WorldWideScience

Sample records for biomolecules perspectivas diagnosticas

  1. Diagnostic and therapeutic perspectives in nuclear medicine: radiolabelled biomolecules; Perspectivas diagnosticas y terapeuticas en medicina nuclear: biomoleculas radiomarcadas

    Energy Technology Data Exchange (ETDEWEB)

    Ferro F, G. [Gerencia de Aplicaciones Nucleares en la Salud. ININ, 11801 Mexico D.F. (Mexico); Murphy, C.A. de; Pedraza L, M. [Departamento de Medicina Nuclear. Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico D.F. (Mexico); Melendez A, L. [Facultad de Medicina, UAEM, 50000 Toluca, Estado de Mexico (Mexico)

    2003-07-01

    From their beginning, the radiopharmaceuticals chemistry has gone to the study of the molecular chemistry. The radiopharmaceuticals are only in their capacity to detect such specific biochemical places as the receivers and the enzymes. With the recent obtaining of the complete structural sequence of the genome, it doesn't fit doubt of the importance that they have acquired the molecular images for the study from the genetic information to the alterations phenotypic in the chemistry of the human body. So, the future of the diagnostic and therapeutic nuclear medicine, practically is based in the study of protein fragments, peptide structures and chains of DNA radiolabelled for the study of the metabolism In vivo. These investigations represent a substantial change in those paradigms of the pharmaceutical development, when using the own organic capacities as source of medications, instead of considering to the organism like a simple assay tube where molecules act, like they are most of the traditional medications. The investigation of new techniques to design complex stable of Tc-99m, Re-188, Lu-177, Y-90 and Dy-166/Ho-l66 with biomolecules that don't alter the specificity and in general the molecular properties of the same ones. it is a topic of world interest in the environment of the radiopharmaceutical chemistry. In this work some achievements and perspectives are presented on those main diagnostic and therapeutic radiopharmaceuticals of third generation. (Author)

  2. Diagnostic and therapeutic perspectives in nuclear medicine: radiolabelled biomolecules; Perspectivas diagnosticas y terapeuticas en medicina nuclear: biomoleculas radiomarcadas

    Energy Technology Data Exchange (ETDEWEB)

    Ferro F, G [Gerencia de Aplicaciones Nucleares en la Salud. ININ, 11801 Mexico D.F. (Mexico); Murphy, C.A. de; Pedraza L, M [Departamento de Medicina Nuclear. Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico D.F. (Mexico); Melendez A, L [Facultad de Medicina, UAEM, 50000 Toluca, Estado de Mexico (Mexico)

    2003-07-01

    From their beginning, the radiopharmaceuticals chemistry has gone to the study of the molecular chemistry. The radiopharmaceuticals are only in their capacity to detect such specific biochemical places as the receivers and the enzymes. With the recent obtaining of the complete structural sequence of the genome, it doesn't fit doubt of the importance that they have acquired the molecular images for the study from the genetic information to the alterations phenotypic in the chemistry of the human body. So, the future of the diagnostic and therapeutic nuclear medicine, practically is based in the study of protein fragments, peptide structures and chains of DNA radiolabelled for the study of the metabolism In vivo. These investigations represent a substantial change in those paradigms of the pharmaceutical development, when using the own organic capacities as source of medications, instead of considering to the organism like a simple assay tube where molecules act, like they are most of the traditional medications. The investigation of new techniques to design complex stable of Tc-99m, Re-188, Lu-177, Y-90 and Dy-166/Ho-l66 with biomolecules that don't alter the specificity and in general the molecular properties of the same ones. it is a topic of world interest in the environment of the radiopharmaceutical chemistry. In this work some achievements and perspectives are presented on those main diagnostic and therapeutic radiopharmaceuticals of third generation. (Author)

  3. Promising Biomolecules.

    Science.gov (United States)

    Oliveira, Isabel; Carvalho, Ana L; Radhouani, Hajer; Gonçalves, Cristiana; Oliveira, J Miguel; Reis, Rui L

    2018-01-01

    The osteochondral defect (OD) comprises the articular cartilage and its subchondral bone. The treatment of these lesions remains as one of the most problematic clinical issues, since these defects include different tissues, requiring distinct healing approaches. Among the growing applications of regenerative medicine, clinical articular cartilage repair has been used for two decades, and it is an effective example of translational medicine; one of the most used cell-based repair strategies includes implantation of autologous cells in degradable scaffolds such as alginate, agarose, collagen, chitosan, chondroitin sulfate, cellulose, silk fibroin, hyaluronic acid, and gelatin, among others. Concerning the repair of osteochondral defects, tissue engineering and regenerative medicine started to design single- or bi-phased scaffold constructs, often containing hydroxyapatite-collagen composites, usually used as a bone substitute. Biomolecules such as natural and synthetic have been explored to recreate the cartilage-bone interface through multilayered biomimetic scaffolds. In this chapter, a succinct description about the most relevant natural and synthetic biomolecules used on cartilage and bone repair, describing the procedures to obtain these biomolecules, their chemical structure, common modifications to improve its characteristics, and also their application in the biomedical fields, is given.

  4. Studio del comportamento di agenti di contrasto in campi ultracustici per tecniche di ecografia diagnostica

    OpenAIRE

    BIAGIONI, ANGELO

    2011-01-01

    Il presente lavoro di ricerca è stato articolato intorno a temi attinenti l’ingegneria biomedica, riguardando, in particolare, lo studio del comportamento di agenti di contrasto in campi ultracustici per tecniche di ecografia diagnostica. Nell’ambito di tale settore scientifico, un ruolo di fondamentale importanza è svolto dalla diagnostica medica per immagini e in particolare dalle tecniche ecografiche. Queste ultime rappresentano un ottimo compromesso tra la pericolosità per l’organismo e l...

  5. Biomolecules in Astrobiology

    OpenAIRE

    Meringer, Markus

    2013-01-01

    Astrobiology is the study of the origin, distribution and future of life in the universe, biomolecules are molecules produced by living organisms. This talk reviews known facts and open questions about biomolecules in the context of Astrobiology and introduces a research project on "Creating a Reference Set of Amino Acids Structures for Use in Multiple Astrobiology Investigations" that tries to find answers using computational methods.

  6. Neural Networks. Diagnostic and inferential measurements; Reti neurali. Diagnostica e misure inferenziali

    Energy Technology Data Exchange (ETDEWEB)

    Bonavita, N. [Apc Group Leader, Abb Industria, Genua (Italy); Parisini, T. [Milan Politecnico, Milan (Italy). Dipt. di Elettronica e Informazione

    2000-09-01

    In this work, the use of neural approximating networks is described in the context of fault diagnosis of industrial plants with a particular emphasis to the technique of inferential measurements. The proposed methodology is related to the current literature emphasizing advantages and disadvantages of the analytical redundancy concept. The use of neural approximators for the generation of inferential measurement is described in the context of industrial distributed control systems. [Italian] In questo articolo viene descritta l'utilizzazione degli approssimatori neurali in problemi di diagnostica d'impianto con particolare riferimento alla tecnica delle misure inferenziali. Viene fornito un inquadramento della metodologia rispetto alla letteratura attuale mettendo in risalto vantaggi e svantaggi del concetto di ridondanza analitica. L'uso degli approssimatori neurali per la generazione di misure inferenziali e' illustrato in un contesto di sistemi di controllo distribuito di tipo industriale.

  7. Frustration in biomolecules.

    Science.gov (United States)

    Ferreiro, Diego U; Komives, Elizabeth A; Wolynes, Peter G

    2014-11-01

    Biomolecules are the prime information processing elements of living matter. Most of these inanimate systems are polymers that compute their own structures and dynamics using as input seemingly random character strings of their sequence, following which they coalesce and perform integrated cellular functions. In large computational systems with finite interaction-codes, the appearance of conflicting goals is inevitable. Simple conflicting forces can lead to quite complex structures and behaviors, leading to the concept of frustration in condensed matter. We present here some basic ideas about frustration in biomolecules and how the frustration concept leads to a better appreciation of many aspects of the architecture of biomolecules, and especially how biomolecular structure connects to function by means of localized frustration. These ideas are simultaneously both seductively simple and perilously subtle to grasp completely. The energy landscape theory of protein folding provides a framework for quantifying frustration in large systems and has been implemented at many levels of description. We first review the notion of frustration from the areas of abstract logic and its uses in simple condensed matter systems. We discuss then how the frustration concept applies specifically to heteropolymers, testing folding landscape theory in computer simulations of protein models and in experimentally accessible systems. Studying the aspects of frustration averaged over many proteins provides ways to infer energy functions useful for reliable structure prediction. We discuss how frustration affects folding mechanisms. We review here how the biological functions of proteins are related to subtle local physical frustration effects and how frustration influences the appearance of metastable states, the nature of binding processes, catalysis and allosteric transitions. In this review, we also emphasize that frustration, far from being always a bad thing, is an essential feature

  8. Biomolecule-functionalized polymer brushes.

    Science.gov (United States)

    Jiang, Hui; Xu, Fu-Jian

    2013-04-21

    Functional polymer brushes have been utilized extensively for the immobilization of biomolecules, which is of crucial importance for the development of biosensors and biotechnology. Recent progress in polymerization methods, in particular surface-initiated atom transfer radical polymerization (ATRP), has provided a unique means for the design and synthesis of new biomolecule-functionalized polymer brushes. This current review summarizes such recent research activities. The different preparation strategies for biomolecule immobilization through polymer brush spacers are described in detail. The functional groups of the polymer brushes used for biomolecule immobilization include epoxide, carboxylic acid, hydroxyl, aldehyde, and amine groups. The recent research activities indicate that functional polymer brushes become versatile and powerful spacers for immobilization of various biomolecules to maximize their functionalities. This review also demonstrates that surface-initiated ATRP is used more frequently than other polymerization methods in the designs of new biomolecule-functionalized polymer brushes.

  9. Dynamics of biomolecules

    International Nuclear Information System (INIS)

    Frauenfelder, H.

    1975-01-01

    The dynamics of the biomolecules is shown by the example of myoglobin (Mb). The photodissociation of MbCO with a laser flash and the recapture process of CO were followed optically in the temperature region of 2 to 350 K. The binding procedure exhibits four components which stretch out over many orders of magnitude of time. Above 250 K, the time dependence of the components is exponential, below 180 K, only one component is present which follows an exponential equation. A potential barrier model is shown to explain the observed courses of binding. See also 'Biochemistry', in printing. (BJ/LH) [de

  10. Nonlinear excitations in biomolecules

    International Nuclear Information System (INIS)

    Peyrard, M.

    1995-01-01

    The aim of the workshop entitled ''Nonlinear Excitations in Biomolecules'' is to attempt to bridge the gap between the physicists and biologists communities which is mainly due to language and cultural barriers. The progress of nonlinear science in the last few decades which have shown that the combination of nonlinearity, which characterize most biological phenomena, and cooperative effects in a system having a large number of degrees of freedom, can give rise to coherent excitations with remarkable properties. New concepts, such as solitons nd nonlinear energy localisation have become familiar to physicists and applied mathematicians. It is thus tempting to make an analogy between these coherent excitations and the exceptional stability of some biological processes, such as for instance DNA transcription, which require the coordination of many events in the ever changing environment of a cell. Physicists are now invoking nonlinear excitations to describe and explain many bio-molecular processes while biologists often doubt that the seemingly infinite variety of phenomena that they are attempting to classify can be reduced to such simple concepts. A large part of the meeting is devoted to tutorial lectures rather than to latest research results. The book provides a pedagogical introduction to the two topics forming the backbone of the meeting: the theory of nonlinear excitations and solitons, and their application in biology; and the structure and function of biomolecules, as well as energy and charge transport in biophysics. In order to emphasize the link between physics and biology, the volume is not divided along these two topics but according to biological subjects. Each chapter starts with a short introduction attempting to help the reader to find his way among the contributions and point out the connection between them. 23 lectures over the 32 presented have been selected and refers to quantum properties of macro-molecules. (J.S.)

  11. A source for microhydrated biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Förstel, M.; Hergenhahn, U., E-mail: uwe.hergenhahn@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald (Germany); Neustetter, M.; Denifl, S. [Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25, 6020 Innsbruck (Austria); Lelievre, F. [Max-Planck-Institut für Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald (Germany); University Paris-Sud 11, Faculté des Science d’Orsay, 91405 Orsay (France)

    2015-07-15

    We describe the construction of an apparatus for the production of a molecular jet of microhydrated biomolecules. Our design uses a water reservoir producing water vapour, which then passes through a separate reservoir containing a vapour of a sublimated biomolecule. The mixture coexpands into a molecular beam apparatus through a conical nozzle. Mass spectra showing water-adenin and water-uracil complexes are shown as typical examples. Suitable expansion conditions are reached without the use of an inert carrier gas.

  12. Biomolecule labelling by 186 Re

    International Nuclear Information System (INIS)

    Lungu, Valeria Viorica; Mihailescu, Gabriela; Dumitrescu, Gabriela

    1998-01-01

    The aim of this study is to develop and improve the existing radiolabelling techniques of peptides and monoclonal antibodies with 186 Re and 188 Re as potential agents for cancer targeted radiotherapy. We selected the following methods and techniques for direct labelling of peptides and monoclonal antibody: 1. Prereduction of -S-S- bridges of biomolecule to sulfhydryls using reducing agents: ascorbic acid, cysteine, active hydrogen, 2,3 dimercaptopropanol. The prereduction reactions are controlled by massic ratios of reduction agents/biomolecule, pH, temperature and time of incubation; 2. Reduction of 186 Re O 4 - stannous chloride in acid and alkaline pH; 3. Coupling reaction of 186 Re (red) with the biomolecule controlled by the time and temperature of incubation, the influence of pH regarding the binding of 186 Re to the biomolecules. The quality control was effected by chromatography techniques (paper and elution gel chromatography) on labeled biomolecule before and after purification. The elution gel chromatography was spectrophotometricaly monitored at 280 nm. In the same time the radioactivity of samples was measured using a gamma counter. All the results confirm in vitro stability of labeled biomolecule. The biological evaluation studies regarding accumulation and biological affinity will be controlled by scintigraphy method. Biodistribution studies will be effected to Walker tumor bearing animals at 4 and 24 hours after injections. (authors)

  13. Ancient Biomolecules and Evolutionary Inference

    DEFF Research Database (Denmark)

    Cappellini, Enrico; Prohaska, Ana; Racimo, Fernando

    2018-01-01

    Over the last decade, studies of ancient biomolecules-particularly ancient DNA, proteins, and lipids-have revolutionized our understanding of evolutionary history. Though initially fraught with many challenges, the field now stands on firm foundations. Researchers now successfully retrieve nucleo...

  14. Ancient Biomolecules and Evolutionary Inference.

    Science.gov (United States)

    Cappellini, Enrico; Prohaska, Ana; Racimo, Fernando; Welker, Frido; Pedersen, Mikkel Winther; Allentoft, Morten E; de Barros Damgaard, Peter; Gutenbrunner, Petra; Dunne, Julie; Hammann, Simon; Roffet-Salque, Mélanie; Ilardo, Melissa; Moreno-Mayar, J Víctor; Wang, Yucheng; Sikora, Martin; Vinner, Lasse; Cox, Jürgen; Evershed, Richard P; Willerslev, Eske

    2018-04-25

    Over the last decade, studies of ancient biomolecules-particularly ancient DNA, proteins, and lipids-have revolutionized our understanding of evolutionary history. Though initially fraught with many challenges, the field now stands on firm foundations. Researchers now successfully retrieve nucleotide and amino acid sequences, as well as lipid signatures, from progressively older samples, originating from geographic areas and depositional environments that, until recently, were regarded as hostile to long-term preservation of biomolecules. Sampling frequencies and the spatial and temporal scope of studies have also increased markedly, and with them the size and quality of the data sets generated. This progress has been made possible by continuous technical innovations in analytical methods, enhanced criteria for the selection of ancient samples, integrated experimental methods, and advanced computational approaches. Here, we discuss the history and current state of ancient biomolecule research, its applications to evolutionary inference, and future directions for this young and exciting field. Expected final online publication date for the Annual Review of Biochemistry Volume 87 is June 20, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  15. BSDB: the Biomolecule Stretching Database

    Science.gov (United States)

    Cieplak, Marek; Sikora, Mateusz; Sulkowska, Joanna I.; Witkowski, Bartlomiej

    2011-03-01

    Despite more than a decade of experiments on single biomolecule manipulation, mechanical properties of only several scores of proteins have been measured. A characteristic scale of the force of resistance to stretching, Fmax , has been found to range between ~ 10 and 480 pN. The Biomolecule Stretching Data Base (BSDB) described here provides information about expected values of Fmax for, currently, 17 134 proteins. The values and other characteristics of the unfolding proces, including the nature of identified mechanical clamps, are available at www://info.ifpan.edu.pl/BSDB/. They have been obtained through simulations within a structure-based model which correlates satisfactorily with the available experimental data on stretching. BSDB also lists experimental data and results of the existing all-atom simulations. The database offers a Protein-Data-Bank-wide guide to mechano-stability of proteins. Its description is provided by a forthcoming Nucleic Acids Research paper. Supported by EC FUNMOL project FP7-NMP-2007-SMALL-1, and European Regional Development Fund: Innovative Economy (POIG.01.01.02-00-008/08).

  16. Structures of Biomolecules by NMR Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    an edge over the X-ray method as it can be used to study biomolecules ... currently as an Associate. Professor. ... Such a wealth of data is made available to the NMR ... important step towards structural characterization of a biomolecule. Box 1.

  17. Biomolecule-based nanomaterials and nanostructures.

    Science.gov (United States)

    Willner, Itamar; Willner, Bilha

    2010-10-13

    Biomolecule-nanoparticle (or carbon nanotube) hybrid systems provide new materials that combine the unique optical, electronic, or catalytic properties of the nanoelements with the recognition or biocatalytic functions of biomolecules. This article summarizes recent applications of biomolecule-nanoparticle (or carbon nanotubes) hybrid systems for sensing, synthesis of nanostructures, and for the fabrication of nanoscale devices. The use of metallic nanoparticles for the electrical contacting of redox enzymes with electrodes, and as catalytic labels for the development of electrochemical biosensors is discussed. Similarly, biomolecule-quantum dot hybrid systems are implemented for optical biosensing, and for monitoring intracellular metabolic processes. Also, the self-assembly of biomolecule-metal nanoparticle hybrids into nanostructures and functional nanodevices is presented. The future perspectives of the field are addressed by discussing future challenges and highlighting different potential applications.

  18. Analysis of nanoparticle biomolecule complexes.

    Science.gov (United States)

    Gunnarsson, Stefán B; Bernfur, Katja; Mikkelsen, Anders; Cedervall, Tommy

    2018-03-01

    Nanoparticles exposed to biological fluids adsorb biomolecules on their surface forming a biomolecular corona. This corona determines, on a molecular level, the interactions and impact the newly formed complex has on cells and organisms. The corona formation as well as the physiological and toxicological relevance are commonly investigated. However, an acknowledged but rarely addressed problem in many fields of nanobiotechnology is aggregation and broadened size distribution of nanoparticles following their interactions with the molecules of biological fluids. In blood serum, TiO 2 nanoparticles form complexes with a size distribution from 30 nm to more than 500 nm. In this study we have separated these complexes, with good resolution, using preparative centrifugation in a sucrose gradient. Two main apparent size populations were obtained, a fast sedimenting population of complexes that formed a pellet in the preparative centrifugation tube, and a slow sedimenting complex population still suspended in the gradient after centrifugation. Concentration and surface area dependent differences are found in the biomolecular corona between the slow and fast sedimenting fractions. There are more immunoglobulins, lipid binding proteins, and lipid-rich complexes at higher serum concentrations. Sedimentation rate and the biomolecular corona are important factors for evaluating any experiment including nanoparticle exposure. Our results show that traditional description of nanoparticles in biological fluids is an oversimplification and that more thorough characterisations are needed.

  19. EVALUACIÓN DE LOS PROTOCOLOS IPSEC Y SSL EN LA TRANSMISIÓN SEGURA DE IMÁGENES DIAGNOSTICAS EN TELERADIOLOGIA UTILIZANDO EL ESTÁNDAR DICOM

    Directory of Open Access Journals (Sweden)

    Jorge Luis Lugo Rosero

    2011-08-01

    Full Text Available Las imágenes diagnosticas digitales constituyen hoy día un paradigma de requerimientos para cualquier sistema informático; se debe garantizar la confidencialidad de la información médica de los pacientes mediante sistemas de comunicación seguros, cumpliendo de esta manera con las políticas de control de calidad en técnicas de Teleradiologia. En este articulo primero se describe un escenario típico de comunicación entre los dispositivos de captura de placas y los elementos de visualizacion y almacenamiento de las mismas, asi como la forma en la que se transmiten dichas tomas diagnosticas de un sitio a otro, posteriormente se realiza la comparación entre  los protocolos más utilizados en esta tarea y finalmente se analizan los resultados obtenidos al transmitir varios estudios medicos por una red LAN garantizando la seguridad y confidencialidad de los datos de trabajo.

  20. Magnetic GMI sensor for detection of biomolecules

    International Nuclear Information System (INIS)

    Chiriac, Horia; Tibu, Mihai; Moga, Anca-Eugenia; Herea, Dumitru D.

    2005-01-01

    A magnetic sensor based on the giant magnetoimpedance (GMI) effect for the detection of biomolecules was made with a CoFeSiB amorphous magnetic microwire as sensing element. Using soft ferromagnetic cobalt microparticles and field sensitivities of the impedance of about 2.5%/A m -1 in the very low field region (less than 200 A m -1 ) at frequencies close to 10 MHz, a highly sensitive response was measured, appropriate for the detection of low biomolecule concentrations

  1. Biomolecule-coated metal nanoparticles on titanium.

    Science.gov (United States)

    Christensen, Stephen L; Chatt, Amares; Zhang, Peng

    2012-02-07

    Immobilizations of nanoparticles and biomolecules on biocompatible substrates such as titanium are two promising approaches to bringing new functionalities to Ti-based biomaterials. Herein, we used a variety of X-ray spectroscopic techniques to study and better understand metal-thiolate interactions in biofunctionalized metal nanoparticle systems supported on Ti substrates. Using a facile one-step procedure, a series of Au nanoparticle samples with varied biomolecule coatings ((2-mercatopropionyl)glycine (MPG) and bovine serum albumin (BSA)) and biomolecule concentrations are prepared. Ag and Pd systems are also studied to observe change with varying metal composition. The structure and properties of these biomolecule-coated nanoparticles are investigated with scanning electron microscopy (SEM) and element-specific X-ray techniques, including extended X-ray absorption fine structure (Au L(3)-edge), X-ray absorption near-edge structure (Au L(3), Ag L(3), Pd L(3), and S K-edge), and X-ray photoelectron spectroscopy (Au 4f, Ag 3d, Pd 3d, and S 2p core level). It was found that, by comparison of SEM and X-ray spectroscopy results, the coating of metal nanoparticles with varying model biomolecule systems can have a significant effect on both surface coverage and organization. This work offers a facile chemical method for bio- and nanofunctionalization of Ti substrates as well as provides a physical picture of the structure and bonding of biocoated metal nanoparticles, which may lead to useful applications in orthopedics and biomedicine.

  2. Thermodynamic stability of biomolecules and evolution.

    Science.gov (United States)

    Chakravarty, Ashim K

    2017-08-01

    The thermodynamic stability of biomolecules in the perspective of evolution is a complex issue and needs discussion. Intra molecular bonds maintain the structure and the state of internal energy (E) of a biomolecule at "local minima". In this communication, possibility of loss in internal energy level of a biomolecule through the changes in the bonds has been discussed, that might earn more thermodynamic stability for the molecule. In the process variations in structure and functions of the molecule could occur. Thus, E of a biomolecule is likely to have energy stature for minimization. Such change in energy status is an intrinsic factor for evolving biomolecules buying more stability and generating variations in the structure and function of DNA molecules undergoing natural selection. Thus, the variations might very well contribute towards the process of evolution. A brief discussion on conserved sequence in the light of proposition in this communication has been made at the end. Extension of the idea may resolve certain standing problems in evolution, such as maintenance of conserved sequences in genome of diverse species, pre- versus post adaptive mutations, 'orthogenesis', etc. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Biomolecules for Removal of Heavy Metal.

    Science.gov (United States)

    Singh, Namita Ashish

    2017-01-01

    Patents reveal that heavy metals are natural constituents of the earth's crust, but some heavy metals like cadmium, lead, mercury, arsenic etc. are injurious to living organisms at higher concentration. Nowadays, anthropogenic activities have altered geochemical cycles and biochemical balance of heavy metals. Biomolecules are used nowadays for removal of heavy metals compared to other synthetic biosorbents due to their environmental friendly nature and cost effectiveness. The goal of this work is to identify the role of biomolecules like polysaccharides, polypeptides, natural compounds containing aromatic acid etc. for heavy metal removal by bio sorption. It has been observed that efficiency of biomolecules can be increased by functionalization e.g. cellulose functionalization with EDTA, chitosan with sulphur groups, alginate with carboxyl/ hydroxyl group etc. It was found that the porous structure of aerogel beads improves both sorption and kinetic properties of the material. Out of polypeptides metallothionein has been widely used for removal of heavy metal up to 88% from seawater after a single centrifugation. These cost effective functionalized biomolecules are significantly used for remediation of heavy metals by immobilizing these biomolecules onto materials. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. On the thermodynamics of biomolecule surface transformations.

    Science.gov (United States)

    Federici, Stefania; Oliviero, Giulio; Maiolo, Daniele; Depero, Laura E; Colombo, Italo; Bergese, Paolo

    2012-06-01

    Biological surface science is receiving great and renewed attention owing the rising interest in applications of nanoscience and nanotechnology to biological systems, with horizons that range from nanomedicine and biomimetic photosynthesis to the unexpected effects of nanomaterials on health and environment. Biomolecule surface transformations are among the fundamental aspects of the field that remain elusive so far and urgently need to be understood to further the field. Our recent findings indicate that surface thermodynamics can give a substantial contribution toward this challenging goal. In the first part of the article, we show that biomolecule surface transformations can be framed by a general and simple thermodynamic model. Then, we explore its effectiveness by addressing some typical cases, including ligand-receptor surface binding, protein thin film machines, nanomechanical aspects of the biomolecule-nanoparticle interface and nanomechanical biosensors. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Polyvalent Display of Biomolecules on Live Cells.

    Science.gov (United States)

    Shi, Peng; Zhao, Nan; Lai, Jinping; Coyne, James; Gaddes, Erin R; Wang, Yong

    2018-06-04

    Surface display of biomolecules on live cells offers new opportunities to treat human diseases and perform basic studies. Existing methods are primarily focused on monovalent functionalization, that is, the display of single biomolecules across the cell surface. Here we show that the surface of live cells can be functionalized to display polyvalent biomolecular structures through two-step reactions under physiological conditions. This polyvalent functionalization enables the cell surface to recognize the microenvironment one order of magnitude more effectively than with monovalent functionalization. Thus, polyvalent display of biomolecules on live cells holds great potential for various biological and biomedical applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Evolved Minimal Frustration in Multifunctional Biomolecules.

    Science.gov (United States)

    Röder, Konstantin; Wales, David J

    2018-05-25

    Protein folding is often viewed in terms of a funnelled potential or free energy landscape. A variety of experiments now indicate the existence of multifunnel landscapes, associated with multifunctional biomolecules. Here, we present evidence that these systems have evolved to exhibit the minimal number of funnels required to fulfil their cellular functions, suggesting an extension to the principle of minimum frustration. We find that minimal disruptive mutations result in additional funnels, and the associated structural ensembles become more diverse. The same trends are observed in an atomic cluster. These observations suggest guidelines for rational design of engineered multifunctional biomolecules.

  7. Microorganisms and biomolecules in space hard environment

    Science.gov (United States)

    Horneck, G.

    1981-01-01

    Microorganisms and biomolecules exposed to space vacuum and to different intensities of selected wavelengths of solar ultraviolet radiation is studied. The influence of these factors, applied singly or simultaneously, on the integrity of microbial systems and biomolecules is measured. Specifically, this experiment will study in Bacillus subtilis spores (1) disturbances in subsequent germination, outgrowth, and colony formation; (2) photochemical reactions of the DNA and protein in vivo and in vitro and their role in biological injury; and (3) the efficiency of repair processes in these events.

  8. Nanofluidic technology for biomolecule applications: a critical review

    NARCIS (Netherlands)

    Napoli, M.; Eijkel, Jan C.T.; Pennathur, S.

    2010-01-01

    In this review, we present nanofluidic phenomena, particularly as they relate to applications involving analysis of biomolecules within nanofabricated devices. The relevant length scales and physical phenomena that govern biomolecule transport and manipulation within nanofabricated nanofluidic

  9. A Multidisciplinary, Open Access Platform for Research on Biomolecules

    Directory of Open Access Journals (Sweden)

    Jürg Bähler

    2011-08-01

    Full Text Available I am pleased to introduce Biomolecules, a new journal to report on all aspects of science that focuses on biologically derived substances, from small molecules to complex polymers. Some examples are lipids, carbohydrates, vitamins, hormones, amino acids, nucleotides, peptides, RNA and polysaccharides, but this list is far from exhaustive. Research on biomolecules encompasses multiple fascinating questions. How are biomolecules synthesized and modified? What are their structures and interactions with other biomolecules? How do biomolecules function in biological processes, at the level of organelles, cells, organs, organisms, or even ecosystems? How do biomolecules affect either the organism that produces them or other organisms of the same or different species? How are biomolecules shaped by evolution, and how in turn do they affect cellular phenotypes? What is the systems-level contribution of biomolecules to biological function?

  10. A Multidisciplinary, Open Access Platform for Research on Biomolecules.

    Science.gov (United States)

    Bähler, Jürg

    2011-08-22

    I am pleased to introduce Biomolecules, a new journal to report on all aspects of science that focuses on biologically derived substances, from small molecules to complex polymers. Some examples are lipids, carbohydrates, vitamins, hormones, amino acids, nucleotides, peptides, RNA and polysaccharides, but this list is far from exhaustive. Research on biomolecules encompasses multiple fascinating questions. How are biomolecules synthesized and modified? What are their structures and interactions with other biomolecules? How do biomolecules function in biological processes, at the level of organelles, cells, organs, organisms, or even ecosystems? How do biomolecules affect either the organism that produces them or other organisms of the same or different species? How are biomolecules shaped by evolution, and how in turn do they affect cellular phenotypes? What is the systems-level contribution of biomolecules to biological function? [...].

  11. Immobilizing Biomolecules Near the Diffraction Limit

    DEFF Research Database (Denmark)

    Skovsen, Esben; Petersen, Maria Teresa Neves; Gennaro, Ane Kold Di

    2009-01-01

    Our group has previously shown that biomolecules containing disulfide bridges in close proximity to aromatic residues can be immobilized, through covalent bonds, onto thiol derivatized surfaces upon UV excitation of the aromatic residue(s). We have also previously shown that our new technology ca...

  12. Tuneable graphene nanopores for single biomolecule detection.

    Science.gov (United States)

    Al-Dirini, Feras; Mohammed, Mahmood A; Hossain, Md Sharafat; Hossain, Faruque M; Nirmalathas, Ampalavanapillai; Skafidas, Efstratios

    2016-05-21

    Solid-state nanopores are promising candidates for next generation DNA and protein sequencing. However, once fabricated, such devices lack tuneability, which greatly restricts their biosensing capabilities. Here we propose a new class of solid-state graphene-based nanopore devices that exhibit a unique capability of self-tuneability, which is used to control their conductance, tuning it to levels comparable to the changes caused by the translocation of a single biomolecule, and hence, enabling high detection sensitivities. Our presented quantum simulation results suggest that the smallest amino acid, glycine, when present in water and in an aqueous saline solution can be detected with high sensitivity, up to a 90% change in conductance. Our results also suggest that passivating the device with nitrogen, making it an n-type device, greatly enhances its sensitivity, and makes it highly sensitive to not only the translocation of a single biomolecule, but more interestingly to intramolecular electrostatics within the biomolecule. Sensitive detection of the carboxyl group within the glycine molecule, which carries a charge equivalent to a single electron, is achieved with a conductance change that reaches as high as 99% when present in an aqueous saline solution. The presented findings suggest that tuneable graphene nanopores, with their capability of probing intramolecular electrostatics, could pave the way towards a new generation of single biomolecule detection devices.

  13. Biomolecule-Responsive Hydrogels in Medicine.

    Science.gov (United States)

    Sharifzadeh, Ghorbanali; Hosseinkhani, Hossein

    2017-12-01

    Recent advances and applications of biomolecule-responsive hydrogels, namely, glucose-responsive hydrogels, protein-responsive hydrogels, and nucleic-acid-responsive hydrogels are highlighted. However, achieving the ultimate purpose of using biomolecule-responsive hydrogels in preclinical and clinical areas is still at the very early stage and calls for more novel designing concepts and advance ideas. On the way toward the real/clinical application of biomolecule-responsive hydrogels, plenty of factors should be extensively studied and examined under both in vitro and in vivo conditions. For example, biocompatibility, biointegration, and toxicity of biomolecule-responsive hydrogels should be carefully evaluated. From the living body's point of view, biocompatibility is seriously depended on the interactions at the tissue/polymer interface. These interactions are influenced by physical nature, chemical structure, surface properties, and degradation of the materials. In addition, the developments of advanced hydrogels with tunable biological and mechanical properties which cause no/low side effects are of great importance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Porous-wall hollow glass microspheres as carriers for biomolecules

    Science.gov (United States)

    Li, Shuyi; Dynan, William S; Wicks, George; Serkiz, Steven

    2013-09-17

    The present invention includes compositions of porous-wall hollow glass microspheres and one or more biomolecules, wherein the one or more biomolecules are positioned within a void location within the hollow glass microsphere, and the use of such compositions for the diagnostic and/or therapeutic delivery of biomolecules.

  15. la perspectiva psicosocial

    Directory of Open Access Journals (Sweden)

    Juan Guerrero

    2007-01-01

    Full Text Available Con la opción de analizar las condiciones de trabajo en oficina, el texto realiza una sucinta pero precisa revisión de la conceptualización sobre productividad y consumo. Se documenta la relación contradictoria entre bienestar y rendimiento en el trabajo al identificar el riesgo de llevar al límite de sus capacidades la participación del trabajador como factor de productividad, ignorando que éste tiene además el rol de consumidor activo de bienes y servicios para que la producción tenga sentido. Se plantea que exigir al trabajador hasta su agotamiento puede mermar sustancialmente su doble condición de productor y consumidor. Específicamente, se presenta la perspectiva del trabajo en o"cinas innovadas conceptual y tecnológicamente, con procesos laborales y patrones de desgaste y morbilidad definidos. El tiempo, el ritmo, la parcelación, el control del trabajo y la reestructuración en las organizaciones son, entre otros, factores que convergen para potenciar fenómenos de sobrecarga o subcarga mental con la consecuente aparición de estrés excedente y sus patologías asociadas.

  16. Biomolecule delivery to engineer the cellular microenvironment for regenerative medicine.

    Science.gov (United States)

    Bishop, Corey J; Kim, Jayoung; Green, Jordan J

    2014-07-01

    To realize the potential of regenerative medicine, controlling the delivery of biomolecules in the cellular microenvironment is important as these factors control cell fate. Controlled delivery for tissue engineering and regenerative medicine often requires bioengineered materials and cells capable of spatiotemporal modulation of biomolecule release and presentation. This review discusses biomolecule delivery from the outside of the cell inwards through the delivery of soluble and insoluble biomolecules as well as from the inside of the cell outwards through gene transfer. Ex vivo and in vivo therapeutic strategies are discussed, as well as combination delivery of biomolecules, scaffolds, and cells. Various applications in regenerative medicine are highlighted including bone tissue engineering and wound healing.

  17. Monitoring the synthesis of biomolecules using mass spectrometry.

    Science.gov (United States)

    Miyagi, Masaru; Kasumov, Takhar

    2016-10-28

    The controlled and selective synthesis/clearance of biomolecules is critical for most cellular processes. In most high-throughput 'omics' studies, we measure the static quantities of only one class of biomolecules (e.g. DNA, mRNA, proteins or metabolites). It is, however, important to recognize that biological systems are highly dynamic in which biomolecules are continuously renewed and different classes of biomolecules interact and affect each other's production/clearance. Therefore, it is necessary to measure the turnover of diverse classes of biomolecules to understand the dynamic nature of biological systems. Herein, we explain why the kinetic analysis of a diverse range of biomolecules is important and how such an analysis can be done. We argue that heavy water ((2)H2O) could be a universal tracer for monitoring the synthesis of biomolecules on a global scale.This article is part of the themed issue 'Quantitative mass spectrometry'. © 2016 The Author(s).

  18. Natural Antioxidants: Fascinating or Mythical Biomolecules?

    Directory of Open Access Journals (Sweden)

    Johannes Van Staden

    2010-10-01

    Full Text Available Research on the use, properties, characteristics and sources of antioxidants especially phenolic compounds, flavonoids, vitamins, synthetic chemicals and some micronutrients began in the late 18th century. Since then antioxidant research has received considerable attention and over a hundred thousand papers have been published on the subject. This has led to a rampant use of antioxidants in order to try to obtain and preserve optimal health. A number of nutraceuticals and food supplements are frequently fortified with synthetic or natural antioxidants. However, some research outcomes have led to the belief that antioxidants exist as mythical biomolecules. This review provides a critical evaluation of some common in vitro antioxidant capacity methods, and a discussion on the role and controversies surrounding non-enzymatic biomolecules, in particular phenolic compounds and non-phenolic compounds, in oxidative processes in an attempt of stemming the tidal wave that is threatening to swamp the concept of natural antioxidants.

  19. Recolecta: estado actual y perspectivas

    OpenAIRE

    López Medina, Alicia

    2010-01-01

    Estado actual del Recolector de ciencia abierta español: Recolecta y proyectos de futuro. López Medina, A. (2010). Recolecta: estado actual y perspectivas. X Workshop Rebiun sobre proyectos digitales. http://hdl.handle.net/10251/8710.

  20. Microfluidic radiolabeling of biomolecules with PET radiometals

    International Nuclear Information System (INIS)

    Zeng Dexing; Desai, Amit V.; Ranganathan, David; Wheeler, Tobias D.; Kenis, Paul J.A.; Reichert, David E.

    2013-01-01

    Introduction: A robust, versatile and compact microreactor has been designed, fabricated and tested for the labeling of bifunctional chelate conjugated biomolecules (BFC-BM) with PET radiometals. Methods: The developed microreactor was used to radiolabel a chelate, either 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) that had been conjugated to cyclo(Arg-Gly-Asp-DPhe-Lys) peptide, with both 64 Cu and 68 Ga respectively. The microreactor radiolabeling conditions were optimized by varying temperature, concentration and residence time. Results: Direct comparisons between the microreactor approach and conventional methods showed improved labeling yields and increased reproducibility with the microreactor under identical labeling conditions, due to enhanced mass and heat transfer at the microscale. More importantly, over 90% radiolabeling yields (incorporation of radiometal) were achieved with a 1:1 stoichiometry of bifunctional chelate biomolecule conjugate (BFC-BM) to radiometal in the microreactor, which potentially obviates extensive chromatographic purification that is typically required to remove the large excess of unlabeled biomolecule in radioligands prepared using conventional methods. Moreover, higher yields for radiolabeling of DOTA-functionalized BSA protein (Bovine Serum Albumin) were observed with 64 Cu/ 68 Ga using the microreactor, which demonstrates the ability to label both small and large molecules. Conclusions: A robust, reliable, compact microreactor capable of chelating radiometals with common chelates has been developed and validated. Based on our radiolabeling results, the reported microfluidic approach overall outperforms conventional radiosynthetic methods, and is a promising technology for the radiometal labeling of commonly utilized BFC-BM in aqueous solutions.

  1. Microfluidic radiolabeling of biomolecules with PET radiometals.

    Science.gov (United States)

    Zeng, Dexing; Desai, Amit V; Ranganathan, David; Wheeler, Tobias D; Kenis, Paul J A; Reichert, David E

    2013-01-01

    A robust, versatile and compact microreactor has been designed, fabricated and tested for the labeling of bifunctional chelate conjugated biomolecules (BFC-BM) with PET radiometals. The developed microreactor was used to radiolabel a chelate, either 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) or 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) that had been conjugated to cyclo(Arg-Gly-Asp-DPhe-Lys) peptide, with both ⁶⁴Cu and ⁶⁸Ga respectively. The microreactor radiolabeling conditions were optimized by varying temperature, concentration and residence time. Direct comparisons between the microreactor approach and conventional methods showed improved labeling yields and increased reproducibility with the microreactor under identical labeling conditions, due to enhanced mass and heat transfer at the microscale. More importantly, over 90% radiolabeling yields (incorporation of radiometal) were achieved with a 1:1 stoichiometry of bifunctional chelate biomolecule conjugate (BFC-BM) to radiometal in the microreactor, which potentially obviates extensive chromatographic purification that is typically required to remove the large excess of unlabeled biomolecule in radioligands prepared using conventional methods. Moreover, higher yields for radiolabeling of DOTA-functionalized BSA protein (Bovine Serum Albumin) were observed with ⁶⁴Cu/⁶⁸Ga using the microreactor, which demonstrates the ability to label both small and large molecules. A robust, reliable, compact microreactor capable of chelating radiometals with common chelates has been developed and validated. Based on our radiolabeling results, the reported microfluidic approach overall outperforms conventional radiosynthetic methods, and is a promising technology for the radiometal labeling of commonly utilized BFC-BM in aqueous solutions. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Site-Specific Biomolecule Labeling with Gold Clusters

    Science.gov (United States)

    Ackerson, Christopher J.; Powell, Richard D.; Hainfeld, James F.

    2013-01-01

    Site-specific labeling of biomolecules in vitro with gold clusters can enhance the information content of electron cryomicroscopy experiments. This chapter provides a practical overview of well-established techniques for forming biomolecule/gold cluster conjugates. Three bioconjugation chemistries are covered: Linker-mediated bioconjugation, direct gold–biomolecule bonding, and coordination-mediated bonding of nickel(II) nitrilotriacetic acid (NTA)-derivatized gold clusters to polyhistidine (His)-tagged proteins. PMID:20887859

  3. Site-Specific Biomolecule Labeling with Gold Clusters

    OpenAIRE

    Ackerson, Christopher J.; Powell, Richard D.; Hainfeld, James F.

    2010-01-01

    Site-specific labeling of biomolecules in vitro with gold clusters can enhance the information content of electron cryomicroscopy experiments. This chapter provides a practical overview of well-established techniques for forming biomolecule/gold cluster conjugates. Three bioconjugation chemistries are covered: Linker-mediated bioconjugation, direct gold–biomolecule bonding, and coordination-mediated bonding of nickel(II) nitrilotriacetic acid (NTA)-derivatized gold clusters to polyhistidine (...

  4. Porous solid ion exchange wafer for immobilizing biomolecules

    Science.gov (United States)

    Arora, Michelle B.; Hestekin, Jamie A.; Lin, YuPo J.; St. Martin, Edward J.; Snyder, Seth W.

    2007-12-11

    A porous solid ion exchange wafer having a combination of a biomolecule capture-resin and an ion-exchange resin forming a charged capture resin within said wafer. Also disclosed is a porous solid ion exchange wafer having a combination of a biomolecule capture-resin and an ion-exchange resin forming a charged capture resin within said wafer containing a biomolecule with a tag. A separate bioreactor is also disclosed incorporating the wafer described above.

  5. Reaction between protein radicals and other biomolecules

    DEFF Research Database (Denmark)

    Østdal, H.; Davies, M.J.; Andersen, Henrik Jørgen

    2002-01-01

    The present study investigates the reactivity of bovine serum albumin (BSA) radicals towards different biomolecules (urate, linoleic acid, and a polypeptide, poly(Glu-Ala-Tyr)). The BSA radical was formed at room temperature through a direct protein-to-protein radical transfer from H(2)O(2....... Subsequent analysis showed a decrease in the concentration of urate upon reaction with the BSA radical, while the BSA radical in the presence of poly(Glu-Ala-Tyr) resulted in increased formation of the characteristic protein oxidation product, dityrosine. Reaction between the BSA radical and a linoleic acid...

  6. Two possible improvements for mass spectrometry analysis of intact biomolecules.

    Science.gov (United States)

    Raznikov, Valeriy V; Zelenov, Vladislav V; Aparina, Elena V; Pikhtelev, Alexander R; Sulimenkov, Ilia V; Raznikova, Marina O

    2017-08-01

    The goals of our study were to investigate abilities of two approaches to eliminate possible errors in electrospray mass spectrometry measurements of biomolecules. Passing of a relatively dense supersonic gas jet through ionization region followed by its hitting the spray of the analyzed solution in low vacuum may be effective to keep an initial biomolecule structure in solution. Provided that retention of charge carriers for some sites in the biomolecule cannot be changed noticeably in electrospray ion source, decomposition and separation of charge-state distributions of electrosprayed ions may give additional information about native structure of biomolecules in solution.

  7. Efficient optimization of electrostatic interactions between biomolecules.

    Energy Technology Data Exchange (ETDEWEB)

    Bardhan, J. P.; Altman, M. D.; White, J. K.; Tidor, B.; Mathematics and Computer Science; MIT

    2007-01-01

    We present a PDE-constrained approach to optimizing the electrostatic interactions between two biomolecules. These interactions play important roles in the determination of binding affinity and specificity, and are therefore of significant interest when designing a ligand molecule to bind tightly to a receptor. Using a popular continuum model and physically reasonable assumptions, the electrostatic component of the binding free energy is a convex, quadratic function of the ligand charge distribution. Traditional optimization methods require exhaustive pre-computation, and the expense has precluded a full exploration of the promise of electrostatic optimization in biomolecule analysis and design. In this paper we describe an approach in which the electrostatic simulations and optimization problem are solved simultaneously; unlike many PDE- constrained optimization frameworks, the proposed method does not incorporate the PDE as a set of equality constraints. This co-optimization approach can be used by itself to solve unconstrained problems or those with linear equality constraints, or in conjunction with primal-dual interior point methods to solve problems with inequality constraints. Model problems demonstrate that the co-optimization method is computationally efficient and can be used to solve realistic problems.

  8. Thermally modulated biomolecule transport through nanoconfined channels.

    Science.gov (United States)

    Liu, Lei; Zhu, Lizhong

    2015-01-01

    In this work, a nanofluidic device containing both a feed cell and a permeation cell linked by nanopore arrays has been fabricated, which is employed to investigate thermally controlled biomolecular transporting properties through confined nanochannels. The ionic currents modulated by the translocations of goat antibody to human immunoglobulin G (IgG) or bovine serum albumin (BSA) are recorded and analyzed. The results suggest that the modulation effect decreases with the electrolyte concentration increasing, while the effects generated by IgG translocation are more significant than that generated by BSA translocation. More importantly, there is a maximum decreasing value in each modulated current curve with biomolecule concentration increasing for thermally induced intermolecular collision. Furthermore, the turning point for the maximum shifts to lower biomolecule concentrations with the system temperature rising (from 4°C to 45°C), and it is mainly determined by the temperature in the feed cell if the temperature difference exists in the two separated cells. These findings are expected to be valuable for the future design of novel sensing device based on nanopore and/or nanopore arrays.

  9. Electrically Excited Plasmonic Nanoruler for Biomolecule Detection.

    Science.gov (United States)

    Dathe, André; Ziegler, Mario; Hübner, Uwe; Fritzsche, Wolfgang; Stranik, Ondrej

    2016-09-14

    Plasmon-based sensors are excellent tools for a label-free detection of small biomolecules. An interesting group of such sensors are plasmonic nanorulers that rely on the plasmon hybridization upon modification of their morphology to sense nanoscale distances. Sensor geometries based on the interaction of plasmons in a flat metallic layer together with metal nanoparticles inherit unique advantages but need a special optical excitation configuration that is not easy to miniaturize. Herein, we introduce the concept of nanoruler excitation by direct, electrically induced generation of surface plasmons based on the quantum shot noise of tunneling currents. An electron tunneling junction consisting of a metal-dielectric-semiconductor heterostructure is directly incorporated into the nanoruler basic geometry. With the application of voltage on this modified nanoruler, the plasmon modes are directly excited without any additional optical component as a light source. We demonstrate via several experiments that this electrically driven nanoruler possesses similar properties as an optically exited one and confirm its sensing capabilities by the detection of the binding of small biomolecules such as antibodies. This new sensing principle could open the way to a new platform of highly miniaturized, integrated plasmonic sensors compatible with monolithic integrated circuits.

  10. SPM for functional identification of individual biomolecules

    Science.gov (United States)

    Ros, Robert; Schwesinger, Falk; Padeste, Celestino; Plueckthun, Andreas; Anselmetti, Dario; Guentherodt, Hans-Joachim; Tiefenauer, Louis

    1999-06-01

    The identification of specific binding molecules is of increasing interest in the context of drug development based on combinatorial libraries. Scanning Probe Microscopy (SPM) is the method of choice to image and probe individual biomolecules on a surface. Functional identification of biomolecules is a first step towards screening on a single molecule level. As a model system we use recombinant single- chain Fv fragment (scFv) antibody molecules directed against the antigen fluorescein. The scFv's are covalently immobilized on a flat gold surface via the C-terminal cysteine, resulting in a high accessibility of the binding site. The antigen is immobilized covalently via a long hydrophilic spacer to the silicon nitride SPM-tip. This arrangement allows a direct measurement of binding forces. Thus, closely related antibody molecules differing in only one amino acid at their binding site could be distinguished. A novel SPM-software has been developed which combines imaging, force spectroscopic modes, and online analysis. This is a major prerequisite for future screening methods.

  11. Synthesizing biomolecule-based Boolean logic gates.

    Science.gov (United States)

    Miyamoto, Takafumi; Razavi, Shiva; DeRose, Robert; Inoue, Takanari

    2013-02-15

    One fascinating recent avenue of study in the field of synthetic biology is the creation of biomolecule-based computers. The main components of a computing device consist of an arithmetic logic unit, the control unit, memory, and the input and output devices. Boolean logic gates are at the core of the operational machinery of these parts, and hence to make biocomputers a reality, biomolecular logic gates become a necessity. Indeed, with the advent of more sophisticated biological tools, both nucleic acid- and protein-based logic systems have been generated. These devices function in the context of either test tubes or living cells and yield highly specific outputs given a set of inputs. In this review, we discuss various types of biomolecular logic gates that have been synthesized, with particular emphasis on recent developments that promise increased complexity of logic gate circuitry, improved computational speed, and potential clinical applications.

  12. Synthesizing Biomolecule-based Boolean Logic Gates

    Science.gov (United States)

    Miyamoto, Takafumi; Razavi, Shiva; DeRose, Robert; Inoue, Takanari

    2012-01-01

    One fascinating recent avenue of study in the field of synthetic biology is the creation of biomolecule-based computers. The main components of a computing device consist of an arithmetic logic unit, the control unit, memory, and the input and output devices. Boolean logic gates are at the core of the operational machinery of these parts, hence to make biocomputers a reality, biomolecular logic gates become a necessity. Indeed, with the advent of more sophisticated biological tools, both nucleic acid- and protein-based logic systems have been generated. These devices function in the context of either test tubes or living cells and yield highly specific outputs given a set of inputs. In this review, we discuss various types of biomolecular logic gates that have been synthesized, with particular emphasis on recent developments that promise increased complexity of logic gate circuitry, improved computational speed, and potential clinical applications. PMID:23526588

  13. Production of teaching materials of nuclear medicine for use in career of Imagenologia Diagnostica y Terapeutica of the Escuela de Tecnologias de Salud of the Universidad de Costa Rica

    International Nuclear Information System (INIS)

    Aguilar Blanco, Luis Alberto; Bertarioni Alfaro, Carol; Elizondo Vargas, David; Gutierrez Villareal, Raul E.; Quesada Silva, Fernando

    2008-01-01

    One of the main obstacles in the career of Imagenologia Diagnostica y Terapeutica of the Escuela de Tecnologias de Salud of the Universidad de Costa Rica has been access to bibliographic material of reference in Spanish. The topics most relevant of nuclear medicine of interest to imaging specialist and other disciplines as: medicine, physics, pharmacy and nursing, have been identified for the purpose of having a bibliographic body; experts have reviewed the selection in each subject. Topics of interest were identified and grouped into five specific teaching areas: 1. Radiation protection, 2. Quality Control of Nuclear Medicine Instruments, 3. Radiopharmacy, 4. Planar Nuclear Medicine, 5. Nuclear Medicine SPECT and PET. (author) [es

  14. Ionic strength independence of charge distributions in solvation of biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, J. J. [Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); James Franck Institute, University of Chicago, Chicago, Illinois 60637 (United States); Sosnick, T. R. [Department of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637 (United States); Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States); Freed, K. F. [Department of Chemistry, University of Chicago, Chicago, Illinois 60637 (United States); James Franck Institute, University of Chicago, Chicago, Illinois 60637 (United States); Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States)

    2014-12-14

    Electrostatic forces enormously impact the structure, interactions, and function of biomolecules. We perform all-atom molecular dynamics simulations for 5 proteins and 5 RNAs to determine the dependence on ionic strength of the ion and water charge distributions surrounding the biomolecules, as well as the contributions of ions to the electrostatic free energy of interaction between the biomolecule and the surrounding salt solution (for a total of 40 different biomolecule/solvent combinations). Although water provides the dominant contribution to the charge density distribution and to the electrostatic potential even in 1M NaCl solutions, the contributions of water molecules and of ions to the total electrostatic interaction free energy with the solvated biomolecule are comparable. The electrostatic biomolecule/solvent interaction energies and the total charge distribution exhibit a remarkable insensitivity to salt concentrations over a huge range of salt concentrations (20 mM to 1M NaCl). The electrostatic potentials near the biomolecule's surface obtained from the MD simulations differ markedly, as expected, from the potentials predicted by continuum dielectric models, even though the total electrostatic interaction free energies are within 11% of each other.

  15. Ionic strength independence of charge distributions in solvation of biomolecules

    International Nuclear Information System (INIS)

    Virtanen, J. J.; Sosnick, T. R.; Freed, K. F.

    2014-01-01

    Electrostatic forces enormously impact the structure, interactions, and function of biomolecules. We perform all-atom molecular dynamics simulations for 5 proteins and 5 RNAs to determine the dependence on ionic strength of the ion and water charge distributions surrounding the biomolecules, as well as the contributions of ions to the electrostatic free energy of interaction between the biomolecule and the surrounding salt solution (for a total of 40 different biomolecule/solvent combinations). Although water provides the dominant contribution to the charge density distribution and to the electrostatic potential even in 1M NaCl solutions, the contributions of water molecules and of ions to the total electrostatic interaction free energy with the solvated biomolecule are comparable. The electrostatic biomolecule/solvent interaction energies and the total charge distribution exhibit a remarkable insensitivity to salt concentrations over a huge range of salt concentrations (20 mM to 1M NaCl). The electrostatic potentials near the biomolecule's surface obtained from the MD simulations differ markedly, as expected, from the potentials predicted by continuum dielectric models, even though the total electrostatic interaction free energies are within 11% of each other

  16. Interactions of heavy ions with biomolecules: a dynamical microscopic approach

    International Nuclear Information System (INIS)

    Zhang Fengshou; Beijing Radiation Center, Beijing; National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou

    2006-01-01

    The status of studying biology system therapy with X-rays, γ-rays, neutron, proton, and heavy ions is reviewed. The depth dose profile, called Bragg profile, makes heavy ion an ideal tool for radiotherapy. The physical process of therapy with heavy ions is analyzed and a 3-step interaction processes of heavy ions with biomolecules is proposed, that is, nuclear fragmentation in nuclear interaction, electron excitation in Coulomb interaction, and the biomolecules relaxation in surroundings, finally leads to a new structure of biomolecule. Since this physical process is the base of the following chemical process and biological process, a dynamical microscopic approach is strongly demanded to be built. (authors)

  17. Noncovalent Labeling of Biomolecules with Red and Near- Infrared Dyes

    Directory of Open Access Journals (Sweden)

    Lucjan Strekowski

    2004-02-01

    Full Text Available Biopolymers such as proteins and nucleic acids can be labeled with a fluorescent marker to allow for their detection. Covalent labeling is achieved by the reaction of an appropriately functionalized dye marker with a reactive group on a biomolecule. The recent trend, however, is the use of noncovalent labeling that results from strong hydrophobic and/or ionic interactions between the marker and biomolecule of interest. The main advantage of noncovalent labeling is that it affects the functional activity of the biomolecule to a lesser extent. The applications of luminescent cyanine and squarylium dyes are reviewed.

  18. Computational simulation of biomolecules transport with multi-physics near microchannel surface for development of biomolecules-detection devices.

    Science.gov (United States)

    Suzuki, Yuma; Shimizu, Tetsuhide; Yang, Ming

    2017-01-01

    The quantitative evaluation of the biomolecules transport with multi-physics in nano/micro scale is demanded in order to optimize the design of microfluidics device for the biomolecules detection with high detection sensitivity and rapid diagnosis. This paper aimed to investigate the effectivity of the computational simulation using the numerical model of the biomolecules transport with multi-physics near a microchannel surface on the development of biomolecules-detection devices. The biomolecules transport with fluid drag force, electric double layer (EDL) force, and van der Waals force was modeled by Newtonian Equation of motion. The model validity was verified in the influence of ion strength and flow velocity on biomolecules distribution near the surface compared with experimental results of previous studies. The influence of acting forces on its distribution near the surface was investigated by the simulation. The trend of its distribution to ion strength and flow velocity was agreement with the experimental result by the combination of all acting forces. Furthermore, EDL force dominantly influenced its distribution near its surface compared with fluid drag force except for the case of high velocity and low ion strength. The knowledges from the simulation might be useful for the design of biomolecules-detection devices and the simulation can be expected to be applied on its development as the design tool for high detection sensitivity and rapid diagnosis in the future.

  19. Microfluidic Radiometal Labeling Systems for Biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, D E; Kenis, P J. A.

    2011-12-29

    In a typical labeling procedure with radiometals, such as Cu-64 and Ga-68; a very large (~ 100-fold) excess of the non-radioactive reactant (precursor) is used to promote rapid and efficient incorporation of the radioisotope into the PET imaging agent. In order to achieve high specific activities, careful control of reaction conditions and extensive chromatographic purifications are required in order to separate the labeled compounds from the cold precursors. Here we propose a microfluidic approach to overcome these problems, and achieve high specific activities in a more convenient, semi-automated fashion and faster time frame. Microfluidic reactors, consisting of a network of micron-sized channels (typical dimensions in the range 10 - 300¼m), filters, separation columns, electrodes and reaction loops/chambers etched onto a solid substrate, are now emerging as an extremely useful technology for the intensification and miniaturization of chemical processes. The ability to manipulate, process and analyze reagent concentrations and reaction interfaces in both space and time within the channel network of a microreactor provides the fine level of reaction control that is desirable in PET radiochemistry practice. These factors can bring radiometal labeling, specifically the preparation of radio-labeled biomolecules such as antibodies, much closer to their theoretical maximum specific activities.

  20. Cell and biomolecule delivery for regenerative medicine

    Science.gov (United States)

    Smith, Ian O; Ma, Peter X

    2010-01-01

    Regenerative medicine is an exciting field that aims to create regenerative alternatives to harvest tissues for transplantation. In this approach, the delivery of cells and biological molecules plays a central role. The scaffold (synthetic temporary extracellular matrix) delivers cells to the regenerative site and provides three-dimensional environments for the cells. To fulfil these functions, we design biodegradable polymer scaffolds with structural features on multiple size scales. To enhance positive cell–material interactions, we design nano-sized structural features in the scaffolds to mimic the natural extracellular matrix. We also integrate micro-sized pore networks to facilitate mass transport and neo tissue regeneration. We also design novel polymer devices and self-assembled nanospheres for biomolecule delivery to recapitulate key events in developmental and wound healing processes. Herein, we present recent work in biomedical polymer synthesis, novel processing techniques, surface engineering and biologic delivery. Examples of enhanced cellular/tissue function and regenerative outcomes of these approaches are discussed to demonstrate the excitement of the biomimetic scaffold design and biologic delivery in regenerative medicine. PMID:27877317

  1. Role of Carbamylated Biomolecules in Human Diseases.

    Science.gov (United States)

    Badar, Asim; Arif, Zarina; Alam, Khursheed

    2018-04-01

    Carbamylation (or carbamoylation) is a non-enzymatic modification of biomolecules mediated by cyanate, a dissociation product of urea. Proteins are more sensitive to carbamylation. Two major sites of carbamylation reaction are: N α -amino moiety of a protein N-terminus and the N ɛ -amino moiety of proteins' lysine residues. In kidney diseases, urea accumulates and the burden of carbamylation increases. This may lead to alteration in the structure and function of many important proteins relevant in maintenance of homeostasis. Carbamylated proteins namely, carbamylated-haemoglobin and carbamylated-low density lipoprotein (LDL) have been implicated in hypoxia and atherosclerosis, respectively. Furthermore, carbamylation of insulin, oxytocin, and erythropoietin have caused changes in the action of these hormones vis-à-vis the metabolic pathways they control. In this short review, authors have compiled the data on role of carbamylated proteins, enzymes, hormones, LDL, and so on, in human diseases. © 2018 IUBMB Life, 70(4):267-275, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

  2. Cellular content of biomolecules in sub-seafloor microbial communities

    DEFF Research Database (Denmark)

    Braun, Stefan; Morono, Yuki; Becker, Kevin W.

    2016-01-01

    the lifetime of their microbial sources. Here we provide for the first time measurements of the cellular content of biomolecules in sedimentary microbial cells. We separated intact cells from sediment matrices in samples from surficial, deeply buried, organic-rich, and organic-lean marine sediments by density...... content. We find that the cellular content of biomolecules in the marine subsurface is up to four times lower than previous estimates. Our approach will facilitate and improve the use of biomolecules as proxies for microbial abundance in environmental samples and ultimately provide better global estimates......Microbial biomolecules, typically from the cell envelope, can provide crucial information about distribution, activity, and adaptations of sub-seafloor microbial communities. However, when cells die these molecules can be preserved in the sediment on timescales that are likely longer than...

  3. Fullerene-biomolecule conjugates and their biomedicinal applications.

    Science.gov (United States)

    Yang, Xinlin; Ebrahimi, Ali; Li, Jie; Cui, Quanjun

    2014-01-01

    Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene-biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene-biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene-biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.

  4. Diffusion phenomena of cells and biomolecules in microfluidic devices.

    Science.gov (United States)

    Yildiz-Ozturk, Ece; Yesil-Celiktas, Ozlem

    2015-09-01

    Biomicrofluidics is an emerging field at the cross roads of microfluidics and life sciences which requires intensive research efforts in terms of introducing appropriate designs, production techniques, and analysis. The ultimate goal is to deliver innovative and cost-effective microfluidic devices to biotech, biomedical, and pharmaceutical industries. Therefore, creating an in-depth understanding of the transport phenomena of cells and biomolecules becomes vital and concurrently poses significant challenges. The present article outlines the recent advancements in diffusion phenomena of cells and biomolecules by highlighting transport principles from an engineering perspective, cell responses in microfluidic devices with emphases on diffusion- and flow-based microfluidic gradient platforms, macroscopic and microscopic approaches for investigating the diffusion phenomena of biomolecules, microfluidic platforms for the delivery of these molecules, as well as the state of the art in biological applications of mammalian cell responses and diffusion of biomolecules.

  5. Cell-selective metabolic labeling of biomolecules with bioorthogonal functionalities.

    Science.gov (United States)

    Xie, Ran; Hong, Senlian; Chen, Xing

    2013-10-01

    Metabolic labeling of biomolecules with bioorthogonal functionalities enables visualization, enrichment, and analysis of the biomolecules of interest in their physiological environments. This versatile strategy has found utility in probing various classes of biomolecules in a broad range of biological processes. On the other hand, metabolic labeling is nonselective with respect to cell type, which imposes limitations for studies performed in complex biological systems. Herein, we review the recent methodological developments aiming to endow metabolic labeling strategies with cell-type selectivity. The cell-selective metabolic labeling strategies have emerged from protein and glycan labeling. We envision that these strategies can be readily extended to labeling of other classes of biomolecules. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Effect of curcumin against oxidation of biomolecules by hydroxyl radicals.

    Science.gov (United States)

    Borra, Sai Krishna; Mahendra, Jaideep; Gurumurthy, Prema; Jayamathi; Iqbal, Shabeer S; Mahendra, Little

    2014-10-01

    Among various reactive oxygen species, hydroxyl radicals have the strongest chemical activity, which can damage a wide range of essential biomolecules such as lipids, proteins, and DNA. The objective of this study was to investigate the beneficial effects of curcumin on prevention of oxidative damage of biomolecules by hydroxyl radicals generated in in vitro by a Fenton like reaction. We have incubated the serum, plasma and whole blood with H2O2/Cu2+/ Ascorbic acid system for 4 hours at 37 0C and observed the oxidation of biomolecules like albumin, lipids, proteins and DNA. Curcumin at the concentrations of 50,100 and 200 μmoles, prevented the formation of ischemia modified albumin, MDA, protein carbonyls, oxidized DNA and increased the total antioxidant levels and GSH significantly. These observations suggest the hydroxyl radical scavenging potentials of curcumin and protective actions to prevent the oxidation of biomolecules by hydroxyl radicals.

  7. On the mobility of biomolecules : a fluorescence microscopy approach

    NARCIS (Netherlands)

    Bogaart, Geert van den

    2008-01-01

    This thesis describes the development and application of a number of fluorescence spectroscopy related techniques (FCS, FRAP, DCFBA) to measure diffusion of biomolecules in cells, in membranes and through membrane pores.

  8. Synthesis of selenium nanorods with assistance of biomolecule

    Indian Academy of Sciences (India)

    that the optical band gap energy is increased with aging time up to 1 day, whereas it decreases in 4 days aging ... researchers have used biomolecule substances such as oleic ..... ther investigation is needed to determine the changes of Se.

  9. Liposome Disruption Assay to Examine Lytic Properties of Biomolecules.

    Science.gov (United States)

    Jimah, John R; Schlesinger, Paul H; Tolia, Niraj H

    2017-08-05

    Proteins may have three dimensional structural or amino acid features that suggest a role in targeting and disrupting lipids within cell membranes. It is often necessary to experimentally investigate if these proteins and biomolecules are able to disrupt membranes in order to conclusively characterize the function of these biomolecules. Here, we describe an in vitro assay to evaluate the membrane lytic properties of proteins and biomolecules. Large unilamellar vesicles (liposomes) containing carboxyfluorescein at fluorescence-quenching concentrations are treated with the biomolecule of interest. A resulting increase in fluorescence due to leakage of the dye from liposomes and subsequent dilution in the buffer demonstrates that the biomolecule is sufficient for disrupting liposomes and membranes. Additionally, since liposome disruption may occur via pore-formation or via general solubilization of lipids similar to detergents, we provide a method to distinguish between these two mechanisms. Pore-formation can be identified and evaluated by examining the blockade of carboxyfluorescein release with dextran molecules that fit the pore. The methods described here were used to determine that the malaria vaccine candidate CelTOS and proapoptotic Bax disrupt liposomes by pore formation (Saito et al. , 2000; Jimah et al. , 2016). Since membrane lipid binding by a biomolecule precedes membrane disruption, we recommend the companion protocol: Jimah et al. , 2017.

  10. An integrated platform for biomolecule interaction analysis

    Science.gov (United States)

    Jan, Chia-Ming; Tsai, Pei-I.; Chou, Shin-Ting; Lee, Shu-Sheng; Lee, Chih-Kung

    2013-02-01

    We developed a new metrology platform which can detect real-time changes in both a phase-interrogation mode and intensity mode of a SPR (surface plasmon resonance). We integrated a SPR and ellipsometer to a biosensor chip platform to create a new biomolecular interaction measurement mechanism. We adopted a conductive ITO (indium-tinoxide) film to the bio-sensor platform chip to expand the dynamic range and improve measurement accuracy. The thickness of the conductive film and the suitable voltage constants were found to enhance performance. A circularly polarized ellipsometry configuration was incorporated into the newly developed platform to measure the label-free interactions of recombinant human C-reactive protein (CRP) with immobilized biomolecule target monoclonal human CRP antibody at various concentrations. CRP was chosen as it is a cardiovascular risk biomarker and is an acute phase reactant as well as a specific prognostic indicator for inflammation. We found that the sensitivity of a phaseinterrogation SPR is predominantly dependent on the optimization of the sample incidence angle. The effect of the ITO layer effective index under DC and AC effects as well as an optimal modulation were experimentally performed and discussed. Our experimental results showed that the modulated dynamic range for phase detection was 10E-2 RIU based on a current effect and 10E-4 RIU based on a potential effect of which a 0.55 (°/RIU) measurement was found by angular-interrogation. The performance of our newly developed metrology platform was characterized to have a higher sensitivity and less dynamic range when compared to a traditional full-field measurement system.

  11. Multi-state modeling of biomolecules.

    Directory of Open Access Journals (Sweden)

    Melanie I Stefan

    2014-09-01

    Full Text Available Multi-state modeling of biomolecules refers to a series of techniques used to represent and compute the behavior of biological molecules or complexes that can adopt a large number of possible functional states. Biological signaling systems often rely on complexes of biological macromolecules that can undergo several functionally significant modifications that are mutually compatible. Thus, they can exist in a very large number of functionally different states. Modeling such multi-state systems poses two problems: the problem of how to describe and specify a multi-state system (the "specification problem" and the problem of how to use a computer to simulate the progress of the system over time (the "computation problem". To address the specification problem, modelers have in recent years moved away from explicit specification of all possible states and towards rule-based formalisms that allow for implicit model specification, including the κ-calculus, BioNetGen, the Allosteric Network Compiler, and others. To tackle the computation problem, they have turned to particle-based methods that have in many cases proved more computationally efficient than population-based methods based on ordinary differential equations, partial differential equations, or the Gillespie stochastic simulation algorithm. Given current computing technology, particle-based methods are sometimes the only possible option. Particle-based simulators fall into two further categories: nonspatial simulators, such as StochSim, DYNSTOC, RuleMonkey, and the Network-Free Stochastic Simulator (NFSim, and spatial simulators, including Meredys, SRSim, and MCell. Modelers can thus choose from a variety of tools, the best choice depending on the particular problem. Development of faster and more powerful methods is ongoing, promising the ability to simulate ever more complex signaling processes in the future.

  12. Miniature Laboratory for Detecting Sparse Biomolecules

    Science.gov (United States)

    Lin, Ying; Yu, Nan

    2005-01-01

    A miniature laboratory system has been proposed for use in the field to detect sparsely distributed biomolecules. By emphasizing concentration and sorting of specimens prior to detection, the underlying system concept would make it possible to attain high detection sensitivities without the need to develop ever more sensitive biosensors. The original purpose of the proposal is to aid the search for signs of life on a remote planet by enabling the detection of specimens as sparse as a few molecules or microbes in a large amount of soil, dust, rocks, water/ice, or other raw sample material. Some version of the system could prove useful on Earth for remote sensing of biological contamination, including agents of biological warfare. Processing in this system would begin with dissolution of the raw sample material in a sample-separation vessel. The solution in the vessel would contain floating microscopic magnetic beads coated with substances that could engage in chemical reactions with various target functional groups that are parts of target molecules. The chemical reactions would cause the targeted molecules to be captured on the surfaces of the beads. By use of a controlled magnetic field, the beads would be concentrated in a specified location in the vessel. Once the beads were thus concentrated, the rest of the solution would be discarded. This procedure would obviate the filtration steps and thereby also eliminate the filter-clogging difficulties of typical prior sample-concentration schemes. For ferrous dust/soil samples, the dissolution would be done first in a separate vessel before the solution is transferred to the microbead-containing vessel.

