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Sample records for biological mechanism ii

  1. Molecular biological mechanism II. Molecular mechanisms of cell cycle regulation

    International Nuclear Information System (INIS)

    Jung, T.

    2000-01-01

    The cell cycle in eukaryotes is regulated by central cell cycle controlling protein kinase complexes. These protein kinase complexes consist of a catalytic subunit from the cyclin-dependent protein kinase family (CDK), and a regulatory subunit from the cyclin family. Cyclins are characterised by their periodic cell cycle related synthesis and destruction. Each cell cycle phase is characterised by a specific set of CDKs and cyclins. The activity of CDK/cyclin complexes is mainly regulated on four levels. It is controlled by specific phosphorylation steps, the synthesis and destruction of cyclins, the binding of specific inhibitor proteins, and by active control of their intracellular localisation. At several critical points within the cell cycle, named checkpoints, the integrity of the cellular genome is monitored. If damage to the genome or an unfinished prior cell cycle phase is detected, the cell cycle progression is stopped. These cell cycle blocks are of great importance to secure survival of cells. Their primary importance is to prevent the manifestation and heritable passage of a mutated genome to daughter cells. Damage sensing, DNA repair, cell cycle control and apoptosis are closely linked cellular defence mechanisms to secure genome integrity. Disregulation in one of these defence mechanisms are potentially correlated with an increased cancer risk and therefore in at least some cases with an increased radiation sensitivity. (orig.) [de

  2. Biology and Mechanics of Blood Flows Part II: Mechanics and Medical Aspects

    CERN Document Server

    Thiriet, Marc

    2008-01-01

    Biology and Mechanics of Blood Flows presents the basic knowledge and state-of-the-art techniques necessary to carry out investigations of the cardiovascular system using modeling and simulation. Part II of this two-volume sequence, Mechanics and Medical Aspects, refers to the extraction of input data at the macroscopic scale for modeling the cardiovascular system, and complements Part I, which focuses on nanoscopic and microscopic components and processes. This volume contains chapters on anatomy, physiology, continuum mechanics, as well as pathological changes in the vasculature walls including the heart and their treatments. Methods of numerical simulations are given and illustrated in particular by application to wall diseases. This authoritative book will appeal to any biologist, chemist, physicist, or applied mathematician interested in the functioning of the cardiovascular system.

  3. Is synthetic biology mechanical biology?

    Science.gov (United States)

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  4. Mechanical Biological Treatment

    DEFF Research Database (Denmark)

    Bilitewski, B-; Oros, Christiane; Christensen, Thomas Højlund

    2011-01-01

    The basic processes and technologies of composting and anaerobic digestion, as described in the previous chapters, are usually used for specific or source-separated organic waste flows. However, in the 1990s mechanical biological waste treatment technologies (MBT) were developed for unsorted...... or residual waste (after some recyclables removed at the source). The concept was originally to reduce the amount of waste going to landfill, but MBT technologies are today also seen as plants recovering fuel as well as material fractions. As the name suggests the technology combines mechanical treatment...... technologies (screens, sieves, magnets, etc.) with biological technologies (composting, anaerobic digestion). Two main technologies are available: Mechanical biological pretreatment (MBP), which first removes an RDF fraction and then biologically treats the remaining waste before most of it is landfilled...

  5. Mechanics rules cell biology

    Directory of Open Access Journals (Sweden)

    Wang James HC

    2010-07-01

    Full Text Available Abstract Cells in the musculoskeletal system are subjected to various mechanical forces in vivo. Years of research have shown that these mechanical forces, including tension and compression, greatly influence various cellular functions such as gene expression, cell proliferation and differentiation, and secretion of matrix proteins. Cells also use mechanotransduction mechanisms to convert mechanical signals into a cascade of cellular and molecular events. This mini-review provides an overview of cell mechanobiology to highlight the notion that mechanics, mainly in the form of mechanical forces, dictates cell behaviors in terms of both cellular mechanobiological responses and mechanotransduction.

  6. Quantum Mechanics predicts evolutionary biology.

    Science.gov (United States)

    Torday, J S

    2018-07-01

    Nowhere are the shortcomings of conventional descriptive biology more evident than in the literature on Quantum Biology. In the on-going effort to apply Quantum Mechanics to evolutionary biology, merging Quantum Mechanics with the fundamentals of evolution as the First Principles of Physiology-namely negentropy, chemiosmosis and homeostasis-offers an authentic opportunity to understand how and why physics constitutes the basic principles of biology. Negentropy and chemiosmosis confer determinism on the unicell, whereas homeostasis constitutes Free Will because it offers a probabilistic range of physiologic set points. Similarly, on this basis several principles of Quantum Mechanics also apply directly to biology. The Pauli Exclusion Principle is both deterministic and probabilistic, whereas non-localization and the Heisenberg Uncertainty Principle are both probabilistic, providing the long-sought after ontologic and causal continuum from physics to biology and evolution as the holistic integration recognized as consciousness for the first time. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Quantum mechanics II advanced topics

    CERN Document Server

    Rajasekar, S

    2015-01-01

    Quantum Mechanics II: Advanced Topics uses more than a decade of research and the authors’ own teaching experience to expound on some of the more advanced topics and current research in quantum mechanics. A follow-up to the authors introductory book Quantum Mechanics I: The Fundamentals, this book begins with a chapter on quantum field theory, and goes on to present basic principles, key features, and applications. It outlines recent quantum technologies and phenomena, and introduces growing topics of interest in quantum mechanics. The authors describe promising applications that include ghost imaging, detection of weak amplitude objects, entangled two-photon microscopy, detection of small displacements, lithography, metrology, and teleportation of optical images. They also present worked-out examples and provide numerous problems at the end of each chapter.

  8. Mechanics of biological polymer composites

    Science.gov (United States)

    Lomakin, Joseph

    2009-12-01

    displayed a darker coloration and significantly increased n of 0.0470.004, suggesting both cuticles to be less cross-linked, a finding consistent with reduced beta-alanine metabolism. Suppression of the tanning enzyme laccase2 (TcLac2) resulted in a pale cuticle with an n of 0.043+/-0.005, implicating laccases in the formation of both pigments and cross-links during sclerotization. Cuticular cross-linking was increased and n decreased with decreased expression of structural proteins, CP10 and CP20. This work establishes n as an important novel parameter for confirming metabolic pathways within load bearing tissues and for understanding structure function relationships within biological polymer composites. Additionally, Tribolium castaneum elytral indentation modulus (800+/-200 MPa) was determined by nanoindentation and a 4nm regular hexagonal pattern on the dorsal side of elytra investigated via scanning, transmission and atomic microscopy. Based on studied biological materials, the combination of rigid macromolecules immersed in a ductile matrix was found to be significant in achieving exceptional mechanical performance. Inspired by this biological design principle, the synthesis, properties and structure of Poly(ethylene glycol) diacrylate/agarose semi-interpenetrating network hydrogels were explored. The resulting novel composite materials were 9x stiffer than agarose and 5x tougher than PEGDA alone and showed good biocompatibility, suggesting promise as a scaffold material for tissue engineering constructs for cartilage regeneration.

  9. Biologically active new Fe(II, Co(II, Ni(II, Cu(II, Zn(II and Cd(II complexes of N-(2-thienylmethylenemethanamine

    Directory of Open Access Journals (Sweden)

    C. SPÎNU

    2008-04-01

    Full Text Available Iron(II, cobalt(II, nickel (II, copper (II, zinc(II and cadmium(II complexes of the type ML2Cl2, where M is a metal and L is the Schiff base N-(2-thienylmethylenemethanamine (TNAM formed by the condensation of 2-thiophenecarboxaldehyde and methylamine, were prepared and characterized by elemental analysis as well as magnetic and spectroscopic measurements. The elemental analyses suggest the stoichiometry to be 1:2 (metal:ligand. Magnetic susceptibility data coupled with electronic, ESR and Mössbauer spectra suggest a distorted octahedral structure for the Fe(II, Co(II and Ni(II complexes, a square-planar geometry for the Cu(II compound and a tetrahedral geometry for the Zn(II and Cd(II complexes. The infrared and NMR spectra of the complexes agree with co-ordination to the central metal atom through nitrogen and sulphur atoms. Conductance measurements suggest the non-electrolytic nature of the complexes, except for the Cu(II, Zn(II and Cd(II complexes, which are 1:2 electrolytes. The Schiff base and its metal chelates were screened for their biological activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the metal chelates were found to possess better antibacterial activity than that of the uncomplexed Schiff base.

  10. Biology and Mechanics of Blood Flows Part I: Biology

    CERN Document Server

    Thiriet, Marc

    2008-01-01

    Biology and Mechanics of Blood Flows presents the basic knowledge and state-of-the-art techniques necessary to carry out investigations of the cardiovascular system using modeling and simulation. Part I of this two-volume sequence, Biology, addresses the nanoscopic and microscopic scales. The nanoscale corresponds to the scale of biochemical reaction cascades involved in cell adaptation to mechanical stresses among other stimuli. The microscale is the scale of stress-induced tissue remodeling associated with acute or chronic loadings. The cardiovascular system, like any physiological system, has a complicated three-dimensional structure and composition. Its time dependent behavior is regulated, and this complex system has many components. In this authoritative work, the author provides a survey of relevant cell components and processes, with detailed coverage of the electrical and mechanical behaviors of vascular cells, tissues, and organs. Because the behaviors of vascular cells and tissues are tightly coupl...

  11. Physical mechanisms of biological molecular motors

    Energy Technology Data Exchange (ETDEWEB)

    Miller, John H. Jr. [Department of Physics and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Ste. 617 SR1 Houston, TX 77204-5005 (United States)], E-mail: jhmiller@uh.edu; Vajrala, Vijayanand; Infante, Hans L. [Department of Physics and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Ste. 617 SR1 Houston, TX 77204-5005 (United States); Claycomb, James R. [Department of Physics and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Ste. 617 SR1 Houston, TX 77204-5005 (United States); Department of Mathematics and Physics, Houston Baptist University, 7502 Fondren Road, Houston, TX 77074-3298 (United States); Palanisami, Akilan; Fang Jie; Mercier, George T. [Department of Physics and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Ste. 617 SR1 Houston, TX 77204-5005 (United States)

    2009-03-01

    Biological motors generally fall into two categories: (1) those that convert chemical into mechanical energy via hydrolysis of a nucleoside triphosphate, usually adenosine triphosphate, regarded as life's chemical currency of energy and (2) membrane bound motors driven directly by an ion gradient and/or membrane potential. Here we argue that electrostatic interactions play a vital role for both types of motors and, therefore, the tools of physics can greatly contribute to understanding biological motors.

  12. Physical mechanisms of biological molecular motors

    International Nuclear Information System (INIS)

    Miller, John H. Jr.; Vajrala, Vijayanand; Infante, Hans L.; Claycomb, James R.; Palanisami, Akilan; Fang Jie; Mercier, George T.

    2009-01-01

    Biological motors generally fall into two categories: (1) those that convert chemical into mechanical energy via hydrolysis of a nucleoside triphosphate, usually adenosine triphosphate, regarded as life's chemical currency of energy and (2) membrane bound motors driven directly by an ion gradient and/or membrane potential. Here we argue that electrostatic interactions play a vital role for both types of motors and, therefore, the tools of physics can greatly contribute to understanding biological motors

  13. Bioinspiration: applying mechanical design to experimental biology.

    Science.gov (United States)

    Flammang, Brooke E; Porter, Marianne E

    2011-07-01

    The production of bioinspired and biomimetic constructs has fostered much collaboration between biologists and engineers, although the extent of biological accuracy employed in the designs produced has not always been a priority. Even the exact definitions of "bioinspired" and "biomimetic" differ among biologists, engineers, and industrial designers, leading to confusion regarding the level of integration and replication of biological principles and physiology. By any name, biologically-inspired mechanical constructs have become an increasingly important research tool in experimental biology, offering the opportunity to focus research by creating model organisms that can be easily manipulated to fill a desired parameter space of structural and functional repertoires. Innovative researchers with both biological and engineering backgrounds have found ways to use bioinspired models to explore the biomechanics of organisms from all kingdoms to answer a variety of different questions. Bringing together these biologists and engineers will hopefully result in an open discourse of techniques and fruitful collaborations for experimental and industrial endeavors.

  14. The mathematics and mechanics of biological growth

    CERN Document Server

    Goriely, Alain

    2017-01-01

    This monograph presents a general mechanical theory for biological growth. It provides both a conceptual and a technical foundation for the understanding and analysis of problems arising in biology and physiology. The theory and methods is illustrated on a wide range of examples and applications. A process of extreme complexity, growth plays a fundamental role in many biological processes and is considered to be the hallmark of life itself. Its description has been one of the fundamental problems of life sciences, but until recently, it has not attracted much attention from mathematicians, physicists, and engineers. The author herein presents the first major technical monograph on the problem of growth since D’Arcy Wentworth Thompson’s 1917 book On Growth and Form. The emphasis of the book is on the proper mathematical formulation of growth kinematics and mechanics. Accordingly, the discussion proceeds in order of complexity and the book is divided into five parts. First, a general introduction on the pro...

  15. Phosphoinositides II: the diverse biological functions

    National Research Council Canada - National Science Library

    Balla, Tamas, Dr; Wymann, Matthias; York, John D

    2012-01-01

    ..., inflammation, neurodegenerative, cardiovascular, metabolic disease and more. In two volumes, this book elucidates the crucial mechanisms that control the dynamics of phosphoinositide conversion...

  16. Biological mechanisms, one molecule at a time

    Science.gov (United States)

    Tinoco, Ignacio; Gonzalez, Ruben L.

    2011-01-01

    The last 15 years have witnessed the development of tools that allow the observation and manipulation of single molecules. The rapidly expanding application of these technologies for investigating biological systems of ever-increasing complexity is revolutionizing our ability to probe the mechanisms of biological reactions. Here, we compare the mechanistic information available from single-molecule experiments with the information typically obtained from ensemble studies and show how these two experimental approaches interface with each other. We next present a basic overview of the toolkit for observing and manipulating biology one molecule at a time. We close by presenting a case study demonstrating the impact that single-molecule approaches have had on our understanding of one of life's most fundamental biochemical reactions: the translation of a messenger RNA into its encoded protein by the ribosome. PMID:21685361

  17. Biological Applications of Hybrid Quantum Mechanics/Molecular Mechanics Calculation

    Directory of Open Access Journals (Sweden)

    Jiyoung Kang

    2012-01-01

    Full Text Available Since in most cases biological macromolecular systems including solvent water molecules are remarkably large, the computational costs of performing ab initio calculations for the entire structures are prohibitive. Accordingly, QM calculations that are jointed with MM calculations are crucial to evaluate the long-range electrostatic interactions, which significantly affect the electronic structures of biological macromolecules. A UNIX-shell-based interface program connecting the quantum mechanics (QMs and molecular mechanics (MMs calculation engines, GAMESS and AMBER, was developed in our lab. The system was applied to a metalloenzyme, azurin, and PU.1-DNA complex; thereby, the significance of the environmental effects on the electronic structures of the site of interest was elucidated. Subsequently, hybrid QM/MM molecular dynamics (MD simulation using the calculation system was employed for investigation of mechanisms of hydrolysis (editing reaction in leucyl-tRNA synthetase complexed with the misaminoacylated tRNALeu, and a novel mechanism of the enzymatic reaction was revealed. Thus, our interface program can play a critical role as a powerful tool for state-of-the-art sophisticated hybrid ab initio QM/MM MD simulations of large systems, such as biological macromolecules.

  18. Mechanical Behaviour of Materials Volume II Fracture Mechanics and Damage

    CERN Document Server

    François, Dominique; Zaoui, André

    2013-01-01

    Designing new structural materials, extending lifetimes and guarding against fracture in service are among the preoccupations of engineers, and to deal with these they need to have command of the mechanics of material behaviour. This ought to reflect in the training of students. In this respect, the first volume of this work deals with elastic, elastoplastic, elastoviscoplastic and viscoelastic behaviours; this second volume continues with fracture mechanics and damage, and with contact mechanics, friction and wear. As in Volume I, the treatment links the active mechanisms on the microscopic scale and the laws of macroscopic behaviour. Chapter I is an introduction to the various damage phenomena. Chapter II gives the essential of fracture mechanics. Chapter III is devoted to brittle fracture, chapter IV to ductile fracture and chapter V to the brittle-ductile transition. Chapter VI is a survey of fatigue damage. Chapter VII is devoted to hydogen embrittlement and to environment assisted cracking, chapter VIII...

  19. The mechanics of soft biological composites.

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thao D. (Sandia National Laboratories, Livermore, CA); Grazier, John Mark; Boyce, Brad Lee; Jones, Reese E. (Sandia National Laboratories, Livermore, CA)

    2007-10-01

    Biological tissues are uniquely structured materials with technologically appealing properties. Soft tissues such as skin, are constructed from a composite of strong fibrils and fluid-like matrix components. This was the first coordinated experimental/modeling project at Sandia or in the open literature to consider the mechanics of micromechanically-based anisotropy and viscoelasticity of soft biological tissues. We have exploited and applied Sandia's expertise in experimentation and mechanics modeling to better elucidate the behavior of collagen fibril-reinforced soft tissues. The purpose of this project was to provide a detailed understanding of the deformation of ocular tissues, specifically the highly structured skin-like tissue in the cornea. This discovery improved our knowledge of soft/complex materials testing and modeling. It also provided insight into the way that cornea tissue is bio-engineered such that under physiologically-relevant conditions it has a unique set of properties which enhance functionality. These results also provide insight into how non-physiologic loading conditions, such as corrective surgeries, may push the cornea outside of its natural design window, resulting in unexpected non-linear responses. Furthermore, this project created a clearer understanding of the mechanics of soft tissues that could lead to bio-inspired materials, such as highly supple and impact resistant body armor, and improve our design of human-machine interfaces, such as micro-electrical-mechanical (MEMS) based prosthetics.

  20. Mechanically driven interface propagation in biological tissues

    International Nuclear Information System (INIS)

    Ranft, Jonas; Joanny, Jean-François; Aliee, Maryam; Jülicher, Frank; Prost, Jacques

    2014-01-01

    Many biological tissues consist of more than one cell type. We study the dynamics of an interface between two different cell populations as it occurs during the growth of a tumor in a healthy host tissue. Recent work suggests that the rates of cell division and cell death are under mechanical control, characterized by a homeostatic pressure. The difference in the homeostatic pressures of two cell types drives the propagation of the interface, corresponding to the invasion of one cell type into the other. We derive a front propagation equation that takes into account the coupling between cell number balance and tissue mechanics. We show that in addition to pulled fronts, pushed-front solutions occur as a result of convection driven by mechanics. (paper)

  1. Quantum mechanics formalism for biological evolution

    International Nuclear Information System (INIS)

    Bianconi, Ginestra; Rahmede, Christoph

    2012-01-01

    Highlights: ► Biological evolution is an off-equilibrium process described by path integrals over phylogenies. ► The phylogenies are sums of linear lineages for asexual populations. ► For sexual populations, each lineage is a tree and the path integral is given by a sum over these trees. ► Quantum statistics describe the stationary state of biological populations in simple cases. - Abstract: We study the evolution of sexual and asexual populations in fitness landscapes compatible with epistatic interactions. We find intriguing relations between the mathematics of biological evolution and quantum mechanics formalism. We give the general structure of the evolution of sexual and asexual populations which is in general an off-equilibrium process that can be expressed by path integrals over phylogenies. These phylogenies are the sum of linear lineages for asexual populations. For sexual populations, instead, each lineage is a tree of branching ratio two and the path integral describing the evolving population is given by a sum over these trees. Finally we show that the Bose–Einstein and the Fermi–Dirac distributions describe the stationary state of biological populations in simple cases.

  2. Free radicals in biology. Volume II

    International Nuclear Information System (INIS)

    Pryor, W.A.

    1976-01-01

    This volume continues the treatment of topics in free radical biology and free radical pathology from Volume I. In the first chapter, pyridinyl radicals, radicals which are models for those derived from NAD, are discussed. Pyridinyl radicals can be synthesized and isolated and directly studied in a number of chemical systems. The next chapter treats the role of glutathione in the cell. It is becoming even more apparent that this vital thiol controls a large number of important cellular functions. The GSH/GSSG balance has recently been implicated as a control for cellular development; this balance also may be important in relaying the effects of oxidants from one site to another in the body. The next chapter outlines the reactions of singlet oxygen; some of these involve free radicals and some do not. This reactive intermediate appears to be important both in photochemical smog and in cellular chemistry where singlet oxygen is produced by nonphotochemical processes. The production of free radicals from dry tissues, a controversial area with conflicting claims is reviewed. The next chapter outlines the current status of the studies of photochemical smog. The next two chapters treat specific reactive materials which are present in smog. The first discusses the chemistry of nitrogen oxides and ozone. The second chapter treats the chemistry of the peroxyacyl nitrites. These compounds, although present in only small concentration, are among the most toxic components of smog. The last two chapters treat radiation damage to proteins and radiation protection and radical reactions produced by radiation in nucleic acids

  3. The Cytoskeleton: Mechanical, Physical, and Biological Interactions

    Science.gov (United States)

    1996-01-01

    This workshop, entitled "The Cytoskeleton: Mechanical, Physical, and Biological Interactions," was sponsored by the Center for Advanced Studies in the Space Life Sciences at the Marine Biological Laboratory. This Center was established through a cooperative agreement between the MBL and the Life Sciences Division of the National Aeronautics and Space Administration. To achieve these goals, the Center sponsors a series of workshops on various topics in the life sciences. Elements of the cytoskeleton have been implicated in the effects of gravity on the growth of plants fungi. An intriguing finding in this regard is the report indicating that an integrin-like protein may be the gravireceptor in the internodal cells of Chara. Involvement of the cytoskeleton in cellular graviperception of the basidiomycete Flammulina velutipes has also been reported. Although the responses of mammalian cells to gravity are not well documented, it has been proposed that integrins can act as mechanochemical transducers in mammalian cells. Little is known about the integrated mechanical and physical properties of cytoplasm, this workshop would be the best place to begin developing interdisciplinary approaches to the effects of mechanical stresses on cells and their most likely responsive cytoplasmic elements- the fibrous proteins comprising the cytoskeleton.

  4. Toward mechanical systems biology in bone.

    Science.gov (United States)

    Trüssel, Andreas; Müller, Ralph; Webster, Duncan

    2012-11-01

    Cyclic mechanical loading is perhaps the most important physiological factor regulating bone mass and shape in a way which balances optimal strength with minimal weight. This bone adaptation process spans multiple length and time scales. Forces resulting from physiological exercise at the organ scale are sensed at the cellular scale by osteocytes, which reside inside the bone matrix. Via biochemical pathways, osteocytes orchestrate the local remodeling action of osteoblasts (bone formation) and osteoclasts (bone resorption). Together these local adaptive remodeling activities sum up to strengthen bone globally at the organ scale. To resolve the underlying mechanisms it is required to identify and quantify both cause and effect across the different scales. Progress has been made at the different scales experimentally. Computational models of bone adaptation have been developed to piece together various experimental observations at the different scales into coherent and plausible mechanisms. However additional quantitative experimental validation is still required to build upon the insights which have already been achieved. In this review we discuss emerging as well as state of the art experimental and computational techniques and how they might be used in a mechanical systems biology approach to further our understanding of the mechanisms governing load induced bone adaptation, i.e., ways are outlined in which experimental and computational approaches could be coupled, in a quantitative manner to create more reliable multiscale models of bone.

  5. Xenon preconditioning: molecular mechanisms and biological effects

    Directory of Open Access Journals (Sweden)

    Liu Wenwu

    2013-01-01

    Full Text Available Abstract Xenon is one of noble gases and has been recognized as an anesthetic for more than 50 years. Xenon possesses many of the characteristics of an ideal anesthetic, but it is not widely applied in clinical practice mainly because of its high cost. In recent years, numerous studies have demonstrated that xenon as an anesthetic can exert neuroprotective and cardioprotective effects in different models. Moreover, xenon has been applied in the preconditioning, and the neuroprotective and cardioprotective effects of xenon preconditioning have been investigated in a lot of studies in which some mechanisms related to these protections are proposed. In this review, we summarized these mechanisms and the biological effects of xenon preconditioning.

  6. The adaptor protein CrkII regulates IGF-1-induced biological behaviors of pancreatic ductal adenocarcinoma.

    Science.gov (United States)

    Liu, Rui; Wang, Qing; Xu, Guangying; Li, Kexin; Zhou, Lingli; Xu, Baofeng

    2016-01-01

    Recently, the adaptor protein CrkII has been proved to function in initiating signals for proliferation and invasion in some malignancies. However, the specific mechanisms underlying insulin-like growth factor 1 (IGF-1)-CrkII signaling-induced proliferation of pancreatic ductal adenocarcinoma (PDAC) were not unraveled. In this work, PDAC tissues and cell lines were subjected to in vitro and in vivo assays. Our findings showed that CrkII was abundantly expressed in PDAC tissues and closely correlated with tumor-node-metastasis (TNM) stage and invasion. When cells were subjected to si-CrkII, si-CrkII inhibited IGF-1-mediated PDAC cell growth. In vitro, we demonstrated the upregulation of CrkII, p-Erk1/2, and p-Akt occurring in IGF-1-treated PDAC cells. Conversely, si-CrkII affected upregulation of CrkII, p-Erk1/2, and p-Akt. In addition, cell cycle and in vivo assay identified that knockdown of CrkII inhibited the entry of G1 into S phase and the increase of PDAC tumor weight. In conclusion, CrkII mediates IGF-1 signaling and further balanced PDAC biological behaviors via Erk1/2 and Akt pathway, which indicates that CrkII gene and protein may act as an effective target for the treatment of PDAC.

  7. Synthetic biology: a challenge to mechanical explanations in biology?

    Science.gov (United States)

    Morange, Michel

    2012-01-01

    In their plans to modify organisms, synthetic biologists have contrasted engineering and tinkering. By drawing this contrast between their endeavors and what has happened during the evolution of organisms by natural selection, they underline the novelty of their projects and justify their ambitions. Synthetic biologists are at odds with a long tradition that has considered organisms as "perfect machines." This tradition had already been questioned by Stephen Jay Gould in the 1970s and received a major blow with the comparison made by François Jacob between organisms and the results of "bricolage" (tinkering). These contrasts between engineering and tinkering, synthetic biology and evolution, have no raison d'être. Machines built by humans are increasingly inspired by observations made on organisms. This is not a simple reversal of the previous trend-the mechanical conception of organisms-in which the characteristics of the latter were explained by comparison with human-built machines. Relations between organisms and machines have always been complex and ambiguous.

  8. Mechanical properties of nanostructure of biological materials

    Science.gov (United States)

    Ji, Baohua; Gao, Huajian

    2004-09-01

    Natural biological materials such as bone, teeth and nacre are nanocomposites of protein and mineral with superior strength. It is quite a marvel that nature produces hard and tough materials out of protein as soft as human skin and mineral as brittle as classroom chalk. What are the secrets of nature? Can we learn from this to produce bio-inspired materials in the laboratory? These questions have motivated us to investigate the mechanics of protein-mineral nanocomposite structure. Large aspect ratios and a staggered alignment of mineral platelets are found to be the key factors contributing to the large stiffness of biomaterials. A tension-shear chain (TSC) model of biological nanostructure reveals that the strength of biomaterials hinges upon optimizing the tensile strength of the mineral crystals. As the size of the mineral crystals is reduced to nanoscale, they become insensitive to flaws with strength approaching the theoretical strength of atomic bonds. The optimized tensile strength of mineral crystals thus allows a large amount of fracture energy to be dissipated in protein via shear deformation and consequently enhances the fracture toughness of biocomposites. We derive viscoelastic properties of the protein-mineral nanostructure and show that the toughness of biocomposite can be further enhanced by the viscoelastic properties of protein.

  9. Biological mechanisms of gallium-67 tumor deposition

    International Nuclear Information System (INIS)

    Okuyama, Shinichi; Takeda, Shumpei; Sato, Tachio; Takusagawa, Kimihiko; Awano, Takayuki.

    1979-01-01

    This investigation was undertaken in order to clarify the tumor deposition mechanisms of 67 Ga citrate, a ''universal tumor labeler''. An interspecies comparison of various tumors in the rat and mouse indicated that its highest deposition was in the undifferentiated cell type. Amongst the siblings of experimental tumors, cellular membrane negative charge is greater in the free-cell types than the island-formers: a short-term labeling study revealed a greater 67 Ga deposition in the free-cell types. A subcellar fractionation showed an initial association of 67 Ga with the nuclear and membrane fractions, and a later transition to the lysosomal. Hypotonic lysis revealed a paralleled release of 67 Ga and lysosomal key enzymes. Morphological abnormality of the cancer lysosomes was thought to agree with their Ga retention. This property was clinically confirmed by a scintiscoring technique. Treatment with cold gallium of tumors modified the biological parameters of tumor growth: in vitro it suppressed cell proliferation, reduced saturation density; and produced cellular pleomorphism. In vivo it increased tumor consistency by reducing central necrosis and increasing the viable cell layer thickness. Thus, 67 Ga deposition is closely related to various biological parameters of malignancy including the cellular membrane negative charge as cancer is a membrane disorder, and the lysosomal morphology and function. (author)

  10. Neurotrophin Propeptides: Biological Functions and Molecular Mechanisms.

    Science.gov (United States)

    Rafieva, Lola M; Gasanov, Eugene V

    2016-01-01

    Neurotrophins constitute a family of growth factors that play a key role in the regulation of the development and function of the central and peripheral nervous systems. A common feature of all the neurotrophins is their synthesis in cells as long precursors (pre-pro-neurotrophins) that contain an N-terminal signal peptide, a following propeptide and the mature neurotrophin. Although the signal peptide functions have been well studied, the role of neurotrophin propeptides is not so clear. Here, we briefly summarize the biochemistry of neurotrophin propeptides, including their role as folding-assistants for the mature factor and their role in processing and in secretion of neurotrophins. In the main part of the review we summarize our current state of knowledge of the biological activity of neurotrophin propeptides, their possible mechanisms of action, and their potential influence on the activity of the mature neurotrophins.

  11. Biological Mechanism of Silver Nanoparticle Toxicity

    Science.gov (United States)

    Armstrong, Najealicka Nicole

    Silver nanoparticles (AgNPs), like almost all nanoparticles, are potentially toxic beyond a certain concentration because the survival of the organism is compromised due to scores of pathophysiological abnormalities above that concentration. However, the mechanism of AgNP toxicity remains undetermined. Instead of applying a toxic dose, these investigations were attempted to monitor the effects of AgNPs at a non-lethal concentration on wild type Drosophila melanogaster by exposing them to nanoparticles throughout their development. All adult flies raised in AgNP doped food indicated that of not more than 50 mg/L had no negative influence on median survival; however, these flies appeared uniformly lighter in body color due to the loss of melanin pigments in their cuticle. Additionally, fertility and vertical movement ability were compromised after AgNP feeding. The determination of the amount of free ionic silver (Ag+) indicated that the observed biological effects had resulted from the AgNPs and not from Ag+. Biochemical analysis suggests that the activity of copper dependent enzymes, namely tyrosinase and Cu-Zn superoxide dismutase, were decreased significantly following the consumption of AgNPs, despite the constant level of copper present in the tissue. Furthermore, copper supplementation restored the loss of AgNP induced demelanization, and the reduction of functional Ctr1 in Ctr1 heterozygous mutants caused the flies to be resistant to demelanization. Consequently, these studies proposed a mechanism whereby consumption of excess AgNPs in association with membrane bound copper transporter proteins cause sequestration of copper, thus creating a condition that resembles copper starvation. This model also explained the cuticular demelanization effect resulting from AgNP since tyrosinase activity is essential for melanin biosynthesis. Finally, these investigations demonstrated that Drosophila, an established genetic model system, can be well utilized for further

  12. Prompt mechanism of type II supernovae

    International Nuclear Information System (INIS)

    Burrows, A.; Lattimer, J.M.

    1985-01-01

    We report in this Letter on an extensive set of hydrodynamical simulations of the stellar collapse of the cores of massive stars. A new hydro technique and a series of state-of-the art equations of state were employed. The purpose of this project was to understand in detail core implosion and immediate postbounce behavior (first 25 ms) and to investigate the viability of the hydrodynamic mechanism for Type II supernovae. We find that the bounce-shock always stalls upon encountering the massive infalling outer core for the calculated cores of stars between 8 and 25 M/sub sun/ and the standard input physics. In particular, it is found that Nomoto's 8l8 m/sub sun/ star and Woosley, Weaver, and Taam's 10 M/sub sun/ star do not explode via the prompt mechanism. Our conclusions appear to depend not on the details of the progenitor structure calculated by others but rather on the generic nature of these structures

  13. Discriminative topological features reveal biological network mechanisms

    Directory of Open Access Journals (Sweden)

    Levovitz Chaya

    2004-11-01

    Full Text Available Abstract Background Recent genomic and bioinformatic advances have motivated the development of numerous network models intending to describe graphs of biological, technological, and sociological origin. In most cases the success of a model has been evaluated by how well it reproduces a few key features of the real-world data, such as degree distributions, mean geodesic lengths, and clustering coefficients. Often pairs of models can reproduce these features with indistinguishable fidelity despite being generated by vastly different mechanisms. In such cases, these few target features are insufficient to distinguish which of the different models best describes real world networks of interest; moreover, it is not clear a priori that any of the presently-existing algorithms for network generation offers a predictive description of the networks inspiring them. Results We present a method to assess systematically which of a set of proposed network generation algorithms gives the most accurate description of a given biological network. To derive discriminative classifiers, we construct a mapping from the set of all graphs to a high-dimensional (in principle infinite-dimensional "word space". This map defines an input space for classification schemes which allow us to state unambiguously which models are most descriptive of a given network of interest. Our training sets include networks generated from 17 models either drawn from the literature or introduced in this work. We show that different duplication-mutation schemes best describe the E. coli genetic network, the S. cerevisiae protein interaction network, and the C. elegans neuronal network, out of a set of network models including a linear preferential attachment model and a small-world model. Conclusions Our method is a first step towards systematizing network models and assessing their predictability, and we anticipate its usefulness for a number of communities.

  14. Mechanical properties of JPDR biological shield concrete

    International Nuclear Information System (INIS)

    Idei, Yoshio; Kamata, Hiroshi; Akutsu, Youichi; Onizawa, Kunio; Nakajima, Nobuya; Sukegawa, Takenori; Kakizaki, Masayoshi.

    1990-11-01

    Plant life of nuclear power plant will be determined by the aging degradation of main components and structures because of the difficulty and the cost of the replacement. These components are the reactor pressure vessel, concrete structures and cables. Authors have performed the investigation of JPDR biological shield which was the succeeded in first generating electricity in Japan and is now being decommissioned in JAERI. The test core samples were bored from the shield concrete and tested to obtain the mechanical properties. Test results are summarized as below, (1) Peak value of fast neutron dose was estimated as 1 x 10 18 n/cm 2 which is equivalent to the dose at the end of life for commercial power reactor. (2) Averaged compressive strength of all specimens had been increased about 20 % compared with initial design strength. (3) It was identified that the compressive strength had a little trend to increase with the increase of neutron dose within the dose range obtained in this study. (4) Tensile strength, Elastic modulus and Poisson's ratio showed little effect of neutron dose. (5) It was suggested that the inside and the mid-section liners were effective to keep the water in concrete and to avoid the reduction in strength. (author)

  15. Biology: An Important Agricultural Engineering Mechanism

    Science.gov (United States)

    Henderson, S. M.

    1974-01-01

    Describes the field of bioengineering with particular emphasis on agricultural engineering, and presents the results of a survey of schools that combine biology and engineering in their curricula. (JR)

  16. Mechanics of Biological Tissues and Biomaterials : Current Trends (editorial)

    NARCIS (Netherlands)

    Zadpoor, A.A.

    2015-01-01

    Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the

  17. Variational principles of continuum mechanics II applications

    CERN Document Server

    Berdichevsky, Victor L

    2009-01-01

    This concise and understandable book about variational principles of continuum mechanics presents the classical models. The book is accessible to applied mathematicians, physicists and engineers who have an interest in continuum mechanics.

  18. Molecular biological mechanisms I. DNA repair

    International Nuclear Information System (INIS)

    Friedl, A.A.

    2000-01-01

    Cells of all living systems possess a variety of mechanisms that allow to repair spontaneous and exogeneously induced DNA damage. DNA repair deficiencies may invoke enhanced sensitivity towards DNA-damaging agents such as ionizing radiation. They may also enhance the risk of cancer development, both spontaneously or after induction. This article reviews several DNA repair mechanisms, especially those dealing with DNA double-strand breaks, and describes hereditary diseases associated with DNA repair defects. (orig.) [de

  19. Low Mass Aeroshell Deployment Mechanism, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group Inc. (CRG) will develop new shape memory polymer (SMP) deployment mechanisms for actuating thermal protection system (TPS) panels to...

  20. Biophysical mechanisms complementing "classical" cell biology.

    Science.gov (United States)

    Funk, Richard H W

    2018-01-01

    This overview addresses phenomena in cell- and molecular biology which are puzzling by their fast and highly coordinated way of organization. Generally, it appears that informative processes probably involved are more on the biophysical than on the classical biochemical side. The coordination problem is explained within the first part of the review by the topic of endogenous electrical phenomena. These are found e.g. in fast tissue organization and reorganization processes like development, wound healing and regeneration. Here, coupling into classical biochemical signaling and reactions can be shown by modern microscopy, electronics and bioinformatics. Further, one can follow the triggered reactions seamlessly via molecular biology till into genetics. Direct observation of intracellular electric processes is very difficult because of e.g. shielding through the cell membrane and damping by other structures. Therefore, we have to rely on photonic and photon - phonon coupling phenomena like molecular vibrations, which are addressed within the second part. Molecules normally possess different charge moieties and thus small electromagnetic (EMF) patterns arise during molecular vibration. These patterns can now be measured best within the optical part of the spectrum - much less in the lower terahertz till kHz and lower Hz part (third part of this review). Finally, EMFs facilitate quantum informative processes in coherent domains of molecular, charge and electron spin motion. This helps to coordinate such manifold and intertwined processes going on within cells, tissues and organs (part 4). Because the phenomena described in part 3 and 4 of the review still await really hard proofs we need concerted efforts and a combination of biophysics, molecular biology and informatics to unravel the described mysteries in "physics of life".

  1. The biological significance of brain barrier mechanisms

    DEFF Research Database (Denmark)

    Saunders, Norman R; Habgood, Mark D; Møllgård, Kjeld

    2016-01-01

    , but more work is required to evaluate the method before it can be tried in patients. Overall, our view is that much more fundamental knowledge of barrier mechanisms and development of new experimental methods will be required before drug targeting to the brain is likely to be a successful endeavor......Barrier mechanisms in the brain are important for its normal functioning and development. Stability of the brain's internal environment, particularly with respect to its ionic composition, is a prerequisite for the fundamental basis of its function, namely transmission of nerve impulses....... In addition, the appropriate and controlled supply of a wide range of nutrients such as glucose, amino acids, monocarboxylates, and vitamins is also essential for normal development and function. These are all cellular functions across the interfaces that separate the brain from the rest of the internal...

  2. Immunomodulatory Effects of Macrolide Antibiotics - Part 1 : Biological Mechanisms

    NARCIS (Netherlands)

    Altenburg, J.; de Graaff, C. S.; van der Werf, T. S.; Boersma, W. G.

    2011-01-01

    Macrolide antibiotics are well known for their antibacterial and anti-inflammatory properties. This article provides an overview of the biological mechanisms through which macrolides exert this 'double effect'. Their antibacterial effect consists of the inhibition of bacterial protein synthesis,

  3. Mechanics of Biological Tissues and Biomaterials: Current Trends

    OpenAIRE

    Amir A. Zadpoor

    2015-01-01

    Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the development of novel biomaterials for new fields of application, along with the emergence of advanced computational techniques. The current Special Issue is a collection of studies that address variou...

  4. Mechanics of Biological Tissues and Biomaterials: Current Trends (editorial)

    OpenAIRE

    Zadpoor, A.A.

    2015-01-01

    Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the development of novel biomaterials for new fields of application, along with the emergence of advanced computational techniques. The current Special Issue is a collection of studies that address variou...

  5. Low dose irradiation and biological defense mechanisms

    International Nuclear Information System (INIS)

    Sugahara, Tsutomu; Sagan, L.A.; Aoyama, Takashi

    1992-01-01

    It has been generally accepted in the context of radiation protection that ionizing radiation has some adverse effect even at low doses. However, epidemiological studies of human populations cannot definitively show its existence or absence. Furthermore, recent studies of populations living in areas of different background radiation levels reported some decrease in adverse health effects at high background levels. Genetic studies of atomic bomb survivors failed to produce statistically significant findings on the mutagenic effects of ionizing radiation. A British study however, suggests that a father's exposure to low dose radiation on the job may increase his children's risk of leukemia. On the other hand, many experimental studies have raised the possibility that low doses of ionizing radiation may not be harmful or may even produce stimulating or adaptive responses. The term 'hormesis' has come to be used to describe these phenomena produced by low doses of ionizing radiation when they were beneficial for the organisms studied. At the end of the International Conference on Low Dose Irradiation one conclusion appeared to be justified: radiation produces an adaptive response, though it is not universally detected yet. The conference failed to obtain any consensus on risk assessment at low doses, but raised many problems to be dealt with by future studies. The editors therefore believe that the Proceedings will be useful for all scientists and people concerned with radiation protection and the biological effects of low-dose irradiation

  6. Modeling the mechanisms of biological GTP hydrolysis

    DEFF Research Database (Denmark)

    Carvalho, Alexandra T.P.; Szeler, Klaudia; Vavitsas, Konstantinos

    2015-01-01

    Enzymes that hydrolyze GTP are currently in the spotlight, due to their molecular switch mechanism that controls many cellular processes. One of the best-known classes of these enzymes are small GTPases such as members of the Ras superfamily, which catalyze the hydrolysis of the γ-phosphate bond...... in GTP. In addition, the availability of an increasing number of crystal structures of translational GTPases such as EF-Tu and EF-G have made it possible to probe the molecular details of GTP hydrolysis on the ribosome. However, despite a wealth of biochemical, structural and computational data, the way...

  7. HYLIFE-II reactor chamber mechanical design

    International Nuclear Information System (INIS)

    House, P.A.

    1992-01-01

    Mechanical design features of the reactor chamber for the HYLIFE-11 inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams are used for shielding and blast protection. The system is designed for an 8 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (20 m/s) salt streams and also recover up to half of the dynamic head

  8. CRISPR-Cas: biology, mechanisms and relevance

    Science.gov (United States)

    Hille, Frank

    2016-01-01

    Prokaryotes have evolved several defence mechanisms to protect themselves from viral predators. Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) display a prokaryotic adaptive immune system that memorizes previous infections by integrating short sequences of invading genomes—termed spacers—into the CRISPR locus. The spacers interspaced with repeats are expressed as small guide CRISPR RNAs (crRNAs) that are employed by Cas proteins to target invaders sequence-specifically upon a reoccurring infection. The ability of the minimal CRISPR-Cas9 system to target DNA sequences using programmable RNAs has opened new avenues in genome editing in a broad range of cells and organisms with high potential in therapeutical applications. While numerous scientific studies have shed light on the biochemical processes behind CRISPR-Cas systems, several aspects of the immunity steps, however, still lack sufficient understanding. This review summarizes major discoveries in the CRISPR-Cas field, discusses the role of CRISPR-Cas in prokaryotic immunity and other physiological properties, and describes applications of the system as a DNA editing technology and antimicrobial agent. This article is part of the themed issue ‘The new bacteriology’. PMID:27672148

  9. Mechanics of Biological Tissues and Biomaterials: Current Trends

    Directory of Open Access Journals (Sweden)

    Amir A. Zadpoor

    2015-07-01

    Full Text Available Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the development of novel biomaterials for new fields of application, along with the emergence of advanced computational techniques. The current Special Issue is a collection of studies that address various topics within the general theme of “mechanics of biomaterials”. This editorial aims to present the context within which the studies of this Special Issue could be better understood. I, therefore, try to identify some of the most important research trends in the study of the mechanical behavior of biological tissues and biomaterials.

  10. Biological iron(II) oxidation as pre-treatment to limestone neutralisation of acid water

    CSIR Research Space (South Africa)

    Maree

    1998-01-01

    Full Text Available at investigating the effect of surface area of the medium that supports bacterial growth on the rate of biological iron (II) oxidation. The study showed that the biological iron (II) oxidation rate is directly proportional to the square root of the medium specific...

  11. On the mechanism of the biological effect of ionizing radiation

    International Nuclear Information System (INIS)

    Margulis, M.A.; Margulis, I.M.

    2005-01-01

    The mechanisms of the biological effects of ionizing radiation (IR) and ultrasound (US) were considered. The current views on the nature of toxicity of IR, which is usually assigned to the formation of radicals in living tissues and to the straight-line collision of an ionizing particle with the DNA molecule, were analyzed. It was established that the amount of radicals formed in biological tissues in conditions of ultrasonically induced cavitation can be as large as that for IR; however, the biological effect of US is much softer as compared to IR. It was shown that the contribution of the indirect mechanism to the total biological effect of IR can be estimated by comparing US and IR in their chemical action; the contribution of the indirect mechanism to the biological effect of IR was found to be negligibly small. An alternative mechanism was proposed to explain the biological effect of IR. In accordance with the proposed model, IR with a high linear energy transfer (LET) value breaks through cell walls and biological membranes and causes damage to them, such that the cell can lose its regenerative capacity. Moreover, high-energy heavy ionizing particles perforate cytoplasm to form channels. Ionizing radiation with a low LET value (γ- and X-rays) causes multiple damages to biological membranes. Ionizing particles can also cause damages to membranes of mitochondria thus affecting the mechanism of cellular respiration, which will cause neoplastic diseases. The straight-line collision of an ionizing particle with a DNA molecule was found to be 5-7 orders of magnitude less probable as compared to the collision with a wall or membrane. It was shown that multiple perforations of cell walls and damages to membranes are characteristic only of ionizing particles, which have sufficiently long tracks, and do not occur upon exposure to ultrasonic waves, microwaves, UV radiation, and magnetic fields [ru

  12. Nondestructive mechanical characterization of developing biological tissues using inflation testing.

    Science.gov (United States)

    Oomen, P J A; van Kelle, M A J; Oomens, C W J; Bouten, C V C; Loerakker, S

    2017-10-01

    One of the hallmarks of biological soft tissues is their capacity to grow and remodel in response to changes in their environment. Although it is well-accepted that these processes occur at least partly to maintain a mechanical homeostasis, it remains unclear which mechanical constituent(s) determine(s) mechanical homeostasis. In the current study a nondestructive mechanical test and a two-step inverse analysis method were developed and validated to nondestructively estimate the mechanical properties of biological tissue during tissue culture. Nondestructive mechanical testing was achieved by performing an inflation test on tissues that were cultured inside a bioreactor, while the tissue displacement and thickness were nondestructively measured using ultrasound. The material parameters were estimated by an inverse finite element scheme, which was preceded by an analytical estimation step to rapidly obtain an initial estimate that already approximated the final solution. The efficiency and accuracy of the two-step inverse method was demonstrated on virtual experiments of several material types with known parameters. PDMS samples were used to demonstrate the method's feasibility, where it was shown that the proposed method yielded similar results to tensile testing. Finally, the method was applied to estimate the material properties of tissue-engineered constructs. Via this method, the evolution of mechanical properties during tissue growth and remodeling can now be monitored in a well-controlled system. The outcomes can be used to determine various mechanical constituents and to assess their contribution to mechanical homeostasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The systems biology of MHC class II antigen presentation

    NARCIS (Netherlands)

    Paul, Petra

    2012-01-01

    Major histocompatibility class II molecules (MHC class II) are one of the key regulators of adaptive immunity because of their specific expression by professional antigen presenting cells (APC). They present peptides derived from endocytosed material to T helper lymphocytes. Consequently, MHC class

  14. Quantum mechanical simulation methods for studying biological systems

    International Nuclear Information System (INIS)

    Bicout, D.; Field, M.

    1996-01-01

    Most known biological mechanisms can be explained using fundamental laws of physics and chemistry and a full understanding of biological processes requires a multidisciplinary approach in which all the tools of biology, chemistry and physics are employed. An area of research becoming increasingly important is the theoretical study of biological macromolecules where numerical experimentation plays a double role of establishing a link between theoretical models and predictions and allowing a quantitative comparison between experiments and models. This workshop brought researchers working on different aspects of the development and application of quantum mechanical simulation together, assessed the state-of-the-art in the field and highlighted directions for future research. Fourteen lectures (theoretical courses and specialized seminars) deal with following themes: 1) quantum mechanical calculations of large systems, 2) ab initio molecular dynamics where the calculation of the wavefunction and hence the energy and forces on the atoms for a system at a single nuclear configuration are combined with classical molecular dynamics algorithms in order to perform simulations which use a quantum mechanical potential energy surface, 3) quantum dynamical simulations, electron and proton transfer processes in proteins and in solutions and finally, 4) free seminars that helped to enlarge the scope of the workshop. (N.T.)

  15. Early mechanisms in radiation-induced biological damage

    International Nuclear Information System (INIS)

    Powers, E.L.

    1983-01-01

    An introduction to the mechanisms of radiation action in biological systems is presented. Several questions about the nature of the radiation damage process are discussed, including recognition of the oxygen effects, dose-response relationships, and the importance of the hydroxyl radical

  16. Synthesis and spectroscopic studies of biologically active tetraazamacrocyclic complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II

    Directory of Open Access Journals (Sweden)

    Monika Tyagi

    2014-01-01

    Full Text Available Complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II were synthesized with the macrocyclic ligand, i.e., 2,3,9,10-tetraketo-1,4,8,11-tetraazacycoletradecane. The ligand was prepared by the [2 + 2] condensation of diethyloxalate and 1,3-diamino propane and characterized by elemental analysis, mass, IR and 1H NMR spectral studies. All the complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic and electron paramagnetic resonance spectral studies. The molar conductance measurements of Mn(II, Co(II and Ni(II complexes in DMF correspond to non electrolyte nature, whereas Pd(II and Pt(II complexes are 1:2 electrolyte. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II, Co(II and Ni(II complexes, whereas square planar geometry assigned for Pd(II and Pt(II. In vitro the ligand and its metal complexes were evaluated against plant pathogenic fungi (Fusarium odum, Aspergillus niger and Rhizoctonia bataticola and some compounds found to be more active as commercially available fungicide like Chlorothalonil.

  17. Nanomaterials modulate stem cell differentiation: biological interaction and underlying mechanisms.

    Science.gov (United States)

    Wei, Min; Li, Song; Le, Weidong

    2017-10-25

    Stem cells are unspecialized cells that have the potential for self-renewal and differentiation into more specialized cell types. The chemical and physical properties of surrounding microenvironment contribute to the growth and differentiation of stem cells and consequently play crucial roles in the regulation of stem cells' fate. Nanomaterials hold great promise in biological and biomedical fields owing to their unique properties, such as controllable particle size, facile synthesis, large surface-to-volume ratio, tunable surface chemistry, and biocompatibility. Over the recent years, accumulating evidence has shown that nanomaterials can facilitate stem cell proliferation and differentiation, and great effort is undertaken to explore their possible modulating manners and mechanisms on stem cell differentiation. In present review, we summarize recent progress in the regulating potential of various nanomaterials on stem cell differentiation and discuss the possible cell uptake, biological interaction and underlying mechanisms.

  18. Biological timing and the clock metaphor: oscillatory and hourglass mechanisms.

    Science.gov (United States)

    Rensing, L; Meyer-Grahle, U; Ruoff, P

    2001-05-01

    Living organisms have developed a multitude of timing mechanisms--"biological clocks." Their mechanisms are based on either oscillations (oscillatory clocks) or unidirectional processes (hourglass clocks). Oscillatory clocks comprise circatidal, circalunidian, circadian, circalunar, and circannual oscillations--which keep time with environmental periodicities--as well as ultradian oscillations, ovarian cycles, and oscillations in development and in the brain, which keep time with biological timescales. These clocks mainly determine time points at specific phases of their oscillations. Hourglass clocks are predominantly found in development and aging and also in the brain. They determine time intervals (duration). More complex timing systems combine oscillatory and hourglass mechanisms, such as the case for cell cycle, sleep initiation, or brain clocks, whereas others combine external and internal periodicities (photoperiodism, seasonal reproduction). A definition of a biological clock may be derived from its control of functions external to its own processes and its use in determining temporal order (sequences of events) or durations. Biological and chemical oscillators are characterized by positive and negative feedback (or feedforward) mechanisms. During evolution, living organisms made use of the many existing oscillations for signal transmission, movement, and pump mechanisms, as well as for clocks. Some clocks, such as the circadian clock, that time with environmental periodicities are usually compensated (stabilized) against temperature, whereas other clocks, such as the cell cycle, that keep time with an organismic timescale are not compensated. This difference may be related to the predominance of negative feedback in the first class of clocks and a predominance of positive feedback (autocatalytic amplification) in the second class. The present knowledge of a compensated clock (the circadian oscillator) and an uncompensated clock (the cell cycle), as well

  19. The mechanism for the primary biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Byakov, Vsevolod M; Stepanov, Sergei V

    2006-01-01

    The primary biological response of living organisms to the passage of fast charged particles is traditionally believed to be dominated by the chemical reactions of the radical products from the radiolysis of cellular water (OH, H, e aq - , O 2 - , H 2 O 2 ) and by the bioradicals that they produce (and which can also result from the direct electronic activation of biomolecules). This understanding has provided insight into how ionizing radiations affect biological systems and, most importantly, what radioprotection and radiosensibilizing effects are produced by chemical compounds introduced into an organism. However, a number of key radiobiological facts remain unexplained by the current theory, stimulating a search for other biologically active factors that may be triggered by radiation. This review examines a fact that is usually ignored in discussing the biological impact of ionizing radiation: the local increase in acidity in the water solution along the track of a charged particle. The acidity in the track is very different from its value for cellular water in a living organism. Biological processes are well-known to be highly sensitive to changes in the environmental acidity. It seems that the biological impact of ionizing radiations is dominated not by the water radiolysis products (mostly radicals) listed above but particles of a different nature, hydroxonium ions H 3 O + , where the term hydroxonium refer to protonated water molecules. This modification of the mechanism of primary radiobiological effects is in good agreement with experimental data. In particular, the extremal dependence of the relative biological efficiency (RBE) of radiations on their ionizing energy losses is accounted for in quantitative terms, as is the increase in the RBE in the relativistic energy range. (reviews of topical problems)

  20. Mechanical design of the CDF SVX II silicon vertex detector

    International Nuclear Information System (INIS)

    Skarha, J.E.

    1994-08-01

    A next generation silicon vertex detector is planned at CDF for the 1998 Tevatron collider run with the Main Injector. The SVX II silicon vertex detector will allow high luminosity data-taking, enable online triggering of secondary vertex production, and greatly increase the acceptance for heavy flavor physics at CDF. The design specifications, geometric layout, and early mechanical prototyping work for this detector are discussed

  1. The Impact of Broccoli II & Tomato II on European patents in conventional breeding, GMO’s and Synthetic Biology:

    DEFF Research Database (Denmark)

    Minssen, Timo; Nordberg, Ana

    2015-01-01

    . The EBA has also clarified that this applies irrespective of if such claims are formulated in a product-by-process format or as a per se product . Moreover, the combined effect of Broccoli & Tomato I & II opens new opportunities for patenting GMOs - provided that all other patent criteria are also met...... if confronted with similar issues in the context of national implementations of the Biotech Directive, which have taken a very different view than the EBA. Moreover, the fierce European opposition against genetically modified organisms (GMOs) and Synthetic Biology remains a major challenge to the industry...... and Nordberg, A., The Impact of Broccoli II & Tomatoes II on European Patents in Conventional Breeding, GMO's and Synthetic Biology: The Grand Finale of a Juicy Patents Tale? (May 19, 2015). Univ. of Copenhagen Dept. of Economics Discussion. Available at SSRN: http://ssrn.com/abstract=2607865 or http...

  2. Cu(II AND Zn(II COMPLEX COMPOUNDS WITH BIGUANIDES AROMATIC DERIVATIVES. SYNTHESIS, CHARACTERIZATION, BIOLOGICAL ACTIVITY

    Directory of Open Access Journals (Sweden)

    Ticuţa Negreanu-Pîrjol

    2011-05-01

    Full Text Available In this paper we report the synthesis, physical-chemical characterization and antimicrobial activity of some new complex compounds of hetero-aromatic biguanides ligands, chlorhexidine base (CHX and chlorhexidine diacetate (CHXac2 with metallic ions Cu(II and Zn(II, in different molar ratio. The synthesized complexes were characterized by elemental chemical analysis and differential thermal analysis. The stereochemistry of the metallic ions was determined by infrared spectra, UV-Vis, EPR spectroscopy and magnetic susceptibility in the aim to establish the complexes structures. The biological activity of the new complex compounds was identified in solid technique by measuring minimum inhibition diameter of bacterial and fungal culture, against three standard pathogen strains, Escherichia coli ATCC 25922, Staphilococcus aureus ATCC 25923 and Candida albicans ATCC 10231. The results show an increased specific antimicrobial activity for the complexes chlorhexidine:Cu(II 1:1 and 1:2 compared with the one of the Zn(II complexes.

