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Sample records for bases moleculares experiencia

  1. experiencia latinoamericana

    Directory of Open Access Journals (Sweden)

    José Ruiz Valerio

    2008-01-01

    Full Text Available Los objetivos del trabajo son: 1 analizar algunas de las principales aportaciones teóricas acerca del presidencialismo de coalición en Amé- rica Latina; 2 analizar las principales características de los gobiernos de coalición bajo sistemas presidenciales, a partir de la experiencia de 11 países de América Latina, proponiendo algunos rasgos comunes que puedan ayudar a definir al presidencialismo de coalición como modelo político; 3 analizar la relación existente entre el presidencialismo y la organización territorial del poder (unitaria o federal en dichos países; 4 analizar el impacto que la organización territorial del poder posee sobre la construcción de coaliciones presidenciales de gobierno; 5 proponer algunas conclusiones que puedan servir de base a nuevos estudios sobre el tema.

  2. UNA EXPERIENCIA EN CUBA

    Directory of Open Access Journals (Sweden)

    Lucy Martin

    2003-01-01

    Full Text Available Este artículo examina, desde una perspectiva so- cial, las experiencias de trabajo que un equipo multidisciplinario del INCA lleva a cabo en tres cooperativas de producción agropecuaria (CPA del sur de La Habana y en una cooperati- va de créditos y servicios (CCS de La Palma, Pinar del Río, con el objetivo de encontrar vías complementarias del fitomejoramiento formal por la vía participativa, se pretende destacar cómo en una experiencia de fitomejoramiento con la participación de los productores, se va operando una movili- zación de cambio no solo técnico sino también social, pero que a su vez reclama, para su éxito, de un movimiento en dos direcciones: participación y descentralización. Importantes lec- turas de esta experiencia son, en primer lugar, la posibilidad de construcción de conocimiento nuevo rompiendo mitos, a tra- vés de un diálogo de saberes y con la participación de los productores al tiempo que se producen cambios no solo de alcance técnico, en el ámbito de las semillas y las variedades, sino también de carácter social. En segundo lugar, revela las posibilidades de una experiencia de esta naturaleza, como ver- tiente del desarrollo sostenible y como vía de reconstrucción desde la base de nuestro proyecto social, al posibilitar el forta- lecimiento de los productores y la articulación entre actores sociales protagónicos en el sistema de semilla y en la vida comunitaria en torno a intereses comunes.

  3. Experiencia docente en diseño de bases de datos con la ayuda de herramientas de e-learning

    OpenAIRE

    Soler Masó, Josep; Boada Oliveras, Immaculada; Prados Carrasco, Ferran; Fabregat Gesa, Ramón; Poch Garcia, Jordi

    2009-01-01

    Una de las competencias básicas en torno a la materia de bases de datos consiste en realizar el diseño conceptual y lógico de una base de datos relacional. En este artículo se presenta la experiencia realizada en el diseño de una base de datos con un número considerable de tablas y en relación a la organización y gestión de una empresa real. Para facilitar las tareas de corrección y evaluación a los profesores implicados se ha utilizado una plataforma de e-learning que corrige diagramas entid...

  4. Experiencia remisión de V. ciencia y experiencia.

    OpenAIRE

    2011-01-01

    [ES] Definición del término Experiencia remisión de V. ciencia y experiencia. en el diccionario Dicter. [EN] Definition of the word Experiencia remisión de V. ciencia y experiencia. in the dictionary Dicter.

  5. Experiencia didactica con dinosaurios

    OpenAIRE

    Santalucita, F.; Aragón, M.; Chiarelli, P.

    2009-01-01

    Esta experiencia se realizo en la ciudad La Plata en el año 2002 en el Parque Ecológico de esa ciudad luego en el 2003, nos invitaron a participar en la institución, La Republica de los Niños de dicha ciudad, hasta mediados de 2008. La experiencia estuvo dirigida a niños entre 4 y 10 años, ofreciendo una visión sobre nuevas teorías, descripción de los diferentes taxones, procesos evolutivos de los diferentes grupos, creímos conveniente introducir otros temas relacionados, como Deriva continen...

  6. Hydantoin-based molecular photoswitches.

    Science.gov (United States)

    Martínez-López, David; Yu, Meng-Long; García-Iriepa, Cristina; Campos, Pedro J; Frutos, Luis Manuel; Golen, James A; Rasapalli, Sivappa; Sampedro, Diego

    2015-04-17

    A new family of molecular photoswitches based on arylidenehydantoins is described together with their synthesis and photochemical and photophysical studies. A series of hydantoin derivatives have been prepared as single isomers using simple and versatile chemistry in good yields. Our studies show that the photostationary states of these compounds can be easily controlled by means of external factors, such as the light source or filters. Moreover, the detailed investigations proved that these switches are efficient (i.e., they make efficient use of the light energy, are high fatigue resistant, and are very photostable). In some cases, the switches can be completely turned on/off, a desirable feature for specific applications. A series of theoretical calculations have also been carried out to understand the photoisomerization mechanism at the molecular level. PMID:25806596

  7. Educación para la democracia como base de la integración en el aula. Una experiencia en Formación Profesional.

    OpenAIRE

    Fabregat Pitarch, Antonio; Gallardo Fernández, Isabel Maria

    2007-01-01

    La búsqueda de una educación democrática tiene tras de sí una amplía tradición de saberes y experiencias que nosotros respetamos y asumimos como propios pero a los que deseamos contribuir con nuevas ideas y experiencias. En el desarrollo de esta experiencia hemos tratado de conseguir el reconocimiento mutuo y estimular el acercamiento a través del trabajo colaborativo aprovechando la diferencia y disfrutando de ella. Las situaciones de aula y las actividades planteadas, han posibilitado: ...

  8. [Molecular bases of prion diseases].

    Science.gov (United States)

    Pokrovskiĭ, V I; Kiselev, O I

    1998-01-01

    The paper briefly analyzes the origin of priones and their association with the cellular gene and homologous protein of diseases in man and animals. There is evidence for a direct relationship of the agents that cause spongious encephalitis in the cattle and a new type of Creutzfeldt-Jacob disease in man. The molecular organization of priones and the conformational cellular protein changes underlying the infectious activation of the cell homologue of priones. Emphasis is first laid on the capacity of the cell homologue of priones and their infectiously active derivative to bind to DNA or RNA. In the context of concepts of the priones yeasts an attempt was made to explain the reproduction through the altered control of translation of mRNA that encodes the cellular homologue of priones, which accounts for the duration of the incubation period of the disease. The infections caused by priones are referred to as the so-called slow infections. But in the context of the proposed hypothesis, an infective process in the tissues did not really have some typical signs of infection and resembles accumulation diseases more without the replicative burst typical of infectious processes. The paper gives data on the vital cycle of priones in infected animals and changes in the accumulation of an infective agent. This assesses the currently available diagnostic methods and gives preference to the methods which will be based on the use of monoclonal antibodies that specifically recognize the conformationally altered form of an infectious prione or on the identification of primary oligomeric forms which manifest the onset of amyloidization of the damaged tissues. The main conclusion of the paper is that protein prionization is a common biological phenomenon and the diseases caused by these processes will increase in number in the near future, which makes it necessary to develop diagnostic methods and universal treatments of diseases, such as bacterial infections by using antibiotics.

  9. Experiencias populistas en Rusia

    Directory of Open Access Journals (Sweden)

    Olga Ulianova

    2003-01-01

    Full Text Available Este artículo parte de la comprensión de populismos como forma de gobierno y/o liderazgo político, como estrategia de ejercicio de poder y/o de llegada al poder, compatible con múltiples discursos ideológicos. Su clave es la relación directa entre el líder (gobernante o pretendiente a gobernante con los gobernados (o potenciales gobernados por encima de los grupos intermedios (“clase política”, sistema partidista de representación, movimientos ideológicos y culturales, etc.. De ahí, se postula que el movimiento de los “narodniki” en Rusia del siglo XIX, nombrado en muchos textos como iniciador del populismo, no tenía el carácter populista. En cambio, múltiples experiencias populistas en la historia de Rusia, desde Iván el Terrible hasta Vladimir Putin se sitúan en el cruce de la relación entre el gobernante, los sectores intermedios y los gobernados

  10. [Molecular bases of cancer immunology].

    Science.gov (United States)

    Barrera-Rodríguez, R; Peralta-Zaragoza, O; Madrid-Marina, V

    1995-01-01

    The immune system is a tight network of different types of cells and molecules. The coordinated action of these elements mounts a precise immune response against tumor cells. However, these cells present several escape mechanisms, leading to tumor progression. This paper shows several cellular and molecular events involved in the regulation of the immune response against tumor cells. The interaction of several molecules such as MHC, TcR, adhesins, tumor antigens and cytokines are discussed, as well as the most recent knowledge about escape mechanisms and immunotherapy. PMID:7502157

  11. Bases de datos bibliográficas de Historia: la experiencia del Instituto de Historia del CSIC

    OpenAIRE

    Fernández-Izquierdo, Francisco

    2000-01-01

    «..Entre los resultados del proyecto de investigación "Historia y Nuevas Tecnologías de la Información", desarrollado entre 1996 y 1999 en el Instituto de Historia del CSIC, se ha desarrollado un sistema de publicación de bases de datos bibliográficas en Internet sencillo y orientado al usuario investigador...».

  12. Experiencias en Western Australia

    Directory of Open Access Journals (Sweden)

    M.A. Pérez Fernández

    2008-01-01

    Full Text Available Décadas de uso inadecuado de los recursos naturales en Australia han llevado a la extinción de numerosas especies autóctonas. Aprendiendo de sus propios errores, se han inicido recientemente diferentes proyectos de conservación en los que participan diversos agentes interesados. La Región de los Central Ranges, en el Desierto de Gibson, pertenece al pueblo aborigen Ngaanyatjarra. En los años 90 se llevó a cabo una campaña de recolección de organismos, patrocinada por el Museo de Western Australia y el Departamento de Conservación Ambiental (DEC, en la que participaron miembros de la comunidad Ngaanyatjarra, conocedores y cuidadores del territorio. El resultado científico se tradujo en la identificación de dos nuevas especies, así como numerosas nuevas citas de plantas y animales para el territorio. La minería es una de las actividades más impactantes en Australia, pero la concienciación social ha llevado a que las compañías desarrollen importantes campañas de protección de especies. El mulgara (Dasycercus cristicaula ocupaba zonas que hoy en día se dedican a la minería, y de las que prácticamente ha desaparecido. Un programa de investigación financiado por la empresa Resolute Resources y dirigido por el Departamento de Conservación y Manejo del Territorio (CALM ha permitido identificar poblaciones de este marsupial carnívoro y diseñar un programa de manejo cuyo objetivo es evitar actuaciones incompatibles con su actividad biológica. El resultado más relevante en ambas iniciativas ha sido la colaboración entre diferentes agentes implicados, con intercambio de conocimientos y experiencias. Especialmente importante ha sido la posibilidad de diseñar planes de manejo y actuación sobre el territorio, orientados a la preservación de valores naturales y culturales antiguos.

  13. Carbon-based ion and molecular channels

    Science.gov (United States)

    Sint, Kyaw; Wang, Boyang; Kral, Petr

    2008-03-01

    We design ion and molecular channels based on layered carboneous materials, with chemically-functionalized pore entrances. Our molecular dynamics simulations demonstrate that these ultra-narrow pores, with diameters around 1 nm, are highly selective to the charges and sizes of the passing (Na^+ and Cl^-) ions and short alkanes. We demonstrate that the molecular flows through these pores can be easily controlled by electrical and mechanical means. These artificial pores could be integrated in fluidic nanodevices and lab-on-a-chip techniques with numerous potential applications. [1] Kyaw Sint, Boyang Wang and Petr Kral, submitted. [2] Boyang Wang and Petr Kral, JACS 128, 15984 (2006).

  14. Bioassays Based on Molecular Nanomechanics

    Directory of Open Access Journals (Sweden)

    Arun Majumdar

    2002-01-01

    Full Text Available Recent experiments have shown that when specific biomolecular interactions are confined to one surface of a microcantilever beam, changes in intermolecular nanomechanical forces provide sufficient differential torque to bend the cantilever beam. This has been used to detect single base pair mismatches during DNA hybridization, as well as prostate specific antigen (PSA at concentrations and conditions that are clinically relevant for prostate cancer diagnosis. Since cantilever motion originates from free energy change induced by specific biomolecular binding, this technique is now offering a common platform for label-free quantitative analysis of protein-protein binding, DNA hybridization DNA-protein interactions, and in general receptor-ligand interactions. Current work is focused on developing “universal microarrays” of microcantilever beams for high-throughput multiplexed bioassays.

  15. Molecular magnetic materials based on porphyrin macrocyles

    OpenAIRE

    ÖNAL, Emel

    2014-01-01

    The preparation of Molecule-Based Magnets is based on the assembling carriers of magnetic moment. These may be the metal ions only with diamagnetic linkers or the metal ions connected through open-shell organic molecule. The building of novel Molecule-Based Magnets architectures following the metal-radical approach relies on the design of innovative open-shell organic molecular blocks. In this regard, we focus our strategy on the synthesis of porphyrins incorporating free radicals. Indeed, po...

  16. Calixarene-based receptors for molecular recognition

    OpenAIRE

    YILMAZ, Mustafa; ERDEMİR, Serkan

    2013-01-01

    Calixarene-based molecular receptors have been a widely developing area in material science and technology for the last few decades. Due to their bowl-shaped geometry, calixarene macrocycles are used as hosts allowing organic and inorganic guests to coordinate/sorb onto their cavity. This work briefly reviews the recent development of calixarenes.

  17. Fortaleciendo experiencias en estudios cooperativos

    OpenAIRE

    Revista Institucional de la Facultad de Ciencias Económicas

    2011-01-01

    Como todos los años docentes del Instituto de Estudios Cooperativos de la Facultad de Ciencias Económicas intercambian en el país y en el exterior experiencias en el campo de la investigación, la docencia y la extensión vinculados al movimiento cooperativo. (Párrafo extraído del texto a modo de resumen)

  18. A nanoplasmonic switch based on molecular machines

    KAUST Repository

    Zheng, Yue Bing

    2009-06-01

    We aim to develop a molecular-machine-driven nanoplasmonic switch for its use in future nanophotonic integrated circuits (ICs) that have applications in optical communication, information processing, biological and chemical sensing. Experimental data show that an Au nanodisk array, coated with rotaxane molecular machines, switches its localized surface plasmon resonances (LSPR) reversibly when it is exposed to chemical oxidants and reductants. Conversely, bare Au nanodisks and disks coated with mechanically inert control compounds, do not display the same switching behavior. Along with calculations based on time-dependent density functional theory (TDDFT), these observations suggest that the nanoscale movements within surface-bound "molecular machines" can be used as the active components in plasmonic devices. ©2009 IEEE.

  19. Nonadiabatic Molecular Dynamics Based on Trajectories

    Directory of Open Access Journals (Sweden)

    Felipe Franco de Carvalho

    2013-12-01

    Full Text Available Performing molecular dynamics in electronically excited states requires the inclusion of nonadiabatic effects to properly describe phenomena beyond the Born-Oppenheimer approximation. This article provides a survey of selected nonadiabatic methods based on quantum or classical trajectories. Among these techniques, trajectory surface hopping constitutes an interesting compromise between accuracy and efficiency for the simulation of medium- to large-scale molecular systems. This approach is, however, based on non-rigorous approximations that could compromise, in some cases, the correct description of the nonadiabatic effects under consideration and hamper a systematic improvement of the theory. With the help of an in principle exact description of nonadiabatic dynamics based on Bohmian quantum trajectories, we will investigate the origin of the main approximations in trajectory surface hopping and illustrate some of the limits of this approach by means of a few simple examples.

  20. Una visión panorámica de las experiencias de Telesalud en Perú

    OpenAIRE

    Ernesto Gozzer Infante

    2015-01-01

    El artículo presenta las principales experiencias de telesalud realizadas en el Perú entre los años 2002 al 2010. Analiza información de literatura publicada y documentos no publicados acerca de experiencias de telesalud públicas y privadas. A partir de esta información se consultó con 26 expertos acerca de las características de las experiencias de telesalud identificadas. Se generó una base de datos de 38 experiencias, que se describen y analizan en esta publicación. Se presenta reflexiones...

  1. Towards the molecular bases of polymerase dynamics

    International Nuclear Information System (INIS)

    One aspect of the strong relationship that is known to exist between the processes of DNA replication and transcription is manifest in the coupling of the rates of movement of the replication fork (rf) and RNA polymerase (rt). We address two issues concerning the largely unexplored area of polymerase dynamics: (i) The validity of an approximate kinematic formula linking rf and rt suggested by experiments in which transcription is initiated in some prokaryotes with the antibiotic streptolydigin, and (ii) What are the molecular bases of the kinematic formula? An analysis of the available data suggests possible molecular bases for polymerase dynamics. In particular, we are led to a hypothesis: In active chromatin rt may depend on the length (λt) of the transcript of the primary messenger RNA (pre-mRNA). This new effect is subject to experimental verification. We discuss possible experiments that may be performed in order to test this prediction. (author). Refs, 6 tabs

  2. Decimal Integer Multiplication based on Molecular Beacons

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2013-12-01

    Full Text Available Due to the enhancement of circuit integration level, and the accelerating of working frequency of traditional computer, it requires components dimension must be constantly decreased. So encapsulation, etching and other problems of chip are becoming more and more difficult to solve, which causes its performance also become unstable. In order to overcome this problem, DNA computing as a new kind of molecular computing mode, with its high parallelism, huge amounts of storage capacity, low energy consumption advantages has received extensive attention. Being the same with traditional electronic computer, DNA computer is composed by arithmetic operations such as addition, subtraction, multiplication and dividing and basic logic units such as AND, OR, NON gate. This paper puts forward a new method to realize decimal integer multiplication based on molecular beacons. The algorithm firstly converts decimal integer to binary number, and then resolves the multiplication process into multiplication of current bit and addition of intermediate result after shifting two steps. Molecular beacon is used as multiplying unit, coding sequence is used as multiplier in this method. Based on the working principle of molecular beacon, multiplication operation of two one-bit binary is simulated. And by recording fluorescence status of molecular beacon to observe intermediate result and carry-bit situation, the final result can be obtained through addition after shifting. Examples prove that this method can realize decimal integer multiplication rapidly and accurately. This method is similar to multiplication system in traditional electronic computer, and it provides a simple, easier operation method for DNA computer to realize arithmetic operation.

  3. Progress on RNAi-based molecular medicines

    OpenAIRE

    Chen J; Xie JP

    2012-01-01

    Jing Chen, Jianping XieInstitute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, Chongqing, ChinaAbstract: RNA interference (RNAi) is a promising strategy to suppress the expression of disease-relevant genes and induce post-transcriptional gene silencing. Their simplicity and stability endow RNAi with great advantages in molecular medicine. Several RNA...

  4. La experiencia docente en un MOOC

    OpenAIRE

    Ramírez Montoya, María Soledad

    2013-01-01

    1. Objetivo de la conferencia; 2. Antecedentes de experiencias de cursos masivos; 3. Experiencia en un curso MOOC-Proyecto SINED-CLARISE para la educación a distancia; 4. Preparación para un curso MOOC en Coursera

  5. MARCAS DE EXPERIENCIA: MARCANDO LA DIFERENCIA

    Directory of Open Access Journals (Sweden)

    ESTELA FERNÁNDEZ SABIOTE

    2011-01-01

    Full Text Available Actualmente, la utilización de la marca como estrategia de diferenciación de la oferta parece adoptar una dimensión experiencial no tenida en cuenta hasta el momento en la literatura académica. El objetivo del presente trabajo es demostrar el interés que tiene para una empresa poseer una marca experiencial. De este modo, sobre la base del trabajo de Brakus, Schmitt y Zarantonello (2009, se adapta la escala desarrollada por estos autores a un contexto de consumo y marcas españolas. Para ello se recogieron, a través de un cuestionario, 278 observaciones de quince marcas pertenecientes a once categorías de producto. Los resultados muestran efectos positivos de la experiencia de marca sobre el capital de marca, la comunicación boca-oreja y la identificación marca-consumidor.

  6. una experiencia en Mauritania

    Directory of Open Access Journals (Sweden)

    J. M. Fernández-Palacios

    2008-01-01

    Full Text Available El macizo del Tagant, en la República Islámica de Mauritania, alberga, a lo largo de una red interconectada de humedales, las últimas poblaciones de cocodrilo del desierto Crocodylus niloticus suchus, que hasta muy poco tiempo se consideraban extintas. Estas poblaciones han sido capaces de resistir la desertización del Sahara ocurrida en el Holoceno gracias a la existencia de una serie de pozas (gueltas en árabe, que se forman tras las lluvias monzónicas y que están conectadas entre sí a través de una red de cauces efímeros o permanentes que forman la Cuenca endorreica del Lago Gabou. Estos humedales, carentes de protección en la actualidad, forman además la base económica de los más de cuarenta mil habitantes del macizo, basada en la ganadería y en una precaria agricultura. Conocedor del potencial naturalístico de la zona, el Gobierno de la RIM encargó a nuestra ONG la preparación de una memoria para dar a conocer y conseguir laproteccióninternacional de la zona en el marco de la Convención Ramsar de protección de humedales (UNESCO. El presente trabajo narra como lautilización de una especie focal, el cocodrilo del desierto, para proteger estos valiosos humedales podría ser compatible con el desarrollo de una actividad turística sostenible, basado en el turismo naturalístico y científico, que posibilite un mayor desarrollo a los habitantes del Tagant.

  7. As bases moleculares da hemofilia A

    Directory of Open Access Journals (Sweden)

    Simone Ferreira Pio

    2009-01-01

    Full Text Available As hemofilias são doenças hemorrágicas resultantes da deficiência de fator VIII (hemofilia A ou de fator IX (hemofilia B da coagulação, decorrentes de mutações nos genes que codificam os fatores VIII ou IX, respectivamente. A hemofilia A é mais frequente que a hemofilia B e acomete aproximadamente 1:10.000 nascimentos masculinos. A gravidade e frequência dos episódios hemorrágicos está relacionado ao nível residual de atividade de fator VIII presente no plasma e este relaciona-se ao tipo de mutação associada à doença. A clonagem do gene do fator VIII tornou possível o conhecimento das bases moleculares da hemofilia A, sendo hoje conhecidas mais de 1.000 mutações associadas à doença. O conhecimento das bases moleculares da hemofilia A permite uma melhor compreensão da relação genótipo-fenótipo da doença, tomada de condutas clínicas diferenciadas em casos de mutações associadas a um maior risco de desenvolvimento de inibidor, determinação da condição de portadora de hemofilia em mulheres relacionadas aos pacientes, implementação de programa de aconselhamento genético/orientação familiar e melhor compreensão das relações estruturais-funcionais do gene-proteína. Este artigo propõe revisar as bases moleculares da hemofilia A, os métodos laboratoriais utilizados para a caracterização das mutações e as implicações clínicas envolvidas no diagnóstico molecular da hemofilia A.Hemophilias are bleeding disorders due to deficiency of the blood coagulation factor VIII (hemophilia A or factor IX (hemophilia B, resulting from mutation on the gene coding for factor VIII or factor IX. Hemophilia A is more frequent than hemophilia B and affects 1:10,000 male newborns. The severity and frequency of hemorrhagic episodes is related to residual activity of factor VIII present in the plasma and relates to the type of mutation associated with the disorder. Cloning of the factor VIII gene has enabled researchers to

  8. Terapia fotodinámica (PDT en piel y estética: procedimiento, materiales y método en base a nuestra experiencia Photodinamic therapy in skin and aesthetics: procedure, matherials and method based on our experience

    Directory of Open Access Journals (Sweden)

    S. Mordon

    2012-09-01

    Full Text Available La terapia fotodinámica (PTD es un procedimiento cada vez más utilizado para tratar diversas afecciones dermatológicas y dermatoestéticas. Su aplicación obtiene buenos resultados en casos de carcinoma basocelular, enfermedad de Bowen, queratosis actínica, acné, rosácea y fotoenvejecimiento cutáneo. Los fotosensibilizantes y las fuentes de luz que se pueden utilizar son cada vez más variados, pero aún existe poco consenso en su metodología de aplicación, sistemas de irradiación y dosificaciones. En este artículo describimos los materiales y métodos disponibles en la actualidad y discutimos algunos detalles que, en base a nuestra experiencia, permiten mejorar los resultados. Presentamos también 5 casos clínicos ilustrativos de diferentes patologías.Photo Dynamic Therapy (PTD is an increasingly used technique in Dermatology and Dermocosmetics. PDT has a wide range of medical applications for the treatment of extended cutaneous cancer, offering also very good results in the treatment of basal cell carcinoma, Bowen's disease, actinic keratosis, acne, rosacea and in cutaneous rejuvenation. The sensitizers and light sources used for photoactivation are also more and more varied but there is still no consensus regarding methods and energy dosage. This study describes material and methods which are currently available and discusses a few details, that based on our own experience, can improve results. Five illustrative cases of different conditions are presented.

  9. Reforma educativa, experiencia e incongruencias

    OpenAIRE

    Vaca Uribe, Dr. Jorge; Universidad Veracruzana

    2012-01-01

    Ni la Secretaria de Educación Pública ni la dirigente sindical del SNTE tienen derecho a embarcar al país en una costosísima Reforma Integral de la Educación Básica (que ya está en marcha aunque poca información pública se dé) sin tomar en cuenta la experiencia acumulada por la propia SEP, por los maestros que sí trabajan y están preocupados por cumplir lo mejor posible con su labor, por los centros de investigación educativa, por las costosas (y a veces reiterativas) evaluaciones que han sid...

  10. La experiencia de Galicia Dixital.

    Directory of Open Access Journals (Sweden)

    Luis Hernández Ibañez

    2008-01-01

    Full Text Available En este artículo se describen las experiencias de los autores en el diseño y la ejecución de tres instalaciones interactivas para museos basados en el concepto de interfaces naturales, es decir, aquellos que hacen uso de los medios de comunicación utilizados por los seres humanos en su relación natural con su entorno a través de capacidades comunes tales como hablar, gesticular, caminar o tocar. Estas instalaciones son parte de la exposición permanente Galicia Dixital, en Santiago de Compostela, que se dedica a ilustrar sobre la cultura de esta región española al tiempo que introduce al visitante en las aplicaciones de las nuevas tecnologías

  11. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  12. Una experiencia de docencia integrada

    Directory of Open Access Journals (Sweden)

    María José LUESMA BARTOLOMÉ

    2014-11-01

    Full Text Available La interdisciplinariedad como estrategia pedagógica, permite corregir la atomización de una ciencia excesivamente individualizada, facilitando la interacción de varias disciplinas encaminada a un conocimiento integral. Y este ha sido el objetivo prioritario planteado en la experiencia piloto que aquí se presenta basada en la metodología del Aprendizaje Basado en Problemas aplicada a las asignaturas de Anatomi?a e Histología Ocular y Fisiología Ocular y del Sistema Visual, impartidas en el primer curso del Grado de Óptica-Optometría. Para ello los estudiantes, asumiendo diferentes roles rotatorios, han resuelto de manera cooperativa problemas teórico-prácticos comunes a ambas asignaturas. En la calificación final se ha tenido en cuenta el contenido correspondiente a cada una de las asignaturas de los portafolios generados durante la resolución de los problemas comunes y de las demás actividades docentes desarrolladas en cada asignatura por separado. Asimismo, se han realizado encuestas a los estudiantes, recogiendo sus expectativas y analizando el grado de satisfacción tras aplicar la metodología innovadora. Los datos indican que se han obtenido mejores resultados de aprendizaje que con otras actividades. En general, los estudiantes se sienten más satisfechos con esta nueva manera de aprender.

  13. Molecular and genetic bases of pancreatic cancer.

    Science.gov (United States)

    Vaccaro, Vanja; Gelibter, Alain; Bria, Emilio; Iapicca, Pierluigi; Cappello, Paola; Di Modugno, Francesca; Pino, Maria Simona; Nuzzo, Carmen; Cognetti, Francesco; Novelli, Francesco; Nistico, Paola; Milella, Michele

    2012-06-01

    Pancreatic cancer remains a formidable challenge for oncologists and patients alike. Despite intensive efforts, attempts at improving survival in the past 15 years, particularly in advanced disease, have failed. This is true even with the introduction of molecularly targeted agents, chosen on the basis of their action on pathways that were supposedly important in pancreatic cancer development and progression: indeed, with the notable exception of the epidermal growth factor receptor (EGFR) inhibitor erlotinib, that has provided a minimal survival improvement when added to gemcitabine, other agents targeting EGFR, matrix metallo-proteases, farnesyl transferase, or vascular endothelial growth factor have not succeeded in improving outcomes over standard gemcitabine monotherapy for a variety of different reasons. However, recent developments in the molecular epidemiology of pancreatic cancer and an ever evolving understanding of the molecular mechanisms underlying pancreatic cancer initiation and progression raise renewed hope to find novel, relevant therapeutic targets that could be pursued in the clinical setting. In this review we focus on molecular epidemiology of pancreatic cancer, epithelial-to-mesenchymal transition and its influence on sensitivity to EGFR-targeted approaches, apoptotic pathways, hypoxia-related pathways, developmental pathways (such as the hedgehog and Notch pathways), and proteomic analysis as keys to a better understanding of pancreatic cancer biology and, most importantly, as a source of novel molecular targets to be exploited therapeutically.

  14. Experiencia del dolor torácico en la mujer con infarto del miocardio

    Directory of Open Access Journals (Sweden)

    EILLEN MARYIBE MILLÁN

    2009-12-01

    Full Text Available Se presentan los resultados de la investigación " La experiencia del dolor torácico en la mujer con infarto agudo del miocardio" . Es un estudio cualitativo fenomenológico, que indagó sobre la experiencia del dolor torácico de la mujer que ha sufrido un infarto agudo del miocardio. Se realizó con nueve mujeres cuyo promedio de edad era de 52 años, en su mayoría amas de casa, entrevistadas personalmente por la investigadora. Se utilizó el sistema de entrevista a profundidad, siendo la base fundamental del estudio las narraciones de las experiencias ante el fenómeno de interés. El estudio permitió identificar los elementos constitutivos de la experiencia de dolor torácico en la mujer durante el infarto, descritos bajo la perspectiva personal de cada entrevistada. Los resultados de la experiencia del dolor permiten señalar que es compleja, atemorizante, con matices dados por las situaciones y vivencias previas, y se acompaña de sentimientos de temor ante la posibilidad de morir, que comprometen los ámbitos físicos, psicológicos y emocionales de la vida de la mujer.

  15. Quantitative Molecular Thermochemistry Based on Path Integrals

    Energy Technology Data Exchange (ETDEWEB)

    Glaesemann, K R; Fried, L E

    2005-03-14

    The calculation of thermochemical data requires accurate molecular energies and heat capacities. Traditional methods rely upon the standard harmonic normal mode analysis to calculate the vibrational and rotational contributions. We utilize path integral Monte Carlo (PIMC) for going beyond the harmonic analysis, to calculate the vibrational and rotational contributions to ab initio energies. This is an application and extension of a method previously developed in our group.

  16. La experiencia de paro La experiencia de paro

    Directory of Open Access Journals (Sweden)

    Enric Sanchis

    2003-01-01

    las implicaciones del paro en contextos caracterizadas por la presencia o ausencia de dispositivos de protección social. Se concluye que los consecuencias no económicas del paro actual pueden ser tan graves como lo fueron durante la Gran Depresión. Dada la relevancia que algunos economistas atribuyen a los sistemas de protección del desempleo en la explicación del nivel y duración del paro europeo, en la segunda porte se analiza la teoría de la búsqueda de empleo y sus implicaciones para la política de mercado de trabajo a la luz de la literatura sobre la experiencia de paro. Se concluye que los recortes en los dispositivos de protección tienen, en el mejor de los casos, efectos positivos muy limitados sobre el paro y que podrían verse contrarrestados por efectos de signo contrario sobre las condiciones de trabajo, localidad de vida de los parados y el grado de cohesión social. En una situación coma la española habría que dar prioridad a las políticas activas de empleo, al tratamiento personalizado de los parados y a la persecución del fraude empresarial a la Seguridad Social

  17. Molecular Bases of Cutaneous and Uveal Melanomas

    Directory of Open Access Journals (Sweden)

    Sudeep Gaudi

    2011-01-01

    Full Text Available Intensive research in recent years has begun to unlock the mysteries surrounding the molecular pathogenesis of melanoma, the deadliest of skin cancers. The high-penetrance, low-frequency susceptibility gene CDKN2A produces tumor suppressor proteins that function in concert with p53 and retinoblastoma protein to thwart melanomagenesis. Aberrant CDKN2A gene products have been implicated in a great many cases of familial cutaneous melanoma. Sporadic cases, on the other hand, often involve constitutive signal transduction along the mitogen-activated protein kinase (MAPK pathway, with particular focus falling upon mutated RAS and RAF protooncogenes. The proliferative effects of the MAPK pathway may be complemented by the antiapoptotic signals of the PI3K/AKT pathway. After skin, melanoma most commonly affects the eye. Data for the constitutive activation of the MAPK pathway in uveal melanoma exists as well, however, not through mutations of RAS and RAF. Rather, evidence implicates the proto-oncogene GNAQ. In the following discussion, we review the major molecular pathways implicated in both familial and sporadic cutaneous melanomagenesis, the former accounting for approximately 10% of cases. Additionally, we discuss the molecular pathways for which preliminary evidence suggests a role in uveal melanomagenesis.

  18. Coal-based carbons with molecular sieve properties

    Energy Technology Data Exchange (ETDEWEB)

    El-Wakil, A.M.; Youssef, A.M.; Tollan, K.A. (Mansoura Univ. (Egypt))

    1991-01-01

    Carbon molecular sieves are used extensively in gas chromatography for the separation of permanent gases and light hydrocarbons. Carbon molecular sieves also find commercial application for the manufacture of pure hydrogen from hydrogen-rich gases such as coke-oven gas, and for the separation of air by the pressure-swing adsorption technique. The objective of this investigation was to prepare carbons from Maghara coal, recently available on the commercial market. Coal-based carbons, if they possess molecular sieve properties, are superior to molecular sieve carbons from agricultural by-products because they have more satisfactory mechanical properties.

  19. Beyond Molecular Wires: Design Molecular Electronic Functions Based on Dipolar Effect.

    Science.gov (United States)

    Lo, Wai-Yip; Zhang, Na; Cai, Zhengxu; Li, Lianwei; Yu, Luping

    2016-09-20

    As the semiconductor companies officially abandoned the pursuit of Moore's law, the limitation of silicone-based semiconductor electronic devices is approaching. Single molecular devices are considered as a potential solution to overcome the physical barriers caused by quantum interferences because the intermolecular interactions are mainly through weak van der Waals force between molecular building blocks. In this bottom-up approach, components are built from atoms up, allowing great control over the molecular properties. Moreover, single molecular devices are powerful tools to understand quantum physics, reaction mechanism, and electron and charge transfer processes in organic semiconductors and molecules. So far, a great deal of effort is focused on understanding charge transport through organic single-molecular wires. However, to control charge transport, molecular diodes, switches, transistors, and memories are crucial. Significant progress in these topics has been achieved in the past years. The introduction and advances of scanning tunneling microscope break-junction (STM-BJ) techniques have led to more detailed characterization of new molecular structures. The modern organic chemistry provides an efficient access to a variety of functional moieties in single molecular device. These moieties have the potential to be incorporated in miniature circuits or incorporated as parts in molecular machines, bioelectronics devices, and bottom-up molecular devices. In this Account, we discuss progress mainly made in our lab in designing and characterizing organic single-molecular electronic components beyond molecular wires and with varied functions. We have synthesized and demonstrated molecular diodes with p-n junction structures through various scanning probe microscopy techniques. The assembly of the molecular diodes was achieved by using Langmuir-Blodgett technique or thiol/gold self-assembly chemistry with orthogonal protecting groups. We have thoroughly

  20. Beyond Molecular Wires: Design Molecular Electronic Functions Based on Dipolar Effect.

    Science.gov (United States)

    Lo, Wai-Yip; Zhang, Na; Cai, Zhengxu; Li, Lianwei; Yu, Luping

    2016-09-20

    As the semiconductor companies officially abandoned the pursuit of Moore's law, the limitation of silicone-based semiconductor electronic devices is approaching. Single molecular devices are considered as a potential solution to overcome the physical barriers caused by quantum interferences because the intermolecular interactions are mainly through weak van der Waals force between molecular building blocks. In this bottom-up approach, components are built from atoms up, allowing great control over the molecular properties. Moreover, single molecular devices are powerful tools to understand quantum physics, reaction mechanism, and electron and charge transfer processes in organic semiconductors and molecules. So far, a great deal of effort is focused on understanding charge transport through organic single-molecular wires. However, to control charge transport, molecular diodes, switches, transistors, and memories are crucial. Significant progress in these topics has been achieved in the past years. The introduction and advances of scanning tunneling microscope break-junction (STM-BJ) techniques have led to more detailed characterization of new molecular structures. The modern organic chemistry provides an efficient access to a variety of functional moieties in single molecular device. These moieties have the potential to be incorporated in miniature circuits or incorporated as parts in molecular machines, bioelectronics devices, and bottom-up molecular devices. In this Account, we discuss progress mainly made in our lab in designing and characterizing organic single-molecular electronic components beyond molecular wires and with varied functions. We have synthesized and demonstrated molecular diodes with p-n junction structures through various scanning probe microscopy techniques. The assembly of the molecular diodes was achieved by using Langmuir-Blodgett technique or thiol/gold self-assembly chemistry with orthogonal protecting groups. We have thoroughly

  1. LA INTERACCION ESCUELA- ENTORNO: UNA EXPERIENCIA INNOVADORA

    Directory of Open Access Journals (Sweden)

    Mildred Carmen Meza Chávez

    2009-01-01

    Full Text Available Este trabajo expone una experiencia investigativa donde se presentan alternativas de solución para el problema de las relaciones escuela-escuela. Desde esta perspectiva, se realiza un análisis bajo diez criterios considerados por Blanco y Messina (2000 que, a grandes rasgos, dan cuenta de las principales características de las innovaciones educativas. El análisis de esta experiencia es concluyente al registrar este tipo de innovación como una innovación social al entender el carácter social de la innovación en doble sentido, es decir: por la naturaleza del cambio en condiciones objetivas, que se logran por hacer algo de manera distinta y por la naturaleza del cambio en condiciones subjetivas, dada por la experiencia de vida que los participantes incorporan durante la dinámica innovadora. En este sentido, esta experiencia transformadora puede ser considerada como una: innovación social que la entendemos como la adquisición de competencias organizacionales para propiciar vías modificadoras con la finalidad de fortalecer la interacción escuela - entorno.

  2. Una visión panorámica de las experiencias de Telesalud en Perú

    Directory of Open Access Journals (Sweden)

    Ernesto Gozzer Infante

    2015-06-01

    Full Text Available El artículo presenta las principales experiencias de telesalud realizadas en el Perú entre los años 2002 al 2010. Analiza información de literatura publicada y documentos no publicados acerca de experiencias de telesalud públicas y privadas. A partir de esta información se consultó con 26 expertos acerca de las características de las experiencias de telesalud identificadas. Se generó una base de datos de 38 experiencias, que se describen y analizan en esta publicación. Se presenta reflexiones y recomendaciones para ampliar el uso de la telesalud en el Perú

  3. Una visión panorámica de las experiencias de Telesalud en Perú

    Directory of Open Access Journals (Sweden)

    Ernesto Gozzer Infante

    2015-04-01

    Full Text Available El artículo presenta las principales experiencias de telesalud realizadas en el Perú entre los años 2002 al 2010. Analiza información de literatura publicada y documentos no publicados acerca de experiencias de telesalud públicas y privadas. A partir de esta información se consultó con 26 expertos acerca de las características de las experiencias de telesalud identificadas. Se generó una base de datos de 38 experiencias, que se describen y analizan en esta publicación. Se presenta reflexiones y recomendaciones para ampliar el uso de la telesalud en el Perú

  4. Los saberes del arte. LA experiencia estética en Nietzsche

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Gama

    2008-01-01

    sobre el arte pueda tener al interior de la esfera estética misma: ¿qué es lo específico del arte frente a otras esferas de la acción humana? ¿En qué consiste propiamente la experiencia estética? ¿Qué resulta para el individuo y para la cultura del encuentro con el fenómeno del arte? El presente artículo constituye un primer intento de responder estas cuestiones. Su base de análisis se concentra en El nacimiento de la tragedia, y en menor medida en la fisiología del arte del Crepúsculo de los ídolos. La tesis central que se defiende es que la experiencia estética para Nietzsche es esencialmente una experiencia de conocimiento, de un tipo de saber que da acceso a la verdad.

  5. Aprender a innovar: una experiencia on line

    Directory of Open Access Journals (Sweden)

    Joaquín MORENO MARCHAL

    2014-11-01

    Full Text Available La creatividad y la innovación se han convertido en recursos clave en la denominada sociedad del conocimiento, que bien podría ser también llamada sociedad de la innovación. Pero innovar es una actividad compleja, que integra la aplicación de múltiples capacidades, el pensamiento divergente y convergente, la gestión de equipos humanos, la comunicación. Ahora bien, a innovar se puede, y se debe, aprender. Aprender a innovar es un reto y también una obligación para el conjunto del sistema educativo en todos sus niveles. Partiendo de estas consideraciones este trabajo expone una experiencia de aprendizaje de la creatividad y de la innovación a través de un curso totalmente on line basado en la plataforma MOODLE, en el marco del Programa de Formación Permanente de la Universidad de Cádiz. Se presenta un modelo del proceso de innovación, denominado CREALAB, de elaboración propia. Este modelo se ha utilizado como base del proceso de aprendizaje de la creatividad y de la innovación y en el diseño del curso, está organizado en torno a actividades y tiene un carácter iterativo y realimentado. Se presentan además el conjunto del diseño metodológico y los resultados obtenidos en las dos ediciones celebradas hasta el momento. El diseño del curso totalmente on line y los resultados alcanzados permiten estimar un alto potencial de aplicación, tanto a nivel personal como a nivel organizacional.

  6. Experiencia del dolor torácico en la mujer con infarto del miocardio

    OpenAIRE

    EILLEN MARYIBE MILLÁN; LUZ PATRICIA DÍAZ H

    2009-01-01

    Se presentan los resultados de la investigación " La experiencia del dolor torácico en la mujer con infarto agudo del miocardio" . Es un estudio cualitativo fenomenológico, que indagó sobre la experiencia del dolor torácico de la mujer que ha sufrido un infarto agudo del miocardio. Se realizó con nueve mujeres cuyo promedio de edad era de 52 años, en su mayoría amas de casa, entrevistadas personalmente por la investigadora. Se utilizó el sistema de entrevista a profundidad, siendo la base fun...

  7. La experiencia del curso "bases romanistas del derecho civil" en la facultad de derecho de la Pontificia Universidad Católica del Perú

    OpenAIRE

    Marcial Rubio Correa

    1986-01-01

    Esta ponencia se inscribe dentro del tema de enseñanza del Derecho que, de acuerdo a las bases establecidas para el V Congreso Latinoamericano de Derecho Romano, es parte de sus trabajos. Es una propuesta que no pretende sustituir, sino antes bien complementar, al curso tradicional de Derecho Romano que se ha dictado desde tiempo atrás.

  8. La experiencia del curso "bases romanistas del derecho civil" en la facultad de derecho de la Pontificia Universidad Católica del Perú

    Directory of Open Access Journals (Sweden)

    Marcial Rubio Correa

    1986-12-01

    Full Text Available Esta ponencia se inscribe dentro del tema de enseñanza del Derecho que, de acuerdo a las bases establecidas para el V Congreso Latinoamericano de Derecho Romano, es parte de sus trabajos. Es una propuesta que no pretende sustituir, sino antes bien complementar, al curso tradicional de Derecho Romano que se ha dictado desde tiempo atrás.

  9. Environmental Phosphorus Recovery Based on Molecular Bioscavengers

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix

    . Finally, it is shown how computational fluid dynamics can be used to optimize large-scale industrial processes using an open-source model, which we have made freely available online to the membrane community, and the advantages/disadvantages of different potential physical implementations of the proposed......Phosphorus is a ubiquitous element of all known life and as such it is found throughout numerous key molecules related to various cellular functions. The supply of phosphorus is tightly linked to global food security, since phosphorus is used to produce agricultural fertilizers, without which...... characteristic amino acid distributions of the binding sites. Quantum mechanical methods are used to investigate how phosphate moieties are described using electronic structure methods, and molecular dynamics in combination with quantum mechanics are used to show how the dynamical interaction between phosphates...

  10. Optimal separable bases and molecular collisions

    International Nuclear Information System (INIS)

    A new methodology is proposed for the efficient determination of Green's functions and eigenstates for quantum systems of two or more dimensions. For a given Hamiltonian, the best possible separable approximation is obtained from the set of all Hilbert space operators. It is shown that this determination itself, as well as the solution of the resultant approximation, are problems of reduced dimensionality for most systems of physical interest. Moreover, the approximate eigenstates constitute the optimal separable basis, in the sense of self-consistent field theory. These distorted waves give rise to a Born series with optimized convergence properties. Analytical results are presented for an application of the method to the two-dimensional shifted harmonic oscillator system. The primary interest however, is quantum reactive scattering in molecular systems. For numerical calculations, the use of distorted waves corresponds to numerical preconditioning. The new methodology therefore gives rise to an optimized preconditioning scheme for the efficient calculation of reactive and inelastic scattering amplitudes, especially at intermediate energies. This scheme is particularly suited to discrete variable representations (DVR's) and iterative sparse matrix methods commonly employed in such calculations. State to state and cumulative reactive scattering results obtained via the optimized preconditioner are presented for the two-dimensional collinear H + H2 → H2 + H system. Computational time and memory requirements for this system are drastically reduced in comparison with other methods, and results are obtained for previously prohibitive energy regimes

  11. Optimal separable bases and molecular collisions

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, L W [Univ. of California, Berkeley, CA (United States)

    1997-12-01

    A new methodology is proposed for the efficient determination of Green`s functions and eigenstates for quantum systems of two or more dimensions. For a given Hamiltonian, the best possible separable approximation is obtained from the set of all Hilbert space operators. It is shown that this determination itself, as well as the solution of the resultant approximation, are problems of reduced dimensionality for most systems of physical interest. Moreover, the approximate eigenstates constitute the optimal separable basis, in the sense of self-consistent field theory. These distorted waves give rise to a Born series with optimized convergence properties. Analytical results are presented for an application of the method to the two-dimensional shifted harmonic oscillator system. The primary interest however, is quantum reactive scattering in molecular systems. For numerical calculations, the use of distorted waves corresponds to numerical preconditioning. The new methodology therefore gives rise to an optimized preconditioning scheme for the efficient calculation of reactive and inelastic scattering amplitudes, especially at intermediate energies. This scheme is particularly suited to discrete variable representations (DVR`s) and iterative sparse matrix methods commonly employed in such calculations. State to state and cumulative reactive scattering results obtained via the optimized preconditioner are presented for the two-dimensional collinear H + H{sub 2} {yields} H{sub 2} + H system. Computational time and memory requirements for this system are drastically reduced in comparison with other methods, and results are obtained for previously prohibitive energy regimes.

  12. Algunas experiencias de innovación educativa

    Directory of Open Access Journals (Sweden)

    de Haro, J. José

    2009-09-01

    Full Text Available In this article we show some experiences in educational innovation area performed by teachers with students of ESO and Bachelor at Amor de Dios school in Barcelona (www.amordedios. org. We also discuss the characteristics of blogs, wikis and social networks, as well as their potential usage, all based on the experience carried out with the students. We also present some useful guidelines about selection of the various systems depending on teachers’ needs.Se presentan algunas de las experiencias llevadas a cabo en el ámbito de la innovación educativa con alumnos de ESO y Bachillerato en el centro concertado de educación primaria y secundaria Amor de Dios de Barcelona (www.amordedios.org. Se discuten las características de blogs, wikis y redes sociales, así como sus posibilidades de uso, todo ello en base a las experiencias realizadas con los alumnos. Igualmente se presentan algunas directrices que pueden ayudar para la selección de unos sistemas u otros según las necesidades educativas del profesor.

  13. Experiencia, pragmatismo y líneas de actuación comunes, bases del nuevo modelo de desarrollo rural del País Vasco

    Directory of Open Access Journals (Sweden)

    Alberdi Collantes, Juan Cruz

    2010-07-01

    Full Text Available In 1998 the Basque Country starts up a model of rural development based on the collaboration between local and regional administrations and to limit the dependency of the Europe communitarian subventions. With the beginning of the renovation of the local development plans a reflection based on the committed errors. Methodological systems there are propose prioritizing inductive, feasible and practical expositions, and a functional model to pass to the local level from the regional level. As result we obtain an interesting proposal of development to in a while consider in which many Communities have to reorganize their networks of rural development before the announced reduction of communitarian contributions.

    En el año 1998 el País Vasco pone en marcha un modelo de desarrollo rural fundamentado en la colaboración entre administraciones locales y regionales frente a la dependencia de las subvenciones comunitarias. Con objeto de la necesaria renovación de los Planes Comarcales se produce una reflexión sobre los errores cometidos y se plantean diferentes alternativas que quedan recogidas en unas propuestas metodológicas que van a primar planteamientos inductivos, prácticos y ejecutables y un modo de funcionar que permite llegar con facilidad de la propuesta local a la puesta en común regional. Como resultado obtenemos una interesante propuesta de desarrollo, a tener en cuenta, en un momento en el que muchas Comunidades Autónomas han de reorganizar sus redes de desarrollo rural ante la anunciada reducción de aportaciones comunitarias. [fr] Durant l’année 1998 le Pays Basque met en marche un modèle de développement rural fondé la collaboration entre des administrations locales et régionales face à la dépendance des subventions communautaires. Dans le but de la rénovation nécessaire des Plans Régionaux se produit une réflexion sur les erreurs commises et on pose différentes alternatives qui sont reprises dans des

  14. Unidirectional Light-Driven Molecular Motors Based on Overcrowded Alkenes

    NARCIS (Netherlands)

    Cnossen, Arjen; Browne, Wesley R.; Feringa, Ben L.; Credi, Alberto; Silvi, Serena; Venturi, Margherita

    2014-01-01

    Over the last two decades, interest in nanotechnology has led to the design and synthesis of a toolbox of nanoscale versions of macroscopic devices and components. In molecular nanotechnology, linear motors based on rotaxanes and rotary motors based on overcrowded alkenes are particularly promising

  15. Una experiencia en Matemáticas

    Directory of Open Access Journals (Sweden)

    Escribano Ródenas, M.C.

    1998-01-01

    Full Text Available Esta comunicación pretende mostrar la experiencia llevada a cabo en la asignatura “Matemáticas” en los cursos primero y cuarto de las licenciaturas en CC. Económicas y Administración y Dirección de Empresas, durante los cursos académicos 1.997/98 y cursos anteriores. El objetivo de la experiencia en primer curso es intentar realizar un repaso de lo más esencial visto por los alumnos en cursos anteriores y establecer unos mínimos de partida para la asignatura “Matemáticas”, de estas dos licenciaturas. La iniciativa fue del Departamento. En cuarto curso la experiencia se ha llevado a cabo a propuesta de los alumnos, y su objetivo ha sido realizar un repaso de la programación matemática vista en el primer curso de carrera, siendo ésta un instrumento necesario para una asignatura de cuarto curso de la licenciatura en Administración y Dirección de Empresas, denominada “Teoría y Métodos de Decisión”.

  16. Environmental Phosphorus Recovery Based on Molecular Bioscavengers

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix

    pressure to develop sustainable phosphorus practices as well as new technologies for phosphorus recovery. Nature has spent billions of years refining proteins that interact with phosphates. This has inspired the present work where the overall ambitions are: to facilitate the development of a recovery......Phosphorus is a ubiquitous element of all known life and as such it is found throughout numerous key molecules related to various cellular functions. The supply of phosphorus is tightly linked to global food security, since phosphorus is used to produce agricultural fertilizers, without which it...... would not be possible to feed the world population. Sadly, the current supply of phosphorus is based on the gradual depletion of limited fossil reserves, and some estimates predict that within 15-25 years we will consume more phosphorus than we can produce. There is therefore a strong international...

  17. Molecular partitioning based on the kinetic energy density

    Science.gov (United States)

    Noorizadeh, Siamak

    2016-05-01

    Molecular partitioning based on the kinetic energy density is performed to a number of chemical species, which show non-nuclear attractors (NNA) in their gradient maps of the electron density. It is found that NNAs are removed using this molecular partitioning and although the virial theorem is not valid for all of the basins obtained in the being used AIM, all of the atoms obtained using the new approach obey this theorem. A comparison is also made between some atomic topological parameters which are obtained from the new partitioning approach and those calculated based on the electron density partitioning.

  18. Induced base transistor fabricated by molecular beam epitaxy

    Science.gov (United States)

    Chang, C.-Y.; Liu, W. C.; Jame, M. S.; Wang, Y. H.; Luryi, S.

    1986-09-01

    A novel three-terminal hot-electron device, the induced base transistor (IBT), has been fabricated by molecular beam epitaxy. Two-dimensional electron gas induced by the applied collector field in an undoped GaAs quantum well is used as the base of the IBT. The common-base current gain alpha has been achieved as high as 0.96 under a collector bias of 2.5 V and an emitter current of 3 mA.

  19. Valoración por los estudiantes de la licenciatura en psicopedagogía, de una experiencia innovadora basada en estrategias de aprendizaje colaborativo y el uso del Courselab / Innovative experience evaluation in initial high school teacher based in...

    Directory of Open Access Journals (Sweden)

    Rocío SERRANO RODRÍGUEZ

    2012-03-01

    valoración positiva tanto de la experiencia como del propio desarrollo de la asignatura.       A technological society in permanent evolution requires teaching professionals with continuous training. Among the main teaching skills that teachers must currently acquire  during process of initial training, we emphasize the educational use of Information and Communication Technologies  (in Spanish its acronym is TIC and teamwork. Through this innovation experience focused on developing a workflow based on cooperative learning using CourseLab application, specific student skills are required in PC use,  navigation through Internet and ability for teamwork and problem resolution. Definitely, we pretend to complete training of future teachers in ICT environments, so they could perform teaching / learning processes  in order to match students interests and motivations, and may contribute to improvement of school success. Results of this study indicate that training teachers demand the use of similar tools to motivate themselves and adapt to teaching and learning processes. We conclude with a positive assessment of both experience and development of the subject.

  20. Protein analysis based on molecular beacon probes and biofunctionalized nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With the completion of the human genome-sequencing project, there has been a resulting change in the focus of studies from genomics to proteomics. By utilizing the inherent advantages of molecular beacon probes and biofunctionalized nanoparticles, a series of novel principles, methods and techniques have been exploited for bioanalytical and biomedical studies. This review mainly discusses the applications of molecular beacon probes and biofunctionalized nanoparticles-based technologies for realtime, in-situ, highly sensitive and highly selective protein analysis, including the nonspecific or specific protein detection and separation, protein/DNA interaction studies, cell surface protein recognition, and antigen-antibody binding process-based bacteria assays. The introduction of molecular beacon probes and biofunctionalized nanoparticles into the protein analysis area would necessarily advance the proteomics research.

  1. Plasmonic-Based Electrochemical Impedance Spectroscopy: Application to Molecular Binding

    Science.gov (United States)

    Lu, Jin; Wang, Wei; Wang, Shaopeng; Shan, Xiaonan; Li, Jinghong; Tao, Nongjian

    2012-01-01

    Plasmonic-based electrochemical impedance spectroscopy (P-EIS) is developed to investigate molecular binding on surfaces. Its basic principle relies on the sensitive dependence of surface plasmon resonance (SPR) signal on surface charge density, which is modulated by applying an AC potential to a SPR chip surface. The AC component of the SPR response gives the electrochemical impedance, and the DC component provides the conventional SPR detection. The plasmonic-based impedance measured over a range of frequency is in quantitative agreement with the conventional electrochemical impedance. Compared to the conventional SPR detection, P-EIS is sensitive to molecular binding taking place on the chip surface, and less sensitive to bulk refractive index changes or non-specific binding. Moreover, this new approach allows for simultaneous SPR and surface impedance analysis of molecular binding processes. PMID:22122514

  2. Fullerene-based Anchoring Groups for Molecular Electronics

    DEFF Research Database (Denmark)

    Martin, Christian A.; Ding, Dapeng; Sørensen, Jakob Kryger;

    2008-01-01

    We present results on a new fullerene-based anchoring group for molecular electronics. Using lithographic mechanically controllable break junctions in vacuum we have determined the conductance and stability of single-molecule junctions of 1,4-bis(fullero[c]pyrrolidin-1-yl)benzene. The compound can...

  3. Molecular Recognition: Detection of Colorless Compounds Based on Color Change

    Science.gov (United States)

    Khalafi, Lida; Kashani, Samira; Karimi, Javad

    2016-01-01

    A laboratory experiment is described in which students measure the amount of cetirizine in allergy-treatment tablets based on molecular recognition. The basis of recognition is competition of cetirizine with phenolphthalein to form an inclusion complex with ß-cyclodextrin. Phenolphthalein is pinkish under basic condition, whereas it's complex form…

  4. Intelligent DNA-based molecular diagnostics using linked genetic markers

    Energy Technology Data Exchange (ETDEWEB)

    Pathak, D.K.; Perlin, M.W.; Hoffman, E.P.

    1994-12-31

    This paper describes a knowledge-based system for molecular diagnostics, and its application to fully automated diagnosis of X-linked genetic disorders. Molecular diagnostic information is used in clinical practice for determining genetic risks, such as carrier determination and prenatal diagnosis. Initially, blood samples are obtained from related individuals, and PCR amplification is performed. Linkage-based molecular diagnosis then entails three data analysis steps. First, for every individual, the alleles (i.e., DNA composition) are determined at specified chromosomal locations. Second, the flow of genetic material among the individuals is established. Third, the probability that a given individual is either a carrier of the disease or affected by the disease is determined. The current practice is to perform each of these three steps manually, which is costly, time consuming, labor-intensive, and error-prone. As such, the knowledge-intensive data analysis and interpretation supersede the actual experimentation effort as the major bottleneck in molecular diagnostics. By examining the human problem solving for the task, we have designed and implemented a prototype knowledge-based system capable of fully automating linkage-based molecular diagnostics in X-linked genetic disorders, including Duchenne Muscular Dystrophy (DMD). Our system uses knowledge-based interpretation of gel electrophoresis images to determine individual DNA marker labels, a constraint satisfaction search for consistent genetic flow among individuals, and a blackboard-style problem solver for risk assessment. We describe the system`s successful diagnosis of DMD carrier and affected individuals from raw clinical data.

  5. Chemical sensors based on molecularly modified metallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Haick, Hossam [Department of Chemical Engineering and Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000 (Israel)

    2007-12-07

    This paper presents a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to the use of molecularly modified metal nanoparticles in or as chemical sensors. This paper attempts to pull together different views and terminologies used in sensors based on molecularly modified metal nanoparticles, including those established upon electrochemical, optical, surface Plasmon resonance, piezoelectric and electrical transduction approaches. Finally, this paper discusses briefly the main advantages and disadvantages of each of the presented class of sensors. (review article)

  6. TICs : Experiencias en e-Government

    OpenAIRE

    Pesado, Patricia Mabel; Pasini, Ariel C.; Chichizola, Franco; Estrebou, César Armando; Feierherd, Guillermo Eugenio; Galdámez, Nicolás; Rodriguez, Ismael Pablo; Pousa, Adrián; Pettoruti, José Enrique; Ibañez, Eduardo; Restelli, Noelia; De Giusti, Armando Eduardo

    2010-01-01

    Esta línea incluye investigación y desarrollo de soluciones de Gobierno Electrónico, utilizando Tecnologías de la Información y la Comunicación, teniendo especial interés las experiencias concretas (tales como el voto electrónico, la certificación de calidad en sistemas y organizaciones, el estudio de sistemas distribuidos de tiempo real en aplicaciones de E-Gov sobre VLDBs y la auditoría de equipamiento específico) realizadas con organismos públicos concretos (las Provincias de Río Negro y B...

  7. TICs aplicadas en e-Government : Experiencias

    OpenAIRE

    Pesado, Patricia Mabel; De Giusti, Armando Eduardo; Pasini, Ariel C.; Estrebou, César Armando; Osella Massa, Germán Leandro; Galdámez, Nicolás; Moralejo, Lucrecia; Rodriguez, Ismael Pablo; Pousa, Adrián; Pettoruti, José Enrique; Champredonde, Raúl; Feierherd, Guillermo Eugenio; Chichizola, Franco

    2008-01-01

    Este proyecto se enfoca en la investigación y desarrollo de soluciones de Gobierno Electrónico, utilizando Tecnologías de la Información y la Comunicación. Asimismo se han iniciado procesos de for-mación de recursos humanos en el área de Civismo Digital y en Ingeniería de Softwa-re aplicada a E-Gov. Especial interés tienen las experiencias concretas (tales como el voto electrónico, la certificación de calidad en sistemas y orga-nizaciones, el estudio de sistemas distribui-dos de tiempo ...

  8. Microchip-based Devices for Molecular Diagnosis of Genetic Diseases.

    Science.gov (United States)

    Cheng; Fortina; Surrey; Kricka; Wilding

    1996-09-01

    Microchips, constructed with a variety of microfabrication technologies (photolithography, micropatterning, microjet printing, light-directed chemical synthesis, laser stereochemical etching, and microcontact printing) are being applied to molecular biology. The new microchip-based analytical devices promise to solve the analytical problems faced by many molecular biologists (eg, contamination, low throughput, and high cost). They may revolutionize molecular biology and its application in clinical medicine, forensic science, and environmental monitoring. A typical biochemical analysis involves three main steps: (1) sample preparation, (2) biochemical reaction, and (3) detection (either separation or hybridization may be involved) accompanied by data acquisition and interpretation. The construction of a miniturized analyzer will therefore necessarily entail the miniaturization and integration of all three of these processes. The literature related to the miniaturization of these three processes indicates that the greatest emphasis so far is on the investigation and development of methods for the detection of nucleic acid, followed by the optimization of a biochemical reaction, such as the polymerase chain reaction. The first step involving sample preparation has received little attention. In this review the state of the art of, microchip-based, miniaturized analytical processes (eg, sample preparation, biochemical reaction, and detection of products) are outlined and the applications of microchip-based devices in the molecular diagnosis of genetic diseases are discussed. PMID:10462559

  9. Graph-based interpretation of the Molecular Interstellar Medium Segmentation

    CERN Document Server

    Colombo, Dario; Ginsburg, Adam; Duarte-Cabral, Ana; Hughes, Annie

    2015-01-01

    We present a generalization of the Giant Molecular Cloud (GMC) identification problem based on cluster analysis. The method we designed, SCIMES (Spectral Clustering for Interstellar Molecular Emission Segmentation) considers the dendrogram of emission in the broader framework of graph theory and utilizes spectral clustering to find discrete regions with similar emission properties. For Galactic molecular cloud structures, we show that the characteristic volume and/or integrated CO luminosity are useful criteria to define the clustering, yielding emission structures that closely reproduce "by-eye" identification results. SCIMES performs best on well-resolved, high-resolution data, making it complementary to other available algorithms. Using 12CO(1-0) data for the Orion-Monoceros complex, we demonstrate that SCIMES provides robust results against changes of the dendrogram-construction parameters, noise realizations and degraded resolution. By comparing SCIMES with other cloud decomposition approaches, we show t...

  10. Gesture Interaction Browser-Based 3D Molecular Viewer.

    Science.gov (United States)

    Virag, Ioan; Stoicu-Tivadar, Lăcrămioara; Crişan-Vida, Mihaela

    2016-01-01

    The paper presents an open source system that allows the user to interact with a 3D molecular viewer using associated hand gestures for rotating, scaling and panning the rendered model. The novelty of this approach is that the entire application is browser-based and doesn't require installation of third party plug-ins or additional software components in order to visualize the supported chemical file formats. This kind of solution is suitable for instruction of users in less IT oriented environments, like medicine or chemistry. For rendering various molecular geometries our team used GLmol (a molecular viewer written in JavaScript). The interaction with the 3D models is made with Leap Motion controller that allows real-time tracking of the user's hand gestures. The first results confirmed that the resulting application leads to a better way of understanding various types of translational bioinformatics related problems in both biomedical research and education.

  11. Capacity of Diffusion-based Molecular Communication with Ligand Receptors

    CERN Document Server

    Einolghozati, Arash; Fekri, Faramarz

    2012-01-01

    A diffusion-based molecular communication system has two major components: the diffusion in the medium, and the ligand-reception. Information bits, encoded in the time variations of the concentration of molecules, are conveyed to the receiver front through the molecular diffusion in the medium. The receiver, in turn, measures the concentration of the molecules in its vicinity in order to retrieve the information. This is done via ligand-reception process. In this paper, we develop models to study the constraints imposed by the concentration sensing at the receiver side and derive the maximum rate by which a ligand-receiver can receive information. Therefore, the overall capacity of the diffusion channel with the ligand receptors can be obtained by combining the results presented in this paper with our previous work on the achievable information rate of molecular communication over the diffusion channel.

  12. Gesture Interaction Browser-Based 3D Molecular Viewer.

    Science.gov (United States)

    Virag, Ioan; Stoicu-Tivadar, Lăcrămioara; Crişan-Vida, Mihaela

    2016-01-01

    The paper presents an open source system that allows the user to interact with a 3D molecular viewer using associated hand gestures for rotating, scaling and panning the rendered model. The novelty of this approach is that the entire application is browser-based and doesn't require installation of third party plug-ins or additional software components in order to visualize the supported chemical file formats. This kind of solution is suitable for instruction of users in less IT oriented environments, like medicine or chemistry. For rendering various molecular geometries our team used GLmol (a molecular viewer written in JavaScript). The interaction with the 3D models is made with Leap Motion controller that allows real-time tracking of the user's hand gestures. The first results confirmed that the resulting application leads to a better way of understanding various types of translational bioinformatics related problems in both biomedical research and education. PMID:27350455

  13. Molecular docking and structure-based drug design strategies.

    Science.gov (United States)

    Ferreira, Leonardo G; Dos Santos, Ricardo N; Oliva, Glaucius; Andricopulo, Adriano D

    2015-07-22

    Pharmaceutical research has successfully incorporated a wealth of molecular modeling methods, within a variety of drug discovery programs, to study complex biological and chemical systems. The integration of computational and experimental strategies has been of great value in the identification and development of novel promising compounds. Broadly used in modern drug design, molecular docking methods explore the ligand conformations adopted within the binding sites of macromolecular targets. This approach also estimates the ligand-receptor binding free energy by evaluating critical phenomena involved in the intermolecular recognition process. Today, as a variety of docking algorithms are available, an understanding of the advantages and limitations of each method is of fundamental importance in the development of effective strategies and the generation of relevant results. The purpose of this review is to examine current molecular docking strategies used in drug discovery and medicinal chemistry, exploring the advances in the field and the role played by the integration of structure- and ligand-based methods.

