity studies. The analysis pointed out that about 3.0 mol% of SnO2 is the most favorable concentration for getting the highest quantum efficiency of orange emission and for the maximum energy transfer with low non-radiative transition probabilities.

  14. Physical, thermal, infrared and optical properties of Nd3+ doped lithium-lead-germanate glasses

    NASA Astrophysics Data System (ADS)

    Veeranna Gowda, V. C.

    2015-01-01

    The structure-property relationships of neodymium doped lithium-lead-germanate glasses were investigated. The density was found to increase with the increase of Nd2O3 concentration and its variation is explained in terms of its molecular mass, structural transformation and packing density. Addition of modifier oxide to lead-germanate glass suggests a decreased free space within the glass matrix, resulting in the formation of stiff network. The increase in glass transition temperature specifies strengthening of glass by forming bridging oxygens. The optical properties of glass were measured employing UV-visible spectroscopy. The refractive index values varied nonlinearly with Nd2O3 concentration and were speculated to depend on the electronic polarizability of oxide glasses. The frequencies of the infrared absorption bands were affected marginally and the absorption peaks revealed that the glass matrix consists of [GeO4/2], [GeO6/2] and [PbO4/2] structural units.

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

    DOEpatents

    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 <1 nm to 10 nm), specially dispersed on titanium silicalite substrate particles. The dual functional catalyst catalyzes both the direct reaction of hydrogen and oxygen to generate hydrogen peroxide intermediate on the noble metal catalyst surface and the reaction of the hydrogen peroxide intermediate with the propylene feed to generate propylene oxide product. Combining both these functions in a single catalyst provides a very efficient integrated process operable below the flammability limits of hydrogen and highly selective for the production of hydrogen peroxide to produce olefin oxides such as propylene oxide without formation of undesired co-products.

  16. Dual-Functional Antifogging/Antimicrobial Polymer Coating.

    PubMed

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

    2016-04-01

    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. PMID:26977525

  17. Orbifold E-functions of dual invertible polynomials

    NASA Astrophysics Data System (ADS)

    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.

  18. Study on hydrogen isotopes permeation in fluidized state of liquid lithium-lead

    SciTech Connect

    Yoshimura, S.; Yoshimura, R.; Okada, M.; Fukada, S.; Edao, Y.

    2015-03-15

    Lithium-lead (Li-Pb) is one of the most promising candidate materials for the liquid blanket of fusion reactors. Hydrogen transfer under a fluidized condition of Li-Pb is investigated experimentally to design a Li-Pb blanket system. Li-Pb eutectic alloy flows inside a Ni tube in the experimental system, where H{sub 2} permeates into and out of the forced Li-Pb flow. The overall H{sub 2} permeation rate is analyzed using a mass balance model. Hydrogen atoms diffuse in Ni and Li-Pb. The steady-state H{sub 2} permeation rate obtained by this experiment is smaller than the result of the calculation model. A resistance factor is introduced to the present analysis in order to evaluate the influence of other H{sub 2} transfer mechanisms, such as diffusion in Li-Pb and dissolution reaction between Ni and Li-Pb. The contribution of the resistance to the overall H{sub 2} permeation rate becomes large when the flow rate of Li-Pb is low. This is because the boundary layer thickness between Ni and Li-Pb affects the overall H{sub 2} permeation rate. When the flow velocity of Li-Pb increases, the thickness of the boundary layer becomes thin, and the driving force of H{sub 2} permeation through the Ni wall becomes bigger. (authors)

  19. Dual-Functionalized Nanostructured Biointerfaces by Click Chemistry

    PubMed Central

    2014-01-01

    The presentation of biologically active molecules at interfaces has made it possible to investigate the responses of cells to individual molecules in their matrix at a given density and spacing. However, more sophisticated methods are needed to create model surfaces that present more than one molecule in a controlled manner in order to mimic at least partially the complexity given in natural environments. Herein, we present dual-functionalized surfaces combining quasi-hexagonally arranged gold nanoparticles with defined spacings and a newly developed PEG-alkyne coating to functionalize the glass in the intermediate space. The PEG-alkyne coating provides an inert background for cell interactions but can be modified orthogonally to the gold nanoparticles with numerous azides, including spectroscopically active molecules, peptides, and biotin at controlled densities by the copper(I)-catalyzed azide alkyne click reaction. The simultaneous presentation of cRGD on the gold nanoparticles with 100 nm spacing and synergy peptide PHSRN in the space between has a striking effect on REF cell adhesion; cells adhere, spread, and form mature focal adhesions on the dual-functionalized surfaces, whereas cells cannot adhere on either monofunctional surface. Combining these orthogonal functionalization methods creates a new platform to study precisely the crosstalk and synergy between different signaling molecules and clustering effects in ligand–receptor interactions. PMID:24856250

  20. Dual-functionalized nanostructured biointerfaces by click chemistry.

    PubMed

    Schenk, Franziska C; Boehm, Heike; Spatz, Joachim P; Wegner, Seraphine V

    2014-06-17

    The presentation of biologically active molecules at interfaces has made it possible to investigate the responses of cells to individual molecules in their matrix at a given density and spacing. However, more sophisticated methods are needed to create model surfaces that present more than one molecule in a controlled manner in order to mimic at least partially the complexity given in natural environments. Herein, we present dual-functionalized surfaces combining quasi-hexagonally arranged gold nanoparticles with defined spacings and a newly developed PEG-alkyne coating to functionalize the glass in the intermediate space. The PEG-alkyne coating provides an inert background for cell interactions but can be modified orthogonally to the gold nanoparticles with numerous azides, including spectroscopically active molecules, peptides, and biotin at controlled densities by the copper(I)-catalyzed azide alkyne click reaction. The simultaneous presentation of cRGD on the gold nanoparticles with 100 nm spacing and synergy peptide PHSRN in the space between has a striking effect on REF cell adhesion; cells adhere, spread, and form mature focal adhesions on the dual-functionalized surfaces, whereas cells cannot adhere on either monofunctional surface. Combining these orthogonal functionalization methods creates a new platform to study precisely the crosstalk and synergy between different signaling molecules and clustering effects in ligand-receptor interactions. PMID:24856250

  1. Dual-Language Education for Low-Income Children: Preliminary Evidence of Benefits for Executive Function

    ERIC Educational Resources Information Center

    Esposito, Alena G.; Baker-Ward, Lynne

    2013-01-01

    This investigation is an initial examination of possible enhancement of executive function through a dual-language (50:50) education model. The ethnically diverse, low-income sample of 120 children from Grades K, 2, and 4 consisted of approximately equal numbers of children enrolled in dual-language and traditional classrooms. Dual-language…

  2. Incredible RNA: Dual Functions of Coding and Noncoding

    PubMed Central

    Nam, Jin-Wu; Choi, Seo-Won; You, Bo-Hyun

    2016-01-01

    Since the RNA world hypothesis was proposed, a large number of regulatory noncoding RNAs (ncRNAs) have been identified in many species, ranging from microorganisms to mammals. During the characterization of these newly discovered RNAs, RNAs having both coding and noncoding functions were discovered, and these were considered bifunctional RNAs. The recent use of computational and high-throughput experimental approaches has revealed increasing evidence of various sources of bifunctional RNAs, such as protein-coding mRNAs with a noncoding isoform and long ncRNAs bearing a small open reading frame. Therefore, the genomic diversity of Janus-faced RNA molecules that have dual characteristics of coding and noncoding indicates that the functional roles of RNAs have to be revisited in cells on a genome-wide scale. Such studies would allow us to further understand the complex gene-regulatory network in cells. In this review, we discuss three major genomic sources of bifunctional RNAs and present a handful of examples of bifunctional RNA along with their functional roles. PMID:27137091

  3. Incredible RNA: Dual Functions of Coding and Noncoding.

    PubMed

    Nam, Jin-Wu; Choi, Seo-Won; You, Bo-Hyun

    2016-05-31

    Since the RNA world hypothesis was proposed, a large number of regulatory noncoding RNAs (ncRNAs) have been identified in many species, ranging from microorganisms to mammals. During the characterization of these newly discovered RNAs, RNAs having both coding and noncoding functions were discovered, and these were considered bifunctional RNAs. The recent use of computational and high-throughput experimental approaches has revealed increasing evidence of various sources of bifunctional RNAs, such as protein-coding mRNAs with a noncoding isoform and long ncRNAs bearing a small open reading frame. Therefore, the genomic diversity of Janus-faced RNA molecules that have dual characteristics of coding and noncoding indicates that the functional roles of RNAs have to be revisited in cells on a genome-wide scale. Such studies would allow us to further understand the complex gene-regulatory network in cells. In this review, we discuss three major genomic sources of bifunctional RNAs and present a handful of examples of bifunctional RNA along with their functional roles. PMID:27137091

  4. Functional Analysis of Dual-Specificity Protein Phosphatases in Angiogenesis.

    PubMed

    Amand, Mathieu; Erpicum, Charlotte; Gilles, Christine; Noël, Agnès; Rahmouni, Souad

    2016-01-01

    Therapeutic perspectives targeting angiogenesis in cancer stimulated an intense investigation of the mechanisms triggering and governing angiogenic processes. Several publications have highlighted the importance of typical dual-specificity phosphatases (DSPs) or MKPs in endothelial cells and their role in controlling different biological functions implicated in angiogenesis such as migration, proliferation, apoptosis, tubulogenesis, and cell adhesion. However, among atypical DSPs, the only one investigated in angiogenesis was DUSP3. We recently identified this DSP as a new key player in endothelial cells and angiogenesis. In this chapter we provide with detailed protocols and models used to investigate the role of DUSP3 in endothelial cells and angiogenesis. We start the chapter with an overview of the role of several DSPs in angiogenesis. We continue with providing a full description of a highly efficient transfection protocol to deplete DUSP3 using small interfering RNA (siRNA) in the primary human umbilical vein endothelial cells (HUVEC). We next describe the major assays used to investigate different processes involved in angiogenesis such as tube formation assay, proliferation assay and spheroids sprouting assay. We finish the chapter by validating our results in DUSP3-knockout mice using in vivo angiogenesis assays such as Matrigel plug and Lewis lung carcinoma cell subcutaneous xenograft model followed by anti-CD31 immunofluorescence and ex vivo aortic ring assay. All methods described can be adapted to other phosphatases and signaling molecules. PMID:27514814

  5. Dual Functionalized Bacteriophage Qβ as a Photocaged Drug Carrier.

    PubMed

    Chen, Zhuo; Li, Na; Chen, Luxi; Lee, Jiyong; Gassensmith, Jeremiah J

    2016-09-01

    Proteinatious nanoparticles are emerging as promising materials in biomedical research owing to their many unique properties and our interest focuses on integrating environmental responsivity into these systems. In this work, the use of a virus-like particle (VLP) derived from bacteriophage Qβ as a photocaged drug delivery system is investigated. Ideally, a photocaged nanoparticle platform should be harmless and inert without activation by light yet, upon photoirradiation, should cause cell death. Approximately 530 photocleavable doxorubicin complexes are installed initially onto the surface of Qβ by CuAAC reaction for photocaging therapy; however, aggregation and precipitation are found to cause cell death at higher concentrations. In order to improve solution stability, thiol-dibromomaleimide chemistry has been developed to orthogonally modify the VLP. This chemistry provides a robust method of incorporating additional functionality at the disulfides on Qβ, which was used to increase the stability and solubility of the drug-loaded VLPs. As a result, the dual functionalied VLPs with polyethylene glycol and photocaged doxorubicin show not only negligible cytotoxicity before photoactivation but also highly controllable photorelease and cell killing power. PMID:27351167

  6. Dual Function of Phosphoubiquitin in E3 Activation of Parkin.

    PubMed

    Walinda, Erik; Morimoto, Daichi; Sugase, Kenji; Shirakawa, Masahiro

    2016-08-01

    Mutations in the gene encoding parkin, an auto-inhibited E3 ubiquitin ligase that functions in the clearance of damaged mitochondria, are the most common cause of autosomal recessive juvenile Parkinsonism. The mechanism regulating parkin activation remains poorly understood. Here we show, by using isothermal titration calorimetry, solution NMR, and fluorescence spectroscopy, that parkin can bind ubiquitin and phosphomimetic ubiquitin by recognizing the canonical hydrophobic patch and C terminus of ubiquitin. The affinity of parkin for both phosphomimetic and unmodified ubiquitin is markedly enhanced upon removal of the ubiquitin-like (UBL) domain of parkin. This suggests that the agonistic binding of ubiquitin to parkin in trans is counterbalanced by the antagonistic activity of the parkin UBL domain in cis Intriguingly, UBL binding is enthalpy-driven, whereas ubiquitin binding is driven by an increase in the total entropy of the system. These thermodynamic differences are explained by different chemistry in the ubiquitin- and UBL-binding pockets of parkin and, as shown by molecular dynamics simulations, are not a consequence of changes in protein conformational entropy. Indeed, comparison of conformational fluctuations reveals that the RING1-IBR element becomes considerably more rigid upon complex formation. A model of parkin activation is proposed in which E2∼Ub binding triggers large scale diffusional motion of the RING2 domain toward the ubiquitin-stabilized RING1-IBR assembly to complete formation of the active parkin-E2∼Ub transfer complex. Thus, ubiquitin plays a dual role in parkin activation by competing with the inhibitory UBL domain and stabilizing the active form of parkin. PMID:27284007

  7. Development of a chemical kinetic measurement apparatus and the determination of the reaction rate constants for lithium-lead/water interaction

    SciTech Connect

    Biney, P.O.

    1993-04-01

    An experimental set-up for accurate measurement of hydrogen generation rate in Lithium-Lead (Li[sub 17]Pb[sub 83]) Steam or water interactions has been designed. The most important features of the design include a pneumatic actuated quick opening and closing high temperature all stainless steel valve used to control the reaction time and the placement of most measuring devices below a water line to minimize leakage of the hydrogen collected. A PC based data acquisition and control system provides remote process sequencing, acquisition and control of all major components of the set-up. Initial tests indicate that the first design objective of maintaining leakproof gas collection chamber has been achieved. Initial pressure tests indicated that the pressure drop over a time span of 30 minutes was within the tolerance of the pressure transducer used to measure the pressure (within 0.690 kPa) at a nominal system pressure of 685 kPa. The experimental system hardware, data acquisition and control programs and data analysis program have been completed, tested and are currently functional.

  8. Dual photo-functionalized amphiphile for photo-reversible liquid crystal alignments.

    PubMed

    Kim, Dae-Yoon; Lee, Sang-A; Park, Minwook; Jeong, Kwang-Un

    2015-01-01

    Without the conventional polymer-based liquid crystal (LC) alignment process, a newly synthesized dual photo-functionalized amphiphile (abbreviated as ADMA1 ) was successfully applied as a robust photo-reversible LC alignment layer by self-assembly and photo-polymerization. The LC alignment layer constructed by directly adding dual photo-functionalized amphiphiles into LC media significantly cuts the manufacturing cost as well as opens new doors for the fabrication of novel electro-optical devices. PMID:25418844

  9. Interaction of Panax quinquefolius Saponin and Dual Antiplatelets on Vascular Endothelial Function in Rats with Acute Myocardial Infarction

    PubMed Central

    Wang, Baojun; Liu, Yue; Shang, Qinghua; Zhang, Qingxiang; Zhang, Lei; Liu, Jiangang; Shi, Dazhuo

    2015-01-01

    The objective of this study is to investigate the interaction of Panax quinquefolius saponin (PQS) and dual antiplatelets (aspirin and clopidogrel) on antiplatelet activity and vascular endothelial function in rats with acute myocardial infarction (AMI). Forty-eight male SD rats were randomly designed into sham group, model group, dual antiplatelet group, and PQS plus dual antiplatelet group. AMI rats were induced by ligation of left anterior descending coronary artery (LAD) and dual antiplatelet agents and additional PQS to dual antiplatelets were intragastrically administered for 28 days, respectively. The ventricular cavity area and cardiac transverse area ratio in PQS + dual antiplatelet group showed a decreased tendency. PAgT(%) decreased significantly in both dual antiplatelet group and PQS + dual antiplatelet group. TXB2 concentration significantly decreased in dual antiplatelet and PQS + dual antiplatelet groups, whereas 6-keto-PGF1α concentration significantly increased in PQS + dual antiplatelet group. Rats in PQS + dual antiplatelet group demonstrated a significant decrease in plasma ET-1 concentration and an increase in serum NO concentration compared with dual antiplatelet group. The combination therapy of PQS and dual antiplatelets showed some beneficial effects on vascular endothelial function and ventricular remodeling in rats with AMI. PMID:26090462

  10. The Role of Control Functions in Mentalizing: Dual-Task Studies of Theory of Mind and Executive Function

    ERIC Educational Resources Information Center

    Bull, Rebecca; Phillips, Louise H.; Conway, Claire A.

    2008-01-01

    Conflicting evidence has arisen from correlational studies regarding the role of executive control functions in Theory of Mind. The current study used dual-task manipulations of executive functions (inhibition, updating and switching) to investigate the role of these control functions in mental state and non-mental state tasks. The "Eyes"…

  11. Estimation of bone Calcium-to-Phosphorous mass ratio using dual-energy nonlinear polynomial functions

    NASA Astrophysics Data System (ADS)

    Sotiropoulou, P.; Koukou, V.; Martini, N.; Michail, C.; Kounadi, E.; Kandarakis, I.; Nikiforidis, G.; Fountos, G.

    2015-09-01

    In this study an analytical approximation of dual-energy inverse functions is presented for the estimation of the calcium-to-phosphorous (Ca/P) mass ratio, which is a crucial parameter in bone health. Bone quality could be examined by the X-ray dual-energy method (XDEM), in terms of bone tissue material properties. Low- and high-energy, log- intensity measurements were combined by using a nonlinear function, to cancel out the soft tissue structures and generate the dual energy bone Ca/P mass ratio. The dual-energy simulated data were obtained using variable Ca and PO4 thicknesses on a fixed total tissue thickness. The XDEM simulations were based on a bone phantom. Inverse fitting functions with least-squares estimation were used to obtain the fitting coefficients and to calculate the thickness of each material. The examined inverse mapping functions were linear, quadratic, and cubic. For every thickness, the nonlinear quadratic function provided the optimal fitting accuracy while requiring relative few terms. The dual-energy method, simulated in this work could be used to quantify bone Ca/P mass ratio with photon-counting detectors.

  12. Transport properties of lithium- lead-vanadium-telluride glass and glass ceramics

    SciTech Connect

    Sathish, M.; Eraiah, B.

    2014-04-24

    Glasses with the chemical composition 35Li{sub 2}O-(45-x)V{sub 2}O{sub 5−}20PbO-xTeO{sub 2} (where x = 2.5, 5, 7.5, 10, 15 mol %) have prepared by conventional melt quenching method. The electrical conductivity of Li{sup +} ion conducting lead vanadium telluride glass samples has been carried out both as a function of temperature and frequency in the temperature range 503K-563K and over frequencies 40 Hz to 10 MHz. The electronic conduction has been observed in the present systems. When these samples annealed around 400°C for 2hour become the glass ceramic, which also shows increase tendency of conductivity. SEM confines glass and glass ceramic nature of the prepared samples.

  13. Scattering equations and virtuous kinematic numerators and dual-trace functions

    NASA Astrophysics Data System (ADS)

    Naculich, Stephen G.

    2014-07-01

    Inspired by recent developments on scattering equations, we present a constructive procedure for computing symmetric, amplitude-encoded, BCJ numerators for n-point gauge-theory amplitudes, thus satisfying the three virtues identified by Broedel and Carrasco. We also develop a constructive procedure for computing symmetric, amplitude-encoded dual-trace functions τ for n-point amplitudes. These can be used to obtain symmetric kinematic numerators that automatically satisfy color-kinematic duality. The S n symmetry of n-point gravity amplitudes formed from these symmetric dual-trace functions is completely manifest. Explicit expressions for four- and five-point amplitudes are presented.

  14. An enzyme-responsive controlled release system based on a dual-functional peptide.

    PubMed

    Li, X; Burger, S; O'Connor, A J; Ong, L; Karas, J A; Gras, S L

    2016-04-14

    A new controlled release system was developed by loading a dual-functional peptide (DFP) on a mesoporous silica material. One-pot synthesis produced a DFP that was stimuli responsive, releasing a therapeutic peptide by protease cleavage. The design provides new steps towards smart biomaterials. PMID:26998533

  15. TRICHLOROETHYLENE SORPTION AND OXIDATION USING A DUAL FUNCTION SORBENT/CATALYST IN A FALLING FURNACE REACTOR

    EPA Science Inventory

    A dual function medium (Cr-ZSM-5), capable of physisorbing trichloroethylene (TCE) at ambient temperature and catalytically oxidizing it at elevated temperature (-350 degrees C) was utilized in a novel continuous falling furnace reactor system to store and periodically destroy t...

  16. Executive Function Development and Early Mathematics: Examination of Dual Language Learners

    ERIC Educational Resources Information Center

    Harvey, Hattie A.

    2011-01-01

    This study examined the convergent validity between a third-party rating scale of executive function (EF) and a task-performance measurement of EF; examined the effects of age, gender, and dual language experience on preschool children's EF skills (inhibition, working memory (WM), and shifting) and on early mathematical skills; and investigated…

  17. Dual-mode imaging of cutaneous tissue oxygenation and vascular function.

    PubMed

    Xu, Ronald X; Huang, Kun; Qin, Ruogu; Huang, Jiwei; Xu, Jeff S; Ding, Liya; Gnyawali, Urmila S; Gordillo, Gayle M; Gnyawali, Surya C; Sen, Chandan K

    2010-01-01

    Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health disorders such as chronic wounds. We report the development of a dual-mode imaging system for non-invasive and non-contact imaging of cutaneous tissue oxygenation and vascular function. The imaging system integrated an infrared camera, a CCD camera, a liquid crystal tunable filter and a high intensity fiber light source. A Labview interface was programmed for equipment control, synchronization, image acquisition, processing, and visualization. Multispectral images captured by the CCD camera were used to reconstruct the tissue oxygenation map. Dynamic thermographic images captured by the infrared camera were used to reconstruct the vascular function map. Cutaneous tissue oxygenation and vascular function images were co-registered through fiduciary markers. The performance characteristics of the dual-mode image system were tested in humans. PMID:21178967

  18. An indecent proposal: the dual functions of indirect speech.

    PubMed

    Chakroff, Aleksandr; Thomas, Kyle A; Haque, Omar S; Young, Liane

    2015-01-01

    People often use indirect speech, for example, when trying to bribe a police officer by asking whether there might be "a way to take care of things without all the paperwork." Recent game theoretic accounts suggest that a speaker uses indirect speech to reduce public accountability for socially risky behaviors. The present studies examine a secondary function of indirect speech use: increasing the perceived moral permissibility of an action. Participants report that indirect speech is associated with reduced accountability for unethical behavior, as well as increased moral permissibility and increased likelihood of unethical behavior. Importantly, moral permissibility was a stronger mediator of the effect of indirect speech on likelihood of action, for judgments of one's own versus others' unethical action. In sum, the motorist who bribes the police officer with winks and nudges may not only avoid public punishment but also maintain the sense that his actions are morally permissible. PMID:25079674

  19. Dual Nerve Transfers for Restoration of Shoulder Function After Brachial Plexus Avulsion Injury.

    PubMed

    Chu, Bin; Wang, Huan; Chen, Liang; Gu, Yudong; Hu, Shaonan

    2016-06-01

    The purpose of this study was to investigate the effectiveness of shoulder function restoration by dual nerve transfers, spinal accessory nerve to the suprascapular nerve and 2 intercostal nerves to the anterior branch of the axillary nerve, in patients with shoulder paralysis that resulted from brachial plexus avulsion injury. It was a retrospective analysis to assess the impact of a variety of factors on reanimation of shoulder functions with dual nerve transfers. A total of 19 patients were included in this study. Most of these patients sustained avulsions of C5, C6, and C7 nerve roots (16 patients). Three of them had avulsions of C5 and C6 roots only. Through a posterior approach, direct coaptation of the intercostal nerves and the anterior branch of the axillary nerve was performed, along with accessory nerve transfer to the suprascapular nerve. Satisfactory shoulder function recovery (93.83° of shoulder abduction and 54.00° of external rotation on average) was achieved after a 62-month follow-up. This dual nerve transfer procedure provided us with a reliable and effective method for shoulder function reconstruction after brachial plexus root avulsion, especially C5/C6/C7 avulsion. The level of evidence is therapeutic IV. PMID:26835823

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

    PubMed

    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. PMID:26414428

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

    NASA Astrophysics Data System (ADS)

    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 $\\int V(\\delta_J)$ and $J\\Delta J$ to $\\delta_{\\phi_c}\\Delta\\delta_{\\phi_c}$ and $\\int V(\\phi_c)$, respectively, with $\\phi_c=\\int J\\Delta$ and $\\Delta$ 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 $T[\\phi_c]=W[J]$ expressed in terms of covariant derivatives acting on 1 $$ T[\\phi_c] = {N\\over N_0} \\exp(-U_0[\\phi_c])\\exp\\Big(-\\int V({\\cal D}_{\\phi_c}^-)\\Big) \\cdot 1 $$ where ${\\cal D}_{\\phi}^{\\pm}(x)=\\mp\\Delta{\\delta\\over\\delta\\phi}(x)+\\phi(x)$. 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 ${\\lambda\\over n!}:\\phi^n:$. Such relations are explicitly derived by using the Fa\\`a di Bruno formula. This also yields the explicit expression of the generating functional of connected Green's functions.