  3. Interaction mechanisms and biological effects of static magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1994-06-01

    Mechanisms through which static magnetic fields interact with living systems are described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving, ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecules structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary is also presented of the biological effects of static magnetic fields. There is convincing experimental evidence for magnetoreception mechanisms in several classes of lower organisms, including bacteria and marine organisms. However, in more highly evolved species of animals, there is no evidence that the interactions of static magnetic fields with flux densities up to 2 Tesla (1 Tesla [T] = 10{sup 4} Gauss) produce either behavioral or physiolocical alterations. These results, based on controlled studies with laboratory animals, are consistent with the outcome of recent epidemiological surveys on human populations exposed occupationally to static magnetic fields.

  4. Elastic Multi-scale Mechanisms: Computation and Biological Evolution.

    Science.gov (United States)

    Diaz Ochoa, Juan G

    2018-01-01

    Explanations based on low-level interacting elements are valuable and powerful since they contribute to identify the key mechanisms of biological functions. However, many dynamic systems based on low-level interacting elements with unambiguous, finite, and complete information of initial states generate future states that cannot be predicted, implying an increase of complexity and open-ended evolution. Such systems are like Turing machines, that overlap with dynamical systems that cannot halt. We argue that organisms find halting conditions by distorting these mechanisms, creating conditions for a constant creativity that drives evolution. We introduce a modulus of elasticity to measure the changes in these mechanisms in response to changes in the computed environment. We test this concept in a population of predators and predated cells with chemotactic mechanisms and demonstrate how the selection of a given mechanism depends on the entire population. We finally explore this concept in different frameworks and postulate that the identification of predictive mechanisms is only successful with small elasticity modulus.

  5. Biological evaluation of transdichloridoplatinum(II) complexes with 3- and 4-acetylpyridine in comparison to cisplatin

    International Nuclear Information System (INIS)

    Filipovic, Lana; Arandelovic, Sandra; Gligorijevic, Nevenka; Krivokuca, Ana; Jankovic, Radmila; Srdic-Rajic, Tatjana; Rakic, Gordana; Tesic, Zivoslav; Radulovic, Sinisa

    2013-01-01

    In our previous study we reported the synthesis and cytotoxicity of two trans-platinum(II) complexes: trans-[PtCl 2 (3-acetylpyridine) 2 ] (1) and trans-[PtCl 2 (4-acetylpyridine) 2 ] (2), revealing significant cytotoxic potential of 2. In order to evaluate the mechanism underlying biological activity of both trans-Pt(II) isomers, comparative studies versus cisplatin were performed in HeLa, MRC-5 and MS1 cells. The cytotoxic activity of the investigated complexes was determined using SRB assay. The colagenolytic activity was determined using gelatin zymography, while the effect of platinum complexes on matrix metalloproteinases 2 and 9 mRNA expression was evaluated by quantitative real-time PCR. Apoptotic potential and cell cycle alterations were determined by FACS analyses. Western blot analysis was used to evaluate the effect on expression of DNA-repair enzyme ERCC1, and quantitative real-time PCR was used for the ERCC1 mRNA expression analysis. In vitro antiangiogenic potential was determined by tube formation assay. Platinum content in intracellular DNA and proteins was determined by inductively coupled plasma-optical emission spectrometry. Compound 2 displayed an apparent cytoselective profile, and flow cytometry analysis in HeLa cells indicated that 2 exerted antiproliferative effect through apoptosis induction, while 1 induced both apoptosis and necrosis. Action of 1 and 2, as analyzed by quantitative real-time PCR and Western blot, was associated with down-regulation of ERCC1. Both trans-complexes inhibited MMP-9 mRNA expression in HeLa, while 2 significantly abrogated in vitro tubulogenesis in MS1 cells. The ability of 2 to induce multiple and selective in vitro cytotoxic effects encourages further investigations of trans-platinum(II) complexes with substituted pyridines

  6. The year's new drugs & biologics 2014 - Part II: trends & challenges.

    Science.gov (United States)

    Graul, A I; Serebrov, M; Cruces, E; Tracy, M; Dulsat, C

    2015-02-01

    2014 was a year of continued high activity in the pharma and biotech industry, as evidenced in part I of this annual two-part review article published last month in this journal (1). As of December 23, 2014, a total of 55 new chemical and biological entities had reached their first markets worldwide, together with another 29 important new line extensions. Another 19 products were approved for the first time during the year but not yet launched by December 23. Furthermore, during the now-traditional year-end sprint, several regulatory agencies issued last-minute approvals for other compounds that missed the deadline for inclusion in that article, bringing the total of new approvals for the year to a somewhat higher number. In addition to the successful development, registration and launch of new drugs and biologics, there are various other trends and tendencies that serve as indicators of the overall health and status of the industry. These include the pursuit of novel programs designed by regulators to stimulate the development of drugs for diseases that are currently under-treated; the regular and pragmatic culling by companies of their R&D pipelines; and the decision to unify pipelines, portfolios and sales forces through mergers and acquisitions. Copyright 2015 Prous Science, S.A.U. or its licensors. All rights reserved.

  7. Quantum selfish gene (biological evolution in terms of quantum mechanics)

    OpenAIRE

    Ozhigov, Yuri I.

    2013-01-01

    I propose to treat the biological evolution of genoms by means of quantum mechanical tools. We start with the concept of meta- gene, which specifies the "selfish gene" of R.Dawkins. Meta- gene encodes the abstract living unity, which can live relatively independently of the others, and can contain a few real creatures. Each population of living creatures we treat as the wave function on meta- genes, which module squared is the total number of creatures with the given meta-gene, and the phase ...

  8. Direct landfill disposal versus Mechanical Biological Treatment (MBT

    Directory of Open Access Journals (Sweden)

    Kulhawik Katarzyna

    2016-09-01

    Full Text Available After the implementation of a new waste management system, in which recycling is the most dominating process, landfill disposal still appears to be the most popular method of waste management in Poland, in which waste undergoes gradual decomposition and the influence of climate conditions, for example, air and atmospheric fallout, leads to the production of leachate and biogas emissions, which contribute to continual threats to the natural environment and humans. The above-mentioned threats can be limited by applying suitable techniques of waste treatment before its disposal. A technology that is oriented to these aims is a mechanical biological treatment (MBT before disposal.

  9. History of respiratory mechanics prior to World War II.

    Science.gov (United States)

    West, John B

    2012-01-01

    The history of respiratory mechanics is reviewed over a period of some 2,500 years from the ancient Greeks to World War II. A cardinal early figure was Galen (130-199 AD) who made remarkably perceptive statements on the diaphragm and the anatomy of the phrenic nerves. The polymath Leonardo da Vinci (1452-1519) contributed observations on pulmonary mechanics including the pleural space and bronchial airflow that still make good reading. Vesalius (1514-1564) produced magnificent illustrations of the lung, ribcage, and diaphragm. In the 17th century, the Oxford School including Boyle, Hooke, Lower, and Mayow were responsible for many contributions on mechanical functions including the intercostal muscles and the pleura. Hales (1677-1761) calculated the size and surface area of the alveoli, the time spent by the blood in the pulmonary capillaries, and intrathoracic pressures. Poiseuille (1799-1869) carried out classical studies of fluid mechanics including one of the first demonstrations of flow limitation in collapsible vessels. The culmination of the pre-World War II period was the outstanding contributions of Rohrer (1888-1926) and his two Swiss countrymen, Wirz (1896-1978) and von Neergaard (1887-1947). Rohrer developed the first comprehensive, quantitative treatment of respiratory mechanics in the space of 10 years including an analysis of flow in airways, and the pressure-volume behavior of the respiratory system. von Neergaard performed landmark studies on the effects of surface tension on pressure-volume behavior. Progress over the 2,500 years was slow and erratic at times, but by 1940 the stage was set for the spectacular developments of the next 70 years. © 2012 American Physiological Society

  10. Molecular biology - Part II: Beneficial liaisons: Radiobiology meets cellular and molecular biology

    International Nuclear Information System (INIS)

    Stevenson, Mary Ann; Coleman, C. Norman

    1997-01-01

    Purpose: The purpose of this course is to familiarize radiation oncologists with the concepts and terminology of molecular and cellular biology that are especially relevant to radiation oncology. The ability of radiation oncologists to remain current with the new discoveries of modern biology is essential to the development of improved therapeutic strategies and, importantly, to the proper balance between investment in technology and biology. Objective: This year, this Refresher Course is part of a three-part ''series'' including Drs. McKenna and Dritschilo. The objective is to provide continuing education for the academic and practicing radiation oncologist, physicist and biologist in the modern biologic concepts of cancer and its treatment. An effort will be made to relate these general concepts to the clinic by providing a broad view as to potential new biological treatments which might enhance the efficacy of radiation therapy. The specific focus of this Course will vary from year to year. Some of the classic radiation biology models which form the basis of clinical practice and laboratory research will be examined and 'newer' models will be presented which take into account the emerging knowledge of cellular and molecular biology. A few techniques in molecular and cellular biology will be described to the extent necessary to understand their basic concepts and their applicability. Aspects of radiation biology which will be covered include cell cycle, radiation-induced changes in the cellular phenotype, and considerations of the effect of the tumor microenvironment. It is not the expectation that the attendees will become experts in the particular subjects presented. Rather, it is the intent to increase their curiosity as to the new knowledge that is emerging and to demonstrate that these seemingly complicated areas can be understood and appreciated with a modicum of the effort

  11. Molecular biology - Part II: Beneficial liaisons: Radiobiology meets cellular and molecular biology

    International Nuclear Information System (INIS)

    Stevenson, Mary Ann; Coleman, C. Norman

    1996-01-01

    Purpose: The purpose of this course is to familiarize radiation oncologists with the concepts and terminology of molecular and cellular biology that are especially relevant to radiation oncology. The ability of radiation oncologists to remain current with the new discoveries of modern biology is essential to the development of improved therapeutic strategies and, importantly, to the proper balance between investment in technology and biology. Objective: This year, this Refresher Course is part of a three-part 'series' including Drs. Martin Brown and Amato Giaccia. The objective is to provide continuing education for the academic and practicing radiation oncologist, physicist and biologist in the modern biologic concepts of cancer and its treatment. An effort will be made to relate these general concepts to the clinic by providing a broad view as to potential new biological treatments which might enhance the efficacy of radiation therapy. The specific focus of this Course will vary from year to year. Some of the classic radiation biology models which form the basis of clinical practice and laboratory research will be examined and 'newer' models will be presented which take into account the emerging knowledge of cellular and molecular biology. A few techniques in molecular and cellular biology will be described to the extent necessary to understand their basic concepts and their applicability. Aspects of radiation biology which will be covered include cell cycle, radiation-induced changes in the cellular phenotype, and considerations of the effect of the tumor microenvironment. It is not the expectation that the attendees will become experts in the particular subjects presented. Rather, it is the intent to increase their curiosity as to the new knowledge that is emerging and to demonstrate that these seemingly complicated areas can be understood and appreciated with a modicum of the effort

  12. Beta II plasma-gun mechanical design and construction

    International Nuclear Information System (INIS)

    Pedrotti, L.; Deis, G.; Wong, R.; Calderon, M.; Chargin, A.; Garner, D.

    1979-01-01

    The magnetized coaxial plasma gun (located on the east end of the Beta II facility at the Lawrence Livermore Laboratory) will be used to test a new method of initiating a field reversed mirror plasma. The field-reversed mirror is expected to improve the mirror-fusion reactor by enhancing the ratio of fusion power to injected power. This paper concentrates on the mechanical design and construction of the magnetized coaxial plasma gun and also discusses the diagnostic devices necessary to demonstrate the formation of field-reversed rings

  13. Synthesis and biological activity of imidazopyridine anticoccidial agents: Part II.

    Science.gov (United States)

    Scribner, Andrew; Dennis, Richard; Lee, Shuliang; Ouvry, Gilles; Perrey, David; Fisher, Michael; Wyvratt, Matthew; Leavitt, Penny; Liberator, Paul; Gurnett, Anne; Brown, Chris; Mathew, John; Thompson, Donald; Schmatz, Dennis; Biftu, Tesfaye

    2008-06-01

    Coccidiosis is the major cause of morbidity and mortality in the poultry industry. Protozoan parasites of the genus Eimeria invade the intestinal lining of the avian host causing tissue pathology, poor weight gain, and in some cases mortality. Resistance to current anticoccidials has prompted the search for new therapeutic agents with potent in vitro and in vivo activity against Eimeria. Recently, we reported the synthesis and biological activity of potent imidazo[1,2-a]pyridine anticoccidial agents. Antiparasitic activity is due to inhibition of a parasite specific cGMP-dependent protein kinase (PKG). In this study, we report the synthesis and anticoccidial activity of a second set of such compounds, focusing on derivatization of the amine side chain at the imidazopyridine 7-position. From this series, several compounds showed subnanomolar in vitro activity and commercial levels of in vivo activity. However, the potential genotoxicity of these compounds precludes them from further development.

  14. Biological low pH Mn(II) oxidation in a manganese deposit influenced by metal-rich groundwater

    Science.gov (United States)

    Bohu, Tsing; Akob, Denise M.; Abratis, Michael; Lazar, Cassandre S.; Küsel, Kirsten

    2016-01-01

    The mechanisms, key organisms, and geochemical significance of biological low-pH Mn(II) oxidation are largely unexplored. Here, we investigated the structure of indigenous Mn(II)-oxidizing microbial communities in a secondary subsurface Mn oxide deposit influenced by acidic (pH 4.8) metal-rich groundwater in a former uranium mining area. Microbial diversity was highest in the Mn deposit compared to the adjacent soil layers and included the majority of known Mn(II)-oxidizing bacteria (MOB) and two genera of known Mn(II)-oxidizing fungi (MOF). Electron X-ray microanalysis showed that romanechite [(Ba,H2O)2(Mn4+,Mn3+)5O10] was conspicuously enriched in the deposit. Canonical correspondence analysis revealed that certain fungal, bacterial, and archaeal groups were firmly associated with the autochthonous Mn oxides. Eight MOB within the Proteobacteria, Actinobacteria, and Bacteroidetes and one MOF strain belonging to Ascomycota were isolated at pH 5.5 or 7.2 from the acidic Mn deposit. Soil-groundwater microcosms demonstrated 2.5-fold-faster Mn(II) depletion in the Mn deposit than adjacent soil layers. No depletion was observed in the abiotic controls, suggesting that biological contribution is the main driver for Mn(II) oxidation at low pH. The composition and species specificity of the native low-pH Mn(II) oxidizers were highly adapted to in situ conditions, and these organisms may play a central role in the fundamental biogeochemical processes (e.g., metal natural attenuation) occurring in the acidic, oligotrophic, and metalliferous subsoil ecosystems.

  15. HYLIFE-II reactor chamber mechanical design: Update

    International Nuclear Information System (INIS)

    House, P.A.

    1992-01-01

    Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li 2 BeF 4 ) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (17 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GW e and 2 GW e reactor chamber are presented

  16. Biological wastewater treatment. II Nutrient elimination; Tratamiento biologico de aguas residuales. II Eliminacion de nutrientes

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C.; Isac, L.; Lebrato, J. [Universidad de Sevilla (Spain)

    2000-07-01

    Most biological wastewater processes are designed for carbonaceous compounds removal. In some cases, nutrient removal is required. In this work, biodiversity and microbial interactions of nitrogen and phosphorus removal are described. (Author) 12 refs.

  17. Lactose Intolerance in Adults: Biological Mechanism and Dietary Management.

    Science.gov (United States)

    Deng, Yanyong; Misselwitz, Benjamin; Dai, Ning; Fox, Mark

    2015-09-18

    Lactose intolerance related to primary or secondary lactase deficiency is characterized by abdominal pain and distension, borborygmi, flatus, and diarrhea induced by lactose in dairy products. The biological mechanism and lactose malabsorption is established and several investigations are available, including genetic, endoscopic and physiological tests. Lactose intolerance depends not only on the expression of lactase but also on the dose of lactose, intestinal flora, gastrointestinal motility, small intestinal bacterial overgrowth and sensitivity of the gastrointestinal tract to the generation of gas and other fermentation products of lactose digestion. Treatment of lactose intolerance can include lactose-reduced diet and enzyme replacement. This is effective if symptoms are only related to dairy products; however, lactose intolerance can be part of a wider intolerance to variably absorbed, fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). This is present in at least half of patients with irritable bowel syndrome (IBS) and this group requires not only restriction of lactose intake but also a low FODMAP diet to improve gastrointestinal complaints. The long-term effects of a dairy-free, low FODMAPs diet on nutritional health and the fecal microbiome are not well defined. This review summarizes recent advances in our understanding of the genetic basis, biological mechanism, diagnosis and dietary management of lactose intolerance.

  18. Training to Improve Hearing Speech in Noise: Biological Mechanisms

    Science.gov (United States)

    Song, Judy H.; Skoe, Erika; Banai, Karen

    2012-01-01

    We investigated training-related improvements in listening in noise and the biological mechanisms mediating these improvements. Training-related malleability was examined using a program that incorporates cognitively based listening exercises to improve speech-in-noise perception. Before and after training, auditory brainstem responses to a speech syllable were recorded in quiet and multitalker noise from adults who ranged in their speech-in-noise perceptual ability. Controls did not undergo training but were tested at intervals equivalent to the trained subjects. Trained subjects exhibited significant improvements in speech-in-noise perception that were retained 6 months later. Subcortical responses in noise demonstrated training-related enhancements in the encoding of pitch-related cues (the fundamental frequency and the second harmonic), particularly for the time-varying portion of the syllable that is most vulnerable to perceptual disruption (the formant transition region). Subjects with the largest strength of pitch encoding at pretest showed the greatest perceptual improvement. Controls exhibited neither neurophysiological nor perceptual changes. We provide the first demonstration that short-term training can improve the neural representation of cues important for speech-in-noise perception. These results implicate and delineate biological mechanisms contributing to learning success, and they provide a conceptual advance to our understanding of the kind of training experiences that can influence sensory processing in adulthood. PMID:21799207

  19. Lactose Intolerance in Adults: Biological Mechanism and Dietary Management

    Directory of Open Access Journals (Sweden)

    Yanyong Deng

    2015-09-01

    Full Text Available Lactose intolerance related to primary or secondary lactase deficiency is characterized by abdominal pain and distension, borborygmi, flatus, and diarrhea induced by lactose in dairy products. The biological mechanism and lactose malabsorption is established and several investigations are available, including genetic, endoscopic and physiological tests. Lactose intolerance depends not only on the expression of lactase but also on the dose of lactose, intestinal flora, gastrointestinal motility, small intestinal bacterial overgrowth and sensitivity of the gastrointestinal tract to the generation of gas and other fermentation products of lactose digestion. Treatment of lactose intolerance can include lactose-reduced diet and enzyme replacement. This is effective if symptoms are only related to dairy products; however, lactose intolerance can be part of a wider intolerance to variably absorbed, fermentable oligo-, di-, monosaccharides and polyols (FODMAPs. This is present in at least half of patients with irritable bowel syndrome (IBS and this group requires not only restriction of lactose intake but also a low FODMAP diet to improve gastrointestinal complaints. The long-term effects of a dairy-free, low FODMAPs diet on nutritional health and the fecal microbiome are not well defined. This review summarizes recent advances in our understanding of the genetic basis, biological mechanism, diagnosis and dietary management of lactose intolerance.

  20. Review: Bioenergetic Fields and Their Biologic Effects Mechanism

    Directory of Open Access Journals (Sweden)

    Zahra Movaffaghi

    2007-04-01

    Full Text Available As interests in complementary and alternative medicine grows, the scientists are looking forward in researches which determine the mechanisms in which they exert their effectiveness. Some of these modalities like Yoga, Acupuncture, and especially other bio-field therapies such as none contact therapeutic touch, affects the bio-field which spreads throughout the body and into the space around it. According to physic’s law, when electricity flows throw the living tissues, like what happens in our heart and brain, biomagnetic fields are being induced in the surrounding space. Beside that moving charges like ions and free radicals which finally produce electromagnetic fields. Using very sensitive magnetometers, biomagnetic fields have been detected and get amplified up to 1000 times by meditation. This phenomenon could be the basis for most of most complementaty therapeutic approaches like therapeutic touch. On the other hand the electrical, magnetic and bio-magnetic fields have a well known application in conventional medicine. Modern research about bio-magnetism and magneto-biology suggests that in term of both aspects, the effects and the mechanisms for all the different looking modalities used in conventional medicine and complementary medicine which have commons in their fundamentals. This article reviews some of the recent works on biological effects of natural or artificial electromagnetic fields.

  1. On the mechanism of biological activation by tritium.

    Science.gov (United States)

    Rozhko, T V; Badun, G A; Razzhivina, I A; Guseynov, O A; Guseynova, V E; Kudryasheva, N S

    2016-06-01

    The mechanism of biological activation by beta-emitting radionuclide tritium was studied. Luminous marine bacteria were used as a bioassay to monitor the biological effect of tritium with luminescence intensity as the physiological parameter tested. Two different types of tritium sources were used: HTO molecules distributed regularly in the surrounding aqueous medium, and a solid source with tritium atoms fixed on its surface (tritium-labeled films, 0.11, 0.28, 0.91, and 2.36 MBq/cm(2)). When using the tritium-labeled films, tritium penetration into the cells was prevented. The both types of tritium sources revealed similar changes in the bacterial luminescence kinetics: a delay period followed by bioluminescence activation. No monotonic dependences of bioluminescence activation efficiency on specific radioactivities of the films were found. A 15-day exposure to tritiated water (100 MBq/L) did not reveal mutations in bacterial DNA. The results obtained give preference to a "non-genomic" mechanism of bioluminescence activation by tritium. An activation of the intracellular bioluminescence process develops without penetration of tritium atoms into the cells and can be caused by intensification of trans-membrane cellular processes stimulated by ionization and radiolysis of aqueous media. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Fluctuating Nonlinear Spring Model of Mechanical Deformation of Biological Particles.

    Directory of Open Access Journals (Sweden)

    Olga Kononova

    2016-01-01

    Full Text Available The mechanical properties of virus capsids correlate with local conformational dynamics in the capsid structure. They also reflect the required stability needed to withstand high internal pressures generated upon genome loading and contribute to the success of important events in viral infectivity, such as capsid maturation, genome uncoating and receptor binding. The mechanical properties of biological nanoparticles are often determined from monitoring their dynamic deformations in Atomic Force Microscopy nanoindentation experiments; but a comprehensive theory describing the full range of observed deformation behaviors has not previously been described. We present a new theory for modeling dynamic deformations of biological nanoparticles, which considers the non-linear Hertzian deformation, resulting from an indenter-particle physical contact, and the bending of curved elements (beams modeling the particle structure. The beams' deformation beyond the critical point triggers a dynamic transition of the particle to the collapsed state. This extreme event is accompanied by a catastrophic force drop as observed in the experimental or simulated force (F-deformation (X spectra. The theory interprets fine features of the spectra, including the nonlinear components of the FX-curves, in terms of the Young's moduli for Hertzian and bending deformations, and the structural damage dependent beams' survival probability, in terms of the maximum strength and the cooperativity parameter. The theory is exemplified by successfully describing the deformation dynamics of natural nanoparticles through comparing theoretical curves with experimental force-deformation spectra for several virus particles. This approach provides a comprehensive description of the dynamic structural transitions in biological and artificial nanoparticles, which is essential for their optimal use in nanotechnology and nanomedicine applications.

  3. Biological and Chemical Removal of Primary Cilia Affects Mechanical Activation of Chondrogenesis Markers in Chondroprogenitors and Hypertrophic Chondrocytes.

    Science.gov (United States)

    Deren, Matthew E; Yang, Xu; Guan, Yingjie; Chen, Qian

    2016-02-04

    Chondroprogenitors and hypertrophic chondrocytes, which are the first and last stages of the chondrocyte differentiation process, respectively, are sensitive to mechanical signals. We hypothesize that the mechanical sensitivity of these cells depends on the cell surface primary cilia. To test this hypothesis, we removed the primary cilia by biological means with transfection with intraflagellar transport protein 88 (IFT88) siRNA or by chemical means with chloral hydrate treatment. Transfection of IFT88 siRNA significantly reduced the percentage of ciliated cells in both chondroprogenitor ATDC5 cells as well as primary hypertrophic chondrocytes. Cyclic loading (1 Hz, 10% matrix deformation) of ATDC5 cells in three-dimensional (3D) culture stimulates the mRNA levels of chondrogenesis marker Type II collagen (Col II), hypertrophic chondrocyte marker Type X collagen (Col X), and a molecular regulator of chondrogenesis and chondrocyte hypertrophy bone morphogenetic protein 2 (BMP-2). The reduction of ciliated chondroprogenitors abolishes mechanical stimulation of Col II, Col X, and BMP-2. In contrast, cyclic loading stimulates Col X mRNA levels in hypertrophic chondrocytes, but not those of Col II and BMP-2. Both biological and chemical reduction of ciliated hypertrophic chondrocytes reduced but failed to abolish mechanical stimulation of Col X mRNA levels. Thus, primary cilia play a major role in mechanical stimulation of chondrogenesis and chondrocyte hypertrophy in chondroprogenitor cells and at least a partial role in hypertrophic chondrocytes.

  4. Biological and Chemical Removal of Primary Cilia Affects Mechanical Activation of Chondrogenesis Markers in Chondroprogenitors and Hypertrophic Chondrocytes

    Directory of Open Access Journals (Sweden)

    Matthew E. Deren

    2016-02-01

    Full Text Available Chondroprogenitors and hypertrophic chondrocytes, which are the first and last stages of the chondrocyte differentiation process, respectively, are sensitive to mechanical signals. We hypothesize that the mechanical sensitivity of these cells depends on the cell surface primary cilia. To test this hypothesis, we removed the primary cilia by biological means with transfection with intraflagellar transport protein 88 (IFT88 siRNA or by chemical means with chloral hydrate treatment. Transfection of IFT88 siRNA significantly reduced the percentage of ciliated cells in both chondroprogenitor ATDC5 cells as well as primary hypertrophic chondrocytes. Cyclic loading (1 Hz, 10% matrix deformation of ATDC5 cells in three-dimensional (3D culture stimulates the mRNA levels of chondrogenesis marker Type II collagen (Col II, hypertrophic chondrocyte marker Type X collagen (Col X, and a molecular regulator of chondrogenesis and chondrocyte hypertrophy bone morphogenetic protein 2 (BMP-2. The reduction of ciliated chondroprogenitors abolishes mechanical stimulation of Col II, Col X, and BMP-2. In contrast, cyclic loading stimulates Col X mRNA levels in hypertrophic chondrocytes, but not those of Col II and BMP-2. Both biological and chemical reduction of ciliated hypertrophic chondrocytes reduced but failed to abolish mechanical stimulation of Col X mRNA levels. Thus, primary cilia play a major role in mechanical stimulation of chondrogenesis and chondrocyte hypertrophy in chondroprogenitor cells and at least a partial role in hypertrophic chondrocytes.

  5. A Method for Selective Depletion of Zn(II) Ions from Complex Biological Media and Evaluation of Cellular Consequences of Zn(II) Deficiency

    Science.gov (United States)

    Richardson, Christopher E. R.; Cunden, Lisa S.; Butty, Vincent L.; Nolan, Elizabeth M.; Lippard, Stephen J.; Shoulders, Matthew D.

    2018-01-01

    We describe the preparation, evaluation, and application of an S100A12 protein-conjugated solid support, hereafter the “A12-resin,” that can remove 99% of Zn(II) from complex biological solutions without significantly perturbing the concentrations of other metal ions. The A12-resin can be applied to selectively deplete Zn(II) from diverse tissue culture media and from other biological fluids, including human serum. To further demonstrate the utility of this approach, we investigated metabolic, transcriptomic, and metallomic responses of HEK293 cells cultured in medium depleted of Zn(II) using S100A12. The resulting data provide insight into how cells respond to acute Zn(II) deficiency. We expect that the A12-resin will facilitate interrogation of disrupted Zn(II) homeostasis in biological settings, uncovering novel roles for Zn(II) in biology. PMID:29334734

  6. Biological Effects of Neutron and Proton Irradiations. Vol. II. Proceedings of the Symposium on Biological Effects of Neutron Irradiations

    International Nuclear Information System (INIS)

    1964-01-01

    During recent years the interest in biological effects caused by neutrons has been increasing steadily as a result of the rapid development of neutron technology and the great number of neutron sources being used. Neutrons, because of their specific physical characteristics and biological effects, form a special type of radiation hazard but, at the same time, are a prospective tool for applied radiobiology. This Symposium, held in Brookhaven at the invitation of the United States Government from 7-11 October 1963, provided an opportunity for scientists to discuss the experimental information at present available on the biological action of neutrons and to evaluate future possibilities. It was a sequel to the Symposium on Neutron Detection, Dosimetry and Standardization, which was organized by the International Atomic Energy Agency in December 1962 at Harwell. The Symposium was attended by 128 participants from 17 countries and 6 international organizations. Fifty-four papers were presented. The following subjects were discussed in various sessions: (1) Dosimetry. Estimation of absorbed dose of neutrons in biological material. (2) Biological effects of high-energy protons. (3) Cellular and genetic effects. (4) Pathology of neutron irradiation, including acute and chronic radiation syndromes (mortality, anatomical and histological changes, biochemical and metabolic disturbances) and delayed consequences. (5) Relative biological effectiveness of neutrons evaluated by different biological tests. A Panel on Biophysical Considerations in Neutron Experimentation, with special emphasis on informal discussions, was organized during the Symposium. The views of the Panel are recorded in Volume II of the Proceedings. Many reports were presented on the important subject of the relative effectiveness of the biological action of neutrons, as well as on the general pathology of neutron irradiation and the cellular and genetic effects related to it. Three survey papers considered

  7. Universal biology and the statistical mechanics of early life

    Science.gov (United States)

    Goldenfeld, Nigel; Biancalani, Tommaso; Jafarpour, Farshid

    2017-11-01

    All known life on the Earth exhibits at least two non-trivial common features: the canonical genetic code and biological homochirality, both of which emerged prior to the Last Universal Common Ancestor state. This article describes recent efforts to provide a narrative of this epoch using tools from statistical mechanics. During the emergence of self-replicating life far from equilibrium in a period of chemical evolution, minimal models of autocatalysis show that homochirality would have necessarily co-evolved along with the efficiency of early-life self-replicators. Dynamical system models of the evolution of the genetic code must explain its universality and its highly refined error-minimization properties. These have both been accounted for in a scenario where life arose from a collective, networked phase where there was no notion of species and perhaps even individuality itself. We show how this phase ultimately terminated during an event sometimes known as the Darwinian transition, leading to the present epoch of tree-like vertical descent of organismal lineages. These examples illustrate concrete examples of universal biology: the quest for a fundamental understanding of the basic properties of living systems, independent of precise instantiation in chemistry or other media. This article is part of the themed issue 'Reconceptualizing the origins of life'.

  8. Dissecting the Molecular Mechanisms of Neurodegenerative Diseases through Network Biology

    Directory of Open Access Journals (Sweden)

    Jose A. Santiago

    2017-05-01

    Full Text Available Neurodegenerative diseases are rarely caused by a mutation in a single gene but rather influenced by a combination of genetic, epigenetic and environmental factors. Emerging high-throughput technologies such as RNA sequencing have been instrumental in deciphering the molecular landscape of neurodegenerative diseases, however, the interpretation of such large amounts of data remains a challenge. Network biology has become a powerful platform to integrate multiple omics data to comprehensively explore the molecular networks in the context of health and disease. In this review article, we highlight recent advances in network biology approaches with an emphasis in brain-networks that have provided insights into the molecular mechanisms leading to the most prevalent neurodegenerative diseases including Alzheimer’s (AD, Parkinson’s (PD and Huntington’s diseases (HD. We discuss how integrative approaches using multi-omics data from different tissues have been valuable for identifying biomarkers and therapeutic targets. In addition, we discuss the challenges the field of network medicine faces toward the translation of network-based findings into clinically actionable tools for personalized medicine applications.

  9. Quantum information and the problem of mechanisms of biological evolution.

    Science.gov (United States)

    Melkikh, Alexey V

    2014-01-01

    One of the most important conditions for replication in early evolution is the de facto elimination of the conformational degrees of freedom of the replicators, the mechanisms of which remain unclear. In addition, realistic evolutionary timescales can be established based only on partially directed evolution, further complicating this issue. A division of the various evolutionary theories into two classes has been proposed based on the presence or absence of a priori information about the evolving system. A priori information plays a key role in solving problems in evolution. Here, a model of partially directed evolution, based on the learning automata theory, which includes a priori information about the fitness space, is proposed. A potential repository of such prior information is the states of biologically important molecules. Thus, the need for extended evolutionary synthesis is discussed. Experiments to test the hypothesis of partially directed evolution are proposed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Can We Describe Biological Systems with Quantum Mechanics?

    International Nuclear Information System (INIS)

    Granados-Ramírez, C G; Benítez-Cardoza, C G; Carbajal-Tinoco, M D

    2016-01-01

    Quantum Mechanics is the favourite theory to predict the structure of any group of atoms, including biological molecules. Due to numerous difficulties, however, it is necessary to introduce a series of approximations to overcome such impediments. We present a coarse-grained model of circular dichroism (CD) that is based on the theory of optical activity, developed by DeVoe, in order to predict CD spectra. In first stage, we determine the polarisability of individual monomers (residues, in the case of peptides) from experiments of molar absorptivity. The complex polarisabilities are used together with peptide structures obtained by density functional theory and other methods to determine their corresponding CD spectra, which are in reasonable agreement with their experimental counterparts. (paper)

  11. Obstructive renal injury: from fluid mechanics to molecular cell biology.

    Science.gov (United States)

    Ucero, Alvaro C; Gonçalves, Sara; Benito-Martin, Alberto; Santamaría, Beatriz; Ramos, Adrian M; Berzal, Sergio; Ruiz-Ortega, Marta; Egido, Jesus; Ortiz, Alberto

    2010-04-22

    Urinary tract obstruction is a frequent cause of renal impairment. The physiopathology of obstructive nephropathy has long been viewed as a mere mechanical problem. However, recent advances in cell and systems biology have disclosed a complex physiopathology involving a high number of molecular mediators of injury that lead to cellular processes of apoptotic cell death, cell injury leading to inflammation and resultant fibrosis. Functional studies in animal models of ureteral obstruction using a variety of techniques that include genetically modified animals have disclosed an important role for the renin-angiotensin system, transforming growth factor-β1 (TGF-β1) and other mediators of inflammation in this process. In addition, high throughput techniques such as proteomics and transcriptomics have identified potential biomarkers that may guide clinical decision-making.

  12. Synthesis, Characterization, and Biological Activity of Nickel (II and Palladium (II Complex with Pyrrolidine Dithiocarbamate (PDTC

    Directory of Open Access Journals (Sweden)

    Sk Imadul Islam

    2016-01-01

    Full Text Available The synthesis of square planar Ni(II and Pd(II complexes with pyrrolidine dithiocarbamate (PDTC was characterized by elemental, physiochemical, and spectroscopic methods. Two complexes were prepared by the reaction of nickel acetate and palladium acetate with pyrrolidine dithiocarbamate (PDTC in 1 : 2 molar ratio. The bovine serum albumin (BSA interaction with complexes was examined by absorption and fluorescence spectroscopic techniques at pH 7.4. All the spectral data suggest that coordination of the pyrrolidine dithiocarbamate (PDTC takes place through the two sulphur atoms in a symmetrical bidentate fashion. All the synthesized compounds were screened for their antimicrobial activity against some species of pathogenic bacteria (Escherichia coli, Vibrio cholerae, Streptococcus pneumonia, and Bacillus cereus. It has been observed that complexes have higher activity than the free ligand.

  13. [Molecular Biology on the Mechanisms of Autism Spectrum Disorder for Clinical Psychiatrists].

    Science.gov (United States)

    Makinodan, Manabu

    2015-01-01

    While, in general, a certain number of clinical psychiatrists might not be familiar with molecular biology, the mechanisms of mental illnesses have been uncovered by molecular biology for decades. Among mental illnesses, even biological psychiatrists and neuroscientists have paid less attention to the biological treatment of autism spectrum disorder (ASD) than Alzheimer's disease and schizophrenia since ASD has been regarded as a developmental disorder that was seemingly untreatable. However, multifaceted methods of molecular biology have revealed the mechanisms that would lead to the medication of ASD. In this article, how molecular biology dissects the pathobiology of ASD is described in order to announce the possibilities of biological treatment for clinical psychiatrists.

  14. Formamidopyrimidines in DNA: mechanisms of formation, repair, and biological effects.

    Science.gov (United States)

    Dizdaroglu, Miral; Kirkali, Güldal; Jaruga, Pawel

    2008-12-15

    Oxidatively induced damage to DNA results in a plethora of lesions comprising modified bases and sugars, DNA-protein cross-links, tandem lesions, strand breaks, and clustered lesions. Formamidopyrimidines, 4,6-diamino-5-formamidopyrimidine (FapyAde) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua), are among the major lesions generated in DNA by hydroxyl radical attack, UV radiation, or photosensitization under numerous in vitro and in vivo conditions. They are formed by one-electron reduction of C8-OH-adduct radicals of purines and thus have a common precursor with 8-hydroxypurines generated upon one-electron oxidation. Methodologies using mass spectrometry exist to accurately measure FapyAde and FapyGua in vitro and in vivo. Formamidopyrimidines are repaired by base excision repair. Numerous prokaryotic and eukaryotic DNA glycosylases are highly specific for removal of these lesions from DNA in the first step of this repair pathway, indicating their biological importance. FapyAde and FapyGua are bypassed by DNA polymerases with the insertion of the wrong intact base opposite them, leading to mutagenesis. In mammalian cells, the mutagenicity of FapyGua exceeds that of 8-hydroxyguanine, which is thought to be the most mutagenic of the oxidatively induced lesions in DNA. The background and formation levels of the former in vitro and in vivo equal or exceed those of the latter under various conditions. FapyAde and FapyGua exist in living cells at significant background levels and are abundantly generated upon exposure to oxidative stress. Mice lacking the genes that encode specific DNA glycosylases accumulate these lesions in different organs and, in some cases, exhibit a series of pathological conditions including metabolic syndrome and cancer. Animals exposed to environmental toxins accumulate formamidopyrimidines in their organs. Here, we extensively review the mechanisms of formation, measurement, repair, and biological effects of formamidopyrimidines

  15. Chemical, mechanical and biological properties of contemporary composite surface sealers.

    Science.gov (United States)

    Anagnostou, Maria; Mountouris, George; Silikas, Nick; Kletsas, Dimitris; Eliades, George

    2015-12-01

    To evaluate the chemical, mechanical, and biological properties of modern composite surface sealers (CSS) having different compositions. The CSS products tested were Biscover LV (BC), Durafinish (DF), G-Coat Plus (GC), and Permaseal (PS). The tests performed were: (A): degree of conversion (DC%) by ATR-FTIR spectroscopy; (B): thickness of O2-inhibition layer by transmission optical microscopy; (C): surface hardness, 10 min after irradiation and following 1 week water storage, employing a Vickers indenter (VHN); (D): color (ΔE*) and gloss changes (ΔGU) after toothbrush abrasion, using L*a*b* colorimetry and glossimetry; (E): accelerated wear (GC,PS only) by an OHSU wear simulator plus 3D profilometric analysis, and (F): cytotoxicity testing of aqueous CSS eluents on human gingival fibroblast cultures employing the methyl-(3)H thymidine DNA labeling method. Statistical analyses included 1-way (A, B, ΔE*, ΔGU) and 2-way (C, F) ANOVAs, plus Tukey post hoc tests. Student's t-test was used to evaluate the results of the accelerated wear test (α=0.05 for all). The rankings of the statistical significant differences were: (A) PS (64.9)>DF,BC,GC (56.1-53.9) DC%; (B) DF,PS (12.3,9.8)>GC,BC (5.2,4.8) μm; (C): GC (37.6)>BC,DF (32.6,31.1)>PS (26.6) VHN (10 min/dry) and BC,DF (29.3,28.7)>GC(26.5)>PS(21.6) VHN (1w/water), with no significant material/storage condition interaction; (D): no differences were found among GC,DF,BC,PS (0.67-1.11) ΔE*, with all values within the visually acceptable range and PS,BC (32.8,29.4)>GC,DF (19.4,12.9) ΔGU; (E): no differences were found between GC and PS in volume loss (0.10,0.11 mm(3)), maximum (113.9,130.5 μm) and mean wear depths (30.3,27.5 μm); (F): at 1% v/v concentration, DF showed toxicity (23% vital cells vs 95-102% for others). However, at 5% v/v concentration DF (0%) and BC (9%) were the most toxic, whereas GC (58%) and PS (56%) showed moderate toxicity. Important chemical, mechanical, and biological properties exist among

  16. Biological mechanisms of radiation effects; Biologische Mechanismen der Strahlenwirkung

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, S.; Doerr, W. [Medizinische Universitaet Wien, ATRAB - Angewandte und Translationale Radiobiologie, Univ.-Klinik fuer Strahlentherapie, Wien (Austria)

    2017-07-15

    Exposure to ionizing radiation for diagnostic purposes is inevitable in modern medicine. The therapeutic application of irradiation is highly effective against cancer; however, this implies exposure of normal tissue structures to significant doses of radiation. Diagnostic or therapeutic exposure to ionizing radiation can result in tissue changes and tumor induction in the long term. Knowledge of the biological mechanisms underlying these effects is essential for individualization of the application. This article examines the biological mechanisms at the tissue and molecular level, the clinical manifestation of radiation effects, dose-dependence of the risk and the temporal progression as well as influencing factors. The time course of the reaction of tissues to radiation exposure extends over wide ranges up to many decades. The effects of radiation on tissues are classified into early and late and their pathobiology is significantly different. Various factors (R) influencing the clinical manifestation of radiation effects have been identified related to the exposure pattern. The radiation tolerance of normal tissue structures regarding the induction of functional deficits shows great variation but always has a threshold value, which is usually not exceeded in diagnostic procedures. The risk of a radiation-induced fatal malignancy (total body exposure 5%/Gy) for a medical administration of radiation must be considered as very low in comparison to the natural risks. Informed consent of patients must reflect this in a balanced way. (orig.) [German] Eine Exposition mit ionisierender Strahlung fuer diagnostische Zwecke ist in der modernen Medizin unumgaenglich. Bei einer Tumorerkrankung ist die therapeutische Anwendung dieser Strahlung hoch effektiv. Dies impliziert immer eine Exposition normaler Gewebestrukturen mit signifikanten Strahlendosen. Die diagnostische oder therapeutische Exposition mit ionisierender Strahlung kann langfristig zu Gewebeveraenderungen und

  17. Cadmium (II) removal mechanisms in microbial electrolysis cells

    Energy Technology Data Exchange (ETDEWEB)

    Colantonio, Natalie; Kim, Younggy, E-mail: younggy@mcmaster.ca

    2016-07-05

    Highlights: • Rapid removal of Cd(II) was achieved in 24 h using microbial electrolysis cells. • Cathodic reduction (electrodeposition) of Cd(II) cannot explain the rapid removal. • H{sub 2} evolution in microbial electrolysis cells increases local pH near the cathode. • High local pH induces Cd(OH){sub 2} and CdCO{sub 3} precipitation only with electric current. • Neutral pH caused by low current and depleted substrate dissolves the precipitated Cd. - Abstract: Cadmium is a toxic heavy metal, causing serious environmental and human health problems. Conventional methods for removing cadmium from wastewater are expensive and inefficient for low concentrations. Microbial electrolysis cells (MECs) can simultaneously treat wastewater, produce hydrogen gas, and remove heavy metals with low energy requirements. Lab-scale MECs were operated to remove cadmium under various electric conditions: applied voltages of 0.4, 0.6, 0.8, and 1.0 V; and a fixed cathode potential of −1.0 V vs. Ag/AgCl. Regardless of the electric condition, rapid removal of cadmium was demonstrated (50–67% in 24 h); however, cadmium concentration in solution increased after the electric current dropped with depleted organic substrate under applied voltage conditions. For the fixed cathode potential, the electric current was maintained even after substrate depletion and thus cadmium concentration did not increase. These results can be explained by three different removal mechanisms: cathodic reduction; Cd(OH){sub 2} precipitation; and CdCO{sub 3} precipitation. When the current decreased with depleted substrates, local pH at the cathode was no longer high due to slowed hydrogen evolution reaction (2H{sup +} + 2e{sup −} → H{sub 2}); thus, the precipitated Cd(OH){sub 2} and CdCO{sub 3} started dissolving. To prevent their dissolution, sufficient organic substrates should be provided when MECs are used for cadmium removal.

  18. Mechanism of biological liquid superlubricity of Brasenia schreberi mucilage.

    Science.gov (United States)

    Liu, Pengxiao; Liu, Yuhong; Yang, Ye; Chen, Zhe; Li, Jinjin; Luo, Jianbin

    2014-04-08

    In the present work, an excellent biological lubricant extracted from an aquatic plant called Brasenia schreberi (B.s) is reported. With a rotary cylinder-on-ring tribometer, the lubrication properties of the B.s mucilage between quartz glass surfaces have been investigated under different rotation velocity, and an ultralow friction coefficient between 0.004 and 0.006 is obtained. It is observed that the ultralow friction coefficient is independent of the rotation speed, when it is less than 0.1 m/s. SEM images indicate that the mucilage surrounding B.s is composed of polysaccharide gels with a layered structure, which are called nanosheets in the following work. Moreover, it can be deduced that the liquid superlubricity is closely related to the B.s mucilage layer absorbed on the quartz glass surface by hydrogen bonds and the superlubricity behavior only occurs when the adsorption layer stably forms between the quartz glass surface and the B.s mucilage. It is also found that superlubricity is closely dependent upon the sheet structure of the B.s mucilage and water molecules in the mucilage. According to these results, a layered nanosheets lubrication mechanism has been revealed, i.e., the ultralow friction coefficient is due to the adsorption layer of polysaccharide on the quartz glass surface and the hydration layers of water molecules bonded on the polysaccharide nanosheets between the sliding surfaces.

  19. Physicochemical Mechanisms of Synergistic Biological Action of Combinations of Aromatic Heterocyclic Compounds

    OpenAIRE

    Evstigneev, Maxim P.

    2013-01-01

    The mechanisms of synergistic biological effects observed in the simultaneous use of aromatic heterocyclic compounds in combination are reviewed, and the specific biological role of heteroassociation of aromatic molecules is discussed.

  20. Effect of the mechanical processing on the mechanical properties of MA956 alloy. II. Mechanical characterization

    International Nuclear Information System (INIS)

    Chao, J.; Gonzalez-Doncel, G.

    1998-01-01

    The mechanical properties at room and low temperature of MA 956 alloy in some stages of their processing route are evaluated. In this study the influence of crystallographic orientation on plastic deformation and brittle fracture, strongly anisotropic phenomena, is also considered. It is concluded that even though MA 956 alloy was designated for high temperature applications it could be also used for cryogenic temperatures applications. (Author) 8 refs

  1. Simulation of a Congress at the Chair of Biology II in Bioengineering

    International Nuclear Information System (INIS)

    Naranjo, A V; Reznichenco, V; Lopez, N; Hernandez, R; Bajinay, S

    2007-01-01

    This work has been developed in the Chair of Biology II, the curricular contents of which correspond to Human Anatomy. This subject is taught in the second semester of the second year of studies in Bioengineering. Our main objective is that the students attending the course may integrate the syllabus contents of Anatomy with those of other subjects in the career. Ever since 1998 we have organized a congress named Congreso Intracatedra de BiologIa II (Intra Chair Congress on Biology II). This is the last assignment in the semester and is compulsory for regular students of the subject. It consists in simulating a scientific congress with international characteristics. The guidelines for the congress are made known to the students at the beginning of the semester. In groups of up to three members, the students must undertake a work that relates aspects of Anatomy with Bioengineering. Students are expected to investigate on diagnostic and/or therapeutic technology in order to write a paper that must be accepted in advance of the event. The presentation of the work must be made through PowerPoint. The originality of the research work done and the wide range of topics selected are surprising. Problems are tackled from the standpoints both of the various medical fields and of bioengineering despite the fact that they are just students of the second year in Bioengineering

  2. The potential biological mechanisms of arsenic-induced diabetes mellitus

    International Nuclear Information System (INIS)

    Tseng, C.-H.

    2004-01-01

    Although epidemiologic studies carried out in Taiwan, Bangladesh, and Sweden have demonstrated a diabetogenic effect of arsenic, the mechanisms remain unclear and require further investigation. This paper reviewed the potential biological mechanisms of arsenic-induced diabetes mellitus based on the current knowledge of the biochemical properties of arsenic. Arsenate can substitute phosphate in the formation of adenosine triphosphate (ATP) and other phosphate intermediates involved in glucose metabolism, which could theoretically slow down the normal metabolism of glucose, interrupt the production of energy, and interfere with the ATP-dependent insulin secretion. However, the concentration of arsenate required for such reaction is high and not physiologically relevant, and these effects may only happen in acute intoxication and may not be effective in subjects chronically exposed to low-dose arsenic. On the other hand, arsenite has high affinity for sulfhydryl groups and thus can form covalent bonds with the disulfide bridges in the molecules of insulin, insulin receptors, glucose transporters (GLUTs), and enzymes involved in glucose metabolism (e.g., pyruvate dehydrogenase and α-ketoglutarate dehydrogenase). As a result, the normal functions of these molecules can be hampered. However, a direct effect on these molecules caused by arsenite at physiologically relevant concentrations seems unlikely. Recent evidence has shown that treatment of arsenite at lower and physiologically relevant concentrations can stimulate glucose transport, in contrary to an inhibitory effect exerted by phenylarsine oxide (PAO) or by higher doses of arsenite. Induction of oxidative stress and interferences in signal transduction or gene expression by arsenic or by its methylated metabolites are the most possible causes to arsenic-induced diabetes mellitus through mechanisms of induction of insulin resistance and β cell dysfunction. Recent studies have shown that, in subjects with chronic

  3. Synthesis, Characterization, and Biological Activity of Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II Complexes of N-Thiophenoyl-N′-Phenylthiocarbohydrazide

    Directory of Open Access Journals (Sweden)

    M. Yadav

    2013-01-01

    Full Text Available Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II complex of N-thiophenoyl -N′-phenylthiocarbohydrazide (H2 TPTH have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, infrared, NMR, electronic, and ESR spectral studies. The complexes were found to have compositions [Mn(H TPTH2], [Co(TPTH (H2O2], [Ni(TPTH (H2O2], [Cu(TPTH], [Zn(H TPTH], [Cd(H TPTH2], and [Fe(H TPTH2(EtOH]. The magnetic and electronic spectral studies suggest square planar geometry for [Cu(TPTH], tetrahedral geometry for [Zn(TPTH] and [Cd(H TPTH2], and octahedral geometry for rest of the complexes. The infrared spectral studies of the 1 : 1 deprotonated complexes suggest bonding through enolic oxygen, thiolato sulfur, and both the hydrazinic nitrogens. Thus, H2TPTH acts as a binegative tetradentate ligand. H2 TPTH and its metal complexes have been screened against several bacteria and fungi.

  4. A proposed chemical mechanism for biological phosphate removal ...

    African Journals Online (AJOL)

    This paper presents an alternative for the ";all biological"; phosphate removal model. It is postulated that a chemical substance in wastewater reacts with orthophosphate under anaerobic conditions to make the so-called luxury uptake of phosphorus possible in biological nutrient removal (BNR) activated sludge plants.

  5. Camels, Cormorants, and Kangaroo Rats: Integration and Synthesis in Organismal Biology After World War II.

    Science.gov (United States)

    Hagen, Joel B

    2015-01-01

    During the decades following World War II diverse groups of American biologists established a variety of distinctive approaches to organismal biology. Rhetorically, organismal biology could be used defensively to distinguish established research traditions from perceived threats from newly emerging fields such as molecular biology. But, organismal biologists were also interested in integrating biological disciplines and using a focus on organisms to synthesize levels of organization from molecules and cells to populations and communities. Part of this broad movement was the development of an area of research variously referred to as physiological ecology, environmental physiology, or ecophysiology. This area of research was distinctive in its self-conscious blend of field and laboratory practices and its explicit integration with other areas of biology such as ecology, animal behavior, and evolution in order to study adaptation. Comparing the intersecting careers of Knut Schmidt-Nielsen and George Bartholomew highlights two strikingly different approaches to physiological ecology. These alternative approaches to studying the interactions of organisms and environments also differed in important ways from the organismal biology championed by leading figures in the modern synthesis.

  6. Biologic Treatments for Sports Injuries II Think Tank-Current Concepts, Future Research, and Barriers to Advancement, Part 1: Biologics Overview, Ligament Injury, Tendinopathy.

    Science.gov (United States)

    LaPrade, Robert F; Geeslin, Andrew G; Murray, Iain R; Musahl, Volker; Zlotnicki, Jason P; Petrigliano, Frank; Mann, Barton J

    2016-12-01

    Biologic therapies, including stem cells, platelet-rich plasma, growth factors, and other biologically active adjuncts, have recently received increased attention in the basic science and clinical literature. At the 2015 AOSSM Biologics II Think Tank held in Colorado Springs, Colorado, a group of orthopaedic surgeons, basic scientists, veterinarians, and other investigators gathered to review the state of the science for biologics and barriers to implementation of biologics for the treatment of sports medicine injuries. This series of current concepts reviews reports the summary of the scientific presentations, roundtable discussions, and recommendations from this think tank. © 2016 The Author(s).

  7. Co(II) and Cd(II) Complexes Derived from Heterocyclic Schiff-Bases: Synthesis, Structural Characterisation, and Biological Activity

    Science.gov (United States)

    Ahmed, Riyadh M.; Yousif, Enaam I.; Al-Jeboori, Mohamad J.

    2013-01-01

    New monomeric cobalt and cadmium complexes with Schiff-bases, namely, N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]furan-2-carbohydrazide (L1) and N′-[(E)-(3-hydroxy-4-methoxyphenyl)methylidene]thiophene-2-carbohydrazide (L2) are reported. Schiff-base ligands L1 and L2 were derived from condensation of 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin) with furan-2-carboxylic acid hydrazide and thiophene-2-carboxylic acid hydrazide, respectively. Complexes of the general formula [M(L)2]Cl2 (where M = Co(II) or Cd(II), L = L1 or L2) have been obtained from the reaction of the corresponding metal chloride with the ligands. The ligands and their metal complexes were characterised by spectroscopic methods (FTIR, UV-Vis, 1H, and 13C NMR spectra), elemental analysis, metal content, magnetic measurement, and conductance. These studies revealed the formation of four-coordinate complexes in which the geometry about metal ion is tetrahedral. Biological activity of the ligands and their metal complexes against gram positive bacterial strain Bacillus (G+) and gram negative bacteria Pseudomonas (G−) revealed that the metal complexes become less resistive to the microbial activities as compared to the free ligands. PMID:24027449

  8. Biological agents and respiratory infections: Causative mechanisms and practice management.

    Science.gov (United States)

    Takayanagi, Noboru

    2015-09-01

    Biological agents are increasingly being used to treat patients with immune-mediated inflammatory disease. In Japan, currently approved biological agents for patients with rheumatoid arthritis (RA) include tumor necrosis factor inhibitors, interleukin-6 receptor-blocking monoclonal antibody, and T-cell costimulation inhibitor. Rheumatologists have recognized that safety issues are critical aspects of treatment decisions in RA. Therefore, a wealth of safety data has been gathered from a number of sources, including randomized clinical trials and postmarketing data from large national registries. These data revealed that the most serious adverse events from these drugs are respiratory infections, especially pneumonia, tuberculosis, nontuberculous mycobacteriosis, and Pneumocystis jirovecii pneumonia, and that the most common risk factors associated with these respiratory infections are older age, concomitant corticosteroid use, and underlying respiratory comorbidities. Because of this background, in 2014, the Japanese Respiratory Society published their consensus statement of biological agents and respiratory disorders. This review summarizes this statement and adds recent evidence, especially concerning respiratory infections in RA patients, biological agents and respiratory infections, and practice management of respiratory infections in patients treated with biological agents. To decrease the incidence of infections and reduce mortality, we should know the epidemiology, risk factors, management, and methods of prevention of respiratory infections in patients receiving biological agents. Copyright © 2015 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

  9. Neuroprotective Effects and Mechanisms of Curcumin–Cu(II and –Zn(II Complexes Systems and Their Pharmacological Implications

    Directory of Open Access Journals (Sweden)

    Fa-Shun Yan

    2017-12-01

    Full Text Available Alzheimer’s disease (AD is the main form of dementia and has a steadily increasing prevalence. As both oxidative stress and metal homeostasis are involved in the pathogenesis of AD, it would be interesting to develop a dual function agent, targeting the two factors. Curcumin, a natural compound isolated from the rhizome of Curcuma longa, is an antioxidant and can also chelate metal ions. Whether the complexes of curcumin with metal ions possess neuroprotective effects has not been evaluated. Therefore, the present study was designed to investigate the protective effects of the complexes of curcumin with Cu(II or Zn(II on hydrogen peroxide (H2O2-induced injury and the underlying molecular mechanisms. The use of rat pheochromocytoma (PC12 cells, a widely used neuronal cell model system, was adopted. It was revealed that curcumin–Cu(II complexes systems possessed enhanced O2·–-scavenging activities compared to unchelated curcumin. In comparison with unchelated curcumin, the protective effects of curcumin–Cu(II complexes systems were stronger than curcumin–Zn(II system. Curcumin–Cu(II or –Zn(II complexes systems significantly enhanced the superoxide dismutase, catalase, and glutathione peroxidase activities and attenuated the increase of malondialdehyde levels and caspase-3 and caspase-9 activities, in a dose-dependent manner. The curcumin–Cu(II complex system with a 2:1 ratio exhibited the most significant effect. Further mechanistic study demonstrated that curcumin–Cu(II or –Zn(II complexes systems inhibited cell apoptosis via downregulating the nuclear factor κB (NF-κB pathway and upregulating Bcl-2/Bax pathway. In summary, the present study found that curcumin–Cu(II or –Zn(II complexes systems, especially the former, possess significant neuroprotective effects, which indicates the potential advantage of curcumin as a promising agent against AD and deserves further study.