  14. Multiferroic materials based on organic transition-metal molecular nanowires.

    Science.gov (United States)

    Wu, Menghao; Burton, J D; Tsymbal, Evgeny Y; Zeng, Xiao Cheng; Jena, Puru

    2012-09-01

    We report on the density functional theory aided design of a variety of organic ferroelectric and multiferroic materials by functionalizing crystallized transition-metal molecular sandwich nanowires with chemical groups such as -F, -Cl, -CN, -NO(2), ═O, and -OH. Such functionalized polar wires exhibit molecular reorientation in response to an electric field. Ferroelectric polarizations as large as 23.0 μC/cm(2) are predicted in crystals based on fully hydroxylized sandwich nanowires. Furthermore, we find that organic nanowires formed by sandwiching transition-metal atoms in croconic and rhodizonic acids, dihydroxybenzoquinone, dichloro-dihydroxy-p-benzoquinone, or benzene decorated by -COOH groups exhibit ordered magnetic moments, leading to a multiferroic organometallic crystal. When crystallized through hydrogen bonds, the microscopic molecular reorientation translates into a switchable polarization through proton transfer. A giant interface magnetoelectric response that is orders of magnitude greater than previously reported for conventional oxide heterostructure interfaces is predicted. PMID:22881120

  15. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Catia Algieri

    2014-07-01

    Full Text Available An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  16. Modelo de capacidad dinámica de aprendizaje organizacional: experiencia de la biotecnología en Cuba

    Directory of Open Access Journals (Sweden)

    Marle Pérez De Armas

    2016-06-01

    Full Text Available La experiencia y práctica internacional fundamentan el conocimiento como recurso estratégico y resultado del aprendizaje organizacional, lo que conduce a plantear la Capacidad Dinámica de Aprendizaje Organizacional vinculada con la obtención de resultados de desempeños positivos y fuente de ventajas competitivas. En este sentido, la empresa de alta tecnología (EAT del sector de la biotecnología en Cuba representa una experiencia singular lo que se vincula con el problema científico, ya que se necesita explicar, sobre bases científicas, cómo el desarrollo de la Capacidad Dinámica de Aprendizaje Organizacional contribuye a fundamentar el éxito alcanzado por empresas líderes del sector, y que a su vez posibiliten su extensión a otras de su tipo en el sector. A partir de la utilización de la metodología de estudio de caso aplicada al Centro de Inmunología Molecular como caso piloto y el juicio de expertos se obtiene como, principal resultado, un modelo conceptual que fundamenta y explica el éxito alcanzado por empresas líderes de alta tecnología del sector biotecnológico cubano desde el desarrollo de la Capacidad Dinámica de Aprendizaje Organizacional y sus tres dimensiones claves: elementos de gestión técnico-organizativos, comportamiento organizacional y actores externos.

  17. Arthropod phylogeny based on eight molecular loci and morphology

    Science.gov (United States)

    Giribet, G.; Edgecombe, G. D.; Wheeler, W. C.

    2001-01-01

    The interrelationships of major clades within the Arthropoda remain one of the most contentious issues in systematics, which has traditionally been the domain of morphologists. A growing body of DNA sequences and other types of molecular data has revitalized study of arthropod phylogeny and has inspired new considerations of character evolution. Novel hypotheses such as a crustacean-hexapod affinity were based on analyses of single or few genes and limited taxon sampling, but have received recent support from mitochondrial gene order, and eye and brain ultrastructure and neurogenesis. Here we assess relationships within Arthropoda based on a synthesis of all well sampled molecular loci together with a comprehensive data set of morphological, developmental, ultrastructural and gene-order characters. The molecular data include sequences of three nuclear ribosomal genes, three nuclear protein-coding genes, and two mitochondrial genes (one protein coding, one ribosomal). We devised new optimization procedures and constructed a parallel computer cluster with 256 central processing units to analyse molecular data on a scale not previously possible. The optimal 'total evidence' cladogram supports the crustacean-hexapod clade, recognizes pycnogonids as sister to other euarthropods, and indicates monophyly of Myriapoda and Mandibulata.

  18. Graph-based interpretation of the molecular interstellar medium segmentation

    Science.gov (United States)

    Colombo, D.; Rosolowsky, E.; Ginsburg, A.; Duarte-Cabral, A.; Hughes, A.

    2015-12-01

    We present a generalization of the giant molecular cloud identification problem based on cluster analysis. The method we designed, SCIMES (Spectral Clustering for Interstellar Molecular Emission Segmentation) considers the dendrogram of emission in the broader framework of graph theory and utilizes spectral clustering to find discrete regions with similar emission properties. For Galactic molecular cloud structures, we show that the characteristic volume and/or integrated CO luminosity are useful criteria to define the clustering, yielding emission structures that closely reproduce `by-eye' identification results. SCIMES performs best on well-resolved, high-resolution data, making it complementary to other available algorithms. Using 12CO(1-0) data for the Orion-Monoceros complex, we demonstrate that SCIMES provides robust results against changes of the dendrogram-construction parameters, noise realizations and degraded resolution. By comparing SCIMES with other cloud decomposition approaches, we show that our method is able to identify all canonical clouds of the Orion-Monoceros region, avoiding the overdivision within high-resolution survey data that represents a common limitation of several decomposition algorithms. The Orion-Monoceros objects exhibit hierarchies and size-line width relationships typical to the turbulent gas in molecular clouds, although `the Scissors' region deviates from this common description. SCIMES represents a significant step forward in moving away from pixel-based cloud segmentation towards a more physical-oriented approach, where virtually all properties of the ISM can be used for the segmentation of discrete objects.

  19. una experiencia de intervención

    Directory of Open Access Journals (Sweden)

    Cecilia Villarreal Montoya

    2007-01-01

    Full Text Available El artículo resume la experiencia de intervención con una familia de la escuela de Villa Esperanza de Pavas. Se trata de un matrimonio con dificultades para disciplinar a sus tres hijos varones de ocho, seis, y cuatro años. En primer lugar, se exponen los principios teóricos y metodológicos, para luego mostrar la aplicación de ellos en el proceso vivido por la familia. Se aplica el modelo de intervención estructural, que busca que la misma familia logre realizar, paso a paso, los cambios requeridos en la dinámica y estructura familiar. En la situación específica de esta familia, se observa el fortalecimiento de la pareja como tal y como madre y padre en la medida que van logrando asumir la autoridad en forma compartida para disciplinar a los hijos. Al compartir esta experiencia, la autora pretende estimular a profesionales en Orientación a asumir el reto de considerar a las familias de la comunidad estudiantil, de las instituciones educativas donde laboran, como parte importante en el quehacer orientador.

  20. Forcefields based molecular modeling on the mechanical and physical properties of emeraldine base polyaniline

    NARCIS (Netherlands)

    Chen, X.; Yuan, C.A.; Wong, C.K.Y.; Zhang, G.Q.

    2010-01-01

    Molecular dynamics (MD) and molecular mechanical (MM) analysis are carried out to provide reliable and accurate model for emeraldine base polyaniline. This study validate the forcefields and model with the physical and mechanical properties of the polyaniline. The temperature effects on non-bond ene

  1. [Evolution and systematics of nematodes based on molecular investigation].

    Science.gov (United States)

    Okulewicz, Anna; Perec, Agnieszka

    2004-01-01

    Evolution and systematics of nematodes based on molecular investigation. The use of molecular phylogenetics to examine the interrelationships between animal parasites, free-living nematodes, and plant parasites versus traditional classification based on morphological-ecological characters was discussed and reviewed. Distinct differences were observed between parasitic nematodes and free-living ones. Within the former group, animal parasites turned out to be distinctly different from plant parasites. Using small subunit of ribosomal RNA gene sequence from a wide range of nematodes, there is a possibility to compare animal-parasitic, plant-parasitic and free-living taxa. Nowadays the parasitic nematodes expressed sequence tag (EST) project is currently generating sequence information to provide a new source of data to examine the evolutionary history of this taxonomic group. PMID:16859012

  2. Organization of a radioisotope based molecular biology laboratory

    International Nuclear Information System (INIS)

    Polymerase chain reaction (PCR) has revolutionized the application of molecular techniques to medicine. Together with other molecular biology techniques it is being increasingly applied to human health for identifying prognostic markers and drug resistant profiles, developing diagnostic tests and genotyping systems and for treatment follow-up of certain diseases in developed countries. Developing Member States have expressed their need to also benefit from the dissemination of molecular advances. The use of radioisotopes, as a step in the detection process or for increased sensitivity and specificity is well established, making it ideally suitable for technology transfer. Many molecular based projects using isotopes for detecting and studying micro organisms, hereditary and neoplastic diseases are received for approval every year. In keeping with the IAEA's programme, several training activities and seminars have been organized to enhance the capabilities of developing Member States to employ in vitro nuclear medicine technologies for managing their important health problems and for undertaking related basic and clinical research. The background material for this publication was collected at training activities and from feedback received from participants at research and coordination meetings. In addition, a consultants' meeting was held in June 2004 to compile the first draft of this report. Previous IAEA TECDOCS, namely IAEA-TECDOC-748 and IAEA-TECDOC-1001, focused on molecular techniques and their application to medicine while the present publication provides information on organization of the laboratory, quality assurance and radio-safety. The technology has specific requirements of the way the laboratory is organized (e.g. for avoiding contamination and false positives in PCR) and of quality assurance in order to provide accurate information to decision makers. In addition while users of the technology accept the scientific rationale of using radio

  3. Molecular Beacon CNT-based Detection of SNPs

    Science.gov (United States)

    Egorova, V. P.; Krylova, H. V.; Lipnevich, I. V.; Veligura, A. A.; Shulitsky, B. G.; Y Fedotenkova, L.

    2015-11-01

    An fluorescence quenching effect due to few-walled carbon nanotubes chemically modified by carboxyl groups has been utilized to discriminate Single Nucleotide Polymorphism (SNP). It was shown that the complex obtained from these nanotube and singlestranded primer DNA is formed due to stacking interactions between the hexagons of the nanotubes and aromatic rings of nucleotide bases as well as due to establishing of hydrogen bonds between acceptor amine groups of nucleotide bases and donor carboxyl groups of the nanotubes. It has been demonstrated that these complexes may be used to make highly effective DNA biosensors detecting SNPs which operate as molecular beacons.

  4. EXPERIENCIA DE LA HISTORICIDAD E HISTORICIDAD DE LA EXPERIENCIA: EL MUNDO COMO ESPACIO HERMENÉUTICO

    Directory of Open Access Journals (Sweden)

    Mauricio Mancilla Muñoz

    2013-07-01

    Full Text Available El siguiente artículo tiene por objetivo mostrar la mutua correspondencia entre experiencia e historicidad en la obra de Hans-Georg Gadamer. La experiencia es entendida como el movimiento fundamental de la existencia histórica, la que articula las diversas esferas de la acción humana. La experiencia hermenéutica pone de manifiesto que el comprender no puede fundarse en un procedimiento metódico, sino en la forma del existir situado en el mundo. El acto hermenéutico es entendido como un continuo proceso de apropiación, que se realiza mediante el lenguaje, y donde se van actualizando nuevos significados que develan el carácter aconteciente y móvil de la interpretación. Por ello, la historicidad de la comprensión será el principio hermenéutico fundamental que excluye la posibilidad de una conciencia histórica absoluta, a favor de una “conciencia de la repercusión histórica” (wirkungsgeschtliches Bewußtseins.

  5. Affinity sensor based on immobilized molecular imprinted synthetic recognition elements.

    Science.gov (United States)

    Lenain, Pieterjan; De Saeger, Sarah; Mattiasson, Bo; Hedström, Martin

    2015-07-15

    An affinity sensor based on capacitive transduction was developed to detect a model compound, metergoline, in a continuous flow system. This system simulates the monitoring of low-molecular weight organic compounds in natural flowing waters, i.e. rivers and streams. During operation in such scenarios, control of the experimental parameters is not possible, which poses a true analytical challenge. A two-step approach was used to produce a sensor for metergoline. Submicron spherical molecularly imprinted polymers, used as recognition elements, were obtained through emulsion polymerization and subsequently coupled to the sensor surface by electropolymerization. This way, a robust and reusable sensor was obtained that regenerated spontaneously under the natural conditions in a river. Small organic compounds could be analyzed in water without manipulating the binding or regeneration conditions, thereby offering a viable tool for on-site application. PMID:25703726

  6. Walter Benjamin: historia, experiencia y modernidad

    Directory of Open Access Journals (Sweden)

    Mario Alejandro Molano

    2014-01-01

    Full Text Available Desde finales del siglo XX, las investigaciones sobre modernidad, orientadas hacia distintos segmentos del campo cultural, han venido ganando un enorme terreno. Las obras de Walter Benjamin, leídas en esta perspectiva, cobran un gran valor. Se busca explorar cuatro temas benjaminianos: a algunos aspectos de su concepto de historia; b el concepto de experiencia, para mostrar su dimensión histórico-crítica con respecto al ascenso de la cultura moderna; c las afinidades entre el modo en que se desarrolla la visión alegórica en el drama barroco alemán y el modo en que Baudelaire afronta las problemáticas de la modernidad; d elementos de algunas formas culturales del arte moderno que entusiasman a Benjamin.

  7. LA EXPERIENCIA VIAJERA EN EDUCACIÓN

    Directory of Open Access Journals (Sweden)

    Gloria Luna Rodrigo

    1999-12-01

    Full Text Available En este trabajo se estudia el uso que se hacia de las experiencias y relatos de viajes para enseaargeografia en la escuela primaria en Gran Bretaña al final del siglo XIX y el primer tercio del XX.Los relatos más importantes eran las aventuras de exploradores y viajeros narradas por ellos mismoso transcritas de sus diarios, series de historias que adaptaban las anteriores para niños pequeños,relatos de viaje de «geógrafos naturalistas» y .movelas geográñcasw. Se consideran libros de consultapara el profesor de los que extraer ideas y vividas imágenes de los fenómenos geográficos que iluminarancon datos llenos de color y concreción los áridos y abstractos hechos de índole científica.

  8. A Molecular Imaging Approach to Mercury Sensing Based on Hyperpolarized (129)Xe Molecular Clamp Probe.

    Science.gov (United States)

    Guo, Qianni; Zeng, Qingbin; Jiang, Weiping; Zhang, Xiaoxiao; Luo, Qing; Zhang, Xu; Bouchard, Louis-S; Liu, Maili; Zhou, Xin

    2016-03-14

    Mercury pollution, in the form of mercury ions (Hg(2+)), is a major health and environmental hazard. Commonly used sensors are invasive and limited to point measurements. Fluorescence-based sensors do not provide depth resolution needed to image spatial distributions. Herein we report a novel sensor capable of yielding spatial distributions by MRI using hyperpolarized (129)Xe. A molecular clamp probe was developed consisting of dipyrrolylquinoxaline (DPQ) derivatives and twocryptophane-A cages. The DPQ derivatives act as cation receptors whereas cryptophane-A acts as a suitable host molecule for xenon. When the DPQ moiety interacts with mercury ions, the molecular clamp closes on the ion. Due to overlap of the electron clouds of the two cryptophane-A cages, the shielding effect on the encapsulated Xe becomes important. This leads to an upfield change of the chemical shift of the encapsulated Xe. This sensor exhibits good selectivity and sensitivity toward the mercury ion. This mercury-activated hyperpolarized (129)Xe-based chemosensor is a new concept method for monitoring Hg(2+) ion distributions by MRI.

  9. Tunneling Nanoelectromechanical Switches Based on Compressible Molecular Thin Films.

    Science.gov (United States)

    Niroui, Farnaz; Wang, Annie I; Sletten, Ellen M; Song, Yi; Kong, Jing; Yablonovitch, Eli; Swager, Timothy M; Lang, Jeffrey H; Bulović, Vladimir

    2015-08-25

    Abrupt switching behavior and near-zero leakage current of nanoelectromechanical (NEM) switches are advantageous properties through which NEMs can outperform conventional semiconductor electrical switches. To date, however, typical NEMs structures require high actuation voltages and can prematurely fail through permanent adhesion (defined as stiction) of device components. To overcome these challenges, in the present work we propose a NEM switch, termed a "squitch," which is designed to electromechanically modulate the tunneling current through a nanometer-scale gap defined by an organic molecular film sandwiched between two electrodes. When voltage is applied across the electrodes, the generated electrostatic force compresses the sandwiched molecular layer, thereby reducing the tunneling gap and causing an exponential increase in the current through the device. The presence of the molecular layer avoids direct contact of the electrodes during the switching process. Furthermore, as the layer is compressed, the increasing surface adhesion forces are balanced by the elastic restoring force of the deformed molecules which can promote zero net stiction and recoverable switching. Through numerical analysis, we demonstrate the potential of optimizing squitch design to enable large on-off ratios beyond 6 orders of magnitude with operation in the sub-1 V regime and with nanoseconds switching times. Our preliminary experimental results based on metal-molecule-graphene devices suggest the feasibility of the proposed tunneling switching mechanism. With optimization of device design and material engineering, squitches can give rise to a broad range of low-power electronic applications. PMID:26244821

  10. Molecular based subtyping of feline mammary carcinomas and clinicopathological characterization.

    Science.gov (United States)

    Soares, Maria; Madeira, Sara; Correia, Jorge; Peleteiro, Maria; Cardoso, Fátima; Ferreira, Fernando

    2016-06-01

    Molecular classification of feline mammary carcinomas (FMC) from which specific behavioral patterns may be estimated has potential applications in veterinary clinical practice and in comparative oncology. In this perspective, the main goal of this study was to characterize both the clinical and the pathological features of the different molecular phenotypes found in a population of FMC (n = 102), using the broadly accepted IHC-based classification established by St. Gallen International Expert Consensus panel. The luminal B/HER2-negative subtype was the most common (29.4%, 30/102) followed by luminal B/HER2-positive subtype (19.6%, 20/102), triple negative basal-like (16.7%, 17/102), luminal A (14.7%, 15/102), triple negative normal-like (12.7%, 13/102) and finally, HER2-positive subtype (6.9%, 7/102). Luminal A subtype was significantly associated with smaller tumors (p = 0.024) and with well differentiated ones (p molecular subtypes in each carcinoma, revealing that all independent lesions should be analyzed in order to improve the clinical management of animals. Finally, the similarities between the subtypes of feline mammary tumors and human breast cancer, reveal that feline can be a valuable model for comparative studies. PMID:27212699

  11. Molecular Docking and Structure-Based Drug Design Strategies

    Directory of Open Access Journals (Sweden)

    Leonardo G. Ferreira

    2015-07-01

    Full Text Available Pharmaceutical research has successfully incorporated a wealth of molecular modeling methods, within a variety of drug discovery programs, to study complex biological and chemical systems. The integration of computational and experimental strategies has been of great value in the identification and development of novel promising compounds. Broadly used in modern drug design, molecular docking methods explore the ligand conformations adopted within the binding sites of macromolecular targets. This approach also estimates the ligand-receptor binding free energy by evaluating critical phenomena involved in the intermolecular recognition process. Today, as a variety of docking algorithms are available, an understanding of the advantages and limitations of each method is of fundamental importance in the development of effective strategies and the generation of relevant results. The purpose of this review is to examine current molecular docking strategies used in drug discovery and medicinal chemistry, exploring the advances in the field and the role played by the integration of structure- and ligand-based methods.

  12. RETOS Y POSIBILIDADES DE LOS CURSOS EN LÍNEA A PARTIR DE UNA EXPERIENCIA CONCRETA.

    Directory of Open Access Journals (Sweden)

    Ana Aurora Vidal Martínez

    2014-01-01

    Full Text Available ste trabajo retoma el modelo de McIsaac y Gunawardena (1996 para el diseño de interfaces de cursos en línea y revisa su eficacia en base a una experiencia. Se describe la plataforma utilizada y las competencias docentes deseables, así como el sistema tutorial brindado y la presentación/manejo de contenidos temáticos y materiales didácticos que dicha plataforma permite. Complementa este análisis los resultados de la experiencia en términos del grado de satisfacción de los participantes (estructura y diseño del curso y el registro de actividad en la plataforma, información que se obtuvo mediante una encuesta de opinión en línea y la observación no participativa.

  13. Accelerating convergence of molecular dynamics-based structural relaxation

    DEFF Research Database (Denmark)

    Christensen, Asbjørn

    2005-01-01

    We describe strategies to accelerate the terminal stage of molecular dynamics (MD)based relaxation algorithms, where a large fraction of the computational resources are used. First, we analyze the qualitative and quantitative behavior of the QuickMin family of MD relaxation algorithms and explore...... an MD trajectory, as another route for final phase acceleration. Our suggestions may be implemented within most MD quench implementations with a few, straightforward lines of code, thus maintaining the appealing simplicity of the MD quench algorithms. In this paper, we also bridge the conceptual gap...

  14. Molecular Dipole Osmosis Based on Induced Charge Electro-Osmosis

    Science.gov (United States)

    Sugioka, Hideyuki

    2016-09-01

    We propose a novel mechanism of producing a large nonlinear electrokinetic vortex flow around a nonconductive polar molecule in an electrolyte. That is, a large nonlinear electrokinetic slip velocity is derived by considering a local giant permittivity due to a molecular electric dipole moment with induced-charge electro-osmosis (ICEO). Different from the conventional ICEO theory, our theory predicts that a nonconductive biomaterial, such as a base of a deoxyribonucleic acid (DNA) molecule, has a significantly high ICEO flow velocity because of its large local permittivity. We consider that our findings will contribute markedly to promising biomedical applications.

  15. Recent advances on polyoxometalate-based molecular and composite materials.

    Science.gov (United States)

    Song, Yu-Fei; Tsunashima, Ryo

    2012-11-21

    Polyoxometalates (POMs) are a subset of metal oxides with unique physical and chemical properties, which can be reliably modified through various techniques and methods to develop sophisticated materials and devices. In parallel with the large number of new crystal structures reported in the literature, the application of these POMs towards multifunctional materials has attracted considerable attention. This critical review summarizes recent progress on POM-based molecular and composite materials, and particularly highlights the emerging areas that are closely related to surface, electronic, energy, environment, life science, etc. (171 references). PMID:22850732

  16. Single-molecular diodes based on opioid derivatives.

    Science.gov (United States)

    Siqueira, M R S; Corrêa, S M; Gester, R M; Del Nero, J; Neto, A M J C

    2015-12-01

    We propose an efficient single-molecule rectifier based on a derivative of opioid. Electron transport properties are investigated within the non-equilibrium Green's function formalism combined with density functional theory. The analysis of the current-voltage characteristics indicates obvious diode-like behavior. While heroin presents rectification coefficient R>1, indicating preferential electronic current from electron-donating to electron-withdrawing, 3 and 6-acetylmorphine and morphine exhibit contrary behavior, Rdiodes. In particular, the rectification rations for heroin diodes show microampere electron current with a maximum of rectification (R=9.1) at very low bias voltage of ∼0.6 V and (R=14.3)∼1.8 V with resistance varying between 0.4 and 1.5 M Ω. Once most of the current single-molecule diodes usually rectifies in nanoampere, are not stable over 1.0 V and present electrical resistance around 10 M. Molecular devices based on opioid derivatives are promising in molecular electronics.

  17. Single-molecular diodes based on opioid derivatives.

    Science.gov (United States)

    Siqueira, M R S; Corrêa, S M; Gester, R M; Del Nero, J; Neto, A M J C

    2015-12-01

    We propose an efficient single-molecule rectifier based on a derivative of opioid. Electron transport properties are investigated within the non-equilibrium Green's function formalism combined with density functional theory. The analysis of the current-voltage characteristics indicates obvious diode-like behavior. While heroin presents rectification coefficient R>1, indicating preferential electronic current from electron-donating to electron-withdrawing, 3 and 6-acetylmorphine and morphine exhibit contrary behavior, Rresonant-tunneling diodes. In particular, the rectification rations for heroin diodes show microampere electron current with a maximum of rectification (R=9.1) at very low bias voltage of ∼0.6 V and (R=14.3)∼1.8 V with resistance varying between 0.4 and 1.5 M Ω. Once most of the current single-molecule diodes usually rectifies in nanoampere, are not stable over 1.0 V and present electrical resistance around 10 M. Molecular devices based on opioid derivatives are promising in molecular electronics. PMID:26613894

  18. Implementation of CCNUGrid-based Computational Environment for Molecular Modeling

    Science.gov (United States)

    Liu, Kai; Luo, Changhua; Ren, Yanliang; Wan, Jian; Xu, Xin

    2007-12-01

    Grid computing technology has being regarded as one of the most promising solutions for the tremendous requirement of computing resources in the field of molecular modeling up to date. Contrast to building a more and more powerful super-computer with novel hardware in a local network, grid technology enable us, in principle, to integrate various previous and present computing resources located in different location into a computing platform as a whole. As a case demonstration, we reported herein that a campus grid entitled CCNUGrid was implemented with grid middleware, consisting of four local computing networks distributed in College of Chemistry, College of Physics, Center for Network, and Center for Education Information Technology and Engineering, respectively, at Central China Normal University. Visualization functions of monitoring computer machines in each local network, monitoring job processing flow, and monitoring computational results were realized in this campus grid-based computational environment, in addition to the conventional components of grid architecture: universal portal, task management, computing node and security. In the last section of this paper, a molecular docking-based virtual screening study was performed at the CCNUGrid, as one example of CCNUGrid applications.

  19. Experiencias de adolescentes embarazadas en control prenatal

    Directory of Open Access Journals (Sweden)

    Hilda Evelia Prías-Vanegas

    2009-01-01

    Full Text Available Objetivo: describir e interpretar las experiencias relacionadas con los sentimientos e ideas experimentados por las adolescentes al conocer su estado de embarazo. Método: se trabajó con un grupo de 22 adolescentes de instituciones públicas de I nivel de salud de Sincelejo, Colombia. El estudio, realizado en 2005, se abordó desde un enfoque cualitativo, con información recogida en entrevistas personales, grabadas con consentimiento de las jóvenes. Resultados: el embarazo genera en la adolescente sentimientos de displacer relacionados con miedo, tristeza, dolor, sufrimiento, culpa, vergüenza y decepción, acompañados de ideas de negación, evasión, duda, arrepentimiento y deseos de abortar, los cuales no aparecen cuando la adolescente cuenta con el apoyo de su compañero sentimental o el de sus padres. Conclusión: las adolescentes necesitan apoyo, comprensión y ayuda, dado que están más sensibles, lábiles, inseguras y con baja autoestima, situación que requiere que el equipo de salud desarrolle y muestre competencias en el área humanística, acercamiento personal, empatía y trato humanizado e individualizado en la atención de la población de adolescentes embarazadas.

  20. EXPERIENCIA INTEGRADORA PARA EDUCACIÓN AMBIENTAL

    Directory of Open Access Journals (Sweden)

    Jorge F. Coronel

    2015-01-01

    Full Text Available En este trabajo se relacionó la práctica experimental de laboratorio co n el análisis de problemas ambientales. El objetivo de este trabajo es analizar una propuesta que vinculó el trabajo experimental con la situación del ambiente local para promover el cuidado de la naturaleza y su uso con sostenibilidad . Esta estrategia brindó un enfoque integrador aportando a los alumnos de profesorado una alternativa de aprendizaje con exper iencias sencillas para el estudio cualitativo de l ambiente local y motivar a l análisis de problemas asociad o s. Las experiencias permitieron caracterizar las muestras de suelo, agua y aire del lugar de residencia de los alumnos. La información experimental obtenida potenció la discusión de la situación ambiental actual. E l enfoque de enseñanza basado en problemas socio - científicos posibilit ó la visión interdisciplinar del tema , redimensionando valores y acciones para el cuidado ambiental y el desarrollo sustentable.

  1. experiencia psicológica del ocio

    Directory of Open Access Journals (Sweden)

    Maria Jesus Monteagudo

    2008-01-01

    Full Text Available El presente artículo aborda desde una perspectiva actual el tema de los Beneficios del Ocio, uno de los conceptos esenciales en el estudio del ocio como factor de desarrollo personal y social. Se aporta una visión evolutiva del concepto a través de diferentes corrientes teóricas, subrayando la importancia de los beneficios del ocio entendidos desde una acepción: como mejora de una condición o situación de una persona, grupo o entidad, como prevención y/o mantenimiento y finalmente, como consecución de una experiencia psicológica satisfactoria en el marco de un ocio ajustado. Desde la perspectiva de la autora, el ocio promueve la consecución de dos tipos de beneficios, intermedios y finales, que contribuyen a mejorar el bienestar y la calidad de vida de los ciudadanos. Los profesionales del ocio procedentes tanto del sector público como del privado deberían tomar conciencia de los beneficios que pueden promoverse a través del ocio e incorporar estos conocimientos en el diseño de políticas, estrategias de gestión y modelos de intervención en ocio

  2. A molecularly based theory for electron transfer reorganization energy

    International Nuclear Information System (INIS)

    Using field-theoretic techniques, we develop a molecularly based dipolar self-consistent-field theory (DSCFT) for charge solvation in pure solvents under equilibrium and nonequilibrium conditions and apply it to the reorganization energy of electron transfer reactions. The DSCFT uses a set of molecular parameters, such as the solvent molecule’s permanent dipole moment and polarizability, thus avoiding approximations that are inherent in treating the solvent as a linear dielectric medium. A simple, analytical expression for the free energy is obtained in terms of the equilibrium and nonequilibrium electrostatic potential profiles and electric susceptibilities, which are obtained by solving a set of self-consistent equations. With no adjustable parameters, the DSCFT predicts activation energies and reorganization energies in good agreement with previous experiments and calculations for the electron transfer between metallic ions. Because the DSCFT is able to describe the properties of the solvent in the immediate vicinity of the charges, it is unnecessary to distinguish between the inner-sphere and outer-sphere solvent molecules in the calculation of the reorganization energy as in previous work. Furthermore, examining the nonequilibrium free energy surfaces of electron transfer, we find that the nonequilibrium free energy is well approximated by a double parabola for self-exchange reactions, but the curvature of the nonequilibrium free energy surface depends on the charges of the electron-transferring species, contrary to the prediction by the linear dielectric theory

  3. A molecularly based theory for electron transfer reorganization energy

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Bilin; Wang, Zhen-Gang, E-mail: zgw@cheme.caltech.edu [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States)

    2015-12-14

    Using field-theoretic techniques, we develop a molecularly based dipolar self-consistent-field theory (DSCFT) for charge solvation in pure solvents under equilibrium and nonequilibrium conditions and apply it to the reorganization energy of electron transfer reactions. The DSCFT uses a set of molecular parameters, such as the solvent molecule’s permanent dipole moment and polarizability, thus avoiding approximations that are inherent in treating the solvent as a linear dielectric medium. A simple, analytical expression for the free energy is obtained in terms of the equilibrium and nonequilibrium electrostatic potential profiles and electric susceptibilities, which are obtained by solving a set of self-consistent equations. With no adjustable parameters, the DSCFT predicts activation energies and reorganization energies in good agreement with previous experiments and calculations for the electron transfer between metallic ions. Because the DSCFT is able to describe the properties of the solvent in the immediate vicinity of the charges, it is unnecessary to distinguish between the inner-sphere and outer-sphere solvent molecules in the calculation of the reorganization energy as in previous work. Furthermore, examining the nonequilibrium free energy surfaces of electron transfer, we find that the nonequilibrium free energy is well approximated by a double parabola for self-exchange reactions, but the curvature of the nonequilibrium free energy surface depends on the charges of the electron-transferring species, contrary to the prediction by the linear dielectric theory.

  4. Preparation and Characterization of a Polymer-Based "Molecular Accordion".

    Science.gov (United States)

    Karoyo, Abdalla H; Wilson, Lee D

    2016-03-29

    A urethane-based polymer material, denoted HDI-1, was obtained from the addition reaction of β-cyclodextrin (β-CD) with 1,6-hexamethylene diisocyanate (HDI) at the 1:1 mole ratio. In aqueous solution and ambient temperature conditions, HDI-1 adopts a compact (coiled) morphology where the cross-linker units become coiled and are partially self-included in the annular hydroxyl (interstitial) region of β-CD. As the temperature is raised or as p-nitrophenol (PNP) was included within the β-CD cavity and the noninclusion sites of the polymer, an extended (uncoiled) morphology was adopted. The equilibrium distribution between the extended and the compact forms of HDI-1 is thermally and chemically switchable, in accordance with the hydration properties and host-guest chemistry of this responsive polymer system. The molecular structure of this water-soluble urethane polymer and its host-guest complexes with PNP were investigated using spectroscopic (Raman, (1)H NMR, induced circular dichroism), dynamic light scattering (DLS), and calorimetric (DSC) methods in aqueous solution at ambient pH, and compared with native β-CD. This study reports on the unique supramolecular properties of a polymer that resembles a thermally and chemically responsive "molecular accordion". PMID:26931298

  5. Bases moleculares de alfa-talasemia en la Argentina

    Directory of Open Access Journals (Sweden)

    Karen G Scheps

    2015-04-01

    Full Text Available La α-talasemia, es uno de los desórdenes hereditarios más frecuentes mundialmente. Al presente, el diagnóstico molecular es la única herramienta que permite el diagnóstico certero. El propósito de este trabajo fue caracterizar las bases moleculares de estos síndromes en nuestro medio, y establecer relaciones genotipo-fenotipo. Mediante la complementación de distintas técnicas de biología molecular e hibridación fluorescente in situ (FISH, se logró poner en evidencia la presencia de mutaciones α-talasémicas en 145 de 184 (78.8% pacientes estudiados con perfil hematológico compatible con α-talasemia. Dentro de este grupo, las deleciones correspondieron al defecto genético más frecuente, prevaleciendo la mutación -α3.7 en genotipos heterocigotas y homocigotas. Asimismo, en pacientes con fenotipo α0 las deleciones prevalentes fueron -MED y -CAL/CAMP. Este estudio permitió también describir una deleción de la región sub-telomérica en un paciente con α-talasemia y retraso mental. En el 7.6% de los pacientes caracterizados clínicamente como posibles α-talasémicos (microcitosis con valores de Hb A2 inferiores al 3.5%, se hallaron mutaciones β-talasémicas en estado heterocigota. Se lograron establecer perfiles hematológicos asociados a los genotipos α+ y α0 para pacientes adultos y niños. Esperamos que este trabajo pueda servir como guía para reconocer posibles portadores α-talasémicos. También permite destacar el trabajo en conjunto de médicos hematólogos, el laboratorio (bioquímico y de biología molecular y de los médicos genetistas, con el fin de proporcionar adecuado consejo genético.

  6. Current Progress of Aptamer-Based Molecular Imaging

    OpenAIRE

    Wang, Andrew Z.; Farokhzad, Omid C.

    2014-01-01

    Aptamers, single-stranded oligonucleotides, are an important class of molecular targeting ligand. Since their discovery, aptamers have been rapidly translated into clinical practice. They have been approved as therapeutics and molecular diagnostics. Aptamers also possess several properties that make them uniquely suited to molecular imaging. This review aims to provide an overview of aptamers’ advantages as targeting ligands and their application in molecular imaging.

  7. Genomic and epigenetic insights into the molecular bases of heterosis.

    Science.gov (United States)

    Chen, Z Jeffrey

    2013-07-01

    Heterosis, also known as hybrid vigour, is widespread in plants and animals, but the molecular bases for this phenomenon remain elusive. Recent studies in hybrids and allopolyploids using transcriptomic, proteomic, metabolomic, epigenomic and systems biology approaches have provided new insights. Emerging genomic and epigenetic perspectives suggest that heterosis arises from allelic interactions between parental genomes, leading to altered programming of genes that promote the growth, stress tolerance and fitness of hybrids. For example, epigenetic modifications of key regulatory genes in hybrids and allopolyploids can alter complex regulatory networks of physiology and metabolism, thus modulating biomass and leading to heterosis. The conceptual advances could help to improve plant and animal productivity through the manipulation of heterosis.

  8. Molecular bases of circadian rhythmicity in renal physiology and pathology.

    Science.gov (United States)

    Bonny, Olivier; Vinciguerra, Manlio; Gumz, Michelle L; Mazzoccoli, Gianluigi

    2013-10-01

    The physiological processes that maintain body homeostasis oscillate during the day. Diurnal changes characterize kidney functions, comprising regulation of hydro-electrolytic and acid-base balance, reabsorption of small solutes and hormone production. Renal physiology is characterized by 24-h periodicity and contributes to circadian variability of blood pressure levels, related as well to nychthemeral changes of sodium sensitivity, physical activity, vascular tone, autonomic function and neurotransmitter release from sympathetic innervations. The circadian rhythmicity of body physiology is driven by central and peripheral biological clockworks and entrained by the geophysical light/dark cycle. Chronodisruption, defined as the mismatch between environmental-social cues and physiological-behavioral patterns, causes internal desynchronization of periodic functions, leading to pathophysiological mechanisms underlying degenerative, immune related, metabolic and neoplastic diseases. In this review we will address the genetic, molecular and anatomical elements that hardwire circadian rhythmicity in renal physiology and subtend disarray of time-dependent changes in renal pathology. PMID:23901050

  9. DNA Aptamer Based Nanodrugs: Molecular Engineering for Efficiency.

    Science.gov (United States)

    Cansiz, Sena; Zhang, Liqin; Wu, Cuichen; Wu, Yuan; Teng, I-Ting; Hou, Weijia; Wang, Yanyue; Wan, Shuo; Cai, Ren; Jin, Chen; Liu, Qiaoling; Tan, Weihong

    2015-10-01

    In the past two decades, the study of cancer therapy has gradually advanced to the "nano" era. Numerous novel nanomaterials armed with unique physical properties have been introduced into biomedical research. At the same time, functional nucleic acid molecules, especially aptamers, have aroused broad attention from the biomedical community. Benefiting from the advancement of molecular engineering strategies, it is now feasible to combine the cancer-specific recognition capability of aptamers with various other special functions of nanomaterials to develop cancer-specific drugs at the nanoscale. Nanodrugs are now offering an unprecedented opportunity to achieve the goal of efficient targeted delivery as well as controlled release. This review highlights some achievements made in multiple aptamer-based nanodrug systems that have emerged in recent years, including studies in the infant stage of "proof-of-concept". PMID:26177853

  10. Molecular Beacon-Based MicroRNA Imaging During Neurogenesis.

    Science.gov (United States)

    Lee, Jonghwan; Kim, Soonhag

    2016-01-01

    The fluorescence monitoring system for examining endogenous microRNA (miRNA) activity in cellular level provides crucial information on not only understanding a critical role of miRNA involving a variety of biological processes, but also evaluating miRNA expression patterns in a noninvasive manner. In this protocol, we report the details of a new procedure for a molecular beacon-based miRNA monitoring system, which includes the illustration scheme for miRNA detection strategy, exogenous miRNA detection, and measurement of endogenous miRNA expression level during neurogenesis. The fluorescence signal of miR-124a beacon quenched by BHQ2 was gradually recovered as increasing concentration of the miR-124a in tube. The functional work of miR-124a beacon was examined in intracellular environment, allowing for the internalization of the miR-124a beacon by lipofectamine, which resulted in activated fluorescent signals of the miR-124a beacon in the HeLa cells after the addition of synthetic miR-124a. The endogenous miR-124a expression level was detected by miR-124a beacon system during neurogenesis, showing brighter fluorescence intensity in cytoplasmic area of P19 cells after induction of neuronal differentiation by retinoic acid. The molecular beacon based-miRNA detection technique could be applicable to the simultaneous visualization of a variety of miRNA expression patterns using different fluorescence dyes. For the study of examining endogenous miRNA expression level using miRNA-beacon system, if cellular differentiation step is already prepared, transfection step of miR-124a beacon into P19 cells, and acquisition of activated fluorescence signal measured by confocal microscope can be conducted approximately within 6 h. PMID:26530921

  11. Molecular Beacon-Based MicroRNA Imaging During Neurogenesis.

    Science.gov (United States)

    Lee, Jonghwan; Kim, Soonhag

    2016-01-01

    The fluorescence monitoring system for examining endogenous microRNA (miRNA) activity in cellular level provides crucial information on not only understanding a critical role of miRNA involving a variety of biological processes, but also evaluating miRNA expression patterns in a noninvasive manner. In this protocol, we report the details of a new procedure for a molecular beacon-based miRNA monitoring system, which includes the illustration scheme for miRNA detection strategy, exogenous miRNA detection, and measurement of endogenous miRNA expression level during neurogenesis. The fluorescence signal of miR-124a beacon quenched by BHQ2 was gradually recovered as increasing concentration of the miR-124a in tube. The functional work of miR-124a beacon was examined in intracellular environment, allowing for the internalization of the miR-124a beacon by lipofectamine, which resulted in activated fluorescent signals of the miR-124a beacon in the HeLa cells after the addition of synthetic miR-124a. The endogenous miR-124a expression level was detected by miR-124a beacon system during neurogenesis, showing brighter fluorescence intensity in cytoplasmic area of P19 cells after induction of neuronal differentiation by retinoic acid. The molecular beacon based-miRNA detection technique could be applicable to the simultaneous visualization of a variety of miRNA expression patterns using different fluorescence dyes. For the study of examining endogenous miRNA expression level using miRNA-beacon system, if cellular differentiation step is already prepared, transfection step of miR-124a beacon into P19 cells, and acquisition of activated fluorescence signal measured by confocal microscope can be conducted approximately within 6 h.

  12. Dissecting plasmodesmata molecular composition by mass spectrometry-based proteomics.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Maria Françoise Bayer

    2013-01-01

    Full Text Available In plants, the intercellular communication through the membranous channels called plasmodesmata (PD; singular plasmodesma plays pivotal roles in the orchestration of development, defence responses and viral propagation. PD are dynamic structures embedded in the plant cell wall that are defined by specialised domains of the endoplasmic reticulum and the plasma membrane. PD structure and unique functions are guaranteed by their particular molecular composition. Yet, up to recent years and despite numerous approaches such as mutant screens, immunolocalisation or screening of random cDNAs, only few PD proteins had been conclusively identified and characterised. A clear breakthrough in the search of PD constituents came from mass-spectrometry-based proteomic approaches coupled with subcellular fractionation strategies. Due to their position, firmly anchored in the extracellular matrix, PD are notoriously difficult to isolate for biochemical analysis. Proteomic-based approaches have therefore first relied on the use of cell wall fractions containing embedded PD then on free PD fractions whereby PD membranes were released from the walls by enzymatic degradation. To discriminate between likely contaminants and PD protein candidates, bioinformatics tools have often been used in combination with proteomic approaches. GFP fusion proteins of selected candidates have confirmed the PD association of several protein families. Here we review the accomplishments and limitations of the proteomic based strategies to unravel the functional and structural complexity of PD. We also discuss the role of the identified PD associated proteins.

  13. "Experiencia en la Universidad de Carabobo"

    Directory of Open Access Journals (Sweden)

    Honmy Rosario

    2008-01-01

    Full Text Available Indudablemente la revolución de la tecnología de la información y comunicación (TIC a través de las telecomunicaciones y la informática han cambiando los estilos de vida en esta sociedad del conocimiento. Esto llega a indicar que estas TIC están aquí, y están para perpetuar en el tiempo. Hoy día se convive con el gran desafió que representa el uso de estas TIC en ambientes educativos por ello la necesidad de preparar y actualizar al personal docente de nuestro sector educativo (escuelas, colegios, tecnológicos, universidades, e institutos educacionales para soportar el reto que implica su implementación. La Web es una de las herramientas de estas tecnologías que inducen a implementar cambios importantes en el proceso de enseñanza aprendizaje, específicamente en el desarrollo de trabajos colaborativos. Esta es una estrategia de aprendizaje que se ha expandido en todas las áreas de conocimiento facilitando a todos los actores del proceso (docentes, estudiantes a una alta interacción de información construyendo su propio aprendizaje. El presente trabajo muestra una experiencia del uso de la web como herramienta en el trabajo colaborativo en cursos de "Diseño de Material Computarizado" en pregrado y postgrado en la Universidad de Carabobo y que demuestran la efectividad en el aprendizaje significativo de los tópicos tratados. Se utiliza como estrategia metodológica la creación de un entorno virtual de aprendizaje con el uso de la plataforma nicenet y el desarrollo de páginas web por parte de cada uno de los participantes de los cursos

  14. BASES MOLECULARES DA ABSORÇÃO DO FERRO

    Directory of Open Access Journals (Sweden)

    A. A. MACHADO

    2009-03-01

    Full Text Available

    O ferro é um elemento essencial a todos os organismos vivos e alterações em sua homeostase resultam em quadro de deficiência ou acúmulo, ambos com alta prevalência e relevância clínica. A última década foi marcada pela geração de conhecimentos importantes, que estão contribuindo para a elucidação dos mecanismos moleculares da homeostase do ferro. Foram identificadas proteínas, envolvidas na absorção intestinal do ferro não-heme, e progressos significativos foram feitos no entendimento da regulação da absorção intestinal do ferro, sendo identificadas várias moléculas candidatas. As bases moleculares da homeostase do ferro ainda não foram totalmente elucidadas, porém as informações já existentes sugerem que, em condições fisiológicas, a absorção, o transporte e o armazenamento sejam feitos por moléculas altamente especializadas e, em especial, a absorção, com mecanismos saturáveis em baixa concentração. No entanto, a absorção pode ocorrer por vias menos sujeitas ao controle, dependendo da sobrecarga e da natureza química do composto utilizado. Estas informações advogam a favor de uma revisão nas estratégias de combate à anemia ferropriva. PALAVRAS-CHAVE: Absorção do ferro; DMT-1; hepahestina; ceruloplasmina; ferroportina; hepcidina.

  15. Pathological Bases for a Robust Application of Cancer Molecular Classification

    Directory of Open Access Journals (Sweden)

    Salvador J. Diaz-Cano

    2015-04-01

    Full Text Available Any robust classification system depends on its purpose and must refer to accepted standards, its strength relying on predictive values and a careful consideration of known factors that can affect its reliability. In this context, a molecular classification of human cancer must refer to the current gold standard (histological classification and try to improve it with key prognosticators for metastatic potential, staging and grading. Although organ-specific examples have been published based on proteomics, transcriptomics and genomics evaluations, the most popular approach uses gene expression analysis as a direct correlate of cellular differentiation, which represents the key feature of the histological classification. RNA is a labile molecule that varies significantly according with the preservation protocol, its transcription reflect the adaptation of the tumor cells to the microenvironment, it can be passed through mechanisms of intercellular transference of genetic information (exosomes, and it is exposed to epigenetic modifications. More robust classifications should be based on stable molecules, at the genetic level represented by DNA to improve reliability, and its analysis must deal with the concept of intratumoral heterogeneity, which is at the origin of tumor progression and is the byproduct of the selection process during the clonal expansion and progression of neoplasms. The simultaneous analysis of multiple DNA targets and next generation sequencing offer the best practical approach for an analytical genomic classification of tumors.

  16. Magnetic and electronic properties of porphyrin-based molecular nanowires

    Directory of Open Access Journals (Sweden)

    Jia-Jia Zheng

    2016-01-01

    Full Text Available Using spin-polarized density functional theory calculations, we performed theoretical investigations on the electronic and magnetic properties of transition metal embedded porphyrin-based nanowires (TM-PNWs, TM = Cr, Mn, Co, Ni, Cu, and Zn. Our results indicate that Ni-PNW and Zn-PNW are nonmagnetic while the rest species are magnetic, and the magnetic moments in TM-PNWs and their corresponding isolated monomer structures are found to be the same. In addition, the spin coupling in the magnetic nanowires can be ignored leading to their degenerate AFM and FM states. These results can be ascribed to the weak intermetallic interactions because of the relatively large distances between neighbor TM atoms. Among all TM-PNW structures considered here, only Mn-PNW shows a half-metallic property while the others are predicted to be semiconducting. The present work paves a new way of obtaining ferromagnetic porphyrin-based nanowires with TM atoms distributed separately and orderly, which are expected to be good candidates for catalysts, energy storage and molecular spintronics.

  17. Magnetic and electronic properties of porphyrin-based molecular nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jia-Jia; Li, Qiao-Zhi; Dang, Jing-Shuang; Zhao, Xiang, E-mail: xzhao@mail.xjtu.edu.cn [Institute for Chemical Physics & Department of Chemistry, MOE Key Laboratory for Non-equilibrium Condensed Matter and Quantum Engineering, School of Science, Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Wei-Wei [Research Center for Computational Science, Institute for Molecular Science, Okazaki, Aichi 444-8585 (Japan)

    2016-01-15

    Using spin-polarized density functional theory calculations, we performed theoretical investigations on the electronic and magnetic properties of transition metal embedded porphyrin-based nanowires (TM-PNWs, TM = Cr, Mn, Co, Ni, Cu, and Zn). Our results indicate that Ni-PNW and Zn-PNW are nonmagnetic while the rest species are magnetic, and the magnetic moments in TM-PNWs and their corresponding isolated monomer structures are found to be the same. In addition, the spin coupling in the magnetic nanowires can be ignored leading to their degenerate AFM and FM states. These results can be ascribed to the weak intermetallic interactions because of the relatively large distances between neighbor TM atoms. Among all TM-PNW structures considered here, only Mn-PNW shows a half-metallic property while the others are predicted to be semiconducting. The present work paves a new way of obtaining ferromagnetic porphyrin-based nanowires with TM atoms distributed separately and orderly, which are expected to be good candidates for catalysts, energy storage and molecular spintronics.

  18. Experiencia en la evaluación de impacto ambiental de carreteras

    Directory of Open Access Journals (Sweden)

    Villarino Valdivieso, Teresa

    1993-08-01

    Full Text Available This article reviews technical and administrative problems to be dealt with in Spain in the application of the procedure of Environmental Impact Assessment based on the experience of the last five years. Special attention is paid to main road infrastructures.

    El presente artículo pasa revista a los problemas técnicos y administrativos que presenta en España la aplicación del procedimiento de Evaluación del Impacto Ambiental en base a la experiencia acumulada durante los últimos cinco años. Se presta especial atención al caso de las grandes infraestructuras viarias.

  19. Experiencia en la evaluación de impacto ambiental de carreteras

    OpenAIRE

    Villarino Valdivieso, Teresa

    1993-01-01

    This article reviews technical and administrative problems to be dealt with in Spain in the application of the procedure of Environmental Impact Assessment based on the experience of the last five years. Special attention is paid to main road infrastructures.

    El presente artículo pasa revista a los problemas técnicos y administrativos que presenta en España la aplicación del procedimiento de Evaluación del Impacto Ambiental en base a la experiencia acumulada durante los últ...

  20. FITOMEJORAMIENTO Y PARTICIPACION LOCAL. UNA EXPERIENCIA EN CUBA

    OpenAIRE

    Lucy Martin; H. Ríos; Gladys Verde; M. Ponce; Ortiz, R.; Sandra Miranda; Rosa Acosta

    2003-01-01

    Este artículo examina, desde una perspectiva so- cial, las experiencias de trabajo que un equipo multidisciplinario del INCA lleva a cabo en tres cooperativas de producción agropecuaria (CPA) del sur de La Habana y en una cooperati- va de créditos y servicios (CCS) de La Palma, Pinar del Río, con el objetivo de encontrar vías complementarias del fitomejoramiento formal por la vía participativa, se pretende destacar cómo en una experiencia de fitomejoramiento con la participación de los produc...

  1. Del mercado a la academia: de la experiencia empresarial a la experiencia en la docencia universitaria

    Directory of Open Access Journals (Sweden)

    Monica Bonifaz

    2012-12-01

    Full Text Available En este artículo se analizan las posibles contribuciones de la experiencia profesional empresarial para el ámbito académico. Expone algunas oportunidades y prácticas de gestión que, sin afectar la misión y la razón de ser de la Universidad, pueden trasladarse del modelo empresarial a las diferentes funciones y roles que desempeña la Universidad, y contribuir con una gestión más eficiente y eficaz de los recursos disponibles en beneficio de la generación y transferencia del conocimiento, y del logro de los resultados académicos esperados.

  2. Optically switchable molecular device using microsphere based junctions

    Science.gov (United States)

    Faramarzi, V.; Raimondo, C.; Reinders, F.; Mayor, M.; Samorı, P.; Doudin, B.

    2011-12-01

    Metallic planar electrodes are bridged using microspheres coated with chemisorbed azobenzene self-assembled monolayers. The circuit exhibits light-induced switching, with reproducibility over 90%, as statistically determined and compared to junctions incorporating photo-insensitive alkanethiol layers. Microsphere interconnects provide direct access to molecular transport properties, with reliability and stability, making multifunctional molecular electronics devices possible.

  3. Molecular dynamics study of surfactant-like peptide based nanostructures.

    Science.gov (United States)

    Colherinhas, Guilherme; Fileti, Eudes

    2014-10-23

    Surfactant-like peptide (SLP) based nanostructures are investigated using all-atomistic molecular dynamics (MD) simulations. We report structure properties of nanostructures belonging to the ANK peptide group. In particular, the mathematical models for the two A3K membranes, A6K nanotube, and A9K nanorod were developed. Our MD simulation results are consistent with the experimental data, indicating that A3K membranes are stable in two different configurations: (1) SLPs are tilted relative to the normal membrane plane; (2) SLPs are interdigitated. The former configuration is energetically more stable. The cylindrical nanostructures feature a certain order of the A6K peptides. In turn, the A9K nanorod does not exhibit any long-range ordering. Both nanotube and nanorod structure contain large amounts of water inside. Consequently, these nanostructures behave similar to hydrogels. This property may be important in the context of biotechnology. Binding energy analysis-in terms of Coulomb and van der Waals contributions-unveils an increase as the peptide size increases. The electrostatic interaction constitutes 70-75% of the noncovalent attraction energy between SLPs. The nanotubular structures are notably stable, confirming that A6K peptides preferentially form nanotubes and A9K peptides preferentially form nanorods. PMID:25264942

  4. Geometría para futuros profesores de primaria: experiencias con el tangram chino

    OpenAIRE

    Fernández, Teresa

    2003-01-01

    Este artículo tiene como objetivo presentar una experiencia sobre didáctica de la geometría llevada a cabo en la facultad de Ciencias de la Educación de Santiago de Compostela con alumnos de la especialidad de maestro en educación primaria. En ella se utilizó un juego de disección (el tangram chino) como base para la realización de una serie de actividades que tienen un objetivo múltiple: concienciar a los alumnos sobre las ventajas del uso de un material manipulativo para el estudio de propi...

  5. Experiencias sencillas aplicando conceptos básicos de Termodinámica

    OpenAIRE

    Piovoso, R.; Lladó, M. (Marie); Jubert, Alicia Haydeé; Soria, Delia B.

    2007-01-01

    Es conocido el hecho que la Termodinámica es una unidad temática dentro de la currícula del tercer año del Polimodal, como así también dentro de las asignaturas correspondientes a la mayoría de las carreras de Ingeniería y Ciencias Exactas. En base a las experiencias realizadas con diferentes grupos de alumnos de distintas carreras y niveles, se pudo observar que ciertos conceptos termodinámicos, tales como, energía, calor, trabajo, entalpía, procesos endo y exotérmicos, entre otros, no llega...

  6. Tumores de células germinales del mediastino: Experiencia con 29 pacientes

    OpenAIRE

    José A Mainieri-Hidalgo; Valeria Rees-Alpízar; Isabel Gamboa-González; Marcelo Mainieri-Breedy

    2013-01-01

    Objetivo: revisar e informar la experiencia adquirida con el manejo de tumores de células germinales del mediastino, en el Hospital Calderón Guardia. Metodología: previa autorización del Comité de Ética del Hospital, se realizó un análisis descriptivo de la información acumulada en la base de datos del Servicio de Cirugía de Tórax y los expedientes clínicos de 29 pacientes con tumores de células germinales del mediastino, operados entre 1986 y 2012. Resultados: se encontró mayor frecuencia en...

  7. Experiencias de envejecimiento en el México rural

    Directory of Open Access Journals (Sweden)

    Treviño-Siller Sandra

    2006-01-01

    Full Text Available OBJETIVO: Explorar la experiencia de envejecimiento de hombres y mujeres mayores de 60 años, que viven en contextos rurales de pobreza en los estados de Guerrero y Morelos, México. MATERIAL Y MÉTODOS: Se diseñó un estudio cualitativo basado en entrevistas semiestructuradas. Se trabajó en comunidades con menos de 2 500 habitantes, pobres y de alta marginación. RESULTADOS: La experiencia de envejecimiento es radicalmente diferente según la condición de género; esta vivencia resulta ser más positiva para las mujeres. La soledad es un factor que configura la experiencia diferencial del envejecimiento, así como las redes sociales y el estado de salud-enfermedad. Los principales temores asociados a la vejez fueron la soledad, la enfermedad, la pobreza y la pérdida de independencia. CONCLUSIONES: La identidad de género desempeña un papel fundamental en la configuración de la experiencia diferencial del proceso de envejecimiento, debido a que las oportunidades de desarrollo y las responsabilidades que se derivan de ella, promueven la desigualdad entre los sexos. Es necesario hacer más eficiente la respuesta institucional, de manera que responda a las necesidades específicas de esta población.

  8. Molecular Split-Ring Resonators Based on Metal String Complexes

    CERN Document Server

    Shen, Yao; Ai, Qing; Peng, Shie-Ming; Jin, Bih-Yaw

    2014-01-01

    Metal string complexes or extended metal atom chains (EMACs) belong to a family of molecules that consist of a linear chain of directly bonded metal atoms embraced helically by four multidentate organic ligands. These four organic ligands are usually made up of repeating pyridyl units, single-nitrogen-substituted heterocyclic annulenes, bridged by independent amido groups. Here, in this paper, we show that these heterocyclic annulenes are actually nanoscale molecular split-ring resonators (SRRs) that can exhibit simultaneous negative electric permittivity and magnetic permeability in the UV-Vis region. Moreover, a monolayer of self-assembled EMACs is a periodic array of molecular SRRs which can be considered as a negative refractive index material. In the molecular scale, where the quantum-size effect is significant, we apply the tight-binding method to obtain the frequency-dependent permittivity and permeability of these molecular SRRs with their tensorial properties carefully considered.

  9. Congenital neutropenia: diagnosis, molecular bases and patient management

    Directory of Open Access Journals (Sweden)

    Chantelot Christine

    2011-05-01

    Full Text Available Abstract The term congenital neutropenia encompasses a family of neutropenic disorders, both permanent and intermittent, severe ( When neutropenia is detected, an attempt should be made to establish the etiology, distinguishing between acquired forms (the most frequent, including post viral neutropenia and auto immune neutropenia and congenital forms that may either be isolated or part of a complex genetic disease. Except for ethnic neutropenia, which is a frequent but mild congenital form, probably with polygenic inheritance, all other forms of congenital neutropenia are extremely rare and have monogenic inheritance, which may be X-linked or autosomal, recessive or dominant. About half the forms of congenital neutropenia with no extra-hematopoetic manifestations and normal adaptive immunity are due to neutrophil elastase (ELANE mutations. Some patients have severe permanent neutropenia and frequent infections early in life, while others have mild intermittent neutropenia. Congenital neutropenia may also be associated with a wide range of organ dysfunctions, as for example in Shwachman-Diamond syndrome (associated with pancreatic insufficiency and glycogen storage disease type Ib (associated with a glycogen storage syndrome. So far, the molecular bases of 12 neutropenic disorders have been identified. Treatment of severe chronic neutropenia should focus on prevention of infections. It includes antimicrobial prophylaxis, generally with trimethoprim-sulfamethoxazole, and also granulocyte-colony-stimulating factor (G-CSF. G-CSF has considerably improved these patients' outlook. It is usually well tolerated, but potential adverse effects include thrombocytopenia, glomerulonephritis, vasculitis and osteoporosis. Long-term treatment with G-CSF, especially at high doses, augments the spontaneous risk of leukemia in patients with congenital neutropenia.

  10. EXPERIENCIAS EXTRASENSORIALES Y EXPERIENCIAS ALUCINATORIAS: EXAMINANDO LA HIPÓTESIS DEL CONTINUO DE EXPERIENCIAS ESQUIZOTÍPICAS/ EXTRASENSORIAL AND HALLUCINATORY EXPERIENCES: EXAMINING THE CONTINUOUS THEORY ON SCHIZOTYPAL EXPERIENCES

    Directory of Open Access Journals (Sweden)

    Alejandro Parra*

    2010-05-01

    Full Text Available RESUMENUna experiencia extrasensorial es aquella en la que parece que la mente de una persona ha adquirido la informaciónremota, es decir, aparentemente sin la mediación de los sentidos humanos conocidos o procesos de inferencia lógica. Portanto, lo «extrasensorial» en la experiencia extrasensorial corresponde a juzgar por las apariencias y no necesariamente a larealidad, mientras que lo «extrasensorial» en la percepcion extrasensorial se refiere a la naturaleza de una presunta realidadparanormal. Se ponen a prueba dos hipótesis específicas: Una muestra de estudiantes argentinos que reportan haber tenidoexperiencias extrasensoriales tienen mayor capacidad de experimentar (1 alucinaciones visuales y táctiles, y (2 propensióna la esquizotipia en comparación con quienes no tuvieron experiencias extrasensoriales. Los resultados mostraron mayornivel de esquizotipia cognitivo-perceptual y propensión a la alucinación en individuos con experiencias que quienes no lastuvieron. Los resultados sugieren que hay procesos disociativos subyacentes, como absorción y propensión a la fantasía,que parecen estar asociadas a las experiencias extrasensoriales.ABSTRACTAn extrasensory experience is one in which it appears that the experient’s mind has acquired information directly, thatis, seemingly without either the mediation of the recognized human senses or the processes of logical inference. The«extrasensory» in extrasensory experience therefore pertains to appearances and not necessarily to reality, whereas the«extrasensory» in extrasensory perception refers to the nature of a hypothesized paranormal reality. Two specific hypothesesare tested: A sample of Argentinean participants who have reported Extrasensorial experiences have a higher capacity for (1visual and tactile hallucination, and (2 schizotypy proneness than non--experients. The results showed a higher level ofcognitive-perceptual schizotypy and hallucination proneness in

  11. Web Based Learning Support for Experimental Design in Molecular Biology.

    Science.gov (United States)

    Wilmsen, Tinri; Bisseling, Ton; Hartog, Rob

    An important learning goal of a molecular biology curriculum is a certain proficiency level in experimental design. Currently students are confronted with experimental approaches in textbooks, in lectures and in the laboratory. However, most students do not reach a satisfactory level of competence in the design of experimental approaches. This…

  12. Molecular Similarity Based on Super-Ball Algorithm

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The molecular similarity of 139 organic compounds was calculated by the topologic index method, the flexible super-ball algorithm was used to scan similar molecules and structures. The results show that the properties of organic compounds estimated from this method are reliable.

  13. Molecular Gastronomy: A Food Fad or an Interface for Science-based Cooking?

    OpenAIRE

    Linden, van der, M.; McClements, D.J.; Ubbink, J.

    2008-01-01

    A review is given over the field of molecular gastronomy and its relation to science and cooking. We begin with a brief history of the field of molecular gastronomy, the definition of the term itself, and the current controversy surrounding this term. We then highlight the distinction between molecular gastronomy and science-based cooking, and we discuss both the similarities and the distinctions between science and cooking. In particular, we highlight the fact that the kitchen serves as an i...

  14. Marcos, horizontes visuales y experiencia del lugar

    Directory of Open Access Journals (Sweden)

    Enrique de Teresa

    2012-12-01

    Full Text Available

    Resumen

    "Habiendo educado mis ojos en el espectáculo de las cosas, intento deciros lo bello que he encontrado" Le Corbusier (El viaje de Oriente

    Desde la temprana fecha de 1911, en que realiza su viaje a Oriente, Le Corbusier nos muestra la capacidad mediadora que tiene la arquitectura para vincular los espacios, para conectar visualmente interior y exterior, para hacernos redescubrir la naturaleza acentuando nuestra percepción consciente. Sus dibujos sobre Villa Adriana, Pompeya, Atenas, etc., son un ejemplo de cómo percibir y plasmar en croquis su observación de la arquitectura y su ámbito exterior, de la captación del papel mediador entre arquitectura y lugar.
    En sus textos posteriores, y especialmente en "Vers une  architecture" (1923, así como a través de la experiencia de sus casas en los años veinte, nos mostrará el valor de las  operaciones que acotan, enmarcan y proporcionan una   dimensión de los espacios y del paisaje. Lo que hace de manera explícita y precisa en el texto "Une petite maison" (1923.
    Alvar Aalto y, posteriormente, Álvaro Siza, recogerán esta  capacidad de mediación entre arquitectura y lugar, buscando estimular la mirada para alentar la consciencia y el goce de los espacios y de la naturaleza. Las estrategias de la visión que  proponen, sobre todo en el último caso, lo llegan a  emparentar con el compromiso de enseñarnos a mirar y  experimentar del Land Art.
    Más allá de las imágenes expresivas y del lenguaje se tratará de ver, mediante ejemplos concretos, como la arquitectura se configura como vehículo de una percepción renovada y  alentadora de los espacios y del lugar.

    Palabras clave

    percepción, arquitectura, mediación, lugar, espacio

    Abstract

    "Having educated my eyes in the spectacle of things, I try to tell you what I have found beautiful." Le Corbusier (The

  15. Chemical Sensors Based on Molecularly Imprinted Sol-Gel Materials

    Directory of Open Access Journals (Sweden)

    Franz L. Dickert

    2010-03-01

    Full Text Available The sol-gel technique is earning the worldwide attention of researchers in the field of material science, due to its versatility in synthesizing inorganic ceramic materials at mild conditions. High purity, homogeneity, controlled porosity, stable temperature and nanoscale structuring are the most remarkable features offered by this method for generating highly sensitive and selective matrices to incorporate analyte molecules. The crafting of sol-gel sensors through molecular imprinting has put great influence on the development of innovative chemical sensors, which can be seen from the growing number of publications in this field. The review provides a brief overview of sol-gel sensor applications, and discusses the contribution of molecular imprinting in exploring the new world of sensors.