  2. Multi-functional angiographic OFDI using frequency-multiplexed dual-beam illumination.

    PubMed

    Kim, SunHee; Park, Taejin; Jang, Sun-Joo; Nam, Ahhyun S; Vakoc, Benjamin J; Oh, Wang-Yuhl

    2015-04-01

    Detection of blood flow inside the tissue sample can be achieved by measuring the local change of complex signal over time in angiographic optical coherence tomography (OCT). In conventional angiographic OCT, the transverse displacement of the imaging beam during the time interval between a pair of OCT signal measurements must be significantly reduced to minimize the noise due to the beam scanning-induced phase decorrelation at the expense of the imaging speed. Recent introduction of dual-beam scan method either using polarization encoding or two identical imaging systems in spectral-domain (SD) OCT scheme shows potential for high-sensitivity vasculature imaging without suffering from spurious phase noise caused by the beam scanning-induced spatial decorrelation. In this paper, we present multi-functional angiographic optical frequency domain imaging (OFDI) using frequency-multiplexed dual-beam illumination. This frequency multiplexing scheme, utilizing unique features of OFDI, provides spatially separated dual imaging beams occupying distinct electrical frequency bands that can be demultiplexed in the frequency domain processing. We demonstrate the 3D multi-functional imaging of the normal mouse skin in the dorsal skin fold chamber visualizing distinct layer structures from the intensity imaging, information about mechanical integrity from the polarization-sensitive imaging, and depth-resolved microvasculature from the angiographic imaging that are simultaneously acquired and automatically co-registered. PMID:25968731

  3. Multi-functional angiographic OFDI using frequency-multiplexed dual-beam illumination

    PubMed Central

    Kim, SunHee; Park, Taejin; Jang, Sun-Joo; Nam, Ahhyun S.; Vakoc, Benjamin J.; Oh, Wang-Yuhl

    2015-01-01

    Detection of blood flow inside the tissue sample can be achieved by measuring the local change of complex signal over time in angiographic optical coherence tomography (OCT). In conventional angiographic OCT, the transverse displacement of the imaging beam during the time interval between a pair of OCT signal measurements must be significantly reduced to minimize the noise due to the beam scanning-induced phase decorrelation at the expense of the imaging speed. Recent introduction of dual-beam scan method either using polarization encoding or two identical imaging systems in spectral-domain (SD) OCT scheme shows potential for high-sensitivity vasculature imaging without suffering from spurious phase noise caused by the beam scanning-induced spatial decorrelation. In this paper, we present multi-functional angiographic optical frequency domain imaging (OFDI) using frequency-multiplexed dual-beam illumination. This frequency multiplexing scheme, utilizing unique features of OFDI, provides spatially separated dual imaging beams occupying distinct electrical frequency bands that can be demultiplexed in the frequency domain processing. We demonstrate the 3D multi-functional imaging of the normal mouse skin in the dorsal skin fold chamber visualizing distinct layer structures from the intensity imaging, information about mechanical integrity from the polarization-sensitive imaging, and depth-resolved microvasculature from the angiographic imaging that are simultaneously acquired and automatically co-registered. PMID:25968731

  4. Use of two-step grafting to fabricate dual-functional films and site-specific functionalized scaffolds.

    PubMed

    Luk, Jing Zhong; Cork, Jorja; Cooper-White, Justin; Grøndahl, Lisbeth

    2015-02-10

    Polycaprolactone (PCL) is a widely utilized bioresorbable polymer in tissue engineering applications. However, the absence of intrinsic functional groups in the polymer backbone necessitates the incorporation of functional chemistries to enable the further addition of bioactive molecules to PCL-based surfaces and scaffolds. The current study aimed to incorporate two different functional groups, amine and carboxylate, first on two-dimensional (2D) spin-coated PCL films and, thereafter, throughout all surfaces within three-dimensional (3D) porous PCL-based scaffolds, produced using the thermally induced phase separation (TIPS) method, but in a spatially separated manner. Specifically, gamma irradiation induced grafting of acrylic acid (AA) and 2-aminoethyl methacrylate hydrochloride (AEMA) onto PCL was performed in selected solvents and the resulting substrates were characterized using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurements to determine the surface free energy. Results demonstrated that stepwise graft copolymerization of AEMA and AA allows the fabrication of dual-functional surfaces, with chemistry depending on the order of grafting of the two monomers. In addition, 3D scaffolds could be decorated exclusively with carboxylate groups in the interior, while the outer surface displayed dual-functionality. This simple surface modification methodology, with the ability to create spatially separated surface functional groups throughout 3D porous scaffolds post their fabrication, has the potential to be applied to many current and future scaffold systems being investigated in the field of tissue engineering. PMID:25598325

  5. Dual-transmitter neurons: Functional implications of co-release and co-transmission

    PubMed Central

    Vaaga, Christopher E; Borisovska, Maria; Westbrook, Gary L

    2014-01-01

    Co-transmission, the ability of a neuron to release multiple transmitters, has long been recognized in selected circuits. However, the release of multiple primary neurotransmitters from a single neuron is only beginning to be appreciated. Here we consider recent examples of co-transmission as well as co-release – the packaging of multiple neurotransmitters into a single vesicle. The properties associated with each mode of release greatly enhance the possible action of such neurons within circuits. The functional importance of dual- (or multi-) transmitter neurons extends beyond actions on postsynaptic receptors, due in part to differential spatial and temporal profiles of each neurotransmitter. Recent evidence also suggests that the dual-transmitter phenotype can be dynamically regulated during development and following injury or disease. PMID:24816154

  6. Dual Functional Peptide-Driven Nanoparticles for Highly Efficient Glioma-Targeting and Drug Codelivery.

    PubMed

    Kuang, Yuyang; Jiang, Xutao; Zhang, Yu; Lu, Yifei; Ma, Haojun; Guo, Yubo; Zhang, Yujie; An, Sai; Li, Jianfeng; Liu, Lisha; Wu, Yinhao; Liang, Jianying; Jiang, Chen

    2016-05-01

    Compared with peripheral tumors, glioma is very difficult to treat, not only because it has general features of tumor but also because the therapy has been restricted by the brain-blood barrier (BBB). The two main features of tumor growth are angiogenesis and proliferation of tumor cells. RNA interference (RNAi) can downregulate VEGF overexpression to inhibit tumor neovascularization. Meanwhile, doxorubicin (DOX) has been used for cytotoxic chemotherapy to kill tumor cells. Thus, combining RNAi and chemotherapy has been regarded as a potential strategy for cancer treatment. However, the BBB limits the shVEGF-DOX codelivery system to direct into glioma. Here, a smart drug delivery system modified with a dual functional peptide was established, which could target to transferrin receptor (TfR) overexpressing on both the BBB and glioma. It showed that the dual-targeting delivery system had high tumor targeting efficiency in vitro and in vivo. PMID:27058780

  7. Accessing Elaborated 2,1-Borazaronaphthalene Cores Using Photoredox/Nickel Dual-Catalytic Functionalization.

    PubMed

    Jouffroy, Matthieu; Davies, Geraint H M; Molander, Gary A

    2016-04-01

    A highly effective method for derivatizing 2,1-borazaronaphthalene cores using ammonium alkylbis(catecholato)silicates via photoredox/nickel dual catalysis is reported. By forging Csp(3)-Csp(2) bonds via this approach, alkyl fragments with various functional groups can be introduced to the azaborine core, affording previously inaccessible heterocyclic isosteres in good to excellent yields. The base-free, room-temperature conditions outlined allow sensitive functional group tolerance, even permitting the cross-coupling of unprotected primary and secondary amines. PMID:26986819

  8. The Theory of Propellers I : Determination of the Circulation Function and the Mass Coefficient for Dual-Rotating Propellers

    NASA Technical Reports Server (NTRS)

    Theodorsen, Theodore

    1944-01-01

    Values of the circulation function have been obtained for dual-rotating propellers. Numerical values are given for four, eight, and twelve-blade dual-rotating propellers and for advance ratios from 2 to about 6. In addition, the circulation function has been determine for single-rotating propellers for the higher values of the advance ratio. The mass coefficient, another quantity of significance in propeller theory, has been introduced.

  9. Evaluation of sperm mitochondrial function using rh123/PI dual fluorescent staining in asthenospermia and oligoasthenozoospermia☆

    PubMed Central

    Zou, Tiejun; Liu, Xiang; Ding, Shangshu; Xing, Junping

    2010-01-01

    Objective The recent advent of flow cytometry (FCM), coupled with fluorescent dyes, has been successfully applied to assess mitochondrial function. The aim of this study was to investigate the feasibility and clinical significance of detecting sperm mitochondrial function and to evaluate sperm mitochondrial function by using Rhodamine 123/propidium (Rh123/PI) dual fluorescent staining and FCM in asthenospermia and oligoasthenozoospermia. Methods Twenty-five fertile men (with normal sperm parameters) and 230 infertile patients were examined. Fifty-five patients of the above 230 patients were selected for idiopathic infertility samples and were divided into two groups: asthenospermia (n = 30) and oligoasthenozoospermia (n = 25). Rh123/PI dual fluorescent staining and FCM were carried out to examine sperm mitochondrial function. Results Significant differences were found between the normal and abnormal semen samples (P < 0.05) when Rh123+/PI−, Rh123−/PI+ and Rh123−/PI− sperm were examined by FCM, but there was no significant difference between the asthenospermia (P = 0.469) and oligoasthenozoospermia group (P = 0.950) when Rh123+/PI− and Rh123−/PI+ sperm were then examined; however, a significant difference was found between the 2 groups (P = 0.003) when Rh123−/PI− sperm were examined. There was no correlation between Rh123−/PI− sperm and semen parameters in the normal group, but there was a significant negative correlation between the sperm concentration and Rh123−/PI− sperm in asthenospermia and oligoasthenozoospermia patients (r = -0.509, -0.660; P = 0.018, 0.038). Conclusion Rh123/PI dual fluorescent staining and FCM can provide reliable information to assess the quality of sperm and reveal differences in mitochondrial membrane potential in asthenospermia and oligoasthenozoospermia. PMID:23554656

  10. Double-Chambered Ferritin Platform: Dual-Function Payloads of Cytotoxic Peptides and Fluorescent Protein.

    PubMed

    Kim, Soyoun; Kim, Gwang Seob; Seo, Junyoung; Gowri Rangaswamy, Gunassekaran; So, In-Seop; Park, Rang-Woon; Lee, Byung-Heon; Kim, In-San

    2016-01-11

    Ferritin cage nanoparticles are promising platforms for targeted delivery of imaging and therapeutic agents. One of the main advantages of cage nanoparticles is the ability to display multiple functionalities through genetic modification so as to achieve desired therapeutic or diagnostic functions. Ferritin complexes formed from short ferritin (sFt) lacking the fifth helix can accommodate dual peptide and protein functionalities on N- and C-terminal sites in sFt monomers. The resulting double-chambered NanoCage (DCNC) offers the potential of dual activities; these activities are augmented by the avidity of the ligands, which do not impede each other's function. Here we demonstrated proof-of-concept of DCNCs, loading the tumor-targeting proapoptotic peptide CGKRK(KLAKLAK)2 onto the N-terminal chamber and green fluorescent protein (GFP) onto the C-terminal chamber. The resulting KLAK-sFt-GFP DCNCs were internalized into the human breast adenocarcinoma cell line MDA-MB-231 and induced apoptosis. These findings suggest that DCNCs containing various combinations of peptides and proteins could be applied as therapeutics in different diseases. PMID:26646195

  11. Dual functions of a melanin-based ornament in the common yellowthroat

    PubMed Central

    Tarof, Scott A; Dunn, Peter O; Whittingham, Linda A

    2005-01-01

    Melanin-based ornaments often function as signals in male–male competition, whereas carotenoid-based ornaments appear to be important in female mate choice. This difference in function is thought to occur because carotenoid pigments are more costly to produce than melanins and are thus more reliable indicators of male quality. We examined the role of melanin- and carotenoid-based ornaments in male–male competition and female choice in the common yellowthroat Geothlypis trichas, a sexually dichromatic passerine. Males display a black facial mask produced by melanin pigmentation and a bright yellow bib (throat, breast and belly) produced by carotenoid pigmentation. In controlled aviary experiments, mask size was the best predictor of both male–male competition and female mate choice, and, therefore, mask size may be regarded as an ornament of dual function. These dual functions may help to maintain the reliability of mask size as an indicator of male quality, despite the potentially low cost of production. The size of the bib was unrelated to male–male competition or female choice, but there was a tendency for females to prefer males with more colourful bibs. We propose that the black mask is important in competition for territories with other males and for attracting females. Our results highlight the need for more studies of the mechanisms of sexual selection in species with ornaments composed of different pigment types. PMID:16024373

  12. An intrinsically disordered domain has a dual function coupled to compartment-dependent redox control.

    PubMed

    Banci, Lucia; Bertini, Ivano; Cefaro, Chiara; Ciofi-Baffoni, Simone; Gajda, Karolina; Felli, Isabella C; Gallo, Angelo; Pavelkova, Anna; Kallergi, Emmanouela; Andreadaki, Maria; Katrakili, Nitsa; Pozidis, Charalambos; Tokatlidis, Kostas

    2013-02-01

    The functional role of unstructured protein domains is an emerging field in the frame of intrinsically disordered proteins. The involvement of intrinsically disordered domains (IDDs) in protein targeting and biogenesis processes in mitochondria is so far not known. Here, we have characterized the structural/dynamic and functional properties of an IDD of the sulfhydryl oxidase ALR (augmenter of liver regeneration) located in the intermembrane space of mitochondria. At variance to the unfolded-to-folded structural transition of several intrinsically disordered proteins, neither substrate recognition events nor redox switch of its shuttle cysteine pair is linked to any such structural change. However, this unstructured domain performs a dual function in two cellular compartments: it acts (i) as a mitochondrial targeting signal in the cytosol and (ii) as a crucial recognition site in the disulfide relay system of intermembrane space. This domain provides an exciting new paradigm for IDDs ensuring two distinct functions that are linked to intracellular organelle targeting. PMID:23207295

  13. A novel method to measure the ambient aerosol phase function based on dual ccd-camera

    NASA Astrophysics Data System (ADS)

    Bian, Yuxuan; Zhao, Chunsheng; Tao, Jiangchuan; Kuang, Ye; Zhao, Gang

    2016-04-01

    Aerosol scattering phase function is a measure of the light intensity scattered from particles as a function of scattering angles. It's important for understanding the aerosol climate effects and remote sensing inversion analysis. In this study, a novel method to measure the ambient aerosol phase function is developed based on a dual charge-coupled device(ccd) camera laser detective system. An integrating nephelometer is used to correct the inversion result. The instrument was validated by both field and laboratory measurements of atmospheric aerosols. A Mie theory model was used with the measurements of particle number size distribution and mass concentration of black carbon to simulate the aerosol phase function for comparison with the values from the instrument. The comparison shows a great consistency.

  14. The effects on dynamic balance of dual-tasking using smartphone functions.

    PubMed

    Hyong, In Hyouk

    2015-02-01

    [Purpose] This study aimed to compare dynamic balance with respect to completing a single task while not using smartrphone function and completing two task while using different smartphone functions, therby preventing falls or injuries resulting from completion of dual tasks. [Subjects and Methods] The subjects of this study were 36 healthy males and females. The experiment was conducted for five situations: a Star Excursion Balance Test (SEBT) was performed (1) during single-tasking without a smartphone and during dual-tasking with a smartphone, (2) when listening to music using a smartphone, (3) when sending message using a smartphone, (4) when surfing the web using a smartphone, and (5) when playing a game using a smartphone. The condition were the same for all five experimentes. Random selection was done to prevent learing. All experiments were conducted three times, and the averaged values were used for analysis. The SEBT was performed in three directions: anterior, posterolateral, and posterormedial. In consideration the differences in leg length of the subjects, their actual leg length were measured to be used as percentages. Their leg length was measured from the anterior superior iliac spine of the femur to the medial malleolus. [Results] Compared with single task not done using a smartphone, dynamic balance statistically significantly changed for dual tasks done using a smartphone in all three directions. Dynamic balance decreased in all three directions when playing games, sending messages, web surfing, and listening to music. [Conclusion] Completing two tasks using a smartphone reduced cognitive ability, decreasing dynamic balance. Therefore, performing a single task rather than using the diverse functions of a smartphone while walking or working is considered a factor that can prevent falls and injuries. PMID:25729208

  15. The effects on dynamic balance of dual-tasking using smartphone functions

    PubMed Central

    Hyong, In Hyouk

    2015-01-01

    [Purpose] This study aimed to compare dynamic balance with respect to completing a single task while not using smartrphone function and completing two task while using different smartphone functions, therby preventing falls or injuries resulting from completion of dual tasks. [Subjects and Methods] The subjects of this study were 36 healthy males and females. The experiment was conducted for five situations: a Star Excursion Balance Test (SEBT) was performed (1) during single-tasking without a smartphone and during dual-tasking with a smartphone, (2) when listening to music using a smartphone, (3) when sending message using a smartphone, (4) when surfing the web using a smartphone, and (5) when playing a game using a smartphone. The condition were the same for all five experimentes. Random selection was done to prevent learing. All experiments were conducted three times, and the averaged values were used for analysis. The SEBT was performed in three directions: anterior, posterolateral, and posterormedial. In consideration the differences in leg length of the subjects, their actual leg length were measured to be used as percentages. Their leg length was measured from the anterior superior iliac spine of the femur to the medial malleolus. [Results] Compared with single task not done using a smartphone, dynamic balance statistically significantly changed for dual tasks done using a smartphone in all three directions. Dynamic balance decreased in all three directions when playing games, sending messages, web surfing, and listening to music. [Conclusion] Completing two tasks using a smartphone reduced cognitive ability, decreasing dynamic balance. Therefore, performing a single task rather than using the diverse functions of a smartphone while walking or working is considered a factor that can prevent falls and injuries. PMID:25729208

  16. High-sensitivity high-resolution dual-function signal and time digitizer

    NASA Astrophysics Data System (ADS)

    Sarwana, Saad; Gupta, Deepnarayan; Kirichenko, Alex F.; Oku, Takayuki; Otani, Chiko; Sato, Hiromi; Shimizu, Hirohiko M.

    2002-03-01

    We have developed a dual-function high sensitivity/high-resolution digitizer. It consists of a superconducting digital integrated circuit, which can operate both as a time-to-digital converter (TDC) and a flux counting analog-to-digital converter (ADC). The TDC has a 30 ps multihit time resolution. The ADC has been designed with a superconducting quantum interference device based detector for a 1 μA full scale range. This digitizer is extremely useful in many applications, e.g., for time-of-flight measurements, or as a radiation resistant, low-noise, low-power ADC for detector readout.

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

    SciTech Connect

    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.

  18. Electrostatic performance improvement of dual material cylindrical gate MOSFET using work-function modulation technique

    NASA Astrophysics Data System (ADS)

    Jena, Biswajit; Dash, Sidhartha; Mishra, Guru Prasad

    2016-09-01

    In a continuous effort to increase the DC and RF figure-of-merits (FOMs), multigate MOSFETs have evolved from classical planar device into a gate all around structure. The unique design with accuracy in device performance has made it a cutting edge device to overcome the scaling and performance barrier of the present VLSI technology. The fabrication process of a surface channel device with proper threshold voltage (Vth) directly depends upon the work-function of the gate electrode. By keeping it in mind, a metal gate with linearly modulated work-function (5-4.2 ev) along the z-axis in a cylindrical surrounding gate MOSFET is introduced. This work demonstrates the potential benefits of work-function modulation based dual material cylindrical gate MOSFET (WMDMCG) in terms of DC performance characteristics. The present model provides improved DC performance as compared to conventional dual material cylindrical surrounding gate MOSFET (DMCG) and the results obtained are validated with TCAD device simulator from Synopsys.

  19. Development of a chemical kinetic measurement apparatus and the determination of the reaction rate constants for lithium-lead/water interaction. Technical status progress report, October 1, 1991--March 15, 1993

    SciTech Connect

    Biney, P.O.

    1993-04-01

    An experimental set-up for accurate measurement of hydrogen generation rate in Lithium-Lead (Li{sub 17}Pb{sub 83}) Steam or water interactions has been designed. The most important features of the design include a pneumatic actuated quick opening and closing high temperature all stainless steel valve used to control the reaction time and the placement of most measuring devices below a water line to minimize leakage of the hydrogen collected. A PC based data acquisition and control system provides remote process sequencing, acquisition and control of all major components of the set-up. Initial tests indicate that the first design objective of maintaining leakproof gas collection chamber has been achieved. Initial pressure tests indicated that the pressure drop over a time span of 30 minutes was within the tolerance of the pressure transducer used to measure the pressure (within 0.690 kPa) at a nominal system pressure of 685 kPa. The experimental system hardware, data acquisition and control programs and data analysis program have been completed, tested and are currently functional.

  20. Dual functional sensing mechanism in SnO₂-ZnO core-shell nanowires.

    PubMed

    Choi, Sun-Woo; Katoch, Akash; Sun, Gun-Joo; Kim, Jae-Hun; Kim, Soo-Hyun; Kim, Sang Sub

    2014-06-11

    We report a dual functional sensing mechanism for ultrasensitive chemoresistive sensors based on SnO2-ZnO core-shell nanowires (C-S NWs) for detection of trace amounts of reducing gases. C-S NWs were synthesized by a two-step process, in which core SnO2 nanowires were first prepared by vapor-liquid-solid growth and ZnO shell layers were subsequently deposited by atomic layer deposition. The radial modulation of the electron-depleted shell layer was accomplished by controlling its thickness. The sensing capabilities of C-S NWs were investigated in terms of CO, which is a typical reducing gas. At an optimized shell thickness, C-S NWs showed the best CO sensing ability, which was quite superior to that of pure SnO2 nanowires without a shell. The dual functional sensing mechanism is proposed as the sensing mechanism in these nanowires and is based on the combination of the radial modulation effect of the electron-depleted shell and the electric field smearing effect. PMID:24836937

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

    PubMed

    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. PMID:22591780

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

    PubMed

    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

  3. Upper-Extremity Dual-Task Function: An Innovative Method to Assess Cognitive Impairment in Older Adults

    PubMed Central

    Toosizadeh, Nima; Najafi, Bijan; Reiman, Eric M.; Mager, Reine M.; Veldhuizen, Jaimeson K.; O’Connor, Kathy; Zamrini, Edward; Mohler, Jane

    2016-01-01

    Background: Difficulties in orchestrating simultaneous tasks (i.e., dual-tasking) have been associated with cognitive impairments in older adults. Gait tests have been commonly used as the motor task component for dual-task assessments; however, many older adults have mobility impairments or there is a lack of space in busy clinical settings. We assessed an upper-extremity function (UEF) test as an alternative motor task to study the dual-task motor performance in older adults. Methods: Older adults (≥65 years) were recruited, and cognitive ability was measured using the Montreal cognitive assessment (MoCA). Participants performed repetitive elbow flexion with their maximum pace, once single-task, and once while counting backward by one (dual-task). Single- and dual-task gait tests were also performed with normal speed. Three-dimensional kinematics was measured both from upper-extremity and lower-extremity using wearable sensors to determine UEF and gait parameters. Parameters were compared between the cognitively impaired and healthy groups using analysis of variance tests, while controlling for age, gender, and body mass index (BMI). Correlations between UEF and gait parameters for dual-task and dual-task cost were assessed using linear regression models. Results: Sixty-seven older adults were recruited (age = 83 ± 10 years). Based on MoCA, 10 (15%) were cognitively impaired. While no significant differences were observed in the single-task condition, within the dual-task condition, the cognitively impaired group showed significantly less arm flexion speed (62%, d = 1.51, p = 0.02) and range of motion (27%, d = 0.93, p = 0.04), and higher speed variability (88%, d = 1.82, p < 0.0001) compared to the cognitively intact group, when adjusted with age, gender, and BMI. Significant correlations were observed between UEF speed parameters and gait stride velocity for dual-task condition (r = 0.55, p < 0.0001) and dual-task cost (r = 0.28, p = 0.03). Conclusion: We

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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 sp3 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 sp3 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.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 sp3 carbon) in the PL of oxygenated GQDs are elucidated in detail. In particular, we found

  5. AMDE-1 Is a Dual Function Chemical for Autophagy Activation and Inhibition

    PubMed Central

    Li, Min; Yang, Zuolong; Vollmer, Laura L.; Gao, Ying; Fu, Yuanyuan; Liu, Cui; Chen, Xiaoyun; Liu, Peiqing; Vogt, Andreas; Yin, Xiao-Ming

    2015-01-01

    Autophagy is the process by which cytosolic components and organelles are delivered to the lysosome for degradation. Autophagy plays important roles in cellular homeostasis and disease pathogenesis. Small chemical molecules that can modulate autophagy activity may have pharmacological value for treating diseases. Using a GFP-LC3-based high content screening assay we identified a novel chemical that is able to modulate autophagy at both initiation and degradation levels. This molecule, termed as Autophagy Modulator with Dual Effect-1 (AMDE-1), triggered autophagy in an Atg5-dependent manner, recruiting Atg16 to the pre-autophagosomal site and causing LC3 lipidation. AMDE-1 induced autophagy through the activation of AMPK, which inactivated mTORC1 and activated ULK1. AMDE-1did not affect MAP kinase, JNK or oxidative stress signaling for autophagy induction. Surprisingly, treatment with AMDE-1 resulted in impairment in autophagic flux and inhibition of long-lived protein degradation. This inhibition was correlated with a reduction in lysosomal degradation capacity but not with autophagosome-lysosome fusion. Further analysis indicated that AMDE-1 caused a reduction in lysosome acidity and lysosomal proteolytic activity, suggesting that it suppressed general lysosome function. AMDE-1 thus also impaired endocytosis-mediated EGF receptor degradation. The dual effects of AMDE-1 on autophagy induction and lysosomal degradation suggested that its net effect would likely lead to autophagic stress and lysosome dysfunction, and therefore cell death. Indeed, AMDE-1 triggered necroptosis and was preferentially cytotoxic to cancer cells. In conclusion, this study identified a new class of autophagy modulators with dual effects, which can be explored for potential uses in cancer therapy. PMID:25894744

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

    PubMed

    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. PMID:25289704

  7. Pristine graphdiyne-hybridized photocatalysts using graphene oxide as a dual-functional coupling reagent.

    PubMed

    Zhang, Xiao; Zhu, Mingshan; Chen, Penglei; Li, Yongjun; Liu, Huibiao; Li, Yuliang; Liu, Minghua

    2015-01-14

    Advanced functional hybrids based on carbon materials (CMs) represent one of the main achievements of scientific communities. To achieve the hybridization, pristine CMs have to be chemically modified, or surfactants, which are nonfunctional for the performances of the hybrids, have to be employed as a cross-linkage. The construction of pristine CM-based hybrids using dual-functional coupling reagents, which work not only as a glue for hybridization but also as a functional component for enhanced performance, is strongly desired. Here, we report that pristine graphdiyne (GD), a recently synthesized new carbon allotrope, can be facilely hybridized with Ag/AgBr using graphene oxide (GO) as a cross-linkage. We demonstrate that compared to Ag/AgBr, Ag/AgBr/GO, and Ag/AgBr/GD, our Ag/AgBr/GO/GD exhibits an enhanced photocatalytic performance toward the degradation of methyl orange (MO) pollutant under visible light irradiation. In our Ag/AgBr/GO/GD, GO serves not only as a glue for a successful hybridization, but also as a functional component for enhanced catalytic performance. Beyond GD, our work likely paves a new avenue for the fabrication of advanced functional hybrids based on pristine carbon allotropes, wherein desired functions or properties might be achieved by choosing desired CMs and desired hybridized components. PMID:25418916

  8. Establishing dual electrogenerated chemiluminescence and multicolor electrochromism in functional ionic transition-metal complexes.

    PubMed

    Puodziukynaite, Egle; Oberst, Justin L; Dyer, Aubrey L; Reynolds, John R

    2012-01-18

    A combination of electrochromism and electroluminescence in functional materials could lead to single-layer dual electrochromic/electroluminescent (EC/EL) display devices, capable of simultaneous operation in emissive and reflective modes. Whereas such next generation displays could provide optimal visibility in any ambient lighting situation, materials available that exhibit such characteristics in the active layer are limited due to the required intrinsic multifunctionality (i.e., redox activity, electroluminescence, electrochromism, and ion conductivity) and to date can only be achieved via the rational design of ionic transition-metal complexes. Reported herein is the synthesis and characterization of a new family of acrylate-containing ruthenium (tris)bipyridine-based coordination complexes with multifunctional characteristics. Potential use of the presented compounds in EC/EL devices is established, as they are applied as cross-linked electrochromic films and electrochemiluminescent layers in light-emitting electrochemical cell devices. Electrochromic switching of the polymeric networks between yellow, orange, green, brown and transmissive states is demonstrated, and electrochemiluminescent devices based on the complexes synthesized show red-orange to deep red emission with λ(max) ranging from 680 to 722 nm and luminance up to 135 cd/m(2). Additionally, a dual EC/EL device prototype is presented where light emission and multicolor electrochromism occur from the same pixel comprised of a single active layer, demonstrating a true combination of these properties in ionic transition-metal complexes. PMID:22239285

  9. Establishing Dual Electrogenerated Chemiluminescence and Multicolor Electrochromism in Functional Ionic Transition-Metal Complexes

    SciTech Connect

    Puodziukynaite, Egle; Oberst, Justin L.; Dyer, Aubrey L.; Reynolds, John R.

    2011-12-29

    A combination of electrochromism and electroluminescence in functional materials could lead to single-layer dual electrochromic/electroluminescent (EC/EL) display devices, capable of simultaneous operation in emissive and reflective modes. Whereas such next generation displays could provide optimal visibility in any ambient lighting situation, materials available that exhibit such characteristics in the active layer are limited due to the required intrinsic multifunctionality (i.e., redox activity, electroluminescence, electrochromism, and ion conductivity) and to date can only be achieved via the rational design of ionic transition-metal complexes. Reported herein is the synthesis and characterization of a new family of acrylate-containing ruthenium (tris)bipyridine-based coordination complexes with multifunctional characteristics. Potential use of the presented compounds in EC/EL devices is established, as they are applied as cross-linked electrochromic films and electrochemiluminescent layers in light-emitting electrochemical cell devices. Electrochromic switching of the polymeric networks between yellow, orange, green, brown and transmissive states is demonstrated, and electrochemiluminescent devices based on the complexes synthesized show red-orange to deep red emission with λmax ranging from 680 to 722 nm and luminance up to 135 cd/m². Additionally, a dual EC/EL device prototype is presented where light emission and multicolor electrochromism occur from the same pixel comprised of a single active layer, demonstrating a true combination of these properties in ionic transition-metal complexes.

  10. Establishing Dual Electrogenerated Chemiluminescence and Multi-Color Electrochromism in Functional Ionic Transition Metal Complexes

    SciTech Connect

    Puodziukynaite, Egle; Oberst, Justin L.; Dyer, Aubrey L.; Reynolds, John R.

    2012-01-18

    A combination of electrochromism and electroluminescence in functional materials could lead to single-layer dual electrochromic/electroluminescent (EC/EL) display devices, capable of simultaneous operation in emissive and reflective modes. Whereas such next generation displays could provide optimal visibility in any ambient lighting situation, materials available that exhibit such characteristics in the active layer are limited due to the required intrinsic multifunctionality (i.e., redox activity, electroluminescence, electrochromism, and ion conductivity) and to date can only be achieved via the rational design of ionic transition-metal complexes. Reported herein is the synthesis and characterization of a new family of acrylate-containing ruthenium (tris)bipyridine-based coordination complexes with multifunctional characteristics. Potential use of the presented compounds in EC/EL devices is established, as they are applied as cross-linked electrochromic films and electrochemiluminescent layers in light-emitting electrochemical cell devices. Electrochromic switching of the polymeric networks between yellow, orange, green, brown and transmissive states is demonstrated, and electrochemiluminescent devices based on the complexes synthesized show red-orange to deep red emission with λ{sub max} ranging from 680 to 722 nm and luminance up to 135 cd/m{sup 2}. Additionally, a dual EC/EL device prototype is presented where light emission and multicolor electrochromism occur from the same pixel comprised of a single active layer, demonstrating a true combination of these properties in ionic transition-metal complexes.