  13. Active immobilization of biomolecules on a hybrid three-dimensional nanoelectrode by dielectrophoresis for single-biomolecule study

    International Nuclear Information System (INIS)

    Yamamoto, Takatoki; Fujii, Teruo

    2007-01-01

    We propose and experimentally demonstrate a method of active immobilization for biomolecules on a three-dimensional nanometre-scale electrode (3D nanoelectrode) using dielectrophoresis to immobilize the biomolecules at predetermined locations for single-biomolecule study. We have developed a novel two-step fabrication process for obtaining a 3D nanoelectrode having a sharp top, which is necessary for immobilizing a single biomolecule at a single point. The first step is to fabricate the backbone structure, which is rigid and defines the shape of the 3D nanoelectrode. It was fabricated with diamond-like carbon (DLC) obtained using focused ion beam assisted chemical vapour deposition followed by post-plasma etching, which reshapes the DLC structure. The second step coats the DLC structure with a thin layer of aluminium, which supplies electrical conductivity to the DLC structure. By applying a high frequency (of the order of megahertz) and high intensity (greater than or equal to a few megavolts per metre) electric field using the 3D nanoelectrodes, the generated dielectrophoresis attracted and then immobilized target biomolecules onto the tops of 3D nanoelectrodes, as a demonstration of active immobilization of biomolecules

  14. Temperature-responsive chromatography for the separation of biomolecules.

    Science.gov (United States)

    Kanazawa, Hideko; Okano, Teruo

    2011-12-09

    Temperature-responsive chromatography for the separation of biomolecules utilizing poly(N-isopropylacrylamide) (PNIPAAm) and its copolymer-modified stationary phase is performed with an aqueous mobile phase without using organic solvent. The surface properties and function of the stationary phase are controlled by external temperature changes without changing the mobile-phase composition. This analytical system is based on nonspecific adsorption by the reversible transition of a hydrophilic-hydrophobic PNIPAAm-grafted surface. The driving force for retention is hydrophobic interaction between the solute molecules and the hydrophobized polymer chains on the stationary phase surface. The separation of the biomolecules, such as nucleotides and proteins was achieved by a dual temperature- and pH-responsive chromatography system. The electrostatic and hydrophobic interactions could be modulated simultaneously with the temperature in an aqueous mobile phase, thus the separation system would have potential applications in the separation of biomolecules. Additionally, chromatographic matrices prepared by a surface-initiated atom transfer radical polymerization (ATRP) exhibit a strong interaction with analytes, because the polymerization procedure forms a densely packed polymer, called a polymer brush, on the surfaces. The copolymer brush grafted surfaces prepared by ATRP was an effective tool for separating basic biomolecules by modulating the electrostatic and hydrophobic interactions. Applications of thermally responsive columns for the separations of biomolecules are reviewed here. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Improved radioiodination of biomolecules using exhaustive Chloramine-T oxidation

    International Nuclear Information System (INIS)

    Robles, Ana M.; Balter, Henia S.; Oliver, Patricia; Welling, Mick M.; Pauwels, Ernest K.J.

    2001-01-01

    To improve standardization in analytical reagents we investigated Chloramine-T radioiodination ( 125 I) of several biomolecules based on the use of a single amount of the oxidizing agent Chloramine-T as the limiting reagent being exhausted during the course of the reaction. Whenever the labeling yield resulted in less than one atom 125 I/molecule, a second amount of the oxidizing agent was added. Thereafter, the integrity of the various biomolecules was assessed using radioimmunoassays, radioreceptor binding assays, or radioimmunometric assays. Purification yields were done by gel permeation (56%±19%, n=230) or by precipitation with trichloroacetic acid (59%±19%, n=230). Specific activity (117±61 MBq/nmol) and the degree of iodine incorporation (1.4±0.8 atoms of 125 I/molecule) were achieved after 300 sec of incubation. A second addition of Chloramine-T resulted in an increased labeling yield of all biomolecules tested by a mean factor of 1.8±0.9. After the second addition of Chloramine-T, we observed for some biomolecules a significant (p<0.001) decreased effect in biological performance. In conclusion, the use of Chloramine-T as a limiting reagent resulted in molecules with appropriate immunological and biological performance. In general, tracers were minimally damaged and assessment of the shelf life as well as storing conditions showed the usefulness of the standardization of biomolecule labeling

  16. Tools and procedures for visualization of proteins and other biomolecules.

    Science.gov (United States)

    Pan, Lurong; Aller, Stephen G

    2015-04-01

    Protein, peptides, and nucleic acids are biomolecules that drive biological processes in living organisms. An enormous amount of structural data for a large number of these biomolecules has been described with atomic precision in the form of structural "snapshots" that are freely available in public repositories. These snapshots can help explain how the biomolecules function, the nature of interactions between multi-molecular complexes, and even how small-molecule drugs can modulate the biomolecules for clinical benefits. Furthermore, these structural snapshots serve as inputs for sophisticated computer simulations to turn the biomolecules into moving, "breathing" molecular machines for understanding their dynamic properties in real-time computer simulations. In order for the researcher to take advantage of such a wealth of structural data, it is necessary to gain competency in the use of computer molecular visualization tools for exploring the structures and visualizing three-dimensional spatial representations. Here, we present protocols for using two common visualization tools--the Web-based Jmol and the stand-alone PyMOL package--as well as a few examples of other popular tools. Copyright © 2015 John Wiley & Sons, Inc.

  17. Printing technologies for biomolecule and cell-based applications.

    Science.gov (United States)

    Ihalainen, Petri; Määttänen, Anni; Sandler, Niklas

    2015-10-30

    Biomolecules, such as enzymes, proteins and other biomacromolecules (polynucleotides, polypeptides, polysaccharides and DNA) that are immobilized on solid surfaces are relevant to many areas of science and technology. These functionalized surfaces have applications in biosensors, chromatography, diagnostic immunoassays, cell culturing, DNA microarrays and other analytical techniques. Printing technologies offer opportunities in this context. The main interests in printing biomolecules are in immobilizing them on surfaces for sensors and catalysts or for controlled delivery of protein-based drugs. Recently, there have been significant developments in the use of inkjet printing for dispensing of proteins, biomacromolecules and cells. This review discusses the use of roll-to-roll and inkjet printing technologies in manufacturing of biomolecule and cell-based applications. Copyright © 2015. Published by Elsevier B.V.

  18. Constraint methods that accelerate free-energy simulations of biomolecules.

    Science.gov (United States)

    Perez, Alberto; MacCallum, Justin L; Coutsias, Evangelos A; Dill, Ken A

    2015-12-28

    Atomistic molecular dynamics simulations of biomolecules are critical for generating narratives about biological mechanisms. The power of atomistic simulations is that these are physics-based methods that satisfy Boltzmann's law, so they can be used to compute populations, dynamics, and mechanisms. But physical simulations are computationally intensive and do not scale well to the sizes of many important biomolecules. One way to speed up physical simulations is by coarse-graining the potential function. Another way is to harness structural knowledge, often by imposing spring-like restraints. But harnessing external knowledge in physical simulations is problematic because knowledge, data, or hunches have errors, noise, and combinatoric uncertainties. Here, we review recent principled methods for imposing restraints to speed up physics-based molecular simulations that promise to scale to larger biomolecules and motions.

  19. Magnetic behavior of iron oxide nanoparticle-biomolecule assembly

    International Nuclear Information System (INIS)

    Kim, Taegyun; Reis, Lynn; Rajan, Krishna; Shima, Mutsuhiro

    2005-01-01

    Iron oxide nanoparticles of 8-20 nm in size were investigated as an assembly with biomolecules synthesized in an aqueous solution. The magnetic behavior of the biomolecule-nanoparticles assembly depends sensitively on the morphology and hence the distribution of the nanoparticles, where the dipole coupling between the nanoparticles governs the overall magnetic behavior. In assemblies of iron oxide nanoparticles with trypsin, we observe a formation of unusual self-alignment of nanoparticles within trypsin molecules. In such an assembly structure, the magnetic particles tend to exhibit a lower spin-glass transition temperature than as-synthesized bare iron oxide nanoparticles probably due to reduced interparticle couplings within the molecular matrix. The observed self-alignment of nanoparticles in biomolecules may be a useful approach for directed nanoparticles assembly

  20. Understanding small biomolecule-biomaterial interactions: a review of fundamental theoretical and experimental approaches for biomolecule interactions with inorganic surfaces.

    Science.gov (United States)

    Costa, Dominique; Garrain, Pierre-Alain; Baaden, Marc

    2013-04-01

    Interactions between biomolecules and inorganic surfaces play an important role in natural environments and in industry, including a wide variety of conditions: marine environment, ship hulls (fouling), water treatment, heat exchange, membrane separation, soils, mineral particles at the earth's surface, hospitals (hygiene), art and buildings (degradation and biocorrosion), paper industry (fouling) and more. To better control the first steps leading to adsorption of a biomolecule on an inorganic surface, it is mandatory to understand the adsorption mechanisms of biomolecules of several sizes at the atomic scale, that is, the nature of the chemical interaction between the biomolecule and the surface and the resulting biomolecule conformations once adsorbed at the surface. This remains a challenging and unsolved problem. Here, we review the state of art in experimental and theoretical approaches. We focus on metallic biomaterial surfaces such as TiO(2) and stainless steel, mentioning some remarkable results on hydroxyapatite. Experimental techniques include atomic force microscopy, surface plasmon resonance, quartz crystal microbalance, X-ray photoelectron spectroscopy, fluorescence microscopy, polarization modulation infrared reflection absorption spectroscopy, sum frequency generation and time of flight secondary ion mass spectroscopy. Theoretical models range from detailed quantum mechanical representations to classical forcefield-based approaches. Copyright © 2012 Wiley Periodicals, Inc.

  1. O ATLETISMO NA PERSPECTIVA EDUCACIONAL

    Directory of Open Access Journals (Sweden)

    Leandro Araujo de Sousa

    2017-06-01

    Full Text Available A educação física escolar deve proporcionar experiências aos alunos para o seu desenvolvimento integral. As aulas muitas vezes são reduzidas ao ensino de esportes tradicionais, o que limita o repertório de movimentos dos alunos. Dessa forma o presente estudo de revisão objetiva problematizar o atletismo no ambiente escolar e propor possibilidades pedagógicas para seu ensino. Nesta pesquisa propomos tratar o ensino do atletismo na escola, caracterizando-o pelo seu repertório de movimentos que são naturais ao ser humano, como correr, saltar e lançar, o que possibilita maior praticidade em sua aplicação pedagógica, porém essas possibilidades não são consideradas no ambiente educacional. Diante dos dados encontrados, sugerimos que esse esporte seja abordado de forma multidimensional no ambiente escolar contextualizando-o à visão de algumas correntes teóricas. Nessa perspectiva do esporte educacional, o atletismo pode, assim como deve ser trabalhado nas aulas de educação física como instrumento pedagógico de ensino e auxiliar na formação do aluno de forma global.

  2. Carioca: a perspectiva da enfermagem

    Directory of Open Access Journals (Sweden)

    Ana Elisa Fernandes Lima

    2015-01-01

    Full Text Available Objetivo: describir las acciones recomendadas por el Programa Cigüeña Carioca para atención a las parturientes y determinar si la aplicación de este Programa tuvo repercusiones en esta asistencia desde la perspectiva del equipo de enfermería. Métodos: estudio descriptivo, con abordaje cualitativo, realizado en una maternidad pública. Entrevistas semiestructuradas se realizaron con cuatro enfermeras obstétricas y siete auxiliares de enfermería que trabajan en el centro de obstetricia de la maternidad. Se utilizó la técnica de análisis de contenido temático. Resultados: las categorías del estudio fueron: Calificación de la atención obstétrica hospitalaria y Repercusiones asistenciales y profesionales del Programa Cigüeña Carioca. Conclusión: el personal de enfermería consideró que la aplicación del Programa ha traído mejoras en la atención al parto, favoreciendo la garantía de los derechos de la mujer y el cumplimiento de la enfermería obstétrica en la red de salud municipal.

  3. A relationship between solvent viscosity and biomolecule picosecond thermal fluctuations

    International Nuclear Information System (INIS)

    Cornicchi, E.; De Francesco, A.; Marconi, M.; Onori, G.; Paciaroni, A.

    2008-01-01

    Through elastic neutron scattering measurements, we investigated the picosecond dynamics of DNA in the hydrated powder state or embedded in glycerol glassy matrix from 20 K to 300 K. We calculated the relaxational contribution of the mean square displacements (MSD) of DNA hydrogen atoms. We found the existence of a linear relationship between the inverse of the biomolecule relaxational MSD and the logarithm of the bulk viscosity of the surrounding environment. From the comparison with the case of lysozyme in the same environments, for which the validity of the relationship was already verified, possible differences and analogies concerning the biomolecule-to-solvent dynamical coupling can be stressed

  4. Necrotizing fasciitis of soft tissues. Diagnostic imaging findings and literature review; Le fascite necrotizzante dei tessuti molli. Ruolo della diagnostica per immagini e revisione della letteratura

    Energy Technology Data Exchange (ETDEWEB)

    Parenti, G.C.; Marri, C. [Ospedale Civile S. Maria delle Croci, Ravenna (Italy). Servizio di Radiodiagnostica; Calandra, G. [Ospedale Civile S. Maria delle Croci, Ravenna (Italy). Unita' operativa di Pronto Soccorso; Morisi, C. [Ospedale Civile S. Maria delle Croci, Ravenna (Italy). Servizio di Anatomia Patologica; Zabberoni, W. [Ospedale Civile S. Maria delle Croci, Ravenna (Italy). Div. di Malattie Infettive, Gruppo di rilevamento dati sulle INPS-ASL

    2000-05-01

    maggio 1991 a febbraio 1998 sono giunti alla nostra osservazione 130 casi di infezioni necrotizzanti progressive dei tessuti molli; in 32 casi l'eta' era compresa fra 22 e 84 anni; la diagnosi istologica retrospettiva e' risultata quella della fascite necrotizzante. Le sedi interessate dal processo sono state: arti (26/32), regioni cervicale (5/32) e perineale (1/32). Diciannove pazienti (19/32) sono stati sottoposti d'urgenza a esame radiografico eseguito anche per lo studio dei tessuti molli. L'esame ecografico e' stato eseguito d'urgenza in tutti i 32 pazienti. La valutazione dei pazienti con sospetto di infezioni necrosanti progressive e' affidata di solito a un gruppo di operatori esperti in diagnostica ecografica dei tessuti molli perischeletrici. L'esame TC e' stato eseguito in 9 casi (9/32); a ognuno di questi pazienti e' stato somministrato mdc iodato per via endovenosa. Con gli esami ecografico ed eco color Doppler, nel sospetto di fascite necrotizzante, e' possibile offrire indicazioni utili e affidabili per il corretto e rapido orientamento diagnostico; in particolare tale metodica e' in grado di rilevare precocemente alterazioni al tessuto adiposo sottocutaneo (28/32), alla fascia (18/32) e al tessuto molecolare (15/32). E' stata riscontrata buona correlazione tra alterazione tissutale rilevata con l'esame ecografico e reperto istologico; l'ecografia non ha evidenziato alterazioni al tessuto adiposo sottocutaneo (3/32) e al tessuto molecolare (8/32) in 11 casi pur evidenti all'esame istologico. La TC con mdc puo' essere utile per la migliore definizione dell'estensione della malattia e per la dimostrazione di eventuali complicanze, soprattutto in sedi difficili da raggiungere con l'ecografia. Le probabilita' di guarigione per i pazienti affetti da fascite necrotizzante sono direttamente proporzionali alla precocita' della diagnosi e all

  5. One-step mild biorefinery of functional biomolecules from microalgae extracts

    NARCIS (Netherlands)

    Desai, R.K.; Monteillet, H.J.M.; Li, Xiaohua; Schuur, Boelo; Wijffels, R.H.; Eppink, M.H.M.

    2018-01-01

    Fractionation of complex matrices such as biomass into diverse functional biomolecules without disrupting the biomolecule functionalities is a real challenge. Known separation processes are designed for the recovery
    of single products such as hydrophilic proteins or hydrophobic pigments,

  6. One-step mild biorefinery of functional biomolecules from microalgae extracts

    NARCIS (Netherlands)

    Desai, Rupali K.; Monteillet, Hélène; Li, Xiaohua; Schuur, Boelo; Kleijn, J. Mieke; Leermakers, Frans A.M.; Wijffels, Rene H.; Eppink, Michel H.M.

    2018-01-01

    Fractionation of complex matrices such as biomass into diverse functional biomolecules without disrupting the biomolecule functionalities is a real challenge. Known separation processes are designed for the recovery of single products such as hydrophilic proteins or hydrophobic pigments, discarding

  7. Fundamentals of Biomolecule Analysis by Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Weinecke, Andrea; Ryzhov, Victor

    2005-01-01

    Electrospray ionization (ESI) is a soft ionization technique that allows transfer of fragile biomolecules directly from solution into the gas phase. An instrumental analysis laboratory experiment is designed that would introduce the students to the ESI technique, major parameters of the ion trap mass spectrometers and some caveats in…

  8. Artificial tongue based on metal-biomolecule coordination polymer nanoparticles.

    Science.gov (United States)

    Pu, Fang; Ran, Xiang; Ren, Jinsong; Qu, Xiaogang

    2016-02-25

    We construct an array-based recognition system (the so-called artificial tongue) through the self-assembly of nucleotides, dyes and lanthanide ions. Metal ions are selected as model analytes for verifying its discrimination ability. The work provides valuable insights into the application and development of biomolecule-based materials.

  9. Photochemical Microscale Electrophoresis Allows Fast Quantification of Biomolecule Binding.

    Science.gov (United States)

    Möller, Friederike M; Kieß, Michael; Braun, Dieter

    2016-04-27

    Intricate spatiotemporal patterns emerge when chemical reactions couple to physical transport. We induce electrophoretic transport by a confined photochemical reaction and use it to infer the binding strength of a second, biomolecular binding reaction under physiological conditions. To this end, we use the photoactive compound 2-nitrobenzaldehyde, which releases a proton upon 375 nm irradiation. The charged photoproducts locally perturb electroneutrality due to differential diffusion, giving rise to an electric potential Φ in the 100 μV range on the micrometer scale. Electrophoresis of biomolecules in this field is counterbalanced by back-diffusion within seconds. The biomolecule concentration is measured by fluorescence and settles proportionally to exp(-μ/D Φ). Typically, binding alters either the diffusion coefficient D or the electrophoretic mobility μ. Hence, the local biomolecule fluorescence directly reflects the binding state. A fit to the law of mass action reveals the dissociation constant of the binding reaction. We apply this approach to quantify the binding of the aptamer TBA15 to its protein target human-α-thrombin and to probe the hybridization of DNA. Dissociation constants in the nanomolar regime were determined and match both results in literature and in control experiments using microscale thermophoresis. As our approach is all-optical, isothermal and requires only nanoliter volumes at nanomolar concentrations, it will allow for the fast screening of biomolecule binding in low volume multiwell formats.

  10. Silica biomineralization via the self-assembly of helical biomolecules.

    Science.gov (United States)

    Liu, Ben; Cao, Yuanyuan; Huang, Zhehao; Duan, Yingying; Che, Shunai

    2015-01-21

    The biomimetic synthesis of relevant silica materials using biological macromolecules as templates via silica biomineralization processes attract rapidly rising attention toward natural and artificial materials. Biomimetic synthesis studies are useful for improving the understanding of the formation mechanism of the hierarchical structures found in living organisms (such as diatoms and sponges) and for promoting significant developments in the biotechnology, nanotechnology and materials chemistry fields. Chirality is a ubiquitous phenomenon in nature and is an inherent feature of biomolecular components in organisms. Helical biomolecules, one of the most important types of chiral macromolecules, can self-assemble into multiple liquid-crystal structures and be used as biotemplates for silica biomineralization, which renders them particularly useful for fabricating complex silica materials under ambient conditions. Over the past two decades, many new silica materials with hierarchical structures and complex morphologies have been created using helical biomolecules. In this review, the developments in this field are described and the recent progress in silica biomineralization templating using several classes of helical biomolecules, including DNA, polypeptides, cellulose and rod-like viruses is summarized. Particular focus is placed on the formation mechanism of biomolecule-silica materials (BSMs) with hierarchical structures. Finally, current research challenges and future developments are discussed in the conclusion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Optical aptasensors for quantitative detection of small biomolecules: a review.

    Science.gov (United States)

    Feng, Chunjing; Dai, Shuang; Wang, Lei

    2014-09-15

    Aptasensors are aptamer-based biosensors with excellent recognition capability towards a wide range of targets. Specially, there have been ever-growing interests in the development of aptasensors for the detection of small molecules. This phenomenon is contributed to two reasons. On one hand, small biomolecules play an important role in living organisms with many kinds of biological function, such as antiarrhythmic effect and vasodilator activity of adenosine. On the other hand, the concentration of small molecules can be an indicator for disease diagnosis, for example, the concentration of ATP is closely associated with cell injury and cell viability. As a potential analysis tool in the construction of aptasensors, optical analysis has attracted much more interest of researchers due to its high sensitivity, quick response and simple operation. Besides, it promises the promotion of aptasensors in performance toward a new level. Review the development of optical aptasensors for small biomolecules will give readers an overall understanding of its progress and provide some theoretical guidelines for its future development. Hence, we give a mini-review on the advance of optical aptasensors for small biomolecules. This review focuses on recent achievements in the design of various optical aptasensors for small biomolecules, containing fluorescence aptasensors, colorimetric aptasensors, chemiluminescence aptasensors and other optical aptasensors. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Recovery of biomolecules from food wastes--a review.

    Science.gov (United States)

    Baiano, Antonietta

    2014-09-17

    Food wastes are produced by a variety of sources, ranging from agricultural operations to household consumption. About 38% occurs during food processing. At present, the European Union legislation encourages the exploitation of co-products. This valorisation can be achieved through the extraction of high-value components such as proteins, polysaccharides, fibres, flavour compounds, and phytochemicals, which can be re-used as nutritionally and pharmacologically functional ingredients. Extraction can proceed according to solid-liquid extraction, Soxhlet extraction, pressurized fluid extraction, supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pulsed electric field extraction, and enzyme-assisted extraction. Nevertheless, these techniques cannot be used indiscriminately and their choice depends on the type of biomolecules and matrix, the scale processing (laboratory or industrial), the ratio between production costs and economic values of the compounds to be extracted. The vegetable wastes include trimmings, peelings, stems, seeds, shells, bran, residues remaining after extraction of oil, starch, sugar, and juice. The animal-derived wastes include wastes from bred animals, wastes from seafood, wastes from dairy processing. The recovered biomolecules and by-products can be used to produce functional foods or as adjuvants in food processing or in medicinal and pharmaceutical preparations. This work is an overview of the type and amounts of food wastes; food waste legislation; conventional and novel techniques suitable for extracting biomolecules; food, medicinal and pharmaceutical uses of the recovered biomolecules and by-products, and future trends in these areas.

  13. Fullerene–biomolecule conjugates and their biomedicinal applications

    Directory of Open Access Journals (Sweden)

    Yang X

    2013-12-01

    Full Text Available Xinlin Yang,1 Ali Ebrahimi,1 Jie Li,1,2 Quanjun Cui11Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Virginia School of Medicine, Charlottesville, VA, USA; 2School of Materials Science, Beijing Institute of Technology, Beijing, People's Republic of ChinaAbstract: Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene–biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene–biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene–biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.Keywords: fullerene, amino acid, peptide, oligonucleotide, sugar, ester

  14. Recovery of Biomolecules from Food Wastes — A Review

    Directory of Open Access Journals (Sweden)

    Antonietta Baiano

    2014-09-01

    Full Text Available Food wastes are produced by a variety of sources, ranging from agricultural operations to household consumption. About 38% occurs during food processing. At present, the European Union legislation encourages the exploitation of co-products. This valorisation can be achieved through the extraction of high-value components such as proteins, polysaccharides, fibres, flavour compounds, and phytochemicals, which can be re-used as nutritionally and pharmacologically functional ingredients. Extraction can proceed according to solid-liquid extraction, Soxhlet extraction, pressurized fluid extraction, supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pulsed electric field extraction, and enzyme-assisted extraction. Nevertheless, these techniques cannot be used indiscriminately and their choice depends on the type of biomolecules and matrix, the scale processing (laboratory or industrial, the ratio between production costs and economic values of the compounds to be extracted. The vegetable wastes include trimmings, peelings, stems, seeds, shells, bran, residues remaining after extraction of oil, starch, sugar, and juice. The animal-derived wastes include wastes from bred animals, wastes from seafood, wastes from dairy processing. The recovered biomolecules and by-products can be used to produce functional foods or as adjuvants in food processing or in medicinal and pharmaceutical preparations. This work is an overview of the type and amounts of food wastes; food waste legislation; conventional and novel techniques suitable for extracting biomolecules; food, medicinal and pharmaceutical uses of the recovered biomolecules and by-products, and future trends in these areas.

  15. Fabrication of Biomolecule Microarrays for Cell Immobilization Using Automated Microcontact Printing.

    Science.gov (United States)

    Foncy, Julie; Estève, Aurore; Degache, Amélie; Colin, Camille; Cau, Jean Christophe; Malaquin, Laurent; Vieu, Christophe; Trévisiol, Emmanuelle

    2018-01-01

    Biomolecule microarrays are generally produced by conventional microarrayer, i.e., by contact or inkjet printing. Microcontact printing represents an alternative way of deposition of biomolecules on solid supports but even if various biomolecules have been successfully microcontact printed, the production of biomolecule microarrays in routine by microcontact printing remains a challenging task and needs an effective, fast, robust, and low-cost automation process. Here, we describe the production of biomolecule microarrays composed of extracellular matrix protein for the fabrication of cell microarrays by using an automated microcontact printing device. Large scale cell microarrays can be reproducibly obtained by this method.

  16. Dielectric Spectroscopy of Biomolecules up to 110 GHz

    Science.gov (United States)

    Laux, Eva-Maria; Ermilova, Elena; Pannwitz, Daniel; Gibbons, Jessica; Hölzel, Ralph; Bier, Frank F.

    2018-03-01

    Radio-frequency fields in the GHz range are increasingly applied in biotechnology and medicine. In order to fully exploit both their potential and their risks detailed information about the dielectric properties of biological material is needed. For this purpose a measuring system is presented that allows the acquisition of complex dielectric spectra over 4 frequency decade up to 110 GHz. Routines for calibration and for data evaluation according to physicochemical interaction models have been developed. The frequency dependent permittivity and dielectric loss of some proteins and nucleic acids, the main classes of biomolecules, and of their sub-units have been determined. Dielectric spectra are presented for the amino acid alanine, the proteins lysozyme and haemoglobin, the nucleotides AMP and ATP, and for the plasmid pET-21, which has been produced by bacterial culture. Characterisation of a variety of biomolecules is envisaged, as is the application to studies on protein structure and function.

  17. Surface Treatment of Polymeric Materials Controlling the Adhesion of Biomolecules

    Directory of Open Access Journals (Sweden)

    Willy Zorzi

    2012-08-01

    Full Text Available This review describes different strategies of surface elaboration for a better control of biomolecule adsorption. After a brief description of the fundamental interactions between surfaces and biomolecules, various routes of surface elaboration are presented dealing with the attachment of functional groups mostly thanks to plasma techniques, with the grafting to and from methods, and with the adsorption of surfactants. The grafting of stimuli-responsive polymers is also pointed out. Then, the discussion is focused on the protein adsorption phenomena showing how their interactions with solid surfaces are complex. The adsorption mechanism is proved to be dependent on the solid surface physicochemical properties as well as on the surface and conformation properties of the proteins. Different behaviors are also reported for complex multiple protein solutions.

  18. Surface Treatment of Polymeric Materials Controlling the Adhesion of Biomolecules

    Science.gov (United States)

    Poncin-Epaillard, Fabienne; Vrlinic, Tjasa; Debarnot, Dominique; Mozetic, Miran; Coudreuse, Arnaud; Legeay, Gilbert; El Moualij, Benaïssa; Zorzi, Willy

    2012-01-01

    This review describes different strategies of surface elaboration for a better control of biomolecule adsorption. After a brief description of the fundamental interactions between surfaces and biomolecules, various routes of surface elaboration are presented dealing with the attachment of functional groups mostly thanks to plasma techniques, with the grafting to and from methods, and with the adsorption of surfactants. The grafting of stimuli-responsive polymers is also pointed out. Then, the discussion is focused on the protein adsorption phenomena showing how their interactions with solid surfaces are complex. The adsorption mechanism is proved to be dependent on the solid surface physicochemical properties as well as on the surface and conformation properties of the proteins. Different behaviors are also reported for complex multiple protein solutions. PMID:24955631

  19. Electronic sputtering of biomolecules and its application in mass spectrometry

    International Nuclear Information System (INIS)

    Haakansson, P.; Sundqvist, B.U.R.

    1989-01-01

    In 1974 Macfarlane discovered that fast heavy ions from a 252-Cf source can desorb and ionize molecules from a solid surface. The mass of the molecules was determined by time-of-flight technique. It has been shown that the desorption mechanism is associated with the electron part of the stopping power of the primary ion and the name 'electron sputtering' has been adopted for the phenomenon to distinguish it from the well-known sputtering process with ions of KeV energy. A review of electronic sputtering of biomolecules will be given as well as recent measurements on Langmuir-Blodgett films. One important application of electronic sputtering is in the field of mass spectrometry. With this technique large and nonvolatile molecules can be studied. Particularly adsorption of biomolecules to a nitrocellulose backing has proven to be very useful. Examples will be given of mass spectra from peptides with a molecular weight above 20,000 u. (author)

  20. Hierarchically Ordered Nanopatterns for Spatial Control of Biomolecules

    Science.gov (United States)

    2015-01-01

    The development and study of a benchtop, high-throughput, and inexpensive fabrication strategy to obtain hierarchical patterns of biomolecules with sub-50 nm resolution is presented. A diblock copolymer of polystyrene-b-poly(ethylene oxide), PS-b-PEO, is synthesized with biotin capping the PEO block and 4-bromostyrene copolymerized within the polystyrene block at 5 wt %. These two handles allow thin films of the block copolymer to be postfunctionalized with biotinylated biomolecules of interest and to obtain micropatterns of nanoscale-ordered films via photolithography. The design of this single polymer further allows access to two distinct superficial nanopatterns (lines and dots), where the PEO cylinders are oriented parallel or perpendicular to the substrate. Moreover, we present a strategy to obtain hierarchical mixed morphologies: a thin-film coating of cylinders both parallel and perpendicular to the substrate can be obtained by tuning the solvent annealing and irradiation conditions. PMID:25363506

  1. Universal scaling for biomolecule desorption induced by swift heavy ions

    International Nuclear Information System (INIS)

    Szenes, G.

    2005-01-01

    A thermal activation mechanism is proposed for the desorption of biomolecules. Good agreement is found with the experiments in a broad range of the electronic stopping power. The activation energies of desorption U are 0.33, 1.57 and 5.35 eV for positive, negative and neutral leucine molecules, respectively, and 2.05 eV for positive ergosterol molecules. The desorption of valine clusters is analyzed. The magnitude of the specific heat shows that the internal degrees of freedom are not excited up to the moment of desorption. The effect of irradiation temperature and of ion velocity on the desorption yield is discussed on the basis of the author's model. The scaling function derived in the model for the desorption of biomolecules is applied also to the sputtering of SiO 2 and U = 0.42 eV is obtained

  2. From clusters to biomolecules: electric dipole, structure and dynamics

    International Nuclear Information System (INIS)

    Broyer, M; Antoine, R; Compagnon, I; Rayane, D; Dugourd, P

    2007-01-01

    In this paper, it is demonstrated that the electric dipole of complex molecules or clusters can be measured by beam deviation in an inhomogeneous electric field. This measurement, associated to appropriate theoretical calculations and simulations, allows us to determine the geometry of these systems and their dynamical behaviour as a function of temperature. Selected examples for mixed clusters (metal-fullerene, metal-benzene, salt) and biomolecules (hydrogen bound amino acids and glycine based polypeptides) are discussed

  3. Thermo-responsive hydrogels for intravitreal injection and biomolecule release

    Science.gov (United States)

    Drapala, Pawel

    In this dissertation, we develop an injectable polymer system to enable localized and prolonged release of therapeutic biomolecules for improved treatment of Age-Related Macular Degeneration (AMD). Thermo-responsive hydrogels derived from N-isopropylacrylamide (NIPAAm) and cross-linked with poly(ethylene glycol) (PEG) poly(L-Lactic acid) (PLLA) copolymer were synthesized via free-radical polymerization. These materials were investigated for (a) phase change behavior, (b) in-vitro degradation, (c) capacity for controlled drug delivery, and (d) biocompatibility. The volume-phase transition temperature (VPTT) of the PNIPAAm- co-PEG-b-PLLA hydrogels was adjusted using hydrophilic and hydrophobic moieties so that it is ca. 33°C. These hydrogels did not initially show evidence of degradation at 37°C due to physical cross-links of collapsed PNIPAAm. Only after addition of glutathione chain transfer agents (CTA)s to the precursor did the collapsed hydrogels become fully soluble at 37°C. CTAs significantly affected the release kinetics of biomolecules; addition of 1.0 mg/mL glutathione to 3 mM cross-linker accelerated hydrogel degradation, resulting in 100% release in less than 2 days. This work also explored the effect of PEGylation in order to tether biomolecules to the polymer matrix. It was demonstrated that non-site-specific PEGylation can postpone the burst release of solutes (up to 10 days in hydrogels with 0.5 mg/mL glutathione). Cell viability assays showed that at least two 20-minute buffer extraction steps were needed to remove cytotoxic elements from the hydrogels. Clinically-used therapeutic biomolecules LucentisRTM and AvastinRTM were demonstrated to be both stable and bioactive after release form PNIPAAm-co-PEG-b-PLLA hydrogels. The thermo-responsive hydrogels presented here offer a promising platform for the localized delivery of proteins such as recombinant antibodies.

  4. Optical Sensors for Biomolecules Using Nanoporous Sol-Gel Materials

    Science.gov (United States)

    Fang, Jonathan; Zhou, Jing C.; Lan, Esther H.; Dunn, Bruce; Gillman, Patricia L.; Smith, Scott M.

    2004-01-01

    An important consideration for space missions to Mars is the ability to detect biosignatures. Solid-state sensing elements for optical detection of biological entities are possible using sol-gel based biologically active materials. We have used these materials as optical sensing elements in a variety of bioassays, including immunoassays and enzyme assays. By immobilizing an appropriate biomolecule in the sol-gel sensing element, we have successfully detected analytes such as amino acids and hormones. In the case of the amino acid glutamate, the enzyme glutamate dehydrogenase was the immobilized molecule, whereas in the case of the hormone cortisol, an anti-cortisol antibody was immobilized in the sensing element. In this previous work with immobilized enzymes and antibodies, excellent sensitivity and specificity were demonstrated in a variety of formats including bulk materials, thin films and fibers. We believe that the sol-gel approach is an attractive platform for bioastronautics sensing applications because of the ability to detect a wide range of entities such as amino acids, fatty acids, hopanes, porphyrins, etc. The sol-gel approach produces an optically transparent 3D silica matrix that forms around the biomolecule of interest, thus stabilizing its structure and functionality while allowing for optical detection. This encapsulation process protects the biomolecule and leads to a more "rugged" sensor. The nanoporous structure of the sol-gel matrix allows diffusion of small target molecules but keeps larger, biomolecules immobilized in the pores. We are currently developing these biologically active sol-gel materials into small portable devices for on-orbit cortisol detection

  5. Transition-Metal-Free Biomolecule-Based Flexible Asymmetric Supercapacitors.

    Science.gov (United States)

    Yang, Yun; Wang, Hua; Hao, Rui; Guo, Lin

    2016-09-01

    A transition-metal-free asymmetric supercapacitor (ASC) is successfully fabricated based on an earth-abundant biomass derived redox-active biomolecule, named lawsone. Such an ASC exhibits comparable or even higher energy densities than most of the recently reported transition-metal-based ASCs, and this green ASC generation from renewable resources is promising for addressing current issues of electronic hazard processing, high cost, and unsustainability. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Renewable-Biomolecule-Based Full Lithium-Ion Batteries.

    Science.gov (United States)

    Hu, Pengfei; Wang, Hua; Yang, Yun; Yang, Jie; Lin, Jie; Guo, Lin

    2016-05-01

    A renewable-biomolecule-based full lithium-ion battery is successfully fabricated for the first time. Naturally derivable emodin and humic acid based electrodes are used as cathode and anode, respectively. The as-assembled batteries exhibit superb specific capacity and substantial operating voltage capable of powering a wearable electronic watch, suggesting the great potential for practical applications with the significant merits of sustainability and biocompatibility. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. In situ hybridization of superparamagnetic iron-biomolecule nanoparticles.

    Science.gov (United States)

    Moghimi, Nafiseh; Donkor, Apraku David; Mohapatra, Mamata; Thomas, Joseph Palathinkal; Su, Zhengding; Tang, Xiaowu Shirley; Leung, Kam Tong

    2014-07-23

    The increase in interest in the integration of organic-inorganic nanostructures in recent years has promoted the use of hybrid nanoparticles (HNPs) in medicine, energy conversion, and other applications. Conventional hybridization methods are, however, often long, complicated, and multistepped, and they involve biomolecules and discrete nanostructures as separate entities, all of which hinder the practical use of the resulting HNPs. Here, we present a novel, in situ approach to synthesizing size-specific HNPs using Fe-biomolecule complexes as the building blocks. We choose an anticancer peptide (p53p, MW 1.8 kDa) and an enzyme (GOx, MW 160 kDa) as model molecules to demonstrate the versatility of the method toward different types of molecules over a large size range. We show that electrostatic interaction for complex formation of metal hydroxide ion with the partially charged side of biomolecule in the solution is the key to hybridization of metal-biomolecule materials. Electrochemical deposition is then used to produce hybrid NPs from these complexes. These HNPs with controllable sizes ranging from 30 nm to 3.5 μm are found to exhibit superparamagnetic behavior, which is a big challenge for particles in this size regime. As an example of greatly improved properties and functionality of the new hybrid material, in vitro toxicity assessment of Fe-GOx HNPs shows no adverse effect, and the Fe-p53p HNPs are found to selectively bind to cancer cells. The superparamagnetic nature of these HNPs (superparamagnetic even above the size regime of 15-20 nm!), their biocompatibility, and the direct integration approach are fundamentally important to biomineralization and general synthesis strategy for bioinspired functional materials.

  8. Development of radioactively labelled cancer seeking biomolecules for targeted radiotherapy

    International Nuclear Information System (INIS)

    Balter, H.; Verdera, S.

    2000-01-01

    The main objective of this project is the labelling and quality control of biomolecules with radionuclides beta emitters with high purity and stability. Techniques and methodology for labelling with 188 Re, 153 Sm, and 125 I as well as quality controls were done according the recommendations of the first research coordination meeting of this CRP. Also some useful chelators reported in the literature were synthesized in our laboratory

  9. Low energy electron-driven damage in biomolecules

    International Nuclear Information System (INIS)

    Sanche, L.

    2005-01-01

    The damage induced by the impact of low energy electrons (LEE) on biomolecules is reviewed from a radiobiological perspective with emphasis on transient anion formation. The major type of experiments, which measure the yields of fragments produced as a function of incident electron energy (0.1 - 30 eV), are briefly described. Theoretical advances are also summarized. Several examples are presented from the results of recent experiments performed in the gas-phase and on bio-molecular films bombarded with LEE under ultra-high vacuum conditions. These include the results obtained from DNA films and those obtained from the fragmentation of elementary components of the DNA molecule (i.e., the bases, sugar and phosphate group analogs and oligonucleotides) and of proteins (e.g. amino acids). By comparing the results from different experiments and theory, it is possible to determine fundamental mechanisms that are involved in the dissociation of the biomolecules and the production of single- and double-strand breaks in DNA. Below 15 eV, electron resonances (i.e., the formation of transient anions) play a dominant role in the fragmentation of all biomolecules investigated. These transient anions fragment molecules by decaying into dissociative electronically excited states or by dissociating into a stable anion and a neutral radical. These fragments can initiate further reactions within large biomolecules or with nearby molecules and thus cause more complex chemical damage. Dissociation of a transient anion within DNA may occur by direct electron attachment at the location of dissociation or by electron transfer from another subunit. Damage to DNA is dependent on the molecular environment, topology, type of counter ion, sequence context and chemical modifications. (author)

  10. Models and algorithms for biomolecules and molecular networks

    CERN Document Server

    DasGupta, Bhaskar

    2016-01-01

    By providing expositions to modeling principles, theories, computational solutions, and open problems, this reference presents a full scope on relevant biological phenomena, modeling frameworks, technical challenges, and algorithms. * Up-to-date developments of structures of biomolecules, systems biology, advanced models, and algorithms * Sampling techniques for estimating evolutionary rates and generating molecular structures * Accurate computation of probability landscape of stochastic networks, solving discrete chemical master equations * End-of-chapter exercises

  11. Nuclear resonance vibrational spectroscopic studies of iron-containing biomolecules

    International Nuclear Information System (INIS)

    Ohta, Takehiro; Seto, Makoto

    2014-01-01

    In this review, we report recent nuclear resonance vibrational spectroscopic (NRVS) studies of iron-containing biomolecules and their model complexes. The NRVS is synchrotron-based element-specific vibrational spectroscopic methods. Unlike Raman and infrared spectroscopy, the NRVS can investigate all iron motions without selection rules, which provide atomic level insights into the structure/reactivity correlation of biologically relevant iron complexes. (author)

  12. Immobilization of biomolecules to plasma polymerized pentafluorophenyl methacrylate.

    Science.gov (United States)

    Duque, Luis; Menges, Bernhard; Borros, Salvador; Förch, Renate

    2010-10-11

    Thin films of plasma polymerized pentafluorophenyl methacrylate (pp-PFM) offer highly reactive ester groups throughout the structure of the film that allow for subsequent reactions with different aminated reagents and biological molecules. The present paper follows on from previous work on the plasma deposition of pentafluorophenyl methacrylate (PFM) for optimum functional group retention (Francesch, L.; Borros, S.; Knoll, W.; Foerch, R. Langmuir 2007, 23, 3927) and reactivity in aqueous solution (Duque, L.; Queralto, N.; Francesch, L.; Bumbu, G. G.; Borros, S.; Berger, R.; Förch, R. Plasma Process. Polym. 2010, accepted for publication) to investigate the binding of a biologically active peptide known to induce cellular adhesion (IKVAV) and of biochemically active proteins such as BSA and fibrinogen. Analyses of the films and of the immobilization of the biomolecules were carried out using infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The attachment of the biomolecules on pulsed plasma polymerized pentafluorophenyl methacrylate was monitored using surface plasmon resonance spectroscopy (SPR). SPR analysis confirmed the presence of immobilized biomolecules on the plasma polymer and was used to determine the mass coverage of the peptide and proteins adsorbed onto the films. The combined analysis of the surfaces suggests the covalent binding of the peptide and proteins to the surface of the pp-PFM.

  13. Titanium Dioxide Nanoparticle-Biomolecule Interactions Influence Oral Absorption.

    Science.gov (United States)

    Jo, Mi-Rae; Yu, Jin; Kim, Hyoung-Jun; Song, Jae Ho; Kim, Kyoung-Min; Oh, Jae-Min; Choi, Soo-Jin

    2016-11-29

    Titanium dioxide (TiO₂) nanoparticles (NPs) have been widely applied in various industrial fields, such as electronics, packaging, food, and cosmetics. Accordingly, concerns about the potential toxicity of TiO₂ NPs have increased. In order to comprehend their in vivo behavior and potential toxicity, we must evaluate the interactions between TiO₂ NPs and biomolecules, which can alter the physicochemical properties and the fate of NPs under physiological conditions. In the present study, in vivo solubility, oral absorption, tissue distribution, and excretion kinetics of food grade TiO₂ (f-TiO₂) NPs were evaluated following a single-dose oral administration to rats and were compared to those of general grade TiO₂ (g-TiO₂) NPs. The effect of the interactions between the TiO₂ NPs and biomolecules, such as glucose and albumin, on oral absorption was also investigated, with the aim of determining the surface interactions between them. The intestinal transport pathway was also assessed using 3-dimensional culture systems. The results demonstrate that slightly higher oral absorption of f-TiO₂ NPs compared to g-TiO₂ NPs could be related to their intestinal transport mechanism by microfold (M) cells, however, most of the NPs were eliminated through the feces. Moreover, the biokinetics of f-TiO₂ NPs was highly dependent on their interaction with biomolecules, and the dispersibility was affected by modified surface chemistry.

  14. Repulsive effects of hydrophobic diamond thin films on biomolecule detection

    Energy Technology Data Exchange (ETDEWEB)

    Ruslinda, A. Rahim, E-mail: ruslindarahim@gmail.com [Institute of Nano Electronic Engineering, Universiti Malaysia Perlis, Jln Kgr-Alor Setar, Seriab, 01000 Kangar, Perlis (Malaysia); Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan); Ishiyama, Y. [Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan); Penmatsa, V. [Department of Mechanical and Materials Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174 (United States); Ibori, S.; Kawarada, H. [Department of Nano Science and Nano Engineering, School of Advance Science and Engineering, Ohkubo 3-4-1, Shinjuku, 169-8555 Tokyo (Japan)

    2015-02-15

    Highlights: • We report the effect of fluorine plasma treatment on diamond thin film to resist the nonspecific adsorption of biomolecules. • The diamond thin film were highly hydrophobic with a surface energy value of ∼25 mN/m. • The repulsive effect shows excellent binding efficiency for both DNA and HIV-1 Tat protein. - Abstract: The repulsive effect of hydrophobic diamond thin film on biomolecule detection, such as single-nucleotide polymorphisms and human immunodeficiency virus type 1 trans-activator of transcription peptide protein detection, was investigated using a mixture of a fluorine-, amine-, and hydrogen-terminated diamond surfaces. These chemical modifications lead to the formation of a surface that effectively resists the nonspecific adsorption of proteins and other biomolecules. The effect of fluorine plasma treatment on elemental composition was also investigated via X-ray photoelectron spectroscopy (XPS). XPS results revealed a fluorocarbon layer on the diamond thin films. The contact angle measurement results indicated that the fluorine-treated diamond thin films were highly hydrophobic with a surface energy value of ∼25 mN/m.

  15. Repulsive effects of hydrophobic diamond thin films on biomolecule detection

    International Nuclear Information System (INIS)

    Ruslinda, A. Rahim; Ishiyama, Y.; Penmatsa, V.; Ibori, S.; Kawarada, H.

    2015-01-01

    Highlights: • We report the effect of fluorine plasma treatment on diamond thin film to resist the nonspecific adsorption of biomolecules. • The diamond thin film were highly hydrophobic with a surface energy value of ∼25 mN/m. • The repulsive effect shows excellent binding efficiency for both DNA and HIV-1 Tat protein. - Abstract: The repulsive effect of hydrophobic diamond thin film on biomolecule detection, such as single-nucleotide polymorphisms and human immunodeficiency virus type 1 trans-activator of transcription peptide protein detection, was investigated using a mixture of a fluorine-, amine-, and hydrogen-terminated diamond surfaces. These chemical modifications lead to the formation of a surface that effectively resists the nonspecific adsorption of proteins and other biomolecules. The effect of fluorine plasma treatment on elemental composition was also investigated via X-ray photoelectron spectroscopy (XPS). XPS results revealed a fluorocarbon layer on the diamond thin films. The contact angle measurement results indicated that the fluorine-treated diamond thin films were highly hydrophobic with a surface energy value of ∼25 mN/m

  16. Applications of polymers for biomolecule immobilization in electrochemical biosensors

    International Nuclear Information System (INIS)

    Teles, F.R.R.; Fonseca, L.P.

    2008-01-01

    Polymers are becoming inseparable from biomolecule immobilization strategies and biosensor platforms. Their original role as electrical insulators has been progressively substituted by their electrical conductive abilities, which opens a new and broad scope of applications. In addition, recent advances in diagnostic chips and microfluidic systems, together with the requirements of mass-production technologies, have raised the need to replace glass by polymeric materials, which are more suitable for production through simple manufacturing processes. Conducting polymers (CPs), in particular, are especially amenable for electrochemical biosensor development for providing biomolecule immobilization and for rapid electron transfer. It is expected that the combination of known polymer substrates, but also new transducing and biocompatible interfaces, with nanobiotechnological structures, like nanoparticles, carbon nanotubes (CNTs) and nanoengineered 'smart' polymers, may generate composites with new and interesting properties, providing higher sensitivity and stability of the immobilized molecules, thus constituting the basis for new and improved analytical devices for biomedical and other applications. This review covers the state-of-the-art and main novelties about the use of polymers for immobilization of biomolecules in electrochemical biosensor platforms

  17. Effect of water and ionic liquids on biomolecules.

    Science.gov (United States)

    Saha, Debasis; Mukherjee, Arnab

    2018-02-08

    The remarkable progress in the field of ionic liquids (ILs) in the last two decades has involved investigations on different aspects of ILs in various conditions. The nontoxic and biocompatible nature of ILs makes them a suitable substance for the storage and application of biomolecules. In this regard, the aqueous IL solutions have attracted a large number of studies to comprehend the role of water in modulating various properties of biomolecules. Here, we review some of the recent studies on aqueous ILs that concern the role of water in altering the behavior of ILs in general and in case of biomolecules solvated in ILs. The different structural and dynamic effects caused by water have been highlighted. We discuss the different modes of IL interaction that are responsible for stabilization and destabilization of proteins and enzymes followed by examples of water effect on this. The role of water in the case of nucleic acid storage in ILs, an area which has mostly been underrated, also has been emphasized. Our discussions highlight the fact that the effects of water on IL behavior are not general and are highly dependent on the nature of the IL under consideration. Overall, we aim to draw attention to the significance of water dynamics in the aqueous IL solutions, a better understanding of which can help in developing superior storage materials for application purposes.

  18. Functionalization of titanium dioxide nanotubes with biomolecules for biomedical applications.

    Science.gov (United States)

    Oliveira, Weslley F; Arruda, Isabel R S; Silva, Germana M M; Machado, Giovanna; Coelho, Luana C B B; Correia, Maria T S

    2017-12-01

    Titanium (Ti) and its alloys are extensively used in the manufacture of implants because they have biocompatibility. The production of a nanostructured surface can be achieved by means of titanium dioxide nanotubes (TNTs) which can have dimensions equivalent to the nanometric components of human bone, in addition to increasing the efficiency of such implants. The search is ongoing for ways to improve the performance of these TNTs in terms of their functionalization through coating these nanotubular matrices with biomolecules. The biocompatibility of the functionalized TNTs can be improved by promoting rapid osseointegration, by preventing the adhesion of bacteria on such surfaces and/or by promoting a more sustained local release of drugs that are loaded into such TNTs. In addition to the implants, these nanotubular matrices have been used in the manufacture of high-performance biosensors capable of immobilizing principally enzymes on their surfaces, which has possible use in disease diagnosis. The objective of this review is to show the main techniques of immobilization of biomolecules in TNTs, evidencing the most recent applications of bioactive molecules that have been functionalized in the nanotubular matrices for use in implants and biosensors. This surveillance also proposes a new class of biomolecules that can be used to functionalize these nanostructured surfaces, lectins. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Nucleobases, nucleosides, and nucleotides: versatile biomolecules for generating functional nanomaterials.

    Science.gov (United States)

    Pu, Fang; Ren, Jinsong; Qu, Xiaogang

    2018-02-21

    The incorporation of biomolecules into nanomaterials generates functional nanosystems with novel and advanced properties, presenting great potential for applications in various fields. Nucleobases, nucleosides and nucleotides, as building blocks of nucleic acids and biological coenzymes, constitute necessary components of the foundation of life. In recent years, as versatile biomolecules for the construction or regulation of functional nanomaterials, they have stimulated interest in researchers, due to their unique properties such as structural diversity, multiplex binding sites, self-assembly ability, stability, biocompatibility, and chirality. In this review, strategies for the synthesis of nanomaterials and the regulation of their morphologies and functions using nucleobases, nucleosides, and nucleotides as building blocks, templates or modulators are summarized alongside selected applications. The diverse applications range from sensing, bioimaging, and drug delivery to mimicking light-harvesting antenna, the construction of logic gates, and beyond. Furthermore, some perspectives and challenges in this emerging field are proposed. This review is directed toward the broader scientific community interested in biomolecule-based functional nanomaterials.

  20. Surface plasmon resonance sensing: from purified biomolecules to intact cells.

    Science.gov (United States)

    Su, Yu-Wen; Wang, Wei

    2018-04-12

    Surface plasmon resonance (SPR) has become a well-recognized label-free technique for measuring the binding kinetics between biomolecules since the invention of the first SPR-based immunosensor in 1980s. The most popular and traditional format for SPR analysis is to monitor the real-time optical signals when a solution containing ligand molecules is flowing over a sensor substrate functionalized with purified receptor molecules. In recent years, rapid development of several kinds of SPR imaging techniques have allowed for mapping the dynamic distribution of local mass density within single living cells with high spatial and temporal resolutions and reliable sensitivity. Such capability immediately enabled one to investigate the interaction between important biomolecules and intact cells in a label-free, quantitative, and single cell manner, leading to an exciting new trend of cell-based SPR bioanalysis. In this Trend Article, we first describe the principle and technical features of two types of SPR imaging techniques based on prism and objective, respectively. Then we survey the intact cell-based applications in both fundamental cell biology and drug discovery. We conclude the article with comments and perspectives on the future developments. Graphical abstract Recent developments in surface plasmon resonance (SPR) imaging techniques allow for label-free mapping the mass-distribution within single living cells, leading to great expansions in biomolecular interactions studies from homogeneous substrates functionalized with purified biomolecules to heterogeneous substrates containing individual living cells.

  1. Retro y perspectiva del (desempleo sonorense

    Directory of Open Access Journals (Sweden)

    Ernesto Peralta

    2012-01-01

    Full Text Available El artículo revisa y actualiza la evolución, estado actual y perspectiva del (desempleo sonorense. Compara su evolución con previos pronósticos y la proyecta hasta 2030 porque los buscadores de empleo viven actualmente; da un marco para políticas que lo reduzcan. La hipótesis es que si bien no suficiente, sí es nece-sario acelerar y cambiar la estructura del crecimiento económico en favor de sectores intensivos en trabajo. Este trabajo tiene cinco secciones: la primera revisa el (desempleo reciente y lo compara con su perspectiva delineada años atrás; la segunda presenta el marco teórico; en la tercera se proyectan y contrastan oferta y demanda laboral; la cuarta revisa tipos de desempleo y la inversión para reducirlo; la quinta es para conclusiones y recomendaciones.

  2. The Importance of Phytoplankton Biomolecule Availability for Secondary Production

    Directory of Open Access Journals (Sweden)

    Elina T. Peltomaa

    2017-10-01

    Full Text Available The growth and reproduction of animals is affected by their access to resources. In aquatic ecosystems, the availability of essential biomolecules for filter-feeding zooplankton depends greatly on phytoplankton. Here, we analyzed the biochemical composition, i.e., the fatty acid, sterol and amino acid profiles and concentrations as well as protein, carbon, nitrogen, and phosphorus content of 17 phytoplankton monocultures representing the seven most abundant phytoplankton classes in boreal and sub-arctic lakes. To examine how the differences in the biochemical composition between phytoplankton classes affect their nutritional quality for consumers, we assessed the performance of Daphnia, on these diets. Furthermore, we defined the most important biomolecules regulating the somatic growth and reproduction of Daphnia, expecting that higher concentrations of certain biomolecules are needed for reproduction than for growth. Finally, we combined these results with phytoplankton field data from over 900 boreal and sub-arctic lakes in order to estimate whether the somatic growth of Daphnia is sterol-limited when the natural phytoplankton communities are cyanobacteria-dominated. Our analysis shows that Daphnia grows best with phytoplankton rich in sterols, ω-3 fatty acids, protein, and amino acids. Their reproduction follows food sterol and ω-3 concentration as well as C:P-ratio being two times higher in Daphnia feeding on cryptophytes than any other diet. Interestingly, we found that a high dietary ω-6 fatty acid concentration decreases both somatic growth and reproduction of Daphnia. When combined with phytoplankton community composition field data, our results indicate that zooplankton is constantly limited by sterols in lakes dominated by cyanobacteria (≥40% of total phytoplankton biomass, and that the absence of cryptophytes can severely hinder zooplankton production in nature.

  3. Simple approach to study biomolecule adsorption in polymeric microfluidic channels

    International Nuclear Information System (INIS)

    Gubala, Vladimir; Siegrist, Jonathan; Monaghan, Ruairi; O’Reilly, Brian; Gandhiraman, Ram Prasad; Daniels, Stephen; Williams, David E.; Ducrée, Jens

    2013-01-01

    Highlights: ► A simple tool to assess biomolecule adsorption onto the surfaces of microchannels. ► Development for dilution by surface-adsorption based depletion of protein samples. ► It can easily be done using a readily available apparatus like a spin-coater. ► The assessment tool is facile and quantitative. ► Straightforward comparison of different surface chemistries. - Abstract: Herein a simple analytical method is presented for the characterization of biomolecule adsorption on cyclo olefin polymer (COP, trade name: Zeonor ® ) substrates which are widely used in microfluidic lab-on-a-chip devices. These Zeonor ® substrates do not possess native functional groups for specific reactions with biomolecules. Therefore, depending on the application, such substrates must be functionalized by surface chemistry methods to either enhance or suppress biomolecular adsorption. This work demonstrates a microfluidic method for evaluating the adsorption of antibodies and oligonucleotides surfaces. The method uses centrifugal microfluidic flow-through chips and can easily be implemented using common equipment such as a spin coater. The working principle is very simple. The user adds 40 L of the solution containing the sample to the starting side of a microfluidic channel, where it is moved through by centrifugal force. Some molecules are adsorbed in the channel. The sample is then collected at the other end in a small reservoir and the biomolecule concentration is measured. As a pilot application, we characterized the adsorption of goat anti-human IgG and a 20-mer DNA on Zeonor ® , and on three types of functionalized Zeonor: 3-aminopropyltriethoxysilane (APTES) modified surface with mainly positive charge, negatively charged surface with immobilized bovine serum albumin (BSA), and neutral, hydrogel-like film with polyethylene glycol (PEG) characteristics. This simple analytical approach adds to the fundamental understanding of the interaction forces in real

  4. Development of radioactively labelled cancer seeking biomolecules for targeted radiotherapy

    International Nuclear Information System (INIS)

    Varvarigou, A.D.; Archimandritis, S.C.

    2000-01-01

    Within the framework of the above project we are studying the labelling of biomolecules, peptides and antibodies, with radionuclides emitting β - and γ radiation. More specifically, for the time being, we have investigated the labelling of peptides with Re-188 and of antibodies with Sm-153 and Re-188. The radiolabelled derivatives are further evaluated in vivo for possible application in Oncology. For these radiobiological studies we are trying to apply ectopic and orthotopic tumour animal models and to develop, in collaboration with other national and foreign institutes, proper imaging devices for small animal imaging

  5. Structure analysis of biomolecules using synchrotron radiation circular dichroism spectrophotometer

    International Nuclear Information System (INIS)

    Gekko, Kunihiko; Matsuo, Koichi

    2004-01-01

    We constructed the vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer, which is capable of measuring circular dichroism spectra to 140 nm for aqueous solutions at temperature from -30 to 70degC, using a small-scale SR source at Hiroshima Synchrotron Radiation Center (HiSOR). This spectrophotometer was used for structural analyses of amino acids, saccharides, and proteins in water. The obtained results demonstrate that a synchrotron radiation VUVCD spectroscopy provides more detailed and new information on the structures of biomolecules, based on the high energy transitions of chromophores such as hydroxyl, acetal, and peptide groups. (author)

  6. Simple approach to study biomolecule adsorption in polymeric microfluidic channels

    Energy Technology Data Exchange (ETDEWEB)

    Gubala, Vladimir, E-mail: V.Gubala@kent.ac.uk [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); Medway School of Pharmacy, University of Kent, Central Avenue, Anson 120, Chatham Maritime, Kent ME4 4TB (United Kingdom); Siegrist, Jonathan; Monaghan, Ruairi; O' Reilly, Brian; Gandhiraman, Ram Prasad [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); Daniels, Stephen [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); National Centre for Plasma Science and Technology (NCPST), Dublin City University, Dublin 9 (Ireland); Williams, David E. [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland); MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical Sciences, University of Auckland, Auckland 1142 (New Zealand); Ducree, Jens [Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9 (Ireland)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer A simple tool to assess biomolecule adsorption onto the surfaces of microchannels. Black-Right-Pointing-Pointer Development for dilution by surface-adsorption based depletion of protein samples. Black-Right-Pointing-Pointer It can easily be done using a readily available apparatus like a spin-coater. Black-Right-Pointing-Pointer The assessment tool is facile and quantitative. Black-Right-Pointing-Pointer Straightforward comparison of different surface chemistries. - Abstract: Herein a simple analytical method is presented for the characterization of biomolecule adsorption on cyclo olefin polymer (COP, trade name: Zeonor{sup Registered-Sign }) substrates which are widely used in microfluidic lab-on-a-chip devices. These Zeonor{sup Registered-Sign} substrates do not possess native functional groups for specific reactions with biomolecules. Therefore, depending on the application, such substrates must be functionalized by surface chemistry methods to either enhance or suppress biomolecular adsorption. This work demonstrates a microfluidic method for evaluating the adsorption of antibodies and oligonucleotides surfaces. The method uses centrifugal microfluidic flow-through chips and can easily be implemented using common equipment such as a spin coater. The working principle is very simple. The user adds 40 L of the solution containing the sample to the starting side of a microfluidic channel, where it is moved through by centrifugal force. Some molecules are adsorbed in the channel. The sample is then collected at the other end in a small reservoir and the biomolecule concentration is measured. As a pilot application, we characterized the adsorption of goat anti-human IgG and a 20-mer DNA on Zeonor{sup Registered-Sign }, and on three types of functionalized Zeonor: 3-aminopropyltriethoxysilane (APTES) modified surface with mainly positive charge, negatively charged surface with immobilized bovine serum albumin (BSA), and

  7. Linkage of biomolecules to solid phases for immunoassay

    International Nuclear Information System (INIS)

    Chapman, R.S.

    1998-01-01

    Topics covered by this lecture include a brief review of the principal methods of linkage of biomolecules to solid phase matrices. Copies of the key self explanatory slides are presented as figures together with reprints of two publications by the author dealing with a preferred chemistry for the covalent linkage of antibodies to hydroxyl and amino functional groups and the effects of changes in solid phase matrix and antibody coupling chemistry on the performance of a typical excess reagent immunoassay for thyroid stimulating hormone

  8. Biomolecule-Functionalized Smart Polydiacetylene for Biomedical and Environmental Sensing.

    Science.gov (United States)

    Cho, Eunae; Jung, Seunho

    2018-01-04

    Polydiacetylene (PDA) has attracted interest for use as a sensing platform in biomedical, environmental, and chemical engineering applications owing to its capacity for colorimetric and fluorescent transition in response to external stimuli. Many researchers have attempted to develop a tailor-made PDA sensor via conjugation of chemical or biological substances to PDA. Here, we review smart bio-conjugates of PDA with various biomolecules such as carbohydrates, lipids, nucleic acids, and proteins. In addition, materialization and signal amplification strategies to improve handling and sensitivity are described.

  9. Low-energy electron scattering from molecules, biomolecules and surfaces

    CERN Document Server

    Carsky, Petr

    2011-01-01

    Since the turn of the 21st century, the field of electron molecule collisions has undergone a renaissance. The importance of such collisions in applications from radiation chemistry to astrochemistry has flowered, and their role in industrial processes such as plasma technology and lighting are vital to the advancement of next generation devices. Furthermore, the development of the scanning tunneling microscope highlights the role of such collisions in the condensed phase, in surface processing, and in the development of nanotechnology.Low-Energy Electron Scattering from Molecules, Biomolecule

  10. Raman spectroscopy detection of biomolecules in biocrusts from differing environmental conditions

    Science.gov (United States)

    Miralles, I.; Jorge-Villar, S. E.; van Wesemael, B.; Lázaro, R.

    2017-01-01

    Lichens and cyanobacteria colonize inhospitable places covering a wide climate range due to their different survival strategies, such as the synthesis of protective biomolecules. The effect of ecological factors on the synthesis of biomolecules has not been widely analysed. This study aimed to assess the effects of four factors (species, microclimate, seasonality and hydration state) and their interactions on the biomolecule frequency detected by Raman Spectroscopy. We included cyanobacterial biocrusts, and the lichens Diploschistes diacapsis, Squamarina lentigera, and Lepraria isidiata; two contrasted microclimates (typical and marginal), two contrasted seasons (hot and dry vs cool and wet) and two hydration states (dry and wet). ;Species; was the most influential factor in the identity and frequency of the main biomolecules. Microclimatic differences in the range of the local specific habitats only influenced the biomolecules in cyanobacteria. There was a quadruple interaction among the factors, the effects being different mainly depending on the species. At D. diacapsis, the production of their main biomolecules depended on microclimate, although it also depended on seasonality. Nevertheless, in L. isidiata and S. lentigera microclimatic differences did not significantly affect the production of biomolecules. In the lichen species, the microhabitats exposed to relatively larger incident radiation did not show significantly larger relative frequency of photoprotective biomolecules. No clear connection between higher production of oxalates and drier microhabitats was found, suggesting that the synthesis of oxalates is not related to water reserve strategy. The pros and cons of monitor biomolecules in biocrust by Raman spectrometry were also discussed.

  11. Active and Dynamic Nanomaterials Based on Active Biomolecules

    Science.gov (United States)

    Koch, Steven J.; Rivera, Susan B.; Boal, Andrew K.; Edwards, J. Matthew; Bauer, Joseph M.; Manginell, Ronald P.; Liu, Jun; Bunker, Bruce C.; Bachand, George D.

    2004-03-01

    Living organisms have evolved dynamic and adaptable materials that fundamentally differ from synthetic materials. These biomaterials use chemical energy to drive non-equilibrium assembly processes, and to reconfigure in response to external stimuli or life cycle changes. Two striking examples are the diatom's active assembly of silica into a patterned cytoskeleton, and the chameleon's active transport of pigment particles to rapidly change skin color. Advances in molecular biology and nanoscale materials synthesis now present the opportunity for integrating biomolecules with synthetic components to produce new types of materials with novel assembly and adaptation capabilities. Our group has begun utilizing kinesin motor proteins and microtubules (MTs) to explore the construction of biomimetic materials. Initial work has focused on characterizing and engineering the properties of the biomolecules for robust performance in artificial systems. We have characterized the biochemical and biophysical properties of a kinesin motor protein from a thermostable fungus, and have evaluated strategies for stabilizing and functionalizing the MTs. We also have developed strategies for directed transport of MT shuttles, and for controlling the loading and unloading of nanoscale cargo.

  12. Biosurfactants: Multifunctional Biomolecules of the 21st Century.

    Science.gov (United States)

    Santos, Danyelle Khadydja F; Rufino, Raquel D; Luna, Juliana M; Santos, Valdemir A; Sarubbo, Leonie A

    2016-03-18

    In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and "green" products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.

  13. Polymeric Nanomaterials as Nanomembrane Entities for Biomolecule and Drug Delivery.

    Science.gov (United States)

    Albisa, Airama; Espanol, Laura; Prieto, Martin; Sebastian, Victor

    2017-01-01

    Bio-nanomaterials assembled into nanomembrane entities are actively studied to circumvent the uncontrollable list of shortcomings of conventional delivery systems: low water solubility, unfavorable stability, short circulation time in plasma, rapid clearance from the human body, poor bioavailability, non-specific toxicity against normal tissue and cells, low cellular uptake and susceptibility to enzyme degradation. Basically, these nanoentities enable to exploit the therapeutic value of many promising biomolecules and drugs (B&D), controlling the mass transport of B&D at a certain rate or even on demand if a stimulus is applied. The large surface-to-volume ratio of bio-nanomaterials as well as their tunable properties enable to increase the biocompatibility, bioavailability, solubility and permeability of many unique B&D which are otherwise difficult to deliver. This review paper will focus on the last advances of bio-nanomaterials applied as nanomembranes in biomolecule and drug delivery, as well as their more remarkable properties and applications in biomedicine. New advances have been drastically established in the production of smart nanomembranes that alter their own structure and function in response to the environment. These new insights have been used for the production of smart drug delivery nanomembranes. These nanomembranes entities have the potential to revolutionize the biomedicine but there are still some shortcomings to address in order to translate the laboratory production to the clinic. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. The nanoparticle biomolecule corona: lessons learned - challenge accepted?

    Science.gov (United States)

    Docter, D; Westmeier, D; Markiewicz, M; Stolte, S; Knauer, S K; Stauber, R H

    2015-10-07

    Besides the wide use of engineered nanomaterials (NMs) in technical products, their applications are not only increasing in biotechnology and biomedicine, but also in the environmental field. While the physico-chemical properties and behaviour of NMs can be characterized accurately under idealized conditions, this is no longer the case in complex physiological or natural environments. Herein, proteins and other biomolecules rapidly bind to NMs, forming a protein/biomolecule corona that critically affects the NMs' (patho)biological and technical identities. As the corona impacts the in vitro and/or in vivo NM applications in humans and ecosystems, a mechanistic understanding of its relevance and of the biophysical forces regulating corona formation is mandatory. Based on recent insights, we here critically review and present an updated concept of corona formation and evolution. We comment on how corona signatures may be linked to effects at the nano-bio interface in physiological and environmental systems. In order to comprehensively analyse corona profiles and to mechanistically understand the coronas' biological/ecological impact, we present a tiered multidisciplinary approach. To stimulate progress in this field, we introduce the potential impact of the corona for NM-microbiome-(human)host interactions and the novel concept of 'nanologicals', i.e., the nanomaterial-specific targeting of molecular machines. We conclude by discussing the relevant challenges that still need to be resolved in this field.

  15. Autonomous Magnetic Microrobots by Navigating Gates for Multiple Biomolecules Delivery.

    Science.gov (United States)

    Hu, Xinghao; Lim, Byeonghwa; Torati, Sri Ramulu; Ding, Junjia; Novosad, Valentine; Im, Mi-Young; Reddy, Venu; Kim, Kunwoo; Jung, Eunjoo; Shawl, Asif Iqbal; Kim, Eunjoo; Kim, CheolGi

    2018-05-08

    The precise delivery of biofunctionalized matters is of great interest from the fundamental and applied viewpoints. In spite of significant progress achieved during the last decade, a parallel and automated isolation and manipulation of rare analyte, and their simultaneous on-chip separation and trapping, still remain challenging. Here, a universal micromagnet junction for self-navigating gates of microrobotic particles to deliver the biomolecules to specific sites using a remote magnetic field is described. In the proposed concept, the nonmagnetic gap between the lithographically defined donor and acceptor micromagnets creates a crucial energy barrier to restrict particle gating. It is shown that by carefully designing the geometry of the junctions, it becomes possible to deliver multiple protein-functionalized carriers in high resolution, as well as MCF-7 and THP-1 cells from the mixture, with high fidelity and trap them in individual apartments. Integration of such junctions with magnetophoretic circuitry elements could lead to novel platforms without retrieving for the synchronous digital manipulation of particles/biomolecules in microfluidic multiplex arrays for next-generation biochips. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Biosurfactants: Multifunctional Biomolecules of the 21st Century

    Directory of Open Access Journals (Sweden)

    Danyelle Khadydja F. Santos

    2016-03-01

    Full Text Available In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and “green” products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.