  16. Effect of molecular electrical doping on polyfuran based photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shuwen; Opitz, Andreas; Salzmann, Ingo, E-mail: ingo.salzmann@physik.hu-berlin.de [Humboldt-Universität zu Berlin, Institut für Physik and IRIS Adlershof, Brook-Taylor Straße 6, 12489 Berlin (Germany); Frisch, Johannes [Helmholtz-Zentrum für Materialien und Energie GmbH, Bereich Solarenergieforschung, Albert-Einstein-Straße 15, 12489 Berlin (Germany); Cohen, Erez; Bendikov, Michael [Department of Organic Chemistry, Weizmann Institute of Science, 76100 Rehovot (Israel); Koch, Norbert [Humboldt-Universität zu Berlin, Institut für Physik and IRIS Adlershof, Brook-Taylor Straße 6, 12489 Berlin (Germany); Helmholtz-Zentrum für Materialien und Energie GmbH, Bereich Solarenergieforschung, Albert-Einstein-Straße 15, 12489 Berlin (Germany)

    2015-05-18

    The electronic, optical, and morphological properties of molecularly p-doped polyfuran (PF) films were investigated over a wide range of doping ratio in order to explore the impact of doping in photovoltaic applications. We find evidence for integer-charge transfer between PF and the prototypical molecular p-dopant tetrafluoro-tetracyanoquinodimethane (F4TCNQ) and employed the doped polymer in bilayer organic solar cells using fullerene as acceptor. The conductivity increase in the PF films at dopant loadings ≤2% significantly enhances the short-circuit current of photovoltaic devices. For higher doping ratios, however, F4TCNQ is found to precipitate at the heterojunction between the doped donor polymer and the fullerene acceptor. Ultraviolet photoelectron spectroscopy reveals that its presence acts beneficial to the energy-level alignment by doubling the open-circuit voltage of solar cells from 0.2 V to ca. 0.4 V, as compared to pristine PF.

  17. [Personalized urooncology based on molecular uropathology: what is the future?].

    Science.gov (United States)

    Dahl, E; Haller, F

    2013-07-01

    Targeted therapies and biomarker validation are key drivers in the advancement of personalized oncology which is a growing topic in all clinical areas. Compared with other professions, such as pulmonology and gynecology, development in urology has so far been retarded but has recently gained increasing momentum. A basis for this is the currently growing and in future accelerated application of new knowledge derived from molecular biology in the field of uropathology. The rapid gain of knowledge is driven by a whole new class of analytical methods, such as massively parallel sequencing (deep sequencing or next generation sequencing), which enables analysis of virtually a new universe of potential biomarkers. This article describes the emerging paradigm shift in molecular pathological diagnostics of urological tumors using the example of prostate cancer.

  18. Choline metabolism-based molecular diagnosis of cancer: an update

    OpenAIRE

    Glunde, Kristine; Penet, Marie-France; Jiang, Lu; Jacobs, Michael A.; Zaver M Bhujwalla

    2015-01-01

    Abnormal choline metabolism continues to be identified in multiple cancers. Molecular causes of abnormal choline metabolism are changes in choline kinase-α, ethanolamine kinase-α, phosphatidylcholine-specific phospholipase C and -D and glycerophosphocholine phosphodiesterases, as well as several choline transporters. The net outcome of these enzymatic changes is an increase in phosphocholine and total choline (tCho) and, in some cancers, a relative decrease of glycerophosphocholine. The incre...

  19. Descifrando las bases moleculares de la resistencia cuantitativa

    OpenAIRE

    Lopez Camilo

    2011-01-01

    Uno de los factores mas importantes que afectan los cultivos son las enfermedades ocasionadas por los patógenos. La resistencia vegetal ha sido clásicamente dividida en dos tipos: i) competa, vertical o cualitativa que es gobernada por un solo gen y ii) incompleta, horizontal o cuantitativa la cual es gobernada por varios genes. Aunque la resistencia cuantitativa provee resistencia de amplio espectro y es durable, los mecanismo moleculares subyacentes no han sido estudiados en detalle. En est...

  20. Electronic Transport in Molecular Junction Based on C20 Cages

    Institute of Scientific and Technical Information of China (English)

    OUYANG Fang-Ping; XU Hui

    2007-01-01

    Choosing closed-ended armchair(5,5)single-wall carbon nanotubes(CCNTs)as electrodes,we investigate the electron transport properties across an all-carbon molecular junction consisting of C20 molecules suspended between two semi-infinite carbon nanotubes.It is shown that the conductances are quite sensitive to the number of C20 molecules between electrodes for both configuration CFl and double-bonded models:the conductances of C20 dimers are markedly smaller than those of monomers.The physics is that incident electrons easily pass the C20 molecules and are predominantly scattered at the C20-C20 junctions.Moreover,we study the doping effect of such molecular junction by doping nitrogen atoms substitutionally.The bonding property of the molecular junction with configuration CFl has been analysed by calculating the Mulliken atomic charges.Our results have revealed that the C atoms in N-doped junctions are more ionic than those in pure-carbon ones,leading to the fact that N-doped junctions have relatively large conductance.

  1. Comprehensive characterization of molecular interactions based on nanomechanics.

    Directory of Open Access Journals (Sweden)

    Murali Krishna Ghatkesar

    Full Text Available Molecular interaction is a key concept in our understanding of the biological mechanisms of life. Two physical properties change when one molecular partner binds to another. Firstly, the masses combine and secondly, the structure of at least one binding partner is altered, mechanically transducing the binding into subsequent biological reactions. Here we present a nanomechanical micro-array technique for bio-medical research, which not only monitors the binding of effector molecules to their target but also the subsequent effect on a biological system in vitro. This label-free and real-time method directly and simultaneously tracks mass and nanomechanical changes at the sensor interface using micro-cantilever technology. To prove the concept we measured lipid vesicle (approximately 748*10(6 Da adsorption on the sensor interface followed by subsequent binding of the bee venom peptide melittin (2840 Da to the vesicles. The results show the high dynamic range of the instrument and that measuring the mass and structural changes simultaneously allow a comprehensive discussion of molecular interactions.

  2. A WAO - ARIA - GA2LEN consensus document on molecular-based allergy diagnostics

    DEFF Research Database (Denmark)

    Canonica, Giorgio Walter; Ansotegui, Ignacio J; Pawankar, Ruby;

    2013-01-01

    Molecular-based allergy (MA) diagnostics is an approach used to map the allergen sensitization of a patient at a molecular level, using purified natural or recombinant allergenic molecules (allergen components) instead of allergen extracts. Since its introduction, MA diagnostics has increasingly ...

  3. Rapid Prototyping of Chemical Microsensors Based on Molecularly Imprinted Polymers Synthesized by Two-Photon Stereolithography.

    Science.gov (United States)

    Gomez, Laura Piedad Chia; Spangenberg, Arnaud; Ton, Xuan-Anh; Fuchs, Yannick; Bokeloh, Frank; Malval, Jean-Pierre; Tse Sum Bui, Bernadette; Thuau, Damien; Ayela, Cédric; Haupt, Karsten; Soppera, Olivier

    2016-07-01

    Two-photon stereolithography is used for rapid prototyping of submicrometre molecularly imprinted polymer-based 3D structures. The structures are evaluated as chemical sensing elements and their specific recognition properties for target molecules are confirmed. The 3D design capability is exploited and highlighted through the fabrication of an all-organic molecularly imprinted polymeric microelectromechanical sensor. PMID:27145145

  4. Rapid Prototyping of Chemical Microsensors Based on Molecularly Imprinted Polymers Synthesized by Two-Photon Stereolithography.

    Science.gov (United States)

    Gomez, Laura Piedad Chia; Spangenberg, Arnaud; Ton, Xuan-Anh; Fuchs, Yannick; Bokeloh, Frank; Malval, Jean-Pierre; Tse Sum Bui, Bernadette; Thuau, Damien; Ayela, Cédric; Haupt, Karsten; Soppera, Olivier

    2016-07-01

    Two-photon stereolithography is used for rapid prototyping of submicrometre molecularly imprinted polymer-based 3D structures. The structures are evaluated as chemical sensing elements and their specific recognition properties for target molecules are confirmed. The 3D design capability is exploited and highlighted through the fabrication of an all-organic molecularly imprinted polymeric microelectromechanical sensor.

  5. Antes de los Estudios Culturales. Robert Warshow y la experiencia

    Directory of Open Access Journals (Sweden)

    Antonio Lastra

    2008-01-01

    Full Text Available Este artículo estudia la influencia del concepto de experiencia que desarrolla Robert Warshow. Warshow ha supuesto el contrapunto americano a las teorías desarrolladas por Walter Benjamien en Europa. Si bien ambos insistieron en la pobreza de la experiencia, como resultado de la tecnificación de la sociedad, Warshow supo introducir matizaciones que influyeron en todo el círculo de intelectuales concentrados en Nueva York durante la etapa de consolidación de los Estudios Culturales. This paper studies the influence of the experience concept by Robert Warshow. Warshow is the American counterpoint to theories developed by Walter Benjamin in Europe. Although both insisted in the poverty of experience, as a result of technique, Warshow knew how to introduce nuances that influenced intellectuals in New York as Cultural Studies emerged.

  6. Molecular recognition of α-cyclodextrin (CD) to choral amino acids based on methyl orange as a molecular probe

    Science.gov (United States)

    Yuexian, Fan; Yu, Yang; Shaomin, Shuang; Chuan, Dong

    2005-03-01

    The molecular recognition interaction of α-CD to chiral amino acids was investigated by using spectrophotometry based on methyl orange as a molecular probe. The molecular recognition ability depended on the inclusion formation constants. The molecular recognition of α-CD to aromatic amino acids was the order: DL-tryptophan > L-tryptophan > L-phenylalanine > L-tyrosine ≈ DL-β-3,4-dihydroxy-phenylalanine; whereas for aliphatic amino acids, the order was: L- iso-leucine > L-leucine ≈ L-methionine ≈ DL-mehtionine > D-leucine. The effect of temperature on the inclusion interaction was examined and the thermodynamic parameters of inclusion process, Δ G, Δ H, Δ S, were determined. The experimental results indicated that the inclusion process was an exothermic and enthalpy-driven process accompanied with a negative or minor positive entropic contribution. The inclusion interaction between α-CD and amino acids satisfied the law of enthalpy-entropy compensation. The compensation temperature was 291 K.

  7. Molecular recognition of alpha-cyclodextrin (CD) to choral amino acids based on methyl orange as a molecular probe.

    Science.gov (United States)

    Yuexian, Fan; Yu, Yang; Shaomin, Shuang; Chuan, Dong

    2005-03-01

    The molecular recognition interaction of alpha-CD to chiral amino acids was investigated by using spectrophotometry based on methyl orange as a molecular probe. The molecular recognition ability depended on the inclusion formation constants. The molecular recognition of alpha-CD to aromatic amino acids was the order: DL-tryptophan > L-tryptophan > L-phenylalanine > L-tyrosine approximately DL-beta-3,4-dihydroxy-phenylalanine; whereas for aliphatic amino acids, the order was: L-iso-leucine > L-leucine approximately L-methionine approximately DL-mehtionine > D-leucine. The effect of temperature on the inclusion interaction was examined and the thermodynamic parameters of inclusion process, delta G, delta H, delta S, were determined. The experimental results indicated that the inclusion process was an exothermic and enthalpy-driven process accompanied with a negative or minor positive entropic contribution. The inclusion interaction between alpha-CD and amino acids satisfied the law of enthalpy-entropy compensation. The compensation temperature was 291 K. PMID:15683802

  8. ¿Metrópolis ingobernables? Experiencias europeas ¿Metrópolis ingobernables? Experiencias europeas

    Directory of Open Access Journals (Sweden)

    Christian Lefèvre

    2010-12-01

    Full Text Available Las áreas metropolitanas se han convertido en lugares en los que tienen lugar algunos de los mayores desafíos para el gobierno de nuestras sociedades (desigualdades sociales y territoriales, desarrollo económico, la diversidad étnica y cultural, la preservación del medio ambiente, etc.. Sin embargo, a pesar de su relevancia como espacios para el tratamiento de estos problemas, las áreas metropolitanas tienen grandes dificultades para transformarse en territorios políticos, es decir, para alcanzar un nivel de agente político suficiente (como actor colectivo para producir políticas adecuadas que aborden estos problemas y produzcan estrategias colectivas que orienten su desarrollo futuro. Para tratar este tema, este artículo se centrará en primer lugar en los principales obstáculos que les impiden alcanzar el nivel de actor político, que son comunes a la mayoría de los países europeos: la resistencia del Estado a otorgar a estos territorios las funciones y recursos adecuados en el proceso de descentralización y su preferencia por el reforzamiento de los niveles de gobierno existentes; la oposición de estos niveles de gobierno y la falta de apoyo de la sociedad civil (actores económicos y población. En un segundo apartado, este artículo presentará diferentes experiencias que han tenido lugar en la última década para superar estos obstáculos. Centrándose en la pacificación de las relaciones de poder a nivel metropolitano mediante conferencias, cartas y pactos metropolitanos y “políticas procedimentales” como la planificación estratégica, el autor considera que estas experiencias no parecen ofrecer potencialidades para la reducción del conflicto político entre actores y concluye con un tono pesimista sobre la gobernabilidad de las áreas metropolitanas.Metropolitan areas have become places where some of the major issues and stakes for the government of our societies are taking place (social and territorial

  9. Unidades locales para la gestión integral del hábitat. Experiencia cubana

    Directory of Open Access Journals (Sweden)

    Deremis Pérez Aguilera

    2011-01-01

    Full Text Available La participación de la población en la conformación de su hábitat reporta ventajas económicas, sociales y ambientales, pero debe ser adecuadamente gestionada para garantizar la calidad de los resultados, lo cual requiere de estructuras organizativas apropiadas. El presente trabajo expone los resultados de una experiencia aplicada en la ciudad de Ciego de Ávila, que se inscribe dentro de las tendencias hacia una mayor descentralización y un incremento de la participación popular en la producción del hábitat que se propone hoy la Política de Vivienda en Cuba. La investigación parte de la experiencia nacional e internacional para identificar las variables de la gestión como independientes y las de la calidad del hábitat como dependientes. Sobre la base de un diagnóstico de la calidad del hábitat y las insuficiencias en su gestión, elabora una propuesta de nuevo modelo para la gestión integral del hábitat a nivel local, lo implementa en tres zonas urbanas de la ciudad seleccionadas como objeto de estudio y evalúa el impacto positivo de los resultados de su aplicación, tanto en el medio físico como en la satisfacción de la población.

  10. Una experiencia en la selección de pilotos aéreos

    Directory of Open Access Journals (Sweden)

    P. BARDERA MORA

    2004-01-01

    Full Text Available El presente artículo recoge una experiencia concreta en la selección de pilotos de aeronaves, la que se lleva a cabo en el Centro de Psicología de La Flota (Base Naval de Rota. Se ha plasmado una experiencia real en la selección de personal, tal y como se lleva a cabo, en virtud de las propias necesidades. Desde que los aspirantes encuentran en la aeronáutica su vocación hasta que llegan a pilotar un avión deberán pasar muchos controles, uno de los primeros, será superar una valoración psicológica, que conlleva, tanto la evaluación aptitudinal, como la de personalidad. La ¿seguridad¿ es nuestro constante objetivo. Uno de los instrumentos que más frutos ha dado en la predicción de errores e incidentes, ha sido el polirreactímetro; pero sin duda el criterio diferencial viene marcado por los rasgos de personalidad. Pilotar aviones es uno de esos puestos de trabajo que entraña riesgo por si mismo, además se manejan máquinas de gran valor económico; las pérdidas que puede acarrear una selección de personal ineficaz son muy elevadas.

  11. La Naturaleza de la Experiencia Estética

    Directory of Open Access Journals (Sweden)

    George Herbert Mead

    2001-04-01

    Full Text Available El texto que presentamos en este número de Athenea Digital es "La Naturaleza de la Experiencia Estética" escrito por G.H.Mead en 1926, traducido e introducido por Estaban Laso y Anna Vitores. Como los mismos traductores explican en la introducción que precede al texto de Mead: El artículo ?La Naturaleza de la Experiencia Estética? (1926 que presentamos en este mismo número ?y que como la inmensa mayoría de los escritos de Mead es muy breve? se inscribe dentro de la orientación hacia la crítica cultural de su obra tardía. En tanto que parte de la brecha entre la esfera instrumental y la de los valores que caracteriza a la actividad y al pensamiento humano en la sociedad moderna, ofrece una buena oportunidad para pensar acerca de la tensión meadiana entre creatividad y normatividad. Y quizás también, para ir más allá y reflexionar sobre la tensión entre cambio y reproducción social, y sobre las formas en que podríamos ofrecer un concepto de acción y de experiencia no individualistas que permitieran articular esta tensión.

  12. Qué sujeto para qué experiencia?

    Directory of Open Access Journals (Sweden)

    Yves SCHWARTZ

    2011-04-01

    Full Text Available En el espacio de un dialogo aquí iniciado con la corriente de didáctica profesional este texto se propone restituir una dinámica intelectual que va del concepto de experiencia al concepto de actividad. Este último concepto parece necesitar lo que se considera como un drama en la experiencia humana (el debate de las normas y mostrar cómo la experiencia como sedimentación inestable de actividades es una matriz permanente de la historia. ¿Cuál puede ser entonces el precepto de los saberes generados por un ser así definido como ser de actividad? Se formulan verdaderos problemas epistemológicos en las relaciones entre las diversas formas del saber y las diversas formas de expresión en el lenguaje, como también para el precepto de los diversos saberes en su relación con la historicidad. Un problema no solo epistemológico sino también político pues podemos apreciar una cartografía de del precepto propio de las relaciones de saberes / poderes y aquellos a la deriva de la gobernanza del trabajo humano. Finalizamos tratando una problemática del , que pueda ser coherente con los patrimonios aquí reivindicados en la construcción del concepto ergológico de actividad.

  13. Museos construidos y reconstruidos. Experiencias educativas para la creatividad

    Directory of Open Access Journals (Sweden)

    Romina Elisondo

    2015-09-01

    Full Text Available Los museos son espacios educativos promisorios para el aprendizaje y la creatividad. En el artículo contamos experiencias vinculadas a la construcción de propuestas educativas en museos, entendidos como construcciones sociales. Específicamente, nos referimos a dos propuestas educativas: un museo construido en el aula y una visita a un museo fuera del aula. Nos interesa describir las propuestas desarrolladas haciendo especial hincapié en las percepciones y valoraciones de los estudiantes respecto de las potencialidades educativas de los museos. Participaron de las experiencias estudiantes de las carreras de Licenciatura en Psicopedagogía y Educación Especial de la Universidad Nacional de Río Cuarto. Los museos, construidos y visitados, generan espacios para aprender y vivenciar experiencias significativas de aprendizaje. También se observan impactos positivos de los museos en la promoción de la creatividad y el desarrollo de innovaciones educativas. Historias personales, grupales y sociales circulan por los museos configurando entornos propicios para construir conocimientos dentro y fuera de las aulas.

  14. Albert Camus: su experiencia y su teoria de la tragedia

    Directory of Open Access Journals (Sweden)

    Inés de Cassagne

    2013-05-01

    Full Text Available Camus encuentra en el género trágico un cauce adecuado para su experiencia. Esta experiencia, cuya savia alimenta todos sus frutos literarios, es la del doble rostro de la existencia humana en este mundo. A ella responde como artista, y como hombre, en el perfecto equilibrio del “rechazo” y el “consentimiento”. Cuando decide en 1956 publicar su primer testimonio juvenil, El revés y el derecho, al prologarlo, confirma aquel testimonio y expone su decisión artística. Cambiar la vida, sin cambiar el mundo. Cambiar la miseria, sin cambiar el sol, la belleza, mediante la fórmula de equilibrio de “rechazo” y “consentimiento”.Esta fórmula no podría cuajar de modo acabado sino en el cauce de la tragedia, herencia de los griegos. Para quien revive la experiencia del destino humano en un mundo sin más allá, la sola trascendencia posible de perfectibilidad sólo puede darse en el espacio ideal del arte, único capaz de acoger dramáticamente la tensión entre los polos contrastantes la vida que colma y a la vez decepciona y pasa.

  15. Molecular group dynamics study on slip flow of thin fluid film based on the Hamaker hypotheses

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The thin fluid film was assumed to consist of a number of spherical fluid molecular groups and the attractive forces of molecular group pairs were calculated by the derived equation according to the three Hamaker homogeneous material hypotheses. Regarding each molecular group as a dynamics individual, the simulation method for the shearing motion of multilayer fluid molecular groups, which was initiated by two moving walls, was proposed based on the Verlet velocity iterative algorithm. The simulations reveal that the velocities of fluid molecular groups change about their respective mean velocities within a narrow range in steady state. It is also found that the velocity slips occur at the wall boundary and in a certain number of fluid film layers close to the wall. Because the dimension of molecular group and the number of group layers are not restricted, the hypothetical thickness of fluid film model can be enlarged from nanometer to micron by using the proposed simulation method.

  16. Molecular dynamics computer simulations based on NMR data

    International Nuclear Information System (INIS)

    In the work described in this thesis atom-atom distance information obtained from two-dimensional cuclear magnetic resonance is combined with molecular dynamics simulaitons. The simulation is used to improve the accuracy of a structure model constructed on the basis of NMR data. During the MD refinement the crude NMR structure is simultaneously optimized with respect to the atomic interaction function and to the set of atom-atom distances or other NMR information. This means that insufficient experimental data is completed with theoretical knowledge and the combination will lead to more reliable structures than would be obtained from one technique alone. (author). 191 refs.; 17 figs.; 12 schemes; 22 tabs

  17. ¿Innovando en la gestión pública? La experiencia mexicana en los gobiernos locales

    Directory of Open Access Journals (Sweden)

    José Juan Sánchez González

    2010-01-01

    Full Text Available El ensayo tiene como propósito describir la experiencia mexicana de los gobiernos locales, para determinar si han innovado o imitado en la gestión pública. La manera de abordarlo es bajo el siguiente esquema: primero, como una aproximación para comprender la innovación, se define y se clasifica con base en las tipologías más comunes. Segundo, para diferenciar la forma de innovación en la gestión pública, se recurre a Drucker (1985 y 2005, quien aporta ideas para innovar en los negocios. Tercero, se revisa la forma de innovar en la gestión pública con los argumentos de Metcalfe (1999. Cuarto, es descrita la experiencia de la Nueva Gestión Pública (NGP en catorce gobiernos estatales en México a partir de sus estrategias de innovación. Quinto, son analizadas las innovaciones en gobiernos locales mexicanos bajo la experiencia del Premio Gobierno y Gestión Local, para contrastar los resultados alcanzados; y por último, se concluye que es necesario pasar de la "imitación" a la "innovación" en los gobiernos locales.

  18. Novel Metal Ion Based Estrogen Mimics for Molecular Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopalan, Raghavan

    2006-01-30

    The overall objective of the SBIR Phase I proposal is to prepare and evaluate a new class of {sup 99m}Tc or {sup 94m}Tc containing estrogen-like small molecules ('estrogen mimics') for SPECT or PET molecular imaging of estrogen receptor positive (ER+) tumors. In this approach, the metal ion is integrated into the estrone skeleton by isosteric substitution of a carbon atom in the steroidal structure to give new class of mimics that are topologically similar to the native estrogen (Fig. 1). Although both N{sub 2}S{sub 2} and N{sub 3}S mimics 1 and 2 were considered as target structures, molecular modeling study revealed that the presence of the acetyl group at position-15 in the N{sub 3}S mimic 2 causes steric hinderance toward binding of 2 to SHBG. Therefore, initial efforts were directed at the synthesis and evaluation of the N{sub 2}S{sub 2} mimic 1.

  19. Fishing the Molecular Bases of Treacher Collins Syndrome

    Science.gov (United States)

    Weiner, Andrea M. J.; Scampoli, Nadia L.; Calcaterra, Nora B.

    2012-01-01

    Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development, and mutations in the TCOF1 gene are responsible for over 90% of TCS cases. The knowledge about the molecular mechanisms responsible for this syndrome is relatively scant, probably due to the difficulty of reproducing the pathology in experimental animals. Zebrafish is an emerging model for human disease studies, and we therefore assessed it as a model for studying TCS. We identified in silico the putative zebrafish TCOF1 ortholog and cloned the corresponding cDNA. The derived polypeptide shares the main structural domains found in mammals and amphibians. Tcof1 expression is restricted to the anterior-most regions of zebrafish developing embryos, similar to what happens in mouse embryos. Tcof1 loss-of-function resulted in fish showing phenotypes similar to those observed in TCS patients, and enabled a further characterization of the mechanisms underlying craniofacial malformation. Besides, we initiated the identification of potential molecular targets of treacle in zebrafish. We found that Tcof1 loss-of-function led to a decrease in the expression of cellular proliferation and craniofacial development. Together, results presented here strongly suggest that it is possible to achieve fish with TCS-like phenotype by knocking down the expression of the TCOF1 ortholog in zebrafish. This experimental condition may facilitate the study of the disease etiology during embryonic development. PMID:22295061

  20. Fishing the molecular bases of Treacher Collins syndrome.

    Science.gov (United States)

    Weiner, Andrea M J; Scampoli, Nadia L; Calcaterra, Nora B

    2012-01-01

    Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development, and mutations in the TCOF1 gene are responsible for over 90% of TCS cases. The knowledge about the molecular mechanisms responsible for this syndrome is relatively scant, probably due to the difficulty of reproducing the pathology in experimental animals. Zebrafish is an emerging model for human disease studies, and we therefore assessed it as a model for studying TCS. We identified in silico the putative zebrafish TCOF1 ortholog and cloned the corresponding cDNA. The derived polypeptide shares the main structural domains found in mammals and amphibians. Tcof1 expression is restricted to the anterior-most regions of zebrafish developing embryos, similar to what happens in mouse embryos. Tcof1 loss-of-function resulted in fish showing phenotypes similar to those observed in TCS patients, and enabled a further characterization of the mechanisms underlying craniofacial malformation. Besides, we initiated the identification of potential molecular targets of treacle in zebrafish. We found that Tcof1 loss-of-function led to a decrease in the expression of cellular proliferation and craniofacial development. Together, results presented here strongly suggest that it is possible to achieve fish with TCS-like phenotype by knocking down the expression of the TCOF1 ortholog in zebrafish. This experimental condition may facilitate the study of the disease etiology during embryonic development.

  1. Fishing the molecular bases of Treacher Collins syndrome.

    Directory of Open Access Journals (Sweden)

    Andrea M J Weiner

    Full Text Available Treacher Collins syndrome (TCS is an autosomal dominant disorder of craniofacial development, and mutations in the TCOF1 gene are responsible for over 90% of TCS cases. The knowledge about the molecular mechanisms responsible for this syndrome is relatively scant, probably due to the difficulty of reproducing the pathology in experimental animals. Zebrafish is an emerging model for human disease studies, and we therefore assessed it as a model for studying TCS. We identified in silico the putative zebrafish TCOF1 ortholog and cloned the corresponding cDNA. The derived polypeptide shares the main structural domains found in mammals and amphibians. Tcof1 expression is restricted to the anterior-most regions of zebrafish developing embryos, similar to what happens in mouse embryos. Tcof1 loss-of-function resulted in fish showing phenotypes similar to those observed in TCS patients, and enabled a further characterization of the mechanisms underlying craniofacial malformation. Besides, we initiated the identification of potential molecular targets of treacle in zebrafish. We found that Tcof1 loss-of-function led to a decrease in the expression of cellular proliferation and craniofacial development. Together, results presented here strongly suggest that it is possible to achieve fish with TCS-like phenotype by knocking down the expression of the TCOF1 ortholog in zebrafish. This experimental condition may facilitate the study of the disease etiology during embryonic development.

  2. PET-based molecular nuclear neuro-imaging

    International Nuclear Information System (INIS)

    Molecular nuclear neuro-imaging in CNS drug discovery and development can be divided into four categories that are clearly inter-related. (1) Neuroreceptor mapping to examine the involvement of specific neurotransmitter system in CNS diseases, drug occupancy characteristics and perhaps examine mechanisms of action;(2) Structural and spectroscopic imaging to examine morphological changes and their consequences;(3) Metabolic mapping to provide evidence of central activity and CNS fingerprinting the neuroanatomy of drug effects;(4) Functional mapping to examine disease-drug interactions. In addition, targeted delivery of therapeutic agents could be achieved by modifying stem cells to release specific drugs at the site of transplantation('stem cell pharmacology'). Future exploitation of stem cell biology, including enhanced release of therapeutic factors through genetic stem cell engineering might thus constitute promising pharmaceutical approaches to treating diseases of the nervous system. With continued improvements in instrumentation, identification of better imaging probes by innovative chemistry, molecular nuclear neuro-imaging promise to play increasingly important roles in disease diagnosis and therapy

  3. Quantum-dots-encoded-microbeads based molecularly imprinted polymer.

    Science.gov (United States)

    Liu, Yixi; Liu, Le; He, Yonghong; He, Qinghua; Ma, Hui

    2016-03-15

    Quantum dots encoded microbeads have various advantages such as large surface area, superb optical properties and the ability of multiplexing. Molecularly imprinted polymer that can mimic the natural recognition entities has high affinity and selectivity for the specific analyte. Here, the concept of utilizing the quantum dots encoded microbeads as the supporting material and the polydopamine as the functional monomer to form the core-shell molecular imprinted polymer was proposed for the first time. The resulted imprinted polymer can provide various merits: polymerization can complete in aqueous environment; fabrication procedure is facile and universal; the obvious economic advantage; the thickness of the imprinting layer is highly controllable; polydopamine coating can improve the biocompatibility of the quantum dot encoded microbeads. The rabbit IgG binding and flow cytometer experiment result showed the distinct advantages of this strategy: cost-saving, facile and fast preparation procedure. Most importantly, the ability for the multichannel detection, which makes the imprinted polydopamine modified encoded-beads very attractive in protein pre-concentration, recognition, separation and biosensing. PMID:26520251

  4. Analysis of Connectivity in Diffusion-Based Molecular Nano Communication Networks

    OpenAIRE

    Fereidouni, Arash

    2013-01-01

    ABSTRACT: A nanonetwork is an interconnection of nano devices that are made up of nano-scale components. Several approaches for designing and implementing nanonetworks have been presented in recent years. Diffusion-based molecular communication is one of these approaches that use molecules as means of transmitting information in network. In diffusion-based molecular communication, molecules or particles diffuse in an aqueous environment under Fick’s laws of diffusion to move from transmitter ...

  5. Electronic Transport Properties of a Naphthopyran-Based Optical Molecular Switch:an ab initio Study

    Institute of Scientific and Technical Information of China (English)

    XIA Cai-Juan; LIU De-Sheng; ZHANG Ying-Tang

    2011-01-01

    The electronic transport properties of a. Naphthopyran-based molecular optical switch are investigated by using the nonequilibrium Green's Function formalism combined with first-principles density functional theory. The molecule that comprises the switch can convert between its open and closed forms upon photoexcitation. Theoretical results show that the current through the open form is significantly larger than that through the closed form, which is different from other optical switches based on ring-opening reactions of the molecular bridge. The maximum on-off ratio (about 90) can be obtained at 1.4 V. The physical origin of the switching behavior is interpreted based on the spatial distributions of molecular orbitals and the HOMO-LUMO gap. Our result shows that the naphthopyran-based molecule is a good candidate for optical molecular switches and will be useful in the near future.%@@ ronic transport properties of a naphthopyran-based molecular optical switch are investigated by using the nonequilibrium Green's function formalism combined with first-principles density functional theory.The molecule that comprises the switch can convert between its open and closed forms upon photoexcitation.Theoretical results show that the current through the open form is significantly larger than that through the closed form,which is different from other optical switches based on ring-opening reactions of the molecular bridge.The maximum on-off ratio(about 90)can be obtained at 1.4 V.The physical origin of the switching behavior is interpreted based on the spatial distributions of molecular orbitals and the HOMO-LUMO gap.Our result shows that the naphthopyran-based molecule is a good candidate for optical molecular switches and will be useful in the near future.

  6. Genetic diversity analysis of common beans based on molecular markers

    Directory of Open Access Journals (Sweden)

    Homar R. Gill-Langarica

    2011-01-01

    Full Text Available A core collection of the common bean (Phaseolus vulgaris L., representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each, as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP +3/+3 primer combinations and seven simple sequence repeats (SSR loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA and molecular variance (AMOVA analyses. AFLP analysis produced 530 bands (88.5% polymorphic while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus. AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  7. Genetic diversity analysis of common beans based on molecular markers.

    Science.gov (United States)

    Gill-Langarica, Homar R; Muruaga-Martínez, José S; Vargas-Vázquez, M L Patricia; Rosales-Serna, Rigoberto; Mayek-Pérez, Netzahualcoyotl

    2011-10-01

    A core collection of the common bean (Phaseolus vulgaris L.), representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico) Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions) was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each), as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP) +3/+3 primer combinations and seven simple sequence repeats (SSR) loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA) and molecular variance (AMOVA) analyses. AFLP analysis produced 530 bands (88.5% polymorphic) while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus). AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

  8. Clinicopathological and Molecular Histochemical Review of Skull Base Metastasis from Differentiated Thyroid Carcinoma

    International Nuclear Information System (INIS)

    Skull base metastasis from differentiated thyroid carcinoma including follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma (PTC) is a rare clinical entity. Eighteen FTC cases and 10 PTC cases showing skull base metastasis have been reported. The most common symptom of skull base metastasis from FTC and PTC is cranial nerve dysfunction. Bone destruction and local invasion to the surrounding soft tissues are common on radiological imaging. Skull base metastases can be the initial clinical presentation of FTC and PTC in the presence of silent primary sites. The possibility of skull base metastasis from FTC and PTC should be considered in patients with the clinical symptoms of cranial nerve dysfunction and radiological findings of bone destruction. A variety of genetic alterations in thyroid tumors have been identified to have a fundamental role in their tumorigenesis. Molecular histochemical studies are useful for elucidating the histopathological features of thyroid carcinoma. Recent molecular findings may provide novel molecular-based treatment strategies for thyroid carcinoma

  9. Tip-induced gating of molecular levels in carbene-based junctions.

    Science.gov (United States)

    Foti, Giuseppe; Vázquez, Héctor

    2016-03-29

    We study the conductance of N-heterocyclic carbene-based (NHC) molecules on gold by means of first-principles calculations based on density-functional theory and non-equilibrium Green's functions. We consider several tip structures and find a strong dependence of the position of the NHC molecular levels with the atomistic structure of the tip. The position of the lowest unoccupied molecular orbital (LUMO) can change by almost 0.8 eV with tip shape. Through an analysis of the net charge transfer, electron redistribution and work function for each tip structure, we rationalize the LUMO shifts in terms of the sum of the work function and the maximum electrostatic potential arising from charge rearrangement. These differences in the LUMO position, effectively gating the molecular levels, result in large conductance variations. These findings open the way to modulating the conductance of NHC-based molecular circuits through the controlled design of the tip atomistic structure. PMID:26891059

  10. A new graph-based molecular descriptor using the canonical representation of the molecule.

    Science.gov (United States)

    Hentabli, Hamza; Saeed, Faisal; Abdo, Ammar; Salim, Naomie

    2014-01-01

    Molecular similarity is a pervasive concept in drug design. The basic idea underlying molecular similarity is the similar property principle, which states that structurally similar molecules will exhibit similar physicochemical and biological properties. In this paper, a new graph-based molecular descriptor (GBMD) is introduced. The GBMD is a new method of obtaining a rough description of 2D molecular structure in textual form based on the canonical representations of the molecule outline shape and it allows rigorous structure specification using small and natural grammars. Simulated virtual screening experiments with the MDDR database show clearly the superiority of the graph-based descriptor compared to many standard descriptors (ALOGP, MACCS, EPFP4, CDKFP, PCFP, and SMILE) using the Tanimoto coefficient (TAN) and the basic local alignment search tool (BLAST) when searches were carried. PMID:25140330

  11. A New Graph-Based Molecular Descriptor Using the Canonical Representation of the Molecule

    Directory of Open Access Journals (Sweden)

    Hamza Hentabli

    2014-01-01

    Full Text Available Molecular similarity is a pervasive concept in drug design. The basic idea underlying molecular similarity is the similar property principle, which states that structurally similar molecules will exhibit similar physicochemical and biological properties. In this paper, a new graph-based molecular descriptor (GBMD is introduced. The GBMD is a new method of obtaining a rough description of 2D molecular structure in textual form based on the canonical representations of the molecule outline shape and it allows rigorous structure specification using small and natural grammars. Simulated virtual screening experiments with the MDDR database show clearly the superiority of the graph-based descriptor compared to many standard descriptors (ALOGP, MACCS, EPFP4, CDKFP, PCFP, and SMILE using the Tanimoto coefficient (TAN and the basic local alignment search tool (BLAST when searches were carried.

  12. Comparison of photovoltaic devices based on MEH-PPV with various molecular weights

    Institute of Scientific and Technical Information of China (English)

    KANG Bonan; WANG Liduo; YANG Yong; QIU Yong

    2004-01-01

    Polymer photovoltaic devices based on poly (2- methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH- PPV) with three weight-average molecular weights (Mw) have been fabricated with the device structure of ITO/PEDOT/ MEH-PPV/Ca/Ag, and the effect of the molecular weight on photovoltaic properties has been investigated. The experimental results show that the high molecular weight of MEH- PPV leads to low series resistance (Rs) and high short-circuit current. The low molecular weight of MEH-PPV leads to high shunt resistance (Rsh) and high open-circuit voltage. When the molecular weight is 6×105, the highest power conversion efficiency was observed.

  13. Tetracycline selective electrode based on molecularly imprinted polymer particles

    Institute of Scientific and Technical Information of China (English)

    Zhi Yong Guo; Pan Pan Gai; Jing Duan; Hui Na Zhang; Sui Wang

    2010-01-01

    Tetracycline selective electrode using molecularly imprinted polymer particles as quasi-ionophore was constructed the first time,and its performance was carefully characterized.Due to the specific recognition of tetracycline by the particles,the selectivity coefficients for routine interferences were less than 10-4.Benefited from the absence of tetracycline in the sensitive membrane and the optimized composition of the inner filling solution,the limit of detection of the electrode was reduced to about 2.5 × 10-8 mol/L.It exhibited a good electrode slope 57.6 mV/decade near the theoretical Nernstian one,with a wide linear working range from6.0 × 10-8 to 1.0 × 10-3 mol/L.The fabricated electrode should be used in pH 2-4,response time of which was less than 200 s when the concentration of tetracycline was higher than 1.0 × 10-6 mol/L and no more than 30 min at the concentration of1.0 × 10-8 mol/L.

  14. Descifrando las bases moleculares de la resistencia cuantitativa

    Directory of Open Access Journals (Sweden)

    Lopez Camilo

    2011-08-01

    Full Text Available Uno de los factores mas importantes que afectan los cultivos son las enfermedades ocasionadas por los patógenos. La resistencia vegetal ha sido clásicamente dividida en dos tipos: i competa, vertical o cualitativa que es gobernada por un solo gen y ii incompleta, horizontal o cuantitativa la cual es gobernada por varios genes. Aunque la resistencia cuantitativa provee resistencia de amplio espectro y es durable, los mecanismo moleculares subyacentes no han sido estudiados en detalle. En esta revisión se propone un modelo basado en la co-localización de genes similares a los clásicos genes de resistencia cualitativa con QTLs (Quantitative Trait Loci para explicar el mecanismo involucrado en el reconocimiento del patógeno durante la resistencia cuantitativa. Además se presenta información acerca del progreso obtenido en los últimos tres años para entender este tipo de resistencia, que culminó con la clonación de varios genes asociados a la resistencia cuantitativa. En conjunto, estos datos proveen nuevas luces sobre la naturaleza genética de este tipo de resistencia y de cómo puede ser empleada en programas de mejoramiento genético.

  15. Polyphosphazene Based Star-Branched and Dendritic Molecular Brushes

    Science.gov (United States)

    Henke, Helena; Posch, Sandra; Brüggemann, Oliver; Teasdale, Ian

    2016-01-01

    A new synthetic procedure is described for the preparation of poly(organo)phosphazenes with star-branched and star dendritic molecular brush type structures, thus describing the first time it has been possible to prepare controlled, highly branched architectures for this type of polymer. Furthermore, as a result of the extremely high-arm density generated by the phosphazene repeat unit, the second-generation structures represent quite unique architectures for any type of polymer. Using two relativity straight forward iterative syntheses it is possible to prepare globular highly branched polymers with up to 30 000 functional end groups, while keeping relatively narrow polydispersities (1.2–1.6). Phosphine mediated polymerization of chlorophosphoranimine is first used to prepare three-arm star polymers. Subsequent substitution with diphenylphosphine moieties gives poly(organo)phosphazenes to function as multifunctional macroinitiators for the growth of a second generation of polyphosphazene arms. Macrosubstitution with Jeffamine oligomers gives a series of large, water soluble branched macromolecules with high-arm density and hydrodynamic diameters between 10 and 70 nm. PMID:27027404

  16. Molecular and biomolecular-based nanomaterials: Tubulin and taxol as molecular constituents

    Science.gov (United States)

    Castro Carmona, Javier Servando

    The new field of protein-based nano-technology takes advantage of the complex interactions between proteins to form unique structures with properties that cannot be achieved with traditional components. Microtubules (MTs), self assembled proteinaceous hollow filaments, offer promise in the development of MT-based nano-systems. The compelling need for the controlled assembly of 3D MT arrays is the fundamental motivation for the first part of this research. We report on the morphology of MTs grown in a crowded environment in the form of high viscosity fluids containing agarose and a novel process that enables the assembly of MTs supported by gel-based 3D scaffolds. Our research on MTs and their interaction with other molecules lead us to discover extraordinary spherulitic structures that changed the course of the project. The novel subject situate us into a complicated dilemma that question the nature of MT asters reported in experiments carried out in cells. The second part of this research is focused in the crystallization of Taxol, a MT stabilizing molecule used as anti-cancer drug. It was confirmed via fluorescent and differential interference contrast microscopy that Taxol crystals can be decorated with fluorescent proteins and fluorochromes without perturbing their morphology. We used theoretical calculations to further investigate Taxol-fluorescent agent interactions. Furthermore, the crystallization of Taxol was studied in pure water, aqueous solutions containing tubulin proteins and tubulin-containing agarose gels. We demonstrated that tubulin is able to heterogeneously nucleate Taxol spherulites. To explain the formation of tubulin-Taxol nuclei a new, secondary Taxol-binding site within the tubulin heterodimer is suggested. Results presented in this work are important for in vivo and in vitro microtubule studies due to the possibility of mistaking these Taxol spherulites for microtubule asters. Thus, we are confirming the need for careful interpretation of

  17. A communication theoretical analysis of FRET-based mobile ad hoc molecular nanonetworks.

    Science.gov (United States)

    Kuscu, Murat; Akan, Ozgur B

    2014-09-01

    Nanonetworks refer to a group of nanosized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a molecular communication method based on Förster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile molecular nanonetworks: FRET-based mobile molecular sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as sensor or actor node; and FRET-based mobile ad hoc molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth-death processes with continuous time Markov chains. We evaluate the performance of FRET-MSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates. PMID:25014963

  18. Molecular Design of Benzodithiophene-Based Organic Photovoltaic Materials.

    Science.gov (United States)

    Yao, Huifeng; Ye, Long; Zhang, Hao; Li, Sunsun; Zhang, Shaoqing; Hou, Jianhui

    2016-06-22

    Advances in the design and application of highly efficient conjugated polymers and small molecules over the past years have enabled the rapid progress in the development of organic photovoltaic (OPV) technology as a promising alternative to conventional solar cells. Among the numerous OPV materials, benzodithiophene (BDT)-based polymers and small molecules have come to the fore in achieving outstanding power conversion efficiency (PCE) and breaking 10% efficiency barrier in the single junction OPV devices. Remarkably, the OPV device featured by BDT-based polymer has recently demonstrated an impressive PCE of 11.21%, indicating the great potential of this class of materials in commercial photovoltaic applications. In this review, we offered an overview of the organic photovoltaic materials based on BDT from the aspects of backbones, functional groups, alkyl chains, and device performance, trying to provide a guideline about the structure-performance relationship. We believe more exciting BDT-based photovoltaic materials and devices will be developed in the near future.

  19. Foraging on the potential energy surface: A swarm intelligence-based optimizer for molecular geometry

    Science.gov (United States)

    Wehmeyer, Christoph; Falk von Rudorff, Guido; Wolf, Sebastian; Kabbe, Gabriel; Schärf, Daniel; Kühne, Thomas D.; Sebastiani, Daniel

    2012-11-01

    We present a stochastic, swarm intelligence-based optimization algorithm for the prediction of global minima on potential energy surfaces of molecular cluster structures. Our optimization approach is a modification of the artificial bee colony (ABC) algorithm which is inspired by the foraging behavior of honey bees. We apply our modified ABC algorithm to the problem of global geometry optimization of molecular cluster structures and show its performance for clusters with 2-57 particles and different interatomic interaction potentials.

  20. Molecular phylogeny of Toxoplasmatinae: comparison between inferences based on mitochondrial and apicoplast genetic sequences

    OpenAIRE

    Michelle Klein Sercundes; Samantha Yuri Oshiro Branco Valadas; Lara Borges Keid; Tricia Maria Ferreira Souza Oliveira; Helena Lage Ferreira; Ricardo Wagner Almeida Vitor; Fábio Gregori; Rodrigo Martins Soares

    2016-01-01

    Abstract Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC) and beta subunit of RNA polymerase (rpoB), and mitochondrial gene coding for cytochrome B (cytB) were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula ...

  1. Molecular Similarity Based on Super-Ball Algorithm

    Institute of Scientific and Technical Information of China (English)

    GUO; Ming

    2001-01-01

    [1]Basak S. C. , Grunwald G. D. , J. Chem. Inf. Comput. Sci. , 35(3), 366(1995)[2]YANG Jia-An, XU Lu, Chemical Journal of Chinese University, 18(6): 880(1997)[3]YAO Jian-Hua, YUAN Shen-Gang, CHEN Hai-Feng et al. , Computers and Applied Chemistry, 16(2):97(1999)[4]Basak S. C. , Bertelsen S. , Grunwald G. D. , J. Chem. Inf. Comput. Sci. , 34(2), 270(1994)[5]Kier L. B. , Hall L. H. , Molecular Connectivity in Chemistry and Drug Researches, Academic Press, New York,175(1976)[6]Martin Y. C., Translated by WANG Er-Hua, Quantitative Drug Design, People Health press, Beijing, 296(1983)[7]Basak S. C, Harriss D. K. , Magnuson V. R. , J. Pharm. , Sci. , 73, 429(1984)[8]Wiener H. , J. Am. Chem. Soc. , 69, 17(1947)[9]Balaban A. T. , Chem. Phys. Lett., 89, 399(1982)[10]XU Lu, The Methods of Chemometrics, Science Press, Beijing, 287(1995)[11]Balaban A. T. , Ciubotariu D. J. , Medeleanu M. , J. Chem. Inf. Comput. Sci. , 31, 517(1991)[12]Hosoya H. , Bull. Chem. Soc. Jpn. , 44, 2 332(1971)[13]Devillers J. , Chambon P. , Zakarya D. et al. , Chemosphere, 15(8), 993(1996)[14]HUANG Guo-Qing, WANG Xiao-Dong, WANG Lian-Sheng, Progress of Organic Pollution chemistry, Chemical Industry Press, Beijing, 141(1998)[15]YAO Yu-Yuan, XU Lu, YUAN Xiu-Shun, Acta Chimica Simica, 51: 1 041(1993)[16]Stouch T. R. , Jurs P. C. , J. Chem. Inf. Comput. Sci. , 26(1), 4(1986)[17]Filimonov D. , Poroikov V. , Borodina Y. et al. , J. Chem. Inf. Comput. Sci. , 39(4), 666(1999)

  2. El Observatorio de Violencia de Género en Bizkaia (OVGB: una Experiencia de Buenas Prácticas (The Observatory on Gender-based Violence in Bizkaia (OVGB: an Experience of Good Practices

    Directory of Open Access Journals (Sweden)

    Berta Díaz Arbesú

    2015-06-01

    Full Text Available The Observatory on Gender-based Violence in Bizkaia (OVGB emerged as an initiative of the Social Action Department of Bizkaia Provincial Council (DFB in 2003.  It began to operate in 2004. This Observatory has two main objectives: To understand the reality and evolution of the situations of violence against women in Bizkaia.To make recommendations and proposals to improve the services and facilities offered by public institutions in the field of gender-based violence. Its work on compiling data on dealing with situations of gender violence within the social sphere, where there are multiple information sources, is of particular interest (123. Data gathering process coordinated by the Indicators Working Party. Along with the information on a social level, the political and legal data make up a database providing a closer view on the care provided to this collective and the analysis of the evolution.  This knowledge is used to issue recommendations as guidelines for public policies. The work carried out can be found on the OVGB website: http://www.bizkaia.eus/Gizartekintza/Genero_Indarkeria/ca_index.html El Observatorio de Violencia de Género en Bizkaia (OVGB surge como iniciativa del Departamento de Acción Social de la Diputación Foral de Bizkaia (DFB en el año 2003. En 2004 comienzan sus actuaciones. Dos son los objetivos principales de este Observatorio: Conocer la realidad y la evolución de las situaciones de violencia contra las mujeres en Bizkaia.Formular recomendaciones y propuestas de mejora en los servicios y prestaciones que se ofertan desde las instituciones públicas, en el ámbito de la violencia de género. De todo el trabajo desarrollado resulta de especial interés la compilación de los datos de las actuaciones efectuadas en atención a las víctimas de violencia de género dentro del ámbito social, en el que existen múltiples fuentes informativas (123, proceso de recogida de datos coordinado por el Grupo de Trabajo sobre

  3. EXPERIENCIA DEL ENTRENAMIENTO MUSICAL EN UNA UNIVERSIDAD PARTICULAR DE LIMA

    OpenAIRE

    Daniel Ravelo Franco

    2012-01-01

    RESUMEN: El objetivo de la Revolución del Entrenamiento Musical es aprovechar las modernas herramientas tecnológicas para la educación, aplicándolas al entrenamiento auditivo, dentro de un programa de formación musical profesional. En este trabajo, se presentará la experiencia de transformación del curso presencial de Nivelación en Lectura y Entrenamiento Auditivo, de un pregrado universitario de Música, a la modalidad b-learning. La modalidad b-learning de este curso se estableció sobre un A...

  4. Proyecto final de estudios, una experiencia académica

    OpenAIRE

    Puglesi, Alfredo E.; Bernasconi, María Susana

    2011-01-01

    Inserto en la temática de las innovaciones, experiencias e investigación en las tecnologías aplicadas, este trabajo describe la realización del último Proyecto Final de Estudios (PFE) por parte de alumnos de la carrera de Ingeniería en Mecatrónica de la Facultad de Ingeniería de la Universidad Nacional de Cuyo y en el marco del convenio que la misma tiene con la de l'École Nationale d'Ingénieurs de Brest (Francia), mediante el cual, dos alumnos concurren anualmente para cursar los...

  5. Historias del arte y experiencias pedagógicas

    OpenAIRE

    Muñoz Cobeñas, Leticia Amelia

    2012-01-01

    El presente trabajo intenta articular la experiencia pedagógica con reflexiones en torno a la historia del arte, su renovación teórica y el acercamiento a diferentes mundos empíricos de las llamadas obras de arte. Desde la cátedra Epistemología de las ciencias sociales de la Facultad de Bellas Artes hemos reconocido los aportes interdisciplinares en la definición de una historia del arte que renueva e incorpora nuevas problemáticas y otros objetos de estudio surgidos al interior del propio...

  6. Educación y envejecimiento activo: una experiencia comunitaria

    OpenAIRE

    Aparicio Alonso, Concepción

    2013-01-01

    La presente tesis doctoral describe una experiencia comunitaria mediante talleres de Educación para la Salud (EpS) (Costa y López, 2008) dirigidos a personas mayores. Contiene diez capítulos divididos en dos partes. En la primera, capítulos uno a cinco, se exponen los fundamentos teóricos de la investigación y en la segunda, capítulos seis a diez, el trabajo de campo realizado. El primer capítulo aborda el fenómeno demográfico denominado envejecimiento de la población y las diversas perspect...

  7. Objetos de aprendizaje: experiencia de curso de posgrado

    OpenAIRE

    Rosanigo, Zulema Beatriz; Bramati, Pedro; Bramati, Silvina

    2012-01-01

    En este artículo se presenta la experiencia desarrollada en el dictado del curso de posgrado sobre “Diseño de materiales en entornos virtuales: Objetos de aprendizaje”. Un Objeto de Aprendizaje “es un recurso docente digital empaquetado conjuntamente con un recubrimiento semántico estandarizado, compatible con diversos ambientes y sistemas de administración de aprendizajes, fácil de migrar de una plataforma a otra, factible de localizar, acceder, archivar y re-utilizar”. El propósito de...

  8. Cruzando la frontera: Experiencias desde los márgenes

    Directory of Open Access Journals (Sweden)

    Alejandra AQUINO MORESCHI

    2012-01-01

    Full Text Available Existen muchos estudios sobre las políticas estatales para el control de las fronteras entre norte y sur; sin embargo, hay muy pocos sobre las estrategias concretas, individuales y colectivas que siguen los migrantes para atravesarlas y sobre cómo experimentan este momento clave en su trayectoria migratoria. El artículo siguiente busca abonar a esta tarea; para ello presenta un análisis etnográfico del cruce de la frontera de jóvenes zapotecas y tojolabales originarios de comunidades rurales de Chiapas y Oaxaca con distinta experiencia migratoria.

  9. HACIA UNA ORGANIZACIÓN QUE APRENDE: UNA EXPERIENCIA CUBANA

    OpenAIRE

    Armando Cuesta Santos

    2004-01-01

    Se enuncian principios y atributos relativos a la organización que aprende, haciéndose consideraciones sobre su aplicación al adoptarse una definición y arribar a una conducción metodológica buscando hacerla viable en la practica empresarial cubana. Ofrecer una reseña sobre tal viabilidad con las experiencias adquiridas reflejando peculiaridades, constituye el objetivo central de este trabajo, reali...

  10. Knowledge-Based Optimization of Molecular Geometries Using Crystal Structures.

    Science.gov (United States)

    Cole, Jason C; Groom, Colin R; Korb, Oliver; McCabe, Patrick; Shields, Gregory P

    2016-04-25

    This paper describes a novel way to use the structural information contained in the Cambridge Structural Database (CSD) to drive geometry optimization of organic molecules. We describe how CSD structural information is transformed into objective functions for gradient-based optimization to provide good quality geometries for a large variety of organic molecules. Performance is assessed by minimizing different sets of organic molecules reporting RMSD movements for bond lengths, valence angles, torsion angles, and heavy atom positions. PMID:26977906

  11. Molecular bases of circadian rhythmicity in renal physiology and pathology

    OpenAIRE

    Bonny, Olivier; Vinciguerra, Manlio; Gumz, Michelle L.; Mazzoccoli, Gianluigi

    2013-01-01

    The physiological processes that maintain body homeostasis oscillate during the day. Diurnal changes characterize kidney functions, comprising regulation of hydro-electrolytic and acid-base balance, reabsorption of small solutes and hormone production. Renal physiology is characterized by 24-h periodicity and contributes to circadian variability of blood pressure levels, related as well to nychthemeral changes of sodium sensitivity, physical activity, vascular tone, autonomic function and neu...

  12. Molecular Engineering of Technetium and Rhenium Based Radiopharmaceuticals

    International Nuclear Information System (INIS)

    The research was based on the observation that despite the extraordinarily rich coordination chemistry of technetium and rhenium and several notable successes in reagent design, the extensive investigations by numerous research groups on a variety of N2S2 and N3S donor type ligands and on HYNIC have revealed that the chemistries of these ligands with Tc and Re are rather complex, giving rise to considerable difficulties in the development of reliable procedures for the development of radiopharmaceutical reagents

  13. iBarcode.org: web-based molecular biodiversity analysis

    OpenAIRE

    Hajibabaei Mehrdad; Singer Gregory AC

    2009-01-01

    Abstract Background DNA sequences have become a primary source of information in biodiversity analysis. For example, short standardized species-specific genomic regions, DNA barcodes, are being used as a global standard for species identification and biodiversity studies. Most DNA barcodes are being generated by laboratories that have an expertise in DNA sequencing but not in bioinformatics data analysis. Therefore, we have developed a web-based suite of tools to help the DNA barcode research...

  14. TARGET-ORIENTED GENERIC FINGERPRINT-BASED MOLECULAR REPRESENTATION

    OpenAIRE

    Petr Skoda; David Hoksza

    2014-01-01

    The screening of chemical libraries is an important step in the drug discovery process. The existing chemical libraries contain up to millions of compounds. As the screening at such scale is expensive, the virtual screening is often utilized. There exist several variants of virtual screening and ligand-based virtual screening is one of them. It utilizes the similarity of screened chemical compounds to known compounds. Besides the employed similarity measure, another aspect grea...

  15. DNA Based Carbon Nanotube Porphyrin Nanohybrids Molecular Recognization and Regeneration

    OpenAIRE

    Riccitelli, Molly M; Zhang, Hanyu; Choi, Jong Hyun

    2013-01-01

    In the search to improve solar cells, scientists are exploring new materials that will provide better current transfer. One material that has emerged as a strong contender is the single walled carbon nanotube (SWNT). Current DNA-SWNT based films combined with chromophores have poor operational lifetimes compared to commercial solar cells. Once exposed to light the chromophore begins to degrade, eventually rendering the solar cell unusable. To solve this problem, we used a method involving mul...

  16. The formation of ZnO-based coatings from solutions containing high-molecular polyvinylpyrrolidone

    Science.gov (United States)

    Evstrop'ev, S. K.; Soshnikov, I. P.; Khrebtov, A. I.

    2016-05-01

    A method for deposition of transparent nanosize ZnO-based coatings on the glass surface from solutions containing high-molecular polyvinylpyrrolidone is described. The method can be used to form transparent homogeneous coatings based on ZnO with an increased energy gap width. It does not require any intricate technological equipment.

  17. Reflexiones sobre la estrategia de rehabilitación basada en la comunidad (RBC: la experiencia de un programa de RBC en Bolivia Reflections on community-based rehabilitation strategy (CBR: the experience of a CBR program in Bolivia

    Directory of Open Access Journals (Sweden)

    Urko Díaz-Aristizabal

    2012-01-01

    Full Text Available La Rehabilitación Basada en la Comunidad (RBC es una estrategia de desarrollo comunitario avalada por la Organización Mundial de la Salud (OMS, la Organización Internacional del Trabajo (OIT y la Organización de las Naciones Unidas para la Educación, la Ciencia y la Cultura (UNESCO, que persigue la rehabilitación, la igualdad de oportunidades y la integración social de las Personas con Discapacidad (PD en sus entornos. Con este objetivo promueve la colaboración entre las PD, sus familias y los diferentes actores de la comunidad involucrados, así como el liderazgo comunitario y la participación de las PD mediante el impulso de la colaboración multisectorial. Este artículo expone los antecedentes históricos y las características fundamentales de la estrategia de RBC a partir de un programa llevado a cabo por una fundación del departamento de Cochabamba (Bolivia, para después incidir en algunos aspectos referentes al contexto sociocultural, que especialmente en situaciones de interculturalidad, pueden determinar que un programa de RBC tenga éxito o esté abocado al fracaso.Community-Based Rehabilitation (CBR is a strategy for community development endorsed by the World Health Organization (WHO, the International Labor Office (ILO and the United Nations Educational, Scientific and Cultural Organization (UNESCO. It is designed to promote rehabilitation, equal opportunity and social inclusion of Disabled Persons (DP in their home communities by fostering cooperation among disabled individuals, their families, and other concerned social actors, it encourages community leadership and full social participation by DP through multi-sector cooperation. This article explores the historical antecedents and basic features of CBR strategy through an analysis of a directed culture change initiative developed by a foundation in the Cochabamba administrative region of Bolivia. Especially in intercultural environments, certain aspects of the socio

  18. TARGET-ORIENTED GENERIC FINGERPRINT-BASED MOLECULAR REPRESENTATION

    Directory of Open Access Journals (Sweden)

    Petr Skoda

    2014-12-01

    Full Text Available The screening of chemical libraries is an important step in the drug discovery process. The existing chemical libraries contain up to millions of compounds. As the screening at such scale is expensive, the virtual screening is often utilized. There exist several variants of virtual screening and ligand-based virtual screening is one of them. It utilizes the similarity of screened chemical compounds to known compounds. Besides the employed similarity measure, another aspect greatly influencing the performance of ligand-based virtual screening is the chosen chemical compound representation. In this paper, we introduce a fragment-based representation of chemical compounds. Our representation utilizes fragments to represent a compound where each fragment is represented by its physico-chemical descriptors. The representation is highly parametrizable, especially in the area of physico-chemical descriptors selection and application. In order to test the performance of our method, we utilized an existing framework for virtual screening benchmarking. The results show that our method is comparable to the best existing approaches and on some data sets it outperforms them.

  19. Molecular engineering of manipulated alginate-based polyurethanes.

    Science.gov (United States)

    Daemi, Hamed; Barikani, Mehdi

    2014-11-01

    The novel soluble alginate-based polyurethanes in organic solvents were synthesized by the reaction of NCO-terminated prepolymers and tributylammonium alginate (TBA-Alg) for the first time. The chemical structures of synthesized polyurethanes were characterized using FTIR, (1)H NMR and TGA. The reaction completion was confirmed by disappearing of NCO band in FTIR spectra. Furthermore, a peak at 4.71 ppm and some small peaks at a range of 4.12-4.37 ppm in the (1)H NMR of alginate-based polyurethanes were assigned to the backbone of alginate. The results of both FTIR and (1)H NMR were remarkably confirmed by TGA data. The ionic nature of polyurethane backbone not only affects on thermal properties of samples, but it also changes the chemically-bonded alginate morphology. Both polyether and polyester based non-ionic polyurethanes extended by TBA-Alg illustrated the distinct alginate, whereas those ionomers extended by alginate were appeared as the continuous systems at nanoscale. PMID:25129793

  20. Next-Generation Sequencing-Based Molecular Diagnosis of Choroideremia

    Directory of Open Access Journals (Sweden)

    Kayo Shimizu

    2015-07-01

    Full Text Available We screened patients with choroideremia using next-generation sequencing (NGS and identified a novel mutation and a known mutation in the CHM gene. One patient presented an atypical fundus appearance for choroideremia. Another patient presented macular hole retinal detachment in the left eye. The present case series shows the utility of NGS-based screening in patients with choroideremia. In addition, the presence of macular hole in 1 of the 2 patients, together with a previous report, indicated the susceptibility of patients with choroideremia to macular hole.

  1. Molecular Engineering of Technetium and Rhenium Based Radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Zubieta, J.

    2003-06-30

    The research was based on the observation that despite the extraordinarily rich coordination chemistry of technetium and rhenium and several notable successes in reagent design, the extensive investigations by numerous research groups on a variety of N{sub 2}S{sub 2} and N{sub 3}S donor type ligands and on HYNIC have revealed that the chemistries of these ligands with Tc and Re are rather complex, giving rise to considerable difficulties in the development of reliable procedures for the development of radiopharmaceutical reagents.

  2. Las experiencias extracorpóreas y las experiencias alucinatorias: relación con variables cognitivas y perceptuales

    Directory of Open Access Journals (Sweden)

    Alejandro Parra

    2008-12-01

    Full Text Available RESUMENLa experiencia fuera del cuerpo (EFC se define como un experiencia mediante la cual el “yo” o centro de conciencia parece ocupar una posición remota respecto a su propio cuerpo. Un total de 648 estudiantes de psicología que incluyó 78% de mujeres y 24% de hombres, completaron un número de escalas para comparar los puntajes de ambos grupos (con EFC N = 132 vs sin EFC N = 516. Los resultados mostraron mayor esquizotipia cognitivo-perceptual, absorción, disociación, propensidad a la fantasía, tendencia a alucinar, imaginería visual en individuos que tienen EFC en comparación con un grupo control. La incidencia de tales experiencias incluye a individuos que han señalado los efectos benéficos de lasEFCs como un modo adaptativo al estrés postraumático.ABSTRACTAbstract. An out-of-body experience or OBE is one in which the “self” or center of awareness seems to the experient to occupy temporarily a position that is spatially remote from his or her body. A total of 648 undergraduate students population included 76% females and 24% males, and who completed a number of scales. Data for experients of OBE were compared with data for those who did not (experients N= 132 vs. non‑experients N= 516. The results showed a higher level of cognitive-perceptual schizotypy, absorption, dissociation, fantasy and hallucination proneness, and visual imagery in OBErs than in non-OBErs. This study suggest that the dissociational model of OBE. Anomalous perceptual experiences and some subjects report beneficial effects from OBEs in an adaptive way.

  3. High-molecular-weight polymers for protein crystallization: poly-γ-glutamic acid-based precipitants

    International Nuclear Information System (INIS)

    High-molecular-weight poly-γ-glutamic acid-based polymers have been synthesized, tested and adopted for protein crystallization. Protein crystallization has been revolutionized by the introduction of high-throughput technologies, which have led to a speeding up of the process while simultaneously reducing the amount of protein sample necessary. Nonetheless, the chemistry dimension of protein crystallization has remained relatively undeveloped. Most crystallization screens are based on the same set of precipitants. To address this shortcoming, the development of new protein precipitants based on poly-γ-glutamic acid (PGA) polymers with different molecular-weight ranges is reported here: PGA-LM (low molecular weight) of ∼400 kDa and PGA-HM (high molecular weight) of >1000 kDa. It is also demonstrated that protein precipitants can be expanded further to polymers with much higher molecular weight than those that are currently in use. Furthermore, the modification of PGA-like polymers by covalent attachments of glucosamine substantially improved their solubility without affecting their crystallization properties. Some preliminary PGA-based screens are presented here

  4. Bio-molecular sensors based on guided mode resonance filters

    Science.gov (United States)

    Saleem, M. R.; Ali, R.; Honkanen, S.; Turunen, J.