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

    PubMed

    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. PMID:25845332

  12. Functional outcome of Schatzker type V and VI tibial plateau fractures treated with dual plates

    PubMed Central

    Prasad, G Thiruvengita; Kumar, T Suresh; Kumar, R Krishna; Murthy, Ganapathy K; Sundaram, Nandkumar

    2013-01-01

    Background: Dual plate fixation in comminuted bicondylar tibial plateau fractures remains controversial. Open reduction and internal fixation, specifically through compromised soft tissues, has historically been associated with major wound complications. Alternate methods of treatment have been described, each with its own merits and demerits. We performed a retrospective study to evaluate the functional outcome of lateral and medial plate fixation of Schatzker type V and VI fractures through an anterolateral approach, and a medial minimally invasive approach or a posteromedial approach. Materials and Methods: We treated 46 tibial plateau fractures Schatzker type V and VI with lateral and medial plates through an anterolateral approach and a medial minimal invasive approach over an 8 years period. Six patients were lost to followup. Radiographs in two planes were taken in all cases. Immediate postoperative radiographs were assessed for quality of reduction and fixation. The functional outcome was evaluated according to the Oxford Knee Score criteria on followup. Results: Forty patients (33 men and 7 women) who completed the followup were included in the study. There were 20 Schatzker type V fractures and 20 Schatzker type VI fractures. The mean duration of followup was 4 years (range 1-8 years). All patients had a satisfactory articular reduction defined as ≤2 mm step-off or gap as assessed on followup. All patients had a good coronal and sagittal plane alignment, and articular width as assessed on supine X-rays of the knee in the anteroposterior (AP) and lateral views. The functional outcome, as assessed by the Oxford Knee Score, was excellent in 30 patients and good in 10 patients. All patients returned to their pre-injury level of activity and employment. There were no instances of deep infection. Conclusions: Dual plate fixation of severe bicondylar tibial plateau fractures is an excellent treatment option as it provides rigid fixation and allows early knee

  13. Dual-functional bio-derived nanoparticulates for apoptotic antitumor therapy.

    PubMed

    Ding, Yang; Wang, Yazhe; Opoku-Damoah, Yaw; Wang, Cheng; Shen, Lingjia; Yin, Lifang; Zhou, Jianping

    2015-12-01

    The application of bio-derived nanoparticulates has gained a remarkable degree of interest as a promising sustained-release, site-targeted and completely biodegradable delivery system for chemotherapeutics. We hereby introduce a dual-functionalized biomimetic nanovector, cell-penetrating peptide (CPP)-anchored recombinant high density lipoproteins (cp-rHDL), which affords high payload and improved targeting of gambogic acid (GA), a therapeutic agent for apoptotic antitumor therapy. GA-loaded cp-rHDL nanoparticles (cp-rHDL/GA) consisted of hydrophobic core modulating GA, apolipoprotein A-I (apo A-I) for attractive integrating and tumor-homing, and lipophilic anchored R6H4 (RRRRRRHHHH, a pH-responsive CPP) offering a pH-controlled penetrating potential. Upon stepwise incubation with apo A-I and R6H4, cp-rHDL/GA presented several merits, including desirable physicochemical properties, superior biostability, and favorable buffering capacity resulting in proton sponge effect. Synergistic intracellular mechanism for scavenger receptor class B type I (SR-BI)-mediated direct transmembrane delivery, and pH-responsive R6H4 associated endocytotic pathway with rapid endo-lysosomal escape was also observed. This tailored cp-rHDL/GA displayed remarkable cytotoxicity and apoptotic effect via triggering p53 pathway, and provided approximately 5-fold increase in IC50 compared to free GA. Moreover, this rational biomimetic therapeutic strategy attained superior tumor accumulation and significant inhibition of tumor growth in HepG2 xenograft tumor animal models without measurable adverse effect. Results of this study demonstrated that bio-derived cp-rHDL/GA presents pH-responsive penetrating potential and efficient cellular internalization. This dual-functionalization model will open an avenue for exploration of multi-functional bio-derived drug delivery, thereby rendering potential broad applications in apoptotic anticancer therapy. PMID:26344366

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

    PubMed

    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. PMID:26731007

  15. Dual role of betel leaf extract on thyroid function in male mice.

    PubMed

    Panda, S; Kar, A

    1998-12-01

    The effects of betel leaf extract (0.10, 0.40, 0.80 and 2.0 g kg-1 day-1 for 15 days) on the alterations in thyroid hormone concentrations. lipid peroxidation (LPO) and on the activities of superoxide dismutase (SOD) and catalase (CAT) were investigated in male Swiss mice. Administration of betel leaf extract exhibited a dual role, depending on the different doses. While the lowest dose decreased thyroxine (T4) and increased serum triiodothyronine (T3) concentrations, reverse effects were observed at two higher doses. Higher doses also increased LPO with a concomitant decrease in SOD and CAT activities. However, with the lowest dose most of these effects were reversed. These findings suggest that betel leaf can be both stimulatory and inhibitory to thyroid function, particularly for T3 generation and lipid peroxidation in male mice, depending on the amount consumed. PMID:9990660

  16. Regulation of Beta-Cell Function and Mass by the Dual Leucine Zipper Kinase.

    PubMed

    Oetjen, Elke

    2016-06-01

    Diabetes mellitus is one of the most rapidly increasing diseases worldwide, whereby approximately 90-95% of patients suffer from type 2 diabetes. Considering its micro- and macrovascular complications like blindness and myocardial infarction, a reliable anti-diabetic treatment is needed. Maintaining the function and the mass of the insulin producing beta-cells despite elevated levels of beta-cell-toxic prediabetic signals represents a desirable mechanism of action of anti-diabetic drugs. The dual leucine zipper kinase (DLK) inhibits the action of two transcription factors within the beta-cell, thereby interfering with insulin secretion and production and the conservation of beta-cell mass. Furthermore, DLK action is regulated by prediabetic signals. Hence, the inhibition of this kinase might protect beta-cells against beta-cell-toxic prediabetic signals and prevent the development of diabetes. DLK might thus present a novel drug target for the treatment of diabetes mellitus type 2. PMID:27100796

  17. Dual Functional Small Molecule Probes as Fluorophore and Ligand for Misfolding Proteins.

    PubMed

    Zhang, Xueli; Ran, Chongzhao

    2013-03-01

    Misfolding of a protein is a destructive process for variety of diseases that include neurodegenerative diseases such as Alzheimer's disease, Parkinson disease, Huntington disease, mad cow disease, amyotrophic lateral sclerosis (ALS), and frontal temporal dementia (FTD), and other non-CNS diseases such as diabetes, cystic fibrosis, and lysosomal storage diseases. Formation of various misfunctional large assembles of the misfolded protein is the primary consequence. To detect the formation of the aggregated species is very important for not only basic mechanism research but also very crucial for diagnosis of the diseases. In this review, we updated references related to the new development of the dual functional fluorescent small molecule probes for detecting the aggregated proteins in vitro and in vivo. PMID:24363605

  18. Dual Functional Small Molecule Probes as Fluorophore and Ligand for Misfolding Proteins

    PubMed Central

    Zhang, Xueli; Ran, Chongzhao

    2013-01-01

    Misfolding of a protein is a destructive process for variety of diseases that include neurodegenerative diseases such as Alzheimer’s disease, Parkinson disease, Huntington disease, mad cow disease, amyotrophic lateral sclerosis (ALS), and frontal temporal dementia (FTD), and other non-CNS diseases such as diabetes, cystic fibrosis, and lysosomal storage diseases. Formation of various misfunctional large assembles of the misfolded protein is the primary consequence. To detect the formation of the aggregated species is very important for not only basic mechanism research but also very crucial for diagnosis of the diseases. In this review, we updated references related to the new development of the dual functional fluorescent small molecule probes for detecting the aggregated proteins in vitro and in vivo. PMID:24363605

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

    NASA Astrophysics Data System (ADS)

    Park, Eun Ji; Yoon, Hye Soo; Kim, Dae Han; Kim, Yong Ho; Kim, Young Dok

    2014-11-01

    Thin film of polydimethylsiloxane (PDMS) was deposited on SiO2 nanoparticles by chemical vapor deposition, and SiO2 became completely hydrophobic after PDMS coating. Mixtures of TiO2 and PDMS-coated SiO2 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 TiO2 and PDMS-coated SiO2 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.

  20. Measurement of the Ion Distribution Function in a Dual Frequency Plasma Etch Tool

    NASA Astrophysics Data System (ADS)

    Gekelman, Walter; Moore, Nathaniel; Pribyl, Patrick; Kushner, Mark

    2015-09-01

    The ion energy distribution function, (IEDF) was measured in detail in an industrial etch tool. The plasma was made with an ICP source (440 kHz, 500 W) and two independently controlled bias sources. The Si wafer was placed on a ceramic electrostatic chuck with an embedded capacitor plate. The first source ran at 2.2 MHz (600 Vpp and 2500 W) with a maximum sheath potential drop of 650 V or 2000V. The second source ran at 19 MHz with Vpp of 600 V. The principal diagnostic was Laser Induced Fluorescence on Argon using 611.49 nm light from a tunable dye laser with ions responding to Doppler shifted light. Using cylindrical lens combinations the laser light was transformed into a sheet 15 cm wide and 0.5 cm thick. The beam could be transverse or parallel to the normal of the wafer. The glowing ions (at 461 nm) were photographed by a CCD camera with 400 micron resolution. The laser was phase locked to the 2.2 MHz rf and the IDDF measured as a function of radial position, height above the wafer and at 8 phases. With Vpp = 600 V the highest energy ions observed were 500 eV, 1.2 mm above the wafer. These observations as well as the angular distribution agreed well with a computer simulation. In the dual frequency case when the potential of the wafer was most negative wrt the bulk plasma the IEDF structure 0.8 mm above the wafer was well fitted by 4 Gaussians. The ion flux to the wafer was far more uniform in the dual frequency case. This research supported by the NSF and DOE.

  1. Dual transcriptional activator and repressor roles of TBX20 regulate adult cardiac structure and function

    PubMed Central

    Sakabe, Noboru J.; Aneas, Ivy; Shen, Tao; Shokri, Leila; Park, Soo-Young; Bulyk, Martha L.; Evans, Sylvia M.; Nobrega, Marcelo A.

    2012-01-01

    The ongoing requirement in adult heart for transcription factors with key roles in cardiac development is not well understood. We recently demonstrated that TBX20, a transcriptional regulator required for cardiac development, has key roles in the maintenance of functional and structural phenotypes in adult mouse heart. Conditional ablation of Tbx20 in adult cardiomyocytes leads to a rapid onset and progression of heart failure, with prominent conduction and contractility phenotypes that lead to death. Here we describe a more comprehensive molecular characterization of the functions of TBX20 in adult mouse heart. Coupling genome-wide chromatin immunoprecipitation and transcriptome analyses (RNA-Seq), we identified a subset of genes that change expression in Tbx20 adult cardiomyocyte-specific knockout hearts which are direct downstream targets of TBX20. This analysis revealed a dual role for TBX20 as both a transcriptional activator and a repressor, and that each of these functions regulates genes with very specialized and distinct molecular roles. We also show how TBX20 binds to its targets genome-wide in a context-dependent manner, using various cohorts of co-factors to either promote or repress distinct genetic programs within adult heart. Our integrative approach has uncovered several novel aspects of TBX20 and T-box protein function within adult heart. Sequencing data accession number (http://www.ncbi.nlm.nih.gov/geo): GSE30943. PMID:22328084

  2. A dual physiological character for sexual function: the role of serotonergic receptors.

    PubMed

    Motofei, Ion G

    2008-03-01

    Anatomically, sexual reflexes are mixed (somatic-autonomic) circuits, represented by emission (sympathetic centre and somatic afferents), expulsion (parasympathetic centre and somatic efferents) and erection (parasympathetic centre and somatic afferents). Physiologically, ejaculation has a dual autonomic mediation, consisting of two distinct and opposite autonomic centres (emission and expulsion), both with a positive contribution to the respective function. Experimentally, serotonin (5HT) has two distinct, opposite and positive effects on sexual function, with 5HT-(1A) agonists decreasing intravaginal ejaculatory latency and erection, and 5HT-(2C) agonists increasing both erection and ejaculatory latency. In this review I assume that 5HT modulates sexual reflexes, establishing a functional connection between the involved somatic and autonomic structures. The 5HT-(1A) receptors are assumed to make the connection between somatic pathways and sympathetic centres while the 5HT-(2C) receptors could establish the connection between somatic pathways and parasympathetic centres. Further studies will develop the cerebral sexual duality, explaining the implication of psychological factors in sexual function and the role of sexuality in psychosocial behaviour. PMID:17922864

  3. 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

    ERIC Educational Resources Information Center

    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…

  4. Dual-head lithotripsy in synchronous mode: Acute effect on renal function and morphology in the pig

    PubMed Central

    Handa, Rajash K.; McAteer, James A.; Willis, Lynn R.; Pishchalnikov, Yuri A.; Connors, Bret A.; Ying, Jun; Lingeman, James E.; Evan, Andrew P.

    2008-01-01

    Objective Lithotripters with two shock heads are now available for use in treating patients. However, little information is available by which to judge the safety of treatment with dual pulses. A study was conducted to assess the effect of dual-head lithotripsy on renal function and morphology in a pig model of shock wave (SW) injury. Methods A dual-head electrohydraulic lithotripter (Direx Duet) was used to treat the lower renal pole of anesthetized pigs with a clinical dose of SWs (2400 dual SWs; n=10) delivered in synchronous mode (i.e. both heads fired simultaneously). For comparison, pigs were treated with either 2400 SWs (n=12) or 4800 SWs (n=8) with a conventional electrohydraulic lithotripter (Dornier HM3). Results Dual SW treatment with the Duet lithotripter caused a decline in glomerular filtration rate (GFR, 4.1 ± 1.9 ml/min) with a trend for effective renal plasma flow (RPF, 31 ± 19 ml/min) to also fall. These changes in renal hemodynamics were comparable to decreases in GFR and RPF in response to treatment with 2400 SWs (4.8 ± 0.8 ml/min and 32 ± 10 ml/min, respectively) or 4800 SWs (5.4 ± 1.0 ml/min and 68 ± 14 ml/min, respectively) with the HM3 lithotripter. Linear association analysis showed that the functional response to dual-pulse SWs was less predictable than with conventional SWs. Morphological quantitation of kidney damage expressed as percentage of functional renal volume (FRV), showed that tissue injury with 2400 paired SWs with the Duet (0.96± 0.39% FRV, n=8) was comparable to injury produced by either 2400 single SWs (1.08±0.38% FRV, n=6), or 4800 single SWs (2.71±1.02% FRV, n=6) with the HM3. However, morphological damage appeared less consistent with the Duet (measurable in only 5 of 8 kidneys) than that observed with the HM3 (measurable in all 12 kidneys). Acoustic output and the timing of dual SWs in synchronous mode increased in variability as the electrodes aged, affecting the amplitude and targeting of focal pressures

  5. Functional Recurrent Mutations in the Human Mitochondrial Phylogeny: Dual Roles in Evolution and Disease

    PubMed Central

    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. PMID:23563965

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

    PubMed

    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. PMID:23563965

  7. Dual amyloid domains promote differential functioning of the chaplin proteins during Streptomyces aerial morphogenesis

    PubMed Central

    Capstick, David S.; Jomaa, Ahmad; Hanke, Chistopher; Ortega, Joaquin; Elliot, Marie A.

    2011-01-01

    The chaplin proteins are functional amyloids found in the filamentous Streptomyces bacteria. These secreted proteins are required for the aerial development of Streptomyces coelicolor, and contribute to an intricate rodlet ultrastructure that decorates the surfaces of aerial hyphae and spores. S. coelicolor encodes eight chaplin proteins. Previous studies have revealed that only three of these proteins (ChpC, ChpE, and ChpH) are necessary for promoting aerial development, and of these three, ChpH is the primary developmental determinant. Here, we show that the model chaplin, ChpH, contains two amyloidogenic domains: one in the N terminus and one in the C terminus of the mature protein. These domains have different polymerization properties as determined using fluorescence spectroscopy, secondary structure analyses, and electron microscopy. We coupled these in vitro assays with in vivo genetic studies to probe the connection between ChpH amyloidogenesis and its biological function. Using mutational analyses, we demonstrated that both N- and C-terminal amyloid domains of ChpH were required for promoting aerial hypha formation, while the N-terminal domain was dispensable for assembly of the rodlet ultrastructure. These results suggest that there is a functional differentiation of the dual amyloid domains in the chaplin proteins. PMID:21628577

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

    PubMed Central

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

    2016-01-01

    Mitochondrial Ca2+ uptake, a process crucial for bioenergetics and Ca2+ signaling, is catalyzed by the mitochondrial calcium uniporter. The uniporter is a multi-subunit Ca2+-activated Ca2+ channel, with the Ca2+ pore formed by the MCU protein and Ca2+-dependent activation mediated by MICU subunits. Recently, a mitochondrial inner membrane protein EMRE was identified as a uniporter subunit absolutely required for Ca2+ 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 Ca2+ landscape. DOI: http://dx.doi.org/10.7554/eLife.15545.001 PMID:27099988

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

    PubMed

    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. PMID:25553534

  10. Thianthrene-functionalized polynorbornenes as high-voltage materials for organic cathode-based dual-ion batteries.

    PubMed

    Speer, Martin E; Kolek, Martin; Jassoy, Jean Jacques; Heine, Jennifer; Winter, Martin; Bieker, Peter M; Esser, Birgit

    2015-10-25

    Thianthrene-functionalized polynorbornenes were investigated as high-voltage organic cathode materials for dual-ion cells. The polymers show reversible oxidation reactions in solution and as a solid in composite electrodes. Constant current investigations displayed a capacity of up to 66 mA h g(-1) at a high potential of 4.1 V vs. Li/Li(+). PMID:26235336

  11. Dual-Functional Nanoparticles for In Situ Sequential Detection and Imaging of ATP and H2 O2.

    PubMed

    Ren, Hong; Long, Zi; Cui, Mengchao; Shao, Kang; Zhou, Kaixiang; Ouyang, Jin; Na, Na

    2016-08-01

    Within a complex biological sample, the in situ sequential detection of multiple molecules without any interference is greatly desirable. Dual-functional nanoparticles are constructed, with the enzyme-based core-shell structures, for the in situ sequential detection of ATP and H2 O2 within the same biological system. PMID:27337683

  12. Selective recognition and extraction of KBr via cooperative interactions with a urea functionalized crown ether dual-host.

    PubMed

    Akhuli, Bidyut; Ghosh, Pradyut

    2015-11-28

    Selective solid-liquid extraction of KBr is demonstrated for the first time with a crown ether based pentafluorophenyl urea functionalized dual-host receptor. (1)H-NMR and ITC studies have been carried out to illustrate the effect of cooperativity towards the recognition of alkali metal salts. PMID:26417887

  13. Two new native ß-glucosidases from Clavispora NRRL Y-50464 confer its dual function as cellobiose fermenting ethanologenic yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clavispora NRRL Y-50464, a dual functional cellobiose fermenting and ethanologenic yeast strain, is a candidate biocatalyst for lower cost lignocellulose-to-ethanol production using simultaneous saccharification and fermentation. A ß-glucosidase BGL1 protein from this strain was recently reported an...

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

    ERIC Educational Resources Information Center

    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)…

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

    PubMed Central

    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. PMID:26079605

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

    PubMed

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

    2017-01-01

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

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

    PubMed

    Kuksenok, Olga; Balazs, Anna C

    2015-01-01

    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. PMID:25924823

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Dual Function of NAC072 in ABF3-Mediated ABA-Responsive Gene Regulation in Arabidopsis

    PubMed Central

    Li, Xiaoyun; Li, Xiaoling; Li, Meijuan; Yan, Youcheng; Liu, Xu; Li, Ling

    2016-01-01

    The NAM, ATAF1/2, and CUC2 (NAC) domain proteins play various roles in plant growth and stress responses. Arabidopsis NAC transcription factor NAC072 has been reported as a transcriptional activator in Abscisic acid (ABA)-responsive gene expression. However, the exact function of NAC072 in ABA signaling is still elusive. In this study, we present evidence for the interrelation between NAC072 and ABA-responsive element binding factor 3 (ABF3) that act as a positive regulator of ABA-responsive gene expression in Arabidopsis. The transcript of NAC072 is up-regulated by ABF3 in ABA response, and NAC072 protein interacts with ABF3. Enhanced ABA sensitivity occurs in nac072 mutant plants that overexpressed ABF3. However, overexpression of NAC072 weakened the ABA sensitivity in the abf3 mutant plants, but instead of recovering the ABA sensitivity of abf3. NAC072 and ABF3 cooperate to regulate RD29A expression, but are antagonistic when regulating RD29B expression. Therefore, NAC072 displays a dual function in ABF3-mediated ABA-responsive gene regulation. PMID:27486475

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

    SciTech Connect

    Kuksenok, Olga; Balazs, Anna C.

    2015-04-30

    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.

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

    DOE PAGESBeta

    Kuksenok, Olga; Balazs, Anna C.

    2015-04-30

    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)more » 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.« less

  3. Inactivation of the dual Bmp/Wnt inhibitor Sostdc1 enhances pancreatic islet function

    PubMed Central

    Henley, Kathryn D.; Gooding, Kimberly A.; Economides, Aris N.

    2012-01-01

    Current endeavors in the type 2 diabetes (T2D) field include gaining a better understanding of extracellular signaling pathways that regulate pancreatic islet function. Recent data suggest that both Bmp and Wnt pathways are operative in pancreatic islets and play a positive role in insulin secretion and glucose homeostasis. Our laboratory found the dual Bmp and Wnt antagonist Sostdc1 to be upregulated in a mouse model of islet dysmorphogenesis and nonimmune-mediated lean diabetes. Because Bmp signaling has been proposed to enhance β-cell function, we evaluated the role of Sostdc1 in adult islet function using animals in which Sostdc1 was globally deleted. While Sostdc1-null animals exhibited no pancreas development phenotype, a subset of mutants exhibited enhanced insulin secretion and improved glucose homeostasis compared with control animals after 12-wk exposure to high-fat diet. Loss of Sostdc1 in the setting of metabolic stress results in altered expression of Bmp-responsive genes in islets but did not affect expression of Wnt target genes, suggesting that Sostdc1 primarily regulates the Bmp pathway in the murine pancreas. Furthermore, our data indicate that removal of Sostdc1 enhances the downregulation of the closely related Bmp inhibitors Ctgf and Gremlin in islets after 8-wk exposure to high-fat diet. These data imply that Sostdc1 regulates expression of these inhibitors and provide a means by which Sostdc1-null animals show enhanced insulin secretion and glucose homeostasis. Our studies provide insights into Bmp pathway regulation in the endocrine pancreas and reveal new avenues for improving β-cell function under metabolic stress. PMID:22829579

  4. Dual functions of autophagy in the response of breast tumor cells to radiation

    PubMed Central

    Bristol, Molly L.; Di, Xu; Beckman, Matthew J.; Wilson, Eden N.; Henderson, Scott C.; Maiti, Aparna; Fan, Zhen; Gewirtz, David A.

    2012-01-01

    In MCF-7 breast tumor cells, ionizing radiation promoted autophagy that was cytoprotective; pharmacological or genetic interference with autophagy induced by radiation resulted in growth suppression and/or cell killing (primarily by apoptosis). The hormonally active form of vitamin D, 1,25D3, also promoted autophagy in irradiated MCF-7 cells, sensitized the cells to radiation and suppressed the proliferative recovery that occurs after radiation alone. 1,25D3 enhanced radiosensitivity and promoted autophagy in MCF-7 cells that overexpress Her-2/neu as well as in p53 mutant Hs578t breast tumor cells. In contrast, 1,25D3 failed to alter radiosensitivity or promote autophagy in the BT474 breast tumor cell line with low-level expression of the vitamin D receptor. Enhancement of MCF-7 cell sensitivity to radiation by 1,25D3 was not attenuated by a genetic block to autophagy due largely to the promotion of apoptosis via the collateral suppression of protective autophagy. However, MCF-7 cells were protected from the combination of 1,25D3 with radiation using a concentration of chloroquine that produced minimal sensitization to radiation alone. The current studies are consistent with the premise that while autophagy mediates a cytoprotective function in irradiated breast tumor cells, promotion of autophagy can also confer radiosensitivity by vitamin D (1,25D3). As both cytoprotective and cytotoxic autophagy can apparently be expressed in the same experimental system in response to radiation, this type of model could be utilized to distinguish biochemical, molecular and/or functional differences in these dual functions of autophagy. PMID:22498493

  5. Dual aptamer-functionalized silica nanoparticles for the highly sensitive detection of breast cancer.

    PubMed

    Jo, Hunho; Her, Jin; Ban, Changill

    2015-09-15

    In this study, we synthesized dual aptamer-modified silica nanoparticles that simultaneously target two types of breast cancer cells: the mucin 1 (MUC1)(+) and human epidermal growth factor receptor 2 (HER2)(+) cell lines. Dual aptamer system enables a broad diagnosis for breast cancer in comparison with the single aptamer system. The dye-doped silica nanoparticles offer great stability with respect to photobleaching and enable the accurate quantification of breast cancer cells. The morphological and spectroscopic characteristics of the designed Dual-SiNPs were demonstrated via diverse methods such as DLS, zeta potential measurements, UV-vis spectroscopy, and fluorescence spectroscopy. Negatively charged Dual-SiNPs with a homogeneous size distribution showed robust and strong fluorescence. In addition, Dual-SiNPs did not affect cell viability, implying that this probe might be readily available for use in an in vivo system. Through ratio optimization of the MUC1 and HER2 aptamers, the binding capacities of the Dual-SiNPs to both cell lines were maximized. Based on Dual-SiNPs, a highly sensitive quantification of breast cancer cells was performed, resulting in a detection limit of 1 cell/100 μL, which is significantly lower compared with those reported in other studies. Moreover, the developed detection platform displayed high selectivity for only the MUC1(+) and HER2(+) cell lines. It is expected that this valuable diagnostic probe will be a noteworthy platform for the diagnosis and prognosis of breast cancer. PMID:25897882

  6. Development of dual-function ELISA for effective antigen and antibody detection against H7 avian influenza virus

    PubMed Central

    2013-01-01

    Background Outbreaks in poultry involving influenza virus from H7 subtype have resulted in human infections, thus causing a major concern for public health, as well as for the poultry industry. Currently, no efficient rapid test is available for large-scale detection of either antigen or antibody of H7 avian influenza viruses. Results In the present study, a dual function ELISA was developed for the effective detection of antigen and antibody against H7 AIVs. The test was established based on antigen-capture-ELISA and epitope blocking ELISA. The two Mabs 62 and 98 which were exploited in the assay were identified to recognize two conformational neutralizing epitopes on H7 HA1. Both of the epitopes exist in all of the human H7 strains, including the recent H7N9 strain from China and > 96.6% of avian H7 strains. The dual ELISA was able to detect all of the five H7 antigens tested without any cross reaction to other influenza subtypes. The antigen detection limit was less than 1 HA unit of H7. For antibody detection, the sensitivity and specificity of the dual ELISA was evaluated and compared to HI and microneutralization using immunized animal sera to different H7 strains and different subtypes of AIVs. Results indicated that antibodies to H7 were readily detected in immunized animal sera by the dual ELISA whereas specimens with antibodies to other AIVs yielded negative results. Conclusions This is the first dual-function ELISA reported for either antigen or antibody detection against H7 AIVs. The assay was highly sensitive and 100% specific in both functions rendering it effective for H7 diagnosis. PMID:24083616

  7. High-throughput functional screening using a homemade dual-glow luciferase assay.

    PubMed

    Baker, Jessica M; Boyce, Frederick M

    2014-01-01

    We present a rapid and inexpensive high-throughput screening protocol to identify transcriptional regulators of alpha-synuclein, a gene associated with Parkinson's disease. 293T cells are transiently transfected with plasmids from an arrayed ORF expression library, together with luciferase reporter plasmids, in a one-gene-per-well microplate format. Firefly luciferase activity is assayed after 48 hr to determine the effects of each library gene upon alpha-synuclein transcription, normalized to expression from an internal control construct (a hCMV promoter directing Renilla luciferase). This protocol is facilitated by a bench-top robot enclosed in a biosafety cabinet, which performs aseptic liquid handling in 96-well format. Our automated transfection protocol is readily adaptable to high-throughput lentiviral library production or other functional screening protocols requiring triple-transfections of large numbers of unique library plasmids in conjunction with a common set of helper plasmids. We also present an inexpensive and validated alternative to commercially-available, dual luciferase reagents which employs PTC124, EDTA, and pyrophosphate to suppress firefly luciferase activity prior to measurement of Renilla luciferase. Using these methods, we screened 7,670 human genes and identified 68 regulators of alpha-synuclein. This protocol is easily modifiable to target other genes of interest. PMID:24962249

  8. High-throughput Functional Screening using a Homemade Dual-glow Luciferase Assay

    PubMed Central

    Baker, Jessica M.; Boyce, Frederick M.