  17. Novel in Vitro Efficiency of Chitosan Biomolecule Against Trichomonas Gallinae

    Directory of Open Access Journals (Sweden)

    SH Pourseyed

    2012-02-01

    Full Text Available Background: Development of new natural agents for parasitic diseases treatment has unexpectedly increased to overcome effectively against emergence and re-emergence of parasitic diseases, the appearance of drug resistant organisms and toxic side effects of current agents. The aim of the study was to evaluate antiprotozoal activities of chitosan biomolecule on trophozoites of Trichomonas gallinae.Methods: The antitrichomonal activity of various low molecular weight chitosan concentrations including 125, 250, 500 and 1250 μg ml-1 against T. gallinae trophozoites cultured in trypticase-yeast extract-maltose medium supplemented with heat-inactivated cold horse serum was evaluated in vitro. Samples containing medium without chitosan were also assayed as controls.Results: The mortality rates at 0, 3 and 6 h post treatment with all concentrations were significantly different from control group (P<0.05. Treated trophozoites showed more susceptibility to the highest concentration reaching mortality rate of 100% at 3h post inoculation. However, at this time, results for 125, 250 and 500 μg ml-1 were 93%, 95% and 96.7%, respectively.Conclusion: The results demonstrate that the application of chitosan biomolecule is a promising option for treatment of trichomoniasis in pigeons.

  18. Sequestration of carbon dioxide and production of biomolecules using cyanobacteria.

    Science.gov (United States)

    Upendar, Ganta; Singh, Sunita; Chakrabarty, Jitamanyu; Chandra Ghanta, Kartik; Dutta, Susmita; Dutta, Abhishek

    2018-07-15

    A cyanobacterial strain, Synechococcus sp. NIT18, has been applied to sequester CO 2 using sodium carbonate as inorganic carbon source due to its efficiency of CO 2 bioconversion and high biomass production. The biomass obtained is used for the extraction of biomolecules - protein, carbohydrate and lipid. The main objective of the study is to maximize the biomass and biomolecules production with CO 2 sequestration using cyanobacterial strain cultivated under different concentrations of CO 2 (5-20%), pH (7-11) and inoculum size (5-12.5%) within a statistical framework. Maximum sequestration of CO 2 and maximum productivities of protein, carbohydrate and lipid are 71.02%, 4.9 mg/L/day, 6.7 mg/L/day and 1.6 mg/L/day respectively, at initial CO 2 concentration: 10%, pH: 9 and inoculum size: 12.5%. Since flue gas contains 10-15% CO 2 and the present strain is able to sequester CO 2 in this range, the strain could be considered as a useful tool for CO 2 mitigation for greener world. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Brexit na perspectiva do Path Dependency

    OpenAIRE

    Giorgio Romano Schutte

    2018-01-01

    Esta pesquisa analisou o Brexit em uma perspectiva histórica, focando a conturbada relação entre a Europa continental e o Reino Unido ao longo do século XX, com ênfase no período pós Segunda Guerra Mundial. Foi utilizado o conceito de path dependency para argumentar sobre o papel de fatores históricos e decisões do passado, embora tomados em outras circunstâncias, ainda com força para influenciar o presente, para entender o Brexit. A premissa básica que será apresentada no ensaio é que o Rein...

  20. Desarrollo social y personalidad. Una perspectiva interdisciplinar

    OpenAIRE

    Riesco González, Manuel

    2012-01-01

    En las siguientes páginas se pretende establecer un diálogo interdisciplinar y abierto sobre cuestiones relevantes acerca del desarrollo social y de la personalidad. A partir de una breve reseña histórica del tema desde una perspectiva psicológica, se trata de comprender, con una visión amplia, el progreso humano como marco general del desarrollo social y de las personas. Finalmente, se muestra un bosquejo de la sociedad actual, definida como “sociedad del conocimiento”, “sociedad abierta” y ...

  1. Integrative self-assembly of functional hybrid nanoconstructs by inorganic wrapping of single biomolecules, biomolecule arrays and organic supramolecular assemblies.

    Science.gov (United States)

    Patil, Avinash J; Li, Mei; Mann, Stephen

    2013-08-21

    Synthesis of functional hybrid nanoscale objects has been a core focus of the rapidly progressing field of nanomaterials science. In particular, there has been significant interest in the integration of evolutionally optimized biological systems such as proteins, DNA, virus particles and cells with functional inorganic building blocks to construct mesoscopic architectures and nanostructured materials. However, in many cases the fragile nature of the biomolecules seriously constrains their potential applications. As a consequence, there is an on-going quest for the development of novel strategies to modulate the thermal and chemical stabilities, and performance of biomolecules under adverse conditions. This feature article highlights new methods of "inorganic molecular wrapping" of single or multiple protein molecules, individual double-stranded DNA helices, lipid bilayer vesicles and self-assembled organic dye superstructures using inorganic building blocks to produce bio-inorganic nanoconstructs with core-shell type structures. We show that spatial isolation of the functional biological nanostructures as "armour-plated" enzyme molecules or polynucleotide strands not only maintains their intact structure and biochemical properties, but also enables the fabrication of novel hybrid nanomaterials for potential applications in diverse areas of bionanotechnology.

  2. Integrative self-assembly of functional hybrid nanoconstructs by inorganic wrapping of single biomolecules, biomolecule arrays and organic supramolecular assemblies

    Science.gov (United States)

    Patil, Avinash J.; Li, Mei; Mann, Stephen

    2013-07-01

    Synthesis of functional hybrid nanoscale objects has been a core focus of the rapidly progressing field of nanomaterials science. In particular, there has been significant interest in the integration of evolutionally optimized biological systems such as proteins, DNA, virus particles and cells with functional inorganic building blocks to construct mesoscopic architectures and nanostructured materials. However, in many cases the fragile nature of the biomolecules seriously constrains their potential applications. As a consequence, there is an on-going quest for the development of novel strategies to modulate the thermal and chemical stabilities, and performance of biomolecules under adverse conditions. This feature article highlights new methods of ``inorganic molecular wrapping'' of single or multiple protein molecules, individual double-stranded DNA helices, lipid bilayer vesicles and self-assembled organic dye superstructures using inorganic building blocks to produce bio-inorganic nanoconstructs with core-shell type structures. We show that spatial isolation of the functional biological nanostructures as ``armour-plated'' enzyme molecules or polynucleotide strands not only maintains their intact structure and biochemical properties, but also enables the fabrication of novel hybrid nanomaterials for potential applications in diverse areas of bionanotechnology.

  3. Electromagnetic study of surface enhanced Raman scattering of plasmonic-biomolecule: An interaction between nanodimer and single biomolecule

    Science.gov (United States)

    Pandey, Gyanendra Krishna; Pathak, Nilesh Kumar; Uma, R.; Sharma, R. P.

    2017-04-01

    In this article we have investigated the electromagnetic surface enhanced Raman scattering (SERS) of single biomolecule adsorbed at the surface of spherical nanodimer. The SERS mechanism has been studied using first principle approach for spherical nanodimer geometry. The coupling of plasmonic concept to biomolecule results the broadband tunable enhancement in Raman gain factor. In this observation the enhancement factor was observed around ≈ 1015. The plasmonic properties of metal nanodimer are analysed in terms of surface plasmon resonances, extinction efficiency and polarisability that have been derived under quasistatic approximation. In this paper, various facets like interdipole separation, molecule distance and size of the plasmonic nanogeometry are taken into account to analyse the Raman gain factor. We also observe that the frequency range expands sufficiently which increases the broad detectability range of the molecule which generates signal even in the outside of Raman range i.e. in between IR to UV region. Lastly, the extinction spectra and electric field profile have been evaluated at resonance wavelength 364 nm. The comparison between electrostatic approach and numerical approach (using DDA) has also been done in terms of extinction spectra.

  4. Biomolecule-nanoparticle interactions: Elucidation of the thermodynamics by isothermal titration calorimetry.

    Science.gov (United States)

    Huang, Rixiang; Lau, Boris L T

    2016-05-01

    Nanomaterials (NMs) are often exposed to a broad range of biomolecules of different abundances. Biomolecule sorption driven by various interfacial forces determines the surface structure and composition of NMs, subsequently governs their functionality and the reactivity of the adsorbed biomolecules. Isothermal titration calorimetry (ITC) is a nondestructive technique that quantifies thermodynamic parameters through in-situ measurement of the heat absorption or release associated with an interaction. This review highlights the recent applications of ITC in understanding the thermodynamics of interactions between various nanoparticles (NPs) and biomolecules. Different aspects of a typical ITC experiment that are crucial for obtaining accurate and meaningful data, as well as the strengths, weaknesses, and challenges of ITC applications to NP research were discussed. ITC reveals the driving forces behind biomolecule-NP interactions and the effects of the physicochemical properties of both NPs and biomolecules by quantifying the crucial thermodynamics parameters (e.g., binding stoichiometry, ΔH, ΔS, and ΔG). Complimentary techniques would strengthen the interpretation of ITC results for a more holistic understanding of biomolecule-NP interactions. The thermodynamic information revealed by ITC and its complimentary characterizations is important for understanding biomolecule-NP interactions that are fundamental to the biomedical and environmental applications of NMs and their toxicological effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Stereoselective assembly of amino acid-based metal-biomolecule nanofibers.

    Science.gov (United States)

    Wu, Hong; Tian, Chunyong; Zhang, Yufei; Yang, Chen; Zhang, Songping; Jiang, Zhongyi

    2015-04-14

    A series of amino acid-based metal-biomolecule nanofibers are fabricated through a coordination-directed assembly process. The chirality and carbon chain length of the amino acids exert a pronounced influence on the assembly process. This study may be extended to design diverse kinds of 1-D metal-biomolecule frameworks (MBioFs).

  6. Soft x-ray circular dichroism of biomolecules

    International Nuclear Information System (INIS)

    Nakagawa, Kazumichi; Tanaka, Makoto; Agui, Akane

    2005-01-01

    We succeeded to observe natural circular dichroism NCD for biomolecules in soft X-ray region for the first time. Evaporated films of amino acids, phenylalanine (phe) and serine (ser) were prepared in vacuum with the thickness of about 300 nm. Measurement was carried out at the soft X-ray undulator beamline BL23SU of the Spring-8, where left- and right-circularly polarized light (LCPL and RCPL) was available from an APPLE-2 undulator. Difference spectra DA(hν) was plotted as a function of photon energy hν of soft X-ray to be the difference between absorption coefficient A L for LCPL and absorption coefficient A R for RCPL, namely, DA(hν) ≡ A L (hν) - A R (hν). Values of A L and A R were determined by means of the photoelectric drain current measurement. In the DA(hν) spectra for L-phe films, negative peak was observed at 407 eV. On the contrary, for D-phe films, positive peak was observed at 407 eV with the same magnitude but opposite sign. Moreover, no signal was observed for racemic phenylalanine (DL-phe). In the wavelength region of visible to ultraviolet, there is well-known general law in which NCD signals for D- and L-enantiomers are the same magnitude but opposite sign and racemic compound does not show NCD spectra. Characteristic features in DA(hν) spectra of the L-phe, D-phe and DL-phe were of good agreement with this well-known general law. Based on this good agreement, we concluded that peaks at 407 eV in the DA(hν) spectra are true NCD peaks. For ser films, we assigned peaks at 540 eV and 548 eV to be NCD peaks in the same manner. We hope that our first observation of NCD for biomolecules at soft X-ray region will open new science and technologies such as basic science including elucidation of fundamental mechanism of NCD and application to manipulate biomolecules using circularly polarized soft X-ray beams. (author)

  7. Bifunctional chelating agent for the design and development of site specific radiopharmaceuticals and biomolecule conjugation strategy

    Science.gov (United States)

    Katti, Kattesh V.; Prabhu, Kandikere R.; Gali, Hariprasad; Pillarsetty, Nagavara Kishore; Volkert, Wynn A.

    2003-10-21

    There is provided a method of labeling a biomolecule with a transition metal or radiometal in a site specific manner to produce a diagnostic or therapeutic pharmaceutical compound by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radio metal or a transition metal, and covalently linking the resulting metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. Also provided is a method of synthesizing the --PR.sub.2 containing biomolecules by synthesizing a P.sub.2 N.sub.2 -bifunctional chelating agent intermediate, complexing the intermediate with a radiometal or a transition metal, and covalently linking the resulting radio metal-complexed bifunctional chelating agent with a biomolecule in a site specific manner. There is provided a therapeutic or diagnostic agent comprising a --PR.sub.2 containing biomolecule.

  8. Sustained delivery of biomolecules from gelatin carriers for applications in bone regeneration.

    Science.gov (United States)

    Song, Jiankang; Leeuwenburgh, Sander Cg

    2014-08-01

    Local delivery of therapeutic biomolecules to stimulate bone regeneration has matured considerably during the past decades, but control over the release of these biomolecules still remains a major challenge. To this end, suitable carriers that allow for tunable spatial and temporal delivery of biomolecules need to be developed. Gelatin is one of the most widely used natural polymers for the controlled and sustained delivery of biomolecules because of its biodegradability, biocompatibility, biosafety and cost-effectiveness. The current study reviews the applications of gelatin as carriers in form of bulk hydrogels, microspheres, nanospheres, colloidal gels and composites for the programmed delivery of commonly used biomolecules for applications in bone regeneration with a specific focus on the relationship between carrier properties and delivery characteristics.

  9. Determination of the three-dimensional structure for weakly aligned biomolecules by NMR spectroscopy

    International Nuclear Information System (INIS)

    Shahkhatuni, Astghik A; Shahkhatuni, Aleksan G

    2002-01-01

    The key achievements and the potential of NMR spectroscopy for weakly aligned biomolecules are considered. Due to weak alignment, it becomes possible to determine a number of NMR parameters dependent on the orientation of biomolecules, which are averaged to zero in usual isotropic media. The addition of new orientational constraints to standard procedures of 3D structure determination markedly increases the achievable accuracy. The possibility of structure determination for biomolecules using only orientation-dependent parameters without invoking other NMR data is discussed. The methods of orientation, experimental techniques, and calculation methods are systematised. The main results obtained and the prospects of using NMR spectroscopy of weakly aligned systems to study different classes of biomolecules and to solve various problems of molecular biology are analysed. Examples of biomolecules whose structures have been determined using orientation-dependent parameters are given. The bibliography includes 508 references.

  10. A printed electronic platform for the specific detection of biomolecules

    Science.gov (United States)

    Doumbia, A.; Webb, M.; Turner, M. L.; Behrendt, J. M.; Wilson, R.

    2017-08-01

    The rapid detection of disease specific biomarkers in a clinically relevant range using a low-cost sensor can facilitate the development of individual treatment plans for a given patient, known as precision, personalized or genomic medicine. In the recent decade Electrolyte-Gated Organic Field Effect Transistors (EGOFETs), a subtype of OFETs where the dielectric is replaced by an electrolyte, have attracted a great deal of attention for sensing applications. This is due to their capacity to operate at low voltage (market are not yet achieved. In this contribution, we describe the development of a stable and reproducible EGOFET sensor that is able to detect biomolecules selectively in real-time. Facile and scalable techniques are used to prepare arrays of these devices. The selectivity of individual EGOFETs is investigated by immobilization of specific ligands to the target molecule of interest on the gate electrode within a microfluidic flow cell.

  11. Laser desorption mass spectrometry for biomolecule detection and its applications

    Science.gov (United States)

    Winston Chen, C. H.; Sammartano, L. J.; Isola, N. R.; Allman, S. L.

    2001-08-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications.

  12. Laser desorption mass spectrometry for biomolecule detection and its applications

    International Nuclear Information System (INIS)

    Winston Chen, C.H.; Allman, S.L.; Sammartano, L.J.; Isola, N.R.

    2001-01-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications

  13. Integrated nanoparticle-biomolecule systems for biosensing and bioelectronics.

    Science.gov (United States)

    Willner, Itamar; Baron, Ronan; Willner, Bilha

    2007-04-15

    The similar dimensions of biomolecules such as enzymes, antibodies or DNA, and metallic or semiconductor nanoparticles (NPs) enable the synthesis of biomolecule-NP hybrid systems where the unique electronic, photonic and catalytic properties of NPs are combined with the specific recognition and biocatalytic properties of biomolecules. The unique functions of biomolecule-NP hybrid systems are discussed with several examples: (i) the electrical contacting of redox enzymes with electrodes is the basis for the development of enzymatic electrodes for amperometric biosensors or biofuel cell elements. The reconstitution of the apo-glucose oxidase or apo-glucose dehydrogenase on flavin adenine dinucleotide (FAD)-functionalized Au NPs (1.4 nm) associated with electrodes, or on pyrroloquinoline quinone (PQQ)-functionalized Au NPs (1.4 nm) associated with electrodes, respectively, yields electrically contacted enzyme electrodes. The aligned, reconstituted enzymes on the electrode surfaces reveal effective electrical contacting, and the glucose oxidase and glucose dehydrogenase reveal turnover rates of 5000 and 11,800 s(-1), respectively. (ii) The photoexcitation of semiconductor nanoparticles yields fluorescence with a wavelength controlled by the size of the NPs. The fluorescence functions of semiconductor NPs are used to develop a fluorescence resonance energy transfer (FRET) assay for nucleic acids, and specifically, for analyzing telomerase activity in cancer cells. CdSe-ZnS NPs are functionalized by a primer recognized by telomerase, and this is elongated by telomerase extracted from HeLa cancer cells in the presence of dNTPs and Texas-red-functionalized dUTP. The dye integrated into the telomers allows the FRET process that is intensified as telomerization proceeds. Also, the photoexcited electron-hole pair generated in semiconductor NPs is used to generate photocurrents in a CdS-DNA hybrid system associated with an electrode. A redox-active intercalator, methylene blue

  14. Electrophoretic transport of biomolecules across liquid-liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Thomas; Hardt, Steffen [Center of Smart Interfaces, TU Darmstadt, Petersenstrasse 32, D-64287 Darmstadt (Germany); Muenchow, Goetz, E-mail: hardt@csi.tu-darmstadt.de [Institut fuer Mikrotechnik Mainz GmbH, Carl-Zeiss-Strasse 18-20, D-55129 Mainz (Germany)

    2011-05-11

    The mass transfer resistance of a liquid-liquid interface in an aqueous two-phase system composed of poly(ethylene glycol) and dextran is investigated. Different types of proteins and DNA stained with fluorescent dyes serve as probes to study the transport processes close to the interface. A microfluidic device is employed to enable the electrophoretic transport of biomolecules from one phase to another. The results obtained for proteins can be explained solely via the different electrophoretic mobilities and different affinities of the molecules to the two phases, without any indications of a significant mass transfer resistance of the liquid-liquid interface. By contrast, DNA molecules adsorb to the interface and only desorb under an increased electric field strength. The desorption process carries the signature of a thermally activated escape from a metastable state, as reflected in the exponential decay of the fluorescence intensity at the interface as a function of time.

  15. Manipulation of Biomolecule-Modified Liquid-Metal Blobs.

    Science.gov (United States)

    Yu, Yue; Miyako, Eijiro

    2017-10-23

    Soft and deformable liquid metals (LMs) are building components in various systems related to uncertain and dynamic task environments. Herein we describe the development of a biomolecule-triggered external-manipulation method involving LM conjugates for the construction of future innovative soft robotics operating in physiological environments. Functional soft hybrids composed of a liquid-metal droplet, a thiolated ligand, and proteins were synthesized for the expression of diverse macroscopic commands, such as attachment to cells, binary fusion, and self-propelled movement through molecular recognition and enzymatic reactions. Our technology could be used to create new state-of-the-art soft robots for chemical and biomedical engineering applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Modification of biomolecules and combined actions by radiation

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Lee, J. W.; Kim, J. H.; Choi, J. I.; Song, B. S.; Kim, J. K.; Park, J. H.; Lee, Y. J.; Ryu, S. H.; Sung, N. Y.; Cha, M. K.; Nam, J. Y.; Park, J. Y.; Cho, E. R.; Ryu, T. H.

    2011-12-01

    Advanced Radiation Technology Institute is a government-supported institute for radiation research and application. It has focused on development of fundamentals for radiation applications based on the existing radiation technology, and on enhancement of biological effectiveness of radiation through theoretical approach to the combined actions of radiation with another factor. Application of radiation technology together with the existing technologies to enhance the physical, chemical, biological characteristics through modification of biomolecules resulted in creation of de novo materials of scientific and industrial values. A theoretical model for combined action of radiation with another physico-chemical factor has been established. Conclusively the results of this study can provide scientific bases for maximizing the efficacy of ionizing radiation in relation to industrial applications

  17. Water Dynamics in the Hydration Shells of Biomolecules

    Science.gov (United States)

    2017-01-01

    The structure and function of biomolecules are strongly influenced by their hydration shells. Structural fluctuations and molecular excitations of hydrating water molecules cover a broad range in space and time, from individual water molecules to larger pools and from femtosecond to microsecond time scales. Recent progress in theory and molecular dynamics simulations as well as in ultrafast vibrational spectroscopy has led to new and detailed insight into fluctuations of water structure, elementary water motions, electric fields at hydrated biointerfaces, and processes of vibrational relaxation and energy dissipation. Here, we review recent advances in both theory and experiment, focusing on hydrated DNA, proteins, and phospholipids, and compare dynamics in the hydration shells to bulk water. PMID:28248491

  18. Interactions of model biomolecules. Benchmark CC calculations within MOLCAS

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Miroslav [Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Bottova 25, SK-917 24 Trnava, Slovakia and Department of Physical and Theoretical Chemistry, Faculty of Natural Scie (Slovakia); Pitoňák, Michal; Neogrády, Pavel; Dedíková, Pavlína [Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava (Slovakia); Hobza, Pavel [Institute of Organic Chemistry and Biochemistry and Center for Complex Molecular Systems and biomolecules, Academy of Sciences of the Czech Republic, Prague (Czech Republic)

    2015-01-22

    We present results using the OVOS approach (Optimized Virtual Orbitals Space) aimed at enhancing the effectiveness of the Coupled Cluster calculations. This approach allows to reduce the total computer time required for large-scale CCSD(T) calculations about ten times when the original full virtual space is reduced to about 50% of its original size without affecting the accuracy. The method is implemented in the MOLCAS computer program. When combined with the Cholesky decomposition of the two-electron integrals and suitable parallelization it allows calculations which were formerly prohibitively too demanding. We focused ourselves to accurate calculations of the hydrogen bonded and the stacking interactions of the model biomolecules. Interaction energies of the formaldehyde, formamide, benzene, and uracil dimers and the three-body contributions in the cytosine – guanine tetramer are presented. Other applications, as the electron affinity of the uracil affected by solvation are also shortly mentioned.

  19. Platinum(II) complexes as spectroscopic probes for biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ratilla, E.

    1990-09-21

    The use of platinum(II) complexes as tags and probes for biomolecules is indeed advantageous for their reactivities can be selective for certain purposes through an interplay of mild reaction conditions and of the ligands bound to the platinum. The use of {sup 195}Pt NMR as a method of detecting platinum and its interactions with biomolecules was carried out with the simplest model of platinum(II) tagging to proteins. Variable-temperature {sup 195}Pt NMR spectroscopy proved useful in studying the stereodynamics of complex thioethers like methionine. The complex, Pt(trpy)Cl{sup +}, with its chromophore has a greater potential for probing proteins. It is a noninvasive and selective tag for histidine and cysteine residues on the surface of cytochrome c at pH 5. The protein derivatives obtained are separable, and the tags are easily quantitated and differentiated through the metal-to-ligand charge transfer bands which are sensitive to the environment of the tag. Increasing the pH to 7.0 led to the modification by Pt(trpy)Cl{sup +}of Arg 91 in cytochrome c. Further studies with guanidine-containing ligands as models for arginine modification by Pt(trpy)Cl{sup +} showed that guanidine can act as a terminal ligand and as a bridging ligand. Owing to the potential utility of Pt(trpy)L{sup n+} as electron dense probes of nucleic acid structure, interactions of this bis-Pt(trpy){sup 2+} complex with nucleic acids was evaluated. Indeed, the complex interacts non-covalently with nucleic acids. Its interactions with DNA are not exactly the same as those of its precedents. Most striking is its ability to form highly immobile bands of DNA upon gel electrophoresis. 232 refs.

  20. Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Mitsunori, E-mail: honda.mitsunori@jaea.go.jp; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

    2014-04-01

    Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds.

  1. Electrochemical immobilization of biomolecules on gold surface modified with monolayered L-cysteine

    International Nuclear Information System (INIS)

    Honda, Mitsunori; Baba, Yuji; Sekiguchi, Tetsuhiro; Shimoyama, Iwao; Hirao, Norie

    2014-01-01

    Immobilization of organic molecules on the top of a metal surface is not easy because of lattice mismatch between organic and metal crystals. Gold atoms bind to thiol groups through strong chemical bonds, and a self-assembled monolayer of sulfur-terminated organic molecules is formed on the gold surface. Herein, we suggested that a monolayer of L-cysteine deposited on a gold surface can act as a buffer layer to immobilize biomolecules on the metal surface. We selected lactic acid as the immobilized biomolecule because it is one of the simplest carboxyl-containing biomolecules. The immobilization of lactic acid on the metal surface was carried out by an electrochemical method in an aqueous environment under the potential range varying from − 0.6 to + 0.8 V. The surface chemical states before and after the electrochemical reaction were characterized using X-ray photoelectron spectroscopy (XPS). The N 1s and C 1s XPS spectra showed that the L-cysteine-modified gold surface can immobilize lactic acid via peptide bonds. This technique might enable the immobilization of large organic molecules and biomolecules. - Highlights: • Monolayer l-cysteine deposited on Au surface as a buffer layer to immobilize biomolecules. • Lactic acid as the immobilized biomolecule as it is simple carboxyl-containing biomolecule. • X-ray photoelectron spectroscopy (XPS) of surface chemical states, before and after. • L-cysteine-modified Au surface can immobilize lactic acid via peptide bonds

  2. Biomolecule-recognition gating membrane using biomolecular cross-linking and polymer phase transition.

    Science.gov (United States)

    Kuroki, Hidenori; Ito, Taichi; Ohashi, Hidenori; Tamaki, Takanori; Yamaguchi, Takeo

    2011-12-15

    We present for the first time a biomolecule-recognition gating system that responds to small signals of biomolecules by the cooperation of biorecognition cross-linking and polymer phase transition in nanosized pores. The biomolecule-recognition gating membrane immobilizes the stimuli-responsive polymer, including the biomolecule-recognition receptor, onto the pore surface of a porous membrane. The pore state (open/closed) of this gating membrane depends on the formation of specific biorecognition cross-linking in the pores: a specific biomolecule having multibinding sites can be recognized by several receptors and acts as the cross-linker of the grafted polymer, whereas a nonspecific molecule cannot. The pore state can be distinguished by a volume phase transition of the grafted polymer. In the present study, the principle of the proposed system is demonstrated using poly(N-isopropylacrylamide) as the stimuli-responsive polymer and avidin-biotin as a multibindable biomolecule-specific receptor. As a result of the selective response to the specific biomolecule, a clear permeability change of an order of magnitude was achieved. The principle is versatile and can be applied to many combinations of multibindable analyte-specific receptors, including antibody-antigen and lectin-sugar analogues. The new gating system can find wide application in the bioanalytical field and aid the design of novel biodevices.

  3. When biomolecules meet graphene: from molecular level interactions to material design and applications.

    Science.gov (United States)

    Li, Dapeng; Zhang, Wensi; Yu, Xiaoqing; Wang, Zhenping; Su, Zhiqiang; Wei, Gang

    2016-12-01

    Graphene-based materials have attracted increasing attention due to their atomically-thick two-dimensional structures, high conductivity, excellent mechanical properties, and large specific surface areas. The combination of biomolecules with graphene-based materials offers a promising method to fabricate novel graphene-biomolecule hybrid nanomaterials with unique functions in biology, medicine, nanotechnology, and materials science. In this review, we focus on a summarization of the recent studies in functionalizing graphene-based materials using different biomolecules, such as DNA, peptides, proteins, enzymes, carbohydrates, and viruses. The different interactions between graphene and biomolecules at the molecular level are demonstrated and discussed in detail. In addition, the potential applications of the created graphene-biomolecule nanohybrids in drug delivery, cancer treatment, tissue engineering, biosensors, bioimaging, energy materials, and other nanotechnological applications are presented. This review will be helpful to know the modification of graphene with biomolecules, understand the interactions between graphene and biomolecules at the molecular level, and design functional graphene-based nanomaterials with unique properties for various applications.

  4. Comprehensive spectroscopic studies on the interaction of biomolecules with surfactant detached multi-walled carbon nanotubes.

    Science.gov (United States)

    Sekar, Gajalakshmi; Mukherjee, Amitava; Chandrasekaran, Natarajan

    2015-04-01

    This paper investigates the interaction of ten diverse biomolecules with surfactant detached Multi-Walled Carbon Nanotubes (MWCNTs) using multiple spectroscopic methods. Declining fluorescence intensity of biomolecules in combination with the hyperchromic effect in UV-Visible spectra confirmed the existence of the ground state complex formation. Quenching mechanism remains static and non-fluorescent. 3D spectral data of biomolecules suggested the possibilities of disturbances to the aromatic microenvironment of tryptophan and tyrosine residues arising out of CNTs interaction. Amide band Shifts corresponding to the secondary structure of biomolecules were observed in the of FTIR and FT-Raman spectra. In addition, there exists an increased Raman intensity of tryptophan residues of biomolecules upon interaction with CNTs. Hence, the binding of the aromatic structures of CNTs with the aromatic amino acid residues, in a particular, tryptophan was evidenced. Far UV Circular spectra have showed the loss of alpha-helical contents in biomolecules upon interaction with CNTs. Near UV CD spectra confirmed the alterations in the tryptophan positions of the peptide backbone. Hence, our results have demonstrated that the interaction of biomolecules with OH-MWCNTs would involve binding cum structural changes and alteration to their aromatic micro-environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. [Novel Hyphenated Techniques of Atomic Spectrometry for Metal Species Interaction with Biomolecules].

    Science.gov (United States)

    Li, Yan; Yan, Xiu-ping

    2015-09-01

    Trace metals may be adopted by biological systems to assist in the syntheses and metabolic functions of genes (DNA and RNA) and proteins in the environment. These metals may be beneficial or may pose a risk to humans and other life forms. Novel hybrid techniques are required for studies on the interaction between different metal species and biomolecules, which is significant for biology, biochemistry, nutrition, agriculture, medicine, pharmacy, and environmental science. In recent years, our group dwells on new hyphenated techniques based on capillary electrophoresis (CE), electrothermal atomic absorption spectrometry (ETAAS), and inductively coupled plasma mass spectroscopy (ICP-MS), and their application for different metal species interaction with biomolecules such as DNA, HSA, and GSH. The CE-ETAAS assay and CE-ICP-MS assay allow sensitively probing the level of biomolecules such as DNA damage by different metal species and extracting the kinetic and thermodynamic information on the interactions of different metal species with biomolecules, provides direct evidences for the formation of different metal species--biomolecule adducts. In addition, the consequent structural information were extracted from circular dichroism (CD) and X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The present works represent the most complete and extensive study to date on the interactions between different metal species with biomolecules, and also provide new evidences for and insights into the interactions of different metal species with biomolecules for further understanding of the toxicological effects of metal species.

  6. GESTIÓN HUMANA: TENDENCIAS Y PERSPECTIVAS

    Directory of Open Access Journals (Sweden)

    JUAN GUILLERMO SALDARRIAGA RÍOS

    2008-01-01

    Full Text Available En este artículo se hace referencia a las tendencias y las perspectivas de gestión humana que se imponen en el mundo en la actualidad y que, a su manera, pretenden optimizar la administración del personal de la organización y contribuir al desarrollo e incremento de la productividad y la competitividad. Mediante la realización de un Estado del Arte se logran determinar algunas de las tendencias más relevantes en la actualidad y se concluye que, cada vez con mayor fuerza, dichas tendencias se sustentan en discursos que pretenden "rescatar" al ser humano dentro de la organización, lo que no necesariamente se traduce en los procesos de gestión humana que se realizan en las organizaciones nacionales e internacionales.

  7. Comparative study of anti-angiogenic activities of luteolin, lectin and lupeol biomolecules.

    Science.gov (United States)

    Ambasta, Rashmi K; Jha, Saurabh Kumar; Kumar, Dhiraj; Sharma, Renu; Jha, Niraj Kumar; Kumar, Pravir

    2015-09-18

    Angiogenesis is a hallmark feature in the initiation, progression and growth of tumour. There are various factors for promotion of angiogenesis on one hand and on the other hand, biomolecules have been reported to inhibit cancer through anti-angiogenesis mechanism. Biomolecules, for instance, luteolin, lectin and lupeol are known to suppress cancer. This study aims to compare and evaluate the biomolecule(s) like luteolin, lupeol and lectin on CAM assay and HT-29 cell culture to understand the efficacy of these drugs. The biomolecules have been administered on CAM assay, HT-29 cell culture, cell migration assay. Furthermore, bioinformatics analysis of the identified targets of these biomolecules have been performed. Luteolin has been found to be better in inhibiting angiogenesis on CAM assay in comparison to lupeol and lectin. In line with this study when biomolecules was administered on cell migration assay via scratch assay method. We provided evidence that Luteolin was again found to be better in inhibiting HT-29 cell migration. In order to identify the target sites of luteolin for inhibition, we used software analysis for identifying the best molecular targets of luteolin. Using software analysis best target protein molecule of these biomolecules have been identified. VEGF was found to be one of the target of luteolin. Studies have found several critical point mutation in VEGF A, B and C. Hence docking analysis of all biomolecules with VEGFR have been performed. Multiple allignment result have shown that the receptors are conserved at the docking site. Therefore, it can be concluded that luteolin is not only comparatively better in inhibiting blood vessel in CAM assay, HT-29 cell proliferation and cell migration assay rather the domain of VEGFR is conserved to be targeted by luteolin, lupeol and lectin.

  8. Raman spectroscopy detection of biomolecules in biocrusts from differing environmental conditions.

    Science.gov (United States)

    Miralles, I; Jorge-Villar, S E; van Wesemael, B; Lázaro, R

    2017-01-15

    Lichens and cyanobacteria colonize inhospitable places covering a wide climate range due to their different survival strategies, such as the synthesis of protective biomolecules. The effect of ecological factors on the synthesis of biomolecules has not been widely analysed. This study aimed to assess the effects of four factors (species, microclimate, seasonality and hydration state) and their interactions on the biomolecule frequency detected by Raman Spectroscopy. We included cyanobacterial biocrusts, and the lichens Diploschistes diacapsis, Squamarina lentigera, and Lepraria isidiata; two contrasted microclimates (typical and marginal), two contrasted seasons (hot and dry vs cool and wet) and two hydration states (dry and wet). "Species" was the most influential factor in the identity and frequency of the main biomolecules. Microclimatic differences in the range of the local specific habitats only influenced the biomolecules in cyanobacteria. There was a quadruple interaction among the factors, the effects being different mainly depending on the species. At D. diacapsis, the production of their main biomolecules depended on microclimate, although it also depended on seasonality. Nevertheless, in L. isidiata and S. lentigera microclimatic differences did not significantly affect the production of biomolecules. In the lichen species, the microhabitats exposed to relatively larger incident radiation did not show significantly larger relative frequency of photoprotective biomolecules. No clear connection between higher production of oxalates and drier microhabitats was found, suggesting that the synthesis of oxalates is not related to water reserve strategy. The pros and cons of monitor biomolecules in biocrust by Raman spectrometry were also discussed. Copyright © 2016. Published by Elsevier B.V.

  9. Advances in the synthesis of nitroxide radicals for use in biomolecule spin labelling.

    Science.gov (United States)

    Haugland, Marius M; Lovett, Janet E; Anderson, Edward A

    2018-02-05

    EPR spectroscopy is an increasingly useful analytical tool to probe biomolecule structure, dynamic behaviour, and interactions. Nitroxide radicals are the most commonly used radical probe in EPR experiments, and many methods have been developed for their synthesis, as well as incorporation into biomolecules using site-directed spin labelling. In this Tutorial Review, we discuss the most practical methods for the synthesis of nitroxides, focusing on the tunability of their structures, the manipulation of their sidechains into spin labelling handles, and their installation into biomolecules.

  10. 18 F-Labeling of Sensitive Biomolecules for Positron Emission Tomography.

    Science.gov (United States)

    Krishnan, Hema S; Ma, Longle; Vasdev, Neil; Liang, Steven H

    2017-11-07

    Positron emission tomography (PET) imaging study of fluorine-18 labeled biomolecules is an emerging and rapidly growing area for preclinical and clinical research. The present review focuses on recent advances in radiochemical methods for incorporating fluorine-18 into biomolecules via "direct" or "indirect" bioconjugation. Recently developed prosthetic groups and pre-targeting strategies, as well as representative examples in 18 F-labeling of biomolecules in PET imaging research studies are highlighted. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Radiation physics and chemistry of biomolecules. Recent developments

    Science.gov (United States)

    Spotheim-Maurizot, Melanie

    2016-11-01

    A chapter of the book ;Radiation chemistry. From basics to application in materials and life sciences (EDP Science, Paris, France, 2008); was devoted to the state-of-the-art in the research on ionizing radiation (IR) effects on biomolecules. An update, eight years later, seemed pertinent enough to the editors of this journal who accepted to dedicate a Special Issue to the latest developments in this area of high interest for cancer radiotherapy, nuclear workers' radioprotection and food radiosterilisation. We sincerely thank them and the authors who accepted to present reviews of their most recent work. Obviously, only a small part of the research in the fascinating domain of molecular radiobiology can be covered here. Some articles are presenting the contribution of biophysical models and computational techniques to the understanding of IR effects on molecules such as DNA and proteins, or on larger systems such as chromatin, chromosomes and even cells (Nikjoo et al., Štěpán & Davídková, Ballarini & Carante, and Nikitaki et al.). In these papers, as well as in many others, several qualities of IR are compared in order to explain the observed differences of effects. The damages induced by the low energy electrons and new techniques involved in their study are discussed in great detail (Sanche and Fromm & Boulanouar). The chemistry behind the IR induced damages (single or clustered), studied in many laboratories around the world is presented in several papers (Cadet & Wagner, Sevilla et al., Chatgilialoglu et al., and Greenberg). One of them addresses a very useful comparison between the effects of IR and UV exposure on DNA (Ravanat & Douki). The majority of the papers in this Special Issue is dealing with DNA and this reflects the real situation: damages of DNA are more studied than those of other biomolecules. This is due to the role of DNA as main support of hereditary information. Nevertheless, more and more studies are outlining the influence of epigenetic

  12. Si Nanopores Development for External Control of Transport of Biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ileri, N; Tringe, J; Letant, S; Palozoglu, A; Stroeve, P; Faller, R

    2008-06-13

    Nazar Ileri has been involved in an independent, multidisciplinary effort to create a new class of molecular sieves for proteins and viruses. Her experimental work has been performed concurrently at two campuses, LLNL and UC Davis, while theoretical components have been largely accomplished at UC Davis. As will be described, the devices she is creating have great potential to improve very significantly the efficiency and selectivity of molecular transport over what is presently available from state-of-the-art membranes. Our biotechnology training program is based on an integrated study of the transport of biomolecules through conically-shaped, nanoporous silicon membranes. The overall objective of this effort is to demonstrate an efficient, highly selective membrane technology that is manufacturable for macroscopic areas and can be employed in sensing, diagnostic and biomedical applications. Our specific aims are to (1) fabricate and characterize the physical characteristics of the membranes, (2) to demonstrate their utility for molecular transport and separation, and (3) to develop models that will facilitate understanding of these devices as well as improved performance of the next generation of devices. We have proposed that the conical pores have superior performance characteristics compared to other porous filters. To study this hypothesis, complementary approaches from different disciplines, such as membrane synthesis, experiment, and molecular simulation need to be combined. This provides an ideal training environment for a future leader in biotechnology. Hence, for this study, Nazar Ileri has started to carry out a full range of experimental and theoretical investigations under our guidance. First, she has begun fabrication of filters with conical/pyramidal pores. She characterized the pores by AFM and SEM, and analyzed the images using wavelets and other mathematical tools. She has also started to conduct biomolecule transport experiments to compare the

  13. 123I and 13I purification for biomolecules labelling

    International Nuclear Information System (INIS)

    Catanoso, Marcela Forli

    2011-01-01

    The 123 I and 131 I are iodine radioisotopes widely used in Nuclear Medicine. The radioisotope 123 I is used in diagnosis through the SPECT technique and is routinely produced at IPEN in cyclotron through the reaction: '1 24 Xe (p, 2n) '1 23 Cs -> 123 Xe -> 123 I. The radioisotope 131 I is used both in diagnosis and therapy due to its physical characteristics of decay by β - and its γ-ray emissions that are softened with the use of specific collimators for diagnosis. It is routinely produced at IPEN using the nuclear reactor through the indirect reaction: 130 Te (n, γ) -> 131 Te -> 131 I, irradiating compounds containing Te. The radiopharmaceuticals prepared with these radioisotopes go through rigorous quality control tests and the chemical purity of the primary radioisotopes 123 I and 131 I are within the permissible limits currently defined. However, the presence of some chemical contaminants can prejudice the biomolecules labeling (monoclonal antibodies and peptides), that will produce radiopharmaceuticals of first generation to the oncology area. The aim of this work was to obtain a new purification method of these radioisotopes, allowing the labeling of biomolecules and also to established a process control on those radioisotopes. The methodology was separated on 3 steps: Evaluation of '1 23 I e 131 I radionuclidic purity using a hyper pure germanium detector, chemical purity using ICP-OES and the retention and elution study of 131 I in several absorbers to choose the most appropriate for the purification tests analyzing the behavior of the possible contaminants. The radionuclidic analyses showed the presence of Te and Co on 131 I samples and Te, Tc e Co on 123 I samples. The chemical purity analyses showed the presence of Al and Mo in 123 I, coming from the window material of the target holder and the presence of Al and Te in 131 I samples, coming from the target holder and the target, respectively. The retention and elution study selected the most

  14. Si Nanopores Development for External Control of Transport of Biomolecules

    International Nuclear Information System (INIS)

    Ileri, N.; Tringe, J.; Letant, S.; Palozoglu, A.; Stroeve, P.; Faller, R.

    2008-01-01

    Nazar Ileri has been involved in an independent, multidisciplinary effort to create a new class of molecular sieves for proteins and viruses. Her experimental work has been performed concurrently at two campuses, LLNL and UC Davis, while theoretical components have been largely accomplished at UC Davis. As will be described, the devices she is creating have great potential to improve very significantly the efficiency and selectivity of molecular transport over what is presently available from state-of-the-art membranes. Our biotechnology training program is based on an integrated study of the transport of biomolecules through conically-shaped, nanoporous silicon membranes. The overall objective of this effort is to demonstrate an efficient, highly selective membrane technology that is manufacturable for macroscopic areas and can be employed in sensing, diagnostic and biomedical applications. Our specific aims are to (1) fabricate and characterize the physical characteristics of the membranes, (2) to demonstrate their utility for molecular transport and separation, and (3) to develop models that will facilitate understanding of these devices as well as improved performance of the next generation of devices. We have proposed that the conical pores have superior performance characteristics compared to other porous filters. To study this hypothesis, complementary approaches from different disciplines, such as membrane synthesis, experiment, and molecular simulation need to be combined. This provides an ideal training environment for a future leader in biotechnology. Hence, for this study, Nazar Ileri has started to carry out a full range of experimental and theoretical investigations under our guidance. First, she has begun fabrication of filters with conical/pyramidal pores. She characterized the pores by AFM and SEM, and analyzed the images using wavelets and other mathematical tools. She has also started to conduct biomolecule transport experiments to compare the

  15. Watching Conformations of Biomolecules: a Microwave Spectroscopy Approach

    Science.gov (United States)

    Lopez, J. C.

    2011-06-01

    The combination of laser ablation with Fourier transform microwave spectroscopy in supersonic jets (LA-MB-FTMW) has made possible the gas-phase study of solid biomolecules with high melting points. In the experiment, solids are efficiently vaporized by a high-energy laser pulse, supersonically expanded into a evacuated Fabry-Perot cavity and characterised by their rotational spectra. Recent improvements such as the use of picosecond pulse lasers, new ablation nozzles and the extension of the range of the spectrometers to low frequecy have notably increased the sensitivity of our experimental setup. To date different α-, β- and γ-amino acids have been studied using this technique, making possible the characterization of their preferred conformations and gaining insight in the role of intramolecular interactions. Even in conformationally challenging systems the different rotamers of such biomolecules can be identified by rotational spectroscopy as can be illustrated by the assignment of six low-energy conformers in cysteine and aspartic acid, seven in serine and threonine,^a and nine in γ-amino butyric acid (GABA). In all cases the low-energy conformers have been conclusive identified from their experimental rotational and 14N quadrupole coupling constants. The spectra of neurotransmitters and of the nucleic acid bases uracil, thymine, cytosine and guanine have also been studied and their preferred conformers or tautomeric forms determined. The complexes between amino acids and nucleic acid bases with water have also been investigated to obtain information on the possible changes induced in the conformational or tautomeric preferences by the addition of solvent molecules. J. L. Alonso, C. Pérez, M. E. Sanz, J. C. López, S. Blanco, Phys. Chem. Chem. Phys. 11, 617-627 (2009) and references therein M. E. Sanz, J. C. López, J. L. Alonso, Phys. Chem. Chem. Phys., 12, 3573-3578 (2010) S. Blanco, J. C. López, S. Mata and J. L. Alonso, Angew. Chem. Int. Ed. 49, 9187

  16. Higher biomolecules yield in phytoplankton under copper exposure.

    Science.gov (United States)

    Silva, Jaqueline Carmo; Echeveste, Pedro; Lombardi, Ana Teresa

    2018-05-30

    Copper is an important metal for industry, and its toxic threshold in natural ecosystems has increased since the industrial revolution. As an essential nutrient, it is required in minute amounts, being toxic in slightly increased concentrations, causing great biochemical transformation in microalgae. This study aimed at investigating the physiology of Scenedesmus quadricauda, a cosmopolitan species, exposed to copper concentrations including those that trigger intracellular biochemical modifications. The Cu exposure concentrations tested ranged from 0.1 to 25 µM, thus including environmentally important levels. Microalgae cultures were kept under controlled environmental conditions and monitored daily for cell density, in vivo chlorophyll a, and photosynthetic quantum yield (Φ M ). After 24 h growth, free Cu 2+ ions were determined, and after 96 h, cellular Cu concentration, total carbohydrates, proteins, lipids, and cell volume were determined. The results showed that both free Cu 2+ ions and cellular Cu increased with Cu increase in culture medium. Microalgae cell abundance and in vivo chlorophyll a were mostly affected at 2.5 µM Cu exposure (3.8 pg Cu cell -1 ) and above. Approximately 31% decrease of photosynthetic quantum yield was obtained at the highest Cu exposure concentration (25 µM; 25 pg Cu cell -1 ) in comparison with the control. However, at environmentally relevant copper concentrations (0.5 µM Cu; 0.4 pg Cu cell -1 ) cell volume increased in comparison with the control. Considering biomolecules accumulation per unit cell volume, the highest carbohydrates and proteins yield was obtained at 1.0 µM Cu (1.1 pg Cu cell -1 ), while for lipids higher Cu was necessary (2.5 µM Cu; 3.8 pg Cu cell -1 ). This study is a contribution to the understanding of the effects of environmentally significant copper concentrations in the physiology of S. quadricauda, as well as to biotechnological approach to increase biomolecule yield in

  17. Masaccio y la perspectiva matemática

    OpenAIRE

    Casalderrey, Martín

    2010-01-01

    En esta enumeración de Alberti, aparece el núcleo de artistas,todos amigos entre sí, que revolucionaron la concepción del arte en el primer renacimiento. Y si hay algo que caracteriza ese periodo en lo que respecta al arte y las matemáticas es la invención de la perspectiva artificialis, o perspectiva matemática.

  18. Graphene-edge dielectrophoretic tweezers for trapping of biomolecules.

    Science.gov (United States)

    Barik, Avijit; Zhang, Yao; Grassi, Roberto; Nadappuram, Binoy Paulose; Edel, Joshua B; Low, Tony; Koester, Steven J; Oh, Sang-Hyun

    2017-11-30

    The many unique properties of graphene, such as the tunable optical, electrical, and plasmonic response make it ideally suited for applications such as biosensing. As with other surface-based biosensors, however, the performance is limited by the diffusive transport of target molecules to the surface. Here we show that atomically sharp edges of monolayer graphene can generate singular electrical field gradients for trapping biomolecules via dielectrophoresis. Graphene-edge dielectrophoresis pushes the physical limit of gradient-force-based trapping by creating atomically sharp tweezers. We have fabricated locally backgated devices with an 8-nm-thick HfO 2 dielectric layer and chemical-vapor-deposited graphene to generate 10× higher gradient forces as compared to metal electrodes. We further demonstrate near-100% position-controlled particle trapping at voltages as low as 0.45 V with nanodiamonds, nanobeads, and DNA from bulk solution within seconds. This trapping scheme can be seamlessly integrated with sensors utilizing graphene as well as other two-dimensional materials.

  19. Acoustic cavity transducers for the manipulation of cells and biomolecules

    Science.gov (United States)

    Tovar, Armando; Patel, Maulik; Lee, Abraham P.

    2010-02-01

    A novel fluidic actuator that is simple to fabricate, integrate, and operate is demonstrated for use within microfluidic systems. The actuator is designed around the use of trapped air bubbles in lateral cavities and the resultant acoustic streaming generated from an outside acoustic energy source. The orientation of the lateral cavities to the main microchannel is used to control the bulk fluid motion within the device. The first order flow generated by the oscillating bubble is used to develop a pumping platform that is capable of driving fluid within a chip. This pump is integrated into a recirculation immunoassay device for enhanced biomolecule binding through fluid flow for convection limited transport. The recirculation system showed an increase in binding site concentration when compared with traditional passive and flow-through methods. The acoustic cavity transducer has also been demonstrated for application in particle switching. Bursts of acoustic energy are used to generate a second order streaming pattern near the cavity interface to drive particles away or towards the cavity. The use of this switching mechanism is being extended to the application of sorting cells and other particles within a microfluidic system.

  20. Interfacial water thickness at inorganic nanoconstructs and biomolecules: Size matters

    Energy Technology Data Exchange (ETDEWEB)

    Cardellini, Annalisa; Fasano, Matteo; Chiavazzo, Eliodoro; Asinari, Pietro, E-mail: pietro.asinari@polito.it

    2016-04-29

    Water molecules in the proximity of solid nanostructures influence both the overall properties of liquid and the structure and functionality of solid particles. The study of water dynamics at solid–liquid interfaces has strong implications in energy, environmental and biomedical fields. This article focuses on the hydration layer properties in the proximity of Carbon Nanotubes (CNTs) and biomolecules (proteins, polypeptides and amino acids). Here we show a quantitative relation between the solid surface extension and the characteristic length of water nanolayer (δ), which is confined at solid–liquid interfaces. Specifically, the size dependence is attributed to the limited superposition of nonbonded interactions in case of small molecules. These results may facilitate the design of novel energy or biomedical colloidal nanosuspensions, and a more fundamental understanding of biomolecular processes influenced by nanoscale water dynamics. - Highlights: • Properties of the water hydration layer are investigated. • New relation between extension of solid size and hydration layer established. • Possible impact on rational design of nanosuspensions.

  1. Diagnostic and therapeutic perspectives in nuclear medicine: radiolabelled biomolecules

    International Nuclear Information System (INIS)

    Ferro F, G.; Murphy, C.A. de; Pedraza L, M.; Melendez A, L.

    2003-01-01

    From their beginning, the radiopharmaceuticals chemistry has gone to the study of the molecular chemistry. The radiopharmaceuticals are only in their capacity to detect such specific biochemical places as the receivers and the enzymes. With the recent obtaining of the complete structural sequence of the genome, it doesn't fit doubt of the importance that they have acquired the molecular images for the study from the genetic information to the alterations phenotypic in the chemistry of the human body. So, the future of the diagnostic and therapeutic nuclear medicine, practically is based in the study of protein fragments, peptide structures and chains of DNA radiolabelled for the study of the metabolism In vivo. These investigations represent a substantial change in those paradigms of the pharmaceutical development, when using the own organic capacities as source of medications, instead of considering to the organism like a simple assay tube where molecules act, like they are most of the traditional medications. The investigation of new techniques to design complex stable of Tc-99m, Re-188, Lu-177, Y-90 and Dy-166/Ho-l66 with biomolecules that don't alter the specificity and in general the molecular properties of the same ones. it is a topic of world interest in the environment of the radiopharmaceutical chemistry. In this work some achievements and perspectives are presented on those main diagnostic and therapeutic radiopharmaceuticals of third generation. (Author)

  2. Comparison of biomolecules on the basis of Molecular Interaction Potentials

    Directory of Open Access Journals (Sweden)

    Rodrigo Jordi

    2002-01-01

    Full Text Available Molecular Interaction Potentials (MIP are frequently used for the comparison of series of compounds displaying related biological behaviors. These potentials are interaction energies between the considered compounds and relevant probes. The interaction energies are computed in the nodes of grids defined around the compounds. There is a need of detailed and objective comparative analyses of MIP distributions in the framework of structure-activity studies. On the other hand, MIP-based studies do not have to be restricted to series of small ligands, since such studies present also interesting possibilities for the analysis and comparison of biological macromolecules. Such analyses can benefit from the application of new methods and computational approaches. The new software MIPSim (Molecular Interaction Potentials Similarity analysis has recently been introduced with the purpose of analyzing and comparing MIP distributions of series of biomolecules. This program is transparently integrated with other programs, like GAMESS or GRID, which can be used for the computation of the potentials to be analyzed or compared. MIPSim incorporates several definitions of similarity coefficients, and is capable of combining several similarity measures into a single one. On the other hand, MIPSim can perform automatic explorations of the maximum similarity alignments between pairs of molecules.

  3. Hybrid carbon nanomaterials for electrochemical detection of biomolecules

    International Nuclear Information System (INIS)

    Laurila, Tomi

    2015-01-01

    Electrochemical detection of different biomolecules in vivo is a promising path towards in situ monitoring of human body and its functions. However, there are several major obstacles, such as sensitivity, selectivity and biocompatiblity, which must be tackled in order to achieve reliably and safely operating sensor devices. Here we show that by utilizing hybrid carbon materials as electrodes to detect two types of neurotransmitters, dopamine and glutamate, several advantages over commonly used electrode materials can be achieved. In particular, we will demonstrate here that it is possible to combine the properties of different carbon allotropes to obtain hybrid materials with greatly improved electrochemical performance. Three following examples of the approach are given: (i) diamond-like carbon (DLC) thin film electrodes with different layer thicknesses, (ii) multi-walled carbon nanotubes grown directly on top of DLC and (iii) carbon nanofibres synthesized on top of DLC thin films. Detailed structural and electrochemical characterization is carried out to rationalize the reasons behind the observed behvior. In addition, results from the atomistic simulations are utilized to obtain more information about the properties of the amorphous carbon thin films. (paper)

  4. Natural Biomolecules and Protein Aggregation: Emerging Strategies against Amyloidogenesis

    Directory of Open Access Journals (Sweden)

    Antonella Sgarbossa

    2012-12-01

    Full Text Available Biomolecular self-assembly is a fundamental process in all organisms. As primary components of the life molecular machinery, proteins have a vast array of resources available to them for self-assembly in a functional structure. Protein self-assembly, however, can also occur in an aberrant way, giving rise to non-native aggregated structures responsible for severe, progressive human diseases that have a serious social impact. Different neurodegenerative disorders, like Huntington’s, Alzheimer’s, and spongiform encephalopathy diseases, have in common the presence of insoluble protein aggregates, generally termed “amyloid,” that share several physicochemical features: a fibrillar morphology, a predominantly beta-sheet secondary structure, birefringence upon staining with the dye Congo red, insolubility in common solvents and detergents, and protease resistance. Conformational constrains, hydrophobic and stacking interactions can play a key role in the fibrillogenesis process and protein–protein and peptide–peptide interactions—resulting in self-assembly phenomena of peptides yielding fibrils—that can be modulated and influenced by natural biomolecules. Small organic molecules, which possess both hydrophilic and hydrophobic moieties able to bind to peptide/protein molecules through hydrogen bonds and hydrophobic and aromatic interactions, are potential candidates against amyloidogenesis. In this review some significant case examples will be critically discussed.

  5. Quantification of specific bindings of biomolecules by magnetorelaxometry

    Directory of Open Access Journals (Sweden)

    Steinhoff Uwe

    2008-03-01

    Full Text Available Abstract The binding reaction of the biomolecules streptavidin and anti-biotin antibody, both labelled by magnetic nanoparticles (MNP, to biotin coated on agarose beads, was quantified by magnetorelaxometry (MRX. Highly sensitive SQUID-based MRX revealed the immobilization of the MNP caused by the biotin-streptavidin coupling. We found that about 85% of streptavidin-functionalised MNP bound specifically to biotin-agarose beads. On the other hand only 20% of antibiotin-antibody functionalised MNP were specifically bound. Variation of the suspension medium revealed in comparison to phosphate buffer with 0.1% bovine serum albumin a slight change of the binding behaviour in human serum, probably due to the presence of functioning (non heated serum proteins. Furthermore, in human serum an additional non-specific binding occurs, being independent from the serum protein functionality. The presented homogeneous bead based assay is applicable in simple, uncoated vials and it enables the assessment of the binding kinetics in a volume without liquid flow. The estimated association rate constant for the MNP-labelled streptavidin is by about two orders of magnitude smaller than the value reported for free streptavidin. This is probably due to the relatively large size of the magnetic markers which reduces the diffusion of streptavidin. Furthermore, long time non-exponential kinetics were observed and interpreted as agglutination of the agarose beads.

  6. GroPBS: Fast Solver for Implicit Electrostatics of Biomolecules

    Directory of Open Access Journals (Sweden)

    Franziska eBertelshofer

    2015-11-01

    Full Text Available Knowledge about the electrostatic potential on the surface of biomolecules or biomembranes under physiological conditions is an important step in the attempt to characterize the physico-chemical properties of these molecules and in particular also their interactions with each other. Additionally, knowledge about solution electrostatics may guide also the design of molecules with specified properties. However, explicit water models come at a high computational cost, rendering them unsuitable for large design studies or for docking purposes. Implicit models with the water phase treated as a continuum require the numerical solution of the Poisson-Boltzmann Equation (PBE. Here, we present a new flexible program for the numerical solution of the PBE, allowing for different geometries, and the explicit and implicit inclusion of membranes. It involves a discretization of space and the computation of the molecular surface. The PBE is solved using finite differences, the resulting set of equations is solved using a Gauss-Seidel method. It is shown for the example of the sucrose transporter ScrY that the implicit inclusion of a surrounding membrane has a strong effect also on the electrostatics within the pore region and thus need to be carefully considered e.g. in design studies on membrane proteins.

  7. Direct patterning of nanoparticles and biomolecules by liquid nanodispensing.

    Science.gov (United States)

    Fabié, Laure; Agostini, Pierre; Stopel, Martijn; Blum, Christian; Lassagne, Benjamin; Subramaniam, Vinod; Ondarçuhu, Thierry

    2015-03-14

    We report on the localized deposition of nanoparticles and proteins, nano-objects commonly used in many nanodevices, by the liquid nanodispensing (NADIS) technique which consists in depositing droplets of a solution through a nanochannel drilled at the apex of an AFM tip. We demonstrate that the size of spots can be adjusted from microns down to sub-50 nm by tuning the channel diameter, independently of the chemical nature of the solute. In the case of nanoparticles, we demonstrated the ultimate limit of the method and showed that large arrays of single (or pairs of) nanoparticles can be reproducibly deposited. We further explored the possibility to deposit different visible fluorescent proteins using NADIS without loss of protein function. The intrinsic fluorescence of these proteins is characteristic of their structural integrity; the retention of fluorescence after NADIS deposition demonstrates that the proteins are intact and functional. This study demonstrates that NADIS can be a viable alternative to other scanning probe lithography techniques since it combines high resolution direct writing of nanoparticles or biomolecules with the versatility of liquid lithography techniques.

  8. Small biomolecule immunosensing with plasmonic optical fiber grating sensor.

    Science.gov (United States)

    Ribaut, Clotilde; Voisin, Valérie; Malachovská, Viera; Dubois, Valentin; Mégret, Patrice; Wattiez, Ruddy; Caucheteur, Christophe

    2016-03-15

    This study reports on the development of a surface plasmon resonance (SPR) optical fiber biosensor based on tilted fiber Bragg grating technology for direct detection of small biomarkers of interest for lung cancer diagnosis. Since SPR principle relies on the refractive index modifications to sensitively detect mass changes at the gold coated surface, we have proposed here a comparative study in relation to the target size. Two cytokeratin 7 (CK7) samples with a molecular weight ranging from 78 kDa to 2.6 kDa, respectively CK7 full protein and CK7 peptide, have been used for label-free monitoring. This work has first consisted in the elaboration and the characterization of a robust and reproducible bioreceptor, based on antibody/antigen cross-linking. Immobilized antibodies were then utilized as binding agents to investigate the sensitivity of the biosensor towards the two CK7 antigens. Results have highlighted a very good sensitivity of the biosensor response for both samples diluted in phosphate buffer with a higher limit of detection for the larger CK7 full protein. The most groundbreaking nature of this study relies on the detection of small biomolecule CK7 peptides in buffer and in the presence of complex media such as serum, achieving a limit of detection of 0.4 nM. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Polyacrylamide medium for the electrophoretic separation of biomolecules

    Science.gov (United States)

    Madabhushi, Ramakrishna S.; Gammon, Stuart A.

    2003-11-11

    A polyacryalmide medium for the electrophoretic separation of biomolecules. The polyacryalmide medium comprises high molecular weight polyacrylamides (PAAm) having a viscosity average molecular weight (M.sub.v) of about 675-725 kDa were synthesized by conventional red-ox polymerization technique. Using this separation medium, capillary electrophoresis of BigDye DNA sequencing standard was performed. A single base resolution of .about.725 bases was achieved in .about.60 minute in a non-covalently coated capillary of 50 .mu.m i.d., 40 cm effective length, and a filed of 160 V/cm at 40.degree. C. The resolution achieved with this formulation to separate DNA under identical conditions is much superior (725 bases vs. 625 bases) and faster (60 min. vs. 75 min.) to the commercially available PAAm, such as supplied by Amersham. The formulation method employed here to synthesize PAAm is straight-forward, simple and does not require cumbersome methods such as emulsion polymerizaiton in order to achieve very high molecular weights. Also, the formulation here does not require separation of PAAm from the reaction mixture prior to reconstituting the polymer to a final concentration. Furthermore, the formulation here is prepared from a single average mol. wt. PAAm as opposed to the mixture of two different average mo. wt. PAAm previously required to achieve high resolution.

  10. Investigation of damage mechanism by ionising radiation on biomolecules

    International Nuclear Information System (INIS)

    Lau How Mooi

    1996-01-01

    Occupational radiation hazard is a very controversial subject. Effects from high radiation doses are well known from past experiences. However, hazard from low doses is still a subject that is hotly debated upon until now. The occupational dosimetry used now is based on a macroscopic scale. Lately, microdosimetry is fast gaining recognition as a more superior way of measuring hazard. More importantly, scientists are researching the basic damage mechanism that leads to biological effects by ionising radiation. In this report, a simulation study of the basic damage mechanism is discussed . This simulation is based upon Monte Carlo calculations and using polyuridylic acid (Poly-U) as the DNA model This simulation tries to relate the physics and chemistry of interactions of ionising radiation with biomolecules. The computer codes used in this simulation, OREC and RADLYS were created by Hamm et al. (1983) in Oak Ridge National Laboratory. The biological endpoints in this simulation are the strand break and base release of the DNA, which is the precursor of all biological effects. These results are compared with model studies that had been done experimentally to check the validity of this simulation. The G-values of strand break and base release from this simulation were -2.35 and 2.75 and compared well with results from irradiation experiments by von Sonntag (I 98 7) from Max Plank's Institute, Germany

  11. Hard X-ray-induced optical luminescence via biomolecule-directed metal clusters†

    Science.gov (United States)

    Pratx, Guillem; Sun, Conroy; Sakamoto, Masanori; Ahmad, Moiz; Volotskova, Olga; Ong, Qunxiang; Teranishi, Toshiharu; Harada, Yoshie

    2014-01-01

    Here, we demonstrate that biomolecule-directed metal clusters are applicable in the study of hard X-ray excited optical luminescence, promising a new direction in the development of novel X-ray-activated imaging probes. PMID:24463467

  12. Morphological changes of calcite single crystals induced by graphene-biomolecule adducts

    Science.gov (United States)

    Calvaresi, Matteo; Di Giosia, Matteo; Ianiro, Alessandro; Valle, Francesco; Fermani, Simona; Polishchuk, Iryna; Pokroy, Boaz; Falini, Giuseppe

    2017-01-01

    Calcite has the capability to interact with a wide variety of molecules. This usually induces changes in shape and morphology of crystals. Here, this process was investigated using sheets of graphene-biomolecule adducts. They were prepared and made dispersible in water through the exfoliation of graphite by tip sonication in the presence tryptophan or N-acetyl-D-glucosamine. The crystallization of calcium carbonate in the presence of these additives was obtained by the vapor diffusion method and only calcite formed. The analysis of the microscopic observations showed that the graphene-biomolecule adducts affected shape and morphology of rhombohedral {10.4} faced calcite crystals, due to their stabilization of additional {hk.0} faces. The only presence of the biomolecule affected minimally shape and morphology of calcite crystals, highlighting the key role of the graphene sheets as 2D support for the adsorption of the biomolecules.

  13. Toward the Atomic-Level Mass Analysis of Biomolecules by the Scanning Atom Probe.

    Science.gov (United States)

    Nishikawa, Osamu; Taniguchi, Masahiro

    2017-04-01

    In 1994, a new type of atom probe instrument, named the scanning atom probe (SAP), was proposed. The unique feature of the SAP is the introduction of a small extraction electrode, which scans over a specimen surface and confines the high field, required for field evaporation of surface atoms in a small space, between the specimen and the electrode. Thus, the SAP does not require a sharp specimen tip. This indicates that the SAP can mass analyze the specimens which are difficult to form in a sharp tip, such as organic materials and biomolecules. Clean single wall carbon nanotubes (CNT), made by high-pressure carbon monoxide process are found to be the best substrates for biomolecules. Various amino acids and dipeptide biomolecules were successfully mass analyzed, revealing characteristic clusters formed by strongly bound atoms in the specimens. The mass analysis indicates that SAP analysis of biomolecules is not only qualitative, but also quantitative.

  14. Single-Molecule Flow Platform for the Quantification of Biomolecules Attached to Single Nanoparticles.

    Science.gov (United States)

    Jung, Seung-Ryoung; Han, Rui; Sun, Wei; Jiang, Yifei; Fujimoto, Bryant S; Yu, Jiangbo; Kuo, Chun-Ting; Rong, Yu; Zhou, Xing-Hua; Chiu, Daniel T

    2018-05-15

    We describe here a flow platform for quantifying the number of biomolecules on individual fluorescent nanoparticles. The platform combines line-confocal fluorescence detection with near nanoscale channels (1-2 μm in width and height) to achieve high single-molecule detection sensitivity and throughput. The number of biomolecules present on each nanoparticle was determined by deconvolving the fluorescence intensity distribution of single-nanoparticle-biomolecule complexes with the intensity distribution of single biomolecules. We demonstrate this approach by quantifying the number of streptavidins on individual semiconducting polymer dots (Pdots); streptavidin was rendered fluorescent using biotin-Alexa647. This flow platform has high-throughput (hundreds to thousands of nanoparticles detected per second) and requires minute amounts of sample (∼5 μL at a dilute concentration of 10 pM). This measurement method is an additional tool for characterizing synthetic or biological nanoparticles.

  15. Synthesis of vaterite and aragonite crystals using biomolecules of tomato and capsicum

    Science.gov (United States)

    Chen, Long; Xu, Wang-Hua; Zhao, Ying-Guo; Kang, Yan; Liu, Shao-Hua; Zhang, Zai-Yong

    2012-12-01

    In this paper, biomimetic synthesis of calcium carbonate (CaCO3) in the presence of biomolecules of two vegetables-tomato and capsicum is investigated. Scanning electron microscopy and X-ray powder diffractometry were used to characterize the CaCO3 obtained. The biomolecules in the extracts of two vegetables are determined by UV-vis or FTIR. The results indicate that a mixture of calcite and vaterite spheres constructed from small particles is produced with the extract of tomato, while aragonite rods or ellipsoids are formed in the presence of extract of capsicum. The possible formation mechanism of the CaCO3 crystals with tomato biomolecules can be interpreted by particle-aggregation based non-classical crystallization laws. The proteins and/or other biomolecules in tomato and capsicum may control the formation of vaterite and aragonite crystals by adsorbing onto facets of them.

  16. Inelastic and quasielastic neutron scattering studies on soft matter and biomolecules

    International Nuclear Information System (INIS)

    Kanaya, Toshiji

    2015-01-01

    Some characteristic features of soft matter and biomolecules in the inelastic and quasielastic neutron scattering (INS and QENS) studies are described. In order to clarify the current situation of the studies the research history on soft matter and biomolecules by INS and QENS are described. As examples of the studies of slow dynamics of soft matter, neutron spin echo studies on breathing mode of polymer micelle and static and dynamics fluctuations in polymer gels. (author)

  17. Enhancing Protease Activity Assay in Droplet-Based Microfluidics Using a Biomolecule Concentrator

    Science.gov (United States)

    Chen, Chia-Hung; Sarkar, Aniruddh; Song, Yong-Ak; Miller, Miles A.; Kim, Sung Jae; Griffith, Linda G.; Lauffenburger, Douglas A.; Han, Jongyoon

    2011-01-01

    We introduce an integrated microfluidic device consisting of a biomolecule concentrator and a microdroplet generator, which enhances the limited sensitivity of low-abundance enzyme assays by concentrating biomolecules before encapsulating them into droplet microreactors. We used this platform to detect ultra low levels of matrix metalloproteinases (MMPs) from diluted cellular supernatant and showed that it significantly (∼10-fold) reduced the time required to complete the assay and the sample volume used. PMID:21671557

  18. LIAD-fs: A novel method for studies of ultrafast processes in gas phase neutral biomolecules

    International Nuclear Information System (INIS)

    Calvert, C R; Kelly, O; Duffy, M J; Belshaw, L; King, R B; Williams, I D; Greenwood, J B

    2012-01-01

    A new experimental technique for femtosecond (fs) pulse studies of gas phase biomolecules is reported. Using Laser-Induced Acoustic Desorption (LIAD) to produce a plume of neutral molecules, a time-delayed fs pulse is employed for ionisation/fragmentation, with subsequent products extracted and mass analysed electrostatically. By varying critical laser pulse parameters, this technique can be used to implement control over molecular fragmentation for a range of small biomolecules, with specific studies of amino acids demonstrated.

  19. Recent advances in exploiting ionic liquids for biomolecules: Solubility, stability and applications.

    Science.gov (United States)

    Sivapragasam, Magaret; Moniruzzaman, Muhammad; Goto, Masahiro

    2016-08-01

    The technological utility of biomolecules (e.g. proteins, enzymes and DNA) can be significantly enhanced by combining them with ionic liquids (ILs) - potentially attractive "green" and "designer" solvents - rather than using in conventional organic solvents or water. In recent years, ILs have been used as solvents, cosolvents, and reagents for biocatalysis, biotransformation, protein preservation and stabilization, DNA solubilization and stabilization, and other biomolecule-based applications. Using ILs can dramatically enhance the structural and chemical stability of proteins, DNA, and enzymes. This article reviews the recent technological developments of ILs in protein-, enzyme-, and DNA-based applications. We discuss the different routes to increase biomolecule stability and activity in ILs, and the design of biomolecule-friendly ILs that can dissolve biomolecules with minimum alteration to their structure. This information will be helpful to design IL-based processes in biotechnology and the biological sciences that can serve as novel and selective processes for enzymatic reactions, protein and DNA stability, and other biomolecule-based applications. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Cell and biomolecule delivery for tissue repair and regeneration in the central nervous system.