  10. Neuroprotective Effects and Mechanisms of Curcumin-Cu(II) and -Zn(II) Complexes Systems and Their Pharmacological Implications.

    Science.gov (United States)

    Yan, Fa-Shun; Sun, Jian-Long; Xie, Wen-Hai; Shen, Liang; Ji, Hong-Fang

    2017-12-28

    Alzheimer's disease (AD) is the main form of dementia and has a steadily increasing prevalence. As both oxidative stress and metal homeostasis are involved in the pathogenesis of AD, it would be interesting to develop a dual function agent, targeting the two factors. Curcumin, a natural compound isolated from the rhizome of Curcuma longa , is an antioxidant and can also chelate metal ions. Whether the complexes of curcumin with metal ions possess neuroprotective effects has not been evaluated. Therefore, the present study was designed to investigate the protective effects of the complexes of curcumin with Cu(II) or Zn(II) on hydrogen peroxide (H₂O₂)-induced injury and the underlying molecular mechanisms. The use of rat pheochromocytoma (PC12) cells, a widely used neuronal cell model system, was adopted. It was revealed that curcumin-Cu(II) complexes systems possessed enhanced O₂ ·- -scavenging activities compared to unchelated curcumin. In comparison with unchelated curcumin, the protective effects of curcumin-Cu(II) complexes systems were stronger than curcumin-Zn(II) system. Curcumin-Cu(II) or -Zn(II) complexes systems significantly enhanced the superoxide dismutase, catalase, and glutathione peroxidase activities and attenuated the increase of malondialdehyde levels and caspase-3 and caspase-9 activities, in a dose-dependent manner. The curcumin-Cu(II) complex system with a 2:1 ratio exhibited the most significant effect. Further mechanistic study demonstrated that curcumin-Cu(II) or -Zn(II) complexes systems inhibited cell apoptosis via downregulating the nuclear factor κB (NF-κB) pathway and upregulating Bcl-2/Bax pathway. In summary, the present study found that curcumin-Cu(II) or -Zn(II) complexes systems, especially the former, possess significant neuroprotective effects, which indicates the potential advantage of curcumin as a promising agent against AD and deserves further study.

  11. Diversity Generator Mechanisms Are Essential Components of Biological Systems: The Two Queen Hypothesis

    Directory of Open Access Journals (Sweden)

    Eric Muraille

    2018-02-01

    Full Text Available Diversity is widely known to fuel adaptation and evolutionary processes and increase robustness at the population, species and ecosystem levels. The Neo-Darwinian paradigm proposes that the diversity of biological entities is the consequence of genetic changes arising spontaneously and randomly, without regard for their usefulness. However, a growing body of evidence demonstrates that the evolutionary process has shaped mechanisms, such as horizontal gene transfer mechanisms, meiosis and the adaptive immune system, which has resulted in the regulated generation of diversity among populations. Though their origins are unrelated, these diversity generator (DG mechanisms share common functional properties. They (i contribute to the great unpredictability of the composition and/or behavior of biological systems, (ii favor robustness and collectivism among populations and (iii operate mainly by manipulating the systems that control the interaction of living beings with their environment. The definition proposed here for DGs is based on these properties and can be used to identify them according to function. Interestingly, prokaryotic DGs appear to be mainly reactive, as they generate diversity in response to environmental stress. They are involved in the widely described Red Queen/arms race/Cairnsian dynamic. The emergence of multicellular organisms harboring K selection traits (longer reproductive life cycle and smaller population size has led to the acquisition of a new class of DGs that act anticipatively to stress pressures and generate a distinct dynamic called the “White Queen” here. The existence of DGs leads to the view of evolution as a more “intelligent” and Lamarckian-like process. Their repeated selection during evolution could be a neglected example of convergent evolution and suggests that some parts of the evolutionary process are tightly constrained by ecological factors, such as the population size, the generation time and

  12. Solving the cardiac hypertrophy riddle: The angiotensin II-mechanical stress connection.

    Science.gov (United States)

    Zablocki, Daniela; Sadoshima, Junichi

    2013-11-08

    A series of studies conducted 20 years ago, documenting the cardiac hypertrophy phenotype and its underlying signaling mechanism induced by angiotensin II (Ang II) and mechanical stress, showed a remarkable similarity between the effect of the Gαq agonist and that of mechanical forces on cardiac hypertrophy. Subsequent studies confirmed the involvement of autocrine/paracrine mechanisms, including stretch-induced release of Ang II in load-induced cardiac hypertrophy. Recent studies showed that the Ang II type 1 (AT1) receptor is also directly activated by mechanical forces, suggesting that AT1 receptors play an important role in mediating load-induced cardiac hypertrophy through both ligand- and mechanical stress-dependent mechanisms.

  13. Mechanical properties of the beetle elytron, a biological composite material

    Science.gov (United States)

    We determined the relationship between composition and mechanical properties of elytral (modified forewing) cuticle of the beetles Tribolium castaneum and Tenebrio molitor. Elytra of both species have similar mechanical properties at comparable stages of maturation (tanning). Shortly after adult ecl...

  14. Uncovering the underlying physical mechanisms of biological systems via quantification of landscape and flux

    International Nuclear Information System (INIS)

    Xu Li; Chu Xiakun; Yan Zhiqiang; Zheng Xiliang; Zhang Kun; Zhang Feng; Yan Han; Wu Wei; Wang Jin

    2016-01-01

    In this review, we explore the physical mechanisms of biological processes such as protein folding and recognition, ligand binding, and systems biology, including cell cycle, stem cell, cancer, evolution, ecology, and neural networks. Our approach is based on the landscape and flux theory for nonequilibrium dynamical systems. This theory provides a unifying principle and foundation for investigating the underlying mechanisms and physical quantification of biological systems. (topical review)

  15. The potential mechanism of Bursal-derived BPP-II on the antibody production and avian pre-B cell.

    Science.gov (United States)

    Feng, Xiuli; Cao, Ruibing; Zhou, Bin; Liu, Qingtao; Liu, Ke; Liu, Xiaodong; Zhang, Yuanpeng; Gu, Jinyan; Miao, Denian; Chen, Puyan

    2013-03-01

    The bursa of Fabricius is critical for the normal development of the B lymphocytes responsible for antibody production. However, the mechanism of the bursal-derived bioactive factor on B cell development is little reported. In this paper, chicks were immunized with BPP-II and AIV vaccine or AIV antigen, and antibody and IL-4 production were detected. The results showed that BPP-II played strongly inducing roles on the humoral immune responses. To investigate the gene expression at transcriptional level, avian pre-B lymphocyte DT40 cells were treated with BPP-II, and were analyzed with the gene microarray. The results proved that BPP-II treatment regulated 11 pathways, in which homologous recombination is a vital mechanism which is involved in antibody Ig gene conversion and diversification during B cell development. These results suggested Bursal-derived biological active factor BPP-II might be involved in the antibody production processes and B cell development, which is vital to the humoral central immune organ, the bursa of Fabricius. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Deciphering complement mechanisms: The contributions of structural biology.

    NARCIS (Netherlands)

    Arlaud, G.J.; Barlow, P.N.; Gaboriaud, C.; Gros, P.; Narayana, S.V.L.

    2007-01-01

    Since the resolution of the first three-dimensional structure of a complement component in 1980, considerable efforts have been put into the investigation of this system through structural biology techniques, resulting in about a hundred structures deposited in the Protein Data Bank by the beginning

  17. Biological Tests for Boron Neutron Capture Therapy Research at the TRIGA Mark II Reactor in Pavia

    Energy Technology Data Exchange (ETDEWEB)

    Protti, N.; Ballarini, F.; Bortolussi, S.; De Bari, A.; Stella, S.; Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Nuclear Physics National Institute (INFN), Pavia (Italy); Bruschi, P. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Bakeine, J.G.; Cansolino, L.; Clerici, A.M. [Laboratory of Experimental Surgery, Department of Surgery, University of Pavia, Pavia (Italy)

    2011-07-01

    The thermal column of the TRIGA Mark II reactor of the Pavia University is used as an irradiation facility to perform biological tests and irradiations of living systems for Boron Neutron Capture Therapy (BNCT) research. The suitability of the facility has been ensured by studying the neutron flux and the photon background in the irradiation chamber inside the thermal column. This characterization has been realized both by flux and dose measurements as well as by Monte Carlo simulations. The routine irradiations concern in vitro cells cultures and different tumor animal models to test the efficacy of the BNCT treatment. Some results about these experiments will be described. (author)

  18. Calculation of neutron fluxes in biological shield of the TRIGA Mark II reactor

    International Nuclear Information System (INIS)

    Bozic, M.; Zagar, T.; Ravnik, M.

    2001-01-01

    The complete calculation of neutron fluxes in biological shield and verification with experimental results is presented. Calculated results are obtained with TORT code (TORT-Three Dimensional Oak Ridge Discrete Ordinates Neutron/Photon Transport Code). Experimental results used for comparison are available from irradiation experiment with selected type of concrete and other materials in irradiation channel 4 in TRIGA Mark II reactor. These experimental results were used as a benchmark. Homogeneous type of problem (without inserted irradiation channel) and problem with asymmetry (inserted beam port 4, filled with different materials) were of interest for neutron flux calculation. Deviation from material data set up as original parameters is also considered (first of all presence of water in concrete and density of concrete) for type of concrete in biological shield and for selected type of concrete in irradiation channel. BUGLE-96 (47 neutron energy groups) library is used. Excellent agreement between calculated and experimental results for reaction rate is received.(author)

  19. Toward a microrealistic version of quantum mechanics. II

    International Nuclear Information System (INIS)

    Maxwell, N.

    1976-01-01

    Possible objections to the propensity microrealistic version of quantum mechanics proposed previously are answered. This version of quantum mechanics is compared with the statistical, particle, microrealistic viewpoint, and a crucial experiment is proposed designed to distinguish between these two microrealistic versions of quantum mechanics

  20. Hybrid printing of mechanically and biologically improved constructs for cartilage tissue engineering applications

    International Nuclear Information System (INIS)

    Xu Tao; Binder, Kyle W; Albanna, Mohammad Z; Dice, Dennis; Zhao Weixin; Yoo, James J; Atala, Anthony

    2013-01-01

    deposition of type II collagen and glycosaminoglycans. Moreover, the printed hybrid scaffolds demonstrated enhanced mechanical properties compared to printed alginate or fibrin–collagen gels alone. This study demonstrates the feasibility of constructing a hybrid inkjet printing system using off-the-shelf components to produce cartilage constructs with improved biological and mechanical properties. (paper)

  1. Nanomechanical strength mechanisms of hierarchical biological materials and tissues.

    Science.gov (United States)

    Buehler, Markus J; Ackbarow, Theodor

    2008-12-01

    Biological protein materials (BPMs), intriguing hierarchical structures formed by assembly of chemical building blocks, are crucial for critical functions of life. The structural details of BPMs are fascinating: They represent a combination of universally found motifs such as alpha-helices or beta-sheets with highly adapted protein structures such as cytoskeletal networks or spider silk nanocomposites. BPMs combine properties like strength and robustness, self-healing ability, adaptability, changeability, evolvability and others into multi-functional materials at a level unmatched in synthetic materials. The ability to achieve these properties depends critically on the particular traits of these materials, first and foremost their hierarchical architecture and seamless integration of material and structure, from nano to macro. Here, we provide a brief review of this field and outline new research directions, along with a review of recent research results in the development of structure-property relationships of biological protein materials exemplified in a study of vimentin intermediate filaments.

  2. Synthesis, characterization and biological studies of metal complexes of Co (II), Ni (II), Cu (II), Zn (II) with sulphadimidine-benzylidene

    International Nuclear Information System (INIS)

    Tahira, F.; Imran, M.; Iqbal, J.

    2009-01-01

    Some novel complexes of Co (II), Ni (II), Cu (II), and Zn (II) have been synthesized with a Schiff base ligand derived from sulphadimidine and benzaldehyde. The structural features of the complexes have been determined by elemental analysis, magnetic susceptibility, conductance measurement, UV/ Vis. and infrared spectroscopy. IR studies revealed that the Schiff base ligand Sulphadimidine-benzylidene has monoanionic bidendate nature and coordinate with metal ions through nitrogen atom of azomethine (>C = N) and deprotonated -NH group. All the complexes were assigned octahedral geometry on the basis of magnetic moment and electronic spectroscopic data. Low value of conductance supports their non-electrolytic nature. The ligand, as well as its complexes were checked for their in vitro antimicrobial activities against two gram positive bacterial strains, Bacillus subtillus. Staphylococcus aureus and one gram negative Salmonella typhae and five fungal strains, Nigrospora oryzae, Curvularia lunata, Drechslera rostrata, Aspergillus niger and Candida olbicans by disc diffusion method and agar plate technique, respectively. Both the antibacterial and antitungal activities of the synthesized metal complexes were found to be more as compared to parent drug and uncomplexed ligand. All the complexes contain coordinated water, which is lost at 141-160 degree C. (author)

  3. SEACAS Theory Manuals: Part II. Nonlinear Continuum Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Attaway, S.W.; Laursen, T.A.; Zadoks, R.I.

    1998-09-01

    This report summarizes the key continuum mechanics concepts required for the systematic prescription and numerical solution of finite deformation solid mechanics problems. Topics surveyed include measures of deformation appropriate for media undergoing large deformations, stress measures appropriate for such problems, balance laws and their role in nonlinear continuum mechanics, the role of frame indifference in description of large deformation response, and the extension of these theories to encompass two dimensional idealizations, structural idealizations, and rigid body behavior. There are three companion reports that describe the problem formulation, constitutive modeling, and finite element technology for nonlinear continuum mechanics systems.

  4. Mechanical Engineering and Design of the LHC Phase II Collimators

    CERN Document Server

    Bertarelli, A; Gentini, L; Mariani, N; Perret, R; Timmins, M A

    2010-01-01

    Phase II collimators will complement the existing system to improve the expected high RF impedance and limited efficiency of Phase I jaws. An international collaborative effort has been launched to identify novel advanced materials responding to the very challenging requirements of the new collimators. Complex numerical calculations simulating extreme conditions and experimental tests are in progress. In parallel, an innovative modular design concept of the jaw assembly is being developed to allow fitting in alternative materials, minimizing the thermally induced deformations, withstanding accidents and accepting high radiation doses. Phase II jaw assembly is made up of a molybdenum back-stiffener ensuring high geometrical stability and a modular jaw split in threes sectors. Each sector is equipped with a high-efficiency independent cooling circuit. Beam position monitors (BPM) are embedded in the jaws to fasten setup time and improve beam monitoring. An adjustment system will permit to fine-tune the jaw flat...

  5. The equivalence myth of quantum mechanics-part II

    Science.gov (United States)

    Muller, F. A.

    The author endeavours to show two things: first, that Schrödingers (and Eckarts) demonstration in March (September) 1926 of the equivalence of matrix mechanics, as created by Heisenberg, Born, Jordan and Dirac in 1925, and wave mechanics, as created by Schrödinger in 1926, is not foolproof; and second, that it could not have been foolproof, because at the time matrix mechanics and wave mechanics were neither mathematically nor empirically equivalent. That they were is the Equivalence Myth. In order to make the theories equivalent and to prove this, one has to leave the historical scene of 1926 and wait until 1932, when von Neumann finished his magisterial edifice. During the period 1926-1932 the original families of mathematical structures of matrix mechanics and of wave mechanics were stretched, parts were chopped off and novel structures were added. To Procrustean places we go, where we can demonstrate the mathematical, empirical and ontological equivalence of 'the final versions of' matrix mechanics and wave mechanics. The present paper claims to be a comprehensive analysis of one of the pivotal papers in the history of quantum mechanics: Schrödingers equivalence paper. Since the analysis is performed from the perspective of Suppes structural view ('semantic view') of physical theories, the present paper can be regarded not only as a morsel of the internal history of quantum mechanics, but also as a morsel of applied philosophy of science. The paper is self-contained and presupposes only basic knowledge of quantum mechanics. For reasons of length, the paper is published in two parts; Part I appeared in the previous issue of this journal. Section 1 contains, besides an introduction, also the papers five claims and a preview of the arguments supporting these claims; so Part I, Section 1 may serve as a summary of the paper for those readers who are not interested in the detailed arguments.

  6. Synthesis, characterization and biological assay of Salicylaldehyde Schiff base Cu(II) complexes and their precursors

    Science.gov (United States)

    Iftikhar, Bushra; Javed, Kanwal; Khan, Muhammad Saif Ullah; Akhter, Zareen; Mirza, Bushra; Mckee, Vickie

    2018-03-01

    Three new Schiff base ligands were synthesized by the reaction of Salicylaldehyde with semi-aromatic diamines, prepared by the reduction of corresponding dinitro-compounds, and were further used for the formation of complexes with Cu(II) metal ion. The structural features of the synthesized compounds were confirmed by their physical properties and infrared, electronic and NMR spectroscopic techniques. The studies revealed that the synthesized Schiff bases existed as tetradentate ligands and bonded to the metal ion through the phenolic oxygen and azomethine nitrogen. One of the dinitro precursors was also analyzed by single crystal X-ray crystallography, which showed that it crystallizes in monoclinic system with space group P2/n. The thermal behavior of the Cu(II) complexes was determined by thermogravimetric analysis (TGA) and kinetic parameters were evaluated from the data. Schiff base ligands, their precursors and metal complexes were also screened for antibacterial, antifungal, antitumor, Brine shrimp lethality, DPPH free radical scavenging and DNA damage assays. The results of these analyses indicated the substantial potential of the synthesized Schiff bases, their precursors and Cu(II) complexes in biological field as future drugs.

  7. Spectroscopic, thermal, catalytic and biological studies of Cu(II) azo dye complexes

    Science.gov (United States)

    El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Shoair, A. F.; Hussein, M. A.; El-Boz, R. A.

    2017-08-01

    New complexes of copper(II) with azo compounds of 5-amino-2-(aryl diazenyl)phenol (HLn) are prepared and investigated by elemental analyses, molar conductance, IR, 1H NMR, UV-Visible, mass, ESR spectra, magnetic susceptibility measurements and thermal analyses. The complexes have a square planar structure and general formula [Cu(Ln)(OAc)]H2O. Study the catalytic activities of Cu(II) complexes toward oxidation of benzyl alcohol derivatives to carbonyl compounds were tested using H2O2 as the oxidant. The intrinsic binding constants (Kb) of the ligands (HLn) and Cu(II) complexes (1-4) with CT-DNA are determined. The formed compounds have been tested for biological activity of antioxidants, antibacterial against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and yeast Candida albicans. Antibiotic (Ampicillin) and antifungal against (Colitrimazole) and cytotoxic compounds HL1, HL2, HL3 and complex (1) showed moderate to good activity against S. aureus, E. coli and Candida albicans, and also to be moderate on antioxidants and toxic substances. Molecular docking is used to predict the binding between the ligands with the receptor of breast cancer (2a91).

  8. Biological pathways and genetic mechanisms involved in social functioning.

    Science.gov (United States)

    Ordoñana, Juan R; Bartels, Meike; Boomsma, Dorret I; Cella, David; Mosing, Miriam; Oliveira, Joao R; Patrick, Donald L; Veenhoven, Ruut; Wagner, Gert G; Sprangers, Mirjam A G

    2013-08-01

    To describe the major findings in the literature regarding associations between biological and genetic factors and social functioning, paying special attention to: (1) heritability studies on social functioning and related concepts; (2) hypothesized biological pathways and genetic variants that could be involved in social functioning, and (3) the implications of these results for quality-of-life research. A search of Web of Science and PubMed databases was conducted using combinations of the following keywords: genetics, twins, heritability, social functioning, social adjustment, social interaction, and social dysfunction. Variability in the definitions and measures of social functioning was extensive. Moderate to high heritability was reported for social functioning and related concepts, including prosocial behavior, loneliness, and extraversion. Disorders characterized by impairments in social functioning also show substantial heritability. Genetic variants hypothesized to be involved in social functioning are related to the network of brain structures and processes that are known to affect social cognition and behavior. Better knowledge and understanding about the impact of genetic factors on social functioning is needed to help us to attain a more comprehensive view of health-related quality-of-life (HRQOL) and will ultimately enhance our ability to identify those patients who are vulnerable to poor social functioning.

  9. Fluctuating Nonlinear Spring Model of Mechanical Deformation of Biological Particles

    NARCIS (Netherlands)

    Kononova, Olga; Snijder, Joost; Kholodov, Yaroslav; Marx, Kenneth A; Wuite, Gijs J L; Roos, Wouter H; Barsegov, Valeri

    The mechanical properties of virus capsids correlate with local conformational dynamics in the capsid structure. They also reflect the required stability needed to withstand high internal pressures generated upon genome loading and contribute to the success of important events in viral infectivity,

  10. Biological evaluation of mechanical circulatory support systems in calves

    NARCIS (Netherlands)

    Rakhorst, G; VanDerMeer, J; Kik, C; Mihaylov, D; Havlik, P; Trinkl, J; Monties, [No Value

    Data from animal experiments with mechanical circulatory support systems (MCSS) performed in Groningen and Marseille over the past years were used to obtain normal values of hematological, coagulation, rheological and blood chemistry parameters in calves. These parameters were divided between two

  11. Understanding the biological mechanisms of Zika virus disease ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This project will use advanced biomolecular, genomics and proteomics techniques to explain the molecular mechanisms by which the Zika virus infects and persists in the human body, how it affects the human reproductive and central nervous system, and how the risk of fetal abnormalities can be better predicted in infected ...

  12. The Mechanism of Graviton Exchange between Bodies, Part II

    DEFF Research Database (Denmark)

    Javadi, Hossein; Forouzbakhsh, Farshid

    2016-01-01

    Further to Special Relativity, modern physics includes two great theories which describe universe in a new different way. One of them is Quantum Mechanics which describes elementary particles, atoms and molecules and the other one is General Relativity which has been replaced the Newtonian...... Gravitational Law by space-time curvature. Quantum gravity is a part of quantum mechanics which is expected to combine these two theories, and it describes gravity force according to the principles of quantum mechanics which has not got the desired result, yet. In CPH theory, after reconsidering and analyzing...... the behavior of photon in the gravitational field, a new definition of graviton based on carrying the gravity force is given. By using this definition, graviton exchange mechanism between bodies/objects is described. As the purpose of quantum gravity is describing the force of gravity by using the principles...

  13. The Belle II silicon vertex detector assembly and mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Adamczyk, K. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Aihara, H. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Angelini, C. [Dipartimento di Fisica, Università di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Aziz, T.; Babu, V. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Bacher, S. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Bahinipati, S. [Indian Institute of Technology Bhubaneswar, Satya Nagar (India); Barberio, E.; Baroncelli, Ti.; Baroncelli, To. [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Basith, A.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Batignani, G. [Dipartimento di Fisica, Università di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bauer, A. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Behera, P.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Bettarini, S., E-mail: stefano.bettarini@pi.infn.it [Dipartimento di Fisica, Università di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bhuyan, B. [Indian Institute of Technology Guwahati, Assam 781039 (India); Bilka, T. [Faculty of Mathematics and Physics, Charles University, 121 16 Prague (Czech Republic); Bosi, F. [INFN Sezione di Pisa, I-56127 Pisa (Italy); Bosisio, L. [Dipartimento di Fisica, Università di Trieste, I-34127 Trieste (Italy); INFN Sezione di Trieste, I-34127 Trieste (Italy); and others

    2017-02-11

    The Belle II experiment at the asymmetric SuperKEKB collider in Japan will operate at an instantaneous luminosity approximately 50 times greater than its predecessor (Belle). The central feature of the experiment is a vertex detector comprising two layers of pixelated silicon detectors (PXD) and four layers of double-sided silicon microstrip detectors (SVD). One of the key measurements for Belle II is CP violation asymmetry in the decays of beauty and charm hadrons, which hinges on a precise charged-track vertex determination and low-momentum track measurement. Towards this goal, a proper assembly of the SVD components with precise alignment ought to be performed and the geometrical tolerances should be checked to fall within the design limits. We present an overview of the assembly procedure that is being followed, which includes the precision gluing of the SVD module components, wire-bonding of the various electrical components, and precision 3D coordinate measurements of the final SVD modules. Finally, some results from the latest test-beam are reported.

  14. Mechanization and Control Concepts for Biologically Inspired Micro Aerial Vehicles

    Science.gov (United States)

    Raney, David L.; Slominski, Eric C.

    2003-01-01

    It is possible that MAV designs of the future will exploit flapping flight in order to perform missions that require extreme agility, such as rapid flight beneath a forest canopy or within the confines of a building. Many of nature's most agile flyers generate flapping motions through resonant excitation of an aeroelastically tailored structure: muscle tissue is used to excite a vibratory mode of their flexible wing structure that creates propulsion and lift. A number of MAV concepts have been proposed that would operate in a similar fashion. This paper describes an ongoing research activity in which mechanization and control concepts with application to resonant flapping MAVs are being explored. Structural approaches, mechanical design, sensing and wingbeat control concepts inspired by hummingbirds, bats and insects are examined. Experimental results from a testbed capable of generating vibratory wingbeat patterns that approximately match those exhibited by hummingbirds in hover, cruise, and reverse flight are presented.

  15. The complete genome sequence of Bacillus velezensis 9912D reveals its biocontrol mechanism as a novel commercial biological fungicide agent.

    Science.gov (United States)

    Pan, Hua-Qi; Li, Qing-Lian; Hu, Jiang-Chun

    2017-04-10

    A Bacillus sp. 9912 mutant, 9912D, was approved as a new biological fungicide agent by the Ministry of Agriculture of the People's Republic of China in 2016 owing to its excellent inhibitory effect on various plant pathogens and being environment-friendly. Here, we present the genome of 9912D with a circular chromosome having 4436 coding DNA sequences (CDSs), and a circular plasmid encoding 59 CDSs. This strain was finally designated as Bacillus velezensis based on phylogenomic analyses. Genome analysis revealed a total of 19 candidate gene clusters involved in secondary metabolite biosynthesis, including potential new type II lantibiotics. The absence of fengycin biosynthetic gene cluster is noteworthy. Our data offer insights into the genetic, biological and physiological characteristics of this strain and aid in deeper understanding of its biocontrol mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Biological Mechanisms by Which Antiproliferative Actions of Resveratrol Are Minimized.

    Science.gov (United States)

    Ho, Yih; Lin, Yu-Syuan; Liu, Hsuan-Liang; Shih, Ya-Jung; Lin, Shin-Ying; Shih, Ai; Chin, Yu-Tang; Chen, Yi-Ru; Lin, Hung-Yun; Davis, Paul J

    2017-09-21

    Preclinical and clinical studies have offered evidence for protective effects of various polyphenol-rich foods against cardiovascular diseases, neurodegenerative diseases, and cancers. Resveratrol is among the most widely studied polyphenols. However, the preventive and treatment effectiveness of resveratrol in cancer remain controversial because of certain limitations in existing studies. For example, studies of the activity of resveratrol against cancer cell lines in vitro have often been conducted at concentrations in the low μM to mM range, whereas dietary resveratrol or resveratrol-containing wine rarely achieve nM concentrations in the clinic. While the mechanisms underlying the failure of resveratrol to inhibit cancer growth in the intact organism are not fully understood, the interference by thyroid hormones with the anticancer activity of resveratrol have been well documented in both in vitro and xenograft studies. Thus, endogenous thyroid hormones may explain the failure of anticancer actions of resveratrol in intact animals, or in the clinic. In this review, mechanisms involved in resveratrol-induced antiproliferation and effects of thyroid hormones on these mechanisms are discussed.

  17. Synthesis and Biological Evaluation of Ru(II) and Pt(II) Complexes Bearing Carboxyl Groups as Potential Anticancer Targeted Drugs.

    Science.gov (United States)

    Martínez, Ma Ángeles; Carranza, M Pilar; Massaguer, Anna; Santos, Lucia; Organero, Juan A; Aliende, Cristina; de Llorens, Rafael; Ng-Choi, Iteng; Feliu, Lidia; Planas, Marta; Rodríguez, Ana M; Manzano, Blanca R; Espino, Gustavo; Jalón, Félix A

    2017-11-20

    The synthesis and characterization of Pt(II) (1 and 2) and Ru(II) arene (3 and 4) or polypyridine (5 and 6) complexes is described. With the aim of having a functional group to form bioconjugates, one uncoordinated carboxyl group has been introduced in all complexes. Some of the complexes were selected for their potential in photodynamic therapy (PDT). The molecular structures of complexes 2 and 5, as well as that of the sodium salt of the 4'-(4-carboxyphenyl)-2,2':6',2″-terpyridine ligand (cptpy), were determined by X-ray diffraction. Different techniques were used to evaluate the binding capacity to model DNA molecules, and MTT cytotoxicity assays were performed against four cell lines. Compounds 3, 4, and 5 showed little tendency to bind to DNA and exhibited poor biological activity. Compound 2 behaves as bonded to DNA probably through a covalent interaction, although its cytotoxicity was very low. Compound 1 and possibly 6, both of which contain a cptpy ligand, were able to intercalate with DNA, but toxicity was not observed for 6. However, compound 1 was active in all cell lines tested. Clonogenic assays and apoptosis induction studies were also performed on the PC-3 line for 1. The photodynamic behavior for complexes 1, 5, and 6 indicated that their nuclease activity was enhanced after irradiation at λ = 447 nm. The cell viability was significantly reduced only in the case of 5. The different behavior in the absence or presence of light makes complex 5 a potential prodrug of interest in PDT. Molecular docking studies followed by molecular dynamics simulations for 1 and the counterpart without the carboxyl group confirmed the experimental data that pointed to an intercalation mechanism. The cytotoxicity of 1 and the potential of 5 in PDT make them good candidates for subsequent conjugation, through the carboxyl group, to "selected peptides" which could facilitate the selective vectorization of the complex toward receptors that are overexpressed in

  18. Reactivity of inorganic nanoparticles in biological environments: insights into nanotoxicity mechanisms

    International Nuclear Information System (INIS)

    Casals, E; Gonzalez, E; Puntes, V F

    2012-01-01

    A deeper understanding of the behaviour of inorganic nanoparticles in biological media is needed not only to fully control and develop the potential of these materials but also to increase knowledge of the physical chemistry of inorganic materials when their morphology approaches that of molecular entities. Although this knowledge and control is not yet entirely acquired, industry and society are already using nanomaterials in greater quantities and in consumer products. As normally happens when something new arrives in society, the interest in the broader implications of this emerging technology has grown together with unfounded ‘nanoeuphoria’ and ‘nanoscares’. In this context, only by understanding the mechanisms of the nano-bio interaction will it be possible to safely develop nanotechnology. In this review, we discuss on how nanoparticles behave once they are naturally or intentionally produced and are exposed to humans and the environment. The response of nanoparticles inside organisms or released to the environment is complex and diverse, and depends on a variety of parameters involved. Mainly, they may (i) be aggregated into microscopic particles or embedded in exposed materials; (ii) the surfaces of the nanoparticles, which determine their bioactivity, experience constant modifications; and (iii) nanoparticles may corrode and dissolve or they can suffer morphological modifications.

  19. Reactivity of inorganic nanoparticles in biological environments: insights into nanotoxicity mechanisms

    Science.gov (United States)

    Casals, E.; Gonzalez, E.; Puntes, V. F.

    2012-11-01

    A deeper understanding of the behaviour of inorganic nanoparticles in biological media is needed not only to fully control and develop the potential of these materials but also to increase knowledge of the physical chemistry of inorganic materials when their morphology approaches that of molecular entities. Although this knowledge and control is not yet entirely acquired, industry and society are already using nanomaterials in greater quantities and in consumer products. As normally happens when something new arrives in society, the interest in the broader implications of this emerging technology has grown together with unfounded ‘nanoeuphoria’ and ‘nanoscares’. In this context, only by understanding the mechanisms of the nano-bio interaction will it be possible to safely develop nanotechnology. In this review, we discuss on how nanoparticles behave once they are naturally or intentionally produced and are exposed to humans and the environment. The response of nanoparticles inside organisms or released to the environment is complex and diverse, and depends on a variety of parameters involved. Mainly, they may (i) be aggregated into microscopic particles or embedded in exposed materials; (ii) the surfaces of the nanoparticles, which determine their bioactivity, experience constant modifications; and (iii) nanoparticles may corrode and dissolve or they can suffer morphological modifications.

  20. Quantum mechanics on Riemannian manifold in Schwinger's quantization approach II

    International Nuclear Information System (INIS)

    Chepilko, N.M.; Romanenko, A.V.

    2001-01-01

    The extended Schwinger quantization procedure is used for constructing quantum mechanics on a manifold with a group structure. The considered manifold M is a homogeneous Riemannian space with the given action of an isometry transformation group. Using the identification of M with the quotient space G/H, where H is the isotropy group of an arbitrary fixed point of M, we show that quantum mechanics on G/H possesses a gauge structure, described by a gauge potential that is the connection 1-form of the principal fiber bundle G(G/H, H). The coordinate representation of quantum mechanics and the procedure for selecting the physical sector of the states are developed. (orig.)

  1. Mechanical simulations of sandia II tests OECD ISP 48 benchmark

    International Nuclear Information System (INIS)

    Ghavamian, Sh.; Courtois, A.; Valfort, J.-L.; Heinfling, G.

    2005-01-01

    This paper illustrates the work carried out by EDF within the framework of ISP48 post-test analysis of NUPEC/NRCN 1:4-scale model of a prestressed pressure containment vessel of a nuclear power plant. EDF as a participant of the International Standard Problem n degree 8 has performed several simulations to determine the ultimate response of the scale model. To determine the most influent parameter in such an analysis several studies were carried out. The mesh was built using a parametric tool to measure the influence of discretization on results. Different material laws of concrete were also used. The purpose of this paper is to illustrate the ultimate behaviour of SANDIA II model obtained by Code-Asterwith comparison to tests records, and also to share the lessons learned from the parametric computations and precautions that must be taken. (authors)

  2. Energy implications of mechanical and mechanical-biological treatment compared to direct waste-to-energy.

    Science.gov (United States)

    Cimpan, Ciprian; Wenzel, Henrik

    2013-07-01

    Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical-biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJprimary/100 MJinput waste, in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3-9.5%, 1-18% and 1-8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat recovery, the biodrying MBS-based system achieved the highest savings, on the condition of SRF co-combustion. As a sensitivity scenario, alternative utilisation of SRF in cement kilns was modelled. It supported similar or higher net savings for all pre-treatment systems compared to mass combustion WtE, except when WtE CHP was possible in the first two background energy scenarios. Recovery of plastics for recycling before energy recovery increased net energy savings in most scenario variations, over those of full

  3. Mechanisms of sound seattering by biological targets and their aggregates

    Directory of Open Access Journals (Sweden)

    Natalia Gorska

    2006-03-01

    Full Text Available Natalia Gorska's thesis is based on a set of 9 papers published in scientific journals (Gorska & Klusek 1998, Gorska 2000, Gorska & Chu 2001a, b, Gorska & Ona 2003a, b and conference proceedings (Gorska & Klusek 1994, Gorska 1999, Gorska & Chu 2000, which broadly summarise her integrated research achievements in underwater acoustics from 1994 to 2003. She is the sole author of two of the articles (Gorska 1999, 2000, and is the first co-author, taking a leading part, in the others (Gorska & Klusek 1994, 1998, Gorska & Chu 2000, Gorska & Chu 200la, b, Gorska & Ona 2003a, b.     Her research objective was to work out the theoretical background to certain problems of sound scattering by biological targets - single individuals and aggregated layers of fish and zooplankton - in relation to environmental conditions in the sea. In the study she focused on acoustical extinction and backscattering, including the phenomenon of echo interference. In conjunction wit h the co-authors of papers Gorska & Ona 2003a, b, Gorska & Chu 2001a, b and Gorska & Chu 2000, she was able to apply and verify her theoretical results empirically.

  4. Lectures on the mathematics of quantum mechanics II selected topics

    CERN Document Server

    Dell'Antonio, Gianfausto

    2016-01-01

    The first volume (General Theory) differs from most textbooks as it emphasizes the mathematical structure and mathematical rigor, while being adapted to the teaching the first semester of an advanced course in Quantum Mechanics (the content of the book are the lectures of courses actually delivered.). It differs also from the very few texts in Quantum Mechanics that give emphasis to the mathematical aspects because this book, being written as Lecture Notes, has the structure of lectures delivered in a course, namely introduction of the problem, outline of the relevant points, mathematical tools needed, theorems, proofs. This makes this book particularly useful for self-study and for instructors in the preparation of a second course in Quantum Mechanics (after a first basic course). With some minor additions it can be used also as a basis of a first course in Quantum Mechanics for students in mathematics curricula. The second part (Selected Topics) are lecture notes of a more advanced course aimed at giving th...

  5. Braid group, knot theory and statistical mechanics II

    CERN Document Server

    Yang Chen Ning

    1994-01-01

    The present volume is an updated version of the book edited by C N Yang and M L Ge on the topics of braid groups and knot theory, which are related to statistical mechanics. This book is based on the 1989 volume but has new material included and new contributors.

  6. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT II, MECHANICAL TRANSMISSIONS.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF MECHANICAL TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) PURPOSE OF TRANSMISSIONS, (2) RATIO DIFFERENCE, (3) CONSTANT MESH TRANSMISSIONS, (4) FOUR-SPEED TRUCK TRANSMISSION POWER FLOW, AND (5) TRANSMISSION TROUBLESHOOTING.…

  7. Zinc electrode shape change II. Process and mechanism

    NARCIS (Netherlands)

    Einerhand, R.E.F.; Visscher, W.; de Goeij, J.J.M.; Barendrecht, E.

    1991-01-01

    The process and mechanism of zinc electrode shape change is investigated with the radiotracer technique. It is shownthat during repeated cycling of the nickel oxide/zinc battery zinc material is transported over the zinc electrode via the battery electrolyte. During charge as well as during

  8. Mechanical Properties of High Performance Cementitious Grout (II)

    DEFF Research Database (Denmark)

    Sørensen, Eigil V.

    The present report is an update of the report “Mechanical Properties of High Performance Cementitious Grout (I)” [1] and describes tests carried out on the high performance grout MASTERFLOW 9500, marked “WMG 7145 FP”, developed by BASF Construction Chemicals A/S and designed for use in grouted...

  9. Bioactive glass/hydroxyapatite composites: mechanical properties and biological evaluation.

    Science.gov (United States)

    Bellucci, Devis; Sola, Antonella; Anesi, Alexandre; Salvatori, Roberta; Chiarini, Luigi; Cannillo, Valeria

    2015-06-01

    Bioactive glass/hydroxyapatite composites for bone tissue repair and regeneration have been produced and discussed. The use of a recently developed glass, namely BG_Ca/Mix, with its low tendency to crystallize, allowed one to sinter the samples at a relatively low temperature thus avoiding several adverse effects usually reported in the literature, such as extensive crystallization of the glassy phase, hydroxyapatite (HA) decomposition and reaction between HA and glass. The mechanical properties of the composites with 80wt.% BG_Ca/Mix and 20wt.% HA are sensibly higher than those of Bioglass® 45S5 reference samples due to the presence of HA (mechanically stronger than the 45S5 glass) and to the thermal behaviour of the BG_Ca/Mix, which is able to favour the sintering process of the composites. Biocompatibility tests, performed with murine fibroblasts BALB/3T3 and osteocites MLO-Y4 throughout a multi-parametrical approach, allow one to look with optimism to the produced composites, since both the samples themselves and their extracts do not induce negative effects in cell viability and do not cause inhibition in cell growth. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Angiotensin II regulation of neuromodulation: downstream signaling mechanism from activation of mitogen-activated protein kinase.

    Science.gov (United States)

    Lu, D; Yang, H; Raizada, M K

    1996-12-01

    Angiotensin II (Ang II) stimulates expression of tyrosine hydroxylase and norepinephrine transporter genes in brain neurons; however, the signal-transduction mechanism is not clearly defined. This study was conducted to determine the involvement of the mitogen-activated protein (MAP) kinase signaling pathway in Ang II stimulation of these genes. MAP kinase was localized in the perinuclear region of the neuronal soma. Ang II caused activation of MAP kinase and its subsequent translocation from the cytoplasmic to nuclear compartment, both effects being mediated by AT1 receptor subtype. Ang II also stimulated SRE- and AP1-binding activities and fos gene expression and its translocation in a MAP kinase-dependent process. These observations are the first demonstration of a downstream signaling pathway involving MAP kinase in Ang II-mediated neuromodulation in noradrenergic neurons.

  11. THE Fe II EMISSION IN ACTIVE GALACTIC NUCLEI: EXCITATION MECHANISMS AND LOCATION OF THE EMITTING REGION

    International Nuclear Information System (INIS)

    Marinello, M.; Rodríguez-Ardila, A.; Garcia-Rissmann, A.; Sigut, T. A. A.; Pradhan, A. K.

    2016-01-01

    We present a study of Fe ii emission in the near-infrared region (NIR) for 25 active galactic nuclei (AGNs) to obtain information about the excitation mechanisms that power it and the location where it is formed. We employ an NIR Fe ii template derived in the literature and find that it successfully reproduces the observed Fe ii spectrum. The Fe ii bump at 9200 Å detected in all objects studied confirms that Lyα fluorescence is always present in AGNs. The correlation found between the flux of the 9200 Å bump, the 1 μm lines, and the optical Fe ii implies that Lyα fluorescence plays an important role in Fe ii production. We determined that at least 18% of the optical Fe ii is due to this process, while collisional excitation dominates the production of the observed Fe ii. The line profiles of Fe ii λ10502, O i λ11287, Ca ii λ8664, and Paβ were compared to gather information about the most likely location where they are emitted. We found that Fe ii, O i and Ca ii have similar widths and are, on average, 30% narrower than Paβ. Assuming that the clouds emitting the lines are virialized, we show that the Fe ii is emitted in a region twice as far from the central source than Paβ. The distance, though, strongly varies: from 8.5 light-days for NGC 4051 to 198.2 light-days for Mrk 509. Our results reinforce the importance of the Fe ii in the NIR to constrain critical parameters that drive its physics and the underlying AGN kinematics, as well as more accurate models aimed at reproducing this complex emission

  12. THE Fe II EMISSION IN ACTIVE GALACTIC NUCLEI: EXCITATION MECHANISMS AND LOCATION OF THE EMITTING REGION

    Energy Technology Data Exchange (ETDEWEB)

    Marinello, M. [Universidade Federal de Itajubá, Rua Doutor Pereira Cabral 1303, 37500-903, Itajubá, MG (Brazil); Rodríguez-Ardila, A.; Garcia-Rissmann, A. [Laboratório Nacional de Astrofísica, Rua Estados Unidos 154, Itajubá, MG, 37504-364 (Brazil); Sigut, T. A. A. [The University of Western Ontario, London, ON N6A 3K7 (Canada); Pradhan, A. K., E-mail: murilo.marinello@gmail.com [McPherson Laboratory, The Ohio State University, 140 W. 18th Ave., Columbus, OH 43210-1173 (United States)

    2016-04-01

    We present a study of Fe ii emission in the near-infrared region (NIR) for 25 active galactic nuclei (AGNs) to obtain information about the excitation mechanisms that power it and the location where it is formed. We employ an NIR Fe ii template derived in the literature and find that it successfully reproduces the observed Fe ii spectrum. The Fe ii bump at 9200 Å detected in all objects studied confirms that Lyα fluorescence is always present in AGNs. The correlation found between the flux of the 9200 Å bump, the 1 μm lines, and the optical Fe ii implies that Lyα fluorescence plays an important role in Fe ii production. We determined that at least 18% of the optical Fe ii is due to this process, while collisional excitation dominates the production of the observed Fe ii. The line profiles of Fe ii λ10502, O i λ11287, Ca ii λ8664, and Paβ were compared to gather information about the most likely location where they are emitted. We found that Fe ii, O i and Ca ii have similar widths and are, on average, 30% narrower than Paβ. Assuming that the clouds emitting the lines are virialized, we show that the Fe ii is emitted in a region twice as far from the central source than Paβ. The distance, though, strongly varies: from 8.5 light-days for NGC 4051 to 198.2 light-days for Mrk 509. Our results reinforce the importance of the Fe ii in the NIR to constrain critical parameters that drive its physics and the underlying AGN kinematics, as well as more accurate models aimed at reproducing this complex emission.

  13. The role of mechanics in biological and bio-inspired systems.

    Science.gov (United States)

    Egan, Paul; Sinko, Robert; LeDuc, Philip R; Keten, Sinan

    2015-07-06

    Natural systems frequently exploit intricate multiscale and multiphasic structures to achieve functionalities beyond those of man-made systems. Although understanding the chemical make-up of these systems is essential, the passive and active mechanics within biological systems are crucial when considering the many natural systems that achieve advanced properties, such as high strength-to-weight ratios and stimuli-responsive adaptability. Discovering how and why biological systems attain these desirable mechanical functionalities often reveals principles that inform new synthetic designs based on biological systems. Such approaches have traditionally found success in medical applications, and are now informing breakthroughs in diverse frontiers of science and engineering.

  14. A study on the ranges of low energy ions in biological samples and its mechanism of biological effects

    International Nuclear Information System (INIS)

    Lu Ting; Xie Liqing; Li Junping; Xia Ji

    1993-01-01

    The seeds of wheat and bean are irradiated by iron ion beam with energy 100 keV. The RBS spectra of the samples are observed and the ranges and distributions of the iron ions in the wheat and bean are calculated theoretically by means of Monte Carlo method. The results of theory and experiment are compared and the mechanism of biological effects induced by ion is discussed

  15. Synthesis, characterization, and biological activity of a new palladium(II) complex with deoxyalliin

    Energy Technology Data Exchange (ETDEWEB)

    Corbi, P.P.; Massabni, A.C. [Inst. de Quimica - UNESP, Dept., Dept. de Quimica Geral e Inoganica, Araraquara (Brazil)]. E-mail: pedrocorbi@yahoo.com; Moreira, A.G. [Inst. de Quimica - UNESP, Dept. de Quimica Geral e Inoganica, Araraquara (Brazil); Faculdade de Medicina de Ribeirao Preto - USP, Dept. de Bioquimica e Imunologia, Ribeirao Preto (Brazil); Medrano, F.J. [Laboratorio Nacional de Luz Sincrotron - LNLS, Campinas (Brazil); Jasiulionis, M.G. [Escola Paulista de Medicina - UNIFESP, Dept. de Micro-Imuno-Parasitologia, Sao Paulo (Brazil); Costa-Neto, C.M. [Faculdade de Medicina de Ribeirao Preto - USP, Dept. de Bioquimica e Imunologia, Ribeirao Preto (Brazil)

    2005-02-15

    Synthesis, characterization, and biological activity of a new water-soluble Pd(II)-deoxyalliin (S-allyl-L-cysteine) complex are described in this article. Elemental and thermal analysis for the complex are consistent with the formula [Pd(C{sub 6}H{sub 10}NO{sub 2}S){sub 2}]. {sup 13}C NMR, {sup 1}H NMR, and IR spectroscopy show coordination of the ligand to Pd(II) through S and N atoms in a square planar geometry. Final residue of the thermal treatment was identified as a mixture of PdO and metallic Pd. Antiproliferative assays using aqueous solutions of the complex against HeLa and TM5 tumor cells showed a pronounced activity of the complex even at low concentrations. After incubation for 24 h, the complex induced cytotoxic effect over HeLa cells when used at concentrations higher than 0.40 mmol/L. At lower concentrations, the complex was nontoxic, indicating its action is probably due to cell cycle arrest, rather than cell death. In agreement with these results, the flow cytometric analysis indicated that after incubation for 24 h at low concentrations of the complex cells are arrested in G0/G1. (author)

  16. Deformation mechanism of the Cryostat in the CADS Injector II

    Science.gov (United States)

    Yuan, Jiandong; Zhang, Bin; Wan, Yuqin; Sun, Guozhen; Bai, Feng; Zhang, Juihui; He, Yuan

    2018-01-01

    Thermal contraction and expansion of the Cryostat will affect its reliability and stability. To optimize and upgrade the Cryostat, we analyzed the heat transfer in a cryo-vacuum environment from the theoretical point first. The simulation of cryo-vacuum deformation based on a finite element method was implemented respectively. The completed measurement based on a Laser Tracker and a Micro Alignment Telescope was conducted to verify its correctness. The monitored deformations were consistent with the simulated ones. After the predictable deformations in vertical direction have been compensated, the superconducting solenoids and Half Wave Resonator cavities approached the ideal "zero" position under liquid helium conditions. These guaranteed the success of 25 MeV@170 uA continuous wave protons of Chinese accelerator driven subcritical system Injector II. By correlating the vacuum and cryo-deformation, we have demonstrated that the complete deformation was the superposition effect of the atmospheric pressure, gravity and thermal stress during both the process of cooling down and warming up. The results will benefit to an optimization for future Cryostat's design.

  17. A comprehensive review and update on the biologic treatment of adult noninfectious uveitis: part II.

    Science.gov (United States)

    Lee, Kyungmin; Bajwa, Asima; Freitas-Neto, Clovis A; Metzinger, Jamie Lynne; Wentworth, Bailey A; Foster, C Stephen

    2014-11-01

    Treatment of adult, noninfectious uveitis remains a major challenge for ophthalmologists around the world, especially in regard to recalcitrant cases. It is reported to comprise approximately 10% of preventable blindness in the USA. The cause of uveitis can be idiopathic or associated with infectious and systemic disorders. The era of biologic medical therapies provides new options for patients with otherwise treatment-resistant inflammatory eye disease. This two-part review gives a comprehensive overview of the existing medical treatment options for patients with adult, noninfectious uveitis, as well as important advances for the treatment ocular inflammation. Part I covers classic immunomodulation and latest information on corticosteroid therapy. In part II, emerging therapies are discussed, including biologic response modifiers, experimental treatments and ongoing clinical studies for uveitis. The hazard of chronic corticosteroid use in the treatment of adult, noninfectious uveitis is well documented. Corticosteroid-sparing therapies, which offer a very favorable risk-benefit profile when administered properly, should be substituted. Although nothing is currently approved for on-label use in this indication, many therapies, through either translation or novel basic science research, have the potential to fill the currently exposed gaps.

  18. Transient resetting: a novel mechanism for synchrony and its biological examples.

    Directory of Open Access Journals (Sweden)

    Chunguang Li

    2006-08-01

    Full Text Available The study of synchronization in biological systems is essential for the understanding of the rhythmic phenomena of living organisms at both molecular and cellular levels. In this paper, by using simple dynamical systems theory, we present a novel mechanism, named transient resetting, for the synchronization of uncoupled biological oscillators with stimuli. This mechanism not only can unify and extend many existing results on (deterministic and stochastic stimulus-induced synchrony, but also may actually play an important role in biological rhythms. We argue that transient resetting is a possible mechanism for the synchronization in many biological organisms, which might also be further used in the medical therapy of rhythmic disorders. Examples of the synchronization of neural and circadian oscillators as well as a chaotic neuron model are presented to verify our hypothesis.

  19. Synthesis, molecular structure, biological properties and molecular docking studies on Mn(II), Co(II) and Zn(II) complexes containing bipyridine-azide ligands.

    Science.gov (United States)

    Thamilarasan, Vijayan; Jayamani, Arumugam; Sengottuvelan, Nallathambi

    2015-01-07

    Metal complexes of the type Mn(bpy)2(N3)2 (1), Co(bpy)2(N3)2·3H2O (2) and Zn2(bpy)2(N3)4 (3) (Where bpy = 2,2-bipyridine) have been synthesized and characterized by elemental analysis and spectral (FT-IR, UV-vis) studies. The structure of complexes (1-3) have been determined by single crystal X-ray diffraction studies and the configuration of ligand-coordinated metal(II) ion was well described as distorted octahedral coordination geometry for Mn(II), Co(II) and distorted square pyramidal geometry for Zn(II) complexes. DNA binding interaction of these complexes (1-3) were investigated by UV-vis absorption, fluorescence circular dichroism spectral and molecular docking studies. The intrinsic binding constants Kb of complexes 1, 2 and 3 with CT-DNA obtained from UV-vis absorption studies were 8.37 × 10(4), 2.23 × 10(5) and 5.52 × 10(4) M(-1) respectively. The results indicated that the three complexes are able to bind to DNA with different binding affinity, in the order 2 > 1 > 3. Complexes (1-3) exhibit a good binding propensity to bovine serum albumin (BSA) proteins having relatively high binding constant values. Gel electrophoresis assay demonstrated the ability of the complexes 1-3 promote the cleavage ability of the pBR322 plasmid DNA in the presence of the reducing agent 3-mercaptopropionic acid (MPA) but with different cleavage mechanisms: the complex 3 cleaves DNA via hydrolytic pathway (T4 DNA ligase assay), while the DNA cleavage by complexes 1 and 2 follows oxidative pathway. The chemical nuclease activity follows the order: 2 > 1 > 3. The effects of various activators were also investigated and the nuclease activity efficacy followed the order MPA > GSH > H2O2 > Asc. The cytotoxicity studies of complexes 1-3 were tested in vitro on breast cancer cell line (MCF-7) and they found to be active. Copyright © 2014. Published by Elsevier Masson SAS.

  20. Relativistic-particle quantum mechanics (applications and approximations) II

    International Nuclear Information System (INIS)

    Coester, F.

    1981-01-01

    In this lecture I hope to show that relativistic-particle quantum mechanics with direct interactions is a useful tool for building models applicable to hadron systems at intermediate energies. To do this I will first describe a class of models designed to incorporate nucleon-nucleon interactions, pion production, absorption and scattering into a single dynamical framework without dressing the nucleons with pion clouds. The second major topic concerns electromagnetic interactions. In the previous lecture I specifically excluded long-rang forces and zero-mass particles. Since many of the experimental data in hadron physics involve electromagnetic interactions this limitation is a major defect which must be addressed

  1. Psycho-neuro-endocrine-immune mechanisms of action of yoga in type II diabetes.

    Science.gov (United States)

    Singh, Vijay Pratap; Khandelwal, Bidita; Sherpa, Namgyal T

    2015-01-01

    Yoga has been found to benefit all the components of health viz. physical, mental, social and spiritual well being by incorporating a wide variety of practices. Pathophysiology of Type II DM and co-morbidities in Type II DM has been correlated with stress mechanisms. Stress suppresses body's immune system and neuro-humoral actions thereby aff ecting normal psychological state. It would not be wrong to state that correlation of diabetes with stress, anxiety and other psychological factors are bidirectional and lead to difficulty in understanding the interrelated mechanisms. Type II DM cannot be understood in isolation with psychological factors such as stress, anxiety and depression, neuro-endocrine and immunological factors. There is no review which tries to understand these mechanisms exclusively. The present literature review aims to understand interrelated Psycho-Neuro-Endocrine and Immunological mechanisms of action of Yoga in Type II Diabetes Mellitus. Published literature concerning mechanisms of action of Yoga in Type II DM emphasizing psycho-neuro-endocrine or immunological relations was retrieved from Pubmed using key words yoga, Type II diabetes mellitus, psychological, neural, endocrine, immune and mechanism of action. Those studies which explained the psycho-neuroendocrine and immune mechanisms of action of yoga were included and rest were excluded. Although primary aim of this study is to explain these mechanisms in Type II DM, some studies in non-diabetic population which had a similar pathway of stress mechanism was included because many insightful studies were available in that area. Search was conducted using terms yoga OR yogic AND diabetes OR diabetic IN title OR abstract for English articles. Of the 89 articles, we excluded non-English articles (22), editorials (20) and letters to editor (10). 37 studies were considered for this review. The postulated mechanism of action of yoga is through parasympathetic activation and the associated anti

  2. Mechanisms of Hg(II) uptake and methylation in methylating bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Morel, Francois M. M. [Princeton Univ., NJ (United States). Geosciences

    2016-10-14

    The goal of this project was to understand the critical factors which control the availability and transport of Hg(II) into cells, a first step in the production of the neurotoxin, methylmercury. Specifically, this research focused on understanding the mechanism of bacterial mercury uptake and how mercury speciation affects the specificity and kinetics of mercury transport. Our research has shown that Hg(II) uptake in three different iron and sulfate-reducing proteobacteria occurs by the following mechanism (1) : Hg(II) uptake is an active transport process requiring energy, (2) it is dependent upon the structure of the Hg binding ligand, and (3) it is mediated by a heavy metal transporter such as one which transports the essential metal, Zn(II). In order to determine whether this mechanism extends to more diverse phylogenetic groups, we have begun examining Hg(II) uptake and bioavailability in two representative Hg methylating strains within the Firmicutes. These organisms have remarkably different membrane structures distinct from the Proteobacteria. Our results show low uptake rates in these two species of Firmicutes relative to the previously characterized Proteobacteria. This may explain the low methylation rates and yields observed in these organisms. Most surprisingly, however, these organisms appear to take up Hg(II) passively, as the addition of a protonophore failed to reduce Hg(II) uptake in these organisms. This is quite different to what has been observed previously for the Proteobacteria and suggests a different mechanism for Hg(II) uptake in the Firmicutes. We are continuing to understand and describe Hg(II) uptake in these organisms. A manuscript is expected to be submitted on this research in June 2016.