    2014-01-01

    We present a rapid and inexpensive high-throughput screening protocol to identify transcriptional regulators of alpha-synuclein, a gene associated with Parkinson's disease. 293T cells are transiently transfected with plasmids from an arrayed ORF expression library, together with luciferase reporter plasmids, in a one-gene-per-well microplate format. Firefly luciferase activity is assayed after 48 hr to determine the effects of each library gene upon alpha-synuclein transcription, normalized to expression from an internal control construct (a hCMV promoter directing Renilla luciferase). This protocol is facilitated by a bench-top robot enclosed in a biosafety cabinet, which performs aseptic liquid handling in 96-well format. Our automated transfection protocol is readily adaptable to high-throughput lentiviral library production or other functional screening protocols requiring triple-transfections of large numbers of unique library plasmids in conjunction with a common set of helper plasmids. We also present an inexpensive and validated alternative to commercially-available, dual luciferase reagents which employs PTC124, EDTA, and pyrophosphate to suppress firefly luciferase activity prior to measurement of Renilla luciferase. Using these methods, we screened 7,670 human genes and identified 68 regulators of alpha-synuclein. This protocol is easily modifiable to target other genes of interest. PMID:24962249

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

    PubMed

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

    2016-02-23

    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. PMID:26753184

  10. Transferrin and cell-penetrating peptide dual-functioned liposome for targeted drug delivery to glioma

    PubMed Central

    Zheng, Chuanyi; Ma, Chunyang; Bai, Enqi; Yang, Kun; Xu, Ruxiang

    2015-01-01

    A brain drug delivery system for glioma chemotherapy based on transferrin and cell-penetrating peptide dual-functioned liposome, Tf/TAT-lip, was made and evaluated with doxorubicin (DOX) as a model drug. TAT conjugated liposome (TAT-lip) loaded with doxorubicin (DOX) were prepared by the thin film hydration methods (lip-DOX) and then conjugated with transferrin (Tf) to yield Tf/TAT-lip-DOX which was characterized for their various physicochemical and pharmaceutical properties. Cellular uptakes were explored in both brain capillary endothelial cells (BCECs) of rats and U87 cells. The blood brain barrier model in vitro was established to evaluate the trans-endothelial ability crossing the BBB. The biodistribution of each formulation was further identified. The Tf/TAT-lip-DOX presents the best anti-proliferative activity against U87 cells. The orthotropic glioma model was established for the evaluation of anti-glioma effect. In conclusion, the experimental data in vitro and in vivo indicated that the Tf/TAT-lip was a promising brain drug delivery system due to its high delivery efficiency across the BBB. PMID:25932094

  11. Dual-Function Vaccine for Pseudomonas aeruginosa: Characterization of Chimeric Exotoxin A-Pilin Protein

    PubMed Central

    Hertle, Ralf; Mrsny, Randall; Fitzgerald, David J.

    2001-01-01

    Pseudomonas aeruginosa is the major infectious agent of concern for cystic fibrosis patients. Strategies to prevent colonization by this bacterium and/or neutralize its virulence factors are clearly needed. Here we characterize a dual-function vaccine designed to generate antibodies to reduce bacterial adherence and to neutralize the cytotoxic activity of exotoxin A. To construct the vaccine, key sequences from type IV pilin were inserted into a vector encoding a nontoxic (active-site deletion) version of exotoxin A. The chimeric protein, termed PE64Δ553pil, was expressed in Escherichia coli, refolded to a near-native conformation, and then characterized by various biochemical and immunological assays. PE64Δ553pil bound specifically to asialo-GM1, and, when injected into rabbits, produced antibodies that reduced bacterial adherence and neutralized the cell-killing activity of exotoxin A. Results support further evaluation of this chimeric protein as a vaccine to prevent Pseudomonas colonization in susceptible individuals. PMID:11598071

  12. A novel dual-functional MEMS sensor integrating both pressure and temperature units

    NASA Astrophysics Data System (ADS)

    Tao, Chen; Zhaohua, Zhang; Tianling, Ren; Gujin, Miao; Changjian, Zhou; Huiwang, Lin; Litian, Liu

    2010-07-01

    This paper proposes a novel miniature dual-functional sensor integrating both pressure and temperature sensitive units on a single chip. The device wafer of SOI is used as a pizeoresistive diaphragm which features excellent consistency in thickness. The conventional anisotropic wet etching has been abandoned, while ICP etching has been employed to etch out the reference cave to minimize the area of individual device in the way that the 57.4° slope has been eliminated. As a result, the average cost of the single chip is reduced. Two PN junctions with constant ratio of the areas of depletion regions have also been integrated on the same chip to serve as a temperature sensor, and each PN junction shows high linearity over -40 to 100 °C and low power consumption. The iron implanting process for PN junction is exactly compatible with the piezoresistor, with no additional expenditure. The pressure sensitivity is 86 mV/MPa, while temperature sensitivity is 1.43 mV/°C, both complying with the design objective.

  13. Dual-Functional Nanoparticles Targeting CXCR4 and Delivering Antiangiogenic siRNA Ameliorate Liver Fibrosis.

    PubMed

    Liu, Chun-Hung; Chan, Kun-Ming; Chiang, Tsaiyu; Liu, Jia-Yu; Chern, Guann-Gen; Hsu, Fu-Fei; Wu, Yu-Hsuan; Liu, Ya-Chi; Chen, Yunching

    2016-07-01

    The progression of liver fibrosis, an intrinsic response to chronic liver injury, is associated with hepatic hypoxia, angiogenesis, abnormal inflammation, and significant matrix deposition, leading to the development of cirrhosis and hepatocellular carcinoma (HCC). Due to the complex pathogenesis of liver fibrosis, antifibrotic drug development has faced the challenge of efficiently and specifically targeting multiple pathogenic mechanisms. Therefore, CXCR4-targeted nanoparticles (NPs) were formulated to deliver siRNAs against vascular endothelial growth factor (VEGF) into fibrotic livers to block angiogenesis during the progression of liver fibrosis. AMD3100, a CXCR4 antagonist that was incorporated into the NPs, served dual functions: it acted as a targeting moiety and suppressed the progression of fibrosis by inhibiting the proliferation and activation of hepatic stellate cells (HSCs). We demonstrated that CXCR4-targeted NPs could deliver VEGF siRNAs to fibrotic livers, decrease VEGF expression, suppress angiogenesis and normalize the distorted vessels in the fibrotic livers in the carbon tetrachloride (CCl4) induced mouse model. Moreover, blocking SDF-1α/CXCR4 by CXCR4-targeted NPs in combination with VEGF siRNA significantly prevented the progression of liver fibrosis in CCl4-treated mice. In conclusion, the multifunctional CXCR4-targeted NPs delivering VEGF siRNAs provide an effective antifibrotic therapeutic strategy. PMID:27224003

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

    PubMed

    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. PMID:23918165

  15. Dual Functionality of Myeloperoxidase in Rotenone-Exposed Brain-Resident Immune Cells

    PubMed Central

    Chang, Chi Young; Song, Mi Jeon; Jeon, Sae-Bom; Yoon, Hee Jung; Lee, Dae Kee; Kim, In-Hoo; Suk, Kyungho; Choi, Dong-Kug; Park, Eun Jung

    2011-01-01

    Rotenone exposure has emerged as an environmental risk factor for inflammation-associated neurodegenerative diseases. However, the underlying mechanisms responsible for the harmful effects of rotenone in the brain remain poorly understood. Herein, we report that myeloperoxidase (MPO) may have a potential regulatory role in rotenone-exposed brain-resident immune cells. We show that microglia, unlike neurons, do not undergo death; instead, they exhibit distinctive activated properties under rotenone-exposed conditions. Once activated by rotenone, microglia show increased production of reactive oxygen species, particularly HOCl. Notably, MPO, an HOCl-producing enzyme that is undetectable under normal conditions, is significantly increased after exposure to rotenone. MPO-exposed glial cells also display characteristics of activated cells, producing proinflammatory cytokines and increasing their phagocytic activity. Interestingly, our studies with MPO inhibitors and MPO-knockout mice reveal that MPO deficiency potentiates, rather than inhibits, the rotenone-induced activated state of glia and promotes glial cell death. Furthermore, rotenone-triggered neuronal injury was more apparent in co-cultures with glial cells from Mpo−/− mice than in those from wild-type mice. Collectively, our data provide evidence that MPO has dual functionality under rotenone-exposed conditions, playing a critical regulatory role in modulating pathological and protective events in the brain. PMID:21704008

  16. Dual RNA-seq unveils noncoding RNA functions in host-pathogen interactions.

    PubMed

    Westermann, Alexander J; Förstner, Konrad U; Amman, Fabian; Barquist, Lars; Chao, Yanjie; Schulte, Leon N; Müller, Lydia; Reinhardt, Richard; Stadler, Peter F; Vogel, Jörg

    2016-01-28

    Bacteria express many small RNAs for which the regulatory roles in pathogenesis have remained poorly understood due to a paucity of robust phenotypes in standard virulence assays. Here we use a generic 'dual RNA-seq' approach to profile RNA expression simultaneously in pathogen and host during Salmonella enterica serovar Typhimurium infection and reveal the molecular impact of bacterial riboregulators. We identify a PhoP-activated small RNA, PinT, which upon bacterial internalization temporally controls the expression of both invasion-associated effectors and virulence genes required for intracellular survival. This riboregulatory activity causes pervasive changes in coding and noncoding transcripts of the host. Interspecies correlation analysis links PinT to host cell JAK-STAT signalling, and we identify infection-specific alterations in multiple long noncoding RNAs. Our study provides a paradigm for a sensitive RNA-based analysis of intracellular bacterial pathogens and their hosts without physical separation, as well as a new discovery route for hidden functions of pathogen genes. PMID:26789254

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

    SciTech Connect

    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.

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

    PubMed

    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. PMID:26776303

  19. Development and design of dual-band, multi-function remote sensing antennas

    NASA Astrophysics Data System (ADS)

    Creticos, Justin P.

    This dissertation details the theoretical development, design, fabrication, and testing of two remote sensing antennas. The antennas operate in Ku and Ka bands and must support multiple beams, polarizations, and frequencies with a single aperture. The first antenna, developed for NASA's High-Altitude Imaging Wind and Rain Airborne Profiler, is a single, offset-fed reflector that supports dual-band beams incident at 30° and 40° off-nadir. The antenna uses two compact, dual-band feeds moved away from the reflector's focal point to meet the dual beam requirement. The radar is to be flown on the Global Hawk Uninhabited Aerial Vehicle which has a small payload bay requiring the feeds to be both rugged and compact. The second antenna, developed for Remote Sensing Solutions' Dual-Wavelength Precipitation Radar, is a dual-offset Gregorian reflector. The antenna supports a single, dual-band, beam with dual-polarization at each band. Additionally, the antenna has high polarization purity and matched half power beamwidths at Ku and Ka bands. The strict requirements of the antenna are met by precisely controlling feed radiation characteristics. The two antennas necessitated several advances in feed design. A foam sleeve is demonstrated as an effective method to reduce the beamwidth of a tapered dielectric rod antenna. The foam sleeve is an attractive design because it allows dual-band feeds where a corrugated horn is used to control radiation at lower frequencies and the sleeve corrected rod is used to control the upper band. By judiciously choosing sleeve material, independent control of the radiation pattern and phase center at each band is achieved allowing higher performance feeds. This dissertation also focuses on new developments in the backend design of feeds. Specifically, the use of tuning arms in the feed backend and double ridged waveguide to couple the signal into the feed allow more compact designs with greater bandwidth.

  20. The effects of dual-channel functional electrical stimulation on stance phase sagittal kinematics in patients with hemiparesis.

    PubMed

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

    2013-04-01

    Sixteen subjects (aged 54.2 ± 14.1 years) with hemiparesis (7.9 ± 7.1 years since diagnosis) demonstrating a foot-drop and hamstrings muscle weakness were fitted with a dual-channel functional electrical stimulation (FES) system activating the dorsiflexors and hamstrings muscles. Measurements of gait performance were collected after a conditioning period of 6 weeks, during which the subjects used the system throughout the day. Gait was assessed with and without the dual-channel FES system, as well as with peroneal stimulation alone. Outcomes included lower limb kinematics and the step length taken with the non-paretic leg. Results with the dual-channel FES indicate that in the subgroup of subjects who demonstrated reduced hip extension but no knee hyperextension (n = 9), hamstrings FES increased hip extension during terminal stance without affecting the knee. Similarly, in the subgroup of subjects who demonstrated knee hyperextension but no limitation in hip extension (n = 7), FES restrained knee hyperextension without having an impact on hip movement. Additionally, step length was increased in all subjects. The peroneal FES had a positive effect only on the ankle. The results suggest that dual-channel FES for the dorsiflexors and hamstrings muscles may affect lower limb control beyond that which can be attributed to peroneal stimulation alone. PMID:23231828

  1. Dual AAV therapy ameliorates exercise-induced muscle injury and functional ischemia in murine models of Duchenne muscular dystrophy

    PubMed Central

    Zhang, Yadong; Yue, Yongping; Li, Liang; Hakim, Chady H.; Zhang, Keqing; Thomas, Gail D.; Duan, Dongsheng

    2013-01-01

    Neuronal nitric oxide synthase (nNOS) membrane delocalization contributes to the pathogenesis of Duchenne muscular dystrophy (DMD) by promoting functional muscle ischemia and exacerbating muscle injury during exercise. We have previously shown that supra-physiological expression of nNOS-binding mini-dystrophin restores normal blood flow regulation and prevents functional ischemia in transgenic mdx mice, a DMD model. A critical next issue is whether systemic dual adeno-associated virus (AAV) gene therapy can restore nNOS-binding mini-dystrophin expression and mitigate muscle activity-related functional ischemia and injury. Here, we performed systemic gene transfer in mdx and mdx4cv mice using a pair of dual AAV vectors that expressed a 6 kb nNOS-binding mini-dystrophin gene. Vectors were packaged in tyrosine mutant AAV-9 and co-injected (5 × 1012 viral genome particles/vector/mouse) via the tail vein to 1-month-old dystrophin-null mice. Four months later, we observed 30–50% mini-dystrophin positive myofibers in limb muscles. Treatment ameliorated histopathology, increased muscle force and protected against eccentric contraction-induced injury. Importantly, dual AAV therapy successfully prevented chronic exercise-induced muscle force drop. Doppler hemodynamic assay further showed that therapy attenuated adrenergic vasoconstriction in contracting muscle. Our results suggest that partial transduction can still ameliorate nNOS delocalization-associated functional deficiency. Further evaluation of nNOS binding mini-dystrophin dual AAV vectors is warranted in dystrophic dogs and eventually in human patients. PMID:23681067

  2. A small synthetic molecule functions as a chloride-bicarbonate dual-transporter and induces chloride secretion in cells.

    PubMed

    Liu, Peng-Yun; Li, Shing-To; Shen, Fang-Fang; Ko, Wing-Hung; Yao, Xiao-Qiang; Yang, Dan

    2016-05-31

    A C2 symmetric small molecule composed of l-phenylalanine and isophthalamide was found to function as a Cl(-)/HCO3(-) dual transporter and self-assemble into chloride channels. In Ussing-chamber based short-circuit current measurements, this molecule elicited chloride-dependent short-circuit current (Isc) increase in both Calu-3 cell and CFBE41o-cell (with F508del mutant CFTR) monolayers. PMID:27188496

  3. Integrating Anatomic and Functional Dual-Mode Magnetic Resonance Imaging: Design and Applicability of a Bifunctional Contrast Agent.

    PubMed

    Ni, Dalong; Shen, Zhiwei; Zhang, Jiawen; Zhang, Chen; Wu, Renhua; Liu, Jianan; Yi, Meizhi; Wang, Jing; Yao, Zhenwei; Bu, Wenbo; Shi, Jianlin

    2016-03-22

    In recent decades, extensive attention has been paid to developing anatomic and functional imaging contrast agents that could provide a wealth of complementary bioimaging information. Among them, dual-mode nanoprobes that combine anatomic magnetic resonance imaging (MRI) with functional fluorescent imaging have been mostly used for separated imaging. However, the lack of a machine for simultaneous dual-mode imaging greatly limits further clinical application. One effective strategy is to rationally design MRI contrast agents that own both anatomic and functional MR imaging capability on a single MRI machine, which is highly attractive but remains a great challenge. Herein, ultrasmall NaGdF4@PLL nanodots (NDs) were developed as a novel class of MR contrast agent, which offers a high longitude relaxivity (6.42 mM(-1) s(-1)) for T1-weighted MRI and an excellent sensitive chemical exchange saturation transfer (CEST) effect for pH mapping (at +3.7 ppm). Further in vivo animal experiments show the feasibility of NaGdF4@PLL NDs as contrast agents for efficient kidney and brain tumor diagnosis and pH mapping, which will undoubtedly enhance the diagnosis accuracy and is beneficial for disease precaution and prognosis. Different from other complex dual-mode nanoprobes, the as-constructed NaGdF4@PLL NDs enable both anatomic and functional imaging on a single MR machine, which is a simple and cost-effective new approach to realize dual-mode MR imaging and holds great potential for future clinical application. PMID:26910513

  4. Effect of Dual-Function Nano-Structured Silicon Oxide Thin Film on Multi-Junction Solar Cells

    SciTech Connect

    Yan, B.; Sivec, L.; Yue, G.; Jiang, C. S.; Yang, J.; Guha, S.

    2011-01-01

    We present our recent study of using nano-structured hydrogenated silicon oxide films (nc-SiO{sub x}:H) as a dual-function layer in multi-junction solar cells. The nc-SiO{sub x}:H films were deposited using very high frequency glow discharge of a SiH{sub 4} (or Si{sub 2}H{sub 6}), CO{sub 2}, PH{sub 3}, and H{sub 2} gas mixture. By optimizing deposition parameters, we obtained 'dual function' nc-SiO{sub x}:H material characterized by a conductivity suitable for use as an n layer and optical properties suitable for use as an inter-reflection layer. We tested the nc-SiO{sub x}:H by replacing the normal n-type material in the tunnel junction of a multi-junction structure. The advantage of the dual-function nc-SiO{sub x}:H layer is twofold; one is to simplify the cell structure, and the other is to reduce any optical loss associated with the inter-reflection layer. Quantum efficiency measurements show the gain in top cell current is equal to or greater than the loss in bottom cell current for a-Si:H/nc-Si:H structures. In addition, a thinner a-Si:H top cell with the nc-SiO{sub x}:H n layer improves the top-cell stability, thereby providing higher stabilized solar cell efficiency. We also used the dual-function layer between the middle and the bottom cells in a-Si:H/a-SiGe:H/nc-Si:H triple-junction structures. The gain in the middle cell current is {approx}1.0 mA/cm{sup 2}, leading to an initial active-area efficiency of 14.8%.

  5. Evaluation of bishexadecyltrimethyl ammonium palladium tetrachloride based dual functional colloidal carrier as an antimicrobial and anticancer agent.

    PubMed

    Kaur, Gurpreet; Kumar, Sandeep; Dilbaghi, Neeraj; Kaur, Baljinder; Kant, Ravi; Guru, Santosh Kumar; Bhushan, Shashi; Jaglan, Sundeep

    2016-04-12

    We have developed a dual function carrier using bishexadecyltrimethyl ammonium palladium tetrachloride, which has anticancer as well as antibacterial activity, using a ligand insertion method with a simple and easy work procedure. The complex is prepared by a simple and cost effective method using hexadecyltrimethyl ammonium chloride and palladium chloride under controlled stoichiometry. Herein, we report the aggregation (self assembly) of the metallosurfactant having palladium as a counter ion, in aqueous medium along with its binding affinity with bovine serum albumin. The palladium surfactant has exhibited excellent antimicrobial efficacy against fungus and bacteria (both Gram-positive and Gram-negative bacteria). Cytotoxicity of palladium surfactant against cancerous (Human leukemia HL-60, pancreatic MIA-Pa-Ca-2 and prostate cancer PC-3) and healthy cells (fR2 human breast epithelial cells) was also evaluated using MTT assay. The present dual functional moiety shows a low IC50 value and has potential to be used as an anticancer agent. Our dual function carrier which itself possesses antimicrobial and anticancer activity represents a simple and effective system and can also be utilized as a drug carrier in the future. PMID:26961498

  6. Fibrillin-1 directly regulates osteoclast formation and function by a dual mechanism

    PubMed Central

    Tiedemann, Kerstin; Boraschi-Diaz, Iris; Rajakumar, Irina; Kaur, Jasvir; Roughley, Peter; Reinhardt, Dieter P.; Komarova, Svetlana V.

    2016-01-01

    Summary Mutations in the fibrillin-1 gene give rise to a number of heritable disorders, which are all characterized by various malformations of bone as well as manifestations in other tissues. However, the role of fibrillin-1 in the development and homeostasis of bone is not well understood. Here, we examined the role of fibrillin-1 in regulating osteoclast differentiation from primary bone-marrow-derived precursors and monocytic RAW 264.7 cells. The soluble N-terminal half of fibrillin-1 (rFBN1-N) strongly inhibited osteoclastogenesis, whereas the C-terminal half (rFBN1-C) did not. By contrast, when rFBN1-N was immobilized on calcium phosphate, it did not affect osteoclastogenesis but modulated osteoclast resorptive activity, which was evident by a larger number of smaller resorption pits. Using a panel of recombinant sub-fragments spanning rFBN1-N, we localized an osteoclast inhibitory activity to the 63 kDa subfragment rF23 comprising the N-terminal region of fibrillin-1. Osteoclastic resorption led to the generation of small fibrillin-1 fragments that were similar to those identified in human vertebral bone extracts. rF23, but not rFBN1-N, was found to inhibit the expression of cathepsin K, matrix metalloproteinase 9 and Dcstamp in differentiating osteoclasts. rFBN1-N, but not rF23, exhibited interaction with RANKL. Excess RANKL rescued the inhibition of osteoclastogenesis by rFBN1-N. By contrast, rF23 disrupted RANKL-induced Ca2+ signaling and activation of transcription factor NFATc1. These studies highlight a direct dual inhibitory role of N-terminal fibrillin-1 fragments in osteoclastogenesis, the sequestration of RANKL and the inhibition of NFATc1 signaling, demonstrating that osteoclastic degradation of fibrillin-1 provides a potent negative feedback that limits osteoclast formation and function. PMID:24039232

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

    PubMed

    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. PMID:26807824

  8. Potts model partition functions for self-dual families of strip graphs

    NASA Astrophysics Data System (ADS)

    Chang, Shu-Chiuan; Shrock, Robert

    2001-12-01

    We consider the q-state Potts model on families of self-dual strip graphs GD of the square lattice of width Ly and arbitrarily great length Lx, with periodic longitudinal boundary conditions. The general partition function Z and the T=0 antiferromagnetic special case P (chromatic polynomial) have the respective forms ∑ j=1 NF, Ly, λcF, Ly, j( λF, Ly, j) Lx, with F= Z, P. For arbitrary Ly, we determine (i) the general coefficient cF, Ly, j in terms of Chebyshev polynomials, (ii) the number nF( Ly, d) of terms with each type of coefficient, and (iii) the total number of terms NF, Ly, λ. We point out interesting connections between the nZ( Ly, d) and Temperley-Lieb algebras, and between the NF, Ly, λ and enumerations of directed lattice animals. Exact calculations of P are presented for 2⩽ Ly⩽4. In the limit of infinite length, we calculate the ground state degeneracy per site (exponent of the ground state entropy), W( q). Generalizing q from Z+ to C, we determine the continuous locus B in the complex q plane where W( q) is singular. We find the interesting result that for all Ly values considered, the maximal point at which B crosses the real q-axis, denoted qc, is the same, and is equal to the value for the infinite square lattice, qc=3. This is the first family of strip graphs of which we are aware that exhibits this type of universality of qc.

  9. Dual Functions, Clamp Opening and Primer-Template Recognition, Define a Key Clamp Loader Subunit

    PubMed Central

    Coman, Maria Magdalena; Jin, Mi; Ceapa, Razvan; Finkelstein, Jeff; O'Donnell, Michael; Chait, Brian T.; Hingorani, Manju M.

    2010-01-01

    Clamp loader proteins catalyze assembly of circular sliding clamps on DNA to enable processive DNA replication. During the reaction, the clamp loader binds primer-template DNA and positions it in the center of a clamp to form a topological link between the two. Clamp loaders are multi-protein complexes, such as the five protein Escherichia coli, Saccharomyces cerevisiae, and human clamp loaders, and the two protein Pyrococcus furiosus and Methanobacterium thermoautotrophicum clamp loaders, and thus far the site(s) responsible for binding and selecting primer-template DNA as the target for clamp assembly remain unknown. To address this issue, we analyzed the interaction between the E. coli γ complex clamp loader and DNA using UV-induced protein–DNA cross-linking and mass spectrometry. The results show that the δ subunit in the γ complex makes close contact with the primer-template junction. Tryptophan 279 in the δ C-terminal domain lies near the 3′-OH primer end and may play a key role in primer-template recognition. Previous studies have shown that δ also binds and opens the β clamp (hydrophobic residues in the N-terminal domain of δ contact β. The clamp-binding and DNA-binding sites on δ appear positioned for facile entry of primer-template into the center of the clamp and exit of the template strand from the complex. A similar analysis of the S. cerevisiae RFC complex suggests that the dual functionality observed for δ in the γ complex may be true also for clamp loaders from other organisms. PMID:15364574

  10. Dual function of partitioning-defective 3 in the regulation of YAP phosphorylation and activation

    PubMed Central

    Zhang, Peng; Wang, Shuting; Wang, Sai; Qiao, Jing; Zhang, Lei; Zhang, Zhe; Chen, Zhengjun

    2016-01-01

    Partitioning-defective 3 (Par3), a key component of the evolutionarily conserved polarity PAR complex (Par3/Par6/aPKC), controls cell polarity and contributes to cell migration, proliferation and tumor development. Emerging evidence indicates that cell polarity proteins function as upstream modulators that regulate the Hippo pathway. However, little is known about Par3’s involvement in the Hippo pathway. Here, we find Par3 and YAP dynamically co-localize in different subcellular compartments; that is, the membrane, cytoplasm and nucleus, in a cell-density-dependent manner. Interestingly, Par3 knockdown promotes YAP phosphorylation, leading to a significant impairment of YAP nuclear translocation at low cell density, but not at high density, in MDCK cells. Furthermore, via its third PDZ domain, Par3 directly binds to the PDZ-binding motif of YAP. The interaction is required for regulating YAP phosphorylation and nuclear localization. Mechanistically, Par3, as a scaffold protein, associates with LATS1 and protein phosphatase 1, α subunit (PP1A) in the cytoplasm and nucleus. Par3 promotes the dephosphorylation of LATS1 and YAP, thus enhancing YAP activation and cell proliferation. Strikingly, we also find that under the condition of PP1A knockdown, Par3 expression promotes YAP hyperphosphorylation, leading to the suppression of YAP activity and its downstream targets. Par3 expression results in differential effects on YAP phosphorylation and activation in different tumor cell lines. These findings indicate that Par3 may have a dual role in regulating the activation of the Hippo pathway, in a manner possibly dependent on cellular context or cell type in response to cell–cell contact and cell polarity signals. PMID:27462467

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2016-12-01

    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. PMID:27465600

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

    NASA Astrophysics Data System (ADS)

    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.

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

    ERIC Educational Resources Information Center

    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…

  15. Functional analysis of liverworts in dual symbiosis with Glomeromycota and Mucoromycotina fungi under a simulated Palaeozoic CO2 decline.

    PubMed

    Field, Katie J; Rimington, William R; Bidartondo, Martin I; Allinson, Kate E; Beerling, David J; Cameron, Duncan D; Duckett, Jeffrey G; Leake, Jonathan R; Pressel, Silvia

    2016-06-01

    Most land plants form mutualistic associations with arbuscular mycorrhizal fungi of the Glomeromycota, but recent studies have found that ancient plant lineages form mutualisms with Mucoromycotina fungi. Simultaneous associations with both fungal lineages have now been found in some plants, necessitating studies to understand the functional and evolutionary significance of these tripartite associations for the first time. We investigate the physiology and cytology of dual fungal symbioses in the early-diverging liverworts Allisonia and Neohodgsonia at modern and Palaeozoic-like elevated atmospheric CO2 concentrations under which they are thought to have evolved. We found enhanced carbon cost to liverworts with simultaneous Mucoromycotina and Glomeromycota associations, greater nutrient gain compared with those symbiotic with only one fungal group in previous experiments and contrasting responses to atmospheric CO2 among liverwort-fungal symbioses. In liverwort-Mucoromycotina symbioses, there is increased P-for-C and N-for-C exchange efficiency at 440 p.p.m. compared with 1500 p.p.m. CO2. In liverwort-Glomeromycota symbioses, P-for-C exchange is lower at ambient CO2 compared with elevated CO2. No characteristic cytologies of dual symbiosis were identified. We provide evidence of a distinct physiological niche for plant symbioses with Mucoromycotina fungi, giving novel insight into why dual symbioses with Mucoromycotina and Glomeromycota fungi persist to the present day. PMID:26613340

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

    PubMed

    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. PMID:24967447

  17. Dual Delivery of Hepatocyte and Vascular Endothelial Growth Factors via a Protease-Degradable Hydrogel Improves Cardiac Function in Rats

    PubMed Central

    Boopathy, Archana V.; Che, Pao-lin; Brown, Milton; García, Andrés J.; Davis, Michael E.