    2016-08-01

    In this work a low surface roughness and homogenous, high refractive index, and amorphous TiO2 layer on corrugated structures of diffractive optical element is coated by Atomic Layer Deposition (ALD) for biosensors. The design of Guided Mode Resonance Filters (GMRFs) is based on refractive indices and thicknesses of the waveguide biomolecular layers. The designed spectral shifts are calculated by Fourier Modal Method (FMM) and depend on the magnitude of the variations in refractive index of the biomolecular layer on waveguide structures. Furthermore, the sensitivity of the biomolecular sensors depends on the thickness of biomolecular layer and periodicity of the structures. The waveguide structures designed for larger periods show an enhancement in the sensitivity (nm/RIU) of the biomolecular sensor at longer wavelengths. The periodicities of nanophotonic structures are varied from 300 to 500 nm in design calculations with predominance of increase in effective index of the structure to support leaky waveguide modes.

  5. Three decades of structure- and property-based molecular design

    DEFF Research Database (Denmark)

    Müller, Klaus

    2014-01-01

    . These developments were accompanied by the rise of miniaturized parallel compound property analytics which resulted in a major paradigm shift in medicinal chemistry from linear to multi-dimensional lead optimization. The rapid growth of huge collections of property data stimulated the development of various novel...... involved in this transformation process, to have been able to collaborate with, direct, guide, or simply encourage outstanding experts in various disciplines to build and further develop what has become a major pillar of modern small-molecule drug discovery. This article is an account of major events......-oriented medicinal chemistry. The exploration of oxetane is given as an example. For the sake of brevity, this account cannot detail all further developments that have taken place in each individual area of structure- and property-based drug discovery and it can only hint at important developments in other...

  6. Molecular diagnostics based on clustering dynamics of magnetic nanobeads

    DEFF Research Database (Denmark)

    Donolato, Marco; Bejhed, Rebecca S.; de la Torre, Teresa Zardán Gómez;

    2014-01-01

    or on the polymerase chain reaction (PCR) [1]. In this work we demonstrate detection of DNA coils formed from a Vibrio Cholerae DNA target at pM concentrations using a novel opto-magnetic approach exploiting the dynamic collective behavior of magnetic nanobeads. The technique relies on measurements of the light...... and isothermal rolling circle amplification from Vibrio cholerae DNA. The detection method is shown in Figure 1. MNBs which specifically bind to the micrometric sized DNA coil cannot rotate under the field action as free beads and form chains; this results in a strongly modified opto-magnetic signal. As a core...... a miniaturized version of the readout system based on the use of a commercial Blu-Ray pickup head used as a single and unique optomagnetic component. Figure 3 shows measurements on Bacillus Globigii spores detected using this novel setup. The data demonstrate fast and low-cost implementation of bacterial DNA...

  7. Highly selective molecular recognition and high throughput detection of melamine based on molecularly imprinted sol-gel film

    Energy Technology Data Exchange (ETDEWEB)

    Yu Jinghua, E-mail: cclj4ever@126.com [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Zhang Congcong; Dai Ping; Ge Shenguang [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)

    2009-10-05

    Multimode reader has been generally applied in immunoassay, and in the proposed paper, the 96 well micro-plate was modified with molecularly imprinted melamine sol-gel film, based on which the highly selective and high throughput detection of melamine was achieved. Melamine was imprinted into silica sol-gel films directly using phenyltrimethoxysilane and methyltrimethoxysilane as functionalized organosilicon precursors. The binding characteristic of the imprinted film to melamine was evaluated by equilibrium binding experiments and the morphology was studied by scanning electronic microscope (SEM). Scatchard analysis was carried out to estimate the binding parameters of the imprinted film. The proposed method exhibited excellent selectivity because of specific recognition of MM by molecularly imprinted film. Under the optimum conditions, the chemiluminescence (CL) intensity had a linear relationship against the concentration of melamine over the range of 0.1-50 {mu}g mL{sup -1} with a lower detection limit of 0.02 {mu}g mL{sup -1}.

  8. SISTEMATIZACIÓN DE EXPERIENCIA: VEREDA LA SUIZA

    Directory of Open Access Journals (Sweden)

    JUAN CARLOS MONSALVE GÓMEZ

    2011-12-01

    Full Text Available El presente artículo muestra los resultados de la sistematización de la experiencia Vereda La Suiza. Un proyecto educativo con estudiantes en educación básica y media que orienta la Fundación Universitaria Católica del Norte a través del Cibercolegio UCN. Dicho grupo está ubicado en el Corregimiento de Palmitas, Vereda La Suiza, ubicada a la salida del túnel de occidente del municipio de Medellín. El tipo de estudio es sistematización de experiencia, en el cual se hicieron entrevistas, encuestas y revisión documental, en el período de tiempo comprendido entre abril de 2009 y abril de 2010.El artículo evidencia el proceso de investigación desarrollado y los beneficios que este tipo de proyectos representan para las comunidades rurales, alejadas de los sistemas educativos convencionales, permitiendo a los miembros de dichas comunidades, adelantar un estudio en diferentes niveles educativos, sin requerirse del desplazamiento de las personas a otros sitios.

  9. UNA EXPERIENCIA DE APRENDIZAJE-SERVICIO EN COMUNIDADES DE APRENDIZAJE

    Directory of Open Access Journals (Sweden)

    Margarita R. Rodríguez-Gallego

    2015-01-01

    Full Text Available Esta investigación describe la experiencia de Aprendizaje-Servicio vivida y desarrollada por 100 estudiantes-servicio de la Universidad de Sevilla, que participaron voluntariamente durante el curso académico 2013-2014y 104 profesionales de centros educativos. Entre los objetivos, valorar el grado de satisfacción de los participantes en el proyecto ApS y conocer supercepcióncomo futurosdocentes. El diseño de la investigación ha sido mixto, por una parte, exploratorio y no experimental (ex post-factopara conocer las opiniones de los estudiantesy, por otra, el método de codificación abierta de la teoría fundamentada a través del análisis de los diariospara conocer las opiniones de los profesionales.Los resultados obtenidos ponen de manifiesto, tanto para estudiantes como profesionales, que esta experiencia de ApS les ha permitido un mejor desarrollo en el ámbito académico al afianzar los conceptos teóricos, así como en el personalalpoder mejorar sushabilidades sociales y comunicativas,en el profesionalpor la adquisición de cualidades y competencias para el ejercicio profesionaly, por último, en el ámbitosocialaltomar conciencia de las desigualdades.

  10. Electronic shift register memory based on molecular electron-transfer reactions

    International Nuclear Information System (INIS)

    The design of a shift register memory at the molecular level is described in detail. The memory elements are based on a chain of electron-transfer molecules incorporated on a very large scale integrated (VLSI) substrate, and the information is shifted by photoinduced electron-transfer reactions. The design requirements for such a system are discussed, and several realistic strategies for synthesizing these systems are presented. The immediate advantage of such a hybrid molecular/VLSI device would arise from the possible information storage density. The prospect of considerable savings of energy per bit processed also exists. This molecular shift register memory element design solves the conceptual problems associated with integrating molecular size components with larger (micron) size features on a chip

  11. Computational Design of Intrinsic Molecular Rectifiers Based on Asymmetric Functionalization of N-Phenylbenzamide.

    Science.gov (United States)

    Ding, Wendu; Koepf, Matthieu; Koenigsmann, Christopher; Batra, Arunabh; Venkataraman, Latha; Negre, Christian F A; Brudvig, Gary W; Crabtree, Robert H; Schmuttenmaer, Charles A; Batista, Victor S

    2015-12-01

    We report a systematic computational search of molecular frameworks for intrinsic rectification of electron transport. The screening of molecular rectifiers includes 52 molecules and conformers spanning over 9 series of structural motifs. N-Phenylbenzamide is found to be a promising framework with both suitable conductance and rectification properties. A targeted screening performed on 30 additional derivatives and conformers of N-phenylbenzamide yielded enhanced rectification based on asymmetric functionalization. We demonstrate that electron-donating substituent groups that maintain an asymmetric distribution of charge in the dominant transport channel (e.g., HOMO) enhance rectification by raising the channel closer to the Fermi level. These findings are particularly valuable for the design of molecular assemblies that could ensure directionality of electron transport in a wide range of applications, from molecular electronics to catalytic reactions.

  12. Detecting Molecular Properties by Various Laser-Based Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hsin, Tse-Ming [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    Four different laser-based techniques were applied to study physical and chemical characteristics of biomolecules and dye molecules. These techniques are liole burning spectroscopy, single molecule spectroscopy, time-resolved coherent anti-Stokes Raman spectroscopy and laser-induced fluorescence microscopy. Results from hole burning and single molecule spectroscopy suggested that two antenna states (C708 & C714) of photosystem I from cyanobacterium Synechocystis PCC 6803 are connected by effective energy transfer and the corresponding energy transfer time is ~6 ps. In addition, results from hole burning spectroscopy indicated that the chlorophyll dimer of the C714 state has a large distribution of the dimer geometry. Direct observation of vibrational peaks and evolution of coumarin 153 in the electronic excited state was demonstrated by using the fs/ps CARS, a variation of time-resolved coherent anti-Stokes Raman spectroscopy. In three different solvents, methanol, acetonitrile, and butanol, a vibration peak related to the stretch of the carbonyl group exhibits different relaxation dynamics. Laser-induced fluorescence microscopy, along with the biomimetic containers-liposomes, allows the measurement of the enzymatic activity of individual alkaline phosphatase from bovine intestinal mucosa without potential interferences from glass surfaces. The result showed a wide distribution of the enzyme reactivity. Protein structural variation is one of the major reasons that are responsible for this highly heterogeneous behavior.

  13. Molecular MRI based on hyper-polarized xenon

    International Nuclear Information System (INIS)

    Magnetic Resonance Imaging (MRI) has a high importance in medicine as it enables the observation of the organs inside the body without the use of radiative or invasive techniques. However it is known to suffer from poor sensitivity. To circumvent this limitation, a key solution resides in the use of hyper-polarized species. Among the entities with which we can drastically increase nuclear polarization, xenon has very specific properties through its interactions with its close environment that lead to a wide chemical shift bandwidth. The goal is thus to use it as a tracer. This PhD thesis focuses on the concept of 129Xe MRI-based sensors for the detection of biological events. In this approach, hyper-polarized xenon is vectorized to biological targets via functionalized host systems, and then localized thanks to fast dedicated MRI sequences. The conception and set-up of a spin-exchange optical pumping device is first described. Then studies about the interaction of the hyper-polarized noble gas with new cryptophanes susceptible to constitute powerful host molecules are detailed. Also the implementation of recent MRI sequences optimized for the transient character of the hyper-polarization and taking profit of the xenon in-out exchange is described. Applications of this approach for the detection of metallic ions and cellular receptors are studied. Finally, our first in vivo results on a small animal model are presented. (author)

  14. Recent advances in molecular electronics based on carbon nanotubes.

    Science.gov (United States)

    Bourgoin, Jean-Philippe; Campidelli, Stéphane; Chenevier, Pascale; Derycke, Vincent; Filoramo, Arianna; Goffman, Marcelo F

    2010-01-01

    Carbon nanotubes (CNTs) have exceptional physical properties that make them one of the most promising building blocks for future nanotechnologies. They may in particular play an important role in the development of innovative electronic devices in the fields of flexible electronics, ultra-high sensitivity sensors, high frequency electronics, opto-electronics, energy sources and nano-electromechanical systems (NEMS). Proofs of concept of several high performance devices already exist, usually at the single device level, but there remain many serious scientific issues to be solved before the viability of such routes can be evaluated. In particular, the main concern regards the controlled synthesis and positioning of nanotubes. In our opinion, truly innovative use of these nano-objects will come from: (i) the combination of some of their complementary physical properties, such as combining their electrical and mechanical properties, (ii) the combination of their properties with additional benefits coming from other molecules grafted on the nanotubes, and (iii) the use of chemically- or bio-directed self-assembly processes to allow the efficient combination of several devices into functional arrays or circuits. In this article, we outline the main issues concerning the development of carbon nanotubes based electronics applications and review our recent results in the field.

  15. Molecular Phylogenetic: Organism Taxonomy Method Based on Evolution History

    Directory of Open Access Journals (Sweden)

    N.L.P Indi Dharmayanti

    2011-03-01

    Full Text Available Phylogenetic is described as taxonomy classification of an organism based on its evolution history namely its phylogeny and as a part of systematic science that has objective to determine phylogeny of organism according to its characteristic. Phylogenetic analysis from amino acid and protein usually became important area in sequence analysis. Phylogenetic analysis can be used to follow the rapid change of a species such as virus. The phylogenetic evolution tree is a two dimensional of a species graphic that shows relationship among organisms or particularly among their gene sequences. The sequence separation are referred as taxa (singular taxon that is defined as phylogenetically distinct units on the tree. The tree consists of outer branches or leaves that represents taxa and nodes and branch represent correlation among taxa. When the nucleotide sequence from two different organism are similar, they were inferred to be descended from common ancestor. There were three methods which were used in phylogenetic, namely (1 Maximum parsimony, (2 Distance, and (3 Maximum likehoood. Those methods generally are applied to construct the evolutionary tree or the best tree for determine sequence variation in group. Every method is usually used for different analysis and data.

  16. Biomedical wellness monitoring system based upon molecular markers

    Science.gov (United States)

    Ingram, Whitney

    2012-06-01

    We wish to assist caretakers with a sensor monitoring systems for tracking the physiological changes of homealone patients. One goal is seeking biomarkers and modern imaging sensors like stochastic optical reconstruction microscopy (STORM), which has achieved visible imaging at the nano-scale range. Imaging techniques like STORM can be combined with a fluorescent functional marker in a system to capture the early transformation signs from wellness to illness. By exploiting both microscopic knowledge of genetic pre-disposition and the macroscopic influence of epigenetic factors we hope to target these changes remotely. We adopt dual spectral infrared imaging for blind source separation (BSS) to detect angiogenesis changes and use laser speckle imaging for hypertension blood flow monitoring. Our design hypothesis for the monitoring system is guided by the user-friendly, veteran-preferred "4-Non" principles (noninvasive, non-contact, non-tethered, non-stop-to-measure) and by the NIH's "4Ps" initiatives (predictive, personalized, preemptive, and participatory). We augment the potential storage system with the recent know-how of video Compressive Sampling (CSp) from surveillance cameras. In CSp only major changes are saved, which reduces the manpower cost of caretakers and medical analysts. This CSp algorithm is based on smart associative memory (AM) matrix storage: change features and detailed scenes are written by the outer-product and read by the inner product without the usual Harsh index for image searching. From this approach, we attempt to design an effective household monitoring approach to save healthcare costs and maintain the quality of life of seniors.

  17. Los derechos de los niños en la experiencia jurídica romana

    Directory of Open Access Journals (Sweden)

    Sebastiano Tafaro

    2009-12-01

    Full Text Available El presente estudio, si bien parte de la premisa de que ciertamente en el derecho romano no existió un elenco de los “derechos de los niños” tal como se encuentra hoy previsto en los diferentes tratados y convenciones internacionales, busca demostrar que los valores que fundamentan tales derechos sí se encontraban, en cambio, presentes en la experiencia jurídica romana, lo que permitía hablar, ya para la época, de un “derecho de nacer” del concebido, cuya tutela se confiaba en forma concurrente a los patres y a la civitas; de un “derecho a la paternidad” o derecho de ser acogido en la familia; de un “derecho al nombre”, con el cual el niño se identificaba en la colectividad y entraba oficialmente en la familia; de un “derecho a la crianza”, esto es, a ser alimentado y criado; además de otras disposiciones dirigidas a la protección jurídica de los niños, tales como la prohibición del trabajo forzado y la prohibición relativa a las convenciones sobre prestaciones laborales, así como el derecho del impúber a ser asistido y protegido por un tutor; sin que pueda perderse de vista, claro está, que tales “derechos” no pueden ser valorados con base en nuestros esquemas, sino de acuerdo con la realidad jurídica de la experiencia romana, que se caracterizó por un sistema abierto de fuentes y que daría vida a principios de indiscutible civilidad jurídica correspondientes a la visión de una sociedad basada en las interacciones entre los derechos del individuo y las formaciones sociales (la primera entre todas, la familia.

  18. Double-hairpin molecular-beacon-based amplification detection for gene diagnosis linked to cancer.

    Science.gov (United States)

    Xu, Huo; Zhang, Rongbo; Li, Feng; Zhou, Yingying; Peng, Ting; Wang, Xuedong; Shen, Zhifa

    2016-09-01

    A powerful double-hairpin molecular beacon (DHMB) was developed for cancer-related KRAS gene detection based on the one-to-two stoichiometry. During target DNA detection, DHMB can execute signal transduction even if no any exogenous element is involved. Unlike the conventional molecular beacon based on the one-to-one interaction, one target DNA not only hybridizes with one DHMB and opens its hairpin but also promotes the interaction between two DHMBs, causing the separation of two fluorophores from quenchers. This leads to an enhanced fluorescence signal. As a result, the target KRAS gene is able to be detected within a wide dynamic range from 0.05 to 200 nM with the detection limit of 50 pM, indicating a dramatic improvement compared with traditional molecular beacons. Moreover, the point mutations existing in target DNAs can be easily screened. The potential application for target species in real samples was indicated by the analysis of PCR amplicons of DNAs from the DNA extracted from SW620 cell. Besides becoming a promising candidate probe for molecular biology research and clinical diagnosis of genetic diseases, the DHMB is expected to provide a significant insight into the design of DNA probe-based homogenous sensing systems. Graphical Abstract A powerful double-hairpin molecular beacon (DHMB) was developed for cancer-related gene KRAS detection based on the one-to-two stoichiometry. Without the help of any exogenous probe, the point mutation is easily screened, and the target DNA can be quantified down to 50 pM, indicating a dramatic improvement compared with traditional molecular beacons.

  19. Double-hairpin molecular-beacon-based amplification detection for gene diagnosis linked to cancer.

    Science.gov (United States)

    Xu, Huo; Zhang, Rongbo; Li, Feng; Zhou, Yingying; Peng, Ting; Wang, Xuedong; Shen, Zhifa

    2016-09-01

    A powerful double-hairpin molecular beacon (DHMB) was developed for cancer-related KRAS gene detection based on the one-to-two stoichiometry. During target DNA detection, DHMB can execute signal transduction even if no any exogenous element is involved. Unlike the conventional molecular beacon based on the one-to-one interaction, one target DNA not only hybridizes with one DHMB and opens its hairpin but also promotes the interaction between two DHMBs, causing the separation of two fluorophores from quenchers. This leads to an enhanced fluorescence signal. As a result, the target KRAS gene is able to be detected within a wide dynamic range from 0.05 to 200 nM with the detection limit of 50 pM, indicating a dramatic improvement compared with traditional molecular beacons. Moreover, the point mutations existing in target DNAs can be easily screened. The potential application for target species in real samples was indicated by the analysis of PCR amplicons of DNAs from the DNA extracted from SW620 cell. Besides becoming a promising candidate probe for molecular biology research and clinical diagnosis of genetic diseases, the DHMB is expected to provide a significant insight into the design of DNA probe-based homogenous sensing systems. Graphical Abstract A powerful double-hairpin molecular beacon (DHMB) was developed for cancer-related gene KRAS detection based on the one-to-two stoichiometry. Without the help of any exogenous probe, the point mutation is easily screened, and the target DNA can be quantified down to 50 pM, indicating a dramatic improvement compared with traditional molecular beacons. PMID:27422649

  20. Photo- and electro-chromism of diarylethene modified ITO electrodes - towards molecular based read-write-erase information storage

    NARCIS (Netherlands)

    Areephong, J.; Browne, W.R.; Katsonis, N.; Feringa, B.L.

    2006-01-01

    Molecular memory devices based on dithienylethene switch modified ITO electrodes undergo reversible ring opening/closing both photo- and electro-chemically with non-destructive electrochemical readout.

  1. Accelerated electronic structure-based molecular dynamics simulations of shock-induced chemistry

    Science.gov (United States)

    Cawkwell, Marc

    2015-06-01

    The initiation and progression of shock-induced chemistry in organic materials at moderate temperatures and pressures are slow on the time scales available to regular molecular dynamics simulations. Accessing the requisite time scales is particularly challenging if the interatomic bonding is modeled using accurate yet expensive methods based explicitly on electronic structure. We have combined fast, energy conserving extended Lagrangian Born-Oppenheimer molecular dynamics with the parallel replica accelerated molecular dynamics formalism to study the relatively sluggish shock-induced chemistry of benzene around 13-20 GPa. We model interatomic bonding in hydrocarbons using self-consistent tight binding theory with an accurate and transferable parameterization. Shock compression and its associated transient, non-equilibrium effects are captured explicitly by combining the universal liquid Hugoniot with a simple shrinking-cell boundary condition. A number of novel methods for improving the performance of reactive electronic structure-based molecular dynamics by adapting the self-consistent field procedure on-the-fly will also be discussed. The use of accelerated molecular dynamics has enabled us to follow the initial stages of the nucleation and growth of carbon clusters in benzene under thermodynamic conditions pertinent to experiments.

  2. Well-Defined Polyethylene-Based Random, Block, and Bilayered Molecular Cobrushes

    KAUST Repository

    Zhang, Hefeng

    2015-06-09

    Novel well-defined polyethylene-based random, block, and bilayered molecular cobrushes were synthesized through the macromonomer strategy. Two steps were involved in this approach: (i) synthesis of norbornyl-terminated macromonomers of polyethylene (PE), polycaprolactone (PCL), poly(ethylene oxide) (PEO), and polystyrene (PS), as well as polyethylene-b-polycaprolactone (PE-b-PCL), by esterification of the hydroxyl-terminated precursors (PE, PCL, PEO, PS, and PE-b-PCL) with 5-norbornene-2-carboxylic acid and (ii) ring-opening metathesis (co)polymerization of the resulting macromonomers to afford the PE-based molecular cobrushes. The PE-macromonomers were synthesized by polyhomologation of dimethylsulfoxonium methylide, while the others by anionic polymerization. Proton nuclear magnetic resonance spectroscopy (1H NMR) and high-temperature gel permeation chromatography (HT-GPC) were used to imprint the molecular characteristics of all macromonomers and molecular brushes and differential scanning calorimetry (DSC) for the thermal properties. The bilayered molecular cobrushes of P(PE-b-PCL) adopt a wormlike morphology on silica wafer as visualized by atomic force microscopy (AFM). © 2015 American Chemical Society.

  3. Fragment-Based Electronic Structure Approach for Computing Nuclear Magnetic Resonance Chemical Shifts in Molecular Crystals.

    Science.gov (United States)

    Hartman, Joshua D; Beran, Gregory J O

    2014-11-11

    First-principles chemical shielding tensor predictions play a critical role in studying molecular crystal structures using nuclear magnetic resonance. Fragment-based electronic structure methods have dramatically improved the ability to model molecular crystal structures and energetics using high-level electronic structure methods. Here, a many-body expansion fragment approach is applied to the calculation of chemical shielding tensors in molecular crystals. First, the impact of truncating the many-body expansion at different orders and the role of electrostatic embedding are examined on a series of molecular clusters extracted from molecular crystals. Second, the ability of these techniques to assign three polymorphic forms of the drug sulfanilamide to the corresponding experimental (13)C spectra is assessed. This challenging example requires discriminating among spectra whose (13)C chemical shifts differ by only a few parts per million (ppm) across the different polymorphs. Fragment-based PBE0/6-311+G(2d,p) level chemical shielding predictions correctly assign these three polymorphs and reproduce the sulfanilamide experimental (13)C chemical shifts with 1 ppm accuracy. The results demonstrate that fragment approaches are competitive with the widely used gauge-invariant projector augmented wave (GIPAW) periodic density functional theory calculations. PMID:26584373

  4. AMPHIDINIUM REVISITED. I. REDEFINITION OF AMPHIDINIUM (DINOPHYCEAE) BASED ON CLADISTIC AND MOLECULAR PHYLOGENETIC ANALYSES

    DEFF Research Database (Denmark)

    Jørgensen, Mårten Flø; Murray, Shauna; Daugbjerg, Niels

    2004-01-01

    , and origin of the sulcus. The description of A. elegans by Grell and Wohlfarth-Bottermann was found to be identical to it. A species fitting the original description of A. operculatum was cultured and included in the analyses. Based on cladistic and molecular analyses, it grouped together with all other...

  5. Molecular Docking of Enzyme Inhibitors: A Computational Tool for Structure-Based Drug Design

    Science.gov (United States)

    Rudnitskaya, Aleksandra; Torok, Bela; Torok, Marianna

    2010-01-01

    Molecular docking is a frequently used method in structure-based rational drug design. It is used for evaluating the complex formation of small ligands with large biomolecules, predicting the strength of the bonding forces and finding the best geometrical arrangements. The major goal of this advanced undergraduate biochemistry laboratory exercise…

  6. Refinement of homology-based protein structures by molecular dynamics simulation techniques

    NARCIS (Netherlands)

    Fan, H; Mark, AE

    2004-01-01

    The use of classical molecular dynamics simulations, performed in explicit water, for the refinement of structural models of proteins generated ab initio or based on homology has been investigated. The study involved a test set of 15 proteins that were previously used by Baker and coworkers to asses

  7. Designing and Implementing a Hands-On, Inquiry-Based Molecular Biology Course

    Science.gov (United States)

    Regassa, Laura B.; Morrison-Shetlar, Alison I.

    2007-01-01

    Inquiry-based learning was used to enhance an undergraduate molecular biology course at Georgia Southern University, a primarily undergraduate institution in rural southeast Georgia. The goal was to use a long-term, in-class project to accelerate higher-order thinking, thereby enabling students to problem solve and apply their knowledge to novel…

  8. PyRosetta: a script-based interface for implementing molecular modeling algorithms using Rosetta

    OpenAIRE

    Chaudhury, Sidhartha; Lyskov, Sergey; Gray, Jeffrey J.

    2010-01-01

    Summary: PyRosetta is a stand-alone Python-based implementation of the Rosetta molecular modeling package that allows users to write custom structure prediction and design algorithms using the major Rosetta sampling and scoring functions. PyRosetta contains Python bindings to libraries that define Rosetta functions including those for accessing and manipulating protein structure, calculating energies and running Monte Carlo-based simulations. PyRosetta can be used in two ways: (i) interactive...

  9. Towards a logic-based method to infer provenance-aware molecular networks

    OpenAIRE

    Aslaoui-Errafi, Zahira; Cohen-Boulakia, Sarah; Froidevaux, Christine; Gloaguen, Pauline; Poupon, Anne; Rougny, Adrien; Yahiaoui, Meriem

    2012-01-01

    International audience Providing techniques to automatically infer molecular networks is particularly important to understand complex relationships between biological objects. We present a logic-based method to infer such networks and show how it allows inferring signalling networks from the design of a knowledge base. Provenance of inferred data has been carefully collected, allowing quality evaluation. More precisely, our method (i) takes into account various kinds of biological experime...

  10. Anthraquinone-based demultiplexer and other multiple operations at the molecular level

    Indian Academy of Sciences (India)

    Navneet Kaur; Subodh Kumar

    2014-01-01

    Anthraquinone-based chemosensor L with pyridine units as additional functional groups has been found to show pH-dependent multiple coordinationmodes towards differentmetal ions (Co2+, Ni2+ and Cu2+). Based on these different absorption changes, this differential colorimetric chemosensor L has found promising applications as a multiple-mode molecular logic system, i.e., OR, three - input NOR, three - input INHIBIT, TRANSFER and 1:2 DEMUX.

  11. Benchmarking ab initio binding energies of hydrogen-bonded molecular clusters based on FTIR spectroscopy

    DEFF Research Database (Denmark)

    Bork, Nicolai Christian; Du, Lin; Reiman, Heidi;

    2014-01-01

    Gibbs free binding energies in molecular complexes and clusters based on gas phase FTIR spectroscopy. The acetonitrile-HCl molecular complex is identified via its redshifted H-Cl stretching vibrational mode. We determine the Gibbs free binding energy, ΔG°295 K, to between 4.8 and 7.9 kJ mol(-1) and......Models of formation and growth of atmospheric aerosols are highly dependent on accurate cluster binding energies. These are most often calculated by ab initio electronic structure methods but remain associated with significant uncertainties. We present a computational benchmarking study of the...

  12. Nonadiabatic molecular dynamics simulation: An approach based on quantum measurement picture

    CERN Document Server

    Feng, Wei; Li, Xin-Qi; Fang, Weihai; Yan, YiJing

    2013-01-01

    Mixed-quantum-classical molecular dynamics simulation implies an effective measurement on the electronic states owing to continuously tracking the atomic forces.Based on this insight, we propose a quantum trajectory mean-field approach for nonadiabatic molecular dynamics simulations. The new protocol provides a natural interface between the separate quantum and classical treatments, without invoking artificial surface hopping algorithm. Moreover, it also bridges two widely adopted nonadiabatic dynamics methods, the Ehrenfest mean-field theory and the trajectory surface-hopping method. Excellent agreement with the exact results is illustrated with representative model systems, including the challenging ones for traditional methods.

  13. Nonadiabatic molecular dynamics simulation: An approach based on quantum measurement picture

    Directory of Open Access Journals (Sweden)

    Wei Feng

    2014-07-01

    Full Text Available Mixed-quantum-classical molecular dynamics simulation implies an effective quantum measurement on the electronic states by the classical motion of atoms. Based on this insight, we propose a quantum trajectory mean-field approach for nonadiabatic molecular dynamics simulations. The new protocol provides a natural interface between the separate quantum and classical treatments, without invoking artificial surface hopping algorithm. Moreover, it also bridges two widely adopted nonadiabatic dynamics methods, the Ehrenfest mean-field theory and the trajectory surface-hopping method. Excellent agreement with the exact results is illustrated with representative model systems, including the challenging ones for traditional methods.

  14. A density functional theory-based chemical potential equalisation approach to molecular polarizability

    Indian Academy of Sciences (India)

    Amita Wadehra; Swapan K Ghosh

    2005-09-01

    The electron density changes in molecular systems in the presence of external electric fields are modeled for simplicity in terms of the induced charges and dipole moments at the individual atomic sites. A chemical potential equalisation scheme is proposed for the calculation of these quantities and hence the dipole polarizability within the framework of density functional theory based linear response theory. The resulting polarizability is expressed in terms of the contributions from individual atoms in the molecule. A few illustrative numerical calculations are shown to predict the molecular polarizabilities in good agreement with available results. The usefulness of the approach to the calculation of intermolecular interaction needed for computer simulation is highlighted.

  15. Optical materials based on molecular nano/microcrystals and ultrathin films

    Indian Academy of Sciences (India)

    A Patra; K Rajesh; T P Radhakrishnan

    2008-06-01

    Methodologies that we developed recently for the fabrication of molecular crystals with size variation in the nano to micro regime and polyelectrolyte templated mono and multilayer Langmuir–Blodgett films, are reviewed. The electronic absorption and strong fluorescence in the molecular nano/microcrystals are found to be size-dependent. Crystal structure and computational investigations provide a unified model to explain these observations. Role of polyelectrolyte templating in achieving stable and enhanced optical second harmonic generation response from LB films based on a hemicyanine amphiphile is highlighted.

  16. Ab initio based force field and molecular dynamics simulations of crystalline TATB.

    Science.gov (United States)

    Gee, Richard H; Roszak, Szczepan; Balasubramanian, Krishnan; Fried, Laurence E

    2004-04-15

    An all-atom force field for 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is presented. The classical intermolecular interaction potential for TATB is based on single-point energies determined from high-level ab initio calculations of TATB dimers. The newly developed potential function is used to examine bulk crystalline TATB via molecular dynamics simulations. The isobaric thermal expansion and isothermal compression under hydrostatic pressures obtained from the molecular dynamics simulations are in good agreement with experiment. The calculated volume-temperature expansion is almost one dimensional along the c crystallographic axis, whereas under compression, all three unit cell axes participate, albeit unequally. PMID:15267608

  17. Isatin based thiosemicarbazone derivatives as potential bioactive agents: Anti-oxidant and molecular docking studies

    Science.gov (United States)

    Haribabu, J.; Subhashree, G. R.; Saranya, S.; Gomathi, K.; Karvembu, R.; Gayathri, D.

    2016-04-01

    A new series of isatin based thiosemicarbazones has been synthesized from benzylisatin and unsubstituted/substituted thiosemicarbazides (1-5). The synthesized compounds were characterized by elemental analyses, and UV-Visible, FT-IR, 1H &13C NMR and mass spectroscopic techniques. Three dimensional molecular structure of three compounds (1, 3 and 4) was determined by single crystal X-ray crystallography. Anti-oxidant activity of the thiosemicarbazone derivatives showed their excellent scavenging effect against free radicals. In addition, all the compounds showed good anti-haemolytic activity. In silico molecular docking studies were performed to screen the anti-inflammatory and anti-tuberculosis properties of thiosemicarbazone derivatives.

  18. Toward molecular trait-based ecology through integration of biogeochemical, geographical and metagenomic data

    DEFF Research Database (Denmark)

    Raes, Jeroen; Letunic, Ivica; Yamada, Takuji;

    2011-01-01

    Using metagenomic 'parts lists' to infer global patterns on microbial ecology remains a significant challenge. To deduce important ecological indicators such as environmental adaptation, molecular trait dispersal, diversity variation and primary production from the gene pool of an ecosystem, we...... integrated 25 ocean metagenomes with geographical, meteorological and geophysicochemical data. We find that climatic factors (temperature, sunlight) are the major determinants of the biomolecular repertoire of each sample and the main limiting factor on functional trait dispersal (absence of biogeographic...... composition derived from metagenomes is an important quantitative readout for molecular trait-based biogeography and ecology....

  19. La experiencia de mediación familiar en Chile

    Directory of Open Access Journals (Sweden)

    Paula Correa Camus

    2014-08-01

    Full Text Available La incorporación de la mediación familiar como un trámite previo y obligatorio al proceso judicial ha generado una amplia discusión en la doctrina y en los operadores del sistema. Uno de los debates más interesantes es aquel que pretende determinar los efectos de la obligatoriedad tanto en los procesos mismos de mediación como en sus resultados. El objetivo de este trabajo es examinar las ventajas y desventajas que traen aparejadas las políticas públicas que incluyen la participación obligatoria en mediación y, en ese contexto, analizar la experiencia chilena en mediación familiar.

  20. EXPERIENCIAS INTERNACIONALES EN MATERIA DE RESPONSABILIDAD SOCIAL UNIVERSITARIA

    Directory of Open Access Journals (Sweden)

    Jiménez Quintero, José Antonio

    2013-01-01

    Full Text Available Este trabajo analiza la relevancia que presenta, en el ámbito internacional, la Responsabilidad Social en las instituciones de educación superior (RSU. Se ha expuesto, después de introducir y delimitar el tema objeto de estudio, un conjunto de experiencias en el contexto referido. Entre ellas, se ha prestado especial atención al Assessment Instrument for Sustainability in Higher Education (Proyecto AISHE, aunque la totalidad de iniciativas presentadas contribuyen a reforzar la incorporación de la Responsabilidad Social en los sistemas de gestión y en las políticas de las universidades y el resto de instituciones de educación superior, poniendo de manifiesto el papel, fundamental y necesario, que desempeña en el avance de las sociedades.

  1. Apuntes sobre historia empresarial: Relatos de algunas experiencias

    Directory of Open Access Journals (Sweden)

    Elber Berdugo Cotera

    2003-10-01

    Full Text Available El presente articulo tiene como objetivo mostrar la importancia de la Historia Empresarial y la constitución de una línea de investigación para el entendimiento de la historia del país y la comprensión de las principales características de nuestros empresarios tanto en el ámbito regional como en el nacional. Se trata igualmente, de dar cuenta de los aspectos teóricos y metodológicos utilizados en la investigación sobre el estudio de caso de Servientrega y sus gestores, lo mismo que de los principales hallazgos encontrados en ella. Por último, señalar cómo ésta clase de experiencias pueden resultar enriquecedoras para aquellas personas que ejercen una función educativa empresarial o pretenden asumir como proyecto personal y familiar de vida ser empresarios.

  2. Aprendizaje con robótica, algunas experiencias

    OpenAIRE

    Pedro Antonio López Ramírez; Hugo Andrade Sosa

    2013-01-01

    Este artículo presenta el análisis de experiencias, revisadas en diversos artículos, acerca de la implementación de la robótica en la educación, con el fin de obtener referentes pertinentes para la construcción de una propuesta para el aprendizaje de la robótica en la educación básica secundaria y media. Se consideran dos ámbitos de aplicación de la robótica en la educación: el primero es el aprendizaje de la robótica mediante la conceptualización de cada uno de los subsistemas de un robot pa...

  3. Experiencias institucionales exitosas en educación a distancia

    Directory of Open Access Journals (Sweden)

    Patricia Camarena Gallardo

    2012-10-01

    Full Text Available El artículo presenta resultados preliminares del proyecto "Calidad, evaluación y acreditación de la educación mediada por las tecnologías de la información y la comunicación (TIC", en particular el análisis realizado con trece expertos en educación a distancia, quienes compartieron las experiencias exitosas de los programas académicos en los cuales habían participado. El contenido del documento resultará de interés para diferentes actores de la educación a distancia, entre ellos gestores, diseñadores y profesores, en virtud de que proporciona conocimiento relevante sobre dicha modalidad educativa.

  4. MOVILIDAD SUSTENTABLE EN CHILE: OPORTUNIDADES, EXPERIENCIAS LOCALES Y REFERENCIAS GLOBALES

    Directory of Open Access Journals (Sweden)

    Jorge Díaz Tejeda

    2012-01-01

    Full Text Available Este artículo propone Premisas Conceptuales, Premisas Metodológicas y el desarrollo de Aspectos Estratégicos para la implementación de soluciones a la Movilidad Urbana. Se inspira en las ideas, experiencias e investigaciones de diversas personas quienes abordan desde lógicas puntuales aspectos temáticos específicos en el marco de la Planificación Urbana en general y de las aplicaciones en Transporte en particular. Chile atraviesa por una oportunidad histórica, quizás paradójicamente, a partir de un evento de catástrofe ocurrido en Febrero del 2010; esta oportunidad es la de re-plantear el proceso de Planificación Urbana bajo los alcances del Desarrollo Sustentable.

  5. The meanings of quality of life: interpretative analysis based on experiences of people in burns rehabilitation Significados para la calidad de vida: análisis interpretativo fundamentado en la experiencia de personas quemadas em rehabilitación Significados de qualidade de vida: análise interpretativa baseada na experiência de pessoas em reabilitação de queimaduras

    Directory of Open Access Journals (Sweden)

    Maria Cristina Silva Costa

    2008-04-01

    Full Text Available This research aimed to interpret the meanings of quality of life, taking into consideration the meanings attributed by those who have undergone serious burns, their experiences and social/cultural background. We used the ethnographic method based on modern hermeneutics. Nineteen patients with burn sequelae, already discharged from the Burns Unit of the Ribeirão Preto Medical School Clinical Hospital participated in this study, along with their relatives. Participants belong to the working class, are between 18 to 50 years old and have been in rehabilitation for at least a year. Data were collected by direct observation and semi-structured interviews. The analysis was processed through the identification of units of meanings and construction of thematic nucleuses. Patients and relatives reported that quality of life had changed because of physical and psychological limitations caused by the burns. The meanings of quality of life are associated with the performance of social roles and are guided by family, work, normality, autonomy and social integration.Con el objetivo de interpretar los significados para la calidad de vida, este estudio parte de la atribución dada por personas que sufrieron quemaduras graves, sus experiencias y su contexto sociocultural. El método etnográfico fue utilizado apoyado en la teoría hermenéutica moderna. Participaron del estudio 19 pacientes con secuelas de quemadura y sus familiares, atendidos en la Unidad de Quemados del Hospital de Clínicas de la Facultad de Medicina de Ribeirão Preto. Los sujetos pertenecían al sector popular, con edades entre 18 y 50 años, participantes del programa de rehabilitación por lo menos un año. Los datos recolectados a través de entrevistas semi-estructuradas y observación directa; siendo su análisis realizado a través de la identificación de unidades de significados y construcción de núcleos temáticos. Los pacientes y sus familiares mencionaron cambios en su calidad

  6. Gold-based hybrid nanomaterials for biosensing and molecular diagnostic applications.

    Science.gov (United States)

    Kim, Jung Eun; Choi, Ji Hye; Colas, Marion; Kim, Dong Ha; Lee, Hyukjin

    2016-06-15

    The properties of gold nanomaterials are particularly of interest to many researchers, since they show unique physiochemical properties such as optical adsorption of specific wavelength of light, high electrical conductance with rich surface electrons, and facile surface modification with sulfhydryl groups. These properties have facilitated the use of gold nanomaterials in the development of various hybrid systems for biosensors and molecular diagnostics. Combined with various synthetic materials such as fluorescence dyes, polymers, oligonucleotides, graphene oxides (GO), and quantum dots (QDs), the gold-based hybrid nanomaterials offer multi-functionalities in molecular detection with high specificity and sensitivity. These two aspects result in the increase of detection speed as well as the lower detection limits, having shown that this diagnosis method is more effective than other conventional ones. In this review, we have highlighted various examples of nanomaterials for biosensing and molecular diagnostics. The gold-based hybrid systems are categorized by three distinct detection approaches, in which include (1) optical, such as surface plasmon resonance (SPR), RAMAN, and surface-enhanced Raman scattering (SERS), (2) fluorescence, such as förster resonance energy transfer (FRET) and nanomaterial surface energy transfer (NSET), and (3) electrochemical, such as potentiometic, amperometric, and conductometric. Each example provides the detailed mechanism of molecular detection as well as the supporting experimental result with the limit of detection (LOD). Lastly, future perspective on novel development of gold-based hybrid nanomaterials is discussed as well as their challenges. PMID:26894985

  7. Asesoramiento en la universidad. Poniendo a trabajar la experiencia

    Directory of Open Access Journals (Sweden)

    Marita Sánchez Moreno

    2008-01-01

    Full Text Available La Universidad española se encuentra en un momento crítico y decisivo. Los retos y desafíos que afrontará en estos próximos años relacionados con la Convergencia Europea van a suponer necesariamente cambios conceptuales y estructurales importantes. Uno de los pilares fundamentales que sustenta este proceso de cambio radica en tomar conciencia de la importancia que supone prestar atención a los procesos de formación de los docentes universitarios, una actividad que tradicionalmente se ha relegado en nuestra universidad. Este artículo argumenta la conveniencia de incorporar procesos de asesoramiento en el contexto universitario de manera sistemática e institucionalizada, como herramienta para la formación de los docentes en este modelo nuevo de universidad, y en consecuencia, como ayuda hacia la mejora y al incremento de la calidad docente. Partimos de la idea de aprovechamiento de recursos humanos existentes en la propia Universidad. Por eso, planteamos la pertinencia de recuperar la experiencia de profesores veteranos en la institución para la puesta en marcha de estos procesos de asesoramiento universitarios, ya que estos profesores conocen bien la cultura institucional y dominan el contenido curricular del área disciplinar. El artículo analiza la figura de estos profesores denominados mentores desde la comprensión de rol como tal, las características que les son atribuidas, la formación requerida para el desempeño de las funciones de asesoramiento, las actividades encomendadas y las dificultades detectadas en el ejercicio del rol. Este análisis queda ilustrado por la experiencia de asesoramiento desarrollada en la Universidad de Sevilla.

  8. Correlation of microarray-based breast cancer molecular subtypes and clinical outcomes: implications for treatment optimization

    International Nuclear Information System (INIS)

    Optimizing treatment through microarray-based molecular subtyping is a promising method to address the problem of heterogeneity in breast cancer; however, current application is restricted to prediction of distant recurrence risk. This study investigated whether breast cancer molecular subtyping according to its global intrinsic biology could be used for treatment customization. Gene expression profiling was conducted on fresh frozen breast cancer tissue collected from 327 patients in conjunction with thoroughly documented clinical data. A method of molecular subtyping based on 783 probe-sets was established and validated. Statistical analysis was performed to correlate molecular subtypes with survival outcome and adjuvant chemotherapy regimens. Heterogeneity of molecular subtypes within groups sharing the same distant recurrence risk predicted by genes of the Oncotype and MammaPrint predictors was studied. We identified six molecular subtypes of breast cancer demonstrating distinctive molecular and clinical characteristics. These six subtypes showed similarities and significant differences from the Perou-Sørlie intrinsic types. Subtype I breast cancer was in concordance with chemosensitive basal-like intrinsic type. Adjuvant chemotherapy of lower intensity with CMF yielded survival outcome similar to those of CAF in this subtype. Subtype IV breast cancer was positive for ER with a full-range expression of HER2, responding poorly to CMF; however, this subtype showed excellent survival when treated with CAF. Reduced expression of a gene associated with methotrexate sensitivity in subtype IV was the likely reason for poor response to methotrexate. All subtype V breast cancer was positive for ER and had excellent long-term survival with hormonal therapy alone following surgery and/or radiation therapy. Adjuvant chemotherapy did not provide any survival benefit in early stages of subtype V patients. Subtype V was consistent with a unique subset of luminal A intrinsic

  9. [Molecular biology of renal cancer: bases for genetic directed therapy in advanced disease].

    Science.gov (United States)

    Maroto Rey, José Pablo; Cillán Narvaez, Elena

    2013-06-01

    There has been expansion of therapeutic options in the management of metastatic renal cell carcinoma due to a better knowledge of the molecular biology of kidney cancers. There are different tumors grouped under the term renal cell carcinoma, being clear cell cancer the most frequent and accounting for 80% of kidney tumors. Mutations in the Von Hippel-Lindau gene can be identified in up to 80% of sporadic clear cell cancer, linking a genetically inheritable disease where vascular tumors are frequent, with renal cell cancer. Other histologic types present specific alterations in molecular pathways, like c-MET in papillary type I tumors, and Fumarase Hydratase in papillary type II tumors. Identification of the molecular alteration for a specific tumor may offer an opportunity for treatment selection based on biomarkers, and, in the future, for developing an engineering designed genetic treatment.

  10. Discovery of Anti-SARS Coronavirus Drug Based on Molecular Docking and Database Screening

    Institute of Scientific and Technical Information of China (English)

    CHEN,Hai-Feng(陈海峰); YAO,Jian-Hua(姚建华); SUN,Jing(孙晶); LI,Qiang(李强); LI,Feng(李丰); FAN,Bo-Tao(范波涛); YUAN,Shen-Gang(袁身刚)

    2004-01-01

    The active site of 3CL proteinase (3CLpro) for coronavirus was identified by comparing the crystal structures of human and porcine coronavirus. The inhibitor of the main protein of rhinovirus (Ag7088) could bind with 3CLpro of human coronavirus, then it was selected as the reference for molecular docking and database screening. The ligands from two databases were used to search potential lead structures with molecular docking. Several structures from natural products and ACD-SC databases were found to have lower binding free energy with 3CLpro than that of Ag7088. These structures have similar hydrophobicity to Ag7088. They have complementary electrostatic potential and hydrogen bond acceptor and donor with 3CLpro, showing that the strategy of anti-SARS drug design based on molecular docking and database screening is feasible.

  11. ARTICLES: Shear Thickening Fluids Based on Additives with Different Concentrations and Molecular Chain Lengths

    Science.gov (United States)

    Xu, Yu-lei; Gong, Xing-long; Peng, Chao; Sun, Ying-qiang; Jiang, Wan-quan; Zhang, Zhong

    2010-06-01

    Shear thickening fluids (STFs) based on additives with different concentrations and molecular chain lengths were investigated. STF samples were prepared with silica and additive dispersed in polyethylene glycol (PEG) 400, where three types of additives with different molecular chain lengths of PEG4000, PEG6000, and PEG10000 were used. For PEG10000, different concentrations, including 0, 1%, 3%, and 5%, were selected to study the influences of additive concentrations. Rheological properties of the samples were measured with a rheometer. The results show that the shear thickening effect was significantly enhanced with the increase of the concentration and the molecular chain length of additives. The mechanism of enhancement was quantitatively explained with the formation of large particles clusters.

  12. A Cucurbit[7]uril Based Molecular Shuttle Encoded by Visible Room-Temperature Phosphorescence.

    Science.gov (United States)

    Gong, Yifan; Chen, Hui; Ma, Xiang; Tian, He

    2016-06-17

    A visible room-temperature phosphorescence (RTP) signal, generated by complexation of cururbit[7]uril (CB[7]) and bromo-substituted isoquinoline in aqueous solution, is employed to address the shuttling of a pH-controlling molecular shuttle fabricated by CB[7] and a phosphor 6-bromoisoquinoline derivative IQC[5]. The CB[7] host shuttles along the axial guest under acidic conditions, accompanied by a weak RTP emission signal, while deprotonation of the guest IQC[5] makes the CB[7] wheel locate on the phosphor group, leading to intense RTP emission. The switching RTP emission of the molecular shuttle, via pH adjusting, can be visibly identified by the naked eye. This is the first CB-based molecular shuttle with an RTP signal as the output address of its shuttling and conformation. PMID:26548653

  13. An Electrically Driven and Readable Molecular Monolayer Switch Based on a Solid Electrolyte.

    Science.gov (United States)

    Marchante, Elena; Crivillers, Núria; Buhl, Moritz; Veciana, Jaume; Mas-Torrent, Marta

    2016-01-01

    The potential application of molecular switches as active elements in information storage has been demonstrated through numerous works. Importantly, such switching capabilities have also been reported for self-assembled monolayers (SAMs). SAMs of electroactive molecules have recently been exploited as electrochemical switches. Typically, the state of these switches could be read out through their optical and/or magnetic response. These output reading processes are difficult to integrate into devices, and furthermore, there is a need to use liquid environments for switching the redox-active molecular systems. In this work, both of these challenges were overcome by using an ionic gel as the electrolyte medium, which led to an unprecedented solid-state device based on a single molecular layer. Moreover, electrochemical impedance has been successfully exploited as the output of the system.

  14. Interference between concurrent resistance and endurance exercise: molecular bases and the role of individual training variables.

    Science.gov (United States)

    Fyfe, Jackson J; Bishop, David J; Stepto, Nigel K

    2014-06-01

    Concurrent training is defined as simultaneously incorporating both resistance and endurance exercise within a periodized training regime. Despite the potential additive benefits of combining these divergent exercise modes with regards to disease prevention and athletic performance, current evidence suggests that this approach may attenuate gains in muscle mass, strength, and power compared with undertaking resistance training alone. This has been variously described as the interference effect or concurrent training effect. In recent years, understanding of the molecular mechanisms mediating training adaptation in skeletal muscle has emerged and provided potential mechanistic insight into the concurrent training effect. Although it appears that various molecular signaling responses induced in skeletal muscle by endurance exercise can inhibit pathways regulating protein synthesis and stimulate protein breakdown, human studies to date have not observed such molecular 'interference' following acute concurrent exercise that might explain compromised muscle hypertrophy following concurrent training. However, given the multitude of potential concurrent training variables and the limitations of existing evidence, the potential roles of individual training variables in acute and chronic interference are not fully elucidated. The present review explores current evidence for the molecular basis of the specificity of training adaptation and the concurrent interference phenomenon. Additionally, insights provided by molecular and performance-based concurrent training studies regarding the role of individual training variables (i.e., within-session exercise order, between-mode recovery, endurance training volume, intensity, and modality) in the concurrent interference effect are discussed, along with the limitations of our current understanding of this complex paradigm.

  15. De novo design of caseinolytic protein proteases inhibitors based on pharmacophore and 2D molecular fingerprints.

    Science.gov (United States)

    Wu, Guanzhong; Zhang, Zhen; Chen, Hong; Lin, Kejiang

    2015-06-01

    Caseinolytic protein proteases (ClpP) are large oligomeric protein complexes that contribute to cell homeostasis as well as virulence regulation in bacteria. Inhibitors of ClpP can significantly attenuate the capability to produce virulence factors of the bacteria. In this work, we developed a workflow to expand the chemical space of potential ClpP inhibitors based on a set of β-lactones. In our workflow, an artificial pharmacophore model was generated based on HipHop and HYPOGEN method. A de novo compound library based on molecular fingerprints was constructed and virtually screened by the pharmacophore model. The results were further investigated by molecular docking study. The workflow successfully achieved potential ClpP inhibitors. It could be applied to design more novel potential ClpP inhibitors and provide theoretical basis for the further optimization of the hit compounds.

  16. Molecular design toward highly efficient photovoltaic polymers based on two-dimensional conjugated benzodithiophene.

    Science.gov (United States)

    Ye, Long; Zhang, Shaoqing; Huo, Lijun; Zhang, Maojie; Hou, Jianhui

    2014-05-20

    As researchers continue to develop new organic materials for solar cells, benzo[1,2-b:4,5-b']dithiophene (BDT)-based polymers have come to the fore. To improve the photovoltaic properties of BDT-based polymers, researchers have developed and applied various strategies leading to the successful molecular design of highly efficient photovoltaic polymers. Novel polymer materials composed of two-dimensional conjugated BDT (2D-conjugated BDT) have boosted the power conversion efficiency of polymer solar cells (PSCs) to levels that exceed 9%. In this Account, we summarize recent progress related to the design and synthesis of 2D-conjugated BDT-based polymers and discuss their applications in highly efficient photovoltaic devices. We introduce the basic considerations for the construction of 2D-conjugated BDT-based polymers and systematic molecular design guidelines. For example, simply modifying an alkoxyl-substituted BDT to form an alkylthienyl-substituted BDT can improve the polymer hole mobilities substantially with little effect on their molecular energy level. Secondly, the addition of a variety of chemical moieties to the polymer can produce a 2D-conjugated BDT unit with more functions. For example, the introduction of a conjugated side chain with electron deficient groups (such as para-alkyl-phenyl, meta-alkoxyl-phenyl, and 2-alkyl-3-fluoro-thienyl) allowed us to modulate the molecular energy levels of 2D-conjugated BDT-based polymers. Through the rational design of BDT analogues such as dithienobenzodithiophene (DTBDT) or the insertion of larger π bridges, we can tune the backbone conformations of these polymers and modulate their photovoltaic properties. We also discuss the influence of 2D-conjugated BDT on polymer morphology and the blends of these polymers with phenyl-C61 (or C71)-butyric acid methyl ester (PCBM). Finally, we summarize the various applications of the 2D-conjugated BDT-based polymers in highly efficient PSC devices. Overall, this Account

  17. Competency-Based Education for the Molecular Genetic Pathology Fellow: A Report of the Association for Molecular Pathology Training and Education Committee

    OpenAIRE

    Talbert, Michael L.; Dunn, S. Terence; Hunt, Jennifer; Hillyard, David R.; Mirza, Imran; Nowak, Jan A.; Van Deerlin, Vivianna; Vnencak-Jones, Cindy L.

    2009-01-01

    The following report represents guidelines for competency-based fellowship training in Molecular Genetic Pathology (MGP) developed by the Association for Molecular Pathology Training and Education Committee and Directors of MGP Programs in the United States. The goals of the effort were to describe each of the Accreditation Council for Graduate Medical Education competencies as they apply to MGP fellowship training, provide a summary of goals and objectives, and recommend assessment tools. Th...

  18. Aprender Disfrutando: una experiencia de ocio para adultos/mayores en la Universidad.

    Directory of Open Access Journals (Sweden)

    Yolanda Lázaro Fernández

    2009-01-01

    en la sociedad actual mostrando unas cifras que, sobre este colectivo, se manejan en el Estado Español, para continuar con una breve delimitación e historia de los programas universitarios de mayores. El artículo sigue avanzando sobre qué se entiende por experiencia de ocio, y los beneficios que ésta proporciona, para acabar reflexionando sobre si estos programas constituyen una experiencia de ocio para quienes los cursan.

  19. Molecular sexing of birds: A comparative review of polymerase chain reaction (PCR)-based methods.

    Science.gov (United States)

    Morinha, F; Cabral, J A; Bastos, E

    2012-09-01

    Accurate identification of sex in birds is important for the management and conservation of avian wildlife in several ways, namely in the development of population, behavioral and ecological studies, as well as in the improvement of ex situ captive breeding programs. In general, nestlings, juveniles and adult birds of a wide number of sexually monomorphic species cannot be sexed based on phenotypic traits. The development of molecular methodologies for avian sexing overcame these difficulties, allowing a reliable gender differentiation for these species. The polymerase chain reaction (PCR)-based methods have been widely applied in molecular sexing of birds, using a large diversity of sex-linked markers. During the last 15 yrs, there was a continuous improvement in the PCR-based protocols for bird sexing, increasing the accuracy, speed and high-throughput applicability of these techniques. The recent advances in real-time PCR platforms and whole genome analysis methods provided new resources for the detection and analysis of novel specific markers and protocols. This review presents a comparative guide of classical and recent advances in PCR-based methods for avian molecular sexing, highlighting its strengths and limitations. Future research opportunities in this field are also addressed.

  20. Molecular-based tumour subtypes of canine mammary carcinomas assessed by immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Sarli Giuseppe

    2010-01-01

    Full Text Available Abstract Background Human breast cancer is classified by gene expression profile into subtypes consisting of two hormone (oestrogen and/or progesterone receptor-positive types (luminal-like A and luminal-like B and three hormone receptor-negative types [human epidermal growth factor receptor 2-expressing, basal-like, and unclassified ("normal-like"]. Immunohistochemical surrogate panels are also proposed to potentially identify the molecular-based groups. The present study aimed to apply an immunohistochemical panel (anti-ER, -PR, -ERB-B2, -CK 5/6 and -CK14 in a series of canine malignant mammary tumours to verify the molecular-based classification, its correlation with invasion and grade, and its use as a prognostic aid in veterinary practice. Results Thirty-five tumours with luminal pattern (ER+ and PR+ were subgrouped into 13 A type and 22 B type, if ERB-B2 positive or negative. Most luminal-like A and basal-like tumours were grade 1 carcinomas, while the percentage of luminal B tumours was higher in grades 2 and 3 (Pearson Chi-square P = 0.009. No difference in the percentage of molecular subtypes was found between simple and complex/mixed carcinomas (Pearson Chi-square P = 0.47. No significant results were obtained by survival analysis, even if basal-like tumours had a more favourable prognosis than luminal-like lesions. Conclusion The panel of antibodies identified only three tumour groups (luminal-like A and B, and basal-like in the dog. Even though canine mammary tumours may be a model of human breast cancer, the existence of the same carcinoma molecular subtypes in women awaits confirmation. Canine mammary carcinomas show high molecular heterogeneity, which would benefit from a classification based on molecular differences. Stage and grade showed independent associations with survival in the multivariate regression, while molecular subtype grouping and histological type did not show associations. This suggests that caution should be

  1. Charge transport and rectification in molecular junctions formed with carbon-based electrodes.

    Science.gov (United States)

    Kim, Taekyeong; Liu, Zhen-Fei; Lee, Chulho; Neaton, Jeffrey B; Venkataraman, Latha

    2014-07-29

    Molecular junctions formed using the scanning-tunneling-microscope-based break-junction technique (STM-BJ) have provided unique insight into charge transport at the nanoscale. In most prior work, the same metal, typically Au, Pt, or Ag, is used for both tip and substrate. For such noble metal electrodes, the density of electronic states is approximately constant within a narrow energy window relevant to charge transport. Here, we form molecular junctions using the STM-BJ technique, with an Au metal tip and a microfabricated graphite substrate, and measure the conductance of a series of graphite/amine-terminated oligophenyl/Au molecular junctions. The remarkable mechanical strength of graphite and the single-crystal properties of our substrates allow measurements over few thousand junctions without any change in the surface properties. We show that conductance decays exponentially with molecular backbone length with a decay constant that is essentially the same as that for measurements with two Au electrodes. More importantly, despite the inherent symmetry of the oligophenylamines, we observe rectification in these junctions. State-of-art ab initio conductance calculations are in good agreement with experiment, and explain the rectification. We show that the highly energy-dependent graphite density of states contributes variations in transmission that, when coupled with an asymmetric voltage drop across the junction, leads to the observed rectification. Together, our measurements and calculations show how functionality may emerge from hybrid molecular-scale devices purposefully designed with different electrodes beyond the so-called "wide band limit," opening up the possibility of assembling molecular junctions with dissimilar electrodes using layered 2D materials.

  2. [Molecular genetic bases of adaptation processes and approaches to their analysis].

    Science.gov (United States)

    Salmenkova, E A

    2013-01-01

    Great interest in studying the molecular genetic bases of the adaptation processes is explained by their importance in understanding evolutionary changes, in the development ofintraspecific and interspecific genetic diversity, and in the creation of approaches and programs for maintaining and restoring the population. The article examines the sources and conditions for generating adaptive genetic variability and contribution of neutral and adaptive genetic variability to the population structure of the species; methods for identifying the adaptive genetic variability on the genome level are also described. Considerable attention is paid to the potential of new technologies of genome analysis, including next-generation sequencing and some accompanying methods. In conclusion, the important role of the joint use of genomics and proteomics approaches in understanding the molecular genetic bases of adaptation is emphasized.

  3. Sputum-Based Molecular Biomarkers for the Early Detection of Lung Cancer: Limitations and Promise

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Connie E. [Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine. 462 First Avenue, NBV 7N24, New York, NY 10016 (United States); Tchou-Wong, Kam-Meng; Rom, William N., E-mail: william.rom@nyumc.org [Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine. 462 First Avenue, NBV 7N24, New York, NY 10016 (United States); Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987 (United States)

    2011-07-19

    Lung cancer is the leading cause of cancer deaths, with an overall survival of 15% at five years. Biomarkers that can sensitively and specifically detect lung cancer at early stage are crucial for improving this poor survival rate. Sputum has been the target for the discovery of non-invasive biomarkers for lung cancer because it contains airway epithelial cells, and molecular alterations identified in sputum are most likely to reflect tumor-associated changes or field cancerization caused by smoking in the lung. Sputum-based molecular biomarkers include morphology, allelic imbalance, promoter hypermethylation, gene mutations and, recently, differential miRNA expression. To improve the sensitivity and reproducibility of sputum-based biomarkers, we recommend standardization of processing protocols, bronchial epithelial cell enrichment, and identification of field cancerization biomarkers.

  4. A chemically powered unidirectional rotary molecular motor based on a palladium redox cycle

    Science.gov (United States)

    Collins, Beatrice S. L.; Kistemaker, Jos C. M.; Otten, Edwin; Feringa, Ben L.

    2016-09-01

    The conversion of chemical energy to drive directional motion at the molecular level allows biological systems, ranging from subcellular components to whole organisms, to perform a myriad of dynamic functions and respond to changes in the environment. Directional movement has been demonstrated in artificial molecular systems, but the fundamental motif of unidirectional rotary motion along a single-bond rotary axle induced by metal-catalysed transformation of chemical fuels has not been realized, and the challenge is to couple the metal-centred redox processes to stepwise changes in conformation to arrive at a full unidirectional rotary cycle. Here, we present the design of an organopalladium-based motor and the experimental demonstration of a 360° unidirectional rotary cycle using simple chemical fuels. Exploiting fundamental reactivity principles in organometallic chemistry enables control of directional rotation and offers the potential of harnessing the wealth of opportunities offered by transition-metal-based catalytic conversions to drive motion and dynamic functions.

  5. Efficient electronic coupling and improved stability with dithiocarbamate-based molecular junctions

    Science.gov (United States)

    von Wrochem, Florian; Gao, Deqing; Scholz, Frank; Nothofer, Heinz-Georg; Nelles, Gabriele; Wessels, Jurina M.

    2010-08-01

    Molecular electronic devices require stable and highly conductive contacts between the metal electrodes and molecules. Thiols and amines are widely used to attach molecules to metals, but they form poor electrical contacts and lack the robustness required for device applications. Here, we demonstrate that dithiocarbamates provide superior electrical contact and thermal stability when compared to thiols on metals. Ultraviolet photoelectron spectroscopy and density functional theory show the presence of electronic states at 0.6 eV below the Fermi level of Au, which effectively reduce the charge injection barrier across the metal-molecule interface. Charge transport measurements across oligophenylene monolayers reveal that the conductance of terphenyl-dithiocarbamate junctions is two orders of magnitude higher than that of terphenyl-thiolate junctions. The stability and low contact resistance of dithiocarbamate-based molecular junctions represent a significant step towards the development of robust, organic-based electronic circuits.

  6. Sputum-Based Molecular Biomarkers for the Early Detection of Lung Cancer: Limitations and Promise

    International Nuclear Information System (INIS)

    Lung cancer is the leading cause of cancer deaths, with an overall survival of 15% at five years. Biomarkers that can sensitively and specifically detect lung cancer at early stage are crucial for improving this poor survival rate. Sputum has been the target for the discovery of non-invasive biomarkers for lung cancer because it contains airway epithelial cells, and molecular alterations identified in sputum are most likely to reflect tumor-associated changes or field cancerization caused by smoking in the lung. Sputum-based molecular biomarkers include morphology, allelic imbalance, promoter hypermethylation, gene mutations and, recently, differential miRNA expression. To improve the sensitivity and reproducibility of sputum-based biomarkers, we recommend standardization of processing protocols, bronchial epithelial cell enrichment, and identification of field cancerization biomarkers

  7. Polymerase chain reaction-based molecular diagnosis of cutaneous infections in dermatopathology.

    Science.gov (United States)

    Swick, Brian L

    2012-12-01

    Conventional methods, including microscopy, culture, and serologic studies, are a mainstay in the diagnosis of cutaneous infection. However, owing to limitations associated with these techniques, such as low sensitivity for standard microscopy and in the case of culture delay in diagnosis, polymerase chain-reaction based molecular techniques have taken on an expanding role in the diagnosis of infectious processes in dermatopathology. In particular, these assays are a useful adjunct in the diagnosis of cutaneous tuberculosis, atypical mycobacterial infection, leprosy, Lyme disease, syphilis, rickettsioses, leishmaniasis, and some fungal and viral infections. Already in the case of tuberculosis and atypical mycobacterial infection, standardized polymerase chain-reaction assays are commonly used for diagnostic purposes. With time, additional molecular-based techniques will decrease in cost and gain increased standardization, thus delivering rapid diagnostic confirmation for many difficult-to-diagnose cutaneous infections from standard formalin-fixed paraffin-embedded tissue specimens.