  3. A Model of How Different Biology Experts Explain Molecular and Cellular Mechanisms

    Science.gov (United States)

    Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

    2015-01-01

    Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do…

  4. Fundamentals of physics II electromagnetism, optics, and quantum mechanics

    CERN Document Server

    Shankar, R

    2016-01-01

    R. Shankar, a well-known physicist and contagiously enthusiastic educator, was among the first to offer a course through the innovative Open Yale Course program. His popular online video lectures on introductory physics have been viewed over a million times. In this second book based on his online Yale course, Shankar explains essential concepts, including electromagnetism, optics, and quantum mechanics. The book begins at the simplest level, develops the basics, and reinforces fundamentals, ensuring a solid foundation in the principles and methods of physics. It provides an ideal introduction for college-level students of physics, chemistry, and engineering; for motivated AP Physics students; and for general readers interested in advances in the sciences.

  5. Change is good: variations in common biological mechanisms in the epsilonproteobacterial genera Campylobacter and Helicobacter.

    Science.gov (United States)

    Gilbreath, Jeremy J; Cody, William L; Merrell, D Scott; Hendrixson, David R

    2011-03-01

    Microbial evolution and subsequent species diversification enable bacterial organisms to perform common biological processes by a variety of means. The epsilonproteobacteria are a diverse class of prokaryotes that thrive in diverse habitats. Many of these environmental niches are labeled as extreme, whereas other niches include various sites within human, animal, and insect hosts. Some epsilonproteobacteria, such as Campylobacter jejuni and Helicobacter pylori, are common pathogens of humans that inhabit specific regions of the gastrointestinal tract. As such, the biological processes of pathogenic Campylobacter and Helicobacter spp. are often modeled after those of common enteric pathogens such as Salmonella spp. and Escherichia coli. While many exquisite biological mechanisms involving biochemical processes, genetic regulatory pathways, and pathogenesis of disease have been elucidated from studies of Salmonella spp. and E. coli, these paradigms often do not apply to the same processes in the epsilonproteobacteria. Instead, these bacteria often display extensive variation in common biological mechanisms relative to those of other prototypical bacteria. In this review, five biological processes of commonly studied model bacterial species are compared to those of the epsilonproteobacteria C. jejuni and H. pylori. Distinct differences in the processes of flagellar biosynthesis, DNA uptake and recombination, iron homeostasis, interaction with epithelial cells, and protein glycosylation are highlighted. Collectively, these studies support a broader view of the vast repertoire of biological mechanisms employed by bacteria and suggest that future studies of the epsilonproteobacteria will continue to provide novel and interesting information regarding prokaryotic cellular biology.

  6. Mechanical testing of hydraulic fluids II; Mechanische Pruefung von Hydraulikfluessigkeiten II

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, M.; Feldmann, D.G.; Laukart, V.

    2001-09-01

    Since May 1996 the Institute for Mechanical Engineering Design 1 of Technical University of Hamburg-Harburg is working on the topic of ''Mechanical Testing of Hydraulic fluids''. The first project lasting 2 1/2 years was completed in 1999, the results are published as the DGMK report 514. Within these project a testing principle for the ''mechanical testing'' of hydraulic fluids has been derived, a prototype of a test rig was designed and set in operation at the authors' institute. This DGMK-report 514-1 describes the results of the second project, which investigates the operating behaviour of the test-rig more in detail. Several test-runs with a total number of 11 different hydraulic fluids show the dependence of the different lubricating behaviour of the tested fluids and their friction and wear behaviour during the tests in a reproducible way. The aim of the project was to derive a testing principle including the design of a suitable test-rig for the mechanical testing of hydraulic fluids. Based on the described results it can be stated that with the developed test it is possible to test the lubricity of hydraulic fluids reproducible and in correlation to field experiences within a relatively short time, so the target was reached. (orig.)

  7. Statistical mechanics in the context of special relativity. II.

    Science.gov (United States)

    Kaniadakis, G

    2005-09-01

    The special relativity laws emerge as one-parameter (light speed) generalizations of the corresponding laws of classical physics. These generalizations, imposed by the Lorentz transformations, affect both the definition of the various physical observables (e.g., momentum, energy, etc.), as well as the mathematical apparatus of the theory. Here, following the general lines of [Phys. Rev. E 66, 056125 (2002)], we show that the Lorentz transformations impose also a proper one-parameter generalization of the classical Boltzmann-Gibbs-Shannon entropy. The obtained relativistic entropy permits us to construct a coherent and self-consistent relativistic statistical theory, preserving the main features of the ordinary statistical theory, which is recovered in the classical limit. The predicted distribution function is a one-parameter continuous deformation of the classical Maxwell-Boltzmann distribution and has a simple analytic form, showing power law tails in accordance with the experimental evidence. Furthermore, this statistical mechanics can be obtained as the stationary case of a generalized kinetic theory governed by an evolution equation obeying the H theorem and reproducing the Boltzmann equation of the ordinary kinetics in the classical limit.

  8. Cyclopentane combustion. Part II. Ignition delay measurements and mechanism validation

    KAUST Repository

    Rachidi, Mariam El

    2017-06-12

    This study reports cyclopentane ignition delay measurements over a wide range of conditions. The measurements were obtained using two shock tubes and a rapid compression machine, and were used to test a detailed low- and high-temperature mechanism of cyclopentane oxidation that was presented in part I of this study (Al Rashidi et al., 2017). The ignition delay times of cyclopentane/air mixtures were measured over the temperature range of 650–1350K at pressures of 20 and 40atm and equivalence ratios of 0.5, 1.0 and 2.0. The ignition delay times simulated using the detailed chemical kinetic model of cyclopentane oxidation show very good agreement with the experimental measurements, as well as with the cyclopentane ignition and flame speed data available in the literature. The agreement is significantly improved compared to previous models developed and investigated at higher temperatures. Reaction path and sensitivity analyses were performed to provide insights into the ignition-controlling chemistry at low, intermediate and high temperatures. The results obtained in this study confirm that cycloalkanes are less reactive than their non-cyclic counterparts. Moreover, cyclopentane, a high octane number and high octane sensitivity fuel, exhibits minimal low-temperature chemistry and is considerably less reactive than cyclohexane. This study presents the first experimental low-temperature ignition delay data of cyclopentane, a potential fuel-blending component of particular interest due to its desirable antiknock characteristics.

  9. Cyclopentane combustion. Part II. Ignition delay measurements and mechanism validation

    KAUST Repository

    Rachidi, Mariam El; Má rmol, Juan C.; Banyon, Colin; Sajid, Muhammad Bilal; Mehl, Marco; Pitz, William J.; Mohamed, Samah; Alfazazi, Adamu; Lu, Tianfeng; Curran, Henry J.; Farooq, Aamir; Sarathy, Mani

    2017-01-01

    This study reports cyclopentane ignition delay measurements over a wide range of conditions. The measurements were obtained using two shock tubes and a rapid compression machine, and were used to test a detailed low- and high-temperature mechanism of cyclopentane oxidation that was presented in part I of this study (Al Rashidi et al., 2017). The ignition delay times of cyclopentane/air mixtures were measured over the temperature range of 650–1350K at pressures of 20 and 40atm and equivalence ratios of 0.5, 1.0 and 2.0. The ignition delay times simulated using the detailed chemical kinetic model of cyclopentane oxidation show very good agreement with the experimental measurements, as well as with the cyclopentane ignition and flame speed data available in the literature. The agreement is significantly improved compared to previous models developed and investigated at higher temperatures. Reaction path and sensitivity analyses were performed to provide insights into the ignition-controlling chemistry at low, intermediate and high temperatures. The results obtained in this study confirm that cycloalkanes are less reactive than their non-cyclic counterparts. Moreover, cyclopentane, a high octane number and high octane sensitivity fuel, exhibits minimal low-temperature chemistry and is considerably less reactive than cyclohexane. This study presents the first experimental low-temperature ignition delay data of cyclopentane, a potential fuel-blending component of particular interest due to its desirable antiknock characteristics.

  10. Structure and dynamics of hydrated Fe(II) and Fe(III) ions. Quantum mechanical and molecular mechanical simulations

    International Nuclear Information System (INIS)

    Remsungnen, T.

    2002-11-01

    Classical molecular dynamics (MD) and combined em ab initio quantum mechanical/molecular mechanical molecular dynamics (QM/MM-MD) simulations have been performed to investigate structural, dynamical and energetical properties of Fe(II), and Fe(III) transition metal ions in aqueous solution. In the QM/MM-MD simulations the ion and its first hydration sphere were treated at the Hartree-Fock ab initio quantum mechanical level, while ab initio generated pair plus three-body potentials were employed for the remaining system. For the classical MD simulation the pair plus three-body potential were employed for all ion-water interactions. The coordination number of the first hydration shell is 100 % of 6 in both cases. The number of waters in the second hydration shell obtained from classical simulations are 13.4 and 15.1 for Fe(II) and Fe(III), respectively, while QM/MM-MD gives the values of 12.4 and 13.4 for Fe(II) and Fe(III). The energies of hydration obtained from MD and QM/MM-MD for Fe(II) are 520 and 500 kcal/mol, and for Fe(III) 1160 and 1100 kcal/mol respectively. The mean residence times of water in the second shell obtained from QM/MM-MD are 24 and 48 ps for Fe(II) and Fe(III), respectively. In contrast to the data obtained from classical MD simulation, the QM/MM-MD values are all in good agreement with the experimental data available. These investigations and results clearly indicate that many-body effects are essential for the proper description of all properties of the aqueous solution of both Fe(II) and Fe(III) ions. (author)

  11. Quantum Information Biology: From Information Interpretation of Quantum Mechanics to Applications in Molecular Biology and Cognitive Psychology

    Science.gov (United States)

    Asano, Masanari; Basieva, Irina; Khrennikov, Andrei; Ohya, Masanori; Tanaka, Yoshiharu; Yamato, Ichiro

    2015-10-01

    We discuss foundational issues of quantum information biology (QIB)—one of the most successful applications of the quantum formalism outside of physics. QIB provides a multi-scale model of information processing in bio-systems: from proteins and cells to cognitive and social systems. This theory has to be sharply distinguished from "traditional quantum biophysics". The latter is about quantum bio-physical processes, e.g., in cells or brains. QIB models the dynamics of information states of bio-systems. We argue that the information interpretation of quantum mechanics (its various forms were elaborated by Zeilinger and Brukner, Fuchs and Mermin, and D' Ariano) is the most natural interpretation of QIB. Biologically QIB is based on two principles: (a) adaptivity; (b) openness (bio-systems are fundamentally open). These principles are mathematically represented in the framework of a novel formalism— quantum adaptive dynamics which, in particular, contains the standard theory of open quantum systems.

  12. Mechanical design of EFW Exo II: A hybrid exoskeleton for elbow-forearm-wrist rehabilitation.

    Science.gov (United States)

    Bian, Hui; Chen, Ziye; Wang, Hao; Zhao, Tieshi

    2017-07-01

    The use of rehabilitation exoskeleton has become an important means for the treatment of stroke patients. A hybrid exoskeleton named EFW Exo II is developed for the motor function rehabilitation of elbow, forearm and wrist. The EFW Exo II is based on a parallel 2-URR/RRS mechanism and a serial R mechanism. It could fit both left and right arms for the symmetrical and open structure, and the distance between the elbow and wrist could automatically adjust for different forearm length. Details of the mechanical design are introduced. Brushless DC servo motors with planetary gear reducer are used as the actuators of the exoskeleton. Gear drive and belt drive are used for power transmission. A three dimensional force sensor is mounted in the handle to regulate the interaction between the exoskeleton and patient. The EFW Exo II can realize rehabilitation exercise for each joint and the ranges of motion meet the rehabilitation demands of daily living.

  13. Structure property relationship of biological nano composites studies by combination of in-situ synchrotron scattering and mechanical tests

    International Nuclear Information System (INIS)

    Martinschitz, K.

    2005-06-01

    Biological materials represent hierarchical nano fibre composites with complicated morphology and architecture varying on the nm level. The mechanical response of those materials is influenced by many parameters like chemical composition and crystal structure of constituents, preferred orientation, internal morphology with specific sizes of features etc. In-situ wide-angle x-ray scattering (WAXS) combined with mechanical tests provide a unique means to evaluate structural changes in biological materials at specific stages of tensile experiments. In this way it is possible to identify distinct architectural/compositional elements responsible for specific mechanical characteristics of the biological materials. In this thesis, structure-property relationship is analyzed using in-situ WAXS in the tissues of Picea abies, coir fibre, bacterial cellulose and cellulose II based composites. The experiments were performed at the beamline ID01 of European synchrotron radiation facility in Grenoble, France. The tissues were strained in a tensile stage, while the structural changes were monitored using WAXS. Complex straining procedures were applied including cyclic straining. One of the main goals was to understand the stiffness recovery and strain hardening effects in the tissues. The results demonstrate that, in all cellulosics, the orientation of the cellulose crystallites is only the function of the external strain while the stiffness depends on the specific stage of the tensile experiment. Whenever the strain is increased, the tissues exhibit stiffness equal or larger than the initial one. The recovery of the mechanical function is attributed to the molecular mechanistic effects operating between the crystalline domains of the cellulose. (author)

  14. [Adsorption kinetics and mechanism of lead (II) on polyamine-functionalized mesoporous activated carbon].

    Science.gov (United States)

    Li, Kun-Quan; Wang, Yan-Jin; Yang, Mei-Rong; Zhu, Zhi-Qiang; Zheng, Zheng

    2014-08-01

    Bagasse mesoporous carbon was prepared by microwave assisted H3 PO4 activation. Amido and imido groups were modified with ethanediamine on the channels' surface of mesoporous carbon through nitric oxidation and amide reaction. The influence of Pb(II) concentration, adsorption time on Pb(II) adsorption on the ethanediamine-modified mesoporous carbon (AC-EDA) was investigated. The adsorption kinetics and mechanism were also discussed. The results showed that AC-EDA had a great performance for Pb(II) adsorption, and more than 70% of Pb(II) was adsorbed in 5 minutes. The adsorption amount of Pb(II) on the carbon increased with the increase of solution pH in acidic conditions. It was found that AC-EDA had different binding energies on different adsorption sites for Pb(II) separation. The Pb(II) adsorption process on AC-EDA was controlled by intra-particle diffusion in the first 3 min, and then film diffusion played the important pole on the adsorption. The adsorption amount increased with the increase of temperature, indicating the adsorption was an endothermic reaction. The high adsorption energy (> 11 kJ x mol(-1)) implied that the) adsorption was a chemical adsorption. The XPS of AC-EDA before and after Pb(II) adsorption showed that the polyamine group was involved in the adsorption, and should be a main factor of the high efficient adsorption.

  15. Changes in diffusion properties of biological tissues associated with mechanical strain

    International Nuclear Information System (INIS)

    Tanaka, Kenichiro; Imae, T.; Mima, Kazuo; Sekino, Masaki; Ohsaki, Hiroyuki; Ueno, Shogo

    2007-01-01

    Mechanical strain in biological tissues causes a change in the diffusion properties of water molecules. This paper proposes a method of estimating mechanical strain in biological tissues using diffusion magnetic resonance imaging (MRI). Measurements were carried out on uncompressed and compressed chicken skeletal muscles. A theoretical model of the diffusion of water molecules in muscle fibers was derived based on Tanner's equation. Diameter of the muscle fibers was estimated by fitting the model equation to the measured signals. Changes in the mean diffusivity (MD), the fractional anisotropy (FA), and diameter of the muscle fiber did not have any statistical significance. The intracellular diffusion coefficient (D int ) was changed by mechanical strain (p<.05). This method has potential applications in the quantitative evaluation of strain in biological tissues, a though it poses several technical challenges. (author)

  16. Potential of development of the mechanical-biological waste treatment; Entwicklungspotenzial der Mechanisch-Biologischen Abfallbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Grundmann, Thomas; Balhar, Michael [ASA e.V., Ennigerloh (Germany); Abfallwirtschaftsgesellschaft des Kreises Warendorf mbH, Ennigerloh (Germany)

    2013-03-01

    The Consortium Material-Specific Waste Treatment eV (Ennigerloh, Federal Republic of Germany) is an association of plant operators having the opinion that an economic and ecologic waste treatment only can be guaranteed by material-specific processes permanently. Due to the specific treatment processes in plants with mechanical-biological waste treatment (MBA) material flows are resulting being available for the recycling or exploitation. Under this aspect, the authors of the contribution under consideration report on the development potential of the mechanical-biological waste treatment. The state of the art of the technology of mechanical-biological waste treatment in Germany as well as the contribution of this technology to the resource protection and climate protection are described. Further aspects of this contribution are the increase of the energy efficiency and reduction of emissions; further development of the efficient sorting technology; development of integrated total conceptions - MBA-sites as centres for the production of renewable energies.

  17. Recent advances in biological effect and molecular mechanism of arabidopsis thaliana irradiated by ion beams

    International Nuclear Information System (INIS)

    Wu Dali; Hou Suiwen; Li Wenjian

    2008-01-01

    Newly research progresses were summarized in effect of ion beams on seed surface, biological effect, growth, development, gravitropism and so on. Furthermore, mutation molecular mechanism of Arabidopsis thaliana was discussed, for example, alteration of DNA bases, DNA damage, chromosomal recombination, characteristics of mutant transmissibility, etc. Meanwhile, the achievements of transfer- ring extraneous gene to Arabidopsis thaliana by ion beams were reviewed in the paper. At last, the future prospective are also discussed here in mutation molecular mechanism and the potential application of biological effect of heavy ion beams. (authors)

  18. DNA binding and biological activity of mixed ligand complexes of Cu(II, Ni(II and Co(II with quinolones and N donor ligand

    Directory of Open Access Journals (Sweden)

    S.M M Akram

    2015-10-01

    Full Text Available  AbstractMixed ligand complexes of  Cu(II, Ni(II and Co(II have been synthesized by using levofloxacin and bipyridyl and characterized using spectral and analytical techniques. The binding behavior of the Ni(II and Cu(II complexes with herring sperm DNA(Hs-DNA were determined using electronic absorption titration, viscometric measurements and cyclic voltammetry measurements. The binding constant calculated  for Cu(II and Ni(II complexes are 2.0 x 104 and 4.0 x 104 M-1 respectively. Detailed analysis reveals that these metal complexes interact with DNA through intercalative binding mode. The nuclease activity of  Cu(II and Ni(II complexes with ct-DNA was carried out using agarose gel electrophoresis technique. The antioxidant activities for the synthesized complexes have been tested and the antibacterial activity for Ni(II complex was also checked.Key words: Intercalation, hypochromism, red shift and  peak potential.

  19. Novel Antitumor Platinum(II) Conjugates Containing the Nonsteroidal Anti-inflammatory Agent Diclofenac: Synthesis and Dual Mechanisms of Antiproliferative Effects.

    Science.gov (United States)

    Intini, Francesco Paolo; Zajac, Juraj; Novohradsky, Vojtech; Saltarella, Teresa; Pacifico, Concetta; Brabec, Viktor; Natile, Giovanni; Kasparkova, Jana

    2017-02-06

    One concept how to improve anticancer effects of conventional metallodrugs consists in conjugation of these compounds with other biologically (antitumor) active agents, acting by a different mechanism. Here, we present synthesis, biological effects, and mechanisms of action of new Pt(II) derivatives containing one or two nonsteroidal anti-inflammatory diclofenac (DCF) ligands also known for their antitumor effects. The antiproliferative properties of these metallic conjugates show that these compounds are potent and cancer cell selective cytotoxic agents exhibiting activity in cisplatin resistant and the COX-2 positive tumor cell lines. One of these compounds, compound 3, in which DCF molecules are coordinated to Pt(II) through their carboxylic group, is more potent than parental conventional Pt(II) drug cisplatin, free DCF and the congeners of 3 in which DCF ligands are conjugated to Pt(II) via a diamine. The potency of 3 is due to several factors including enhanced internalization that correlates with enhanced DNA binding and cytotoxicity. Mechanistic studies show that 3 combines multiple effects. After its accumulation in cells, it releases Pt(II) drug capable of binding/damaging DNA and DCF ligands, which affect distribution of cells in individual phases of the cell cycle, inhibit glycolysis and lactate transport, collapse mitochondrial membrane potential, and suppress the cellular properties characteristic of metastatic progression.

  20. Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Jahnavi, S [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai, TN 600036 (India); Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Saravanan, U [Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, TN 600036 (India); Arthi, N [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai, TN 600036 (India); Bhuvaneshwar, G S [Department of Engineering Design, Indian Institute of Technology Madras, Chennai, TN 600036 (India); Kumary, T V [Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Rajan, S [Madras Medical Mission, Institute of Cardio-Vascular Diseases, Mogappair, Chennai, Tamil Nadu 600037 (India); Verma, R S, E-mail: vermars@iitm.ac.in [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai, TN 600036 (India)

    2017-04-01

    Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties. CD44{sup +}, αSMA{sup +}, Vimentin{sup +} and CD105{sup −} human valve interstitial cells were isolated and seeded on these Bio-Hybrid scaffolds. Subsequent biological evaluation revealed interstitial cell proliferation with dense extra cellular matrix deposition that indicated the viability for growth and proliferation of seeded cells on the scaffolds. Uniaxial mechanical tests along axial direction showed that the Bio-Hybrid scaffolds has at least 20 times the strength of the native valves and its stiffness is nearly 3 times more than that of native valves. Biaxial and uniaxial mechanical studies on valve interstitial cells cultured Bio-Hybrid scaffolds revealed that the response along the axial and circumferential direction was different, similar to native valves. Overall, our findings suggest that Bio-Hybrid scaffold is a promising material for future development of regenerative heart valve constructs in children. - Highlights: • We report detailed biological and mechanical investigations of a Bio-Hybrid scaffold. • Optimized polymer thickness yielded desired biological and mechanical properties. • Bio-Hybrid scaffold revealed hVIC proliferation with dense ECM deposition. • Biaxial testing indicated that Bio-Hybrid scaffolds are mechanically stronger than native valves. • Bio-Hybrid scaffold is a promising material for autologous valve tissue engineering.

  1. Regulation of Caenorhabditis elegans vitellogenesis by DAF-2/IIS through separable transcriptional and posttranscriptional mechanisms.

    Science.gov (United States)

    DePina, Ana S; Iser, Wendy B; Park, Sung-Soo; Maudsley, Stuart; Wilson, Mark A; Wolkow, Catherine A

    2011-07-12

    Evolutionary theories of aging propose that longevity evolves as a competition between reproduction and somatic maintenance for a finite pool of resources. Reproduction is thought to shorten lifespan by depleting resources from processes promoting somatic maintenance. Maternal yolk production, vitellogenesis, represents a significant maternal cost for reproduction and is suppressed under genetic and environmental conditions that extend lifespan. However, little is known about the pathways regulating vitellogenesis in response to prolongevity cues. In order to identify mechanisms that suppress vitellogenesis under prolongevity conditions, we studied factors regulating vitellogenesis in C. elegans nematodes. In C. elegans, vitellogenesis is depressed in the absence of insulin-like signaling (IIS). We found that the C. elegans daf-2/IIS pathway regulates vitellogenesis through two mechanisms. vit-2 transcript levels in daf-2 mutants were indirectly regulated through a germline-dependent signal, and could be rescued by introduction of daf-2(+) sperm. However, yolk protein (YP) levels in daf-2 mutants were also regulated by germline-independent posttranscriptional mechanisms. C. elegans vitellogenesis is regulated transcriptionally and posttranscriptionally in response to environmental and reproductive cues. The daf-2 pathway suppressed vitellogenesis through transcriptional mechanisms reflecting reproductive phenotypes, as well as distinct posttranscriptional mechanisms. This study reveals that pleiotropic effects of IIS pathway mutations can converge on a common downstream target, vitellogenesis, as a mechanism to modulate longevity.

  2. Regulation of Caenorhabditis elegans vitellogenesis by DAF-2/IIS through separable transcriptional and posttranscriptional mechanisms

    Directory of Open Access Journals (Sweden)

    Wilson Mark A

    2011-07-01

    Full Text Available Abstract Background Evolutionary theories of aging propose that longevity evolves as a competition between reproduction and somatic maintenance for a finite pool of resources. Reproduction is thought to shorten lifespan by depleting resources from processes promoting somatic maintenance. Maternal yolk production, vitellogenesis, represents a significant maternal cost for reproduction and is suppressed under genetic and environmental conditions that extend lifespan. However, little is known about the pathways regulating vitellogenesis in response to prolongevity cues. Results In order to identify mechanisms that suppress vitellogenesis under prolongevity conditions, we studied factors regulating vitellogenesis in C. elegans nematodes. In C. elegans, vitellogenesis is depressed in the absence of insulin-like signaling (IIS. We found that the C. elegans daf-2/IIS pathway regulates vitellogenesis through two mechanisms. vit-2 transcript levels in daf-2 mutants were indirectly regulated through a germline-dependent signal, and could be rescued by introduction of daf-2(+ sperm. However, yolk protein (YP levels in daf-2 mutants were also regulated by germline-independent posttranscriptional mechanisms. Conclusions C. elegans vitellogenesis is regulated transcriptionally and posttranscriptionally in response to environmental and reproductive cues. The daf-2 pathway suppressed vitellogenesis through transcriptional mechanisms reflecting reproductive phenotypes, as well as distinct posttranscriptional mechanisms. This study reveals that pleiotropic effects of IIS pathway mutations can converge on a common downstream target, vitellogenesis, as a mechanism to modulate longevity.

  3. Ni(II, Pd(II and Pt(II complexes with ligand containing thiosemicarbazone and semicarbazone moiety: synthesis, characterization and biological investigation

    Directory of Open Access Journals (Sweden)

    SULEKH CHANDRA

    2008-07-01

    Full Text Available The synthesis of nickel(II, palladium(II and platinum(II complexes with thiosemicarbazone and semicarbazone of p-tolualdehyde are reported. All the new compounds were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, 1H-NMR, IR and electronic spectral studies. Based on the molar conductance measurements in DMSO, the complexes may be formulated as [Ni(L2Cl2] and [M(L2]Cl2 (where M = Pd(II and Pt(II due to their non-electrolytic and 1:2 electrolytic nature, respectively. The spectral data are consistent with an octahedral geometry around Ni(II and a square planar geometry for Pd(II and Pt(II, in which the ligands act as bidentate chelating agents, coordinated through the nitrogen and sulphur/oxygen atoms. The ligands and their metal complexes were screened in vitro against fungal species Alternaria alternata, Aspergillus niger and Fusarium odum, using the food poison technique.

  4. On the mechanisms of interaction of low-intensity millimeter waves with biological objects

    Energy Technology Data Exchange (ETDEWEB)

    Betskii, O.V.

    1994-07-01

    The interaction of low-intensity millimeter-band electromagnetic waves with biological objects is examined. These waves are widely used in medical practice as a means of physiotherapy for the treatment of various human disorders. Principal attention is given to the mechanisms through which millimeter waves act on the human organism.

  5. I'm so tired: biological and genetic mechanisms of cancer-related fatigue

    NARCIS (Netherlands)

    Barsevick, Andrea; Frost, Marlene; Zwinderman, Aeilko; Hall, Per; Halyard, Michele; Abertnethy, Amy P.; Baas, Frank; Barsevick, Andrea M.; Bartels, Meike; Boomsma, Dorret I.; Chauhan, Cynthia; Cleeland, Charles S.; Dueck, Amylou C.; Frost, Marlene H.; Halyard, Michele Y.; Klepstad, Pål; Martin, Nicholas G.; Miaskowski, Christine; Mosing, Miriam; Movsas, Benjamin; van Noorden, Cornelis J. F.; Patrick, Donald L.; Pedersen, Nancy L.; Ropka, Mary E.; Shi, Quiling; Shinozaki, Gen; Singh, Jasvinder A.; Sloan, Jeff A.; Sprangers, Mirjam A. G.; Veenhoven, Ruut; Yang, Ping

    2010-01-01

    Objective The goal of this paper is to discuss cancer-related fatigue (CRF) and address issues related to the investigation into potential biological and genetic causal mechanisms. The objectives are to: (1) describe CRF as a component of quality of life (QOL); (2) address measurement issues that

  6. How preconditioning affects the measurement of poro-viscoelastic mechanical properties in biological tissues

    NARCIS (Netherlands)

    Hosseini, S.M.; Wilson, W.; Ito, K.; Donkelaar, van C.C.

    2014-01-01

    It is known that initial loading curves of soft biological tissues are substantially different from subsequent loadings. The later loading curves are generally used for assessing the mechanical properties of a tissue, and the first loading cycles, referred to as preconditioning, are omitted.

  7. Biological mechanisms underlying the role of physical fitness in health and resilience

    OpenAIRE

    Silverman, Marni N.; Deuster, Patricia A.

    2014-01-01

    Physical fitness, achieved through regular exercise and/or spontaneous physical activity, confers resilience by inducing positive psychological and physiological benefits, blunting stress reactivity, protecting against potentially adverse behavioural and metabolic consequences of stressful events and preventing many chronic diseases. In this review, we discuss the biological mechanisms underlying the beneficial effects of physical fitness on mental and physical health. Physical fitness appear...

  8. Phase I to II cross-induction of xenobiotic metabolizing enzymes: A feedforward control mechanism for potential hormetic responses

    International Nuclear Information System (INIS)

    Zhang Qiang; Pi Jingbo; Woods, Courtney G.; Andersen, Melvin E.

    2009-01-01

    Hormetic responses to xenobiotic exposure likely occur as a result of overcompensation by the homeostatic control systems operating in biological organisms. However, the mechanisms underlying overcompensation that leads to hormesis are still unclear. A well-known homeostatic circuit in the cell is the gene induction network comprising phase I, II and III metabolizing enzymes, which are responsible for xenobiotic detoxification, and in many cases, bioactivation. By formulating a differential equation-based computational model, we investigated in this study whether hormesis can arise from the operation of this gene/enzyme network. The model consists of two feedback and one feedforward controls. With the phase I negative feedback control, xenobiotic X activates nuclear receptors to induce cytochrome P450 enzyme, which bioactivates X into a reactive metabolite X'. With the phase II negative feedback control, X' activates transcription factor Nrf2 to induce phase II enzymes such as glutathione S-transferase and glutamate cysteine ligase, etc., which participate in a set of reactions that lead to the metabolism of X' into a less toxic conjugate X''. The feedforward control involves phase I to II cross-induction, in which the parent chemical X can also induce phase II enzymes directly through the nuclear receptor and indirectly through transcriptionally upregulating Nrf2. As a result of the active feedforward control, a steady-state hormetic relationship readily arises between the concentrations of the reactive metabolite X' and the extracellular parent chemical X to which the cell is exposed. The shape of dose-response evolves over time from initially monotonically increasing to J-shaped at the final steady state-a temporal sequence consistent with adaptation-mediated hormesis. The magnitude of the hormetic response is enhanced by increases in the feedforward gain, but attenuated by increases in the bioactivation or phase II feedback loop gains. Our study suggests a

  9. Phase I to II cross-induction of xenobiotic metabolizing enzymes: a feedforward control mechanism for potential hormetic responses.

    Science.gov (United States)

    Zhang, Qiang; Pi, Jingbo; Woods, Courtney G; Andersen, Melvin E

    2009-06-15

    Hormetic responses to xenobiotic exposure likely occur as a result of overcompensation by the homeostatic control systems operating in biological organisms. However, the mechanisms underlying overcompensation that leads to hormesis are still unclear. A well-known homeostatic circuit in the cell is the gene induction network comprising phase I, II and III metabolizing enzymes, which are responsible for xenobiotic detoxification, and in many cases, bioactivation. By formulating a differential equation-based computational model, we investigated in this study whether hormesis can arise from the operation of this gene/enzyme network. The model consists of two feedback and one feedforward controls. With the phase I negative feedback control, xenobiotic X activates nuclear receptors to induce cytochrome P450 enzyme, which bioactivates X into a reactive metabolite X'. With the phase II negative feedback control, X' activates transcription factor Nrf2 to induce phase II enzymes such as glutathione S-transferase and glutamate cysteine ligase, etc., which participate in a set of reactions that lead to the metabolism of X' into a less toxic conjugate X''. The feedforward control involves phase I to II cross-induction, in which the parent chemical X can also induce phase II enzymes directly through the nuclear receptor and indirectly through transcriptionally upregulating Nrf2. As a result of the active feedforward control, a steady-state hormetic relationship readily arises between the concentrations of the reactive metabolite X' and the extracellular parent chemical X to which the cell is exposed. The shape of dose-response evolves over time from initially monotonically increasing to J-shaped at the final steady state-a temporal sequence consistent with adaptation-mediated hormesis. The magnitude of the hormetic response is enhanced by increases in the feedforward gain, but attenuated by increases in the bioactivation or phase II feedback loop gains. Our study suggests a

  10. I: Hydrodynamic-focusing microreactor II: Mechanically interlocked molecules for functional materials

    Science.gov (United States)

    Coti, Karla Karina

    I: Microreactors, a class of microfluidics, offer numerous benefits -- such as small sample requirement, short analysis times and automations -- and have been used to study reactions of chemical and biological reagents. In order to understand the relationship between fast mixing, product regioselectivity, as well as the ability to separate, in time and space, the nanoparticle (NP) formation stages, a microreactor capable of fast and controllable mixing was developed (Chapter 1) based on multi-lamination and hydrodynamic-focusing. By taking advantage of the fast and controllable mixing properties of this novel microreactor one can control the time when chemical reactions commence inside the microchannels. These properties of the microreactor can be exploited to improve the product regioselectivity of a diazo-coupling reaction to attain a product distribution of monoazo to diazo product of ˜1:99, a selectivity unprecedented in both conventional, macroscopic reactors and other microfluidic systems. Additionally, the ability to separate different stages during the NP formation process inside the microreactor, allowed us to study the aggregation of polypyrrole NPs. II: Supramolecular actuators and molecular interlocked molecules, such as catenanes and rotaxanes, have attracted considerable attention because of their sophisticated topology and their application in functional molecular devices. The blending of supramolecular and mechanostereochemistry with mesoporous silica NPs has proven to be a powerful combination, leading to the development of a new class of materials -- mechanized silica nanoparticles ( Chapter 2). These new hybrid materials are designed to release their content in response to an external stimuli and their development is being driven by the need to improve current drug delivery technologies. In an effort to explore how the stimuli-controlled mechanical movement of switchable, bistable [2]rotaxanes -- based on a cyclobis(paraquat-p-phenylene) ring

  11. Angiotensin II increases phosphodiesterase 5A expression in vascular smooth muscle cells: A mechanism by which angiotensin II antagonizes cGMP signaling

    Science.gov (United States)

    Kim, Dongsoo; Aizawa, Toru; Wei, Heng; Pi, Xinchun; Rybalkin, Sergei D.; Berk, Bradford C.; Yan, Chen

    2014-01-01

    Angiotensin II (Ang II) and nitric oxide (NO)/natriuretic peptide (NP) signaling pathways mutually regulate each other. Imbalance of Ang II and NO/NP has been implicated in the pathophysiology of many vascular diseases. cGMP functions as a key mediator in the interaction between Ang II and NO/NP. Cyclic nucleotide phosphodiesterase 5A (PDE5A) is important in modulating cGMP signaling by hydrolyzing cGMP in vascular smooth muscle cells (VSMC). Therefore, we examined whether Ang II negatively modulates intracellular cGMP signaling in VSMC by regulating PDE5A. Ang II rapidly and transiently increased PDE5A mRNA levels in rat aortic VSMC. Upregulation of PDE5A mRNA was associated with a time-dependent increase of both PDE5 protein expression and activity. Increased PDE5A mRNA level was transcription-dependent and mediated by the Ang II type 1 receptor. Ang II-mediated activation of extracellular signal-regulated kinases 1/2 (ERK1/2) was essential for Ang II-induced PDE5A upregulation. Pretreatment of VSMC with Ang II inhibited C-type NP (CNP) stimulated cGMP signaling, such as cGMP dependent protein kinase (PKG)-mediated phosphorylation of vasodilator-stimulated-phosphoprotein (VASP). Ang II-mediated inhibition of PKG was blocked when PDE5 activity was decreased by selective PDE5 inhibitors, suggesting that upregulation of PDE5A expression is an important mechanism for Ang II to attenuate cGMP signaling. PDE5A may also play a critical role in the growth promoting effects of Ang II because inhibition of PDE5A activity significantly decreased Ang II-stimulated VSMC growth. These observations establish a new mechanism by which Ang II antagonizes cGMP signaling and stimulates VSMC growth. PMID:15623434

  12. Enhancement mechanisms of graphene in nano-58S bioactive glass scaffold: mechanical and biological performance.

    Science.gov (United States)

    Gao, Chengde; Liu, Tingting; Shuai, Cijun; Peng, Shuping

    2014-04-16

    Graphene is a novel material and currently popular as an enabler for the next-generation nanocomposites. Here, we report the use of graphene to improve the mechanical properties of nano-58S bioactive glass for bone repair and regeneration. And the composite scaffolds were fabricated by a homemade selective laser sintering system. Qualitative and quantitative analysis demonstrated the successful incorporation of graphene into the scaffold without obvious structural damage and weight loss. The optimum compressive strength and fracture toughness reached 48.65 ± 3.19 MPa and 1.94 ± 0.10 MPa · m(1/2) with graphene content of 0.5 wt%, indicating significant improvements by 105% and 38% respectively. The mechanisms of pull-out, crack bridging, crack deflection and crack tip shielding were found to be responsible for the mechanical enhancement. Simulated body fluid and cell culture tests indicated favorable bioactivity and biocompatibility of the composite scaffold. The results suggest a great potential of graphene/nano-58S composite scaffold for bone tissue engineering applications.

  13. Shell and membrane theories in mechanics and biology from macro- to nanoscale structures

    CERN Document Server

    Mikhasev, Gennadi

    2015-01-01

    This book presents the latest results related to shells  characterize and design shells, plates, membranes and other thin-walled structures, a multidisciplinary approach from macro- to nanoscale is required which involves the classical disciplines of mechanical/civil/materials engineering (design, analysis, and properties) and physics/biology/medicine among others. The book contains contributions of a meeting of specialists (mechanical engineers, mathematicians, physicists and others) in such areas as classical and non-classical shell theories. New trends with respect to applications in mechanical, civil and aero-space engineering, as well as in new branches like medicine and biology are presented which demand improvements of the theoretical foundations of these theories and a deeper understanding of the material behavior used in such structures.

  14. Mechanism of selective recruitment of RNA polymerases II and III to snRNA gene promoters.

    Science.gov (United States)

    Dergai, Oleksandr; Cousin, Pascal; Gouge, Jerome; Satia, Karishma; Praz, Viviane; Kuhlman, Tracy; Lhôte, Philippe; Vannini, Alessandro; Hernandez, Nouria

    2018-05-01

    RNA polymerase II (Pol II) small nuclear RNA (snRNA) promoters and type 3 Pol III promoters have highly similar structures; both contain an interchangeable enhancer and "proximal sequence element" (PSE), which recruits the SNAP complex (SNAPc). The main distinguishing feature is the presence, in the type 3 promoters only, of a TATA box, which determines Pol III specificity. To understand the mechanism by which the absence or presence of a TATA box results in specific Pol recruitment, we examined how SNAPc and general transcription factors required for Pol II or Pol III transcription of SNAPc-dependent genes (i.e., TATA-box-binding protein [TBP], TFIIB, and TFIIA for Pol II transcription and TBP and BRF2 for Pol III transcription) assemble to ensure specific Pol recruitment. TFIIB and BRF2 could each, in a mutually exclusive fashion, be recruited to SNAPc. In contrast, TBP-TFIIB and TBP-BRF2 complexes were not recruited unless a TATA box was present, which allowed selective and efficient recruitment of the TBP-BRF2 complex. Thus, TBP both prevented BRF2 recruitment to Pol II promoters and enhanced BRF2 recruitment to Pol III promoters. On Pol II promoters, TBP recruitment was separate from TFIIB recruitment and enhanced by TFIIA. Our results provide a model for specific Pol recruitment at SNAPc-dependent promoters. © 2018 Dergai et al.; Published by Cold Spring Harbor Laboratory Press.

  15. A Systems Biology Approach Reveals Converging Molecular Mechanisms that Link Different POPs to Common Metabolic Diseases.

    Science.gov (United States)

    Ruiz, Patricia; Perlina, Ally; Mumtaz, Moiz; Fowler, Bruce A

    2016-07-01

    A number of epidemiological studies have identified statistical associations between persistent organic pollutants (POPs) and metabolic diseases, but testable hypotheses regarding underlying molecular mechanisms to explain these linkages have not been published. We assessed the underlying mechanisms of POPs that have been associated with metabolic diseases; three well-known POPs [2,3,7,8-tetrachlorodibenzodioxin (TCDD), 2,2´,4,4´,5,5´-hexachlorobiphenyl (PCB 153), and 4,4´-dichlorodiphenyldichloroethylene (p,p´-DDE)] were studied. We used advanced database search tools to delineate testable hypotheses and to guide laboratory-based research studies into underlying mechanisms by which this POP mixture could produce or exacerbate metabolic diseases. For our searches, we used proprietary systems biology software (MetaCore™/MetaDrug™) to conduct advanced search queries for the underlying interactions database, followed by directional network construction to identify common mechanisms for these POPs within two or fewer interaction steps downstream of their primary targets. These common downstream pathways belong to various cytokine and chemokine families with experimentally well-documented causal associations with type 2 diabetes. Our systems biology approach allowed identification of converging pathways leading to activation of common downstream targets. To our knowledge, this is the first study to propose an integrated global set of step-by-step molecular mechanisms for a combination of three common POPs using a systems biology approach, which may link POP exposure to diseases. Experimental evaluation of the proposed pathways may lead to development of predictive biomarkers of the effects of POPs, which could translate into disease prevention and effective clinical treatment strategies. Ruiz P, Perlina A, Mumtaz M, Fowler BA. 2016. A systems biology approach reveals converging molecular mechanisms that link different POPs to common metabolic diseases. Environ

  16. Biologically inspired control and modeling of (biorobotic systems and some applications of fractional calculus in mechanics

    Directory of Open Access Journals (Sweden)

    Lazarević Mihailo P.

    2013-01-01

    Full Text Available In this paper, the applications of biologically inspired modeling and control of (biomechanical (nonredundant mechanisms are presented, as well as newly obtained results of author in mechanics which are based on using fractional calculus. First, it is proposed to use biological analog-synergy due to existence of invariant features in the execution of functional motion. Second, the model of (biomechanical system may be obtained using another biological concept called distributed positioning (DP, which is based on the inertial properties and actuation of joints of considered mechanical system. In addition, it is proposed to use other biological principles such as: principle of minimum interaction, which takes a main role in hierarchical structure of control and self-adjusting principle (introduce local positive/negative feedback on control with great amplifying, which allows efficiently realization of control based on iterative natural learning. Also, new, recently obtained results of the author in the fields of stability, electroviscoelasticity, and control theory are presented which are based on using fractional calculus (FC. [Projekat Ministarstva nauke Republike Srbije, br. 35006

  17. Mechanisms of energy transfer and conversion in plant Light-Harvesting Complex II

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Tiago Ferreira de

    2009-09-24

    subject of this thesis. From the results obtained during this doctoral work, five main conclusions can be drawn concerning the mechanism of qE: 1. Substitution of Vio by Zea in LHC-II is not sufficient for efficient dissipation of excess excitation energy. 2. Aggregation quenching of LHC-II does not require Vio, Neo nor a specific Chl pair. 3. With one exception, the pigment structure in LHC-II is rigid. 4. The two X-ray structures of LHC-II show the same energy transmitting state of the complex. 5. Crystalline LHC-II resembles the complex in the thylakoid membrane. Models of the aggregation quenching mechanism in vitro and the qE mechanism in vivo are presented as a corollary of this doctoral work. LHC-II aggregation quenching in vitro is attributed to the formation of energy sinks on the periphery of LHC-II through random interaction with other trimers, free pigments or impurities. A similar but unrelated process is proposed to occur in the thylakoid membrane, by which excess excitation energy is dissipated upon specific interaction between LHC-II and a PsbS monomer carrying Zea. At the end of this thesis, an innovative experimental model for the analysis of all key aspects of qE is proposed in order to finally solve the qE enigma, one of the last unresolved problems in photosynthesis research. (orig.)

  18. The prognosis of infective endocarditis treated with biological valves versus mechanical valves: A meta-analysis.

    Science.gov (United States)

    Tao, Ende; Wan, Li; Wang, WenJun; Luo, YunLong; Zeng, JinFu; Wu, Xia

    2017-01-01

    Surgery remains the primary form of treatment for infective endocarditis (IE). However, it is not clear what type of prosthetic valve provides a better prognosis. We conducted a meta-analysis to compare the prognosis of infective endocarditis treated with biological valves to cases treated with mechanical valves. Pubmed, Embase and Cochrane databases were searched from January 1960 to November 2016.Randomized controlled trials, retrospective cohorts and prospective studies comparing outcomes between biological valve and mechanical valve management for infective endocarditis were analyzed. The Newcastle-Ottawa Scale(NOS) was used to evaluate the quality of the literature and extracted data, and Stata 12.0 software was used for the meta-analysis. A total of 11 publications were included; 10,754 cases were selected, involving 6776 cases of biological valves and 3,978 cases of mechanical valves. The all-cause mortality risk of the biological valve group was higher than that of the mechanical valve group (HR = 1.22, 95% CI 1.03 to 1.44, P = 0.023), as was early mortality (RR = 1.21, 95% CI 1.02 to 1.43, P = 0.033). The recurrence of endocarditis (HR = 1.75, 95% CI 1.26 to 2.42, P = 0.001), as well as the risk of reoperation (HR = 1.79, 95% CI 1.15 to 2.80, P = 0.010) were more likely to occur in the biological valve group. The incidence of postoperative embolism was less in the biological valve group than in the mechanical valve group, but this difference was not statistically significant (RR = 0.90, 95% CI 0.76 to 1.07, P = 0.245). For patients with prosthetic valve endocarditis (PVE), there was no significant difference in survival rates between the biological valve group and the mechanical valve group (HR = 0.91, 95% CI 0.68 to 1.21, P = 0.520). The results of our meta-analysis suggest that mechanical valves can provide a significantly better prognosis in patients with infective endocarditis. There were significant differences in the clinical features of patients

  19. Relative biological effectiveness of 160 MeV protons. II. Biological data and their interpretation in terms of microdosimetry

    International Nuclear Information System (INIS)

    Hall, E.J.; Kellerer, A.M.; Rossi, H.H.; Lam, Y.M.P.

    1978-01-01

    The radiobiological effectiveness of 160 MeV protons was measured relative to 60 Co γ rays using Chinese hamster cells cultured in vitro. Separate experiments were performed with cells irradiated in suspension, or attached to plastic tissue culture flasks. Proton irradiations were performed in the incident plateau of the depth dose profile and with the Bragg peak spread out to cover 10 cm. In all cases the relative biological effectiveness (RBE) for protons relative to gamma rays was 1.2 for doses in excess of about 200 rad. The attached cell experiments indicate an increasing RBE at low doses, which is consistent with the microdosimetric measurements

  20. Biological mechanisms associated with triazophos (TAP) removal by horizontal subsurface flow constructed wetlands (HSFCW)

    International Nuclear Information System (INIS)

    Wu, Juan; Feng, Yuqin; Dai, Yanran; Cui, Naxin; Anderson, Bruce; Cheng, Shuiping

    2016-01-01

    Triazophos (TAP) is a widely used pesticide that is easily accumulated in the environment due to its relatively high stability: this accumulation from agricultural runoff results in potential hazards to aquatic ecosystems. Constructed wetlands are generally considered to be an effective technology for treating TAP polluted surface water. However, knowledge about the biological mechanisms of TAP removal is still lacking. This study investigates the responses of a wetland plant (Canna indica), substrate enzymes and microbial communities in bench-scale horizontal subsurface-flow constructed wetlands (HSCWs) loaded with different TAP concentrations (0, 0.1, 0.5 and 5 mg·L"−"1). The results indicate that TAP stimulated the activities of superoxide dismutase (SOD) and peroxidase (POD) in the roots of C. indica. The highest TAP concentrations significantly inhibited photosynthetic activities, as shown by a reduced effective quantum yield of PS II (Φ_P_S_I_I) and lower electron transport rates (ETR). However, interestingly, the lower TAP loadings exhibited some favorable effects on these two variables, suggesting that C. indica is a suitable species for use in wetlands designed for treatment of low TAP concentrations. Urease and alkaline phosphatase (ALP) in the wetland substrate were activated by TAP. Two-way ANOVA demonstrated that urease activity was influenced by both the TAP concentrations and season, while acidphosphatase (ACP) only responded to seasonal variations. Analysis of high throughput sequencing of 16S rRNA revealed seasonal variations in the microbial community structure of the wetland substrate at the phylum and family levels. In addition, urease activity had a greater correlation with the relative abundance of some functional microbial groups, such as the Bacillaceae family, and the ALP and ACP may be influenced by the plant more than substrate microbial communities. - Highlights: • Physiological responses of the wetland plant to triazophos loads

  1. Biological mechanisms associated with triazophos (TAP) removal by horizontal subsurface flow constructed wetlands (HSFCW)

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Juan; Feng, Yuqin; Dai, Yanran; Cui, Naxin [State Key Laboratory of Pollution Control and ResourceReuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Anderson, Bruce [Department of Civil Engineering, Queen' s University, Kingston K7L3N6 (Canada); Cheng, Shuiping, E-mail: shpcheng@tongji.edu.cn [State Key Laboratory of Pollution Control and ResourceReuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2016-05-15

    Triazophos (TAP) is a widely used pesticide that is easily accumulated in the environment due to its relatively high stability: this accumulation from agricultural runoff results in potential hazards to aquatic ecosystems. Constructed wetlands are generally considered to be an effective technology for treating TAP polluted surface water. However, knowledge about the biological mechanisms of TAP removal is still lacking. This study investigates the responses of a wetland plant (Canna indica), substrate enzymes and microbial communities in bench-scale horizontal subsurface-flow constructed wetlands (HSCWs) loaded with different TAP concentrations (0, 0.1, 0.5 and 5 mg·L{sup −1}). The results indicate that TAP stimulated the activities of superoxide dismutase (SOD) and peroxidase (POD) in the roots of C. indica. The highest TAP concentrations significantly inhibited photosynthetic activities, as shown by a reduced effective quantum yield of PS II (Φ{sub PSII}) and lower electron transport rates (ETR). However, interestingly, the lower TAP loadings exhibited some favorable effects on these two variables, suggesting that C. indica is a suitable species for use in wetlands designed for treatment of low TAP concentrations. Urease and alkaline phosphatase (ALP) in the wetland substrate were activated by TAP. Two-way ANOVA demonstrated that urease activity was influenced by both the TAP concentrations and season, while acidphosphatase (ACP) only responded to seasonal variations. Analysis of high throughput sequencing of 16S rRNA revealed seasonal variations in the microbial community structure of the wetland substrate at the phylum and family levels. In addition, urease activity had a greater correlation with the relative abundance of some functional microbial groups, such as the Bacillaceae family, and the ALP and ACP may be influenced by the plant more than substrate microbial communities. - Highlights: • Physiological responses of the wetland plant to triazophos

  2. A Model of How Different Biology Experts Explain Molecular and Cellular Mechanisms

    Science.gov (United States)

    Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

    2015-01-01

    Constructing explanations is an essential skill for all science learners. The goal of this project was to model the key components of expert explanation of molecular and cellular mechanisms. As such, we asked: What is an appropriate model of the components of explanation used by biology experts to explain molecular and cellular mechanisms? Do explanations made by experts from different biology subdisciplines at a university support the validity of this model? Guided by the modeling framework of R. S. Justi and J. K. Gilbert, the validity of an initial model was tested by asking seven biologists to explain a molecular mechanism of their choice. Data were collected from interviews, artifacts, and drawings, and then subjected to thematic analysis. We found that biologists explained the specific activities and organization of entities of the mechanism. In addition, they contextualized explanations according to their biological and social significance; integrated explanations with methods, instruments, and measurements; and used analogies and narrated stories. The derived methods, analogies, context, and how themes informed the development of our final MACH model of mechanistic explanations. Future research will test the potential of the MACH model as a guiding framework for instruction to enhance the quality of student explanations. PMID:25999313

  3. Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering.

    Science.gov (United States)

    Jahnavi, S; Saravanan, U; Arthi, N; Bhuvaneshwar, G S; Kumary, T V; Rajan, S; Verma, R S

    2017-04-01

    Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties. CD44 + , αSMA + , Vimentin + and CD105 - human valve interstitial cells were isolated and seeded on these Bio-Hybrid scaffolds. Subsequent biological evaluation revealed interstitial cell proliferation with dense extra cellular matrix deposition that indicated the viability for growth and proliferation of seeded cells on the scaffolds. Uniaxial mechanical tests along axial direction showed that the Bio-Hybrid scaffolds has at least 20 times the strength of the native valves and its stiffness is nearly 3 times more than that of native valves. Biaxial and uniaxial mechanical studies on valve interstitial cells cultured Bio-Hybrid scaffolds revealed that the response along the axial and circumferential direction was different, similar to native valves. Overall, our findings suggest that Bio-Hybrid scaffold is a promising material for future development of regenerative heart valve constructs in children. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Dynamics of ligand exchange mechanism at Cu(II) in water: An ab initio quantum mechanical charge field molecular dynamics study with extended quantum mechanical region

    International Nuclear Information System (INIS)

    Moin, Syed Tarique; Hofer, Thomas S.; Weiss, Alexander K. H.; Rode, Bernd M.

    2013-01-01

    Ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) were successfully applied to Cu(II) embedded in water to elucidate structure and to understand dynamics of ligand exchange mechanism. From the simulation studies, it was found that using an extended large quantum mechanical region including two shells of hydration is required for a better description of the dynamics of exchanging water molecules. The structural features characterized by radial distribution function, angular distribution function and other analytical parameters were consistent with experimental data. The major outcome of this study was the dynamics of exchange mechanism and reactions in the first hydration shell that could not be studied so far. The dynamical data such as mean residence time of the first shell water molecules and other relevant data from the simulations are close to the results determined experimentally. Another major characteristic of hydrated Cu(II) is the Jahn-Teller distortion which was also successfully reproduced, leading to the final conclusion that the dominating aqua complex is a 6-coordinated species. The ab initio QMCF-MD formalism proved again its capabilities of unraveling even ambiguous properties of hydrated species that are far difficult to explore by any conventional quantum mechanics/molecular mechanics (QM/MM) approach or experiment

  5. Dynamics of ligand exchange mechanism at Cu(II) in water: an ab initio quantum mechanical charge field molecular dynamics study with extended quantum mechanical region.

    Science.gov (United States)

    Moin, Syed Tarique; Hofer, Thomas S; Weiss, Alexander K H; Rode, Bernd M

    2013-07-07

    Ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) were successfully applied to Cu(II) embedded in water to elucidate structure and to understand dynamics of ligand exchange mechanism. From the simulation studies, it was found that using an extended large quantum mechanical region including two shells of hydration is required for a better description of the dynamics of exchanging water molecules. The structural features characterized by radial distribution function, angular distribution function and other analytical parameters were consistent with experimental data. The major outcome of this study was the dynamics of exchange mechanism and reactions in the first hydration shell that could not be studied so far. The dynamical data such as mean residence time of the first shell water molecules and other relevant data from the simulations are close to the results determined experimentally. Another major characteristic of hydrated Cu(II) is the Jahn-Teller distortion which was also successfully reproduced, leading to the final conclusion that the dominating aqua complex is a 6-coordinated species. The ab initio QMCF-MD formalism proved again its capabilities of unraveling even ambiguous properties of hydrated species that are far difficult to explore by any conventional quantum mechanics/molecular mechanics (QM/MM) approach or experiment.