    2012-01-01

    Acute myocardial infarction (MI) caused by ischemia and reperfusion (IR) is the most common cause of cardiac dysfunction due to local cell death and a temporally regulated inflammatory response. Current therapeutics are limited by delivery vehicles that do not address spatial and temporal aspects of healing. The aim of this study was to engineer biotherapeutic delivery materials to harness endogenous cell repair to enhance myocardial repair and function. We have previously engineered poly(ethylene glycol) (PEG)-based hydrogels to present cell adhesive motifs and deliver VEGF to promote vascularization in vivo. In the current study, bioactive hydrogels with a protease-degradable crosslinker were loaded with hepatocyte and vascular endothelial growth factors (HGF and VEGF, respectively) and delivered to the infarcted myocardium of rats. Release of both growth factors was accelerated in the presence of collagenase due to hydrogel degradation. When delivered to the border zones following ischemia-reperfusion injury, there was no acute effect on cardiac function as measured by echocardiography. Over time there was a significant increase in angiogenesis, stem cell recruitment, and a decrease in fibrosis in the dual growth factor delivery group that was significant compared with single growth factor therapy. This led to an improvement in chronic function as measured by both invasive hemodynamics and echocardiography. These data demonstrate that dual growth factor release of HGF and VEGF from a bioactive hydrogel has the capacity to significantly improve cardiac remodeling and function following IR injury. PMID:23226440

  18. Dual Function for U2AF35 in AG-Dependent Pre-mRNA Splicing

    PubMed Central

    Guth, Sabine; Tange, Thomas O/.; Kellenberger, Esther; Valcárcel, Juan

    2001-01-01

    interaction of U2AF35 with a consensus 3′ splice site triggers events in spliceosome assembly in addition to stabilizing U2AF65 binding, thus revealing a dual function for U2AF35 in pre-mRNA splicing. PMID:11604503

  19. Off-axis point spread function reconstruction from a dual deformable mirror adaptive optics system

    NASA Astrophysics Data System (ADS)

    Keskin, O.; Conan, R.; Bradley, C.; Blain, C.

    2008-07-01

    In AO applications, PSF reconstruction is used in calibrating image analysis techniques for astrometry, and in the deconvolution of images to enhance their contrast. The partial correction provided by the AO system is due to the finite sampling of the wavefront sensor, the DM (limited number of freedoms on the DM, i.e., the number of actuators) and the finite bandwidth of the control system. Furthermore, the correction provided by an AO system degrades across the field of view, depending on the angular separation between the guide star and the target object (anisoplanatism). In this paper, an end to end numerical model of an off-axis dual DM AO system has been implemented to accommodate for the anisoplanatic errors that degrade the performance of AO systems at greater angular distances from the guide star. An improved off-axis PSF reconstruction methodology has been developed and numerically evaluated for the dual DM (Woofer/Tweeter) off-axis AO architecture.

  20. Metformin Plays a Dual Role in MIN6 Pancreatic β Cell Function through AMPK-dependent Autophagy

    PubMed Central

    Jiang, Yingling; Huang, Wei; Wang, Jing; Xu, Zhipeng; He, Jieyu; Lin, Xiaohong; Zhou, Zhiguang; Zhang, Jingjing

    2014-01-01

    Metformin improves insulin sensitivity in insulin sensitive tissues such as liver, muscle and fat. However, the functional roles and the underlying mechanism of metformin action in pancreatic β cells remain elusive. Here we show that, under normal growth condition, metformin suppresses MIN6 β cell proliferation and promotes apoptosis via an AMPK-dependent and autophagy-mediated mechanism. On the other hand, metformin protects MIN6 cells against palmitic acid (PA)-induced apoptosis. Our findings indicate that metformin plays a dual role in β cell survival and overdose of this anti-diabetic drug itself may lead to potential β cell toxicity. PMID:24644425

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

    PubMed

    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. PMID:27239986

  2. Walking in School-Aged Children in a Dual-Task Paradigm Is Related to Age But Not to Cognition, Motor Behavior, Injuries, or Psychosocial Functioning

    PubMed Central

    Hagmann-von Arx, Priska; Manicolo, Olivia; Lemola, Sakari; Grob, Alexander

    2016-01-01

    Age-dependent gait characteristics and associations with cognition, motor behavior, injuries, and psychosocial functioning were investigated in 138 typically developing children aged 6.7–13.2 years (M = 10.0 years). Gait velocity, normalized velocity, and variability were measured using the walkway system GAITRite without an additional task (single task) and while performing a motor or cognitive task (dual task). Assessment of children’s cognition included tests for intelligence and executive functions; parents reported on their child’s motor behavior, injuries, and psychosocial functioning. Gait variability (an index of gait regularity) decreased with increasing age in both single- and dual-task walking. Dual-task gait decrements were stronger when children walked in the motor compared to the cognitive dual-task condition and decreased with increasing age in both dual-task conditions. Gait alterations from single- to dual-task conditions were not related to children’s cognition, motor behavior, injuries, or psychosocial functioning. PMID:27014158

  3. A dual function of V0-ATPase a1 provides an endolysosomal degradation mechanism in Drosophila melanogaster photoreceptors

    PubMed Central

    Williamson, W. Ryan; Wang, Dong; Haberman, Adam S.

    2010-01-01

    The vesicular adenosine triphosphatase (v-ATPase) is a proton pump that acidifies intracellular compartments. In addition, mutations in components of the membrane-bound v-ATPase V0 sector cause acidification-independent defects in yeast, worm, fly, zebrafish, and mouse. In this study, we present a dual function for the neuron-specific V0 subunit a1 orthologue v100 in Drosophila melanogaster. A v100 mutant that selectively disrupts proton translocation rescues a previously characterized synaptic vesicle fusion defect and vesicle fusion with early endosomes. Correspondingly, V100 selectively interacts with syntaxins on the respective target membranes, and neither synaptic vesicles nor early endosomes require v100 for their acidification. In contrast, V100 is required for acidification once endosomes mature into degradative compartments. As a consequence of the complete loss of this neuronal degradation mechanism, photoreceptors undergo slow neurodegeneration, whereas selective rescue of the acidification-independent function accelerates cell death by increasing accumulations in degradation-incompetent compartments. We propose that V100 exerts a temporally integrated dual function that increases neuronal degradative capacity. PMID:20513768

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

    PubMed

    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. PMID:26030542

  5. Conversion of arterial input functions for dual pharmacokinetic modeling using Gd-DTPA/MRI and 18F-FDG/PET.

    PubMed

    Poulin, Eric; Lebel, Réjean; Croteau, Etienne; Blanchette, Marie; Tremblay, Luc; Lecomte, Roger; Bentourkia, M'hamed; Lepage, Martin

    2013-03-01

    Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) in MRI, into a (18)F-fluorodeoxyglucose ((18)F-FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98-Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (K(trans)), the extravascular-extracellular volume fraction (ν(e)), and the blood volume fraction (ν(p)) calculated with the Gd-DTPA AIF and the Gd-DTPA AIF converted from (18)F-FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with (18) F-FDG AIF and with (18) F-FDG AIF obtained from Gd-DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI-PET pharmacokinetic modeling in small animal models. PMID:22570280

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

    PubMed Central

    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. PMID:26284144

  7. Dual-functional Polyurea Microcapsules for Chronic Wound Care Dressings: Sustained Drug Delivery and Non-leaching Infection Control

    NASA Astrophysics Data System (ADS)

    He, Wei

    A new design of dual-functional polyurea microcapsules was proposed for chronic wound dressings to provide both non-leaching infection control and sustained topical drug delivery functionalities. Quaternary ammonium functionalized polyurea microcapsules (MCQs) were synthesized under mild conditions through an interfacial crosslinking reaction between branched polyethylenimine (PEI) and 2,4-toluene diisocyanate (TDI) in a dimethylformamide/cyclohexane emulsion. An in-situ modification method was developed to endow non-leaching surface antimicrobial properties to MCQs via bonding antimicrobial surfactants to surface isocyanate residues on the polyurea shells. The resultant robust MCQs with both non-leaching antimicrobial properties and sustained drug releasing properties have potential applications in medical textiles, such as chronic wound dressings, for infection control and drug delivery.

  8. High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

    PubMed Central

    Kang, Bong Jin; Park, Jinhyoung; Kim, Jieun; Kim, Hyung Ham; Lee, Changyang; Hwang, Jae Youn; Lien, Ching-Ling; Shung, K. Kirk

    2015-01-01

    Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s−1 with high accuracy (p-value = 0.974 > 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E/Em < 10, E/A < 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation. PMID:25505135

  9. Targeted Delivery of Anticancer Agents via a Dual Function Nanocarrier with an Interfacial Drug-Interactive Motif

    PubMed Central

    2015-01-01

    We have developed a dual-function drug carrier, polyethylene glycol (PEG)-derivatized farnesylthiosalicylate (FTS). Here we report that incorporation of a drug-interactive motif (Fmoc) into PEG5k–FTS2 led to further improvement in both drug loading capacity and formulation stability. Doxorubicin (DOX) formulated in PEG5k–Fmoc–FTS2 showed sustained release kinetics slower than those of DOX loaded in PEG5k–FTS2. The maximum tolerated dose of DOX- or paclitaxel (PTX)-loaded PEG5k–Fmoc–FTS2 was significantly higher than that of the free drug. Pharmacokinetics and biodistribution studies showed that DOX/PEG5k–Fmoc–FTS2 mixed micelles were able to retain DOX in the bloodstream for a significant amount of time and efficiently deliver the drug to tumor sites. More importantly, drug (DOX or PTX)-loaded PEG5k–Fmoc–FTS2 led to superior antitumor activity over other treatments including drugs formulated in PEG5k–FTS2 in breast cancer and prostate cancer models. Our improved dual function carrier with a built-in drug-interactive motif represents a simple and effective system for targeted delivery of anticancer agents. PMID:25325795

  10. Preparation of a silver nanoparticle-based dual-functional sensor using a complexation-reduction method.

    PubMed

    Mi, Fwu-Long; Wu, Shao-Jung; Zhong, Wen-Qi; Huang, Cheng-Yu

    2015-09-01

    A dual-functional sensor based on silver nanoparticles was synthesized by a two-stage procedure consisting of a low-temperature chitosan-Ag(+) complexation followed by a high-temperature reduction of the complex to form chitosan-capped silver nanoparticles (CS-capped Ag NPs). The surface plasmon resonance (SPR) absorption and fluorescence emission of the silver nanoparticles were influenced by the concentration and degradation time of chitosan, and the temperatures of the complexation and reduction reactions. The SPR absorption band was blue-shifted while the intensities of emission and absorption were decreased after reacting the silver nanoparticles with Hg(2+) ions. The silver nanoparticles reacted with Hg(2+) were characterized by high resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and surface-enhanced Raman scattering spectroscopy (SERS). The results suggested that the particle growth and aggregation of the silver nanoparticles were caused by the adsorption of Hg(2+) and deposition of Hg(0) on the nanoparticle surface. Direct correlations of the SPR absorption and fluorescence emission with the concentration of Hg(2+) were useful for quantitative analysis of Hg(2+). It was possible to use the dual-functional silver nanoparticles as a colorimetric and fluorescent sensor for sensitive and selective detection of Hg(2+) ions. PMID:25619929

  11. A dual-factor model of mental health: toward a more comprehensive understanding of youth functioning.

    PubMed

    Antaramian, Susan P; Scott Huebner, E; Hills, Kimberly J; Valois, Robert F

    2010-10-01

    Traditional mental health models focus on psychological problems and distress; accordingly, health is viewed as the absence of illness or disability. In contrast, a dual-factor model of mental health incorporates both indicators of positive subjective well-being (SWB) and measures of psychopathological symptoms to comprehensively determine an individual's psychological adjustment. This study used such a dual-factor model to measure the mental health status of young adolescents. A total of 764 middle school students were classified into one of four distinct groups based on having high or low psychopathology and high or low SWB. Furthermore, group differences in student engagement, academic achievement, and environmental support for learning were investigated. Results demonstrated the existence of a traditionally neglected group of adolescents (low SWB and low psychopathology) who are nonetheless at risk for academic and behavior problems in school and who performed no better than the most troubled group of adolescents. Overall, both the presence of positive well-being and the absence of symptoms were necessary for ensuring the most advantageous school performance. These results highlight the importance of incorporating positive indicators of well-being along with traditional negative factors in more fully understanding relationships between individuals' mental health and educational outcomes. PMID:20950287

  12. ``Green'' functionalization of magnetic nanoparticles via tea polyphenol for magnetic resonance/fluorescent dual-imaging

    NASA Astrophysics Data System (ADS)

    Jiang, Wen; Lai, Kuilin; Liu, Kexia; Xia, Rui; Gao, Fabao; Wu, Yao; Gu, Zhongwei

    2014-01-01

    Tea polyphenol serves as an environmentally friendly ligand-exchange molecule to synthesize multifunctional metal-doped superparamagnetic iron oxide nanoparticles via a catechol-metal coordination interaction. The resultant particles not only exhibit excellent hydrophilicity and protein adsorption resistance, but also are applicable as magnetic resonance/fluorescent dual-imaging probes due to their high T2 relaxivity, autofluorescence and large cellular uptake.Tea polyphenol serves as an environmentally friendly ligand-exchange molecule to synthesize multifunctional metal-doped superparamagnetic iron oxide nanoparticles via a catechol-metal coordination interaction. The resultant particles not only exhibit excellent hydrophilicity and protein adsorption resistance, but also are applicable as magnetic resonance/fluorescent dual-imaging probes due to their high T2 relaxivity, autofluorescence and large cellular uptake. Electronic supplementary information (ESI) available: Additional information and figures (Fig. S1-S7), including experimental sections, characterization of the products, protein corona analysis, cytotoxicity and cellular uptake quantification. See DOI: 10.1039/c3nr05003c

  13. A novel method to calibrate DOI function of a PET detector with a dual-ended-scintillator readout

    SciTech Connect

    Shao Yiping; Yao Rutao; Ma Tianyu

    2008-12-15

    The detection of depth-of-interaction (DOI) is a critical detector capability to improve the PET spatial resolution uniformity across the field-of-view and will significantly enhance, in particular, small bore system performance for brain, breast, and small animal imaging. One promising technique of DOI detection is to use dual-ended-scintillator readout that uses two photon sensors to detect scintillation light from both ends of a scintillator array and estimate DOI based on the ratio of signals (similar to Anger logic). This approach needs a careful DOI function calibration to establish accurate relationship between DOI and signal ratios, and to recalibrate if the detection condition is shifted due to the drift of sensor gain, bias variations, or degraded optical coupling, etc. However, the current calibration method that uses coincident events to locate interaction positions inside a single scintillator crystal has severe drawbacks, such as complicated setup, long and repetitive measurements, and being prone to errors from various possible misalignments among the source and detector components. This method is also not practically suitable to calibrate multiple DOI functions of a crystal array. To solve these problems, a new method has been developed that requires only a uniform flood source to irradiate a crystal array without the need to locate the interaction positions, and calculates DOI functions based solely on the uniform probability distribution of interactions over DOI positions without knowledge or assumption of detector responses. Simulation and experiment have been studied to validate the new method, and the results show that the new method, with a simple setup and one single measurement, can provide consistent and accurate DOI functions for the entire array of multiple scintillator crystals. This will enable an accurate, simple, and practical DOI function calibration for the PET detectors based on the design of dual-ended-scintillator readout. In

  14. A novel method to calibrate DOI function of a PET detector with a dual-ended-scintillator readout.

    PubMed

    Shao, Yiping; Yao, Rutao; Ma, Tianyu

    2008-12-01

    The detection of depth-of-interaction (DOI) is a critical detector capability to improve the PET spatial resolution uniformity across the field-of-view and will significantly enhance, in particular, small bore system performance for brain, breast, and small animal imaging. One promising technique of DOI detection is to use dual-ended-scintillator readout that uses two photon sensors to detect scintillation light from both ends of a scintillator array and estimate DOI based on the ratio of signals (similar to Anger logic). This approach needs a careful DOI function calibration to establish accurate relationship between DOI and signal ratios, and to recalibrate if the detection condition is shifted due to the drift of sensor gain, bias variations, or degraded optical coupling, etc. However, the current calibration method that uses coincident events to locate interaction positions inside a single scintillator crystal has severe drawbacks, such as complicated setup, long and repetitive measurements, and being prone to errors from various possible misalignments among the source and detector components. This method is also not practically suitable to calibrate multiple DOI functions of a crystal array. To solve these problems, a new method has been developed that requires only a uniform flood source to irradiate a crystal array without the need to locate the interaction positions, and calculates DOI functions based solely on the uniform probability distribution of interactions over DOI positions without knowledge or assumption of detector responses. Simulation and experiment have been studied to validate the new method, and the results show that the new method, with a simple setup and one single measurement, can provide consistent and accurate DOI functions for the entire array of multiple scintillator crystals. This will enable an accurate, simple, and practical DOI function calibration for the PET detectors based on the design of dual-ended-scintillator readout. In

  15. Dual function armchair graphene nanoribbon-based spin-photodetector: Optical spin-valve and light helicity detector

    SciTech Connect

    Ostovari, Fatemeh; Moravvej-Farshi, Mohammad Kazem

    2014-08-18

    We show an armchair graphene nanoribbon channel connected between asymmetric ferromagnetic source-drain structure—i.e., p-type Co/Au/graphene source and n-type Co/Cu/graphene drain—can operate as dual function spin-photodetector, under zero external biases at room temperature. It can function as an optical spin-valve with magnetoresistance of greater than 60% and responsivity as high as 25.12 A/mW, when irradiated by an un-polarized light of energy ∼3.03 eV. Under a circularly polarized illumination, this optical spin-valve can also operate as a light helicity detector. The calculated magnetoresistances for right and left circularly polarized lights are both greater than 60%.

  16. Dual-functioning phage-derived peptides encourage human bone marrow cell-specific attachment to mineralized biomaterials.

    PubMed

    Ramaraju, Harsha; Miller, Sharon J; Kohn, David H

    2014-08-01

    Cell instructive mineralized biomaterials are a promising alternative to conventional auto-, allo-, and xenograft therapies for the reconstruction of critical sized defects. Extracellular matrix proteins, peptide domains, and functional motifs demonstrating cell and mineral binding activity have been used to improve cell attachment. However, these strategies vary in their tissue regeneration outcomes due to lack of specificity to both regenerative cell populations and the material substrates. In order to mediate cell-specific interactions on apatite surfaces, we identified peptide sequences with high affinity towards apatite (VTKHLNQISQSY, VTK) and clonally derived human bone marrow stromal cells (DPIYALSWSGMA, DPI) using phage display. The primary aims of this study were to measure apatite binding affinity, human bone marrow stromal cell (hBMSC) adhesion strength, and peptide specificity to hBMSCs when the apatite and cell-specific peptides are combined into a dual-functioning peptide. To assess binding affinity to hydroxyapatite (HA), binding isotherms were constructed and peptide binding affinity (K1) determined. HBMSC, MC3T3 and mouse dermal fibroblast (MDF) adhesion strength on biomimetic apatite functionalized with single- and dual-functioning peptide sequences were evaluated using a centrifugation assay. DPI-VTK had the highest binding strength towards hBMSCs (p < 0.01). DPI-VTK, while promoting strong initial attachment to hBMSCs, did not encourage strong adhesions to MC3T3s or fibroblasts (p < 0.01). Taken together, phage display is a promising strategy to identify preferential cell and material binding peptide sequences that can tether specific cell populations onto specific biomaterial chemistries. PMID:25158203

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

    NASA Astrophysics Data System (ADS)

    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

  18. Tetralogy of Fallot Cardiac Function Evaluation and Intelligent Diagnosis Based on Dual-Source Computed Tomography Cardiac Images.

    PubMed

    Cai, Ken; Rongqian, Yang; Li, Lihua; Xie, Zi; Ou, Shanxing; Chen, Yuke; Dou, Jianhong

    2016-05-01

    Tetralogy of Fallot (TOF) is the most common complex congenital heart disease (CHD) of the cyanotic type. Studies on ventricular functions have received an increasing amount of attention as the development of diagnosis and treatment technology for CHD continues to advance. Reasonable options for imaging examination and accurate assessment of preoperative and postoperative left ventricular functions of TOF patients are important in improving the cure rate of TOF radical operation, therapeutic evaluation, and judgment prognosis. Therefore, with the aid of dual-source computed tomography (DSCT), cardiac images with high temporal resolution and high definition, we measured the left ventricular time-volume curve using image data and calculating the left ventricular function parameters to conduct the preliminary evaluation on TOF patients. To comprehensively evaluate the cardiac function, the segmental ventricular wall function parameters were measured, and the measurement results were mapped to a bull's eye diagram to realize the standardization of segmental ventricular wall function evaluation. Finally, we introduced a new clustering method based on auto-regression model parameters and combined this method with Euclidean distance measurements to establish an intelligent diagnosis of TOF. The results of this experiment show that the TOF evaluation and the intelligent diagnostic methods proposed in this article are feasible. PMID:26496001

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

    NASA Technical Reports Server (NTRS)

    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.

  20. From ATP to PTP and back. A dual function for the mitochondrial ATP synthase

    PubMed Central

    Bernardi, Paolo; Di Lisa, Fabio; Fogolari, Federico; Lippe, Giovanna

    2015-01-01

    Mitochondria play a fundamental role in heart physiology, but are also key effectors of dysfunction and death. This dual role assumes a new meaning following recent advances on the nature and regulation of the permeability transition pore, an inner membrane channel whose opening requires matrix Ca2+ and is modulated by many effectors including reactive oxygen species, matrix cyclophilin D, Pi and matrix pH. The recent demonstration that the F-ATP synthase can reversibly undergo a Ca2+-dependent transition to form a channel that mediates the permeability transition opens new perspectives to the field. These findings demand a reassessment of the modifications of F-ATP synthase that take place in the heart under pathological conditions and of their potential role in determining the transition of F-ATP synthase from and energy-conserving into an energy-dissipating device. PMID:25999424

  1. Dual functional activity of semaphorin 3B is required for positioning the anterior commissure.

    PubMed

    Falk, Julien; Julien, Falk; Bechara, Ahmad; Fiore, Roberto; Nawabi, Homaira; Zhou, Heather; Hoyo-Becerra, Carolina; Bozon, Muriel; Rougon, Geneviève; Grumet, Martin; Püschel, Andreas W; Sanes, Joshua R; Castellani, Valérie

    2005-10-01

    Chemorepulsion by semaphorins plays a critical role during the development of neuronal projections. Although semaphorin-induced chemoattraction has been reported in vitro, the contribution of this activity to axon pathfinding is still unclear. Using genetic and culture models, we provide evidence that both attraction and repulsion by Sema3B, a secreted semaphorin, are critical for the positioning of a major brain commissural projection, the anterior commissure (AC). NrCAM, an immunoglobulin superfamily adhesion molecule of the L1 subfamily, associates with neuropilin-2 and is a component of a receptor complex for Sema3B and Sema3F. Finally, we show that activation of the FAK/Src signaling cascade distinguishes Sema3B-mediated attractive from repulsive axonal responses of neurons forming the AC, revealing a mechanism underlying the dual activity of this guidance cue. PMID:16202709

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

    PubMed

    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. PMID:27382602

  3. Horseradish peroxidase and aptamer dual-functionalized nanoprobe for the amplification detection of alpha-methylacyl-CoA racemase.

    PubMed

    Zeng, Yongyi; Zheng, Aixian; Wu, Jing; Cai, Zhixiong; Huang, Aimin; Liu, Xiaolong

    2015-10-29

    Alpha-methylacyl-CoA racemase (AMACR) is over-expressed in many cancer types and can serve as a novel diagnostic biomarker. Development of convenient and sensitive detection methods of AMACR is of particular importance for cancer diagnosis. Aptamers are a type of recognition elements, which possess many advantages over antibody, making them suitable for applications in biosensing and biotechnology. In this work, we use the efficient surface modification of gold nanoparticles (AuNPs) to prepare the horseradish peroxidase (HRP) and aptamer dual-functionalized nanoprobe. The immobilization of HRP and thiol-terminated aptamer on the surface of AuNPs can be achieved through electrostatic interaction and the formation of Au-S bond, respectively. This nanoprobe, which is used as discriminating and catalytic probe, can be combined with enzyme immunoassay method to increase the detection sensitivity of AMACR. The detection limit can reach as low as 4.6 pg mL(-1) due to the dual signal amplification from enzymatic cycling and the high loading of enzymes on AuNPs. This sensitivity is about three orders of magnitude higher than that of AMACR aptamer based fluorescence method, which is also comparable to or one order of magnitude higher than that of ELISA. Furthermore, this method is more simple and effective, which not only avoids the conjugation between recognition element and the catalytic enzyme, but also achieves greater signal amplification. This assay could be used as a sensitive and selective platform for the detection of target protein. PMID:26547498

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

    PubMed Central

    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. PMID:27382602

  5. A dual-functional E. coli vector for expressing recombinant protein with high solubility and antigen presentation ability.

    PubMed

    Chuang, Chin-Kai; Su, Yu-Show; Fan, Chiu-Tin; Lee, Wen-Chuan; Chen, Ming-Yu

    2009-05-01

    A dual-functional Escherichia coli expression vector capable of producing soluble recombinant proteins with high immunogenicity in animals is introduced. This vector expresses polypeptides fused to a PTD-J-domain peptide. The J-domain peptide is derived from murine Hsp40 by using optimized codons for E. coli. The association of the J-domain to the nucleotide binding domain of the DnaK chaperone increases the probability that the fused polypeptide will be folded by the DnaK and hence increases the solubility of the recombinant protein. The PTD-J-domain can also enhance the immunogenicity of the fused chicken IGF-I polypeptide as well as an oligo-peptide derived from haptoglobin in rodents, possibly via the association with either the extracellular or intracellular Hsp70 proteins. PMID:19162194

  6. The Dual Function of Reactive Oxygen/Nitrogen Species in Bioenergetics and Cell Death: The Role of ATP Synthase

    PubMed Central

    Kaludercic, Nina

    2016-01-01

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) targeting mitochondria are major causative factors in disease pathogenesis. The mitochondrial permeability transition pore (PTP) is a mega-channel modulated by calcium and ROS/RNS modifications and it has been described to play a crucial role in many pathophysiological events since prolonged channel opening causes cell death. The recent identification that dimers of ATP synthase form the PTP and the fact that posttranslational modifications caused by ROS/RNS also affect cellular bioenergetics through the modulation of ATP synthase catalysis reveal a dual function of these modifications in the cells. Here, we describe mitochondria as a major site of production and as a target of ROS/RNS and discuss the pathophysiological conditions in which oxidative and nitrosative modifications modulate the catalytic and pore-forming activities of ATP synthase. PMID:27034734

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

    PubMed

    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. PMID:26482030

  8. Targeted Aucore-Agshell nanorods as a dual-functional contrast agent for photoacoustic imaging and photothermal therapy

    PubMed Central

    Shi, Yiwen; Peng, Dong; Wang, Kun; Chai, Xinyu; Ren, Qiushi; Tian, Jie; Zhou, Chuanqing

    2016-01-01

    Optimizing contrast enhancement is essential for producing specific signals in biomedical imaging and therapy. The potential of using Aucore-Agshell nanorods (Au@Ag NRs) as a dual-functional theranostic contrast agent is demonstrated for effective cancer imaging and treatments. Due to its strong NIR absorption and high efficiency of photothermal conversion, effects of both photoacoustic tomography (PAT) and photothermal therapy (PTT) are enhanced significantly. The PAT signal grows by 45.3% and 82% in the phantom and in vivo experiments, respectively, when compared to those using Au NRs. In PTT, The maximum increase of tissue temperature treated with Au@Ag NRs is 22.8 °C, twice that with Au NRs. Results of the current study show the feasibility of using Au@Ag NRs for synergetic PAT with PTT. And it will enhance the potential application on real-time PAT guided PTT, which will greatly benefit the customized PTT treatment of cancer. PMID:27231624

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    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. PMID:23224192

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

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

    2012-01-01

    Abstract. 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. PMID:23224192

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

    PubMed

    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. PMID:22025913

  14. Dual role of Ski in pancreatic cancer cells: tumor-promoting versus metastasis-suppressive function.

    PubMed

    Wang, Peng; Chen, Zhen; Meng, Zhi-Qiang; Fan, Jie; Luo, Jian-Min; Liang, Wang; Lin, Jun-Hua; Zhou, Zhen-Hua; Chen, Hao; Wang, Kun; Shen, Ye-Hua; Xu, Zu-De; Liu, Lu-Ming

    2009-09-01

    Ski used to be defined as an oncogene that contributes to the resistance of tumor cells to transforming growth factor-beta (TGF-beta)-induced growth arrest. As TGF-beta has a dual effect on tumor growth with both tumor-suppressing and -promoting activity depending on the stage of carcinogenesis and the cell type, the precise role of Ski in carcinogenesis remains unclear. In this study, we show that downregulation of Ski through lentivirus-mediated RNA interference decreases tumor growth both in vitro and in vivo, yet promotes cell invasiveness in vitro, and lung metastasis in vivo in the pancreatic cancer cell line SW1990, which contain wild-type Smad4 expression, and the BxPC3 cell line, which is Smad4 deficient. We also show that the downregulation of Ski increases TGF-beta-induced transcriptional activity, which is associated with increased TGF-beta-dependent Smad2/3 phosphorylation, and results in an altered expression profile of TGF-beta-inducible genes involved in metastasis, angiogenesis and cell proliferation and epithelial-mesenchymal transition. Immunohistochemical analysis of specimens from 71 patients with pancreatic adenocarcinoma showed a significant association between overexpression of Ski and decreased patient survival time (P = 0.0024). Our results suggest that Ski may act as a tumor proliferation-promoting factor or as a metastatic suppressor in human pancreatic cancer. PMID:19546161