  8. Arylazopyrazoles as Light-Responsive Molecular Switches in Cyclodextrin-Based Supramolecular Systems.

    Science.gov (United States)

    Stricker, Lucas; Fritz, Eva-Corinna; Peterlechner, Martin; Doltsinis, Nikos L; Ravoo, Bart Jan

    2016-04-01

    A simple and high yield synthesis of water-soluble arylazopyrazoles (AAPs) featuring superior photophysical properties is reported. The introduction of a carboxylic acid allows the diverse functionalization of AAPs. Based on structural modifications of the switching unit the photophysical properties of the AAPs could be tuned to obtain molecular switches with favorable photostationary states. Furthermore, AAPs form stable and light-responsive host-guest complexes with β-cyclodextrin (β-CD). Our most efficient AAP shows binding affinities comparable to azobenzenes, but more effective switching and higher thermal stability of the Z-isomer. As a proof-of-principle, we investigated two CD-based supramolecular systems, containing either cyclodextrin vesicles (CDVs) or cyclodextrin-functionalized gold nanoparticles (CDAuNPs), which revealed excellent reversible, light-responsive aggregation and dispersion behavior. To conclude, AAPs have great potential to be incorporated as molecular switches in highly demanding and multivalent photoresponsive systems. PMID:26972671

  9. Important issues facing model-based approaches to tunneling transport in molecular junctions

    CERN Document Server

    Baldea, Ioan

    2015-01-01

    Extensive studies on thin films indicated a generic cubic current-voltage $I-V$ dependence as a salient feature of charge transport by tunneling. A quick glance at $I-V$ data for molecular junctions suggests a qualitatively similar behavior. This would render model-based studies almost irrelevant, since, whatever the model, its parameters can always be adjusted to fit symmetric (asymmetric) $I-V$ curves characterized by two (three) expansion coefficients. Here, we systematically examine popular models based on tunneling barrier or tight-binding pictures and demonstrate that, for a quantitative description at biases of interest ($V$ slightly higher than the transition voltage $V_t$), cubic expansions do not suffice. A detailed collection of analytical formulae as well as their conditions of applicability are presented to facilitate experimentalists colleagues to process and interpret their experimental data by obtained by measuring currents in molecular junctions. We discuss in detail the limits of applicabili...

  10. Bases moleculares de la cancerización de cavidad oral Molecular basis on oral cavity cancerization

    Directory of Open Access Journals (Sweden)

    M.A. González-Moles

    2008-02-01

    Full Text Available Se presenta una revisión bibliográfica breve sobre los principales aspectos moleculares de interés en la cancerización de cavidad oral. Se hace referencia a los conocimientos más recientes sobre las aberraciones cromosómicas más comunes y las alteraciones de los oncogenes y genes supresores tumorales que están implicados en la carcinogénesis oral. Así mismo, se resume la teoría molecular actual que explica el proceso de cancerización de campo.A review about the main molecular aspects on oral cavity cancerization is presented, with special reference to the common chromosomal aberration, oncogenes and tumour suppressor genes implied in oral carcinogenesis. A summary about molecular theory explaining the field cancerization process is also presented.

  11. Cellulose acetate-based molecularly imprinted polymeric membrane for separation of vanillin and o-vanillin

    OpenAIRE

    Chunjing Zhang; Shian Zhong; Zhengpeng Yang

    2008-01-01

    Cellulose acetate-based molecularly imprinted polymeric membranes were prepared using vanillin as template molecule. The microscopic structure of the resultant polymeric membranes was characterized by SEM and FTIR spectroscopy, and the selective binding properties and separation capacity of the membranes for vanillin and o-vanillin were tested with binding experiments and separate experiments, respectively. The results showed that the vanillin-imprinted polymeric membranes displayed higher bi...

  12. Molecular-Based Assay for Simultaneous Detection of Four Plasmodium spp. and Wuchereria bancrofti Infections

    OpenAIRE

    MEHLOTRA, RAJEEV K.; Gray, Laurie R; Blood-Zikursh, Melinda J.; Kloos, Zachary; Henry-Halldin, Cara N.; Tisch, Daniel J.; Thomsen, Edward; Reimer, Lisa; Kastens, Will; Baea, Manasseh; Baea, Kaye; Baisor, Moses; Tarongka, Nandao; Kazura, James W; Zimmerman, Peter A

    2010-01-01

    Four major malaria-causing Plasmodium spp. and lymphatic filariasis-causing Wuchereria bancrofti are co-endemic in many tropical and sub-tropical regions. Among molecular diagnostic assays, multiplex polymerase chain reaction (PCR)–based assays for the simultaneous detection of DNAs from these parasite species are currently available only for P. falciparum and W. bancrofti or P. vivax and W. bancrofti. Using a post-PCR oligonucleotide ligation detection reaction–fluorescent microsphere assay ...

  13. Multi-scale computational framework for evaluating of the performance of molecular based flash cells

    OpenAIRE

    Georgiev, Vihar; Asenov, Asen

    2015-01-01

    In this work we present a multi-scale computational framework for evaluation of statistical variability in a molecular based non-volatile memory cell. As a test case we analyse a BULK flash cell with polyoxometalates (POM) inorganic molecules used as storage centres. We focuse our discussions on the methodology and development of our innovative and unique computational framework. The capability of the discussed multi-scale approach is demonstrated by establishing a link between the threshold ...

  14. Prediction of Substrate-Enzyme-Product Interaction Based on Molecular Descriptors and Physicochemical Properties

    OpenAIRE

    Bing Niu; Guohua Huang; Linfeng Zheng; Xueyuan Wang; Fuxue Chen; Yuhui Zhang; Tao Huang

    2013-01-01

    It is important to correctly and efficiently predict the interaction of substrate-enzyme and to predict their product in metabolic pathway. In this work, a novel approach was introduced to encode substrate/product and enzyme molecules with molecular descriptors and physicochemical properties, respectively. Based on this encoding method, KNN was adopted to build the substrate-enzyme-product interaction network. After selecting the optimal features that are able to represent the main factors of...

  15. Dithienogermole-based solution-processed molecular solar cells with efficiency over 9.

    Science.gov (United States)

    Gupta, Vinay; Lai, Lai Fan; Datt, Ram; Chand, Suresh; Heeger, Alan J; Bazan, Guillermo C; Singh, Surya Prakash

    2016-06-30

    A molecular donor of intermediate dimensions based on dithienogermole (DTG) as the central electron rich unit, coded as DTG(FBT2Th2)2, was designed and synthesized for use in bulk heterojunction, solution-processed organic solar cells. Under optimized conditions, a maximum power conversion efficiency (PCE) of 9.1% can be achieved with [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) as the acceptor semiconductor component. PMID:27321642

  16. Reusable molecular sensor based on photonic activation control of DNA probes

    OpenAIRE

    Nishimura, Takahiro; Ogura, Yusuke; Tanida, Jun

    2012-01-01

    We propose a photoactivatable and resettable molecular sensor using DNA probes. The functionality is achieved by reversible change of DNA structure induced via photonic signals. Based on the mechanism, the sensor can detect target molecules at a desired instant and can be returned to its initial state after detection. The experimental results demonstrate that the concentrations of the target molecules are detected correctly and repeatedly according to the light signal.

  17. Remote Detection of Xenon-based Molecular Sensors and the Development of Novel Paramagnetic Agents

    OpenAIRE

    Smith, Monica A.

    2012-01-01

    Applications of laser-polarized xenon nuclear magnetic resonance (NMR) spectroscopy and imaging have grown in number due to the exceptional sensitivity of xenon to its local environment. When paired with microfluidic technology, xenon-based molecular sensors (XBMS) have the potential to be used in a broad range of applications from medical devices to geochemistry. Detection of XBMS on a microfluidic chip requires remote detection NMR methodology, where the encoding and detection of aqueous...

  18. X-ray MCD Measurements in a high Tc molecular-based magnet

    NARCIS (Netherlands)

    Arrio, M.-A.; Sainctavit, Ph.; Cartier dit Moulin, Ch.; Brouder, Ch.; Groot, F.M.F. de; Mallah, T.; Verdaguer, M.

    2001-01-01

    The molecular based magnet Cs^(I)[Ni^(II)Cr^(III)(CN)6]. 2H2O is a ferromagnet with a Curie temperature Tc = 90 K. Its structure consists of face centred cubic lattice of Ni^(II) ions connected by Cr(CN)6 entities. We have recorded X-ray Magnetic Circular Dichroism (XMCD) at nickel L2,3 edges. It cl

  19. Measurement of Magnetic Moment at the Atomic Scale in a High TC Molecular Based Magnet

    NARCIS (Netherlands)

    Arrio, M.-A.; Sainctavit, Ph.; Cartier dit Moulin, Ch.; Brouder, Ch.; Groot, F.M.F. de; Mallah, T.; Verdaguer, M.

    2001-01-01

    The molecular-based magnet Cs^(I) [Ni^(II) Cr^(III) (CN)6]-2H2O is a ferromagnetic with a Curie temperature TC ) 90 K. Its structure consists of face-centered cubic lattice of Ni^(II) ions connected by Cr(CN)6 entities. We have recorded X-ray magnetic circular dichroism (XMCD) at nickel L2,3 edges.

  20. Synthetic molecular systems based on porphyrins as models for the study of energy transfer in photosynthesis

    Science.gov (United States)

    Konovalova, Nadezhda V.; Evstigneeva, Rima P.; Luzgina, Valentina N.

    2001-11-01

    The published data on the synthesis and photochemical properties of porphyrin-based molecular ensembles which represent models of natural photosynthetic light-harvesting complexes are generalised and systematised. The dependence of the transfer of excitation energy on the distance between donor and acceptor components, their mutual arrangement, electronic and environmental factors are discussed. Two mechanisms of energy transfer reactions, viz., 'through space' and 'through bond', are considered. The bibliography includes 96 references.

  1. Molecular Characterization of Soil Ammonia-Oxidizing Bacteria Based on the Genes Encoding Ammonia Monooxygenase

    OpenAIRE

    Alzerreca, Jose Javier

    1999-01-01

    Ammonia-oxidizing bacteria (AOB) are chemolithotrophs that oxidize ammonia/ammonium to nitrite in a two-step process to obtain energy for survival. AOB are difficult to isolate from the environment and iso lated strains may not represent the diversity in soil. A genetic database and molecular tools were developed based on the ammonia monooxygenase (AMO) encoding genes that can be used to assess the diversity of AOB that exist in soil and aquatic environments without the isolation of pure cult...

  2. Molecular phylogeny of Toxoplasmatinae: comparison between inferences based on mitochondrial and apicoplast genetic sequences

    Directory of Open Access Journals (Sweden)

    Michelle Klein Sercundes

    2016-03-01

    Full Text Available Abstract Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC and beta subunit of RNA polymerase (rpoB, and mitochondrial gene coding for cytochrome B (cytB were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula and Sarcocystis neurona were investigated, along with Neospora caninum, Neospora hughesi, Toxoplasma gondii (strains RH, CTG and PTG, Besnoitia akodoni, Hammondia hammondiand two genetically divergent lineages of Hammondia heydorni. The molecular analysis based on organellar genes did not clearly differentiate between N. caninum and N. hughesi, but the two lineages of H. heydorni were confirmed. Slight differences between the strains of S. falcatula and S. neurona were encountered in all markers. In conclusion, congruent phylogenies were inferred from the three different genes and they might be used for screening undescribed sarcocystid parasites in order to ascertain their phylogenetic relationships with organisms of the family Sarcocystidae. The evolutionary studies based on organelar genes confirm that the genusHammondia is paraphyletic. The primers used for amplification of clpC and rpoB were able to amplify genetic sequences of organisms of the genus Sarcocystisand organisms of the subfamily Toxoplasmatinae as well.

  3. Molecular phylogeny of Toxoplasmatinae: comparison between inferences based on mitochondrial and apicoplast genetic sequences.

    Science.gov (United States)

    Sercundes, Michelle Klein; Valadas, Samantha Yuri Oshiro Branco; Keid, Lara Borges; Oliveira, Tricia Maria Ferreira Souza; Ferreira, Helena Lage; Vitor, Ricardo Wagner de Almeida; Gregori, Fábio; Soares, Rodrigo Martins

    2016-01-01

    Phylogenies within Toxoplasmatinae have been widely investigated with different molecular markers. Here, we studied molecular phylogenies of the Toxoplasmatinae subfamily based on apicoplast and mitochondrial genes. Partial sequences of apicoplast genes coding for caseinolytic protease (clpC) and beta subunit of RNA polymerase (rpoB), and mitochondrial gene coding for cytochrome B (cytB) were analyzed. Laboratory-adapted strains of the closely related parasites Sarcocystis falcatula and Sarcocystis neurona were investigated, along with Neospora caninum, Neospora hughesi, Toxoplasma gondii (strains RH, CTG and PTG), Besnoitia akodoni, Hammondia hammondiand two genetically divergent lineages of Hammondia heydorni. The molecular analysis based on organellar genes did not clearly differentiate between N. caninum and N. hughesi, but the two lineages of H. heydorni were confirmed. Slight differences between the strains of S. falcatula and S. neurona were encountered in all markers. In conclusion, congruent phylogenies were inferred from the three different genes and they might be used for screening undescribed sarcocystid parasites in order to ascertain their phylogenetic relationships with organisms of the family Sarcocystidae. The evolutionary studies based on organelar genes confirm that the genus Hammondia is paraphyletic. The primers used for amplification of clpC and rpoB were able to amplify genetic sequences of organisms of the genus Sarcocystisand organisms of the subfamily Toxoplasmatinae as well. PMID:27007245

  4. Feasibility study of molecular memory device based on DNA using methylation to store information

    Science.gov (United States)

    Jiang, Liming; Qiu, Wanzhi; Al-Dirini, Feras; Hossain, Faruque M.; Evans, Robin; Skafidas, Efstratios

    2016-07-01

    DNA, because of its robustness and dense information storage capability, has been proposed as a potential candidate for next-generation storage media. However, encoding information into the DNA sequence requires molecular synthesis technology, which to date is costly and prone to synthesis errors. Reading the DNA strand information is also complex. Ideally, DNA storage will provide methods for modifying stored information. Here, we conduct a feasibility study investigating the use of the DNA 5-methylcytosine (5mC) methylation state as a molecular memory to store information. We propose a new 1-bit memory device and study, based on the density functional theory and non-equilibrium Green's function method, the feasibility of electrically reading the information. Our results show that changes to methylation states lead to changes in the peak of negative differential resistance which can be used to interrogate memory state. Our work demonstrates a new memory concept based on methylation state which can be beneficial in the design of next generation DNA based molecular electronic memory devices.

  5. La formación de posgrado en Epidemiología: estrategias pedagógicas de una experiencia

    Directory of Open Access Journals (Sweden)

    Ana Cecília Augsburger

    2007-04-01

    Full Text Available El artículo describe y analiza la experiencia de elaboración e implementación de un proyecto educativo destinado a formar profesionales de la salud en el área epidemiológica. Con el propósito de profundizar la reflexión en torno a las diferentes estrategias pedagógicas adoptadas y, en particular valorar las posibilidades de innovación que la pedagogía crítica permite, se analiza la experiencia de enseñanza-aprendizaje vinculada al desarrollo de trabajos de campo en la formación de especialistas en Epidemiología. En primer lugar se aborda el contexto socio-sanitario en el cual se diseña e implementa la carrera de Epidemiología en la Universidad Nacional de Rosario (Argentina. Luego se profundiza en las posibilidades de integración entre prácticas educativas e intervenciones sanitarias a través de la elaboración del plan curricular; para finalmente examinar la estrategia pedagógica adoptada. Se concluye identificando algunos de los desafíos que se presentan con base en la evaluación educativa realizada.

  6. Fiber optic profenofos sensor based on surface plasmon resonance technique and molecular imprinting.

    Science.gov (United States)

    Shrivastav, Anand M; Usha, Sruthi P; Gupta, Banshi D

    2016-05-15

    A successful approach for the fabrication and characterization of an optical fiber sensor for the detection of profenofos based on surface plasmon resonance (SPR) and molecular imprinting is introduced. Molecular imprinting technology is used for the creation of three dimensional binding sites having complementary shape and size of the specific template molecule over a polymer for the recognition of the same. Binding of template molecule with molecularly imprinted polymer (MIP) layer results in the change in the dielectric nature of the sensing surface (polymer) and is identified by SPR technique. Spectral interrogation method is used for the characterization of the sensing probe. The operating profenofos concentration range of the sensor is from 10(-4) to 10(-1)µg/L. A red shift of 18.7 nm in resonance wavelength is recorded for this profenofos concentration range. The maximum sensitivity of the sensor is 12.7 nm/log (µg/L) at 10(-4)µg/L profenofos concentration. Limit of detection (LOD) of the sensor is found to be 2.5×10(-6)µg/L. Selectivity measurements predict the probe highly selective for the profenofos molecule. Besides high sensitivity due to SPR technique and selectivity due to molecular imprinting, proposed sensor has numerous other advantages like immunity to electromagnetic interference, fast response, low cost and capability of online monitoring and remote sensing of analyte due to the fabrication of the probe on optical fiber. PMID:26706813

  7. Which, when and why? Rational use of tissue-based molecular testing in localized prostate cancer.

    Science.gov (United States)

    Ross, A E; D'Amico, A V; Freedland, S J

    2016-03-01

    An increased molecular understanding of localized prostate cancer and the improved ability for molecular testing of pathologic tissue has led to the development of multiple clinical assays. Here we review the relevant molecular biology of localized prostate cancer, currently available tissue-based tests and describe which is best supported for use in various clinical scenarios. Literature regarding testing of human prostate cancer tissue with Ki-67, PTEN (by immunohistochemistry (IHC) or fluroescence in situ hybridization (FISH)), ProMark, Prolaris, OncotypeDX Prostate and Decipher was reviewed to allow for generation of expert opinions. At diagnosis, evaluation of PTEN status, use of ProMark or OncotypeDX Prostate in men with Gleason 6 or 3+4=7 disease may help guide the use of active surveillance. For men with Gleason 7 or above disease considering watchful waiting, Ki-67 and Prolaris add independent prognostic information. For those men who have undergone prostatectomy and have adverse pathology, Decipher testing may aid in the decision to undergo adjuvant radiation. Newly available molecular tests bring opportunities to improve decision making for men with localized prostate cancer. A review of the currently available data suggests clinical scenarios for which each of these tests may have the greatest utility. PMID:26123120

  8. Molecular phylogeny and evolution of Scomber (Teleostei: Scombridae) based on mitochondrial and nuclear DNA sequences

    Institute of Scientific and Technical Information of China (English)

    CHENG Jiao; GAO Tianxiang; MIAO Zhenqing; YANAGIMOTO Takashi

    2011-01-01

    A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial (COI, Cyt b and control region) and nuclear (5S rDNA) DNA sequence data in multigene perspective. A variety of phylogenetic analytic methods were used to clarify the current taxonomic classification and to assess phylogenetic relationships and the evolutionary history of this genus. The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber. We confirmed that S. japonicus and S. colias were genetically distinct. Although morphologically and ecologically similar to S. colias, the molecular data showed that S. japonicus has a greater molecular affinity with S. australasicus, which conflicts with the traditional taxonomy. This phyiogenetic pattern was corroborated by the mtDNA data, but incompletely by the nuclear DNA data. Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes supports an Atlantic origin for Scomber. The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus. The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events. In addition, our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution, from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.

  9. Characterization-Based Molecular Design of Biofuel Additives Using Chemometric and Property Clustering Techniques

    Directory of Open Access Journals (Sweden)

    Subin eHada

    2014-06-01

    Full Text Available In this work, multivariate characterization data such as infrared (IR spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis (PCA allowed capturing important features of the molecular architecture from complex data to build appropriate latent variable models. Combining the property clustering techniques and group contribution methods (GCM based on characterization data in a reverse problem formulation enabled identifying candidate components by combining or mixing molecular fragments until the resulting properties match the targets. The developed methodology is demonstrated using molecular design of biodiesel additive which when mixed with off-spec biodiesel produces biodiesel that meets the desired fuel specifications. The contribution of this work is that the complex structures and orientations of the molecule can be included in the design, thereby allowing enumeration of all feasible candidate molecules that matched the identified target but were not part of original training set of molecules.

  10. Fiber optic profenofos sensor based on surface plasmon resonance technique and molecular imprinting.

    Science.gov (United States)

    Shrivastav, Anand M; Usha, Sruthi P; Gupta, Banshi D

    2016-05-15

    A successful approach for the fabrication and characterization of an optical fiber sensor for the detection of profenofos based on surface plasmon resonance (SPR) and molecular imprinting is introduced. Molecular imprinting technology is used for the creation of three dimensional binding sites having complementary shape and size of the specific template molecule over a polymer for the recognition of the same. Binding of template molecule with molecularly imprinted polymer (MIP) layer results in the change in the dielectric nature of the sensing surface (polymer) and is identified by SPR technique. Spectral interrogation method is used for the characterization of the sensing probe. The operating profenofos concentration range of the sensor is from 10(-4) to 10(-1)µg/L. A red shift of 18.7 nm in resonance wavelength is recorded for this profenofos concentration range. The maximum sensitivity of the sensor is 12.7 nm/log (µg/L) at 10(-4)µg/L profenofos concentration. Limit of detection (LOD) of the sensor is found to be 2.5×10(-6)µg/L. Selectivity measurements predict the probe highly selective for the profenofos molecule. Besides high sensitivity due to SPR technique and selectivity due to molecular imprinting, proposed sensor has numerous other advantages like immunity to electromagnetic interference, fast response, low cost and capability of online monitoring and remote sensing of analyte due to the fabrication of the probe on optical fiber.

  11. NGS-based Molecular diagnosis of 105 eyeGENE(®) probands with Retinitis Pigmentosa.

    Science.gov (United States)

    Ge, Zhongqi; Bowles, Kristen; Goetz, Kerry; Scholl, Hendrik P N; Wang, Feng; Wang, Xinjing; Xu, Shan; Wang, Keqing; Wang, Hui; Chen, Rui

    2015-12-15

    The National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE(®)) was established in an effort to facilitate basic and clinical research of human inherited eye disease. In order to provide high quality genetic testing to eyeGENE(®)'s enrolled patients which potentially aids clinical diagnosis and disease treatment, we carried out a pilot study and performed Next-generation sequencing (NGS) based molecular diagnosis for 105 Retinitis Pigmentosa (RP) patients randomly selected from the network. A custom capture panel was designed, which incorporated 195 known retinal disease genes, including 61 known RP genes. As a result, disease-causing mutations were identified in 52 out of 105 probands (solving rate of 49.5%). A total of 82 mutations were identified, and 48 of them were novel. Interestingly, for three probands the molecular diagnosis was inconsistent with the initial clinical diagnosis, while for five probands the molecular information suggested a different inheritance model other than that assigned by the physician. In conclusion, our study demonstrated that NGS target sequencing is efficient and sufficiently precise for molecular diagnosis of a highly heterogeneous patient cohort from eyeGENE(®).

  12. Synchrotron based mass spectrometry to investigate the molecular properties of mineral-organic associations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Suet Yi; Kleber, Markus; Takahashi, Lynelle K.; Nico, Peter; Keiluweit, Marco; Ahmed, Musahid

    2013-04-01

    Soil organic matter (OM) is important because its decay drives life processes in the biosphere. Analysis of organic compounds in geological systems is difficult because of their intimate association with mineral surfaces. To date there is no procedure capable of quantitatively separating organic from mineral phases without creating artifacts or mass loss. Therefore, analytical techniques that can (a) generate information about both organic and mineral phases simultaneously and (b) allow the examination of predetermined high-interest regions of the sample as opposed to conventional bulk analytical techniques are valuable. Laser Desorption Synchrotron Postionization (synchrotron-LDPI) mass spectrometry is introduced as a novel analytical tool to characterize the molecular properties of organic compounds in mineral-organic samples from terrestrial systems, and it is demonstrated that when combined with Secondary Ion Mass Spectrometry (SIMS), can provide complementary information on mineral composition. Mass spectrometry along a decomposition gradient in density fractions, verifies the consistency of our results with bulk analytical techniques. We further demonstrate that by changing laser and photoionization energies, variations in molecular stability of organic compounds associated with mineral surfaces can be determined. The combination of synchrotron-LDPI and SIMS shows that the energetic conditions involved in desorption and ionization of organic matter may be a greater determinant of mass spectral signatures than the inherent molecular structure of the organic compounds investigated. The latter has implications for molecular models of natural organic matter that are based on mass spectrometric information.

  13. Wide-field fluorescence molecular tomography with compressive sensing based preconditioning.

    Science.gov (United States)

    Yao, Ruoyang; Pian, Qi; Intes, Xavier

    2015-12-01

    Wide-field optical tomography based on structured light illumination and detection strategies enables efficient tomographic imaging of large tissues at very fast acquisition speeds. However, the optical inverse problem based on such instrumental approach is still ill-conditioned. Herein, we investigate the benefit of employing compressive sensing-based preconditioning to wide-field structured illumination and detection approaches. We assess the performances of Fluorescence Molecular Tomography (FMT) when using such preconditioning methods both in silico and with experimental data. Additionally, we demonstrate that such methodology could be used to select the subset of patterns that provides optimal reconstruction performances. Lastly, we compare preconditioning data collected using a normal base that offers good experimental SNR against that directly acquired with optimal designed base. An experimental phantom study is provided to validate the proposed technique.

  14. Neoliberalismo, corporativismo y experiencias posicionales: Los casos de Chile y Francia Neoliberalism, corporatism and positional experiences: The cases of Chile and France

    Directory of Open Access Journals (Sweden)

    Catalina Arteaga A.

    2012-06-01

    Full Text Available Apoyándose en un conjunto de investigaciones cualitativas, el artículo propone una comparación de las experiencias posicionales en las sociedades chilena y francesa. Sin descuidar las diferencias que se observan a este respecto entre los grupos sociales en cada uno de los países estudiados, el artículo se interesa sobre todo en los disímiles perfiles nacionales de estas experiencias. Se diseñan, así, claramente, dos modelos de experiencia posicional, a través de la articulación de modelos sociales de estratificación, naturaleza de las consistencias posicionales, conductas individuales y malestares subjetivos.Based on a set of qualitative research, the article proposes a comparison of positional experience in Chilean and French societies. Without neglecting the observable differences between social groups within each of the countries studied, the article is primarily concerned with the different national profiles of these experiences. Two models of positional experience are clearly designed by articulating social stratification patterns, nature of positional consistencies, individual behavior and subjective discomfort.

  15. Doping effects for organic photovoltaic cells based on small-molecular-weight semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Taima, Tetsuya; Yamanari, Toshihiro; Saito, Kazuhiro [Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 2, 1-1-1 Umezono, Tsukuba 305-8568 (Japan); Sakai, Jun [Advanced Technologies Development Laboratory, Matsushita Electric Works, Ltd., 1048 Kadoma, Osaka 571-8686 (Japan)

    2009-06-15

    We have studied highly efficient organic photovoltaic (OPV) cells based on small-molecular-weight semiconductors: zinc phthalocyanine (ZnPc) and C60. To improve the efficiency furthermore, open-circuit voltage (V{sub oc}) has to be increased. We reported that 5,6,11,12-tetraphenylnaphthacene (rubrene) produces the highest V{sub oc} of 0.91 V by p-n heterojunction OPV cells with C60. In this paper, we report rubrene doping effects for OPV cells based on ZnPc to obtain higher V{sub oc}. (author)

  16. Fast screening of ketamine in biological samples based on molecularly imprinted photonic hydrogels

    International Nuclear Information System (INIS)

    Graphical abstract: A novel label-free colorimetric chemosensor: with the increase in the concentration of ketamine, the Bragg diffraction peak of MIPHs gradually shifted to the longer wavelength region. Accompanying the peak shift, the color change of MIPHs was also observed obviously: from green to red. Highlights: ► We developed the label-free colorimetric MIPHs for handy and fast screening of ketamine. ► The obvious color change of MIPHs was observed upon ketamine. ► The MIPHs exhibited good sensing abilities in an aqueous environment. ► The sensing mechanisms of the water-compatible MIPHs were investigated. ► The MIPHs were employed to screening ketamine in real biological samples. -- Abstract: A novel label-free colorimetric chemosensor was developed for handy and fast screening of ketamine with high sensitivity and specificity based on molecularly imprinted photonic hydrogels (MIPHs) that combined the colloidal-crystal with molecular imprinting technique. The unique inverse opal arrays with a thin polymer wall in which the imprinted nanocavities of ketamine moleculars distributed allowed high sensitive, quick responsive, specific detection of the target analyte, and good regenerating ability in an aqueous environment. Due to the hierarchical inverse opal structural characteristics, the specific ketamine molecular recognition process can induce obvious swelling of the MIPHs to be directly transferred into visually perceptible optical signal (change in color) which can be detected by the naked eye through Bragg diffractive shifts of ordered macroporous arrays. In order to enhance the recognition ability in aqueous environments, the MIPHs were designed as water-compatible and synthesized in a water–methanol system. The molecular recognition mechanisms were investigated. The proposed MIPHs were successfully employed to screen trace level ketamine in human urine and saliva samples, exhibiting high sensitivity, rapid response, and specificity in the

  17. Fast screening of ketamine in biological samples based on molecularly imprinted photonic hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Liang [Department of Forensic Science, People' s Public Security University of China, Beijing (China); Meng, Pinjia, E-mail: mengpinjia@163.com [Department of Forensic Science, People' s Public Security University of China, Beijing (China); Zhang, Qingqing; Wang, Yanji [Department of Forensic Science, People' s Public Security University of China, Beijing (China)

    2013-04-10

    Graphical abstract: A novel label-free colorimetric chemosensor: with the increase in the concentration of ketamine, the Bragg diffraction peak of MIPHs gradually shifted to the longer wavelength region. Accompanying the peak shift, the color change of MIPHs was also observed obviously: from green to red. Highlights: ► We developed the label-free colorimetric MIPHs for handy and fast screening of ketamine. ► The obvious color change of MIPHs was observed upon ketamine. ► The MIPHs exhibited good sensing abilities in an aqueous environment. ► The sensing mechanisms of the water-compatible MIPHs were investigated. ► The MIPHs were employed to screening ketamine in real biological samples. -- Abstract: A novel label-free colorimetric chemosensor was developed for handy and fast screening of ketamine with high sensitivity and specificity based on molecularly imprinted photonic hydrogels (MIPHs) that combined the colloidal-crystal with molecular imprinting technique. The unique inverse opal arrays with a thin polymer wall in which the imprinted nanocavities of ketamine moleculars distributed allowed high sensitive, quick responsive, specific detection of the target analyte, and good regenerating ability in an aqueous environment. Due to the hierarchical inverse opal structural characteristics, the specific ketamine molecular recognition process can induce obvious swelling of the MIPHs to be directly transferred into visually perceptible optical signal (change in color) which can be detected by the naked eye through Bragg diffractive shifts of ordered macroporous arrays. In order to enhance the recognition ability in aqueous environments, the MIPHs were designed as water-compatible and synthesized in a water–methanol system. The molecular recognition mechanisms were investigated. The proposed MIPHs were successfully employed to screen trace level ketamine in human urine and saliva samples, exhibiting high sensitivity, rapid response, and specificity in the

  18. Initiating heavy-atom-based phasing by multi-dimensional molecular replacement.

    Science.gov (United States)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu; Karlsen, Jesper Lykkegaard; Nissen, Poul

    2016-03-01

    To obtain an electron-density map from a macromolecular crystal the phase problem needs to be solved, which often involves the use of heavy-atom derivative crystals and concomitant heavy-atom substructure determination. This is typically performed by dual-space methods, direct methods or Patterson-based approaches, which however may fail when only poorly diffracting derivative crystals are available. This is often the case for, for example, membrane proteins. Here, an approach for heavy-atom site identification based on a molecular-replacement parameter matrix (MRPM) is presented. It involves an n-dimensional search to test a wide spectrum of molecular-replacement parameters, such as different data sets and search models with different conformations. Results are scored by the ability to identify heavy-atom positions from anomalous difference Fourier maps. The strategy was successfully applied in the determination of a membrane-protein structure, the copper-transporting P-type ATPase CopA, when other methods had failed to determine the heavy-atom substructure. MRPM is well suited to proteins undergoing large conformational changes where multiple search models should be considered, and it enables the identification of weak but correct molecular-replacement solutions with maximum contrast to prime experimental phasing efforts.

  19. Releyendo Frankfurt: la Experiencia Estética en Adorno

    Directory of Open Access Journals (Sweden)

    Stra, Sebastián Matías

    2013-01-01

    Full Text Available [es]Intentaremos en este trabajo explorar la noción de Experiencia Estética en la obra de Theodor Adorno, entendiéndola como una compleja mediación conceptual que nos puede permitir dar cuenta de las oscuras configuraciones de la relación entre arte, cultura y conocimiento en la producción del pensador de Frankfurt. En este marco, cruzaremos las reflexiones estéticas adornianas con lecturas más cercanas a nuestro campo disciplinar, como la noción de Industria Cultural y la interpretación del mito y su derivación en la conformación de la racionalidad moderna. [en] In this work, we will try to explore the notion of Aesthetic Experience in Theodor Adorno`s work, understanding it as a complex conceptual mediation that can allow us getting in the dark settings of the relationship between art, culture and knowledge in the production of Frankfurt`s thinker. Like this, we are going to cross adornians aesthetic reflections with readings that are going to be closer to our disciplinary field, as the notion of cultural industry and the interpretation of myth and its derivation in the configuration of modern rationality.

  20. El EEES: una experiencia piloto en la uex

    Directory of Open Access Journals (Sweden)

    Guerrero, M.M.

    2006-01-01

    Full Text Available El proceso de Convergencia Europea en la Educación superior y la creciente importancia que en los últimos años está teniendo la evaluación de la calidad de la docencia suponen nuevas exigencias en nuestra planificación docente. Los cambios que todo este proceso implicarán serán importantes y numerosos, y para llevarlos a buen término es necesario que vengan acompañados por otros de índole metodológica que potencien el objetivo último de mejora de la calidad de la enseñanza universitaria. Ante esta situación y en nuestra parcela de los Métodos Cuantitativos, nos hemos planteado llevar a cabo “experiencias pilotos” en asignaturas como Estadística e Introducción a la Econometría y Matemáticas, dentro de la convocatoria de acciones para la adaptación de la UEX al EEES, que nos sirvan de referencia para el futuro próximo. En este trabajo presentamos los resultados obtenidos en el curso 2005/2006, en cuanto al trabajo del alumno, el nuestro como profesores, y las conclusiones a las que hemos llegado.

  1. High-resolution mesoscopic fluorescence molecular tomography based on compressive sensing.

    Science.gov (United States)

    Yang, Fugang; Ozturk, Mehmet S; Zhao, Lingling; Cong, Wenxiang; Wang, Ge; Intes, Xavier

    2015-01-01

    Mesoscopic fluorescence molecular tomography (MFMT) is new imaging modality aiming at 3-D imaging of molecular probes in a few millimeter thick biological samples with high-spatial resolution. In this paper, we develop a compressive sensing-based reconstruction method with l1-norm regularization for MFMT with the goal of improving spatial resolution and stability of the optical inverse problem. Three-dimensional numerical simulations of anatomically accurate microvasculature and real data obtained from phantom experiments are employed to evaluate the merits of the proposed method. Experimental results show that the proposed method can achieve 80 μm spatial resolution for a biological sample of 3 mm thickness and more accurate quantifications of concentrations and locations for the fluorophore distribution than those of the conventional methods.

  2. Surface plasmon resonance based optical fiber riboflavin sensor by using molecularly imprinted gel

    Science.gov (United States)

    Verma, Roli; Gupta, Banshi D.

    2013-05-01

    We report the fabrication and characterization of surface plasmon resonance (SPR) based optical fiber riboflavin/vitamin B2 sensor using combination of colloidal crystal templating and molecularly imprinted gel. The sensor works on spectral interrogation method. The operating range of the sensor lies from 0 μg/ml to 320 μg/ml, the suitable amount of intakes of riboflavin recommended for different age group. The SPR spectra show blue shift with increasing concentration of riboflavin, which is due to the interaction of riboflavin molecule over specific binding sites caused by molecular imprinting. The present sensor has many advantageous features such as fast response, small probe size, low cost and can be used for remote/online monitoring.

  3. A nitrogen-vacancy spin based molecular structure microscope using multiplexed projection reconstruction

    CERN Document Server

    Lazariev, Andrii

    2015-01-01

    Methods and techniques to measure and image beyond the state-of-the-art have always been influential in propelling basic science and technology. Because current technologies are venturing into nanoscopic and molecular-scale fabrication, atomic-scale measurement techniques are inevitable. One such emerging sensing method uses the spins associated with nitrogen-vacancy (NV) defects in diamond. The uniqueness of this NV sensor is its atomic size and ability to perform precision sensing under ambient conditions conveniently using light and microwaves (MW). These advantages have unique applications in nanoscale sensing and imaging of magnetic fields from nuclear spins in single biomolecules. During the last few years, several encouraging results have emerged towards the realization of an NV spin-based molecular structure microscope. Here, we present a projection-reconstruction method that retrieves the three-dimensional structure of a single molecule from the nuclear spin noise signatures. We validate this method ...

  4. Self-consistent field theory based molecular dynamics with linear system-size scaling.

    Science.gov (United States)

    Richters, Dorothee; Kühne, Thomas D

    2014-04-01

    We present an improved field-theoretic approach to the grand-canonical potential suitable for linear scaling molecular dynamics simulations using forces from self-consistent electronic structure calculations. It is based on an exact decomposition of the grand canonical potential for independent fermions and does neither rely on the ability to localize the orbitals nor that the Hamilton operator is well-conditioned. Hence, this scheme enables highly accurate all-electron linear scaling calculations even for metallic systems. The inherent energy drift of Born-Oppenheimer molecular dynamics simulations, arising from an incomplete convergence of the self-consistent field cycle, is circumvented by means of a properly modified Langevin equation. The predictive power of the present approach is illustrated using the example of liquid methane under extreme conditions.

  5. Self-consistent field theory based molecular dynamics with linear system-size scaling

    Energy Technology Data Exchange (ETDEWEB)

    Richters, Dorothee [Institute of Mathematics and Center for Computational Sciences, Johannes Gutenberg University Mainz, Staudinger Weg 9, D-55128 Mainz (Germany); Kühne, Thomas D., E-mail: kuehne@uni-mainz.de [Institute of Physical Chemistry and Center for Computational Sciences, Johannes Gutenberg University Mainz, Staudinger Weg 7, D-55128 Mainz (Germany); Technical and Macromolecular Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn (Germany)

    2014-04-07

    We present an improved field-theoretic approach to the grand-canonical potential suitable for linear scaling molecular dynamics simulations using forces from self-consistent electronic structure calculations. It is based on an exact decomposition of the grand canonical potential for independent fermions and does neither rely on the ability to localize the orbitals nor that the Hamilton operator is well-conditioned. Hence, this scheme enables highly accurate all-electron linear scaling calculations even for metallic systems. The inherent energy drift of Born-Oppenheimer molecular dynamics simulations, arising from an incomplete convergence of the self-consistent field cycle, is circumvented by means of a properly modified Langevin equation. The predictive power of the present approach is illustrated using the example of liquid methane under extreme conditions.

  6. Molecular Solutions for the Set-Partition Problem on Dna-Based Computing

    Directory of Open Access Journals (Sweden)

    Sientang Tsai

    2013-12-01

    Full Text Available Consider that the every element in a finite set S h aving q elements is a positive integer. The set-par tition problem is to determine whether there is a subset T ⊆ S such that , ∑ ∑ ∈ ∈ = T x T x x x where T = { x| x ∈ S and x ∉ T } . This research demonstrates that molecular operati ons can be applied to solve the set-partition problem. In order to perform this goal, we offer tw o DNA-based algorithms, an unsigned parallel adder and a parallel Exclusive-OR (XOR operation, that f ormally demonstrate our designed molecular solution s for solving the set-partition problem.

  7. Single molecular switch based on thiol tethered iron(II)clathrochelate on gold

    International Nuclear Information System (INIS)

    Molecular electronics has been associated with high density nano-electronic devices. Developments of molecular electronic devices were based on reversible switching of molecules between the two conductive states. In this paper, self-assembled monolayers of dodecanethiol (DDT) and thiol tethered iron(II)clathrochelate (IC) have been prepared on gold film. The electrochemical and electronic properties of IC molecules inserted into the dodecanethiol monolayer (IC-DDT SAM) were investigated using voltammetric, electrochemical impedance spectroscopy (EIS), scanning tunneling microscopy (STM) and cross-wire tunneling measurements. The voltage triggered switching behaviour of IC molecules on mixed SAM was demonstrated. Deposition of polyaniline on the redox sites of IC-DDT SAM using electrochemical polymerization of aniline was performed in order to confirm that this monolayer acts as nano-patterned semiconducting electrode surface.

  8. Titanium compounds as catalysts of higher alpha-olefin-based super-high-molecular polymers synthesis

    Science.gov (United States)

    Konovalov, K. B.; Kazaryan, M. A.; Manzhay, V. N.; Vetrova, O. V.

    2016-01-01

    The synthesis of polymers of 10 million or more molecular weight is a difficult task even in a chemical lab. Higher α-olefin-based polymer agents of such kind have found a narrow but quite important niche, the reduction of drag in the turbulent flow of hydrocarbon fluids such as oil and oil-products. In its turn, searching for a catalytic system capable to produce molecules of such a high length and to synthesize polymers of a low molecular-mass distribution is part of a global task of obtaining a high-quality product. In this paper we had observed a number of industrial catalysts with respect to their suitability for higher poly-α- olefins synthesis. A number samples representing copolymers of 1-hexene with 1-decene obtained on a previous generation catalyst, a microsphere titanium chloride catalytic agent had been compared to samples synthesized using a titanium-magnesium catalyst both in solution and in a polymer medium.

  9. Molecular thermodynamic modeling of ionic liquids using the perturbation-based linear Yukawa isotherm regularity

    Science.gov (United States)

    Sohrabi Mahboub, Mahdi; Farrokhpour, Hossein

    2016-06-01

    In this paper, we present the results of an extensive study on a novel approach to the molecular modeling of pure ionic liquids (ILs) that incorporates the perturbed thermodynamic linear Yukawa isotherm regularity (LYIR), which is derived based on an effective nearest neighboring pair attractive interaction of the Yukawa potential. The LYIR was used to model the densities of ILs up to high pressures (35 MPa) and in the temperature range 293.15 to 393.15 K. To use the LYIR for ILs, a simple molecular model was proposed to describe their molecular structure, in which they were considered as a liquid consisting of the ion pairs moving together in the fluid, and each ion pair was assumed to be a one-center spherical united atom. The ILs under consideration contained one of the IL cations [C2mim]+, [C4mim]+, [C7mim]+, [C8mim]+, [C3mpy]+, [C3mpip]+, [C3mpyr]+ or [C4mpyr]+, and one of the IL anions [BF4]-, [C(CN)3]-, [CF3SO4]- or [NTf2]-. The reliability and physical significance of the parameters as well as the proposed molecular model were tested by calculating the densities of pure imidazolium-, pyridinium-, piperidinium- and pyrrolidimium-based ILs. The results showed that the LYIR can be used to predict and reproduce the density of ILs in good agreement with the experimental data. In addition, the LYIR enabled us to determine the physical quantities, such as an effective Yukawa screening length, λ eff, the product of the effective energy well depth and the effective coordination number, (ɛ eff/k)z eff, the contribution of the non-reference thermal pressure and also the influence of the anionic and cationic structure on the λ eff parameter. The standard deviation of the IL densities predicted in this work is lower than those calculated by the one other important equation of state reported in the literature.

  10. Microwave assisted one-pot synthesis of novel molecular clefts with only one chiral arm based on deoxycholic acid

    Institute of Scientific and Technical Information of China (English)

    Bi Tao Zeng; Zhi Gang Zhao; Xing Li Liu; Yun Shi

    2008-01-01

    A rapid, safe, and efficient method for the synthesis of novel molecular clefts based" on deoxycholic acid was reported. Sevennew molecular clefts have been synthesized in good yields (89-98%). This method proved to be extremely simple and highlyefficient. The structures of these receptors were confirmed by 1H NMR, IR, MS spectra and elemental analysis.

  11. A molecular beacon-based DNA switch for reversible pH sensing in vesicles and live cells.

    Science.gov (United States)

    Narayanaswamy, Nagarjun; Nair, Raji R; Suseela, Y V; Saini, Deepak Kumar; Govindaraju, T

    2016-07-01

    In this Communication, a molecular beacon-based DNA switch (LMB) is developed as an efficient and reversible pH sensing probe. Remarkably, LMB exhibited reversible structural transition between the closed (molecular beacon) and open (A-motif) states very efficiently in synthetic vesicles and live cells without the need for any transfection agents.

  12. A molecular beacon-based DNA switch for reversible pH sensing in vesicles and live cells.

    Science.gov (United States)

    Narayanaswamy, Nagarjun; Nair, Raji R; Suseela, Y V; Saini, Deepak Kumar; Govindaraju, T

    2016-07-01

    In this Communication, a molecular beacon-based DNA switch (LMB) is developed as an efficient and reversible pH sensing probe. Remarkably, LMB exhibited reversible structural transition between the closed (molecular beacon) and open (A-motif) states very efficiently in synthetic vesicles and live cells without the need for any transfection agents. PMID:27338808

  13. APRENDIENDO CON LAS TIC: UNA EXPERIENCIA UNIVERSITARIA (LEARNING FROM THE ICTS: A UNIVERSITY EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Regueyra Edelman María Gabriela

    2011-06-01

    Full Text Available Resumen:Se comparte en este artículo la experiencia del uso de las TIC en dos cursos que se imparten en la carrera de Trabajo Social de la Universidad de Costa Rica. Se detallan los recursos tecnológicos utilizados y el uso que se da a cada uno: Facebook, Blogger, Moodle, correo electrónico, se complementa la experiencia con la incorporación de las opiniones de la población estudiantil matriculada en los cursos y destacando los retos que el uso de las TIC presenta a la población docentes en particular y a la Universidad de Costa Rica en general. El artículo retoma discusión de la Sociedad del Conocimiento y la Información, y las TIC como procesos que han transformado la sociedad actual, con su incorporación tanto en el campo económico, social y laboral como en los ámbitos educativo, familiar y personal, lo que ha generado nuevas interacciones sociales y una brecha entre la población que tiene acceso a la tecnología y la que no lo tiene, situación que ha impactado fundamentalmente el ámbito educativo, donde se han ido incorporando las TIC de manera progresiva, con algunas reservas tanto de la población docente como de la población estudiantil.Abstract: This article deals with the experience of using the Information and Communication Technologies (ICTs for two courses in the Social Work Major at the University of Costa Rica. The use of technological resources such as Facebook, Blogger, Moodle and e-mail are described. The usability of this experience is complemented with opinions from students who registered in those courses, by highlighting the challenges encountered by faculty in particular and by the University of Costa Rica in general, regarding the implementation of ICTs. This article recognizes that the Community and Information-Based Knowledge and the ICTs are means for the transformation of the community itself as they are introduced in the economic, social, labor, family, personal and educational fields. Although the

  14. High performance computing for three-dimensional agent-based molecular models.

    Science.gov (United States)

    Pérez-Rodríguez, G; Pérez-Pérez, M; Fdez-Riverola, F; Lourenço, A

    2016-07-01

    Agent-based simulations are increasingly popular in exploring and understanding cellular systems, but the natural complexity of these systems and the desire to grasp different modelling levels demand cost-effective simulation strategies and tools. In this context, the present paper introduces novel sequential and distributed approaches for the three-dimensional agent-based simulation of individual molecules in cellular events. These approaches are able to describe the dimensions and position of the molecules with high accuracy and thus, study the critical effect of spatial distribution on cellular events. Moreover, two of the approaches allow multi-thread high performance simulations, distributing the three-dimensional model in a platform independent and computationally efficient way. Evaluation addressed the reproduction of molecular scenarios and different scalability aspects of agent creation and agent interaction. The three approaches simulate common biophysical and biochemical laws faithfully. The distributed approaches show improved performance when dealing with large agent populations while the sequential approach is better suited for small to medium size agent populations. Overall, the main new contribution of the approaches is the ability to simulate three-dimensional agent-based models at the molecular level with reduced implementation effort and moderate-level computational capacity. Since these approaches have a generic design, they have the major potential of being used in any event-driven agent-based tool.

  15. High performance computing for three-dimensional agent-based molecular models.

    Science.gov (United States)

    Pérez-Rodríguez, G; Pérez-Pérez, M; Fdez-Riverola, F; Lourenço, A

    2016-07-01

    Agent-based simulations are increasingly popular in exploring and understanding cellular systems, but the natural complexity of these systems and the desire to grasp different modelling levels demand cost-effective simulation strategies and tools. In this context, the present paper introduces novel sequential and distributed approaches for the three-dimensional agent-based simulation of individual molecules in cellular events. These approaches are able to describe the dimensions and position of the molecules with high accuracy and thus, study the critical effect of spatial distribution on cellular events. Moreover, two of the approaches allow multi-thread high performance simulations, distributing the three-dimensional model in a platform independent and computationally efficient way. Evaluation addressed the reproduction of molecular scenarios and different scalability aspects of agent creation and agent interaction. The three approaches simulate common biophysical and biochemical laws faithfully. The distributed approaches show improved performance when dealing with large agent populations while the sequential approach is better suited for small to medium size agent populations. Overall, the main new contribution of the approaches is the ability to simulate three-dimensional agent-based models at the molecular level with reduced implementation effort and moderate-level computational capacity. Since these approaches have a generic design, they have the major potential of being used in any event-driven agent-based tool. PMID:27372059

  16. Rectifying Properties of a Nitrogen/Boron-Doped Capped-Carbon-Nanotube-Based Molecular Junction

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng; LIU De-Sheng; ZHANG Ying; WANG Pei-Ji; ZHANG Zhong

    2011-01-01

    @@ Based on the non-equilibrium Green's function method and first-principles density functional theory calculations, we investigate the electronic transport properties of a nitrogen/boron-doped capped-single-walled carbonnanotube-based molecular junction.Obvious rectifying behavior is observed and it is strongly dependent on the doping site.The best rectifying performance can be carried out when the nitrogen/boron atom dopes at a carbon site in the second layer.Moreover, the rectifying performance can be further improved by adjusting the distance between the Cso nanotube caps.%Based on the non-equilibrium Green's function method and first-principles density functional theory calculations, we investigate the electronic transport properties of a nitrogen/boron-doped capped-single-walled carbon-nanotube-based molecular junction. Obvious rectifying behavior is observed and it is strongly dependent on the doping site. The best rectifying performance can be carried out when the nitrogen/boron atom dopes at a carbon site in the second layer. Moreover, the rectifying performance can be further improved by adjusting the distance between the C60 nanotube caps.

  17. Molecular classification based on apomorphic amino acids (Arthropoda, Hexapoda): Integrative taxonomy in the era of phylogenomics.

    Science.gov (United States)

    Wu, Hao-Yang; Wang, Yan-Hui; Xie, Qiang; Ke, Yun-Ling; Bu, Wen-Jun

    2016-06-17

    With the great development of sequencing technologies and systematic methods, our understanding of evolutionary relationships at deeper levels within the tree of life has greatly improved over the last decade. However, the current taxonomic methodology is insufficient to describe the growing levels of diversity in both a standardised and general way due to the limitations of using only morphological traits to describe clades. Herein, we propose the idea of a molecular classification based on hierarchical and discrete amino acid characters. Clades are classified based on the results of phylogenetic analyses and described using amino acids with group specificity in phylograms. Practices based on the recently published phylogenomic datasets of insects together with 15 de novo sequenced transcriptomes in this study demonstrate that such a methodology can accommodate various higher ranks of taxonomy. Such an approach has the advantage of describing organisms in a standard and discrete way within a phylogenetic framework, thereby facilitating the recognition of clades from the view of the whole lineage, as indicated by PhyloCode. By combining identification keys and phylogenies, the molecular classification based on hierarchical and discrete characters may greatly boost the progress of integrative taxonomy.

  18. Electronic Transport Properties of an Anthraquinone-Based Molecular Switch with Carbon Nanotube Electrodes

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng; LIU De-Sheng

    2012-01-01

    Based on the nonequilibrium Green's function method and density functional theory calculations,we theoretically investigate the electronic transport properties of an anthraquinone-based molecular switch with carbon nanotube electrodes.The molecules that comprise the switch can convert between reduced hydroquinone (HQ) and oxidized anthraquinne (AQ) states via redox reactions.Our results show that the on-off ratio is increased one order of magnitude when compared to the case of gold electrodes.Moreover,an obvious negative differential resistance behavior at much low bias (0.07 V) is observed in the HQ form.%Based on the nonequilihrium Green's function method and density functional theory calculations, we theoretically investigate the electronic transport properties of an anthraquinone-based molecular switch with carbon nanotube electrodes. The molecules that comprise the switch can convert between reduced hydroquinone (HQ) and oxidized anthraquinne (AQ) states via redox reactions. Our results show that the on-off ratio is increased one order of magnitude when compared to the case of gold electrodes. Moreover, an obvious negative differential resistance behavior at much low bias (0.07 V) is observed in the HQ form.

  19. Molecular dynamics simulation based on the multi-component molecular orbital method: Application to H5O2+,D5O2+,andT5O2+

    International Nuclear Information System (INIS)

    Graphical abstract: Molecular dynamics method based on multi-component molecular orbital method was applied to basic hydrogen bonding systems, H5O2+, and its isotopomers (D5O2+andT5O2+). Highlights: ► Molecular dynamics method with nuclear quantum effect was developed. ► Multi-component molecular orbital method was used as ab initio MO calculation. ► Developed method applied to basic hydrogen bonding system, H5O2+, and isotopomers. ► O⋯O vibrational stretching reflected to the distribution of protonic wavefunctions. ► H/D/T isotope effect was also analyzed. - Abstract: We propose a molecular dynamics (MD) method based on the multi-component molecular orbital (MCMO) method, which takes into account the quantum effect of proton directly, for the detailed analyses of proton transfer in hydrogen bonding system. The MCMO based MD (MCMO-MD) method is applied to the basic structures, H5O2+ (called “Zundel ion”), and its isotopomers (D5O2+andT5O2+). We clearly demonstrate the geometrical difference of hydrogen bonded O⋯O distance induced by H/D/T isotope effect because the O⋯O in H-compound was longer than that in D- or T-compound. We also find the strong relation between stretching vibration of O⋯O and the distribution of hydrogen bonded protonic wavefunction because the protonic wavefunction tends to delocalize when the O⋯O distance becomes short during the dynamics. Our proposed MCMO-MD simulation is expected as a powerful tool to analyze the proton dynamics in hydrogen bonding systems.

  20. Generalized energy-based fragmentation approach and its applications to macromolecules and molecular aggregates.

    Science.gov (United States)

    Li, Shuhua; Li, Wei; Ma, Jing

    2014-09-16

    Conspectus The generalized energy-based fragmentation (GEBF) approach provides a very simple way of approximately evaluating the ground-state energy or properties of a large system in terms of ground-state energies of various small "electrostatically embedded" subsystems, which can be calculated with any traditional ab initio quantum chemistry (X) method (X = Hartree-Fock, density functional theory, and so on). Due to its excellent parallel efficiency, the GEBF approach at the X theory level (GEBF-X) allows full quantum mechanical (QM) calculations to be accessible for systems with hundreds and even thousands of atoms on ordinary workstations. The implementation of the GEBF approach at various theoretical levels can be easily done with existing quantum chemistry programs. This Account reviews the methodology, implementation, and applications of the GEBF-X approach. This method has been successfully applied to optimize the structures of various large systems including molecular clusters, polypeptides, proteins, and foldamers. Such investigations could allow us to elucidate the origin and nature of the cooperative interaction in secondary structures of long peptides or the driving force of the self-assembly processes of aromatic oligoamides. These GEBF-based QM calculations reveal that the structures and stability of various complex systems result from a subtle balance of many types of noncovalent interactions such as hydrogen bonding and van der Waals interactions. The GEBF-based ab initio molecular dynamics (AIMD) method also allows the investigation of dynamic behaviors of large systems on the order of tens of picoseconds. It was demonstrated that the conformational dynamics of two model peptides predicted by GEBF-based AIMD are noticeably different from those predicted by the classical force field MD method. With the target of extending QM calculations to molecular aggregates in the condensed phase, we have implemented the GEBF-based multilayer hybrid models

  1. Guest-responsive structural adaptation of a rationally-designed molecular tweezer based on Tröger’s base

    Indian Academy of Sciences (India)

    Ishita Neogi; Alankriti Bajpai; Jarugu Narasimha Moorthy

    2014-09-01

    We have designed and synthesized a modified Tröger’s base TB in which the sterically-rigidified aryl rings that protrude into its groove were envisaged to preclude self-inclusion. From a limited preliminary experimentation, TB has been found to exhibit guest inclusion. The X-ray determined structures of the crystals of guest-free TB and its inclusion compounds with acetonitrile and -dichlorobenzene reveal remarkable adaptability of the TB core to undergo subtle structural changes in response to the guest that is included. The structural analyses demonstrate the fact that TB behaves like a molecular tweezer.

  2. DNA molecular wire-based nanoelectronics: New insight and high frequency AC electrical characterization

    Science.gov (United States)

    Wibowo, Denni Ari

    While recent research in electron-transport mechanism on a double strands DNA seems to converge into a consensus, experiments in direct electrical measurements on a long DNA molecules still lead to a conflicting result. This research investigates experimentally the attachment of DNA molecular wire to high aspect ratio three-dimensional (3D) metal electrode and the effect of temperature to its AC electrical conductivity. The 3-D microelectrode was built on a silicone oxide substrate using patterned thick layers of negative tone photoresist covered by sputtered gold on the top surface. Attachment of lambda-DNA to the microelectrode was demonstrated using oligonucleotide-DNA phosphate backbone ligation and thiol-gold covalent bonding. Electrical characterizations based on I-V and AC impedance analysis of several repeatable data points of attachment with varying lambda-DNA concentration (500 ng/microL to 0.0625 ng/microL) showed measurable and significant conductivity of lambda-DNA molecular wires. Further study was carried out by measuring I-V and impedance while ramping up the temperature to reach complete denaturation (~1100C) resulting in no current transduction. Subsequent re-annealing of the DNA through incubation in TM buffer at annealing temperature (~900C) resulted in recovery of electrical conduction, providing a strong proof that DNA molecular wire is the one generate the electrical conductivity. lambda-DNA molecular wires reported to have differing impedance response at two temperature regions: impedance increases (conductivity decrease) between 40C -- 400C, and then decreases from 400C until DNA completely denatured (~1100C). The increase conductivity after 400C is an experimental support the long distance electron transport mechanism referred as "thermal hopping" mechanism. We believe that this research represents a significant departure from previous studies and makes unique contributions through (i) modification of DNA attachment methods has increase

  3. Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics

    Directory of Open Access Journals (Sweden)

    BETTY MAULIYA BUSTAM

    2010-01-01

    Full Text Available Bustam BM (2010 Systematic studies of Australian stipoid grasses (Austrostipa based on micro-morphological and molecular characteristics. Biodiversitas 11: 9-14. This research is one of many studies on stipoid grasses organized by the International Stipeae Working Group (ISWG. This research tested the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996 and tested how informative the micro morphological characters used. Data were collected from herbarium specimens of 36 species (33 species of Austrostipa, two species of Hesperostipa and one species of Anemanthele at Royal Botanic Gardens, Sydney. Twenty eight micro morphological characters were used. The data were collected from both adaxial and abaxial surfaces of leaves, and from the lemma epidermis using a scanning electron microscope (SEM. ISWG provided the molecular data. Parsimony analysis and a distance method (Unweighteic Pair Group with Arithmatic Mean: UPGMA were used to analyze mico morphological and molecular data separately. Only UPGMA analysis was used to analyze the combined data. The results support the monophyly of Austrostipa. However, there is a little support for the subgeneric classification of Austrostipa proposed by Jacobs and Everett (1996, other than for the consistent recognition of Falcatae. The characters for comparisons between genera are too homoplasious at this level and do not contain enough information for analyses at subgeneric level, a problem apparently shared with the DNA sequences.

  4. Label-Free Sensing of Adenosine Based on Force Variations Induced by Molecular Recognition

    Directory of Open Access Journals (Sweden)

    Jingfeng Li

    2015-03-01

    Full Text Available We demonstrate a simple force-based label-free strategy for the highly sensitive sensing of adenosine. An adenosine ssDNA aptamer was bound onto an atomic force microscopy (AFM probe by covalent modification, and the molecular-interface adsorption force between the aptamer and a flat graphite surface was measured by single-molecule force spectroscopy (SMFS. In the presence of adenosine, the molecular recognition between adenosine and the aptamer resulted in the formation of a folded, hairpin-like DNA structure and hence caused a variation of the adsorption force at the graphite/water interface. The sensitive force response to molecular recognition provided an adenosine detection limit in the range of 0.1 to 1 nM. The addition of guanosine, cytidine, and uridine had no significant interference with the sensing of adenosine, indicating a strong selectivity of this sensor architecture. In addition, operational parameters that may affect the sensor, such as loading rate and solution ionic strength, were investigated.

  5. Quantitative Description of a Protein Fitness Landscape Based on Molecular Features.

    Science.gov (United States)

    Meini, María-Rocío; Tomatis, Pablo E; Weinreich, Daniel M; Vila, Alejandro J

    2015-07-01

    Understanding the driving forces behind protein evolution requires the ability to correlate the molecular impact of mutations with organismal fitness. To address this issue, we employ here metallo-β-lactamases as a model system, which are Zn(II) dependent enzymes that mediate antibiotic resistance. We present a study of all the possible evolutionary pathways leading to a metallo-β-lactamase variant optimized by directed evolution. By studying the activity, stability and Zn(II) binding capabilities of all mutants in the preferred evolutionary pathways, we show that this local fitness landscape is strongly conditioned by epistatic interactions arising from the pleiotropic effect of mutations in the different molecular features of the enzyme. Activity and stability assays in purified enzymes do not provide explanatory power. Instead, measurement of these molecular features in an environment resembling the native one provides an accurate description of the observed antibiotic resistance profile. We report that optimization of Zn(II) binding abilities of metallo-β-lactamases during evolution is more critical than stabilization of the protein to enhance fitness. A global analysis of these parameters allows us to connect genotype with fitness based on quantitative biochemical and biophysical parameters.

  6. Quantitative Description of a Protein Fitness Landscape Based on Molecular Features

    Science.gov (United States)

    Meini, María-Rocío; Tomatis, Pablo E.; Weinreich, Daniel M.; Vila, Alejandro J.

    2015-01-01

    Understanding the driving forces behind protein evolution requires the ability to correlate the molecular impact of mutations with organismal fitness. To address this issue, we employ here metallo-β-lactamases as a model system, which are Zn(II) dependent enzymes that mediate antibiotic resistance. We present a study of all the possible evolutionary pathways leading to a metallo-β-lactamase variant optimized by directed evolution. By studying the activity, stability and Zn(II) binding capabilities of all mutants in the preferred evolutionary pathways, we show that this local fitness landscape is strongly conditioned by epistatic interactions arising from the pleiotropic effect of mutations in the different molecular features of the enzyme. Activity and stability assays in purified enzymes do not provide explanatory power. Instead, measurement of these molecular features in an environment resembling the native one provides an accurate description of the observed antibiotic resistance profile. We report that optimization of Zn(II) binding abilities of metallo-β-lactamases during evolution is more critical than stabilization of the protein to enhance fitness. A global analysis of these parameters allows us to connect genotype with fitness based on quantitative biochemical and biophysical parameters. PMID:25767204

  7. "Molecular beacon"-based fluorescent assay for selective detection of glutathione and cysteine.

    Science.gov (United States)

    Xu, Hui; Hepel, Maria

    2011-02-01

    We report on the development of a fluorescence turn-on "molecular beacon" probe for the detection of glutathione (GSH) and cysteine (Cys). The method is based on a competitive ligation of Hg(2+) ions by GSH/Cys and thymine-thymine (T-T) mismatches in a DNA strand of the self-hybridizing beacon strand. The assay relies on the distance-dependent optical properties of the fluorophore/quencher pair attached to the ends of the molecular beacon DNA strand. In a very selective coordination of Hg(2+) to GSH/Cys, the fluorophore/quencher distance increases concomitantly with the dehybridization and dissociation of the beacon stem T-Hg(2+)-T due to the extraction of Hg(2+) ions. This process results in switching the molecular beacon to the "on" state. The concentration range of the probe is 4-200 nM with the limit of detection (LOD) of 4.1 nM for GSH and 4.2 nM Cys. The probe tested satisfactorily against interference for a range of amino acids including sulfur-containing methionine.

  8. Molecular phylogeny of the lionfish genera Dendrochirus and Pterois (Scorpaenidae, Pteroinae) based on mitochondrial DNA sequences.

    Science.gov (United States)

    Kochzius, Marc; Söller, Rainer; Khalaf, Maroof A; Blohm, Dietmar

    2003-09-01

    This study investigates the molecular phylogeny of seven lionfishes of the genera Dendrochirus and Pterois. MP, ML, and NJ phylogenetic analysis based on 964 bp of partial mitochondrial DNA sequences (cytochrome b and 16S rDNA) revealed two main clades: (1) "Pterois" clade (Pterois miles and Pterois volitans), and (2) "Pteropterus-Dendrochirus" clade (remainder of the sampled species). The position of Dendrochirus brachypterus either basal to the main clades or in the "Pteropterus-Dendrochirus" clade cannot be resolved. However, the molecular phylogeny did not support the current separation of the genera Pterois and Dendrochirus. The siblings P. miles and P. volitans are clearly separated and our results support the proposed allopatric or parapatric distribution in the Indian and Pacific Ocean. However, the present analysis cannot reveal if P. miles and P. volitans are separate species or two populations of a single species, because the observed separation in different clades can be either explained by speciation or lineage sorting. Molecular clock estimates for the siblings P. miles and P. volitans suggest a divergence time of 2.4-8.3 mya, which coincide with geological events that created vicariance between populations of the Indian and Pacific Ocean. PMID:12927126

  9. Computational prediction and experimental selectivity coefficients for hydroxyzine and cetirizine molecularly imprinted polymer based potentiometric sensors

    Energy Technology Data Exchange (ETDEWEB)

    Azimi, Abolfazl; Javanbakht, Mehran, E-mail: mehranjavanbakht@gmail.com

    2014-02-17

    Graphical abstract: -- Highlights: •Possible configurations template/monomer complexes were designed and optimized. •Effect of the electrostatic force on the selectivity of MIPs was investigated. •A correlation between selectivity of sensors and a charge distribution was obtained. -- Abstract: In spite of the increasing usages number of molecularly imprinted polymers (MIPs) in many scientific applications, the theoretical aspects of participating intra molecular forces are not fully understood. This work investigates effects of the electrostatic force, the Mulliken charge and the role of cavity's backbone atoms on the selectivity of MIPs. Moreover, charge distribution, which is a computational parameter, was proposed for the prediction of the selectivity coefficients of MIP-based sensors. In the computational approaches and experimental study, methacrylic acid (MAA) was chosen as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross linker for hydroxyzine and cetirizine imprinted polymers. Ab initio, DFT B3LYP method was carried out on molecular optimization. With regard to results obtained from molecules optimization and hydrogen bonding properties, possible configurations of 1:n (n ≤ 5) template/monomer complexes were designed and optimized. The binding energy for each complex in gas phase was calculated. Depending on the most stable configuration, hydroxyzine and cetirizine imprinted polymer models were designed. The calculations including the porogen were also investigated. The theoretical charge distributions for the template and some potential interfering molecules were calculated. The results showed a correlation between the selectivity coefficients and the theoretical charge distributions. The results surprisingly show that charge distribution based model was able to predict the selectivity coefficients of MIP based potentiometric sensors.