    Science.gov (United States)

    Elliott Donaghue, Irja; Tam, Roger; Sefton, Michael V; Shoichet, Molly S

    2014-09-28

    Tissue engineering frequently involves cells and scaffolds to replace damaged or diseased tissue. It originated, in part, as a means of effecting the delivery of biomolecules such as insulin or neurotrophic factors, given that cells are constitutive producers of such therapeutic agents. Thus cell delivery is intrinsic to tissue engineering. Controlled release of biomolecules is also an important tool for enabling cell delivery since the biomolecules can enable cell engraftment, modulate inflammatory response or otherwise benefit the behavior of the delivered cells. We describe advances in cell and biomolecule delivery for tissue regeneration, with emphasis on the central nervous system (CNS). In the first section, the focus is on encapsulated cell therapy. In the second section, the focus is on biomolecule delivery in polymeric nano/microspheres and hydrogels for the nerve regeneration and endogenous cell stimulation. In the third section, the focus is on combination strategies of neural stem/progenitor cell or mesenchymal stem cell and biomolecule delivery for tissue regeneration and repair. In each section, the challenges and potential solutions associated with delivery to the CNS are highlighted. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Bio-NCs--the marriage of ultrasmall metal nanoclusters with biomolecules.

    Science.gov (United States)

    Goswami, Nirmal; Zheng, Kaiyuan; Xie, Jianping

    2014-11-21

    Ultrasmall metal nanoclusters (NCs) have attracted increasing attention due to their fascinating physicochemical properties. Today, functional metal NCs are finding growing acceptance in biomedical applications. To achieve a better performance in biomedical applications, metal NCs can be interfaced with biomolecules, such as proteins, peptides, and DNA, to form a new class of biomolecule-NC composites (or bio-NCs in short), which typically show synergistic or novel physicochemical and physiological properties. This feature article focuses on the recent studies emerging at the interface of metal NCs and biomolecules, where the interactions could impart unique physicochemical properties to the metal NCs, as well as mutually regulate biological functions of the bio-NCs. In this article, we first provide a broad overview of key concepts and developments in the novel biomolecule-directed synthesis of metal NCs. A special focus is placed on the key roles of biomolecules in metal NC synthesis. In the second part, we describe how the encapsulated metal NCs affect the structure and function of biomolecules. Followed by that, we discuss several unique synergistic effects observed in the bio-NCs, and illustrate them with examples highlighting their potential biomedical applications. Continued interdisciplinary efforts are required to build up in-depth knowledge about the interfacial chemistry and biology of bio-NCs, which could further pave their ways toward biomedical applications.

  2. Generating multiplex gradients of biomolecules for controlling cellular adhesion in parallel microfluidic channels.

    Science.gov (United States)

    Didar, Tohid Fatanat; Tabrizian, Maryam

    2012-11-07

    Here we present a microfluidic platform to generate multiplex gradients of biomolecules within parallel microfluidic channels, in which a range of multiplex concentration gradients with different profile shapes are simultaneously produced. Nonlinear polynomial gradients were also generated using this device. The gradient generation principle is based on implementing parrallel channels with each providing a different hydrodynamic resistance. The generated biomolecule gradients were then covalently functionalized onto the microchannel surfaces. Surface gradients along the channel width were a result of covalent attachments of biomolecules to the surface, which remained functional under high shear stresses (50 dyn/cm(2)). An IgG antibody conjugated to three different fluorescence dyes (FITC, Cy5 and Cy3) was used to demonstrate the resulting multiplex concentration gradients of biomolecules. The device enabled generation of gradients with up to three different biomolecules in each channel with varying concentration profiles. We were also able to produce 2-dimensional gradients in which biomolecules were distributed along the length and width of the channel. To demonstrate the applicability of the developed design, three different multiplex concentration gradients of REDV and KRSR peptides were patterned along the width of three parallel channels and adhesion of primary human umbilical vein endothelial cell (HUVEC) in each channel was subsequently investigated using a single chip.

  3. Desalting by crystallization: detection of attomole biomolecules in picoliter buffers by mass spectrometry.

    Science.gov (United States)

    Gong, Xiaoyun; Xiong, Xingchuang; Wang, Song; Li, Yanyan; Zhang, Sichun; Fang, Xiang; Zhang, Xinrong

    2015-10-06

    Sensitive detection of biomolecules in small-volume samples by mass spectrometry is, in many cases, challenging because of the use of buffers to maintain the biological activities of proteins and cells. Here, we report a highly effective desalting method for picoliter samples. It was based on the spontaneous separation of biomolecules from salts during crystallization of the salts. After desalting, the biomolecules were deposited in the tip of the quartz pipet because of the evaporation of the solvent. Subsequent detection of the separated biomolecules was achieved using solvent assisted electric field induced desorption/ionization (SAEFIDI) coupled with mass spectrometry. It allowed for direct desorption/ionization of the biomolecules in situ from the tip of the pipet. The organic component in the assistant solvent inhibited the desorption/ionization of salts, thus assured successful detection of biomolecules. Proteins and peptides down to 50 amol were successfully detected using our method even if there were 3 × 10(5) folds more amount of salts in the sample. The concentration and ion species of the salts had little influence on the detection results.

  4. Bio-NCs - the marriage of ultrasmall metal nanoclusters with biomolecules

    Science.gov (United States)

    Goswami, Nirmal; Zheng, Kaiyuan; Xie, Jianping

    2014-10-01

    Ultrasmall metal nanoclusters (NCs) have attracted increasing attention due to their fascinating physicochemical properties. Today, functional metal NCs are finding growing acceptance in biomedical applications. To achieve a better performance in biomedical applications, metal NCs can be interfaced with biomolecules, such as proteins, peptides, and DNA, to form a new class of biomolecule-NC composites (or bio-NCs in short), which typically show synergistic or novel physicochemical and physiological properties. This feature article focuses on the recent studies emerging at the interface of metal NCs and biomolecules, where the interactions could impart unique physicochemical properties to the metal NCs, as well as mutually regulate biological functions of the bio-NCs. In this article, we first provide a broad overview of key concepts and developments in the novel biomolecule-directed synthesis of metal NCs. A special focus is placed on the key roles of biomolecules in metal NC synthesis. In the second part, we describe how the encapsulated metal NCs affect the structure and function of biomolecules. Followed by that, we discuss several unique synergistic effects observed in the bio-NCs, and illustrate them with examples highlighting their potential biomedical applications. Continued interdisciplinary efforts are required to build up in-depth knowledge about the interfacial chemistry and biology of bio-NCs, which could further pave their ways toward biomedical applications.

  5. Os conflitos conjugais na perspectiva dos filhos

    Directory of Open Access Journals (Sweden)

    Viviane Ribeiro Goulart

    2013-01-01

    Full Text Available Se investigó sobre la perspectiva de los hijos en los conflictos conyugales. Participaron 17 estudiantes de una escuela pública de Porto Alegre (RS, de ambos sexos, reunidos en dos grupos focales: uno con 8 niños (8-9 años, y otro con 9 jóvenes (12-13 años, que vivían con sus padres. Cada grupo ha tenido sólo una cita en la escuela. Las informaciones fueron grabadas, transcritas y el contenido analizado a partir de los temas emergentes. De acuerdo con los niños, los conflictos conyugales van desde una discusión hasta la agresión física, son recurrientes, versan sobre cualquier tema, y su expresión es predominantemente negativa. Los niños reconocen la existencia del conflicto pero ni siempre entienden sus causas y todavía sufren sus consecuencias. Los niños adoptan distintas estrategias para lidiar con los conflictos, desde ignorarlos hasta las actitudes autodestructivas. Se concluye que los sujetos son conscientes de los conflictos conyugales de sus padres y reconocen sus repercusiones.

  6. en perspectiva de género

    Directory of Open Access Journals (Sweden)

    Elena Hernández Corrochano

    2008-01-01

    Full Text Available Los estudios sobre la familia, desde las diferentes perspectivas que aquí trato, nos muestran no sólo la importancia del parentesco en las relaciones sociales y en la construcción de la identidad de los sujetos, sino que nos indica cómo en sociedades definidas como modernizadas –donde los Estado sólo tienen interés en alcanzar un cambio económico y el acceso a las nuevas tecnologías, olvidándose de las cuestiones sociales, políticas o filosóficas que caracterizan a la modernidad– a mayor individualismo en las acciones de los varones, mayor sujeción de las mujeres al grupo. En estas sociedades la “autorización” que la comunidad da a los hombres para actuar en relación con sus intereses personales, “endurece” la posición de las mujeres que deben, con relación a su bienestar, mantener un orden social comunitario simbolizado por la buena familia y custodiado por una opinión pública que limita su capacidad de actuar como individuos.

  7. Brexit na perspectiva do Path Dependency

    Directory of Open Access Journals (Sweden)

    Giorgio Romano Schutte

    2018-02-01

    Full Text Available Esta pesquisa analisou o Brexit em uma perspectiva histórica, focando a conturbada relação entre a Europa continental e o Reino Unido ao longo do século XX, com ênfase no período pós Segunda Guerra Mundial. Foi utilizado o conceito de path dependency para argumentar sobre o papel de fatores históricos e decisões do passado, embora tomados em outras circunstâncias, ainda com força para influenciar o presente, para entender o Brexit. A premissa básica que será apresentada no ensaio é que o Reino Unido nunca participou de fato da ideia da Europa e sempre se viu como um país diferente por sua história e seu papel no mundo. Quando entrou, foi com uma perna só, a outra sempre ficou atrás, inclusive devido às especificidades de sua estrutura econômica herdada do passado, em particular no que diz respeito à agricultura. Desta forma, defende-se que, embora longe de ter sido inevitável, se tratou de um fenômeno limitado ao Reino Unido que tinha pouquíssima probabilidade de se repetir em outros países da União Europeia.

  8. Productividad, trabajo y salud: la perspectiva psicosocial

    Directory of Open Access Journals (Sweden)

    York Iván Puerto Barrios

    2007-07-01

    Full Text Available Con la opción de analizar las condiciones de trabajo en oficina, el texto realiza una sucinta pero precisa revisión de la conceptualización sobre productividad y consumo. Se documenta la relación contradictoria entre bienestar y rendimiento en el trabajo al identificar el riesgo de llevar al límite de sus capacidades la participación del trabajador como factor de productividad, ignorando que éste tiene además el rol de consumidor activo de bienes y servicios para que la producción tenga sentido. Se plantea que exigir al trabajador hasta su agotamiento puede mermar sustancialmente su doble condición de productor y consumidor. Específicamente, se presenta la perspectiva del trabajo en oficinas innovadas conceptual y tecnológicamente, con procesos laborales y patrones de desgaste y morbilidad de"nidos. El tiempo, el ritmo, la parcelación, el control del trabajo y la reestructuración en las organizaciones son, entre otros, factores que convergen para potenciar fenómenos de sobrecarga o subcarga mental con la consecuente aparición de estrés excedente y sus patologías asociadas.

  9. An analytical method for computing atomic contact areas in biomolecules.

    Science.gov (United States)

    Mach, Paul; Koehl, Patrice

    2013-01-15

    We propose a new analytical method for detecting and computing contacts between atoms in biomolecules. It is based on the alpha shape theory and proceeds in three steps. First, we compute the weighted Delaunay triangulation of the union of spheres representing the molecule. In the second step, the Delaunay complex is filtered to derive the dual complex. Finally, contacts between spheres are collected. In this approach, two atoms i and j are defined to be in contact if their centers are connected by an edge in the dual complex. The contact areas between atom i and its neighbors are computed based on the caps formed by these neighbors on the surface of i; the total area of all these caps is partitioned according to their spherical Laguerre Voronoi diagram on the surface of i. This method is analytical and its implementation in a new program BallContact is fast and robust. We have used BallContact to study contacts in a database of 1551 high resolution protein structures. We show that with this new definition of atomic contacts, we generate realistic representations of the environments of atoms and residues within a protein. In particular, we establish the importance of nonpolar contact areas that complement the information represented by the accessible surface areas. This new method bears similarity to the tessellation methods used to quantify atomic volumes and contacts, with the advantage that it does not require the presence of explicit solvent molecules if the surface of the protein is to be considered. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.

  10. Microcontact printing with aminosilanes: creating biomolecule micro- and nanoarrays for multiplexed microfluidic bioassays.

    Science.gov (United States)

    Sathish, Shivani; Ricoult, Sébastien G; Toda-Peters, Kazumi; Shen, Amy Q

    2017-05-21

    Microfluidic systems integrated with protein and DNA micro- and nanoarrays have been the most sought-after technologies to satisfy the growing demand for high-throughput disease diagnostics. As the sensitivity of these systems relies on the bio-functionalities of the patterned recognition biomolecules, the primary concern has been to develop simple technologies that enable biomolecule immobilization within microfluidic devices whilst preserving bio-functionalities. To address this concern, we introduce a two-step patterning approach to create micro- and nanoarrays of biomolecules within microfluidic devices. First, we introduce a simple aqueous based microcontact printing (μCP) method to pattern arrays of (3-aminopropyl)triethoxysilane (APTES) on glass substrates, with feature sizes ranging from a few hundred microns down to 200 nm (for the first time). Next, these substrates are integrated with microfluidic channels to then covalently couple DNA aptamers and antibodies with the micro- and nanopatterned APTES. As these biomolecules are covalently tethered to the device substrates, the resulting bonds enable them to withstand the high shear stresses originating from the flow in these devices. We further demonstrated the flexibility of this technique, by immobilizing multiple proteins onto these APTES-patterned substrates using liquid-dispensing robots to create multiple microarrays. Next, to validate the functionalities of these microfluidic biomolecule microarrays, we perform (i) aptamer-based sandwich immunoassays to detect human interleukin 6 (IL6); and (ii) antibody-based sandwich immunoassays to detect human c-reactive protein (hCRP) with the limit of detection at 5 nM, a level below the range required for clinical screening. Lastly, the shelf-life potential of these ready-to-use microfluidic microarray devices is validated by effectively functionalizing the patterns with biomolecules up to 3 months post-printing. In summary, with a single printing step, this

  11. Selective chromogenic detection of thiol-containing biomolecules using carbonaceous nanospheres loaded with silver nanoparticles as carrier.

    Science.gov (United States)

    Hu, Bo; Zhao, Yang; Zhu, Hai-Zhou; Yu, Shu-Hong

    2011-04-26

    Thiol-containing biomolecules show strong affinity with noble metal nanostructures and could not only stably protect them but also control the self-assembly process of these special nanostructures. A highly selective and sensitive chromogenic detection method has been designed for the low and high molecular weight thiol-containing biomolecules, including cysteine, glutathione, dithiothreitol, and bovine serum albumin, using a new type of carbonaceous nanospheres loaded with silver nanoparticles (Ag NPs) as carrier. This strategy relies upon the place-exchange process between the reporter dyes on the surface of Ag NPs and the thiol groups of thiol-containing biomolecules. The concentration of biomolecules can be determined by monitoring with the fluorescence intensity of reporter dyes dispersed in solution. This new chromogenic assay method could selectively detect these biomolecules in the presence of various other amino acids and monosaccharides and even sensitively detect the thiol-containing biomolecules with different molecular weight, even including proteins.

  12. O banco do futuro: perspectivas e desafios

    Directory of Open Access Journals (Sweden)

    André Accorsi

    2014-03-01

    Full Text Available Neste artigo, apresentam-se as perspectivas e os desafios dos bancos no futuro. Com o referencial teórico sobre o tema, construiu-se um questionário para identificar o grau de importância atribuído a 20 diferentes questões. Na pesquisa de campo, abarcaram-se 93 bancários dos níveis gerencial e operacional dos principais bancos brasileiros e 9 professores universitários especialistas em mercado financeiro. Os dados coletados foram analisados estatisticamente usando-se o software Statistical Package for the Social Sciences, versão 13.0. Observando-se as principais conclusões da amostra, não há diferença estatística entre os funcionários dos bancos pesquisados, mas o mesmo não ocorreu entre bancários e professores. Algumas variáveis apresentaram maior relevância: combate às fraudes, business intelligence, bancarização e atendimento rápido. A partir da análise fatorial, identificaram-se seis fatores: sustentabilidade e papel do Brasil; mobilidade e segurança; regulação e novas tecnologias; globalização, inserção e privacidade; atendimento inteligente e bancarização. Pela análise discriminante, classificaram-se corretamente 79,3 e 66,7% dos funcionários do Bradesco e do Banco do Brasil, respectivamente, e 78,8% dos gerentes.

  13. El bienestar subjetivo: Actualidad y perspectivas

    Directory of Open Access Journals (Sweden)

    Guillermo Díaz Llanes

    2001-12-01

    Full Text Available Se realizó una revisión de los trabajos sobre bienestar subjetivo publicados en el mundo en los últimos años y se analizaron críticamente los resultados obtenidos tomando en consideración algunos de los fundamentos epistemológicos que les sirvieron de sustento. La enorme vigencia de los estudios sobre bienestar subjetivo en la actualidad pone de manifiesto la creciente conciencia de los investigadores acerca de la importancia del estudio de los factores que tributan a la salud desde una perspectiva positiva. La comprensión de la compleja madeja de interacciones que determinan el bienestar subjetivo en los niveles macrosocial, microsocial e individual, resulta requisito indispensable para la instrumentación de intervenciones en el nivel primario de atención y así elevar dicho indicador, tan ligado a la salud.A review of the papers on subjective well-being published in the world during the last years was made. The results obtained were critically analyzed taking into account the epistemological foundations that served as a sustenance. The fact that the studies about subjective well-being are still in force shows the increasing awareness of the investigators about the importance of studying those factors influencing positively on health. The understanding of the complex skein of interactions determining the subjective well-being at the macrosocial, microsocial and individual levels is an indispensable requirement for the implementation of interventions at the primary health care level and for elevating this indicator so closely related to health.

  14. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    International Nuclear Information System (INIS)

    Susanto, H.; Roihatin, A.; Aryanti, N.; Anggoro, D.D.; Ulbricht, M.

    2012-01-01

    We characterized the membranes before and after modification. ► We examined the unmodified and modified membranes for biomolecules filtration. ► All the modifications changed the membrane characteristics and the membrane performance. ► All the modifications resulted in UF membranes having higher resistance towards fouling.

  15. Formation of noble metal nanocrystals in the presence of biomolecules

    Science.gov (United States)

    Burt, Justin Lockheart

    One of the most promising, yet least studied routes for producing biocompatible nanostructures involves synthesis in the presence of biomolecules. I hypothesized that globular proteins could provide a suitable framework to regulate the formation of noble metal nanocrystals. As proof of concept, I designed two novel synthesis protocols utilizing bovine serum albumin (BSA) protein to regulate the formation of gold nanocrystals. In the first case, the standard protocol for polyol reduction was modified by replacing ethylene glycol with glycerin, replacing synthetic polymers with BSA as protecting agent, and decreasing the reaction temperature. In the second case, the Brust-Schiffrin two-phase reduction was modified by replacing alkylthiols with BSA as protecting agent, which facilitated a strictly aqueous phase synthesis. Due to superior product yield and rapid reduction at room temperature, the aqueous protocol became the foundation for subsequent studies. I extended this approach to produce well-dispersed ˜2nm silver, gold, and platinum nanocrystals. Having demonstrated the feasibility of BSA-functionalized nanocrystals, some potential uses were explored. BSA-functionalized silver nanocrystals were employed in a broader study on the interaction of silver nanocrystals with HIV. BSA-functionalized gold nanocrystals were utilized for in vivo dosage of a contrast enhancing agent to bacteria. BSA-functionalized platinum nanocrystals were studied as hydrogenation catalysts. Since many intriguing uses for protein-functionalized nanocrystals involve incorporation into biosystems, I sought to enhance biocompatibility by using ascorbic acid as reducing agent. Initial experiments revealed elongated and branched nanocrystals. Such structures were not observed in previous synthesis protocols with BSA, so I hypothesized ascorbic acid was driving their formation. To test my assertion, I reduced ionic gold in an aqueous solution of ascorbic acid, thereby discovering a new method

  16. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    Energy Technology Data Exchange (ETDEWEB)

    Susanto, H., E-mail: heru.susanto@undip.ac.id [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Roihatin, A.; Aryanti, N.; Anggoro, D.D. [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Ulbricht, M. [Lehrstuhl fuer Technische Chemie, Universitaet Duisburg-Essen, Germany, Universitaetstr. 5, Essen (Germany)

    2012-10-01

    fouling ultrafiltration (UF) membranes. Black-Right-Pointing-Pointer We characterized the membranes before and after modification. Black-Right-Pointing-Pointer We examined the unmodified and modified membranes for biomolecules filtration. Black-Right-Pointing-Pointer All the modifications changed the membrane characteristics and the membrane performance. Black-Right-Pointing-Pointer All the modifications resulted in UF membranes having higher resistance towards fouling.

  17. Room temperature ionic liquids interacting with bio-molecules: an overview of experimental and computational studies

    Science.gov (United States)

    Benedetto, Antonio; Ballone, Pietro

    2016-03-01

    We briefly review experimental and computational studies of room temperature ionic liquids (RTILs) interacting with important classes of biomolecules, including phospholipids, peptides and proteins, nucleic acids and carbohydrates. Most of these studies have been driven by the interest for RTILs applications as solvents. Thus, available experimental data cover primarily thermodynamic properties such as the reciprocal solubility of RTILs and bio-molecules, as well as phase boundaries. Less extensive data are also available on transport properties such as diffusion and viscosity of homogeneous binary (RTILs/biomolecules) and ternary (RTIL/biomolecules/water) solutions. Most of the structural information at the atomistic level, of interest especially for biochemical, pharmaceutical and nanotechnology applications, has been made available by molecular dynamics simulations. Major exceptions to this statement are represented by the results from NMR and circular dichroism spectroscopy, by selected neutron and X-ray scattering data, and by recent neutron reflectometry measurements on lipid bilayers on surfaces, hydrated by water-RTIL solutions. A final section of our paper summarizes new developments in the field of RTILs based on amino acids, that combine in themselves the two main aspects of our discussion, i.e. ionic liquids and bio-molecules.

  18. Different size biomolecules anchoring on porous silicon surface: fluorescence and reflectivity pores infiltration comparative studies

    Energy Technology Data Exchange (ETDEWEB)

    Giovannozzi, Andrea M.; Rossi, Andrea M. [National Institute for Metrological Research, Thermodynamic Division, Strada delle Cacce 91, 10135 Torino (Italy); Renacco, Chiara; Farano, Alessandro [Ribes Ricecrhe Srl, Via Lavoratori Vittime del Col du Mont 24, 11100 Aosta (Italy); Derosas, Manuela [Biodiversity Srl, Via Corfu 71, 25124 Brescia (Italy); Enrico, Emanuele [National Institute for Metrological Research, Electromagnetism Division, Strada delle Cacce 91, 10135 Torino (Italy)

    2011-06-15

    The performance of porous silicon optical based biosensors strongly depends on material nanomorphology, on biomolecules distribution inside the pores and on the ability to link sensing species to the pore walls. In this paper we studied the immobilization of biomolecules with different size, such as antibody anti aflatoxin (anti Aflatox Ab, {proportional_to}150 KDa), malate dehydrogenase (MDH, {proportional_to}36KDa) and metallothionein (MT, {proportional_to}6KDa) at different concentrations on mesoporous silicon samples ({proportional_to}15 nm pores diameter). Fluorescence measurements using FITC- labeled biomolecules and refractive index analysis based on reflectivity spectra have been employed together to detect the amount of proteins bound to the surface and to evaluate their diffusion inside the pores. Here we suggest that these two techniques should be used together to have a better understanding of what happens at the porous silicon surface. In fact, when pores dimensions are not perfectly tuned to the protein size a higher fluorescence signal doesn't often correspond to a higher biomolecules distribution inside the pores. When a too much higher concentration of biomolecule is anchored on the surface, steric crowd effects and repulsive interactions probably take over and hinder pores infiltration, inducing a small or absent shift in the fringe pattern even if a higher fluorescence signal is registered. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Conditions to minimize soft single biomolecule deformation when imaging with atomic force microscopy.

    Science.gov (United States)

    Godon, Christian; Teulon, Jean-Marie; Odorico, Michael; Basset, Christian; Meillan, Matthieu; Vellutini, Luc; Chen, Shu-Wen W; Pellequer, Jean-Luc

    2017-03-01

    A recurrent interrogation when imaging soft biomolecules using atomic force microscopy (AFM) is the putative deformation of molecules leading to a bias in recording true topographical surfaces. Deformation of biomolecules comes from three sources: sample instability, adsorption to the imaging substrate, and crushing under tip pressure. To disentangle these causes, we measured the maximum height of a well-known biomolecule, the tobacco mosaic virus (TMV), under eight different experimental conditions positing that the maximum height value is a specific indicator of sample deformations. Six basic AFM experimental factors were tested: imaging in air (AIR) versus in liquid (LIQ), imaging with flat minerals (MICA) versus flat organic surfaces (self-assembled monolayers, SAM), and imaging forces with oscillating tapping mode (TAP) versus PeakForce tapping (PFT). The results show that the most critical parameter in accurately measuring the height of TMV in air is the substrate. In a liquid environment, regardless of the substrate, the most critical parameter is the imaging mode. Most importantly, the expected TMV height values were obtained with both imaging with the PeakForce tapping mode either in liquid or in air at the condition of using self-assembled monolayers as substrate. This study unambiguously explains previous poor results of imaging biomolecules on mica in air and suggests alternative methodologies for depositing soft biomolecules on well organized self-assembled monolayers. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Role of PAMAM-OH dendrimers against the fibrillation pathway of biomolecules.

    Science.gov (United States)

    Sekar, Gajalakshmi; Florance, Ida; Sivakumar, A; Mukherjee, Amitava; Chandrasekaran, Natarajan

    2016-12-01

    The binding behavior of nanoparticle with proteins determines its biocompatibility. This study reports the interaction of ten different biomolecules (proteins-BSA, HSA, haemoglobin, gamma globulin, transferrin and enzymes-hog and bacillus amylase, lysozyme from chicken and human and laccases from Tramates versicolor) with a surface group hydroxylated Poly AMido AMide dendrimer (PAMAM) of generation 5. The study has utilized various spectroscopic methods like UV-vis spectroscopy, Fluorescence emission, Synchronous, 3-D spectroscopy and Circular Dichroism to detect the binding induced structural changes in biomolecules that occur upon interaction with mounting concentration of the dendrimers. Aggregation of proteins results in the formation of amyloid fibrils causing several human diseases. In this study, fibrillar samples of all ten biomolecules formed in the absence and the presence of dendrimers were investigated with Congo Red absorbance and ThT Assay to detect fibril formation, Trp Emission and 3-D scan to evaluate the effect of fibrillation on aromatic environment of biomolecules, and CD spectroscopy to measure the conformational changes in a quantitative manner. These assays have generated useful information on the role of dendrimers in amyloid fibril formation of biomolecules. The outcomes of the study remain valuable in evaluating the biological safety of PAMAM-OH dendrimers for their biomedical application in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Constructing Optimal Coarse-Grained Sites of Huge Biomolecules by Fluctuation Maximization.

    Science.gov (United States)

    Li, Min; Zhang, John Zenghui; Xia, Fei

    2016-04-12

    Coarse-grained (CG) models are valuable tools for the study of functions of large biomolecules on large length and time scales. The definition of CG representations for huge biomolecules is always a formidable challenge. In this work, we propose a new method called fluctuation maximization coarse-graining (FM-CG) to construct the CG sites of biomolecules. The defined residual in FM-CG converges to a maximal value as the number of CG sites increases, allowing an optimal CG model to be rigorously defined on the basis of the maximum. More importantly, we developed a robust algorithm called stepwise local iterative optimization (SLIO) to accelerate the process of coarse-graining large biomolecules. By means of the efficient SLIO algorithm, the computational cost of coarse-graining large biomolecules is reduced to within the time scale of seconds, which is far lower than that of conventional simulated annealing. The coarse-graining of two huge systems, chaperonin GroEL and lengsin, indicates that our new methods can coarse-grain huge biomolecular systems with up to 10,000 residues within the time scale of minutes. The further parametrization of CG sites derived from FM-CG allows us to construct the corresponding CG models for studies of the functions of huge biomolecular systems.

  2. Immobilization of biomolecules on cysteamine-modified polyaniline film for highly sensitive biosensing.

    Science.gov (United States)

    Cai, Qi; Xu, Baojian; Ye, Lin; Di, Zengfeng; Zhang, Jishen; Jin, Qinghui; Zhao, Jianlong; Xue, Jian; Chen, Xianfeng

    2014-03-01

    We present a new cysteamine (CS)-modified polyaniline (PANI) film for highly efficient immobilization of biomolecules in biosensing technology. This electrochemical deposited PANI film treated with CS and glutaraldehyde could be employed as an excellent substrate for biomolecules immobilization. The parameters of PANI growth were optimized to obtain suitable surface morphology of films for biomolecules combination with the help of electron and atomic force microscopy. Cyclic voltammetry (CV) was utilized to illustrate the different electrochemical activities of each modified electrode. Due to the existence of sulfydryl group and amino group in CS, surface modification with CS was proven to reduce oxidized units on PANI film remarkably, as evidenced by both ATR-FTIR and Raman spectroscopy characterizations. Furthermore, bovine serum albumin (BSA) was used as the model protein to investigate the immobilization efficiency of biomolecules on the PANI film, comparative study using quartz crystal microbalance (QCM) showed that BSA immobilized on CS-modified PANI could be increased by at least 20% than that without CS-modified PANI in BSA solution with the concentration of 0.1-1mg/mL. The CS-modified PANI film would be significant for the immobilization and detection of biomolecules and especially promising in the application of immunosensor for ultrasensitive detection. © 2013 Published by Elsevier B.V.

  3. Fabrication of biomolecules self-assembled on Au nanodot array for bioelectronic device.

    Science.gov (United States)

    Lee, Taek; Kumar, Ajay Yagati; Yoo, Si-Youl; Jung, Mi; Min, Junhong; Choi, Jeong-Woo

    2013-09-01

    In the present study, an nano-platform composed of Au nanodot arrays on which biomolecules could be self-assembled was developed and investigated for a stable bioelectronic device platform. Au nanodot pattern was fabricated using a nanoporous alumina template. Two different biomolecules, a cytochrome c and a single strand DNA (ssDNA), were immobilized on the Au nanodot arrays. Cytochorme c and single stranded DNA could be immobilized on the Au nanodot using the chemical linker 11-MUA and thiol-modification by covalent bonding, respectively. The atomic structure of the fabricated nano-platform device was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrical conductivity of biomolecules immobilized on the Au nanodot arrays was confirmed by scanning tunneling spectroscopy (STS). To investigate the activity of biomolecule-immobilized Au-nano dot array, the cyclic voltammetry was carried out. This proposed nano-platform device, which is composed of biomolecules, can be used for the construction of a novel bioelectronic device.

  4. A new algorithm for construction of coarse-grained sites of large biomolecules.

    Science.gov (United States)

    Li, Min; Zhang, John Z H; Xia, Fei

    2016-04-05

    The development of coarse-grained (CG) models for large biomolecules remains a challenge in multiscale simulations, including a rigorous definition of CG representations for them. In this work, we proposed a new stepwise optimization imposed with the boundary-constraint (SOBC) algorithm to construct the CG sites of large biomolecules, based on the s cheme of essential dynamics CG. By means of SOBC, we can rigorously derive the CG representations of biomolecules with less computational cost. The SOBC is particularly efficient for the CG definition of large systems with thousands of residues. The resulted CG sites can be parameterized as a CG model using the normal mode analysis based fluctuation matching method. Through normal mode analysis, the obtained modes of CG model can accurately reflect the functionally related slow motions of biomolecules. The SOBC algorithm can be used for the construction of CG sites of large biomolecules such as F-actin and for the study of mechanical properties of biomaterials. © 2015 Wiley Periodicals, Inc.

  5. Radical Reactions in the Gas Phase: Recent Development and Application in Biomolecules

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2014-01-01

    Full Text Available This review summarizes recent literature describing the use of gas phase radical reactions for structural characterization of complex biomolecules other than peptides. Specifically, chemical derivatization, in-source chemical reaction, and gas phase ion/ion reactions have been demonstrated as effective ways to generate radical precursor ions that yield structural informative fragments complementary to those from conventional collision-induced dissociation (CID. Radical driven dissociation has been applied to a variety of biomolecules including peptides, nucleic acids, carbohydrates, and phospholipids. The majority of the molecules discussed in this review see limited fragmentation from conventional CID, and the gas phase radical reactions open up completely new dissociation channels for these molecules and therefore yield high fidelity confirmation of the structures of the target molecules. Due to the extensively studied peptide fragmentation, this review focuses only on nonpeptide biomolecules such as nucleic acids, carbohydrates, and phospholipids.

  6. Control of Target Molecular Recognition in a Small Pore Space with Biomolecule-Recognition Gating Membrane.

    Science.gov (United States)

    Okuyama, Hiroto; Oshiba, Yuhei; Ohashi, Hidenori; Yamaguchi, Takeo

    2018-05-01

    A biomolecule-recognition gating membrane, which introduces thermosensitive graft polymer including molecular recognition receptor into porous membrane substrate, can close its pores by recognizing target biomolecule. The present study reports strategies for improving both versatility and sensitivity of the gating membrane. First, the membrane is fabricated by introducing the receptor via a selectively reactive click reaction improving the versatility. Second, the sensitivity of the membrane is enhanced via an active delivering method of the target molecules into the pores. In the method, the tiny signal of the target biomolecule is amplified as obvious pressure change. Furthermore, this offers 15 times higher sensitivity compared to the previously reported passive delivering method (membrane immersion to sample solution) with significantly shorter recognition time. The improvement will aid in applying the gating membrane to membrane sensors in medical fields. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The origin of methane and biomolecules from a CO2 cycle on terrestrial planets

    Science.gov (United States)

    Civiš, Svatopluk; Knížek, Antonín; Ivanek, Ondřej; Kubelík, Petr; Zukalová, Markéta; Kavan, Ladislav; Ferus, Martin

    2017-10-01

    Understanding the chemical evolution of newly formed terrestrial planets involves uncertainties in atmospheric chemical composition and assessing the plausibility of biomolecule synthesis. In this study, an original scenario for the origin of methane on Mars and terrestrial planets is suggested. Carbon dioxide in Martian and other planetary atmospheres can be abiotically converted into a mixture of methane and carbon monoxide by `methanogenesis' on porous mineral photoactive surfaces under soft ultraviolet irradiation. On young planets exposed to heavy bombardment by interplanetary matter, this process can be followed by biomolecule synthesis through the reprocessing of reactive reducing atmospheres by impact-induced shock waves. The proposed mechanism of methanogenesis may help to answer the question concerning the formation of methane and carbon monoxide by photochemical processes, the formation of biomolecules on early Earth and other terrestrial planets, and the source and seasonal variation of methane concentrations on Mars.

  8. Light-triggerable formulations for the intracellular controlled release of biomolecules.

    Science.gov (United States)

    Lino, Miguel M; Ferreira, Lino

    2018-05-01

    New therapies based on the use of biomolecules [e.g., proteins, peptides, and non-coding (nc)RNAs] have emerged during the past few years. Given their instability, adverse effects, and limited ability to cross cell membranes, delivery systems are required to fully reveal their biological potential. Sophisticated nanoformulations responsive to light offer an excellent opportunity for the controlled release of these biomolecules, enabling the control of timing, duration, location, and dosage. In this review, we discuss the design principles for the delivery of biomolecules, in particular proteins and RNA-based therapeutics, by light-triggerable formulations. We further discuss the opportunities offered by these formulations in terms of endosomal escape, as well as their limitations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Recoil halogen reactions in liquid and frozen aqueous solutions of biomolecules

    International Nuclear Information System (INIS)

    Arsenault, L.J.; Blotcky, A.J.; Firouzbakht, M.L.; Rack, E.P.; Nebraska Univ., Omaha

    1982-01-01

    Reactions of recoil 38 Cl, 80 Br and 128 I have been studied in crystalline systems of 5-halouracil, 5-halo-2'-deoxyuridine and 5-halouridine as well as liquid and frozen aqueous solutions of these halogenated biomolecules. In all systems expect crystalline 5-iuodouracil the major product was the radio-labelled halide ion. There was no evidence for other halogen inorganic species. The major labelled organic product was the parent molecule. A recoil atom tracer technique was developed to acquire site information of the biomolecule solutes in the liquid and frozen aqueous systems. For all liquid and frozen aqueous systems, the halogenated biomolecules tended to aggregate. For liquid systems, the tendency for aggregation diminished as the solute concentration approached zero, where the probable state of the solute approached a monomolecular dispersion. Unlike the liquid state, the frozen ice lattice demonstated a ''caging effect'' for the solute aggregates which resulted in constant product yields over the whole concentration range. (orig.)

  10. Could comets be carriers of intact homochiral biomolecules from interstellar space?

    International Nuclear Information System (INIS)

    Navarro Gonzales, R.; Khanna, R.K.; Ponnamperuma, C.

    1992-01-01

    It has been suggested that the synchrotron circularly polarized ultraviolet light produced off-angle to the orbit of neutron star remnants of supernova explosions interacted with interstellar grains from the presolar nebula producing chiral molecules. Furthermore, it has also been suggested that comets were the carriers of such extraterrestrial sources of homochirality from interstellar space to the primitive Earth. We present here a computer model calculation of the effect of ionizing radiation on cometary material. The external (cosmic rays) and internal (embedded radionuclides) contributions were considered to determine the degree of destruction of possible homochiral biomolecules present such as amino acids and carboxylic acids. Our results suggest that an insignificant degree of destruction (2-12%) of the homochiral biomolecules could be expected. Therefore, comets could be carriers of intact homochiral biomolecules. (author)

  11. SERS imaging of cell-surface biomolecules metabolically labeled with bioorthogonal Raman reporters.

    Science.gov (United States)

    Xiao, Ming; Lin, Liang; Li, Zefan; Liu, Jie; Hong, Senlian; Li, Yaya; Zheng, Meiling; Duan, Xuanming; Chen, Xing

    2014-08-01

    Live imaging of biomolecules with high specificity and sensitivity as well as minimal perturbation is essential for studying cellular processes. Here, we report the development of a bioorthogonal surface-enhanced Raman scattering (SERS) imaging approach that exploits small Raman reporters for visualizing cell-surface biomolecules. The cells were cultured and imaged by SERS microscopy on arrays of Raman-enhancing nanoparticles coated on silicon wafers or glass slides. The Raman reporters including azides, alkynes, and carbondeuterium bonds are small in size and spectroscopically bioorthogonal (background-free). We demonstrated that various cell-surface biomolecules including proteins, glycans, and lipids were metabolically incorporated with the corresponding precursors bearing a Raman reporter and visualized by SERS microscopy. The coupling of SERS microscopy with bioorthogonal Raman reporters expands the capabilities of live-cell microscopy beyond the modalities of fluorescence and label-free imaging. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Composite Scaffold of Poly(Vinyl Alcohol) and Interfacial Polyelectrolyte Complexation Fibers for Controlled Biomolecule Delivery

    Science.gov (United States)

    Cutiongco, Marie Francene A.; Choo, Royden K. T.; Shen, Nathaniel J. X.; Chua, Bryan M. X.; Sju, Ervi; Choo, Amanda W. L.; Le Visage, Catherine; Yim, Evelyn K. F.

    2015-01-01

    Controlled delivery of hydrophilic proteins is an important therapeutic strategy. However, widely used methods for protein delivery suffer from low incorporation efficiency and loss of bioactivity. The versatile interfacial polyelectrolyte complexation (IPC) fibers have the capacity for precise spatiotemporal release and protection of protein, growth factor, and cell bioactivity. Yet its weak mechanical properties limit its application and translation into a viable clinical solution. To overcome this limitation, IPC fibers can be incorporated into polymeric scaffolds such as the biocompatible poly(vinyl alcohol) hydrogel (PVA). Therefore, we explored the use of a composite scaffold of PVA and IPC fibers for controlled biomolecule release. We first observed that the permeability of biomolecules through PVA films were dependent on molecular weight. Next, IPC fibers were incorporated in between layers of PVA to produce PVA–IPC composite scaffolds with different IPC fiber orientation. The composite scaffold demonstrated excellent mechanical properties and efficient biomolecule incorporation. The rate of biomolecule release from PVA–IPC composite grafts exhibited dependence on molecular weight, with lysozyme showing near-linear release for 1 month. Angiogenic factors were also incorporated into the PVA–IPC grafts, as a potential biomedical application of the composite graft. While vascular endothelial growth factor only showed a maximum cumulative release of 3%, the smaller PEGylated-QK peptide showed maximum release of 33%. Notably, the released angiogenic biomolecules induced endothelial cell activity thus indicating retention of bioactivity. We also observed lack of significant macrophage response against PVA–IPC grafts in a rabbit model. Showing permeability, mechanical strength, precise temporal growth factor release, and bioinertness, PVA–IPC fibers composite scaffolds are excellent scaffolds for controlled biomolecule delivery in soft tissue

  13. Composite scaffold of poly(vinyl alcohol) and interfacial polyelectrolyte complexation fibers for controlled biomolecule delivery.

    Science.gov (United States)

    Cutiongco, Marie Francene A; Choo, Royden K T; Shen, Nathaniel J X; Chua, Bryan M X; Sju, Ervi; Choo, Amanda W L; Le Visage, Catherine; Yim, Evelyn K F

    2015-01-01

    Controlled delivery of hydrophilic proteins is an important therapeutic strategy. However, widely used methods for protein delivery suffer from low incorporation efficiency and loss of bioactivity. The versatile interfacial polyelectrolyte complexation (IPC) fibers have the capacity for precise spatiotemporal release and protection of protein, growth factor, and cell bioactivity. Yet its weak mechanical properties limit its application and translation into a viable clinical solution. To overcome this limitation, IPC fibers can be incorporated into polymeric scaffolds such as the biocompatible poly(vinyl alcohol) hydrogel (PVA). Therefore, we explored the use of a composite scaffold of PVA and IPC fibers for controlled biomolecule release. We first observed that the permeability of biomolecules through PVA films were dependent on molecular weight. Next, IPC fibers were incorporated in between layers of PVA to produce PVA-IPC composite scaffolds with different IPC fiber orientation. The composite scaffold demonstrated excellent mechanical properties and efficient biomolecule incorporation. The rate of biomolecule release from PVA-IPC composite grafts exhibited dependence on molecular weight, with lysozyme showing near-linear release for 1 month. Angiogenic factors were also incorporated into the PVA-IPC grafts, as a potential biomedical application of the composite graft. While vascular endothelial growth factor only showed a maximum cumulative release of 3%, the smaller PEGylated-QK peptide showed maximum release of 33%. Notably, the released angiogenic biomolecules induced endothelial cell activity thus indicating retention of bioactivity. We also observed lack of significant macrophage response against PVA-IPC grafts in a rabbit model. Showing permeability, mechanical strength, precise temporal growth factor release, and bioinertness, PVA-IPC fibers composite scaffolds are excellent scaffolds for controlled biomolecule delivery in soft tissue engineering.

  14. New method for immobilization of biomolecules using preirradiation grafting at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Liang Chang Dong; Hoffman, A.S.

    1986-01-01

    A new method of biomolecule immobilization is described in which a monomer-conjugated enzyme (asparaginase, Asp) is grafted together with free monomer (acrylamide, AAm) onto a cellulose sheet which had been preirradiated in a /sup 60/Co source. The preirradiation and grafting steps are carried out in air at - 78/sup 0/C and in vacuum at 0/sup 0/C respectively. The grafting is probably caused by trapped radicals. The immobilized enzyme retains significant activity and is stable to storage. The technique is applicable to immobilization of a wide variety of biomolecules, such as enzymes, antibodies and drugs. The products may be used for therapeutic or diagnostic applications.

  15. Induction of Biomolecules in Mature Leaves of Terminalia arjuna Due to Feeding of Antheraea mylitta Drury

    Directory of Open Access Journals (Sweden)

    G. Abraham

    2004-01-01

    Full Text Available Terminalia arjuna is an important food plant of the tasar silkworm, Antheraea mylitta Drury. In this study, we investigated the induction of biomolecules in mature leaves of these plants subjected to insect feeding. Increase in total tannin content, lipid peroxidation, and trypsin inhibitor activity have been observed in mature leaves damaged by the insects. The growth rate of Vth instar larvae of A. mylitta fed on previously damaged foliage reduced by 87.1%. Induction of biomolecules for defense mechanisms in relation to herbivore damage has been discussed.

  16. Photopatterning of self assembled monolayers on oxide surfaces for the selective attachment of biomolecules.

    Science.gov (United States)

    Hazarika, Pompi; Behrendt, Jonathan M; Petersson, Linn; Wingren, Christer; Turner, Michael L

    2014-03-15

    The immobilization of functional biomolecules to surfaces is a critical process for the development of biosensors for disease diagnostics. In this work we report the patterned attachment of single chain fragment variable (scFv) antibodies to the surface of metal oxides by the photodeprotection of self-assembled monolayers, using near-UV light. The photodeprotection step alters the functionality at the surface; revealing amino groups that are utilized to bind biomolecules in the exposed regions of the substrate only. The patterned antibodies are used for the detection of specific disease biomarker proteins in buffer and in complex samples such as human serum. © 2013 Elsevier B.V. All rights reserved.

  17. A new method for immobilization of biomolecules using preirradiation grafting at low temperature

    International Nuclear Information System (INIS)

    Liang Chang Dong; Hoffman, A.S.

    1986-01-01

    A new method of biomolecule immobilization is described in which a monomer-conjugated enzyme (asparaginase, Asp) is grafted together with free monomer (acrylamide, AAm) onto a cellulose sheet which had been preirradiated in a 60 Co source. The preirradiation and grafting steps are carried out in air at - 78 0 C and in vacuum at 0 0 C respectively. The grafting is probably caused by trapped radicals. The immobilized enzyme retains significant activity and is stable to storage. The technique is applicable to immobilization of a wide variety of biomolecules, such as enzymes, antibodies and drugs. The products may be used for therapeutic or diagnostic applications. (author)

  18. Fabrication of Biomolecule Microarrays Using Rapid Photochemical Surface Patterning in Thiol-Ene-Based Microfluidic Devices.

    Science.gov (United States)

    Jönsson, Alexander; Lafleur, Josiane P

    2018-01-01

    In many biochip applications, it is advantageous to be able to immobilize biomolecules at specific locations on the surface of solid supports. In this protocol, we describe a photochemical surface patterning procedure based on thiol-ene/yne photochemistry which allows for the simple and rapid selective patterning of biomolecules on thiol-ene solid supports. We describe the preparation of solid supports which are required for the immobilization, including porous monoliths, as well as two different immobilization schemes based on biotin-streptavidin interactions and covalent linkage via free amino groups respectively.

  19. Study of interactions between cells and microbubbles in high speed centrifugation field for biomolecule delivery.

    Science.gov (United States)

    He, Chuan; Chen, Jie

    2014-01-01

    Biomolecule delivery has a very wide range of applications in biology and medicine. In this study, a microbubble based delivery method was developed. In a high centrifugation field, cells deform and collide with microbubbles to induce intracellular pathways on cell membranes. As a result, biomaterials can then easily enter cells. Experimental results show that this delivery method can achieve high delivery efficiency. Simulation results showed that cells with more deformed structure experienced higher strain on cell membranes than cells with less deformed structure. The models can help explain how centrifugation affects cell membrane permeability. By controlling cell morphology and its mechanical properties, high biomolecule delivery efficiency can be achieved.

  20. Metal Stable Isotope Tagging: Renaissance of Radioimmunoassay for Multiplex and Absolute Quantification of Biomolecules.

    Science.gov (United States)

    Liu, Rui; Zhang, Shixi; Wei, Chao; Xing, Zhi; Zhang, Sichun; Zhang, Xinrong

    2016-05-17

    The unambiguous quantification of biomolecules is of great significance in fundamental biological research as well as practical clinical diagnosis. Due to the lack of a detectable moiety, the direct and highly sensitive quantification of biomolecules is often a "mission impossible". Consequently, tagging strategies to introduce detectable moieties for labeling target biomolecules were invented, which had a long and significant impact on studies of biomolecules in the past decades. For instance, immunoassays have been developed with radioisotope tagging by Yalow and Berson in the late 1950s. The later languishment of this technology can be almost exclusively ascribed to the use of radioactive isotopes, which led to the development of nonradioactive tagging strategy-based assays such as enzyme-linked immunosorbent assay, fluorescent immunoassay, and chemiluminescent and electrochemiluminescent immunoassay. Despite great success, these strategies suffered from drawbacks such as limited spectral window capacity for multiplex detection and inability to provide absolute quantification of biomolecules. After recalling the sequences of tagging strategies, an apparent question is why not use stable isotopes from the start? A reasonable explanation is the lack of reliable means for accurate and precise quantification of stable isotopes at that time. The situation has changed greatly at present, since several atomic mass spectrometric measures for metal stable isotopes have been developed. Among the newly developed techniques, inductively coupled plasma mass spectrometry is an ideal technique to determine metal stable isotope-tagged biomolecules, for its high sensitivity, wide dynamic linear range, and more importantly multiplex and absolute quantification ability. Since the first published report by our group, metal stable isotope tagging has become a revolutionary technique and gained great success in biomolecule quantification. An exciting research highlight in this area

  1. Crisis vital desde una perspectiva de género

    OpenAIRE

    Castro, Eva; Flores López, Olga

    2004-01-01

    A continuación se presenta el caso de una mujer de 55 años que presenta una crisis de identidad, abordado desde una perspectiva de género y un modelo explicativo y terapéutico que incluye elementos del análisis transaccional y la terapia constructivista.

  2. Engineered collagen hydrogels for the sustained release of biomolecules and imaging agents: promoting the growth of human gingival cells.

    Science.gov (United States)

    Choi, Jonghoon; Park, Hoyoung; Kim, Taeho; Jeong, Yoon; Oh, Myoung Hwan; Hyeon, Taeghwan; Gilad, Assaf A; Lee, Kwan Hyi

    2014-01-01

    We present here the in vitro release profiles of either fluorescently labeled biomolecules or computed tomography contrast nanoagents from engineered collagen hydrogels under physiological conditions. The collagen constructs were designed as potential biocompatible inserts into wounded human gingiva. The collagen hydrogels were fabricated under a variety of conditions in order to optimize the release profile of biomolecules and nanoparticles for the desired duration and amount. The collagen constructs containing biomolecules/nanoconstructs were incubated under physiological conditions (ie, 37°C and 5% CO2) for 24 hours, and the release profile was tuned from 20% to 70% of initially loaded materials by varying the gelation conditions of the collagen constructs. The amounts of released biomolecules and nanoparticles were quantified respectively by measuring the intensity of fluorescence and X-ray scattering. The collagen hydrogel we fabricated may serve as an efficient platform for the controlled release of biomolecules and imaging agents in human gingiva to facilitate the regeneration of oral tissues.

  3. Quantification of the activity of biomolecules in microarrays obtained by direct laser transfer.

    Science.gov (United States)

    Dinca, V; Ranella, A; Farsari, M; Kafetzopoulos, D; Dinescu, M; Popescu, A; Fotakis, C

    2008-10-01

    The direct-writing technique laser-induced forward transfer has been employed for the micro-array printing of liquid solutions of the enzyme horseradish peroxidase and the protein Titin on nitrocellulose solid surfaces. The effect of two UV laser pulse lengths, femtosecond and nanosecond has been studied in relation with maintaining the activity of the transferred biomolecules. The quantification of the active biomolecules after transfer has been carried out using Bradford assay, quantitative colorimetric enzymatic assay and fluorescence techniques. Spectrophotometric measurements of the HRP and the Titin activity as well as chromatogenic and fluorescence assay studies have revealed a connection between the properties of the deposited, biologically active biomolecules, the experimental conditions and the target composition. The bioassays have shown that up to 78% of the biomolecules remained active after femtosecond laser transfer, while this value reduced to 54% after nanosecond laser transfer. The addition of glycerol in a percentage up to 70% in the solution to be transferred has contributed to the stabilization of the micro-array patterns and the increase of their resolution.

  4. Microwave synthesis of metal nanocatalysts for the electrochemical oxidation of small biomolecules

    DEFF Research Database (Denmark)

    Jensen, Kathrine Schiørring Steen; Sun, Hongyu; Werchmeister, Rebecka Maria Larsen

    2017-01-01

    Electrochemical oxidation of small biomolecules provides an approach to generate clean energy from a sustainable resource. It serves as a principle for anode reactions in fuel cells to convert energy stored in chemical bonds into electrical power. Efficient and robust nanocatalysts are essential ...

  5. A photocleavable affinity tag for the enrichment of alkyne-modified biomolecules

    NARCIS (Netherlands)

    Koopmans, Timo; Dekker, Frank J.; Martin, Nathaniel I.

    2012-01-01

    A new photocleavable affinity tag for use in the enrichment of alkyne-labelled biomolecules is reported. The tag is prepared via a concise synthetic route using readily available materials. The photolytic conditions employed for cleavage of the tag provide for a clean release of enriched

  6. Immobilization of biomolecules onto surfaces according to ultraviolet light diffraction patterns

    DEFF Research Database (Denmark)

    Petersen, Steffen B.; Gennaro, Ane Kold Di; Neves Petersen, Teresa

    2010-01-01

    We developed a method for immobilization of biomolecules onto thiol functionalized surfaces according to UV diffraction patterns. UV light-assisted molecular immobilization proceeds through the formation of free, reactive thiol groups that can bind covalently to thiol reactive surfaces. We demons......, with a fine structured interference pattern superimposed. (C) 2010 Optical Society of America...

  7. Nanocoating for biomolecule delivery using layer-by-layer self-assembly.

    Science.gov (United States)

    Keeney, M; Jiang, X Y; Yamane, M; Lee, M; Goodman, S; Yang, F

    2015-11-07

    Since its introduction in the early 1990s, layer-by-layer (LbL) self-assembly of films has been widely used in the fields of nanoelectronics, optics, sensors, surface coatings, and controlled drug delivery. The growth of this industry is propelled by the ease of film manufacture, low cost, mild assembly conditions, precise control of coating thickness, and versatility of coating materials. Despite the wealth of research on LbL for biomolecule delivery, clinical translation has been limited and slow. This review provides an overview of methods and mechanisms of loading biomolecules within LbL films and achieving controlled release. In particular, this review highlights recent advances in the development of LbL coatings for the delivery of different types of biomolecules including proteins, polypeptides, DNA, particles and viruses. To address the need for co-delivery of multiple types of biomolecules at different timing, we also review recent advances in incorporating compartmentalization into LbL assembly. Existing obstacles to clinical translation of LbL technologies and enabling technologies for future directions are also discussed.

  8. High sensitivity detection of desorbed biomolecules by photoionization with tunable VUV

    International Nuclear Information System (INIS)

    Moore, J.F.; Calaway, W.F.; Veryovkin, I.V.; Pellin, M.J.; Lewellen, J.W.; Li, Y.; Milton, S.V.; King, B.V.

    2004-01-01

    Full text: The spectral region from 7 to 11eV has two attributes that make it attractive for biomolecule photoionization: 1. high photoionization cross sections, leading to high detection efficiency, and 2. overlap with nearly all first ionization energies of biomolecules, allowing possible control over fragmentation by accessing different final states via tuning. The lack of available tunable lasers in this energy range has generally hindered exploitation of these features thus far. A free-electron laser in operation at Argonne National Laboratory provides high pulse energy, widely tunable VUV pulses of 300 fs duration. Coupled with a novel time-of-flight mass spectrometer, this laser is able to photoionize and detect biomolecules, including peptides and nucleosides. Either laser desorption or primary ion beams are used to desorb sample material, followed by photoionization with a VUV laser. The instrument uses novel ion optics to extract photoions from a large volume while maintaining high mass resolution. This approach is capable of yielding dramatically improved detection limits over more conventional methods such as MALDI and SIMS. In the case of the common peptide substance P, for example, a substantial improvement over the MALDI signal was observed using VUV photoionization with very little observed fragmentation of the molecule. Nucleosides and cisplatin were also measured with typically order of magnitude improvements in signal. These and other examples show clearly the benefits that can be obtained in high sensitivity mass spectrometry of biomolecules with the increasing availability of VUV laser sources

  9. Preparation of Biomolecule Microstructures and Microarrays by Thiol–ene Photoimmobilization

    NARCIS (Netherlands)

    Weinrich, Dirk; Köhn, Maja; Jonkheijm, Pascal; Westerlind, Ulrika; Dehmelt, Leif; Engelkamp, Hans; Christianen, Peter C.M.; Kuhlmann, Jürgen; Maan, Jan C.; Nüsse, Dirk; Schröder, Hendrik; Wacker, Ron; Voges, Edgar; Breinbauer, Rolf; Kunz, Horst; Niemeyer, Christof M.; Waldmann, Herbert

    2010-01-01

    A mild, fast and flexible method for photoimmobilization of biomolecules based on the light-initiated thiol–ene reaction has been developed. After investigation and optimization of various surface materials, surface chemistries and reaction parameters, microstructures and microarrays of biotin,

  10. Sensitive Detection of Biomolecules by Surface Enhanced Raman Scattering using Plant Leaves as Natural Substrates

    Directory of Open Access Journals (Sweden)

    Sharma Vipul

    2017-01-01

    Full Text Available Detection of biomolecules is highly important for biomedical and other biological applications. Although several methods exist for the detection of biomolecules, surface enhanced Raman scattering (SERS has a unique role in greatly enhancing the sensitivity. In this work, we have demonstrated the use of natural plant leaves as facile, low cost and eco-friendly SERS substrates for the sensitive detection of biomolecules. Specifically, we have investigated the influence of surface topography of five different plant leaf based substrates, deposited with Au, on the SERS performance by using L-cysteine as a model biomolecule. In addition, we have also compared the effect of sputter deposition of Au thin film with dropcast deposition of Au nanoparticles on the leaf substrates. Our results indicate that L-cysteine could be detected with high sensitivity using these plant leaf based substrates and the leaf possessing hierarchical micro/nanostructures on its surface shows higher SERS enhancement compared to a leaf having a nearplanar surface. Furthermore, leaves with drop-casted Au nanoparticle clusters performed better than the leaves sputter deposited with a thin Au film.

  11. In situ biomolecule production by bacteria; a synthetic biology approach to medicine.

    Science.gov (United States)

    Flores Bueso, Yensi; Lehouritis, Panos; Tangney, Mark

    2018-04-10

    The ability to modify existing microbiota at different sites presents enormous potential for local or indirect management of various diseases. Because bacteria can be maintained for lengthy periods in various regions of the body, they represent a platform with enormous potential for targeted production of biomolecules, which offer tremendous promise for therapeutic and diagnostic approaches for various diseases. While biological medicines are currently limited in the clinic to patient administration of exogenously produced biomolecules from engineered cells, in situ production of biomolecules presents enormous scope in medicine and beyond. The slow pace and high expense of traditional research approaches has particularly hampered the development of biological medicines. It may be argued that bacterial-based medicine has been "waiting" for the advent of enabling technology. We propose that this technology is Synthetic Biology, and that the wait is over. Synthetic Biology facilitates a systematic approach to programming living entities and/or their products, using an approach to Research and Development (R&D) that facilitates rapid, cheap, accessible, yet sophisticated product development. Full engagement with the Synthetic Biology approach to R&D can unlock the potential for bacteria as medicines for cancer and other indications. In this review, we describe how by employing Synthetic Biology, designer bugs can be used as drugs, drug-production factories or diagnostic devices, using oncology as an exemplar for the concept of in situ biomolecule production in medicine. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. The Polygonal Model: A Simple Representation of Biomolecules as a Tool for Teaching Metabolism

    Science.gov (United States)

    Bonafe, Carlos Francisco Sampaio; Bispo, Jose Ailton Conceição; de Jesus, Marcelo Bispo

    2018-01-01

    Metabolism involves numerous reactions and organic compounds that the student must master to understand adequately the processes involved. Part of biochemical learning should include some knowledge of the structure of biomolecules, although the acquisition of such knowledge can be time-consuming and may require significant effort from the student.…

  13. Biomolecule Analogues 2-Hydroxypyridine and 2-Pyridone Base Pairing on Ice Nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Rubovič, Peter; Pysanenko, Andriy; Lengyel, Jozef; Nachtigallová, Dana; Fárník, Michal

    2016-01-01

    Roč. 120, č. 27 (2016), s. 4720-4730 ISSN 1089-5639 R&D Projects: GA ČR GA14-14082S Institutional support: RVO:61388955 ; RVO:61388963 Keywords : doped nanoparticles * argon * biomolecule s Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.847, year: 2016

  14. Systematic methods for defining coarse-grained maps in large biomolecules.

    Science.gov (United States)

    Zhang, Zhiyong

    2015-01-01

    Large biomolecules are involved in many important biological processes. It would be difficult to use large-scale atomistic molecular dynamics (MD) simulations to study the functional motions of these systems because of the computational expense. Therefore various coarse-grained (CG) approaches have attracted rapidly growing interest, which enable simulations of large biomolecules over longer effective timescales than all-atom MD simulations. The first issue in CG modeling is to construct CG maps from atomic structures. In this chapter, we review the recent development of a novel and systematic method for constructing CG representations of arbitrarily complex biomolecules, in order to preserve large-scale and functionally relevant essential dynamics (ED) at the CG level. In this ED-CG scheme, the essential dynamics can be characterized by principal component analysis (PCA) on a structural ensemble, or elastic network model (ENM) of a single atomic structure. Validation and applications of the method cover various biological systems, such as multi-domain proteins, protein complexes, and even biomolecular machines. The results demonstrate that the ED-CG method may serve as a very useful tool for identifying functional dynamics of large biomolecules at the CG level.

  15. Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems

    Science.gov (United States)

    Louros, Cláudia L. S.; Cláudio, Ana Filipa M.; Neves, Catarina M. S. S.; Freire, Mara G.; Marrucho, Isabel M.; Pauly, Jérôme; Coutinho, João A. P.

    2010-01-01

    Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, were measured and are reported. The studied phosphonium-based ILs have shown to be more effective in promoting ABS compared to the imidazolium-based counterparts with similar anions. Moreover, the extractive capability of such systems was assessed for distinct biomolecules (including amino acids, food colourants and alkaloids). Densities and viscosities of both aqueous phases, at the mass fraction compositions used for the biomolecules extraction, were also determined. The evaluated IL-based ABS have been shown to be prospective extraction media, particularly for hydrophobic biomolecules, with several advantages over conventional polymer-inorganic salt ABS. PMID:20480041

  16. Cellular Viscosity in Prokaryotes and Thermal Stability of Low Molecular Weight Biomolecules.

    Science.gov (United States)

    Cuecas, Alba; Cruces, Jorge; Galisteo-López, Juan F; Peng, Xiaojun; Gonzalez, Juan M

    2016-08-23

    Some low molecular weight biomolecules, i.e., NAD(P)H, are unstable at high temperatures. The use of these biomolecules by thermophilic microorganisms has been scarcely analyzed. Herein, NADH stability has been studied at different temperatures and viscosities. NADH decay increased at increasing temperatures. At increasing viscosities, NADH decay rates decreased. Thus, maintaining relatively high cellular viscosity in cells could result in increased stability of low molecular weight biomolecules (i.e., NADH) at high temperatures, unlike what was previously deduced from studies in diluted water solutions. Cellular viscosity was determined using a fluorescent molecular rotor in various prokaryotes covering the range from 10 to 100°C. Some mesophiles showed the capability of changing cellular viscosity depending on growth temperature. Thermophiles and extreme thermophiles presented a relatively high cellular viscosity, suggesting this strategy as a reasonable mechanism to thrive under these high temperatures. Results substantiate the capability of thermophiles and extreme thermophiles (growth range 50-80°C) to stabilize and use generally considered unstable, universal low molecular weight biomolecules. In addition, this study represents a first report, to our knowledge, on cellular viscosity measurements in prokaryotes and it shows the dependency of prokaryotic cellular viscosity on species and growth temperature. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  17. Prospects of biomolecule sequencing with the techniques of translocation through nanopores: A review

    International Nuclear Information System (INIS)

    Nosik, V. L.; Rudakova, E. B.

    2013-01-01

    The interest in the functional properties of biomolecules in native solutions (in particular, their interaction with membranes) constantly increases with accumulation of data on the macromolecular structure, obtained by X-ray diffraction (with synchrotron radiation sources), nuclear magnetic resonance, and mass spectrometry; this interest is closely related to the development of new technologies of sequencing (i.e., determining the sequence of nucleotides in DNA biomolecule). One of the most promising “physical” approaches to sequencing is the application of methods based on the use of nanochannels or nanopores, through which biomolecules pass in ionic solutions under an electric field applied. A nanopore provides spatial localization of molecules and makes it possible to detect a signal (electric, fluorescent, etc.) from an individual nucleotide. In view of the development of new high-intensity pulsed X-ray sources, the popularity of fluorescence analysis constantly increases. The existing methods for simulating the motion of biomolecules and interpreting their structure, sequencing techniques, and the prospects of further development of investigations in this field are discussed

  18. Photonic crystal fiber based evanescent-wave sensor for detection of biomolecules in aqueous solutions

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Pedersen, Lars H.; Hoiby, Poul E.

    2004-01-01

    We demonstrate highly efficient evanescent-wave detection of fluorophore-labeled biomolecules in aqueous solutions positioned in the air holes of the microstructured part of a photonic crystal fiber. The air-suspended silica structures located between three neighboring air holes in the cladding c...

  19. Surface enhanced Raman spectroscopy detection of biomolecules using EBL fabricated nanostructured substrates.

    Science.gov (United States)

    Peters, Robert F; Gutierrez-Rivera, Luis; Dew, Steven K; Stepanova, Maria

    2015-03-20

    Fabrication and characterization of conjugate nano-biological systems interfacing metallic nanostructures on solid supports with immobilized biomolecules is reported. The entire sequence of relevant experimental steps is described, involving the fabrication of nanostructured substrates using electron beam lithography, immobilization of biomolecules on the substrates, and their characterization utilizing surface-enhanced Raman spectroscopy (SERS). Three different designs of nano-biological systems are employed, including protein A, glucose binding protein, and a dopamine binding DNA aptamer. In the latter two cases, the binding of respective ligands, D-glucose and dopamine, is also included. The three kinds of biomolecules are immobilized on nanostructured substrates by different methods, and the results of SERS imaging are reported. The capabilities of SERS to detect vibrational modes from surface-immobilized proteins, as well as to capture the protein-ligand and aptamer-ligand binding are demonstrated. The results also illustrate the influence of the surface nanostructure geometry, biomolecules immobilization strategy, Raman activity of the molecules and presence or absence of the ligand binding on the SERS spectra acquired.

  20. Label Free Detection of Biomolecules Using Charge-Plasma-Based Gate Underlap Dielectric Modulated Junctionless TFET

    Science.gov (United States)

    Wadhwa, Girish; Raj, Balwinder

    2018-05-01

    Nanoscale devices are emerging as a platform for detecting biomolecules. Various issues were observed during the fabrication process such as random dopant fluctuation and thermal budget. To reduce these issues charge-plasma-based concept is introduced. This paper proposes the implementation of charge-plasma-based gate underlap dielectric modulated junctionless tunnel field effect transistor (DM-JLTFET) for the revelation of biomolecule immobilized in the open cavity gate channel region. In this p+ source and n+ drain regions are introduced by employing different work function over the intrinsic silicon. Also dual material gate architecture is implemented to reduce short channel effect without abandoning any other device characteristic. The sensitivity of biosensor is studied for both the neutral and charge-neutral biomolecules. The effect of device parameters such as channel thickness, cavity length and cavity thickness on drain current have been analyzed through simulations. This paper investigates the performance of charge-plasma-based gate underlap DM-JLTFET for biomolecule sensing applications while varying dielectric constant, charge density at different biasing conditions.

  1. Large pore mesoporous silica nanomaterials for application in delivery of biomolecules

    Science.gov (United States)

    Knežević, Nikola Ž.; Durand, Jean-Olivier

    2015-01-01

    Various approaches for the synthesis of mesoporous silicate nanoparticles (MSN) with large pore (LP) diameters (in the range of 3-50 nm) are reviewed in this article. The work also covers the construction of magnetic analogues of large pore-mesoporous silica nanoparticles (LPMMSN) and their biomedical applications. The constructed materials exhibit vast potential for application in the loading and delivery of large drug molecules and biomolecules. Literature reports on the application of LPMSN and LPMMSN materials for the adsorption and delivery of proteins, enzymes, antibodies, and nucleic acids are covered in depth, which exemplify their highly potent characteristics for use in drug and biomolecule delivery to diseased tissues.Various approaches for the synthesis of mesoporous silicate nanoparticles (MSN) with large pore (LP) diameters (in the range of 3-50 nm) are reviewed in this article. The work also covers the construction of magnetic analogues of large pore-mesoporous silica nanoparticles (LPMMSN) and their biomedical applications. The constructed materials exhibit vast potential for application in the loading and delivery of large drug molecules and biomolecules. Literature reports on the application of LPMSN and LPMMSN materials for the adsorption and delivery of proteins, enzymes, antibodies, and nucleic acids are covered in depth, which exemplify their highly potent characteristics for use in drug and biomolecule delivery to diseased tissues. Dedicated to Professor Jeffrey I. Zink on the occasion of his 70th birthday.

  2. Exploring the flexible chemistry of 4-fluoro-3-nitrophenyl azide for biomolecule immobilization and bioconjugation.

    Science.gov (United States)

    Kumar, Saroj; Kumar, Dileep; Ahirwar, Rajesh; Nahar, Pradip

    2016-10-01

    Bioconjugation and functionalization of polymer surfaces are two major tasks in materials chemistry which are accomplished using a variety of coupling agents. Immobilization of biomolecules onto polymer surfaces and the construction of bioconjugates are essential requirements of many biochemical assays and chemical syntheses. Different linkers with a variety of functional groups are used for these purposes. Among them, the benzophenones, aryldiazirines, and arylazides represent the most commonly used photolinker to produce the desired chemical linkage upon their photo-irradiation. In this review, we describe the versatile applications of 4-fluoro-3-nitrophenyl azide, one of the oldest photolinkers used for photoaffinity labeling in the late 1960s. Surprisingly, this photolinker, historically known as 1-fluoro-2-nitro-4-azidobenzene (FNAB), has remained unexplored for a long time because of apprehension that FNAB forms ring-expanded dehydroazepine as a major product and hence cannot activate an inert polymer. The first evidence of photochemical activation of an inert surface by FNAB through nitrene insertion reaction was reported in 2001, and the FNAB-activated surface was found to conjugate a biomolecule without any catalyst, reagent, or modification. FNAB has distinct advantages over perfluorophenyl azide derivatives, which are contemporary nitrene-generating photolinkers, because of its simple, single-step preparation and ease of thermochemical and photochemical reactions with versatile polymers and biomolecules. Covering these aspects, the present review highlights the flexible chemistry of FNAB and its applications in the field of surface engineering, immobilization of biomolecules such as antibodies, enzymes, cells, carbohydrates, oligonucleotides, and DNA aptamers, and rapid diagnostics. Graphical Abstract An overview of the FNAB-engineered activated polymer surfaces for covalent ligation of versatile biomolecules.