  15. A Dual-Microphone Speech Enhancement Algorithm Based on the Coherence Function

    PubMed Central

    2011-01-01

    A novel dual-microphone speech enhancement technique is proposed in the present paper. The technique utilizes the coherence between the target and noise signals as a criterion for noise reduction and can be generally applied to arrays with closely-spaced microphones, where noise captured by the sensors is highly correlated. The proposed algorithm is simple to implement and requires no estimation of noise statistics. In addition, it offers the capability of coping with multiple interfering sources that might be located at different azimuths. The proposed algorithm was evaluated with normal hearing listeners using intelligibility listening tests and compared against a well-established beamforming algorithm. Results indicated large gains in speech intelligibility relative to the baseline (front microphone) algorithm in both single and multiple-noise source scenarios. The proposed algorithm was found to yield substantially higher intelligibility than that obtained by the beamforming algorithm, particularly when multiple noise sources or competing talker(s) were present. Objective quality evaluation of the proposed algorithm also indicated significant quality improvement over that obtained by the beamforming algorithm. The intelligibility and quality benefits observed with the proposed coherence-based algorithm make it a viable candidate for hearing aid and cochlear implant devices. PMID:22207823

  16. Azo Polymer Janus Particles Possessing Photodeformable and Magnetic-Field-Responsive Dual Functions.

    PubMed

    Zhou, Xinran; Du, Yi; Wang, Xiaogong

    2016-08-01

    It is of great fundamental and practical significance to endow Janus particles with various field-responsive properties. In this study, a new strategy with a wide range of application possibilities is developed to fabricate JPs composed of a methacrylate-based azo polymer, polystyrene, and Fe3 O4 nanoparticles. The JPs are obtained through microphase separation in a confined volume of the dispersed droplets. The azo polymer and PS are incorporated in JPs in a core-compartmentalized manner, and Fe3 O4 are proved to exist in the azo polymer phase. The JPs show responsive movement in the magnetic field and can be easily oriented with the help of the field. By variation of the intersection angle between the particle symmetrical axis and the polarization direction of the linearly polarized laser beam, different deformation modes are feasibly achieved for the JPs. By exploiting the dual-responsive properties, JPs with designed shapes can be fabricated by exposing the JPs to linearly polarized light. PMID:27309125

  17. Structural Basis and Catalytic Mechanism for the Dual Functional Endo-β-N-Acetylglucosaminidase A

    PubMed Central

    Shaw, Neil; Li, Yang; Song, Jing Katherine; Zhang, Wenpeng; Xia, Chengfeng; Zhang, Rongguang; Joachimiak, Andrzej; Zhang, Hou-Cheng; Wang, Lai-Xi; Liu, Zhi-Jie; Wang, Peng

    2009-01-01

    Endo-β-N-acetylglucosaminidases (ENGases) are dual specificity enzymes with an ability to catalyze hydrolysis and transglycosylation reactions. Recently, these enzymes have become the focus of intense research because of their potential for synthesis of glycopeptides. We have determined the 3D structures of an ENGase from Arthrobacter protophormiae (Endo-A) in 3 forms, one in native form, one in complex with Man3GlcNAc-thiazoline and another in complex with GlcNAc-Asn. The carbohydrate moiety sits above the TIM-barrel in a cleft region surrounded by aromatic residues. The conserved essential catalytic residues – E173, N171 and Y205 are within hydrogen bonding distance of the substrate. W216 and W244 regulate access to the active site during transglycosylation by serving as “gate-keepers”. Interestingly, Y299F mutation resulted in a 3 fold increase in the transglycosylation activity. The structure provides insights into the catalytic mechanism of GH85 family of glycoside hydrolases at molecular level and could assist rational engineering of ENGases. PMID:19252736

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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. PMID:24589584

  20. Dual-function sRNA encoded peptide SR1P modulates moonlighting activity of B. subtilis GapA

    PubMed Central

    Gimpel, Matthias; Brantl, Sabine

    2016-01-01

    ABSTRACT SR1 is a dual-function sRNA from B. subtilis that acts as a base-pairing regulatory RNA and as a peptide-encoding mRNA. Both functions of SR1 are highly conserved. Previously, we uncovered that the SR1 encoded peptide SR1P binds the glycolytic enzyme GapA resulting in stabilization of gapA mRNA. Here, we demonstrate that GapA interacts with RNases Y and J1, and this interaction was RNA-independent. About 1% of GapA molecules purified from B. subtilis carry RNase J1 and about 2% RNase Y. In contrast to the GapA/RNase Y interaction, the GapA/RNaseJ1 interaction was stronger in the presence of SR1P. GapA/SR1P-J1/Y displayed in vitro RNase activity on known RNase J1 substrates. Moreover, the RNase J1 substrate SR5 has altered half-lives in a ΔgapA strain and a Δsr1 strain, suggesting in vivo functions of the GapA/SR1P/J1 interaction. Our results demonstrate that the metabolic enzyme GapA moonlights in recruiting RNases while GapA bound SR1P promotes binding of RNase J1 and enhances its activity. PMID:27449348

  1. Simultaneous Exfoliation and Functionalization of MoSe2 Nanosheets to Prepare "Smart" Nanocomposite Hydrogels with Tunable Dual Stimuli-Responsive Behavior.

    PubMed

    Lei, Zhouyue; Zhou, Yuanyuan; Wu, Peiyi

    2016-06-01

    A facile polymer-assisted method achieves simultaneous exfoliation and noncovalent functionalization of MoSe2 nanosheets. The nanosheet dispersion can further assemble into a novel "smart" nanocomposite hydrogel, whose dual-responsive (photo- and thermoresponsive) behavior is reversible and can be controllably tailored by varying the distribution of hydrophilic and hydrophobic groups in the polymer. PMID:27135442

  2. Direct coprecipitation route to monodisperse dual-functionalized magnetic iron oxide nanocrystals without size selection.

    PubMed

    Li, Zhen; Tan, Bien; Allix, Mathieu; Cooper, Andrew I; Rosseinsky, Matthew J

    2008-02-01

    Water-soluble monodisperse superparamagnetic Fe3O4 nanocrystals decorated with two distinct functional groups are prepared in a single-step procedure by injecting iron precursors into a refluxing aqueous solution of a polymer ligand, trithiol-terminated poly(methacrylic acid) (PMAA-PTTM), bearing both carboxylate and thiol functionalities. The ratio of carboxylic acid groups in the polymer-protecting ligand to the iron precursors plays a key role in determining the particle size and particle size distribution. The surface functionalities of the ligands allow post-synthesis modification of the materials to produce water-soluble fluorescent magnetic nanocrystals. PMID:18213671

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

    PubMed

    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. PMID:26358403

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

    NASA Astrophysics Data System (ADS)

    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.

  5. Synthesis and characterization of dual-functionalized core-shell fluorescent microspheres for bioconjugation and cellular delivery.

    PubMed

    Behrendt, Jonathan M; Nagel, David; Chundoo, Evita; Alexander, Lois M; Dupin, Damien; Hine, Anna V; Bradley, Mark; Sutherland, Andrew J

    2013-01-01

    The efficient transport of micron-sized beads into cells, via a non-endocytosis mediated mechanism, has only recently been described. As such there is considerable scope for optimization and exploitation of this procedure to enable imaging and sensing applications to be realized. Herein, we report the design, synthesis and characterization of fluorescent microsphere-based cellular delivery agents that can also carry biological cargoes. These core-shell polymer microspheres possess two distinct chemical environments; the core is hydrophobic and can be labeled with fluorescent dye, to permit visual tracking of the microsphere during and after cellular delivery, whilst the outer shell renders the external surfaces of the microspheres hydrophilic, thus facilitating both bioconjugation and cellular compatibility. Cross-linked core particles were prepared in a dispersion polymerization reaction employing styrene, divinylbenzene and a thiol-functionalized co-monomer. These core particles were then shelled in a seeded emulsion polymerization reaction, employing styrene, divinylbenzene and methacrylic acid, to generate orthogonally functionalized core-shell microspheres which were internally labeled via the core thiol moieties through reaction with a thiol reactive dye (DY630-maleimide). Following internal labeling, bioconjugation of green fluorescent protein (GFP) to their carboxyl-functionalized surfaces was successfully accomplished using standard coupling protocols. The resultant dual-labeled microspheres were visualized by both of the fully resolvable fluorescence emissions of their cores (DY630) and shells (GFP). In vitro cellular uptake of these microspheres by HeLa cells was demonstrated conventionally by fluorescence-based flow cytometry, whilst MTT assays demonstrated that 92% of HeLa cells remained viable after uptake. Due to their size and surface functionalities, these far-red-labeled microspheres are ideal candidates for in vitro, cellular delivery of proteins

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

    PubMed

    Jurado, Sabine; Smyth, Ian; van Denderen, Bryce; Tenis, Nora; Hammet, Andrew; Hewitt, Kimberly; Ng, Jane-Lee; McNees, Carolyn J; Kozlov, Sergei V; Oka, Hayato; Kobayashi, Masahiko; Conlan, Lindus A; Cole, Timothy J; Yamamoto, Ken-Ichi; Taniguchi, Yoshihito; Takeda, Shunichi; Lavin, Martin F; Heierhorst, Jörg

    2010-10-01

    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. PMID:20975950

  7. Dual Functions of ASCIZ in the DNA Base Damage Response and Pulmonary Organogenesis

    PubMed Central

    Tenis, Nora; Hammet, Andrew; Hewitt, Kimberly; Ng, Jane-Lee; McNees, Carolyn J.; Kozlov, Sergei V.; Oka, Hayato; Kobayashi, Masahiko; Conlan, Lindus A.; Cole, Timothy J.; Yamamoto, Ken-ichi; Taniguchi, Yoshihito; Takeda, Shunichi; Lavin, Martin F.; Heierhorst, Jörg

    2010-01-01

    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 or 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. PMID:20975950

  8. Use of internal scintillator radioactivity to calibrate DOI function of a PET detector with a dual-ended-scintillator readout

    SciTech Connect

    Bircher, Chad; Shao Yiping

    2012-02-15

    Purpose: Positron emission tomography (PET) detectors that use a dual-ended-scintillator readout to measure depth-of-interaction (DOI) must have an accurate DOI function to provide the relationship between DOI and signal ratios to be used for detector calibration and recalibration. In a previous study, the authors used a novel and simple method to accurately and quickly measure DOI function by irradiating the detector with an external uniform flood source; however, as a practical concern, implementing external uniform flood sources in an assembled PET system is technically challenging and expensive. In the current study, therefore, the authors investigated whether the same method could be used to acquire DOI function from scintillator-generated (i.e., internal) radiation. The authors also developed a method for calibrating the energy scale necessary to select the events within the desired energy window. Methods: The authors measured the DOI function of a PET detector with lutetium yttrium orthosilicate (LYSO) scintillators. Radiation events originating from the scintillators' internal Lu-176 beta decay were used to measure DOI functions which were then compared with those measured from both an external uniform flood source and an electronically collimated external point source. The authors conducted these studies with several scintillators of differing geometries (1.5 x 1.5 and 2.0 x 2.0 mm{sup 2} cross-section area and 20, 30, and 40 mm length) and various surface finishes (mirror-finishing, saw-cut rough, and other finishes in between), and in a prototype array. Results: All measured results using internal and external radiation sources showed excellent agreement in DOI function measurement. The mean difference among DOI values for all scintillators measured from internal and external radiation sources was less than 1.0 mm for different scintillator geometries and various surface finishes. Conclusions: The internal radioactivity of LYSO scintillators can be used

  9. A dual molecular analogue tuner for dissecting protein function in mammalian cells.

    PubMed

    Brosh, Ran; Hrynyk, Iryna; Shen, Jessalyn; Waghray, Avinash; Zheng, Ning; Lemischka, Ihor R

    2016-01-01

    Loss-of-function studies are fundamental for dissecting gene function. Yet, methods to rapidly and effectively perturb genes in mammalian cells, and particularly in stem cells, are scarce. Here we present a system for simultaneous conditional regulation of two different proteins in the same mammalian cell. This system harnesses the plant auxin and jasmonate hormone-induced degradation pathways, and is deliverable with only two lentiviral vectors. It combines RNAi-mediated silencing of two endogenous proteins with the expression of two exogenous proteins whose degradation is induced by external ligands in a rapid, reversible, titratable and independent manner. By engineering molecular tuners for NANOG, CHK1, p53 and NOTCH1 in mammalian stem cells, we have validated the applicability of the system and demonstrated its potential to unravel complex biological processes. PMID:27230261

  10. A dual molecular analogue tuner for dissecting protein function in mammalian cells

    PubMed Central

    Brosh, Ran; Hrynyk, Iryna; Shen, Jessalyn; Waghray, Avinash; Zheng, Ning; Lemischka, Ihor R.

    2016-01-01

    Loss-of-function studies are fundamental for dissecting gene function. Yet, methods to rapidly and effectively perturb genes in mammalian cells, and particularly in stem cells, are scarce. Here we present a system for simultaneous conditional regulation of two different proteins in the same mammalian cell. This system harnesses the plant auxin and jasmonate hormone-induced degradation pathways, and is deliverable with only two lentiviral vectors. It combines RNAi-mediated silencing of two endogenous proteins with the expression of two exogenous proteins whose degradation is induced by external ligands in a rapid, reversible, titratable and independent manner. By engineering molecular tuners for NANOG, CHK1, p53 and NOTCH1 in mammalian stem cells, we have validated the applicability of the system and demonstrated its potential to unravel complex biological processes. PMID:27230261

  11. The use of a dual PEDOT and RGD-functionalized alginate hydrogel coating to provide sustained drug delivery and improved cochlear implant function

    PubMed Central

    Chikar, JA; Hendricks, JL; Richardson-Burns, SM; Raphael, Y; Pfingst, BE; Martin, DC

    2011-01-01

    Cochlear implants provide hearing by electrically stimulating the auditory nerve. Implant function can be hindered by device design variables, including electrode size and electrode-to-nerve distance, and cochlear environment variables, including the degeneration of the auditory nerve following hair cell loss. We have developed a dual component cochlear implant coating to improve both the electrical function of the implant and the biological stability of the inner ear, thereby facilitating the long-term perception of sound through a cochlear implant. This coating is a combination of an arginine-glycine-aspartic acid (RGD)-functionalized alginate hydrogel and the conducting polymer poly(3, 4-ethylenedioxythiophene) (PEDOT). Both in vitro and in vivo assays on the effects of these electrode coatings demonstrated improvements in device performance. We found that the coating reduced electrode impedance, improved charge delivery, and locally released significant levels of a trophic factor into cochlear fluids. This coating is non-cytotoxic, clinically relevant, and has the potential to significantly improve the cochlear implant user’s experience. PMID:22182748

  12. The dual role of oxygen functions in coal pretreatment and liquefaction: Crosslinking and cleavage reactions

    SciTech Connect

    Serio, M.A.; Kroo, E.; Teng, Hsisheng; Charpenay, S.; Solomon, P.R.

    1991-01-01

    One objective of this program is to prepare polymer models having phenolic, carboxylic, and/or aryl ether groups considered to be important in low rank coals. In order to study the chemistry of these functional groups in a polymeric matrix, it is necessary that the polymer backbone itself should not be subject to cleavage under the reaction conditions. It is expected that poly(phenylene) would fulfill this requirement as a backbone, while providing simple mechanical routes for attaching other functional groups. During this reporting period, the synthesis of oligomeric species such as sexi(phenylene) and octa(phenylene) was explored. The procedure of Bamfield and Quam was followed, which involves heating a paste of bromoarenes, water, sodium formate and Pd/C. The reaction products turned out to be very insoluble and difficult to purify. The insolubility of these products makes them difficult to work with, and it is doubtful that we will be able to prepare well-characterized polymers in the 10,000 Da range. We are presently considering other polymeric substrates that might serve as the backbone. Pending the resolution of the polymeric substrate issue, the thermal behavior of the carboxyl and phenolic functions and the effect of ion-exchange will be studied using monomeric models. These studies will be needed to establish the baseline for considering the effect of the polymeric environment.

  13. Nxnl2 splicing results in dual functions in neuronal cell survival and maintenance of cell integrity

    PubMed Central

    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

  14. Structural basis of the mercury(II)-mediated conformational switching of the dual-function transcriptional regulator MerR

    PubMed Central

    Chang, Chih-Chiang; Lin, Li-Ying; Zou, Xiao-Wei; Huang, Chieh-Chen; Chan, Nei-Li

    2015-01-01

    The mer operon confers bacterial resistance to inorganic mercury (Hg2+) and organomercurials by encoding proteins involved in sensing, transport and detoxification of these cytotoxic agents. Expression of the mer operon is under tight control by the dual-function transcriptional regulator MerR. The metal-free, apo MerR binds to the mer operator/promoter region as a repressor to block transcription initiation, but is converted into an activator upon Hg2+-binding. To understand how MerR interacts with Hg2+ and how Hg2+-binding modulates MerR function, we report here the crystal structures of apo and Hg2+-bound MerR from Bacillus megaterium, corresponding respectively to the repressor and activator conformation of MerR. To our knowledge, the apo-MerR structure represents the first visualization of a MerR family member in its intact and inducer-free form. And the Hg2+-MerR structure offers the first view of a triligated Hg2+-thiolate center in a metalloprotein, confirming that MerR binds Hg2+ via trigonal planar coordination geometry. Structural comparison revealed the conformational transition of MerR is coupled to the assembly/disassembly of a buried Hg2+ binding site, thereby providing a structural basis for the Hg2+-mediated functional switching of MerR. The pronounced Hg2+-induced repositioning of the MerR DNA-binding domains suggests a plausible mechanism for the transcriptional regulation of the mer operon. PMID:26150423

  15. Loss- and Gain-of-Function Approaches Indicate a Dual Role Exerted by Regulatory T Cells in Pulmonary Paracoccidioidomycosis

    PubMed Central

    Bazan, Silvia B.; Costa, Tania A.; de Araújo, Eliseu Frank; Feriotti, Claudia; Loures, Flávio V.; Pretel, Fernando D.; Calich, Vera L. G.

    2015-01-01

    Paracoccidioidomycosis (PCM), is a pulmonary fungal disease whose severity depends on the adequate development of T cell immunity. Although regulatory T (Treg) cells were shown to control immunity against PCM, deleterious or protective effects were described in different experimental settings. To clarify the function of Treg cells in pulmonary PCM, loss-and gain-of-function approaches were performed with Foxp3GFP knock-in mice and immunodeficient Rag1-/- mice, respectively, which were intratracheally infected with 106 yeast cells. The activity of Foxp3-expressing Treg cells in pulmonary PCM was determined in Foxp3GFP transgenic mice. First, it was verified that natural Treg cells migrate to the lungs of infected mice, where they become activated. Depletion of Treg cells led to reduced fungal load, diminished pathogen dissemination and increased Th1/Th2/Th17 immunity. Further, adoptive transfer of diverse T cell subsets to Rag1-/- mice subsequently infected by the pulmonary route demonstrated that isolated CD4+Foxp3+ Treg cells were able to confer some degree of immunoprotection and that CD4+Foxp3- T cells alone reduced fungal growth and enhanced T cell immunity, but induced vigorous inflammatory reactions in the lungs. Nevertheless, transfer of Treg cells combined with CD4+Foxp3- T cells generated more efficient and balanced immune Th1/Th2/Th17 responses able to limit pathogen growth and excessive tissue inflammation, leading to regressive disease and increased survival rates. Altogether, these loss- and gain-of-function approaches allow us to clearly demonstrate the dual role of Treg cells in pulmonary PCM, their deleterious effects by impairing T cell immunity and pathogen eradication, and their protective role by suppressing exacerbated tissue inflammation. PMID:26512987

  16. A Neuronal Activity-Dependent Dual Function Chromatin-Modifying Complex Regulates Arc Expression1,2,3

    PubMed Central

    Oey, Nicodemus E.; Leung, How Wing; Ezhilarasan, Rajaram; Zhou, Lei; Beuerman, Roger W.; VanDongen, Hendrika M.A.

    2015-01-01

    Abstract Chromatin modification is an important epigenetic mechanism underlying neuroplasticity. Histone methylation and acetylation have both been shown to modulate gene expression, but the machinery responsible for mediating these changes in neurons has remained elusive. Here we identify a chromatin-modifying complex containing the histone demethylase PHF8 and the acetyltransferase TIP60 as a key regulator of the activity-induced expression of Arc, an important mediator of synaptic plasticity. Clinically, mutations in PHF8 cause X-linked mental retardation while TIP60 has been implicated in the pathogenesis of Alzheimer’s disease. Within minutes of increased synaptic activity, this dual function complex is rapidly recruited to the Arc promoter, where it specifically counteracts the transcriptionally repressive histone mark H3K9me2 to facilitate the formation of the transcriptionally permissive H3K9acS10P, thereby favoring transcriptional activation. Consequently, gain-of-function of the PHF8−TIP60 complex in primary rat hippocampal neurons has a positive effect on early activity-induced Arc gene expression, whereas interfering with the function of this complex abrogates it. A global proteomics screen revealed that the majority of common interactors of PHF8 and TIP60 were involved in mRNA processing, including PSF, an important molecule involved in neuronal gene regulation. Finally, we proceeded to show, using super-resolution microscopy, that PHF8 and TIP60 interact at the single molecule level with PSF, thereby situating this chromatin modifying complex at the crossroads of transcriptional activation. These findings point toward a mechanism by which an epigenetic pathway can regulate neuronal activity-dependent gene transcription, which has implications in the development of novel therapeutics for disorders of learning and memory. PMID:26464965

  17. TRIM25 has a dual function in the p53/Mdm2 circuit.

    PubMed

    Zhang, P; Elabd, S; Hammer, S; Solozobova, V; Yan, H; Bartel, F; Inoue, S; Henrich, T; Wittbrodt, J; Loosli, F; Davidson, G; Blattner, C

    2015-11-12

    P53 is an important tumor suppressor that, upon activation, induces growth arrest and cell death. Control of p53 is thus of prime importance for proliferating cells, but also for cancer therapy, where p53 activity contributes to the eradication of tumors. Mdm2 functionally inhibits p53 and targets the tumor suppressor protein for degradation. In a genetic screen, we identified TRIM25 as a novel regulator of p53 and Mdm2. TRIM25 increased p53 and Mdm2 abundance by inhibiting their ubiquitination and degradation in 26 S proteasomes. TRIM25 co-precipitated with p53 and Mdm2 and interfered with the association of p300 and Mdm2, a critical step for p53 polyubiquitination. Despite the increase in p53 levels, p53 activity was inhibited in the presence of TRIM25. Downregulation of TRIM25 resulted in an increased acetylation of p53 and p53-dependent cell death in HCT116 cells. Upon genotoxic insults, TRIM25 dampened the p53-dependent DNA damage response. The downregulation of TRIM25 furthermore resulted in massive apoptosis during early embryogenesis of medaka, which was rescued by the concomitant downregulation of p53, demonstrating the functional relevance of the regulation of p53 by TRIM25 in an organismal context. PMID:25728675

  18. A dual-functional asymmetric squaraine-based low band gap hole transporting material for efficient perovskite solar cells.

    PubMed

    Paek, Sanghyun; Rub, Malik Abdul; Choi, Hyeju; Kosa, Samia A; Alamry, Khalid A; Cho, Jin Woo; Gao, Peng; Ko, Jaejung; Asiri, Abdullah M; Nazeeruddin, Mohammad Khaja

    2016-03-17

    We demonstrate for the first time an asymmetric squaraine-based low band-gap hole transporting material, which acted as both light harvesting and hole transporting layers in methylammonium lead triiodide perovskite solar cells. Opto-electrochemical characterization revealed extremely high molar extinction coefficients of the absorption bands in the low energy region and prominent space charge delocalization due to its electronically asymmetric nature. A suitable band alignment of the squaraine HOMO level with the valence band edge of the perovskite, and the conduction band of the TiO2 with LUMO of the perovskite allowed a cascade of hole extraction and electron injection, respectively. Red-shifted absorption was observed for both HTMs in thin films coated on the perovskite, and the optimized devices exhibited an impressive PCE of 14.7% under full sunlight illumination (100 mW cm(-2), AM1.5 G). The efficiency value is comparable to that of the devices using a state-of-the-art spiro-OMeTAD hole transport layer under similar conditions. Ambient stability after 300 h revealed that 88% of the initial efficiency remained for , and almost no change for , indicating that the devices had good long-term stability thus suggesting that the asymmetric squaraines have great potential as a dual-functional HTM for high performance perovskite solar cells. PMID:26511537

  19. Universal expression and dual function of the atypical chemokine receptor D6 on innate-like B cells in mice

    PubMed Central

    Hansell, Chris A. H.; Schiering, Chris; Kinstrie, Ross; Ford, Laura; Bordon, Yvonne; McInnes, Iain B.; Goodyear, Carl S.; Nibbs, Robert J. B.

    2011-01-01

    Mouse innate-like B cells are a heterogeneous collection of multifunctional cells that control infection, play housekeeping roles, contribute to adaptive immunity, and suppress inflammation. We show that, amongst leukocytes, chemokine internalisation by the D6 receptor is a unique and universal feature of all known innate-like B cell populations and, to our knowledge, the most effective unifying marker of these cells. Moreover, we identify novel D6active B1 cell subsets, including those we term B1d, which lack CD5 and CD11b but exhibit typical B1 cell properties, including spontaneous ex vivo production of IgM, interleukin-10, and anti-phosphorylcholine antibody. The unprecedented opportunity to examine D6 on primary cells has allowed us to clarify its ligand specificity and show that, consistent with a scavenging role, D6 internalises chemokines but cannot induce Ca2+ fluxes or chemotaxis. Unexpectedly, however, D6 can also suppress the function of CXCR5, a critical chemokine receptor in innate-like B cell biology. This is associated with a reduction in B1 cells and circulating class-switched anti-phosphorylcholine antibody in D6-deficient mice. Thus, we identify a unifying marker of innate-like B cells; describe novel B1 cell subsets; reveal a dual role for D6; and provide the first evidence of defects in resting D6-deficient mice. PMID:21450903

  20. Highly mesoporous single-crystalline zeolite beta synthesized using a nonsurfactant cationic polymer as a dual-function template.

    PubMed

    Zhu, Jie; Zhu, Yihan; Zhu, Liangkui; Rigutto, Marcello; van der Made, Alexander; Yang, Chengguang; Pan, Shuxiang; Wang, Liang; Zhu, Longfeng; Jin, Yinying; Sun, Qi; Wu, Qinming; Meng, Xiangju; Zhang, Daliang; Han, Yu; Li, Jixue; Chu, Yueying; Zheng, Anmin; Qiu, Shilun; Zheng, Xiaoming; Xiao, Feng-Shou

    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. PMID:24450997

  1. Graphene oxide as a dual-function conductive binder for PEEK-derived microporous carbons in high performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Kim, Christine H. J.; Zhang, Hongbo; Liu, Jie

    2015-06-01

    Microporous carbons (MPCs) are promising electrode materials for supercapacitors because of their high surface area and accessible pores. However, their low electrical conductivity and mechanical instability result in limited power density and poor cycle life. This work proposes a unique two-layered film made of polyetheretherketone-derived MPCs and reduced graphene oxide (rGO) as an electrode for supercapacitors. Electrochemical characterizations of films show that such a layered structure is more effective in increasing the accessibility of ions to the hydrophilic MPCs and establishing conductive paths through the rGO network than a simple mixed composite film. The two-layered structure increases the capacitance by ˜124% (237 F g-1) with excellent cycling stability (˜93% after 6000 cycles). More importantly, we demonstrate that such performance improvements result from an optimal balance between electrical conductivity and ion accessibility, which maximizes the synergistic effects of MPC and rGO. The MPCs, which are exposed to the surface, provide a highly accessible surface area for ion adsorption. The rGO serves a dual function as a conductive filler to increase the electrical conductivity and as a binder to interconnect individual MPC particles into a robust and flexible film. These findings provide a rational basis for the design of MPC-based electrodes in high performance supercapacitors.

  2. A facile and sensitive electrochemiluminescence biosensor for Hg2+ analysis based on a dual-function oligonucleotide probe.