  10. Comparative Molecular Mechanics and Quantum Mechanics Study of Microhydration of Nucleic Acid Bases

    CERN Document Server

    Lino, J; Deriabina, A; Velasco, M; Poltev, V

    2013-01-01

    DNA is the most important biological molecule, and its hydration contributes essentially to the structure and functions of the double helix. We analyze the microhydration of the individual bases of nucleic acids and their methyl derivatives using methods of molecular mechanics (MM) with the Poltev-Malenkov (PM), AMBER and OPLS force fields, as well as ab initio Quantum Mechanics (QM) calculations at MP2/6-31G(d,p) level of theory. A comparison is made between the calculated interaction energies and the experimental enthalpies of microhydration of bases, obtained from mass spectrometry at low temperatures. Each local water-base interaction energy minimum obtained with MM corresponds to the minimum obtained with QM. General qualitative agreement was observed in the geometrical characteristics of the local minima obtained via the two groups of methods. MM minima correspond to slightly more coplanar structures than those obtained via QM methods, and the absolute MM energy values overestimate corresponding values ...

  11. Molecular design, synthesis and cell based HCV replicon assay of novel benzoxazole derivatives.

    Science.gov (United States)

    Ismail, M A H; Adel, M; Ismail, N S M; Abouzid, K A M

    2013-03-01

    Hepatitis C virus inhibitors based on benzoxazole scaffold were designed based on molecular modeling simulation study including docking into the NS5B polymerase active site. Several compounds showed significant high simulation docking scores relative to the assigned benzimidazole lead compound. The designed compounds were synthesized, structurally elucidated and their antiviral activity was evaluated through cell-based replicon in cultured Huh 5-2 cells. A number of the synthesized compounds showed significant inhibitory activity ranging from (52.2% inhibition up to 98% at<50 µg/mL). N-Benzyl-2-phenylbenzo[1,3]oxazole-5-carboxamide (8b) and N-Phenethyl-2-phenylbenzo[1,3] oxazole-5-carboxamide (8c) demonstrated genuine HCV inhibitory activity with EC50 values of 41.6 and 24.5 µg/mL respectively.

  12. Synthesis of molecular complexes based on porphyrins for the investigation of the energy transfer and primary charge separation in photosynthesis

    Science.gov (United States)

    Gribkova, S. E.; Evstigneeva, Rima P.; Luzgina, Valentina N.

    1993-10-01

    Data on the synthesis, steric structures, and photochemical properties of molecular diad systems based on porphyrins as synthetic models of the reaction centre in photosynthesis are considered and treated systematically. The bibliography includes 102 references.

  13. Laser-based methods for the analysis of low molecular weight compounds in biological matrices.

    Science.gov (United States)

    Kiss, András; Hopfgartner, Gérard

    2016-07-15

    Laser-based desorption and/or ionization methods play an important role in the field of the analysis of low molecular-weight compounds (LMWCs) because they allow direct analysis with high-throughput capabilities. In the recent years there were several new improvements in ionization methods with the emergence of novel atmospheric ion sources such as laser ablation electrospray ionization or laser diode thermal desorption and atmospheric pressure chemical ionization and in sample preparation methods with the development of new matrix compounds for matrix-assisted laser desorption/ionization (MALDI). Also, the combination of ion mobility separation with laser-based ionization methods starts to gain popularity with access to commercial systems. These developments have been driven mainly by the emergence of new application fields such as MS imaging and non-chromatographic analytical approaches for quantification. This review aims to present these new developments in laser-based methods for the analysis of low-molecular weight compounds by MS and several potential applications. PMID:27107904

  14. Monitoring molecular orientational order in NLO push-pull based polymeric films via photoacoustic measurements

    Science.gov (United States)

    Torres-Zúñiga, V.; Castañeda-Guzmán, R.; Morales-Saavedra, O. G.; Pérez-Martínez, A. L.; Ogawa, T.

    2011-12-01

    The pulsed-laser photoacoustic-technique (PLPA) was implemented to characterize molecular orientational order and anisotropy in push-pull poled polymeric films as function of temperature and laser polarization. Traditionally, photoacoustic signals are considered to be directly proportional to the linear optical absorption in amorphous media. In this work, however, it is shown that photoacoustic signals can also be highly sensitive to the material anisotropy when convenient polarization dependent photoacoustic analyses are performed. Thus, variation of the molecular orientation in organic films, comprising rod-like polar chromophores, can be unambiguously monitored via rms-analyses performed on the amplitude of the generated opto-acoustical PLPA-signals as function of the incident laser polarization. This result can be useful for the characterization of organic-based nonlinear optical (NLO) poled films and, in general, in studies of anisotropic materials. In fact, in this work we were able to accurately determine the molecular order parameter ( ϕ) of a NLO-active spin-coated polymeric film containing optically active push-pull chromophores. These molecules, previously oriented via an electrical-poling procedure, are capable to exhibit strong second harmonic generation (SHG) effects. The PLPA-measurements were systematically compared to the linear UV-vis optical absorbance spectra while heating the poled film sample in order to monitor the thermally induced molecular disorder, so that the order parameter may be photo-acoustically evaluated via the PLPA-signals generated from the poled to the unpoled film phase. These PLPA-experiments were performed taking into account the UV-vis reference spectra for calibration and comparison purposes in the evaluation of the order parameter. A significant advantage of the PLPA-technique over commonly used optical spectral methodologies is its convenient applicability in samples exhibiting poor or null optical transmission.

  15. Sensors based on carbon nanotube field-effect transistors and molecular recognition approaches

    OpenAIRE

    Cid Salavert, Cristina Carlota

    2009-01-01

    La unión de las propiedades de los CNT con los principios de reconocimiento molecular se presenta como una base adecuada para el desarrollo de sensores altamente específicos. El objetivo de la presente tesis ha sido desarrollar sensores químicos, del tipo transistores de efecto campo (CNTFET), basados en interacciones receptor-analito, mediante el empleo de los nanotubos de pared sencilla (SWCNT), que actúan como transductores de la señal analítica.Las principales etapas de la parte experimen...

  16. Synthesis and Anion Recognition of Novel Molecular Tweezer Receptors Based on Carbonyl Thiosemicarbazide for Fluoride Ions

    Institute of Scientific and Technical Information of China (English)

    WEI,Wei; ZHANG,You-Ming; WEI,Tai-Bao

    2008-01-01

    Three title compounds have been designed and synthesized in high yields as novel anion receptors, which show a higher selectivity for F- than other halide ions. The binding properties for fluoride ions of the receptors have been examined by UV-Vis and 1H NMR spectroscopy, indicating that a 1 : 1 stoichiometry complex is formed between the receptors and fluoride ions through hydrogen bonding interactions in DMSO solution. In addition, because these receptors have more binding points, they have better binding properties for anions than the molecular tweezer receptors based on thiourea we reported last time.

  17. Carnitine tailored Sensors on Surface Molecular Imprinting based on Graphene layers

    OpenAIRE

    Truta, Liliana A.A.N.A.; Nádia S. Ferreira; M. Goreti F. Sales

    2013-01-01

    III Jornadas de Electroquímica e Inovação (Electroquímica e Nanomateriais), na Universidade de Trás-os-Montes e Alto Douro, Vila Real, 16 a 17 de Setembro de 2013 A new biosensor based on surface molecularly imprinted polymer (MIP) on graphene layers was successfully developed. It consists in a 3D polymeric network created on top of surface and around the target template, Carnitine (CRT), a potential biomarker of ovary cancer. The polymeric structure was obtained after radical polyme...

  18. Liposome Formulation of Fullerene-Based Molecular Diagnostic and Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Zhiguo Zhou

    2013-10-01

    Full Text Available Fullerene medicine is a new but rapidly growing research subject. Fullerene has a number of desired structural, physical and chemical properties to be adapted for biological use including antioxidants, anti-aging, anti-inflammation, photodynamic therapy, drug delivery, and magnetic resonance imaging contrast agents. Chemical functionalization of fullerenes has led to several interesting compounds with very promising preclinical efficacy, pharmacokinetic and safety data. However, there is no clinical evaluation or human use except in fullerene-based cosmetic products for human skincare. This article summarizes recent advances in liposome formulation of fullerenes for the use in therapeutics and molecular imaging.

  19. Molecular Solid EOS based on Quasi-Harmonic Oscillator approximation for phonons

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-02

    A complete equation of state (EOS) for a molecular solid is derived utilizing a Helmholtz free energy. Assuming that the solid is nonconducting, phonon excitations dominate the specific heat. Phonons are approximated as independent quasi-harmonic oscillators with vibrational frequencies depending on the specific volume. The model is suitable for calibrating an EOS based on isothermal compression data and infrared/Raman spectroscopy data from high pressure measurements utilizing a diamond anvil cell. In contrast to a Mie-Gruneisen EOS developed for an atomic solid, the specific heat and Gruneisen coefficient depend on both density and temperature.

  20. Theoretical study of the molecular bases that control photochemical processes with biological and nanotechnological interest

    OpenAIRE

    Saurí Peris, Vicenta

    2013-01-01

    El trabajo desarrollado en la tesis doctoral que lleva por título "Theoretical study of the molecular bases that control photochemical processes with biological and nanotechnological interest" se enmarca en las líneas de investigación del grupo QCEXVAL (Quantum Chemistry of the Excited State University of Valencia), que nació en el seno del departamento de Química Física de la Universitat de València en 1993. Se han abordado temas de interés metodológico, biológico y nanotecnológico. La prime...

  1. Ion Pair in Extreme Aqueous Environments, Molecular-Based and Electric Conductance Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Chialvo, Ariel A [ORNL; Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Simonson, J Michael {Mike} [ORNL; Palmer, Donald [ORNL; Cole, David R [ORNL

    2009-01-01

    We determine by molecular-based simulation the density profiles of the Na+!Cl! ion-pair association constant in steam environments along three supercritical isotherms to interrogate the behavior of ion speciation in dilute aqueous solutions at extreme conditions. Moreover, we describe a new ultra-sensitive flow-through electric conductance apparatus designed to bridge the gap between the currently lowest steam-density conditions at which we are experimentally able to attain electric conductance measurements and the theoretically-reachable zero-density limit. Finally, we highlight important modeling challenges encountered near the zero-density limit and discuss ways to overcome them.

  2. Determination of phylogenetic position of Pipizini (Diptera: Syrphidae): based on molecular biological and morphological data

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the sequence analysis of 5.8S subunit and internal transcribed spacers (ITS ) of ribosomal RNA gene (rDNA), the molecular phylogenetic tree of representative species of Pipizini and three groups of Syrphidae with different feeding habits (seven species belong to six genera) was constructed. Meanwhile, the phylogenetic tree of tribes (including Pipizini and other 17 tribes of Syrphidae) was constructed using morphological characteristics of adults and larvae and the number of chromosomes. Both the results show that the relationship between Pipizini and predatory groups is closer than that between Pipizini and saprophagous groups. So it is suggested that Pipizini be transferred from Milesiinae to Syrphinae.

  3. Molecular Solid EOS based on Quasi-Harmonic Oscillator approximation for phonons

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-02

    A complete equation of state (EOS) for a molecular solid is derived utilizing a Helmholtz free energy. Assuming that the solid is nonconducting, phonon excitations dominate the specific heat. Phonons are approximated as independent quasi-harmonic oscillators with vibrational frequencies depending on the specific volume. The model is suitable for calibrating an EOS based on isothermal compression data and infrared/Raman spectroscopy data from high pressure measurements utilizing a diamond anvil cell. In contrast to a Mie-Gr ̈uneisen EOS developed for an atomic solid, the specific heat and Gr ̈uneisen coefficient depend on both density and temperature.

  4. Hydration of methanol in water. A DFT-based molecular dynamics study

    CERN Document Server

    Van Erp, T S; Erp, Titus S. van; Meijer, Evert Jan

    2000-01-01

    We studied the hydration of a single methanol molecule in aqueous solution by first-principle DFT-based molecular dynamics simulation. The calculations show that the local structural and short-time dynamical properties of the water molecules remain almost unchanged by the presence of the methanol, confirming the observation from recent experimental structural data for dilute solutions. We also see, in accordance with this experimental work, a distinct shell of water molecules that consists of about 15 molecules. We found no evidence for a strong tangential ordering of the water molecules in the first hydration shell.

  5. A description of the mechanical behavior of composite solid propellants based on molecular theory

    Science.gov (United States)

    Landel, R. F.

    1976-01-01

    Both the investigation and the representation of the stress-strain response (including rupture) of gum and filled elastomers can be based on a simple functional statement. Internally consistent experiments are used to sort out the effects of time, temperature, strain and crosslink density on gum rubbers. All effects are readily correlated and shown to be essentially independent of the elastomer when considered in terms of non-dimensionalized stress, strain and time. A semiquantitative molecular theory is developed to explain this result. The introduction of fillers modifies the response, but, guided by the framework thus provided, their effects can be readily accounted for.

  6. Framework for single input single output nanonetwork-based realistic molecular communication.

    Science.gov (United States)

    Abd El-Atty, Saied M; Gharsseldien, Zakaria M; Lizos, Konstantinos A

    2015-12-01

    Mobile ad hoc molecular nanonetwork (MAMNET) is a new paradigm for the realisation of future nanonetworks. In MAMNET, transmission of nanoscale information from nanomachine to infostation is based on collision and adhesion. In this study, the authors develop a realistic framework for encompassing the electronic structure of the neurotransmitter in the process of transmitting nanoscale information at a single input single output nanonetwork. Nanonetwork performance is evaluated in terms of average packet delay, throughput and incurred traffic rate. Numerical results demonstrate the influence of the neurotransmitter's electronic structure over the performance of nanonetworks.

  7. Nanoscale switch based on interacting molecular dipoles: Cooperativity can improve the device characteristics

    Science.gov (United States)

    Mafé, , Salvador; Manzanares, , José A.; Reiss, Howard

    2011-02-01

    We propose a nanoscale switch, giving a nonlinear function with two conductive states separated by a sharp transition region, on the basis of an array of molecular dipoles. We show theoretically that the local interactions between dipoles result in cooperative phenomena that can significantly improve the switching characteristics. We demonstrate the general validity of the concept in the cases of (i) an electrical switch robust to the finite size and variability effects inherent to the nanoscale and (ii) a sensing layer based on the voltage and ligand concentration dependence of the dipole array conductance.

  8. Carfilzomib en el tratamiento de mieloma múltiple: revisión sistemática de la literatura y experiencia colombiana basada en RIPS / Carfilzomib for the Treatment of Multiple Myeloma: Systematic Review of the Literature and Colombian Experience Based on RIPS / Carfilzomib no tratamento do mieloma múltiplo: revisão da literatura e da experiência colombiana baseada em RIPS

    Directory of Open Access Journals (Sweden)

    Camilo Castañeda, MD.

    2014-11-01

    Full Text Available Introducción: El mieloma múltiple es un tumor maligno y progresivo de las células B asociado a lesiones osteolíticas, inmunodeficiencia y disfunción renal que ha sido tratado desde 2008 con bortezomib con el cual se logró un aumento del tiempo de sobrevida de los pacientes, sin embargo su uso se vio limitado por efectos adversos dependientes de la dosis, en especial la neuropatía periférica dolorosa. Recientemente ha entrado en uso carfilzomib (agente inhibidor de proteosoma de segunda generación aprobado por la FDA en 2012 como agente único para tratamiento de enfermedad refractaria y recaídas de mieloma múltiple. Objetivo: Realizar una revisión de la literatura y determinar la experiencia colombiana con el medicamento carfilzomib teniendo en cuenta las estadísticas nacionales consignadas en los registros individuales de prestación de servicios de salud. Además se describe la situación de un caso clínico. Metodología: La revisión se hizo con base en literatura indexada en PubMed; como criterio de inclusión se tuvo en cuenta que los artículos a revisar fueran estudios clínicos de fase 2 y 3 de carfilzomib en manejo de mieloma múltiple. Respecto a la experiencia colombiana se identificaron 37 pacientes colombianos con mieloma múltiple diagnosticado entre 2003 y 2012 y a quienes se hubiera prescrito carfilzomib, teniendo en cuenta información proporcionada por Biotoscana. Resultados: En total se localizaron 8 estudios clínicos con asignación al azar que evidencian efectos adversos no hematológicos como fatiga (367 de los 678 pacientes, 54%, y náusea (323 pacientes, 48%. En el caso de los RIPS, de los 37 pacientes, 22 pacientes recibieron de 1 a 8 ciclos de carfilzomib (promedio 3.0, mediana 3. Se evaluó la respuesta clínica en 9 de ellos, encontrándose 4 pacientes (22% en respuesta parcial muy buena, 4 pacientes (22% en respuesta parcial, 1 paciente (6% con enfermedad estable. Conclusiones: Se encontró diferencia

  9. Cambiar paradigmas: una experiencia en educación superior

    Directory of Open Access Journals (Sweden)

    Gisella Vargas Chinchilla

    2004-09-01

    Full Text Available

    Resumen. Una experiencia en educación superior, al estilo de investigación-acción, donde una “comunidad de aprendizaje” constituida por docentes y estudiantes, busca convertirse en entes multiplicadores del desarrollo sostenible, dentro del plan de formación de docentes de Educación Preescolar.

    Esta investigación constituye el Trabajo final de Graduación, requisito de un grupo de estudiantes para obtener el grado de Licenciadas en Educación Preescolar, en la Universidad de Costa Rica. El proceso metodológico dio inicio con un diagnóstico, para seguir con un plan de acción, organizado y desarrollado en conjunto, estudiantes y docentes, para culminar con la aceptación de “compromisos ambientales” asumidos por las personas participantes.

     

    Abstract. This is a research-action type of experience in higher education lived by a “learning community” conformed by teachers and students whose aim is to become fostering agents for sustainable development. The experience was carried out as part of the plan for teacher training in Preschool Education.

    This paper is the authors' Final Graduation Paper, a requirement to obtain a Licentiate degree in Preschool Education at the University of Costa Rica. The research began with a diagnosis that would lead to the implementation of an action plan that was organized and carried out jointly by the students and their teachers. The project finished with the participants' acceptance of some “environmental commitments”.

  10. Phylogeny of genera Laminaria and Saccharina (Laminariales, Phaeophyceae) based on three molecular markers

    Institute of Scientific and Technical Information of China (English)

    CHI Shan; QIAN Hao; LI Tianyong; WANG Xumin; LIU Cui; REN Lei; TANG Xuexi; LIU Tao

    2014-01-01

    In the past two decades, many studies have focused on the classification within genus Laminaria, ultimately trying to divide it into two subgroups or genera:Laminaria and Saccharina. A significant debate still sur-rounds the question of its division, as the conflicting phylogenetic hypotheses that have resulted from the classification studies are based on different taxon sampling, molecular markers, or analysis methods. It is aimed at elucidate the molecular phylogeny within Laminaria and Saccharina. The nine species of Lami-nariales are sampled from northern Asia and Europe, and 23 new sequences in the nuclear, plastid, and mitochondrial genomes are determined to identify their taxonomic status. The phylogenetic analyses of 71 species are performed, including representatives from six of the seven families of the order Laminariales, based on three separate data sets. An evidence is provided to strongly support a clear split that maintains the two recognized genera, Laminaria and Saccharina, with Laminaria appearing to be the ancestor group. Further, analyses indicate that all taxa in Saccharina and Laminaria did not form a monophyletic lineage, instead Laminariaceae and Lessoniaceae grouped together interlacedly, and Costariaceae appeared as the sister taxon of the Lessoniaceae-Laminariaceae clade. In the phylogenetic analysis, mitochondrial c oxi-dase I (COI) sequences appeared to be the most credible molecular marker which was more befitting than nuclear encoded internal transcribed spacer (ITS) and plastid encoded rbcL for establishment of Laminari-ales systematics. It is the most comprehensive phylogeny of the order Laminariales, and contributes to an enhanced understanding and estimation of the phylogenetic relationships for the economically important seaweeds, Laminaria and Saccharina.

  11. Hybrid Materials Based on Magnetic Layered Double Hydroxides: A Molecular Perspective.

    Science.gov (United States)

    Abellán, Gonzalo; Martí-Gastaldo, Carlos; Ribera, Antonio; Coronado, Eugenio

    2015-06-16

    Design of functional hybrids lies at the very core of synthetic chemistry as it has enabled the development of an unlimited number of solids displaying unprecedented or even improved properties built upon the association at the molecular level of quite disparate components by chemical design. Multifunctional hybrids are a particularly appealing case among hybrid organic/inorganic materials. Here, chemical knowledge is used to deploy molecular components bearing different functionalities within a single solid so that these properties can coexist or event interact leading to unprecedented phenomena. From a molecular perspective, this can be done either by controlled assembly of organic/inorganic molecular tectons into an extended architecture of hybrid nature or by intercalation of organic moieties within the empty channels or interlamellar space offered by inorganic solids with three-dimensional (MOFs, zeolites, and mesoporous hosts) or layered structures (phosphates, silicates, metal dichalcogenides, or anionic clays). This Account specifically illustrates the use of layered double hydroxides (LDHs) in the preparation of magnetic hybrids, in line with the development of soft inorganic chemistry processes (also called "Chimie Douce"), which has significantly contributed to boost the preparation hybrid materials based on solid-state hosts and subsequent development of applications. Several features sustain the importance of LDHs in this context. Their magnetism can be manipulated at a molecular level by adequate choice of constituting metals and interlayer separation for tuning the nature and extent of magnetic interactions across and between planes. They display unparalleled versatility in accommodating a broad range of anionic species in their interlamellar space that encompasses not only simple anions but chemical systems of increasing dimensionality and functionalities. Their swelling characteristics allow for their exfoliation in organic solvents with high

  12. Experiencia de podcasting en la enseñanza de una segunda lengua

    Directory of Open Access Journals (Sweden)

    Heidy Selene Robles Noriega

    2011-01-01

    Full Text Available Hoy en día el aprendizaje móvil está adquiriendo bastante auge en todas las áreas del conocimiento, en especial en el aprendizaje de una segunda lengua. El presente artículo tiene por objetivo describir los resultados de una experiencia piloto realizada con un grupo de estudiantes de primer semestre de Relaciones Internacionales en la asignatura de inglés, nivelatorio. La finalidad de esta experiencia es mejorar las habilidades auditivas apoyadas con aprendizaje móvil. Para ello, se implementaron archivos de audio llamados podcasts a través de dispositivos móviles. Se diseñaron siete podcasts teniendo en cuenta las necesidades y falencias de los estudiantes. Los resultados de esta experiencia fueron favorables.

  13. A clinical-molecular update on azanucleoside-based therapy for the treatment of hematologic cancers.

    Science.gov (United States)

    Diesch, Jeannine; Zwick, Anabel; Garz, Anne-Kathrin; Palau, Anna; Buschbeck, Marcus; Götze, Katharina S

    2016-01-01

    The azanucleosides azacitidine and decitabine are currently used for the treatment of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) in patients not only eligible for intensive chemotherapy but are also being explored in other hematologic and solid cancers. Based on their capacity to interfere with the DNA methylation machinery, these drugs are also referred to as hypomethylating agents (HMAs). As DNA methylation contributes to epigenetic regulation, azanucleosides are further considered to be among the first true "epigenetic drugs" that have reached clinical application. However, intriguing new evidence suggests that DNA hypomethylation is not the only mechanism of action for these drugs. This review summarizes the experience from more than 10 years of clinical practice with azanucleosides and discusses their molecular actions, including several not related to DNA methylation. A particular focus is placed on possible causes of primary and acquired resistances to azanucleoside treatment. We highlight current limitations for the success and durability of azanucleoside-based therapy and illustrate that a better understanding of the molecular determinants of drug response holds great potential to overcome resistance. PMID:27330573

  14. Molecular Imaging of Tumor Hypoxia: Existing Problems and Their Potential Model-Based Solutions.

    Science.gov (United States)

    Shi, Kuangyu; Ziegler, Sibylle I; Vaupel, Peter

    2016-01-01

    Molecular imaging of tissue hypoxia generates contrast in hypoxic areas by applying hypoxia-specific tracers in organisms. In cancer tissue, the injected tracer needs to be transported over relatively long distances and accumulates slowly in hypoxic regions. Thus, the signal-to-background ratio of hypoxia imaging is very small and a non-specific accumulation may suppress the real hypoxia-specific signals. In addition, the heterogeneous tumor microenvironment makes the assessment of the tissue oxygenation status more challenging. In this study, the diffusion potential of oxygen and of a hypoxia tracer for 4 different hypoxia subtypes: ischemic acute hypoxia, hypoxemic acute hypoxia, diffusion-limited chronic hypoxia and anemic chronic hypoxia are theoretically assessed. In particular, a reaction-diffusion equation is introduced to quantitatively analyze the interstitial diffusion of the hypoxia tracer [(18)F]FMISO. Imaging analysis strategies are explored based on reaction-diffusion simulations. For hypoxia imaging of low signal-to-background ratio, pharmacokinetic modelling has advantages to extract underlying specific binding signals from non-specific background signals and to improve the assessment of tumor oxygenation. Different pharmacokinetic models are evaluated for the analysis of the hypoxia tracer [(18)F]FMISO and optimal analysis model were identified accordingly. The improvements by model-based methods for the estimation of tumor oxygenation are in agreement with experimental data. The computational modelling offers a tool to explore molecular imaging of hypoxia and pharmacokinetic modelling is encouraged to be employed in the corresponding data analysis. PMID:27526129

  15. Network analysis of genes regulated in renal diseases: implications for a molecular-based classification

    Directory of Open Access Journals (Sweden)

    Jagadish HV

    2009-09-01

    Full Text Available Abstract Background Chronic renal diseases are currently classified based on morphological similarities such as whether they produce predominantly inflammatory or non-inflammatory responses. However, such classifications do not reliably predict the course of the disease and its response to therapy. In contrast, recent studies in diseases such as breast cancer suggest that a classification which includes molecular information could lead to more accurate diagnoses and prediction of treatment response. This article describes how we extracted gene expression profiles from biopsies of patients with chronic renal diseases, and used network visualizations and associated quantitative measures to rapidly analyze similarities and differences between the diseases. Results The analysis revealed three main regularities: (1 Many genes associated with a single disease, and fewer genes associated with many diseases. (2 Unexpected combinations of renal diseases that share relatively large numbers of genes. (3 Uniform concordance in the regulation of all genes in the network. Conclusion The overall results suggest the need to define a molecular-based classification of renal diseases, in addition to hypotheses for the unexpected patterns of shared genes and the uniformity in gene concordance. Furthermore, the results demonstrate the utility of network analyses to rapidly understand complex relationships between diseases and regulated genes.

  16. Lipid-based nanocarrier for quercetin delivery: system characterization and molecular interactions studies.

    Science.gov (United States)

    Hädrich, Gabriela; Monteiro, Samantha Oliveira; Rodrigues, Marisa Raquel; de Lima, Vânia Rodrigues; Putaux, Jean-Luc; Bidone, Juliana; Teixeira, Helder Ferreira; Muccillo-Baisch, Ana Luiza; Dora, Cristiana Lima

    2016-07-01

    The flavonoid quercetin (QU) is a naturally occurring compound with several biological activities. However, the oral bioavailability of this compound is very low due to the high pre-systemic metabolism in the colon and liver and its low water solubility. In this context, the development of QU-loaded nanocarriers (NEs) is a promising approach to improve the drug oral bioavailability. This study investigates the variation of the concentration of 12-hydroxystearic acid-polyethylene glycol copolymer, lecithin and castor oil (CO) as to increase the amount of QU encapsulated while maintaining physicochemical characteristics described in previous studies. To better understand the ability to load and release the drug, we investigated the molecular interactions between QU and NE. Lipid-based NEs were prepared using CO as oily phase and PEG 660-stearate and lecithin as surfactants. Hot solvent diffusion and phase inversion temperature were methods employed to produce NEs. The QU-NEs were investigated for physicochemical characteristics and in vitro drug release. Molecular interactions between QU and the NEs were monitored through the complementary infrared (Fourier transform infrared) and NMR. The results revealed that it was possible to incorporate higher amounts of QU in a lipid-based NE with a reduced size (20 nm). The system developed allow a sustained release of QU probably due to the shell formed by the surfactants around the NE and the flavonoid ordering effect in the emulsion hydrophobic regions, which may reduce the system permeability. PMID:26571009

  17. Hydrazone based molecular glasses for solid-state dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Biscarbazole and terthiophene based molecular glasses with hydrazone functional goups (named respectively 2CzMPH and 3TDPH) have been synthesized and the thermal, optical and electrochemical properties have been studied. Differential scanning calorimetry characterizations confirm the metastable amorphous properties of these molecules with glass transition temperatures at 80 deg. C for the 3TDPH and 93 deg. C for the 2CzMPH. Their electrochemical properties have been studied and showed the effect of the conjugated hydrazone groups on the electronic delocalization of the structures. The concept of solid state dye-sensitized solar cells using hydrazone based molecular glasses has been verified with the elaboration of a SnO2: F/nc-TiO2/Ru-dye/2CzMPH /Au devices. Under full sunlight (98 mW/cm2, air mass 1.5) the I-V characterization of the device give a short circuit photocurrents Isc = 0.42 mA/cm2, open circuit voltage Voc = 500 mV with a fill factor of 0.35

  18. Molecular beacon-based enzyme-free strategy for amplified DNA detection.

    Science.gov (United States)

    Huang, Jiahao; Wu, Jueqi; Li, Zhigang

    2016-05-15

    We report an enzyme-free, sensitive strategy for DNA detections through fluorescence amplification. The sensing method employs molecular beacons (MBs) and two single-stranded helper DNA probes. In the presence of a DNA target, it binds and opens an MB. This triggers the hybridizations between the MB and helper probes, and consequently releases the DNA target, which becomes available to react with another MB and enhances the fluorescence emission of the MBs. The detection limit of the proposed strategy is 0.58 pM, which is about 3 orders of magnitude better than the conventional MB-based method. This method is also fast and exhibits good selectivity. It is superior to previous MB-based amplification approaches employing enzymes or nanomaterials. PMID:26774091

  19. Remote Stabilization of Copper Paddlewheel Based Molecular Building Blocks in Metal-Organic Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wen-Yang; Cai, Rong; Pham, Tony; Forrest, Katherine A.; Hogan, Adam; Nugent, Patrick; Williams, Kia; Wojtas, Lukasz; Luebke, Ryan; Weseli; #324; ski, Lukasz J.; Zaworotko, Michael J.; Space, Brian; Chen, Yu-Sheng; Eddaoudi, Mohamed; Shi, Xiaodong; Ma, Shengqian (KAUST); (UC); (USF); (WVU)

    2015-08-21

    Copper paddlewheel based molecular building blocks (MBBs) are ubiquitous and have been widely employed for the construction of highly porous metal–organic frameworks (MOFs). However, most copper paddlewheel based MOFs fail to retain their structural integrity in the presence of water. This instability is directly correlated to the plausible displacement of coordinating carboxylates in the copper paddlewheel MBB, [Cu₂(O₂C-)₄], by the strongly coordinating water molecules. In this comprehensive study, we illustrate the chemical stability control in the rht-MOF platform via strengthening the coordinating bonds within the triangular inorganic MBB, [Cu₃O(N4–x(CH)xC-)₃] (x = 0, 1, or 2). Remotely, the chemical stabilization propagated into the paddlewheel MBB to afford isoreticular rht-MOFs with remarkably enhanced water/chemical stabilities compared to the prototypal rht-MOF-1.

  20. Functionality in Electrospun Nanofibrous Membranes Based on Fiber’s Size, Surface Area, and Molecular Orientation

    Directory of Open Access Journals (Sweden)

    Akihiko Tanioka

    2011-08-01

    Full Text Available Electrospinning is a versatile method for forming continuous thin fibers based on an electrohydrodynamic process. This method has the following advantages: (i the ability to produce thin fibers with diameters in the micrometer and nanometer ranges; (ii one-step forming of the two- or three-dimensional nanofiber network assemblies (nanofibrous membranes; and (iii applicability for a broad spectrum of molecules, such as synthetic and biological polymers and polymerless sol-gel systems. Electrospun nanofibrous membranes have received significant attention in terms of their practical applications. The major advantages of nanofibers or nanofibrous membranes are the functionalities based on their nanoscaled-size, highly specific surface area, and highly molecular orientation. These functionalities of the nanofibrous membranes can be controlled by their fiber diameter, surface chemistry and topology, and internal structure of the nanofibers. This report focuses on our studies and describes fundamental aspects and applications of electrospun nanofibrous membranes.

  1. Ribozyme probe based on molecular beacon for real time monitoring of enzymatic cleavage process

    Institute of Scientific and Technical Information of China (English)

    MENG Xiangxian; WANG Kemin; TAN Weihong; LI Jun; TANG Zhiwen; GUO Qiuping; HUANG Shasheng; LI Du

    2003-01-01

    Ribozyme probe based on molecular beacon (MBR) for monitoring enzymatic cleavage process in real time is designed and studied. The approach relies on ribozyme substrates modified at the two arms, with a fluorescent moiety attached to the end of one arm and a non-fluorescent quenching moiety attached to the end of the other arm. MBR is employed to directly convert the cleavage information into fluorescence signal in real time. Compared with traditional approach, this method provides a no-radiolabeling, sensitive and effective way to research on the ribozyme activity, enzymatic dynamic process and ribozyme function during gene therapy. The activity of the ribozyme against hepatitis C virus RNA (HCV-RNA) is studied based on this assay.

  2. Molecular beacon-based enzyme-free strategy for amplified DNA detection.

    Science.gov (United States)

    Huang, Jiahao; Wu, Jueqi; Li, Zhigang

    2016-05-15

    We report an enzyme-free, sensitive strategy for DNA detections through fluorescence amplification. The sensing method employs molecular beacons (MBs) and two single-stranded helper DNA probes. In the presence of a DNA target, it binds and opens an MB. This triggers the hybridizations between the MB and helper probes, and consequently releases the DNA target, which becomes available to react with another MB and enhances the fluorescence emission of the MBs. The detection limit of the proposed strategy is 0.58 pM, which is about 3 orders of magnitude better than the conventional MB-based method. This method is also fast and exhibits good selectivity. It is superior to previous MB-based amplification approaches employing enzymes or nanomaterials.

  3. SchiffBase Dinuclear Complex Catalyst for Oxidation of Cyclohexene with Molecular Oxygen

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ In the past decades, the oxidation of hydrocarbons by transition metal complexes has been studied extensively. The current progress of the research on synthetic quasiporphyrin catalysts has led to the development of several systems that are able to reproduce the hene-enzyme mediated oxygenation and oxidation reactions[1]. In our group[2,51, the mononuclear complexes of amino acid Schiff base have been synthesized and their catalytic oxidation has been studied. In this paper, two dinuclear complexes, such as Salicylidence-β-alanine-Co(II)-Cu(II) and Salicylidence-β-alanine-Co(II)Mn(II), were prepared with amino acid Schiff bases and metal ions. In the presence of these dinuclear complexes, cyclohexene was effectively oxidized under 1 atm of molecular oxygen without any coreductants. The allylic hydroperoxide was obtained as an important product, which suggested a clear allylic pathway of oxidation of cyclohexene.

  4. SchiffBase Dinuclear Complex Catalyst for Oxidation of Cyclohexene with Molecular Oxygen

    Institute of Scientific and Technical Information of China (English)

    SHAO; DongXu

    2001-01-01

    In the past decades, the oxidation of hydrocarbons by transition metal complexes has been studied extensively. The current progress of the research on synthetic quasiporphyrin catalysts has led to the development of several systems that are able to reproduce the hene-enzyme mediated oxygenation and oxidation reactions[1]. In our group[2,51, the mononuclear complexes of amino acid Schiff base have been synthesized and their catalytic oxidation has been studied. In this paper, two dinuclear complexes, such as Salicylidence-β-alanine-Co(II)-Cu(II) and Salicylidence-β-alanine-Co(II)Mn(II), were prepared with amino acid Schiff bases and metal ions. In the presence of these dinuclear complexes, cyclohexene was effectively oxidized under 1 atm of molecular oxygen without any coreductants. The allylic hydroperoxide was obtained as an important product, which suggested a clear allylic pathway of oxidation of cyclohexene.  ……

  5. Initiating Heavy-atom Based Phasing by Multi-Dimensional Molecular Replacement

    DEFF Research Database (Denmark)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu;

    2014-01-01

    in the determination of a membrane protein structure, the CopA Cu+-ATPase, when other methods had failed to resolve the heavy atom substructure. MRPM is particularly suited for proteins undergoing large conformational changes where multiple search models should be generated, and it enables the identification of weak......To obtain an electron-density map from a macromolecular crystal the phase-problem needs to be solved, which often involves the use of heavy-atom derivative crystals and concomitantly the determination of the heavy atom substructure. This is customarily done by direct methods or Patterson......-based approaches, which however may fail when only poorly diffracting derivative crystals are available, as often the case for e.g. membrane proteins. Here we present an approach for heavy atom site identification based on a Molecular Replacement Parameter Matrix (MRPM) search. It involves an n-dimensional search...

  6. Labyrinthine water flow across multilayer graphene-based membranes: molecular dynamics versus continuum predictions

    CERN Document Server

    Yoshida, Hiroaki

    2016-01-01

    In this paper we investigate the hydrodynamic permeance of water through graphene-based membranes, inspired by recent experimental findings on graphene-oxide membranes. We consider the flow across multiple graphene layers having nanoslits in a staggered alignment, with an inter-layer distance ranging from sub- nanometer to a few nanometers. We compare results for the permeability obtained by means of molecular dynamics simulations to continuum predictions obtained by using the lattice Boltzmann calculations and hydrodynamic modelization. This highlights that, in spite of extreme confinement, the permeability across the graphene-based membrane is quantitatively predicted on the basis of a continuum expression, taking properly into account entrance and slippage effects of the confined water flow. Our predictions refute the breakdown of hydrodynamics at small scales in these membrane systems. They constitute a benchmark to which we compare published experimental data.

  7. Syntheses of Ferrocenyl Schiff Bases Using Molecular Sieves and AlCl3 as Catalysts

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In order to study the donor ability of ferrocenylimines as directing ortho metalation group(DMG) to lithium alkylide to prepare planar chiral ferrocene, a series of ferrocenyl schiff bases were synthesized by new methods using molecular sieves(0.4nm) and AlCl3 as catalysts. The reaction periods were reduced using these two catalysts in contrast with Al2O3, which was a traditional method used in the literature. In addition, as an important feature of these schiff bases, we found that they were unstable as oils in air or when filtrated through silica gel, but were stable as solids. The structures of the new compounds were confirmed by IR, 1H NMR and HRMS.

  8. Innovative molecular-based fluorescent nanoparticles for multicolor single particle tracking in cells

    Science.gov (United States)

    Daniel, Jonathan; Godin, Antoine G.; Palayret, Matthieu; Lounis, Brahim; Cognet, Laurent; Blanchard-Desce, Mireille

    2016-03-01

    Based on an original molecular-based design, we present bright and photostable fluorescent organic nanoparticles (FONs) showing excellent colloidal stability in various aqueous environments. Complementary near-infrared emitting and green emitting FONs were prepared using a simple, fast and robust protocol. Both types of FONs could be simultaneously imaged at the single-particle level in solution as well as in biological environments using a monochromatic excitation and a dual-color fluorescence microscope. No evidence of acute cytotoxicity was found upon incubation of live cells with mixed solutions of FONs, and both types of nanoparticles were found internalized in the cells where their motion could be simultaneously tracked at video-rate up to minutes. These fluorescent organic nanoparticles open a novel non-toxic alternative to existing nanoparticles for imaging biological structures, compatible with live-cell experiments and specially fitted for multicolor single particle tracking.

  9. Exploring Programmable Self-Assembly in Non-DNA based Molecular Computing

    CERN Document Server

    Terrazas, German; Krasnogor, Natalio

    2013-01-01

    Self-assembly is a phenomenon observed in nature at all scales where autonomous entities build complex structures, without external influences nor centralised master plan. Modelling such entities and programming correct interactions among them is crucial for controlling the manufacture of desired complex structures at the molecular and supramolecular scale. This work focuses on a programmability model for non DNA-based molecules and complex behaviour analysis of their self-assembled conformations. In particular, we look into modelling, programming and simulation of porphyrin molecules self-assembly and apply Kolgomorov complexity-based techniques to classify and assess simulation results in terms of information content. The analysis focuses on phase transition, clustering, variability and parameter discovery which as a whole pave the way to the notion of complex systems programmability.

  10. Remote stabilization of copper paddlewheel based molecular building blocks in metal-organic frameworks

    KAUST Repository

    Gao, Wenyang

    2015-03-24

    Copper paddlewheel based molecular building blocks (MBBs) are ubiquitous and have been widely employed for the construction of highly porous metal-organic frameworks (MOFs). However, most copper paddlewheel based MOFs fail to retain their structural integrity in the presence of water. This instability is directly correlated to the plausible displacement of coordinating carboxylates in the copper paddlewheel MBB, [Cu2(O2C-)4], by the strongly coordinating water molecules. In this comprehensive study, we illustrate the chemical stability control in the rht-MOF platform via strengthening the coordinating bonds within the triangular inorganic MBB, [Cu3O(N4-x(CH)xC-)3] (x = 0, 1, or 2). Remotely, the chemical stabilization propagated into the paddlewheel MBB to afford isoreticular rht-MOFs with remarkably enhanced water/chemical stabilities compared to the prototypal rht-MOF-1. © 2015 American Chemical Society.

  11. Molecular thermodynamic modeling of ionic liquids using the perturbation-based linear Yukawa isotherm regularity.

    Science.gov (United States)

    Sohrabi Mahboub, Mahdi; Farrokhpour, Hossein

    2016-06-15

    In this paper, we present the results of an extensive study on a novel approach to the molecular modeling of pure ionic liquids (ILs) that incorporates the perturbed thermodynamic linear Yukawa isotherm regularity (LYIR), which is derived based on an effective nearest neighboring pair attractive interaction of the Yukawa potential. The LYIR was used to model the densities of ILs up to high pressures (35 MPa) and in the temperature range 293.15 to 393.15 K. To use the LYIR for ILs, a simple molecular model was proposed to describe their molecular structure, in which they were considered as a liquid consisting of the ion pairs moving together in the fluid, and each ion pair was assumed to be a one-center spherical united atom. The ILs under consideration contained one of the IL cations [C2mim](+), [C4mim](+), [C7mim](+), [C8mim](+), [C3mpy](+), [C3mpip](+), [C3mpyr](+) or [C4mpyr](+), and one of the IL anions [BF4](-), [C(CN)3](-), [CF3SO4](-) or [NTf2](-). The reliability and physical significance of the parameters as well as the proposed molecular model were tested by calculating the densities of pure imidazolium-, pyridinium-, piperidinium- and pyrrolidimium-based ILs. The results showed that the LYIR can be used to predict and reproduce the density of ILs in good agreement with the experimental data. In addition, the LYIR enabled us to determine the physical quantities, such as an effective Yukawa screening length, λ eff, the product of the effective energy well depth and the effective coordination number, (ε eff/k)z eff, the contribution of the non-reference thermal pressure and also the influence of the anionic and cationic structure on the λ eff parameter. The standard deviation of the IL densities predicted in this work is lower than those calculated by the one other important equation of state reported in the literature. PMID:27157142

  12. Molecular thermodynamic modeling of ionic liquids using the perturbation-based linear Yukawa isotherm regularity

    Science.gov (United States)

    Sohrabi Mahboub, Mahdi; Farrokhpour, Hossein

    2016-06-01

    In this paper, we present the results of an extensive study on a novel approach to the molecular modeling of pure ionic liquids (ILs) that incorporates the perturbed thermodynamic linear Yukawa isotherm regularity (LYIR), which is derived based on an effective nearest neighboring pair attractive interaction of the Yukawa potential. The LYIR was used to model the densities of ILs up to high pressures (35 MPa) and in the temperature range 293.15 to 393.15 K. To use the LYIR for ILs, a simple molecular model was proposed to describe their molecular structure, in which they were considered as a liquid consisting of the ion pairs moving together in the fluid, and each ion pair was assumed to be a one-center spherical united atom. The ILs under consideration contained one of the IL cations [C2mim]+, [C4mim]+, [C7mim]+, [C8mim]+, [C3mpy]+, [C3mpip]+, [C3mpyr]+ or [C4mpyr]+, and one of the IL anions [BF4]‑, [C(CN)3]‑, [CF3SO4]‑ or [NTf2]‑. The reliability and physical significance of the parameters as well as the proposed molecular model were tested by calculating the densities of pure imidazolium-, pyridinium-, piperidinium- and pyrrolidimium-based ILs. The results showed that the LYIR can be used to predict and reproduce the density of ILs in good agreement with the experimental data. In addition, the LYIR enabled us to determine the physical quantities, such as an effective Yukawa screening length, λ eff, the product of the effective energy well depth and the effective coordination number, (ε eff/k)z eff, the contribution of the non-reference thermal pressure and also the influence of the anionic and cationic structure on the λ eff parameter. The standard deviation of the IL densities predicted in this work is lower than those calculated by the one other important equation of state reported in the literature.

  13. Una experiencia de conocimiento situado: la línea de Jóvenes y Culturas Juveniles del DIUC

    Directory of Open Access Journals (Sweden)

    José Fernando Serrano A.

    2009-04-01

    Full Text Available El artículo presenta una mirada retrospectiva a la línea de Investigación en Jóvenes y Culturas Juveniles del IESCO (DIUC entre 1998-2004. Para ello, se observan las preguntas de partida, los ejes de la reflexión y sus resultados. A lo largo del período observado se produce una pérdida de seguridad en la comprensión de los sujetos jóvenes desde lógicas descriptivas, y se pasa más bien a observar los procesos de subjetivación juvenil. Con base en ello, se caracteriza el conocimiento producido por la línea como una experiencia parcial, localizada, corporeizada y crítica de los estudios de juventud.

  14. Explorando el rol de la visualización en experiencias de cátedra

    OpenAIRE

    Torroba, Estela; Etcheverry, Nilda; Reid, Marisa

    2009-01-01

    El presente trabajo incursiona en la conjunción tecnología-educación matemática. Presenta el relato de experiencias desarrolladas con estudiantes universitarios al trabajar en un ambiente computacional con una propuesta didáctica diferencial basada en la visualización. Se reportan observaciones que muestran características del trabajo realizado por estudiantes y docentes en el ambiente en el cual se llevaron a cabo las experiencias y algunas conclusiones vinculadas con el rol de la visuali...

  15. La Experiencia y el tiempo de la creación siendo fiel al origen

    OpenAIRE

    Varela-Rodríguez, M. Elisa

    2007-01-01

    Quiero tratar el tiempo de la creación acercando mi experiencia en el trabajo como historiadora y docente sin perder el punto de vista del origen. Pero, ¿qué es el tiempo? Podía contestar, con María Zambrano, el tiempo es el medio donde se hace la persona, donde se realiza. La vida humana es la confluencia de la persona en lo que tiene de inmóvil y del tiempo. Cada criatura humana tiene el tiempo, sus múltiples tiempos. El tiempo -la temporalidad- es una experiencia intensa, cierta, no monóto...

  16. APRENDIENDO CON LAS TIC: UNA EXPERIENCIA UNIVERSITARIA (LEARNING FROM THE ICTS: A UNIVERSITY EXPERIENCE)

    OpenAIRE

    Regueyra Edelman María Gabriela

    2011-01-01

    Resumen:Se comparte en este artículo la experiencia del uso de las TIC en dos cursos que se imparten en la carrera de Trabajo Social de la Universidad de Costa Rica. Se detallan los recursos tecnológicos utilizados y el uso que se da a cada uno: Facebook, Blogger, Moodle, correo electrónico, se complementa la experiencia con la incorporación de las opiniones de la población estudiantil matriculada en los cursos y destacando los retos que el uso de las TIC presenta a la población docentes en p...

  17. El diseño de la experiencia del turismo gastronómico en Bilbao

    OpenAIRE

    Jiang, Xiaoqing

    2012-01-01

    El presente trabajo se centra en el diseño de una experiencia de turismo gastronómico en Bilbao con el objetivo de que los turistas disfruten de su estancia en Bilbao gracias a recursos gastronómicos. En la primera parte, establecemos el marco conceptual del trabajo: aclaramos los conceptos de turismo cultural, turismo gastronómico, experiencia de ocio e innovación en servicios. En la segunda parte utilizamos los datos obtenidos de las encuestas realizadas por Basquetour, entrevistamos a la D...

  18. La escritura en los procesos de sistematización de experiencias educativas

    OpenAIRE

    Ochoa Sierra, Ligia; Osorio, Cielo

    2013-01-01

    Este artículo presenta un análisis del proceso de sistematización y escritura de experiencias significativas en el aula, llevado a cabo por docentes de educación básica y media en el marco de la convocatoria del Ministerio de Educación Nacional en el año 2009, sobre el tema de la pertinencia educativa. Los resultados muestran que solo los profesores que han sido protagonistas principales de las experiencias pueden cifrarlas y socializarlas, y que un buen acompañamiento supone, así mismo, aden...

  19. Programación estructurada en un curso introductorio : Una experiencia explorando Python

    OpenAIRE

    Lovos, Edith; Gibelli, Tatiana Inés; Bertone, Rodolfo Alfredo

    2015-01-01

    En este artículo se presentan los resultados preliminares alcanzados en relación al uso del lenguaje Python, en el marco de la implementación de una propuesta pedagógica para la enseñanza y aprendizaje de la programación estructurada. La experiencia se desarrolló en el marco de una asignatura correspondiente al primer año de la carrera Licenciatura en Sistemas de la Sede Atlántica de la Universidad Nacional de Río Negro. A partir de la experiencia, se analizan los beneficios y debilidades que...

  20. Manejo de sacudidas petroleras negativas: la experiencia venezolana en los años 80

    OpenAIRE

    Ricardo Hausmann

    1995-01-01

    (Disponible en idioma inglés únicamente) La experiencia venezolana en los años 80 es un terreno especialmente fértil para el análisis de sacudidas negativas. Se produjeron dos sacudidas de gran magnitud en regímenes de control muy distintos, lo que puso de manifiesto el papel que desempeña la estructura institucional en la determinación de la respuesta. Además, la experiencia puede arrojar una luz distinta sobre la conveniencia de regímenes cambiarios alternativos de países sujetos a sacudida...

  1. El climaterio y las inmigrantes ecuatorianas: una experiencia natural en manos de otros

    OpenAIRE

    Juan Manuel Leyva-Moral

    2013-01-01

    Introducción: El modelo biomédico describe la menopausia como un problema de salud. Los científicos sociales sostienen que se trata de un proceso biológico normal individual cuya experiencia viene determinada por factores culturales. Objetivo: Comprender la experiencia de la menopausia entre las inmigrantes ecuatorianas que viven en Barcelona (España). Diseño: Estudio cualitativo fenomenológico hermenéutico. Trece mujeres ecuatorianas menopáusicas fueron entrevistadas en sus hogares durante e...

  2. Papel de la experiencia en la aceptación vs. rechazo del paciente con esquizofrenia

    OpenAIRE

    Carmen Senra-Rivera; Alessandra de Arriba-Rossetto; Gloria Seoane-Pesqueira

    2008-01-01

    En esta investigación se analiza la influencia que pueden tener distintos tipos y grados de experiencia con la enfermedad mental en la aceptación vs. rechazo del paciente con esquizofrenia. Participaron en el estudio 236 estudiantes universitarios que cumplimentaron una escala de distancia social relacionada con una viñeta en la que se describe un episodio psicótico de un paciente (hombre o mujer) con esquizofrenia y una escala que evalúa distintos tipos y grados de experiencia co...

  3. Arte y medio ambiente: la naturaleza como experiencia artística

    OpenAIRE

    José Luis Lozano Jiménez

    2010-01-01

    La naturaleza y, en consecuencia, los espacios naturales han impulsado a los artistas a desarrollar un cierto tipo de proyectos artísticos que nacen de la interpretación de aquélla como material de creación plástica y como fuente de experiencia estética. La presente noticia resume las experiencias recogidas en la coordinación de los talleres que impartieron los artistas Ricardo Calero y Miguel Ángel Blanco en el curso-taller sobre intervenciones artísticas contemporáneas Arte y Medio Ambiente...

  4. Structure-based de novo design, molecular docking and molecular dynamics of primaquine analogues acting as quinone reductase II inhibitors.

    Science.gov (United States)

    Murce, Erika; Cuya-Guizado, Teobaldo Ricardo; Padilla-Chavarria, Helmut Isaac; França, Tanos Celmar Costa; Pimentel, Andre Silva

    2015-11-01

    Primaquine is a traditional antimalarial drug with low parasitic resistance and generally good acceptance at higher doses, which has been used for over 60 years in malaria treatment. However, several limitations related to its hematotoxicity have been reported. It is believed that this toxicity comes from the hydroxylation of the C-5 and C-6 positions of its 8-aminoquinoline ring before binding to the molecular target: the quinone reductase II (NQO2) human protein. In this study we propose primaquine derivatives, with substitution at position C-6 of the 8-aminoquinoline ring, planned to have better binding to NQO2, compared to primaquine, but with a reduced toxicity related to the C-5 position being possible to be oxidized. On this sense the proposed analogues were suggested in order to reduce or inhibit hydroxylation and further oxidation to hemotoxic metabolites. Five C-6 substituted primaquine analogues were selected by de novo design and further submitted to docking and molecular dynamics simulations. Our results suggest that all analogues bind better to NQO2 than primaquine and may become better antimalarials. However, the analogues 3 and 4 are predicted to have a better activity/toxicity balance.

  5. Cyndi: a multi-objective evolution algorithm based method for bioactive molecular conformational generation

    Directory of Open Access Journals (Sweden)

    Li Honglin

    2009-03-01

    Full Text Available Abstract Background Conformation generation is a ubiquitous problem in molecule modelling. Many applications require sampling the broad molecular conformational space or perceiving the bioactive conformers to ensure success. Numerous in silico methods have been proposed in an attempt to resolve the problem, ranging from deterministic to non-deterministic and systemic to stochastic ones. In this work, we described an efficient conformation sampling method named Cyndi, which is based on multi-objective evolution algorithm. Results The conformational perturbation is subjected to evolutionary operation on the genome encoded with dihedral torsions. Various objectives are designated to render the generated Pareto optimal conformers to be energy-favoured as well as evenly scattered across the conformational space. An optional objective concerning the degree of molecular extension is added to achieve geometrically extended or compact conformations which have been observed to impact the molecular bioactivity (J Comput -Aided Mol Des 2002, 16: 105–112. Testing the performance of Cyndi against a test set consisting of 329 small molecules reveals an average minimum RMSD of 0.864 Å to corresponding bioactive conformations, indicating Cyndi is highly competitive against other conformation generation methods. Meanwhile, the high-speed performance (0.49 ± 0.18 seconds per molecule renders Cyndi to be a practical toolkit for conformational database preparation and facilitates subsequent pharmacophore mapping or rigid docking. The copy of precompiled executable of Cyndi and the test set molecules in mol2 format are accessible in Additional file 1. Conclusion On the basis of MOEA algorithm, we present a new, highly efficient conformation generation method, Cyndi, and report the results of validation and performance studies comparing with other four methods. The results reveal that Cyndi is capable of generating geometrically diverse conformers and outperforms

  6. Molecular and cell-based therapies for muscle degenerations: a road under construction

    Directory of Open Access Journals (Sweden)

    Maurilio eSampaolesi

    2014-04-01

    Full Text Available There are no specific treatments for muscular degeneration caused by muscular dystrophies and for muscle wasting caused by cachexia or sarcopenia. Corticosteroid medications for dystrophic patients only helps to control inflammatory process and slightly delay the progression of the disease. Walkers and wheel chairs are the only options to maintain patients’ independence and walking capabilities until respiratory muscles become weak and mechanical ventilation is mandatory. On the other hand myostatin inhibition, melanocortin-4 receptor antagonists, β-blockers, IL-6 antagonism, and synthetic ghrelin are promising treatments for cachectic animal models. Although in both cases muscular degeneration is relevant the translational therapeutic attempts to find a possible cure are well defined. Molecular treatments are common options to explore beneficial treatments for cachexia, and gene/cell therapies are mostly employed to induce the phenotypic improvement of dystrophic muscles. This review deals with the use of molecular administrations and gene/stem cell therapy to treat muscular degenerations. It reviews previous trials using cell delivery protocols in mice and patients starting with the use of donor myoblasts, outlining the likely causes for their poor results and briefly focusing on satellite cell studies that raise new hope. Then it proceeds to describe recently identified stem/progenitor cells in relationship to their ability to home within a dystrophic muscle and to differentiate into skeletal muscle cells. Different known features of various stem cells are compared in this perspective, and the few available examples of their use in animal models of muscular degeneration are reported. This review also provides an outline of the role of microRNAs to control myogenic commitment. Finally, based on our current knowledge and the rapid advance in stem cell biology a prediction of clinical translation for cell therapy protocols combined with

  7. Molecular similarity-based predictions of the Tox21 screening outcome

    Directory of Open Access Journals (Sweden)

    Malgorzata Natalia Drwal

    2015-07-01

    Full Text Available To assess the toxicity of new chemicals and drugs, regulatory agencies require in vivo testing for many toxic endpoints, resulting in millions of animal experiments conducted each year. However, following the Replace, Reduce, Refine (3R principle, the development and optimization of alternative methods, in particular in silico methods, has been put into focus in the recent years. It is generally acknowledged that the more complex a toxic endpoint, the more difficult it is to model. Therefore, computational toxicology is shifting from modelling general and complex endpoints to the investigation and modelling of pathways of toxicity and the underlying molecular effects.The U.S. Toxicology in the 21st Century (Tox21 initiative has screened a large library of compounds, including approximately 10K environmental chemicals and drugs, for different mechanisms responsible for eliciting toxic effects, and made the results publicly available. Through the Tox21 Data Challenge, the consortium has established a platform for computational toxicologists to develop and validate their predictive models.Here, we present a fast and successful method for the prediction of different outcomes of the nuclear receptor and stress response pathway screening from the Tox21 Data Challenge 2014. The method is based on the combination of molecular similarity calculations and a naïve Bayes machine learning algorithm and has been implemented as a KNIME pipeline. Molecules are represented as binary vectors consisting of a concatenation of common two-dimensional molecular fingerprint types with topological compound properties. The prediction method has been optimized individually for each modelled target and evaluated in a cross-validation as well as with the independent Tox21 validation set. Our results show that the method can achieve good prediction accuracies and rank among the top algorithms submitted to the prediction challenge, indicating its broad applicability in

  8. A distance-dependent metal-enhanced fluorescence sensing platform based on molecular beacon design.

    Science.gov (United States)

    Zhou, Zhenpeng; Huang, Hongduan; Chen, Yang; Liu, Feng; Huang, Cheng Zhi; Li, Na

    2014-02-15

    A new metal-enhanced fluorescence (MEF) based platform was developed on the basis of distance-dependent fluorescence quenching-enhancement effect, which combined the easiness of Ag-thiol chemistry with the MEF property of noble-metal structures as well as the molecular beacon design. For the given sized AgNPs, the fluorescence enhancement factor was found to increase with a d(6) dependency in agreement with fluorescence resonance energy transfer mechanism at shorter distance and decrease with a d(-3) dependency in agreement with plasmonic enhancement mechanism at longer distance between the fluorophore and the AgNP surface. As a proof of concept, the platform was demonstrated by a sensitive detection of mercuric ions, using thymine-containing molecular beacon to tune silver nanoparticle (AgNP)-enhanced fluorescence. Mercuric ions were detected via formation of a thymine-mercuric-thymine structure to open the hairpin, facilitating fluorescence recovery and AgNP enhancement to yield a limit of detection of 1 nM, which is well below the U.S. Environmental Protection Agency regulation of the Maximum Contaminant Level Goal (10nM) in drinking water. Since the AgNP functioned as not only a quencher to reduce the reagent blank signal but also an enhancement substrate to increase fluorescence of the open hairpin when target mercuric ions were present, the quenching-enhancement strategy can greatly improve the detection sensitivity and can in principle be a universal approach for various targets when combined with molecular beacon design.

  9. Potentiometric Sensors Based on Surface Molecular Imprinting: Detection of Cancer Biomarkers and Viruses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Zhang, Z; Jain, V; Yi, J; Mueller, S; Sokolov, J; Liu, Z; Levon, K; Rigas, B; Rafailovich, M

    2010-01-01

    The continuing discovery of cancer biomarkers necessitates improved methods for their detection. Molecular imprinting using artificial materials provides an alternative to the detection of a wide range of substances. We applied surface molecular imprinting using self-assembled monolayers to design sensing elements for the detection of cancer biomarkers and other proteins. These elements consist of a gold-coated silicon chip onto which hydroxyl-terminated alkanethiol molecules and template biomolecule are co-adsorbed, where the thiol molecules are chemically bound to the metal substrate and self-assembled into highly ordered monolayers, the biomolecules can be removed, creating the foot-print cavities in the monolayer matrix for this kind of template molecules. Re-adsorption of the biomolecules to the sensing chip changes its potential, which can be measured potentiometrically. We applied this method to the detection of carcinoembryonic antigen (CEA) in both solutions of purified CEA and in the culture medium of a CEA-producing human colon cancer cell line. The CEA assay, validated also against a standard immunoassay, was both sensitive (detection range 2.5-250 ng/mL) and specific (no cross-reactivity with hemoglobin; no response by a non-imprinted sensor). Similar results were obtained for human amylase. In addition, we detected virions of poliovirus in a specific manner (no cross-reactivity to adenovirus, no response by a non-imprinted sensor). Our findings demonstrate the application of the principles of molecular imprinting to the development of a new method for the detection of protein cancer biomarkers and to protein-based macromolecular structures such as the capsid of a virion. This approach has the potential of generating a general assay methodology that could be highly sensitive, specific, simple and likely inexpensive.

  10. Probing ligand-binding modes and binding mechanisms of benzoxazole-based amide inhibitors with soluble epoxide hydrolase by molecular docking and molecular dynamics simulation.

    Science.gov (United States)

    Chen, Hang; Zhang, Ying; Li, Liang; Han, Ju-Guang

    2012-08-30

    Soluble epoxide hydrolase (sEH) has become a new therapeutic target for treating a variety of human diseases. The inhibition of human sEH hydrolase activity was studied by molecular docking and molecular dynamics (MD) simulation techniques. A set of six benzoxazole-based amide inhibitors binding to sEH has been studied through molecular docking, MD simulation, free energy calculations, and energy decomposition analysis. On the basis of molecular mechanics-generalized Born/surface area (MM-GB/SA) computation and normal-mode analysis (NMA), the obtained results indicate that the rank of calculated binding free energies (ΔΔGTOT) of these inhibitors is in excellent agreement with that of experimental bioactivity data (IC50). The correlation coefficient (r(2)) between the predicted ΔΔGTOT and IC50 is 0.88. van der Waals energies are the largest component of the total energies, and the entropy changes play an indispensable role in determining the ΔΔGTOT. Rational binding modes were discussed and determined by the docking results and binding free energies. The free energy decomposition of each residue reveals that the residue Trp334 dominates the most binding free energies among all residues and that the activities for these molecules to the sEH are not decided by hydrogen bonds or a certain residue but by the common effect of multiple side chains in the active site.

  11. Photorefractive effect in triphenylamine-based monolithic molecular glasses with low Tg

    International Nuclear Information System (INIS)

    Research highlights: → A series of triphenylamine-based molecular glasses with low Tg and long-term stability were designed and prepared via simple reactions. → Single-component M1 exhibited the better PR performance with a gain coefficient of 52 cm-1 (0 V μm-1) and 165 cm-1 (40 V μm-1). Fast response time of 0.025-0.23 s were obtained at low electric field for these glasses. → The overall performances suggest that the present triphenylamine-based molecules are potentially good candidates for commercial application in organic photorefractive devices. - Abstract: A novel series of triphenylamine-based photorefractive molecules M1-M5 with the different push-pull structures were designed and prepared. These molecules can form stable glasses with low glass transition temperature and their optical absorptions as well as photoconductivities at 633 nm increase systematically with increasing acceptor strength and conjugation length. As an unambiguous evidence, the two-beam-coupling experiment was performed to prove the photorefractive effect in each compound with or without an additional sensitizer. Obvious two-beam-coupling effects were obtained for the molecules with good film-forming ability and long-term stability, and among them single-component M1 which has a highly asymmetric structure using both a nitrobenzene and a cyano group as the acceptor showed the best PR performance with a gain coefficient of 52 cm-1 at 0 V μm-1 and 165 cm-1 at 40 V μm-1. Fast response time of 0.025-0.23 s were also obtained at low electric field for these glasses. The correlation of the molecular structure with the PR property was discussed, and a possible explanation for the unique energy transfer observed in M1 and M2 under zero field was proposed.

  12. Systematics of the blindsnakes (Serpentes: Scolecophidia: Typhlopoidea) based on molecular and morphological evidence.