  6. Stochastic Simulation of Isotopic Exchange Mechanisms for Fe(II)-Catalyzed Recrystallization of Goethite

    Energy Technology Data Exchange (ETDEWEB)

    Zarzycki, Piotr [Energy; Institute; Rosso, Kevin M. [Pacific Northwest

    2017-06-15

    Understanding Fe(II)-catalyzed transformations of Fe(III)- (oxyhydr)oxides is critical for correctly interpreting stable isotopic distributions and for predicting the fate of metal ions in the environment. Recent Fe isotopic tracer experiments have shown that goethite undergoes rapid recrystallization without phase change when exposed to aqueous Fe(II). The proposed explanation is oxidation of sorbed Fe(II) and reductive Fe(II) release coupled 1:1 by electron conduction through crystallites. Given the availability of two tracer exchange data sets that explore pH and particle size effects (e.g., Handler et al. Environ. Sci. Technol. 2014, 48, 11302-11311; Joshi and Gorski Environ. Sci. Technol. 2016, 50, 7315-7324), we developed a stochastic simulation that exactly mimics these experiments, while imposing the 1:1 constraint. We find that all data can be represented by this model, and unifying mechanistic information emerges. At pH 7.5 a rapid initial exchange is followed by slower exchange, consistent with mixed surface- and diffusion-limited kinetics arising from prominent particle aggregation. At pH 5.0 where aggregation and net Fe(II) sorption are minimal, that exchange is quantitatively proportional to available particle surface area and the density of sorbed Fe(II) is more readily evident. Our analysis reveals a fundamental atom exchange rate of ~10-5 Fe nm-2 s-1, commensurate with some of the reported reductive dissolution rates of goethite, suggesting Fe(II) release is the rate-limiting step in the conduction mechanism during recrystallization.

  7. Mechanical-biological waste conditioning with controlled venting - the Meisenheim mechanical-biological waste conditioning plant; Mechanisch-biologische Restabfallbehandlung nach dem Kaminzugverfahren - MBRA Meisenheim

    Energy Technology Data Exchange (ETDEWEB)

    Hangen, H.O. [Abfallwirtschaftsbetrieb Landkreis Bad Kreuznach, Bad Kreuznach (Germany)

    1998-12-31

    The decision of the rural district of Bad Kreuznach to propose creating facilities for mechanical-biological waste conditioning at the new northern Meisenheim landfill was consistent and correct. It will ensure that the material deposited at this new, state-of-the-art landfill is organically `lean` and can be deposited with a high density. Preliminary sifting of the material prior to depositing safeguards that no improper components are inadvertently included. Three years of operation warrant the statement that waste components that cannot be appropriately biologically conditioned should be eliminated prior to rotting. (orig.) [Deutsch] Die Entscheidung des Landkreises Bad Kreuznach, der neu eingerichteten Norddeponie Meisenheim eine MBRA vorzuschlaten, war auf jeden Fall konsequent und richtig. Es ist damit sicher gestellt, dass in diesem neuen nach dem Stand der Technik eingerichteten Deponiebereich von Anfang an ein Material eingelagert wird, das `organisch abgemagert` ist und mit hoher Einbaudichte eingebaut werden kann. Die Sichtung des gesamten Deponie-Inputs in der Vorsortierhalle gibt ein Stueck Sicherheit, dass keine nicht zugelassenen Stoffe verdeckt dem Ablagerungsbereich der Deponie zugefuehrt werden. Nach mehr als 3 Jahren Betriebszeit kann festgestellt werden, dass biologisch nicht sinnvoll behandelbare Abfallbestandteile vor dem Rotteprozess abgetrennt werden sollten. (orig.)

  8. New Methods of Simulation of Mn(II) EPR Spectra: Single Crystals, Polycrystalline and Amorphous (Biological) Materials

    Science.gov (United States)

    Misra, Sushil K.

    Biological systems exhibit properties of amorphous materials. The Mn(II) ion in amorphous materials is characterized by distributions of spin-Hamiltonian parameters around mean values. It has a certain advantage over other ions, being one of the most abundant elements on the earth. The extent to which living organisms utilize manganese varies from one organism to the other. There is a fairly high concentration of the Mn(II) ion in green plants, which use it in the O2 evolution reaction of photosynthesis (Sauer, 1980). Structure-reactivity relationships in Mn(II)-O2 complexes are given in a review article by Coleman and Taylor (1980). Manganese is a trace requirement in animal nutrition; highly elevated levels of manganese in the diet can be toxic, probably because of an interference with iron homeostasis (Underwood, 1971). On the other hand, animals raised with a dietary deficiency of manganese exhibit severe abnormalities in connective tissue; these problems have been attributed to the obligatory role of Mn(II) in mucopolysaccharide metabolism (Leach, 1971). Mn(II) has been detected unequivocally in living organisms.

  9. Exploring the MACH Model's Potential as a Metacognitive Tool to Help Undergraduate Students Monitor Their Explanations of Biological Mechanisms

    Science.gov (United States)

    Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

    2016-01-01

    When undergraduate biology students learn to explain biological mechanisms, they face many challenges and may overestimate their understanding of living systems. Previously, we developed the MACH model of four components used by expert biologists to explain mechanisms: Methods, Analogies, Context, and How. This study explores the implementation of…

  10. Solid recovered fuel production through the mechanical-biological treatment of wastes

    OpenAIRE

    Velis, C. A.

    2010-01-01

    This thesis is concerned with the production of solid recovered fuel (SRF) from municipal solid waste using mechanical biological treatment (MBT) plants. It describes the first in-depth analysis of a UK MBT plant and addresses the fundamental research question: are MBT plants and their unit operations optimised to produce high quality SRF in the UK? A critical review of the process science and engineering of MBT provides timely insights into the quality management and standa...

  11. Stress Biology and Aging Mechanisms: Toward Understanding the Deep Connection Between Adaptation to Stress and Longevity

    OpenAIRE

    Epel, Elissa S.; Lithgow, Gordon J.

    2014-01-01

    The rate of biological aging is modulated in part by genes interacting with stressor exposures. Basic research has shown that exposure to short-term stress can strengthen cellular responses to stress (“hormetic stress”). Hormetic stress promotes longevity in part through enhanced activity of molecular chaperones and other defense mechanisms. In contrast, prolonged exposure to stress can overwhelm compensatory responses (“toxic stress”) and shorten lifespan. One key question is whether the str...

  12. Influences of mechanical pretreatment on the non-biological treatment of municipal wastewater by forward osmosis.

    Science.gov (United States)

    Hey, Tobias; Zarebska, Agata; Bajraktari, Niada; Vogel, Jörg; Hélix-Nielsen, Claus; la Cour Jansen, Jes; Jönsson, Karin

    2017-09-01

    Municipal wastewater treatment involves mechanical, biological and chemical treatment steps for protecting the environment from adverse effects. The biological treatment step consumes the most energy and can create greenhouse gases. This study investigates municipal wastewater treatment without the biological treatment step, including the effects of different pretreatment configurations, for example, direct membrane filtration before forward osmosis. Forward osmosis was tested using raw wastewater and wastewater subjected to different types of mechanical pretreatment, for example, microsieving and microfiltration permeation, as a potential technology for municipal wastewater treatment. Forward osmosis was performed using Aquaporin Inside™ and Hydration Technologies Inc. (HTI) membranes with NaCl as the draw solution. Both types of forward osmosis membranes were tested in parallel for the different types of pretreated feed and evaluated in terms of water flux and solute rejection, that is, biochemical oxygen demand (BOD 7 ) and total and soluble phosphorus contents. The Aquaporin and HTI membranes achieved a stable water flux with rejection rates of more than 96% for BOD 7 and total and soluble phosphorus, regardless of the type of mechanical pretreated wastewater considered. This result indicates that forward osmosis membranes can tolerate exposure to municipal waste water and that the permeate can fulfil the Swedish discharge limits.

  13. Behavior of selected organic pollutants in municipal waste during the mechanical-biological progress of composting

    International Nuclear Information System (INIS)

    Drahosch, W.

    1998-06-01

    Municipal waste was investigated during the mechanical-biological process of composting. Waste from Burgenland is treated mechanically and biologically to reduce organic matter in the material and to keep gas building potential low before deposition. Samples were taken and analyzed during a period of 80 days. The parameters: temperature, dry-weight, glow loss, ammonium, nitrate and phenolic substances were measured to follow the composting process. It was found that the process was almost finished after a period of 40 days in which the material was breathed intensively. The content of polycyclic aromatic hydrocarbons and polychlorinated phenols decreased slightly. It was not clear whether this was due to microbiological activity or blowing-out effects. Polychlorinated biphenyls were found to be stable during composting. The concentrations were considered as high. Hepta- and octachlorinated dibenzodioxines were formed during the first 10 days. The increase of octachlorinated dibenzodioxin was threefold. Other dioxines and furanes remained unchanged. Finally it was found out that mechanical-biological waste treatment is insufficient in order to reduce organic pollutants effectively. (author)

  14. Borderline personality disorder and childhood trauma: exploring the affected biological systems and mechanisms.

    Science.gov (United States)

    Cattane, Nadia; Rossi, Roberta; Lanfredi, Mariangela; Cattaneo, Annamaria

    2017-06-15

    According to several studies, the onset of the Borderline Personality Disorder (BPD) depends on the combination between genetic and environmental factors (GxE), in particular between biological vulnerabilities and the exposure to traumatic experiences during childhood. We have searched for studies reporting possible alterations in several biological processes and brain morphological features in relation to childhood trauma experiences and to BPD. We have also looked for epigenetic mechanisms as they could be mediators of the effects of childhood trauma in BPD vulnerability. We prove the role of alterations in Hypothalamic-Pituitary-Adrenal (HPA) axis, in neurotrasmission, in the endogenous opioid system and in neuroplasticity in the childhood trauma-associated vulnerability to develop BPD; we also confirm the presence of morphological changes in several BPD brain areas and in particular in those involved in stress response. Not so many studies are available on epigenetic changes in BPD patients, although these mechanisms are widely investigated in relation to stress-related disorders. A better comprehension of the biological and epigenetic mechanisms, affected by childhood trauma and altered in BPD patients, could allow to identify "at high risk" subjects and to prevent or minimize the development of the disease later in life.

  15. Effects of Ionizing Radiation on Biological Molecules—Mechanisms of Damage and Emerging Methods of Detection

    Science.gov (United States)

    Reisz, Julie A.; Bansal, Nidhi; Qian, Jiang; Zhao, Weiling

    2014-01-01

    Abstract Significance: The detrimental effects of ionizing radiation (IR) involve a highly orchestrated series of events that are amplified by endogenous signaling and culminating in oxidative damage to DNA, lipids, proteins, and many metabolites. Despite the global impact of IR, the molecular mechanisms underlying tissue damage reveal that many biomolecules are chemoselectively modified by IR. Recent Advances: The development of high-throughput “omics” technologies for mapping DNA and protein modifications have revolutionized the study of IR effects on biological systems. Studies in cells, tissues, and biological fluids are used to identify molecular features or biomarkers of IR exposure and response and the molecular mechanisms that regulate their expression or synthesis. Critical Issues: In this review, chemical mechanisms are described for IR-induced modifications of biomolecules along with methods for their detection. Included with the detection methods are crucial experimental considerations and caveats for their use. Additional factors critical to the cellular response to radiation, including alterations in protein expression, metabolomics, and epigenetic factors, are also discussed. Future Directions: Throughout the review, the synergy of combined “omics” technologies such as genomics and epigenomics, proteomics, and metabolomics is highlighted. These are anticipated to lead to new hypotheses to understand IR effects on biological systems and improve IR-based therapies. Antioxid. Redox Signal. 21: 260–292. PMID:24382094

  16. Australian Biology Test Item Bank, Years 11 and 12. Volume II: Year 12.

    Science.gov (United States)

    Brown, David W., Ed.; Sewell, Jeffrey J., Ed.

    This document consists of test items which are applicable to biology courses throughout Australia (irrespective of course materials used); assess key concepts within course statement (for both core and optional studies); assess a wide range of cognitive processes; and are relevant to current biological concepts. These items are arranged under…

  17. Thermal, spectral, magnetic and biological studies of thiosemicarbazones complexes with metal ions: Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO2(VI)

    International Nuclear Information System (INIS)

    Mashaly, M.M.; Seleem, H.S.; El-Behairy, M.A.; Habib, H.A.

    2004-01-01

    Thiosemicarbazones ligands, isatin-3-thiosemicarbazone(HIT) and N-acetylisatin-3-thiosemicarbazone (HAIT), which have tridentate ONN coordinating sites were prepared. The complexes of both ligands with Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO 2 (VI) ions were isolated. The ligands and their metal complexes were characterized by elemental analysis, IR, UV-Vis and mass spectra, also by conductance, magnetic moment and TG-DSC measurements. All the transition metal complexes have octahedral configurations, except Cu-complexes which have planar geometry and the UO 2 (VI) complexes which have coordination number 8 and may acquire the distorted dodecahedral geometry. Thermal studies explored the possibility of obtaining new complexes. Inversion from octahedral to square-planar configuration occurred upon heating the parent Ni-HIAT complex to form the corresponding pyrolytic product. The antifungal activity against the tested organisms showed that some metal complexes enhanced the activity with respect to the parent ligands. (author)

  18. Features of Knowledge Building in Biology: Understanding Undergraduate Students' Ideas about Molecular Mechanisms.

    Science.gov (United States)

    Southard, Katelyn; Wince, Tyler; Meddleton, Shanice; Bolger, Molly S

    2016-01-01

    Research has suggested that teaching and learning in molecular and cellular biology (MCB) is difficult. We used a new lens to understand undergraduate reasoning about molecular mechanisms: the knowledge-integration approach to conceptual change. Knowledge integration is the dynamic process by which learners acquire new ideas, develop connections between ideas, and reorganize and restructure prior knowledge. Semistructured, clinical think-aloud interviews were conducted with introductory and upper-division MCB students. Interviews included a written conceptual assessment, a concept-mapping activity, and an opportunity to explain the biomechanisms of DNA replication, transcription, and translation. Student reasoning patterns were explored through mixed-method analyses. Results suggested that students must sort mechanistic entities into appropriate mental categories that reflect the nature of MCB mechanisms and that conflation between these categories is common. We also showed how connections between molecular mechanisms and their biological roles are part of building an integrated knowledge network as students develop expertise. We observed differences in the nature of connections between ideas related to different forms of reasoning. Finally, we provide a tentative model for MCB knowledge integration and suggest its implications for undergraduate learning. © 2016 K. Southard et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  19. A MODELING AND SIMULATION LANGUAGE FOR BIOLOGICAL CELLS WITH COUPLED MECHANICAL AND CHEMICAL PROCESSES.

    Science.gov (United States)

    Somogyi, Endre; Glazier, James A

    2017-04-01

    Biological cells are the prototypical example of active matter. Cells sense and respond to mechanical, chemical and electrical environmental stimuli with a range of behaviors, including dynamic changes in morphology and mechanical properties, chemical uptake and secretion, cell differentiation, proliferation, death, and migration. Modeling and simulation of such dynamic phenomena poses a number of computational challenges. A modeling language describing cellular dynamics must naturally represent complex intra and extra-cellular spatial structures and coupled mechanical, chemical and electrical processes. Domain experts will find a modeling language most useful when it is based on concepts, terms and principles native to the problem domain. A compiler must then be able to generate an executable model from this physically motivated description. Finally, an executable model must efficiently calculate the time evolution of such dynamic and inhomogeneous phenomena. We present a spatial hybrid systems modeling language, compiler and mesh-free Lagrangian based simulation engine which will enable domain experts to define models using natural, biologically motivated constructs and to simulate time evolution of coupled cellular, mechanical and chemical processes acting on a time varying number of cells and their environment.

  20. Mass balance to assess the efficiency of a mechanical-biological treatment

    International Nuclear Information System (INIS)

    Araujo Morais, J. de; Ducom, G.; Achour, F.; Rouez, M.; Bayard, R.

    2008-01-01

    Using mechanical-biological treatment of residual municipal solid waste, it is possible to significantly lower landfill volume and gas and leachate emissions. Moreover, the landfill characteristics are improved. The performance of the Mende (France) mechanical-biological treatment plant is assessed via mass balances coupled with manual sorting according to the MODECOM TM methodology and biochemical methane potential after 90 days of incubation. The site includes mechanical sorting operations, a rotary sequential bioreactor, controlled aerobic stabilisation corridors, maturation platforms, and a sanitary landfill site for waste disposal in separated cells. Results showed that several steps could be improved: after a first sieving step, about 12% of the potentially biodegradable matter is landfilled directly without any treatment; mechanical disintegration of papers and cardboards in the rotary sequential bioreactor is insufficient and leads to a high proportion of papers and cardboards being landfilled without further treatment. Two fine fractions go through stabilisation and maturation steps. At the end of the maturation step, about 54% of the potentially biodegradable matter is degraded. The biochemical methane potential after 90 days of incubation is reduced by 81% for one of the two fine fractions and reduced by 88% for the other one. Considering the whole plant, there is a reduction of nearly 20% DM of the entering residual municipal solid waste

  1. Biological mechanisms discriminating growth rate and adult body weight phenotypes in two Chinese indigenous chicken breeds.

    Science.gov (United States)

    Dou, Tengfei; Zhao, Sumei; Rong, Hua; Gu, Dahai; Li, Qihua; Huang, Ying; Xu, Zhiqiang; Chu, Xiaohui; Tao, Linli; Liu, Lixian; Ge, Changrong; Te Pas, Marinus F W; Jia, Junjing

    2017-06-20

    Intensive selection has resulted in increased growth rates and muscularity in broiler chickens, in addition to adverse effects, including delayed organ development, sudden death syndrome, and altered metabolic rates. The biological mechanisms underlying selection responses remain largely unknown. Non-artificially-selected indigenous Chinese chicken breeds display a wide variety of phenotypes, including differential growth rate, body weight, and muscularity. The Wuding chicken breed is a fast growing large chicken breed, and the Daweishan mini chicken breed is a slow growing small chicken breed. Together they form an ideal model system to study the biological mechanisms underlying broiler chicken selection responses in a natural system. The objective of this study was to study the biological mechanisms underlying differential phenotypes between the two breeds in muscle and liver tissues, and relate these to the growth rate and body development phenotypes of the two breeds. The muscle tissue in the Wuding breed showed higher expression of muscle development genes than muscle tissue in the Daweishan chicken breed. This expression was accompanied by higher expression of acute inflammatory response genes in Wuding chicken than in Daweishan chicken. The muscle tissue of the Daweishan mini chicken breed showed higher expression of genes involved in several metabolic mechanisms including endoplasmic reticulum, protein and lipid metabolism, energy metabolism, as well as specific immune traits than in the Wuding chicken. The liver tissue showed fewer differences between the two breeds. Genes displaying higher expression in the Wuding breed than in the Daweishan breed were not associated with a specific gene network or biological mechanism. Genes highly expressed in the Daweishan mini chicken breed compared to the Wuding breed were enriched for protein metabolism, ABC receptors, signal transduction, and IL6-related mechanisms. We conclude that faster growth rates and larger

  2. THE RENIN-ANGIOTENSIN SYSTEM AND THE BIOLOGY OF SKELETAL MUSCLE: MECHANISMS OF MUSCLE WASTING IN CHRONIC DISEASE STATES.

    Science.gov (United States)

    Delafontaine, Patrice; Yoshida, Tadashi

    2016-01-01

    Sarcopenia and cachexia are muscle-wasting syndromes associated with aging and with many chronic diseases such as congestive heart failure, diabetes, cancer, chronic obstructive pulmonary disease, and renal failure. While mechanisms are complex, these conditions are often accompanied by elevated angiotensin II (Ang II). We found that Ang II infusion in rodents leads to skeletal muscle wasting via alterations in insulin-like growth factor-1 signaling, increased apoptosis, enhanced muscle protein breakdown via the ubiquitin-proteasome system, and decreased appetite resulting from downregulation of hypothalamic orexigenic neuropeptides orexin and neuropeptide Y. Furthermore, Ang II inhibits skeletal muscle stem cell proliferation, leading to lowered muscle regenerative capacity. Distinct stem cell Ang II receptor subtypes are critical for regulation of muscle regeneration. In ischemic mouse congestive heart failure model skeletal muscle wasting and attenuated muscle regeneration are Ang II dependent. These data suggest that the renin-angiotensin system plays a critical role in mechanisms underlying cachexia in chronic disease states.

  3. Neutrinos from type-II supernovae and the neutrino-driven supernova mechanism

    International Nuclear Information System (INIS)

    Janka, H.T.

    1996-01-01

    Supernova 1987A has confirmed fundamental aspects of our theoretical view of type-II supernovae: Type-II supernovae are a consequence of the collapse of the iron core of a massive evolved star and lead to the formation of a neutron star or black hole. This picture is most strongly supported by the detection of electron antineutrinos in the IMB and Kamiokande II experiments in connection with SN 1987A. However, the mechanism causing the supernova explosion is not yet satisfactorily understood. In this paper the properties of the neutrino emission from supernovae and protoneutron stars will be reviewed; analytical estimates will be derived and results of numerical simulations will be shown. It will be demonstrated that the spectral distributions of the emitted neutrinos show clear and systematic discrepancies compared with thermal (black body-type) emission. This must be taken into account when neutrino observations from supernovae are to be interpreted, or when implications of the neutrino emission on nucleosynthesis processes in mantle and envelope of the progenitor star are to be investigated. Furthermore, the influence of neutrinos on the supernova dynamics will be discussed, in particular their crucial role in causing the explosion by Wilson's neutrino-driven delayed mechanism. Possible implications of convection inside the newly born neutron star and between surface and the supernova shock will be addressed and results of multi-dimensional simulations will be presented. (author) 7 figs., 1 tab., refs

  4. Sorption mechanism of Cd(II) from water solution onto chicken eggshell

    Science.gov (United States)

    Flores-Cano, Jose Valente; Leyva-Ramos, Roberto; Mendoza-Barron, Jovita; Guerrero-Coronado, Rosa María; Aragón-Piña, Antonio; Labrada-Delgado, Gladis Judith

    2013-07-01

    The mechanism and capacity of eggshell for sorbing Cd(II) from aqueous solution was examined in detail. The eggshell was characterized by several techniques. The eggshell was mainly composed of Calcite (CaCO3). The surface charge distribution was determined by acid-base titration and the point of zero charge (PZC) of the eggshell was found to be 11.4. The sorption equilibrium data were obtained in a batch adsorber, and the adsorption isotherm of Langmuir fitted the data quite well. The sorption capacity of eggshell increased while raising the pH from 4 to 6, this tendency was attributed to the electrostatic interaction between the Cd2+ in solution and the surface of the eggshell. Furthermore, the sorption capacity was augmented by increasing the temperature from 15 to 35 °C because the sorption was endothermic. The sorption of Cd(II) occurred mainly onto the calcareous layer of the eggshell, but slightly on the membrane layer. It was demonstrated that the sorption of Cd(II) was not reversible, and the main sorption mechanisms were precipitation and ion exchange. The precipitation of (Cd,Ca)CO3 on the surface of the eggshell was corroborated by SEM and XRD analysis.

  5. Neutrinos from type-II supernovae and the neutrino-driven supernova mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Janka, H T [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

    1996-11-01

    Supernova 1987A has confirmed fundamental aspects of our theoretical view of type-II supernovae: Type-II supernovae are a consequence of the collapse of the iron core of a massive evolved star and lead to the formation of a neutron star or black hole. This picture is most strongly supported by the detection of electron antineutrinos in the IMB and Kamiokande II experiments in connection with SN 1987A. However, the mechanism causing the supernova explosion is not yet satisfactorily understood. In this paper the properties of the neutrino emission from supernovae and protoneutron stars will be reviewed; analytical estimates will be derived and results of numerical simulations will be shown. It will be demonstrated that the spectral distributions of the emitted neutrinos show clear and systematic discrepancies compared with thermal (black body-type) emission. This must be taken into account when neutrino observations from supernovae are to be interpreted, or when implications of the neutrino emission on nucleosynthesis processes in mantle and envelope of the progenitor star are to be investigated. Furthermore, the influence of neutrinos on the supernova dynamics will be discussed, in particular their crucial role in causing the explosion by Wilson`s neutrino-driven delayed mechanism. Possible implications of convection inside the newly born neutron star and between surface and the supernova shock will be addressed and results of multi-dimensional simulations will be presented. (author) 7 figs., 1 tab., refs.

  6. Improvement of mechanical and biological properties of Polycaprolactone loaded with Hydroxyapatite and Halloysite nanotubes.

    Science.gov (United States)

    Torres, E; Fombuena, V; Vallés-Lluch, A; Ellingham, T

    2017-06-01

    Hydroxyapatite (HA) and Halloysite nanotubes (HNTs) percentages have been optimized in Polycaprolactone (PCL) polymeric matrices to improve mechanical, thermal and biological properties of the composites, thus, to be applied in bone tissue engineering or as fixation plates. Addition of HA guarantees a proper compatibility with human bone due to its osteoconductive and osteoinductive properties, facilitating bone regeneration in tissue engineering applications. Addition of HNTs ensures the presence of tubular structures for subsequent drug loading in their lumen, of molecules such as curcumin, acting as controlled drug delivery systems. The addition of 20% of HA and different amounts of HNTs leads to a substantial improvement in mechanical properties with values of flexural strength up to 40% over raw PCL, with an increase in degradation temperature. DMA analyses showed stability in mechanical and thermal properties, having as a result a potential composite to be used as tissue engineering scaffold or resorbable fixation plate. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Systems biology elucidates common pathogenic mechanisms between nonalcoholic and alcoholic-fatty liver disease.

    Directory of Open Access Journals (Sweden)

    Silvia Sookoian

    Full Text Available The abnormal accumulation of fat in the liver is often related either to metabolic risk factors associated with metabolic syndrome in the absence of alcohol consumption (nonalcoholic fatty liver disease, NAFLD or to chronic alcohol consumption (alcoholic fatty liver disease, AFLD. Clinical and histological studies suggest that NAFLD and AFLD share pathogenic mechanisms. Nevertheless, current data are still inconclusive as to whether the underlying biological process and disease pathways of NAFLD and AFLD are alike. Our primary aim was to integrate omics and physiological data to answer the question of whether NAFLD and AFLD share molecular processes that lead to disease development. We also explored the extent to which insulin resistance (IR is a distinctive feature of NAFLD. To answer these questions, we used systems biology approaches, such as gene enrichment analysis, protein-protein interaction networks, and gene prioritization, based on multi-level data extracted by computational data mining. We observed that the leading disease pathways associated with NAFLD did not significantly differ from those of AFLD. However, systems biology revealed the importance of each molecular process behind each of the two diseases, and dissected distinctive molecular NAFLD and AFLD-signatures. Comparative co-analysis of NAFLD and AFLD clarified the participation of NAFLD, but not AFLD, in cardiovascular disease, and showed that insulin signaling is impaired in fatty liver regardless of the noxa, but the putative regulatory mechanisms associated with NAFLD seem to encompass a complex network of genes and proteins, plausible of epigenetic modifications. Gene prioritization showed a cancer-related functional map that suggests that the fatty transformation of the liver tissue is regardless of the cause, an emerging mechanism of ubiquitous oncogenic activation. In conclusion, similar underlying disease mechanisms lead to NAFLD and AFLD, but specific ones depict a

  8. In search of mitochondrial mechanisms: interfield excursions between cell biology and biochemistry.

    Science.gov (United States)

    Bechtel, William; Abrahamsen, Adele

    2007-01-01

    Developing models of biological mechanisms, such as those involved in respiration in cells, often requires collaborative effort drawing upon techniques developed and information generated in different disciplines. Biochemists in the early decades of the 20th century uncovered all but the most elusive chemical operations involved in cellular respiration, but were unable to align the reaction pathways with particular structures in the cell. During the period 1940-1965 cell biology was emerging as a new discipline and made distinctive contributions to understanding the role of the mitochondrion and its component parts in cellular respiration. In particular, by developing techniques for localizing enzymes or enzyme systems in specific cellular components, cell biologists provided crucial information about the organized structures in which the biochemical reactions occurred. Although the idea that biochemical operations are intimately related to and depend on cell structures was at odds with the then-dominant emphasis on systems of soluble enzymes in biochemistry, a reconceptualization of energetic processes in the 1960s and 1970s made it clear why cell structure was critical to the biochemical account. This paper examines how numerous excursions between biochemistry and cell biology contributed a new understanding of the mechanism of cellular respiration.

  9. Methods of Celestial Mechanics Volume II: Application to Planetary System, Geodynamics and Satellite Geodesy

    CERN Document Server

    Beutler, Gerhard

    2005-01-01

    G. Beutler's Methods of Celestial Mechanics is a coherent textbook for students as well as an excellent reference for practitioners. Volume II is devoted to the applications and to the presentation of the program system CelestialMechanics. Three major areas of applications are covered: (1) Orbital and rotational motion of extended celestial bodies. The properties of the Earth-Moon system are developed from the simplest case (rigid bodies) to more general cases, including the rotation of an elastic Earth, the rotation of an Earth partly covered by oceans and surrounded by an atmosphere, and the rotation of an Earth composed of a liquid core and a rigid shell (Poincaré model). (2) Artificial Earth Satellites. The oblateness perturbation acting on a satellite and the exploitation of its properties in practice is discussed using simulation methods (CelestialMechanics) and (simplified) first order perturbation methods. The perturbations due to the higher-order terms of the Earth's gravitational potential and reso...

  10. Mechanisms of electron transfer from structrual Fe(II) in reduced nontronite to oxygen for production of hydroxyl radicals

    Science.gov (United States)

    Yuan, Songhu; Liu, Xixiang; Liao, Wenjuan; Zhang, Peng; Wang, Xiaoming; Tong, Man

    2018-02-01

    Production of hydroxyl radicals (radOH) has been recently revealed upon oxygenation of sediments in redox-dynamic subsurface environments. In particular, Fe(II)-bearing clay minerals are the major sediment components contributing to radOH production upon oxygenation, and the produced radOH can oxidize contaminants and inactivate bacteria. Whereas, the mechanisms of radOH production from oxygenation of Fe(II)-bearing clay minerals remain elusive. The objectives of this study were to identify the structural variation of Fe(II) entities during the oxidation of Fe(II)-bearing clay minerals by O2, and to unravel the mechanisms of electron transfer within the mineral structure and from mineral to O2 for radOH production. Nontronite (NAu-2, 23% Fe) which was chemically reduced to 54.5% Fe(II) in total Fe was used as a model Fe(II)-bearing clay mineral. Production of radOH and oxidation of Fe(II) were measured during the oxidation of reduced NAu-2 by O2. A wide spectrum of spectroscopic techniques, including Fourier transform infrared spectroscopy (FTIR), Fe K-edge X-ray absorption spectroscopy (XAS), Mössbauer spectra, and X-ray photoelectron spectroscopy (XPS), were employed to explore the structural variation of Fe(II) entities in NAu-2 and the electron transfer within NAu-2 and from NAu-2 to O2. For 180 min oxidation of 1 g/L reduced NAu-2, a biphasic radOH production was observed, being quick within the initial 15 min and slow afterwards. Production of radOH correlates well with oxidation of Fe(II) in the reduced NAu-2. Within the initial 15 min, trioctahedral Fe(II)-Fe(II)-Fe(II) entities and edge Fe(II) in the reduced NAu-2 were preferentially and quickly oxidized, and electrons from the interior Fe(II)-Fe(II)-Fe(II) entities were most likely ejected from the basal siloxane plane to O2. Meanwhile, trioctahedral Fe(II)-Fe(II)-Fe(II) entities were mainly transformed to dioctahedral Fe(II)-Fe(II) entities. When the time of oxygenation was longer than 15 min

  11. [Functional properties of taste bud cells. Mechanisms of afferent neurotransmission in Type II taste receptor cells].

    Science.gov (United States)

    Romanov, R A

    2013-01-01

    Taste Bud cells are heterogeneous in their morphology and functionality. These cells are responsible for sensing a wide variety of substances and for associating detected compounds with a different taste: bitter, sweet, salty, sour and umami. Today we know that each of the five basic tastes corresponds to distinct cell populations organized into three basic morpho-functional cell types. In addition, some receptor cells of the taste bud demonstrate glia-related functions. In this article we expand on some properties of these three morphological receptor cell types. Main focus is devoted to the Type II cells and unusual mechanism for afferent neurotransmission in these cells. Taste cells of the Type II consist of three populations detecting bitter, sweet and umami tastes, and, thus, evoke a serious scientific interest.

  12. Confronting actual influence of radiation on human bodies and biological defense mechanism

    International Nuclear Information System (INIS)

    Matsubara, Junko

    2012-01-01

    After the accident at Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, social, economical, psychological pressures on local residents and fears of radiation among the general public have not been resolved. Based on the assumption that the negligence of specialists to clearly explain the influence of radiation on human bodies to the general public is the factor for above mentioned pressures and fears, the influence of radiation from a realistic view was discussed. The topics covered are: (1) understanding the meaning of radiation regulation, (2) radiation and threshold values, (3) actual influence of low-dose radiation, (4) chemical and biological defense in defense mechanism against radiation, (5) problems raised by Fukushima Daiichi nuclear accident. Furthermore, the article explains the principles and the applications of biological defense function activation, and suggested that self-help efforts to fight against stress are from now on. (S.K.)

  13. Large and almost maximal neutrino mixing within the type II see-saw mechanism

    International Nuclear Information System (INIS)

    Lindner, Manfred; Rodejohann, Werner

    2007-01-01

    Within the type II see-saw mechanism the light neutrino mass matrix is given by a sum of a direct (or triplet) mass term and the conventional (type I) see-saw term. Both versions of the see-saw mechanism explain naturally small neutrino masses, but the type II scenario offers interesting additional possibilities to explain large or almost maximal or vanishing mixings which are discussed in this paper. We first introduce 'type II enhancement' of neutrino mixing, where moderate cancellations between the two terms can lead to large neutrino mixing even if all individual mass matrices and terms generate small mixing. However, nearly maximal or vanishing mixings are not naturally explained in this way, unless there is a certain initial structure (symmetry) which enforces certain elements of the matrices to be identical or related in a special way. We therefore assume that the leading structure of the neutrino mass matrix is the triplet term and corresponds to zero U e3 and maximal θ 23 . Small but necessary corrections are generated by the conventional see-saw term. Then we assume that one of the two terms corresponds to an extreme mixing scenario, such as bimaximal or tri-bimaximal mixing. Deviations from this scheme are introduced by the second term. One can mimic Quark-Lepton Complementarity in this way. Finally, we note that the neutrino mass matrix for tri-bimaximal mixing can be-depending on the mass hierarchy-written as a sum of two terms with simple structure. Their origin could be the two terms of type II see-saw

  14. Features of Knowledge Building in Biology: Understanding Undergraduate Students’ Ideas about Molecular Mechanisms

    Science.gov (United States)

    Southard, Katelyn; Wince, Tyler; Meddleton, Shanice; Bolger, Molly S.

    2016-01-01

    Research has suggested that teaching and learning in molecular and cellular biology (MCB) is difficult. We used a new lens to understand undergraduate reasoning about molecular mechanisms: the knowledge-integration approach to conceptual change. Knowledge integration is the dynamic process by which learners acquire new ideas, develop connections between ideas, and reorganize and restructure prior knowledge. Semistructured, clinical think-aloud interviews were conducted with introductory and upper-division MCB students. Interviews included a written conceptual assessment, a concept-mapping activity, and an opportunity to explain the biomechanisms of DNA replication, transcription, and translation. Student reasoning patterns were explored through mixed-method analyses. Results suggested that students must sort mechanistic entities into appropriate mental categories that reflect the nature of MCB mechanisms and that conflation between these categories is common. We also showed how connections between molecular mechanisms and their biological roles are part of building an integrated knowledge network as students develop expertise. We observed differences in the nature of connections between ideas related to different forms of reasoning. Finally, we provide a tentative model for MCB knowledge integration and suggest its implications for undergraduate learning. PMID:26931398

  15. Synthesis, thermal, spectral, and biological properties of zinc(II) 4-aminobenzoate complexes

    Czech Academy of Sciences Publication Activity Database

    Homzová, K.; Györyová, K.; Hudecová, D.; Koman, M.; Melník, M.; Kovářová, Jana

    2017-01-01

    Roč. 129, č. 2 (2017), s. 1065-1082 ISSN 1388-6150 Institutional support: RVO:61389013 Keywords : zinc(II) 4-aminobenzoate * thermal * spectral Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.953, year: 2016

  16. Contact angle study on the activation mechanisms of sphalerite with Cu(II) and Pb(II); Estudio de los mecanismos de activacion de la esfalerita con Cu(II) y Pb(II)

    Energy Technology Data Exchange (ETDEWEB)

    Davila Pulido, G. I.; Uribe Salas, A.

    2011-07-01

    This article presents results of an experimental study on the sphalerite activation with Cu(II) and Pb(II), whose main objective was to investigate the activation mechanisms and to evaluate the magnitude of the hydrophobization achieved with both chemical species. The hydrophobicity acquired by the mineral due to the interaction with the activator and collector (sodium isopropyl xanthate) is characterized making use of the contact angle technique. The results show that Cu(II) replaces the Zn of the external layers of the mineral, promoting the sulfide (S{sup 2}-) oxidation to produce a mixture of CuS, Cu{sub 2}S and S{sup o}, of hydrophobic nature. The subsequent interaction with xanthate increases the hydrophobicity of the mineral surface. In turn, Pb(II) activation of sphalerite is due to the formation of a PbS layer that reacts with xanthate to produce hydrophobic species (e.g., PbX{sub 2}). It is also observed that the hydrophobicity of sphalerite activated with Pb(II) is favored under air atmospheres, as compared to that obtained under nitrogen atmospheres. It is concluded that the hydrophobicity achieved by lead activation may be of the same order of magnitude to that deliverately induced by copper activation. (Author) 11 refs.

  17. A comparison of molecular biology mechanism of Shewanella putrefaciens between fresh and terrestrial sewage wastewater

    Directory of Open Access Journals (Sweden)

    Jiajie Xu

    2016-11-01

    Full Text Available Municipal and industrial wastewater is often discharged into the environment without appropriate treatment, especially in developing countries. As a result, many rivers and oceans are contaminated. It is urgent to control and administer treatments to these contaminated rivers and oceans. However, most mechanisms of bacterial colonization in contaminated rivers and oceans were unknown, especially in sewage outlets. We found Shewanella putrefaciens to be the primary bacteria in the terrestrial sewage wastewater outlets around Ningbo City, China. Therefore, in this study, we applied a combination of differential proteomics, metabolomics, and real-time fluorescent quantitative PCR techniques to identify bacteria intracellular metabolites. We found S. putrefaciens had 12 different proteins differentially expressed in freshwater culture than when grown in wastewater, referring to the formation of biological membranes (Omp35, OmpW, energy metabolism (SOD, deoxyribose-phosphate pyrophosphokinase, fatty acid metabolism (beta-ketoacyl synthase, secondary metabolism, TCA cycle, lysine degradation (2-oxoglutarate reductase, and propionic acid metabolism (succinyl coenzyme A synthetase. The sequences of these 12 differentially expressed proteins were aligned with sequences downloaded from NCBI. There are also 27 differentially concentrated metabolites detected by NMR, including alcohols (ethanol, isopropanol, amines (dimethylamine, ethanolamine, amino acids (alanine, leucine, amine compounds (bilinerurine, nucleic acid compounds (nucleosides, inosines, organic acids (formate, acetate. Formate and ethanolamine show significant difference between the two environments and are possibly involved in energy metabolism, glycerophospholipid and ether lipids metabolism to provide energy supply and material basis for engraftment in sewage. Because understanding S. putrefaciens’s biological mechanism of colonization (protein, gene express and metabolites in

  18. Modeling of the bacterial mechanism of methicillin-resistance by a systems biology approach.

    Directory of Open Access Journals (Sweden)

    Ida Autiero

    Full Text Available BACKGROUND: A microorganism is a complex biological system able to preserve its functional features against external perturbations and the ability of the living systems to oppose to these external perturbations is defined "robustness". The antibiotic resistance, developed by different bacteria strains, is a clear example of robustness and of ability of the bacterial system to acquire a particular functional behaviour in response to environmental changes. In this work we have modeled the whole mechanism essential to the methicillin-resistance through a systems biology approach. The methicillin is a beta-lactamic antibiotic that act by inhibiting the penicillin-binding proteins (PBPs. These PBPs are involved in the synthesis of peptidoglycans, essential mesh-like polymers that surround cellular enzymes and are crucial for the bacterium survival. METHODOLOGY: The network of genes, mRNA, proteins and metabolites was created using CellDesigner program and the data of molecular interactions are stored in Systems Biology Markup Language (SBML. To simulate the dynamic behaviour of this biochemical network, the kinetic equations were associated with each reaction. CONCLUSIONS: Our model simulates the mechanism of the inactivation of the PBP by methicillin, as well as the expression of PBP2a isoform, the regulation of the SCCmec elements (SCC: staphylococcal cassette chromosome and the synthesis of peptidoglycan by PBP2a. The obtained results by our integrated approach show that the model describes correctly the whole phenomenon of the methicillin resistance and is able to respond to the external perturbations in the same way of the real cell. Therefore, this model can be useful to develop new therapeutic approaches for the methicillin control and to understand the general mechanism regarding the cellular resistance to some antibiotics.

  19. Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure

    Science.gov (United States)

    Thomas, Linnea M.; Jorgenson, Zachary G.; Brigham, Mark E.; Choy, Steven J.; Moore, Jeremy N.; Banda, Jo A.; Gefell, D.J.; Minarik, Thomas A.; Schoenfuss, Heiko L.

    2017-01-01

    The Laurentian Great Lakes contain one fifth of the world’s surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations.

  20. Floral biology and reproductive mechanisms of the Ocimum canum Sims (Lamiaceae

    Directory of Open Access Journals (Sweden)

    Cláudio Lúcio Fernandes Amaral

    2008-06-01

    Full Text Available The Ocimum genus (Lamiaceae presents essential oils used in the pharmaceutical, perfume, cosmetics and culinary industries. The aim of this paper was to study the fl oral biology and breeding mechanisms of Ocimum canum Sims. in relation to improved plant breeding. Ocimum canum has inflorescences with white, protandrous and hermaphoditic flowers. The osmophores are located at the anthers and stigma. Anthesis occurs between 10:30 and 11:30 a.m. The main fl oral visitors were bees of the Apis and Augochloropsis genuses. Ocimum canum presents a breeding system with a predominance of outcrossing that possibly demonstrates the wide reproductive flexibility of this species.

  1. Biosorption of Sr(II) from aqueous solutions using aerobic granules. Equilibrium and mechanisms

    International Nuclear Information System (INIS)

    Li Wang; Xiang Liu; Xiao-feng Chen; Duu-Jong Lee; Joo-Hwa Tay; Yi Zhang; Chun-li Wan

    2015-01-01

    Aqueous strontium biosorption using aerobic granules was investigated. Parameters affecting the biosorption were optimized, including initial pH, biomass dosage, temperature, and rotation speed. The equilibrium data were fitted using Langmuir and Freundlich models, and both could well describe the process (R 2 = 0.987 and 0.989, respectively). Ion exchange and water-desorption experiments were conducted, and ion exchange together with physical adsorption were found to be the main mechanisms. The aerobic granules were characterized with methods including scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The results showed that surface complexation could also be involved in the Sr(II) biosorption. (author)

  2. Mechanical Design and Analysis of LCLS II 2 K Cold Box

    Science.gov (United States)

    Yang, S.; Dixon, K.; Laverdure, N.; Rath, D.; Bevins, M.; Bai, H.; Kaminski, S.; Ravindranath, V.

    2017-12-01

    The mechanical design and analysis of the LCLS II 2 K cold box are presented. Its feature and functionality are discussed. ASME B31.3 was used to design its internal piping, and compliance of the piping code was ensured through flexibility analysis. The 2 K cold box was analyzed using ANSYS 17.2; the requirements of the applicable codes—ASME Section VIII Division 2 and ASCE 7-10—were satisfied. Seismic load was explicitly considered in both analyses.

  3. Leach behavior and mechanical-integrity studies of irradiated Epicor-II waste products

    International Nuclear Information System (INIS)

    Barletta, R.E.; Swyler, K.J.; Chan, S.F.; Davis, R.E.

    1982-01-01

    The leachability of Cs and Sr from cement solidified ion exchange media claimed to be representative of the Epicor-II prefilters (D-mix) is presented. The Cs and Sr release is significantly lower than that typically observed for organic ion exchange resin/cement composites. The effect of radiation up to a total dose of 10 7 Gy upon the leachability and mechanical integrity (as measured by MCC-11) of D-mix/cement composites has been investigated. No deleterious effects were found. 6 figures

  4. A Fe(II)/citrate/UV/PMS process for carbamazepine degradation at a very low Fe(II)/PMS ratio and neutral pH: The mechanisms.

    Science.gov (United States)

    Ling, Li; Zhang, Dapeng; Fan, Chihhao; Shang, Chii

    2017-11-01

    A novel Fe(II)/citrate/UV/PMS process for degrading a model micropollutant, carbamazepine (CBZ), at a low Fe(II)/PMS ratio and neutral pH has been proposed in this study, and the mechanisms of radical generation in the system was explored. With a UV dose of 302.4 mJ/cm 2 , an initial pH of 7, and CBZ, PMS, Fe(II) and citrate at initial concentrations of 10, 100, 12 and 26 μM, respectively, the CBZ degradation efficiency reached 71% in 20 min in the Fe(II)/citrate/UV/PMS process, which was 4.7 times higher than that in either the citrate/UV/PMS or Fe(II)/citrate/PMS process. The enhanced CBZ degradation in the Fe(II)/citrate/UV/PMS process was mainly attributed to the continuous activation of PMS by the UV-catalyzed regenerated Fe(II) from a Fe(III)-citrate complex, [Fe 3 O(cit) 3 H 3 ] 2- , which not only maintained Fe(III) soluble at neutral pH, but also increased 6.6 and 2.6 times of its molar absorbance and quantum yield as compared to those of ionic Fe(III), respectively. In the Fe(II)/citrate/UV/PMS process, the SO 4 •- produced from the fast reaction between PMS and the initially-added Fe(II) contributed 11% of CBZ degradation. The PMS activation by the UV radiation and regenerated Fe(II) contributed additional 14% and 46% of CBZ removal, respectively. The low iron and citrate doses and the fast radical generation at neutral pH make the Fe(II)/citrate/UV/PMS process suitable for degrading recalcitrant organic compounds in potable water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. High stability and biological activity of the copper(II) complexes of alloferon 1 analogues containing tryptophan.

    Science.gov (United States)

    Kadej, Agnieszka; Kuczer, Mariola; Czarniewska, Elżbieta; Urbański, Arkadiusz; Rosiński, Grzegorz; Kowalik-Jankowska, Teresa

    2016-10-01

    Copper(II) complex formation processes between the alloferon 1 (Allo1) (HGVSGHGQHGVHG) analogues where the tryptophan residue is introducing in the place His residue H1W, H6W, H9W and H12W have been studied by potentiometric, UV-visible, CD and EPR spectroscopic, and MS methods. For all analogues of alloferon 1 complex speciation have been obtained for a 1:1 metal-to-ligand molar ratio and 2:1 of H1W because of precipitation at higher (2:1, 3:1 and 4:1) ratios. At physiological pH7.4 and a 1:1 metal-to-ligand molar ratio the tryptophan analogues of alloferon 1 form the CuH -1 L and/or CuH -2 L complexes with the 4N binding mode. The introduction of tryptophan in place of histidine residues changes the distribution diagram of the complexes formed with the change of pH and their stability constants compared to the respective substituted alanine analogues of alloferon 1. The CuH -1 L, CuH -2 L and CuH -3 L complexes of the tryptophan analogues are more stable from 1 to 5 log units in comparison to those of the alanine analogues. This stabilization of the complexes may result from cation(Cu(II))-π and indole/imidazole ring interactions. The induction of apoptosis in vivo, in Tenebrio molitor cells by the ligands and their copper(II) complexes at pH7.4 was studied. The biological results show that copper(II) ions in vivo did not cause any apparent apoptotic features. The most active were the H12W peptide and Cu(II)-H12W complex formed at pH7.4. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Beyond the therapeutic shackles of the monoamines: New mechanisms in bipolar disorder biology.

    Science.gov (United States)

    Data-Franco, João; Singh, Ajeet; Popovic, Dina; Ashton, Melanie; Berk, Michael; Vieta, Eduard; Figueira, M L; Dean, Olivia M

    2017-01-04

    Multiple novel biological mechanisms putatively involved in the etiology of bipolar disorders are being explored. These include oxidative stress, altered glutamatergic neurotransmission, mitochondrial dysfunction, inflammation, cell signaling, apoptosis and impaired neurogenesis. Important clinical translational potential exists for such mechanisms to help underpin development of novel therapeutics - much needed given limitations of current therapies. These new mechanisms also help improve our understanding of how current therapeutics might exert their effects. Lithium, for example, appears to have antioxidant, immunomodulatory, signaling, anti-apoptotic and neuroprotective properties. Similar properties have been attributed to other mood stabilizers such as valproate, lamotrigine, and quetiapine. Perhaps of greatest translational value has been the recognition of such mechanisms leading to the emergence of novel therapeutics for bipolar disorders. These include the antioxidant N-acetylcysteine, the anti-inflammatory celecoxib, and ketamine - with effects on the glutamatergic system and microglial inhibition. We review these novel mechanisms and emerging therapeutics, and comment on next steps in this space. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Epigenetic Mechanisms in Bone Biology and Osteoporosis: Can They Drive Therapeutic Choices?

    Science.gov (United States)

    Marini, Francesca; Cianferotti, Luisella; Brandi, Maria Luisa

    2016-08-12

    Osteoporosis is a complex multifactorial disorder of the skeleton. Genetic factors are important in determining peak bone mass and structure, as well as the predisposition to bone deterioration and fragility fractures. Nonetheless, genetic factors alone are not sufficient to explain osteoporosis development and fragility fracture occurrence. Indeed, epigenetic factors, representing a link between individual genetic aspects and environmental influences, are also strongly suspected to be involved in bone biology and osteoporosis. Recently, alterations in epigenetic mechanisms and their activity have been associated with aging. Also, bone metabolism has been demonstrated to be under the control of epigenetic mechanisms. Runt-related transcription factor 2 (RUNX2), the master transcription factor of osteoblast differentiation, has been shown to be regulated by histone deacetylases and microRNAs (miRNAs). Some miRNAs were also proven to have key roles in the regulation of Wnt signalling in osteoblastogenesis, and to be important for the positive or negative regulation of both osteoblast and osteoclast differentiation. Exogenous and environmental stimuli, influencing the functionality of epigenetic mechanisms involved in the regulation of bone metabolism, may contribute to the development of osteoporosis and other bone disorders, in synergy with genetic determinants. The progressive understanding of roles of epigenetic mechanisms in normal bone metabolism and in multifactorial bone disorders will be very helpful for a better comprehension of disease pathogenesis and translation of this information into clinical practice. A deep understanding of these mechanisms could help in the future tailoring of proper individual treatments, according to precision medicine's principles.

  8. Biologically Safe Poly(l-lactic acid) Blends with Tunable Degradation Rate: Microstructure, Degradation Mechanism, and Mechanical Properties.

    Science.gov (United States)

    Oyama, Hideko T; Tanishima, Daisuke; Ogawa, Ryohei

    2017-04-10

    Although poly(l-lactic acid) (PLLA) is reputed to be biodegradable in the human body, its hydrophobic nature lets it persist for ca. 5.5 years. This study demonstrates that biologically safe lactide copolymers, poly(aspartic acid-co-l-lactide) (PAL) and poly(malic acid-co-l-lactide) (PML), dispersed in the PLLA function as detonators (triggers) for its hydrolytic degradation under physiological conditions. The copolymers significantly enhance hydrolysis, and consequently, the degradation rate of PLLA becomes easily tunable by controlling the amounts of PAL and PML. The present study elucidates the effects of uniaxial drawing on the structural development, mechanical properties, and hydrolytic degradation under physiological conditions of PLLA blend films. At initial degradation stages, the mass loss was not affected by uniaxial drawing; however, at late degradation stages, less developed crystals as well as amorphous chains were degradable at low draw ratio (DR), whereas not only highly developed crystals but also the oriented amorphous chains became insensitive to hydrolysis at high DR. Our work provides important molecular level results that demonstrate that biodegradable materials can have superb mechanical properties and also disappear in a required time under physiological conditions.

  9. High energy fast neutrons from the Harwell variable energy cyclotron. II. Biologic studies in mammalian systems

    International Nuclear Information System (INIS)

    Berry, R.J.; Bance, D.A.; Barnes, D.W.H.; Cox, R.; Goodhead, D.T.; Sansom, J.M.; Thacker, J.

    1977-01-01

    A high energy fast neutron beam potentially suitable for radiotherapy has been described in a companion paper. Its biologic effects have been studied in the following experimental systems: clonal survival and mutation induction after irradiation in vitro in Chinese hamster cells and human diploid fibroblasts; survival of reproductive capacity in vivo of murine hemopoietic colony-forming cells and murine intestinal crypts after irradiation in vivo; survival of reproductive capacity in vivo after irradiation in vitro or in vivo of murine lymphocytic leukemia cells; acute intestinal death following total body irradiation of mice and guinea pigs; and hemopoietic death following total body irradiation of mice and guinea pigs. The relative biologic effectiveness of these high energy neutrons varied among the different biologic systems, and in several cases varied with the size of the radiation dose. The oxygen enhancement ratio was studied in murine lymphocytic leukemia cells irradiated under aerobic or hypoxic conditions in vitro and assayed for survival of reproductive capacity in vivo. Compared with x-rays, the potential therapeutic gain factor for these neutrons was about 1.5. This work represents a ''radiobiologic calibration'' program which it is suggested should be undertaken before new and unknown fast neutron spectra are used for experimental radiotherapy. The results are compared with biologic studies carried out at high energy fast neutron generators in the United States

  10. A ruthenium(II) complex as turn-on Cu(II) luminescent sensor based on oxidative cyclization mechanism and its application in vivo

    Science.gov (United States)

    Zhang, Yunfei; Liu, Zonglun; Yang, Kui; Zhang, Yi; Xu, Yongqian; Li, Hongjuan; Wang, Chaoxia; Lu, Aiping; Sun, Shiguo

    2015-02-01

    Copper ions play a vital role in a variety of fundamental physiological processes not only in human beings and plants, but also for extensive insects and microorganisms. In this paper, a novel water-soluble ruthenium(II) complex as a turn-on copper(II) ions luminescent sensor based on o-(phenylazo)aniline was designed and synthesized. The azo group would undergo a specific oxidative cyclization reaction with copper(II) ions and turn into high luminescent benzotriazole, triggering significant luminescent increasements which were linear to the concentrations of copper(II) ions. The sensor distinguished by its high sensitivity (over 80-fold luminescent switch-on response), good selectivity (the changes of the emission intensity in the presence of other metal ions or amino acids were negligible) and low detection limit (4.42 nM) in water. Moreover, the copper(II) luminescent sensor exhibited good photostability under light irradiation. Furthermore, the applicability of the proposed sensor in biological samples assay was also studied and imaged copper(II) ions in living pea aphids successfully.

  11. Biological defense mechanisms against DNA double-strand break and their possible medical applications

    International Nuclear Information System (INIS)

    Matsumoto, Yoshihisa

    2011-01-01

    Radiation is now widely used for clinical diagnosis and therapeutics. On the other hand, radiation influences various tissues represented by immunological and reproductive systems, and is also recognized as one of the cause of carcinogenesis. Such pleiotropic effects of radiation are mediated through generation of damages on DNA molecule, vitally important genetic macromolecule. Among various types of DNA damages, double-strand break (DSB) is considered most critical and, therefore, responsible for biological effects. DSB is repaired mainly through two pathways: non-homologous end joining (NHEJ) and homologous recombination (HR). Understanding of these mechanisms has been greatly deepened in past 20 years and is now providing a promising approach toward cancer therapy. We have studied the mechanisms of NHEJ, focusing especially on the role of phosphorylation and the assembly of machinery therein, which will be introduced below. (author)

  12. Microstructure, mechanical properties, and biological response to functionally graded HA coatings

    International Nuclear Information System (INIS)

    Rabiei, Afsaneh; Blalock, Travis; Thomas, Brent; Cuomo, Jerry; Yang, Y.; Ong, Joo

    2007-01-01

    Hydroxyapatite (HA) [Ca 10 (PO 4 ) 6 (OH) 2 ] is the primary mineral content, representing 43% by weight, of bone. Applying a thin layer of HA, to the surface of a metal implant, can promote osseointegration and increase the mechanical stability of the implant. In this study, a biocompatible coating comprising an HA film with functionally graded crystallinity is being deposited on a heated substrate in an Ion Beam Assisted Deposition (IBAD) system. The microstructure of the film was studied using Transmission Electron Microscopy techniques. Finally, initial cell adhesion and cell differentiation on the coating was evaluated using ATCC CRL 1486 human embryonic palatal mesenchymal cell, an osteoblast precursor cell line. The results have shown superior mechanical properties and biological response to the functionally graded HA film

  13. Effects of major histocompatibility complex class II knockout on mouse bone mechanical properties during development

    Science.gov (United States)

    Simske, Steven J.; Bateman, Ted A.; Smith, Erin E.; Ferguson, Virginia L.; Chapes, Stephen K.