    PubMed

    Huang, Rong-Fu; Liu, Hui-Xin; Gai, Qi-Qi; Liu, Gai-Juan; Wei, Zheng

    2015-09-15

    In this study, a sensitive electrochemiluminescent (ECL) biosensor for the detection of Hg(2+) was easily prepared by self-assembling mercury-specific oligonucleotide on the surface of gold nanoparticles (AuNPs) modified indium tin oxide (ITO) electrode. A conformation change of the oligonucleotide from linear chain to hairpin occurs upon the binding of Hg(2+) through thymine-Hg(2+)-thymine coordination. The dual-function oligonucleotide serves as the probe to Hg(2+) but also a carrier of signal-generating molecules, [Ru(bpy)2(dppz)](BF4)2. It was estimated that one oligonucleotide was able to load with eight ECL signal molecules; a ratio of four or five oligonucleotides per gold nanoparticle was obtained basing on the calculation with surface density. Without tedious multiple-labeling procedures and special modification of oligonucleotide probe for signal transduction/amplification, a detection limit of 5.1 pM Hg(2+) was outstanding from the interference of other ten metal ions. Results of spiked water samples were in good agreement with that obtained by atomic fluorescent spectrometry. PMID:25909339

  3. Fluorescence assay for glycan expression on living cancer cells based on competitive strategy coupled with dual-functionalized nanobiocomposites.

    PubMed

    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. PMID:24098881

  4. Demonstrating and optimizing the dual dispersion and focusing functionality of grating-Fresnel lens

    NASA Astrophysics Data System (ADS)

    Zhou, Qian; Zhang, Jinchao; Ni, Kai; Pang, Jinchao; Tian, Rui

    2014-11-01

    As optical spectroscopy plays a vital role in many of modern science and engineering, there is a growing need for developing an inexpensive and miniature spectrometers. Many attempts have been tried to solve the issue. Grating-Fresnel is a hybrid device that fuses the functions of a grating and Fresnel lens into a single device. In this paper, we try to simulate reflection type and transmission type G-Fresnel device in ZAMAX. And with the aids of ZEMAX, we try to optimize the Fresnel lens, grating pattern. A better alignment for the CCD detector could also improve sensitivity of the system as well. In order to improve the resolution and sensitivity, the length between Fresnel lens and gratings will be optimized.

  5. Dual functions of TiC nanoparticles on tribological performance of Al/graphite composites

    NASA Astrophysics Data System (ADS)

    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.

  6. Structure of dual function iron regulatory protein 1 complexed with ferritin IRE-RNA

    SciTech Connect

    Walden, William E.; Selezneva, Anna I.; Dupuy, Jérôme; Volbeda, Anne; Fontecilla-Camps, Juan C.; Theil, Elizabeth C.; Volz1, Karl

    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.

  7. The dual function of flavodiiron proteins: oxygen and/or nitric oxide reductases.

    PubMed

    Romão, Célia V; Vicente, João B; Borges, Patrícia T; Frazão, Carlos; Teixeira, Miguel

    2016-03-01

    Flavodiiron proteins have emerged in the last two decades as a newly discovered family of oxygen and/or nitric oxide reductases widespread in the three life domains, and present in both aerobic and anaerobic organisms. Herein we present the main features of these fascinating enzymes, with a particular emphasis on the metal sites, as more appropriate for this special issue in memory of the exceptional bioinorganic scientist R. J. P. Williams who pioneered the notion of (metal) element availability-driven evolution. We also compare the flavodiiron proteins with the other oxygen and nitric oxide reductases known until now, highlighting how throughout evolution Nature arrived at different solutions for similar functions, in some cases adding extra features, such as energy conservation. These enzymes are an example of the (bioinorganic) unpredictable diversity of the living world. PMID:26767750

  8. Polyamine metabolism-based dual functional gene delivery system to synergistically inhibit the proliferation of cancer.

    PubMed

    Cui, Peng-Fei; Xing, Lei; Qiao, Jian-Bin; Zhang, Jia-Liang; He, Yu-Jing; Zhang, Mei; Lyu, Jin-Yuan; Luo, Cheng-Qiong; Jin, Liang; Jiang, Hu-Lin

    2016-06-15

    Polyamine content, which is associated with tumor growth, can be regulated by ornithine decarboxylase (ODC) and S-adenosyl methionine decarboxylase (SAMDC), two key enzymes in polyamine biosynthesis. Here we aim to develop a pH-responsive cationic poly(agmatine) based on a polyamine analogue-agmatine that can dually function as a gene delivery vector as well as an anticancer agent by inhibiting ODC after intracellular degradation. The core-shell nanoparticles, formed by poly(agmatine)/SAMDC siRNA complex as a core, were coated with bovine serum albumin for better in vivo circulation stability and tumor targeting. When the nanoparticles were taken up by tumor cells via endocytosis and degraded in endosome, the released agmatine and SAMDC siRNA can synergistically inhibit polyamines biosynthesis, inducing inhibition of tumor proliferation. Our study offered a potential way in tumor therapy based on polyamine metabolism. PMID:27102990

  9. Dual-selection for evolution of in vivo functional aptazymes as riboswitch parts.

    PubMed

    Goler, Jonathan A; Carothers, James M; Keasling, Jay D

    2014-01-01

    Both synthetic biology and metabolic engineering are aided by the development of genetic control parts. One class of riboswitch parts that has great potential for sensing and regulation of protein levels is aptamer-coupled ribozymes (aptazymes). These devices are comprised of an aptamer domain selected to bind a particular ligand, a ribozyme domain, and a communication module that regulates the ribozyme activity based on the state of the aptamer. We describe a broadly applicable method for coupling a novel, newly selected aptamer to a ribozyme to generate functional aptazymes via in vitro and in vivo selection. To illustrate this approach, we describe experimental procedures for selecting aptazymes assembled from aptamers that bind p-amino-phenylalanine and a hammerhead ribozyme. Because this method uses selection, it does not rely on sequence-specific design and thus should be generalizable for the generation of in vivo operational aptazymes that respond to any targeted molecules. PMID:24549623

  10. Dual function of MIPS1 as a metabolic enzyme and transcriptional regulator.

    PubMed

    Latrasse, David; Jégu, Teddy; Meng, Pin-Hong; Mazubert, Christelle; Hudik, Elodie; Delarue, Marianne; Charon, Céline; Crespi, Martin; Hirt, Heribert; Raynaud, Cécile; Bergounioux, Catherine; Benhamed, Moussa

    2013-03-01

    Because regulation of its activity is instrumental either to support cell proliferation and growth or to promote cell death, the universal myo-inositol phosphate synthase (MIPS), responsible for myo-inositol biosynthesis, is a critical enzyme of primary metabolism. Surprisingly, we found this enzyme to be imported in the nucleus and to interact with the histone methyltransferases ATXR5 and ATXR6, raising the question of whether MIPS1 has a function in transcriptional regulation. Here, we demonstrate that MIPS1 binds directly to its promoter to stimulate its own expression by locally inhibiting the spreading of ATXR5/6-dependent heterochromatin marks coming from a transposable element. Furthermore, on activation of pathogen response, MIPS1 expression is reduced epigenetically, providing evidence for a complex regulatory mechanism acting at the transcriptional level. Thus, in plants, MIPS1 appears to have evolved as a protein that connects cellular metabolism, pathogen response and chromatin remodeling. PMID:23341037

  11. A Novel Dual Expression Platform for High Throughput Functional Screening of Phage Libraries in Product like Format

    PubMed Central

    Mugabe, Sheila; Gao, Changshou; Tkaczyk, Christine; Mazor, Yariv; Pavlik, Peter; Wu, Herren; Dall’Acqua, William; Chowdhury, Partha Sarathi

    2015-01-01

    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 are then used for

  12. A Novel Dual Expression Platform for High Throughput Functional Screening of Phage Libraries in Product like Format.

    PubMed

    Xiao, Xiaodong; Chen, Yan; Mugabe, Sheila; Gao, Changshou; Tkaczyk, Christine; Mazor, Yariv; Pavlik, Peter; Wu, Herren; Dall'Acqua, William; Chowdhury, Partha Sarathi

    2015-01-01

    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 are then used for

  13. Dual epithelial and immune cell function of Dvl1 regulates gut microbiota composition and intestinal homeostasis

    PubMed Central

    Belinson, Haim; Savage, Adam K.; Fadrosh, Douglas; Kuo, Yien-Ming; Lin, Din; Valladares, Ricardo; Nusse, Ysbrand; Wynshaw-Boris, Anthony; Lynch, Susan V.; Locksley, Richard M.; Klein, Ophir D.

    2016-01-01

    Homeostasis of the gastrointestinal (GI) tract is controlled by complex interactions between epithelial and immune cells and the resident microbiota. Here, we studied the role of Wnt signaling in GI homeostasis using Disheveled 1 knockout (Dvl1−/−) mice, which display an increase in whole gut transit time. This phenotype is associated with a reduction and mislocalization of Paneth cells and an increase in CD8+ T cells in the lamina propria. Bone marrow chimera experiments demonstrated that GI dysfunction requires abnormalities in both epithelial and immune cells. Dvl1−/− mice exhibit a significantly distinct GI microbiota, and manipulation of the gut microbiota in mutant mice rescued the GI transit abnormality without correcting the Paneth and CD8+ T cell abnormalities. Moreover, manipulation of the gut microbiota in wild-type mice induced a GI transit abnormality akin to that seen in Dvl1−/− mice. Together, these data indicate that microbiota manipulation can overcome host dysfunction to correct GI transit abnormalities. Our findings illustrate a mechanism by which the epithelium and immune system coregulate gut microbiota composition to promote normal GI function. PMID:27525310

  14. Dual functionality of O-GlcNAc transferase is required for Drosophila development.

    PubMed

    Mariappa, Daniel; Zheng, Xiaowei; Schimpl, Marianne; Raimi, Olawale; Ferenbach, Andrew T; Müller, H-Arno J; van Aalten, Daan M F

    2015-12-01

    Post-translational modification of intracellular proteins with O-linked N-acetylglucosamine (O-GlcNAc) catalysed by O-GlcNAc transferase (OGT) has been linked to regulation of diverse cellular functions. OGT possesses a C-terminal glycosyltransferase catalytic domain and N-terminal tetratricopeptide repeats that are implicated in protein-protein interactions. Drosophila OGT (DmOGT) is encoded by super sex combs (sxc), mutants of which are pupal lethal. However, it is not clear if this phenotype is caused by reduction of O-GlcNAcylation. Here we use a genetic approach to demonstrate that post-pupal Drosophila development can proceed with negligible OGT catalysis, while early embryonic development is OGT activity-dependent. Structural and enzymatic comparison between human OGT (hOGT) and DmOGT informed the rational design of DmOGT point mutants with a range of reduced catalytic activities. Strikingly, a severely hypomorphic OGT mutant complements sxc pupal lethality. However, the hypomorphic OGT mutant-rescued progeny do not produce F2 adults, because a set of Hox genes is de-repressed in F2 embryos, resulting in homeotic phenotypes. Thus, OGT catalytic activity is required up to late pupal stages, while further development proceeds with severely reduced OGT activity. PMID:26674417

  15. Inhibition of Monocyte Adhesion to Brain-Derived Endothelial Cells by Dual Functional RNA Chimeras

    PubMed Central

    Hu, Jing; Xiao, Feng; Hao, Xin; Bai, Shuhua; Hao, Jiukuan

    2014-01-01

    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. PMID:25368913

  16. Dual functionality of O-GlcNAc transferase is required for Drosophila development

    PubMed Central

    Mariappa, Daniel; Zheng, Xiaowei; Schimpl, Marianne; Raimi, Olawale; Ferenbach, Andrew T.; Müller, H.-Arno J.; van Aalten, Daan M. F.

    2015-01-01

    Post-translational modification of intracellular proteins with O-linked N-acetylglucosamine (O-GlcNAc) catalysed by O-GlcNAc transferase (OGT) has been linked to regulation of diverse cellular functions. OGT possesses a C-terminal glycosyltransferase catalytic domain and N-terminal tetratricopeptide repeats that are implicated in protein–protein interactions. Drosophila OGT (DmOGT) is encoded by super sex combs (sxc), mutants of which are pupal lethal. However, it is not clear if this phenotype is caused by reduction of O-GlcNAcylation. Here we use a genetic approach to demonstrate that post-pupal Drosophila development can proceed with negligible OGT catalysis, while early embryonic development is OGT activity-dependent. Structural and enzymatic comparison between human OGT (hOGT) and DmOGT informed the rational design of DmOGT point mutants with a range of reduced catalytic activities. Strikingly, a severely hypomorphic OGT mutant complements sxc pupal lethality. However, the hypomorphic OGT mutant-rescued progeny do not produce F2 adults, because a set of Hox genes is de-repressed in F2 embryos, resulting in homeotic phenotypes. Thus, OGT catalytic activity is required up to late pupal stages, while further development proceeds with severely reduced OGT activity. PMID:26674417

  17. Dual-recognition detection of Staphylococcus aureus using vancomycin-functionalized magnetic beads as concentration carriers.

    PubMed

    Yang, Shijia; Ouyang, Hui; Su, Xiaoxiao; Gao, Hongfei; Kong, Weijun; Wang, Mengyao; Shu, Qi; Fu, Zhifeng

    2016-04-15

    Vancomycin, which has a strong antibacterial effect to Gram-positive bacteria, was adopted as one molecular recognition agent for bacterial detection. Magnetic beads (MBs) were functionalized with this antibiotic to effectively concentrate Staphylococcus aureus (S. aureus). In addition, alkaline phosphatase (ALP)-tagged rabbit immunoglobulin G (ALP-IgG) was used as the second recognition agent to improve the specificity based on the binding between the Fc region of rabbit IgG and protein A in the cell wall of S. aureus. MBs-concentrated sandwich complex of vancomycin/S. aureus/ALP-IgG was formed with a one-step incubation protocol. Then ALP chemiluminescent reaction was triggered by injecting substrate solution to quantitate S. aureus. Based on the sandwich molecular recognition mechanism and MBs concentration, an ultrasensitive, specific and rapid method was developed for S. aureus detection. The linear range for S. aureus detection was 12-1.2 × 10(6)CFU mL(-1), with a very low detection limit of 3.3 CFU mL(-1). The whole detection process could be completed in 75 min. Other Gram-positive bacteria and Gram-negative bacteria, including Escherichia coli, Salmonella, Pseudomonas aeruginosa, Micrococcus luteus, Bacillus cereus and Bacillus subtilis, showed negligible interference to S. aureus detection. This method was successfully used to quantitate S. aureus in lake water, milk, human urine and human saliva with acceptable recoveries ranging from 70.0% to 116.7%. PMID:26606309

  18. Evaluation of benzaldehyde derivatives from Morinda officinalis as anti-mite agents with dual function as acaricide and mite indicator.

    PubMed

    Yang, Ji-Yeon; Kim, Min-Gi; Park, Jun-Hwan; Hong, Seong-Tshool; Lee, Hoi-Seon

    2014-01-01

    Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus with 12-30% fatality rate. Despite severity of the disease, any medication or treatment for SFTS has not developed yet. One approach to prevent SFTS spreading is to control the arthropod vector carrying SFTS virus. We report that 2-methylbenzaldehyde analogues from M. officinalis have a dual function as acaricide against Dermatophagoides spp. and Haemaphysalis longicornis and indicator (color change) against Dermatophagoides spp. Based on the LD50 values, 2,4,5-trimethylbenzaldehyde (0.21, 0.19, and 0.68 μg/cm(3)) had the highest fumigant activity against D. farinae, D. pteronyssinus, and H. longicornis, followed by 2,3-dimethylbenzaldehyde (0.46, 0.44, and 0.79 μg/cm(3)), 2,4-dimethylbenzaldehyde (0.66, 0.59, and 0.95 μg/cm(3)), 2,5-dimethylbenzaldehyde (0.65, 0.68, and 0.88 μg/cm(3)), 2-methylbenzaldehyde (0.95, 0.87, and 1.28 μg/cm(3)), 3-methylbenzaldehyde (0.99, 0.93, and 1.38 μg/cm(3)), 4-methylbenzaldehyde (1.17, 1.15, and 3.67 μg/cm(3)), and M. officinalis oil (7.05, 7.00, and 19.70 μg/cm(3)). Furthermore, color alteration of Dermatophagoides spp. was shown to be induced, from colorless to dark brown, by the treatment of 2,3-dihydroxybenzaldehyde. These finding indicated that 2-methylbenzaldehyde analogues could be developed as functional agent associated with the arthropod vector of SFTS virus and allergen. PMID:25434408

  19. Evaluation of benzaldehyde derivatives from Morinda officinalis as anti-mite agents with dual function as acaricide and mite indicator

    PubMed Central

    Yang, Ji-Yeon; Kim, Min-Gi; Park, Jun-Hwan; Hong, Seong-Tshool; Lee, Hoi-Seon

    2014-01-01

    Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus with 12–30% fatality rate. Despite severity of the disease, any medication or treatment for SFTS has not developed yet. One approach to prevent SFTS spreading is to control the arthropod vector carrying SFTS virus. We report that 2–methylbenzaldehyde analogues from M. officinalis have a dual function as acaricide against Dermatophagoides spp. and Haemaphysalis longicornis and indicator (color change) against Dermatophagoides spp. Based on the LD50 values, 2,4,5–trimethylbenzaldehyde (0.21, 0.19, and 0.68 μg/cm3) had the highest fumigant activity against D. farinae, D. pteronyssinus, and H. longicornis, followed by 2,3–dimethylbenzaldehyde (0.46, 0.44, and 0.79 μg/cm3), 2,4–dimethylbenzaldehyde (0.66, 0.59, and 0.95 μg/cm3), 2,5–dimethylbenzaldehyde (0.65, 0.68, and 0.88 μg/cm3), 2–methylbenzaldehyde (0.95, 0.87, and 1.28 μg/cm3), 3–methylbenzaldehyde (0.99, 0.93, and 1.38 μg/cm3), 4–methylbenzaldehyde (1.17, 1.15, and 3.67 μg/cm3), and M. officinalis oil (7.05, 7.00, and 19.70 μg/cm3). Furthermore, color alteration of Dermatophagoides spp. was shown to be induced, from colorless to dark brown, by the treatment of 2,3–dihydroxybenzaldehyde. These finding indicated that 2–methylbenzaldehyde analogues could be developed as functional agent associated with the arthropod vector of SFTS virus and allergen. PMID:25434408

  20. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    NASA Astrophysics Data System (ADS)

    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

  1. Functional test of pedotransfer functions to predict water flow and solute transport with the dual-permeability model MACRO

    NASA Astrophysics Data System (ADS)

    Moeys, J.; Larsbo, M.; Bergström, L.; Brown, C. D.; Coquet, Y.; Jarvis, N. J.

    2012-02-01

    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 parameterisation 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

  2. Novel Dual-Functional Membrane for Controlling Carbon Dioxide Emissions from Fossil Fuel Power Plants

    SciTech Connect

    C. Brinker; George Xomeritakis; C.-Y. Tsai; Ying-Bing Jiang

    2009-04-30

    CO{sub 2} captured from coal-fired power plants represents three-quarters of the total cost of an entire carbon sequestration process. Conventional amine absorption or cryogenic separation requires high capital investment and is very energy intensive. Our novel membrane process is energy efficient with great potential for economical CO{sub 2} capture. Three classes of microporous sol-gel derived silica-based membranes were developed for selective CO{sub 2} removal under simulated flue gas conditions (SFG), e.g. feed of 10% vol. CO{sub 22} in N{sub 2}, 1 atm total pressure, T = 50-60 C, RH>50%, SO2>10 ppm. A novel class of amine-functional microporous silica membranes was prepared using an amine-derivatized alkoxysilane precursor, exhibiting enhanced (>70) CO{sub 2}:N{sub 2} selectivity in the presence of H{sub 2}O vapor, but its CO{sub 2} permeance was lagging (<1 MPU). Pure siliceous membranes showed higher CO{sub 2} permeance (1.5-2 MPU) but subsequent densification occurred under prolonged SFG conditions. We incorporated NiO in the microporous network up to a loading of Ni:Si = 0.2 to retard densification and achieved CO2 permeance of 0.5 MPU and CO{sub 2}:N{sub 2} selectivity of 50 after 163 h exposure to SFG conditions. However, CO{sub 2} permeance should reach greater than 2.0 MPU in order to achieve the cost of electricity (COE) goal set by DOE. We introduced the atomic layer deposition (ALD), a molecular deposition technique that substantially reduces membrane thickness with intent to improve permeance and selectivity. The deposition technique also allows the incorporation of Ni or Ag cations by proper selection of metallorganic precursors. In addition, preliminary economic analysis provides a sensitivity study on the performance and cost of the proposed membranes for CO{sub 2} capture. Significant progress has been made toward the practical applications for CO{sub 2} capture. (1 MPU = 1.0 cm{sup 3}(STP){center_dot}cm-2{center_dot}min-1{center_dot}atm-1)

  3. Two New Native β-Glucosidases from Clavispora NRRL Y-50464 Confer Its Dual Function as Cellobiose Fermenting Ethanologenic Yeast.

    PubMed

    Wang, Xu; Liu, Z Lewis; Weber, Scott A; Zhang, Xiaoping

    2016-01-01

    Yeast strain Clavispora NRRL Y-50464 is able to produce cellulosic ethanol from lignocellulosic materials without addition of external β-glucosidase by simultaneous saccharification and fermentation. A β-glucosidase BGL1 protein from this strain was recently reported supporting its cellobiose utilization capability. Here, we report two additional new β-glucosidase genes encoding enzymes designated as BGL2 and BGL3 from strain NRRL Y-50464. Quantitative gene expression was analyzed and the gene function of BGL2 and BGL3 was confirmed by heterologous expression using cellobiose as a sole carbon source. Each gene was cloned and partially purified protein obtained separately for direct enzyme assay using varied substrates. Both proteins showed the highest specific activity at pH 5 and relatively strong affinity with a Km of 0.08 and 0.18 mM for BGL2 and BGL3, respectively. The optimum temperature was found to be 50°C for BGL2 and 55°C for BGL3. Both proteins were able to hydrolyze 1,4 oligosaccharides evaluated in this study. They also showed a strong resistance to glucose product inhibition with a Ki of 61.97 and 38.33 mM for BGL2 and BGL3, respectively. While BGL3 was sensitive showing a significantly reduced activity to 4% ethanol, BGL2 demonstrated tolerance to ethanol. Its activity was enhanced in the presence of ethanol but reduced at concentrations greater than 16%. The presence of the fermentation inhibitors furfural and HMF did not affect the enzyme activity. Our results suggest that a β-glucosidase gene family exists in Clavispora NRRL Y-50464 with at least three members in this group that validate its cellobiose hydrolysis functions for lower-cost cellulosic ethanol production. Results of this study confirmed the cellobiose hydrolysis function of strain NRRL Y-50464, and further supported this dual functional yeast as a candidate for lower-cost cellulosic ethanol production and next-generation biocatalyst development in potential industrial

  4. Two New Native β-Glucosidases from Clavispora NRRL Y-50464 Confer Its Dual Function as Cellobiose Fermenting Ethanologenic Yeast

    PubMed Central

    Wang, Xu; Liu, Z. Lewis; Weber, Scott A.; Zhang, Xiaoping

    2016-01-01

    Yeast strain Clavispora NRRL Y-50464 is able to produce cellulosic ethanol from lignocellulosic materials without addition of external β-glucosidase by simultaneous saccharification and fermentation. A β-glucosidase BGL1 protein from this strain was recently reported supporting its cellobiose utilization capability. Here, we report two additional new β-glucosidase genes encoding enzymes designated as BGL2 and BGL3 from strain NRRL Y-50464. Quantitative gene expression was analyzed and the gene function of BGL2 and BGL3 was confirmed by heterologous expression using cellobiose as a sole carbon source. Each gene was cloned and partially purified protein obtained separately for direct enzyme assay using varied substrates. Both proteins showed the highest specific activity at pH 5 and relatively strong affinity with a Km of 0.08 and 0.18 mM for BGL2 and BGL3, respectively. The optimum temperature was found to be 50°C for BGL2 and 55°C for BGL3. Both proteins were able to hydrolyze 1,4 oligosaccharides evaluated in this study. They also showed a strong resistance to glucose product inhibition with a Ki of 61.97 and 38.33 mM for BGL2 and BGL3, respectively. While BGL3 was sensitive showing a significantly reduced activity to 4% ethanol, BGL2 demonstrated tolerance to ethanol. Its activity was enhanced in the presence of ethanol but reduced at concentrations greater than 16%. The presence of the fermentation inhibitors furfural and HMF did not affect the enzyme activity. Our results suggest that a β-glucosidase gene family exists in Clavispora NRRL Y-50464 with at least three members in this group that validate its cellobiose hydrolysis functions for lower-cost cellulosic ethanol production. Results of this study confirmed the cellobiose hydrolysis function of strain NRRL Y-50464, and further supported this dual functional yeast as a candidate for lower-cost cellulosic ethanol production and next-generation biocatalyst development in potential industrial

  5. Structure of the dual-function fructose-1,6/sedoheptulose-1,7-bisphosphatase from Thermosynechococcus elongatus bound with sedoheptulose-7-phosphate.

    PubMed

    Cotton, Charles A R; Kabasakal, Burak V; Miah, Nishat A; Murray, James W

    2015-10-01

    The dual-function fructose-1,6/sedoheptulose-1,7-bisphosphatase (FBP/SBPase) in cyanobacteria carries out two activities in the Calvin cycle. Structures of this enzyme from the cyanobacterium Synechocystis sp. PCC 6803 exist, but only with adenosine monophosphate (AMP) or fructose-1,6-bisphosphate and AMP bound. The mechanisms which control both selectivity between the two sugars and the structural mechanisms for redox control are still unresolved. Here, the structure of the dual-function FBP/SBPase from the thermophilic cyanobacterium Thermosynechococcus elongatus is presented with sedoheptulose-7-phosphate bound and in the absence of AMP. The structure is globally very similar to the Synechocystis sp. PCC 6803 enzyme, but highlights features of selectivity at the active site and loop ordering at the AMP-binding site. Understanding the selectivity and control of this enzyme is critical for understanding the Calvin cycle in cyanobacteria and for possible biotechnological application in plants. PMID:26457528

  6. 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

    NASA Astrophysics Data System (ADS)

    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.

  7. A dual enzyme functionalized nanostructured thulium oxide based interface for biomedical application

    NASA Astrophysics Data System (ADS)

    Singh, Jay; Roychoudhury, Appan; Srivastava, Manish; Solanki, Pratima R.; Lee, Dong Won; Lee, Seung Hee; Malhotra, B. D.

    2013-12-01

    nanorods has been electrophoretically deposited (EPD) onto an indium-tin-oxide (ITO) glass substrate. The n-Tm2O3 nanorods are found to provide improved sensing characteristics to the electrode interface in terms of electroactive surface area, diffusion coefficient, charge transfer rate constant and electron transfer kinetics. The structural and morphological studies of n-Tm2O3 nanorods have been carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopic techniques. This interfacial platform has been used for fabrication of a total cholesterol biosensor by immobilizing cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) onto a Tm2O3 nanostructured surface. The results of response studies of the fabricated ChEt-ChOx/n-Tm2O3/ITO bioelectrode show a broad linear range of 8-400 mg dL-1, detection limit of 19.78 mg (dL cm-2)-1, and high sensitivity of 0.9245 μA (mg per dL cm-2)-1 with a response time of 40 s. Further, this bioelectrode has been utilized for estimation of total cholesterol with negligible interference (3%) from analytes present in human serum samples. The utilization of this n-Tm2O3 modified electrode for enzyme-based biosensor analysis offers an efficient strategy and a novel interface for application of the rare earth metal oxide materials in the field of electrochemical sensors and bioelectronic devices. Electronic supplementary information (ESI) available: XPS spectra of n-Tm2O3, differential pulse voltammograms, magnitude of potential difference as a function of scan rate (10-100 mV s-1), effect of working potential, amount of enzyme used for immobilization, amount of enzyme loading, effect of interferents, response time, effect of temperature, determination of cholesterol in serum samples and photometric enzyme activity studies. See DOI: 10.1039/c3nr05043b

  8. A dual-functional asymmetric squaraine-based low band gap hole transporting material for efficient perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Paek, Sanghyun; Rub, Malik Abdul; Choi, Hyeju; Kosa, Samia A.; Alamry, Khalid A.; Cho, Jin Woo; Gao, Peng; Ko, Jaejung; Asiri, Abdullah M.; Nazeeruddin, Mohammad Khaja

    2016-03-01

    We demonstrate for the first time an asymmetric squaraine-based low band-gap hole transporting material, which acted as both light harvesting and hole transporting layers in methylammonium lead triiodide perovskite solar cells. Opto-electrochemical characterization revealed extremely high molar extinction coefficients of the absorption bands in the low energy region and prominent space charge delocalization due to its electronically asymmetric nature. A suitable band alignment of the squaraine HOMO level with the valence band edge of the perovskite, and the conduction band of the TiO2 with LUMO of the perovskite allowed a cascade of hole extraction and electron injection, respectively. Red-shifted absorption was observed for both HTMs in thin films coated on the perovskite, and the optimized devices exhibited an impressive PCE of 14.7% under full sunlight illumination (100 mW cm-2, AM1.5 G). The efficiency value is comparable to that of the devices using a state-of-the-art spiro-OMeTAD hole transport layer under similar conditions. Ambient stability after 300 h revealed that 88% of the initial efficiency remained for JK-216D, and almost no change for JK-217D, indicating that the devices had good long-term stability thus suggesting that the asymmetric squaraines have great potential as a dual-functional HTM for high performance perovskite solar cells.We demonstrate for the first time an asymmetric squaraine-based low band-gap hole transporting material, which acted as both light harvesting and hole transporting layers in methylammonium lead triiodide perovskite solar cells. Opto-electrochemical characterization revealed extremely high molar extinction coefficients of the absorption bands in the low energy region and prominent space charge delocalization due to its electronically asymmetric nature. A suitable band alignment of the squaraine HOMO level with the valence band edge of the perovskite, and the conduction band of the TiO2 with LUMO of the perovskite allowed

  9. A dual positional specific lipoxygenase functions in the generation of flavor compounds during climacteric ripening of apple

    PubMed Central

    Schiller, Doreen; Contreras, Carolina; Vogt, Jörg; Dunemann, Frank; Defilippi, Bruno G; Beaudry, Randolph; Schwab, Wilfried

    2015-01-01

    Lipoxygenase (LOX) is an important contributor to the formation of aroma-active C6 aldehydes in apple (Malus × domestica) fruit upon tissue disruption but little is known about its role in autonomously produced aroma volatiles from intact tissue. We explored the expression of 22 putative LOX genes in apple throughout ripening, but only six LOXs were expressed in a ripening-dependent manner. Recombinant LOX1:Md:1a, LOX1:Md:1c, LOX2:Md:2a and LOX2:Md:2b proteins showed 13/9-LOX, 9-LOX, 13/9-LOX and 13-LOX activity with linoleic acid, respectively. While products of LOX1:Md:1c and LOX2:Md:2b were S-configured, LOX1:Md:1a and LOX2:Md:2a formed 13(R)-hydroperoxides as major products. Site-directed mutagenesis of Gly567 to an alanine converted the dual positional specific LOX1:Md:1a to an enzyme with a high specificity for 9(S)-hydroperoxide formation. The high expression level of the corresponding MdLOX1a gene in stored apple fruit, the genetic association with a quantitative trait locus for fruit ester and the remarkable agreement in regio- and stereoselectivity of the LOX1:Md:1a reaction with the overall LOX activity found in mature apple fruits, suggest a major physiological function of LOX1:Md:1a during climacteric ripening of apples. While LOX1:Md:1c, LOX2:Md:2a and LOX2:Md:2b may contribute to aldehyde production in immature fruit upon cell disruption our results furnish additional evidence that LOX1:Md:1a probably regulates the availability of precursors for ester production in intact fruit tissue. PMID:26504564

  10. A dual positional specific lipoxygenase functions in the generation of flavor compounds during climacteric ripening of apple.