    Science.gov (United States)

    Pyron, Robert Alexander; Wallach, Van

    2014-01-01

    The blindsnake superfamily Typhlopoidea (Gerrhopilidae, Typhlopidae, and Xenotyphlopidae) is a diverse, widespread part of the global snake fauna. A recent systematic revision based on molecular phylogenetic analyses and some morphological evidence presented a preliminary solution to the non-monophyly of many previously recognized genera, but additional clarification is needed regarding the recognition of some species and genera. We rectify these problems here with a new molecular phylogenetic analysis including 95 of the 275 currently recognized, extant typhlopoids, incorporating both nuclear and mitochondrial loci. We supplement this with data on the external, visceral, and hemipenial morphology of nearly all species to generate a revised classification for Typhlopoidea. Based on morphological data, we re-assign Cathetorhinus from Typhlopidae to Gerrhopilidae. Xenotyphlopidae maintains its current contents (Xenotyphlops). In Typhlopidae, one monotypic genus is synonymized with its larger sister-group as it cannot be unambiguously diagnosed morphologically (Sundatyphlops with Anilios), and two genera are synonymizedwith Typhlops (Antillotyphlops and Cubatyphlops), as they are not reciprocally monophyletic. The genus Asiatyphylops is renamed Argyrophis, the senior synonym for the group. We erect one new genus (Lemuriatyphlops) for a phylogenetically distinct species-group in Asiatyphlopinae. Fourteen of eighteen recognized typhlopid genera are maintained in four subfamilies: Afrotyphlopinae (Afrotyphlops, Grypotyphlops [re-assigned from Asiatyphlopinae], Letheobia, and Rhinotyphlops), Asiatyphlopinae (Acutotyphlops, Anilios, Cyclotyphlops, Indotyphlops, Malayotyphlops, Ramphotyphlops, and Xerotyphlops), Madatyphlopinae (Madatyphlops), and Typhlopinae (Amerotyphlops and Typhlops), some with altered contents. Diagnoses based on morphology are provided for all 19 typhlopoid genera, accounting for all 275 species. This taxonomy provides a robust platform for future

  13. Ecotope-Based Entomological Surveillance and Molecular Xenomonitoring of Multidrug Resistant Malaria Parasites in Anopheles Vectors

    Directory of Open Access Journals (Sweden)

    Prapa Sorosjinda-Nunthawarasilp

    2014-01-01

    Full Text Available The emergence and spread of multidrug resistant (MDR malaria caused by Plasmodium falciparum or Plasmodium vivax have become increasingly important in the Greater Mekong Subregion (GMS. MDR malaria is the heritable and hypermutable property of human malarial parasite populations that can decrease in vitro and in vivo susceptibility to proven antimalarial drugs as they exhibit dose-dependent drug resistance and delayed parasite clearance time in treated patients. MDR malaria risk situations reflect consequences of the national policy and strategy as this influences the ongoing national-level or subnational-level implementation of malaria control strategies in endemic GMS countries. Based on our experience along with current literature review, the design of ecotope-based entomological surveillance (EES and molecular xenomonitoring of MDR falciparum and vivax malaria parasites in Anopheles vectors is proposed to monitor infection pockets in transmission control areas of forest and forest fringe-related malaria, so as to bridge malaria landscape ecology (ecotope and ecotone and epidemiology. Malaria ecotope and ecotone are confined to a malaria transmission area geographically associated with the infestation of Anopheles vectors and particular environments to which human activities are related. This enables the EES to encompass mosquito collection and identification, salivary gland DNA extraction, Plasmodium- and species-specific identification, molecular marker-based PCR detection methods for putative drug resistance genes, and data management. The EES establishes strong evidence of Anopheles vectors carrying MDR P. vivax in infection pockets epidemiologically linked with other data obtained during which a course of follow-up treatment of the notified P. vivax patients receiving the first-line treatment was conducted. For regional and global perspectives, the EES would augment the epidemiological surveillance and monitoring of MDR falciparum and

  14. Synchrotron-Based Microspectroscopic Analysis of Molecular and Biopolymer Structures Using Multivariate Techniques and Advanced Multi-Components Modeling

    International Nuclear Information System (INIS)

    More recently, advanced synchrotron radiation-based bioanalytical technique (SRFTIRM) has been applied as a novel non-invasive analysis tool to study molecular, functional group and biopolymer chemistry, nutrient make-up and structural conformation in biomaterials. This novel synchrotron technique, taking advantage of bright synchrotron light (which is million times brighter than sunlight), is capable of exploring the biomaterials at molecular and cellular levels. However, with the synchrotron RFTIRM technique, a large number of molecular spectral data are usually collected. The objective of this article was to illustrate how to use two multivariate statistical techniques: (1) agglomerative hierarchical cluster analysis (AHCA) and (2) principal component analysis (PCA) and two advanced multicomponent modeling methods: (1) Gaussian and (2) Lorentzian multi-component peak modeling for molecular spectrum analysis of bio-tissues. The studies indicated that the two multivariate analyses (AHCA, PCA) are able to create molecular spectral corrections by including not just one intensity or frequency point of a molecular spectrum, but by utilizing the entire spectral information. Gaussian and Lorentzian modeling techniques are able to quantify spectral omponent peaks of molecular structure, functional group and biopolymer. By application of these four statistical methods of the multivariate techniques and Gaussian and Lorentzian modeling, inherent molecular structures, functional group and biopolymer onformation between and among biological samples can be quantified, discriminated and classified with great efficiency.

  15. Aprendizaje con robótica, algunas experiencias

    Directory of Open Access Journals (Sweden)

    Pedro Antonio López Ramírez

    2013-01-01

    Full Text Available Este artículo presenta el análisis de experiencias, revisadas en diversos artículos, acerca de la implementación de la robótica en la educación, con el fin de obtener referentes pertinentes para la construcción de una propuesta para el aprendizaje de la robótica en la educación básica secundaria y media. Se consideran dos ámbitos de aplicación de la robótica en la educación: el primero es el aprendizaje de la robótica mediante la conceptualización de cada uno de los subsistemas de un robot para luego realizar la construcción de robots con diferentes propósitos, en este ámbito el objetivo es desarrollar las competencias, en los estudiantes, para el diseño y construcción de tecnofactos robóticos, mediante un proceso de construcción del conocimiento necesario para hacerlo; el segundo ámbito de aplicación es la utilización de la robótica como medio que motiva y da sentido a la construcción de conocimiento en diversas áreas, promoviendo habilidades y competencias en los estudiantes. Además, el aprendizaje de la robótica y el aprendizaje con robótica pueden ser mediados por la informática, la cual aporta tecnologías y herramientas software como los lenguajes de modelado matemático y simulación, tutoriales multimediales, laboratorios virtuales y remotos, entre otros. Así, este artículo se propone destacar cómo la robótica en el aula de clase permite, por una parte, el enriquecer estrategias de aprendizaje como apoyo a la formación integral de los estudiantes, y por otra, es un campo que presenta una demanda creciente en la atención de docentes e investigadores, así como en los estímulos para su investigación, desarrollo y divulgación de parte del estado.

  16. La experiencia del Centro Centroamericano de Población

    Directory of Open Access Journals (Sweden)

    Carmen Marín

    2006-01-01

    Full Text Available Introducción.- Las NTIC abren nuevas posibilidades para la educación. Aprender en entornos mediados por NTIC supone flexibilidad en espacio y tiempo e interacción entre los participantes para el aprendizaje significativo. Las universidades al implementar ofertas formativas de carácter virtual deben reconsiderar sus modelos de enseñanza y de aprendizaje e iniciar procesos de análisis y revisión de las experiencias realizadas. El presente artículo pretende sistematizar el accionar del proyecto CapDis del Centro Centroamericano de Población (CCP al introducir el uso de las nuevas tecnologías de información y comunicación en la educación superior en la Universidad de Costa Rica (UCR. Métodos.- Se basa en un estudio de caso que aplica el método cualitativo mediante revisión documental y registro de eventos. Resultados.- En CapDis se identifican las siguientes etapas: I. Páginas web vinculadas; II. Páginas web integradas y III. Learning Management System. En las primeras dos etapas se dio soporte a los profesores y se asumió la mayor parte de las tareas de implementación y mantenimiento. Cuando se incorporó moodle.org, se facilitó la participación de más profesores quienes asumieron un rol más activo en CapDis. A marzo 2005, la comparación de metas y resultados evidencia que fueron superados los resultados esperados. Discusión.- El presente artículo se constituye en un insumo útil en la identificación de las dificultades, alcances y limitaciones de la incorporación de las NTIC en la docencia en educación superior en la Universidad de Costa Rica. Las etapas identificadas en CapDis han sido descritas en términos del alcance de los recursos NTIC puestos en práctica. Más allá de los aspectos tecnológicos y administrativos descritos, el proceso seguido por CapDis logró enriquecer la interacción de una modalidad asíncrona (diferida a una síncrona (inmediata, lo que abre la oportunidad de contribuir a una mejor

  17. EXPERIENCIA DEL ENTRENAMIENTO MUSICAL EN UNA UNIVERSIDAD PARTICULAR DE LIMA

    Directory of Open Access Journals (Sweden)

    Daniel Ravelo Franco

    2012-12-01

    Full Text Available RESUMEN: El objetivo de la Revolución del Entrenamiento Musical es aprovechar las modernas herramientas tecnológicas para la educación, aplicándolas al entrenamiento auditivo, dentro de un programa de formación musical profesional. En este trabajo, se presentará la experiencia de transformación del curso presencial de Nivelación en Lectura y Entrenamiento Auditivo, de un pregrado universitario de Música, a la modalidad b-learning. La modalidad b-learning de este curso se estableció sobre un Aula Virtual en una plataforma Moodle. El trabajo en línea, dentro de esta Aula Virtual, incluyó foros de comunicación, foros académicos, recursos autoinstructivos de entrenamiento auditivo y tareas académicas. La estrategia del trabajo online del curso consideró varios aspectos: 1 Estructura del Aula Virtual; 2 Comunicación dentro del Aula Virtual; 3 Administración del Aula Virtual; 4 Creación y organización de contenidos; 5 Planteamiento de una metodología de estudio en línea; 6 Diseño y puesta en marcha de las actividades en línea; 7 Calificación de las actividades realizadas en línea; 8 Evaluación de todo el proceso. Los resultados obligaron a replantear los contenidos del mismo curso en los niveles siguientes debido a los importantes avances alcanzados. ABSTRACT: The aim of the Musical Training Revolution is to take advantage of the modern educational technology tools, to apply them to the auditory training in a professional music training program. In this paper, the experience of transforming the classroom course in Leveling in Reading and Ear Training is presented, from a university undergraduate Music, to a b-learning mode. b-learning mode of this course is set on a virtual classroom on the Moodle platform. Online work within this virtual classroom included communication forums, academic forums, ear training self-instructive resources and academic tasks. The working strategy of on-line courses considered several aspects: 1

  18. Una experiencia en Arqueología de la Arquitectura

    Directory of Open Access Journals (Sweden)

    Caballero Zoreda, Luis

    2004-12-01

    Full Text Available Experience of CSIC (Instituto de Historia, Madrid Archaeology of Architecture research group. The intervention analyzes relations with the promoter, work objectives and characteristics, financing, means, team and relations with archaeological interventions underground and architectonic interventions in the building. The methodology includes special analysis of the stratigraphy: fast reading, team reading, documentation unit, impossible readings, in addition to written sources and dating problems, chronological indicators, absolute dating and its relation to explanatory models. Lastly, outstanding criteria and mensiochronology. The conclusion notes the scarce interest in this method and advocates making archaeological reading of the historic building compulsory by law prior to and during intervention (in parallel with archaeological excavation legislation and the need for normalization, proper training and sufficient financing.Experiencia del grupo de investigación del CSIC (Instituto de Historia, Madrid en Arqueología de la Arquitectura. Con respecto a la intervención se analizan las relaciones con el promotor, el objetivo y las características del encargo, financiación, medios y equipo y las relaciones con las intervenciones arqueológica del subsuelo y arquitectónica del edificio. Con respecto a la metodología se analiza especialmente la estratigrafía: lectura veloz, lectura en equipo, unidad de documentación, lecturas imposibles. También las fuentes escritas y los problemas de datación, indicadores cronológicos, dataciones absolutas y su relación con los modelos explicativos. Finalmente, los criterios discriminantes y la mensiocronología. En conclusión se denota el escaso interés por este método y se aboga por la obligación legal de la lectura arqueológica del edificio histórico, previamente y durante su intervención (en paralelo con la legislación sobre excavaciones arqueológicas, y por la necesidad de su normalizaci

  19. Enabling Metabolomics Based Biomarker Discovery Studies Using Molecular Phenotyping of Exosome-Like Vesicles.

    Directory of Open Access Journals (Sweden)

    Tatiana Altadill

    Full Text Available Identification of sensitive and specific biomarkers with clinical and translational utility will require smart experimental strategies that would augment expanding the breadth and depth of molecular measurements within the constraints of currently available technologies. Exosomes represent an information rich matrix to discern novel disease mechanisms that are thought to contribute to pathologies such as dementia and cancer. Although proteomics and transcriptomic studies have been reported using Exosomes-Like Vesicles (ELVs from different sources, exosomal metabolome characterization and its modulation in health and disease remains to be elucidated. Here we describe methodologies for UPLC-ESI-MS based small molecule profiling of ELVs from human plasma and cell culture media. In this study, we present evidence that indeed ELVs carry a rich metabolome that could not only augment the discovery of low abundance biomarkers but may also help explain the molecular basis of disease progression. This approach could be easily translated to other studies seeking to develop predictive biomarkers that can subsequently be used with simplified targeted approaches.

  20. Molecular Description of Macroorchis spinulosus (Digenea: Nanophyetidae) Based on ITS1 Sequences

    Science.gov (United States)

    Won, Eun Jeong; Kim, Deok-Gyu; Cho, Jaeeun; Jung, Bong-Kwang; Kim, Min-Jae; Yun, Yong Woon; Chai, Jong-Yil; Ryang, Dong Wook

    2016-01-01

    We performed a molecular genetic study on the sequences of 18S ribosomal RNA (ITS1 region) gene in 4-day-old adult worms of Macroorchis spinulosus recovered in mice experimentally infected with metacercariae from crayfish in Jeollanam-do Province, Korea. The metacercariae were round, 180 μm in average diameter, encysted with 2 layers of thick walls, but the stylet on the oral sucker was not clearly seen. The adult flukes were oval shape, and 760-820 μm long and 320-450 μm wide, with anterolateral location of 2 large testes. The phylogenetic tree based on ITS1 sequences of 6 M. spinulosus samples showed their distinguished position from other trematode species in GenBank. The most closely resembled group was Paragonimus spp. which also take crayfish or crabs as the second intermediate host. The present study is the first molecular characterization of M. spinulosus and provided a basis for further phylogenetic studies to compare with other trematode fauna in Korea. PMID:26951989

  1. Epitope engineering and molecular metrics of immunogenicity: a computational approach to VLP-based vaccine design.

    Science.gov (United States)

    Joshi, Harshad; Lewis, Kristen; Singharoy, Abhishek; Ortoleva, Peter J

    2013-10-01

    Developing antiviral vaccines is increasingly challenging due to associated time and cost of production as well as emerging drug-resistant strains. A computer-aided vaccine design strategy is presented that could greatly accelerate the discovery process and yield vaccines with high immunogenicity and thermal stability. Our strategy is based on foreign viral epitopes engineered onto well-established virus-like particles (VLPs) and demonstrates that such constructs present similar affinity for antibodies as does a native virus. This binding affinity serves as one molecular metric of immunogenicity. As a demonstration, we engineered a preS1 epitope of hepatitis B virus (HBV) onto the EF loop of human papillomavirus VLP (HPV-VLP). HBV-associated HzKR127 antibody displayed binding affinity for this structure at distances and strengths similar to those for the complex of the antibody with the full HBV (PDBID: 2EH8). This antibody binding affinity assessment, along with other molecular immunogenicity metrics, could be a key component of a computer-aided vaccine design strategy. PMID:23933338

  2. The effects of zeolite molecular sieve based surface treatments on the properties of wool fabrics

    International Nuclear Information System (INIS)

    Wool is a natural composite fiber, with keratin and keratin-associated proteins as the key molecular components. The outermost surface of wool fibers comprises a hydrophobic lipid layer that can lead to unsatisfactory processing and properties of fabric products. In this study, molecular sieve 5A, a Na+ and Ca2+ exchanged type A zeolite with a 1:1 Si:Al ratio was integrated onto the surface of wool using 3-mercaptopropyl trimethoxy silane. The resultant surface morphology, hydrophilicity and mechanical performance of the treated wool fabrics were then evaluated. Notably, the surface hydrophilicity of wool was observed to increase dramatically. When wool was treated with a dispersion of 2 wt% acetic acid, 2.5 wt% zeolite and 0.3 wt% or more silane, the water contact angle was observed to decrease from an average value of 148° to 0° over a period of approximately 30 s. Scanning electron microscopic imaging indicated good coverage of the wool surface with zeolite particles, with infrared spectroscopic evaluation indicating strong bonding of the dealuminated zeolite to wool keratins. This application of zeolite showed no adverse effects on the tensile and other mechanical properties of the fabric. This study indicates that zeolite-based treatment is a potentially efficient approach to increasing the surface hydrophilicity and modifying other key surface properties of wool and wool fabrics

  3. Structural changes in a Schiff base molecular assembly initiated by scanning tunneling microscopy tip

    Science.gov (United States)

    Tomak, A.; Bacaksiz, C.; Mendirek, G.; Sahin, H.; Hur, D.; Görgün, K.; Senger, R. T.; Birer, Ö.; Peeters, F. M.; Zareie, H. M.

    2016-08-01

    We report the controlled self-organization and switching of newly designed Schiff base (E)-4-((4-(phenylethynyl) benzylidene) amino) benzenethiol (EPBB) molecules on a Au (111) surface at room temperature. Scanning tunneling microscopy and spectroscopy (STM/STS) were used to image and analyze the conformational changes of the EPBB molecules. The conformational change of the molecules was induced by using the STM tip while increasing the tunneling current. The switching of a domain or island of molecules was shown to be induced by the STM tip during scanning. Unambiguous fingerprints of the switching mechanism were observed via STM/STS measurements. Surface-enhanced Raman scattering was employed, to control and identify quantitatively the switching mechanism of molecules in a monolayer. Density functional theory calculations were also performed in order to understand the microscopic details of the switching mechanism. These calculations revealed that the molecular switching behavior stemmed from the strong interaction of the EPBB molecules with the STM tip. Our approach to controlling intermolecular mechanics provides a path towards the bottom-up assembly of more sophisticated molecular machines.

  4. Anisotropy induced Kondo splitting in a mechanically stretched molecular junction: A first-principles based study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoli; Hou, Dong, E-mail: houdong@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zheng, Xiao, E-mail: xz58@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Institute of Applied Physics, Guizhou Normal College, Guiyang, Guizhou 550018 (China); Yan, YiJing [Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, Hefei, Anhui 230026 (China); Department of Chemistry, Hong Kong University of Science and Technology, Hong Kong (China)

    2016-01-21

    The magnetic anisotropy and Kondo phenomena in a mechanically stretched magnetic molecular junction are investigated by combining the density functional theory (DFT) and hierarchical equations of motion (HEOM) approach. The system is comprised of a magnetic complex Co(tpy–SH){sub 2} sandwiched between adjacent gold electrodes, which is mechanically stretched in experiments done by Parks et al. [Science 328, 1370 (2010)]. The electronic structure and mechanical property of the stretched system are investigated via the DFT calculations. The HEOM approach is then employed to characterize the Kondo resonance features, based on the Anderson impurity model parameterized from the DFT results. It is confirmed that the ground state prefers the S = 1 local spin state. The structural properties, the magnetic anisotropy, and corresponding Kondo peak splitting in the axial stretching process are systematically evaluated. The results reveal that the strong electron correlations and the local magnetic properties of the molecule magnet are very sensitive to structural distortion. This work demonstrates that the combined DFT+HEOM approach could be useful in understanding and designing mechanically controlled molecular junctions.

  5. Diagnosing rejection in renal transplants: a comparison of molecular- and histopathology-based approaches.

    Science.gov (United States)

    Reeve, J; Einecke, G; Mengel, M; Sis, B; Kayser, N; Kaplan, B; Halloran, P F

    2009-08-01

    The transcriptome has considerable potential for improving biopsy diagnoses. However, to realize this potential the relationship between the molecular phenotype of disease and histopathology must be established. We assessed 186 consecutive clinically indicated kidney transplant biopsies using microarrays, and built a classifier to distinguish rejection from nonrejection using predictive analysis of microarrays (PAM). Most genes selected by PAM were interferon-gamma-inducible or cytotoxic T-cell associated, for example, CXCL9, CXCL11, GBP1 and INDO. We then compared the PAM diagnoses to those from histopathology, which are based on the Banff diagnostic criteria. Disagreement occurred in approximately 20% of diagnoses, principally because of idiosyncratic limitations in the histopathology scoring system. The problematic diagnosis of 'borderline rejection' was resolved by PAM into two distinct classes, rejection and nonrejection. The diagnostic discrepancies between Banff and PAM in these cases were largely due to the Banff system's requirement for a tubulitis threshold in defining rejection. By examining the discrepancies between gene expression and histopathology, we provide external validation of the main features of the histopathology diagnostic criteria (the Banff consensus system), recommend improvements and outline a pathway for introducing molecular measurements.

  6. Fluorescent molecularly imprinted polymer based on Navicula sp. frustules for optical detection of lysozyme.

    Science.gov (United States)

    Lim, Guat Wei; Lim, Jit Kang; Ahmad, Abdul Latif; Chan, Derek Juinn Chieh

    2016-03-01

    The direct correlation between disease and lysozyme (LYZ) levels in human body fluids makes the sensitive and convenient detection of LYZ the focus of scientific research. Fluorescent molecularly imprinted polymer has emerged as a new alternative for LYZ detection in order to resolve the limitation of immunoassays, which are expensive, unstable, require complex preparation, and are time consuming. In this study, a novel fluorescence molecularly imprinted polymer based on Navicula sp. frustules (FITC-MIP) has been synthesized via post-imprinting treatment for LYZ detection. Navicula sp. frustules were used as supported material because of their unique properties of moderate surface area, reproducibility, and biocompatibility, to address the drawbacks of nanoparticle core material with low adsorption capacity. The FITC acts as recognition signal and optical readout, whereas MIP provides LYZ selectivity. The synthesized FITC-MIP showed a response time as short as 5 min depending on the concentration of LYZ. It is found that the LYZ template can significantly quench the fluorescence intensity of FITC-MIP linearly within a concentration range of 0 to 0.025 mg mL(-1), which is well described by Stern-Volmer equation. The FITC-MIP can selectively and sensitively detect down to 0.0015 mg mL(-1) of LYZ concentration. The excellent sensing performance of FITC-MIP suggests that FITC-MIP is a potential biosensor in clinical diagnosis applications. PMID:26842746

  7. Prediction of transport properties of new functional lanthanum-strontium cuprates based materials: molecular dynamics calculations

    International Nuclear Information System (INIS)

    Molecular dynamics method is used for the properties prediction of new lanthanum-strontium cuprates La2-xSrxCuO4-δ based functional materials. The most interesting phases have been synthesized, and electrophysical and thermomechanical properties have been investigated for the verification of acquired calculated data. High values of oxygen diffusion constants is demonstrated to be occurred in solid solutions La2-xSrxCuO4-δ with fine degree of substitution Sr→La (to x=1). Values of lattice parameters, thermal expansion coefficients and oxygen diffusion constants are agree with experimental data. Observed anisotropy of anion transport for all studied compositions is responsible for peculiarities of crystal structure of complex oxides. Applied molecular dynamics method permits to reveal the contribution of separate kinds of oxygen ions (equatorial and apical) in ionic transport at microscopic level, as well as really prove that the oxygen diffusion happens in the ordinary jump mechanism, mainly in (CuO2)-layers

  8. Inquiry-Based Learning: Inflammation as a Model to Teach Molecular Techniques for Assessing Gene Expression

    Directory of Open Access Journals (Sweden)

    Kathryn E. Gunn

    2013-08-01

    Full Text Available This laboratory module simulates the process used by working scientists to ask and answer a question of biological interest. Instructors facilitate acquisition of knowledge using a comprehensive, inquiry-based approach in which students learn theory, hypothesis development, experimental design, and data interpretation and presentation. Using inflammation in macrophages as a model system, students perform a series of molecular biology techniques to address the biological question: “Does stimulus ‘X’ induce inflammation?” To ask this question, macrophage cells are treated with putative inflammatory mediators and then assayed for evidence of inflammatory response. Students become familiar with their assigned mediator and the relationship between their mediator and inflammation by conducting literature searches, then using this information to generate hypotheses which address the effect of their mediator on induction of inflammation. The cellular and molecular approaches used to test their hypotheses include transfection and luciferase reporter assay, immunoblot, fluorescence microscopy, enzyme-linked immunosorbent assay, and quantitative PCR. Quantitative and qualitative reasoning skills are developed through data analysis and demonstrated by successful completion of post-lab worksheets and the generation and oral presentation of a scientific poster. Learning objective assessment relies on four instruments: pre-lab quizzes, post-lab worksheets, poster presentation, and posttest. Within three cohorts (n = 85 more than 95% of our students successfully achieved the learning objectives.

  9. Molecular-Based Theory for Electron-Transfer Reorganization Energy in Solvent Mixtures.

    Science.gov (United States)

    Zhuang, Bilin; Wang, Zhen-Gang

    2016-07-01

    Using statistical-field techniques, we develop a molecular-based dipolar self-consistent-field theory (DSCFT) for charge solvation in liquid mixtures under equilibrium and nonequilibrium conditions, and apply it to compute the solvent reorganization energy of electron-transfer reactions. In addition to the nonequilibrium orientational polarization, the reorganization energy in liquid mixtures is also determined by the out-of-equilibrium solvent composition around the reacting species due to preferential solvation. Using molecular parameters that are readily available, the DSCFT naturally accounts for the dielectric saturation effect and the spatially varying solvent composition in the vicinity of the reacting species. We identify three general categories of binary solvent mixtures, classified by the relative optical and static dielectric permittivities of the solvent components. Each category of mixture is shown to produce a characteristic local solvent composition profile in the vicinity of the reacting species, which gives rise to the distinctive composition dependence of the reorganization energy that cannot be predicted using the dielectric permittivities of the homogeneous solvent mixtures. PMID:27187110

  10. Structural changes in a Schiff base molecular assembly initiated by scanning tunneling microscopy tip.

    Science.gov (United States)

    Tomak, A; Bacaksiz, C; Mendirek, G; Sahin, H; Hur, D; Görgün, K; Senger, R T; Birer, Ö; Peeters, F M; Zareie, H M

    2016-08-19

    We report the controlled self-organization and switching of newly designed Schiff base (E)-4-((4-(phenylethynyl) benzylidene) amino) benzenethiol (EPBB) molecules on a Au (111) surface at room temperature. Scanning tunneling microscopy and spectroscopy (STM/STS) were used to image and analyze the conformational changes of the EPBB molecules. The conformational change of the molecules was induced by using the STM tip while increasing the tunneling current. The switching of a domain or island of molecules was shown to be induced by the STM tip during scanning. Unambiguous fingerprints of the switching mechanism were observed via STM/STS measurements. Surface-enhanced Raman scattering was employed, to control and identify quantitatively the switching mechanism of molecules in a monolayer. Density functional theory calculations were also performed in order to understand the microscopic details of the switching mechanism. These calculations revealed that the molecular switching behavior stemmed from the strong interaction of the EPBB molecules with the STM tip. Our approach to controlling intermolecular mechanics provides a path towards the bottom-up assembly of more sophisticated molecular machines. PMID:27378765

  11. Anisotropy induced Kondo splitting in a mechanically stretched molecular junction: A first-principles based study

    International Nuclear Information System (INIS)

    The magnetic anisotropy and Kondo phenomena in a mechanically stretched magnetic molecular junction are investigated by combining the density functional theory (DFT) and hierarchical equations of motion (HEOM) approach. The system is comprised of a magnetic complex Co(tpy–SH)2 sandwiched between adjacent gold electrodes, which is mechanically stretched in experiments done by Parks et al. [Science 328, 1370 (2010)]. The electronic structure and mechanical property of the stretched system are investigated via the DFT calculations. The HEOM approach is then employed to characterize the Kondo resonance features, based on the Anderson impurity model parameterized from the DFT results. It is confirmed that the ground state prefers the S = 1 local spin state. The structural properties, the magnetic anisotropy, and corresponding Kondo peak splitting in the axial stretching process are systematically evaluated. The results reveal that the strong electron correlations and the local magnetic properties of the molecule magnet are very sensitive to structural distortion. This work demonstrates that the combined DFT+HEOM approach could be useful in understanding and designing mechanically controlled molecular junctions

  12. A Study on the Structure and Photodetachment Dynamics of Copper Based Molecular Anions Using Photoelectron Spectroscopy

    Science.gov (United States)

    Holtgrewe, Nicholas Stephen

    This dissertation represents a study of the effects of electron molecule interactions in the detachment and dissociation dynamics of copper based molecular anions. Results are presented on the photodetachment of small copper oxide CuOn-- (n = 1, 2) and copper fluoride CuFn-- (n = 1, 2) molecular anions. Effects of different resonances are explored using the photoelectron angular distributions (PADs) and the relative intensity variations in vibrational channel cross sections. The specific resonances studied include dipole bound resonances, in which the electric dipole moment of the neutral molecule captures the outgoing electron, and electronic Feshbach resonances, in which the anion undergoes absorption to an excited anion state (lying energetically above the neutral) followed by relaxation via autodetachment into the electronic continuum. In addition to electron scattering resonances, the effects of dissociation dynamics on linear CuO2-- are studied, wherein the linear anion isomer was found to dissociate to Cu-- fragments. This dissociation process is interpreted with experimental data acquired from nanosecond photoelectron images and a femtosecond time resolved study.

  13. The effects of zeolite molecular sieve based surface treatments on the properties of wool fabrics

    Science.gov (United States)

    Carran, Richard S.; Ghosh, Arun; Dyer, Jolon M.

    2013-12-01

    Wool is a natural composite fiber, with keratin and keratin-associated proteins as the key molecular components. The outermost surface of wool fibers comprises a hydrophobic lipid layer that can lead to unsatisfactory processing and properties of fabric products. In this study, molecular sieve 5A, a Na+ and Ca2+ exchanged type A zeolite with a 1:1 Si:Al ratio was integrated onto the surface of wool using 3-mercaptopropyl trimethoxy silane. The resultant surface morphology, hydrophilicity and mechanical performance of the treated wool fabrics were then evaluated. Notably, the surface hydrophilicity of wool was observed to increase dramatically. When wool was treated with a dispersion of 2 wt% acetic acid, 2.5 wt% zeolite and 0.3 wt% or more silane, the water contact angle was observed to decrease from an average value of 148° to 0° over a period of approximately 30 s. Scanning electron microscopic imaging indicated good coverage of the wool surface with zeolite particles, with infrared spectroscopic evaluation indicating strong bonding of the dealuminated zeolite to wool keratins. This application of zeolite showed no adverse effects on the tensile and other mechanical properties of the fabric. This study indicates that zeolite-based treatment is a potentially efficient approach to increasing the surface hydrophilicity and modifying other key surface properties of wool and wool fabrics.

  14. Phylogenetic Study of Haemonchus Species from Iran Based On Morpho-Molecular Characterization.

    Directory of Open Access Journals (Sweden)

    Behnam Meshgi

    2015-06-01

    Full Text Available Haemonchosis has a negative effect on the farming industry throughout the world, especially in the tropic and sub-tropic countries. The present study was carried out to differentiate Haemonchus species from its main hosts in Iran, including sheep, goat and camel.The identification took place based on the morphometrics of the spicules and molecular characters. Two hundred seventy adult male nematodes were collected from the abomasums of different ruminants (90 samples from each animal at the slaughterhouses from different localities in Iran. Samples were morphologically identified according to the spicules' morphometric measurements. In the section on molecular study, 10 samples of each Haemonchus isolates were genetically examined. A simple PCR-restriction fragment length polymorphism (PCR-RFLP assay of the second internal transcribed spacer of ribosomal DNA (ITS2-rDNA were described to confirm the PCR results.PCR-RFLP profile obtained from the restriction enzyme HPa1 in H. contortus and H. longistipes indicated 1 (278 bp and 2 (113 and 135 bp different fragments, respectively. The morphological parameters clearly distinguish H. contortus from H. longistipes. Moreover, regarding the ITS2-rDNA, sequences of 295 bp and 314 bp were obtained from H. contortus and H. longistipes, respectively.The genotypic results are in agreement with the phenotypic findings of both species.

  15. Receivers for Diffusion-Based Molecular Communication: Exploiting Memory and Sampling Rate

    CERN Document Server

    Mosayebi, Reza; Gohari, Amin; Kenari, Masoumeh Nasiri; Mitra, Urbashi

    2014-01-01

    In this paper, a diffusion-based molecular communication channel between two nano-machines is considered. The effect of the amount of memory on performance is characterized, and a simple memory-limited decoder is proposed and its performance is shown to be close to that of the best possible imaginable decoder (without any restriction on the computational complexity or its functional form), using Genie-aided upper bounds. This effect is specialized for the case of Molecular Concentration Shift Keying; it is shown that a four-bits memory achieved nearly the same performance as infinite memory. Then a general class of threshold decoders is considered and shown not to be optimal for Poisson channel with memory, unless SNR is higher than a value specified in the paper. Another contribution is to show that receiver sampling at a rate higher than the transmission rate, i.e., a multi-read system, can significantly improve the performance. The associated decision rule for this system is shown to be a weighted sum of t...

  16. Classification of signaling proteins based on molecular star graph descriptors using Machine Learning models.

    Science.gov (United States)

    Fernandez-Lozano, Carlos; Cuiñas, Rubén F; Seoane, José A; Fernández-Blanco, Enrique; Dorado, Julian; Munteanu, Cristian R

    2015-11-01

    Signaling proteins are an important topic in drug development due to the increased importance of finding fast, accurate and cheap methods to evaluate new molecular targets involved in specific diseases. The complexity of the protein structure hinders the direct association of the signaling activity with the molecular structure. Therefore, the proposed solution involves the use of protein star graphs for the peptide sequence information encoding into specific topological indices calculated with S2SNet tool. The Quantitative Structure-Activity Relationship classification model obtained with Machine Learning techniques is able to predict new signaling peptides. The best classification model is the first signaling prediction model, which is based on eleven descriptors and it was obtained using the Support Vector Machines-Recursive Feature Elimination (SVM-RFE) technique with the Laplacian kernel (RFE-LAP) and an AUROC of 0.961. Testing a set of 3114 proteins of unknown function from the PDB database assessed the prediction performance of the model. Important signaling pathways are presented for three UniprotIDs (34 PDBs) with a signaling prediction greater than 98.0%. PMID:26297890

  17. Molecular Quantum Spintronics: Supramolecular Spin Valves Based on Single-Molecule Magnets and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Wolfgang Wernsdorfer

    2011-10-01

    Full Text Available We built new hybrid devices consisting of chemical vapor deposition (CVD grown carbon nanotube (CNT transistors, decorated with TbPc2 (Pc = phthalocyanine rare-earth based single-molecule magnets (SMMs. The drafting was achieved by tailoring supramolecular π-π interactions between CNTs and SMMs. The magnetoresistance hysteresis loop measurements revealed steep steps, which we can relate to the magnetization reversal of individual SMMs. Indeed, we established that the electronic transport properties of these devices depend strongly on the relative magnetization orientations of the grafted SMMs. The SMMs are playing the role of localized spin polarizer and analyzer on the CNT electronic conducting channel. As a result, we measured magneto-resistance ratios up to several hundred percent. We used this spin valve effect to confirm the strong uniaxial anisotropy and the superparamagnetic blocking temperature (TB ~ 1 K of isolated TbPc2 SMMs. For the first time, the strength of exchange interaction between the different SMMs of the molecular spin valve geometry could be determined. Our results introduce a new design for operable molecular spintronic devices using the quantum effects of individual SMMs.

  18. Molecular quantum spintronics: supramolecular spin valves based on single-molecule magnets and carbon nanotubes.

    Science.gov (United States)

    Urdampilleta, Matias; Nguyen, Ngoc-Viet; Cleuziou, Jean-Pierre; Klyatskaya, Svetlana; Ruben, Mario; Wernsdorfer, Wolfgang

    2011-01-01

    We built new hybrid devices consisting of chemical vapor deposition (CVD) grown carbon nanotube (CNT) transistors, decorated with TbPc(2) (Pc = phthalocyanine) rare-earth based single-molecule magnets (SMMs). The drafting was achieved by tailoring supramolecular π-π interactions between CNTs and SMMs. The magnetoresistance hysteresis loop measurements revealed steep steps, which we can relate to the magnetization reversal of individual SMMs. Indeed, we established that the electronic transport properties of these devices depend strongly on the relative magnetization orientations of the grafted SMMs. The SMMs are playing the role of localized spin polarizer and analyzer on the CNT electronic conducting channel. As a result, we measured magneto-resistance ratios up to several hundred percent. We used this spin valve effect to confirm the strong uniaxial anisotropy and the superparamagnetic blocking temperature (T(B) ~ 1 K) of isolated TbPc(2) SMMs. For the first time, the strength of exchange interaction between the different SMMs of the molecular spin valve geometry could be determined. Our results introduce a new design for operable molecular spintronic devices using the quantum effects of individual SMMs. PMID:22072910

  19. Molecular targets of Chinese herbs: a clinical study of hepatoma based on network pharmacology

    Science.gov (United States)

    Gao, Li; Wang, Xiao-dong; Niu, Yang-yang; Duan, Dan-dan; Yang, Xue; Hao, Jian; Zhu, Cui-hong; Chen, Dan; Wang, Ke-xin; Qin, Xue-mei; Wu, Xiong-zhi

    2016-01-01

    Traditional Chinese medicine (TCM) has been used to treat tumors for years and has been demonstrated to be effective. However, the underlying molecular mechanisms of herbs remain unclear. This study aims to ascertain molecular targets of herbs prolonging survival time of patients with advanced hepatocellular carcinoma (HCC) based on network pharmacology, and to establish a research method for accurate treatment of TCM. The survival benefit of TCM treatment with Chinese herbal medicine (CHM) was proved by Kaplan–Meier method and Cox regression analysis among 288 patients. The correlation between herbs and survival time was performed by bivariate correlation analysis. Network pharmacology method was utilized to construct the active ingredient-target networks of herbs that were responsible for the beneficial effects against HCC. Cox regression analysis showed CHM was an independent favorable prognostic factor. The median survival time was 13 months and the 5-year overall survival rates were 2.61% in the TCM group, while there were 6 months, 0 in the non-TCM group. Correlation analysis demonstrated that 8 herbs closely associated with prognosis. Network pharmacology analysis revealed that the 8 herbs regulated multiple HCC relative genes, among which the genes affected proliferation (KRAS, AKT2, MAPK), metastasis (SRC, MMP), angiogenesis (PTGS2) and apoptosis (CASP3) etc. PMID:27143508

  20. Multispectral excitation based multiple fluorescent targets resolving in fluorescence molecular tomography

    Science.gov (United States)

    Zhou, Yuan; Guang, Huizhi; Pu, Huangsheng; Zhang, Jiulou; Bai, Jing; Luo, Jianwen

    2016-04-01

    Fluorescence molecular tomography (FMT) can visualize biological activities at cellular and molecular levels in vivo, and has been extensively used in drug delivery and tumor detection research of small animals. The ill-posedness of the FMT inverse problem makes it difficult to reconstruct and resolve multiple adjacent fluorescent targets that have different functional features but are labeled with the same fluorochrome. An algorithm based on independent component analysis (ICA) for multispectral excited FMT is proposed to resolve multiple fluorescent targets in this study. Fluorescent targets are excited by multispectral excitation, and the three-dimensional distribution of fluorescent yields under the excitation spectrum is reconstructed by an iterative Tikhonov regularization algorithm. Subsequently, multiple fluorescent targets are resolved from mixed fluorescence signals by employing ICA. Simulations were performed and the results demonstrate that multiple adjacent fluorescent targets can be resolved if the number of excitation wavelengths is not smaller than that of fluorescent targets with different concentrations. The algorithm obtains both independent components that provide spatial information of different fluorescent targets and spectral courses that reflect variation trends of fluorescent yields along with the excitation spectrum. By using this method, it is possible to visualize the metabolism status of drugs in different structure organs, and quantitatively depict the variation trends of fluorescent yields of each functional organ under the excitation spectrum. This method may provide a pattern for tumor detection, drug delivery and treatment monitoring in vivo.

  1. COMPOSITE POLYMERICADDITIVESDESIGNATED FORCONCRETEMIXES BASED ONPOLYACRYLATES, PRODUCTS OF THERMAL DECOMPOSITION OF POLYAMIDE-6 AND LOW-MOLECULAR POLYETHYLENE

    OpenAIRE

    Polyakov Vyacheslav Sergeevich; Padokhin Valeriy Alekseevich; Akulova Marina Vladimirovna -

    2012-01-01

    The goal of the present research is to develop polymeric additives based on aqueous dispersions of (meth)acrylic polymers, including polymethacrylates, polyacrylates, products of thermal decomposition of polyamide-6 in the vegetable oil media, and low-molecular polyethylene. Decomposition of polyamide-6 took 8…10 hours at the temperature of 245…275 °С. The mixture of low-molecular polyamides, the average molecular weight of which reached 3400…8600, was used both independently and as a consti...

  2. Isoindigo-based polymer photovoltaics: modifying polymer molecular structures to control the nanostructural packing motif.

    Science.gov (United States)

    Kim, Yu Jin; Lee, Yun-Ji; Kim, Yun-Hi; Park, Chan Eon

    2016-07-21

    Donor molecular structures, and their packing aspects in donor:acceptor active blends, play a crucial role in the photovoltaic performance of polymer solar cells. We systematically investigated a series of isoindigo-based donor polymers within the framework of a three-dimensional (3D) crystalline motif by modifying their chemical structures, thereby affecting device performances. Although our isoindigo-based polymer series contained polymers that differed only by their alkyl side chains and/or donating units, they showed quite different nanoscale morphological properties, which resulted in significantly different device efficiencies. Notably, blends of our isoindigo-based donor polymer systems with an acceptor compound, whereby the blends had more intermixed network morphologies and stronger face-on orientations of the polymer crystallites, provided better-performing photovoltaic devices. This behavior was analyzed using atomic force microscopy (AFM) and two-dimensional grazing incidence wide angle X-ray diffraction (2D-GIWAXD). To the best of our knowledge, no correlation has been reported previously between 3D nano-structural donor crystallites and device performances, particularly for isoindigo-based polymer systems. PMID:27326694

  3. Isoindigo-based polymer photovoltaics: modifying polymer molecular structures to control the nanostructural packing motif.

    Science.gov (United States)

    Kim, Yu Jin; Lee, Yun-Ji; Kim, Yun-Hi; Park, Chan Eon

    2016-07-21

    Donor molecular structures, and their packing aspects in donor:acceptor active blends, play a crucial role in the photovoltaic performance of polymer solar cells. We systematically investigated a series of isoindigo-based donor polymers within the framework of a three-dimensional (3D) crystalline motif by modifying their chemical structures, thereby affecting device performances. Although our isoindigo-based polymer series contained polymers that differed only by their alkyl side chains and/or donating units, they showed quite different nanoscale morphological properties, which resulted in significantly different device efficiencies. Notably, blends of our isoindigo-based donor polymer systems with an acceptor compound, whereby the blends had more intermixed network morphologies and stronger face-on orientations of the polymer crystallites, provided better-performing photovoltaic devices. This behavior was analyzed using atomic force microscopy (AFM) and two-dimensional grazing incidence wide angle X-ray diffraction (2D-GIWAXD). To the best of our knowledge, no correlation has been reported previously between 3D nano-structural donor crystallites and device performances, particularly for isoindigo-based polymer systems.

  4. Electroanalysis of myoglobin based on electropolymerized molecularly imprinted polymer poly-o-phenylenediamine and carbon nanotubes/screen printed electrode.

    Science.gov (United States)

    Shumyantseva, V V; Bulko, T V; Sigolaeva, L V; Kuzikov, A V; Archakov, A I

    2016-05-01

    Electroanalysis of myoglobin as a marker of acute myocardial infarction by means of screenprinted electrodes modified with multiwalled carbon nanotubes and polymeric artificial antibodies is developed. Plastic antibodies to myoglobin (molecularly imprinted polymers, MIPs) based on o-phenylenediamine were produced by electropolymerization. Molecular imprinting technology in biosensor analysis was used as alternative to natural receptors (namely, antibodies) and demonstrated high sensitivity (1.5 × 10(-2) A/nmol of myoglobin) and selectivity.

  5. Research Update: Comparison of salt- and molecular-based iodine treatments of PbS nanocrystal solids for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jähnig, Fabian; Bozyigit, Deniz; Yarema, Olesya; Wood, Vanessa [Laboratory for Nanoelectronics, ETH Zurich Gloriastrasse 35, Zurich 8044 (Switzerland)

    2015-02-01

    Molecular- and salt-based chemical treatments are believed to passivate electronic trap states in nanocrystal-based semiconductors, which are considered promising for solar cells but suffer from high carrier recombination. Here, we compare the chemical, optical, and electronic properties of PbS nanocrystal-based solids treated with molecular iodine and tetrabutylammonium iodide. Surprisingly, both treatments increase—rather than decrease—the number density of trap states; however, the increase does not directly influence solar cell performance. We explain the origins of the observed impact on solar cell performance and the potential in using different chemical treatments to tune charge carrier dynamics in nanocrystal-solids.

  6. Quantitative detection of ING1 mRNA under different gene regulation based on molecular beacon

    Institute of Scientific and Technical Information of China (English)

    LIU Bin; WANG Kemin; XIAO Zhiqiang; WANG Wei; TAN Weihong; SUN Yi; TANG Hongxing; YANG Xiaohai

    2006-01-01

    The effects of drug treatment, gene transfection, and p53 RNA interference (RNAi) on level of ING1 mRNA in tumor cells were quantitatively detected with the help of ING1 molecular beacon (MB)/cRNA standard curve based on MB detection technology. Results showed that the level of ING1 mRNA could be upregulated by 5-FU treatment or ING1 transfection in low expression cell line of MCF-7 and be inhibited by silencing p53 with RNAi technology in normal expression cell line of CNE2. The level of ING1 varied from 7.7×10-16 to 53.4×10-16 mol/ug total RNA of tumor cells. The results not only provided evidence for the regulation effects of gene expression but also were applied to investigating the interaction of multigenes on signal transduction pathway.

  7. Deformation characteristics of various grain boundary angles on AFM-based nanolithography using molecular dynamics

    International Nuclear Information System (INIS)

    Molecular dynamics simulations are performed to verify the deformation characteristics of grain boundaries on the AFM-based nanolithography. The model used has about 750,000 (Cu) atoms and is composed of two different crystal orientations. The grain boundaries are located in the center of model and have 45, 90, 135, and -135 degree angles in the xz-plane. The tool is made of rigid diamond-like carbon and is in the shape of the Berkovich indenter. The simulation has four different stages: relaxation, indentation, re-relaxation, and lithography. The simulation results reveal that the lithography deforms the grain boundary shape by the tool. The deformation of grain boundary's angle proceeds to minimize the total potential energy of whole system. Consequently, the grain boundary angle is changed about 90 degrees

  8. Prediction of Substrate-Enzyme-Product Interaction Based on Molecular Descriptors and Physicochemical Properties

    Directory of Open Access Journals (Sweden)

    Bing Niu

    2013-01-01

    Full Text Available It is important to correctly and efficiently predict the interaction of substrate-enzyme and to predict their product in metabolic pathway. In this work, a novel approach was introduced to encode substrate/product and enzyme molecules with molecular descriptors and physicochemical properties, respectively. Based on this encoding method, KNN was adopted to build the substrate-enzyme-product interaction network. After selecting the optimal features that are able to represent the main factors of substrate-enzyme-product interaction in our prediction, totally 160 features out of 290 features were attained which can be clustered into ten categories: elemental analysis, geometry, chemistry, amino acid composition, predicted secondary structure, hydrophobicity, polarizability, solvent accessibility, normalized van der Waals volume, and polarity. As a result, our predicting model achieved an MCC of 0.423 and an overall prediction accuracy of 89.1% for 10-fold cross-validation test.

  9. Prediction of substrate-enzyme-product interaction based on molecular descriptors and physicochemical properties.

    Science.gov (United States)

    Niu, Bing; Huang, Guohua; Zheng, Linfeng; Wang, Xueyuan; Chen, Fuxue; Zhang, Yuhui; Huang, Tao

    2013-01-01

    It is important to correctly and efficiently predict the interaction of substrate-enzyme and to predict their product in metabolic pathway. In this work, a novel approach was introduced to encode substrate/product and enzyme molecules with molecular descriptors and physicochemical properties, respectively. Based on this encoding method, KNN was adopted to build the substrate-enzyme-product interaction network. After selecting the optimal features that are able to represent the main factors of substrate-enzyme-product interaction in our prediction, totally 160 features out of 290 features were attained which can be clustered into ten categories: elemental analysis, geometry, chemistry, amino acid composition, predicted secondary structure, hydrophobicity, polarizability, solvent accessibility, normalized van der Waals volume, and polarity. As a result, our predicting model achieved an MCC of 0.423 and an overall prediction accuracy of 89.1% for 10-fold cross-validation test. PMID:24455714

  10. Treatment of Chronic Inflammatory Demyelinating Polyneuropathy: From Molecular Bases to Practical Considerations

    Directory of Open Access Journals (Sweden)

    Paolo Ripellino

    2014-01-01

    Full Text Available Chronic inflammatory demyelinating polyneuropathy (CIDP is an autoimmune disease of the peripheral nervous system, in which both cellular and humoral immune responses are involved. The disease is clinically heterogeneous with some patients displaying pure motor form and others also showing a variable degree of sensory dysfunction; disease evolution may also differ from patient to patient, since monophasic, progressive, and relapsing forms are reported. Underlying such clinical variability there is probably a broad spectrum of molecular dysfunctions that are and will be the target of therapeutic strategies. In this review we first explore the biological bases of current treatments and subsequently we focus on the practical management that must also take into account pharmacoeconomic issues.

  11. Spin-dependent Otto quantum heat engine based on a molecular substance

    Science.gov (United States)

    Hübner, Wolfgang; Lefkidis, Georgios; Dong, Chuanding; Chaudhuri, Debapriya; Chotorlishvili, Levan; Berakdar, Jamal

    2015-03-01

    We explore the potential of single molecules for thermodynamic cycles. To this end we propose two molecular heat engines based on the realistic Ni2 dimer: a quantum Otto engine and a modified quantum Otto engine for which laser-induced optical excitations substitute for one of the heat-exchange points. For reliable predictions and to inspect the role of spin and electronic correlations we perform fully correlated ab initio calculations of the electronic structure and the excited states. We analyze the efficiency and the word output of the derived engines and find an enhancement when the spin degree of freedom is included. We also use the von Neumann entropy to describe correlations and entanglement of the engines during the cycles. Furthermore, we link our results to previous results regarding an isobaric stroke and a magnetic quantum Diesel engine on the same substance.

  12. Microspheres Sensor Based on Molecularly Imprinted Polymer Synthesized by Precipitation Polymerization

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Zhao-Hui; LONG,Yu-Mei; LIU,Ying-Ju; YAO,Shou-Zhuo

    2003-01-01

    A new biomimetic bulk acoustic wave sensor based on molecularly imprinted microspheres(MIM) technique was described.The sensing materials were synthesized by precipitation polymerization.By using the Scatchard analysis,the equilibrium dissociation constant KD and the apparent maximum number Qmax of the binding sites were calculated to be 3.70 mmol·L-1 and 9.11 μmol·g-1,respectively.The sensor exhibited a sensitive response to detection limit of 2×10-9 mol·L-1.The recoveries of the sensor were 95.1%-105.4%.Studies presented in this paper show that the stability of this sensor is excellent.The sensor has been applied successfully to the determination of dipyridmaole in human urine.

  13. Isopropylation of benzene with 2-propanol over substituted large pore aluminophosphate-based molecular sieves

    Indian Academy of Sciences (India)

    K Joseph Antony Raj; V R Vijayaraghavan

    2004-03-01

    Large pore aluminophosphate-based molecular sieves like AlPO4-5, MAPO-5, MnAPO-5 and ZAPO-5 were synthesised hydrothermally using triethylamine as a structure directing agent. These materials were characterised by X-ray diffraction (XRD), 27Al and 31P MAS-NMR, ICP-MS, -butylamine- TPD, BET and SEM. The catalytic performance of these materials was tested for isopropylation of benzene with 2-propanol at 250, 300, 350 and 400°C. The products were cumene, -DIPB (-diisopropylbenzene) and -DIPB (-diisopropylbenzene). MnAPO-5 was found to be more active than the other catalysts. Maximum conversion (20%) was noted at 350°C over MnAPO-5. The selectivity to DIPB was found to decrease with time on stream but the selectivity to cumene showed an increase after 3 h of time on stream.

  14. Synthesis and Bioconjugation of Gold Nanoparticles as Potential Molecular Probes for Light-Based Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Raja Gopal Rayavarapu

    2007-01-01

    Full Text Available We have synthesized and characterized gold nanoparticles (spheres and rods with optical extinction bands within the “optical imaging window.” The intense plasmon resonant driven absorption and scattering peaks of these nanoparticles make them suitable as contrast agents for optical imaging techniques. Further, we have conjugated these gold nanoparticles to a mouse monoclonal antibody specific to HER2 overexpressing SKBR3 breast carcinoma cells. The bioconjugation protocol uses noncovalent modes of binding based on a combination of electrostatic and hydrophobic interactions of the antibody and the gold surface. We discuss various aspects of the synthesis and bioconjugation protocols and the characterization results of the functionalized nanoparticles. Some proposed applications of these potential molecular probes in the field of biomedical imaging are also discussed.

  15. Diversity surveys of soil bacterial community by cultivation-based methods and molecular fingerprinting techniques

    Institute of Scientific and Technical Information of China (English)

    LUO Hai-feng; QI Hong-yan; ZHANG Hong-xun

    2004-01-01

    By combining the cultivation methods with molecular fingerprinting techniques, the diversity surveys of soil bacterial community in 13 areas of China were carried out. The cultivable heterotrophic diversity was investigated by colony morphology on solid LB medium. Genetic diversity was measured as bands on denaturing gradient gel electrophoresis(DGGE) by the extraction and purification of the total soil DNA, and amplification of bacterial 16S rDNA fragments by polymerase chain reaction ( PCR). The Shannon-Wiener indices of diversity (H), richness (S)and evenness( EH ) were employed to estimate the diversity of soil bacterial community. The results showed that there was an obvious diversification existed in soil from the different areas. However, the genetic diversity estimated by PCR-DGGE can provide more comprehensive information on bacterial community than the cultivation-based methods. Therefore, it is suggested to combine the traditional methods with genetic fingerprinting techniques to survey and estimate soil bacterial diversity.

  16. Asymptotic Analysis of Microtubule-Based Transport by Multiple Identical Molecular Motors

    CERN Document Server

    McKinley, Scott A; Fricks, John; Kramer, Peter R

    2011-01-01

    We describe a system of stochastic differential equations (SDEs) which model the interaction between processive molecular motors, such as kinesin and dynein, and the biomolecular cargo they tow as part of microtubule-based intracellular transport. We show that the classical experimental environment fits within a parameter regime which is qualitatively distinct from conditions one expects to find in living cells. Through an asymptotic analysis of our system of SDEs, we develop a means for applying in vitro observations of the nonlinear response by motors to forces induced on the attached cargo to make analytical predictions for two parameter regimes that have thus far eluded direct experimental observation: 1) highly viscous in vivo transport and 2) dynamics when multiple identical motors are attached to the cargo and microtubule.

  17. Hybrid Decomposition Method in Parallel Molecular Dynamics Simulation Based on SMP Cluster Architecture

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; SHU Jiwu; ZHENG Weimin; WANG Jinzhao; CHEN Min

    2005-01-01

    A hybrid decomposition method for molecular dynamics simulations was presented, using simultaneously spatial decomposition and force decomposition to fit the architecture of a cluster of symmetric multi-processor (SMP) nodes. The method distributes particles between nodes based on the spatial decomposition strategy to reduce inter-node communication costs. The method also partitions particle pairs within each node using the force decomposition strategy to improve the load balance for each node. Simulation results for a nucleation process with 4 000 000 particles show that the hybrid method achieves better parallel performance than either spatial or force decomposition alone, especially when applied to a large scale particle system with non-uniform spatial density.

  18. Estimation of Linear Viscoelasticity of Polymer Melts in Molecular Dynamics Simulations Based on Relaxation Mode Analysis

    Science.gov (United States)

    Iwaoka, Nobuyuki; Hagita, Katsumi; Takano, Hiroshi

    2014-03-01

    On the basis of relaxation mode analysis (RMA), we present an efficient method to estimate the linear viscoelasticity of polymer melts in a molecular dynamics (MD) simulation. Slow relaxation phenomena appeared in polymer melts cause a problem that a calculation of the stress relaxation function in MD simulations, especially in the terminal time region, requires large computational efforts. Relaxation mode analysis is a method that systematically extracts slow relaxation modes and rates of the polymer chain from the time correlation of its conformations. We show the computational cost may be drastically reduced by combining a direct calculation of the stress relaxation function based on the Green-Kubo formula with the relaxation rates spectra estimated by RMA. N. I. acknowledges the Graduate School Doctoral Student Aid Program from Keio University.

  19. Construyendo aprendizajes a partir de la experiencia, el caso del curso de Introducción a las Ciencias Agrarias y Forestales

    OpenAIRE

    Larrañaga, Gustavo; Mendicino, Lorena; Seibane, Cecilia; Huinca, Yanet; May, Paula; Landaburu, Marcelo; Zarate, Yanina; Gramundo, Aldo; Recatume, Gustavo; Olguin, Francisco; Riachi, Juan; Ciocchini, Florencia

    2012-01-01

    Desde nuestro curso al entender la realidad de manera multicausal y en base a un enfoque constructivista del proceso de enseñanza aprendizaje intentamos aportar una mirada holística en la formación de los estudiantes. Consideramos importante que el educando transite experiencias vinculadas a fenómenos de la realidad natural y social, para él mismo “aprender haciendo”. Las salidas a campo, son una estrategia didáctica que nos permite concretar nuestra propuesta conceptual y metodológica. A par...

  20. Design and Synthesis of Chiral Molecular Tweezers Based on Deoxycholic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms.Instead of using toxic phosgene,the triphosgene was employed in synthesis of the molecular tweezers receptors.These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.

  1. Electrochemical control of quantum interference in anthraquinone-based molecular switches

    DEFF Research Database (Denmark)

    Markussen, Troels; Schiøtz, Jakob; Thygesen, Kristian Sommer

    2010-01-01

    absent in the hydroquinone molecular bridge. A simple explanation of the interference effect is achieved by transforming the frontier molecular orbitals into localized molecular orbitals thereby obtaining a minimal tight-binding model describing the transport in the relevant energy range in terms of...

  2. Oxidative desulfurization of dibenzothiophene based on molecular oxygen and iron phthalocyanine

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinrui; Li, Juan; Wang, Xiuna; Jin, Kun; Ma, Wei [State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012 (China)

    2009-02-15

    Direct oxidation of dibenzothiophene (DBT) based on molecular oxygen and iron tetranitrophthalocyanine (FePc(NO{sub 2}){sub 4}) catalyst was performed in hydrocarbon solvent under water-free condition for deep desulfurization. Conversion of DBT in decalin reached 98.7 wt.% at 100 C and 0.3 MPa of initial pressure with 1 wt.% of FePc(NO{sub 2}){sub 4} over the whole solution for 2 h. In addition to FePc(NO{sub 2}){sub 4}, another two catalysts, FePc(NO{sub 2}){sub 3}NH{sub 2} and FePc(NH{sub 2}){sub 4}, were synthesized to investigate the effect of substituents of iron phthalocyanines on their catalytic activities. The results show that the catalytic activity of these phthalocyanines decreases in the order of FePc(NO{sub 2}){sub 4} > FePc(NO{sub 2}){sub 3}NH{sub 2} > FePc(NH{sub 2}){sub 4}, indicating that the electron-donating group has negative effect on the catalytic properties. Activity of FePc(NO{sub 2}){sub 4} was kept unchanged after 5 runs of oxidation; whereas, activity of FePc(NH{sub 2}){sub 4} decreased because of its decomposition. Moreover, FePc(NO{sub 2}){sub 3}NH{sub 2} was supported on a polyacrylic cationic exchange resin and its activity was remarkably enhanced to the level of FePc(NO{sub 2}){sub 4}. Oxidative desulfurization of a model fuel, 500 {mu}g/g solution of DBT in decalin, was performed based on the catalytic oxidation using molecular oxygen and FePc(NO{sub 2}){sub 4} catalyst. The lowest sulfur content in the model fuel could be decreased to less than 4 {mu}g/g after the treatment of this oxidation and a combined adsorption. (author)

  3. Molecular bases for parallel evolution of translucent bracts in an alpine "glasshouse" plant Rheum alexandrae (Polygonaceae)

    Institute of Scientific and Technical Information of China (English)

    Bing-Bing LIU; Lars OPGENOORTH; Georg MIEHE; Dong-Yuan ZHANG; Dong-Shi WAN; Chang-Ming ZHAO; Dong-Rui JIA

    2013-01-01

    Parallel evolution provides an excellent framework to infer the genetic bases of adaptive traits and understand the importance of natural selection in shaping current biodiversity.The upper leaves of the "glasshouse plants" transform into translucent bracts that show numerous adaptions in alpine habitats.It remains unknown whether similar molecular changes occur under the parallel bract evolution of different "glasshouse" species.In this study,we compared the results on phenotypic and physiological differences and presented the results of cDNA-AFLP analyses of transcriptional changes between translucent bracts and normal leaves in Rheum alexandrae.We also examined the homologous candidate genes with the same expression changes between this species and another "glasshouse" species,R.nobile.We found that bracts ofR.alexandrae are similar to those ofR.nobile in anatomical features:chloroplasts have degenerated and chlorophyll contents are greatly reduced,which suggests that foliar photosynthetic functions in bracts of both species have been reduced or totally altered.Among the 6000 transcript-derived fragments (TDFs) in bracts and leaves of R.alexandrae,420 (7%) were differentially expressed (up-or downregulated) between bracts and normal leaves.There were a total of 13 homologous TDFs with the same expression changes between R.alexandrae and the previously studied R.nobile.Except for the two that were not functionally annotated,eight of the homologous TDFs were found to be involved in stress and defense responses whereas the other three were related to photosynthesis.The up-or downregulation of these candidate genes was highly congruent with anatomical characteristics and adaptive functions of the bracts found for "glasshouse" plants.These findings suggested that the "glasshouse" phenotypes may have common molecular bases underlying their parallel evolution of similar adaptive functions and highlighted the importance of the natural selection in producing such

  4. Bases moleculares del cáncer oral: Revisión bibliográfica

    Directory of Open Access Journals (Sweden)

    V García García

    2005-12-01

    Full Text Available El cáncer oral representa del 2 al 4% de todos los cánceres diagnosticados, con un incremento anual de 5000 nuevos casos por año, aunque cabe destacar la marcada variabilidad geográfica respecto a su incidencia. Histológicamente, el carcinoma de células escamosas o epidermoide es el tumor más común encontrado en la cavidad oral. Es indiscutible el papel del odontólogo en la prevención primaria (promocionando un estilo de vida saludable y secundaria (diagnóstico precoz del cáncer oral. Entender las bases moleculares del cáncer oral supone una tarea ardua que trataremos de resolver simplificando lo máximo posible y ayudándonos de esquemas esclarecedores para comprender la raíz de esta inquietante y desconocida enfermedad.Oral cancer represents 2%-4% of the all types of cancer that are diagnosed with an annual increment of 5000 new cases per year, and it´s related to the variety that exist in the different geographical areas. Histologically, escamous cell carcinoma or epidermal carcinoma is the most common tumour found in the oral cavity. The dentist has a very important role about primary prevention (by promoting a health life style and about secondary prevention( early diagnose of oral cancer. To simplify the knowledge of molecular bases of oral cancer we will use diagrams to clarify this disturbing and unknown illnesses.

  5. Molecular Biomarker-Based Biokinetic Modeling of a PCE-Dechlorinating and Methanogenic Mixed Culture

    Energy Technology Data Exchange (ETDEWEB)

    Heavner, Gretchen L. W.; Rowe, Annette R.; Mansfeldt, Cresten B.; Pan, Ju Khuan; Gossett, James M.; Richardson, Ruth E.