  3. Preparation of supramolecular hydrogel-enzyme hybrids exhibiting biomolecule-responsive gel degradation.

    Science.gov (United States)

    Shigemitsu, Hajime; Fujisaku, Takahiro; Onogi, Shoji; Yoshii, Tatsuyuki; Ikeda, Masato; Hamachi, Itaru

    2016-09-01

    Hydrogelators are small, self-assembling molecules that form supramolecular nanofiber networks that exhibit unique dynamic properties. Development of supramolecular hydrogels that degrade in response to various biomolecules could potentially be used for applications in areas such as drug delivery and diagnostics. Here we provide a synthetic procedure for preparing redox-responsive supramolecular hydrogelators that are used to create hydrogels that degrade in response to oxidizing or reducing conditions. The synthesis takes ∼2-4 d, and it can potentially be carried out in parallel to prepare multiple hydrogelator candidates. This described solid-phase peptide synthesis protocol can be used to produce previously described hydrogelators or to construct a focused molecular library to efficiently discover and optimize new hydrogelators. In addition, we describe the preparation of redox-responsive supramolecular hydrogel-enzyme hybrids that are created by mixing aqueous solutions of hydrogelators and enzymes, which requires 2 h for completion. The resultant supramolecular hydrogel-enzyme hybrids exhibit gel degradation in response to various biomolecules, and can be rationally designed by connecting the chemical reactions of the hydrogelators with enzymatic reactions. Gel degradation in response to biomolecules as triggers occurs within a few hours. We also describe the preparation of hydrogel-enzyme hybrids arrayed on flat glass slides, enabling high-throughput analysis of biomolecules such as glucose, uric acid, lactate and so on by gel degradation, which is detectable by the naked eye. The protocol requires ∼6 h to prepare the hydrogel-enzyme hybrid array and to complete the biomolecule assay.

  4. Self-organized pattern formation of biomolecules at silicon surfaces: Intended application of a dislocation network

    International Nuclear Information System (INIS)

    Kittler, M.; Yu, X.; Vyvenko, O.F.; Birkholz, M.; Seifert, W.; Reiche, M.; Wilhelm, T.; Arguirov, T.; Wolff, A.; Fritzsche, W.; Seibt, M.

    2006-01-01

    Defined placement of biomolecules at Si surfaces is a precondition for a successful combination of Si electronics with biological applications. We aim to realize this by Coulomb interaction of biomolecules with dislocations in Si. The dislocations form charged lines and they will be surrounded with a space charge region being connected with an electric field. The electric stray field in a solution of biomolecules, caused by dislocations located close to the Si surface, was estimated to yield values up to few kVcm -1 . A regular dislocation network can be formed by wafer direct bonding at the interface between the bonded wafers in case of misorientation. The adjustment of misorientation allows the variation of the distance between dislocations in a range from 10 nm to a few μm. This is appropriate for nanobiotechnology dealing with protein or DNA molecules with sizes in the nm and lower μm range. Actually, we achieved a distance between the dislocations of 10-20 nm. Also the existence of a distinct electric field formed by the dislocation network was demonstrated by the technique of the electron-beam-induced current (EBIC). Because of the relatively short range of the field, the dislocations have to be placed close to the surface. We positioned the dislocation network in an interface being 200 nm parallel to the Si surface by layer transfer techniques using hydrogen implantation and bonding. Based on EBIC and luminescence data we postulate a barrier of the dislocations at the as bonded interface < 100 meV. We plan to dope the dislocations with metal atoms to increase the electric field. We demonstrated that regular periodic dislocation networks close to the Si surface formed by bonding are realistic candidates for self-organized placing of biomolecules. Experiments are underway to test whether biomolecules decorate the pattern of the dislocation lines

  5. UNA PERSPECTIVA NEUROCIENTÍFICA SOBRE LA HISTERIA

    Directory of Open Access Journals (Sweden)

    Lucía Amoruso

    2010-01-01

    Full Text Available En la última década, el desarrollo y la puesta en marcha delas modernas técnicas de neuroimagen en el campo de laneurociencia cognitiva han proporcionado una nueva vía deacercamiento al estudio experimental de algunos trastornosmentales. Dentro de esta perspectiva, denominada por algunosautores “neuropsiquiatría cognitiva”, la histeria (o trastornode conversión, de acuerdo con la clasificación psiquiátricaactual ha cobrado un amplio protagonismo. De acuerdo conlo anterior, el objetivo del presente trabajo consiste en introducirestudios pioneros basados en una perspectiva neurocientíficade la histeria. Conviene destacar que, si bien estosaportan evidencia significativa sobre algunas de las áreascerebrales y las disfunciones cognitivas comprometidas enel mencionado trastorno, los resultados obtenidos a la fechadistan aún de ser concluyentes.

  6. Tomasello y Stern: Dos perspectivas actuales incluyentes del Desarrollo Infantil

    Directory of Open Access Journals (Sweden)

    Mata Isabel López

    2011-01-01

    Full Text Available El presente artículo tiene como objetivo ilustrar dos perspectivas actuales del desarrollo infantil incluyentes más que excluyentes -Michael Tomasello (cognitivo y Daniel Stern (social-subjetivo-, en cuanto a que integran a su explicación los descubrimientos de las capacidades tempranas del bebé -realizados a partir de 1970/80- y, sin renunciar al paradigma teórico particular del que provienen, reconocen junto a estas competencias tempranas el rol fundamental de los diversos factores intervinientes en el desarrollo -lo innato y lo ambiental (social y cultural-, los diferentes métodos de investigación y las limitaciones de una mirada reduccionista. Además, postulan que se hace necesaria la conversación entre las diferentes perspectivas teóricas, para lograr una descripción del infante como una unidad.

  7. Perspectiva espiritual de la mujer con cáncer

    Directory of Open Access Journals (Sweden)

    Milena Alexandra Galvis-López

    2011-01-01

    Full Text Available Objetivo: comparar la perspectiva espiritual de las mujeres diagnosticadas con cáncer propio de su género (seno, útero, ovarios y de las mujeres diagnosticadas con otros tipos de cáncer. Método: diseño cuantitativo de tipo descriptivo comparativo, de corte transversal. Se empleó una encuesta sociodemográfica para caracterizar la población y la Escala de perspectiva espiritual de Pamela Reed, a la cual se le realizó el análisis de confiabilidad que reportó un alfa de Cronbach de 0,799 en el grupo 1 y 0,763 en el grupo 2. La muestra incluyó a 100 mujeres que se encuentran en tratamiento contra el cáncer. Resultados: la perspectiva espiritual de las mujeres con cáncer propio de su género es moderada al igual que la de las mujeres con otros tipos de cáncer; al hacer la comparación de estos dos grupos no se encontró evidencia estadística que demostrara una diferencia significativa. Discusión: los resultados de este estudio aportan nuevos elementos para el cuidado de las mujeres con enfermedad oncológica y señalan que una perspectiva espiritual moderada puede ser un potencial para su cuidado integral, en el que la enfermera reconozca sus objetivos en el cuidado de la mujer como un ser total, más que el tipo de cáncer que tiene.

  8. Los derivados financieros desde una perspectiva jurídica

    OpenAIRE

    Cuartas Gómez, Lucas; Sierra Vásquez, Paula

    2008-01-01

    El importante aumento en el uso de los contratos de derivados en Colombia1 y el mundo, además de la dificultad que puede traer su comprensión, nos ha llevado a escribir el presente trabajo, con el fin de darle a el lector una perspectiva general sobre el funcionamiento de estos instrumentos financieros, su regulación en Colombia y la forma como éstos se han venido contratando a nivel internacional.

  9. Effect of biomolecules adsorption on oxide layers developed on metallic materials used in cooling water systems

    International Nuclear Information System (INIS)

    Torres-Bautista, Blanca-Estela

    2014-01-01

    This thesis was carried out in the frame of the BIOCOR ITN European project, in collaboration with the industrial partner RSE S.p.A. (Italy). Metallic materials commonly used in cooling systems of power plants may be affected by bio-corrosion induced by biofilm formation. The objective of this work was to study the influence of biomolecules adsorption, which is the initial stage of biofilm formation, on the electrochemical behaviour and the surface chemical composition of three metallic materials (70Cu-30Ni alloy, 304L stainless steel and titanium) in seawater environments. In a first step, the interactions between a model protein, the bovine serum albumin (BSA), and the surface of these materials were investigated. Secondly, tightly bound (TB) and loosely bound (LB) extracellular polymeric substances (EPS), that play a fundamental role in the different stages of biofilm formation, maturation and maintenance, were extracted from Pseudomonas NCIMB 2021 marine strain, and their effects on oxide layers were also evaluated. For that purpose, electrochemical measurements (corrosion potential E(corr) vs time, polarization curves and electrochemical impedance spectroscopy (EIS)) performed during the very first steps of oxide layers formation (1 h immersion time) were combined to surface analysis by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ions mass spectrometry (ToF-SIMS). Compared to 70Cu-30Ni alloy in static artificial seawater (ASW) without biomolecules, for which a thick duplex oxide layer (outer redeposited Cu 2 O layer and inner oxidized nickel layer) is shown, the presence of BSA, TB EPS and LB EPS leads to a mixed oxide layer (oxidized copper and nickel) with a lower thickness. In the biomolecules-containing solutions, this oxide layer is covered by an adsorbed organic layer, mainly composed of proteins. A model is proposed to analyse impedance data obtained at E(corr). The results show a slow-down of the anodic reaction in the presence

  10. Spin boson models for quantum decoherence of electronic excitations of biomolecules and quantum dots in a solvent

    International Nuclear Information System (INIS)

    Gilmore, Joel; McKenzie, Ross H

    2005-01-01

    We give a theoretical treatment of the interaction of electronic excitations (excitons) in biomolecules and quantum dots with the surrounding polar solvent. Significant quantum decoherence occurs due to the interaction of the electric dipole moment of the solute with the fluctuating electric dipole moments of the individual molecules in the solvent. We introduce spin boson models which could be used to describe the effects of decoherence on the quantum dynamics of biomolecules which undergo light-induced conformational change and on biomolecules or quantum dots which are coupled by Foerster resonant energy transfer

  11. SOBRE LOS CAMBIOS DE PERSPECTIVA EN EL CONOCIMIENTO

    Directory of Open Access Journals (Sweden)

    LUZ MARINA BARRETO

    2007-01-01

    Full Text Available El propósito de este artículo es explorar el significado y los alcances de los cambios de perspectiva que a veces ocurren cuando vemos las cosas desde el punto de vista teórico, al producirse un cambio de paradigma en el conocimiento, o, si las vemos desde el uso práctico de la razón, cuando se produce un cambio en la personalidad o una "conversión". La mera cuestión sobre la posibilidad de un cambio radical de perspectiva es filosófica en un sentido profundo: sugiere la existencia de un campo de conocimiento metafísico que sería "libre" respecto de las proyecciones categoriales específicas y determinaciones que descansan en el sujeto de conocimiento, de manera que sería posible ver las cosas desde un punto de vista radicalmente diferente, uno que no sería posible sino al interior de un paradigma. Mis intuiciones son, en primer lugar, que la pregunta por la naturaleza de los cambios de perspectiva, metafísica como es, es más importante para la epistemología de lo que se ha admitido en la filosofía analítica y, en segundo lugar, que esta pregunta puede ser encarada no necesariamente al interior del marco de referencia de la metafísica, sino desde un concepto amplio de razón. En este sentido, los cambios de perspectiva pueden ser entendidos como una posibilidad que sólo puede hacerse inteligible dentro de una noción unificada de la razón, una concepción que ha sido ignorada por concepciones epistemológicas que acentúan su lado instrumental y que podemos remontar a algunos conceptos de la ontología fenomenológica que han sido re-interpretados a través de la lente de la teoría de la experiencia kantiana. Finalmente, sugiero que si miramos los cambios de perspectiva desde el punto de vista de una concepción unificada de la razón, de ello resulta una teoría del conocimiento mucho más fluida y más ligada al uso práctico de la razón que lo que se admite en las epistemologías analíticas que fueron populares durante

  12. Analysis of gate underlap channel double gate MOS transistor for electrical detection of bio-molecules

    Science.gov (United States)

    Ajay; Narang, Rakhi; Saxena, Manoj; Gupta, Mridula

    2015-12-01

    In this paper, an analytical model for gate drain underlap channel Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistor (DG-MOSFET) for label free electrical detection of biomolecules has been proposed. The conformal mapping technique has been used to derive the expressions for surface potential, lateral electric field, energy bands (i.e. conduction and valence band) and threshold voltage (Vth). Subsequently a full drain current model to analyze the sensitivity of the biosensor has been developed. The shift in the threshold voltage and drain current (after the biomolecules interaction with the gate underlap channel region of the MOS transistor) has been used as a sensing metric. All the characteristic trends have been verified through ATLAS (SILVACO) device simulation results.

  13. Heme biomolecule as redox mediator and oxygen shuttle for efficient charging of lithium-oxygen batteries

    Science.gov (United States)

    Ryu, Won-Hee; Gittleson, Forrest S.; Thomsen, Julianne M.; Li, Jinyang; Schwab, Mark J.; Brudvig, Gary W.; Taylor, André D.

    2016-01-01

    One of the greatest challenges with lithium-oxygen batteries involves identifying catalysts that facilitate the growth and evolution of cathode species on an oxygen electrode. Heterogeneous solid catalysts cannot adequately address the problematic overpotentials when the surfaces become passivated. However, there exists a class of biomolecules which have been designed by nature to guide complex solution-based oxygen chemistries. Here, we show that the heme molecule, a common porphyrin cofactor in blood, can function as a soluble redox catalyst and oxygen shuttle for efficient oxygen evolution in non-aqueous Li-O2 batteries. The heme's oxygen binding capability facilitates battery recharge by accepting and releasing dissociated oxygen species while benefiting charge transfer with the cathode. We reveal the chemical change of heme redox molecules where synergy exists with the electrolyte species. This study brings focus to the rational design of solution-based catalysts and suggests a sustainable cross-link between biomolecules and advanced energy storage. PMID:27759005

  14. Tiny Grains Give Huge Gains: Nanocrystal–Based Signal Amplification for Biomolecule Detection

    Science.gov (United States)

    Tong, Sheng; Ren, Binbin; Zheng, Zhilan; Shen, Han; Bao, Gang

    2013-01-01

    Nanocrystals, despite their tiny sizes, contain thousands to millions of atoms. Here we show that the large number of atoms packed in each metallic nanocrystal can provide a huge gain in signal amplification for biomolecule detection. We have devised a highly sensitive, linear amplification scheme by integrating the dissolution of bound nanocrystals and metal-induced stoichiometric chromogenesis, and demonstrated that signal amplification is fully defined by the size and atom density of nanocrystals, which can be optimized through well-controlled nanocrystal synthesis. Further, the rich library of chromogenic reactions allows implementation of this scheme in various assay formats, as demonstrated by the iron oxide nanoparticle linked immunosorbent assay (ILISA) and blotting assay developed in this study. Our results indicate that, owing to the inherent simplicity, high sensitivity and repeatability, the nanocrystal based amplification scheme can significantly improve biomolecule quantification in both laboratory research and clinical diagnostics. This novel method adds a new dimension to current nanoparticle-based bioassays. PMID:23659350

  15. Large scale commercial fabrication of high quality graphene-based assays for biomolecule detection

    Science.gov (United States)

    Lerner, Mitchell; Gao, Yingning; Goldsmith, Brett; Barron, Francie

    Large numbers of high quality graphene transistors with mobility approximately 5000 cm2 / V * s were fabricated by chemical vapor deposition and packaged into ceramic carriers with an open cavity design. The ceramic carrier is compatible with standard electronics assembly, enabling the readout of graphene properties on the benchtop without large, expensive probing systems. After chemical functionalization, these sensors demonstrate sensitivity in the pM range and selectivity to many classes of biomolecules as a three terminal liquid-gated field effect transistor. High precision measurements of protein kinetics captured using this technology, commercially known as AGILE R100, are comparable and can exceed the capabilities of state-of-the-art biomolecule characterization tools. Recently published in Sensors and Actuators B

  16. A review on recent developments for biomolecule separation at analytical scale using microfluidic devices.

    Science.gov (United States)

    Tetala, Kishore K R; Vijayalakshmi, M A

    2016-02-04

    Microfluidic devices with their inherent advantages like the ability to handle 10(-9) to 10(-18) L volume, multiplexing of microchannels, rapid analysis and on-chip detection are proving to be efficient systems in various fields of life sciences. This review highlights articles published since 2010 that reports the use of microfluidic devices to separate biomolecules (DNA, RNA and proteins) using chromatography principles (size, charge, hydrophobicity and affinity) along with microchip capillary electrophoresis, isotachophoresis etc. A detailed overview of stationary phase materials and the approaches to incorporate them within the microchannels of microchips is provided as well as a brief overview of chemical methods to immobilize ligand(s). Furthermore, we review research articles that deal with microfluidic devices as analytical tools for biomolecule (DNA, RNA and protein) separation. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Fed-Batch Biomolecule Production by Bacillus subtilis: A State of the Art Review.

    Science.gov (United States)

    Ÿztürk, Sibel; Ÿalık, Pınar; Ÿzdamar, Tunçer H

    2016-04-01

    Bacillus subtilis is a highly promising production system for various biomolecules. This review begins with the algorithm of fed-batch operations (FBOs) and then illustrates the approaches to design the initial production medium and/or feed stream. Additionally, the feeding strategies developed with or without feedback control for fed-batch B. subtilis fermentations were compiled with a special emphasis on recombinant protein (r-protein) production. For biomolecule production by wild-type B. subtilis, due to the different intracellular production patterns, no consensus exists on the FBO strategy that gives the maximum productivity, whereas for r-protein production appropriate feeding strategies vary depending on the promoter used. Thus, we conclude that the B. subtilis community is still seeking an approved strong promoter and generalized FBO strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Immobilization of biomolecules onto surfaces according to ultraviolet light diffraction patterns

    International Nuclear Information System (INIS)

    Bjoern Petersen, Steffen; Kold di Gennaro, Ane; Neves-Petersen, Maria Teresa; Skovsen, Esben; Parracino, Antonietta

    2010-01-01

    We developed a method for immobilization of biomolecules onto thiol functionalized surfaces according to UV diffraction patterns. UV light-assisted molecular immobilization proceeds through the formation of free, reactive thiol groups that can bind covalently to thiol reactive surfaces. We demonstrate that, by shaping the pattern of the UV light used to induce molecular immobilization, one can control the pattern of immobilized molecules onto the surface. Using a single-aperture spatial mask, combined with the Fourier transforming property of a focusing lens, we show that submicrometer (0.7 μm) resolved patterns of immobilized prostate-specific antigen biomolecules can be created. If a dual-aperture spatial mask is used, the results differ from the expected Fourier transform pattern of the mask. It appears as a superposition of two diffraction patterns produced by the two apertures, with a fine structured interference pattern superimposed.

  19. Recent advances in chemical functionalization of nanoparticles with biomolecules for analytical applications.

    Science.gov (United States)

    Oh, Ju-Hwan; Park, Do Hyun; Joo, Jang Ho; Lee, Jae-Seung

    2015-11-01

    The recent synthetic development of a variety of nanoparticles has led to their widespread application in diagnostics and therapeutics. In particular, the controlled size and shape of nanoparticles precisely determine their unique chemical and physical properties, which is highly attractive for accurate analysis of given systems. In addition to efforts toward controlling the synthesis and properties of nanoparticles, the surface functionalization of nanoparticles with biomolecules has been intensively investigated since the mid-1990s. The complicated yet programmable properties of biomolecules have proved to substantially enhance and enrich the novel functions of nanoparticles to achieve "smart" nanoparticle materials. In this review, the advances in chemical functionalization of four types of representative nanoparticle with DNA and protein molecules in the past five years are critically reviewed, and their future trends are predicted.

  20. Live-cell stimulated Raman scattering imaging of alkyne-tagged biomolecules.

    Science.gov (United States)

    Hong, Senlian; Chen, Tao; Zhu, Yuntao; Li, Ang; Huang, Yanyi; Chen, Xing

    2014-06-02

    Alkynes can be metabolically incorporated into biomolecules including nucleic acids, proteins, lipids, and glycans. In addition to the clickable chemical reactivity, alkynes possess a unique Raman scattering within the Raman-silent region of a cell. Coupling this spectroscopic signature with Raman microscopy yields a new imaging modality beyond fluorescence and label-free microscopies. The bioorthogonal Raman imaging of various biomolecules tagged with an alkyne by a state-of-the-art Raman imaging technique, stimulated Raman scattering (SRS) microscopy, is reported. This imaging method affords non-invasiveness, high sensitivity, and molecular specificity and therefore should find broad applications in live-cell imaging. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A simplified biomolecule attachment strategy for biosensing using a porous Si oxide interferometer

    Science.gov (United States)

    Perelman, Loren A.; Schwartz, Michael P.; Wohlrab, Aaron M.; VanNieuwenhze, Michael S.; Sailor, Michael J.

    2008-01-01

    A simple strategy for linking biomolecules to porous Si surfaces and detecting peptide/drug binding is described. Porous Si is prepared using an electrochemical etch and then thermally oxidized by heating in ambient atmosphere. Bovine serum albumin (BSA) is then non-covalently adsorbed to the inner pore walls of the porous Si oxide (PSiO2) matrix. The BSA layer is used as a linker for covalent attachment of the peptide Ac-L-Lysine-D-Alanine-D-Alanine (KAA) using published bioconjugation chemistry. BSA-coated surfaces functionalized with KAA display specificity for the glycopeptide vancomycin while resisting adsorption of non-specific reagents. While the biomolecule attachment strategy reported here is used to bind peptides, the scheme can be generalized to the linking of any primary amine-containing molecule to PSiO2 surfaces. PMID:18458749

  2. Etymology of transition metal biomolecules as a learning aid in Biological Chemistry

    International Nuclear Information System (INIS)

    Silva, Jose A.L. da

    2013-01-01

    Numerous functional biomolecules are associated with metals, i.e. the metallobiomolecules; more specifically, some are dependent on transition metals required for several crucial biological roles. Nevertheless, their names can lead to ambiguous interpretations concerning the properties and performances of this group of biological molecules. Their etymology may be useful by providing a more perceptive insight into their features. However, etymology can lead to incongruous conclusions, requiring an especially careful approach to prevent errors. Examples illustrating these subjects shall be examined (author)

  3. Electrochemistry of single molecules and biomolecules, molecular scale nanostructures, and low-dimensional systems

    DEFF Research Database (Denmark)

    Nazmutdinov, Renat R.; Zinkicheva, Tamara T.; Zinkicheva, Tamara T.

    2018-01-01

    Electrochemistry at ultra-small scales, where even the single molecule or biomolecule can be characterized and manipulated, is on the way to a consolidated status. At the same time molecular electrochemistry is expanding into other areas of sophisticated nano- and molecular scale systems includin...... molecular scale metal and semiconductor nanoparticles (NPs) and other nanostructures, e.g. nanotubes, “nanoflowers” etc.. The new structures offer both new electronic properties and highly confined novel charge transfer environments....

  4. Novel triphenylamine-cored two-photon absorbing dyes for labeling of biomolecules

    International Nuclear Information System (INIS)

    Xiao Haibo; Mei Chong; Wang Yaochuan; Li, Hui; Qian Shixiong; Yin Hongyao; Xu Zhisong

    2011-01-01

    Highlights: → Two novel triphenylamine-cored chromophores were synthesized. → These two dyes have sizable two-photon absorption cross-section at 800 nm. → They possess reasonable water solubility and are suitable as labels in aqueous biological environments. → These dyes have strong chelating ability. → They display a large set of reactivity for coupling to biomolecules. - Abstract: Two novel, V-shaped and Y-shaped dipicolinate derivatives branched from triphenylamine, {4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl)vinyl]}-N-phenyl-N-{4- [(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl)vinylphenyl]}aniline (1) and {4-[(E)-2-(2,6-dimethoxycarbonylpyridin-4-yl) vinyl]}-N,N-bis {4-[(E)-2-(2,6-dimethoxycarbonyl pyridin-4-yl)vinylphenyl]}aniline (2) were synthesized. These compounds were designed for large two-photon absorption and in particular for labeling of biomolecules. Their linear absorption, fluorescence properties and their two-photon absorption properties as well as two-photon fluorescence cell imaging were examined. When excited at 800 nm, the two-photon absorption cross-section values of chromophores 1 and 2 in THF were 208 GM, 376 GM, respectively. These two-photon absorbing dyes possess reasonable water solubility, strong chelating ability and display a large set of reactivity for coupling to biomolecules, which are apparently due to the two methoxycarbonyl groups in pyridine ring. This work suggests that chromophores 1 and 2 are promising labels potentially applicable for the tracking of biomolecules using two-photon scanning microscopy.

  5. Strategies to balance covalent and non-covalent biomolecule attachment within collagen-GAG biomaterials.

    Science.gov (United States)

    Pence, Jacquelyn C; Gonnerman, Emily A; Bailey, Ryan C; Harley, Brendan A C

    2014-09-01

    Strategies to integrate instructive biomolecular signals into a biomaterial are becoming increasingly complex and bioinspired. While a large majority of reports still use repeated treatments with soluble factors, this approach can be prohibitively costly and difficult to translate in vivo for applications where spatial control over signal presentation is necessary. Recent efforts have explored the use of covalent immobilization of biomolecules to the biomaterial, via both bulk (ubiquitous) as well as spatially-selective light-based crosslinking, as a means to both enhance stability and bioactivity. However, little is known about how processing conditions during immobilization impact the degree of unintended non-covalent interactions, or fouling, that takes place between the biomaterial and the biomolecule of interest. Here we demonstrate the impact of processing conditions for bulk carbodiimide (EDC) and photolithography-based benzophenone (BP) crosslinking on specific attachment vs. fouling of a model protein (Concanavalin A, ConA) within collagen-glycosaminoglycan (CG) scaffolds. Collagen source significantly impacts the selectivity of biomolecule immobilization. EDC crosslinking intensity and ligand concentration significantly impacted selective immobilization. For benzophenone photoimmobilization we observed that increased UV exposure time leads to increased ConA immobilization. Immobilization efficiency for both EDC and BP strategies was maximal at physiological pH. Increasing ligand concentration during immobilization process led to enhanced immobilization for EDC chemistry, no impact on BP immobilization, but significant increases in non-specific fouling. Given recent efforts to covalently immobilize biomolecules to a biomaterial surface to enhance bioactivity, improved understanding of the impact of crosslinking conditions on selective attachment versus non-specific fouling will inform the design of instructive biomaterials for applications across tissue

  6. Development of radioactively labelled cancer seeking biomolecules for targeted radiotherapy. Uruguay

    International Nuclear Information System (INIS)

    Balter, H.; Verdera, S.

    2000-01-01

    The main objective of this project is the labelling and quality control of biomolecules with radionuclides beta emitters with high purity and stability. Techniques and methodology for labelling with 188 Re, 153 Sm, and 125 I as well as quality controls were done according to the recommendations of the first research coordination meeting of this CRP. Also some useful chelators reported in the literature were synthesized in our laboratory)

  7. Sensitivity and Resolution Enhanced Solid-State NMR for Paramagnetic Systems and Biomolecules under Very Fast Magic Angle Spinning

    KAUST Repository

    Parthasarathy, Sudhakar; Nishiyama, Yusuke; Ishii, Yoshitaka

    2013-01-01

    Recent research in fast magic angle spinning (MAS) methods has drastically improved the resolution and sensitivity of NMR spectroscopy of biomolecules and materials in solids. In this Account, we summarize recent and ongoing developments

  8. Intensity of diffracted X-rays from biomolecules with radiation damage caused by strong X-ray pulses

    International Nuclear Information System (INIS)

    Kai, Takeshi; Tokuhisa, Atsushi; Moribayashi, Kengo; Fukuda, Yuji; Kono, Hidetoshi; Go, Nobuhiro

    2014-01-01

    In order to realize the coherent X-ray diffractive imaging of single biomolecules, the diffraction intensities, per effective pixel of a single biomolecule with radiation damage, caused by irradiation using a strong coherent X-ray pulse, were examined. A parameter survey was carried out for various experimental conditions, using a developed simulation program that considers the effect of electric field ionization, which was slightly reported on in previous studies. The two simple relationships among the parameters were identified as follows: (1) the diffraction intensity of a biomolecule slightly increases with the incident X-ray energy; and that (2) the diffraction intensity is approximately proportional to the target radius, when the radius is longer than 400 Å, since the upper limit of the incident intensity for damage to the biomolecules marginally changes with respect to the target radius. (author)

  9. A method for detection of hydroxyl radicals in the vicinity of biomolecules using radiation-induced fluorescence of coumarin

    International Nuclear Information System (INIS)

    Makrigiorgos, G.M.; Baranowska-Kortylewicz, J.; Bump, E.; Sahu, S.K.; Berman, R.M.; Kassis, A.I.

    1993-01-01

    A novel method is described to quantitate radiation-induced hydroxyl radicals in the vicinity of biomolecules in aqueous solutions. Coumarin-3-carboxylic acid (CCA) is a non-fluorescent molecule that, upon interaction with radiation in aqueous solution, produces fluorescent products. CCA was derivatized to its succinimidyl ester (SECCA) and coupled to free primary amines of albumin, avidin, histone-H1, polylysine, and an oligonucleotide. When SECCA-biomolecule conjugates were irradiated, the relationship between induced fluorescence and dose was linear in the dose range examined (0.01-10 Gy). The data indicate that the induction of fluorescence on SECCA-biomolecule conjugates records specifically the presence of the hydroxyl radical in the immediate vicinity of the irradiated biomolecule. The method is rapid and sensitive, uses standard instrumentation, and the sample remains available for further studies. (Author)

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

    Science.gov (United States)

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

    2013-11-01

    A versatile method of dual chemical functionalization of graphene oxide (GO) with Tris-[nitrilotris(acetic acid)] (Tris-NTA) and biotin for cellular delivery of oligohistidine- and biotin-tagged biomolecules is reported. Orthogonally functionalized GO surfaces with Tris-NTA and biotin to obtain a dual-functionalized GO (DFGO) are prepared and characterized by various spectroscopic and microscopic techniques. Fluorescence microscopic images reveal that DFGO surfaces are capable of binding oligohistidine-tagged biomolecules/proteins and avidin/biotin-tagged biomolecules/proteins orthogonally. The DFGO nanoparticles are non-cytotoxic in nature and can deliver oligohistidine- and biotin-tagged biomolecules simultaneously into the cell. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Computational On-Chip Imaging of Nanoparticles and Biomolecules using Ultraviolet Light

    KAUST Repository

    Daloglu, Mustafa Ugur

    2017-03-09

    Significant progress in characterization of nanoparticles and biomolecules was enabled by the development of advanced imaging equipment with extreme spatial-resolution and sensitivity. To perform some of these analyses outside of well-resourced laboratories, it is necessary to create robust and cost-effective alternatives to existing high-end laboratory-bound imaging and sensing equipment. Towards this aim, we have designed a holographic on-chip microscope operating at an ultraviolet illumination wavelength (UV) of 266 nm. The increased forward scattering from nanoscale objects at this short wavelength has enabled us to detect individual sub-30 nm nanoparticles over a large field-of-view of >16 mm2 using an on-chip imaging platform, where the sample is placed at ≤0.5 mm away from the active area of an opto-electronic sensor-array, without any lenses in between. The strong absorption of this UV wavelength by biomolecules including nucleic acids and proteins has further enabled high-contrast imaging of nanoscopic aggregates of biomolecules, e.g., of enzyme Cu/Zn-superoxide dismutase, abnormal aggregation of which is linked to amyotrophic lateral sclerosis (ALS) - a fatal neurodegenerative disease. This UV-based wide-field computational imaging platform could be valuable for numerous applications in biomedical sciences and environmental monitoring, including disease diagnostics, viral load measurements as well as air- and water-quality assessment.

  12. Development of new probes for NMR based analysis of biomolecules' cellular functions

    International Nuclear Information System (INIS)

    Fernandes, Laetitia

    2015-01-01

    Most NMR studies are carried out in vitro, but the structure and dynamics of some biomolecules inside cells differ from those in vitro. It thus becomes interesting to analyze biomolecules such as proteins in their natural environment: the cell. Recent progress of in cell NMR allowed to better understand the behaviour of proteins: their dynamics and their interactions with other biomolecules in the cell. But the low concentration of proteins leads to low signal intensity. Moreover, the viscosity of the environment induces faster transverse relaxation, resulting in line broadening for proteins signals. The use of the Long-Lived States and Coherencies (LLS and LLC, respectively) as well as dissolution Dynamic Nuclear Polarization (dissolution-DNP) can improve NMR observations in cells. LLS were used to understand and characterize the structure of the N-terminal domain of c-Src, which is intrinsically disordered. To follow the phosphorylation of proteins, a first preliminary study of a 21-aa peptides derived from IKBa electroporated into HepG2 cell lines was carried out. (author)

  13. A novel platform based on defect-rich knotted graphene nanotubes for detection of small biomolecules

    International Nuclear Information System (INIS)

    Lan, Shumin; Song, Yingpan; Chen, Qidi; Guo, Zhiyong; Zhan, Hongbing

    2016-01-01

    Highlights: • Curvature of the SC-CNTs’ cavities had more local pressure, leading to form k-GNTs. • k-GNTs are divided into sections by knots with abundant edge-plane sites/defects. • k-GNTs exhibited excellent catalytic activity, sensitivity and reproducibility. - Abstract: Detection of disease-related small biomolecules was of great significance for clinical diagnostics and treatment. In this work, we synthesized defect-rich knotted graphene nanotubes (k-GNTs) via chemical oxidative etching of stacked-up carbon nanotubes (SC-CNTs) followed by chemical reduction, to detect disease-related small biomolecules. We further studied the electrochemical properties using three representative redox probes and analyzed their biosensitivity using five biomolecules. The k-GNT-modified electrodes exhibited excellent electrochemical response, with the lowest ΔE p and the highest k 0 . Besides, the modified electrodes could simultaneously detect and discriminate between dopamine (DA), ascorbic acid and uric acid (UA), as well as differentiate phenethylamine (PEA) and epinephrine (EP) existed in newborn rat serum, providing the wide linear detection ranges with high sensitivities for DA, UA, PEA, and EP. These excellent electrocatalytic properties could be ascribe to the unique knotted graphene nanotube structure with high proportion of defect/edge sites, large, accessible, three-dimensional, accessible surface area, fewer oxygen-containing groups and doped N atoms. Our work reveals defect-rich k-GNTs as a promising platform for further applications in electrochemical biosensing and electrocatalysis.

  14. Electron Paramagnetic Resonance of a Single NV Nanodiamond Attached to an Individual Biomolecule.

    Science.gov (United States)

    Teeling-Smith, Richelle M; Jung, Young Woo; Scozzaro, Nicolas; Cardellino, Jeremy; Rampersaud, Isaac; North, Justin A; Šimon, Marek; Bhallamudi, Vidya P; Rampersaud, Arfaan; Johnston-Halperin, Ezekiel; Poirier, Michael G; Hammel, P Chris

    2016-05-10

    Electron paramagnetic resonance (EPR), an established and powerful methodology for studying atomic-scale biomolecular structure and dynamics, typically requires in excess of 10(12) labeled biomolecules. Single-molecule measurements provide improved insights into heterogeneous behaviors that can be masked in ensemble measurements and are often essential for illuminating the molecular mechanisms behind the function of a biomolecule. Here, we report EPR measurements of a single labeled biomolecule. We selectively label an individual double-stranded DNA molecule with a single nanodiamond containing nitrogen-vacancy centers, and optically detect the paramagnetic resonance of nitrogen-vacancy spins in the nanodiamond probe. Analysis of the spectrum reveals that the nanodiamond probe has complete rotational freedom and that the characteristic timescale for reorientation of the nanodiamond probe is slow compared with the transverse spin relaxation time. This demonstration of EPR spectroscopy of a single nanodiamond-labeled DNA provides the foundation for the development of single-molecule magnetic resonance studies of complex biomolecular systems. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  15. [Probabilistic calculations of biomolecule charge states that generate mass spectra of multiply charged ions].

    Science.gov (United States)

    Raznikova, M O; Raznikov, V V

    2015-01-01

    In this work, information relating to charge states of biomolecule ions in solution obtained using the electrospray ionization mass spectrometry of different biopolymers is analyzed. The data analyses have mainly been carried out by solving an inverse problem of calculating the probabilities of retention of protons and other charge carriers by ionogenic groups of biomolecules with known primary structures. The approach is a new one and has no known to us analogues. A program titled "Decomposition" was developed and used to analyze the charge distribution of ions of native and denatured cytochrome c mass spectra. The possibility of splitting of the charge-state distribution of albumin into normal components, which likely corresponds to various conformational states of the biomolecule, has been demonstrated. The applicability criterion for using previously described method of decomposition of multidimensional charge-state distributions with two charge carriers, e.g., a proton and a sodium ion, to characterize the spatial structure of biopolymers in solution has been formulated. In contrast to known mass-spectrometric approaches, this method does not require the use of enzymatic hydrolysis or collision-induced dissociation of the biopolymers.

  16. Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review

    International Nuclear Information System (INIS)

    Yang, Cheng; Denno, Madelaine E.; Pyakurel, Poojan; Venton, B. Jill

    2015-01-01

    Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors. - Highlights: • We review the types of carbon nanomaterials used in electrochemical sensors. • Different materials and sensor designs are compared for classes of biomolecules. • Future challenges of better sensor design and implementation are assessed

  17. Morphological Effect of Non-targeted Biomolecule-Modified MNPs on Reticuloendothelial System.

    Science.gov (United States)

    Li, Xiao; Hu, Yan; Xiao, Jie; Cheng, Dengfeng; Xiu, Yan; Shi, Hongcheng

    2015-12-01

    Magnetic nanoparticles (MNPs) with special morphology were commonly used as biomaterials, while morphological effects of non-targeted biomolecule-modified MNPs on biological behaviors were still unclear. In this research, spherical and rod-like Fe3O4 in a comparable size were synthesized and then surface-modified by bovine serum albumin (BSA) as a model of non-targeted biomolecule-modified MNPs. Morphological effects were featured by TEM and quantification of in vitro phagocytic uptake, as well as the in vivo quantification of particles in reticuloendothelial system (RES)-related organs of normal Kunming mice. For these non-targeted BSA-modified MNPs, intracellular distributions were the same, but the rod-like MNPs were more likely to be uptake by macrophages; furthermore, the BSA-modified MNPs gathered in RES-related organs soon after intravenous injection, but the rod-like ones were expelled from the lung more quickly and expelled from the spleen more slowly. These preliminary results may be referable if MNPs or other similar biomolecule-modified nanoparticles were used.

  18. Biocompatible Water Soluble Polyacrylic Acid Coated CdSe/Cu Quantum Dot Conjugates for Biomolecule Detection.

    Science.gov (United States)

    Gomaa, Ola M; Okasha, Aly; Hosni, Hany M; El-Hag Ali, Amr

    2018-01-01

    Biocompatible polyacrylic acid functionalized CdSe/Cu quantum dot conjugates were synthesized to be used for biomolecules detection. The study results demonstrate the conjugation of the 2.5-3 nm QD with gram negative bacteria with a low detection limit of 28 cfu/ml. The photoluminescence (PL) intensity was correlated to bacterial count, cellular proteins and exopolysaccharides in the tested samples. Confocal Scanning Laser Microscopy (CSLM) images showed significant QD uptake within the cells, both cytoplasm and DNA were the predominant targeted biomolecules, higher fluorescent uptake was shown in gram negative bacteria than that observed for gram positive bacteria. Moreover, PL showed that there was a distinction between live and dead cells as well as gram negative and gram positive cells. Cell viability was not affected even after 6 days (100% viability) rendering it a non-toxic QD. The method is simple and is performed in a single step within approximately 10 min as compared to multi-step protocols for classical microbial count or fluorescent dye staining. All the above results indicate that the CdSe/Cu-PAA QDs are suitable for biomolecule detection, bio-labeling and bioimaging applications.

  19. Biomolecule conjugation strategy using novel water-soluble phosphine-based chelating agents

    Science.gov (United States)

    Katti, Kattesh V.; Gali, Hariprasad; Volkert, Wynn A.

    2004-08-24

    This invention describes a novel strategy to produce phosphine-functionalized biomolecules (e.g. peptides or proteins) for potential use in the design and development of site-specific radiopharmaceuticals for diagnosis or therapy of specific cancers. Hydrophilic alkyl phosphines, in general, tend to be oxidatively unstable. Therefore, incorporation of such phosphine functionalities on peptide (and other biomolecule) backbones, without oxidizing the P.sup.III centers, is difficult. In this context this discovery reports on a new technology by which phosphines, in the form of bifunctional chelating agents, can be directly incorporated on biomolecular backbones using manual synthetic or solid phase peptide synthesis methodologies. The superior ligating abilities of phosphine ligands, with various diagnostically (e.g. TC-99m) or therapeutically (e.g. Re186/188, Rh-105, Au-199) useful radiometals, coupled with the findings that the resulting complexes demonstrate high in vivo stability makes this approach useful in the development of radiolabeled biomolecules for applications in the design of tumor-specific radiopharmaceuticals.

  20. Graphene-Templated Synthesis of Magnetic Metal Organic Framework Nanocomposites for Selective Enrichment of Biomolecules.

    Science.gov (United States)

    Cheng, Gong; Wang, Zhi-Gang; Denagamage, Sachira; Zheng, Si-Yang

    2016-04-27

    Successful control of homogeneous and complete coating of graphene or graphene-based composites with well-defined metal organic framework (MOF) layers is a great challenge. Herein, novel magnetic graphene MOF composites were constructed via a simple strategy for self-assembly of well-distributed, dense, and highly porous MOFs on both sides of graphene nanosheets. Graphene functionalized with magnetic nanoparticles and carboxylic groups on both sides was explored as the backbone and template to direct the controllable self-assembly of MOFs. The prepared composite materials have a relatively high specific surface area (345.4 m(2) g(-1)), and their average pore size is measured to be 3.2 nm. Their relatively high saturation magnetization (23.8 emu g(-1)) indicates their strong magnetism at room temperature. Moreover, the multifunctional composite was demonstrated to be a highly effective affinity material in selective extraction and separation of low-concentration biomolecules from biological samples, in virtue of the size-selection property of the unique porous structure and the excellent affinity of the composite materials. Besides providing a solution for the construction of well-defined functional graphene-based MOFs, this work could also contribute to selective extraction of biomolecules, in virtue of the universal affinity between immobilized metal ions and biomolecules.

  1. Computational On-Chip Imaging of Nanoparticles and Biomolecules using Ultraviolet Light.

    Science.gov (United States)

    Daloglu, Mustafa Ugur; Ray, Aniruddha; Gorocs, Zoltan; Xiong, Matthew; Malik, Ravinder; Bitan, Gal; McLeod, Euan; Ozcan, Aydogan

    2017-03-09

    Significant progress in characterization of nanoparticles and biomolecules was enabled by the development of advanced imaging equipment with extreme spatial-resolution and sensitivity. To perform some of these analyses outside of well-resourced laboratories, it is necessary to create robust and cost-effective alternatives to existing high-end laboratory-bound imaging and sensing equipment. Towards this aim, we have designed a holographic on-chip microscope operating at an ultraviolet illumination wavelength (UV) of 266 nm. The increased forward scattering from nanoscale objects at this short wavelength has enabled us to detect individual sub-30 nm nanoparticles over a large field-of-view of >16 mm 2 using an on-chip imaging platform, where the sample is placed at ≤0.5 mm away from the active area of an opto-electronic sensor-array, without any lenses in between. The strong absorption of this UV wavelength by biomolecules including nucleic acids and proteins has further enabled high-contrast imaging of nanoscopic aggregates of biomolecules, e.g., of enzyme Cu/Zn-superoxide dismutase, abnormal aggregation of which is linked to amyotrophic lateral sclerosis (ALS) - a fatal neurodegenerative disease. This UV-based wide-field computational imaging platform could be valuable for numerous applications in biomedical sciences and environmental monitoring, including disease diagnostics, viral load measurements as well as air- and water-quality assessment.

  2. Enzyme assisted extraction of biomolecules as an approach to novel extraction technology: A review.

    Science.gov (United States)

    Nadar, Shamraja S; Rao, Priyanka; Rathod, Virendra K

    2018-06-01

    An interest in the development of extraction techniques of biomolecules from various natural sources has increased in recent years due to their potential applications particularly for food and nutraceutical purposes. The presence of polysaccharides such as hemicelluloses, starch, pectin inside the cell wall, reduces the extraction efficiency of conventional extraction techniques. Conventional techniques also suffer from low extraction yields, time inefficiency and inferior extract quality due to traces of organic solvents present in them. Hence, there is a need of the green and novel extraction methods to recover biomolecules. The present review provides a holistic insight to various aspects related to enzyme aided extraction. Applications of enzymes in the recovery of various biomolecules such as polyphenols, oils, polysaccharides, flavours and colorants have been highlighted. Additionally, the employment of hyphenated extraction technologies can overcome some of the major drawbacks of enzyme based extraction such as longer extraction time and immoderate use of solvents. This review also includes hyphenated intensification techniques by coupling conventional methods with ultrasound, microwave, high pressure and supercritical carbon dioxide. The last section gives an insight on application of enzyme immobilization as a strategy for large scale extraction. Immobilization of enzymes on magnetic nanoparticles can be employed to enhance the operational performance of the system by multiple use of expensive enzymes making them industrially and economically feasible. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Raman Microscopy: A Noninvasive Method to Visualize the Localizations of Biomolecules in the Cornea.

    Science.gov (United States)

    Kaji, Yuichi; Akiyama, Toshihiro; Segawa, Hiroki; Oshika, Tetsuro; Kano, Hideaki

    2017-11-01

    In vivo and in situ visualization of biomolecules without pretreatment will be important for diagnosis and treatment of ocular disorders in the future. Recently, multiphoton microscopy, based on the nonlinear interactions between molecules and photons, has been applied to reveal the localizations of various molecules in tissues. We aimed to use multimodal multiphoton microscopy to visualize the localizations of specific biomolecules in rat corneas. Multiphoton images of the corneas were obtained from nonlinear signals of coherent anti-Stokes Raman scattering, third-order sum frequency generation, and second-harmonic generation. The localizations of the adhesion complex-containing basement membrane and Bowman layer were clearly visible in the third-order sum frequency generation images. The fine structure of type I collagen was observed in the corneal stroma in the second-harmonic generation images. The localizations of lipids, proteins, and nucleic acids (DNA/RNA) was obtained in the coherent anti-Stokes Raman scattering images. Imaging technologies have progressed significantly and been applied in medical fields. Optical coherence tomography and confocal microscopy are widely used but do not provide information on the molecular structure of the cornea. By contrast, multiphoton microscopy provides information on the molecular structure of living tissues. Using this technique, we successfully visualized the localizations of various biomolecules including lipids, proteins, and nucleic acids in the cornea. We speculate that multiphoton microscopy will provide essential information on the physiological and pathological conditions of the cornea, as well as molecular localizations in tissues without pretreatment.

  4. Non-linear vibrational modes in biomolecules: A periodic orbits description

    International Nuclear Information System (INIS)

    Kampanarakis, Alexandros; Farantos, Stavros C.; Daskalakis, Vangelis; Varotsis, Constantinos

    2012-01-01

    Graphical abstract: Vibrational frequency shifts in Fe IV = O species of the active site of cytochrome c oxidase are attributed to changes in the surrounding Coulomb field. Periodic orbits analysis assists to find the most anharmonic modes in model biomolecules. Highlights: ► Periodic orbits are extended to multidimensional potentials of biomolecules. ► Highly anharmonic vibrational modes and center-saddle bifurcations are detected. ► Vibrational frequencies shifts in Oxoferryl species of CcO are observed. - Abstract: The vibrational harmonic normal modes of a molecule, which are valid at energies close to an equilibrium point (a minimum, maximum or saddle of the potential energy surface), are extended by periodic orbits to high energies where anharmonicity and coupling of the degrees of freedom are significant. In this way the assignment of the spectra, and thus the extraction of dynamics in highly excited molecules, can be obtained. New vibrational modes emanating from bifurcations of periodic orbits and long living localized trajectories signal the birth and localization of new quantum states. In this article we review and further study non-linear vibrational modes for model biomolecules such as alanine dipeptide and the active site in the oxoferryl oxidation state of the enzyme cytochrome c oxidase. We locate periodic orbits which exhibit high anhamonicity and lead to center-saddle bifurcations. These modes are associated to an isomerization process in alanine dipeptide and to frequency shifts in the oxoferryl observed by modifying the Coulomb field around the Imidazole–Fe IV = O species.

  5. Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cheng; Denno, Madelaine E.; Pyakurel, Poojan; Venton, B. Jill, E-mail: jventon@virginia.edu

    2015-08-05

    Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors. - Highlights: • We review the types of carbon nanomaterials used in electrochemical sensors. • Different materials and sensor designs are compared for classes of biomolecules. • Future challenges of better sensor design and implementation are assessed.

  6. Quantification of biomolecules in herring (Clupea harengus) industry processing waters and their recovery using electroflocculation and ultrafiltration

    DEFF Research Database (Denmark)

    Osman, Ali; Gringer, Nina; Svendsen, Tore

    2015-01-01

    Four types of herring industry processing waters; refrigerated sea water (RSW), storage water (SW), processing water from cutting (PW) and pre-salting brines (SB) were subjected to chemical characterization and biomolecule recovery using electroflocculation (EF) and ultrafiltration (UF). The high......Four types of herring industry processing waters; refrigerated sea water (RSW), storage water (SW), processing water from cutting (PW) and pre-salting brines (SB) were subjected to chemical characterization and biomolecule recovery using electroflocculation (EF) and ultrafiltration (UF...

  7. Designing the nanoparticle-biomolecule interface for "targeting and therapeutic delivery".

    Science.gov (United States)

    Mahon, Eugene; Salvati, Anna; Baldelli Bombelli, Francesca; Lynch, Iseult; Dawson, Kenneth A

    2012-07-20

    The endogenous transport mechanisms which occur in living organisms have evolved to allow selective transport and processing operate on a scale of tens of nanometers. This presents the possibility of unprecedented access for engineered nanoscale materials to organs and sub-cellular locations, materials which may in principle be targeted to precise locations for diagnostic or therapeutic gain. For this reason, nano-architectures could represent a truly radical departure as delivery agents for drugs, genes and therapies to treat a host of diseases. Thus, for active targeting, unlike the case of small molecular drugs where molecular structure has evolved to promote higher physiochemical affinity to specific sites, one aims to exploit these energy dependant endogenous processes. Many active targeting strategies have been developed, but despite this truly remarkable potential, in applications they have met with mixed success to date. This situation may have more to do with our current understanding and integration of knowledge across disciplines, than any intrinsic limitation on the vision itself. In this review article we suggest that much more fundamental and detailed control of the nanoparticle-biomolecule interface is required for sustained and general success in this field. In the simplest manifestation, pristine nanoparticles in biological fluids act as a scaffold for biomolecules, which adsorb rapidly to the nanoparticles' surface, conferring a new biological identity to the nanoparticles. It is this nanoparticle-biomolecule interface that is 'read' and acted upon by the cellular machinery. Moreover, where targeting moieties are grafted onto nanoparticles, they may not retain their function as a result of poor orientation, and structural or conformational disruption. Further surface adsorption of biomolecules from the surrounding environment i.e. the formation of a biomolecule corona may also obscure specific surface recognition. To transfer the remarkable

  8. Possibility of single biomolecule imaging with coherent amplification of weak scattering x-ray photons.

    Science.gov (United States)

    Shintake, Tsumoru

    2008-10-01

    The number of photons produced by coherent x-ray scattering from a single biomolecule is very small because of its extremely small elastic-scattering cross section and low damage threshold. Even with a high x-ray flux of 3 x 10;{12} photons per 100-nm -diameter spot and an ultrashort pulse of 10 fs driven by a future x-ray free electron laser (x-ray FEL), it has been predicted that only a few 100 photons will be produced from the scattering of a single lysozyme molecule. In observations of scattered x rays on a detector, the transfer of energy from wave to matter is accompanied by the quantization of the photon energy. Unfortunately, x rays have a high photon energy of 12 keV at wavelengths of 1A , which is required for atomic resolution imaging. Therefore, the number of photoionization events is small, which limits the resolution of imaging of a single biomolecule. In this paper, I propose a method: instead of directly observing the photons scattered from the sample, we amplify the scattered waves by superimposing an intense coherent reference pump wave on it and record the resulting interference pattern on a planar x-ray detector. Using a nanosized gold particle as a reference pump wave source, we can collect 10;{4}-10;{5} photons in single shot imaging where the signal from a single biomolecule is amplified and recorded as two-dimensional diffraction intensity data. An iterative phase retrieval technique can be used to recover the phase information and reconstruct the image of the single biomolecule and the gold particle at the same time. In order to precisely reconstruct a faint image of the single biomolecule in Angstrom resolution, whose intensity is much lower than that of the bright gold particle, I propose a technique that combines iterative phase retrieval on the reference pump wave and the digital Fourier transform holography on the sample. By using a large number of holography data, the three-dimensional electron density map can be assembled.

  9. Justicia y sistema tributario. Una mirada desde la perspectiva inglesa

    Directory of Open Access Journals (Sweden)

    Patricio Masbernat

    2014-01-01

    Full Text Available Este artículo expone que la doctrina chilena aborda la cuestión de la justicia tributaria desde una triple perspectiva, económica, filosófica y jurídica. Con todo, desconfía de las posibilidades de esta última, para desarrollar soluciones genuinas de los complejos problemas que enfrenta la justicia tributaria. A partir de dicha evidencia, el autor indaga el desarrollo de este asunto en el mundo anglosajón, especialmente de Inglaterra. El autor recorre el camino que filósofos, economistas y juristas efectúan acerca de los elementos más determinantes de la justicia tributaria. Para tales efectos, luego de plantear el problema y la perspectiva analítica del artículo, revisa la idea de justicia tributaria en las doctrinas liberales clásicas, la justificación de la imposición de tributos y los fines del Estado, el concepto de tributo, la justicia conmutativa y la justicia distributiva, las finalidades extra fiscales del tributo, el principio de igualdad como expresión normativa de la justicia en la tributación. El autor concluye que no obstante que el mundo anglosajón se aborda esta cuestión desde esta triple perspectiva, y de un modo muy diferente al del Derecho Continental, la doctrina jurídica ha sido capaz de discutir acerca de estos complejos problemas jurídicos con éxito.

  10. Liberalismo y democracia en la perspectiva de Norberto Bobbio

    OpenAIRE

    Luis Antonio Córdoba Gómez

    2008-01-01

    En el presente artículo se desarrolla un análisis, abordado desde la filosofía política, en torno a la concepción que el filósofo italiano Norberto Bobbio (1909-2004) planteara acerca de dos de las más importantes tradiciones políticas que ha producido la cultura occidental, y que son, sin duda alguna, pilares sobre los que se ha edificado la modernidad: la democracia y el liberalismo. Desde esta perspectiva se identifican aproximaciones y puntos de encuentro, lo mismo que las tensiones que d...

  11. Editorial Mercadotecnia Latinoamericana desde una perspectiva de México

    OpenAIRE

    Thel Augusto Monteiro; Emigdio Larios-Gómez

    2017-01-01

    La presente Edición Especial: Mercadotecnia Latinoamericana desde una perspectiva de México, es un esfuerzo de investigadores de diferentes universidades reconocidos por sus aportaciones científicas sobre Mercadotecnia en México. Las comunicaciones esta edición describen las Estrategias de Mercadotecnia y su Aplicación en México, está estructurada en ocho aportaciones científicas representan el quehacer académico y de investigación diario de la mercadotecnia, tratando temas de frontera relaci...

  12. El autismo desde una perspectiva neuropsicológica

    OpenAIRE

    Justo Rodríguez, Marta

    2013-01-01

    En la presente revisión bibliográfica se pretende dar una aproximación al autismo. Se revisarán diversos abordajes que atraviesa este trastorno desde sus inicios hasta la actualidad. Se tienen en cuenta los rasgos fundamentales del autismo revisando el conocimiento de la etiología de dicha enfermedad en la que la tríada la conformarían la ausencia de relaciones sociales, las dificultades para la comunicación, el comportamiento rutinario y obsesivo. Desde una perspectiva neuropsicológica se an...

  13. Desigualdad laboral desde la perspectiva de género

    OpenAIRE

    Laura de Pablos Escobar

    2001-01-01

    Se enuncian y se comentan algunas de las situaciones laborales sufridas por las mujeres, que más nos llaman la atención. Por ejemplo: tasas de paro, contratos temporales, trabajo no remunerado, desigualdad de ingresos, etc. Los datos que se ofrecen, siempre que sea posible, incluirán experiencia comparada. Se refiere a las políticas públicas aplicadas en la actualidad en nuestro país al objeto de solventar la desigualdad laboral desde la perspectiva de género. Nos referiremos tanto a las ayud...

  14. Crisis y perspectivas de la industria automotriz argentina

    Directory of Open Access Journals (Sweden)

    Damián Andrés Bil

    2016-12-01

    Full Text Available Con la conformación del Mercosur, la automotriz argentina se expandió. Durante los últimos años alcanzó récords de producción, exportaciones y ventas; al punto que se la señala como ejemplo de una nueva etapa productiva. No obstante, desde finales de 2013 el complejo experimenta una crisis que provocó una considerable caída de los indicadores, con suspensiones e incluso despidos en las empresas de autopartes. En este artículo, proponemos revisar los indicadores de la actividad (escala y mercado, productividad, costo laboral, saldo comercial en perspectiva histórica y en el contexto de la competencia internacional. El objetivo es determinar si la situación actual corresponde a un inconveniente coyuntural, o si por el contrario expresa límites históricos que la automotriz argentina no ha superado; y sus perspectivas. *Palabras clave: Argentina, automotriz, crisis, competitividad, Mercosur

  15. Marketing de lugar: estado da arte e perspectivas futuras

    Directory of Open Access Journals (Sweden)

    Marco Antonio de Moraes Ocke

    2014-12-01

    Full Text Available O objetivo neste trabalho é contribuir com o repensar da natureza e do significado do marketing de lugar presente na literatura, descrevendo as três principais perspectivas influentes em seu desenvolvimento – promoção, planejamento e branding – e apresentar uma análise crítica de seu processo de evolução. No intuito de orientar o entendimento, evitar interpretações individuais e propor uma linguagem comum, a análise compreende a convergência das perspectivas em um conceito caracterizado como uma importante ferramenta de gerenciamento das trocas que ocorrem em âmbito territorial visando ao desenvolvimento socioeconômico da localidade. Como contribuição, sugere-se uma estruturação para investigações futuras identificando lacunas entre a teoria do marketing de lugar e a forma como é compreendido, assim como as dificuldades significativas para sua implementação.

  16. Como entender la formacion docente. Concepciones y perspectivas en Argentina

    Directory of Open Access Journals (Sweden)

    Marcelo Gastón Jorge Navarro

    2015-08-01

    Full Text Available El objetivo del artículo es comprender la formación docente bajo el enfoque de distintas concepciones que desde diversos supuestos y puntos de partida entretejen un complejo entramado de prácticas al interior de las aulas en Argentina. La idea de concepciones nos permite entender los procesos por los cuales se construye, reproduce, y/o se transforma la idea de ser docente. De acuerdo a la concepción de formación docente que se tenga, puede entenderse cuales son los mecanismos más adecuados para llevarla a cabo. Palabras clave: Formación docente, Práctica docente, Concepciones, Perspectivas. O objetivo do artigo é compreender a formação docente mediante o enfoque de diferentes concepções que filiadas aos mais diversos pressupostos e pontos de partida, tecem uma trama complexa de práticas em sala de aula na Argentina. A ideia de concepções nos permite entender os processos através dos quais se produz, reproduz e/ou se transforma a ideia de ser docente. De acordo com a concepção de formação docente que se tenha, pode-se entender quais são os mecanismos mais adequados para seguir adiante. Palavras-chave: Formação docente, Prática docente, Concepções, Perspectivas.

  17. Microfossils, biomolecules and biominerals in carbonaceous meteorites: implications to the origin of life

    Science.gov (United States)

    Hoover, Richard B.

    2012-11-01

    Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) investigations have shown that a wide variety of carbonaceous meteorites contain the remains of large filaments embedded within freshly fractured interior surfaces of the meteorite rock matrix. The filaments occur singly or in dense assemblages and mats and are often encased within carbon-rich, electron transparent sheaths. Electron Dispersive X-ray Spectroscopy (EDS) spot analysis and 2D X-Ray maps indicate the filaments rarely have detectable nitrogen levels and exhibit elemental compositions consistent with that interpretation that of the meteorite rock matrix. Many of the meteorite filaments are exceptionally well-preserved and show evidence of cells, cell-wall constrictions and specialized cells and processes for reproduction, nitrogen fixation, attachment and motility. Morphological and morphometric analyses permit many of the filaments to be associated with morphotypes of known genera and species of known filamentous trichomic prokaryotes (cyanobacteria and sulfur bacteria). The presence in carbonaceous meteorites of diagenetic breakdown products of chlorophyll (pristane and phytane) along with indigenous and extraterrestrial chiral protein amino acids, nucleobases and other life-critical biomolecules provides strong support to the hypothesis that these filaments represent the remains of cyanobacteria and other microorganisms that grew on the meteorite parent body. The absence of other life-critical biomolecules in the meteorites and the lack of detectable levels of nitrogen indicate the filaments died long ago and can not possibly represent modern microbial contaminants that entered the stones after they arrived on Earth. This paper presents new evidence for microfossils, biomolecules and biominerals in carbonaceous meteorites and considers the implications to some of the major hypotheses for the Origin of Life.

  18. Azadioxatriangulenium: a long fluorescence lifetime fluorophore for large biomolecule binding assay

    International Nuclear Information System (INIS)

    Sørensen, Thomas Just; Thyrhaug, Erling; Szabelski, Mariusz; Gryczynski, Ignacy; Gryczynski, Zygmunt; Luchowski, Rafal; Laursen, Bo W

    2013-01-01

    Of the many optical bioassays available, sensing by fluorescence anisotropy has great advantages as it provides a sensitive, instrumentally simple, ratiometric method of detection. However, it is hampered by a severe limitation, as the emission lifetime of the label needs to be comparable to the correlation lifetime (tumbling time) of the biomolecule which is labelled. For proteins of moderate size this is on the order of 20–200 ns, which due to practical issues currently limits the choice of labels to the dansyl-type dyes and certain aromatic dyes. These have the significant drawback of UV/blue absorption and emission as well as an often significant solvent sensitivity. Here, we report the synthesis and characterization of a new fluorescent label for high molecular weight biomolecule assay based on the azadioxatriangulenium motif. The NHS ester of the long fluorescence lifetime, red-emitting fluorophore: azadioxatriangulenium (ADOTA-NHS) was conjugated to anti-rabbit Immunoglobulin G (antiIgG). The long fluorescence lifetime was exploited to determine the correlation time of the high molecular weight antibody and its complex with rabbit Immunoglobulin G (IgG) with steady-state fluorescence anisotropy and time-resolved methods: solution phase immuno-assay was performed following either steady-state or time-resolved fluorescence anisotropy. By performing a variable temperature experiment it was determined that the binding of the ligand resulted in an increase in correlation time of more than 75%, and an increase in the steady-state anisotropy of 18%. The results show that the triangulenium class of dyes can be used in anisotropy assay to detect binding events involving biomolecules of far larger size than what is possible with most other red-emitting organic dyes. (paper)

  19. Azadioxatriangulenium: a long fluorescence lifetime fluorophore for large biomolecule binding assay

    Science.gov (United States)

    Just Sørensen, Thomas; Thyrhaug, Erling; Szabelski, Mariusz; Luchowski, Rafal; Gryczynski, Ignacy; Gryczynski, Zygmunt; Laursen, Bo W.

    2013-06-01

    Of the many optical bioassays available, sensing by fluorescence anisotropy has great advantages as it provides a sensitive, instrumentally simple, ratiometric method of detection. However, it is hampered by a severe limitation, as the emission lifetime of the label needs to be comparable to the correlation lifetime (tumbling time) of the biomolecule which is labelled. For proteins of moderate size this is on the order of 20-200 ns, which due to practical issues currently limits the choice of labels to the dansyl-type dyes and certain aromatic dyes. These have the significant drawback of UV/blue absorption and emission as well as an often significant solvent sensitivity. Here, we report the synthesis and characterization of a new fluorescent label for high molecular weight biomolecule assay based on the azadioxatriangulenium motif. The NHS ester of the long fluorescence lifetime, red-emitting fluorophore: azadioxatriangulenium (ADOTA-NHS) was conjugated to anti-rabbit Immunoglobulin G (antiIgG). The long fluorescence lifetime was exploited to determine the correlation time of the high molecular weight antibody and its complex with rabbit Immunoglobulin G (IgG) with steady-state fluorescence anisotropy and time-resolved methods: solution phase immuno-assay was performed following either steady-state or time-resolved fluorescence anisotropy. By performing a variable temperature experiment it was determined that the binding of the ligand resulted in an increase in correlation time of more than 75%, and an increase in the steady-state anisotropy of 18%. The results show that the triangulenium class of dyes can be used in anisotropy assay to detect binding events involving biomolecules of far larger size than what is possible with most other red-emitting organic dyes.

  20. Al18F-Labeling Of Heat-Sensitive Biomolecules for Positron Emission Tomography Imaging.

    Science.gov (United States)

    Cleeren, Frederik; Lecina, Joan; Ahamed, Muneer; Raes, Geert; Devoogdt, Nick; Caveliers, Vicky; McQuade, Paul; Rubins, Daniel J; Li, Wenping; Verbruggen, Alfons; Xavier, Catarina; Bormans, Guy

    2017-01-01

    Positron emission tomography (PET) using radiolabeled biomolecules is a translational molecular imaging technology that is increasingly used in support of drug development. Current methods for radiolabeling biomolecules with fluorine-18 are laborious and require multistep procedures with moderate labeling yields. The Al 18 F-labeling strategy involves chelation in aqueous medium of aluminum mono[ 18 F]fluoride ({Al 18 F} 2+ ) by a suitable chelator conjugated to a biomolecule. However, the need for elevated temperatures (100-120 °C) required for the chelation reaction limits its widespread use. Therefore, we designed a new restrained complexing agent (RESCA) for application of the AlF strategy at room temperature. Methods. The new chelator RESCA was conjugated to three relevant biologicals and the constructs were labeled with {Al 18 F} 2+ to evaluate the generic applicability of the one-step Al 18 F-RESCA-method. Results. We successfully labeled human serum albumin with excellent radiochemical yields in less than 30 minutes and confirmed in vivo stability of the Al 18 F-labeled protein in rats. In addition, we efficiently labeled nanobodies targeting the Kupffer cell marker CRIg, and performed µPET studies in healthy and CRIg deficient mice to demonstrate that the proposed radiolabeling method does not affect the functional integrity of the protein. Finally, an affibody targeting HER2 (PEP04314) was labeled site-specifically, and the distribution profile of (±)-[ 18 F]AlF(RESCA)-PEP04314 in a rhesus monkey was compared with that of [ 18 F]AlF(NOTA)-PEP04314 using whole-body PET/CT. Conclusion. This generic radiolabeling method has the potential to be a kit-based fluorine-18 labeling strategy, and could have a large impact on PET radiochemical space, potentially enabling the development of many new fluorine-18 labeled protein-based radiotracers.

  1. Azadioxatriangulenium (ADOTA+): A long fluorescence lifetime fluorophore for large biomolecule binding assay

    Science.gov (United States)

    Sørensen, Thomas Just; Thyrhaug, Erling; Szabelski, Mariusz; Luchowski, Rafal; Gryczynski, Ignacy; Gryczynski, Zygmunt; Laursen, Bo W.

    2013-01-01

    Of the many optical bioassays available, sensing by fluorescence anisotropy have great advantages as it provides a sensitive, instrumentally simple, ratiometric method of detection. However, it is hampered by a severe limitation as the emission lifetime of the label needs to be comparable to the correlation lifetime (tumbling time) of the biomolecule which is labelled. For proteins of moderate size this is in the order of 20–200 ns, which due to practical issues currently limits the choice of labels to the dansyl-type dyes and certain aromatics dyes. These have the significant drawback of UV/blue absorption and emission as well as an often significant solvent sensitivity. Here, we report the synthesis and characterization of a new fluorescent label for high molecular weight biomolecules assay based on the azadioxatriangulenium motif. The NHS ester of the long fluorescence lifetime, red emitting fluorophore: azadioxatriangulenium (ADOTA-NHS) was conjugated to anti-rabbit Immunoglobulin G (antiIgG). The long fluorescence lifetime was exploited to determine the correlation time of the high molecular weight antibody and its complex with rabbit Immuniglobulin G (IgG) with steady-state fluorescence anisotropy and time-resolved methods: solution phase immuno-assay was performed following either steady-state or time-resolved fluorescence anisotropy. By performing a variable temperature experiment it was determined that the binding of the ligand resulted in an increase in correlation time by more than 75 %, and a change in the steady-state anisotropy increase of 18%. The results show that the triangulenium class of dyes can be used in anisotropy assay for detecting binding events involving biomolecules of far larger size than what is possible with the other red emitting organic dyes. PMID:24058730

  2. Injectable, Biomolecule-Responsive Polypeptide Hydrogels for Cell Encapsulation and Facile Cell Recovery through Triggered Degradation.

    Science.gov (United States)

    Xu, Qinghua; He, Chaoliang; Zhang, Zhen; Ren, Kaixuan; Chen, Xuesi

    2016-11-16

    Injectable hydrogels have been widely investigated in biomedical applications, and increasing demand has been proposed to achieve dynamic regulation of physiological properties of hydrogels. Herein, a new type of injectable and biomolecule-responsive hydrogel based on poly(l-glutamic acid) (PLG) grafted with disulfide bond-modified phloretic acid (denoted as PLG-g-CPA) was developed. The hydrogels formed in situ via enzymatic cross-linking under physiological conditions in the presence of horseradish peroxidase and hydrogen peroxide. The physiochemical properties of the hydrogels, including gelation time and the rheological property, were measured. Particularly, the triggered degradation of the hydrogel in response to a reductive biomolecule, glutathione (GSH), was investigated in detail. The mechanical strength and inner porous structure of the hydrogel were influenced by the addition of GSH. The polypeptide hydrogel was used as a three-dimensional (3D) platform for cell encapsulation, which could release the cells through triggered disruption of the hydrogel in response to the addition of GSH. The cells released from the hydrogel were found to maintain high viability. Moreover, after subcutaneous injection into rats, the PLG-g-CPA hydrogels with disulfide-containing cross-links exhibited a markedly faster degradation behavior in vivo compared to that of the PLG hydrogels without disulfide cross-links, implying an interesting accelerated degradation process of the disulfide-containing polypeptide hydrogels in the physiological environment in vivo. Overall, the injectable and biomolecule-responsive polypeptide hydrogels may serve as a potential platform for 3D cell culture and easy cell collection.

  3. Biomolecule-assisted hydrothermal synthesis of silver bismuth sulfide with nanostructures

    International Nuclear Information System (INIS)

    Kaowphong, Sulawan

    2012-01-01

    Silver bismuth sulfide (AgBiS 2 ) nanostructures were successfully prepared via a simple biomolecule-assisted hydrothermal synthesis at 200 °C for 12–72 h. Silver nitrate, bismuth nitrate and L-cysteine were used as starting materials. Here, the biomolecule, L-cysteine, was served as the sulfide source and a complexing agent. The products, characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), were cubic AgBiS 2 nanoparticles with a diameter range of about 20–75 nm. It was found that their crystallinity and particle size increased with increasing reaction time. The energy dispersive X-ray spectroscopy (EDX) and inductively coupled plasma optical emission spectrophotometry (ICP-OES) analyses were used to confirm the stoichiometry of AgBiS 2 . The optical band gap of the AgBiS 2 nanoparticles, calculated from UV–vis spectra, was 3.0 eV which indicated a strong blue shift because of the quantum confinement effect. A possible formation mechanism of the AgBiS 2 nanoparticles was also discussed. - Graphical abstract: The optical band gap of the as-prepared AgBiS 2 nanoparticles displays a strong blue shift comparing to the 2.46 eV of bulk AgBiS 2 caused by the quantum confinement effects. Highlights: ► A simple biomolecule-assisted hydrothermal method is developed to prepare AgBiS 2 . ► L-Cysteine is served as the sulfide source and a complexing agent. ► Increase in band gap of the AgBiS 2 nanoparticles attributes to the quantum confinement effects.