    2002-01-01

    We investigated the effect of major histocompatibility complex class II (MHC II) knockout on the development of the mouse peripheral skeleton. These C2D mice had less skeletal development at 8, 12 and 16 weeks of age compared to wild-type C57BL/6J (B6) male mice. The C2D mice had decreased femur mechanical, geometric and compositional measurements compared to wild type mice at each of these ages. C2D femur stiffness (S), peak force in 3-pt bending (Pm), and mineral mass (Min-M) were 74%, 64% and 66%, respectively, of corresponding B6 values at 8 weeks of age. Similar differences were measured at 12 weeks (for which C2D femoral S, Pm and Min-M were 71%, 72% and 73%, respectively, of corresponding B6 values) and at 16 weeks (for which C2D femoral S, Pm and Min-M were 80%, 66% and 61%, respectively, of corresponding B6 values). MHC II knockout delays the development of adult bone properties and is accompanied by lower body mass compared to wild-type controls.

  14. A few nascent methods for measuring mechanical properties of the biological cell.

    Energy Technology Data Exchange (ETDEWEB)

    Thayer, Gayle Echo; de Boer, Maarten Pieter; Corvalan, Carlos (Purdue University, West Lafayette, IN); Corwin, Alex David; Campanella, Osvaldo H. (Purdue University, West Lafayette, IN); Nivens, David (Purdue University, West Lafayette, IN); Werely, Steven (Purdue University, West Lafayette, IN); Sumali, Anton Hartono; Koch, Steven John

    2006-01-01

    This report summarizes a survey of several new methods for obtaining mechanical and rheological properties of single biological cells, in particular: (1) The use of laser Doppler vibrometry (LDV) to measure the natural vibrations of certain cells. (2) The development of a novel micro-electro-mechanical system (MEMS) for obtaining high-resolution force-displacement curves. (3) The use of the atomic force microscope (AFM) for cell imaging. (4) The adaptation of a novel squeezing-flow technique to micro-scale measurement. The LDV technique was used to investigate the recent finding reported by others that the membranes of certain biological cells vibrate naturally, and that the vibration can be detected clearly with recent instrumentation. The LDV has been reported to detect motions of certain biological cells indirectly through the motion of a probe. In this project, trials on Saccharomyces cerevisiae tested and rejected the hypothesis that the LDV could measure vibrations of the cell membranes directly. The MEMS investigated in the second technique is a polysilicon surface-micromachined force sensor that is able to measure forces to a few pN in both air and water. The simple device consists of compliant springs with force constants as low as 0.3 milliN/m and Moire patterns for nanometer-scale optical displacement measurement. Fields from an electromagnet created forces on magnetic micro beads glued to the force sensors. These forces were measured and agreed well with finite element prediction. It was demonstrated that the force sensor was fully functional when immersed in aqueous buffer. These results show the force sensors can be useful for calibrating magnetic forces on magnetic beads and also for direct measurement of biophysical forces on-chip. The use of atomic force microscopy (AFM) for profiling the geometry of red blood cells was the third technique investigated here. An important finding was that the method commonly used for attaching the cells to a

  15. Chitosan fibers with improved biological and mechanical properties for tissue engineering applications.

    Science.gov (United States)

    Albanna, Mohammad Z; Bou-Akl, Therese H; Blowytsky, Oksana; Walters, Henry L; Matthew, Howard W T

    2013-04-01

    The low mechanical properties of hydrogel materials such as chitosan hinder their broad utility for tissue engineering applications. Previous research efforts improved the mechanical properties of chitosan fiber through chemical and physical modifications; however, unfavorable toxicity effects on cells were reported. In this paper, we report the preparation of chitosan fibers with improved mechanical and biocompatibility properties. The structure-property relationships of extruded chitosan fibers were explored by varying acetic acid (AA) concentration, ammonia concentration, annealing temperature and degree of heparin crosslinking. Results showed that optimizing AA concentration to 2vol% improved fiber strength and stiffness by 2-fold. Extruding chitosan solution into 25wt% of ammonia solution reduced fiber diameters and improved fiber strength by 2-fold and stiffness by 3-fold, due to an increase in crystallinity as confirmed by XRD. Fiber annealing further reduced fiber diameter and improved fiber strength and stiffness as temperature increased. Chitosan fibers crosslinked with heparin had increased diameter but lower strength and stiffness properties and higher breaking strain values. When individual parameters were combined, further improvement in fiber mechanical properties was achieved. All mechanically improved fibers and heparin crosslinked fibers promoted valvular interstitial cells (VIC) attachment and growth over 10 day cultures. Our results demonstrate the ability to substantially improve the mechanical properties of chitosan fibers without adversely affecting their biological properties. The investigated treatments offer numerous advantages over previous physical/chemical modifications and thus are expected to expand the utility of chitosan fibers with tunable mechanical properties in various tissue engineering applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Investigations on mechanical biological treatment of waste in South America: Towards more sustainable MSW management strategies

    International Nuclear Information System (INIS)

    Bezama, Alberto; Aguayo, Pablo; Konrad, Odorico; Navia, Rodrigo; Lorber, Karl E.

    2007-01-01

    This work presents an analysis on the suitability of mechanical biological treatment of municipal solid waste in South America, based on two previous experimental investigations carried out in two different countries. The first experiment was performed for determining the mass and volume reduction of MSW in the province of Concepcion (Chile). The implemented bench-scale process consisted of a manual classification and separation stage, followed by an in-vessel biological degradation process. The second experiment consisted of a full-scale experiment performed in the city of Estrela (Brazil), where the existing municipal waste management facility was adapted to enhance the materials sorting and separation. Expressed in wet weight composition, 85.5% of the material input in the first experiment was separated for biological degradation. After 27 days of processing, 60% of the initial mass was reduced through degradation and water evaporation. The final fraction destined for landfilling equals 59% of the total input mass, corresponding to about 50% of the initial volume. In the second experiment, the fraction destined to landfill reaches 46.6% of the total input waste mass, whilst also significantly reducing the total volume to be disposed. These results, and the possible recovery of material streams suitable for recycling or for preparing solid recovered fuels, are the main advantages of the studied process

  17. The biological basis of treating jaw discrepancies: An interplay of mechanical forces and skeletal configuration.

    Science.gov (United States)

    Karamesinis, Konstantinos; Basdra, Efthimia K

    2018-05-01

    Jaw discrepancies and malrelations affect a large proportion of the general population and their treatment is of utmost significance for individuals' health and quality of life. The aim of their therapy is the modification of aberrant jaw development mainly by targeting the growth potential of the mandibular condyle through its cartilage, and the architectural shape of alveolar bone through a suture type of structure, the periodontal ligament. This targeted treatment is achieved via external mechanical force application by using a wide variety of intraoral and extraoral appliances. Condylar cartilage and sutures exhibit a remarkable plasticity due to the mechano-responsiveness of the chondrocytes and the multipotent mesenchymal cells of the sutures. The tissues respond biologically and adapt to mechanical force application by a variety of signaling pathways and a final interplay between the proliferative activity and the differentiation status of the cells involved. These targeted therapeutic functional alterations within temporo-mandibular joint ultimately result in the enhancement or restriction of mandibular growth, while within the periodontal ligament lead to bone remodeling and change of its architectural structure. Depending on the form of the malrelation presented, the above treatment approaches, in conjunction or separately, lead to the total correction of jaw discrepancies and the achievement of facial harmony and function. Overall, the treatment of craniofacial and jaw anomalies can be seen as an interplay of mechanical forces and adaptations occurring within temporo-mandibular joint and alveolar bone. The aim of the present review is to present up-to-date knowledge on the mechano-biology behind jaw growth modification and alveolar bone remodeling. Furthermore, future molecular targeted therapeutic strategies are discussed aiming at the improvement of mechanically-driven chondrogenesis and osteogenesis. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Structural, spectral, DFT and biological studies on macrocyclic mononuclear ruthenium (II) complexes

    Science.gov (United States)

    Muthukkumar, M.; Kamal, C.; Venkatesh, G.; Kaya, C.; Kaya, S.; Enoch, Israel V. M. V.; Vennila, P.; Rajavel, R.

    2017-11-01

    Macrocyclic mononuclear ruthenium (II) complexes have been synthesized by condensation method [Ru (L1, L2, L3) Cl2] L1 = (C36 H31 N9), L2= (C42H36N8), L3= (C32H32 N8)]. These ruthenium complexes have been established by elemental analyses and spectroscopic techniques (Fourier transform infrared spectroscopy (FT-IR), 1H- nuclear magnetic resonance (NMR), 13C- NMR and Electrospray ionization mass spectrometry (ESI-MS)). The coordination mode of the ligand has been confirmed and the octahedral geometry around the ruthenium ion has been revealed. Binding affinity and binding mode of ruthenium (II) complexes with Bovine serum Albumin (BSA) have been characterized by Emission spectra analysis. UV-Visible and fluorescence spectroscopic techniques have also been utilized to examine the interaction between ligand and its complexes L1, L2, & L3 with BSA. Chemical parameters and molecular structure of Ru (II) complexes L1H, L2H, & L3H have been determined by DFT coupled with B3LYP/6-311G** functional in both the gaseous and aqueous phases.

  19. New Mn(II, Ni(II, Cd(II, Pb(II complexes with 2-methylbenzimidazole and other ligands. Synthesis, spectroscopic characterization, crystal structure, magnetic susceptibility and biological activity studies

    Directory of Open Access Journals (Sweden)

    Shayma A. Shaker

    2016-11-01

    Full Text Available Synthesis and characterization of Mn(II, Ni(II, Cd(II and Pb(II mixed ligand complexes of 2-methylbenzimidazole with other ligands have been reported. The structure of the ligands and their complexes was investigated using elemental analysis, IR, UV–Vis, (1H, 13C NMR spectroscopy, molar conductivity and magnetic susceptibility measurements. In all the studies of complexes, the 2-methylbenzimidazole behaves as a neutral monodentate ligand which is coordinated with the metal ions through the N atom. While benzotriazole behaves as a neutral bidentate ligand which is coordinated with the Ni(II ion through the two N atoms. Moreover, the N-acetylglycine behaves as a bidentate ligand which is coordinated with the Mn(II, Ni(II and Pb(II ions through the N atom and the terminal carboxyl oxygen atom. The magnetic and spectral data indicate the tetrahedral geometry for Mn(II complex, irregular tetrahedral geometry for Pb(II complex and octahedral geometry for Ni(II complex. The X-ray single crystal diffraction method was used to confirm a centrosymmetric dinuclear Cd(II complex as each two metal ions are linked by a pair of thiocyanate N = S bridge. Two 2-methylbenzimidazole N-atom donors and one terminal thiocyanate N atom complete a highly distorted square pyramid geometry around the Cd atom. Besides, different cell types were used to determine the inhibitory effect of Mn(II, Ni(II, Cd(II and Pb(II complexes on cell growth using MTT assay. Cd(II complex showed cytotoxic effect on various types of cancer cell lines with different EC50 values.

  20. Tritium in the Physical and Biological Sciences. Vol. II. Proceedings of the Symposium on the Detection and Use of Tritium in the Physical and Biological Sciences

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-02-15

    The use of tritium for research in physics, chemistry, biology and hydrology has in recent years become increasingly important. It was for this reason that the first international conference to discuss the progress of new developments was organized by the IAEA in conjunction with the Joint Commission on Applied Radioactivity and held from 3 - 10 May 1961, in Vienna. The first five sessions of the Symposium were devoted to the use of tritium in hydrology, physics and chemistry. Special emphasis was laid on the role of tritium as a tracer in hydrology, especially in the study of water movement. The establishment and improvement of counting and detection techniques to facilitate the application of tritium as a tracer was another aspect discussed in this part of the proceedings. Papers were read on the preparation of tritiated compounds and it was generally agreed that further clarification of the mechanism of various techniques, and of the Wilzbach gas exposure technique in particular, would lead to further developments in the synthesis of a number of tritium compounds important in biology. Other papers were concerned with tritium applications to studies of the mechanism of some chemical reactions together with the effects of tritium isotopes. During the second part of the Symposium the biological applications of tritium and tritiated compounds were discussed. These included general problems connected with the biological uses of tritium and the radiation effects of tritium on living organisms such as viruses, bacteria and cancer cells. The value of tritium in biological studies became apparent because of the ease with which a large number of metabolically active compounds such as hormones, vitamins and other important constituents in the body can be labelled with tritium. Tritium is also a weak beta-emitter and autoradiographs of tissues and single cells containing tritium-labelled compounds allow an excellent localization of the tracer. The Symposium was attended by

  1. Tritium in the Physical and Biological Sciences. Vol. II. Proceedings of the Symposium on the Detection and Use of Tritium in the Physical and Biological Sciences

    International Nuclear Information System (INIS)

    1962-01-01

    The use of tritium for research in physics, chemistry, biology and hydrology has in recent years become increasingly important. It was for this reason that the first international conference to discuss the progress of new developments was organized by the IAEA in conjunction with the Joint Commission on Applied Radioactivity and held from 3 — 10 May 1961, in Vienna. The first five sessions of the Symposium were devoted to the use of tritium in hydrology, physics and chemistry. Special emphasis was laid on the role of tritium as a tracer in hydrology, especially in the study of water movement. The establishment and improvement of counting and detection techniques to facilitate the application of tritium as a tracer was another aspect discussed in this part of the proceedings. Papers were read on the preparation of tritiated compounds and it was generally agreed that further clarification of the mechanism of various techniques, and of the Wilzbach gas exposure technique in particular, would lead to further developments in the synthesis of a number of tritium compounds important in biology. Other papers were concerned with tritium applications to studies of the mechanism of some chemical reactions together with the effects of tritium isotopes. During the second part of the Symposium the biological applications of tritium and tritiated compounds were discussed. These included general problems connected with the biological uses of tritium and the radiation effects of tritium on living organisms such as viruses, bacteria and cancer cells. The value of tritium in biological studies became apparent because of the ease with which a large number of metabolically active compounds such as hormones, vitamins and other important constituents in the body can be labelled with tritium. Tritium is also a weak beta-emitter and autoradiographs of tissues and single cells containing tritium-labelled compounds allow an excellent localization of the tracer. The Symposium was attended

  2. Introducing memory and association mechanism into a biologically inspired visual model.

    Science.gov (United States)

    Qiao, Hong; Li, Yinlin; Tang, Tang; Wang, Peng

    2014-09-01

    A famous biologically inspired hierarchical model (HMAX model), which was proposed recently and corresponds to V1 to V4 of the ventral pathway in primate visual cortex, has been successfully applied to multiple visual recognition tasks. The model is able to achieve a set of position- and scale-tolerant recognition, which is a central problem in pattern recognition. In this paper, based on some other biological experimental evidence, we introduce the memory and association mechanism into the HMAX model. The main contributions of the work are: 1) mimicking the active memory and association mechanism and adding the top down adjustment to the HMAX model, which is the first try to add the active adjustment to this famous model and 2) from the perspective of information, algorithms based on the new model can reduce the computation storage and have a good recognition performance. The new model is also applied to object recognition processes. The primary experimental results show that our method is efficient with a much lower memory requirement.

  3. Quality of Life Theory II. Quality of Life as the Realization of Life Potential: A Biological Theory of Human Being

    Directory of Open Access Journals (Sweden)

    Soren Ventegodt

    2003-01-01

    Full Text Available This review presents one of the eight theories of the quality of life (QOL used for making the SEQOL (self-evaluation of quality of life questionnaire or the quality of life as realizing life potential. This theory is strongly inspired by Maslow and the review furthermore serves as an example on how to fulfill the demand for an overall theory of life (or philosophy of life, which we believe is necessary for global and generic quality-of-life research.Whereas traditional medical science has often been inspired by mechanical models in its attempts to understand human beings, this theory takes an explicitly biological starting point. The purpose is to take a close view of life as a unique entity, which mechanical models are unable to do. This means that things considered to be beyond the individual's purely biological nature, notably the quality of life, meaning in life, and aspirations in life, are included under this wider, biological treatise. Our interpretation of the nature of all living matter is intended as an alternative to medical mechanism, which dates back to the beginning of the 20th century. New ideas such as the notions of the human being as nestled in an evolutionary and ecological context, the spontaneous tendency of self-organizing systems for realization and concord, and the central role of consciousness in interpreting, planning, and expressing human reality are unavoidable today in attempts to scientifically understand all living matter, including human life.

  4. Mechanisms of action of sacubitril/valsartan on cardiac remodeling: a systems biology approach.

    Science.gov (United States)

    Iborra-Egea, Oriol; Gálvez-Montón, Carolina; Roura, Santiago; Perea-Gil, Isaac; Prat-Vidal, Cristina; Soler-Botija, Carolina; Bayes-Genis, Antoni

    2017-01-01

    Sacubitril/Valsartan, proved superiority over other conventional heart failure management treatments, but its mechanisms of action remains obscure. In this study, we sought to explore the mechanistic details for Sacubitril/Valsartan in heart failure and post-myocardial infarction remodeling, using an in silico, systems biology approach. Myocardial transcriptome obtained in response to myocardial infarction in swine was analyzed to address post-infarction ventricular remodeling. Swine transcriptome hits were mapped to their human equivalents using Reciprocal Best (blast) Hits, Gene Name Correspondence, and InParanoid database. Heart failure remodeling was studied using public data available in gene expression omnibus (accession GSE57345, subseries GSE57338), processed using the GEO2R tool. Using the Therapeutic Performance Mapping System technology, dedicated mathematical models trained to fit a set of molecular criteria, defining both pathologies and including all the information available on Sacubitril/Valsartan, were generated. All relationships incorporated into the biological network were drawn from public resources (including KEGG, REACTOME, INTACT, BIOGRID, and MINT). An artificial neural network analysis revealed that Sacubitril/Valsartan acts synergistically against cardiomyocyte cell death and left ventricular extracellular matrix remodeling via eight principal synergistic nodes. When studying each pathway independently, Valsartan was found to improve cardiac remodeling by inhibiting members of the guanine nucleotide-binding protein family, while Sacubitril attenuated cardiomyocyte cell death, hypertrophy, and impaired myocyte contractility by inhibiting PTEN. The complex molecular mechanisms of action of Sacubitril/Valsartan upon post-myocardial infarction and heart failure cardiac remodeling were delineated using a systems biology approach. Further, this dataset provides pathophysiological rationale for the use of Sacubitril/Valsartan to prevent post

  5. Effect of calcium hydroxide on mechanical strength and biological properties of bioactive glass.

    Science.gov (United States)

    Shah, Asma Tufail; Batool, Madeeha; Chaudhry, Aqif Anwar; Iqbal, Farasat; Javaid, Ayesha; Zahid, Saba; Ilyas, Kanwal; Bin Qasim, Saad; Khan, Ather Farooq; Khan, Abdul Samad; Ur Rehman, Ihtesham

    2016-08-01

    In this manuscript for the first time calcium hydroxide (Ca(OH)2) has been used for preparation of bioactive glass (BG-2) by co-precipitation method and compared with glass prepared using calcium nitrate tetrahydrate Ca(NO3)2·4H2O (BG-1), which is a conventional source of calcium. The new source positively affected physical, biological and mechanical properties of BG-2. The glasses were characterized by Fourier transform infrared (FTIR), X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA-DSC), BET surface area analysis and Knoop hardness. The results showed that BG-2 possessed relatively larger surface properties (100m(2)g(-1) surface area) as compared to BG-1 (78m(2)g(-1)), spherical morphology and crystalline phases (wollastonite and apatite) after sintering at lower than conventional temperature. These properties contribute critical role in both mechanical and biological properties of glasses. The Knoop hardness measurements revealed that BG-2 possessed much better hardness (0.43±0.06GPa at 680°C and 2.16±0.46GPa at 980°C) than BG-1 (0.24±0.01 at 680°C and 0.57±0.07GPA at 980°C) under same conditions. Alamar blue Assay and confocal microscopy revealed that BG-2 exhibited better attachment and proliferation of MG63 cells. Based on the improved biological properties of BG-2 as a consequent of novel calcium source selection, BG-2 is proposed as a bioactive ceramic for hard tissue repair and regeneration applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Molecular mechanisms of temperature-dependent sex determination in the context of ecological developmental biology.

    Science.gov (United States)

    Matsumoto, Yuiko; Crews, David

    2012-05-06

    Temperature-dependent sex determination (TSD) is a prime example of phenotypic plasticity in that gonadal sex is determined by the temperature of the incubating egg. In the red-eared slider turtle (Trachemys scripta), the effect of temperature can be overridden by exogenous ligands, i.e., sex steroid hormones and steroid metabolism enzyme inhibitors, during the temperature-sensitive period (TSP) of development. Precisely how the physical signal of temperature is transduced into a biological signal that ultimately results in sex determination remains unknown. In this review, we discuss the sex determining pathway underlying TSD by focusing on two candidate sex determining genes, Forkhead box protein L2 (FoxL2) and Doublesex mab3- related transcription factor 1 (Dmrt1). They appear to be involved in transducing the environmental temperature signal into a biological signal that subsequently determines gonadal sex. FoxL2 and Dmrt1 exhibit gonad-typical patterns of expression in response to temperature during the TSP in the red-eared slider turtle. Further, the biologically active ligands regulate the expression of FoxL2 and Dmrt1 during development to modify gonad trajectory. The precise regulatory mechanisms of expression of these genes by temperature or exogenous ligands are not clear. However, the environment often influences developmental gene expression by altering the epigenetic status in regulatory regions. Here, we will discuss if the regulation of FoxL2 and Dmrt1 expression by environment is mediated through epigenetic mechanisms during development in species with TSD. Published by Elsevier Ireland Ltd.

  7. Application of Biologically Activated Brown Coal in Cu(II Sorption

    Directory of Open Access Journals (Sweden)

    Andrea Beňová

    2004-12-01

    Full Text Available The removal of heavy metal ions from wastewaters using different adsorbents is currently of great interest. Adsorption of cooper ions from aqueous solutions on biologically activated brown coal was investigated. Four families of adsorbents were prepared from brown coal by microorganisms activity. There were used soi microfungi such as Aspergillus niger, Aspergillus clavatus, Penicillium glabrum and Trichoderma viride. The equilibrium of the adsorption process was well described by the Langmuir isotherm and the maximum capacity of the sorbents was determined.

  8. Toward modular biological models: defining analog modules based on referent physiological mechanisms.

    Science.gov (United States)

    Petersen, Brenden K; Ropella, Glen E P; Hunt, C Anthony

    2014-08-16

    Currently, most biomedical models exist in isolation. It is often difficult to reuse or integrate models or their components, in part because they are not modular. Modular components allow the modeler to think more deeply about the role of the model and to more completely address a modeling project's requirements. In particular, modularity facilitates component reuse and model integration for models with different use cases, including the ability to exchange modules during or between simulations. The heterogeneous nature of biology and vast range of wet-lab experimental platforms call for modular models designed to satisfy a variety of use cases. We argue that software analogs of biological mechanisms are reasonable candidates for modularization. Biomimetic software mechanisms comprised of physiomimetic mechanism modules offer benefits that are unique or especially important to multi-scale, biomedical modeling and simulation. We present a general, scientific method of modularizing mechanisms into reusable software components that we call physiomimetic mechanism modules (PMMs). PMMs utilize parametric containers that partition and expose state information into physiologically meaningful groupings. To demonstrate, we modularize four pharmacodynamic response mechanisms adapted from an in silico liver (ISL). We verified the modularization process by showing that drug clearance results from in silico experiments are identical before and after modularization. The modularized ISL achieves validation targets drawn from propranolol outflow profile data. In addition, an in silico hepatocyte culture (ISHC) is created. The ISHC uses the same PMMs and required no refactoring. The ISHC achieves validation targets drawn from propranolol intrinsic clearance data exhibiting considerable between-lab variability. The data used as validation targets for PMMs originate from both in vitro to in vivo experiments exhibiting large fold differences in time scale. This report demonstrates

  9. Field Surveys, IOC Valleys. Biological Resources Survey, Dry Lake Valley, Nevada. Volume II, Part I.

    Science.gov (United States)

    1981-08-01

    years ago; the transplant was considered unsuccessful. Sagebrush is the principal item in the diet of adult sage grouse (Centrocercus urophasianus), and...canyon areas in the normal chukar partridge range but can also extend its range to areas too dry for the chukar. The transplant was not con- sidered...determined. - Ertee E-TR-48-II-I SSL1’N SL xx- C - - _ 0S91’ - - I. 009t N - - 0’J o,, s). N, - . ,o 09 -SW,- - - ,o T z X -4 oseo 0L91 - N - = - ozot ma

  10. Studies on Brewers Spent Grains (BSG) Biomethanation: II - Biological Efficiency of Digester Manure

    International Nuclear Information System (INIS)

    Ezeonu, F. C.; Udedi, S. C.; Okaka, A. N. C.; Okonkwo, C. J.

    2002-01-01

    Dangogo and Fernando suggested that a laboratory qualitative assessment of the manurial quality of digester slurry can be achieved by analyzing nitrogen (N) phosphorus (P) and potassium (K) content. Analyzing data from our study indicate an approximate range of nutrient contents of BSG digester manure to be within the following ranges, 0.50 - 0.61%, phosphorus, 0.55- 0.58% potassium and 3.14 - 3.48'% nitrogen for dried sludge. (Figures are not corrected for loss of nitrogen and other nutrients on drying). From the field study, it is apparent from the percentage biological yield that the digester dry manure is a better fertilizer than humus

  11. Epigenetic Mechanisms in Bone Biology and Osteoporosis: Can They Drive Therapeutic Choices?

    Directory of Open Access Journals (Sweden)

    Francesca Marini

    2016-08-01

    Full Text Available Osteoporosis is a complex multifactorial disorder of the skeleton. Genetic factors are important in determining peak bone mass and structure, as well as the predisposition to bone deterioration and fragility fractures. Nonetheless, genetic factors alone are not sufficient to explain osteoporosis development and fragility fracture occurrence. Indeed, epigenetic factors, representing a link between individual genetic aspects and environmental influences, are also strongly suspected to be involved in bone biology and osteoporosis. Recently, alterations in epigenetic mechanisms and their activity have been associated with aging. Also, bone metabolism has been demonstrated to be under the control of epigenetic mechanisms. Runt-related transcription factor 2 (RUNX2, the master transcription factor of osteoblast differentiation, has been shown to be regulated by histone deacetylases and microRNAs (miRNAs. Some miRNAs were also proven to have key roles in the regulation of Wnt signalling in osteoblastogenesis, and to be important for the positive or negative regulation of both osteoblast and osteoclast differentiation. Exogenous and environmental stimuli, influencing the functionality of epigenetic mechanisms involved in the regulation of bone metabolism, may contribute to the development of osteoporosis and other bone disorders, in synergy with genetic determinants. The progressive understanding of roles of epigenetic mechanisms in normal bone metabolism and in multifactorial bone disorders will be very helpful for a better comprehension of disease pathogenesis and translation of this information into clinical practice. A deep understanding of these mechanisms could help in the future tailoring of proper individual treatments, according to precision medicine’s principles.

  12. Engineering the mechanical and biological properties of nanofibrous vascular grafts for in situ vascular tissue engineering.

    Science.gov (United States)

    Henry, Jeffrey J D; Yu, Jian; Wang, Aijun; Lee, Randall; Fang, Jun; Li, Song

    2017-08-17

    Synthetic small diameter vascular grafts have a high failure rate, and endothelialization is critical for preventing thrombosis and graft occlusion. A promising approach is in situ tissue engineering, whereby an acellular scaffold is implanted and provides stimulatory cues to guide the in situ remodeling into a functional blood vessel. An ideal scaffold should have sufficient binding sites for biomolecule immobilization and a mechanical property similar to native tissue. Here we developed a novel method to blend low molecular weight (LMW) elastic polymer during electrospinning process to increase conjugation sites and to improve the mechanical property of vascular grafts. LMW elastic polymer improved the elasticity of the scaffolds, and significantly increased the amount of heparin conjugated to the micro/nanofibrous scaffolds, which in turn increased the loading capacity of vascular endothelial growth factor (VEGF) and prolonged the release of VEGF. Vascular grafts were implanted into the carotid artery of rats to evaluate the in vivo performance. VEGF treatment significantly enhanced endothelium formation and the overall patency of vascular grafts. Heparin coating also increased cell infiltration into the electrospun grafts, thus increasing the production of collagen and elastin within the graft wall. This work demonstrates that LMW elastic polymer blending is an approach to engineer the mechanical and biological property of micro/nanofibrous vascular grafts for in situ vascular tissue engineering.

  13. Effects of human serun albumin in some biological properties of rhodium(II complexes

    Directory of Open Access Journals (Sweden)

    Espósito Breno P.

    2000-01-01

    Full Text Available The affinities for human albumin (HSA of five rhodium(II complexes of general formula [Rh2(bridge4] (bridge = acetate, propionate, butyrate, trifluoroacetate and trifluoroacetamidate were determined by spectrophotometry. In the case of the alkylcarboxylates, an inverse correlation of affinity with their liposolubilities was observed. Diffusion of the free or protein-bound complexes into Ehrlich cells in vitro seems to be primarily governed by the hydrophobic character of the complex. The complex [Rh2(tfc4] exhibited affinity towards the protein (K = 214.1 as well as cell partition both in the absence (32.1% and presence (48.6% of HSA. The compound HSA: [Rh2(tfc4] has had its antitumoral action in tumor-bearing Balb-c mice investigated, showing that HSA can be a drug reservoir for the rhodium complex.

  14. Heteroleptic Palladium(II) dithiocarbamates: Synthesis, characterization and in vitro biological screening

    Science.gov (United States)

    Khan, Shahan Zeb; Zia-ur-Rehman; Amir, Muhammad Kashif; Ullah, Imdad; Akhter, M. S.; Bélanger-Gariepy, Francine

    2018-03-01

    Two new heteroleptic Pd(II) complexes of sodium 4-(2-pyrimidyl)piperazine-1-carbodithioate with tris-p-flourophenylphosphine (1) and tris-p-chlorophenylphosphine (2) were prepared and characterized by elemental analysis, FT-IR, multinuclear NMR {1H, 13C and 31P} and single-crystal X-ray diffraction measurement. In both complexes, Pd exhibit pseudo square planner geometry mediated by SS chelate, P and Cl. In vitro cytotoxicity against five different cancer cell lines using staurosporine as a standard revealed 1 to be more cytotoxic than 2, though both complexes are more active than cisplatin. Subsequent DNA binding studies revealed that non-covalent complex-DNA interaction may be the reason for arresting cancer cell growth. Furthermore, 1 and 2 are potent antioxidant agents.

  15. Chemical and biological effects of heavy distillate recycle in the SRC-II process

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, B.W.; Pelroy, R.A.; Anderson, R.P.; Freel, J.

    1983-12-01

    Recent work from the Merriam Laboratory continuous coal liquefaction units shows that heavy distillate from the SRC-II process can be recycled to extinction, and hence a distillate product boiling entirely below 310/sup 0/C (590/sup 0/F) (or other selected boiling points) is feasible. In these runs distillate yield was not reduced; gas make was unaffected; and hydrogen consumption was increased only slightly, in keeping with the generally higher hydrogen content of lighter end products. Total distillate yield (C/sub 5/-590/sup 0/F) was 56 wt %, MAF coal in runs with subbituminous coal from the Amax Belle Ayr mine. Product endpoint is well below 371/sup 0/C (700/sup 0/F), the temperature above which coal distillates appear to become genotoxic; and the product was shown to be free of mutagenic activity in the Ames test. Chemical analyses showed both the < 270/sup 0/C (< 518/sup 0/F) and the < 310/sup 0/C (< 590/sup 0/F) distillates to be essentially devoid of several reference polycyclic compounds known to be carcinogenic in laboratory animals. Tests for tumorigenic or carcinogenic activity were not carried out on these materials. However, a comparison of chemical data from the Merriam heavy distillate samples with data on the other SRC-II distillates where carcinogenesis or tumorigenesis data is available leads to the expectation that < 371/sup 0/C (< 700/sup 0/F) materials from the Merriam Laboratory will have greatly reduced tumorigenic and carcinogenic activity in skin painting tests. Other studies suggest the product should be more readily upgraded than full-range (C/sub 5/-900/sup 0/F) distillate.

  16. Kinetics and mechanism of ligand-exchange reactions of Cd(II) chelates

    Energy Technology Data Exchange (ETDEWEB)

    Nivorozhkin, L.E.; Kalabin, G.A.; Nivorozhkin, A.L.; Valeev, R.B.; Minkin, V.I.

    1987-03-01

    Tetrahedral Cd(II) bis(5-thio(or seleno)pyrazole-4-carboxaldiminates) of types II and III have been synthesized for the first time. The kinetics of the degenerate ligand exchange and enantiomerization of the complexes obtained have been studied by dynamic /sup 111/Cd, /sup 77/Se, and /sup 1/H (s = 1/2) NMR. The rate of intramolecular enantiomerization (k = 1/tau) is more than an order of magnitude greater than the corresponding values for processes of degenerate ligand exchange (a second-order reaction) determined from the dynamics of the averaging of the /sup 111/Cd-/sup 77/Se and /sup 111/Cd-N=CH spin-spin coupling constants. The cleavage and formation processes of the Cd-Se and Cd-N bonds are isoenergetic (..delta.. G/sub 298//sup not equal to/ = 14.4 kcal/mole for chelate II with X = Se and R = CH/sub 2/C/sub 6/H/sub 5/). The free energies of activation of degenerate ligand exchange determined form the dynamics of the averaging of the /sup 111/Cd N=CH spin-spin coupling constant increase from 12.7 to 17.9 kcal/mole along the following series for R: C/sub 2/H/sub 5/ < Ar < CH/sub 2/C/sub 6/H/sub 5/ < t-C/sub 4/H/sub 9/ < cyclo-C/sub 6/H/sub 11/. Replacement of the sulfur atom in the chelate ring by selenium results in increases in the rates of ligand exchange. A mechanism of degenerate ligand exchange has been proposed.

  17. A literature survey of the biological effects and mechanics of electromagnetic radiation

    International Nuclear Information System (INIS)

    Zeh, K.A.

    1985-01-01

    The following report discusses the very controversial subject of electromagnetic interaction with the human body. The project was undertaken in the form of a literature survey to investigate the biological mechanisms responsible for the interaction, the theoretical models and associated mathematical techniques required to model the human body, the resulting energy deposition in the human and the factors which effect this. It was established that at present the most realistic model of man can be obtained using a block model and moment method technique with improved methods such as conjugate gradients or band approximation for the necessary matrix inversion. The impedance method of modelling could be very promising for future research. From the literature studied on biological effects no scientific evidence was found which definitely proves or disproves hazardous effects exist at low field intensities ( -2 ). The testes and the lens of the eye can be harmed, however, if the intensity is sufficient to cause a temperature rise of 1 degree Celsius in these organs

  18. Dysfunctional Hematopoietic Stem Cell Biology: Underlying Mechanisms and Potential Therapeutic Strategies

    Directory of Open Access Journals (Sweden)

    Anja Geiselhart

    2012-01-01

    Full Text Available Fanconi anemia (FA is the most common inherited bone marrow failure syndrome. FA patients suffer to varying degrees from a heterogeneous range of developmental defects and, in addition, have an increased likelihood of developing cancer. Almost all FA patients develop a severe, progressive bone marrow failure syndrome, which impacts upon the production of all hematopoietic lineages and, hence, is thought to be driven by a defect at the level of the hematopoietic stem cell (HSC. This hypothesis would also correlate with the very high incidence of MDS and AML that is observed in FA patients. In this paper, we discuss the evidence that supports the role of dysfunctional HSC biology in driving the etiology of the disease. Furthermore, we consider the different model systems currently available to study the biology of cells defective in the FA signaling pathway and how they are informative in terms of identifying the physiologic mediators of HSC depletion and dissecting their putative mechanism of action. Finally, we ask whether the insights gained using such disease models can be translated into potential novel therapeutic strategies for the treatment of the hematologic disorders in FA patients.

  19. Screening of biologically important Zn2 + by a chemosensor with fluorescent turn on-off mechanism

    Science.gov (United States)

    Khan, Tanveer A.; Sheoran, Monika; Nikhil Raj M., Venkata; Jain, Surbhi; Gupta, Diksha; Naik, Sunil G.

    2018-01-01

    Reported herein the synthesis, characterization and biologically important zinc ion binding propensity of a weakly fluorescent chemosensor, 4-methyl-2,6-bis((E)-(2-(4-phenylthiazol-2-yl)hydrazono)methyl)phenol (1). 1H NMR spectroscopic titration experiment reveals the binding knack of 1 to the essential Zn2 +. The photo-physical studies of 1 exhibit an enhancement in the fluorescence by several folds upon binding with the zinc ions attributed to PET-off process, with a binding constant value of 5.22 × 103 M- 1. 1 exhibits an excellent detection range for Zn2 + with lower detection limit value of 2.31 × 10- 8 M. The selectivity of 1 was studied with various mono and divalent metal cations and it was observed that most cations either quenches the fluorescence or remains unchanged except for Cd2 +, which shows a slight enhancement in fluorescence intensity of 1. The ratiometric displacement of Cd2 + ions by Zn2 + ions shows an excellent selectivity towards in-situ detection of Zn2 + ions. Photo-physical studies also support the reversible binding of 1 to Zn2 + ions having on and off mechanism in presence of EDTA. Such recognition of the biologically important zinc ions finds potential application in live cell imaging.

  20. Heavy-ion radiobiology: new approaches to delineate mechanisms underlying enhanced biological effectiveness

    Science.gov (United States)

    Blakely, E. A.; Kronenberg, A.; Chatterjee, A. (Principal Investigator)

    1998-01-01

    Shortly after the discovery of polonium and radium by Marie Curie and her husband and colleague, Pierre Curie, it was learned that exposure to these alpha-particle emitters produced deleterious biological effects. The mechanisms underlying the increased biological effectiveness of densely ionizing radiations, including alpha particles, neutrons and highly energetic heavy charged particles, remain an active area of investigation. In this paper, we review recent advances in several areas of the radiobiology of these densely ionizing radiations, also known as heavy ions. Advances are described in the areas of DNA damage and repair, chromosome aberrations, mutagenesis, neoplastic transformation in vitro, genomic instability, normal tissue radiobiology and carcinogenesis in vivo. We focus on technical innovations, including novel applications of pulsed-field gel electrophoresis, fluorescence in situ hybridization (FISH), linkage analysis, and studies of gene expression and protein expression. We also highlight the use of new cellular and animal systems, including those with defined DNA repair deficiencies, as well as epithelial cell model systems to assess neoplastic transformation both in vitro and in vivo. The studies reviewed herein have had a substantial impact on our understanding of the genotoxic effects of heavy ions as well as their distinct effects on tissue homeostasis. The use of these radiations in cancer therapy is also discussed. The use of both heavy-ion and proton therapy is on the upswing in several centers around the world, due to their unique energy deposition characteristics that enhance the therapeutic effect and help reduce damage to normal tissue.

  1. Beyond COX-1: the effects of aspirin on platelet biology and potential mechanisms of chemoprevention.

    Science.gov (United States)

    Ornelas, Argentina; Zacharias-Millward, Niki; Menter, David G; Davis, Jennifer S; Lichtenberger, Lenard; Hawke, David; Hawk, Ernest; Vilar, Eduardo; Bhattacharya, Pratip; Millward, Steven

    2017-06-01

    After more than a century, aspirin remains one of the most commonly used drugs in western medicine. Although mainly used for its anti-thrombotic, anti-pyretic, and analgesic properties, a multitude of clinical studies have provided convincing evidence that regular, low-dose aspirin use dramatically lowers the risk of cancer. These observations coincide with recent studies showing a functional relationship between platelets and tumors, suggesting that aspirin's chemopreventive properties may result, in part, from direct modulation of platelet biology and biochemistry. Here, we present a review of the biochemistry and pharmacology of aspirin with particular emphasis on its cyclooxygenase-dependent and cyclooxygenase-independent effects in platelets. We also correlate the results of proteomic-based studies of aspirin acetylation in eukaryotic cells with recent developments in platelet proteomics to identify non-cyclooxygenase targets of aspirin-mediated acetylation in platelets that may play a role in its chemopreventive mechanism.

  2. Intended process water management concept for the mechanical biological treatment of municipal solid waste

    Institute of Scientific and Technical Information of China (English)

    D. Weichgrebe; S. Maerker; T. Boning; H. Stegemann

    2008-01-01

    Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment (MBT) makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT and also enhance resource recovery of the organic and inorganic fraction. The MBT plant at Gescher, Germany, is used as an example in order to determine the quantity and composition of process water and leachates from intensive and subsequent rotting, pressing water from anaerobic digestion and scrubber water from acid exhaust air treatment, and hence prepare an MBT water balance. The potential of, requirements for and limits to internal process water reuse as well as the possibilities of resource recovery from scrubber water are also examined. Finally, an assimilated process water management concept with the purpose of an extensive reduction of wastewater quantity and freshwater demand is presented.

  3. Atomistic modeling of structure II gas hydrate mechanics: Compressibility and equations of state

    Directory of Open Access Journals (Sweden)

    Thomas M. Vlasic

    2016-08-01

    Full Text Available This work uses density functional theory (DFT to investigate the poorly characterized structure II gas hydrates, for various guests (empty, propane, butane, ethane-methane, propane-methane, at the atomistic scale to determine key structure and mechanical properties such as equilibrium lattice volume and bulk modulus. Several equations of state (EOS for solids (Murnaghan, Birch-Murnaghan, Vinet, Liu were fitted to energy-volume curves resulting from structure optimization simulations. These EOS, which can be used to characterize the compressional behaviour of gas hydrates, were evaluated in terms of their robustness. The three-parameter Vinet EOS was found to perform just as well if not better than the four-parameter Liu EOS, over the pressure range in this study. As expected, the Murnaghan EOS proved to be the least robust. Furthermore, the equilibrium lattice volumes were found to increase with guest size, with double-guest hydrates showing a larger increase than single-guest hydrates, which has significant implications for the widely used van der Waals and Platteeuw thermodynamic model for gas hydrates. Also, hydrogen bonds prove to be the most likely factor contributing to the resistance of gas hydrates to compression; bulk modulus was found to increase linearly with hydrogen bond density, resulting in a relationship that could be used predictively to determine the bulk modulus of various structure II gas hydrates. Taken together, these results fill a long existing gap in the material chemical physics of these important clathrates.

  4. Atomistic modeling of structure II gas hydrate mechanics: Compressibility and equations of state

    Energy Technology Data Exchange (ETDEWEB)

    Vlasic, Thomas M.; Servio, Phillip; Rey, Alejandro D., E-mail: alejandro.rey@mcgill.ca [Department of Chemical Engineering, McGill University, Montreal H3A 0C5 (Canada)

    2016-08-15

    This work uses density functional theory (DFT) to investigate the poorly characterized structure II gas hydrates, for various guests (empty, propane, butane, ethane-methane, propane-methane), at the atomistic scale to determine key structure and mechanical properties such as equilibrium lattice volume and bulk modulus. Several equations of state (EOS) for solids (Murnaghan, Birch-Murnaghan, Vinet, Liu) were fitted to energy-volume curves resulting from structure optimization simulations. These EOS, which can be used to characterize the compressional behaviour of gas hydrates, were evaluated in terms of their robustness. The three-parameter Vinet EOS was found to perform just as well if not better than the four-parameter Liu EOS, over the pressure range in this study. As expected, the Murnaghan EOS proved to be the least robust. Furthermore, the equilibrium lattice volumes were found to increase with guest size, with double-guest hydrates showing a larger increase than single-guest hydrates, which has significant implications for the widely used van der Waals and Platteeuw thermodynamic model for gas hydrates. Also, hydrogen bonds prove to be the most likely factor contributing to the resistance of gas hydrates to compression; bulk modulus was found to increase linearly with hydrogen bond density, resulting in a relationship that could be used predictively to determine the bulk modulus of various structure II gas hydrates. Taken together, these results fill a long existing gap in the material chemical physics of these important clathrates.

  5. Atomistic modeling of structure II gas hydrate mechanics: Compressibility and equations of state

    Science.gov (United States)

    Vlasic, Thomas M.; Servio, Phillip; Rey, Alejandro D.

    2016-08-01

    This work uses density functional theory (DFT) to investigate the poorly characterized structure II gas hydrates, for various guests (empty, propane, butane, ethane-methane, propane-methane), at the atomistic scale to determine key structure and mechanical properties such as equilibrium lattice volume and bulk modulus. Several equations of state (EOS) for solids (Murnaghan, Birch-Murnaghan, Vinet, Liu) were fitted to energy-volume curves resulting from structure optimization simulations. These EOS, which can be used to characterize the compressional behaviour of gas hydrates, were evaluated in terms of their robustness. The three-parameter Vinet EOS was found to perform just as well if not better than the four-parameter Liu EOS, over the pressure range in this study. As expected, the Murnaghan EOS proved to be the least robust. Furthermore, the equilibrium lattice volumes were found to increase with guest size, with double-guest hydrates showing a larger increase than single-guest hydrates, which has significant implications for the widely used van der Waals and Platteeuw thermodynamic model for gas hydrates. Also, hydrogen bonds prove to be the most likely factor contributing to the resistance of gas hydrates to compression; bulk modulus was found to increase linearly with hydrogen bond density, resulting in a relationship that could be used predictively to determine the bulk modulus of various structure II gas hydrates. Taken together, these results fill a long existing gap in the material chemical physics of these important clathrates.

  6. Neurodevelopmental consequences in offspring of mothers with preeclampsia during pregnancy: underlying biological mechanism via imprinting genes.

    Science.gov (United States)

    Nomura, Yoko; John, Rosalind M; Janssen, Anna Bugge; Davey, Charles; Finik, Jackie; Buthmann, Jessica; Glover, Vivette; Lambertini, Luca

    2017-06-01

    Preeclampsia is known to be a leading cause of mortality and morbidity among mothers and their infants. Approximately 3-8% of all pregnancies in the US are complicated by preeclampsia and another 5-7% by hypertensive symptoms. However, less is known about its long-term influence on infant neurobehavioral development. The current review attempts to demonstrate new evidence for imprinting gene dysregulation caused by hypertension, which may explain the link between maternal preeclampsia and neurocognitive dysregulation in offspring. Pub Med and Web of Science databases were searched using the terms "preeclampsia," "gestational hypertension," "imprinting genes," "imprinting dysregulation," and "epigenetic modification," in order to review the evidence demonstrating associations between preeclampsia and suboptimal child neurodevelopment, and suggest dysregulation of placental genomic imprinting as a potential underlying mechanism. The high mortality and morbidity among mothers and fetuses due to preeclampsia is well known, but there is little research on the long-term biological consequences of preeclampsia and resulting hypoxia on the fetal/child neurodevelopment. In the past decade, accumulating evidence from studies that transcend disciplinary boundaries have begun to show that imprinted genes expressed in the placenta might hold clues for a link between preeclampsia and impaired cognitive neurodevelopment. A sudden onset of maternal hypertension detected by the placenta may result in misguided biological programming of the fetus via changes in the epigenome, resulting in suboptimal infant development. Furthering our understanding of the molecular and cellular mechanisms through which neurodevelopmental trajectories of the fetus/infant are affected by preeclampsia and hypertension will represent an important first step toward preventing adverse neurodevelopment in infants.

  7. Shear strength characteristics of mechanically biologically treated municipal solid waste (MBT-MSW) from Bangalore

    International Nuclear Information System (INIS)

    Sivakumar Babu, G.L.; Lakshmikanthan, P.; Santhosh, L.G.

    2015-01-01

    Highlights: • Shear strength properties of mechanically biologically treated municipal solid waste. • Effect of unit weight and particle size on the shear strength of waste. • Effect of particle size on the strength properties. • Stiffness ratio and the strength ratio of MSW. - Abstract: Strength and stiffness properties of municipal solid waste (MSW) are important in landfill design. This paper presents the results of comprehensive testing of shear strength properties of mechanically biologically treated municipal solid waste (MBT-MSW) in laboratory. Changes in shear strength of MSW as a function of unit weight and particle size were investigated by performing laboratory studies on the MSW collected from Mavallipura landfill site in Bangalore. Direct shear tests, small scale and large scale consolidated undrained and drained triaxial tests were conducted on reconstituted compost reject MSW samples. The triaxial test results showed that the MSW samples exhibited a strain-hardening behaviour and the strength of MSW increased with increase in unit weight. Consolidated drained tests showed that the mobilized shear strength of the MSW increased by 40% for a unit weight increase from 7.3 kN/m 3 to 10.3 kN/m 3 at 20% strain levels. The mobilized cohesion and friction angle ranged from 5 to 9 kPa and 8° to 33° corresponding to a strain level of 20%. The consolidated undrained tests exhibited reduced friction angle values compared to the consolidated drained tests. The friction angle increased with increase in the unit weight from 8° to 55° in the consolidated undrained tests. Minor variations were found in the cohesion values. Relationships for strength and stiffness of MSW in terms of strength and stiffness ratios are developed and discussed. The stiffness ratio and the strength ratio of MSW were found to be 10 and 0.43

  8. Geomagnetic polarity reversals as a mechanism for the punctuated equilibrium model of biological evolution

    International Nuclear Information System (INIS)

    Welsh, J.S.; Welsh, A.L.; Welsh, W.F.

    2003-01-01

    In contrast to what is predicted by classical Darwinian theory (phyletic gradualism), the fossil record typically displays a pattern of relatively sudden, dramatic changes as detailed by Eldregde and Gould's model of punctuated equilibrium. Evolutionary biologists have been at a loss to explain the ultimate source of the new mutations that drive evolution. One hypothesis holds that the abrupt speciation seen in the punctuated equilibrium model is secondary to an increased mutation rate resulting from periodically increased levels of ionizing radiation on the Earth's surface. Sporadic geomagnetic pole reversals, occurring every few million years on the average, are accompanied by alterations in the strength of the Earth's magnetic field and magnetosphere. This diminution may allow charged cosmic radiation to bombard Earth with less attenuation, thereby resulting in increased mutation rates. This episodic fluctuation in the magnetosphere is an attractive mechanism for the observed fossil record. Selected periods and epochs of geologic history for which data was available were reviewed for both geomagnetic pole reversal history and fossil record. Anomalies in either were scrutinized in greater depth and correlations were made. A 35 million year span (118-83 Ma) was identified during the Early/Middle Cretaceous period that was devoid of geomagnetic polarity reversals(the Cretaceous normal superchron). Examination of the fossil record (including several invertebrate and vertebrate taxons) during the Cretaceous normal superchron does not reveal any significant gap or slowing of speciation. Although increased terrestrial radiation exposure due to a diminution of the Earth's magnetosphere caused by a reversal of geomagnetic polarity is an attractive explanation for the mechanism of punctuated equilibrium, our investigation suggests that such polarity reversals cannot fully provide the driving force behind biological evolution. Further research is required to determine if

  9. Shear strength characteristics of mechanically biologically treated municipal solid waste (MBT-MSW) from Bangalore

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar Babu, G.L., E-mail: gls@civil.iisc.ernet.in [Department of Civil Engineering, Indian Institute of Science, Bangalore 560012 (India); Lakshmikanthan, P., E-mail: lakshmikanthancp@gmail.com [Centre for Sustainable Technologies (CST), Indian Institute of Science, Bangalore 560012 (India); Santhosh, L.G., E-mail: lgsanthu2006@gmail.com [Centre for Sustainable Technologies (CST), Indian Institute of Science, Bangalore 560012 (India)

    2015-05-15

    Highlights: • Shear strength properties of mechanically biologically treated municipal solid waste. • Effect of unit weight and particle size on the shear strength of waste. • Effect of particle size on the strength properties. • Stiffness ratio and the strength ratio of MSW. - Abstract: Strength and stiffness properties of municipal solid waste (MSW) are important in landfill design. This paper presents the results of comprehensive testing of shear strength properties of mechanically biologically treated municipal solid waste (MBT-MSW) in laboratory. Changes in shear strength of MSW as a function of unit weight and particle size were investigated by performing laboratory studies on the MSW collected from Mavallipura landfill site in Bangalore. Direct shear tests, small scale and large scale consolidated undrained and drained triaxial tests were conducted on reconstituted compost reject MSW samples. The triaxial test results showed that the MSW samples exhibited a strain-hardening behaviour and the strength of MSW increased with increase in unit weight. Consolidated drained tests showed that the mobilized shear strength of the MSW increased by 40% for a unit weight increase from 7.3 kN/m{sup 3} to 10.3 kN/m{sup 3} at 20% strain levels. The mobilized cohesion and friction angle ranged from 5 to 9 kPa and 8° to 33° corresponding to a strain level of 20%. The consolidated undrained tests exhibited reduced friction angle values compared to the consolidated drained tests. The friction angle increased with increase in the unit weight from 8° to 55° in the consolidated undrained tests. Minor variations were found in the cohesion values. Relationships for strength and stiffness of MSW in terms of strength and stiffness ratios are developed and discussed. The stiffness ratio and the strength ratio of MSW were found to be 10 and 0.43.

  10. Electronics and mechanics for the Silicon Vertex Detector of the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Irmler, C; Bergauer, T; Friedl, M; Gfall, I; Valentan, M, E-mail: irmler@hephy.oeaw.ac.a [Institute of High Energy Physics, Austrian Academy of Sciences, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria)

    2010-12-15

    A major upgrade of the KEK-B factory (Tsukuba, Japan), aiming at a peak luminosity of 8 x 10{sup 35}cm{sup -2}s{sup -1}, which is 40 times the present value, is foreseen until 2014. Consequently an upgrade of the Belle detector and in particular its Silicon Vertex Detector (SVD) is required. We will introduce the concept and prototypes of the full readout chain of the Belle II SVD. Its APV25 based front-end utilizes the Origami chip-on-sensor concept, while the back-end VME system provides online data processing as well as hit time finding using FPGAs. Furthermore, the design of the double-sided silicon detectors and the mechanics will be discussed.

  11. Mechanical performance of carbon-epoxy laminates. Part II: quasi-static and fatigue tensile properties

    Directory of Open Access Journals (Sweden)

    José Ricardo Tarpani

    2006-06-01

    Full Text Available In Part II of this work, quasi-static tensile properties of four aeronautical grade carbon-epoxy composite laminates, in both the as-received and pre-fatigued states, have been determined and compared. Quasi-static mechanical properties assessed were tensile strength and stiffness, tenacity (toughness at the maximum load and for a 50% load drop-off. In general, as-molded unidirectional cross-ply carbon fiber (tape reinforcements impregnated with either standard or rubber-toughened epoxy resin exhibited the maximum performance. The materials also displayed a significant tenacification (toughening after exposed to cyclic loading, resulting from the increased stress (the so-called wear-in phenomenon and/or strain at the maximum load capacity of the specimens. With no exceptions, two-dimensional woven textile (fabric pre-forms fractured catastrophically under identical cyclic loading conditions imposed to the fiber tape architecture, thus preventing their residual properties from being determined.

  12. Synthesis, characterization and biological studies of 2-(4-nitro phenylaminocarbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

    International Nuclear Information System (INIS)

    Aqeel Ashraf, M.; Jamil Maah, M.; Yusuf, I.

    2012-01-01

    Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) salts of 2-(4-nitro phenylaminocarbonyl)benzoic acid were characterized by physical, analytical and spectroscopic studies and checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis (Gram +ve), Escherichia coli (Gram -ve), Pseudomonas aeuroginosa (Gram -ve) and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. The antimicrobial activities of the metal complexes - were found to be greater than those of 2-(4-nitro phenylaminocarbonyl)benzoic acid alone.

  13. Performance and mechanism of simultaneous removal of Cd(II) and Congo red from aqueous solution by hierarchical vaterite spherulites

    Science.gov (United States)

    Chen, Yuan-Yuan; Yu, Sheng-Hui; Jiang, Hao-Fan; Yao, Qi-Zhi; Fu, Sheng-Quan; Zhou, Gen-Tao

    2018-06-01

    Hierarchical vaterite spherulites, synthesized by a simple injection-precipitation method at room temperature, were applied for the simultaneous removal of heavy metal Cd(II) and dye Congo red (CR) from aqueous solution. Batch experiments reveal that the maximum removal capacities of as-prepared vaterite spherulites to Cd(II) and CR are 984.5 and 89.0 mg/g, respectively, showing excellent removal performance for Cd(II) and CR. Furthermore, in the binary Cd(II)-CR system, the removal capacity of vaterite to Cd(II) is significantly enhanced at lower CR concentration (100 mg/L). In contrast, the concurrent Cd(II) shows negligible effect on the CR removal. The simultaneous removal mechanism was investigated by FESEM, EDX, XRD, FT-IR and XPS techniques. The simultaneous removal of Cd(II) and CR in the binary system is shown to be a multistep process, involving the preferential adsorption of dye CR, stabilization of CR to vaterite, coordination of the adsorbed CR molecules with Cd(II), and transformation of vaterite into otavite. Given the facile and green synthesis procedure, and effective removal of Cd(II) and CR in the binary system, the obtained vaterite spherulites have considerable practical interest in integrative treatment of wastewater contaminated by heavy metals and dyes.