    PubMed

    Schiller, Doreen; Contreras, Carolina; Vogt, Jörg; Dunemann, Frank; Defilippi, Bruno G; Beaudry, Randolph; Schwab, Wilfried

    2015-01-01

    Lipoxygenase (LOX) is an important contributor to the formation of aroma-active C6 aldehydes in apple (Malus × domestica) fruit upon tissue disruption but little is known about its role in autonomously produced aroma volatiles from intact tissue. We explored the expression of 22 putative LOX genes in apple throughout ripening, but only six LOXs were expressed in a ripening-dependent manner. Recombinant LOX1:Md:1a, LOX1:Md:1c, LOX2:Md:2a and LOX2:Md:2b proteins showed 13/9-LOX, 9-LOX, 13/9-LOX and 13-LOX activity with linoleic acid, respectively. While products of LOX1:Md:1c and LOX2:Md:2b were S-configured, LOX1:Md:1a and LOX2:Md:2a formed 13(R)-hydroperoxides as major products. Site-directed mutagenesis of Gly567 to an alanine converted the dual positional specific LOX1:Md:1a to an enzyme with a high specificity for 9(S)-hydroperoxide formation. The high expression level of the corresponding MdLOX1a gene in stored apple fruit, the genetic association with a quantitative trait locus for fruit ester and the remarkable agreement in regio- and stereoselectivity of the LOX1:Md:1a reaction with the overall LOX activity found in mature apple fruits, suggest a major physiological function of LOX1:Md:1a during climacteric ripening of apples. While LOX1:Md:1c, LOX2:Md:2a and LOX2:Md:2b may contribute to aldehyde production in immature fruit upon cell disruption our results furnish additional evidence that LOX1:Md:1a probably regulates the availability of precursors for ester production in intact fruit tissue. PMID:26504564

  11. Dual functional BAFF receptor aptamers inhibit ligand-induced proliferation and deliver siRNAs to NHL cells

    PubMed Central

    Zhou, Jiehua; Tiemann, Katrin; Chomchan, Pritsana; Alluin, Jessica; Swiderski, Piotr; Burnett, John; Zhang, Xizhe; Forman, Stephen; Chen, Robert; Rossi, John

    2013-01-01

    The B-cell–activating factor (BAFF)-receptor (BAFF-R) is restrictedly expressed on B-cells and is often overexpressed in B-cell malignancies, such as non-Hodgkin’s lymphoma. On binding to its ligand BAFF, proliferation and cell survival are increased, enabling cancer cells to proliferate faster than normal B-cells. Nucleic acid aptamers can bind to target ligands with high specificity and affinity and may offer therapeutic advantages over antibody-based approaches. In this study, we isolated several 2′-F–modified RNA aptamers targeting the B-cell–specific BAFF-R with nanomolar affinity using in vitro SELEX technology. The aptamers efficiently bound to BAFF-R on the surface of B-cells, blocked BAFF-mediated B-cell proliferation and were internalized into B-cells. Furthermore, chimeric molecules between the BAFF-R aptamer and small interfering RNAs (siRNAs) were specifically delivered to BAFF-R expressing cells with a similar efficiency as the aptamer alone. We demonstrate that a signal transducer and activator of transcription 3 (STAT3) siRNA delivered by the BAFF-R aptamer was processed by Dicer and efficiently reduced levels of target mRNA and protein in Jeko-1 and Z138 human B-cell lines. Collectively, our results demonstrate that the dual-functional BAFF-R aptamer–siRNA conjugates are able to deliver siRNAs and block ligand mediated processes, suggesting it might be a promising combinatorial therapeutic agent for B-cell malignancies. PMID:23470998

  12. Magnetic multiwall carbon nanotubes modified with dual hydroxy functional ionic liquid for the solid-phase extraction of protein.

    PubMed

    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. PMID:25826781

  13. Functional and Radiological Outcome of Schatzker type V and VI Tibial Plateau Fracture Treatment with Dual Plates with Minimum 3 years follow-up: A Prospective Study

    PubMed Central

    Suri, Harpreet Singh; Gangrade, Kewal

    2016-01-01

    Introduction High energy intra-articular fractures involving the tibial plateau causes various problems related to management like wound dehiscence, severe comminution leading to malalignment and delayed complications like varus collapse, implant failure and arthritis of knee joint. Aim This study was done to determine functional, radiological outcome and the complications of Schatzker V and VI tibial plateau fractures treated with bipillar plating with dual plates with a regular follow-up of atleast 3 years. Materials and Methods Total 34 cases of tibial plateau fracture type V and VI treated with dual plating were studied from January 2011 to December 2013 in KIMS Hospital were followed for minimum of 3 years. The patients were operated through an anterolateral approach for lateral plate and a medial column plate was put through a minimally invasive medial approach or an open posteromedial approach. Results Total 34 patients were evaluated postoperatively thoroughly for functional outcome using The Knee Society Score and radiological outcomes by Modified Rasmussen Assessment criteria which showed 29 patients (85.29%) had excellent and 5 patients (14.71%) had good objective knee society score. 24 patients (70.59%) had excellent, 8 patients (23.53%) had good and 1patient (2.94%) were each of poor and fair functional knee society score. Eleven patients (32.35%) had excellent, 21patients (61.76%) had good and 2 patients (5.88%) had fair radiological outcome. Conclusion We conclude that open reduction and internal fixation of high-energy tibial plateau fractures with dual plates via 2 incisions gives excellent to good functional outcome with minimal soft tissue complications. Thus, a minimally invasive approach should be used which helps in preventing soft tissue problems and helps in early wound healing. Fixation done by bipillar plating is important for early mobilization of knee joint. Early mobilization leads to better range of movements and thereby better

  14. Dual-Task Processing as a Measure of Executive Function: A Comparison between Adults with Williams and Down Syndromes

    ERIC Educational Resources Information Center

    Kittler, Phyllis M.; Krinsky-McHale, Sharon J.; Devenny, Darlynne A.

    2008-01-01

    Behavioral phenotypes of individuals with Williams syndrome and individuals with Down syndrome have been contrasted in relation to short-term memory. People with Down syndrome are stronger visuospatially and those with Williams syndrome are stronger verbally. We examined short-term memory, then explored whether dual-task processing further…

  15. Dual-modal fluorescent/magnetic bioprobes based on small sized upconversion nanoparticles of amine-functionalized BaGdF5:Yb/Er

    NASA Astrophysics Data System (ADS)

    Zeng, Songjun; Tsang, Ming-Kiu; Chan, Chi-Fai; Wong, Ka-Leung; Fei, Bin; Hao, Jianhua

    2012-07-01

    A new type of BaGdF5:Yb/Er nanoprobe for dual-modal fluorescent and magnetic resonance imaging (MRI) is demonstrated. Water soluble and amine-functionalized BaGdF5:Yb/Er nanoparticles (NPs) with average size of about 10 nm were synthesized by a facile one-pot hydrothermal method. The in vitro up-converted emission of BaGdF5:Yb/Er NPs is observed in HeLa cells with near-infrared excitation at 980 nm and served as a fluorescent label. In addition, the cytotoxicity assay in HeLa cells shows low cell toxicity of the amine-functionalized BaGdF5:Yb/Er NPs. Moreover, these BaGdF5 NPs exhibit excellent intrinsic paramagnetic properties and enhanced T1-weighted MRI images with increased concentrations of BaGdF5 NPs. Therefore, these results suggest that the amine-functionalized BaGdF5 NPs with an optimized size and low cell toxicity are promising dual-modal bioprobes for optical bioimaging and MRI.A new type of BaGdF5:Yb/Er nanoprobe for dual-modal fluorescent and magnetic resonance imaging (MRI) is demonstrated. Water soluble and amine-functionalized BaGdF5:Yb/Er nanoparticles (NPs) with average size of about 10 nm were synthesized by a facile one-pot hydrothermal method. The in vitro up-converted emission of BaGdF5:Yb/Er NPs is observed in HeLa cells with near-infrared excitation at 980 nm and served as a fluorescent label. In addition, the cytotoxicity assay in HeLa cells shows low cell toxicity of the amine-functionalized BaGdF5:Yb/Er NPs. Moreover, these BaGdF5 NPs exhibit excellent intrinsic paramagnetic properties and enhanced T1-weighted MRI images with increased concentrations of BaGdF5 NPs. Therefore, these results suggest that the amine-functionalized BaGdF5 NPs with an optimized size and low cell toxicity are promising dual-modal bioprobes for optical bioimaging and MRI. Electronic supplementary information (ESI) available: FTIR spectra, EDS, and the simplified energy-level diagrams of Yb3+/Er3+. See DOI: 10.1039/c2nr31294h

  16. The dual role of oxygen functions in coal pretreatment and liquefaction: Crosslinking and cleavage reactions. First annual report, April 1, 1991--March 31, 1992

    SciTech Connect

    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.

  17. The Dual Functions of WLIM1a in Cell Elongation and Secondary Wall Formation in Developing Cotton Fibers[C][W

    PubMed Central

    Han, Li-Bo; Li, Yuan-Bao; Wang, Hai-Yun; Wu, Xiao-Min; Li, Chun-Li; Luo, Ming; Wu, Shen-Jie; Kong, Zhao-Sheng; Pei, Yan; Jiao, Gai-Li; Xia, Gui-Xian

    2013-01-01

    LIN-11, Isl1 and MEC-3 (LIM)-domain proteins play pivotal roles in a variety of cellular processes in animals, but plant LIM functions remain largely unexplored. Here, we demonstrate dual roles of the WLIM1a gene in fiber development in upland cotton (Gossypium hirsutum). WLIM1a is preferentially expressed during the elongation and secondary wall synthesis stages in developing fibers. Overexpression of WLIM1a in cotton led to significant changes in fiber length and secondary wall structure. Compared with the wild type, fibers of WLIM1a-overexpressing plants grew longer and formed a thinner and more compact secondary cell wall, which contributed to improved fiber strength and fineness. Functional studies demonstrated that (1) WLIM1a acts as an actin bundler to facilitate elongation of fiber cells and (2) WLIM1a also functions as a transcription factor to activate expression of Phe ammonia lyase–box genes involved in phenylpropanoid biosynthesis to build up the secondary cell wall. WLIM1a localizes in the cytosol and nucleus and moves into the nucleus in response to hydrogen peroxide. Taken together, these results demonstrate that WLIM1a has dual roles in cotton fiber development, elongation, and secondary wall formation. Moreover, our study shows that lignin/lignin-like phenolics may substantially affect cotton fiber quality; this finding may guide cotton breeding for improved fiber traits. PMID:24220634

  18. Redoxable heteronanocrystals functioning magnetic relaxation switch for activatable T1 and T2 dual-mode magnetic resonance imaging.

    PubMed

    Kim, Myeong-Hoon; Son, Hye-Young; Kim, Ga-Yun; Park, Kwangyeol; Huh, Yong-Min; Haam, Seungjoo

    2016-09-01

    T1/T2 dual-mode magnetic resonance (MR) contrast agents (DMCAs) have gained much attention because of their ability to improve accuracy by providing two pieces of complementary information with one instrument. However, most of these agents are "always ON" systems that emit MR contrast regardless of their interaction with target cells or biomarkers, which may result in poor target-to-background ratios. Herein, we introduce a rationally designed magnetic relaxation switch (MGRS) for an activatable T1/T2 dual MR imaging system. Redox-responsive heteronanocrystals, consisting of a superparamagnetic Fe3O4 core and a paramagnetic Mn3O4 shell, are synthesized through seed-mediated growth and subsequently surface-modified with polysorbate 80. The Mn3O4 shell acts as both a protector of Fe3O4 in aqueous environments to attenuate T2 relaxation and as a redoxable switch that can be activated in intracellular reducing environments by glutathione. This simultaneously generates large amounts of magnetically decoupled Mn(2+) ions and allows Fe3O4 to interact with the water protons. This smart nanoplatform shows an appropriate hydrodynamic size for the EPR effect (10-100 nm) and demonstrates biocompatibility. Efficient transitions of OFF/ON dual contrast effects are observed by in vitro imaging and MR relaxivity measurements. The ability to use these materials as DMCAs is demonstrated via effective passive tumor targeting for T1- and T2-weighted MR imaging in tumor-bearing mice. PMID:27281684

  19. Dual-modality imaging

    NASA Astrophysics Data System (ADS)

    Hasegawa, Bruce; Tang, H. Roger; Da Silva, Angela J.; Wong, Kenneth H.; Iwata, Koji; Wu, Max C.

    2001-09-01

    In comparison to conventional medical imaging techniques, dual-modality imaging offers the advantage of correlating anatomical information from X-ray computed tomography (CT) with functional measurements from single-photon emission computed tomography (SPECT) or with positron emission tomography (PET). The combined X-ray/radionuclide images from dual-modality imaging can help the clinician to differentiate disease from normal uptake of radiopharmaceuticals, and to improve diagnosis and staging of disease. In addition, phantom and animal studies have demonstrated that a priori structural information from CT can be used to improve quantification of tissue uptake and organ function by correcting the radionuclide data for errors due to photon attenuation, partial volume effects, scatter radiation, and other physical effects. Dual-modality imaging therefore is emerging as a method of improving the visual quality and the quantitative accuracy of radionuclide imaging for diagnosis of patients with cancer and heart disease.

  20. Dual-beam ELF wave generation as a function of power, frequency, modulation waveform, and receiver location

    NASA Astrophysics Data System (ADS)

    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.

  1. Sensitive Immunosensor for Cancer Biomarker Based on Dual Signal Amplification Strategy of Graphene Sheets and Multi-Enzyme Functionalized Carbon Nanospheres

    SciTech Connect

    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.

  2. Dual Esterase- and Steroid-Responsive Energy Transfer Modulation of Ruthenium(II) and Rhenium(I) Complex Functionalized Gold Nanoparticles.

    PubMed

    Leung, Frankie Chi-Ming; Au, Vonika Ka-Man; Song, Hai-Ou; Yam, Vivian Wing-Wah

    2015-11-01

    A number of adamantane-containing ruthenium(II) and rhenium(I) complexes have been synthesized, characterized, and noncovalently functionalized with β-cyclodextrin-capped gold nanoparticles (β-CD-GNPs) through the host-guest interaction between cyclodextrin and adamantane. The resultant nanoconjugates have been characterized by transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), and 2D ROESY (1) H NMR experiments. The Förster resonance energy transfer (FRET) properties of the nanoconjugates can be modulated by both esterase-accelerated hydrolysis and competitive displacement of steroid, by monitoring the emission intensity and luminescence lifetime. The FRET efficiencies are found to vary with the nature of the chromophores and the length of the spacer between the transition metal complexes and the GNPs. This work constitutes a "proof-of-principle" assay method for the dual-functional detection of important classes of biomolecules, such as enzymes and steroids. PMID:26395881

  3. Reversal of multidrug resistance by co-delivery of paclitaxel and lonidamine using a TPGS and hyaluronic acid dual-functionalized liposome for cancer treatment.

    PubMed

    Assanhou, Assogba G; Li, Wenyuan; Zhang, Lei; Xue, Lingjing; Kong, Lingyi; Sun, Hongbin; Mo, Ran; Zhang, Can

    2015-12-01

    Multidrug resistance (MDR) remains the primary issue in cancer therapy, which is characterized by the overexpressed P-glycoprotein (P-gp)-included efflux pump or the upregulated anti-apoptotic proteins. In this study, a D-alpha-tocopheryl poly (ethylene glycol 1000) succinate (TPGS) and hyaluronic acid (HA) dual-functionalized cationic liposome containing a synthetic cationic lipid, 1,5-dioctadecyl-N-histidyl-L-glutamate (HG2C18) was developed for co-delivery of a small-molecule chemotherapeutic drug, paclitaxel (PTX) with a chemosensitizing agent, lonidamine (LND) to treat the MDR cancer. It was demonstrated that the HG2C18 lipid contributes to the endo-lysosomal escape of the liposome following internalization for efficient intracellular delivery. The TPGS component was confirmed able to elevate the intracellular accumulation of PTX by inhibiting the P-gp efflux, and to facilitate the mitochondrial-targeting of the liposome. The intracellularly released LND suppressed the intracellular ATP production by interfering with the mitochondrial function for enhanced P-gp inhibition, and additionally, sensitized the MDR breast cancer (MCF-7/MDR) cells to PTX for promoted induction of apoptosis through a synergistic effect. Functionalized with the outer HA shell, the liposome preferentially accumulated at the tumor site and showed a superior antitumor efficacy in the xenograft MCF-7/MDR tumor mice models. These findings suggest that this dual-functional liposome for co-delivery of a cytotoxic drug and an MDR modulator provides a promising strategy for reversal of MDR in cancer treatment. PMID:26426537

  4. Multi-functionalized hyaluronic acid nanogels crosslinked with carbon dots as dual receptor-mediated targeting tumor theranostics.

    PubMed

    Jia, Xu; Han, Yu; Pei, Mingliang; Zhao, Xubo; Tian, Kun; Zhou, Tingting; Liu, Peng

    2016-11-01

    Hyaluronic acid (HA)-based theranostic nanogels were designed for the tumor diagnosis and chemotherapy, by crosslinking the folate-terminated poly(ethylene glycol) modified hyaluronic acid (FA-PEG-HA) with carbon dots (CDs) for the first time. Due to the extraordinary fluorescence property of the integrated CDs, the theranostic nanogels could be used for the real-time and noninvasive location tracking to cancer cells. HA could load Doxorubicin (DOX) via electrostatic interaction with a drug-loading capacity (DLC) of 32.5%. The nanogels possessed an ideal release of DOX in the weak acid environment, while it was restrained in the neutral media, demonstrating the pH-responsive controlled release behavior. The cytotoxicity and cellular uptake results clearly illustrated that most DOX was released and accumulated in the cell nuclei and killed the cancer cells efficaciously, due to their dual receptor-mediated targeting characteristics. PMID:27516286

  5. Effects of cognitive function on gait and dual tasking abilities in patients with Parkinson's disease suffering from motor response fluctuations.

    PubMed

    Plotnik, Meir; Dagan, Yaacov; Gurevich, Tanya; Giladi, Nir; Hausdorff, Jeffrey M

    2011-01-01

    Recent studies have demonstrated that cognitive loading aggravates the gait impairments that are typically seen in Parkinson's disease (PD). To better understand the relationship between cognition and gait in PD, we evaluated 30 subjects with PD who suffer from motor response fluctuations. The subjects were clinically and cognitively assessed using standard clinical (e.g., Unified Parkinson's Disease Rating Scale) and cognitive tests while in the "ON" period of the medication cycle. In addition, the subjects wore force-sensitive insoles to quantify the timing of the gait cycles during 80-m walks at a self-selected, comfortable pace during three randomly presented gait conditions: (1) usual-walking, (2) dual tasking (DT), performing serial 3 subtractions (DT_S3), and (3) DT_S7. Stride length, gait speed, gait variability and bilateral coordination of gait were affected by DT, compared to the usual-walking (P < 0.001) as was gait asymmetry (P = 0.024). Stepwise regression analyses showed that a subset of the cognitive performance scores accounted for the changes seen in the gait parameters during DT, e.g., set shifting capabilities as expressed by the Trial Making Test Scores (P < 0.001). Affect (e.g., anxiety) was not associated with DT-related gait changes. For most gait features, DT had a large impact on the DT_S3 condition with only minimal additional effect in the DT_S7 condition. These results demonstrate that the complex cognitive-motor interplay in the control of gait in patients with PD who suffer from motor response fluctuations has a profound and marked effect during DT conditions on gait variability, asymmetry and bilateral coordination, even in the "ON" state when patients are likely to be most active, mobile and vulnerable to the negative effects of dual tasking. PMID:21063692

  6. Development of a Functional Ruthenium(II) Complex that Can Act as a Photoluminescent and Electrochemiluminescent Dual-signaling Probe for Hypochlorous Acid.

    PubMed

    Yu, Xiaojing; Zhang, Wenzhu; Ye, Zhiqiang; Song, Bo; Yuan, Jingli

    2015-07-01

    A functional ruthenium(II) complex that can act as a probe for response to hypochlorous acid (HOCl) in aqueous media with photoluminescence (PL) and electrochemiluminescence (ECL) dual-signals, [Ru(bpy)2(DB-phen)](PF6)2 [bpy: 2,2'-bipyridine; DB-phen: 5-(2,4-dimethoxybenzylamino)-1,10-phenanthroline)], has been designed and synthesized. The complex is highly luminescent both under the light excitation and the electrochemical induction. It can specifically react with HOCl in physiological pH aqueous media to afford its chlorinated derivative, [Ru(bpy)2(DBCA-phen)](PF6)2 [DBCA-phen: 5-(2,4-dimethoxybenzyl-chloroamino)- 1,10-phenanthroline], accompanied by remarkable decreases in its PL and ECL intensities. The PL and ECL abatements of [Ru(bpy)2(DB-phen)](PF6)2 show good linear correlation to the concentration of HOCl with detection limits at low micromolar concentration level, and the PL and ECL responses of the complex to HOCl are highly specific without interferences of other reactive oxygen/nitrogen species. These features enabled [Ru(bpy)2(DB-phen)](PF6)2 to be used as a probe for the highly selective and sensitive detection of HOCl in aqueous media with PL and ECL dual-modes. PMID:25962768

  7. Inhibition of MDR1 gene expression and enhancing cellular uptake for effective colon cancer treatment using dual-surface–functionalized nanoparticles

    PubMed Central

    Xiao, Bo; Zhang, Mingzhen; Viennois, Emilie; Zhang, Yuchen; Wei, Na; Baker, Mark T.; Jung, Yunjin; Merlin, Didier

    2015-01-01

    Nanomedicine options for colon cancer therapy have been limited by the lack of suitable carriers capable of delivering sufficient drug into tumors to cause lethal toxicity. To circumvent this limitation, we fabricated a camptothecin (CPT)-loaded poly(lactic-co-glycolic acid) nanoparticle (NP) with dual-surface functionalization—Pluronic F127 and chitosan—for inhibiting multi-drug resistant gene 1 (MDR1) expression and enhancing tumor uptake. The resultant spherical NPs-P/C had a desirable particle size (~268 nm), slightly positive zeta-potential, and the ability to efficiently down-regulate the expression of MDR1. In vitro cytotoxicity tests revealed that the 24 and 48 h IC50 values of NPs-P/C1 were 2.03 and 0.67 µM, respectively, which were much lower than those for free CPT and other NPs. Interestingly, NPs-P/C1 showed the highest cellular uptake efficiency (approximately 85.5%) among the different drug formulations. Most importantly, treatment of colon tumor-bearing mice with various drug formulations confirmed that the introduction of Pluronic F127 and chitosan to the NP surface significantly enhanced the therapeutic efficacy of CPT, induced tumor cell apoptosis, and reduced systemic toxicity. Collectively, these findings suggest that our one-step–fabricated, dual-surface–functionalized NPs may hold promise as a readily scalable and effective drug carrier with clinical potential in colon cancer therapy. PMID:25701040

  8. Calix[8]arene functionalized single-walled carbon nanohorns for dual-signalling electrochemical sensing of aconitine based on competitive host-guest recognition.

    PubMed

    Yang, Long; Ran, Xin; Cai, Le; Li, Yucong; Zhao, Hui; Li, Can-Peng

    2016-09-15

    A dual-signalling electrochemical approach has been developed towards aconitine based on competitive host-guest interaction by selecting methylene blue (MB) and p-sulfonated calix[8]arene functionalized single-walled carbon nanohorns (SCX8-SWCNHs) as the "reporter pair". Upon the presence of aconitine to the performed SCX8-SWCNHs·MB complex, the MB molecules are displaced by aconitine. This results in a decreased oxidation peak current of MB and the appearance of an oxidation peak of aconitine, and the changes of these signals correlate linearly with the concentration of aconitine. A linear response range of 1.00-10.00μM for aconitine with a low detection limit of 0.18μM (S/N=3) was obtained by using the proposed method. This method could be successfully utilized to detect aconitine in serum samples. This dual-signalling sensor can provide more sensitive target recognition and will have important applications in the sensitive and selective electrochemical detection of aconitine. PMID:27135940

  9. The dual function of PRMT1 in modulating epithelial-mesenchymal transition and cellular senescence in breast cancer cells through regulation of ZEB1

    PubMed Central

    Gao, Yanyan; Zhao, Yaping; Zhang, Juechao; Lu, Yang; Liu, Xin; Geng, Pengyu; Huang, Baiqu; Zhang, Yu; Lu, Jun

    2016-01-01

    Although the involvement of protein arginine methyltransferase 1 (PRMT1) in tumorigenesis has been reported, its roles in breast cancer progression and metastasis has not been elucidated. Here we identified PRMT1 as a key regulator of the epithelial-mesenchymal transition (EMT) in breast cancer. We showed that the EMT program induced by PRMT1 endowed the human mammary epithelial cells with cancer stem cell properties. Moreover, PRMT1 promoted the migratory and invasive behaviors in breast cancer cells. We also demonstrated that abrogation of PRMT1 expression in breast cancer cells abated metastasis in vivo in mouse model. In addition, knockdown of PRMT1 arrested cell growth in G1 tetraploidy and induced cellular senescence. Mechanistically, PRMT1 impacted EMT process and cellular senescence by mediating the asymmetric dimethylation of arginine 3 of histone H4 (H4R3me2as) at the ZEB1 promoter to activate its transcription, indicating the essential roles of this epigenetic control both in EMT and in senescence. Thus, we unraveled a dual function of PRMT1 in modulation of both EMT and senescence via regulating ZEB1. This finding points to the potent value of PRMT1 as a dual therapeutic target for preventing metastasis and for inhibiting cancer cell growth in malignant breast cancer patients. PMID:26813495

  10. A novel p-type and metallic dual-functional Cu-Al2O3 ultra-thin layer as the back electrode enabling high performance of thin film solar cells.

    PubMed

    Lin, Qinxian; Su, Yantao; Zhang, Ming-Jian; Yang, Xiaoyang; Yuan, Sheng; Hu, Jiangtao; Lin, Yuan; Liang, Jun; Pan, Feng

    2016-09-14

    Increasing the open-circuit voltage (Voc) along with the fill factor (FF) is pivotal for the performance improvement of solar cells. In this work, we report the design and construction of a new structure of CdS/CdTe/Al2O3/Cu using the atomic layer deposition (ALD) method, and then we control Cu diffusion through the Al2O3 atomic layer into the CdTe layer. Surprisingly, this generates a novel p-type and metallic dual-functional Cu-Al2O3 atomic layer. Due to this dual-functional character of the Cu-Al2O3 layer, an efficiency improvement of 2% in comparison with the standard cell was observed. This novel dual-functional back contact structure could also be introduced into other thin film solar cells for their efficiency improvement. PMID:27384986