  4. Study on the preparation and stability of 188Re biomolecules via EHDP

    International Nuclear Information System (INIS)

    Ferro-Flores, G.; Garcia-Salinas, L.; Paredes-Gutierrez, L.; Hashimoto, K.; Melendez-Alafort, L.; Murphy, C.A.

    2001-01-01

    A direct labelling technique via ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand was developed for the preparation of several biomolecules: 188 Re-monoclonal antibody ior cea1 against carcinoembryonic antigen ( 188 Re-MoAb), biotinylated 188 Re-MoAb ( 188 Re-MoAb-biotin), 188 Re-polyclonal IgG ( 188 Re-IgG), 188 Re-peptide (somatostatine analogue peptide b-(2-naphtyl)-D-Ala-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-amide), 188 Re-MoAb fragments ( 188 Re-F(ab') 2 ) and biotinylated 188 Re-F(ab') 2 ( 188 Re-F(ab') 2 -biotin). The reaction conditions such as pH, temperature, weak ligand concentration and stannous chloride concentration were optimized during the radiolabelling of each biomolecule. Before the labelling procedure, disulphide bridge groups of the biomolecules were reduced with 2-mercaptoethanol (2-ME). To obtain 188 Re labelled antibodies and peptides in high radiochemical yields (>90%) via EHDP, it was necessary to use acidic conditions and a high concentration of stannous chloride to allow the redox reaction Re +7 →Re +5 :Re +4 . The labelling of MoAb and F(ab') 2 with 188 Re via EHDP was also evaluated employing a pretargeted technique by avidin-biotin strategy in normal mice, demonstrating that the 188 Re-labelled biotinylated antibodies are stable complexes in vivo. The 188 Re-peptide complex prepared by this method, was stable for 24 h and no radiolytic degradation was observed. (author)

  5. Al18F-Labeling Of Heat-Sensitive Biomolecules for Positron Emission Tomography Imaging

    Science.gov (United States)

    Cleeren, Frederik; Lecina, Joan; Ahamed, Muneer; Raes, Geert; Devoogdt, Nick; Caveliers, Vicky; McQuade, Paul; Rubins, Daniel J; Li, Wenping; Verbruggen, Alfons; Xavier, Catarina; Bormans, Guy

    2017-01-01

    Positron emission tomography (PET) using radiolabeled biomolecules is a translational molecular imaging technology that is increasingly used in support of drug development. Current methods for radiolabeling biomolecules with fluorine-18 are laborious and require multistep procedures with moderate labeling yields. The Al18F-labeling strategy involves chelation in aqueous medium of aluminum mono[18F]fluoride ({Al18F}2+) by a suitable chelator conjugated to a biomolecule. However, the need for elevated temperatures (100-120 °C) required for the chelation reaction limits its widespread use. Therefore, we designed a new restrained complexing agent (RESCA) for application of the AlF strategy at room temperature. Methods. The new chelator RESCA was conjugated to three relevant biologicals and the constructs were labeled with {Al18F}2+ to evaluate the generic applicability of the one-step Al18F-RESCA-method. Results. We successfully labeled human serum albumin with excellent radiochemical yields in less than 30 minutes and confirmed in vivo stability of the Al18F-labeled protein in rats. In addition, we efficiently labeled nanobodies targeting the Kupffer cell marker CRIg, and performed µPET studies in healthy and CRIg deficient mice to demonstrate that the proposed radiolabeling method does not affect the functional integrity of the protein. Finally, an affibody targeting HER2 (PEP04314) was labeled site-specifically, and the distribution profile of (±)-[18F]AlF(RESCA)-PEP04314 in a rhesus monkey was compared with that of [18F]AlF(NOTA)-PEP04314 using whole-body PET/CT. Conclusion. This generic radiolabeling method has the potential to be a kit-based fluorine-18 labeling strategy, and could have a large impact on PET radiochemical space, potentially enabling the development of many new fluorine-18 labeled protein-based radiotracers. PMID:28824726

  6. The polygonal model: A simple representation of biomolecules as a tool for teaching metabolism.

    Science.gov (United States)

    Bonafe, Carlos Francisco Sampaio; Bispo, Jose Ailton Conceição; de Jesus, Marcelo Bispo

    2018-01-01

    Metabolism involves numerous reactions and organic compounds that the student must master to understand adequately the processes involved. Part of biochemical learning should include some knowledge of the structure of biomolecules, although the acquisition of such knowledge can be time-consuming and may require significant effort from the student. In this report, we describe the "polygonal model" as a new means of graphically representing biomolecules. This model is based on the use of geometric figures such as open triangles, squares, and circles to represent hydroxyl, carbonyl, and carboxyl groups, respectively. The usefulness of the polygonal model was assessed by undergraduate students in a classroom activity that consisted of "transforming" molecules from Fischer models to polygonal models and vice and versa. The survey was applied to 135 undergraduate Biology and Nursing students. Students found the model easy to use and we noted that it allowed identification of students' misconceptions in basic concepts of organic chemistry, such as in stereochemistry and organic groups that could then be corrected. The students considered the polygonal model easier and faster for representing molecules than Fischer representations, without loss of information. These findings indicate that the polygonal model can facilitate the teaching of metabolism when the structures of biomolecules are discussed. Overall, the polygonal model promoted contact with chemical structures, e.g. through drawing activities, and encouraged student-student dialog, thereby facilitating biochemical learning. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(1):66-75, 2018. © 2017 The International Union of Biochemistry and Molecular Biology.

  7. Stable functionalization of germanium surface and its application in biomolecules immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Qi [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Xu, Baojian [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Ye, Lin [Sate Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Tang, Teng; Huang, Shanluo; Du, Xiaowei [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); University of Chinese Academy of Sciences, No.19A, Yuquan Road, Beijing 100049 (China); Bian, Xiaojun; Zhang, Jishen [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Di, Zengfeng, E-mail: zfdi@mail.sim.ac.cn [Sate Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Jin, Qinghui [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China); Zhao, Jianlong, E-mail: jlzhao@mail.sim.ac.cn [State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, No.865, Changning Road, Shanghai 200050 (China)

    2014-10-15

    Highlights: • An effective method to immobilize biomolecules on the functionalized Ge surface. • The surface of Ge was functionalized with 11-Mercaptoundecanoic acid (11-MUA). • Stable and uniform SAMs was obtained on Ge surface after 11-MUA treatment. • The functionalized Ge was employed as substrate for protein immobilization. • Paving the way of Ge for further applications in bioelectronics field. - Abstract: As a typical semiconductor material, germanium (Ge) has the potential to be utilized in microelectronics and bioelectronics. Herein, we present a simple and effective method to immobilize biomolecules on the surface of functionalized Ge. The surface oxide of Ge was removed with the pretreatment of hydrochloric acid and the Cl-terminated Ge reacted with 11-Mercaptoundecanoic acid (11-MUA). The surface of Ge was coated with 11-MUA self-assembled monolayers (SAMs) due to the bonding reaction between the sulfhydryl group of 11-MUA and Cl-terminated Ge. Furthermore, typical biomolecule, a green fluorescent protein was chosen to be immobilized on the surface of the functionalized Ge. Contact angle analysis, atomic force microscopy and X-ray photoelectron spectroscopy were used to study the characteristics including wettability, stability, roughness and component of the functionalized Ge, respectively. Fluorescence microscopy was utilized to indicate the efficiency of protein immobilization on the surface of the functionalized Ge. With these studies, stable and uniform functionalized monolayer was obtained on the surface of Ge after 11-MUA treatment and the functionalized Ge was effectively applied in protein immobilization. Furthermore, this study may pave the way for further applications such as the integration of bioelectronics and biosensors with the attractive semiconductor material-Ge in future work.

  8. Mass spectrometry in structural biology and biophysics architecture, dynamics, and interaction of biomolecules

    CERN Document Server

    Kaltashov, Igor A; Desiderio, Dominic M; Nibbering, Nico M

    2012-01-01

    The definitive guide to mass spectrometry techniques in biology and biophysics The use of mass spectrometry (MS) to study the architecture and dynamics of proteins is increasingly common within the biophysical community, and Mass Spectrometry in Structural Biology and Biophysics: Architecture, Dynamics, and Interaction of Biomolecules, Second Edition provides readers with detailed, systematic coverage of the current state of the art. Offering an unrivalled overview of modern MS-based armamentarium that can be used to solve the most challenging problems in biophysics, structural biol

  9. Development of radioactively labelled cancer seeking biomolecules for targeted radiotherapy. Greece

    International Nuclear Information System (INIS)

    Varvarigou, Alexandra D.; Archimandritis, Spyridon C.

    2000-01-01

    Within the framework of the above project we are studying the labelling of biomolecules, peptides and antibodies, with radionuclides emitting β - and γ radiation. More specifically, for the time being, we have investigated the labelling of peptides with Re-188 and of antibodies with Sm-153 and Re-188. The radiolabelled derivatives are further evaluated in vivo for possible application in Oncology. For these radiobiological studies we are trying to apply ectopic and orthotopic tumour animal models and to develop, in collaboration with other national and foreign institutes, proper imaging devices for small animal imaging

  10. MPAI (mass probes aided ionization) method for total analysis of biomolecules by mass spectrometry.

    Science.gov (United States)

    Honda, Aki; Hayashi, Shinichiro; Hifumi, Hiroki; Honma, Yuya; Tanji, Noriyuki; Iwasawa, Naoko; Suzuki, Yoshio; Suzuki, Koji

    2007-01-01

    We have designed and synthesized various mass probes, which enable us to effectively ionize various molecules to be detected with mass spectrometry. We call the ionization method using mass probes the "MPAI (mass probes aided ionization)" method. We aim at the sensitive detection of various biological molecules, and also the detection of bio-molecules by a single mass spectrometry serially without changing the mechanical settings. Here, we review mass probes for small molecules with various functional groups and mass probes for proteins. Further, we introduce newly developed mass probes for proteins for highly sensitive detection.

  11. Visible wavelength surface-enhanced Raman spectroscopy from In-InP nanopillars for biomolecule detection

    Science.gov (United States)

    Murdoch, B. J.; Portoles, J. F.; Tardio, S.; Barlow, A. J.; Fletcher, I. W.; Cumpson, P. J.

    2016-12-01

    Visible wavelength surface-enhanced Raman spectroscopy (SERS) has been observed from bovine serum albumin (BSA) using In-InP nanopillars synthesised by Ar gas cluster ion beam sputtering of InP wafers. InP provides a high local refractive index for plasmonic In structures, which increases the wavelength of the In surface plasmon resonance. The Raman scattering signal was determined to be up to 285 times higher for BSA deposited onto In-InP nanopillars when compared with Si wafer substrates. These substrates demonstrate the label-free detection of biomolecules by visible wavelength SERS, without the use of noble metal particles.

  12. Relationship between cross section measurements and understanding radiation induced damage to biomolecules

    International Nuclear Information System (INIS)

    DuBois, R.D.; Braby, L.A.

    1993-10-01

    Experimental research performed at the Pacific Northwest Laboratory relating to energy deposition by energetic charged particles is described. How cross section data obtained from gaseous- and condensed-phase studies are related to understanding damage to biomolecules is discussed. Studies to date stress the need for information about energy deposition in individual interactions and show that multiple ionization may play a very significant role in biological damage. Current efforts to relate this gas-phase information to condensed-phase processes and biologically relevant targets are outlined

  13. Plastic Trash goes Biohybrid"-Rapid and Selective Functionalization of Inert Plastic Surfaces with Biomolecules

    DEFF Research Database (Denmark)

    Schiller, Stefan M; Kambhampati, Dev; Stengel, Gudrun

    2010-01-01

    The covalent functionalization of "inert" polymers such as polypropylene with biomolecules for biocompatible or biosensor surfaces is challenging. Here we present a powerful approach to covalently modify "inert" macromolecular surfaces with biomacromolecules reusing old plastic material. A special...... emphasis was placed on easily accessible materials and a process which is easy, fast, efficient, cheap, and reliable. "Plastic trash" (lids from Eppendorf® pipet tip containers) was used as a polymer substrate to demonstrate the use/reuse of commercial packing material to covalently modify this material...

  14. Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations

    Directory of Open Access Journals (Sweden)

    Christopher M. Mahoney

    2018-05-01

    Full Text Available Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

  15. Current Therapeutic Strategies for Adipose Tissue Defects/Repair Using Engineered Biomaterials and Biomolecule Formulations.

    Science.gov (United States)

    Mahoney, Christopher M; Imbarlina, Cayla; Yates, Cecelia C; Marra, Kacey G

    2018-01-01

    Tissue engineered scaffolds for adipose restoration/repair has significantly evolved in recent years. Patients requiring soft tissue reconstruction, caused by defects or pathology, require biomaterials that will restore void volume with new functional tissue. The gold standard of autologous fat grafting (AFG) is not a reliable option. This review focuses on the latest therapeutic strategies for the treatment of adipose tissue defects using biomolecule formulations and delivery, and specifically engineered biomaterials. Additionally, the clinical need for reliable off-the-shelf therapies, animal models, and challenges facing current technologies are discussed.

  16. Biomolecule-to-fluorescent-color encoder: modulation of fluorescence emission via DNA structural changes

    Science.gov (United States)

    Nishimura, Takahiro; Ogura, Yusuke; Yamada, Kenji; Ohno, Yuko; Tanida, Jun

    2014-01-01

    A biomolecule-to-fluorescent-color (B/F) encoder for optical readout of biomolecular information is proposed. In the B/F encoder, a set of fluorescence wavelengths and their intensity levels are used for coding of a biomolecular signal. A hybridization chain reaction of hairpin DNAs labeled with fluorescent reporters was performed to generate the fluorescence color codes. The fluorescence is modulated via fluorescence resonance energy transfer, which is controlled by DNA structural changes. The results demonstrate that fluorescent color codes can be configured based on two wavelengths and five intensities using the B/F encoder, and the assigned codes can be retrieved via fluorescence measurements. PMID:25071950

  17. From phosphorous to arsenic: changing the classic paradigm for the structure of biomolecules.

    Science.gov (United States)

    Knodle, Ryan; Agarwal, Pratima; Brown, Mark

    2012-05-30

    Biomolecules are composed primarily of the elements carbon, nitrogen, hydrogen, oxygen, sulfur, and phosphorus. The structured assembly of these elements forms the basis for proteins, nucleic acids and lipids. However, the recent discovery of a new bacterium, strain GFAJ-1 of the Halomonadaceae, has shaken the classic paradigms for the architecture of life. Mounting evidence supports the claim that these bacteria substitute arsenic for phosphorus in macromolecules. Herein, we provide a brief commentary and fuel the debate related to what may be a most unusual organism.

  18. Proceedings of the international conference on molecular spectroscopy of advanced materials and biomolecules

    International Nuclear Information System (INIS)

    Sajan, D.

    2012-01-01

    This conference was an effort towards exploring advanced applications, with emphasis on recent trends in the Infrared and Raman spectra of advanced materials and biomolecules. The conference topics focused on a wide range of molecular spectroscopy, yet connected with molecular biological systems and materials. As molecular spectroscopy is finding tremendous significance in various fields of materials science, biomedical, pharmaceutical, planetary, mineral and forensic sciences, IMSAB 2012, provided a very dynamic and interactive platform for the international scientific community specializing in the field. Papers relevant to INIS are indexed separately

  19. Thiol-ene and photo-cleavage chemistry for controlled presentation of biomolecules in hydrogels.

    Science.gov (United States)

    Grim, Joseph C; Marozas, Ian A; Anseth, Kristi S

    2015-12-10

    Hydrogels have emerged as promising scaffolds in regenerative medicine for the delivery of biomolecules to promote healing. However, increasing evidence suggests that the context that biomolecules are presented to cells (e.g., as soluble verses tethered signals) can influence their bioactivity. A common approach to deliver biomolecules in hydrogels involves physically entrapping them within the network, such that they diffuse out over time to the surrounding tissues. While simple and versatile, the release profiles in such system are highly dependent on the molecular weight of the entrapped molecule relative to the network structure, and it can be difficult to control the release of two different signals at independent rates. In some cases, supraphysiologically high loadings are used to achieve therapeutic local concentrations, but uncontrolled release can then cause deleterious off-target side effects. In vivo, many growth factors and cytokines are stored in the extracellular matrix (ECM) and released on demand as needed during development, growth, and wound healing. Thus, emerging strategies in biomaterial chemistry have focused on ways to tether or sequester biological signals and engineer these bioactive scaffolds to signal to delivered cells or endogenous cells. While many strategies exist to achieve tethering of peptides, protein, and small molecules, this review focuses on photochemical methods, and their usefulness as a mild reaction that proceeds with fast kinetics in aqueous solutions and at physiological conditions. Photo-click and photo-caging methods are particularly useful because one can direct light to specific regions of the hydrogel to achieve spatial patterning. Recent methods have even demonstrated reversible introduction of biomolecules to mimic the dynamic changes of native ECM, enabling researchers to explore how the spatial and dynamic context of biomolecular signals influences important cell functions. This review will highlight how two

  20. Studies of metal-biomolecule systems in liquids with beta-detected NMR

    CERN Document Server

    Walczak, Michal

    2017-01-01

    My internship took place within a small research team funded via the European Research Council (ERC Starting Grant: Beta-Drop NMR) at ISOLDE. It was devoted to laser spin-polarization and beta-detected NMR techniques and their future applications in chemistry and biology. I was involved in the design and tests of the beta-NMR spectrometer which will be used in the upcoming experiments. In this way I have been exposed to many topics in physics (atomic and nuclear physics), experimental techniques (vacuum technology, lasers, beta detectors, electronics, DAQ software), as well as chemistry and biology (NMR on metal ions, metal ion binding to biomolecules, quantum chemistry calculations).

  1. The origin of methane and biomolecules from a CO2 cycle on terrestrial planets

    Czech Academy of Sciences Publication Activity Database

    Civiš, Svatopluk; Knížek, Antonín; Ivanek, Ondřej; Kubelík, Petr; Zukalová, Markéta; Kavan, Ladislav; Ferus, Martin

    2017-01-01

    Roč. 1, č. 10 (2017), s. 721-726 E-ISSN 2397-3366 R&D Projects: GA ČR GA17-05076S; GA ČR GA13-07724S Grant - others:Akademie věd - GA AV ČR(CZ) R200401721; Akademie věd - GA AV ČR(CZ) R200401521 Institutional support: RVO:61388955 Keywords : biomolecules * CO2 cycle on terrestrial planets * Mars Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry

  2. Time-resolved circular dichroism: Application to the study of conformal changes in biomolecules

    Science.gov (United States)

    Hache, F.

    2010-06-01

    Circular dichroism (CD) is known to be a very sensitive probe of the conformation of molecules and biomolecules. It is therefore tempting to implement CD in a pump-probe experiment in order to measure ultrarapid conformational changes which occur in photochemical processes. We present two technical developments of such time-resolved CD experiments. The first one relies on the modulation of the probe polarization from left to right circular whereas the second one measures the pump-induced ellipticity of the probe with a Babinet-Soleil compensator. Some applications are described and extension of these techniques towards the study of elementary protein folding processes is discussed.

  3. Time-resolved circular dichroism: Application to the study of conformal changes in biomolecules

    Directory of Open Access Journals (Sweden)

    Hache F.

    2010-06-01

    Full Text Available Circular dichroism (CD is known to be a very sensitive probe of the conformation of molecules and biomolecules. It is therefore tempting to implement CD in a pump-probe experiment in order to measure ultrarapid conformational changes which occur in photochemical processes. We present two technical developments of such time-resolved CD experiments. The first one relies on the modulation of the probe polarization from left to right circular whereas the second one measures the pump-induced ellipticity of the probe with a Babinet-Soleil compensator. Some applications are described and extension of these techniques towards the study of elementary protein folding processes is discussed.

  4. High-yielding and photolabile approaches to the covalent attachment of biomolecules to surfaces via hydrazone chemistry.

    Science.gov (United States)

    Lee, Ju Hun; Domaille, Dylan W; Noh, Hyunwoo; Oh, Taeseok; Choi, Chulmin; Jin, Sungho; Cha, Jennifer N

    2014-07-22

    The development of strategies to couple biomolecules covalently to surfaces is necessary for constructing sensing arrays for biological and biomedical applications. One attractive conjugation reaction is hydrazone formation--the reaction of a hydrazine with an aldehyde or ketone--as both hydrazines and aldehydes/ketones are largely bioorthogonal, which makes this particular reaction suitable for conjugating biomolecules to a variety of substrates. We show that the mild reaction conditions afforded by hydrazone conjugation enable the conjugation of DNA and proteins to the substrate surface in significantly higher yields than can be achieved with traditional bioconjugation techniques, such as maleimide chemistry. Next, we designed and synthesized a photocaged aryl ketone that can be conjugated to a surface and photochemically activated to provide a suitable partner for subsequent hydrazone formation between the surface-anchored ketone and DNA- or protein-hydrazines. Finally, we exploit the latent functionality of the photocaged ketone and pattern multiple biomolecules on the same substrate, effectively demonstrating a strategy for designing substrates with well-defined domains of different biomolecules. We expect that this approach can be extended to the production of multiplexed assays by using an appropriate mask with sequential photoexposure and biomolecule conjugation steps.

  5. Large-scale DNA Barcode Library Generation for Biomolecule Identification in High-throughput Screens.

    Science.gov (United States)

    Lyons, Eli; Sheridan, Paul; Tremmel, Georg; Miyano, Satoru; Sugano, Sumio

    2017-10-24

    High-throughput screens allow for the identification of specific biomolecules with characteristics of interest. In barcoded screens, DNA barcodes are linked to target biomolecules in a manner allowing for the target molecules making up a library to be identified by sequencing the DNA barcodes using Next Generation Sequencing. To be useful in experimental settings, the DNA barcodes in a library must satisfy certain constraints related to GC content, homopolymer length, Hamming distance, and blacklisted subsequences. Here we report a novel framework to quickly generate large-scale libraries of DNA barcodes for use in high-throughput screens. We show that our framework dramatically reduces the computation time required to generate large-scale DNA barcode libraries, compared with a naїve approach to DNA barcode library generation. As a proof of concept, we demonstrate that our framework is able to generate a library consisting of one million DNA barcodes for use in a fragment antibody phage display screening experiment. We also report generating a general purpose one billion DNA barcode library, the largest such library yet reported in literature. Our results demonstrate the value of our novel large-scale DNA barcode library generation framework for use in high-throughput screening applications.

  6. [INVITED] Surface plasmon cavities on optical fiber end-facets for biomolecule and ultrasound detection

    Science.gov (United States)

    Yang, Tian; He, Xiaolong; Zhou, Xin; Lei, Zeyu; Wang, Yalin; Yang, Jie; Cai, De; Chen, Sung-Liang; Wang, Xueding

    2018-05-01

    Integrating surface plasmon resonance (SPR) devices upon single-mode fiber (SMF) end facets renders label-free sensing systems that have a simple dip-and-read configuration, a small form factor, high compatibility with fiber-optic techniques, and invasive testing capability. Such devices are not only low cost replacement of current equipments in centralized laboratories, but also highly desirable for opening paths to new applications of label-free optical sensing technologies, such as point-of-care immunological tests and intravascular ultrasound imaging. In this paper, we explain the requirements and challenges for such devices from the perspectives of biomolecule and ultrasound detection applications. In such a context, we review our recent work on SMF end-facet SPR cavities. This include a glue-and-strip fabrication method to transfer a nano-patterned thin gold film to the SMF end-facet with high yield, high quality and high alignment precision, the designs of distributed Bragg reflector (DBR) and distributed feedback (DFB) SPR cavities that couple efficiently with the SMF guided mode and reach quality factors of over 100, and the preliminary results for biomolecule interaction sensing and ultrasound detection. The particular advantages and potential values of these devices have been discussed, in terms of sensitivity, data reliability, reproducibility, bandwidth, etc.

  7. Simplified TiO2 force fields for studies of its interaction with biomolecules

    Science.gov (United States)

    Luan, Binquan; Huynh, Tien; Zhou, Ruhong

    2015-06-01

    Engineered TiO2 nanoparticles have been routinely applied in nanotechnology, as well as in cosmetics and food industries. Despite active experimental studies intended to clarify TiO2's biological effects, including potential toxicity, the relation between experimentally inferred nanotoxicity and industry standards for safely applying nanoparticles remains somewhat ambiguous with justified concerns. Supplemental to experiments, molecular dynamics simulations have proven to be efficacious in investigating the molecular mechanism of a biological process occurring at nanoscale. In this article, to facilitate the nanotoxicity and nanomedicine research related to this important metal oxide, we provide a simplified force field, based on the original Matsui-Akaogi force field but compatible to the Lennard-Jones potentials normally used in modeling biomolecules, for simulating TiO2 nanoparticles interacting with biomolecules. The force field parameters were tested in simulating the bulk structure of TiO2, TiO2 nanoparticle-water interaction, as well as the adsorption of proteins on the TiO2 nanoparticle. We demonstrate that these simulation results are consistent with experimental data/observations. We expect that simulations will help to better understand the interaction between TiO2 and molecules.

  8. Molecular dynamics simulation of potentiometric sensor response: the effect of biomolecules, surface morphology and surface charge.

    Science.gov (United States)

    Lowe, B M; Skylaris, C-K; Green, N G; Shibuta, Y; Sakata, T

    2018-05-10

    The silica-water interface is critical to many modern technologies in chemical engineering and biosensing. One technology used commonly in biosensors, the potentiometric sensor, operates by measuring the changes in electric potential due to changes in the interfacial electric field. Predictive modelling of this response caused by surface binding of biomolecules remains highly challenging. In this work, through the most extensive molecular dynamics simulation of the silica-water interfacial potential and electric field to date, we report a novel prediction and explanation of the effects of nano-morphology on sensor response. Amorphous silica demonstrated a larger potentiometric response than an equivalent crystalline silica model due to increased sodium adsorption, in agreement with experiments showing improved sensor response with nano-texturing. We provide proof-of-concept that molecular dynamics can be used as a complementary tool for potentiometric biosensor response prediction. Effects that are conventionally neglected, such as surface morphology, water polarisation, biomolecule dynamics and finite-size effects, are explicitly modelled.

  9. Correlation dynamics and enhanced signals for the identification of serial biomolecules and DNA bases

    International Nuclear Information System (INIS)

    Ahmed, Towfiq; Haraldsen, Jason T; Balatsky, Alexander V; Rehr, John J; Di Ventra, Massimiliano; Schuller, Ivan

    2014-01-01

    Nanopore-based sequencing has demonstrated a significant potential for the development of fast, accurate, and cost-efficient fingerprinting techniques for next generation molecular detection and sequencing. We propose a specific multilayered graphene-based nanopore device architecture for the recognition of single biomolecules. Molecular detection and analysis can be accomplished through the detection of transverse currents as the molecule or DNA base translocates through the nanopore. To increase the overall signal-to-noise ratio and the accuracy, we implement a new ‘multi-point cross-correlation’ technique for identification of DNA bases or other molecules on the single molecular level. We demonstrate that the cross-correlations between each nanopore will greatly enhance the transverse current signal for each molecule. We implement first-principles transport calculations for DNA bases surveyed across a multilayered graphene nanopore system to illustrate the advantages of the proposed geometry. A time-series analysis of the cross-correlation functions illustrates the potential of this method for enhancing the signal-to-noise ratio. This work constitutes a significant step forward in facilitating fingerprinting of single biomolecules using solid state technology. (paper)

  10. Correlation dynamics and enhanced signals for the identification of serial biomolecules and DNA bases

    Science.gov (United States)

    Ahmed, Towfiq; Haraldsen, Jason T.; Rehr, John J.; Di Ventra, Massimiliano; Schuller, Ivan; Balatsky, Alexander V.

    2014-03-01

    Nanopore-based sequencing has demonstrated a significant potential for the development of fast, accurate, and cost-efficient fingerprinting techniques for next generation molecular detection and sequencing. We propose a specific multilayered graphene-based nanopore device architecture for the recognition of single biomolecules. Molecular detection and analysis can be accomplished through the detection of transverse currents as the molecule or DNA base translocates through the nanopore. To increase the overall signal-to-noise ratio and the accuracy, we implement a new ‘multi-point cross-correlation’ technique for identification of DNA bases or other molecules on the single molecular level. We demonstrate that the cross-correlations between each nanopore will greatly enhance the transverse current signal for each molecule. We implement first-principles transport calculations for DNA bases surveyed across a multilayered graphene nanopore system to illustrate the advantages of the proposed geometry. A time-series analysis of the cross-correlation functions illustrates the potential of this method for enhancing the signal-to-noise ratio. This work constitutes a significant step forward in facilitating fingerprinting of single biomolecules using solid state technology.

  11. DPPH and oxygen free radicals as pro-oxidant of biomolecules.

    Science.gov (United States)

    Letelier, María Eugenia; Molina-Berríos, Alfredo; Cortés-Troncoso, Juan; Jara-Sandoval, José; Holst, Marianne; Palma, Karina; Montoya, Margarita; Miranda, Dante; González-Lira, Víctor

    2008-03-01

    Numerous investigations exist about the alterations that oxygen free radicals can provoke on biomolecules; these modifications can be prevented and/or reversed by different antioxidants agents. On the other hand, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), a stable nitrogen synthetic radical, is used to evaluate the antioxidant capacity of medicinal herbal products; however, the structural changes that this radical provoke on the herbal active principles are not clear yet. In this work, we compared the redox reactivity of oxygen free radicals and DPPH radical on phospholipids and protein thiol groups present in rat liver microsomes. Cu2+/ascorbate was used as generator system of oxygen free radical and as antioxidant, an extract of Buddleja globosa's leaves. Cu2+/ascorbate provoked microsomal lipid peroxidation, microsomal thiols oxidation and oxygen consumption; all of these phenomena were inhibited by B. globosa extract. On the other hand, DPPH was bleached in different extension by the herbal extract and phosphatidyl choline; beside, DPPH decreased microsomal thiols content, but this phenomenon were not prevented by the herbal extract. Furthermore, DPPH did not induce oxygen consumption and neither modified the oxygen consumption induced by Cu2+/ascorbate. Distinct redox mechanisms may explain the differences between the reactivity of DPPH and oxygen free radicals on biomolecules, which is discussed.

  12. Recent trends in carbon nanomaterial-based electrochemical sensors for biomolecules: A review

    Science.gov (United States)

    Yang, Cheng; Denno, Madelaine E.; Pyakurel, Poojan; Venton, B. Jill

    2015-01-01

    Carbon nanomaterials are advantageous for electrochemical sensors because they increase the electroactive surface area, enhance electron transfer, and promote adsorption of molecules. Carbon nanotubes (CNTs) have been incorporated into electrochemical sensors for biomolecules and strategies have included the traditional dip coating and drop casting methods, direct growth of CNTs on electrodes and the use of CNT fibers and yarns made exclusively of CNTs. Recent research has also focused on utilizing many new types of carbon nanomaterials beyond CNTs. Forms of graphene are now increasingly popular for sensors including reduced graphene oxide, carbon nanohorns, graphene nanofoams, graphene nanorods, and graphene nanoflowers. In this review, we compare different carbon nanomaterial strategies for creating electrochemical sensors for biomolecules. Analytes covered include neurotransmitters and neurochemicals, such as dopamine, ascorbic acid, and serotonin; hydrogen peroxide; proteins, such as biomarkers; and DNA. The review also addresses enzyme-based electrodes that are used to detect non-electroactive species such as glucose, alcohols, and proteins. Finally, we analyze some of the future directions for the field, pointing out gaps in fundamental understanding of electron transfer to carbon nanomaterials and the need for more practical implementation of sensors. PMID:26320782

  13. Synchrotron and small bio-molecules in gas phase and liquid environment: new opportunities in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Naves de Brito, A. [State University of Campinas (UNICAMP), SP (Brazil). Dept. of Applied Physics

    2011-07-01

    Full text: Two techniques are critically related to the photoelectric law, namely: photoelectron spectroscopy and photoelectron-photoion coincidence spectroscopy. Both are strongly used now a day within synchrotron laboratories. Our group is employing both to investigate fragmentation of bio-molecules in gas phase such as amino acids and DNA basis using V UV and soft x-ray photons. In the near future lager scale instruments developed in Brazil will allow unique opportunities to apply these two spectroscopic methods to molecules immersed in liquids such as water. We will present details from this advanced x-ray source and experimental stations with capabilities not present in other places in the world. Experiments connected to the molecular origin of live will be shown. Among them an experiment where we mimic the atmosphere at Titan moon producing bio- molecules will discussed. Another experiment will be presented where we test the Panspermia viability using special bacteria. We will also present experiments where frozen simple molecules connected to pre-biotic mate- rial are bombardment by UV photons and energetic particles showing interesting trends. Spectroscopic studies of gas phase photo-fragmentation of bio-molecules may be critical to understand in the future these molecules immersed in liquids. We plan to spend some time showing our recent results in this area. (author)

  14. Electrochemical processes and mechanistic aspects of field-effect sensors for biomolecules

    Science.gov (United States)

    Huang, Weiguo; Diallo, Abdou Karim; Dailey, Jennifer L.; Besar, Kalpana

    2017-01-01

    Electronic biosensing is a leading technology for determining concentrations of biomolecules. In some cases, the presence of an analyte molecule induces a measured change in current flow, while in other cases, a new potential difference is established. In the particular case of a field effect biosensor, the potential difference is monitored as a change in conductance elsewhere in the device, such as across a film of an underlying semiconductor. Often, the mechanisms that lead to these responses are not specifically determined. Because improved understanding of these mechanisms will lead to improved performance, it is important to highlight those studies where various mechanistic possibilities are investigated. This review explores a range of possible mechanistic contributions to field-effect biosensor signals. First, we define the field-effect biosensor and the chemical interactions that lead to the field effect, followed by a section on theoretical and mechanistic background. We then discuss materials used in field-effect biosensors and approaches to improving signals from field-effect biosensors. We specifically cover the biomolecule interactions that produce local electric fields, structures and processes at interfaces between bioanalyte solutions and electronic materials, semiconductors used in biochemical sensors, dielectric layers used in top-gated sensors, and mechanisms for converting the surface voltage change to higher signal/noise outputs in circuits. PMID:29238595

  15. On Macroscopic Quantum Phenomena in Biomolecules and Cells: From Levinthal to Hopfield

    Directory of Open Access Journals (Sweden)

    Dejan Raković

    2014-01-01

    Full Text Available In the context of the macroscopic quantum phenomena of the second kind, we hereby seek for a solution-in-principle of the long standing problem of the polymer folding, which was considered by Levinthal as (semiclassically intractable. To illuminate it, we applied quantum-chemical and quantum decoherence approaches to conformational transitions. Our analyses imply the existence of novel macroscopic quantum biomolecular phenomena, with biomolecular chain folding in an open environment considered as a subtle interplay between energy and conformation eigenstates of this biomolecule, governed by quantum-chemical and quantum decoherence laws. On the other hand, within an open biological cell, a system of all identical (noninteracting and dynamically noncoupled biomolecular proteins might be considered as corresponding spatial quantum ensemble of these identical biomolecular processors, providing spatially distributed quantum solution to a single corresponding biomolecular chain folding, whose density of conformational states might be represented as Hopfield-like quantum-holographic associative neural network too (providing an equivalent global quantum-informational alternative to standard molecular-biology local biochemical approach in biomolecules and cells and higher hierarchical levels of organism, as well.

  16. Precise fabrication of a 5 nm graphene nanopore with a helium ion microscope for biomolecule detection

    Science.gov (United States)

    Deng, Yunsheng; Huang, Qimeng; Zhao, Yue; Zhou, Daming; Ying, Cuifeng; Wang, Deqiang

    2017-01-01

    We report a scalable method to fabricate high-quality graphene nanopores for biomolecule detection using a helium ion microscope (HIM). HIM milling shows promising capabilities for precisely controlling the size and shape, and may allow for the potential production of nanopores at wafer scale. Nanopores could be fabricated at different sizes ranging from 5 to 30 nm in diameter in few minutes. Compared with the current solid-state nanopore fabrication techniques, e.g. transmission electron microscopy, HIM is fast. Furthermore, we investigated the exposure-time dependence of graphene nanopore formation: the rate of pore expansion did not follow a simple linear relationship with exposure time, but a fast expansion rate at short exposure time and a slow rate at long exposure time. In addition, we performed biomolecule detection with our patterned graphene nanopore. The ionic current signals induced by 20-base single-stranded DNA homopolymers could be used as a basis for homopolymer differentiation. However, the charge interaction of homopolymer chains with graphene nanopores, and the conformations of homopolymer chains need to be further considered to improve the accuracy of discrimination.

  17. Biomolecule-embedded metal-organic frameworks as an innovative sensing platform.

    Science.gov (United States)

    Kempahanumakkagari, Sureshkumar; Kumar, Vanish; Samaddar, Pallabi; Kumar, Pawan; Ramakrishnappa, Thippeswamy; Kim, Ki-Hyun

    Technological advancements combined with materials research have led to the generation of enormous types of novel substrates and materials for use in various biological/medical, energy, and environmental applications. Lately, the embedding of biomolecules in novel and/or advanced materials (e.g., metal-organic frameworks (MOFs), nanoparticles, hydrogels, graphene, and their hybrid composites) has become a vital research area in the construction of an innovative platform for various applications including sensors (or biosensors), biofuel cells, and bioelectronic devices. Due to the intriguing properties of MOFs (e.g., framework architecture, topology, and optical properties), they have contributed considerably to recent progresses in enzymatic catalysis, antibody-antigen interactions, or many other related approaches. Here, we aim to describe the different strategies for the design and synthesis of diverse biomolecule-embedded MOFs for various sensing (e.g., optical, electrochemical, biological, and miscellaneous) techniques. Additionally, the benefits and future prospective of MOFs-based biomolecular immobilization as an innovative sensing platform are discussed along with the evaluation on their performance to seek for further development in this emerging research area. Copyright © 2018. Published by Elsevier Inc.

  18. Concentration-related response potentiometric titrations to study the interaction of small molecules with large biomolecules.

    Science.gov (United States)

    Hamidi-Asl, Ezat; Daems, Devin; De Wael, Karolien; Van Camp, Guy; Nagels, Luc J

    2014-12-16

    In the present paper, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small-molecule interactions is reported. This approach is fast, sensitive, reproducible, and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small-molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed into a concentration-related signal over the entire concentration interval, also at low concentrations, where the millivolt (y-axis) versus log canalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anticocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis(4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using surface plasmon resonance. The potentiometric titration approach called "concentration-related response potentiometry" is used to study molecular interaction for seven macromolecular target molecules and four small-molecule ligands.

  19. Biomolecules in the treatment of lichen planus refractory to corticosteroid therapy: Clinical and histopathological assessment.

    Science.gov (United States)

    Piñas, Laura; Alkhraisat, Mohammad Hamdan; Suárez-Fernández, Ricardo; Anitua, Eduardo

    2018-03-01

    Local deficit of several biomolecules have been described in oral lichen planus (OLP). Such a deficit impairs cellular functions and cell-matrix communication. Assess the efficacy of the local application of autologous biomolecules in the treatment of erosive OLP. In this study, the use of plasma rich in growth factors (PRGF) as a source of blood-derived and autologous growth factors and proteins were tested in erosive oral lichen planus refractory to corticosteroids. Histopathological features of the disease were also analysed at the time of diagnosis. Clinical data were the number of recurrences and achievement of pain reduction and complete healing of the lesions. A total of 10 patients with erosive OLP refractory to treatment by corticosteroids were included in the study. All patients were females with a mean age of 48±12years. A complete remission of the disease was achieved after one infiltration of PRGF in 8 patients. Only 2 patients required a total of 2 infiltrations to heal. Hydropic degeneration of the epithelium basal layer, band-like subepithelial lymphocytic infiltration and fibrin deposits in the epithelium were observed in all patients. Interestingly plasma cells were present in 2 patients. All patients presenting plasma cells healed after only one PRGF infiltration. However, 2 patients out of 6 (no plasma cells) required 2 infiltrations. The local administration of autologous local factors could overcome the deficit of biomolecular clues and thus improve cell functions and restore cell-matrix communication. Copyright © 2017 Elsevier GmbH. All rights reserved.

  20. Biomolecule detection using a silicon nanoribbon: accumulation mode versus inversion mode

    International Nuclear Information System (INIS)

    Elfstroem, Niklas; Linnros, Jan

    2008-01-01

    Silicon nanoribbons were fabricated using standard optical lithography from silicon on insulator material with top silicon layer thicknesses of 100, 60 and 45 nm. Electrically these work as Schottky-barrier field-effect transistors and, depending on the substrate voltage, electron or hole injection is possible. The current through the nanoribbon is extremely sensitive to charge changes at the oxidized top surface and can be used for biomolecule detection in a liquid. We show that for detection of streptavidin molecules the response is larger in the accumulation mode than in the inversion mode, although not leading to higher detection sensitivity due to increased noise. The effect is attributed to the location in depth of the conducting channel, which for holes is closer to the screened surface charges of the biomolecules. Furthermore, the response increases for decreasing silicon thickness in both the accumulation mode and the inversion mode. The results are verified qualitatively and quantitatively through a two-dimensional simulation model on a cross section along the nanoribbon device

  1. Carbon-14 labelling of biomolecules induced by 14CO ionized gas

    International Nuclear Information System (INIS)

    Lier, J.E. van; Sanche, L.

    1979-01-01

    Ionized 14 CO gas provides a rapid method for producing 14 C-labelled biomolecules. The apparatus consists of a high vacuum system in which a small amount of 14 CO is ionized by electron impact. The resulting species drift towards a target where they interact with the molecule of interest to produce 14 C-labelled compounds. Since the reaction time is only 2 minutes, the method is particularly promising for producing tracer biomolecules with short-lived 11 C at high specific activities. The applicability of the method to various classes of compounds of biological importance, including steroids, alkaloids, prostaglandins, nucleosides, amino acids and proteins has been studied. All compounds treated gave rise to 14 C addition and degradation products. Furthermore, for some compounds, chromatographic analysis in multiple systems followed by derivatization and crystallization to constant specific activity, indicated that carbon exchange may occur to produce the labelled, but otherwise unaltered substrate in yields of the order of 10-100 mCi/mol. More conclusive proof of radiochemical identity must await production of larger quantities of material and rigorous purification including at least two different chromatographic techniques. (author)

  2. Impact of low-temperature plasmas on Deinococcus radiodurans and biomolecules

    Science.gov (United States)

    Mogul, Rakesh; Bol'shakov, Alexander A.; Chan, Suzanne L.; Stevens, Ramsey M.; Khare, Bishun N.; Meyyappan, M.; Trent, Jonathan D.

    2003-01-01

    The effects of cold plasma on Deinococcus radiodurans, plasmid DNA, and model proteins were assessed using microbiological, spectrometric, and biochemical techniques. In low power O(2) plasma (approximately 25 W, approximately 45 mTorr, 90 min), D. radiodurans, a radiation-resistant bacterium, showed a 99.999% reduction in bioburden. In higher power O(2) plasma (100 W and 500 mTorr), the reduction rate increased about 10-fold and observation by atomic force microscopy showed significant damage to the cell. Damage to cellular lipids, proteins, and chromosome was indicated by losses of infrared spectroscopic peaks at 2930, 1651, 1538, and 1245 cm(-1), respectively. In vitro experiments show that O(2) plasmas induce DNA strand scissions and cross-linking as well as reduction of enzyme activity. The observed degradation and removal of biomolecules was power-dependent. Exposures to 200 W at 500 mTorr removed biomolecules to below detection limits in 60 s. Emission spectroscopy indicated that D. radiodurans cells were volatilized into CO(2), CO, N(2), and H(2)O, confirming that these plasmas were removing complex biological matter from surfaces. A CO(2) plasma was not as effective as the O(2) plasma, indicating the importance of plasma composition and the dominant role of chemical degradation. Together, these findings have implications for NASA planetary protection schemes and for the contamination of Mars.

  3. Influence of Immobilized Biomolecules on Magnetic Bead Plug Formation and Retention in Capillary Electrophoresis

    Science.gov (United States)

    Henken, Rachel L.; Chantiwas, Rattikan; Gilman, S. Douglass

    2012-01-01

    Significant changes in the formation and retention of magnetic bead plugs in a capillary during electrophoresis were studied, and it was demonstrated that these effects were due to the type of biological molecule immobilized on the surface of these beads. Three biological molecules, an antibody, an oligonucleotide and alkaline phosphatase, were attached to otherwise identical streptavidin-coated magnetic beads through biotin-avidin binding in order to isolate differences in bead immobilization in a magnetic field resulting from the type of biological molecule immobilized on the bead surface. Alkaline phosphatase also was attached to the magnetic beads using epoxy groups on the bead surfaces (instead of avidin-biotin binding) to study the impact of immobilization chemistry. The formation and retention of magnetic bead plugs were studied quantitatively using light scattering detection of magnetic particles eluting from the bead plugs and qualitatively using microscopy. Both the type of biomolecule immobilized on the magnetic bead surface and the chemistry used to link the biomolecule to the magnetic bead impacted the formation and retention of the bead plugs. PMID:22437880

  4. In Situ Hot-Spot Assembly as a General Strategy for Probing Single Biomolecules.

    Science.gov (United States)

    Liu, Huiqiao; Li, Qiang; Li, Mingmin; Ma, Sisi; Liu, Dingbin

    2017-05-02

    Single-molecule detection using surface-enhanced Raman spectroscopy (SERS) has attracted increasing attention in chemical and biomedical analysis. However, it remains a major challenge to probe single biomolecules by means of SERS hot spots owing to the small volume of hot spots and their random distribution on substrates. We here report an in situ hot-spot assembly method as a general strategy for probing single biomolecules. As a proof-of-concept, this proposed strategy was successfully used for the detection of single microRNA-21 (miRNA-21, a potential cancer biomarker) at the single-cell level, showing great capability in differentiating the expression of miRNA-21 in single cancer cells from normal cells. This approach was further extended to single-protein detection. The versatility of the strategy opens an exciting avenue for single-molecule detection of biomarkers of interest and thus holds great promise in a variety of biological and biomedical applications.

  5. 3D Plasma Nanotextured® Polymeric Surfaces for Protein or Antibody Arrays, and Biomolecule and Cell Patterning.

    Science.gov (United States)

    Tsougeni, Katerina; Ellinas, Kosmas; Koukouvinos, George; Petrou, Panagiota S; Tserepi, Angeliki; Kakabakos, Sotirios E; Gogolides, Evangelos

    2018-01-01

    Plasma micro-nanotexturing is a generic technology for topographical and chemical modification of surfaces and their implementation in microfluidics and microarrays. Nanotextured surfaces with desirable chemical functionality (and wetting behavior) have shown excellent biomolecule immobilization and cell adhesion. Specifically, nanotextured hydrophilic areas show (a) strong binding of biomolecules and (b) strong adhesion of cells, while nanotextured superhydrophobic areas show null adsorption of (a) proteins and (b) cells. Here we describe the protocols for (a) biomolecule adsorption control on nanotextured surfaces for microarray fabrication and (b) cell adhesion on such surfaces. 3D plasma nanotextured® substrates are commercialized through Nanoplasmas private company, a spin-off of the National Centre for Scientific Research Demokritos.

  6. Accessibility of nucleic acid-complexed biomolecules to hydroxyl radicals correlates with their conformation: a fluorescence polarization spectroscopy study

    International Nuclear Information System (INIS)

    Makrigiorgos, G.M.; Bump, E.; Huang, C.; Kassis, A.I.; Baranowska-Kortylewicz, J.

    1994-01-01

    A fluorescence methodology has been developed to examine the relationship between the conformational state of specific biomolecules in simple chromatin models and their accessibility to hydroxyl radicals ( . OH). Polylysine and histone H1 were labelled with SECCA, the succinimidyl ester of coumarin-3-carboxylic acid, which generates the fluorescent derivative 7-OH-SECCA following its interaction with radiation-induced . OH in aqueous solution. The fluorescence induced per unit γ-ray dose reflecting the accessibility of . OH to such SECCA-conjugated biomolecules was recorded. The biomolecules were also labelled with the fluorescent derivative 7-OH-SECCA in trace amounts to study their conformation under identical conditions via fluorescence polarization spectroscopy. (author)

  7. Adolescencia y suicidio: Entre la perspectiva neuropsicológica de Diamond y Psicoevolutiva de Dolto

    OpenAIRE

    Mónica Viviana Gómez; Diego Alejandro Calle; José Flórez Ocampo; Luisa Victoria Álvarez

    2015-01-01

    Este artículo presenta una reflexión sobre la problemática del suicidio en la adolescencia, tomando en consideración algunos aspectos comunes asociados al concepto de desarrollo entre la perspectiva neuropsicológica de Adele Diamond y la perspectiva psicoevolutiva de Françoise Dolto. Las dos perspectivas permiten un acercamiento a las nociones de temporalidad y vulnerabilidad, claves para la comprensión de dicha problemática, la cual está ligada a las condiciones socio históricas de la époc...

  8. Three-dimensional structure determination protocol for noncrystalline biomolecules using x-ray free-electron laser diffraction imaging.

    Science.gov (United States)

    Oroguchi, Tomotaka; Nakasako, Masayoshi

    2013-02-01

    Coherent and intense x-ray pulses generated by x-ray free-electron laser (XFEL) sources are paving the way for structural determination of noncrystalline biomolecules. However, due to the small scattering cross section of electrons for x rays, the available incident x-ray intensity of XFEL sources, which is currently in the range of 10(12)-10(13) photons/μm(2)/pulse, is lower than that necessary to perform single-molecule diffraction experiments for noncrystalline biomolecules even with the molecular masses of megadalton and submicrometer dimensions. Here, we propose an experimental protocol and analysis method for visualizing the structure of those biomolecules by the combined application of coherent x-ray diffraction imaging and three-dimensional reconstruction methods. To compensate the small scattering cross section of biomolecules, in our protocol, a thin vitreous ice plate containing several hundred biomolecules/μm(2) is used as sample, a setup similar to that utilized by single-molecule cryoelectron microscopy. The scattering cross section of such an ice plate is far larger than that of a single particle. The images of biomolecules contained within irradiated areas are then retrieved from each diffraction pattern, and finally provide the three-dimensional electron density model. A realistic atomic simulation using large-scale computations proposed that the three-dimensional structure determination of the 50S ribosomal subunit embedded in a vitreous ice plate is possible at a resolution of 0.8 nm when an x-ray beam of 10(16) photons/500×500 nm(2)/pulse is available.

  9. Determination of partition coefficients of biomolecules in a microfluidic aqueous two phase system platform using fluorescence microscopy.

    Science.gov (United States)

    Silva, D F C; Azevedo, A M; Fernandes, P; Chu, V; Conde, J P; Aires-Barros, M R

    2017-03-03

    Aqueous two phase systems (ATPS) offer great potential for selective separation of a wide range of biomolecules by exploring differences in molecular solubility in each of the two immiscible phases. However, ATPS use has been limited due to the difficulty in predicting the behavior of a given biomolecule in the partition environment together with the empirical and time-consuming techniques that are used for the determination of partition and extraction parameters. In this work, a fast and novel technique based on a microfluidic platform and using fluorescence microscopy was developed to determine the partition coefficients of biomolecules in different ATPS. This method consists of using a microfluidic device with a single microchannel and three inlets. In two of the inlets, solutions containing the ATPS forming components were loaded while the third inlet was fed with the FITC tagged biomolecule of interest prepared in milli-Q water. Using fluorescence microscopy, it was possible to follow the location of the FITC-tagged biomolecule and, by simply varying the pumping rates of the solutions, to quickly test a wide variety of ATPS compositions. The ATPS system is allowed 4min for stabilization and fluorescence micrographs are used to determine the partition coefficient.The partition coefficients obtained were shown to be consistent with results from macroscale ATPS partition. This process allows for faster screening of partition coefficients using only a few microliters of material for each ATPS composition and is amenable to automation. The partitioning behavior of several biomolecules with molecular weights (MW) ranging from 5.8 to 150kDa, and isoelectric points (pI) ranging from 4.7 to 6.4 was investigated, as well as the effect of the molecular weight of the polymer ATPS component. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. EL DERECHO DE AUTOR EN COLOMBIA DESDE UNA PERSPECTIVA HUMANISTA

    Directory of Open Access Journals (Sweden)

    Ramiro Rodríguez López

    2012-01-01

    Full Text Available Se considera que el Pacto Internacional de Derechos Económicos, Sociales y Culturales, promulgado por las Naciones Unidas en 1966, determinó la necesidad de garantizar a las personas el derecho a beneficiarse tanto de los intereses morales como de los materiales sobre las creaciones del intelecto, denominadas propiedad intelectual. Al respecto, se considera posible plantear su estudio desde una perspectiva humanista, iniciando el análisis desde la precisión de derechos de autor. Para ello, se estudia su consagración normativa en las constituciones políticas de 1886 y 1991; la importancia de los instrumentos internacionales a los cuales ha adherido el Estado colombiano y su desarrollo en la jurisprudencia nacional, donde se ha hecho una clara referencia del derecho de autor como un derecho contenido en el artículo 27 de la Declaración Universal de los Derechos Humanos de 1948.

  11. Gestión humana: tendencias y perspectivas

    Directory of Open Access Journals (Sweden)

    Juan Guillermo Saldarriaga Ríos

    2008-04-01

    Full Text Available En este artículo se hace referencia a las tendencias y las perspectivas de gestión humana que se imponen en el mundo en la actualidad y que, a su manera, pretenden optimizar la administración del personal de la organización y contribuir al desarrollo e incremento de la productividad y la competitividad. Mediante la realización de un Estado del Arte se logran determinar algunas de las tendencias más relevantes en la actualidad y se concluye que, cada vez con mayor fuerza, dichas tendencias se sustentan en discursos que pretenden “rescatar” al ser humano dentro de la organización, lo que no necesariamente se traduce en los procesos de gestión humana que se realizan en las organizaciones nacionales e internacionales.

  12. Imunidade tributária : perspectivas da imunidade religiosa

    OpenAIRE

    Jackson Urquiza da Costa e Silva

    2012-01-01

    O presente trabalho tem por objetivo discutir os limites e as perspectivas da imunidade tributária religiosa prevista na Constituição da República Federativa do Brasil. Antes de discutir-se a essência dessa questão, fez-se uma breve passagem histórica da evolução da imunidade tributária, desde seu surgimento no império romano ao estado moderno; e especificamente no Brasil, desde os tempos como colônia de Portugal à Constituição de 1988. Após serem fixados os critérios informadores da ...

  13. La autonomía personal y la perspectiva comunitarista

    Directory of Open Access Journals (Sweden)

    Álvarez, Silvina

    1999-11-01

    Full Text Available Not available

    El presente artículo analiza el planteamiento que algunos autores comunitaristas han hecho de la noción de autonomía personal. En primer lugar centraré la atención en la formulación kantiana de la autonomía y en las posteriores reformulaciones que se han hecho de la propuesta original. En la segunda parte expondré algunos aspectos generales de la teoría comunitarista para luego desarrollar la propuesta de Charles Taylor, específicamente la ética de la autenticidad. En el análisis se destacan los problemas que surgen de entender la autonomía desde la perspectiva de una ética comprehensiva que concibe al sujeto como continuador de una tradición moral colectiva.

  14. Editorial Mercadotecnia Latinoamericana desde una perspectiva de México

    Directory of Open Access Journals (Sweden)

    Thel Augusto Monteiro

    2017-10-01

    Full Text Available La presente Edición Especial: Mercadotecnia Latinoamericana desde una perspectiva de México, es un esfuerzo de investigadores de diferentes universidades reconocidos por sus aportaciones científicas sobre Mercadotecnia en México. Las comunicaciones esta edición describen las Estrategias de Mercadotecnia y su Aplicación en México, está estructurada en ocho aportaciones científicas representan el quehacer académico y de investigación diario de la mercadotecnia, tratando temas de frontera relacionados con el Branding Laboral, el Emprendimiento Social, la Compra Compulsiva, la Inteligencia Emocional, la Mercadotecnia Musical, el Nuevo Perfil de Consumidor Mexicano, el Marketing de Lugares (Caso: Real de Catorce y el Marketing Gastronómico (Caso: Salsa Chimichurri.

  15. Micropatterning of biomolecules on a glass substrate in fused silica microchannels by using photolabile linker-based surface activation

    International Nuclear Information System (INIS)

    Jang, K.; Mawatari, K.; Kitamori, T.; Xu, Y.; Sato, K.; Tanaka, Y.

    2012-01-01

    We report on a straightforward method for creating micropatterns of multiple biomolecules. The anti-fouling agent 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer and a photolabile linker (PL) were covalently linked to an amino-terminated silane surface. Patterns were generated by selective removal of the MPC polymer via UV irradiation. Multiple micropatterns of fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (BSA) and rhodamine-labeled goat fragment antigen-binding fragments (FAB) were deposited on a same glass substrate. We also employed micropatterning of multiple biomolecules in that Texas red-labeled BSA and FITC-labeled rabbit anti-mouse IgG were placed inside a microchannel. (author)

  16. Light-induced immobilisation of biomolecules as an attractive alternative to micro-droplet dispensing-based arraying technologies (vol 7, pg 3491, 2007)

    DEFF Research Database (Denmark)

    Duroux, Meg; Skovsen, Esben; Neves Petersen, Teresa

    2008-01-01

    The present work shows how UV ‘light-induced molecular immobilisation' (LIMI) of biomolecules onto thiol reactive surfaces can be used to make biosensors, without the need for traditional microdispensing technologies. Using ‘LIMI,' arrays of biomolecules can be created with a high degree of repro...

  17. Identification of biomolecule mass transport and binding rate parameters in living cells by inverse modeling

    Directory of Open Access Journals (Sweden)

    Shirmohammadi Adel

    2006-10-01

    Full Text Available Abstract Background Quantification of in-vivo biomolecule mass transport and reaction rate parameters from experimental data obtained by Fluorescence Recovery after Photobleaching (FRAP is becoming more important. Methods and results The Osborne-Moré extended version of the Levenberg-Marquardt optimization algorithm was coupled with the experimental data obtained by the Fluorescence Recovery after Photobleaching (FRAP protocol, and the numerical solution of a set of two partial differential equations governing macromolecule mass transport and reaction in living cells, to inversely estimate optimized values of the molecular diffusion coefficient and binding rate parameters of GFP-tagged glucocorticoid receptor. The results indicate that the FRAP protocol provides enough information to estimate one parameter uniquely using a nonlinear optimization technique. Coupling FRAP experimental data with the inverse modeling strategy, one can also uniquely estimate the individual values of the binding rate coefficients if the molecular diffusion coefficient is known. One can also simultaneously estimate the dissociation rate parameter and molecular diffusion coefficient given the pseudo-association rate parameter is known. However, the protocol provides insufficient information for unique simultaneous estimation of three parameters (diffusion coefficient and binding rate parameters owing to the high intercorrelation between the molecular diffusion coefficient and pseudo-association rate parameter. Attempts to estimate macromolecule mass transport and binding rate parameters simultaneously from FRAP data result in misleading conclusions regarding concentrations of free macromolecule and bound complex inside the cell, average binding time per vacant site, average time for diffusion of macromolecules from one site to the next, and slow or rapid mobility of biomolecules in cells. Conclusion To obtain unique values for molecular diffusion coefficient and

  18. An alternative origin for extraterrestrial biomolecules from the hot and ionized photosphere of the protosolar nebula.

    Science.gov (United States)

    Bekaert, D. V.; Derenne, S.; Tissandier, L.; Marrocchi, Y.; Anquetil, C.; Marty, B.

    2017-12-01

    Organic matter (OM) synthesized from plasma experiments (so-called Nebulotron) can provide an insight into the processes of organosynthesis within the ionized gas phase of the protosolar nebula (PSN). Organic materials recovered from Nebulotron experiments have a record of success in reproducing key features of chondritic insoluble organic matter (IOM), including the aromatic/aliphatic and soluble/insoluble ratios [1], the occurrence of D/H hot and cold spots [2], spectral features as well as elementary and isotopic patterns observed in trapped noble gases [3]. However, up until now little attention has been paid to the soluble fraction of the recovered OM (SOM). In this study, a high-vacuum plasma setting was designed to produce organic condensates from a CO-N2-H2 gas mixture reminiscent of the PSN. The chemical diversity of the synthetized SOM has been investigated by gas chromatography - mass spectrometry. Our results show that a large range of biomolecules detected in meteorites and comets could have been directly synthetized from the gas phase of the PSN under high ionization rates and temperatures > 800 K. Among other molecules, urea, formamide, glycerol, hydantoin, carboxylic acids, as well as amino acid and nucleobase derivatives are reported. While photochemical processing of interstellar icy grains or asteroidal aqueous alteration are often advocated for the origin of biomolecules in extraterrestrial samples, our results suggest that biomolecule production was also effective in the hot and ionized photosphere of the PSN. Interestingly, solid-state 13C Nuclear Magnetic Resonance spectra of the Nebulotron IOM, indicates that they are very low in aromatics relative to extraterrestrial samples. Given that aromatic units in meteoritic IOM likely result from the cyclization/aromatization of aliphatic chains in the gas [1], Nebulotron-like aliphatic materials could represent the initial precursors of meteoritic OM [4]. These materials would be widespread in the

  19. Identification of Biomolecular Building Blocks by Recognition Tunneling: Stride towards Nanopore Sequencing of Biomolecules

    Science.gov (United States)

    Sen, Suman

    DNA, RNA and Protein are three pivotal biomolecules in human and other organisms, playing decisive roles in functionality, appearance, diseases development and other physiological phenomena. Hence, sequencing of these biomolecules acquires the prime interest in the scientific community. Single molecular identification of their building blocks can be done by a technique called Recognition Tunneling (RT) based on Scanning Tunneling Microscope (STM). A single layer of specially designed recognition molecule is attached to the STM electrodes, which trap the targeted molecules (DNA nucleoside monophosphates, RNA nucleoside monophosphates or amino acids) inside the STM nanogap. Depending on their different binding interactions with the recognition molecules, the analyte molecules generate stochastic signal trains accommodating their "electronic fingerprints". Signal features are used to detect the molecules using a machine learning algorithm and different molecules can be identified with significantly high accuracy. This, in turn, paves the way for rapid, economical nanopore sequencing platform, overcoming the drawbacks of Next Generation Sequencing (NGS) techniques. To read DNA nucleotides with high accuracy in an STM tunnel junction a series of nitrogen-based heterocycles were designed and examined to check their capabilities to interact with naturally occurring DNA nucleotides by hydrogen bonding in the tunnel junction. These recognition molecules are Benzimidazole, Imidazole, Triazole and Pyrrole. Benzimidazole proved to be best among them showing DNA nucleotide classification accuracy close to 99%. Also, Imidazole reader can read an abasic monophosphate (AP), a product from depurination or depyrimidination that occurs 10,000 times per human cell per day. In another study, I have investigated a new universal reader, 1-(2-mercaptoethyl)pyrene (Pyrene reader) based on stacking interactions, which should be more specific to the canonical DNA nucleosides. In addition

  20. New Chelators for Low Temperature Al(18)F-Labeling of Biomolecules.

    Science.gov (United States)

    Cleeren, Frederik; Lecina, Joan; Billaud, Emilie M F; Ahamed, Muneer; Verbruggen, Alfons; Bormans, Guy M

    2016-03-16

    The Al(18)F labeling method is a relatively new approach that allows radiofluorination of biomolecules such as peptides and proteins in a one-step procedure and in aqueous solution. However, the chelation of the {Al(18)F}(2+) core with the macrocyclic chelators NOTA or NODA requires heating to 100-120 °C. Therefore, we have developed new polydentate ligands for the complexation of {Al(18)F}(2+) with good radiochemical yields at a temperature of 40 °C. The stability of the new Al(18)F-complexes was tested in phosphate buffered saline (PBS) at pH 7.4 and in rat serum. The stability of the Al(18)F-L3 complex was found to be comparable to that of the previously reported Al(18)F-NODA complex up to 60 min in rat serum. Moreover, the biodistribution of Al(18)F-L3 in healthy mice showed the absence of in vivo defluorination since no significant bone uptake was observed, whereas the major fraction of activity at 60 min p.i. was observed in liver and intestines, indicating hepatobiliary clearance of the radiolabeled ligand. The acyclic chelator H3L3 proved to be a good lead candidate for labeling of heat-sensitive biomolecules with fluorine-18. In order to obtain a better understanding of the different factors influencing the formation and stability of the complex, we carried out more in-depth experiments with ligand H3L3. As a proof of concept, we successfully conjugated the new AlF-chelator with the urea-based PSMA inhibitor Glu-NH-CO-NH-Lys to form Glu-NH-CO-NH-Lys(Ahx)L3, and a biodistribution study in healthy mice was performed with the Al(18)F-labeled construct. This new class of AlF-chelators may have a great impact on PET radiochemical space as it will stimulate the rapid development of new fluorine-18 labeled peptides and other heat-sensitive biomolecules.

  1. Hydrogels Based on Ag+ -Modulated Assembly of 5'-Adenosine Monophosphate for Enriching Biomolecules.

    Science.gov (United States)

    Hu, Yuanyuan; Xie, Dong; Wu, Yang; Lin, Nangui; Song, Aixin; Hao, Jingcheng

    2017-11-07

    Supramolecular hydrogels obtained by combining 5'-adenosine monophosphate (AMP) with Ag + were fabricated in this work. Their gelation capability was enhanced by increasing the concentration of Ag + or decreasing the pH. The gels are very sensitive to light, which endows them with potential applications as visible-light photosensitive materials. Coordination between the nucleobase of AMP and Ag + , as well as π-π stacking of nucleobases, are considered to be the main driving forces for self-assembly. The hydrogels successfully achieved the encapsulation and enrichment of biomolecules. Hydrogen bonding between the amino group of guest molecules and silver nanoparticles along the nanofibers drives the enrichment and is considered to be a crucial interaction. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Elemental speciation in biomolecules by LC-ICP-MS with magnetic sector and collision cell instruments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin [Iowa State Univ., Ames, IA (United States)

    1999-11-08

    A methodology that can monitor and identify inorganic elements in biological and environmental systems was developed. Size exclusion chromatography (SEC) separates biomolecules, which are then nebulized by a microconcentric nebulizer. The resulting aerosol is desolved and introduced into either a high resolution ICP-MS device or a quadrupole device with a collision cell. Because of the high sensitivity and spectral resolution and high sample introduction efficiency, many unusual or difficult elements, such as Cr, Se, Cd and U, can be observed at ambient levels bound to proteins in human serum. These measurements are made in only a few minutes without preliminary isolation and preconcentration steps. Serum samples can be titrated with spikes of various elements to determine which proteins bind a given metal and oxidation state. Experiments concerning the effects of breaking disulfide linkages and denaturation on metal binding in proteins were also investigated. Elemental distribution in liver extract was also obtained.

  3. Automated astatination of biomolecules - a stepping stone towards multicenter clinical trials

    DEFF Research Database (Denmark)

    Aneheim, Emma; Albertsson, Per; Bäck, Tom

    2015-01-01

    To facilitate multicentre clinical studies on targeted alpha therapy, it is necessary to develop an automated, on-site procedure for conjugating rare, short-lived, alpha-emitting radionuclides to biomolecules. Astatine-211 is one of the few alpha-emitting nuclides with appropriate chemical...... vector, which can guide the radiation to the cancer cells. Consequently, an appropriate method is required for coupling the nuclide to the vector. To increase the availability of astatine-211 radiopharmaceuticals for targeted alpha therapy, their production should be automated. Here, we present a method...... challenging, alpha-emitting radionuclide. In this work, we describe the process platform, and we demonstrate the production of both astaine-211, for preclinical use, and astatine-211 labelled antibodies....

  4. A novel experimental system of high stability and lifetime for the laser-desorption of biomolecules.

    Science.gov (United States)

    Taherkhani, Mehran; Riese, Mikko; BenYezzar, Mohammed; Müller-Dethlefs, Klaus

    2010-06-01

    A novel laser desorption system, with improved signal stability and extraordinary long lifetime, is presented for the study of jet-cooled biomolecules in the gas phase using vibrationally resolved photoionization spectroscopy. As a test substance tryptophane is used to characterize this desorption source. A usable lifetime of above 1 month (for a laser desorption repetition rate of 20 Hz) has been observed by optimizing the pellets (graphite/tryptophane, 3 mm diameter and 6 mm length) from which the substance is laser-desorbed. Additionally, the stability and signal-to-noise ratio has been improved by averaging the signal over the entire sample pellet by synchronizing the data acquisition with the rotation of the sample rod. The results demonstrate how a combination of the above helps to produce stable and conclusive spectra of tryptophane using one-color and two-color resonant two-photon ionization studies.

  5. Elemental speciation in biomolecules by LC-ICP-MS with magnetic sector and collision cell instruments

    International Nuclear Information System (INIS)

    Wang, Jin

    1999-01-01

    A methodology that can monitor and identify inorganic elements in biological and environmental systems was developed. Size exclusion chromatography (SEC) separates biomolecules, which are then nebulized by a microconcentric nebulizer. The resulting aerosol is desolved and introduced into either a high resolution ICP-MS device or a quadrupole device with a collision cell. Because of the high sensitivity and spectral resolution and high sample introduction efficiency, many unusual or difficult elements, such as Cr, Se, Cd and U, can be observed at ambient levels bound to proteins in human serum. These measurements are made in only a few minutes without preliminary isolation and preconcentration steps. Serum samples can be titrated with spikes of various elements to determine which proteins bind a given metal and oxidation state. Experiments concerning the effects of breaking disulfide linkages and denaturation on metal binding in proteins were also investigated. Elemental distribution in liver extract was also obtained

  6. Structural Change of Biomolecules and Application of Synergistic Interaction by Radiation

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Kim, J. H.; Yang, J. S.

    2008-12-01

    It is expected that motivation and basic technologies for the future R and D plans can be provided from the results of this study. This study has been done to develop fundamentals for radiation applications based on the existing radiation technology, and to establish technical basis for enhancing efficacy of radiation utilization by studying the simultaneous application of ionizing radiation with another factor. Application of radiation technology together with the existing technologies to enhance the physical, chemical, biological characteristics through structural changes of biomolecules will exert a favorable influence on the creation of de novo scientific and industrial values. A theoretical model for the combined action of ionizing radiation with another factor can make it possible to predict a prior the maximum value of synergistic interaction and the conditions for it. Furthermore, the results of this study give a clues for establishment of fundamental theories associated with positive efficacy of radiation applications

  7. Simple and universal model for electron-impact ionization of complex biomolecules

    Science.gov (United States)

    Tan, Hong Qi; Mi, Zhaohong; Bettiol, Andrew A.

    2018-03-01

    We present a simple and universal approach to calculate the total ionization cross section (TICS) for electron impact ionization in DNA bases and other biomaterials in the condensed phase. Evaluating the electron impact TICS plays a vital role in ion-beam radiobiology simulation at the cellular level, as secondary electrons are the main cause of DNA damage in particle cancer therapy. Our method is based on extending the dielectric formalism. The calculated results agree well with experimental data and show a good comparison with other theoretical calculations. This method only requires information of the chemical composition and density and an estimate of the mean binding energy to produce reasonably accurate TICS of complex biomolecules. Because of its simplicity and great predictive effectiveness, this method could be helpful in situations where the experimental TICS data are absent or scarce, such as in particle cancer therapy.