  14. Mechanisms of bands and spirals formation during the drying of watery solutions of mercury (II) chloride with agar-agar

    International Nuclear Information System (INIS)

    Suarez-DomInguez, Edgardo Jonathan; Betancourt-Mar, Juvencio Alberto

    2005-01-01

    It is proposed two mechanisms to explain the formation of periodic and non periodic bands and spirals as thin films of gelatinous aqueous solutions of mercury (II) chloride are dried. The first mechanism supposes an homogeneous drying, where the height of the film decreases at constant rate, forming Liesegang bands. The second mechanism implies a non homogeneous drying where an evaporation front drives the formation of periodic bands and spirals

  15. Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

    Science.gov (United States)

    Bandelow, Borwin; Baldwin, David; Abelli, Marianna; Bolea-Alamanac, Blanca; Bourin, Michel; Chamberlain, Samuel R.; Cinosi, Eduardo; Davies, Simon; Domschke, Katharina; Fineberg, Naomi; Grünblatt, Edna; Jarema, Marek; Kim, Yong-Ku; Maron, Eduard; Masdrakis, Vasileios; Mikova, Olya; Nutt, David; Pallanti, Stefano; Pini, Stefano; Ströhle, Andreas; Thibaut, Florence; Vaghix, Matilde M.; Won, Eunsoo; Wedekind, Dirk; Wichniak, Adam; Woolley, Jade; Zwanzger, Peter; Riederer, Peter

    2017-01-01

    Objective Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD). Methods Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network. Results The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics. Conclusions Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD. PMID:27419272

  16. Biologically important conformational features of DNA as interpreted by quantum mechanics and molecular mechanics computations of its simple fragments.

    Science.gov (United States)

    Poltev, V; Anisimov, V M; Dominguez, V; Gonzalez, E; Deriabina, A; Garcia, D; Rivas, F; Polteva, N A

    2018-02-01

    Deciphering the mechanism of functioning of DNA as the carrier of genetic information requires identifying inherent factors determining its structure and function. Following this path, our previous DFT studies attributed the origin of unique conformational characteristics of right-handed Watson-Crick duplexes (WCDs) to the conformational profile of deoxydinucleoside monophosphates (dDMPs) serving as the minimal repeating units of DNA strand. According to those findings, the directionality of the sugar-phosphate chain and the characteristic ranges of dihedral angles of energy minima combined with the geometric differences between purines and pyrimidines determine the dependence on base sequence of the three-dimensional (3D) structure of WCDs. This work extends our computational study to complementary deoxydinucleotide-monophosphates (cdDMPs) of non-standard conformation, including those of Z-family, Hoogsteen duplexes, parallel-stranded structures, and duplexes with mispaired bases. For most of these systems, except Z-conformation, computations closely reproduce experimental data within the tolerance of characteristic limits of dihedral parameters for each conformation family. Computation of cdDMPs with Z-conformation reveals that their experimental structures do not correspond to the internal energy minimum. This finding establishes the leading role of external factors in formation of the Z-conformation. Energy minima of cdDMPs of non-Watson-Crick duplexes demonstrate different sequence-dependence features than those known for WCDs. The obtained results provide evidence that the biologically important regularities of 3D structure distinguish WCDs from duplexes having non-Watson-Crick nucleotide pairing.

  17. Angiotensin II (AngII) induces the expression of suppressor of cytokine signaling (SOCS)-3 in rat hypothalamus - a mechanism for desensitization of AngII signaling.

    Science.gov (United States)

    Torsoni, Márcio A; Carvalheira, José B; Calegari, Vivian C; Bezerra, Rosangela M N; Saad, Mário J A; Gontijo, José A; Velloso, Lício A

    2004-04-01

    Angiotensin II exerts a potent dypsogenic stimulus on the hypothalamus, which contributes to its centrally mediated participation in the control of water balance and blood pressure. Repetitive intracerebroventricular (i.c.v.) injections of angiotensin II lead to a loss of effect characterized as physiological desensitization to the peptide's action. In the present study, we demonstrate that angiotensin II induces the expression of suppressor of cytokine signaling (SOCS)-3 via angiotensin receptor 1 (AT1) and JAK-2, mostly located at the median preoptic lateral and anterodorsal preoptic nuclei. SOCS-3 produces an inhibitory effect upon the signal transduction pathways of several cytokines and hormones that employ members of the JAK/STAT families as intermediaries. The partial inhibition of SOCS-3 translation by antisense oligonucleotide was sufficient to significantly reduce the refractoriness of repetitive i.c.v. angiotensin II injections, as evaluated by water ingestion. Thus, by acting through AT1 on the hypothalamus, angiotensin II induces the expression of SOCS-3 which, in turn, blocks further activation of the pathway and consequently leads to desensitization to angiotensin II stimuli concerning its dypsogenic effect.

  18. Significant Deregulated Pathways in Diabetes Type II Complications Identified through Expression Based Network Biology

    Science.gov (United States)

    Ukil, Sanchaita; Sinha, Meenakshee; Varshney, Lavneesh; Agrawal, Shipra

    Type 2 Diabetes is a complex multifactorial disease, which alters several signaling cascades giving rise to serious complications. It is one of the major risk factors for cardiovascular diseases. The present research work describes an integrated functional network biology approach to identify pathways that get transcriptionally altered and lead to complex complications thereby amplifying the phenotypic effect of the impaired disease state. We have identified two sub-network modules, which could be activated under abnormal circumstances in diabetes. Present work describes key proteins such as P85A and SRC serving as important nodes to mediate alternate signaling routes during diseased condition. P85A has been shown to be an important link between stress responsive MAPK and CVD markers involved in fibrosis. MAPK8 has been shown to interact with P85A and further activate CTGF through VEGF signaling. We have traced a novel and unique route correlating inflammation and fibrosis by considering P85A as a key mediator of signals. The next sub-network module shows SRC as a junction for various signaling processes, which results in interaction between NF-kB and beta catenin to cause cell death. The powerful interaction between these important genes in response to transcriptionally altered lipid metabolism and impaired inflammatory response via SRC causes apoptosis of cells. The crosstalk between inflammation, lipid homeostasis and stress, and their serious effects downstream have been explained in the present analyses.

  19. Mechanical, Corrosion and Biological Properties of Room-Temperature Sputtered Aluminum Nitride Films with Dissimilar Nanostructure

    Directory of Open Access Journals (Sweden)

    Cristina Besleaga

    2017-11-01

    Full Text Available Aluminum Nitride (AlN has been long time being regarded as highly interesting material for developing sensing applications (including biosensors and implantable sensors. AlN, due to its appealing electronic properties, is envisaged lately to serve as a multi-functional biosensing platform. Although generally exploited for its intrinsic piezoelectricity, its surface morphology and mechanical performance (elastic modulus, hardness, wear, scratch and tensile resistance to delamination, adherence to the substrate, corrosion resistance and cytocompatibility are also essential features for high performance sustainable biosensor devices. However, information about AlN suitability for such applications is rather scarce or at best scattered and incomplete. Here, we aim to deliver a comprehensive evaluation of the morpho-structural, compositional, mechanical, electrochemical and biological properties of reactive radio-frequency magnetron sputtered AlN nanostructured thin films with various degrees of c-axis texturing, deposited at a low temperature (~50 °C on Si (100 substrates. The inter-conditionality elicited between the base pressure level attained in the reactor chamber and crystalline quality of AlN films is highlighted. The potential suitability of nanostructured AlN (in form of thin films for the realization of various type of sensors (with emphasis on bio-sensors is thoroughly probed, thus unveiling its advantages and limitations, as well as suggesting paths to safely exploit the remarkable prospects of this type of materials.

  20. Mechanical sludge disintegration for the production of carbon source for biological nutrient removal.

    Science.gov (United States)

    Kampas, P; Parsons, S A; Pearce, P; Ledoux, S; Vale, P; Churchley, J; Cartmell, E

    2007-04-01

    The primary driver for a successful biological nutrient removal is the availability of suitable carbon source, mainly in the form of volatile fatty acids (VFA). Several methods have been examined to increase the amount of VFAs in wastewater. This study investigates the mechanism of mechanical disintegration of thickened surplus activated sludge by a deflaker technology for the production of organic matter. This equipment was able to increase the soluble carbon in terms of VFA and soluble chemical oxygen demand (SCOD) with the maximum concentration to be around 850 and 6530 mgl(-1), for VFA and SCOD, respectively. The particle size was reduced from 65.5 to 9.3 microm after 15 min of disintegration with the simultaneous release of proteins (1550 mgl(-1)) and carbohydrates (307 mgl(-1)) indicating floc disruption and breakage. High performance size exclusion chromatography investigated the disintegrated sludge and confirmed that the deflaker was able to destroy the flocs releasing polymeric substances that are typically found outside of cells. When long disintegration times were applied (>or=10 min or >or=9000 kJkg(-1)TS of specific energy) smaller molecular size materials were released to the liquid phase, which are considered to be found inside the cells indicating cell lysis.

  1. The Role of Biologically Active Ingredients from Natural Drug Treatments for Arrhythmias in Different Mechanisms.

    Science.gov (United States)

    Li, Jie; Hu, Dan; Song, Xiaoli; Han, Tao; Gao, Yonghong; Xing, Yanwei

    2017-01-01

    Arrhythmia is a disease that is caused by abnormal electrical activity in the heart rate or rhythm. It is the major cause of cardiovascular morbidity and mortality. Although several antiarrhythmic drugs have been used in clinic for decades, their application is often limited by their adverse effects. As a result, natural drugs, which have fewer side effects, are now being used to treat arrhythmias. We searched for all articles on the role of biologically active ingredients from natural drug treatments for arrhythmias in different mechanisms in PubMed. This study reviews 19 natural drug therapies, with 18 active ingredient therapies, such as alkaloids, flavonoids, saponins, quinones, and terpenes, and two kinds of traditional Chinese medicine compound (Wenxin-Keli and Shensongyangxin), all of which have been studied and reported as having antiarrhythmic effects. The primary focus is the proposed antiarrhythmic mechanism of each natural drug agent. Conclusion . We stress persistent vigilance on the part of the provider in discussing the use of natural drug agents to provide a solid theoretical foundation for further research on antiarrhythmia drugs.

  2. Mechanical, Corrosion and Biological Properties of Room-Temperature Sputtered Aluminum Nitride Films with Dissimilar Nanostructure.

    Science.gov (United States)

    Besleaga, Cristina; Dumitru, Viorel; Trinca, Liliana Marinela; Popa, Adrian-Claudiu; Negrila, Constantin-Catalin; Kołodziejczyk, Łukasz; Luculescu, Catalin-Romeo; Ionescu, Gabriela-Cristina; Ripeanu, Razvan-George; Vladescu, Alina; Stan, George E

    2017-11-17

    Aluminum Nitride (AlN) has been long time being regarded as highly interesting material for developing sensing applications (including biosensors and implantable sensors). AlN, due to its appealing electronic properties, is envisaged lately to serve as a multi-functional biosensing platform. Although generally exploited for its intrinsic piezoelectricity, its surface morphology and mechanical performance (elastic modulus, hardness, wear, scratch and tensile resistance to delamination, adherence to the substrate), corrosion resistance and cytocompatibility are also essential features for high performance sustainable biosensor devices. However, information about AlN suitability for such applications is rather scarce or at best scattered and incomplete. Here, we aim to deliver a comprehensive evaluation of the morpho-structural, compositional, mechanical, electrochemical and biological properties of reactive radio-frequency magnetron sputtered AlN nanostructured thin films with various degrees of c -axis texturing, deposited at a low temperature (~50 °C) on Si (100) substrates. The inter-conditionality elicited between the base pressure level attained in the reactor chamber and crystalline quality of AlN films is highlighted. The potential suitability of nanostructured AlN (in form of thin films) for the realization of various type of sensors (with emphasis on bio-sensors) is thoroughly probed, thus unveiling its advantages and limitations, as well as suggesting paths to safely exploit the remarkable prospects of this type of materials.

  3. Radon as a medicine. Therapeutic effectiveness, biological mechanism and comparative risk assessment

    International Nuclear Information System (INIS)

    Deetjen, Peter; Falkenbach, Albrecht; Harder, Dietrich; Joeckel, Hans; Kaul, Alexander; Philipsborn, Henning von

    2014-01-01

    Proofs of the therapeutic efficiency of balneological radon applications administered to patients suffering from rheumatic diseases, investigations into the biological action mechanism associated with the alpha particles emitted by radon and its radioactive daughter products, and the comparative risk assessment of radon treatment and medicinal pain therapy have been the research projects whose results are summarized in this book. Controlled clinical studies, if possible performed as prospective, randomized and placebo-controlled double blind studies, have given evidence that the therapeutic effects of balneological radon applications - long-lasting pain reduction and reduced consumption of medicines compared with controls - are significantly persisting over many post-treatment months. The molecular and cellular mechanism of action underlying these long-lasting therapeutic effects has been identified as the down-regulation of cellular immune responses, initiated by cellular apoptosis sequential to low alpha particle doses and by the subsequent release of anti-inflammatory cytokines. The unwanted side-effects of non-steroidal anti-rheumatic drug treatments have to be compared with the absence of side effects from the balneological radon applications which merely involve radiation doses well below the mean value and the fluctuation width of the annual doses attributable to everybody's natural radiation exposure.

  4. Performance of mechanical biological treatment of residual municipal waste in Poland

    Science.gov (United States)

    den Boer, Emilia; Jędrczak, Andrzej

    2017-11-01

    The number and capacity of mechanical-biological treatment (MBT) plants in Europe increased significantly in the past two decades as a response to the legal obligation to limit the landfilling of biodegradable waste in landfills and to increase recycling and energy recovery from waste. The aim of these plants is to prepare residual municipal waste for recovery and disposal operations, including especially separation and stabilization of the easily biodegradable fraction (the biofraction). The final products of MBP technology are recyclables, stabilate, high calorific fraction which is used for the production of refuse derived fuel (RDF) and the remaining residual fraction. The shares of the output fractions, especially of the recyclables and RDF determine the overall efficiency of MBT technology in diverting waste from landfills. In this paper results of an assessment of one exemplary MBT plant are provided. The analysis was performed within a comparative study in which 20 selected MBT plants in Poland were subject to a detailed analysis, focusing, both at the design parameters as well as operational ones. The selected plant showed relatively higher overall materials recovery efficiency. With the view to circular economy targets, increased automation of the mechanical waste treatment will be required to support achieving high level diversion from landfills. The study reviled that stabilisation of biofraction should be improved by a better control of process conditions, especially moisture content.

  5. Radon as a medicine. Therapeutic effectiveness, biological mechanism and comparative risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, Peter; Falkenbach, Albrecht; Harder, Dietrich; Joeckel, Hans; Kaul, Alexander; Philipsborn, Henning von

    2014-07-01

    Proofs of the therapeutic efficiency of balneological radon applications administered to patients suffering from rheumatic diseases, investigations into the biological action mechanism associated with the alpha particles emitted by radon and its radioactive daughter products, and the comparative risk assessment of radon treatment and medicinal pain therapy have been the research projects whose results are summarized in this book. Controlled clinical studies, if possible performed as prospective, randomized and placebo-controlled double blind studies, have given evidence that the therapeutic effects of balneological radon applications - long-lasting pain reduction and reduced consumption of medicines compared with controls - are significantly persisting over many post-treatment months. The molecular and cellular mechanism of action underlying these long-lasting therapeutic effects has been identified as the down-regulation of cellular immune responses, initiated by cellular apoptosis sequential to low alpha particle doses and by the subsequent release of anti-inflammatory cytokines. The unwanted side-effects of non-steroidal anti-rheumatic drug treatments have to be compared with the absence of side effects from the balneological radon applications which merely involve radiation doses well below the mean value and the fluctuation width of the annual doses attributable to everybody's natural radiation exposure.

  6. Radiation-induced secretory protein, clusterin. Its inductive mechanism and biological significance

    International Nuclear Information System (INIS)

    Suzuki, Masatoshi; Boothman, D.A.

    2007-01-01

    This paper describes biochemistry of secretory clusterin (C), its radiation-inductive mechanism and biological significance. C is a glycoprotein found to be secreted from cells given various stresses like radiation and ultraviolet (UV)-ray, and participates to red cell clustering. Human C gene locates on the chromosome 8p21-p12, C has MW of 60 kDa, its precursor undergoes the degrading processing to α- and β-chains to form their heterodimer before glycosylation, and the C is finally secreted. So many other names have been given to C due to its numerous functions which have been discovered in other fields, such as apolipoprotein J. C is abundant in plasma, milk, urine, cerebrospinal fluid, semen, etc. Within 24 hr after X-ray irradiation, extracellular insulin-like growth factor-1 (IGF-1) level is elevated, and through its binding to the receptor, Src/MAPK signaling participates to C expression. Nuclear C, also induced by radiation, is a splicing variant of C and not secreted from cells. C is induced by radiation with as low dose as 2 cGy, which is different from induction of nuclear C. Secreted C is incorporated in cells by endocytosis and promotes the intracellular survival reaction through IGF-1 receptor/MAPK/Egr-1 pathway, whereas nuclear C induces cell apoptosis via unknown mechanism. Further studies are required for elucidation of the roles of secretory and nuclear C in cellular radiation responses. (R.T.)

  7. Epigenetics and type II diabetes mellitus: underlying mechanisms of prenatal predisposition

    Directory of Open Access Journals (Sweden)

    J. David Sterns

    2014-05-01

    Full Text Available Type II diabetes mellitus (T2DM is a widespread metabolic disorder characterized by insulin resistance resulting in abnormally high blood glucose levels. While the onset of T2DM is known to be influenced by a number of genetic factors, emerging research has demonstrated the additional role of a variety of epigenetic mechanisms in the development of this disorder. Epigenetics relates to the heritable changes in gene expression that cannot be explained by simple variations in the primary DNA sequence and includes DNA methylation and histone modification. These changes impact many processes, including stem cell differentiation into pancreatic endocrine cells as well as normal β-cell function. Recent studies focusing on the effects of maternal health, specifically as it is affected by famine and hyperglycemia, have found possible mechanisms to explain the increased likelihood of the fetus developing risk factors such as altered atherogenic lipid profiles, increased obesity and BMI, as well as impaired glucose tolerance (IGT for the development of T2DM later in life. It is suggested that these epigenetic influences happen early during gestation and are less susceptible to the effects of postnatal environmental modification as was previously thought. Regardless, emerging research into epigenetic-based treatment approaches for T2DM are promising and offer yet another means by which to limit the impact of this global epidemic.

  8. DACS II - A distributed thermal/mechanical loads data acquisition and control system

    Science.gov (United States)

    Zamanzadeh, Behzad; Trover, William F.; Anderson, Karl F.

    1987-01-01

    A distributed data acquisition and control system has been developed for the NASA Flight Loads Research Facility. The DACS II system is composed of seven computer systems and four array processors configured as a main computer system, three satellite computer systems, and 13 analog input/output systems interconnected through three independent data networks. Up to three independent heating and loading tests can be run concurrently on different test articles or the entire system can be used on a single large test such as a full scale hypersonic aircraft. Thermal tests can include up to 512 independent adaptive closed loop control channels. The control system can apply up to 20 MW of heating to a test specimen while simultaneously applying independent mechanical loads. Each thermal control loop is capable of heating a structure at rates of up to 150 F per second over a temperature range of -300 to +2500 F. Up to 64 independent mechanical load profiles can be commanded along with thermal control. Up to 1280 analog inputs monitor temperature, load, displacement and strain on the test specimens with real time data displayed on up to 15 terminals as color plots and tabular data displays. System setup and operation is accomplished with interactive menu-driver displays with extensive facilities to assist the users in all phases of system operation.

  9. Systematic review of biological effects of exposure to static electric fields. Part II: Invertebrates and plants.

    Science.gov (United States)

    Schmiedchen, Kristina; Petri, Anne-Kathrin; Driessen, Sarah; Bailey, William H

    2018-01-01

    The construction of high-voltage direct current (HVDC) lines for the long-distance transport of energy is becoming increasingly popular. This has raised public concern about potential environmental impacts of the static electric fields (EF) produced under and near HVDC power lines. As the second part of a comprehensive literature analysis, the aim of this systematic review was to assess the effects of static EF exposure on biological functions in invertebrates and plants and to provide the basis for an environmental impact assessment of such exposures. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used to guide the methodological conduct and reporting. Thirty-three studies - 14 invertebrate and 19 plant studies - met the eligibility criteria and were included in this review. The reported behavioral responses of insects and planarians upon exposure strongly suggest that invertebrates are able to perceive the presence of a static EF. Many other studies reported effects on physiological functions that were expressed as, for example, altered metabolic activity or delayed reproductive and developmental stages in invertebrates. In plants, leaf damage, alterations in germination rates, growth and yield, or variations in the concentration of essential elements, for example, have been reported. However, these physiological responses and changes in plant morphology appear to be secondary to surface stimulation by the static EF or caused by concomitant parameters of the electrostatic environment. Furthermore, all of the included studies suffered from methodological flaws, which lowered credibility in the results. At field levels encountered from natural sources or HVDC lines (plants. At far higher field levels (> 35kV/m), adverse effects on physiology and morphology, presumably caused by corona-action, appear to be more likely. Higher quality studies are needed to unravel the role of air ions, ozone, nitric oxide and corona current on

  10. Biological Reclaiming of Recycled Rubber and Its Effect on Mechanical Properties of New Rubber Vulcanizates

    Directory of Open Access Journals (Sweden)

    Maryam Mansourirad

    2014-12-01

    Full Text Available Nowadays, due to environmental concerns, there has been great attention to recycling and reclaiming of tires. Different methods have been used for reclaiming or desulfurization of rubber. One of these methods, in which desulfurization of rubber happens with no damage to the polymer structure, is desulfurization by biological microorganisms. In this research the application and performance of thermophilic and sulfur oxidizing bacteria, Acidianus brierleyi for this purpose was investigated. Ground tire rubber was detoxified with organic solvents, and the optimum conditions for growing microorganisms in the existence of rubber powder in the shaker flasks were determined. In order to accelerate the process, the suitable conditions for growth of bacteria and desulfurization in the bioreactor were adopted. Fourier transfer infrared spectroscopy and scanning electron microscopy were employed to characterize desulfurization of bio-treated powder from bioreactor. The results indicated that morphological changes on powder surface and reduction of sulfur bonds have occurred. Samples from bioreactors, with and without bacteria and also untreated rubber powder were compounded with virgin styrene butadiene rubber. Tensile and dynamic properties were investigated using uni-direction tensile test and dynamic-mechanical-thermal analysis, respectively. Although some differences in dynamic-mechanical-thermal properties of samples pointed to stronger interaction between rubber matrix and treated rubber powder, no significant improvements in the mechanical properties of vulcanizates containing A.brierleyi-treated powder were observed. Low concentration of sulfur in rubber vulcanizates, chemical bonds of sulfur, and low efficiency of A. brierleyi in breaking sulfur bonds and reclaiming rubber were considered as the reasons for low efficiency of this treatment process.

  11. Sorption Mechanisms of Cesium on Cu II2Fe II(CN) 6and Cu II3[Fe III(CN) 6] 2Hexacyanoferrates and Their Relation to the Crystalline Structure

    Science.gov (United States)

    Ayrault, S.; Jimenez, B.; Garnier, E.; Fedoroff, M.; Jones, D. J.; Loos-Neskovic, C.

    1998-12-01

    CuII2FeII(CN)6·xH2O and CuII3[FeIII(CN)6]2·xH2O can be prepared with reproducible chemical compositions and structures after careful washing. They have cubicFmoverline3mstructures with iron vacancies. In CuII2FeII(CN)6, copper occupies two different sites: Cu1 in position 4blinked to Fe through the CN groups, and Cu2 not linked to the CN groups and partially occupying the interstitial 24epositions. The second type of site is not present in CuII3[FeIII(CN)6]2. Sorption kinetics and isotherms were determined for cesium on both hexacyanoferrates by batch experiments. On CuII3[FeIII(CN)6]2, the maximum uptake is only 0.073 Cs/Fe (at./at.). On CuII2FeII(CN)6, the uptake reaches 1.5 Cs/Fe. The sorption kinetics include at least two steps: at1/2variation until approximately 72 h and then a slow evolution studied up to 6 months. The sorption mechanism is complex. The main process seems to be diffusion of ion pairs, followed by a reorganization of the solid, resulting in one or more new solid phases. The presence of the Cu2 site seems to play a favorable role in the sorption. Owing to its good midterm stability and the first rapid step of exchange, CuII2FeII(CN)6·xH2O seems to be one of the most promising compounds for the recovery of cesium from nuclear liquid wastes.

  12. Photoactive platinum(II) complexes of nonsteroidal anti-inflammatory drug naproxen: Interaction with biological targets, antioxidant activity and cytotoxicity.

    Science.gov (United States)

    Srivastava, Payal; Singh, Khushbu; Verma, Madhu; Sivakumar, Sri; Patra, Ashis K

    2018-01-20

    The effect on the therapeutic efficacy of Pt(II) complexes on combining non-steroidal anti-inflammatory drugs (NSAIDs) is an attractive strategy to circumvent chronic inflammation mediated by cancer and metastasis. Two square-planar platinum(II) complexes: [Pt(dach)(nap)Cl] (1) and [Pt(dach)(nap) 2 ] (2), where dach = (1R,2R)-dichloro(cyclohexane-1,2-diamine) and NSAID drug naproxen (nap), have been designed for studying their biological activity. The naproxen bound to the Pt(II) centre get released upon photoirradiation with low-power UV-A light as confirmed by the significant enhancement in emission intensities of the complexes. The compounds were evaluated for their photophysical properties, photostability, reactivity with 5'-guanosine monophophosphate (5'-GMP), interactions with CT-DNA and BSA, antioxidant activity and reactive oxygen species mediated photo-induced DNA damage properties. ESI-MS studies demonstrated the formation of bis-adduct with 5'-GMP and the formation of Pt II -DNA crosslinks by gel electrophoretic mobility shift assay and ITC studies. The interaction of the complexes 1 and 2 with the CT-DNA exhibits potential binding affinity (K b  ∼ 10 4  M -1 , K app ∼ 10 5  M -1 ), implying intercalation to CT-DNA through planar naphthyl ring of the complexes. Both the complexes also exhibit strong binding affinity towards BSA (K BSA ∼ 10 5  M -1 ). The complexes exhibit efficient DNA damage activity on irradiation at 365 nm via formation of singlet oxygen ( 1 O 2 ) and hydroxyl radical ( • OH) under physiological conditions. Both the complexes were cytotoxic in dark and exhibit significant enhancement of cytotoxicity upon photo-exposure against HeLa and HepG2 cancer cells giving IC 50 values ranging from 8 to 12 μM for 1 and 2. The cellular internalization data showed cytosolic and nuclear localization of the complexes in the HeLa cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Self-Organization of Genome Expression from Embryo to Terminal Cell Fate: Single-Cell Statistical Mechanics of Biological Regulation

    Directory of Open Access Journals (Sweden)

    Alessandro Giuliani

    2017-12-01

    Full Text Available A statistical mechanical mean-field approach to the temporal development of biological regulation provides a phenomenological, but basic description of the dynamical behavior of genome expression in terms of autonomous self-organization with a critical transition (Self-Organized Criticality: SOC. This approach reveals the basis of self-regulation/organization of genome expression, where the extreme complexity of living matter precludes any strict mechanistic approach. The self-organization in SOC involves two critical behaviors: scaling-divergent behavior (genome avalanche and sandpile-type critical behavior. Genome avalanche patterns—competition between order (scaling and disorder (divergence reflect the opposite sequence of events characterizing the self-organization process in embryo development and helper T17 terminal cell differentiation, respectively. On the other hand, the temporal development of sandpile-type criticality (the degree of SOC control in mouse embryo suggests the existence of an SOC control landscape with a critical transition state (i.e., the erasure of zygote-state criticality. This indicates that a phase transition of the mouse genome before and after reprogramming (immediately after the late 2-cell state occurs through a dynamical change in a control parameter. This result provides a quantitative open-thermodynamic appreciation of the still largely qualitative notion of the epigenetic landscape. Our results suggest: (i the existence of coherent waves of condensation/de-condensation in chromatin, which are transmitted across regions of different gene-expression levels along the genome; and (ii essentially the same critical dynamics we observed for cell-differentiation processes exist in overall RNA expression during embryo development, which is particularly relevant because it gives further proof of SOC control of overall expression as a universal feature.

  14. Lead levels in some biological samples of auto-mechanics in Abeokuta, Nigeria.

    Science.gov (United States)

    Babalola, O O; Ojo, L O; Aderemi, M O

    2005-12-01

    Lead levels were determined in the blood, scalp hair and fingernails of 38, all male auto-mechanics (aged 18-45 years) from Abeokuta, South-western Nigeria. The subjects were classified into four sub-groups based on the period of exposure namely: 1-5, 6-10, 11-15, and >16 years. Thirty-two occupationally unexposed subjects (mainly office workers) served as the control. The weight, height and body mass indexes of all subjects were noted, in addition to other information obtained through structured questionnaire. The mean values of blood lead (BPb), hair lead (HPb) and fingernail lead (NPb) of the occupationally exposed subjects (n=38) were 48.50 +/- 9.08 microg/dL, 17.75 +/- 5.16 microg/g, and 5.92 +/- 3.30 microg/g respectively, while the corresponding mean values for these parameters in the control subjects (n = 32) were 33.(,5 +/- 10.09 microg/dL, 14.30 +/- 5.90 microg/g and 5.31 +/- 2.77 microg/g respectively. The differences in BPb and HPb levels of the two groups were statistically significant (P <0.05 and P <0.01 respectively), while that of NPb was not significant. The levels of lead in the biological samples appeared to have no relationship with the number of years on the job. From these results, it was obvious that the higher levels of lead in the biological samples of test subjects, compared with those of the controls were from environmental sources.

  15. Radiation-induced DNA-protein cross-links: Mechanisms and biological significance.

    Science.gov (United States)

    Nakano, Toshiaki; Xu, Xu; Salem, Amir M H; Shoulkamy, Mahmoud I; Ide, Hiroshi

    2017-06-01

    Ionizing radiation produces various DNA lesions such as base damage, DNA single-strand breaks (SSBs), DNA double-strand breaks (DSBs), and DNA-protein cross-links (DPCs). Of these, the biological significance of DPCs remains elusive. In this article, we focus on radiation-induced DPCs and review the current understanding of their induction, properties, repair, and biological consequences. When cells are irradiated, the formation of base damage, SSBs, and DSBs are promoted in the presence of oxygen. Conversely, that of DPCs is promoted in the absence of oxygen, suggesting their importance in hypoxic cells, such as those present in tumors. DNA and protein radicals generated by hydroxyl radicals (i.e., indirect effect) are responsible for DPC formation. In addition, DPCs can also be formed from guanine radical cations generated by the direct effect. Actin, histones, and other proteins have been identified as cross-linked proteins. Also, covalent linkages between DNA and protein constituents such as thymine-lysine and guanine-lysine have been identified and their structures are proposed. In irradiated cells and tissues, DPCs are repaired in a biphasic manner, consisting of fast and slow components. The half-time for the fast component is 20min-2h and that for the slow component is 2-70h. Notably, radiation-induced DPCs are repaired more slowly than DSBs. Homologous recombination plays a pivotal role in the repair of radiation-induced DPCs as well as DSBs. Recently, a novel mechanism of DPC repair mediated by a DPC protease was reported, wherein the resulting DNA-peptide cross-links were bypassed by translesion synthesis. The replication and transcription of DPC-bearing reporter plasmids are inhibited in cells, suggesting that DPCs are potentially lethal lesions. However, whether DPCs are mutagenic and induce gross chromosomal alterations remains to be determined. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Virtual Agonist-antagonist Mechanisms Produce Biological Muscle-like Functions: An Application for Robot Joint Control

    DEFF Research Database (Denmark)

    Xiong, Xiaofeng; Wörgötter, Florentin; Manoonpong, Poramate

    2014-01-01

    Purpose – Biological muscles of animals have a surprising variety of functions, i.e., struts, springs, and brakes. According to this, the purpose of this paper is to apply virtual agonist-antagonist mechanisms to robot joint control allowing for muscle-like functions and variably compliant joint......, variably compliant joint motions can be produced without mechanically bulky and complex mechanisms or complex force/toque sensing at each joint. Moreover, through tuning the damping coefficient of the VAAM, the functions of the VAAM are comparable to biological muscles. Originality/value – The model (i.......e., VAAM) provides a way forward to emulate muscle-like functions that are comparable to those found in physiological experiments of biological muscles. Based on these muscle-like functions, the robotic joints can easily achieve variable compliance that does not require complex physical components...

  17. Mechanism of interaction of Al3+ with the proteins composition of photosystem II.

    Directory of Open Access Journals (Sweden)

    Imed Hasni

    Full Text Available The inhibitory effect of Al3+on photosystem II (PSII electron transport was investigated using several biophysical and biochemical techniques such as oxygen evolution, chlorophyll fluorescence induction and emission, SDS-polyacrylamide and native green gel electrophoresis, and FTIR spectroscopy. In order to understand the mechanism of its inhibitory action, we have analyzed the interaction of this toxic cation with proteins subunits of PSII submembrane fractions isolated from spinach. Our results show that Al 3+, especially above 3 mM, strongly inhibits oxygen evolution and affects the advancement of the S states of the Mn4O5Ca cluster. This inhibition was due to the release of the extrinsic polypeptides and the disorganization of the Mn4O5Ca cluster associated with the oxygen evolving complex (OEC of PSII. This fact was accompanied by a significant decline of maximum quantum yield of PSII (Fv/Fm together with a strong damping of the chlorophyll a fluorescence induction. The energy transfer from light harvesting antenna to reaction centers of PSII was impaired following the alteration of the light harvesting complex of photosystem II (LHCII. The latter result was revealed by the drop of chlorophyll fluorescence emission spectra at low temperature (77 K, increase of F0 and confirmed by the native green gel electrophoresis. FTIR measurements indicated that the interaction of Al 3+ with the intrinsic and extrinsic polypeptides of PSII induces major alterations of the protein secondary structure leading to conformational changes. This was reflected by a major reduction of α-helix with an increase of β-sheet and random coil structures in Al 3+-PSII complexes. These structural changes are closely related with the functional alteration of PSII activity revealed by the inhibition of the electron transport chain of PSII.

  18. Mechanism of Hg(II) Immobilization in Sediments by Sulfate-Cement Amendment.

    Science.gov (United States)

    Serrano, Susana; Vlassopoulos, Dimitri; O'Day, Peggy A

    2016-04-01

    polynuclear chloromercury(II) salt as the primary immobilization mechanism.

  19. Synthesis, characterization and biological studies of 2-(4-nitrophenylamino-carbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

    International Nuclear Information System (INIS)

    Imran, M; Nazir, S.; Latif, S.; Mahmood, Z.

    2010-01-01

    Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of 2-(4-Nitrophenyl aminocarbonyl)benzoic acid were synthesized and characterized on the basis of physical, analytical and spectroscopic data. The ligands, as well as its metal complexes were checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis, Escherichia coli, Pseudomonas aeuroginosa, and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. Disc diffusion method and Tube diffusion test were used for antibacterial and antifungal activities, respectively. The synthesized complexes only show significant antifungal activity but inactive for antibacterial, however, in general, the metal complexes were found to be more active against antimicrobial activities as compared to their un complexed ligand. (author)

  20. Mechanism of the biological response to winter cooling in the northeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; PrasannaKumar, S.; Bhattathiri, P.M.A.; DileepKumar, M.; Raghukumar, S.; Nair, K.K.C.; Ramaiah, N.

    The Arabian Sea is one of the most biologically productive ocean regions, mainly due to the upwelling of nutrients during the summer (southwest) monsoon. But the northern Arabian Sea continues to sustain fairly high biological production after...

  1. Antidiabetic mechanisms of angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists: beyond the renin-angiotensin system

    Czech Academy of Sciences Publication Activity Database

    Kurtz, T. W.; Pravenec, Michal

    2004-01-01

    Roč. 22, č. 12 (2004), s. 2253-2261 ISSN 0263-6352 R&D Projects: GA ČR GA301/03/0751 Grant - others:HHMI(US) HHMI55000331 Institutional research plan: CEZ:AV0Z5011922 Keywords : angiotensin II receptors * metabolic syndrome * peroxisome proliferator activated receptors Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.871, year: 2004

  2. Physicochemical impact studies of gamma rays on "aspirin" analgesics drug and its metal complexes in solid form: Synthesis, spectroscopic and biological assessment of Ca(II), Mg(II), Sr(II) and Ba(II) aspirinate complexes

    Science.gov (United States)

    Refat, Moamen S.; Sharshar, T.; Elsabawy, Khaled M.; Heiba, Zein K.

    2013-09-01

    Metal aspirinate complexes, M2(Asp)4, where M is Mg(II), Ca(II), Sr(II) or Ba(II) are formed by refluxed of aspirin (Asp) with divalent non-transition metal ions of group (II) and characterized by elemental analysis and spectroscopic measurements (infrared, electronic, 1H NMR, Raman, X-ray powder diffraction and scanning electron microscopy). Elemental analysis of the chelates suggests the stoichiometry is 1:2 (metal:ligand). Infrared spectra of the complexes agree with the coordination to the central metal atom through three donation sites of two oxygen atoms of bridge bidentate carboxylate group and oxygen atom of sbnd Cdbnd O of acetyl group. Infrared spectra coupled with the results of elemental analyzes suggested a distorted octahedral structure for the M(II) aspirinate complexes. Gamma irradiation was tested as a method for stabilization of aspirin as well as their complexes. The effect of gamma irradiation, with dose of 80 Gy, on the properties of aspirinate complexes was studied. The aspirinate chelates have been screened for their in vitro antibacterial activity against four bacteria, gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two strains of fungus (Aspergillus flavus and Candida albicans). The metal chelates were shown to possess more antibacterial activity than the free aspirin chelate.

  3. Effects of alginate hydrogel cross-linking density on mechanical and biological behaviors for tissue engineering.

    Science.gov (United States)

    Jang, Jinah; Seol, Young-Joon; Kim, Hyeon Ji; Kundu, Joydip; Kim, Sung Won; Cho, Dong-Woo

    2014-09-01

    An effective cross-linking of alginate gel was made through reaction with calcium carbonate (CaCO3). We used human chondrocytes as a model cell to study the effects of cross-linking density. Three different pore size ranges of cross-linked alginate hydrogels were fabricated. The morphological, mechanical, and rheological properties of various alginate hydrogels were characterized and responses of biosynthesis of cells encapsulated in each gel to the variation in cross-linking density were investigated. Desired outer shape of structure was maintained when the alginate solution was cross-linked with the applied method. The properties of alginate hydrogel could be tailored through applying various concentrations of CaCO3. The rate of synthesized GAGs and collagens was significantly higher in human chondrocytes encapsulated in the smaller pore structure than that in the larger pore structure. The expression of chondrogenic markers, including collagen type II and aggrecan, was enhanced in the smaller pore structure. It was found that proper structural morphology is a critical factor to enhance the performance and tissue regeneration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Activation of chemical biological defense mechanisms and remission of vital oxidative injury by low dose radiation

    International Nuclear Information System (INIS)

    Yamaoka, K.; Nomura, T.; Kojima, S.

    2000-01-01

    Excessive active oxygen produced in vivo by various causes is toxic. Accumulation of oxidation injuries due to excessive active causes cell and tissue injuries, inducing various pathologic conditions such as aging and carcinogenesis. On the other hand, there are chemical defense mechanisms in the body that eliminate active oxygen or repair damaged molecules, defending against resultant injury. It is interesting reports that appropriate oxidation stress activate the chemical biological defense mechanisms. In this study, to elucidate these phenomena and its mechanism by low dose radiation, we studied on the below subjects. Activation of chemical biological defense mechanisms by low dose radiation: (1) The effects radiation on lipid peroxide (LPO) levels in the organs, membrane fluidity and the superoxide dismutase (SOD) activity were examined in rats and rabbits. Rats were irradiated with low dose X-ray over their entire bodies, and rabbits inhaled vaporized radon spring water, which primarily emitted α-ray. The following results were obtained. Unlike high dose X-ray, low dose X-ray and radon inhalation both reduced LPO levels and made the state of the SH-group on membrane-bound proteins closer to that of juvenile animals, although the sensitivity to radioactivity varied depending on the age of the animals and among different organs and tissues. The SOD activity was elevated, suggesting that low dose X-ray and radon both activate the host defensive function. Those changes were particularly marked in the organs related to immune functions of the animals which received low dose X-ray, while they were particularly marked in the brain after radon inhalation. It was also found that those changes continued for longer periods after low dose X-irradiation. (2) Since SOD is an enzyme that mediates the dismutation of O 2 - to H 2 O 2 , the question as to whether the resultant H 2 O 2 is further detoxicated into H 2 O and O 2 or not must still be evaluated. Hence, we studied

  5. Mechanical-biological waste treatment and the associated occupational hygiene in Finland

    International Nuclear Information System (INIS)

    Tolvanen, Outi K.; Haenninen, Kari I.

    2006-01-01

    A special feature of waste management in Finland has been the emphasis on the source separation of kitchen biowaste (catering waste); more than two-thirds of the Finnish population participates in this separation. Source-separated biowaste is usually treated by composting. The biowaste of about 5% of the population is handled by mechanical-biological treatment. A waste treatment plant at Mustasaari is the only plant in Finland using digestion for kitchen biowaste. For the protection of their employees, the plant owners commissioned a study on environmental factors and occupational hygiene in the plant area. During 1998-2000 the concentrations of dust, microbes and endotoxins and noise levels were investigated to identify possible problems at the plant. Three different work areas were investigated: the pre-processing and crushing hall, the bioreactor hall and the drying hall. Employees were asked about work-related health problems. Some problems with occupational hygiene were identified: concentrations of microbes and endotoxins may increase to levels harmful to health during waste crushing and in the bioreactor hall. Because employees complained of symptoms such as dry cough and rash or itching appearing once or twice a month, it is advisable to use respirator masks (class P3) during dusty working phases. The noise level in the drying hall exceeded the Finnish threshold value of 85 dBA. Qualitatively harmful factors for the health of employees are similar in all closed waste treatment plants in Finland. Quantitatively, however, the situation at the Mustasaari treatment plant is better than at some Finnish dry waste treatment plants. Therefore is reasonable to conclude that mechanical sorting, which produces a dry waste fraction for combustion and a biowaste fraction for anaerobic treatment, is in terms of occupational hygiene better for employees than combined aerobic treatment and dry waste treatment

  6. Formation of organizational and economic mechanism of rational use of aquatic biological resources

    Directory of Open Access Journals (Sweden)

    Stolbov A. G.

    2017-09-01

    Full Text Available The state of fisheries has been researched based on a systematic approach and comprehensive analysis of statistical data, the following issues have been characterized: the catch of aquatic biological resources (ABR, consumption of fish products, problems in the development of the fishing industry (fleet aging, lack of innovative technologies, the proliferation of IUU fishing4 , the high level of retail prices for fish, low degree of processing export products, overshoot "improper objects" of fishing, the gap in aquaculture development, low economic efficiency. To improve the quality of fishery management it has been proposed to form the organizational and economic mechanism of ABR rational use, which should include effective tools for the implementation of management decisions. Instead of the so-called "historical" principle it has been suggested to use the investment principle of quota allocation and rental payments. The basis for management of fishing industry should be scientifically based on the bioeconomic concept of ABR rational use, the essence of which is to preserve the ABR and at the same time to obtain the maximum output of finished products with high added value. To form the organizational and economic mechanism it is necessary to develop a programme of innovative development of the fisheries sector, a calendar programme of upgrading of fishing fleet, wellreasoned differential rates of rent payments for the ABR use, scenarios and graphic organization of work of fishing vessels in specific fishing areas, to form regional financial and industrial clusters, to expand the authority of the Fisheries Agency, to improve corporate social responsibility of the fishing business communities. Modernization of management system for ABR rational use can significantly reduce environmental pollution, ensure the effective delivery of catch to shore, their high-quality processing and the needs of the population in fish products.

  7. Integrated structural biology to unravel molecular mechanisms of protein-RNA recognition.

    Science.gov (United States)

    Schlundt, Andreas; Tants, Jan-Niklas; Sattler, Michael

    2017-04-15

    Recent advances in RNA sequencing technologies have greatly expanded our knowledge of the RNA landscape in cells, often with spatiotemporal resolution. These techniques identified many new (often non-coding) RNA molecules. Large-scale studies have also discovered novel RNA binding proteins (RBPs), which exhibit single or multiple RNA binding domains (RBDs) for recognition of specific sequence or structured motifs in RNA. Starting from these large-scale approaches it is crucial to unravel the molecular principles of protein-RNA recognition in ribonucleoprotein complexes (RNPs) to understand the underlying mechanisms of gene regulation. Structural biology and biophysical studies at highest possible resolution are key to elucidate molecular mechanisms of RNA recognition by RBPs and how conformational dynamics, weak interactions and cooperative binding contribute to the formation of specific, context-dependent RNPs. While large compact RNPs can be well studied by X-ray crystallography and cryo-EM, analysis of dynamics and weak interaction necessitates the use of solution methods to capture these properties. Here, we illustrate methods to study the structure and conformational dynamics of protein-RNA complexes in solution starting from the identification of interaction partners in a given RNP. Biophysical and biochemical techniques support the characterization of a protein-RNA complex and identify regions relevant in structural analysis. Nuclear magnetic resonance (NMR) is a powerful tool to gain information on folding, stability and dynamics of RNAs and characterize RNPs in solution. It provides crucial information that is complementary to the static pictures derived from other techniques. NMR can be readily combined with other solution techniques, such as small angle X-ray and/or neutron scattering (SAXS/SANS), electron paramagnetic resonance (EPR), and Förster resonance energy transfer (FRET), which provide information about overall shapes, internal domain

  8. Current antiviral drugs and their analysis in biological materials - Part II: Antivirals against hepatitis and HIV viruses.

    Science.gov (United States)

    Nováková, Lucie; Pavlík, Jakub; Chrenková, Lucia; Martinec, Ondřej; Červený, Lukáš

    2018-01-05

    This review is a Part II of the series aiming to provide comprehensive overview of currently used antiviral drugs and to show modern approaches to their analysis. While in the Part I antivirals against herpes viruses and antivirals against respiratory viruses were addressed, this part concerns antivirals against hepatitis viruses (B and C) and human immunodeficiency virus (HIV). Many novel antivirals against hepatitis C virus (HCV) and HIV have been introduced into the clinical practice over the last decade. The recent broadening portfolio of these groups of antivirals is reflected in increasing number of developed analytical methods required to meet the needs of clinical terrain. Part II summarizes the mechanisms of action of antivirals against hepatitis B virus (HBV), HCV, and HIV, their use in clinical practice, and analytical methods for individual classes. It also provides expert opinion on state of art in the field of bioanalysis of these drugs. Analytical methods reflect novelty of these chemical structures and use by far the most current approaches, such as simple and high-throughput sample preparation and fast separation, often by means of UHPLC-MS/MS. Proper method validation based on requirements of bioanalytical guidelines is an inherent part of the developed methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Chemically induced aneuploidy in mammalian cells: mechanisms and biological significance in cancer

    Energy Technology Data Exchange (ETDEWEB)

    Oshimura, M.; Barrett, J.C.

    1986-01-01

    A literature review with over 200 references examines the growing body of evidence from human and animal cancer cytogenetics that aneuploidy is an important chromosome change in carcinogenesis. Evidence from in vitro cell transformation studies supports the idea that aneuploidy has a direct effect on the conversion of a normal cell to a preneoplastic or malignant cell. Induction of an aneuploid state in a preneoplastic or neoplastic cell could have any of the following four biological effects: a change in gene dosage, a change in gene balance, expression of a recessive mutation, or a change in genetic instability (which could secondarily lead to neoplasia). There are a number of possible mechanisms by which chemicals might induce aneuploidy, including effects on microtubules, damage to essential elements for chromosome function reduction in chromosome condensation or pairing, induction of chromosome interchanges, unresolved recombination structures, increased chromosome stickiness, damage to centrioles, impairment of chromosome alignment ionic alterations during mitosis, damage to the nuclear membrane, and a physical disruption of chromosome segregation. Therefore, a number of different targets exist for chemically induced aneuploidy.

  10. Carbon source recovery from excess sludge by mechanical disintegration for biological denitrification.

    Science.gov (United States)

    Zubrowska-Sudol, M

    2018-04-01

    The goal of the study was to evaluate the possibility of carbon source recovery from excess sludge by mechanical disintegration for biological denitrification. The total efficiency of denitrification, unit demand for organic compounds for denitrification, unit volume of disintegrated sludge and unit cost of nitrogen removal as a function of energy density used for excess sludge disintegration (70, 140 and 210 kJ/L) were analyzed. In the study a full-scale disc disintegrator was used (motor power: 30 kWh, motor speed: 2,950 rpm). It was shown that the amounts of organic compounds released from the activated sludge flocs at all tested levels of energy density are high enough to be used to intensify the removal of nitrogen compounds from wastewater. It was also documented that the energy density provided during process of disintegration was an important factor determining the characteristics of organic compounds obtained under the disintegration for their use in order to intensify the process of denitrification. The highest value of total efficiency of denitrification (50.5 ± 3.1 mg N/L) was obtained for carbon source recovery from excess sludge at 70 kJ/L, but the lowest unit cost of nitrogen removal occurred for 140 kJ/L (0.0019 ± 0.0011 EUR/g N).

  11. Stress biology and aging mechanisms: toward understanding the deep connection between adaptation to stress and longevity.

    Science.gov (United States)

    Epel, Elissa S; Lithgow, Gordon J

    2014-06-01

    The rate of biological aging is modulated in part by genes interacting with stressor exposures. Basic research has shown that exposure to short-term stress can strengthen cellular responses to stress ("hormetic stress"). Hormetic stress promotes longevity in part through enhanced activity of molecular chaperones and other defense mechanisms. In contrast, prolonged exposure to stress can overwhelm compensatory responses ("toxic stress") and shorten lifespan. One key question is whether the stressors that are well understood in basic models of aging can help us understand psychological stressors and human health. The psychological stress response promotes regulatory changes important in aging (e.g., increases in stress hormones, inflammation, oxidative stress, insulin). The negative effects of severe stress are well documented in humans. Potential positive effects of acute stress (stress resistance) are less studied, especially at the cellular level. Can stress resistance slow the rate of aging in humans, as it does in model organisms? If so, how can we promote stress resistance in humans? We urge a new research agenda embracing the continuum from cellular stress to psychological stress, using basic and human research in tandem. This will require interdisciplinary novel approaches that hold much promise for understanding and intervening in human chronic disease. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Water regime of mechanical-biological pretreated waste materials under fast-growing trees.

    Science.gov (United States)

    Rüth, Björn; Lennartz, Bernd; Kahle, Petra

    2007-10-01

    In this study mechanical-biological pre-treated waste material (MBP) was tested for suitability to serve as an alternative surface layer in combination with fast-growing and water-consumptive trees for final covers at landfill sites. The aim was to quantify evapotranspiration and seepage losses by numerical model simulations for two sites in Germany. In addition, the leaf area index (LAI) of six tree species over the growing season as the driving parameter for transpiration calculations was determined experimentally. The maximum LAI varied between 3.8 and 6.1 m2 m(-2) for poplar and willow clones, respectively. The evapotranspiration calculations revealed that the use of MBP waste material for re-cultivation enhanced evapotranspiration by 40 mm year(-1) (10%) over an 11 year calculation period compared to a standard mineral soil. Between 82% (for LAI(max) = 3.8) and 87% (for LAI(max) = 6.1) of the average annual precipitation (506 mm) could be retained from the surface layer assuming eastern German climate conditions, compared with a retention efficiency between 79 and 82% for a mineral soil. Although a MBP layer in conjunction with water-consumptive trees can reduce vertical water losses as compared to mineral substrates, the effect is not sufficient to meet legal regulations.

  13. Constraints on Biological Mechanism from Disease Comorbidity Using Electronic Medical Records and Database of Genetic Variants.

    Directory of Open Access Journals (Sweden)

    Steven C Bagley

    2016-04-01

    Full Text Available Patterns of disease co-occurrence that deviate from statistical independence may represent important constraints on biological mechanism, which sometimes can be explained by shared genetics. In this work we study the relationship between disease co-occurrence and commonly shared genetic architecture of disease. Records of pairs of diseases were combined from two different electronic medical systems (Columbia, Stanford, and compared to a large database of published disease-associated genetic variants (VARIMED; data on 35 disorders were available across all three sources, which include medical records for over 1.2 million patients and variants from over 17,000 publications. Based on the sources in which they appeared, disease pairs were categorized as having predominant clinical, genetic, or both kinds of manifestations. Confounding effects of age on disease incidence were controlled for by only comparing diseases when they fall in the same cluster of similarly shaped incidence patterns. We find that disease pairs that are overrepresented in both electronic medical record systems and in VARIMED come from two main disease classes, autoimmune and neuropsychiatric. We furthermore identify specific genes that are shared within these disease groups.

  14. Epigenetic Mechanisms Shape the Biological Response to Trauma and Risk for PTSD: A Critical Review

    Directory of Open Access Journals (Sweden)

    Morgan Heinzelmann

    2013-01-01

    Full Text Available Posttraumatic stress disorder (PTSD develops in approximately one-quarter of trauma-exposed individuals, leading us and others to question the mechanisms underlying this heterogeneous response to trauma. We suggest that the reasons for the heterogeneity relate to a complex interaction between genes and the environment, shaping each individual’s recovery trajectory based on both historical and trauma-specific variables. Epigenetic modifications provide a unique opportunity to elucidate how preexisting risk factors may contribute to PTSD risk through changes in the methylation of DNA. Preexisting risks for PTSD, including depression, stress, and trauma, result in differential DNA methylation of endocrine genes, which may then result in a different biological responses to trauma and subsequently a greater risk for PTSD onset. Although these relationships are complex and currently inadequately described, we provide a critical review of recent studies to examine how differences in genetic and proteomic biomarkers shape an individual’s vulnerability to PTSD development, thereby contributing to a heterogeneous response to trauma.

  15. Quinoxaline 1, 4-di-N-oxides: Biological activities and mechanisms of actions

    Directory of Open Access Journals (Sweden)

    Guyue eCheng

    2016-03-01

    Full Text Available Quinoxaline 1, 4-di-N-oxides (QdNOs have manifold biological properties, including antimicrobial, antitumoral, antitrypanosomal and antiinflammatory/antioxidant activities. These diverse activities endow them broad applications and prospects in human and veterinary medicines. As QdNOs arouse widespread interest, the evaluation of their medicinal chemistry is still in progress. In the meantime, adverse effects have been reported in some of the QdNO derivatives. For example, genotoxicity and bacterial resistance have been found in QdNO antibacterial growth promoters, conferring urgent need for discovery of new QdNO drugs. However, the modes of actions of QdNOs are not fully understood, hindering the development and innovation of these promising compounds. Here, QdNOs are categorized based on the activities and usages, among which the antimicrobial activities are consist of antibacterial, antimycobacterial and anticandida activities, and the antiprotozoal activities include antitrypanosomal, antimalarial, antitrichomonas and antiamoebic activities. The structure-activity relationship and the mode of actions of each type of activity of QdNOs are summarized, and the toxicity and the underlying mechanisms are also discussed, providing insight for the future research and development of these fascinating compounds.

  16. Physical Activity and Gastrointestinal Cancers: Primary and Tertiary Preventive Effects and Possible Biological Mechanisms

    Directory of Open Access Journals (Sweden)

    Karen Steindorf

    2015-07-01

    Full Text Available Gastrointestinal cancers account for 37% of all cancer deaths worldwide, underlining the need to further investigate modifiable factors for gastrointestinal cancer risk and prognosis. This review summarizes the corresponding evidence for physical activity (PA, including, briefly, possible biological mechanisms. Despite high public health relevance, there is still a scarcity of studies, especially for tertiary prevention. Besides the convincing evidence of beneficial effects of PA on colon cancer risk, clear risk reduction for gastroesophageal cancer was identified, as well as weak indications for pancreatic cancer. Inverse associations were observed for liver cancer, yet based on few studies. Only for rectal cancer, PA appeared to be not associated with cancer risk. With regard to cancer-specific mortality of the general population, published data were rare but indicated suggestive evidence of protective effects for colon and liver cancer, and to a lesser extent for rectal and gastroesophageal cancer. Studies in cancer patients on cancer-specific and total mortality were published for colorectal cancer only, providing good evidence of inverse associations with post-diagnosis PA. Overall, evidence of associations of PA with gastrointestinal cancer risk and progression is promising but still limited. However, the already available knowledge further underlines the importance of PA to combat cancer.

  17. Preparation and Biological Evaluation of Two Novel Platinum(II Complexes Based on the Ligands of Dipicolyamine Bisphosphonate Esters

    Directory of Open Access Journals (Sweden)

    Ling Qiu

    2016-02-01

    Full Text Available Two new platinum(II-based complexes bearing a bone-targeting group were synthesized and characterized. They both have excellent affinity for hydroxyapatite (HA, which is abundant in human bone tissues. Their antitumor activities against five human cancer cell lines (U2OS, A549, HCT116, MDA-MB-231 and HepG2 were evaluated and compared with cisplatin (CDDP. Though the antitumor efficacies of new complexes are lower than that of CDDP, they show higher selectivity against the HepG2 hepatoma cell line than the L02 normal liver cell line. Morphology studies exhibited typical characteristics of cell apoptosis and the cell cycle distribution analysis indicated that the complexes can inhibit cancer cells by inducing cell cycle arrest at the G2/M phase, a similar mechanism of action to CDDP.