    2013-04-16

    Bioremediation of chlorinated ethenes via anaerobic reductive dechlorination relies upon the activity of specific microbial population-most notably Dehalococcoides (DHC) strains. In the lab and field Dehalococcoides grow most robustly in mixed communities which usually contain both fermenters and methanogens. Recently, researchers have been developing quantitative molecular biomarkers to aid in field site diagnostics and it is hoped that these biomarkers could aid in the modeling of anaerobic reductive dechlorination. A comprehensive biokinetic model of a community containing Dehalococcoides mccartyi (formerly D. ethenogenes) was updated to describe continuously fed reactors with specific biomass levels based on quantitative PCR (qPCR)-based population data (DNA and RNA). The model was calibrated and validated with subsets of chemical and molecular biological data from various continuous feed experiments (n = 24) with different loading rates of the electron acceptor (1.5 to 482 μeeq/L-h), types of electron acceptor (PCE, TCE, cis-DCE) and electron donor to electron acceptor ratios. The resulting model predicted the sum of dechlorination products vinyl chloride (VC) and ethene (ETH) well. However, VC alone was under-predicted and ETH was over predicted. Consequently, competitive inhibition among chlorinated ethenes was examined and then added to the model. Additionally, as 16S rRNA gene copy numbers did not provide accurate model fits in all cases, we examined whether an improved fit could be obtained if mRNA levels for key functional enzymes could be used to infer respiration rates. The resulting empirically derived mRNA “adjustment factors” were added to the model for both DHC and the main methanogen in the culture (a Methanosaeta species) to provide a more nuanced prediction of activity. Results of this study suggest that at higher feeding rates competitive inhibition is important and mRNA provides a more accurate indicator of a population’s instantaneous

  6. Application of fluorescence-based semi-automated allelotyping to the molecular characterization of tumors

    Energy Technology Data Exchange (ETDEWEB)

    Jedlicka, A.E.; DiSilvestre, D.; Holroyd, K.J. [Johns Hopkins Medical Institutions, Baltimore, MD (United States)] [and others

    1994-09-01

    In cancer genetics, identifying loss of heterozygosity (LOH) defines candidate regions which warrant further analyses to determine the presence of tumor suppressor genes. In addition, demonstrating LOH has potential utility for improving the pathologic classification of tumors. Molecular methods that improve the efficiency and accuracy of LOH studies will be helpful in both clinical and research applications. Here we demonstrate a fluorescence-based semi-automated alleotyping method for studies of LOH in cancer, using gliomas as an example. Gliomas are tumors arising from neuroglia, the supporting tissue intermingled with essential elements of the brain and spinal cord. Since this method utilizes PCR-based highly polymorphic simple sequence repeat markers, it is suitable for small and archival tumor specimens. We collected tumor tissue from a variety of gliomas, and DNA was extracted. White blood cells from the same individuals served as a source of {open_quotes}control{close_quotes} DNA. We PCR amplified markers from tumor and genomic DNA to detect molecular alterations in six people. Simultaneous analysis of 14 loci near gene candidates on chromosomes 5, 7, 9, 10, 11, and 22, were evaluated. Strikingly, in most cases there was allelic loss in brain tumor compared to genomic DNA for at least one of these loci. In addition, alleles of lesser intensity were also shown at a few loci of the tumor DNA, suggesting possible genetic instability. We conclude from these data that fluorescent semi-automated allelotyping is a quantitative and efficient process for determining and analyzing LOH in gliomas, and possibly other tumors. These methods will facilitate the identification of candidate loci critical in the development and progression of tumors.

  7. Experiencias creativas universitarias para la generación de un modelo de gestión de innovatividad

    Directory of Open Access Journals (Sweden)

    María Eunice Di Fiore Subero

    2013-06-01

    Full Text Available El presente trabajo se desarrolla en la Universidad Nacional Experimental “Rafael María Baralt” (UNERMB, de Venezuela, donde existe un equipo interdisciplinario de docentes, que durante 14 años de trabajo ininterrumpido realizan una labor que parte de la experiencia con estudiantes de los programas académicos de la institución (Administración, Educación, Ingeniería y Salud, en un proceso constante de captación y desarrollo del talento creativo; se trata de la Comisión Eureka-UNERMB. El proceso deviene en un modelo abstracto sobre el desarrollo del talento creativo estudiantil. Este modelo tiene características propias, es auto-gestionado, con componentes en constante interacción, fundamentado para su sistematización en una primera visión, siguiendo los planteamientos realizados en el trabajo Sistematización de Experiencias y Generación de Teorías (Barrera, 2010. Las investigaciones se generan sobre la base de una metodología sustentada en diversos paradigmas de investigación, tomando en consideración las áreas del conocimiento abordadas: Innovatividad Técnica, Social, Desarrollo Sostenible, Diseño, Arte, Recreación, Arte Comunitario y Salud. Epistemológicamente la propuesta está basada en el enfoque de investigación holístico (Hurtado, 2008, así como el modelo integrativo o multimodal (Hernández, Fernández y Batista, 2010, los cuales se soportan en la integración coherente de paradigmas, desde una perspectiva basada en la complementariedad de la ciencia, en cuanto a temáticas, enfoques y metódica de investigación.

  8. [Genetic polymorphism of flax Linum usitatissimum based on use of molecular cytogenetic markers].

    Science.gov (United States)

    Rachinskaia, O A; Lemesh, V A; Muravenko, O V; Iurkevich, O Iu; Guzenko, E V; Bol'sheva, N L; Bogdanova, M V; Samatadze, T E; Popov, K V; Malyshev, S V; Shostak, N G; Heller, K; Khotyleva, L V; Zelenin, A V

    2011-01-01

    Using a set of approaches based on the use of molecular cytogenetic markers (DAPI/C-banding, estimation of the total area of DAPI-positive regions in prophase nuclei, FISH with 26S and 5S rDNA probes) and the microsatellite (SSR-PCR) assay, we studied genomic polymorphism in 15 flax (Linum usitatissimum L.) varieties from different geographic regions belonging to three directions of selection (oil, fiber, and intermediate flaxes) and in the k-37 x Viking hybrid. All individual chromosomes have been identified in the karyotypes of these varieties on the basis of the patterns of differential DAPI/C-banding and the distribution of 26S and 5S rDNA, and idiograms of the chromosomes have been generated. Unlike the oil flax varieties, the chromosomes in the karyotypes of the fiber flax varieties have, as a rule, pericentromeric and telomeric DAPI-positive bands of smaller size, but contain larger intercalary regions. Two chromosomal rearrangements (chromosome 3 inversions) were discovered in the variety Luna and in the k-37 x Viking hybrid. In both these forms, no colocalization of 26S rDNA and 5S rDNA on the satellite chromosome was detected. The SSR assay with the use of 20 polymorphic pairs of primers revealed 22 polymorphic loci. Based on the SSR data, we analyzed genetic similarity of the flax forms studied and constructed a genetic similarity dendrogram. The genotypes studied here form three clusters. The oil varieties comprise an independent cluster. The genetically related fiber flax varieties Vita and Luna, as well as the landrace Lipinska XIII belonging to the intermediate type, proved to be closer to the oil varieties than the remaining fiber flax varieties. The results of the molecular chromosomal analysis in the fiber and oil flaxes confirm their very close genetic similarity. In spite of this, the combined use of the chromosomal and molecular markers has opened up unique possibilities for describing the genotypes of flax varieties and creating their genetic

  9. Una experiencia con QSB+ en Matemáticas de primer curso

    Directory of Open Access Journals (Sweden)

    Ordás Amo, Pilar

    2001-01-01

    Full Text Available Nuestro objetivo con este trabajo es presentar una experiencia que hemos llevado a cabo con los alumnos de primer curso, en la asignatura de Matemáticas, de las Licenciaturas en Ciencias Económicas y Administración y Dirección de Empresas, durante los cursos 1999/2000 y 2000/2001. El propósito de la experiencia es que los alumnos de primer curso vean una parte de la optimización matemática, como es la programación lineal, y el método del Símplex, a través de un software informático sencillo como es el QSB+, en el aula de ordenadores. Para llevar a cabo la experiencia, se añadió una hora lectiva al horario de los alumnos implicados y de los profesores de Matemáticas de primer curso, con plan nuevo (plan 99, durante el segundo semestre, de forma totalmente voluntaria para los alumnos, aunque la materia explicada en estas clases “extras” formaba parte del examen final de la asignatura. El nombre oficial de la experiencia fue Seminario de Programación Lineal, y tuvo una duración aproximada de quince horas lectivas.

  10. Experiencias y vivencias del embarazo en adolescentes explicadas desde lo social

    Directory of Open Access Journals (Sweden)

    VIRGINIA INÉS SOTO

    2008-12-01

    Full Text Available Describir y explicar desde lo social las experiencias y vivencias de las adolescentes embarazadas, como el contexto para una provisión de cuidado integral, individualizado y contextualizado, es necesario para la práctica de enfermería, y tratar este fenómeno como hecho social exige asimilar las realidades del mundo social a las del mundo exterior, adoptando el principio de que se ignora por completo lo que son, reconociendo que el hecho social no puede ser modificado por un simple decreto de la voluntad, sino que exige un esfuerzo laborioso, considerando la experiencia desde los ámbitos interno y externo. Presentar un marco conceptual y referencial desde lo social, interpretando la experiencia y la vivencia, permitirá a la enfermera comprender este fenómeno cuando dichas experiencias involucran o ponen en riesgo la salud de la adolescente gestante, máxime que la práctica clínica de enfermería se ha estudiado primariamente desde una perspectiva sociológica, pues comparte una importancia social destacada y un fin social, centrada en facilitar, apoyar y atender a los individuos, familias, comunidades y/o sociedades para realzar, mantener y recuperar la salud, y reducir y aliviar los efectos de la enfermedad, con el resultado explícito de promover la calidad de vida relacionada con la salud dentro de contextos ambientales inmediatos y más amplios.

  11. Derecho constitucional y género. La experiencia de la red feminista de Derecho Constitucional

    OpenAIRE

    Sevilla Merino, Julia; I Seminario de Innovación y Calidad Educativa en Derecho Constitucional

    2009-01-01

    ''Derecho constitucional y género. La experiencia de la red feminista de derecho constitucional'', Julia Sevilla Letrada Corts Valencianes, U. Valencia y Mar Esquembre Valdés, U. Alicante. I Seminario de Innovación y Calidad Educativa en Derecho Constitucional. Centro de Estudios Políticos y Constitucionales, Madrid, 17 junio 2009Duración: 12M

  12. Experiencia de intercambio docente en dos asignaturas de Inteligencia Artificial en universidades argentinas

    OpenAIRE

    Mariño, Sonia Itatí; Rambo, Alice

    2014-01-01

    En ámbitos de Educación Superior se propicia la generación de redes de intercambio y difusión de conocimientos y experiencias. Se describe una iniciativa docente desarrollada en dos asignaturas que abordan temas de Inteligencia Artificial.

  13. Aplicación de la experiencia de aprendizaje mediado a la estrategia de aprendizaje basado en problemas en estudiantes del tercer semestre de medicina, Universidad Autónoma de Bucaramanga, Colombia = Application of Mediated Learning Experience to the Problem Based Learning strategy on third semester medical students at a Colombian university

    Directory of Open Access Journals (Sweden)

    González Olaya, Hilda Leonor

    2011-12-01

    Full Text Available Introducción: el Aprendizaje Basado en Problemas (ABP, ha mostrado logros importantes en la enseñanza de la medicina. La Experiencia del Aprendizaje Mediado (EAM, derivada de la Teoría de la Modificabilidad Cognitiva, podría aumentar los alcances de la estrategia ABP y contribuir al logro de aprendizajes significativos en estudiantes de medicina. En el presente estudio se evaluaron los beneficios sobre el aprendizaje significativo de incorporar la EAM al ABP en estudiantes de medicina. Materiales y métodos: se hizo un estudio controlado y con asignación aleatoria con los estudiantes del tercer semestre de medicina de la Universidad Autónoma de Bucaramanga, Colombia. El primer grupo recibió solamente la metodología ABP y el segundo, dicha metodología articulada con la EAM. En subgrupos de ocho estudiantes asistieron a 16 sesiones (2 horas/semana para desarrollar problemas relacionados con el propósito homeostático ''mantener un adecuado aporte de oxígeno a los tejidos''. Se utilizaron dos pruebas de conocimiento: selección múltiple y resolución de problemas. Se describieron cualitativamente los resultados de la observación del desempeño cognitivo y de las autoevaluaciones, coevaluaciones y heteroevaluaciones. Resultados y conclusiones: los promedios y porcentajes de aprobación de las pruebas de conocimiento fueron mayores en el grupo de intervención, pero estas diferencias solo fueron estadísticamente significativas en la prueba de selección múltiple. Es posible que la estrategia ABP por sí misma potencie el aprendizaje significativo, pero las observaciones cualitativas demuestran que la EAM favorece la motivación y un ambiente propicio para potenciar las funciones cognitivas por lo que podría aumentar los beneficios del ABP.

  14. New Educational Environments Aimed at Developing Intercultural Understanding While Reinforcing the Use of English in Experience-Based Learning Nuevos entornos educativos destinados a desarrollar la comprensión intercultural y a reforzar el uso del inglés mediante el aprendizaje basado en experiencias

    Directory of Open Access Journals (Sweden)

    Leonard R Bruguier

    2012-12-01

    Full Text Available New learning environments with communication and information tools are increasingly accessible with technology playing a crucial role in expanding and reconceptualizing student learning experiences. This paper reviews the outcome of an innovative course offered by four universities in three countries: Canada, the United States, and Mexico. Course objectives focused on broadening the understanding of indigenous and non-indigenous peoples primarily in relation to identity as it encouraged students to reflect on their own identity while improving their English skills in an interactive and experiential manner and thus enhancing their intercultural competence.Cada vez es más fácil tener acceso a nuevos entornos de aprendizaje que utilizan herramientas de comunicación e información en las que la tecnología desempeña un papel crucial en la expansión y la reconceptualización de las experiencias de aprendizaje del estudiante. En este artículo se revisa el resultado de un curso innovador que se ofreció en cuatro universidades de tres países: Canadá, Estados Unidos y México. Los objetivos del curso se centraron en ampliar la comprensión de los pueblos indígenas y no indígenas, en particular en relación con la identidad. Esto alentó a los estudiantes a reflexionar sobre su propia identidad, a la vez que mejoraban sus habilidades del inglés de una manera interactiva y experimental, logrando así mejorar su competencia intercultural.

  15. Molecular-Based Optical Measurement Techniques for Transition and Turbulence in High-Speed Flow

    Science.gov (United States)

    Bathel, Brett F.; Danehy, Paul M.; Cutler, Andrew D.

    2013-01-01

    High-speed laminar-to-turbulent transition and turbulence affect the control of flight vehicles, the heat transfer rate to a flight vehicle's surface, the material selected to protect such vehicles from high heating loads, the ultimate weight of a flight vehicle due to the presence of thermal protection systems, the efficiency of fuel-air mixing processes in high-speed combustion applications, etc. Gaining a fundamental understanding of the physical mechanisms involved in the transition process will lead to the development of predictive capabilities that can identify transition location and its impact on parameters like surface heating. Currently, there is no general theory that can completely describe the transition-to-turbulence process. However, transition research has led to the identification of the predominant pathways by which this process occurs. For a truly physics-based model of transition to be developed, the individual stages in the paths leading to the onset of fully turbulent flow must be well understood. This requires that each pathway be computationally modeled and experimentally characterized and validated. This may also lead to the discovery of new physical pathways. This document is intended to describe molecular based measurement techniques that have been developed, addressing the needs of the high-speed transition-to-turbulence and high-speed turbulence research fields. In particular, we focus on techniques that have either been used to study high speed transition and turbulence or techniques that show promise for studying these flows. This review is not exhaustive. In addition to the probe-based techniques described in the previous paragraph, several other classes of measurement techniques that are, or could be, used to study high speed transition and turbulence are excluded from this manuscript. For example, surface measurement techniques such as pressure and temperature paint, phosphor thermography, skin friction measurements and

  16. Characterization of Metarhizium species and varieties based on molecular analysis, heat tolerance and cold activity

    Science.gov (United States)

    Fernandes, E.K.K.; Keyser, C.A.; Chong, J.P.; Rangel, D.E.N.; Miller, M.P.; Roberts, D.W.

    2010-01-01

    Aims: The genetic relationships and conidial tolerances to high and low temperatures were determined for isolates of several Metarhizium species and varieties. Methods and Results: Molecular-based techniques [AFLP and rDNA (ITS1, ITS2 and 5??8S) gene sequencing] were used to characterize morphologically identified Metarhizium spp. isolates from a wide range of sources. Conidial suspensions of isolates were exposed to wet heat (45 ?? 0??2??C) and plated on potato dextrose agar plus yeast extract (PDAY) medium. After 8-h exposure, the isolates divided clearly into two groups: (i) all isolates of Metarhizium anisopliae var. anisopliae (Ma-an) and Metarhizium from the flavoviride complex (Mf) had virtually zero conidial relative germination (RG), (ii) Metarhizium anisopliae var. acridum (Ma-ac) isolates demonstrated high heat tolerance (c. 70-100% RG). Conidial suspensions also were plated on PDAY and incubated at 5??C for 15 days, during which time RGs for Ma-an and Ma-ac isolates were virtually zero, whereas the two Mf were highly cold active (100% RG). Conclusions: Heat and cold exposures can be used as rapid tools to tentatively identify some important Metarhizium species and varieties. Significance and Impact of the Study: Identification of Metarhizium spp. currently relies primarily on DNA-based methods; we suggest a simple temperature-based screen to quickly obtain tentative identification of isolates as to species or species complexes. ?? 2009 The Society for Applied Microbiology.

  17. Predicting Molecular Targets for Small-Molecule Drugs with a Ligand-Based Interaction Fingerprint Approach.

    Science.gov (United States)

    Cao, Ran; Wang, Yanli

    2016-06-20

    The computational prediction of molecular targets for small-molecule drugs remains a great challenge. Herein we describe a ligand-based interaction fingerprint (LIFt) approach for target prediction. Together with physics-based docking and sampling methods, we assessed the performance systematically by modeling the polypharmacology of 12 kinase inhibitors in three stages. First, we examined the capacity of this approach to differentiate true targets from false targets with the promiscuous binder staurosporine, based on native complex structures. Second, we performed large-scale profiling of kinase selectivity on the clinical drug sunitinib by means of computational simulation. Third, we extended the study beyond kinases by modeling the cross-inhibition of bromodomain-containing protein 4 (BRD4) for 10 well-established kinase inhibitors. On this basis, we made prospective predictions by exploring new kinase targets for the anticancer drug candidate TN-16, originally known as a colchicine site binder and microtubule disruptor. As a result, p38α was highlighted from a panel of 187 different kinases. Encouragingly, our prediction was validated by an in vitro kinase assay, which showed TN-16 as a low-micromolar p38α inhibitor. Collectively, our results suggest the promise of the LIFt approach in predicting potential targets for small-molecule drugs. PMID:26222196

  18. Molecular rectification and conductance switching in carbon-based molecular junctions by structural rearrangement accompanying electron injection.

    Science.gov (United States)

    McCreery, Richard; Dieringer, Jon; Solak, Ali Osman; Snyder, Brian; Nowak, Aletha M; McGovern, William R; DuVall, Stacy

    2003-09-01

    Molecular junctions were fabricated consisting of a 3.7 nm thick layer of nitroazobenzene (NAB) molecules between a pyrolyzed photoresist substrate (PPF) and a titanium top contact which was protected from oxidation by a layer of gold. Raman spectroscopy, XPS, and AFM revealed that the NAB layer was 2-3 molecules thick and was bonded to the two conducting contacts by C-C and N-Ti covalent bonds. The current/voltage behavior of the PPF/NAB(3.7)/Ti junctions showed strong and reproducible rectification, with the current at +2 V exceeding that at -2 V by a factor of 600. The observed current density at +3 V was 0.71 A/cm(2), or about 10(5) e(-)/s/molecule. The i/V response was strongly dependent on temperature and scan rate, with the rectification ratio decreasing for lower temperature and faster scans. Junction conductivity increased with time over several seconds at room temperature in response to positive voltage pulses, with the rate of increase larger for more positive potentials. Voltage pulses to positive potentials and back to zero volts revealed that electrons are injected from the Ti to the NAB, to the extent of about 0.1-1 e(-)/molecule for a +3 V pulse. These electrons cause an activated transition of the NAB into a more conductive quinoid state, which in turn causes an increase in conductivity. The transition to the quinoid state involves nuclear rearrangement which occurs on a submillisecond to several second time scale, depending on the voltage applied. The quinoid state is stable as long as the applied electric field is present, but reverts back to NAB within several minutes after the field is relaxed. The results are interpreted in terms of a thermally activated, potential dependent electron transfer into the 3.7 nm NAB layer, which brings about a conductivity increase of several orders of magnitude.

  19. Bio-AIMS Collection of Chemoinformatics Web Tools based on Molecular Graph Information and Artificial Intelligence Models.

    Science.gov (United States)

    Munteanu, Cristian R; Gonzalez-Diaz, Humberto; Garcia, Rafael; Loza, Mabel; Pazos, Alejandro

    2015-01-01

    The molecular information encoding into molecular descriptors is the first step into in silico Chemoinformatics methods in Drug Design. The Machine Learning methods are a complex solution to find prediction models for specific biological properties of molecules. These models connect the molecular structure information such as atom connectivity (molecular graphs) or physical-chemical properties of an atom/group of atoms to the molecular activity (Quantitative Structure - Activity Relationship, QSAR). Due to the complexity of the proteins, the prediction of their activity is a complicated task and the interpretation of the models is more difficult. The current review presents a series of 11 prediction models for proteins, implemented as free Web tools on an Artificial Intelligence Model Server in Biosciences, Bio-AIMS (http://bio-aims.udc.es/TargetPred.php). Six tools predict protein activity, two models evaluate drug - protein target interactions and the other three calculate protein - protein interactions. The input information is based on the protein 3D structure for nine models, 1D peptide amino acid sequence for three tools and drug SMILES formulas for two servers. The molecular graph descriptor-based Machine Learning models could be useful tools for in silico screening of new peptides/proteins as future drug targets for specific treatments.

  20. Rúbricas, currículo y trabajo docente colaborativo: una experiencia práctica

    Directory of Open Access Journals (Sweden)

    Gabriela de la Cruz Flores

    2012-12-01

    Full Text Available Se analiza la relevancia de vincular el currículo con el proceso de construcción de rúbricas, priorizando la selección de situaciones de aprendizaje y actividades significativas para desarrollar conocimientos clave que fomenten la adquisición de competencias en estudiantes de Educación Superior. Se presenta una experiencia en una universidad mexicana en la que un grupo de profesores pertenecientes a diversas carreras de grado elaboraron de manera colaborativa rúbricas de las competencias transversales y específicas establecidas en cada plan de estudios. La conjunción de los distintos puntos de vista emanados de las diversas profesiones logró dos objetivos centrales: primero, la generación de rúbricas con enfoques multidisciplinarios y, segundo, la revitalización del trabajo colaborativo entre los mismos docentes. In this paper, we analyze the effectiveness of linking curricula to the process of creating rubrics, with priority given to the selection of key learning situations and activities that promote competency-based learning among students enrolled in higher education. We present the experience of a Mexican university, in which a group of professors from diverse fields worked collectively to develop rubrics for transversal and specific competencies related to each individual study plan. By combining diverse points of view from the different professions, the group achieved two main objectives: first, the construction of rubrics with a multidisciplinary approach, and second, the revitalization of collaborative work among the professors.

  1. A general SNP-based molecular barcode for Plasmodium falciparum identification and tracking

    Directory of Open Access Journals (Sweden)

    Rosen David

    2008-10-01

    Full Text Available Abstract Background Single nucleotide polymorphism (SNP genotyping provides the means to develop a practical, rapid, inexpensive assay that will uniquely identify any Plasmodium falciparum parasite using a small amount of DNA. Such an assay could be used to distinguish recrudescence from re-infection in drug trials, to monitor the frequency and distribution of specific parasites in a patient population undergoing drug treatment or vaccine challenge, or for tracking samples and determining purity of isolates in the laboratory during culture adaptation and sub-cloning, as well as routine passage. Methods A panel of twenty-four SNP markers has been identified that exhibit a high minor allele frequency (average MAF > 35%, for which robust TaqMan genotyping assays were constructed. All SNPs were identified through whole genome sequencing and MAF was estimated through Affymetrix array-based genotyping of a worldwide collection of parasites. These assays create a "molecular barcode" to uniquely identify a parasite genome. Results Using 24 such markers no two parasites known to be of independent origin have yet been found to have the same allele signature. The TaqMan genotyping assays can be performed on a variety of samples including cultured parasites, frozen whole blood, or whole blood spotted onto filter paper with a success rate > 99%. Less than 5 ng of parasite DNA is needed to complete a panel of 24 markers. The ability of this SNP panel to detect and identify parasites was compared to the standard molecular methods, MSP-1 and MSP-2 typing. Conclusion This work provides a facile field-deployable genotyping tool that can be used without special skills with standard lab equipment, and at reasonable cost that will unambiguously identify and track P. falciparum parasites both from patient samples and in the laboratory.

  2. Theragnosis-based combined cancer therapy using doxorubicin-conjugated microRNA-221 molecular beacon.

    Science.gov (United States)

    Lee, Jonghwan; Choi, Kyung-Ju; Moon, Sung Ung; Kim, Soonhag

    2016-01-01

    Recently, microRNA (miRNA or miR) has emerged as a new cancer biomarker because of its high expression level in various cancer types and its role in the control of tumor suppressor genes. In cancer studies, molecular imaging and treatment based on target cancer markers have been combined to facilitate simultaneous cancer diagnosis and therapy. In this study, for combined therapy with diagnosis of cancer, we developed a doxorubicin-conjugated miR-221 molecular beacon (miR-221 DOXO MB) in a single platform composed of three different nucleotides: miR-221 binding sequence, black hole quencher 1 (BHQ1), and doxorubicin binding site. Imaging of endogenous miR-221 was achieved by specific hybridization between miR-221 and the miR-221 binding site in miR-221 DOXO MB. The presence of miR-221 triggered detachment of the quencher oligo and subsequent activation of a fluorescent signal of miR-221 DOXO MB. Simultaneous cancer therapy in C6 astrocytoma cells and nude mice was achieved by inhibition of miRNA-221 function that downregulates tumor suppressor genes. The detection of miR-221 expression and inhibition of miR-221 function by miR-221 DOXO MB provide the feasibility as a cancer theragnostic probe. Furthermore, a cytotoxic effect was induced by unloading of doxorubicin intercalated into miR-221 DOXO MB inside cells. Loss of miR-221 function and cytotoxicity induced by the miR-221 DOXO MB provides combined therapeutic efficacy against cancers. This method could be used as a new theragnostic probe with enhanced therapy to detect and inhibit many cancer-related miRNAs.

  3. Molecularly imprinted polymerization-based surface plasmon resonance sensing for glucose detection in human urine

    Science.gov (United States)

    Banerji, Soame; Peng, Wei; Kim, Yoon-Chang; Booksh, Karl S.

    2006-10-01

    A novel Surface Plasmon Resonance (SPR) sensor to detect glucose using molecularly imprinted polymer (MIP) will be presented in this paper. SPR has been traditionally used as a probe for surface interaction of large molecules but harder to measure small molecules since the effective change in the SPR condition becomes smaller. The accurate measurement of glucose in complex physiological fluids like urine is particularly challenging since the constituents of these fluids vary significantly from person to person and even throughout the day for a particular individual. The polymer was prepared by crosslinking polyallyamine in the presence of Glucose Phosphate, monobarium salt (GPS-Ba) and attached to a 50 nm thin film of gold which had been sputtered on top of a glass slide, via amide coupling. Upon removal of the template, this sensor was used to detect glucose in human urine in physiologically significant levels (1-20 mg/ml). Enhancement of the glucose sensor was made possible by incorporating gold nanoparticles which improved the signal. This study has demonstrated the specific detection of glucose in a complex physiological fluid using SPR spectroscopy. The association of glucose to the imprinted polymer results in the swelling of the polymer that can be tracked by the minima in SPR spectra. The sensitivity of this method, while lower than protein based detection schemes, is sufficient for quantitative measurement of glucose in urine at physiologically significant levels without extensive pre-treatment of the sample. Given the nature of the weak non-covalent binding of glucose to the amine functional groups, the scheme used here can be adapted to detect a number of different molecular species of sizes comparable to that of glucose without the need for extensive sample preparation or use of chemicals with limited shelf life.

  4. Theragnosis-based combined cancer therapy using doxorubicin-conjugated microRNA-221 molecular beacon.

    Science.gov (United States)

    Lee, Jonghwan; Choi, Kyung-Ju; Moon, Sung Ung; Kim, Soonhag

    2016-01-01

    Recently, microRNA (miRNA or miR) has emerged as a new cancer biomarker because of its high expression level in various cancer types and its role in the control of tumor suppressor genes. In cancer studies, molecular imaging and treatment based on target cancer markers have been combined to facilitate simultaneous cancer diagnosis and therapy. In this study, for combined therapy with diagnosis of cancer, we developed a doxorubicin-conjugated miR-221 molecular beacon (miR-221 DOXO MB) in a single platform composed of three different nucleotides: miR-221 binding sequence, black hole quencher 1 (BHQ1), and doxorubicin binding site. Imaging of endogenous miR-221 was achieved by specific hybridization between miR-221 and the miR-221 binding site in miR-221 DOXO MB. The presence of miR-221 triggered detachment of the quencher oligo and subsequent activation of a fluorescent signal of miR-221 DOXO MB. Simultaneous cancer therapy in C6 astrocytoma cells and nude mice was achieved by inhibition of miRNA-221 function that downregulates tumor suppressor genes. The detection of miR-221 expression and inhibition of miR-221 function by miR-221 DOXO MB provide the feasibility as a cancer theragnostic probe. Furthermore, a cytotoxic effect was induced by unloading of doxorubicin intercalated into miR-221 DOXO MB inside cells. Loss of miR-221 function and cytotoxicity induced by the miR-221 DOXO MB provides combined therapeutic efficacy against cancers. This method could be used as a new theragnostic probe with enhanced therapy to detect and inhibit many cancer-related miRNAs. PMID:26454049

  5. Molecular pharmacognosy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This article analyzes the background and significance of molecular pharmacognosy,including the molecular identification of medicinal raw materials,phylogenetic evolution of medicinal plants and animals,evaluation and preservation of germplasm resources for medicinal plants and animals,etiology of endangerment and protection of endangered medicinal plants and animals,biosynthesis and bioregulation of active components in medicinal plants,and characteristics and the molecular bases of top-geoherbs.

  6. The evidence base for the use of internal dosimetry in the clinical practice of molecular radiotherapy

    International Nuclear Information System (INIS)

    Molecular radiotherapy (MRT) has demonstrated unique therapeutic advantages in the treatment of an increasing number of cancers. As with other treatment modalities, there is related toxicity to a number of organs at risk. Despite the large number of clinical trials over the past several decades, considerable uncertainties still remain regarding the optimization of this therapeutic approach and one of the vital issues to be answered is whether an absorbed radiation dose-response exists that could be used to guide personalized treatment. There are only limited and sporadic data investigating MRT dosimetry. The determination of dose-effect relationships for MRT has yet to be the explicit aim of a clinical trial. The aim of this article was to collate and discuss the available evidence for an absorbed radiation dose-effect relationships in MRT through a review of published data. Based on a PubMed search, 92 papers were found. Out of 79 studies investigating dosimetry, an absorbed dose-effect correlation was found in 48. The application of radiobiological modelling to clinical data is of increasing importance and the limited published data on absorbed dose-effect relationships based on these models are also reviewed. Based on National Cancer Institute guideline definition, the studies had a moderate or low rate of clinical relevance due to the limited number of studies investigating overall survival and absorbed dose. Nevertheless, the evidence strongly implies a correlation between the absorbed doses delivered and the response and toxicity, indicating that dosimetry-based personalized treatments would improve outcome and increase survival. (orig.)

  7. A bayesian mixed regression based prediction of quantitative traits from molecular marker and gene expression data.

    Directory of Open Access Journals (Sweden)

    Madhuchhanda Bhattacharjee

    Full Text Available Both molecular marker and gene expression data were considered alone as well as jointly to serve as additive predictors for two pathogen-activity-phenotypes in real recombinant inbred lines of soybean. For unobserved phenotype prediction, we used a bayesian hierarchical regression modeling, where the number of possible predictors in the model was controlled by different selection strategies tested. Our initial findings were submitted for DREAM5 (the 5th Dialogue on Reverse Engineering Assessment and Methods challenge and were judged to be the best in sub-challenge B3 wherein both functional genomic and genetic data were used to predict the phenotypes. In this work we further improve upon this previous work by considering various predictor selection strategies and cross-validation was used to measure accuracy of in-data and out-data predictions. The results from various model choices indicate that for this data use of both data types (namely functional genomic and genetic simultaneously improves out-data prediction accuracy. Adequate goodness-of-fit can be easily achieved with more complex models for both phenotypes, since the number of potential predictors is large and the sample size is not small. We also further studied gene-set enrichment (for continuous phenotype in the biological process in question and chromosomal enrichment of the gene set. The methodological contribution of this paper is in exploration of variable selection techniques to alleviate the problem of over-fitting. Different strategies based on the nature of covariates were explored and all methods were implemented under the bayesian hierarchical modeling framework with indicator-based covariate selection. All the models based in careful variable selection procedure were found to produce significant results based on permutation test.

  8. Trichocyanines: a Red-Hair-Inspired Modular Platform for Dye-Based One-Time-Pad Molecular Cryptography

    OpenAIRE

    Leone, Loredana; Pezzella, Alessandro; Crescenzi, Orlando; Napolitano, Alessandra; Barone, Vincenzo; d’Ischia, Marco

    2015-01-01

    Current molecular cryptography (MoCryp) systems are almost exclusively based on DNA chemistry and reports of cryptography technologies based on other less complex chemical systems are lacking. We describe herein, as proof of concept, the prototype of the first asymmetric MoCryp system, based on an 8-compound set of a novel bioinspired class of cyanine-type dyes called trichocyanines. These novel acidichromic cyanine-type dyes inspired by red hair pigments were synthesized and characterized wi...

  9. The semantic metadatabase (SEMEDA): ontology based integration of federated molecular biological data sources.

    Science.gov (United States)

    Köhler, Jacob; Schulze-Kremer, Steffen

    2002-01-01

    A system for "intelligent" semantic integration and querying of federated databases is being implemented by using three main components: A component which enables SQL access to integrated databases by database federation (MARGBench), an ontology based semantic metadatabase (SEMEDA) and an ontology based query interface (SEMEDA-query). In this publication we explain and demonstrate the principles, architecture and the use of SEMEDA. Since SEMEDA is implemented as 3 tiered web application database providers can enter all relevant semantic and technical information about their databases by themselves via a web browser. SEMEDA' s collaborative ontology editing feature is not restricted to database integration, and might also be useful for ongoing ontology developments, such as the "Gene Ontology" [2]. SEMEDA can be found at http://www-bm.cs.uni-magdeburg.de/semeda/. We explain how this ontologically structured information can be used for semantic database integration. In addition, requirements to ontologies for molecular biological database integration are discussed and relevant existing ontologies are evaluated. We further discuss how ontologies and structured knowledge sources can be used in SEMEDA and whether they can be merged supplemented or updated to meet the requirements for semantic database integration. PMID:12542408

  10. Molecular dynamics-based refinement and validation for sub-5 Å cryo-electron microscopy maps.

    Science.gov (United States)

    Singharoy, Abhishek; Teo, Ivan; McGreevy, Ryan; Stone, John E; Zhao, Jianhua; Schulten, Klaus

    2016-07-07

    Two structure determination methods, based on the molecular dynamics flexible fitting (MDFF) paradigm, are presented that resolve sub-5 Å cryo-electron microscopy (EM) maps with either single structures or ensembles of such structures. The methods, denoted cascade MDFF and resolution exchange MDFF, sequentially re-refine a search model against a series of maps of progressively higher resolutions, which ends with the original experimental resolution. Application of sequential re-refinement enables MDFF to achieve a radius of convergence of ~25 Å demonstrated with the accurate modeling of β-galactosidase and TRPV1 proteins at 3.2 Å and 3.4 Å resolution, respectively. The MDFF refinements uniquely offer map-model validation and B-factor determination criteria based on the inherent dynamics of the macromolecules studied, captured by means of local root mean square fluctuations. The MDFF tools described are available to researchers through an easy-to-use and cost-effective cloud computing resource on Amazon Web Services.

  11. Network analysis shows novel molecular mechanisms of action for copper-based chemotherapy

    Directory of Open Access Journals (Sweden)

    Jesús eEspinal-Enríquez

    2016-01-01

    Full Text Available The understanding of the mechanisms associated with the action of chemotherapeutic agents is fundamental to assess and account for possible side-effects of such treatments. Casiope'inas have demonstrated a cytotoxic effect by activation of pro-apoptotic processes in malignant cells. Such processes have been proved to activate the apoptotic intrinsic route, as well as cell cycle arrest. Despite this knowledge, the whole mechanism of action of Casiope'inas is yet to be completely understood. In this work, we implement a systems biology approach based on two pathway analysis tools (Over-Representation Analysis and Causal Network Analysis, to observe changes in some hallmarks of cancer, induced by this copper-based chemotherapeutic agent in HeLa cell lines. We find that the metabolism of metal ions is exacerbated, as well as cell division processes being globally diminished. We also show that cellular migration and proliferation events are decreased. Moreover, the molecular mechanisms of liver protection are increased in the cell cultures under the actions of Casiope'inas, unlike the case in many other cytotoxic drugs. We argue that this chemotherapeutic agent may be promising, given its protective hepatic function, concomitant with its cytotoxic participation in the onset of apoptotic processes in malignant cells.

  12. Photoisomerization dynamics of a rhodopsin-based molecule (potential molecular switch) with high quantum yields

    Science.gov (United States)

    Allen, Roland; Jiang, Chen-Wei; Zhang, Xiu-Xing; Fang, Ai-Ping; Li, Hong-Rong; Xie, Rui-Hua; Li, Fu-Li

    2015-03-01

    It is worthwhile to explore the detailed reaction dynamics of various candidates for molecular switches, in order to understand, e.g., the differences in quantum yields and switching times. Here we report density-functional-based simulations for the rhodopsin-based molecule 4-[4-Methylbenzylidene]-5-p-tolyl-3,4-dihydro-2H-pyrrole (MDP), synthesized by Sampedro et al. We find that the photoisomerization quantum yields are remarkably high: 82% for cis-to-trans, and 68% for trans-to-cis. The lifetimes of the S1 excited state in cis-MDP in our calculations are in the range of 900-1800 fs, with a mean value of 1270 fs, while the range of times required for full cis-to-trans isomerization are 1100-2000 fs, with a mean value of 1530 fs. In trans-MDP, the calculated S1 excited state lifetimes are 860-2140 fs, with a mean value of 1330 fs, and with the full trans-to-cis isomerization completed about 200 fs later. In both cases, the dominant reaction mechanism is rotation around the central C =C bond (connected to the pyrroline ring), and de-excitation occurs at an avoided crossing between the ground state and the lowest singlet state, near the midpoint of the rotational pathway. Research Fund for the Doctoral Program of Higher Education of China; Fundamental Research Funds for the Central Universities; Robert A. Welch Foundation; National Natural Science Foundation of China.

  13. CCSD(T)/CBS fragment-based calculations of lattice energy of molecular crystals

    Science.gov (United States)

    Červinka, Ctirad; Fulem, Michal; Růžička, Květoslav

    2016-02-01

    A comparative study of the lattice energy calculations for a data set of 25 molecular crystals is performed using an additive scheme based on the individual energies of up to four-body interactions calculated using the coupled clusters with iterative treatment of single and double excitations and perturbative triples correction (CCSD(T)) with an estimated complete basis set (CBS) description. The CCSD(T)/CBS values on lattice energies are used to estimate sublimation enthalpies which are compared with critically assessed and thermodynamically consistent experimental values. The average absolute percentage deviation of calculated sublimation enthalpies from experimental values amounts to 13% (corresponding to 4.8 kJ mol-1 on absolute scale) with unbiased distribution of positive to negative deviations. As pair interaction energies present a dominant contribution to the lattice energy and CCSD(T)/CBS calculations still remain computationally costly, benchmark calculations of pair interaction energies defined by crystal parameters involving 17 levels of theory, including recently developed methods with local and explicit treatment of electronic correlation, such as LCC and LCC-F12, are also presented. Locally and explicitly correlated methods are found to be computationally effective and reliable methods enabling the application of fragment-based methods for larger systems.

  14. Piperprotrusum (Piperaceae), a new species from southern Thailand based on morphological and molecular evidence

    Institute of Scientific and Technical Information of China (English)

    Runglawan SUDMOON; Tawatchai TANEE; Arunrat CHAVEERACH

    2011-01-01

    Piper protrusum Chaveer.& Tanee,sp.nov.is described and illustrated.It dominantly comprises three branching types with three different types of leaf blades,bases,and apexes.The critical distinguishing character is the protruded receptacle having a bract and nine stamens.Individual plants have been discovered in areas of Southern Thailand since 2004 without reproductive parts.The investigated sites were revisited several times,and an individual with flowers was finally found in July 2009.Phylogenetic analysis of the new species and five similar species is carried out based on DNA figerpfinting.The genetic distances between the new species and five similar species range from 0.25 to 0.35,supporting new species designation.Molecular data conform to morphological data in validating that it is a new species.Additionally,its DNA barcodes have been provided for further identification in case the morphological data is unclear.The sequence data have been submitted to the GenBank database under accession numbers GU980898 (rpoB gene),GU980899 (rpoC1 gene),and GU980900 (psbA-trnH region).

  15. A Buffered Alcohol-Based Fixative for Histomorphologic and Molecular Applications.

    Science.gov (United States)

    Perry, Candice; Chung, Joon-Yong; Ylaya, Kris; Choi, Chel Hun; Simpson, Amari; Matsumoto, Kaipo T; Smith, William A; Hewitt, Stephen M

    2016-07-01

    Formalin-fixed paraffin-embedded (FFPE) tissue is the predominant preparation for diagnostic histopathological evaluation and increasingly the biospecimen on which molecular diagnostics are performed. However, formalin is carcinogenic and results in cross-linking of proteins and nicking and alterations of nucleic acids. Alternative fixatives, including 70% ethanol, improved biomolecular integrity; however, they have yet to replace neutral-buffered formalin (NBF). Herein, we describe the phosphate-buffered ethanol 70% (BE70) fixative. The histomorphology of BE70-fixed tissue is very similar to that of NBF; however, it is a non-cross-linking fixative and lacks the carcinogenic profile of formaldehyde-based fixatives. RNA isolated from tissue fixed in BE70 was of substantially higher quality and quantity than that was recovered from formalin-fixed tissue. Furthermore, the BE70 fixative showed excellent RNA and DNA integrity compared with that of NBF fixative based on real-time polymerase chain reaction analysis results. Immunohistochemical staining was similar for the antigen tested. In conclusion, BE70 is a non-cross-linking fixative that is superior to NBF and 70% ethanol with reference to biomolecule recovery and quality from paraffin-embedded tissue. Additional studies to compare the histomorphologic and immunohistochemical performance and utility in a clinical setting are required. PMID:27221702

  16. Molecular phylogeny of western Atlantic Farfantepenaeus and Litopenaeus shrimp based on mitochondrial 16S partial sequences.

    Science.gov (United States)

    Maggioni, R; Rogers, A D; Maclean, N; D'Incao, F

    2001-01-01

    Partial sequences for the 16S rRNA mitochondrial gene were obtained from 10 penaeid shrimp species: Farfantepenaeus paulensis, F. brasiliensis, F. subtilis, F. duorarum, F. aztecus, Litopenaeus schmitti, L. setiferus, and Xiphopenaeus kroyeri from the western Atlantic and L. vannamei and L. stylirostris from the eastern Pacific. Sequences were also obtained from an undescribed morphotype of pink shrimp (morphotype II) usually identified as F. subtilis. The phylogeny resulting from the 16S partial sequences showed that these species form two well-supported monophyletic clades consistent with the two genera proposed in a recent systematic review of the suborder Dendrobranchiata. This contrasted with conclusions drawn from recent molecular phylogenetic work on penaeid shrimps based on partial sequences of the mitochondrial COI region that failed to support recent revisions of the Dendrobranchiata based on morphological analysis. Consistent differences observed in the sequences for morphotype II, coupled with previous allozyme data, support the conclusion that this is a previously undescribed species of Farfantepenaeus. PMID:11161743

  17. Cleavable Molecular Beacon for Hg(2+) Detection Based on Phosphorothioate RNA Modifications.

    Science.gov (United States)

    Huang, Po-Jung Jimmy; Wang, Feng; Liu, Juewen

    2015-07-01

    Mercury is a highly toxic heavy metal, and detection of Hg(2+) by biosensors has attracted extensive research interest in the past decade. In particular, a number of DNA-based sensing strategies have been developed. Well-known examples include thymine-Hg(2+) interactions and Hg(2+)-activated DNAzymes. However, these mechanisms are highly dependent on buffer conditions or require hybridization with another DNA strand. Herein, we report a new mechanism based on Hg(2+)-induced cleavage of phosphorothioate (PS) modified RNA. Among the various metal ions tested, Hg(2+) induced the most significant cleavage (∼16%), while other metals cleaved less than 2% of the same substrate. The uncleaved substrate undergoes desulfurization in the presence of Hg(2+). This cleavage reaction yields a similar amount of product from pH 3.5 to 7 and in the temperature range between 20 and 90 °C. Various PS RNA junctions can be cleaved with a similar efficiency, but PS DNA junctions cannot be cleaved. A molecular beacon containing three PS RNA modifications is designed, detecting Hg(2+) down to 1.7 nM with excellent selectivity. This sensor can also detect Hg(2+) in the Lake Ontario water sample, although its response is significantly masked by fish tissues. PMID:26060876

  18. Molecular simulation-based structural prediction of protein complexes in mass spectrometry: the human insulin dimer.

    Science.gov (United States)

    Li, Jinyu; Rossetti, Giulia; Dreyer, Jens; Raugei, Simone; Ippoliti, Emiliano; Lüscher, Bernhard; Carloni, Paolo

    2014-09-01

    Protein electrospray ionization (ESI) mass spectrometry (MS)-based techniques are widely used to provide insight into structural proteomics under the assumption that non-covalent protein complexes being transferred into the gas phase preserve basically the same intermolecular interactions as in solution. Here we investigate the applicability of this assumption by extending our previous structural prediction protocol for single proteins in ESI-MS to protein complexes. We apply our protocol to the human insulin dimer (hIns2) as a test case. Our calculations reproduce the main charge and the collision cross section (CCS) measured in ESI-MS experiments. Molecular dynamics simulations for 0.075 ms show that the complex maximizes intermolecular non-bonded interactions relative to the structure in water, without affecting the cross section. The overall gas-phase structure of hIns2 does exhibit differences with the one in aqueous solution, not inferable from a comparison with calculated CCS. Hence, care should be exerted when interpreting ESI-MS proteomics data based solely on NMR and/or X-ray structural information. PMID:25210764

  19. Molecular simulation-based structural prediction of protein complexes in mass spectrometry: the human insulin dimer.

    Directory of Open Access Journals (Sweden)

    Jinyu Li

    2014-09-01

    Full Text Available Protein electrospray ionization (ESI mass spectrometry (MS-based techniques are widely used to provide insight into structural proteomics under the assumption that non-covalent protein complexes being transferred into the gas phase preserve basically the same intermolecular interactions as in solution. Here we investigate the applicability of this assumption by extending our previous structural prediction protocol for single proteins in ESI-MS to protein complexes. We apply our protocol to the human insulin dimer (hIns2 as a test case. Our calculations reproduce the main charge and the collision cross section (CCS measured in ESI-MS experiments. Molecular dynamics simulations for 0.075 ms show that the complex maximizes intermolecular non-bonded interactions relative to the structure in water, without affecting the cross section. The overall gas-phase structure of hIns2 does exhibit differences with the one in aqueous solution, not inferable from a comparison with calculated CCS. Hence, care should be exerted when interpreting ESI-MS proteomics data based solely on NMR and/or X-ray structural information.

  20. Paper-based sample-to-answer molecular diagnostic platform for point-of-care diagnostics.

    Science.gov (United States)

    Choi, Jane Ru; Tang, Ruihua; Wang, ShuQi; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng

    2015-12-15

    Nucleic acid testing (NAT), as a molecular diagnostic technique, including nucleic acid extraction, amplification and detection, plays a fundamental role in medical diagnosis for timely medical treatment. However, current NAT technologies require relatively high-end instrumentation, skilled personnel, and are time-consuming. These drawbacks mean conventional NAT becomes impractical in many resource-limited disease-endemic settings, leading to an urgent need to develop a fast and portable NAT diagnostic tool. Paper-based devices are typically robust, cost-effective and user-friendly, holding a great potential for NAT at the point of care. In view of the escalating demand for the low cost diagnostic devices, we highlight the beneficial use of paper as a platform for NAT, the current state of its development, and the existing challenges preventing its widespread use. We suggest a strategy involving integrating all three steps of NAT into one single paper-based sample-to-answer diagnostic device for rapid medical diagnostics in the near future.

  1. Molecular Dynamics Study of Stability and Diffusion of Graphene-Based Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    Xiunan Wang

    2015-01-01

    Full Text Available Graphene, a two-dimensional nanomaterial with unique biomedical properties, has attracted great attention due to its potential applications in graphene-based drug delivery systems (DDS. In this work graphene sheets with various sizes and graphene oxide functionalized with polyethylene glycol (GO-PEG are utilized as nanocarriers to load anticancer drug molecules including CE6, DOX, MTX, and SN38. We carried out molecular dynamics calculations to explore the energetic stabilities and diffusion behaviors of the complex systems with focuses on the effects of the sizes and functionalization of graphene sheets as well as the number and types of drug molecules. Our study shows that the binding of graphene-drug complex is favorable when the drug molecules and finite graphene sheets become comparable in sizes. The boundaries of finite sized graphene sheets restrict the movement of drug molecules. The double-side loading often slows down the diffusion of drug molecules compared with the single-side loading. The drug molecules bind more strongly with GO-PEG than with pristine graphene sheets, demonstrating the advantages of functionalization in improving the stability and biocompatibility of graphene-based DDS.

  2. Structure-based inference of molecular functions of proteins of unknown function from Berkeley Structural Genomics Center

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung-Hou; Shin, Dong Hae; Hou, Jingtong; Chandonia, John-Marc; Das, Debanu; Choi, In-Geol; Kim, Rosalind; Kim, Sung-Hou

    2007-09-02

    Advances in sequence genomics have resulted in an accumulation of a huge number of protein sequences derived from genome sequences. However, the functions of a large portion of them cannot be inferred based on the current methods of sequence homology detection to proteins of known functions. Three-dimensional structure can have an important impact in providing inference of molecular function (physical and chemical function) of a protein of unknown function. Structural genomics centers worldwide have been determining many 3-D structures of the proteins of unknown functions, and possible molecular functions of them have been inferred based on their structures. Combined with bioinformatics and enzymatic assay tools, the successful acceleration of the process of protein structure determination through high throughput pipelines enables the rapid functional annotation of a large fraction of hypothetical proteins. We present a brief summary of the process we used at the Berkeley Structural Genomics Center to infer molecular functions of proteins of unknown function.

  3. Ultra high molecular weight polyethylene as a base material for shielding cosmic radiation in aerospace applications

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Marlon A., E-mail: marlon@ieav.cta.br [Instituto de Estudos Avancados (IEAv), Sao Jose dos Campos, SP (Brazil). Divisao de Fisica Aplicada; Goncalez, Odair L. [Instituto Tecnologico de Aeronautica (PG/CTE/ITA), Sao Jose dos Campos, SP (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnologias Espaciais

    2013-07-01

    Materials with high content of hydrogen have good properties of shielding against the effects of cosmic rays (CR) because are less effective than materials with high nuclear masses in the generation of secondary radiation. Beside the Aluminum, Polyethylene has been used as a reference and as a base material for composites applied in structures and in shielding of ionizing radiation for aerospace applications. Ultra high molecular weight polyethylene (UHMWPE), pure and doped 10% by mass with cadmium chloride, had its shielding properties for CR evaluated in this paper. Methodology used was based in conventional radioactive sources employed on simple geometries experiments and then computational simulation for isotropic fluxes of cosmic-ray high energy particles. Transmission experiments were performed with a3.7GBq (100 mCi){sup 241}Am-Be neutron source and a set of conventional calibration gamma radiation sources. Samples were characterized according to their gamma total attenuation coefficients from 59 to 1,408 keV, dose deposition curve for {sup 60}Co gamma-rays, fast neutron transmission coefficient, generation and self-absorption of thermal neutrons as well as their generation of internal cascades of secondary electrons and gamma-rays by nuclear interactions of fast neutrons with shielding material. Main effects of the additive in the polyethylene base were the most effective removal of gamma radiation and of secondary electrons with energies below 200 keV, the reduction of the albedo as well as the thermal neutrons transmission. Dose reduction due to primary CR were not significant, since the largest contribution to the doses due to high energy ionizing particles transmitted and, also, due to secondary radiation with energy above 1 MeV produced in shielding. (author)

  4. Molecular dynamics simulations for pure epsilon-CL-20 and epsilon-CL-20-based PBXs.

    Science.gov (United States)

    Xu, Xiao-Juan; Xiao, He-Ming; Xiao, Ji-Jun; Zhu, Wei; Huang, Hui; Li, Jin-Shan

    2006-04-13

    Molecular dynamics has been employed to simulate the well-known high energy density compound epsilon-CL-20 (hexanitrohexaazaisowurtzitane) crystal and 12 epsilon-CL-20-based PBXs (polymer bonded explosives) with four kinds of typical fluorine polymers, i.e., polyvinylidenedifluoride, polychlorotrifluoroethylene, fluorine rubber (F(2311)), and fluorine resin (F(2314)) individually. The elastic coefficients, isotropic mechanical properties (tensile moduli, bulk moduli, shear moduli, and poission's ratios), and bonding energy are first reported for epsilon-CL-20 crystal and epsilon-CL-20-based polymer bonded explosives (PBXs). The mechanical properties of epsilon-CL-20 can be effectively improved by blending with a small amount of fluorine polymers, and the whole effect of the adding fluorine polymers to improve mechanical properties of PBXs along the three crystalline surfaces of epsilon-CL-20 is found to be (100) approximately (001) > (010). The interaction between each of the crystalline surfaces and each of the fluorine polymers is different, and the ordering of binding energy for the three surfaces is (001) > (100) > (010); F(2314) always has the strongest binding ability with the three different surfaces. F(2314) can best improve the ductibility and tenacity of PBX when it is positioned on epsilon-CL-20 (001) crystal surface. The calculations on detonation performances for pure epsilon-CL-20 crystal and the four epsilon-CL-20-based PBXs show that adding a small amount of fluorine polymer into pure epsilon-CL-20 will lower detonation performance, but each detonation parameter of the obtained PBXs is still excellent. PMID:16599487

  5. Ultra high molecular weight polyethylene as a base material for shielding cosmic radiation in aerospace applications

    International Nuclear Information System (INIS)

    Materials with high content of hydrogen have good properties of shielding against the effects of cosmic rays (CR) because are less effective than materials with high nuclear masses in the generation of secondary radiation. Beside the Aluminum, Polyethylene has been used as a reference and as a base material for composites applied in structures and in shielding of ionizing radiation for aerospace applications. Ultra high molecular weight polyethylene (UHMWPE), pure and doped 10% by mass with cadmium chloride, had its shielding properties for CR evaluated in this paper. Methodology used was based in conventional radioactive sources employed on simple geometries experiments and then computational simulation for isotropic fluxes of cosmic-ray high energy particles. Transmission experiments were performed with a3.7GBq (100 mCi)241Am-Be neutron source and a set of conventional calibration gamma radiation sources. Samples were characterized according to their gamma total attenuation coefficients from 59 to 1,408 keV, dose deposition curve for 60Co gamma-rays, fast neutron transmission coefficient, generation and self-absorption of thermal neutrons as well as their generation of internal cascades of secondary electrons and gamma-rays by nuclear interactions of fast neutrons with shielding material. Main effects of the additive in the polyethylene base were the most effective removal of gamma radiation and of secondary electrons with energies below 200 keV, the reduction of the albedo as well as the thermal neutrons transmission. Dose reduction due to primary CR were not significant, since the largest contribution to the doses due to high energy ionizing particles transmitted and, also, due to secondary radiation with energy above 1 MeV produced in shielding. (author)

  6. Characterization-Based Molecular Design of Bio-Fuel Additives Using Chemometric and Property Clustering Techniques

    OpenAIRE

    Subin eHada; Charles Conrad Solvason; Mario Richard Eden

    2014-01-01

    In this work, multivariate characterization data such as infrared spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis allowed capturing important features of the molecular architecture from enormous amount of complex data to build appropriate latent variable models. Combining the property clusterin...

  7. Molecular Gastronomy: A Food Fad or an Interface for Science-based Cooking?

    NARCIS (Netherlands)

    Linden, van der E.; McClements, D.J.; Ubbink, J.

    2008-01-01

    A review is given over the field of molecular gastronomy and its relation to science and cooking. We begin with a brief history of the field of molecular gastronomy, the definition of the term itself, and the current controversy surrounding this term. We then highlight the distinction between molecu

  8. Design and synthesis of novel chiral molecular tweezers based on deoxycholic acid

    Institute of Scientific and Technical Information of China (English)

    Zhi Gang Zhao; Xing Li Liu; Yi Zhong

    2008-01-01

    A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.

  9. Electrochemical sensor for dopamine based on a novel graphene-molecular imprinted polymers composite recognition element

    DEFF Research Database (Denmark)

    Mao, Yan; Bao, Yu; Gan, Shiyu;

    2011-01-01

    A novel composite of graphene sheets/Congo red-molecular imprinted polymers (GSCR-MIPs) was synthesized through free radical polymerization (FRP) and applied as a molecular recognition element to construct dopamine (DA) electrochemical sensor. The template molecules (DA) were firstly absorbed at ...

  10. Teaching the Process of Molecular Phylogeny and Systematics: A Multi-Part Inquiry-Based Exercise

    Science.gov (United States)

    Lents, Nathan H.; Cifuentes, Oscar E.; Carpi, Anthony

    2010-01-01

    Three approaches to molecular phylogenetics are demonstrated to biology students as they explore molecular data from "Homo sapiens" and four related primates. By analyzing DNA sequences, protein sequences, and chromosomal maps, students are repeatedly challenged to develop hypotheses regarding the ancestry of the five species. Although these…

  11. New conjugated molecular scaffolds based on [2,2]paracyclophane as electron acceptors for organic photovoltaic cells.

    Science.gov (United States)

    Yang, Yang; Zhang, Guanxin; Yu, Chenmin; He, Chang; Wang, Jianguo; Chen, Xin; Yao, Jingjing; Liu, Zitong; Zhang, Deqing

    2014-09-01

    Two conjugated molecules with a [2,2]paracyclophane core were designed as non-fullerene electron acceptors for photovoltaic cells. Using as the donor, a high power conversion efficiency (2.69%) is achieved for the blending thin film of with , which is relatively high for solution-processed OPVs based on small molecular non-fullerene acceptors and as the electron donor.

  12. A DNA tetrahedron-based molecular beacon for tumor-related mRNA detection in living cells.

    Science.gov (United States)

    Xie, Nuli; Huang, Jin; Yang, Xiaohai; Yang, Yanjing; Quan, Ke; Wang, He; Ying, Le; Ou, Min; Wang, Kemin

    2016-02-01

    Due to its low cytotoxicity, high resistance to enzymatic degradation, and cellular permeability, a DNA tetrahedron-based molecular beacon (DTMB) is designed for tumor-related TK1 mRNA detection in living cells, where the target sequence can induce the tetrahedron from contraction to extension, resulting in fluorescence restoration. PMID:26729323

  13. Phenylalanine-containing cyclic dipeptides--the lowest molecular weight hydrogelators based on unmodified proteinogenic amino acids.

    Science.gov (United States)

    Kleinsmann, Alexander J; Nachtsheim, Boris J

    2013-09-14

    Cyclic dipeptides (diketopiperazines - DKPs) that are based on the proteinogenic amino acid phenylalanine in combination with serine, cysteine, glutamate, histidine and lysine are described as simple and remarkable low molecular weight hydrogelators. Blends of selected DKPs show remarkable pH-dependent properties and can be applied as easy to tune materials in drug delivery.

  14. Fluorescence- and capillary electrophoresis (CE)-based SSR DNA fingerprinting and a molecular identity database for the Louisiana sugarcane industry

    Science.gov (United States)

    A database of Louisiana sugarcane molecular identity has been constructed and is being updated annually using FAM or HEX or NED fluorescence- and capillary electrophoresis (CE)-based microsatellite (SSR) fingerprinting information. The fingerprints are PCR-amplified from leaf DNA samples of current ...

  15. Network-based integration of molecular and physiological data elucidates regulatory mechanisms underlying adaptation to high-fat diet

    NARCIS (Netherlands)

    Derous, D.; Kelder, T.; Schothorst, E.M. van; Erk, M. van; Voigt, A.; Klaus, S.; Keijer, J.; Radonjic, M.

    2015-01-01

    Health is influenced by interplay of molecular, physiological and environmental factors. To effectively maintain health and prevent disease, health-relevant relations need to be understood at multiple levels of biological complexity. Network-based methods provide a powerful platform for integration

  16. A DNA tetrahedron-based molecular beacon for tumor-related mRNA detection in living cells.

    Science.gov (United States)

    Xie, Nuli; Huang, Jin; Yang, Xiaohai; Yang, Yanjing; Quan, Ke; Wang, He; Ying, Le; Ou, Min; Wang, Kemin

    2016-02-01

    Due to its low cytotoxicity, high resistance to enzymatic degradation, and cellular permeability, a DNA tetrahedron-based molecular beacon (DTMB) is designed for tumor-related TK1 mRNA detection in living cells, where the target sequence can induce the tetrahedron from contraction to extension, resulting in fluorescence restoration.

  17. The Development of Molecular-Based Materials for Electrical and Electronic Applications

    Science.gov (United States)

    Babalola, P. O.; Inegbenebor, A. O.; Bolu, C. A.; Inegbenebor, A. I.

    2015-04-01

    Aluminum silicon carbide (AlSiC) metal matrix composite materials have a unique set of material properties that are ideally suited for electronics, hence the development of molecular-based materials (MBM) for the electrical and electronic industries. The low material density of AlSiC (3 g/cm3) makes it ideal for weight-sensitive applications such as portable devices over traditional thermal management materials like copper molybdenum (10 g/cm3) and copper tungsten (16 g/cm3). The aim of this work is to develop MBM for electrical and electronic industries. Aluminum (99.66% C.P.) and silicon carbide (SiC) particulates of 240 grit (45 µm), 320 grit (29 µm), 600 grit (9 µm) and 1200 grit (3 µm) at 2.5% weight fraction were used to achieve the objective. The aluminum was melted at 750°C for 25 min in a graphite crucible tilting furnace designed for this work using oil as a firing medium. After melting, a two-step mixing method of stir casting technique was adopted. The cast samples were further analyzed for mechanical and electrical properties. The electrical properties were carried out by using a 4-point probe machine. The result showed that hardness increases at lower grit level, while the electrical properties marginally increased at higher grit. It is therefore recommended that, to make AlSiC composite materials for electrical industries, the higher grit of SiC should be preferred.

  18. Microbial diversity in an Armenian geothermal spring assessed by molecular and culture-based methods.

    Science.gov (United States)

    Panosyan, Hovik; Birkeland, Nils-Kåre

    2014-11-01

    The phylogenetic diversity of the prokaryotic community thriving in the Arzakan hot spring in Armenia was studied using molecular and culture-based methods. A sequence analysis of 16S rRNA gene clone libraries demonstrated the presence of a diversity of microorganisms belonging to the Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Epsilonproteobacteria, Firmicutes, Bacteroidetes phyla, and Cyanobacteria. Proteobacteria was the dominant group, representing 52% of the bacterial clones. Denaturing gradient gel electrophoresis profiles of the bacterial 16S rRNA gene fragments also indicated the abundance of Proteobacteria, Bacteroidetes, and Cyanobacteria populations. Most of the sequences were most closely related to uncultivated microorganisms and shared less than 96% similarity with their closest matches in GenBank, indicating that this spring harbors a unique community of novel microbial species or genera. The majority of the sequences of an archaeal 16S rRNA gene library, generated from a methanogenic enrichment, were close relatives of members of the genus Methanoculleus. Aerobic endospore-forming bacteria mainly belonging to Bacillus and Geobacillus were detected only by culture-dependent methods. Three isolates were successfully obtained having 99, 96, and 96% 16S rRNA gene sequence similarities to Arcobacter sp., Methylocaldum sp., and Methanoculleus sp., respectively. PMID:24740751

  19. Confirmation of a natural hybrid species in Petrocosmea (Gesneriaceae) based on molecular and morphological evidence

    Institute of Scientific and Technical Information of China (English)

    Zhi-Jing QIU; Zu-Li YUAN; Zhen-Yu LI; yin-Zheng WANG

    2011-01-01

    A natural hybrid species in Petrocosmea named Longianthera in Yanshan County,Yunnan Province is confirmed for the first time based on molecular and morphological evidence.The character count procedure of the variable characters show that Longianthera populations are characteristic of the intermediate morphological traits between its putative parents Yanshan and Petrocosmea martinii.The nuclear ribosomal internal transcribed spacer region and three chloroplast regions of matK,trnL-F,and trnT-L are sequenced in the putativehybrid and the related species.Both alignment of DNA sequences and the phylogenetic trees could exclude all the other species in Petrocosmea as the parental species except for Yanshan and P martinii.Eight haplotypes in the 31 internal transcribed spacer sequences and six haplotypes in 42 cpDNA sequences were found from 14 individuals of Longianthera populations.The analyses of DNA sequences,haplotypes,and phylogenetic trees indicate that Longianthera is likely a hybrid species between its putative parents Yanshan and P martinii,in which Yanshan might be the most possible maternal parent.Several factors may contribute to the natural hybridization between these two parental species in Petrocosmea,such as the overlapped geographic distribution,habitats,flowering periods,and shared pollinators.Finally,the new species of Yanshan and the natural hybrid species of Longianthera are described.

  20. Molecular phylogenetic analysis of Indonesia Solanaceae based on DNA sequences of internal transcribed spacer region

    Science.gov (United States)

    Hidayat, Topik; Priyandoko, Didik; Islami, Dina Karina; Wardiny, Putri Yunitha

    2016-02-01

    Solanaceae is one of largest family in Angiosperm group with highly diverse in morphological character. In Indonesia, this group of plant is very popular due to its usefulness as food, ornamental and medicinal plants. However, investigation on phylogenetic relationship among the member of this family in Indonesia remains less attention. The purpose of this study was to evaluate the phylogenetics relationship of the family especially distributed in Indonesia. DNA sequences of Internal Transcribed Spacer (ITS) region of 19 species of Solanaceae and three species of outgroup, which belongs to family Convolvulaceae, Apocynaceae, and Plantaginaceae, were isolated, amplified, and sequenced. Phylogenetic tree analysis based on parsimony method was conducted with using data derived from the ITS-1, 5.8S, and ITS-2, separately, and the combination of all. Results indicated that the phylogenetic tree derived from the combined data established better pattern of relationship than separate data. Thus, three major groups were revealed. Group 1 consists of tribe Datureae, Cestreae, and Petunieae, whereas group 2 is member of tribe Physaleae. Group 3 belongs to tribe Solaneae. The use of the ITS region as a molecular markers, in general, support the global Solanaceae relationship that has been previously reported.