  8. The interplay of biomolecules and water at the origin of the active behavior of living organisms

    International Nuclear Information System (INIS)

    Del Giudice, E; Stefanini, P; Tedeschi, A; Vitiello, G

    2011-01-01

    It is shown that the main component of living matter, namely liquid water, is not an ensemble of independent molecules but an ensemble of phase correlated molecules kept in tune by an electromagnetic (e.m) field trapped in the ensemble. This field and the correlated potential govern the interaction among biomolecules suspended in water and are in turn affected by the chemical interactions of molecules. In particular, the phase of the coherent fields appears to play an important role in this dynamics. Recent experiments reported by the Montagnier group seem to corroborate this theory. Some features of the dynamics of human organisms, as reported by psychotherapy, holistic medicine and Eastern traditions, are analyzed in this frame and could find a rationale in this context.

  9. Recent results for electron scattering from biomolecules and molecules formed due to plasma treatment of biomass

    Science.gov (United States)

    Brunger, Michael

    2016-09-01

    We have been concentrating our recent experimental studies, for determining absolute cross sections, on both biomolecules (e.g. pyrimidine and benzoquinone) and molecules that result when biomass undergoes treatment by plasmas (e.g. phenol and furfural). All this work was supported and informed by computations from the Brazilian SMC groups and the Madrid IAM-SCAR group. A major rationale for these investigations was to provide cross section data for relevant modelling studies, and in this talk I will also present some results from those modelling studies. Possible further investigations will be canvassed in this presentation. Work done in conjunction with: D. B. Jones, L. Campbell, R. D. White, S. J. Buckman, M. A. P. Lima, M. C. A. Lopes, M. H. F. Bettega, M. T. do N. Varella, R. F. da Costa, G. García, P. Limão-Vieira, D. H. Madison, O. Ingólfsson and many other friends and colleagues.

  10. Structural Change of Biomolecules and Application of Synergistic Interaction by Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Kim, J. H.; Yang, J. S.

    2008-12-15

    It is expected that motivation and basic technologies for the future R and D plans can be provided from the results of this study. This study has been done to develop fundamentals for radiation applications based on the existing radiation technology, and to establish technical basis for enhancing efficacy of radiation utilization by studying the simultaneous application of ionizing radiation with another factor. Application of radiation technology together with the existing technologies to enhance the physical, chemical, biological characteristics through structural changes of biomolecules will exert a favorable influence on the creation of de novo scientific and industrial values. A theoretical model for the combined action of ionizing radiation with another factor can make it possible to predict a prior the maximum value of synergistic interaction and the conditions for it. Furthermore, the results of this study give a clues for establishment of fundamental theories associated with positive efficacy of radiation applications

  11. The effective atomic numbers of some biomolecules calculated by two methods: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Manohara, S. R.; Hanagodimath, S. M.; Gerward, L. [Department of Physics, Gulbarga University, Gulbarga, Karnataka 585 106 (India); Department of Physics, Technical University of Denmark, Lyngby DK-2800 (Denmark)

    2009-01-15

    The effective atomic numbers Z{sub eff} of some fatty acids and amino acids have been calculated by two numerical methods, a direct method and an interpolation method, in the energy range of 1 keV-20 MeV. The notion of Z{sub eff} is given a new meaning by using a modern database of photon interaction cross sections (WinXCom). The results of the two methods are compared and discussed. It is shown that for all biomolecules the direct method gives larger values of Z{sub eff} than the interpolation method, in particular at low energies (1-100 keV) At medium energies (0.1-5 MeV), Z{sub eff} for both methods is about constant and equal to the mean atomic number of the material. Wherever possible, the calculated values of Z{sub eff} are compared with experimental data.

  12. The effective atomic numbers of some biomolecules calculated by two methods: A comparative study

    International Nuclear Information System (INIS)

    Manohara, S. R.; Hanagodimath, S. M.; Gerward, L.

    2009-01-01

    The effective atomic numbers Z eff of some fatty acids and amino acids have been calculated by two numerical methods, a direct method and an interpolation method, in the energy range of 1 keV-20 MeV. The notion of Z eff is given a new meaning by using a modern database of photon interaction cross sections (WinXCom). The results of the two methods are compared and discussed. It is shown that for all biomolecules the direct method gives larger values of Z eff than the interpolation method, in particular at low energies (1-100 keV) At medium energies (0.1-5 MeV), Z eff for both methods is about constant and equal to the mean atomic number of the material. Wherever possible, the calculated values of Z eff are compared with experimental data.

  13. A differential weak measurement system based on Sagnac interferometer for self-referencing biomolecule detection

    Science.gov (United States)

    Li, Dongmei; Guan, Tian; He, Yonghong; He, Qinghua; Zhang, Yilong; Wang, Xiangnan; Shen, Zhiyuan; Yang, Yuxuan; Qiao, Zhen; Ji, Yanhong

    2017-12-01

    A differential weak measurement system was presented, exhibiting the self-referencing function for biomolecule real time detection as a label-free optical biosensor. We built a Sagnac interferometer, which limited horizontal (H) and vertical (V) polarization to propagating along the common path but in opposite directions to realize weak measurements with two measuring channels installed in two corners of this Sagnac interferometer. By introducing two half wave plates into the system alternately with the two channels to convert between H and V polarization, we obtained a differential measurement for phase delay, which could quantitatively characterize the refractive index change corresponding to the concentration of samples in the channels. With this system, a real time monitor of molecule concentration in the dialysis process was accomplished, demonstrating the function of self-referencing, which is important for optical label-free molecule detection in a complex biological sample solution.

  14. Microreactor and method for preparing a radiolabeled complex or a biomolecule conjugate

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, David E; Kenis, Paul J. A.; Wheeler, Tobias D; Desai, Amit V; Zeng, Dexing; Onal, Birce C

    2015-03-17

    A microreactor for preparing a radiolabeled complex or a biomolecule conjugate comprises a microchannel for fluid flow, where the microchannel comprises a mixing portion comprising one or more passive mixing elements, and a reservoir for incubating a mixed fluid. The reservoir is in fluid communication with the microchannel and is disposed downstream of the mixing portion. A method of preparing a radiolabeled complex includes flowing a radiometal solution comprising a metallic radionuclide through a downstream mixing portion of a microchannel, where the downstream mixing portion includes one or more passive mixing elements, and flowing a ligand solution comprising a bifunctional chelator through the downstream mixing portion. The ligand solution and the radiometal solution are passively mixed while in the downstream mixing portion to initiate a chelation reaction between the metallic radionuclide and the bifunctional chelator. The chelation reaction is completed to form a radiolabeled complex.

  15. Theoretical predictor for candidate structure assignment from IMS data of biomolecule-related conformational space.

    Science.gov (United States)

    Schenk, Emily R; Nau, Frederic; Fernandez-Lima, Francisco

    2015-06-01

    The ability to correlate experimental ion mobility data with candidate structures from theoretical modeling provides a powerful analytical and structural tool for the characterization of biomolecules. In the present paper, a theoretical workflow is described to generate and assign candidate structures for experimental trapped ion mobility and H/D exchange (HDX-TIMS-MS) data following molecular dynamics simulations and statistical filtering. The applicability of the theoretical predictor is illustrated for a peptide and protein example with multiple conformations and kinetic intermediates. The described methodology yields a low computational cost and a simple workflow by incorporating statistical filtering and molecular dynamics simulations. The workflow can be adapted to different IMS scenarios and CCS calculators for a more accurate description of the IMS experimental conditions. For the case of the HDX-TIMS-MS experiments, molecular dynamics in the "TIMS box" accounts for a better sampling of the molecular intermediates and local energy minima.

  16. The interplay of biomolecules and water at the origin of the active behavior of living organisms

    Science.gov (United States)

    Del Giudice, E.; Stefanini, P.; Tedeschi, A.; Vitiello, G.

    2011-12-01

    It is shown that the main component of living matter, namely liquid water, is not an ensemble of independent molecules but an ensemble of phase correlated molecules kept in tune by an electromagnetic (e.m) field trapped in the ensemble. This field and the correlated potential govern the interaction among biomolecules suspended in water and are in turn affected by the chemical interactions of molecules. In particular, the phase of the coherent fields appears to play an important role in this dynamics. Recent experiments reported by the Montagnier group seem to corroborate this theory. Some features of the dynamics of human organisms, as reported by psychotherapy, holistic medicine and Eastern traditions, are analyzed in this frame and could find a rationale in this context.

  17. Near-infrared dyes and upconverting phosphors as biomolecule labels and probes

    Science.gov (United States)

    Patonay, Gabor; Strekowski, Lucjan; Nguyen, Diem-Ngoc; Seok, Kim Jun

    2007-02-01

    Near-Infrared (NIR) absorbing chromophores have been used in analytical and bioanalytical chemistry extensively, including for determination of properties of biomolecules, DNA sequencing, immunoassays, capillary electrophoresis (CE) separations, etc. The major analytical advantages of these dyes are low background interference and high molar absorptivities. NIR dyes have additional advantages due to their sensitivity to microenvironmental changes. Spectral changes induced by the microenvironment are not desirable if the labels are used as a simple reporting group, e.g., during a biorecognition reaction. For these applications upconverting phosphors seem to be a better choice. There are several difficulties in utilizing upconverting phosphors as reporting labels. These are: large physical size, no reactive groups and insolubility in aqueous systems. This presentation will discuss how these difficulties can be overcome for bioanalytical and forensic applications. During these studies we also have investigated how to reduce physical size of the phosphor by simple grinding without losing activity and how to attach reactive moiety to the phosphor to covalently bind to the biomolecule of interest. It has to be emphasized that the described approach is not suitable for medical applications and the results of this research are not applicable in medical applications. For bioanalytical and forensic applications upconverting phosphors used as reporting labels have several advantages. They are excited with lasers that are red shifted respective to phosphorescence, resulting in no light scatter issues during detection. Also some phosphors are excited using eye safe lasers. In addition energy transfer to NIR dyes is possible, allowing detection schemes using donor-acceptor pairs. Data is presented to illustrate the feasibility of this phenomenon. If microenvironmental sensitivity is required, then specially designed NIR dyes can be used as acceptor labels. Several novel dyes

  18. IL 7: Theoretical investigation of the ultrafast dissociation of ionized biomolecules immersed in water

    International Nuclear Information System (INIS)

    Vuilleumier, R.; Herve du Penhoat, M.A.; Politis, M.F.; Gaigeot, M.P.; Lopez-Tarifa, P.; Alcami, M.; Martin, F.; Tavernelli, I.

    2010-01-01

    We apply time-dependent density functional theory and Ehrenfest dynamics to investigate, at a molecular level, direct and indirect effects of ionising radiations in DNA, in the particular case of irradiation by swift heavy ions such as those used in hadron therapy. Molecular double ionisation arising from irradiation by swift heavy ions (about 10% of ionisation events by ions whose velocity is about the third of speed of light), as a primary event, though maybe less probable than other events resulting from the electronic cascading (for instance, electronic excitations, electron attachments), may be systematically more damageable (and more lethal), as supported by studies of damages created by K holes in DNA. In the past recent years, we have developed the modeling at the microscopic level of the early stages of the Coulomb explosion of DNA molecules immersed in liquid water that follows the irradiation by swift heavy ions. To that end, Time-Dependent Density Functional Theory molecular dynamics simulations (TD-DFT MD) have been developed where localised Wannier orbitals are propagated. This latter enables to separate molecular orbitals of each water molecule from the molecular orbitals of the biomolecule. We find that the double ionisation of one molecule of the liquid sample, either one water molecule from the solvent or the biomolecule, may both be responsible for the formation of an atomic oxygen as a direct consequence of the molecule Coulomb explosion. The chemical reactivity of the produced atomic oxygen with other radicals present in the medium will ultimately lead to chemical products that are harmful to DNA. We will review our theoretical methodology and results on the production of atomic oxygen as a result of the double ionisation of water or as a result of the double ionisation of the Uracil RNA base will be presented. (authors)

  19. Analysis of mebendazole binding to its target biomolecule by laser flash photolysis.

    Science.gov (United States)

    Jornet, Dolors; Bosca, Francisco; Andreu, Jose M; Domingo, Luis R; Tormos, Rosa; Miranda, Miguel A

    2016-02-01

    Mebendazole (MBZ) and related anticancer benzimidazoles act binding the β-subunit of Tubulin (TU) before dimerization with α-TU with subsequent blocking microtubule formation. Laser flash photolysis (LFP) is a new tool to investigate drug-albumin interactions and to determine binding parameters such as affinity constant or population of binding sites. The aim of this study was to evaluate the interactions between the nonfluorescent mebendazole (MBZ) and its target biomolecule TU using this technique. Before analyzing the MBZ@TU complex it was needed to determine the photophysical properties of MBZ triplet excited state ((3)MBZ(⁎)) in different media. Hence, (3)MBZ(⁎) showed a transient absorption spectrum with maxima at 520 and 375 nm and a lifetime much longer in acetonitrile (12.5 μs) than in water (260 ns). The binding of MBZ to TU produces a greater increase of the lifetime of (3)MBZ(⁎) (25 μs). This fact and the strong electron acceptor capability observed for (3)MBZ* evidence that MBZ must not be located close to any electron donor amino acid of TU such as its tryptophan or cysteine residues. Adding increasing amounts of MBZ to aqueous TU was determined the MBZ-TU binding constant (2.0 ± 0.5 × 10(5)M(-1) at 298K) which decreased with increasing temperature. The LFP technique has proven to be a powerful tool to analyze the binding of drug-TU systems when the drug has a detectable triplet excited state. Results indicate that LFP could be the technique of choice to study the interactions of non-fluorescent drugs with their target biomolecules. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Chemical and biological effects of β-decay and inner shell ionization in biomolecules

    International Nuclear Information System (INIS)

    Stoecklin, G.

    1979-01-01

    Tritium and iodine-125, and the Auger effect either caused by the EC-decay of 125 I or by the inner shell vacancy created selectively by mono-energetic X-ray are reviewed in this paper. The specifically labelled precursors to bound 3 H large biomolecules were prepared by conventional syntheses, and then incorporated into the DNA of proliferating cells. The effects like DNA strand breaks or mutational changes are likely to be affected by the localization of the carbonium ions in biological molecules. In contrast to lethality, it was demonstrated that 3 H transmutation effect contributed to DNA strand breaks and played a key role in producing genetic effects. The decay of 3 H in uracil-5- 3 H in the DNA of E. coli was about 7 times as mutagenic as that in uracil-6- 3 H, and 500-fold greater in bacteriophage S13. Drastic chemical consequences are associated with the Auger effect occurring as a possible relaxation process whenever inner shell ionization is initiated. When the vacancy is filled by an electron from an outer shell, the bond energy difference between inner shell electron and outer shell electron is released either in the form of an X-ray fluorescence photon or it can be transmitted to another outer electron which is then ejected. The radioactive decay in specifically labelled biomolecules or the inner shell ionization in heavy constituent atoms caused by resonant X-ray are relevant to a) selective microsurgery in biological macromolecules for the correlation of biological and chemical functions, b) radiotoxicity estimation, and c) radiation therapy. (Yamashita, S.)

  1. Distribution of Biomolecules in Porous Nitrocellulose Membrane Pads Using Confocal Laser Scanning Microscopy and High-Speed Cameras

    NARCIS (Netherlands)

    Mujawar, Liyakat Hamid; Maan, Abid Aslam; Khan, Muhammad Kashif Iqbal; Norde, Willem; van Amerongen, Aart

    2013-01-01

    The main focus of our research was to study the distribution of inkjet printed biomolecules in porous nitrocellulose membrane pads of different brands. We produced microarrays of fluorophore-labeled IgG and bovine serum albumin (BSA) on FAST, Unisart, and Oncyte-Avid slides and compared the spot

  2. Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

    International Nuclear Information System (INIS)

    Gunda, Naga Siva Kumar; Singh, Minashree; Norman, Lana; Kaur, Kamaljit; Mitra, Sushanta K.

    2014-01-01

    In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody–antigen–antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

  3. Elemental labelling combined with liquid chromatography inductively coupled plasma mass spectrometry for quantification of biomolecules: A review

    International Nuclear Information System (INIS)

    Kretschy, Daniela; Koellensperger, Gunda; Hann, Stephan

    2012-01-01

    Highlights: ► Survey of bio-analytical approaches utilizing biomolecule labelling. ► Detailed discussion of methodology and chemistry of elemental labelling. ► Biomedical and bio-analytical applications of elemental labelling. ► FI-ICP-MS and LC–ICP-MS for quantification of elemental labelled biomolecules. ► Review of selected applications. - Abstract: This article reviews novel quantification concepts where elemental labelling is combined with flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS) or liquid chromatography inductively coupled plasma mass spectrometry (LC–ICP-MS), and employed for quantification of biomolecules such as proteins, peptides and related molecules in challenging sample matrices. In the first sections an overview on general aspects of biomolecule quantification, as well as of labelling will be presented emphasizing the potential, which lies in such methodological approaches. In this context, ICP-MS as detector provides high sensitivity, selectivity and robustness in biological samples and offers the capability for multiplexing and isotope dilution mass spectrometry (IDMS). Fundamental methodology of elemental labelling will be highlighted and analytical, as well as biomedical applications will be presented. A special focus will lie on established applications underlining benefits and bottlenecks of such approaches for the implementation in real life analysis. Key research made in this field will be summarized and a perspective for future developments including sophisticated and innovative applications will given.

  4. Fragmentation study of isolated and nano-solvated biomolecules induced by collision with multiply charged ions and neutral particles

    International Nuclear Information System (INIS)

    Bernigaud, V.

    2009-01-01

    This thesis concerns a gas phase study of the fragmentation of bio-molecular systems induced by slow collisions with multiply charged ions (in the keV-region), alkali atoms and rare gases. The main objective was to study the physical processes involved in the dissociation of highly electronically excited systems. In order to elucidate the intrinsic properties of certain biomolecules (porphyrins and amino acids) we have performed experiments in the gas phase with isolated systems. The obtained results demonstrate the high stability of porphyrins after electron removal and attachment. Furthermore, a dependence of the fragmentation pattern produced by multiply charged ions on the isomeric structure of the alanine molecule has been shown. In a second part of the thesis, a strong influence of the environment of the biomolecule on the fragmentation channels, their modification and their new opening, has been clearly proven. This phenomenon occurs in the presence of other surrounding biomolecules (clusters of nucleobases) as well as for molecules of a solvent (molecules of water, methanol and acetonitrile) in which the biomolecule is embedded. In order to extend these studies to larger systems, a new experimental set-up, based on an electro-spray ion source combined with a quadrupole mass filter has been developed. Due to the successful tests and proposed improvements of the device future experiments will become available concerning the fragmentation of large charged and solvated bio-molecular systems induced by collision processes. (author) [fr

  5. Effect of channel-width and chirality on graphene field-effect transistor based real-time biomolecule sensing

    Directory of Open Access Journals (Sweden)

    Letian Lyu

    2018-03-01

    Full Text Available Graphene field-effect transistors (GFET hold promise in biomolecule sensing due to the outstanding properties of graphene materials. Charges in biomolecules are transduced into a change in the GFET current, which allows real-time monitoring of the biomolecule concentrations. Here we theoretically evaluate the performance of GFET based real-time biomolecule sensing, aiming to better understand the width-scaling limit in GFET based biosensors. In particular, we study the effect of the channel-width and the chirality on FET sensitivity by taking the percentage change of the FET current per unit charge density as the sensing signal. Firstly, GFETs made of graphene nanoribbons (GNR and graphene sheets (GS show comparable sensing signals to each other when gated at 1011 – 1012 cm-2 carrier densities. Sensing signals in GNRs are enhanced when gated near the sub-band thresholds, and increase their values in wider GNRs due to the change in device conductance and quantum capacitance. Secondly, the GNR chirality is found to fine tune the sensing signals. Armchair GNRs with smaller energy bandgaps appear to have an enhanced sensing signal close to 1011 cm-2 carrier densities. These results may help understand the scaling limit in GFET based biosensors along the width direction, and shed light on forming all-electrical bio-arrays.

  6. Nucleus-staining with biomolecule-mimicking nitrogen-doped carbon dots prepared by a fast neutralization heat strategy.

    Science.gov (United States)

    Kang, Yan-Fei; Fang, Yang-Wu; Li, Yu-Hao; Li, Wen; Yin, Xue-Bo

    2015-12-11

    Biomolecule-mimicking nitrogen-doped carbon dots (N-Cdots) were synthesized from dopamine by a neutralization heat strategy. Fluorescence imaging of various cells validated their nucleus-staining efficiency. The dopamine-mimicking N-Cdots "trick" nuclear membranes to achieve nuclear localization and imaging.

  7. Biomolecule-Assisted Hydrothermal Synthesis and Self-Assembly of Bi2Te3 Nanostring-Cluster Hierarchical Structure

    DEFF Research Database (Denmark)

    Mi, Jianli; Lock, Nina; Sun, Ting

    2010-01-01

    A simple biomolecule-assisted hydrothermal approach has been developed for the fabrication of Bi2Te3 thermoelectric nanomaterials. The product has a nanostring-cluster hierarchical structure which is composed of ordered and aligned platelet-like crystals. The platelets are100 nm in diameter...

  8. Patterning Multi-Nanostructured Poly(l-lactic acid) Fibrous Matrices to Manipulate Biomolecule Distribution and Functions.

    Science.gov (United States)

    Xiao, Wenwu; Li, Qingtao; He, Huimin; Li, Wenxiu; Cao, Xiaodong; Dong, Hua

    2018-03-14

    Precise manipulation of biomolecule distribution and functions via biomolecule-matrix interaction is very important and challenging for tissue engineering and regenerative medicine. As a well-known biomimetic matrix, electrospun fibers often lack the unique spatial complexity compared to their natural counterparts in vivo and thus cannot deliver fully the regulatory cues to biomolecules. In this paper, we report a facile and reliable method to fabricate micro- and nanostructured poly(l-lactic acid) (PLLA) fibrous matrices with spatial complexity by a combination of advanced electrospinning and agarose hydrogel stamp-based micropatterning. Specifically, advanced electrospinning is used to construct multi-nanostructures of fibrous matrices while solvent-loaded agarose hydrogel stamps are used to create microstructures. Compared with other methods, our method shows extreme simplicity and flexibility originated from the mono-/multi-spinneret conversion and limitless micropatterns of agarose hydrogel stamps. Three types of PLLA fibrous matrices including patterned nano-Ag/PLLA hybrid fibers, patterned bicompartment polyethylene terephthalate/PLLA fibers, and patterned hollow PLLA fibers are fabricated and their capability to manipulate biomolecule distribution and functions, that is, bacterial distribution and antibacterial performance, cell patterning and adhesion/spreading behaviors, and protein adsorption and delivery, is demonstrated in detail. The method described in our paper provides a powerful tool to restore spatial complexity in biomimetic matrices and would have promising applications in the field of biomedical engineering.

  9. Combinational Effect of Cell Adhesion Biomolecules and Their Immobilized Polymer Property to Enhance Cell-Selective Adhesion

    Directory of Open Access Journals (Sweden)

    Rio Kurimoto

    2016-01-01

    Full Text Available Although surface immobilization of medical devices with bioactive molecules is one of the most widely used strategies to improve biocompatibility, the physicochemical properties of the biomaterials significantly impact the activity of the immobilized molecules. Herein we investigate the combinational effects of cell-selective biomolecules and the hydrophobicity/hydrophilicity of the polymeric substrate on selective adhesion of endothelial cells (ECs, fibroblasts (FBs, and smooth muscle cells (SMCs. To control the polymeric substrate, biomolecules are immobilized on thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide (poly(NIPAAm-co-CIPAAm-grafted glass surfaces. By switching the molecular conformation of the biomolecule-immobilized polymers, the cell-selective adhesion performances are evaluated. In case of RGDS (Arg-Gly-Asp-Ser peptide-immobilized surfaces, all cell types adhere well regardless of the surface hydrophobicity. On the other hand, a tri-Arg-immobilized surface exhibits FB-selectivity when the surface is hydrophilic. Additionally, a tri-Ile-immobilized surface exhibits EC-selective cell adhesion when the surface is hydrophobic. We believe that the proposed concept, which is used to investigate the biomolecule-immobilized surface combination, is important to produce new biomaterials, which are highly demanded for medical implants and tissue engineering.

  10. Effect of channel-width and chirality on graphene field-effect transistor based real-time biomolecule sensing

    Science.gov (United States)

    Lyu, Letian; Jaswal, Perveshwer; Xu, Guangyu

    2018-03-01

    Graphene field-effect transistors (GFET) hold promise in biomolecule sensing due to the outstanding properties of graphene materials. Charges in biomolecules are transduced into a change in the GFET current, which allows real-time monitoring of the biomolecule concentrations. Here we theoretically evaluate the performance of GFET based real-time biomolecule sensing, aiming to better understand the width-scaling limit in GFET based biosensors. In particular, we study the effect of the channel-width and the chirality on FET sensitivity by taking the percentage change of the FET current per unit charge density as the sensing signal. Firstly, GFETs made of graphene nanoribbons (GNR) and graphene sheets (GS) show comparable sensing signals to each other when gated at 1011 - 1012 cm-2 carrier densities. Sensing signals in GNRs are enhanced when gated near the sub-band thresholds, and increase their values in wider GNRs due to the change in device conductance and quantum capacitance. Secondly, the GNR chirality is found to fine tune the sensing signals. Armchair GNRs with smaller energy bandgaps appear to have an enhanced sensing signal close to 1011 cm-2 carrier densities. These results may help understand the scaling limit in GFET based biosensors along the width direction, and shed light on forming all-electrical bio-arrays.

  11. Accurate and computationally efficient prediction of thermochemical properties of biomolecules using the generalized connectivity-based hierarchy.

    Science.gov (United States)

    Sengupta, Arkajyoti; Ramabhadran, Raghunath O; Raghavachari, Krishnan

    2014-08-14

    In this study we have used the connectivity-based hierarchy (CBH) method to derive accurate heats of formation of a range of biomolecules, 18 amino acids and 10 barbituric acid/uracil derivatives. The hierarchy is based on the connectivity of the different atoms in a large molecule. It results in error-cancellation reaction schemes that are automated, general, and can be readily used for a broad range of organic molecules and biomolecules. Herein, we first locate stable conformational and tautomeric forms of these biomolecules using an accurate level of theory (viz. CCSD(T)/6-311++G(3df,2p)). Subsequently, the heats of formation of the amino acids are evaluated using the CBH-1 and CBH-2 schemes and routinely employed density functionals or wave function-based methods. The calculated heats of formation obtained herein using modest levels of theory and are in very good agreement with those obtained using more expensive W1-F12 and W2-F12 methods on amino acids and G3 results on barbituric acid derivatives. Overall, the present study (a) highlights the small effect of including multiple conformers in determining the heats of formation of biomolecules and (b) in concurrence with previous CBH studies, proves that use of the more effective error-cancelling isoatomic scheme (CBH-2) results in more accurate heats of formation with modestly sized basis sets along with common density functionals or wave function-based methods.

  12. Quantitative Photochemical Immobilization of Biomolecules on Planar and Corrugated Substrates: A Versatile Strategy for Creating Functional Biointerfaces

    Science.gov (United States)

    Martin, Teresa A.; Herman, Christine T.; Limpoco, Francis T.; Michael, Madeline C.; Potts, Gregory K.; Bailey, Ryan C.

    2014-01-01

    Methods for the generation of substrates presenting biomolecules in a spatially controlled manner are enabling tools for applications in biosensor systems, microarray technologies, fundamental biological studies and biointerface science. We have implemented a method to create biomolecular patterns by using light to control the direct covalent immobilization of biomolecules onto benzophenone-modified glass substrates. We have generated substrates presenting up to three different biomolecules patterned in sequence, and demonstrate biomolecular photopatterning on corrugated substrates. The chemistry of the underlying monolayer was optimized to incorporate poly(ethylene glycol) to enable adhesive cell adhesion onto patterned extracellular matrix proteins. Substrates were characterized with contact angle goniometry, AFM, and immunofluorescence microscopy. Importantly, radioimmunoassays were performed to quantify the site density of immobilized biomolecules on photopatterned substrates. Retention of function of photopatterned proteins was demonstrated both by native ligand recognition and cell adhesion to photopatterned substrates, revealing that substrates generated with this method are suitable for probing specific cell receptor-ligand interactions. This molecularly general photochemical patterning method is an enabling tool that will allow the creation of substrates presenting both biochemical and topographical variation, which is an important feature of many native biointerfaces. PMID:21793535

  13. Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

    Energy Technology Data Exchange (ETDEWEB)

    Gunda, Naga Siva Kumar [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada); Singh, Minashree [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Norman, Lana [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada T6G 2V4 (Canada); Kaur, Kamaljit [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Mitra, Sushanta K., E-mail: sushanta.mitra@ualberta.ca [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada)

    2014-06-01

    In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody–antigen–antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

  14. Production, Isolation and Radiolabeling Methods for 211AT- Labeling of Biomolecules

    International Nuclear Information System (INIS)

    Wilbur, D.S.; Hamlin, D.K.; Chyan, M.

    2009-01-01

    Targeted alpha therapy with 211 At-labeled compounds holds great promise for treatment of cancer, particularly compartmentalized cancer (e.g. ovarian cancer), minimal residual cancer after surgery and metastatic disease. Unfortunately, 211 At has limited availability and, due to its unique nature, has the potential to be readily dissociated from the cancer-targeting agents used in vivo. Finding methods to circumvent these two problems has occupied a large amount of our efforts over the past few years. 211 At is produced at the University of Washington on a Scanditronix MC-50 using a 28 MeV alpha beam. Our initial preclinical studies were conducted using a small target assembly with irradiations of a 10 □ A alpha beam, but our desire to ultimately conduct clinical studies led to the design and installation of a new target assembly that had much larger irradiation surface and would withstand beam energies of 50 □A or more. Prior to this upgrade, 211 At was efficiently isolated (60-80%) from the irradiated aluminum-backed bismuth targets by dry distillation at 650 o C. However, the dry distillation method gave low recovery yields (e.g. 10-40%) when the much larger new targets were used. After some attempts to improve the distillation yields, we have more recently conducted a wet chemistry approach to the 211 At isolation. While this method still needs to be optimized, it has provided good recovery (60-90%) of the 211 At. Our radiolabeling methods have undergone a similar transition in the past few years. Until recently our 211 At studies were limited to the use of intact monoclonal antibodies (MAb) labeled using conjugates containing aryl-astatine derivatives due to the deastatination of more rapidly metabolized targeting biomolecules. This limitation made it all but impossible to label important biomolecules such as MAb fragments, engineered proteins, peptides and small molecules. This critical shortcoming of labeling methods for 211 At led to our investigating

  15. Perspectivas sobre el desarrollo económico localizado

    Directory of Open Access Journals (Sweden)

    A. H. J. (Bert Helmsing

    2002-09-01

    Full Text Available La creciente movilidad de la producción y de los factores de producción puede haber generado una reversión de la polarización. Sin embargo, el desarrollo económico se localiza crecientemente en aglomeraciones económicas. La globalización es un fenómeno muy localizado. El propósito de este artículo es revisar tres perspectivas parcialmente sobrepuestas sobre el desarrollo económico local. Estas perspectivas corresponden en gran medida a tres factores que refuerzan la naturaleza localizada del desarrollo económico, es decir externalidades, aprendizaje colectivo y gobernabilidad. Las externalidades se refieren a fenómenos conocidos asociados con aglomeración. Más nuevo es el hecho de que constituyen una fuente de retornos crecientes. Se revisará esta nueva escuela de economía geográfica. Al mismo tiempo surgió una nueva geografía económica en base a agrupamientos y distritos industriales. Las externalidades se extienden y cambian de forma. La dinámica del desarrollo económico local puede ser vista desde la perspectiva de la economía evolucionaria. El aprendizaje en general y el aprendizaje colectivo en particular son conceptos centrales a nivel de las empresas y también a nivel de las instituciones territoriales. El aprendizaje aumenta y renueva las competencias locales para formular e implementar políticas económicas. La complejización de las relaciones entre empresas y entre empresas e instituciones territoriales es una fuente importante de sinergias y economías externas pero requiere nuevas formas de gobernabilidad, tanto a nivel industrial como territorialThe growing mobility of production and production factors could have contributed to a polarization reversal. However, it appears that economic development is increasingly localized in economic agglomerations. Globalization is a localized phenomenon. The purpose of this article is to review three partially overlapping perspectives on local economic development

  16. Discovering the enzyme mimetic activity of metal-organic framework (MOF) for label-free and colorimetric sensing of biomolecules.

    Science.gov (United States)

    Wang, Ying; Zhu, Yingjing; Binyam, Atsebeha; Liu, Misha; Wu, Yinan; Li, Fengting

    2016-12-15

    A label-free sensing strategy based on the enzyme-mimicking activity of MOF was demonstrated for colorimetric detection of biomolecules. Firstly obvious blue color was observed due to the high efficiency of peroxidase-like catalytic activity of Fe-MIL-88A (an ion-based MOF material) toward 3,3',5,5'-tetramethylbenzidine (TMB). Then in the presence of target biomolecule and corresponding aptamer, the mimetic activity of Fe-MIL-88A can be strongly inhibited and used directly to realize the colorimetric detection. On the basis of the interesting findings, we designed a straightforward, label-free and sensitive colorimetric method for biomolecule detection by using the enzyme mimetic property of MOF coupling with molecular recognition element. Compared with the existed publications, our work breaks the routine way by setting up an inorganic-organic MOF-aptamer hybrid platform for colorimetric determination of biomolecules, expanding the targets scope from H2O2 or glucose to biomolecules. As a proof of concept, thrombin and thrombin aptamer was used as a model analyte. The limit of detection of 10nM can be achieved with naked eyes and ultrahigh selectivity of thrombin toward numerous interfering substances with 10-fold concentration was demonstrated significantly. Of note, the method was further applied for the detection of thrombin in human serum samples, showing the results in agreement with those values obtained in an immobilization buffer by the colorimetric method. This inorganic-organic MOF-aptamer sensing strategy may in principle be universally applicable for the detection of a range of environmental or biomedical molecules of interests. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Dynamic membrane interactions of antibacterial and antifungal biomolecules, and amyloid peptides, revealed by solid-state NMR spectroscopy.

    Science.gov (United States)

    Naito, Akira; Matsumori, Nobuaki; Ramamoorthy, Ayyalusamy

    2018-02-01

    A variety of biomolecules acting on the cell membrane folds into a biologically active structure in the membrane environment. It is, therefore, important to determine the structures and dynamics of such biomolecules in a membrane environment. While several biophysical techniques are used to obtain low-resolution information, solid-state NMR spectroscopy is one of the most powerful means for determining the structure and dynamics of membrane bound biomolecules such as antibacterial biomolecules and amyloidogenic proteins; unlike X-ray crystallography and solution NMR spectroscopy, applications of solid-state NMR spectroscopy are not limited by non-crystalline, non-soluble nature or molecular size of membrane-associated biomolecules. This review article focuses on the applications of solid-state NMR techniques to study a few selected antibacterial and amyloid peptides. Solid-state NMR studies revealing the membrane inserted bent α-helical structure associated with the hemolytic activity of bee venom melittin and the chemical shift oscillation analysis used to determine the transmembrane structure (with α-helix and 3 10 -helix in the N- and C-termini, respectively) of antibiotic peptide alamethicin are discussed in detail. Oligomerization of an amyloidogenic islet amyloid polypeptide (IAPP, or also known as amylin) resulting from its aggregation in a membrane environment, molecular interactions of the antifungal natural product amphotericin B with ergosterol in lipid bilayers, and the mechanism of lipid raft formation by sphingomyelin studied using solid state NMR methods are also discussed in this review article. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Mercury and selenium binding biomolecules in terrestrial mammals (Cervus elaphus and Sus scrofa) from a mercury exposed area.

    Science.gov (United States)

    Ropero, M J Patiño; Fariñas, N Rodríguez; Krupp, E; Mateo, R; Nevado, J J Berzas; Martín-Doimeadios, R C Rodríguez

    2016-06-01

    Mercury (Hg) is likely bound to large biomolecules (e.g. proteins) in living organisms, and in order to assess Hg metabolic pathways and possible toxicological effects, it is essential to study these Hg containing biomolecules. However, the exact nature of most metal binding biomolecules is unknown. Such studies are still in their infancy and information on this topic is scarce because the analysis is challenging, mainly due to their lability upon digestion or extraction from the tissue. New analytical methods that allow complex Hg-biomolecules to be analysed intact are needed and only few very recent studies deal with this approach. Therefore, as an initial step towards the characterization of Hg containing biomolecules, an analytical procedure has been optimised using size-exclusion chromatography (SEC) with inductively coupled plasma mass spectrometry (ICP-MS) detection. We applied this technique to elucidate the distribution and elution profile of Hg and Se, and some physiological important elements such as Fe, Ni, Zn and Cu, to assess metal binding profiles in liver and kidney samples of red deer (Cervus elaphus) and wild boar (Sus scrofa) who roam freely within the largest Hg mining district on Earth, Almadén in Spain. Elemental fractionation profiles of the extracts from different tissues were obtained using two different SEC columns (BioSep-SEC-S2000 GL 300-1kDa and Superdex 75 10/300 GL 70-3kDa). Similar profiles of Hg were observed in red deer and wild boar; however, significant differences were evident for liver and kidney. Moreover, the profiles of Se showed a single peak at high-medium molecular weight in all investigated tissues, while co-elution of Hg with Fe, Ni, Zn and Cu was observed. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Diagnostica di processi molecolari in scariche a pressione atmosferica

    OpenAIRE

    Scarduelli, Giorgina

    2009-01-01

    This work reports on the study of the products obtained by the plasma treatment of methane mixtures or benzene mixtures in a coaxial cylindrical dielectric barrier discharge reactor at atmospheric pressure. The plasma products have been analyzed by spectroscopic and mass spectrometric techniques (GC-MS, FT-IR, NMR, MALDI-TOF MS). Moreover, in this work we report the plasma phase characterization in a parallel plate DBD reactor by using OES and LIF tecniques.

  20. Perspectivas psicossociais para o estudo do cotidiano de trabalho

    Directory of Open Access Journals (Sweden)

    Fábio de Oliveira

    2014-04-01

    Full Text Available Este estudo teve por objetivo analisar o debate e o aprofundamento teórico e metodológico desenvolvido nos estudos sobre a vida cotidiana no trabalho. A investigação partiu do diálogo interdisciplinar entre a antropologia do trabalho, a ergologia e a psicologia social do trabalho e sistematizou as contribuições mútuas entre esses campos científicos, suas aproximações e seus afastamentos da tematização e da apropriação da atividade humana no trabalho sob a perspectiva do cotidiano. A análise comparativa destacou eixos que diferenciam as formas de aproximação ao objeto, que se referem às relações estabelecidas entre saberes práticos e técnico-científicos e aos modos de intervenção sobre as situações de trabalho. As abordagens comparativas compartilham o interesse em conhecer o trabalho real, o valor conferido aos conhecimentos dos trabalhadores e a sensibilidade às dimensões micropolíticas do cotidiano. Conclui-se que a localização em cada um desses eixos depende da maior ou menor filiação às tradições da antropologia ou da ergonomia.

  1. La muerte como proceso: una perspectiva antropológica

    Directory of Open Access Journals (Sweden)

    Bárbara Martínez

    2013-09-01

    Full Text Available Este artículo, desde una perspectiva antropológica, combina recientes aproximaciones que cuestionan la homología entre muerte y deceso biológico, con la tradición de estudios que revisan los rituales de muerte en el área geográfica andina. En particular, examina cómo se produce en El Cajón, Catamarca, noroeste argentino, la incorporación de un fallecido al esquema cosmológico, y cómo la muerte, que es un puntapié inicial para ello ocurra, no es meramente un evento biológico sino también un proceso social de gran dinamismo. A partir del trabajo de campo etnográfico, y tomando como herramientas metodológicas entrevistas abiertas de sesiones múltiples y observación participante, presenta una propuesta analítica que procura superar la homología entre muerte y deceso biológico, sugiriendo una noción que incluye la dimensión orgánica, pero también la social: el proceso de la muerte.

  2. Perspectivas da agricultura sustentável no Brasil

    Directory of Open Access Journals (Sweden)

    Rosângela Ap. de Medeiros Hespanhol

    2008-03-01

    -technological development as the only road capable to solve the derived problems of the shortage of foods and the exhaustion of the natural resources; and those that are opposed to this perspective. They propose more maintainable forms, which could be joined under the Alternative Agriculture denomination. It was also tried to discuss the challenges and the perspectives that come in terms of viability terms to discuss and of expansion of the maintainable production systems in environmental and social terms in the agriculture of small scale in Brazil, to example of the organic production.  O processo de incorporação tecnológica ocorrida na agricultura ao longo da história e, mais precisamente, a difusão do pacote da Revolução Verde após a Segunda Guerra Mundial produziu várias implicações sócio-ambientais. Com o agravamento desses problemas em escala mundial e, sobretudo em países como o Brasil, houve a incorporação, ainda limitada, de preocupações ambientais em relação à agricultura. Essa mudança fomentou a discussão e levou à formulação de perspectivas de análise e de intervenção antagônicas e conflitantes entre si, refletindo diferentes interesses e posicionamentos sobre os modelos de desenvolvimento dos países e sobre a própria sustentabilidade. Nesse sentido, procurou-se identificar duas destas perspectivas no Brasil: a que ainda concebe o desenvolvimento científico-tecnológico como a única via capaz de resolver os problemas derivados da escassez de alimentos e do esgotamento dos recursos naturais; e aquelas que se opõem a esta perspectiva e propõem formas mais sustentáveis, que poderiam ser agrupadas sob a denominação de Agricultura Alternativa. Procurou também discutir os desafios e as perspectivas que se apresentam em termos de viabilidade e de expansão dos sistemas de produção sustentáveis em termos ambientais e sociais na agricultura de pequena escala no Brasil, a exemplo da produção orgânica.

  3. PERSPECTIVAS DO SISTEMA DE TRANSPORTE URBANO DE LONDRINA - PARANÁ

    Directory of Open Access Journals (Sweden)

    Mirian Vizintim Fernandes Barros

    2014-03-01

    Full Text Available O artigo propõe indicar os problemas encontrados no atual sistema de transporte urbano na cidade de Londrina - Paraná, marcado pela predominância do uso do transporte individual e do coletivo ineficiente e de alto custo. Para tanto, utilizou-se ferramenta dos Sistemas de Informação Geográfica (SIG para, por meio da manipulação dos dados, confirmar a ideia da intrínseca e necessária integração entre o planejamento do uso e ocupação do solo (sobretudo da densidade demográfica e do transporte urbano, essencial para delinear diretrizes de melhorias no sistema coletivo de deslocamento. Identificado os principais problemas, propostas são traçadas e, algumas perspectivas são discutidas objetivando, além da melhoria no sistema de transporte urbano de Londrina, a reflexão sobre o ideal de uma cidade inclusiva, do ponto de vista dos transportes.

  4. perspectiva da antropologia pós-moderna

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    Mara Ambrosina de Oliveira Vargas

    2007-01-01

    Full Text Available Basado en la perspectiva teórica de la Antropología Posmoderna, el presente artículo discute una de las maneras posibles de narrar la historia del yo en el mundo contemporáneo, demarcando el impacto de la saturación social en la forma de cómo se conceptúa el(los yo(s, con inferencia en los “diferentes procesos” del vivir humano. De este modo, el análisis busca considerar la noción de que la formación de los más diferentes grupos está cruzada por un ideal regulador del yo, en sus formas de experiencia de vida. Cuestiona también la búsqueda por la verdad del sujeto en visiones totales, comprendiendo que somos y vivimos dentro de narrativas construidas a muchas manos, y, que tal supuesto, abre muchas posibilidades teóricas en el abordaje de antiguos y nuevos temas que interesan a los profesionales de la salud, para los cuales se consolidan nuevas relaciones entre las ciencias de la salud, las ciencias humanas y las ciencias sociales.

  5. Perspectivas da profissão contábil

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    Nivaldo João dos Santos

    2002-11-01

    Full Text Available As perspectivas profissionais na área contábil são muito promissoras. É natural que estudantes demonstrem apreensão acerca da carreira que advirá após a conclusão do curso de graduação em ciências contábeis, pois trata-se de investimento elevado - envolvendo muito tempo e dinheiro. De tempos em tempos leigos anunciam a extinção da atividade contábil, sem nenhum fundamento. A atividade contábil é das que mais evolui e sua essencialidade se revela com mais força quando são descobertas fraudes contábeis e novos artifícios ilícitos visando iludir acionistas e investidores. Apesar do grande contingente de pessoas que conclui cursos na área, muitas novas empresas são constituídas, outras formas de sociedades são desenvolvidas, todas necessitando de serviços de profissionais contabilistas. O grande desafio da classe contábil consiste no contínuo aperfeiçoamento e na consolidação do elevado nível intelectual que o mercado globalizado requisita.

  6. Una Perspectiva desde la psicología

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    Rosa María Raich

    2004-01-01

    Full Text Available En este trabajo se describen algunas definiciones y el concepto de imagen corporal y laspreocupaciones exageradas acerca de sí mismo que pueden llegar a constituir el trastorno dismórfico.Se analizan las características clínicas de este trastorno, así como las quejas que sobre la aparienciason más frecuentes. Se estudia la relación de este trastorno con nivel de autoestima, identidad degénero, ansiedad interpersonal y depresión. Se hace un repaso a diferentes técnicas de evaluación yde tratamiento de este trastorno. Finalmente se describen algunas perspectivas de futuro en relación al estudio de este trastorno. Tras analizar los resultados observados en diferentes estudios se llega ala conclusión de que la presión por la estética es muy superior en las mujeres que en los hombres yque presentan mayor insatisfacción al valorar su apariencia en todas las áreas.

  7. O CUIDADO COTIDIANO DA CRIANÇA NA PERSPECTIVA WINNICOTTIANA

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    Débora Falleiros de Mello

    2012-01-01

    Full Text Available El objetivo fue describir como la atención cotidiana a niños menores de dos años de edad es vista por madres, para proporcionar subsidios a las prácticas y conocimientos en salud del niño, en el contexto de la atención primaria de salud. Estudio descriptivo-exploratorio, con análisis cualitativo, en la perspectiva del abordaje de Winnicott, a partir de entrevistas grabadas con 17 madres. Los resultados están organizados en los temas: responsabilidad materna y atención al niño; atención al niño y su ambiente; confort e interacción familiar. Fue posible tomar significados de las experiencias cotidianas, discutidas a la luz de los conceptos Winnicottianos: madre suficientemente buena, holding, entorno facilitador y espacio transicional. Conocer la rutina cuanto al cuidado materno es importante para profesionales de salud en la búsqueda de soporte a las madres y familias, disminuir ansiedad, evaluar problemas en el entorno de atención al niño, con disponibilidad asistencia cualificada y humanizada.

  8. La Ha de la infancia en Italia. Problemas y perspectiva

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    Enzo CATARSI

    2010-03-01

    Full Text Available RESUMEN: La historiografía italiana de la infancia, como la de otros muchos países europeos, está hoy embarcada en una tarea de desarrollo y profundización que permitirá recuperar los retrasos que la han caracterizado. En efecto, también en Italia la historia de la infancia y su individuación como «objeto» historiografía constituyen una adquisición reciente, lograda con la ayuda de diversas influencias. La primera, estrechamente vinculada a la historia de las mentalidades, representada por la obra de Ph. Aries, «El niño y la vida familiar en el Antiguo Régimen», traducido al italiano en 1968. La segunda es la historia social, orientada al estudio de los diversos aspectos de la vida de una sociedad, y más atenta a sus acontecimientos. La tercera la representa el estructuralismo, especialmente el francés, y en concreto M. Foucault. La particular influencia que, también en el contexto italiano, han alcanzado los trabajos de Ph. Aries y L. DeMause, muy importantes por haber abierto una línea de investigación, aunque con las obligadas diferencias, ha conducido a privilegiar una perspectiva exclusiva de historia de las mentalidades que se muestra muy ambigua y claramente interpretativa en exceso.

  9. Intracellular delivery of nanomaterials for sub-cellular imaging and tracking of biomolecules

    Science.gov (United States)

    Medepalli, Krishna Kiran

    Nanomaterials have many intriguing applications in biology and medicine. Unique properties such as enhanced electrical properties, increased chemical reactivity and resistance to degradation, novel optical properties and comparable size to that of biological systems have led to their use in various biomedical applications. The most important applications of nanomaterials for medicine are in drug delivery and imaging. This research focuses on utilizing the biocompatibility of single walled Carbon nanotubes (SWCNTs) and optical properties colloidal quantum dots (QDs) for cellular drug delivery and imaging of biomolecules. The first part of this research deals with single walled carbon nanotubes which are excellent candidates for targeted drug delivery applications due their unique structural and functional properties. However, prior to their use in therapeutics, their biocompatibility needs to be thoroughly investigated. The objectives of this research were to establish the biocompatibility of SWCNTs and demonstrate their use as drug delivery carriers into cells. Blood, a living tissue, is chosen as the biological system as it contains various cells which can potentially interact with SWCNTs during the delivery mechanism. The interactions of these cells in the blood (specifically white blood cells or leukocytes) with the SWCNTs provide vital information regarding the immune response of the host to the nanotubes. This research investigates the immune response of white blood cells due to SWCNTs via (a) direct interaction---presence of nanotubes in the blood and, (b) indirect interaction---presentation of nanotubes by antigen-presenting-cells to white blood cells. These two interactions recreate the innate and adaptive immune responses occurring in the body to any foreign substance. SWCNTs are functionalized with single stranded DNA (ss-DNA), which serves as a dispersant of nanotubes as well as a backbone for further attachment of other biomolecules of interest

  10. Distribution of biomolecules in porous nitrocellulose membrane pads using confocal laser scanning microscopy and high-speed cameras.

    Science.gov (United States)

    Mujawar, Liyakat Hamid; Maan, Abid Aslam; Khan, Muhammad Kashif Iqbal; Norde, Willem; van Amerongen, Aart

    2013-04-02

    The main focus of our research was to study the distribution of inkjet printed biomolecules in porous nitrocellulose membrane pads of different brands. We produced microarrays of fluorophore-labeled IgG and bovine serum albumin (BSA) on FAST, Unisart, and Oncyte-Avid slides and compared the spot morphology of the inkjet printed biomolecules. The distribution of these biomolecules within the spot embedded in the nitrocellulose membrane was analyzed by confocal laser scanning microscopy in the "Z" stack mode. By applying a "concentric ring" format, the distribution profile of the fluorescence intensity in each horizontal slice was measured and represented in a graphical color-coded way. Furthermore, a one-step diagnostic antibody assay was performed with a primary antibody, double-labeled amplicons, and fluorophore-labeled streptavidin in order to study the functionality and distribution of the immune complex in the nitrocellulose membrane slides. Under the conditions applied, the spot morphology and distribution of the primary labeled biomolecules was nonhomogenous and doughnut-like on the FAST and Unisart nitrocellulose slides, whereas a better spot morphology with more homogeneously distributed biomolecules was observed on the Oncyte-Avid slide. Similar morphologies and distribution patterns were observed when the diagnostic one-step nucleic acid microarray immunoassay was performed on these nitrocellulose slides. We also investigated possible reasons for the differences in the observed spot morphology by monitoring the dynamic behavior of a liquid droplet on and in these nitrocellulose slides. Using high speed cameras, we analyzed the wettability and fluid flow dynamics of a droplet on the various nitrocellulose substrates. The spreading of the liquid droplet was comparable for the FAST and Unisart slides but different, i.e., slower, for the Oncyte-Avid slide. The results of the spreading of the droplet and the penetration behavior of the liquid in the

  11. Theoretical and experimental proof of the accumulating transfer of tritium from water into DNA and other biomolecules in vitro and in vivo

    International Nuclear Information System (INIS)

    Baumgaertner, F.

    2000-01-01

    Heisenberg's Uncertainity Relation leads to the conclusion, tritium accumulates in the exchangeable hydrogen positions of biomolecules if it is administered in the state of water. Appropriate tests of fishsperm DNA and the biomolecules of piglet's liver resulted in a fractionation factor of about 2 favouring such organically bound tritium. Furthermore, a fractionation factor of 1.4 is found in the hydration sheet of the biomolecules. The logistic growth analysis of maize and barley confirms the accumulation of tritium from water in the tissue solids of the plants. (orig.) [de

  12. Development of polymer-biomolecule core-shell particles for biomedical applications

    Science.gov (United States)

    Suthiwangcharoen, Nisaraporn

    Developing efficient strategies to introduce biomolecules around polymeric nanoparticles (NPs) is critical for targeted delivery of therapeutic or diagnostic agents. Although polymeric NPs have been well established, problems such as toxicity, stability, and immunoresistance remain potential concerns. The first part of this dissertation focuses on the development of nanosized targeted drug delivery vehicle in cancer chemotherapy. The vehicle was created by the self-assembly of folate-grafted filamentous bacteriophage M13 with poly(caprolactone- b-2-vinylpyridine) while doxorubicin, the antitumor drugs, was successfully loaded in the interior of the vehicles. These particles offer unique properties of being able to selectively target tumor cells while appearing to be safe and non-toxic to normal cells. Although they have shown great prospects in many biomedical applications, less is known about the interactions between biomolecules and polymers. The next part of the dissertation focuses on the self-assembly of proteins and polymers to create polymer-protein core-shell nanoparticles (PPCS-NPs). Several proteins with different isoelectric points and molecular weights were employed to demonstrate a versatility of our assembly method while a series of esterified derivatives of poly(2-hydroxyethyl methacrylate) (pHEMA) were synthesized to evaluate the interaction between proteins and polymers. Our data indicated that the polymers containing pyridine residues can successfully assemble with proteins, and the mechanism is mainly governed by hydrogen bonding and the hydrophobic/hydrophilic interactions. This in turn helps retaining proteins' folding conformation and functionality, which are also demonstrated in the in vitro/in vivo cellular uptake of the PPCS-NPs in endothelial cells. The last part of the dissertation focuses on the self-assembly of the bienzyme-polymer NPs. Glucose oxidase (GOX) together with horseradish peroxidase (HRP) were employed to construct bienzyme

  13. Synthesis and structures of a pincer-type rhodium(iii) complex: reactivity toward biomolecules.

    Science.gov (United States)

    Milutinović, Milan M; Bogojeski, Jovana V; Klisurić, Olivera; Scheurer, Andreas; Elmroth, Sofi K C; Bugarčić, Živadin D

    2016-10-04

    A novel rhodium(iii) complex [Rh III (H 2 L tBu )Cl 3 ] (1) (H 2 L tBu = 2,6-bis(5-tert-butyl-1H-pyrazol-3-yl)pyridine) containing a pincer type, tridentate nitrogen-donor chelate system was synthesized. Single crystal X-ray structure analysis revealed that 1 crystallizes in the orthorhombic space group Pbcn with a = 20.7982(6), b = 10.8952(4), c = 10.9832(4) Å, V = 2488.80(15) Å 3 , and eight molecules in the unit cell. The rhodium center in the complex [Rh III (H 2 L tBu )Cl 3 ] (1) is coordinated in a slightly distorted octahedral geometry by the tridentate N,N,N-donor and three chloro ligands, adopting a mer arrangement with an essentially planar ligand skeleton. Due to the tridentate coordination of the N,N,N-donor, the central nitrogen atom N1 is located closer to the Rh III center. The reactivity of the synthesized complex toward small biomolecules (l-methionine (l-Met), guanosine-5'-monophosphate (5'-GMP), l-histidine (l-His) and glutathione (GSH)) and to a series of duplex DNAs and RNA was investigated. The order of reactivity of the studied small biomolecules is: 5'-GMP > GSH > l-Met > l-His. Duplex RNA reacts faster with the [Rh III (H 2 L tBu )Cl 3 ] complex than duplex DNA, while shorter duplex DNA (15mer GG) reacts faster compared with 22mer GG duplex DNA. In addition, a higher reactivity is achieved with a DNA duplex with a centrally located GG-sequence than with a 22GTG duplex DNA, in which the GG-sequence is separated by a T base. Furthermore, the interaction of this metal complex 1 with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) was examined by absorption (UV-Vis) and emission spectral studies (EthBr displacement studies). Overall, the studied complex exhibited good DNA and BSA interaction ability.

  14. Burnout en profesores: Una perspectiva social del intercambio

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    WILMAR B. SCHAUFELI

    2005-01-01

    Full Text Available Se propone una perspectiva teórica sobre burnout en profesores, basada en principios de intercambio social. Se argumenta que el burnout se produce por una falta de reciprocidad; por un desajuste entre inversiones y resultados. Los profesores quemados se caracterizan por haber dado demasiado durante demasiado tiempo y por recibir demasiado poco a cambio. Según la teoría del intercambio social, la falta de reciprocidad podría desarrollarse a tres niveles: interpersonal (relación con estudiantes, a nivel de equipo (relaciones con compañeros, y a nivel organizacional (relación con la escuela. Estudios empíricos en profesores mostraron que el ajuste entre 'dar y recibir' se rompe, sobretodo en los niveles interpersonal y organizacional. Además, la falta de reciprocidad se asocia con distrés y conductas de abandono. Se observa un efecto genérico: cuando el equilibrio 'dar y recibir' se rompe se produce agotamiento emocional (síntoma corazón del burnout. Además, se observan efectos de las conductas de abandono específico para cada nivel de intercambio social: la falta de reciprocidad con los estudiantes provoca despersonalización (segunda dimensión del burnout; la falta de reciprocidad con los colegas acaba en conductas de abandono de los colegas; y la falta de reciprocidad con la escuela en abandono psicológico (reducido compromiso organizacional y conductual (absentismo por enfermedad de la escuela.

  15. Las acciones punitivas físicas: una perspectiva intercultural

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    María del Mar BADIA MARTÍN

    2009-11-01

    Full Text Available RESUMEN: En este artículo se enmarca el término de castigo corporal diferenciándolo del de abuso físico, a la vez que se realiza un análisis sobre la perspectiva de diferentes países con relación a la aplicación de dicha forma de castigo. La investigación y la teoría analizada, muestran cómo ciertas sociedades todavía reclaman el uso del castigo corporal como una forma más para frenar los comportamientos molestos. Esto nos puede llevar a pensar que no se debe abandonar la tesis sobre el hecho de que esta estrategia es rechazada en la actualidad por todos los sectores de la sociedad, sino que debemos ser sensibles a la idea de que ciertos profesionales y familias lo consideran un instrumento más para la corrección de conductas consideradas como no correctas.ABSTRACT: In this article the term corporal punishment is differentiated from that of physical abuse, and at the same time an analysis is made of the perspective of different countries in relation to the application of this type of punishment. The research and theory analysed show how certain societies still call for the use of corporal punishment as one more way to stop troublesome behaviour. This can lead us to think that the thesis that this strategy is currently rejected by all sectors of society should not be abandoned, but we should be aware that certain professionals and families still consider it one more instrument for correcting behaviour considered as incorrect.

  16. COMERCIO ELECTRÓNICO EN AMÉRICA LATINA. PERSPECTIVAS

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    Félix Fernández Peña

    2003-04-01

    Full Text Available

    Internet constituye una plataforma adecuada para la comunicación de información con alcance global. Las condiciones de la economía actual exigen la internacionalización de la economía de un país, a través, fundamentalmente, de las exportaciones / importaciones de sus empresas. Por su parte, el uso de la red de redes en el desarrollo empresarial ha estado caracterizado por el éxito rotundo de ideas creadoras y también por la bancarrota, de la noche a la mañana, de negocios aparentemente muy prósperos. Si bien el movimiento financiero a través de la red no es para nada despreciable, su dinámica es actualmente muy inestable. Las perspectivas del comercio electrónico para América Latina se ven muchas veces disipadas por la falta de infraestructura tecnológica, pero fundamentalmente por las dificultades para lograr la competitividad frente a las grandes empresas ya establecidas. Las posibilidades reales del fortalecimiento empresarial electrónico en Latinoamérica, para soportar los embates empresariales de una economía globalizada, radican en la gestión ágil y efectiva de las empresas, sus recursos, y su mercado, en una palabra, que logren adaptarse a la era de la información. Para lograrlo, al menos en una primera etapa será decisiva la unión de esfuerzos y recursos y el apoyo gubernamental.

  17. La confianza interpersonal brasileña en perspectiva comparada

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    Timothy Joseph POWER

    2009-11-01

    Full Text Available RESUMEN: Uno de los aspectos menos estudiados de la cultura política del Brasil es su tasa extraordinariamente baja de confianza interpersonal. Después de revisar la literatura sobre confianza interpersonal, el presente artículo examina el nivel brasileño de confianza social en perspectiva regional y global. Analiza datos de sondeos recientes y demuestra que el mejor predictor de confianza es la educación, una área en que Brasil presenta un desarrollo inferior al de sus vecinos. El artículo también sugiere una agenda de investigación futura para estudiar este aspecto singular de la cultura política brasileña, dentro de la cual las variables de desigualdad social y de exposición a la televisión tendrían papeles importantes. Tal agenda de investigación es de gran consecuencia dado el papel importante de la confianza interpersonal, tanto para el desarrollo económico como para la consolidación democrática.ABSTRACT: One of the most understudied aspects of Brazilian political culture is the country’s extraordinarily low rates of interpersonal trust. After reviewing the literature on interpersonal trust, this paper provides regional and global perspective on Brazil’s level of social trust. It examines data from recent public opinion surveys in Brazil and demonstrates that the strongest predictor of trust is education, an area in which Brazil lags behind its neighbors. The paper also suggests a future research agenda for investigating this unique aspect of Brazilian political culture, in which the variables of inequality and television exposure would play important roles. Such a research agenda is critical given the important role played by trust in both economic development and democratic consolidation.

  18. Historiografía comparada: problemas y perspectivas

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    Chris Lorenz

    2005-12-01

    Full Text Available In this text contributions related are abridged - direct or indirectly - with the historiography of world war two. The comparative historiography is placed as a gender related to a typology that classified historiography theories over an extended sequence from the general and philosophical to the particular and empirical. Resides, it also places the recent debates on the “fragmentation " of the historiography in a comparative perspective. Due that historiography is the history of the written history -and therefore a reconstruction of reconstructions- we find the problem of comparison in historiography twice. The historiographer is not alone confronting with relative comparative judgments of the historic reconstructions themselves but also related to the historiography reconstructions of those historic reconstructions.//En este texto se compendian contribuciones relacionadas - directa o indirectamente - con la historiografía de la segunda guerra mundial. Se ubica a la historiografía comparada como un género en relación a una tipología que clasifica teorías de historiografía sobre una secuencia extendida de lo general y filosófico a lo particular y empírico. Además, coloca los recientes debates sobre la "fragmentación" de la historiografía en una perspectiva comparada. Debido a que la historiografía es la historia de la historia escrita - y por lo tanto una reconstrucción de reconstrucciones - encontramos el problema de la comparación en historiografía dos veces. El historiógrafo no sólo está confrontado con los juicios comparados relativos a las reconstrucciones históricas mismas, sino también relativas a las reconstrucciones historiográficas de aquellas reconstrucciones históricas.

  19. Perspectivas e principais alterações no DSM-5

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    Janaína Bandeira

    2017-04-01

    Full Text Available Introdução: com o avanço das pesquisas em neurobiologia e a necessidade de optimização dos critérios diagnósticos, a 5ª edição do Manual Diagnóstico e Estatístico de Transtornos Mentais (DSM-5 realizou importantes mudanças no modo de classificar, catalogar e diagnosticar as doenças mentais. Material e métodos: empreendemos pesquisa de artigos na Pubmed com análises sob diferentes perspectivas com o propósito de obter uma ampla visão das limitações e conquistas com sua publicação. Desenvolvimento: a nova edição do manual efetuou inúmeras alterações em relação à anterior, como a mudança do sistema de classificação multiaxial para dimensional, a fim de melhor abordar os sintomas como um continuum de intensidade, e a elaboração de critérios com maior especificidade para reduzir os diagnósticos “sem outra especificação”. Por fim, citamos o projeto Research Domain Criteria Project (RDoC, ressaltando o contexto e os motivos de sua criação em torno do DSM-5. Conclusão: a atualização conseguiu apenas parcialmente seu objetivo de adotar amplamente o sistema dimensional e não obteve sucesso em incluir critérios genéticos ou neurobiológicos. Contudo, sua possibilidade de contínua revisão possibilita que seja renovada de acordo com as descobertas relevantes.

  20. Desengajamento moral na perspectiva da teoria social cognitiva

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    Roberta Gurgel Azzi

    Full Text Available O ensaio aborda o desengajamento moral descrito pela perspectiva da teoria social cognitiva de Albert Bandura. Toma-se como interlocução central os artigos do autor sobre o tema, sistematizam-se suas ideias e apresentam-se estudos da literatura sobre desengajamento moral. O texto está estruturado em cinco partes, iniciando por uma breve contextualização do tópico no conjunto da produção de Bandura, seguida de exposição do desengajamento moral e da teoria social cognitiva. Posteriormente, apresenta os oito mecanismos de desengajamento moral desenvolvidos por Bandura: justificativa moral, comparação vantajosa, linguagem eufemística, minimização, ignorância ou distorção das consequências, desumanização, atribuição de culpa, deslocamento de responsabilidade e difusão de responsabilidade. Após a apresentação dos mecanismos, introduzem-se os dez trabalhos mais recentes do autor sobre o assunto, textos publicados entre 2000 e 2009, e que foram apresentados sob as seguintes categorias temáticas: questões teóricoempíricas, execução penal, terrorismo, ecologia e mundo coorporativo. Ao final, problematiza desafios, postos a partir da discussão desenvolvida no ensaio, que possam servir para a construção de uma sociedade mais humanizada.

  1. Produtivismo acadêmico baseado em uma perspectiva habermasiana

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    Fábio Vizeu

    Full Text Available Resumo Este artigo argumenta que a questão da ética na prática acadêmica deve ser tratada com o mesmo cuidado adotado em outras práticas profissionais. Na verdade, uma dificuldade no debate sobre ética na prática acadêmica é desconsiderar que esta também consiste em uma prática social condicionada pelos mesmos problemas que a sociedade contemporânea enfrenta, especialmente em sua dimensão econômica. Nesse sentido, discute-se o utilitarismo na prática acadêmica com base no referencial da ética discursiva de Jürgen Habermas, explorando algumas inquietações sobre o produtivismo acadêmico brasileiro. Metodologicamente, usa-se o ensaio teórico como procedimento argumentativo, visando à construção de um texto menos formal e mais provocativo, instigando a reflexão e o debate, no meio, das questões pontuadas. Especificamente, observamos o problema da valorização quantitativa da produção sem a consideração da qualidade do trabalho acadêmico associado à tentativa de mensuração da atividade acadêmica, além da falta da devida reflexão sobre os valores ético-morais que circunscrevem a atividade científico-educacional no Brasil. Por último, para ilustrar a perspectiva apresentada, recorremos a situações hipotéticas da prática acadêmica e fazemos inferências sobre quatro correlações entre a orientação pragmática e questões éticas, considerando o constructo habermasiano da ação estratégica.

  2. Computational solvation analysis of biomolecules in aqueous ionic liquid mixtures : From large flexible proteins to small rigid drugs.

    Science.gov (United States)

    Zeindlhofer, Veronika; Schröder, Christian

    2018-06-01

    Based on their tunable properties, ionic liquids attracted significant interest to replace conventional, organic solvents in biomolecular applications. Following a Gartner cycle, the expectations on this new class of solvents dropped after the initial hype due to the high viscosity, hydrolysis, and toxicity problems as well as their high cost. Since not all possible combinations of cations and anions can be tested experimentally, fundamental knowledge on the interaction of the ionic liquid ions with water and with biomolecules is mandatory to optimize the solvation behavior, the biodegradability, and the costs of the ionic liquid. Here, we report on current computational approaches to characterize the impact of the ionic liquid ions on the structure and dynamics of the biomolecule and its solvation layer to explore the full potential of ionic liquids.

  3. Development of a combined surface plasmon resonance/surface acoustic wave device for the characterization of biomolecules

    International Nuclear Information System (INIS)

    Bender, Florian; Tsortos, Achilleas; Papadakis, George; Gizeli, Electra; Roach, Paul; Newton, Michael I; McHale, Glen

    2009-01-01

    It is known that acoustic sensor devices, if operated in liquid phase, are sensitive not just to the mass of the analyte but also to various other parameters, such as size, shape, charge and elastic constants of the analyte as well as bound and viscously entrained water. This can be used to extract valuable information about a biomolecule, particularly if the acoustic device is combined with another sensor element which is sensitive to the mass or amount of analyte only. The latter is true in good approximation for various optical sensor techniques. This work reports on the development of a combined surface plasmon resonance/surface acoustic wave sensor system which is designed for the investigation of biomolecules such as proteins or DNA. Results for the deposition of neutravidin and DNA are reported

  4. Modification by cystamine of radiation-induced free radical damages to biomolecules in tissues of mouse organs

    International Nuclear Information System (INIS)

    Svistunenko, D.A.; Gudtsova, K.V.

    1989-01-01

    The method of low-temperature ESR-spectroscopy was used to study a modifying effect of cystamine on the yield of radiation-induced free radicals in different biomolecules of liver and spleen tissues of mice. Intraperitoneal administration of cystamine (150 mg/kg) 15 min before isolation and freezing of the tissues was shown to reduce by 11 per cent the yield of radicals of H-adducts of thymine DNA bases, to decrease by 23 per cent the yield of radicals of triacyglycerol and phospholipid radiolysis, and to increase by 24 per cent the yield of radicals of lipid fatty acid residues in splenic tissues. According to the criterion used, cystamine has no modyfying action on the yield of free-radical damages to liver biomolecules

  5. Effect of pore size on performance of monolithic tube chromatography of large biomolecules.

    Science.gov (United States)

    Podgornik, Ales; Hamachi, Masataka; Isakari, Yu; Yoshimoto, Noriko; Yamamoto, Shuichi

    2017-11-01

    Effect of pore size on the performance of ion-exchange monolith tube chromatography of large biomolecules was investigated. Radial flow 1 mL polymer based monolith tubes of different pore sizes (1.5, 2, and 6 μm) were tested with model samples such as 20 mer poly T-DNA, basic proteins, and acidic proteins (molecular weight 14 000-670 000). Pressure drop, pH transient, the number of binding site, dynamic binding capacity, and peak width were examined. Pressure drop-flow rate curves and dynamic binding capacity values were well correlated with the nominal pore size. While duration of the pH transient curves depends on the pore size, it was found that pH duration normalized on estimated surface area was constant, indicating that the ligand density is the same. This was also confirmed by the constant number of binding site values being independent of pore size. The peak width values were similar to those for axial flow monolith chromatography. These results showed that it is easy to scale up axial flow monolith chromatography to radial flow monolith tube chromatography by choosing the right pore size in terms of the pressure drop and capacity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. A Practical Quantum Mechanics Molecular Mechanics Method for the Dynamical Study of Reactions in Biomolecules.

    Science.gov (United States)

    Mendieta-Moreno, Jesús I; Marcos-Alcalde, Iñigo; Trabada, Daniel G; Gómez-Puertas, Paulino; Ortega, José; Mendieta, Jesús

    2015-01-01

    Quantum mechanics/molecular mechanics (QM/MM) methods are excellent tools for the modeling of biomolecular reactions. Recently, we have implemented a new QM/MM method (Fireball/Amber), which combines an efficient density functional theory method (Fireball) and a well-recognized molecular dynamics package (Amber), offering an excellent balance between accuracy and sampling capabilities. Here, we present a detailed explanation of the Fireball method and Fireball/Amber implementation. We also discuss how this tool can be used to analyze reactions in biomolecules using steered molecular dynamics simulations. The potential of this approach is shown by the analysis of a reaction catalyzed by the enzyme triose-phosphate isomerase (TIM). The conformational space and energetic landscape for this reaction are analyzed without a priori assumptions about the protonation states of the different residues during the reaction. The results offer a detailed description of the reaction and reveal some new features of the catalytic mechanism. In particular, we find a new reaction mechanism that is characterized by the intramolecular proton transfer from O1 to O2 and the simultaneous proton transfer from Glu 165 to C2. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Zinc Oxide-Based Self-Powered Potentiometric Chemical Sensors for Biomolecules and Metal Ions.

    Science.gov (United States)

    Israr-Qadir, Muhammad; Jamil-Rana, Sadaf; Nur, Omer; Willander, Magnus

    2017-07-19

    Advances in the miniaturization and portability of the chemical sensing devices have always been hindered by the external power supply problem, which has focused new interest in the fabrication of self-powered sensing devices for disease diagnosis and the monitoring of analytes. This review describes the fabrication of ZnO nanomaterial-based sensors synthesized on different conducting substrates for extracellular detection, and the use of a sharp borosilicate glass capillary (diameter, d = 700 nm) to grow ZnO nanostructures for intracellular detection purposes in individual human and frog cells. The electrocatalytic activity and fast electron transfer properties of the ZnO materials provide the necessary energy to operate as well as a quick sensing device output response, where the role of the nanomorphology utilized for the fabrication of the sensor is crucial for the production of the operational energy. Simplicity, design, cost, sensitivity, selectivity and a quick and stable response are the most important features of a reliable sensor for routine applications. The review details the extra- and intra-cellular applications of the biosensors for the detection and monitoring of different metallic ions present in biological matrices, along with the biomolecules glucose and cholesterol.

  8. Optically directed molecular transport and 3D isoelectric positioning of amphoteric biomolecules

    International Nuclear Information System (INIS)

    Hafeman, Dean G.; Harkins, James B.; Witkowski, Charles E. II; Lewis, Nathan S.; Brown, Gilbert M.; Warmack, Robert J. Bruce; Thundat, Thomas George

    2006-01-01

    We demonstrate the formation of charged molecular packets and their transport within optically created electrical force-field traps in a pH-buffered electrolyte. We call this process photoelectrophoretic localization and transport (PELT). The electrolyte is in contact with a photoconductive semiconductor electrode and a counterelectrode that are connected through an external circuit. A light beam directed to coordinates on the photoconductive electrode surface produces a photocurrent within the circuit and electrolyte. Within the electrolyte, the photocurrent creates localized force-field traps centered at the illuminated coordinates. Charged molecules, including polypeptides and proteins, electrophoretically accumulate into the traps and subsequently can be transported in the electrolyte by moving the traps over the photoconductive electrode in response to movement of the light beam. The molecules in a single trap can be divided into aliquots, and the aliquots can be directed along multiple routes simultaneously by using multiple light beams. This photoelectrophoretic transport of charged molecules by PELT resembles the electrostatic transport of electrons within force-field wells of solid-state charge-coupled devices. The molecules, however, travel in a liquid electrolyte rather than a solid. Furthermore, we have used PELT to position amphoteric biomolecules in three dimensions. A 3D pH gradient was created in an electrolyte medium by controlling the illumination position on a photoconductive anode where protons were generated electrolytically. Photoelectrophoretic transport of amphoteric molecules through the pH gradient resulted in accumulation of the molecules at their apparent 3D isoelectric coordinates in the medium.

  9. Interaction of electrons with biomolecules and development of a helium cluster source

    International Nuclear Information System (INIS)

    Denifl, S.

    2004-07-01

    In the main part of the present work electron interaction (attachment/ionization) with molecules of biological relevance has been studied in the electron energy range from about 0 to 70 eV. For these measurements a crossed neutral / high resolution electron beams apparatus in conjunction with a quadrupole mass spectrometer has been used. The present work should evaluate the description of the damage induced by high energy radiation since low secondary electrons with energies below 20 eV are created in a large amount in the interaction of the primary radiation with cell compounds. Thus dissociative electron attachment (DEA) and electron impact ionization near the threshold of biomulecules has been studied below 20 eV under isolated conditions. DEA to the DNA/RNA molecules thymine, cytosine and uracil has been carried out. As for most of the recently studied simple biomolecules (like isolated DNA bases, amino acids and sugars) no parent ion has been observed. It turned out that the most abundant fragment ions for DNA/RNA bases are the dehydrogenated bases. In addition to DNA/RNA bases also electron interaction with 6-Chlorouracil has been studied. Another part of this thesis is the construction of a He cluster source. Helium clusters are most difficult to produce as temperatures of about 10 K have to be reached in the stagnation chamber at the stagnation pressure of about 20 bar. The newly developed source allows achieving stagnation conditions for a helium cluster production. (author)

  10. Studies on mass deposition effect and energy effect of biomolecules implanted by N+ ion beam

    International Nuclear Information System (INIS)

    Shao Chunlin; Yu Zengliang

    1994-05-01

    By analyzing some spectrum of tyrosine sample implanted by N + ion beam, it is deduced that the implantation N + could react with the tyrosine molecule and substitute =C 5 H- group of benzene ring to produce a N-heterocyclic compound. This compound would notably affect the residual activity of the sample. Moreover, the percentage of the product molecules to the damaged tyrosine molecules is larger than the reciprocal of the proportion of their extinction coefficients. On the other hand, by comparing the release of inorganic phosphate, it is found that the radiation sensibility for four basic nucleotides is 5'-dTMP>5'-CMP>5'-GMP>5'-AMP. to implanted nucleotides, alkali treatment and heat treatment could increase the amount of inorganic phosphate. The amount of inorganic phosphate in the nucleotide samples directly implanted by ions beam is about 60% of the total amount of inorganic phosphate that could be released from the implanted samples heated at 90 degree C for 1.75 hours. Alkali treatment could damage and split the free bases released from the implanted nucleotides, but heat treatment might repair those damaged bases. Above results prove that ions implantation to biomolecules has the mass deposition effects and energy effects

  11. Mapping the subcellular distribution of biomolecules at the ultrastructural level by ion microscopy.

    Science.gov (United States)

    Galle, P; Escaig, F; Dantin, F; Zhang, L

    1996-05-01

    Analytical ion microscopy, a method proposed and developed in 1960 by Casting and Slodzian at the Orsay University (France), makes it possible to obtain easily and rapidly analytical images representing the distribution in a tissue section of elements or isotopes (beginning from the three isotopes of hydrogen until to transuranic elements), even when these elements or isotopes are at a trace concentration of 1 ppm or less. This method has been applied to study the subcellular distribution of different varieties of biomolecules. The subcellular location of these molecules can be easily determined when the molecules contain in their structures a specific atom such as fluorine, iodine, bromine or platinum, what is the case of many pharmaceutical drugs. In this situation, the distribution of these specific atoms can be considered as representative of the distribution of the corresponding molecule. In other cases, the molecules must be labelled with an isotope which may be either radioactive or stable. Recent developments in ion microscopy allow the obtention of their chemical images at ultra structural level. In this paper we present the results obtained with the prototype of a new Scanning Ion Microscope used for the study of the intracellular distribution of different varieties of molecules: glucocorticoids, estrogens, pharmaceutical drugs and pyrimidine analogues.

  12. Photoemission study of metallic iron nanoparticles surface aging in biological fluids. Influence on biomolecules adsorption

    International Nuclear Information System (INIS)

    Canivet, L.; Denayer, F.O.; Champion, Y.; Cenedese, P.; Dubot, P.

    2014-01-01

    Iron nanoparticles (nFe) prepared by vaporization and cryogenic condensation process (10–100 nm) has been exposed to Hank's balanced salt solution (HBSS) and the B-Ali cell growth fluids. These media can be used for cellular growth to study nFe penetration through cell membrane and its induced cytotoxicity. Surface chemistry of nFe exposed to such complex fluids has been characterized as the nanoparticles surface can be strongly changed by adsorption or corrosion processes before reaching intracellular medium. Particle size and surface chemistry have been characterized by scanning electron microscopy (SEM) and high-resolution X-ray photoelectron spectroscopy (HR-XPS). Exposition of nFe particles to growth and differentiation media leads to the formation of an oxy-hydroxide layer containing chlorinated species. We found that the passivated Fe 2 O 3 layer of the bare nFe particles is rapidly transformed into a thicker oxy-hydroxide layer that has a greater ability to adsorb molecular ions or ionic biomolecules like proteins or DNA.

  13. Porous PLGA microspheres tailored for dual delivery of biomolecules via layer-by-layer assembly.

    Science.gov (United States)

    Go, Dewi P; Palmer, Jason A; Mitchell, Geraldine M; Gras, Sally L; O'Connor, Andrea J

    2015-05-01

    Tissue engineering is a complex and dynamic process that requires varied biomolecular cues to promote optimal tissue growth. Consequently, the development of delivery systems capable of sequestering more than one biomolecule with controllable release profiles is a key step in the advancement of this field. This study develops multilayered polyelectrolyte films incorporating alpha-melanocyte stimulating hormone (α-MSH), an anti-inflammatory molecule, and basic fibroblast growth factor (bFGF). The layers were successfully formed on macroporous poly lactic-co-glycolic acid microspheres produced using a combined inkjet and thermally induced phase separation technique. Release profiles could be varied by altering layer properties including the number of layers and concentrations of layering molecules. α-MSH and bFGF were released in a sustained manner and the bioactivity of α-MSH was shown to be preserved using an activated macrophage cell assay in vitro. The system performance was also tested in vivo subcutaneously in rats. The multilayered microspheres reduced the inflammatory response induced by a carrageenan stimulus 6 weeks after implantation compared to the non-layered microspheres without the anti-inflammatory and growth factors, demonstrating the potential of such multilayered constructs for the controlled delivery of bioactive molecules. © 2014 Wiley Periodicals, Inc.

  14. Optimization of extraction conditions for secondary biomolecules from various plant species

    Directory of Open Access Journals (Sweden)

    Šibul Filip S.

    2016-01-01

    Full Text Available Extraction of plant secondary metabolites is an essential step in isolation of natural products. Non-optimized extraction conditions can lead to losses, degradation and modification of the biomolecules. In this paper, the influence of different solvent mixtures, solvent amounts, temperature, extraction time, and procedures for defatting on yield and profile of various classes of secondary metabolites was investigated. Rumex alpinus was used for the extraction of anthraquinones, Glycine max for isoflavonoids, Chaerophyllum bulbosum for flavonoids and phenolic acids, Anthriscus sylvestris for lignans and coumarins, alkaloids were extracted from Lupinus albus and sesquiterpene lactones from Artemisia absinthium. Extraction efficiency was evaluated by use of LC-DAD-ESI-MS/MS. The compromise extraction solvent for all of the examined compounds is 80 % methanol, mixed in ratio 13 : 1 with plant material. Maceration should last for six hours, repeated four times with fresh solvent. Defatting of the extracts does not lead to significant losses of the compounds of interest. It is acceptable to use extraction and evaporation temperature of 60ºC, while the extracts should be stored in the dark, on -20ºC. [Projekat Ministarstva nauke Republike Srbije, br. 172058

  15. Biomolecule Analogues 2-Hydroxypyridine and 2-Pyridone Base Pairing on Ice Nanoparticles.

    Science.gov (United States)

    Rubovič, Peter; Pysanenko, Andriy; Lengyel, Jozef; Nachtigallová, Dana; Fárník, Michal

    2016-07-14

    Ice nanoparticles (H2O)N, N ≈ 450 generated in a molecular beam experiment pick up individual gas phase molecules of 2-hydroxypyridine and 2-pyridone (HP) evaporated in a pickup cell at temperatures between 298 and 343 K. The mass spectra of the doped nanoparticles show evidence for generation of clusters of adsorbed molecules (HP)n up to n = 8. The clusters are ionized either by 70 eV electrons or by two photons at 315 nm (3.94 eV). The two ionization methods yield different spectra, and their comparison provides an insight into the neutral cluster composition, ionization and intracluster ion-molecule reactions, and cluster fragmentation. Quite a few molecules were reported not to coagulate on ice nanoparticles previously. The (HP)n cluster generation on ice nanoparticles represents the first evidence for coagulating of molecules and cluster formation on free ice nanoparticles. For comparison, we investigate the coagulation of HP molecules picked up on large clusters ArN, N ≈ 205, and also (HP)n clusters generated in supersonic expansions with Ar buffer gas. This comparison points to a propensity for the (HP)2 dimer generation on ice nanoparticles. This shows the feasibility of base pairing for model of biological molecules on free ice nanoparticles. This result is important for hypotheses of the biomolecule synthesis on ice grains in the space. We support our findings by theoretical calculations that show, among others, the HP dimer structures on water clusters.

  16. Phenolic Content and Biomolecule Oxidation Protective Activity of Globularia alypum Extracts

    Directory of Open Access Journals (Sweden)

    Hamama Bouriche

    2017-08-01

    Full Text Available ABSTRACT The protective activity of methanolic (Met E and aqueous (Aq E extracts of Globularia alypum L. (G. alypum against DNA, lipid and protein oxidative damage was investigated. Moreover, the scavenging, chelating, and reducing power activities of the extracts were also evaluated. Phytochemical analysis was performed to determine phenolic compounds. Results showed that Met E and Aq E were rich in phenolic compounds, and were able to scavenge DPPH˙ with IC50 values of 48.61 µg/mL and 51.97 µg/mL, respectively. In addition, both extracts were able to chelate ferrous ions. At 300 μg/mL, the chelating activity was 97.53% and 91.02%, respectively. The reducing power of these extracts was also remarkable and concentration dependent. At 100 µg/mL, both extracts inhibited lipid peroxidatin by only 42.45% and 4.03%. However, the DNA oxidation damage was inhibited dose-dependently in the presence of G. alypum extracts. At 1 mg/mL, both extracts suppressed DNA cleavage by 83%-84%. The protein oxidation was also inhibited by G. alypum extracts. At 1 mg/mL, Aq E and Met E protected BSA fragmentation by 77%-99%. The overall results suggest that G. alypum extracts exerted antioxidant activity and protect biomolecules against oxidative damage; hence it may serve as a potential source of natural antioxidants.

  17. Molecular MRI in the Earth's Magnetic Field Using Continuous Hyperpolarization of a Biomolecule in Water.

    Science.gov (United States)

    Rovedo, Philipp; Knecht, Stephan; Bäumlisberger, Tim; Cremer, Anna Lena; Duckett, Simon B; Mewis, Ryan E; Green, Gary G R; Burns, Michael; Rayner, Peter J; Leibfritz, Dieter; Korvink, Jan G; Hennig, Jürgen; Pütz, Gerhard; von Elverfeldt, Dominik; Hövener, Jan-Bernd

    2016-06-30

    In this work, we illustrate a method to continuously hyperpolarize a biomolecule, nicotinamide, in water using parahydrogen and signal amplification by reversible exchange (SABRE). Building on the preparation procedure described recently by Truong et al. [ J. Phys. Chem. B , 2014 , 118 , 13882 - 13889 ], aqueous solutions of nicotinamide and an Ir-IMes catalyst were prepared for low-field NMR and MRI. The (1)H-polarization was continuously renewed and monitored by NMR experiments at 5.9 mT for more than 1000 s. The polarization achieved corresponds to that induced by a 46 T magnet (P = 1.6 × 10(-4)) or an enhancement of 10(4). The polarization persisted, although reduced, if cell culture medium (DPBS with Ca(2+) and Mg(2+)) or human cells (HL-60) were added, but was no longer observable after the addition of human blood. Using a portable MRI unit, fast (1)H-MRI was enabled by cycling the magnetic field between 5 mT and the Earth's field for hyperpolarization and imaging, respectively. A model describing the underlying spin physics was developed that revealed a polarization pattern depending on both contact time and magnetic field. Furthermore, the model predicts an opposite phase of the dihydrogen and substrate signal after one exchange, which is likely to result in the cancelation of some signal at low field.

  18. Biotin-Streptavidin Competition Mediates Sensitive Detection of Biomolecules in Enzyme Linked Immunosorbent Assay.

    Science.gov (United States)

    Lakshmipriya, Thangavel; Gopinath, Subash C B; Tang, Thean-Hock

    2016-01-01

    Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors.

  19. Magnetic molecularly imprinted polymer for the isolation and detection of biotin and biotinylated biomolecules.

    Science.gov (United States)

    Ben Aissa, A; Herrera-Chacon, A; Pupin, R R; Sotomayor, M D P T; Pividori, M I

    2017-02-15

    Magnetic separation based on biologically-modified magnetic particles is a preconcentration procedure commonly integrated in magneto actuated platforms for the detection of a huge range of targets. However, the main drawback of this material is the low stability and high cost. In this work, a novel hybrid molecularly-imprinted polymer with magnetic properties is presented with affinity towards biotin and biotinylated biomolecules. During the synthesis of the magneto core-shell particles, biotin was used as a template. The characterization of this material by microscopy techniques including SEM, TEM and confocal microscopy is presented. The application of the magnetic-MIPs for the detection of biotin and biotinylated DNA in magneto-actuated platforms is also described for the first time. The magnetic-MIP showed a significant immobilization capacity of biotinylated molecules, giving rise to a cheaper and a robust method (it is not required to be stored at 4°C) with high binding capacity for the separation and purification under magnetic actuation of a wide range of biotinylated molecules, and their downstream application including determination of their specific targets. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. In Situ Caging of Biomolecules in Graphene Hybrids for Light Modulated Bioactivity.

    Science.gov (United States)

    Cheng, Gong; Han, Xiao-Hui; Hao, Si-Jie; Nisic, Merisa; Zheng, Si-Yang

    2018-01-31

    Remote and noninvasive modulation of protein activity is essential for applications in biotechnology and medicine. Optical control has emerged as the most attractive approach owing to its high spatial and temporal resolutions; however, it is challenging to engineer light responsive proteins. In this work, a near-infrared (NIR) light-responsive graphene-silica-trypsin (GST) nanoreactor is developed for modulating the bioactivity of trypsin molecules. Biomolecules are spatially confined and protected in the rationally designed compartment architecture, which not only reduces the possible interference but also boosts the bioreaction efficiency. Upon NIR irradiation, the photothermal effect of the GST nanoreactor enables the ultrafast in situ heating for remote activation and tuning of the bioactivity. We apply the GST nanoreactor for remote and ultrafast proteolysis of proteins, which remarkably enhances the proteolysis efficiency and reduces the bioreaction time from the overnight of using free trypsin to seconds. We envision that this work not only provides a promising tool of ultrafast and remotely controllable proteolysis for in vivo proteomics in study of tissue microenvironment and other biomedical applications but also paves the way for exploring smart artificial nanoreactors in biomolecular modulation to gain insight in dynamic biological transformation.

  1. Unconstrained Enhanced Sampling for Free Energy Calculations of Biomolecules: A Review

    Science.gov (United States)

    Miao, Yinglong; McCammon, J. Andrew

    2016-01-01

    Free energy calculations are central to understanding the structure, dynamics and function of biomolecules. Yet insufficient sampling of biomolecular configurations is often regarded as one of the main sources of error. Many enhanced sampling techniques have been developed to address this issue. Notably, enhanced sampling methods based on biasing collective variables (CVs), including the widely used umbrella sampling, adaptive biasing force and metadynamics, have been discussed in a recent excellent review (Abrams and Bussi, Entropy, 2014). Here, we aim to review enhanced sampling methods that do not require predefined system-dependent CVs for biomolecular simulations and as such do not suffer from the hidden energy barrier problem as encountered in the CV-biasing methods. These methods include, but are not limited to, replica exchange/parallel tempering, self-guided molecular/Langevin dynamics, essential energy space random walk and accelerated molecular dynamics. While it is overwhelming to describe all details of each method, we provide a summary of the methods along with the applications and offer our perspectives. We conclude with challenges and prospects of the unconstrained enhanced sampling methods for accurate biomolecular free energy calculations. PMID:27453631

  2. Spatially controlled immobilisation of biomolecules: A complete approach in green chemistry

    Science.gov (United States)

    Grinenval, Eva; Nonglaton, Guillaume; Vinet, Françoise

    2014-01-01

    The development of 'green' sensors is a challenging task in the field of biomolecule sensing, for example in the detection of cardiac troponin-I (cTnI). In the present work a complete approach in green chemistry was developed to create chemically active patterns for the immobilisation of biological probes. This key technology is discussed on the basis of the twelve green chemistry principles, and is a combination of surface patterning by spotting and surface chemistries modified by molecular vapour deposition. The (1H,1H,2H,2H)-perfluorodecyltrichlorosilane (FDTS) was used as a novel anti-adsorption layer while the 3,4-epoxybutyltrimethoxysilane (EBTMOS) was used to immobilise probes. Oligonucleotides and the anti-cTnI antibody were studied. The spatially controlled immobilisation of probes was characterised by fluorescence. The demonstrated surface modification has broad applications in areas such as diagnostics and bio-chemical sensing. Moreover, the environmental impacts of surface patterning and surface chemistry were discussed from a 'greenness' point of view.

  3. Photoemission study of metallic iron nanoparticles surface aging in biological fluids. Influence on biomolecules adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Canivet, L.; Denayer, F.O. [Université de Lille 2, Droit et Santé, 42 rue P. Duez, 59000 Lille (France); Champion, Y.; Cenedese, P. [CNRS-ICMPE, 2 rue H. Dunant, 94320 Thiais (France); Dubot, P., E-mail: pdubot@icmpe.cnrs.fr [CNRS-ICMPE, 2 rue H. Dunant, 94320 Thiais (France)

    2014-07-01

    Iron nanoparticles (nFe) prepared by vaporization and cryogenic condensation process (10–100 nm) has been exposed to Hank's balanced salt solution (HBSS) and the B-Ali cell growth fluids. These media can be used for cellular growth to study nFe penetration through cell membrane and its induced cytotoxicity. Surface chemistry of nFe exposed to such complex fluids has been characterized as the nanoparticles surface can be strongly changed by adsorption or corrosion processes before reaching intracellular medium. Particle size and surface chemistry have been characterized by scanning electron microscopy (SEM) and high-resolution X-ray photoelectron spectroscopy (HR-XPS). Exposition of nFe particles to growth and differentiation media leads to the formation of an oxy-hydroxide layer containing chlorinated species. We found that the passivated Fe{sub 2}O{sub 3} layer of the bare nFe particles is rapidly transformed into a thicker oxy-hydroxide layer that has a greater ability to adsorb molecular ions or ionic biomolecules like proteins or DNA.

  4. A Universal Method for Fishing Target Proteins from Mixtures of Biomolecules using Isothermal Titration Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X.; Sun, Q; Kini, R; Sivaraman, J

    2008-01-01

    The most challenging tasks in biology include the identification of (1) the orphan receptor for a ligand, (2) the ligand for an orphan receptor protein, and (3) the target protein(s) for a given drug or a lead compound that are critical for the pharmacological or side effects. At present, several approaches are available, including cell- or animal-based assays, affinity labeling, solid-phase binding assays, surface plasmon resonance, and nuclear magnetic resonance. Most of these techniques are not easy to apply when the target protein is unknown and the compound is not amenable to labeling, chemical modification, or immobilization. Here we demonstrate a new universal method for fishing orphan target proteins from a complex mixture of biomolecules using isothermal titration calorimetry (ITC) as a tracking tool. We took snake venom, a crude mixture of several hundred proteins/peptides, as a model to demonstrate our proposed ITC method in tracking the isolation and purification of two distinct target proteins, a major component and a minor component. Identities of fished out target proteins were confirmed by amino acid sequencing and inhibition assays. This method has the potential to make a significant advancement in the area of identifying orphan target proteins and inhibitor screening in drug discovery and characterization.

  5. Microfluidic paper-based biomolecule preconcentrator based on ion concentration polarization.

    Science.gov (United States)

    Han, Sung Il; Hwang, Kyo Seon; Kwak, Rhokyun; Lee, Jeong Hoon

    2016-06-21

    Microfluidic paper-based analytical devices (μPADs) for molecular detection have great potential in the field of point-of-care diagnostics. Currently, a critical problem being faced by μPADs is improving their detection sensitivity. Various preconcentration processes have been developed, but they still have complicated structures and fabrication processes to integrate into μPADs. To address this issue, we have developed a novel paper-based preconcentrator utilizing ion concentration polarization (ICP) with minimal addition on lateral-flow paper. The cation selective membrane (i.e., Nafion) is patterned on adhesive tape, and this tape is then attached to paper-based channels. When an electric field is applied across the Nafion, ICP is initiated to preconcentrate the biomolecules in the paper channel. Departing from previous paper-based preconcentrators, we maintain steady lateral fluid flow with the separated Nafion layer; as a result, fluorescent dyes and proteins (FITC-albumin and bovine serum albumin) are continuously delivered to the preconcentration zone, achieving high preconcentration performance up to 1000-fold. In addition, we demonstrate that the Nafion-patterned tape can be integrated with various geometries (multiplexed preconcentrator) and platforms (string and polymer microfluidic channel). This work would facilitate integration of various ICP devices, including preconcentrators, pH/concentration modulators, and micro mixers, with steady lateral flows in paper-based platforms.

  6. Reduced and oxidised scytonemin: theoretical protocol for Raman spectroscopic identification of potential key biomolecules for astrobiology.

    Science.gov (United States)

    Varnali, Tereza; Edwards, Howell G M

    2014-01-03

    Scytonemin is an important UV-radiation protective biomolecule synthesised by extremophilic cyanobacteria in stressed terrestrial environments. Scytonemin and its reduced form have been both isolated experimentally and the Raman spectrum for scytonemin has been assigned and characterised experimentally both in extracts and in living extremophilic cyanobacterial colonies. Scytonemin is recognised as a key biomarker molecule for terrestrial organisms in stressed environments. We propose a new, theoretically plausible structure for oxidised scytonemin which has not been mentioned in the literature hitherto. DFT calculations for scytonemin, reduced scytonemin and the new structure modelled and proposed for oxidised scytonemin are reported along with their Raman spectroscopic data and λmax UV-absorption data obtained theoretically. Comparison of the vibrational spectroscopic assignments allows the three forms of scytonemin to be detected and identified and assist not only in the clarification of the major features in the experimentally observed Raman spectral data for the parent scytonemin but also support a protocol proposed for their analytical discrimination. The results of this study provide a basis for the search for molecules of this type in future astrobiological missions of exploration and the search for extinct and extant life terrestrially. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Biomolecule detection using wheatstone bridge giant magnetoresistance (GMR) sensors based on CoFeB spin-valve thin film

    Science.gov (United States)

    Elda Swastika, P.; Antarnusa, G.; Suharyadi, E.; Kato, T.; Iwata, S.

    2018-04-01

    A potential wheatstone bridge giant magnetoresistance (GMR) biosensor have been successfully developed for biomolecule detection. [IrMn(10 nm)/CoFe(3 nm)/Cu(2.2 nm)/CoFeB(10 nm)] spin-valve structure has been chosen as the magnetic sensing surface, showing a magnetoresistance (MR) of 6% fabricated by DC magnetron sputtering method. The Fe3O4 magnetic nanoparticles used as biomolecular labels (nanotags) was synthesized by co-precipitation method, exhibiting soft magnetic behavior with saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) is 77.2 emu/g, 7.8 emu/g and 51 Oe, respectively. The X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images showed that Fe3O4 was well crystallized and grew in their inverse spinel structure, highly uniform morphology with an average grain size was about 20 nm. Fe3O4 was coated with polyethylene-glycol (PEG)-4000 for surface functionalization. Detection of biomolecule such as formalin, gelatin from bovine-skin and porcine-skin were dispersed in ethanol at room temperature. Induction would cause a shift in output voltage with a minimum delta output voltage (ΔV) 4.937 mV (10%) for formalin detection, 2.268 mV (7%) for bovine-skin gelatin and 2.943 mV (7%) for porcine-skin gelatin detection. The ΔV of the wheatstone bridge in real-time measurement decrease by increase in biomolecules concentration. The change of ΔV with various concentration of biomolecule indicates that the spin-valve thin film with wheatstone-bridge circuit is potential as a biosensor.

  8. DNA-based Nanoconstructs for the Detection of Ions and Biomolecules with Related Raman/SERS Signature Studies

    Science.gov (United States)

    Brenneman, Kimber L.

    The utilization of DNA aptamers and semiconductor quantum dots (QDs) for the detection of ions and biomolecules was investigated. In recent years, there have been many studies based on the use of DNA and RNA aptamers, which are single stranded oligonucleotides capable of binding to biomolecules, other molecules, and ions. In many of these cases, the conformational changes of these DNA and RNA aptamers are suitable to use fluorescence resonant energy transfer (FRET) or nanometal surface energy transfer (NSET) techniques to detect such analytes. Coupled with this growth in such uses of aptamers, there has been an expanded use of semiconductor quantum dots as brighter, longer-lasting alternatives to fluorescent dyes in labeling and detection techniques of interest in biomedicine and environmental monitoring. Thrombin binding aptamer (TBA) and a zinc aptamer were used to detect mercury, lead, zinc, and cadmium. These probes were tested in a liquid assay as well as on a filter paper coupon. Biomolecules were also studied and detected using surface-enhanced Raman spectroscopy (SERS), including DNA aptamers and C-reactive protein (CRP). Raman spectroscopy is a useful tool for sensor development, label-free detection, and has the potential for remote sensing. Raman spectra provide information on the vibrational modes or phonons, between and within molecules. Therefore, unique spectral fingerprints for single molecules can be obtained. SERS is accomplished through the use of substrates with nanometer scale geometries made of metals with many free electrons, such as silver, gold, or copper. In this research silver SERS substrates were used to study the SERS signature of biomolecules that typically produce very weak Raman signals.

  9. Sputum Active Polymyxin Lipopeptides: Activity against Cystic Fibrosis Pseudomonas aeruginosa Isolates and Their Interactions with Sputum Biomolecules.

    Science.gov (United States)

    Schneider-Futschik, Elena K; Paulin, Olivia K A; Hoyer, Daniel; Roberts, Kade D; Ziogas, James; Baker, Mark A; Karas, John; Li, Jian; Velkov, Tony

    2018-05-11

    The mucoid biofilm mode of growth of Pseudomonas aeruginosa ( P. aeruginosa) in the lungs of cystic fibrosis patients makes eradication of infections with antibiotic therapy very difficult. The lipopeptide antibiotics polymyxin B and colistin are currently the last-resort therapies for infections caused by multidrug-resistant P. aeruginosa. In the present study, we investigated the antibacterial activity of a series of polymyxin lipopeptides (polymyxin B, colistin, FADDI-003, octapeptin A 3 , and polymyxin A 2 ) against a panel of polymyxin-susceptible and polymyxin-resistant P. aeruginosa cystic fibrosis isolates grown under planktonic or biofilm conditions in artificial sputum and their interactions with sputum component biomolecules. In sputum media under planktonic conditions, the lipopeptides FADDI-003 and octapeptin A 3 displayed very promising activity against the polymyxin-resistant isolate FADDI-PA066 (polymyxin B minimum inhibitory concentration (MIC) = 32 mg/L), while retaining their activity against the polymyxin-sensitive strains FADDI-PA021 (polymyxin B MIC = 1 mg/L) and FADDI-PA020 (polymyxin B MIC = 2 mg/L). Polymyxin A 2 was only effective against the polymyxin-sensitive isolates. However, under biofilm growth conditions, the hydrophobic lipopeptide FADDI-003 was inactive compared to the more hydrophilic lipopeptides, octapeptin A 3 , polymyxin A 2 , polymyxin B, and colistin. Transmission electron micrographs revealed octapeptin A 3 caused reduction in the cell numbers in biofilm as well as biofilm disruption/"antibiofilm" activity. We therefore assessed the interactions of the lipopeptides with the component sputum biomolecules, mucin, deoxyribonucleic acid (DNA), surfactant, F-actin, lipopolysaccharide, and phospholipids. We observed the general trend that sputum biomolecules reduce lipopeptide antibacterial activity. Collectively, our data suggests that, in the airways, lipopeptide binding to component sputum biomolecules may reduce

  10. Chemometric analysis of the consumption of oral rinse chlorite (ClO2-) by human salivary biomolecules.

    Science.gov (United States)

    Chang, Hubert; Blackburn, John; Grootveld, Martin

    2013-12-01

    Oral rinse formulations containing chlorite anion (ClO(2)(-)) as an active agent exert a range of valuable oral healthcare activities. However, salivary biomolecules which chemically react with this oxidant can, at least in principle, serve as potentially significant barriers to these therapeutic properties in the oral environment. Therefore, in this investigation, we have explored the extent of ClO(2)(-) consumption by biomolecules which scavenge this agent in human salivary supernatants (HSSs) in vitro. HSS samples were equilibrated with oral rinse formulations containing this active agent (30 s at 35 °C in order to mimic oral rinsing episodes). Differential spectrophotometric and ion-pair reversed-phase high-performance liquid chromatographic analyses were employed to determine residual ClO(2)(-) in these admixtures. Bioanalytical data acquired revealed the rapid consumption of ClO(2)(-) by biomolecular electron donors and/or antioxidants present in HSS samples. Mean ± 95 % confidence interval (CI) consumption levels of 7.14 ± 0.69 and 5.34 ± 0.69 % of the total ClO(2)(-) available were found for oral rinse products containing 0.10 and 0.40 % (w/v) ClO(2)(-), respectively. A mixed model analysis-of-variance performed on experimental data acquired demonstrated highly-significant differences between oral rinse ClO(2)(-) contents (p biomolecules for both oral rinse formulations investigated. These observations are of much clinical significance in view of the retention of these products' active agent, i.e. biomolecules within recommended 30 s oral rinsing episodes, and hence, the bulk of this oxyhalogen oxidant (>90 %) may effectively exert its essential microbicidal, anti-periodontal and oral malodour-neutralising actions.

  11. Hitos de la perspectiva molar del condicionamiento clásico

    Directory of Open Access Journals (Sweden)

    Andrés M. Pérez Acosta

    2003-01-01

    Full Text Available En este artículo se revisan los acontecimientos históricos fundamentales en la teoría del condicionamiento clásico como fenómeno psicológico –comportamental o cognoscitivo–, es decir, desde una perspectiva molar, en oposición a una perspectiva molecular, que es propia de las neurociencias. Se analizan los siguientes acontecimientos o hitos: la teoría reflexológica de Vladimir Bechterev, la perspectiva conductista radical de B. F. Skinner, el modelo de Rescorla y Wagner (1972, los modelos atencionales de Mackintosh (1975 y de Pearce y Hall (1980, las teorías que se basan en los procesos oponentes, de Allan Wagner (1981; Wagner & Brandon, 1989, y las teorías que se basan en el control temporal del comportamiento (Gallistel & Gibbon, 2002.

  12. Theoretical foundation and experimental proof of the accumulating transfer of tritium from water into DNA and other biomolecules in vitro and in vivo

    International Nuclear Information System (INIS)

    Baumgartner, F.

    2000-01-01

    Theoretical foundation and experimental proof of the accumulating transfer of tritium from water into DNA and other biomolecules were presented using the data of experiments on fish sperm DNA and piglet's liver (in vitro tests) and maize and barley (in vivo tests). Heisenberg's uncertainty principle, which describes a fundamental property of matter, predicts the light hydrogen isotope to prefer strong hydrogen bridge positions (with large local uncertainty). In contrast, the heavy hydrogen isotope tritium originally localized in water, should finally be found in the exchangeable hydrogen bridge positions of proteins, carbohydrates and nucleotides which are definitely less strong than those of water. Fractionation factor of tritium and protonium measured between water and DNA as well as the mixture of biomolecules of liver confirm this conclusion and show tritium accumulation biomolecules. Furthermore, the elevated rate of natural increase in tritium concentration in tissue solids of growing maize and barley confirm the accumulating tritium transfer from water to biomolecules taking place in vivo [ru

  13. Preparation and characterization of fluorophenylboronic acid-functionalized affinity monolithic columns for the selective enrichment of cis-diol-containing biomolecules.

    Science.gov (United States)

    Li, Qianjin; Liu, Zhen

    2015-01-01

    Boronate affinity monolithic columns have been developed into an important means for the selective recognition and capture of cis-diol-containing biomolecules, such as glycoproteins, nucleosides and saccharides. The ligands of boronic acids are playing an important role in boronate affinity monolithic columns. Although several boronate affinity monoliths with high affinity toward cis-diol-containing biomolecules have been reported, only few publications are focused on their detailed procedures for preparation and characterization. This chapter describes in detail the preparation and characterization of a boronate affinity monolithic column applying 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA) as a ligand. The DFFPBA-functionalized monolithic column not only exhibited an ultrahigh boronate affinity toward cis-diol-containing biomolecules, but also showed great potential for the selective enrichment of cis-diol-containing biomolecules in real samples.

  14. Correction: Kousholt, A.N. et al. Pathways for Genome Integrity in G2 Phase of the Cell Cycle. Biomolecules 2012, 2, 579-607.

    Science.gov (United States)

    Kousholt, Arne Nedergaard; Menzel, Tobias; Sørensen, Claus Storgaard

    2013-01-15

    We have discovered an error in our paper published in Biomolecules [1], in Figure 1 on page 589. The protein names ATR and ATRIP have been swapped. A corrected version of the Figure 1 is provided below. [...].

  15. NCG61/33: Plan de Estudios de M??ster en Educaci??n Musical, una Perspectiva Multidisciplinar

    OpenAIRE

    Universidad de Granada

    2012-01-01

    Plan de Estudios de M??ster en Educaci??n Musical, una Perspectiva Multidisciplinar. Resoluci??n de 5 de marzo de 2012, de la Universidad de Granada, por la que se publica el plan de estudios de M??ster en Educaci??n Musical, una Perspectiva Multidisciplinar

  16. Detection of prostate-specific antigen with biomolecule-gated AlGaN/GaN high electron mobility transistors

    Science.gov (United States)

    Li, Jia-dong; Cheng, Jun-jie; Miao, Bin; Wei, Xiao-wei; Xie, Jie; Zhang, Jin-cheng; Zhang, Zhi-qiang; Wu, Dong-min

    2014-07-01

    In order to improve the sensitivity of AlGaN/GaN high electron mobility transistor (HEMT) biosensors, a simple biomolecule-gated AlGaN/GaN HEMT structure was designed and successfully fabricated for prostate specific antigen (PSA) detection. UV/ozone was used to oxidize the GaN surface and then a 3-aminopropyl trimethoxysilane (APTES) self-assembled monolayer was bound to the sensing region. This monolayer serves as a binding layer for attachment of the prostate specific antibody (anti-PSA). The biomolecule-gated AlGaN/GaN HEMT sensor shows a rapid and sensitive response when the target prostate-specific antigen in buffer solution was added to the antibody-immobilized sensing area. The current change showed a logarithm relationship against the PSA concentration from 0.1 pg/ml to 0.993 ng/ml. The sensitivity of 0.215% is determined for 0.1 pg/ml PSA solution. The above experimental result of the biomolecule-gated AlGaN/GaN HEMT biosensor suggested that this biosensor might be a useful tool for prostate cancer screening.

  17. Detection of prostate-specific antigen with biomolecule-gated AlGaN/GaN high electron mobility transistors

    International Nuclear Information System (INIS)

    Li, Jia-dong; Miao, Bin; Wei, Xiao-wei; Xie, Jie; Wu, Dong-min; Cheng, Jun-jie; Zhang, Jin-cheng; Zhang, Zhi-qiang

    2014-01-01

    In order to improve the sensitivity of AlGaN/GaN high electron mobility transistor (HEMT) biosensors, a simple biomolecule-gated AlGaN/GaN HEMT structure was designed and successfully fabricated for prostate specific antigen (PSA) detection. UV/ozone was used to oxidize the GaN surface and then a 3-aminopropyl trimethoxysilane (APTES) self-assembled monolayer was bound to the sensing region. This monolayer serves as a binding layer for attachment of the prostate specific antibody (anti-PSA). The biomolecule-gated AlGaN/GaN HEMT sensor shows a rapid and sensitive response when the target prostate-specific antigen in buffer solution was added to the antibody-immobilized sensing area. The current change showed a logarithm relationship against the PSA concentration from 0.1 pg/ml to 0.993 ng/ml. The sensitivity of 0.215% is determined for 0.1 pg/ml PSA solution. The above experimental result of the biomolecule-gated AlGaN/GaN HEMT biosensor suggested that this biosensor might be a useful tool for prostate cancer screening. (paper)

  18. Nanorods of a new metal-biomolecule coordination polymer showing novel bidirectional electrocatalytic activity and excellent performance in electrochemical sensing.

    Science.gov (United States)

    Yang, Jiao; Zhou, Bo; Yao, Jie; Jiang, Xiao-Qing

    2015-05-15

    Metal organic coordination polymers (CPs), as most attractive multifunctional materials, have been studied extensively in many fields. However, metal-biomolecule CPs and CPs' electrochemical properties and applications were studied much less. We focus on this topic aiming at electrochemical biosensors with excellent performance and high biocompatibility. A new nanoscaled metal-biomolecule CP, Mn-tyr, containing manganese and tyrosine, was synthesized hydrothermally and characterized by various techniques, including XRD, TEM, EDS, EDX mapping, elemental analysis, XPS, and IR. Electrode modified with Mn-tyr showed novel bidirectional electrocatalytic ability toward both reduction and oxidation of H2O2, which might be due to Mn. With the assistance of CNTs, the sensing performance of Mn-tyr/CNTs/GCE was improved to a much higher level, with high sensitivity of 543 mA mol(-1) L cm(-2) in linear range of 1.00×10(-6)-1.02×10(-4) mol L(-1), and detection limit of 3.8×10(-7) mol L(-1). Mn-tyr/CNTs/GCE also showed fast response, high selectivity, high steadiness and reproducibility. The excellent performance implies that the metal-biomolecule CPs are promising candidates for using in enzyme-free electrochemical biosensing. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Design of a Modular DNA Triangular-Prism Sensor Enabling Ratiometric and Multiplexed Biomolecule Detection on a Single Microbead.

    Science.gov (United States)

    Liu, Yu; Chen, Qiaoshu; Liu, Jianbo; Yang, Xiaohai; Guo, Qiuping; Li, Li; Liu, Wei; Wang, Kemin

    2017-03-21

    DNA nanostructures have emerged as powerful and versatile building blocks for the construction of programmable nanoscale structures and functional sensors for biomarker detection, disease diagnostics, and therapy. Here we integrated multiple sensing modules into a single DNA three-dimensional (3D) nanoarchitecture with a triangular-prism (TP) structure for ratiometric and multiplexed biomolecule detection on a single microbead. In our design, the complementary hybridization of three clip sequences formed TP nanoassemblies in which the six single-strand regions in the top and bottom faces act as binding sites for different sensing modules, including an anchor module, reference sequence module, and capture sequence module. The multifunctional modular TP nanostructures were thus exploited for ratiometric and multiplexed biomolecule detection on microbeads. Microbead imaging demonstrated that, after ratiometric self-calibration analysis, the imaging deviations resulting from uneven fluorescence intensity distribution and differing probe concentrations were greatly reduced. The rigid nanostructure also conferred the TP as a framework for geometric positioning of different capture sequences. The inclusion of multiple targets led to the formation of sandwich hybridization structures that gave a readily detectable optical response at different fluorescence channels and distinct fingerprint-like pattern arrays. This approach allowed us to discriminate multiplexed biomolecule targets in a simple and efficient fashion. In this module-designed strategy, the diversity of the controlled DNA assembly coupled with the geometrically well-defined rigid nanostructures of the TP assembly provides a flexible and reliable biosensing approach that shows great promise for biomedical applications.

  20. Thermo-optical Characterization of Photothermal Optical Phase Shift Detection in Extended-Nano Channels and UV Detection of Biomolecules.

    Science.gov (United States)

    Shimizu, Hisashi; Miyawaki, Naoya; Asano, Yoshihiro; Mawatari, Kazuma; Kitamori, Takehiko

    2017-06-06

    The expansion of microfluidics research to nanofluidics requires absolutely sensitive and universal detection methods. Photothermal detection, which utilizes optical absorption and nonradiative relaxation, is promising for the sensitive detection of nonlabeled biomolecules in nanofluidic channels. We have previously developed a photothermal optical phase shift (POPS) detection method to detect nonfluorescent molecules sensitively, while a rapid decrease of the sensitivity in nanochannels and the introduction of an ultraviolet (UV) excitation system were issues to be addressed. In the present study, our primary aim is to characterize the POPS signal in terms of the thermo-optical properties and quantitatively evaluate the causes for the decrease in sensitivity. The UV excitation system is then introduced into the POPS detector to realize the sensitive detection of nonlabeled biomolecules. The UV-POPS detection system is designed and constructed from scratch based on a symmetric microscope. The results of simulations and experiments reveal that the sensitivity decreases due to a reduction of the detection volume, dissipation of the heat, and cancellation of the changes in the refractive indices. Finally, determination of the concentration of a nonlabeled protein (bovine serum albumin) is performed in a very thin 900 nm deep nanochannel. As a result, the limit of detection (LOD) is 2.3 μM (600 molecules in the 440 attoliter detection volume), which is as low as that previously obtained for our visible POPS detector. UV-POPS detection is thus expected be a powerful technique for the study of biomolecules, including DNAs and proteins confined in nanofluidic channels.

  1. Redox Reactivity of Cerium Oxide Nanoparticles Induces the Formation of Disulfide Bridges in Thiol-Containing Biomolecules.

    Science.gov (United States)

    Rollin-Genetet, Françoise; Seidel, Caroline; Artells, Ester; Auffan, Mélanie; Thiéry, Alain; Vidaud, Claude

    2015-12-21

    The redox state of disulfide bonds is implicated in many redox control systems, such as the cysteine-cystine couple. Among proteins, ubiquitous cysteine-rich metallothioneins possess thiolate metal binding groups susceptible to metal exchange in detoxification processes. CeO2 NPs are commonly used in various industrial applications due to their redox properties. These redox properties that enable dual oxidation states (Ce(IV)/Ce(III)) to exist at their surface may act as oxidants for biomolecules. The interaction among metallothioneins, cysteine, and CeO2 NPs was investigated through various biophysical approaches to shed light on the potential effects of the Ce(4+)/Ce(3+) redox system on the thiol groups of these biomolecules. The possible reaction mechanisms include the formation of a disulfide bridge/Ce(III) complex resulting from the interaction between Ce(IV) and the thiol groups, leading to metal unloading from the MTs, depending on their metal content and cluster type. The formation of stable Ce(3+) disulfide complexes has been demonstrated via their fluorescence properties. This work provides the first evidence of thiol concentration-dependent catalytic oxidation mechanisms between pristine CeO2 NPs and thiol-containing biomolecules.

  2. Label-free detection of protein biomolecules secreted from a heart-on-a-chip model for drug cardiotoxicity evaluation

    Science.gov (United States)

    DeLuna, Frank; Zhang, Yu Shrike; Bustamante, Gilbert; Li, Le; Lauderdale, Matthew; Dokmeci, Mehmet R.; Khademhosseini, Ali; Ye, Jing Yong

    2018-02-01

    Efficient methods for the accurate analysis of drug toxicities are in urgent demand as failures of newly discovered drug candidates due to toxic side effects have resulted in about 30% of clinical attrition. The high failure rate is partly due to current inadequate models to study drug side effects, i.e., common animal models may fail due to its misrepresentation of human physiology. Therefore, much effort has been allocated in the development of organ-on-a-chip models which offer a variety of human organ models mimicking a multitude of human physiological conditions. However, it is extremely challenging to analyze the transient and long-term response of the organ models to drug treatments during drug toxicity tests, as the proteins secreted from the organ-on-a-chip model are minute due to its volumetric size, and current methods for detecting said biomolecules are not suitable for real-time monitoring. As protein biomolecules are being continuously secreted from the human organ model, fluorescence techniques are practically impossible to achieve real-time fluorescence labeling in the dynamically changing environment, thus making a label-free approach highly desirable for the organ-on-achip applications. In this paper, we report the use of a photonic-crystal biosensor integrated with a microfluidic system for sensitive label-free bioassays of secreted protein biomolecules from a heart-on-the-chip model created with cardiomyocytes derived from human induced pluripotent stem cells.

  3. Side-by-Side Comparison of Commonly Used Biomolecules That Differ in Size and Affinity on Tumor Uptake and Internalization

    Science.gov (United States)

    Leelawattanachai, Jeerapond; Kwon, Keon-Woo; Michael, Praveesuda; Ting, Richard; Kim, Ju-Young; Jin, Moonsoo M.

    2015-01-01

    The ability to use a systemically injected agent to image tumor is influenced by tumor characteristics such as permeability and vascularity, and the size, shape, and affinity of the imaging agent. In this study, six different imaging biomolecules, with or without specificity to tumor, were examined for tumor uptake and internalization at the whole body, ex-vivo tissue, and cellular levels: antibodies, antibody fragments (Fab), serum albumin, and streptavidin. The time of peak tumor uptake was dependent solely on the size of molecules, suggesting that molecular size is the major factor that influences tumor uptake by its effect on systemic clearance and diffusion into tumor. Affinity to tumor antigen failed to augment tumor uptake of Fab above non-specific accumulation, which suggests that Fab fragments of typical monoclonal antibodies may fall below an affinity threshold for use as molecular imaging agents. Despite abundant localization into the tumor, albumin and streptavidin were not found on cell surface or inside cells. By comparing biomolecules differing in size and affinity, our study highlights that while pharmacokinetics are a dominant factor in tumor uptake for biomolecules, affinity to tumor antigen is required for tumor binding and internalization. PMID:25901755

  4. Precise and Arbitrary Deposition of Biomolecules onto Biomimetic Fibrous Matrices for Spatially Controlled Cell Distribution and Functions.

    Science.gov (United States)

    Jia, Chao; Luo, Bowen; Wang, Haoyu; Bian, Yongqian; Li, Xueyong; Li, Shaohua; Wang, Hongjun

    2017-09-01

    Advances in nano-/microfabrication allow the fabrication of biomimetic substrates for various biomedical applications. In particular, it would be beneficial to control the distribution of cells and relevant biomolecules on an extracellular matrix (ECM)-like substrate with arbitrary micropatterns. In this regard, the possibilities of patterning biomolecules and cells on nanofibrous matrices are explored here by combining inkjet printing and electrospinning. Upon investigation of key parameters for patterning accuracy and reproducibility, three independent studies are performed to demonstrate the potential of this platform for: i) transforming growth factor (TGF)-β1-induced spatial differentiation of fibroblasts, ii) spatiotemporal interactions between breast cancer cells and stromal cells, and iii) cancer-regulated angiogenesis. The results show that TGF-β1 induces local fibroblast-to-myofibroblast differentiation in a dose-dependent fashion, and breast cancer clusters recruit activated stromal cells and guide the sprouting of endothelial cells in a spatially resolved manner. The established platform not only provides strategies to fabricate ECM-like interfaces for medical devices, but also offers the capability of spatially controlling cell organization for fundamental studies, and for high-throughput screening of various biomolecules for stem cell differentiation and cancer therapeutics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Sensitivity improvement of an electrical sensor achieved by control of biomolecules based on the negative dielectrophoretic force.

    Science.gov (United States)

    Kim, Hye Jin; Kim, Jinsik; Yoo, Yong Kyoung; Lee, Jeong Hoon; Park, Jung Ho; Hwang, Kyo Seon

    2016-11-15

    Effective control of nano-scale biomolecules can enhance the sensitivity and limit of detection of an interdigitated microelectrode (IME) sensor. Manipulation of the biomolecules by dielectrophoresis (DEP), especially the negative DEP (nDEP) force, so that they are trapped between electrodes (sensing regions) was predicted to increase the binding efficiency of the antibody and target molecules, leading to a more effective reaction. To prove this concept, amyloid beta 42 (Aβ42) and prostate specific antigen (PSA) protein were respectively trapped between the sensing region owing to the nDEP force under 5V and 0.05V, which was verified with COMSOL simulation. Using the simulation value, the resistance change (ΔR/Rb) of the IME sensor from the specific antibody-antigen reaction of the two biomolecules and the change in fluorescence intensity were compared in the reference (pDEP) and nDEP conditions. The ΔR/Rb value improved by about 2-fold and 1.66-fold with nDEP compared to the reference condition with various protein concentrations, and these increases were confirmed with fluorescence imaging. Overall, nDEP enhanced the detection sensitivity for Aβ42 and PSA by 128% and 258%, respectively, and the limit of detection improved by up to 2-orders of magnitude. These results prove that DEP can improve the biosensor's performance. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Composite system based on biomolecules-functionalized multiwalled carbon nanotube and ionic liquid: Electrochemistry and electrocatalysis of tryptophane

    International Nuclear Information System (INIS)

    Li Li; Bu Caihong; Zhang Yijun; Du Jie; Lu Xiaoquan; Liu Xiuhui

    2011-01-01

    The combination of biomolecules-functionalized multiwalled carbon nanotube (MWNTs) and ionic liquid (IL) yields nanostructured biointerfaces, formed a novel kind of structurally uniform and bioelectrocatalytic activity material. Rutin was chosen as a model biomolecules to investigate the composite system. The MWNTs–Rutin–IL composite film was characterized by different methods including thermogravimetric analysis (TGA), UV–vis spectra, electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscope (SECM). A pair of well-defined quasi reversible redox peaks of rutin was obtained at the MWNTs–Rutin–IL composite film modified glassy carbon electrode (GCE) by direct electron transfer between the rutin and the GCE electrode. Dramatically enhanced biocatalytic and electrocatalytic activity was exemplified at the MWNTs–Rutin–IL/GCE electrode by the oxidized of tryptophane. The oxidation peak currents of tryptophane in such modified electrode increased linearly with the concentrations of tryptophane in the range from 8 × 10 −8 to 2 × 10 −5 mol L −1 with a detection limit of 3.0 × 10 −8 mol L −1 . The unique composite material based on biomolecules-functionalized carbon nanotube and ionic liquid have wide potential applications in direct electrochemistry, biosensors, and biocatalysis.

  7. Perspectivas cualitativa y cuantitativa en investigación ¿inconmensurables?

    OpenAIRE

    de Andrea, Nidia Georgina

    2017-01-01

    Este trabajo expone las epistemologías de base de las perspectivas cuantitativa y cualitativa en investigación, considerando que diversos autores realizan esta diferenciación. Luego, se establece una relación entre ambas, sin dejar de atender a las posturas que plantean que no hay epistemologías distintas para dichas metodologías. Efectivamente, la metodología de la investigación desde una perspectiva netamente cuantitativa tiene sus bases epistemológicas en el positivismo y el postpositivism...

  8. Lealtad de marca: antecedentes y perspectivas de investigación.

    OpenAIRE

    Julián Ramírez Angulo; Edison Jair Duque Oliva; Carlos Alberto Rodríguez Romero

    2013-01-01

    Este documento revisa la caracterización de la lealtad de marca, como variable multidimensional del marketing y sus perspectivas para la investigación. Para tal fin, en primer lugar se hace una revisión de los antecedentes conceptuales, para posteriormente ilustrar la evolución y la tendencia creciente en la investigación sobre el tema. Esto conduce a presentar tres posibles perspectivas de investigación sobre la lealtad, vinculadas a su examen como innovaciones, a través de la logística y en...

  9. Desigualdad y maternidad, experiencias de arteterapia desde una perspectiva de género

    OpenAIRE

    Cerda Mardones. Javiera

    2010-01-01

    La investigación corresponde a un trabajo de campo en arteterapia con perspectiva de género realizada con mujeres embarazadas en riesgo de exclusión social. Su propósito contribuir al desarrollo de la autoestima y empoderamiento de las participantes, el arteterapia y la perspectiva de género son los modelos de orientación teórica. Cuando los movimientos feministas se hacen cargo del papel de la mujer otorgado en el seno patriarcal se empieza a cuestionar la función de la matern...

  10. La sexualidad como producto cultural. Perspectiva histórica y psicosocial

    OpenAIRE

    Barriga, Silverio

    2013-01-01

    Desde perspectivas histórica y psicosocial, este artículo argumenta que la sexualidad es instinto básico y, especialmente, un producto cultural. Se desarrolla en primer lugar una síntesis histórica de la concepción del sexo, desde la antigua Grecia a nuestros días. A finales del siglo XIX se origina la sexología e inaugura el derecho a la salud sexual abriendo una perspectiva piscosocial de la sexualidad. La sexualidad en las relaciones personales de pareja y entre los géneros también se t...

  11. Negociaciones de paz y agencias de seguridad: perspectivas para el caso colombiano

    OpenAIRE

    Restrepo Villamil, José Libardo

    2014-01-01

    En el presente trabajo de tesis se propone una perspectiva comparada sobre las agendas de negociaciones de paz con las guerrillas centroamericanas y Colombia, en lo relacionado con las transformaciones de las agencias de seguridad, con la intención de tener perspectivas analíticas para el actual proceso de paz que se desarrolla en la Habana-Cuba entre la guerrilla de las FARC-EP y el gobierno colombiano. This tesis job proposes a comparative perspective about the peace negotiation diary be...

  12. New Method to Study the Vibrational Modes of Biomolecules in the Terahertz Range Based on a Single-Stage Raman Spectrometer.

    Science.gov (United States)

    Kalanoor, Basanth S; Ronen, Maria; Oren, Ziv; Gerber, Doron; Tischler, Yaakov R

    2017-03-31

    The low-frequency vibrational (LFV) modes of biomolecules reflect specific intramolecular and intermolecular thermally induced fluctuations that are driven by external perturbations, such as ligand binding, protein interaction, electron transfer, and enzymatic activity. Large efforts have been invested over the years to develop methods to access the LFV modes due to their importance in the studies of the mechanisms and biological functions of biomolecules. Here, we present a method to measure the LFV modes of biomolecules based on Raman spectroscopy that combines volume holographic filters with a single-stage spectrometer, to obtain high signal-to-noise-ratio spectra in short acquisition times. We show that this method enables LFV mode characterization of biomolecules even in a hydrated environment. The measured spectra exhibit distinct features originating from intra- and/or intermolecular collective motion and lattice modes. The observed modes are highly sensitive to the overall structure, size, long-range order, and configuration of the molecules, as well as to their environment. Thus, the LFV Raman spectrum acts as a fingerprint of the molecular structure and conformational state of a biomolecule. The comprehensive method we present here is widely applicable, thus enabling high-throughput study of LFV modes of biomolecules.

  13. O Linux e a perspectiva da dádiva

    Directory of Open Access Journals (Sweden)

    Renata Apgaua

    2004-06-01

    Full Text Available O objetivo deste trabalho é analisar o surgimento e consolidação do sistema operacional Linux em um contexto marcado pela hegemonia de sistemas operacionais comerciais, sendo o Windows/Microsoft o exemplo paradigmático. O idealizador do Linux optou por abrir o seu código-fonte e oferecê-lo, gratuitamente, na Internet. Desde então, pessoas de diversas partes do mundo têm participado do seu desenvolvimento. Busca-se, assim, através deste estudo, analisar as características desse espaço de sociabilidade, onde as trocas apontam para outra lógica que não a do mercado. A proposta de compreender os laços sociais no universo Linux, a partir da perspectiva da dádiva, acaba remetendo a outra discussão, que também merecerá atenção nesse estudo, qual seja: a atualidade da dádiva. Releituras de Mauss, feitas por Godbout e Caillé, indicam que a dádiva, em seu "sistema de transformações", encontra-se presente nas sociedades contemporâneas, mas não apenas nos interstícios sociais, conforme afirmava o próprio Mauss.This work's goal is to analyze the appearance and consolidation of the Linux operational system in a context marked by the hegemony of commercial operational systems, taking the Windows/Microsoft as the paradigmatic example. The creator of Linux chose to make it open-source and offer it free of charge, in the Internet. Since then, people from the various parts of the world have participated in its development. This study, therefore, seeks to analyse the features of this space of sociability, where the exchange points to another logic different of that one adopted by the market. The proposal of comprehending the social ties of the Linux universe through the perspective of gift ends up sending us into another discussion, which will also deserve attention in this study, that would be: the recentness of gift. Re-interpretations of Mauss, made by Godbout and Caillé, indicate that gif, in its "changing system", is present in

  14. TANTRISMO Y PSICOANÁLISIS. UNA PERSPECTIVA ANTROPOLÓGICA

    Directory of Open Access Journals (Sweden)

    Carlos Reynoso

    2016-01-01

    Full Text Available Presentamos este ensayo del Dr. Carlos Reynoso que, si bien fue publicado en el año 1981, es para nosotros de extrema importancia en la temática de la revista. Por eso queremos ofrecerlo a nuestros lectores ya que como dice el propio autor esta "escondido en lo más hondo de mi sitio". Comité Editorial Resumen del ensayo El tema está netamente establecido: por un lado, la formulación reichiana del psicoanálisis (de la función del orgasmo al pequeño hombrecito, con los acumuladores de orgón entre ambos; por el otro, una religión de la India que se presenta como transgresora, marginal, heterodoxa, y que adopta como sacramentos lo que para la ortodoxia serían más bien abominaciones. Nada más opuesto en apariencia; nada más análogo en realidad. Como se muestra en la figura, hasta las concepciones sobre cuerpo son casi idénticas, o en todo caso más parecidas entre sí de la que cada una lo es con respecto a las de cualquier corriente psicoanalítica o religión concebible. A la luz de la filosofía de Nelson Goodman (pienso hoy un juego de analogías y contrastes como el que desarrollé en este ensayo se torna merecidamente cuestionable. Y sin embargo, aún desde una perspectiva opuesta como la que hoy promuevo, los hechos que en él documento me siguen resultando insinuantes y su elaboración persuasiva. Mucho más, en todo caso, que la etnología tautegórica, caricatura de fenomenología, el dogma de la época, frente al cual este libro en el que apenas creo se constituyó en respuesta.

  15. Perspectiva del (desempleo en Sonora, 2000-2015

    Directory of Open Access Journals (Sweden)

    Ernesto Peralta

    2004-01-01

    Full Text Available El objetivo de este artículo es pronosticar el número de personas que ofrecerán sus servicios frente al de los que podrían tener un empleo permanente1 en el estado mexicano de Sonora entre los años 2000 y 2015, contrastando el escenario de continuar las tendencias históricas del empleo con el de una propuesta de mayor crecimiento y reestructuración productiva que priorice actividades que exigen mano de obra en abundancia. Generar empleo formal o permanente implica esfuerzos de investigación e instrumentación en áreas como las de tecnología, educación, capacitación o financiamiento a la inversión, entre otras, lo cual requiere del análisis de especialistas. El objetivo aquí planteado es más modesto, pero dimensionar el número de los que ofrecerán sus servicios de trabajo contra la perspectiva de creación de empleos permanentes implica un reto a la economía sonorense, pues las personas que buscarán trabajo en el horizonte referido ya existen. La hipótesis que aquí se plantea es: si no se promueve el empleo permanente más allá de lo que la extensión de la tendencia histórica conlleva entre los años 2000 y 2015, la generación de este tipo de empleo se rezagará considerablemente respecto a la población que buscará ocuparse, ampliando el desempleo abierto y disfrazado.2 Este artículo tiene cuatro secciones. En la primera se presenta el rezago del empleo permanente respecto a la fuerza de trabajo; en la segunda se describe el marco teórico y el respectivo modelo de referencia; en la tercera, el método de trabajo y sus resultados, incluyendo las actividades propuestas para aumentar el empleo y las tasas de inversión para acelerar el crecimiento económico y la creación de empleos formales; la cuarta contiene conclusiones y recomendaciones. Se presenta un anexo estadístico con proyecciones demográficas y de fuerza de trabajo, así como la matriz de insumo-producto de Sonora.

  16. Development of methods for the purification of 67Ga and 68Ga for biomolecules labeling

    International Nuclear Information System (INIS)

    Costa, Renata Ferreira

    2012-01-01

    For more than fifty years, the long-lived 68 Ge/ 68 Ga generators have been in development, obtaining 68 Ga without the need of having in house cyclotron, which is a considerable convenience for PET centers that have no nearby cyclotrons. 68 Ga decays 89% by positron emission and low photon emission (1077 keV) and the physical half life of 67.7 minutes is compatible with the pharmacokinetics of low biomolecular weight substances like peptides and antibody fragments. Moreover, its established metallic chemistry allows it to be stably bound to the carrier peptide sequence via a suitable bifunctional chelator, such as DOTA. All these reasons together with the technology of PET/CT allowed advances in molecular imaging, in particular in the diagnosis of neuroendocrine diseases. However, the eluate from the commercial 68 Ge/ 68 Ga generators still contains high levels of long lived 68 Ge, besides other metallic impurities, which competes with 68 Ga with a consequent reduction of the labeling yield of biomolecules, such as Fe 3+ and Zn 2+ . Thus, the lower the amount of impurities in the eluate, the competition between the radiolabeled and unlabeled peptide by the receptor will be smaller and the quality of imaging will be better, a subsequent purification step is needed after the generator elution. The aim of this work is to evaluate different purifications methods of 68 Ga to label biomolecules, with emphasis on the study of the chemical impurities contained in the eluate and to develop a new purification method. Several purification methods were studied. Many cationic resin were tested simulating the commercial process. 68 Ga is adsorbed in cationic resin, which is not commercial available and eluted in acid/acetone solution. The use of minor particles of cationic resin AG50W-X4 (200-400 mesh) showed the best results. An innovate method was the extraction chromatography, which is based on the absorption of diisopropyl ether in XAD 16 and 68 Ga recovery in deionized

  17. Cytoplasmic electric fields and electroosmosis: possible solution for the paradoxes of the intracellular transport of biomolecules.

    Science.gov (United States)

    Andreev, Victor P

    2013-01-01

    The objective of the paper is to show that electroosmotic flow might play an important role in the intracellular transport of biomolecules. The paper presents two mathematical models describing the role of electroosmosis in the transport of the negatively charged messenger proteins to the negatively charged nucleus and in the recovery of the fluorescence after photobleaching. The parameters of the models were derived from the extensive review of the literature data. Computer simulations were performed within the COMSOL 4.2a software environment. The first model demonstrated that the presence of electroosmosis might intensify the flux of messenger proteins to the nucleus and allow the efficient transport of the negatively charged phosphorylated messenger proteins against the electrostatic repulsion of the negatively charged nucleus. The second model revealed that the presence of the electroosmotic flow made the time of fluorescence recovery dependent on the position of the bleaching spot relative to cellular membrane. The magnitude of the electroosmotic flow effect was shown to be quite substantial, i.e. increasing the flux of the messengers onto the nucleus up to 4-fold relative to pure diffusion and resulting in the up to 3-fold change in the values of fluorescence recovery time, and therefore the apparent diffusion coefficient determined from the fluorescence recovery after photobleaching experiments. Based on the results of the modeling and on the universal nature of the electroosmotic flow, the potential wider implications of electroosmotic flow in the intracellular and extracellular biological processes are discussed. Both models are available for download at ModelDB.

  18. A Study of Biomolecules as Growth Modifiers of Calcium Oxalate Crystals

    Science.gov (United States)

    Kwak, Junha John

    Crystallization processes are ubiquitous in nature, science, and technology. Controlling crystal growth is pivotal in many industries as material properties and functions can be tailored by tuning crystal habits (e.g. size, shape, phase). In biomineralization, organisms exert excellent control over bottom-up synthesis and assembly of inorganic-organic structures (e.g. bones, teeth, exoskeletons). This is made possible by growth modifiers that range from small molecules to macromolecules, such as proteins. Molecular recognition of the mineral phase allows proteins to function as nucleation templates, matrices, and growth inhibitors or promoters. We are interested in taking a biomimetic approach to control crystallization via biomolecular growth modifiers. We investigated calcium oxalate monohydrate (COM), found in plants and kidney stones, as a model system of crystallization. We studied the effects of four common proteins on COM crystallization: bovine serum albumin (BSA), transferrin, lactoferrin, and lysozyme. Through kinetic studies of COM crystallization, we classified BSA and lysozyme as COM growth inhibitor and promoter respectively. Their inhibition and promotion effects were also evident in the macroscopic crystal habit. Through adsorption and microscopy experiments, we showed that BSA exhibits binding specificity for the apical surfaces of macroscopic COM crystals. Lysozyme, on the other, functions via a non-binding mechanism at the surface to accelerate the growth of the apical surfaces. We also synthesized and studied peptides derived from the protein primary sequences to identify putative domains responsible for these inhibition and promotion effects. Collectively, our study of physiologically relevant biomolecules suggests potential roles of COM modifiers in pathological crystallization and helps to develop guidelines for rational design of biomolecular growth modifiers for applications in crystal engineering.

  19. Thermochemical Fragment Energy Method for Biomolecules: Application to a Collagen Model Peptide.

    Science.gov (United States)

    Suárez, Ernesto; Díaz, Natalia; Suárez, Dimas

    2009-06-09

    Herein, we first review different methodologies that have been proposed for computing the quantum mechanical (QM) energy and other molecular properties of large systems through a linear combination of subsystem (fragment) energies, which can be computed using conventional QM packages. Particularly, we emphasize the similarities among the different methods that can be considered as variants of the multibody expansion technique. Nevertheless, on the basis of thermochemical arguments, we propose yet another variant of the fragment energy methods, which could be useful for, and readily applicable to, biomolecules using either QM or hybrid quantum mechanical/molecular mechanics methods. The proposed computational scheme is applied to investigate the stability of a triple-helical collagen model peptide. To better address the actual applicability of the fragment QM method and to properly compare with experimental data, we compute average energies by carrying out single-point fragment QM calculations on structures generated by a classical molecular dynamics simulation. The QM calculations are done using a density functional level of theory combined with an implicit solvent model. Other free-energy terms such as attractive dispersion interactions or thermal contributions are included using molecular mechanics. The importance of correcting both the intermolecular and intramolecular basis set superposition error (BSSE) in the QM calculations is also discussed in detail. On the basis of the favorable comparison of our fragment-based energies with experimental data and former theoretical results, we conclude that the fragment QM energy strategy could be an interesting addition to the multimethod toolbox for biomolecular simulations in order to investigate those situations (e.g., interactions with metal clusters) that are beyond the range of applicability of common molecular mechanics methods.

  20. Microfluidic labeling of biomolecules with radiometals for use in nuclear medicine.

    Science.gov (United States)

    Wheeler, Tobias D; Zeng, Dexing; Desai, Amit V; Önal, Birce; Reichert, David E; Kenis, Paul J A

    2010-12-21

    Radiometal-based radiopharmaceuticals, used as imaging and therapeutic agents in nuclear medicine, consist of a radiometal that is bound to a targeting biomolecule (BM) using a bifunctional chelator (BFC). Conventional, macroscale radiolabeling methods use an excess of the BFC-BM conjugate (ligand) to achieve high radiolabeling yields. Subsequently, to achieve maximal specific activity (minimal amount of unlabeled ligand), extensive chromatographic purification is required to remove unlabeled ligand, often resulting in longer synthesis times and loss of imaging sensitivity due to radioactive decay. Here we describe a microreactor that overcomes the above issues through integration of efficient mixing and heating strategies while working with small volumes of concentrated reagents. As a model reaction, we radiolabel 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) conjugated to the peptide cyclo(Arg-Gly-Asp-DPhe-Lys) with (64)Cu(2+). We show that the microreactor (made from polydimethylsiloxane and glass) can withstand 260 mCi of activity over 720 hours and retains only minimal amounts of (64)Cu(2+) (50 µM), yields of over 90% can be achieved in the microreactor when using a 1:1 stoichiometry of radiometal to BFC-BM. These high yields eliminate the need for use of excess amounts of often precious BM and obviate the need for a chromatographic purification process to remove unlabeled ligand. The results reported here demonstrate the potential of microreactor technology to improve the production of patient-tailored doses of radiometal-based radiopharmaceuticals in the clinic.