  18. Structural elucidation of the hormonal inhibition mechanism of the bile acid cholate on human carbonic anhydrase II

    Energy Technology Data Exchange (ETDEWEB)

    Boone, Christopher D. [University of Florida, PO Box 100267, Gainesville, FL 32610 (United States); Tu, Chingkuang [University of Florida, PO Box 100245, Gainesville, FL 32610 (United States); McKenna, Robert, E-mail: rmckenna@ufl.edu [University of Florida, PO Box 100267, Gainesville, FL 32610 (United States)

    2014-06-01

    The structure of human carbonic anhydrase II in complex with cholate has been determined to 1.54 Å resolution. Elucidation of the novel inhibition mechanism of cholate will aid in the development of a nonsulfur-containing, isoform-specific therapeutic agent. The carbonic anhydrases (CAs) are a family of mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO{sub 2} into bicarbonate and a proton. Human isoform CA II (HCA II) is abundant in the surface epithelial cells of the gastric mucosa, where it serves an important role in cytoprotection through bicarbonate secretion. Physiological inhibition of HCA II via the bile acids contributes to mucosal injury in ulcerogenic conditions. This study details the weak biophysical interactions associated with the binding of a primary bile acid, cholate, to HCA II. The X-ray crystallographic structure determined to 1.54 Å resolution revealed that cholate does not make any direct hydrogen-bond interactions with HCA II, but instead reconfigures the well ordered water network within the active site to promote indirect binding to the enzyme. Structural knowledge of the binding interactions of this nonsulfur-containing inhibitor with HCA II could provide the template design for high-affinity, isoform-specific therapeutic agents for a variety of diseases/pathological states, including cancer, glaucoma, epilepsy and osteoporosis.

  19. The mechanisms behind decreased internalization of angiotensin II type 1 receptor.

    Science.gov (United States)

    Bian, Jingwei; Zhang, Suli; Yi, Ming; Yue, Mingming; Liu, Huirong

    2018-04-01

    The internalization of angiotensin II type 1 receptor (AT 1 R) plays an important role in maintaining cardiovascular homeostasis. Decreased receptor internalization is closely related to cardiovascular diseases induced by the abnormal activation of AT 1 R, such as hypertension. However, the mechanism behind reduced AT 1 R internalization is not fully understood. This review focuses on four parts of the receptor internalization process (the combination of agonists and receptors, receptor phosphorylation, endocytosis, and recycling) and summarizes the possible mechanisms by which AT 1 R internalization is reduced based on these four parts of the process. (1) The agonist has a large molecular weight or a stronger ability to hydrolyze phosphatidylinositol 4,5-bisphosphate (PtdIns (4,5) P 2 ), which can increase the consumption of PtdIns (4,5) P 2 . (2) AT 1 R phosphorylation is weakened because of an abnormal function of phosphorylated kinase or changes in phospho-barcoding and GPCR-β-arrestin complex conformation. (3) The abnormal formation of vesicles or AT 1 R heterodimers with fewer endocytic receptors results in less AT 1 R endocytosis. (4) The enhanced activity and upregulated expression of small GTP-binding protein 4 (Rab4) and 11 (Rab11), which regulate receptor recycling, and phosphatidylinositol 3-kinase increase AT 1 R recycling. In addition, lower expression of AT 1 R-associated protein (ATRAP) or higher expression of AT 1 R-associated protein 1 (ARAP1) can reduce receptor internalization. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Voltage from mechanical stress in type-II superconductors: Depinning of the magnetic flux by moving dislocations

    OpenAIRE

    Albert, Jaroslav; Chudnovsky, Eugene M.

    2008-01-01

    Mechanical stress causes motion of defects in solids. We show that in a type-II superconductor a moving dislocation generates a pattern of current that exerts the depinning force on the surrounding vortex lattice. Concentration of dislocations and the mechanical stress needed to produce critical depinning currents are shown to be within practical range. When external magnetic field and transport current are present this effect generates voltage across the superconductor. Thus a superconductor...

  1. Mechanism and efficiency of cell death of type II photosensitizers: effect of zinc chelation.

    Science.gov (United States)

    Pavani, Christiane; Iamamoto, Yassuko; Baptista, Maurício S

    2012-01-01

    A series of meso-substituted tetra-cationic porphyrins, which have methyl and octyl substituents, was studied in order to understand the effect of zinc chelation and photosensitizer subcellular localization in the mechanism of cell death. Zinc chelation does not change the photophysical properties of the photosensitizers (all molecules studied are type II photosensitizers) but affects considerably the interaction of the porphyrins with membranes, reducing mitochondrial accumulation. The total amount of intracellular reactive species induced by treating cells with photosensitizer and light is similar for zinc-chelated and free-base porphyrins that have the same alkyl substituent. Zinc-chelated porphyrins, which are poorly accumulated in mitochondria, show higher efficiency of cell death with features of apoptosis (higher MTT response compared with trypan blue staining, specific acridine orange/ethidium bromide staining, loss of mitochondrial transmembrane potential, stronger cytochrome c release and larger sub-G1 cell population), whereas nonchelated porphyrins, which are considerably more concentrated in mitochondria, triggered mainly necrotic cell death. We hypothesized that zinc-chelation protects the photoinduced properties of the porphyrins in the mitochondrial environment. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  2. AN INTEGRATIVE WAY OF TEACHING MOLECULAR CELL BIOLOGY AND PROTEIN CHEMISTRY USING ACTIN IMMOBILIZATION ON CHITIN FOR PURIFYING MYOSIN II.

    Directory of Open Access Journals (Sweden)

    M.G. Souza

    2007-05-01

    Full Text Available Our intent is to present our experience on teaching Molecular Cell Biology andProtein Chemistry at UNIRIO through an innovative approach that includes myosin IIextraction and purification. We took advantage of the properties of muscle contractionand propose a simple method for purifying myosin II by affinity chromatography. Thisoriginal method is based on the preparation of an affinity column containing actinmolecules covalently bound to chitin particles. We propose a three-week syllabus thatincludes lectures and bench experimental work. The syllabus favors the activelearning of protein extraction and purification, as well as, of scientific concepts suchas muscle contraction, cytoskeleton structure and its importance for the living cell. Italso promotes the learning of the biotechnological applications of chitin and theapplications of protein immobilization in different industrial fields. Furthermore, theactivities also target the development of laboratorial technical abilities, thedevelopment of problem solving skills and the ability to write up a scientific reportfollowing the model of a scientific article. It is very important to mention that thissyllabus can be used even in places where a facility such as ultra-centrifugation islacking.

  3. Formation of the vertical heterogeneity in the Lake Shira ecosystem: the biological mechanisms and the mathematical model

    NARCIS (Netherlands)

    Degermendzhy, A.G.; Belolipetsky, V.M.; Zotina, T.A.; Gulati, R.D.

    2002-01-01

    Data on the seasonal changes in vertical heterogeneity of the physical-chemical and biological parameters of the thermally stratified Shira Lake ecosystem (Khakasia, Siberia) in 1996–2000 have been analyzed. The interaction mechanisms involving: (1) The plankton populations in aerobic and anaerobic

  4. Selective recovery of Pd(II) from extremely acidic solution using ion-imprinted chitosan fiber: Adsorption performance and mechanisms

    International Nuclear Information System (INIS)

    Lin, Shuo; Wei, Wei; Wu, Xiaohui; Zhou, Tao; Mao, Juan; Yun, Yeoung-Sang

    2015-01-01

    Highlights: • An acid-resisting chitosan fiber was prepared by ion-imprinting technique. • Pd(II) and ECH were as template and two-step crosslinking agent, respectively. • IIF showed a good adsorption and selectivity performance on Pd(II) solutions. • Selectivity was due to the electrostatic attraction between −NH_3"+ and [PdCl_4]"2"−. • Stable sorption/desorption performance shows a potential in further application. - Abstract: A novel, selective and acid-resisting chitosan fiber adsorbent was prepared by the ion-imprinting technique using Pd(II) and epichlorohydrin as the template and two-step crosslinking agent, respectively. The resulting ion-imprinted chitosan fibers (IIF) were used to selectively adsorb Pd(II) under extremely acidic synthetic metal solutions. The adsorption and selectivity performances of IIF including kinetics, isotherms, pH effects, and regeneration were investigated. Pd(II) rapidly adsorbed on the IIF within 100 min, achieving the adsorption equilibrium. The isotherm results showed that the maximum Pd(II) uptake on the IIF was maintained as 324.6–326.4 mg g"−"1 in solutions containing single and multiple metals, whereas the Pd(II) uptake on non-imprinted fibers (NIF) decreased from 313.7 to 235.3 mg g"−"1 in solution containing multiple metals. Higher selectivity coefficients values were obtained from the adsorption on the IIF, indicating a better Pd(II) selectivity. The amine group, supposedly the predominant adsorption site for Pd(II), was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The pH value played a significant role on the mechanism of the selective adsorption in the extremely acidic conditions. Furthermore, the stabilized performance for three cycles of sorption/desorption shows a potential for further large-scale applications.

  5. Selective recovery of Pd(II) from extremely acidic solution using ion-imprinted chitosan fiber: Adsorption performance and mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shuo [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Wei, Wei [School of Chemical Engineering, Chonbuk National University, Jeonbuk 561-756 (Korea, Republic of); Wu, Xiaohui; Zhou, Tao [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Mao, Juan, E-mail: monicamao45@hust.edu.cn [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Yun, Yeoung-Sang, E-mail: ysyun@jbnu.ac.kr [School of Chemical Engineering, Chonbuk National University, Jeonbuk 561-756 (Korea, Republic of)

    2015-12-15

    Highlights: • An acid-resisting chitosan fiber was prepared by ion-imprinting technique. • Pd(II) and ECH were as template and two-step crosslinking agent, respectively. • IIF showed a good adsorption and selectivity performance on Pd(II) solutions. • Selectivity was due to the electrostatic attraction between −NH{sub 3}{sup +} and [PdCl{sub 4}]{sup 2−}. • Stable sorption/desorption performance shows a potential in further application. - Abstract: A novel, selective and acid-resisting chitosan fiber adsorbent was prepared by the ion-imprinting technique using Pd(II) and epichlorohydrin as the template and two-step crosslinking agent, respectively. The resulting ion-imprinted chitosan fibers (IIF) were used to selectively adsorb Pd(II) under extremely acidic synthetic metal solutions. The adsorption and selectivity performances of IIF including kinetics, isotherms, pH effects, and regeneration were investigated. Pd(II) rapidly adsorbed on the IIF within 100 min, achieving the adsorption equilibrium. The isotherm results showed that the maximum Pd(II) uptake on the IIF was maintained as 324.6–326.4 mg g{sup −1} in solutions containing single and multiple metals, whereas the Pd(II) uptake on non-imprinted fibers (NIF) decreased from 313.7 to 235.3 mg g{sup −1} in solution containing multiple metals. Higher selectivity coefficients values were obtained from the adsorption on the IIF, indicating a better Pd(II) selectivity. The amine group, supposedly the predominant adsorption site for Pd(II), was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The pH value played a significant role on the mechanism of the selective adsorption in the extremely acidic conditions. Furthermore, the stabilized performance for three cycles of sorption/desorption shows a potential for further large-scale applications.

  6. Earth mechanisms (fluid and solid), life mechanisms and stable isotope tracers. Isotopes and biology, a great project

    International Nuclear Information System (INIS)

    Fromageot, P.

    1997-01-01

    Historical and recent review of the development and use of radioactive isotopes for biological studies in France: study of the intermediate metabolism with 14 C tracers in organic molecules; study and biosynthesis of macromolecules (DNA, RNA and polynucleotides) through the use of marked nucleotides; tracer proteins for use in NMR and protein engineering, use of tritium for the study of hormonal regulation

  7. Space radiation-induced bystander effect: kinetics of biologic responses, mechanisms, and significance of secondary radiations

    International Nuclear Information System (INIS)

    Gonon, Geraldine

    2011-01-01

    Widespread evidence indicates that exposure of cell cultures to a particles results in significant biological changes in both the irradiated and non-irradiated bystander cells in the population. The induction of non-targeted biological responses in cell cultures exposed to low fluences of high charge (Z) and high energy (E) particles is relevant to estimates of the health risks of space radiation and to radiotherapy. Here, we investigated the mechanisms underlying the induction of stressful effects in confluent normal human fibroblast cultures exposed to low fluences of 1000 MeV/u iron ions (linear energy transfer (LET) 151 keV/μm), 600 MeV/u silicon ions (LET 50 keV/μm) or 290 MeV/u carbon ions (LET 13 keV/μm). We compared the results with those obtained in cell cultures exposed, in parallel, to low fluences of 0.92 MeV/u a particles (LET 109 keV/μm). Induction of DNA damage, changes in gene expression, protein carbonylation and lipid peroxidation during 24 h after exposure of confluent cultures to mean doses as low as 0.2 cGy of iron or silicon ions strongly supported the propagation of stressful effects from irradiated to bystander cells. At a mean dose of 0.2 cGy, only 1 and 3 % of the cells would be targeted through the nucleus by an iron or silicon ion, respectively. Within 24 h post-irradiation, immunoblot analyses revealed significant increases in the levels of phospho-TP53 (serine 15), p21Waf1 (also known as CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation. The magnitude of the responses suggested participation of non-targeted cells in the response. Furthermore, when the irradiated cell populations were subcultured in fresh medium shortly after irradiation, greater than expected increases in the levels of these markers were also observed during 24 h. Together, the results imply a rapidly propagated and persistent bystander effect. In situ analyses in confluent cultures showed 53BP1 foci formation, a marker of DNA damage, in

  8. Clinical indications and biological mechanisms of splenic irradiation in autoimmune diseases

    International Nuclear Information System (INIS)

    Weinmann, M.; Becker, G.; Einsele, H.; Bamberg, M.

    2001-01-01

    Background: Splenic irradiation (SI) is a fairly unknown treatment modality in autoimmune disorders like autoimmune thrombocytopenia (AIT) or autoimmune hemolytic anemia (AIHA), which may provide an effective, low toxic and cost-effective treatment for selected patients. Patients, Materials and Methods: This article reviews the limited experiences on splenic irradiation in autoimmune thrombocytopenia by analyzing the current studies including 71 patients and some preliminary reports on splenic irradiation in autoimmune hemolytic anemia. Results: In autoimmune thrombocytopenia between 40 and 90% of all patients responded, but most of them relapsed within 4 to 6 months after splenic irradiation. Between 10 and 20% of all patients had a sustained response. The efficacy of splenic irradiation in HIV-associated cases of thrombocytopenia is probably lower than in other forms of autoimmune thrombocytopenia, but especially in this group immunosuppressive drug treatment of autoimmune thrombocytopenia exposes some problems. In autoimmune hemolytic anemia there are some case reports about efficacy of splenic irradiation. Toxicity of splenic irradiation in both diseases was very moderate. Conclusions: For HIV patients, for elderly patients or patients at high risk for complications following splenectomy splenic irradiation might be a treatment option. Splenic irradiation as preoperative treatment in patients not responding to or not suitable for immunosuppressive drugs prior to splenectomy may be a promising new application of splenic irradiation to reduce adverse effects of splenectomy in thrombocytopenic patients. A further analysis of the biological mechanisms underlying splenic irradiation may help to improve patient selection, to optimize dose concepts and treatment schedules and will improve understanding of radiotherapy as an immunomodulatory treatment modality. (orig.) [de

  9. ASTEROSEISMOLOGY OF THE NEARBY SN II PROGENITOR RIGEL. II. {epsilon}-MECHANISM TRIGGERING GRAVITY-MODE PULSATIONS?

    Energy Technology Data Exchange (ETDEWEB)

    Moravveji, Ehsan [Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Moya, Andres [Departamento de Astrofisica, Centro de Astrobiologia (INTA-CSIC), P.O. Box 78, 28691 Villanueva de la Canada, Madrid (Spain); Guinan, Edward F., E-mail: moravveji@iasbs.ac.ir [Department of Astronomy, Villanova University, 800 Lancaster Avenue, Villanova, PA (United States)

    2012-04-10

    The cores of luminous B- and A-type (BA) supergiant stars are the seeds of later core-collapse supernovae. Thus, constraining the near-core conditions in this class of stars can place tighter constraints on the size, mass, and chemical composition of supernova remnants. Asteroseismology of these massive stars is one possible approach into such investigations. Recently, Moravveji et al. in 2012 (hereafter Paper I) extracted 19 significant frequencies from a 6-year radial velocity monitoring of Rigel ({beta} Ori, B8 Ia). The periods they determined broadly range from 1.22 to 74.74 days. Based on our differentially rotating stellar structure and evolution model, Rigel, at its current evolutionary state, is undergoing core He burning and shell H burning. Linear fully non-adiabatic non-radial stability analyses result in the excitation of a dense spectrum of non-radial gravity-dominated mixed modes. The fundamental radial mode (l = 0) and its overtones are all stable. When the hydrogen-burning shell is located even partially in the radiative zone, a favorable condition for destabilization of g-modes through the so-called {epsilon}-mechanism becomes viable. Only those g-modes that have high relative amplitudes in the hydrogen-burning (radiative) zone can survive the strong radiative damping. From the entire observed range of variability periods of Rigel (found in Paper I), and based on our model, only those modes with periods ranging between 21 and 127 days can be theoretically explained by the {epsilon}-mechanism. The origin of the short-period variations (found in Paper I) still remains unexplained. Because Rigel is similar to other massive BA supergiants, we believe that the {epsilon}-mechanism may be able to explain the long-period variations in {alpha} Cygni class of pulsating stars.

  10. Radiochemistry - Applications in the study of radical mechanisms of biological interest

    International Nuclear Information System (INIS)

    Foos, Jacques

    1982-01-01

    In biology, oxygen reducing processes give rise to the formation of intermediate radicals. One of the major breakthroughs of radiation chemistry of aqueous solutions is the identification of these compounds. The author describes the techniques used to study the reaction of these radicals (of radiolytic origin) with biological molecules [fr

  11. An alternative bactericidal mechanism of action for lantibiotic peptides that target lipid II

    NARCIS (Netherlands)

    Hasper, Hester E.; Kramer, Naomi E.; Smith, James L.; Hillman, J. D.; Zachariah, Cherian; Kuipers, Oscar P.; de Kruijff, Ben; Breukink, Eefjan

    2006-01-01

    Lantibiotics are polycyclic peptides containing unusual amino acids, which have binding specificity for bacterial cells, targeting the bacterial cell wall component lipid II to form pores and thereby lyse the cells. Yet several members of these lipid II - targeted lantibiotics are too short to be

  12. Emerging systems biology approaches in nanotoxicology: Towards a mechanism-based understanding of nanomaterial hazard and risk

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Pedro M.; Fadeel, Bengt, E-mail: Bengt.Fadeel@ki.se

    2016-05-15

    Engineered nanomaterials are being developed for a variety of technological applications. However, the increasing use of nanomaterials in society has led to concerns about their potential adverse effects on human health and the environment. During the first decade of nanotoxicological research, the realization has emerged that effective risk assessment of the multitudes of new nanomaterials would benefit from a comprehensive understanding of their toxicological mechanisms, which is difficult to achieve with traditional, low-throughput, single end-point oriented approaches. Therefore, systems biology approaches are being progressively applied within the nano(eco)toxicological sciences. This novel paradigm implies that the study of biological systems should be integrative resulting in quantitative and predictive models of nanomaterial behaviour in a biological system. To this end, global ‘omics’ approaches with which to assess changes in genes, proteins, metabolites, etc. are deployed allowing for computational modelling of the biological effects of nanomaterials. Here, we highlight omics and systems biology studies in nanotoxicology, aiming towards the implementation of a systems nanotoxicology and mechanism-based risk assessment of nanomaterials. - Highlights: • Systems nanotoxicology is a multi-disciplinary approach to quantitative modelling. • Transcriptomics, proteomics and metabolomics remain the most common methods. • Global “omics” techniques should be coupled to computational modelling approaches. • The discovery of nano-specific toxicity pathways and biomarkers is a prioritized goal. • Overall, experimental nanosafety research must endeavour reproducibility and relevance.

  13. Emerging systems biology approaches in nanotoxicology: Towards a mechanism-based understanding of nanomaterial hazard and risk

    International Nuclear Information System (INIS)

    Costa, Pedro M.; Fadeel, Bengt

    2016-01-01

    Engineered nanomaterials are being developed for a variety of technological applications. However, the increasing use of nanomaterials in society has led to concerns about their potential adverse effects on human health and the environment. During the first decade of nanotoxicological research, the realization has emerged that effective risk assessment of the multitudes of new nanomaterials would benefit from a comprehensive understanding of their toxicological mechanisms, which is difficult to achieve with traditional, low-throughput, single end-point oriented approaches. Therefore, systems biology approaches are being progressively applied within the nano(eco)toxicological sciences. This novel paradigm implies that the study of biological systems should be integrative resulting in quantitative and predictive models of nanomaterial behaviour in a biological system. To this end, global ‘omics’ approaches with which to assess changes in genes, proteins, metabolites, etc. are deployed allowing for computational modelling of the biological effects of nanomaterials. Here, we highlight omics and systems biology studies in nanotoxicology, aiming towards the implementation of a systems nanotoxicology and mechanism-based risk assessment of nanomaterials. - Highlights: • Systems nanotoxicology is a multi-disciplinary approach to quantitative modelling. • Transcriptomics, proteomics and metabolomics remain the most common methods. • Global “omics” techniques should be coupled to computational modelling approaches. • The discovery of nano-specific toxicity pathways and biomarkers is a prioritized goal. • Overall, experimental nanosafety research must endeavour reproducibility and relevance.

  14. The electrochemical performance and mechanism of cobalt (II) fluoride as anode material for lithium and sodium ion batteries

    International Nuclear Information System (INIS)

    Tan, Jinli; Liu, Li; Guo, Shengping; Hu, Hai; Yan, Zichao; Zhou, Qian; Huang, Zhifeng; Shu, Hongbo; Yang, Xiukang; Wang, Xianyou

    2015-01-01

    Highlights: •The as-prepared CoF 2 shows excellent electrochemical performance as anode material for lithium ion batteries. •The Li insertion/extraction mechanism of CoF 2 below 1.2 V was firstly proposed. •The electrochemical performance of CoF 2 as anode material in sodium ion batteries was firstly studied. -- Abstract: Cobalt (II) fluoride begins to enter into the horizons of people along with the research upsurge of metal fluorides. It is very significative and theoretically influential to make certain its electrochemical reaction mechanism. In this work, we discover a new and unrevealed reversible interfacial intercalation mechanism reacting below 1.2 V for cobalt (II) fluoride electrode material, which contributes a combined discharge capacity of about 400 mA h g −1 with the formation of SEI film at the initial discharge process. A highly reversible storage capacity of 120 mA h g −1 is observed when the cell is cycled over the voltage of 0.01-1.2 V at 0.2 C, and the low-potential voltage reaction process has a significant impact for the whole electrochemical process. Electrochemical analyses suggest that pure cobalt (II) fluoride shows better electrochemical performance when it is cycled at 3.2-0.01 V compared to the high range (1.0-4.5 V). So, we hold that cobalt (II) fluoride is more suitable to serve as anode material for lithium ion batteries. In addition, we also try to reveal the relevant performance and reaction mechanism, and realize the possibility of cobalt (II) fluoride as anode material for sodium ion batteries

  15. Tripodal chelating ligand-based sensor for selective determination of Zn(II) in biological and environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Singh, Ashok; Mehtab, Sameena; Singh, Udai P.; Aggarwal, Vaibhave [Indian Institute of Technology-Roorkee, Department of Chemistry, Roorkee (India)

    2007-08-15

    Potassium hydrotris(N-tert-butyl-2-thioimidazolyl)borate [KTt{sup t-Bu}] and potassium hydrotris(3-tert-butyl-5-isopropyl-l-pyrazolyl)borate [KTp{sup t-Bu,i-Pr}] have been synthesized and evaluated as ionophores for preparation of a poly(vinyl chloride) (PVC) membrane sensor for Zn(II) ions. The effect of different plasticizers, viz. benzyl acetate (BA), dioctyl phthalate (DOP), dibutyl phthalate (DBP), tributyl phosphate (TBP), and o-nitrophenyl octyl ether (o-NPOE), and the anion excluders sodium tetraphenylborate (NaTPB), potassium tetrakis(p-chlorophenyl)borate (KTpClPB), and oleic acid (OA) were studied to improve the performance of the membrane sensor. The best performance was obtained from a sensor with a of [KTt{sup t-Bu}] membrane of composition (mg): [KTt{sup t-Bu}] (15), PVC (150), DBP (275), and NaTPB (4). This sensor had a Nernstian response (slope, 29.4 {+-} 0.2 mV decade of activity) for Zn{sup 2+} ions over a wide concentration range (1.4 x 10{sup -7} to 1.0 x 10{sup -1} mol L{sup -1}) with a limit of detection of 9.5 x 10{sup -8} mol L{sup -1}. It had a relatively fast response time (12 s) and could be used for 3 months without substantial change of the potential. The membrane sensor had very good selectivity for Zn{sup 2+} ions over a wide variety of other cations and could be used in a working pH range of 3.5-7.8. The sensor was also found to work satisfactorily in partially non-aqueous media and could be successfully used for estimation of zinc at trace levels in biological and environmental samples. (orig.)

  16. Platinum(II/palladium(II complexes with n-propyldithiocarbamate and 2,2′-bipyridine: synthesis, characterization, biological activity and interaction with calf thymus DNA

    Directory of Open Access Journals (Sweden)

    Hassan Mansouri-Torshizi

    2014-12-01

    Full Text Available Two Pd(II and Pt(II complexes ([Pt(bpy(pr-dtc]Br and [Pd(bpy(pr-dtc]Br, where bpy=2, 2′-bipyridine and pr-dtc = n-propyldithiocarbamate were synthesized and characterized by elemental analysis (CHN, molar conductivity measurements, Fourier transform infrared, 1H nuclear magnetic resonance and UV–visible techniques. In these complexes, the dithiocarbamato ligand coordinates to Pt(II or Pd(II center as bidentate with two sulfur atoms. The binding of these complexes to calf thymus DNA (CT-DNA was investigated using various physicochemical methods such as spectrophotometric, spectrofluorometric and gel filtration technique. The experimental results indicate that Pt(II and Pd(II complexes interact with CT-DNA in the intercalative mode. Both complexes unexpectedly denatured DNA at low concentration. Gel filtration studies indicated that the binding of complexes with DNA is strong enough and does not break readily. The cytotoxic activity of these metal complexes has been tested against human cell tumor lines (K562 and revealed much lower 50% cytotoxic concentration (Cc50 less than that of cisplatin. Several binding and thermodynamic parameters are also described.

  17. Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

    Energy Technology Data Exchange (ETDEWEB)

    Cimpan, Ciprian, E-mail: cic@kbm.sdu.dk; Wenzel, Henrik

    2013-07-15

    Highlights: • Compared systems achieve primary energy savings between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste.} • Savings magnitude is foremost determined by chosen primary energy and materials production. • Energy consumption and process losses can be upset by increased technology efficiency. • Material recovery accounts for significant shares of primary energy savings. • Direct waste-to-energy is highly efficient if cogeneration (CHP) is possible. - Abstract: Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical–biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste}, in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3–9.5%, 1–18% and 1–8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat

  18. Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

    International Nuclear Information System (INIS)

    Cimpan, Ciprian; Wenzel, Henrik

    2013-01-01

    Highlights: • Compared systems achieve primary energy savings between 34 and 140 MJ primary /100 MJ input waste. • Savings magnitude is foremost determined by chosen primary energy and materials production. • Energy consumption and process losses can be upset by increased technology efficiency. • Material recovery accounts for significant shares of primary energy savings. • Direct waste-to-energy is highly efficient if cogeneration (CHP) is possible. - Abstract: Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical–biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJ primary /100 MJ input waste , in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3–9.5%, 1–18% and 1–8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat recovery, the biodrying MBS

  19. Study of the interaction mechanism in the biosorption of copper(II) ions onto posidonia oceanica and peat

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Marta; Marzal, Paula; Gabaldon, Carmen [Departamento de Ingenieria Quimica, Escuela Tecnica Superior de Ingenieria, Universitat de Valencia, Valencia (Spain); Silvetti, Margherita; Castaldi, Paola [Dipartimento di Scienze Ambientali e Agrarie e Biotecnologie Agro-Alimentari, Sez. Chimica Agraria ed Ambientale, University of Sassari, Sassari (Italy)

    2012-04-15

    A systematic approach was used to characterize the biosorption of copper(II) onto two biosorbents, Posidonia oceanica and peat, focusing on the interaction mechanisms, the copper(II) sorption-desorption process and the thermal behavior of the biosorbents. Sorption isotherms at pH 4-6 were obtained and the experimental data were fitted to the Langmuir model with a maximum uptake (q{sub max}) at pH 6 of 85.78 and 49.69 mg g{sup -1}, for P. oceanica and peat, respectively. A sequential desorption (SD) with water, Ca(NO{sub 3}){sub 2}, and EDTA was applied to copper-saturated biosorbents. Around 65-70% copper(II) were desorbed with EDTA, indicating that this heavy metal was strongly bound. The reversibility of copper(II) sorption was obtained by desorption with HCl and SD. Fourier transform IR spectroscopy (FTIR) analysis detected the presence of peaks associated with OH groups in aromatic and aliphatic structures, CH, CH{sub 2}, and CH{sub 3} in aliphatic structures, COO{sup -} and COOH groups and unsaturated aromatic structures on the surface of both biosorbents, as well as peaks corresponding to Si-O groups on the surface of peat. The results of SEM-EDX and FTIR analysis of copper-saturated samples demonstrated that ion exchange was one of the mechanisms involved in copper(II) retention. Thermal analysis of biosorbent samples showed that copper(II) sorption-desorption processes affected the thermal stability of the biosorbents. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Interpretation of biological and mechanical variations between the Lowry versus Bradford method for protein quantification

    OpenAIRE

    Tzong-Shi Lu; Szu-Yu Yiao; Kenneth Lim; Roderick V. Jensen; Li-Li Hsiao

    2010-01-01

    Background: The identification of differences in protein expression resulting from methodical variations is an essential component to the interpretation of true, biologically significant results. Aims: We used the Lowry and Bradford methods- two most commonly used methods for protein quantification, to assess whether differential protein expressions are a result of true biological or methodical variations. Material & Methods: Differential protein expression patterns was assessed by western bl...

  1. Keratin: Structure, mechanical properties, occurrence in biological organisms, and efforts at bioinspiration

    OpenAIRE

    Wang, B; Yang, W; McKittrick, J; Meyers, MA

    2016-01-01

    © 2015 Elsevier Ltd. A ubiquitous biological material, keratin represents a group of insoluble, usually high-sulfur content and filament-forming proteins, constituting the bulk of epidermal appendages such as hair, nails, claws, turtle scutes, horns, whale baleen, beaks, and feathers. These keratinous materials are formed by cells filled with keratin and are considered 'dead tissues'. Nevertheless, they are among the toughest biological materials, serving as a wide variety of interesting func...

  2. FEBEX II Project Final report on thermo-hydro-mechanical laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Lloret, A.; Romero, E.; Villar, M. V.

    2004-07-01

    The results of the thermo-hydro-mechanical (THM) study of the FEBEX bentonite performed during FEBEX II are presented. The laboratory test program continued in part with the works carried out during FEBEX I, particularly in activities related to tests aimed to the calibration of the models, the acquisition of parameters by back-analysis and the improvement of the knowledge on the behaviour of expansive clays. But the program has also included tests on new areas: investigations about the influence of the microstructure changes in bentonite, of temperature and of the solute concentration on the behaviour of clay. Besides, several tests were proposed in order to understand the unexpected behaviour observed in the mock-up test, towards the end of year 2. Temperature effects on water retention curves in confined and unconfined conditions were determined, and swelling pressure, hydraulic conductivity and swelling and consolidation strains as a function of temperature were successfully measured. Different experimental techniques and equipments were developed to study thermal induced changes under partially saturated states, covering a wide range of suctions. FEBEX bentonite remains suitable as a sealing material in HLW repositories (from the hydro- mechanical point of view) for temperatures of up to 80 C, as it keeps its high water retention capacity, low permeability and self-healing ability. The extrapolation of results points out to the preservation of properties for at least up to 100 C. Mercury intrusion porosimetry and environmental scanning electron microscopy provided promising results in order to characterise the bentonite microstructure and to give information about the mechanisms influencing pore size distribution changes on high active clays. The use of digital imaging techniques allowed verifying that at micro-scale level, where chemical phenomena prevail, strains are almost reversible as it is considered in the two-level elasto-plastic models. The swelling

  3. FEBEX II Project Final report on thermo-hydro-mechanical laboratory tests

    International Nuclear Information System (INIS)

    Lloret, A.; Romero, E.; Villar, M. V.

    2004-01-01

    The results of the thermo-hydro-mechanical (THM) study of the FEBEX bentonite performed during FEBEX II are presented. The laboratory test program continued in part with the works carried out during FEBEX I, particularly in activities related to tests aimed to the calibration of the models, the acquisition of parameters by back-analysis and the improvement of the knowledge on the behaviour of expansive clays. But the program has also included tests on new areas: investigations about the influence of the microstructure changes in bentonite, of temperature and of the solute concentration on the behaviour of clay. Besides, several tests were proposed in order to understand the unexpected behaviour observed in the mock-up test, towards the end of year 2. Temperature effects on water retention curves in confined and unconfined conditions were determined, and swelling pressure, hydraulic conductivity and swelling and consolidation strains as a function of temperature were successfully measured. Different experimental techniques and equipments were developed to study thermal induced changes under partially saturated states, covering a wide range of suctions. FEBEX bentonite remains suitable as a sealing material in HLW repositories (from the hydro- mechanical point of view) for temperatures of up to 80 C, as it keeps its high water retention capacity, low permeability and self-healing ability. The extrapolation of results points out to the preservation of properties for at least up to 100 C. Mercury intrusion porosimetry and environmental scanning electron microscopy provided promising results in order to characterise the bentonite microstructure and to give information about the mechanisms influencing pore size distribution changes on high active clays. The use of digital imaging techniques allowed verifying that at micro-scale level, where chemical phenomena prevail, strains are almost reversible as it is considered in the two-level elasto-plastic models. The swelling

  4. Fluorescent copper(II complexes: The electron transfer mechanism, interaction with bovine serum albumin (BSA and antibacterial activity

    Directory of Open Access Journals (Sweden)

    Madhumita Hazra

    2017-01-01

    Full Text Available Dinuclear copper(II complexes with formula [Cu2(L2(N32] (1 and [Cu2(L2(NCS2] (2 HL = (1-[(3-methyl-pyridine-2-ylimino-methyl]-naphthalen-2-ol were synthesized by controlling the molar ratio of Cu(OAC2·6H2O, HL, sodium azide (1 and ammonium thiocyanate (2. The end on bridges appear exclusively in azide and thiocyanate to copper complexes. The electron transfer mechanism of copper(II complexes is examined by cyclic voltammetry indicating copper(II complexes are Cu(II/Cu(I couple. The interactions of copper(II complexes towards bovine serum albumin (BSA were examined with the help of absorption and fluorescence spectroscopic tools. We report a superficial solution-based route for the synthesis of micro crystals of copper complexes with BSA. The antibacterial activity of the Schiff base and its copper complexes were investigated by the agar disc diffusion method against some species of pathogenic bacteria (Escherichia coli, Vibrio cholerae, Streptococcus pneumonia and Bacillus cereus. It has been observed that the antibacterial activity of all complexes is higher than the ligand.

  5. Leptin Inhibits the Proliferation of Vascular Smooth Muscle Cells Induced by Angiotensin II through Nitric Oxide-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Amaia Rodríguez

    2010-01-01

    Full Text Available Objective. This study was designed to investigate whether leptin modifies angiotensin (Ang II-induced proliferation of aortic vascular smooth muscle cells (VSMCs from 10-week-old male Wistar and spontaneously hypertensive rats (SHR, and the possible role of nitric oxide (NO. Methods. NO and NO synthase (NOS activity were assessed by the Griess and 3H-arginine/citrulline conversion assays, respectively. Inducible NOS (iNOS and NADPH oxidase subutnit Nox2 expression was determined by Western-blot. The proliferative responses to Ang II were evaluated through enzymatic methods. Results. Leptin inhibited the Ang II-induced proliferative response of VSMCs from control rats. This inhibitory effect of leptin was abolished by NOS inhibitor, NMMA, and iNOS selective inhibitor, L-NIL, and was not observed in leptin receptor-deficient fa/fa rats. SHR showed increased serum leptin concentrations and lipid peroxidation. Despite a similar leptin-induced iNOS up-regulation, VSMCs from SHR showed an impaired NOS activity and NO production induced by leptin, and an increased basal Nox2 expression. The inhibitory effect of leptin on Ang II-induced VSMC proliferation was attenuated. Conclusion. Leptin blocks the proliferative response to Ang II through NO-dependent mechanisms. The attenuation of this inhibitory effect of leptin in spontaneous hypertension appears to be due to a reduced NO bioavailability in VSMCs.

  6. Determination of the active site and mechanism for alkene isomerization in Cu(II) exchnaged Y-type zeolite

    Energy Technology Data Exchange (ETDEWEB)

    John, C S; Leach, H F

    1977-01-01

    An ESR study of 1-butene isomerization at 315/sup 0/-375/sup 0/C, 3,3-dimethyl-1-butene isomerization to 2,3-dimethyl-1- and -2-butene at 293/sup 0/K, and deuterium redistribution in 3,3-dideuteriopropene at 363/sup 0/-396/sup 0/K showed the presence of two copper(II) species in different environments, which reacted with the olefins at different rates. Although activation energies for the three reactions differed and only dideuteriopropene showed an induction period, a similar mechanism is proposed in all cases, involving preliminary reduction of copper(II), with the rates of reduction and isomerization differing from olefin to olefin. Apparently, the active site for the isomerization is a Broensted acid generated by the reduction, and the isomerization follows an associative (proton addition-elimination) mechanism with a carbonium ion intermediate. Spectra, graphs, diagram, and 12 references.

  7. Thermal-Mechanical Study of 3.9 GHz CW Coupler and Cavity for LCLS-II Project

    Energy Technology Data Exchange (ETDEWEB)

    Gonin, Ivan [Fermilab; Harms, Elvin [Fermilab; Khabiboulline, Timergali [Fermilab; Solyak, Nikolay [Fermilab; Yakovlev, Vyacheslav [Fermilab

    2017-05-01

    Third harmonic system was originally developed by Fermilab for FLASH facility at DESY and then was adopted and modified by INFN for the XFEL project [1-3]. In contrast to XFEL project, all cryomodules in LCLS-II project will operate in CW regime with higher RF average power for 1.3 GHz and 3.9 GHz cavities and couplers. Design of the cavity and fundamental power coupler has been modified to satisfy LCLS-II requirements. In this paper we discuss the results of COMSOL thermal and mechanical analysis of the 3.9 GHz coupler and cavity to verify proposed modifica-tion of the design. For the dressed cavity we present simulations of Lorentz force detuning, helium pressure sensitivity df/dP and major mechanical resonances.

  8. Tower Shielding Reactor II design and operation report. Vol. 3. Assembling and testing of the control mechanism assembly

    International Nuclear Information System (INIS)

    Ward, D.R.; Holland, L.B.

    1979-09-01

    The mechanisms that are operated to control the reactivity of the Tower Shielding Reactor II(TSR-II) are mounted on a Control Mechanism Housing (CMH) that is centered inside the reactor core. The information required to procure, fabricate, inspect, and assemble a CMH is contained in the ORNL engineering drawings listed in the appropriate sections. The components are fabricated and inspected from these drawings in accordance with a Quality Assurance Plan and a Manufacturing Plan. The material in this report describes the acceptance and performance tests of CMH subassemblies used ty the Tower Shielding Facility (TSF) staff but it can also be used by personnel fabricating the components. This information which was developed and used before the advent of the formalized QA Program and Manufacturing Plans evolved during the fabrication and testing of the first five CMHs

  9. Improvement of the thermo-mechanical position stability of the beam position monitor in the PLS-II

    Science.gov (United States)

    Ha, Taekyun; Hong, Mansu; Kwon, Hyuckchae; Han, Hongsik; Park, Chongdo

    2016-09-01

    In the storage ring of the Pohang Light Source-II (PLS-II), we reduced the mechanical displacement of the electron-beam position monitors (e-BPMs) that is caused by heating during e-beam storage. The BPM pickup itself must be kept stable to sub-micrometer precision in order for a stable photon beam to be provided to beamlines because the orbit feedback system is programmed to make the electron beam pass through the center of the BPM. Thermal deformation of the vacuum chambers on which the BPM pickups are mounted is inevitable when the electron beam current is changed by an unintended beam abort. We reduced this deformation by improving the vacuum chamber support and by enhancing the water cooling. We report a thermo-mechanical analysis and displacement measurements for the BPM pickups after improvements.

  10. RESEARCH OF KINETIC AND DIFFUSIVE MECHANISMS IN THE ADSORPTION OF Cu (II IN SUGAR CANE BAGASSE ASH

    Directory of Open Access Journals (Sweden)

    Julio Omar Prieto García

    2016-10-01

    Full Text Available In this paper a kinetic and diffusive study regarding adsorption of ions Cu (II on a sample of sugar cane bagasse ash is made. The results show that the second-order kinetic model better adjusts the experimental data than the Elovich and first-order kinetic model. The diffusive mechanism study shows that the diffusion in the liquid pellicle and in the micro-pores of the adsorbent prevail in the adsorption phenomenon.

  11. Does a plant for mechanical-biological waste treatment require a sanitary landfill?; Braucht die MBA eine Deponie?

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Burkart [GVoA mbH und Co. KG, Hille (Germany)

    2012-11-01

    In mechanical-biological waste treatment, an interesting recyclable fraction is dumped in landfill together with other treatment residues. This may be 10-20% depending on the energy content of the initial material. Some operators of mechanical-biological waste treatment plants are currently working on modifying their waste treatment processes. Results so far have shown that this may also reduce the cost. (orig.) [German] Bei der bisherigen Abfallentsorgung mittels einer MBA (mechanisch-biologische Abfallbehandlung) wird immer noch ein interessanter Wertstoffanteil mit dem Deponat auf der Deponie abgelagert. Je nach Qualitaet der Vorbehandlung sind dies alleine vom Energieinhalt des Eingangsmaterials ca. 10-20%. Um auch diesen Anteil zu verwerten, sind aktuell einige MBA-Betreiber dabei, ihre Verfahren entsprechend umzustellen. Erste Ergebnisse zeigen, dass dies auch noch zu Kosteneinsparungen fuehren kann. (orig.)

  12. MODELLING OF RING-SHAPED ULTRASONIC WAVEGUIDES FOR TESTING OF MECHANICAL PROPERTIES AND THERAPEUTIC TREATMENT OF BIOLOGICAL TISSUES

    Directory of Open Access Journals (Sweden)

    V. T. Minchenya

    2011-01-01

    Full Text Available The article presents results of modelling of ring-shaped waveguide tool for ultrasonic treatment of biological materials, particularly malignant tumours, and testing of their mechanical properties. Harmonic analysis of forced flexural vibration of the waveguide using ANSYS software and APDL programming language was implemented for determination of waveguide geometric parameters providing its resonance for the given excitation frequency. The developed finite element model accounts for interaction between the waveguide and tumour tissue as well as initial prestressing of tissue radially compressed by the waveguide. Resonant curves of the waveguide in terms of its thickness and diameter are calculated and presented. Principle of application of the developed modeling technique for extraction of diagnostic data on mechanical properties of biological tissues is described.

  13. keV right-handed neutrinos from type II seesaw mechanism in a 3-3-1 model

    International Nuclear Information System (INIS)

    Cogollo, D.; Diniz, H.; Pires, C.A. de S

    2009-01-01

    We adapt the type II seesaw mechanism to the framework of the 3-3-1 model with right-handed neutrinos. We emphasize that the mechanism is capable of generating small masses for the left-handed and right-handed neutrinos and the structure of the model allows that both masses arise from the same Yukawa coupling. For typical values of the free parameters of the model we may obtain at least one right-handed neutrino with mass in the keV range. Right-handed neutrino with mass in this range is a viable candidate for the warm component of the dark matter existent in the universe.

  14. Catecholase activity of dicopper(II)-bispidine complexes: stabilities and structures of intermediates, kinetics and reaction mechanism.

    Science.gov (United States)

    Born, Karin; Comba, Peter; Daubinet, André; Fuchs, Alexander; Wadepohl, Hubert

    2007-01-01

    A mechanism for the oxidation of 3,5-di-tert-butylcatechol (dtbc) with dioxygen to the corresponding quinone (dtbq), catalyzed by bispidine-dicopper complexes (bispidines are various mono- and dinucleating derivatives of 3,7-diazabicyclo[3.3.1]nonane with bis-tertiary-amine-bispyridyl or bis-tertiary-amine-trispyridyl donor sets), is proposed on the basis of (1) the stoichiometry of the reaction as well as the stabilities and structures [X-ray, density functional theory (B3LYP, TZV)] of the bispidine-dicopper(II)-3,4,5,6-tetrachlorcatechol intermediates, (2) formation kinetics and structures (molecular mechanics, MOMEC) of the end-on peroxo-dicopper(II) complexes and (3) kinetics of the stoichiometric (anaerobic) and catalytic (aerobic) copper-complex-assisted oxidation of dtbc. This involves (1) the oxidation of the dicopper(I) complexes with dioxygen to the corresponding end-on peroxo-dicopper(II) complexes, (2) coordination of dtbc as a bridging ligand upon liberation of H(2)O(2) and (3) intramolecular electron transfer to produce dtbq, which is liberated, and the dicopper(I) catalyst. Although the bispidine complexes have reactivities comparable to those of recently published catalysts with macrocyclic ligands, which seem to reproduce the enzyme-catalyzed process in various reaction sequences, a strikingly different oxidation mechanism is derived from the bispidine-dicopper-catalyzed reaction.

  15. Drug testing with alternative matrices II. Mechanisms of cocaine and codeine deposition in hair.

    Science.gov (United States)

    Joseph, R E; Höld, K M; Wilkins, D G; Rollins, D E; Cone, E J

    1999-10-01

    A 10-week inpatient study was performed to evaluate cocaine, codeine, and metabolite disposition in biological matrices collected from volunteers. An initial report described drug disposition in plasma, sebum, and stratum corneum collected from five African-American males. This report focuses on drug disposition in hair and sweat collected from the same five subjects. Following a three-week washout period, three doses of cocaine HCl (75 mg/70 kg, subcutaneous) and three doses of codeine SO4 (60 mg/70 kg, oral) were administered on alternating days in week 4 (low-dose week). The same dosing sequence was repeated in week 8 with doubled doses (high-dose week). Hair was collected by shaving the entire scalp once each week. Hair from the anterior vertex was divided into two portions. One portion was washed with isopropanol and phosphate buffer; the other portion was not washed. Hair was enzymatically digested, samples were centrifuged, and the supernatant was collected. Sweat was collected periodically by placing PharmChek sweat patches on the torso. Drugs were extracted from sweat patches with methanol/0.2 M sodium acetate buffer (75:25, v/v). Supernatants from hair digests, hair washes, and sweat patch extracts were processed by solid-phase extraction followed by gas chromatography-mass spectrometry analysis for cocaine, codeine, 6-acetylmorphine, and metabolites. Cocaine and codeine were the primary analytes identified in sweat patches and hair. Drugs were detected in sweat within 8 h after dosing, and drug secretion primarily occurred within 24 h after dosing. No clear relationship was observed between dose and drug concentrations in sweat. Drug incorporation into hair appeared to be dose-dependent. Drugs were detected in hair within 1-3 days after the last drug administration; peak drug concentrations generally occurred in the following 1-2 weeks; thereafter, drug concentrations decreased. Solvent washes removed 50-55% of cocaine and codeine from hair collected 1

  16. Mechanical and biological properties of the micro-/nano-grain functionally graded hydroxyapatite bioceramics for bone tissue engineering.

    Science.gov (United States)

    Zhou, Changchun; Deng, Congying; Chen, Xuening; Zhao, Xiufen; Chen, Ying; Fan, Yujiang; Zhang, Xingdong

    2015-08-01

    Functionally graded materials (FGM) open the promising approach for bone tissue repair. In this study, a novel functionally graded hydroxyapatite (HA) bioceramic with micrograin and nanograin structure was fabricated. Its mechanical properties were tailored by composition of micrograin and nanograin. The dynamic mechanical analysis (DMA) indicated that the graded HA ceramics had similar mechanical property compared to natural bones. Their cytocompatibility was evaluated via fluorescent microscopy and MTT colorimetric assay. The viability and proliferation of rabbit bone marrow mesenchymal stem cells (BMSCs) on ceramics indicated that this functionally graded HA ceramic had better cytocompatibility than conventional HA ceramic. This study demonstrated that functionally graded HA ceramics create suitable structures to satisfy both the mechanical and biological requirements of bone tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Investigation of the impact of mechanical stress on the properties of silicon sensor modules for the ATLAS Phase II upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Stegler, Martin; Polay, Luise; Spehrlich, Dennis; Bloch, Ingo [DESY, Zeuthen (Germany)

    2016-07-01

    The new ATLAS tracker for phase II will be composed of silicon pixel and strip sensor modules. Such a module consists of silicon sensors, boards and readout chips. In a currently ongoing study new adhesives to connect the modular components thermally and mechanically are examined. It was shown that the silicon sensor is exposed to mechanical stress when part of a module. Mechanical stress can cause damage to a sensor and can change the tensors of electrical properties. The study of the effects of mechanical stress on characteristics of the silicon sensor modules are the focus in this presentation. The thermal induced tensile stress near to the surface of a silicon sensor build in a module was simulated. A four point bending setup was used to measure the maximum tensile stress of silicon and to verify the piezoresistive effect on ATLAS07 sensors. The results of the electrical measurements and simulations of stressed silicon sensor modules are shown in the presentation.

  18. Animal model for angiotensin II effects in the internal anal sphincter smooth muscle: mechanism of action.

    Science.gov (United States)

    Fan, Ya-Ping; Puri, Rajinder N; Rattan, Satish

    2002-03-01

    Effect of ANG II was investigated in in vitro smooth muscle strips and in isolated smooth muscle cells (SMC). Among different species, rat internal and sphincter (IAS) smooth muscle showed significant and reproducible contraction that remained unmodified by different neurohumoral inhibitors. The AT(1) antagonist losartan but not AT(2) antagonist PD-123319 antagonized ANG II-induced contraction of the IAS smooth muscle and SMC. ANG II-induced contraction of rat IAS smooth muscle and SMC was attenuated by tyrosine kinase inhibitors genistein and tyrphostin, protein kinase C (PKC) inhibitor H-7, Ca(2+) channel blocker nicardipine, Rho kinase inhibitor Y-27632 or p(44/42) mitogen-activating protein kinase (MAPK(44/42)) inhibitor PD-98059. Combinations of nicardipine and H-7, Y-27632, and PD-98059 caused further attenuation of the ANG II effects. Western blot analyses revealed the presence of both AT(1) and AT(2) receptors. We conclude that ANG II causes contraction of rat IAS smooth muscle by the activation of AT(1) receptors at the SMC and involves multiple intracellular pathways, influx of Ca(2+), and activation of PKC, Rho kinase, and MAPK(44/42).

  19. Thermodynamic modeling of transcription: sensitivity analysis differentiates biological mechanism from mathematical model-induced effects.

    Science.gov (United States)

    Dresch, Jacqueline M; Liu, Xiaozhou; Arnosti, David N; Ay, Ahmet

    2010-10-24

    Quantitative models of gene expression generate parameter values that can shed light on biological features such as transcription factor activity, cooperativity, and local effects of repressors. An important element in such investigations is sensitivity analysis, which determines how strongly a model's output reacts to variations in parameter values. Parameters of low sensitivity may not be accurately estimated, leading to unwarranted conclusions. Low sensitivity may reflect the nature of the biological data, or it may be a result of the model structure. Here, we focus on the analysis of thermodynamic models, which have been used extensively to analyze gene transcription. Extracted parameter values have been interpreted biologically, but until now little attention has been given to parameter sensitivity in this context. We apply local and global sensitivity analyses to two recent transcriptional models to determine the sensitivity of individual parameters. We show that in one case, values for repressor efficiencies are very sensitive, while values for protein cooperativities are not, and provide insights on why these differential sensitivities stem from both biological effects and the structure of the applied models. In a second case, we demonstrate that parameters that were thought to prove the system's dependence on activator-activator cooperativity are relatively insensitive. We show that there are numerous parameter sets that do not satisfy the relationships proferred as the optimal solutions, indicating that structural differences between the two types of transcriptional enhancers analyzed may not be as simple as altered activator cooperativity. Our results emphasize the need for sensitivity analysis to examine model construction and forms of biological data used for modeling transcriptional processes, in order to determine the significance of estimated parameter values for thermodynamic models. Knowledge of parameter sensitivities can provide the necessary

  20. Neuroimaging mechanisms of change in psychotherapy for addictive behaviors: emerging translational approaches that bridge biology and behavior.

    Science.gov (United States)

    Feldstein Ewing, Sarah W; Chung, Tammy

    2013-06-01

    Research on mechanisms of behavior change provides an innovative method to improve treatment for addictive behaviors. An important extension of mechanisms of change research involves the use of translational approaches, which examine how basic biological (i.e., brain-based mechanisms) and behavioral factors interact in initiating and sustaining positive behavior change as a result of psychotherapy. Articles in this special issue include integrative conceptual reviews and innovative empirical research on brain-based mechanisms that may underlie risk for addictive behaviors and response to psychotherapy from adolescence through adulthood. Review articles discuss hypothesized mechanisms of change for cognitive and behavioral therapies, mindfulness-based interventions, and neuroeconomic approaches. Empirical articles cover a range of addictive behaviors, including use of alcohol, cigarettes, marijuana, cocaine, and pathological gambling and represent a variety of imaging approaches including fMRI, magneto-encephalography, real-time fMRI, and diffusion tensor imaging. Additionally, a few empirical studies directly examine brain-based mechanisms of change, whereas others examine brain-based indicators as predictors of treatment outcome. Finally, two commentaries discuss craving as a core feature of addiction, and the importance of a developmental approach to examining mechanisms of change. Ultimately, translational research on mechanisms of behavior change holds promise for increasing understanding of how psychotherapy may modify brain structure and functioning and facilitate the initiation and maintenance of positive treatment outcomes for addictive behaviors. 2013 APA, all rights reserved

  1. Electron spin interactions in chemistry and biology fundamentals, methods, reactions mechanisms, magnetic phenomena, structure investigation

    CERN Document Server

    Likhtenshtein, Gertz

    2016-01-01

    This book presents the versatile and pivotal role of electron spin interactions in nature. It provides the background, methodologies and tools for basic areas related to spin interactions, such as spin chemistry and biology, electron transfer, light energy conversion, photochemistry, radical reactions, magneto-chemistry and magneto-biology. The book also includes an overview of designing advanced magnetic materials, optical and spintronic devices and photo catalysts. This monograph appeals to scientists and graduate students working in the areas related to spin interactions physics, biophysics, chemistry and chemical engineering.

  2. Corpuls cpr resuscitation device generates superior emulated flows and pressures than LUCAS II in a mechanical thorax model.

    Science.gov (United States)

    Eichhorn, S; Mendoza Garcia, A; Polski, M; Spindler, J; Stroh, A; Heller, M; Lange, R; Krane, M

    2017-06-01

    The provision of sufficient chest compression is among the most important factors influencing patient survival during cardiopulmonary resuscitation (CPR). One approach to optimize the quality of chest compressions is to use mechanical-resuscitation devices. The aim of this study was to compare a new device for chest compression (corpuls cpr) with an established device (LUCAS II). We used a mechanical thorax model consisting of a chest with variable stiffness and an integrated heart chamber which generated blood flow dependent on the compression depth and waveform. The method of blood-flow generation could be changed between direct cardiac-compression mode and thoracic-pump mode. Different chest-stiffness settings and compression modes were tested to generate various blood-flow profiles. Additionally, an endurance test at high stiffness was performed to measure overall performance and compression consistency. Both resuscitation machines were able to compress the model thorax with a frequency of 100/min and a depth of 5 cm, independent of the chosen chest stiffness. Both devices passed the endurance test without difficulty. The corpuls cpr device was able to generate about 10-40% more blood flow than the LUCAS II device, depending on the model settings. In most scenarios, the corpuls cpr device also generated a higher blood pressure than the LUCAS II. The peak compression forces during CPR were about 30% higher using the corpuls cpr device than with the LUCAS II. In this study, the corpuls cpr device had improved blood flow and pressure outcomes than the LUCAS II device. Further examination in an animal model is required to prove the findings of this preliminary study.

  3. Clinical indications and biological mechanisms of splenic irradiation in autoimmune diseases

    Energy Technology Data Exchange (ETDEWEB)

    Weinmann, M.; Becker, G. [Tuebingen Univ. (Germany). Abt. fuer Strahlenonkologie; Einsele, H.; Bamberg, M. [Tuebingen Univ. (Germany). Abt. fuer Innere Medizin 2

    2001-02-01

    Background: Splenic irradiation (SI) is a fairly unknown treatment modality in autoimmune disorders like autoimmune thrombocytopenia (AIT) or autoimmune hemolytic anemia (AIHA), which may provide an effective, low toxic and cost-effective treatment for selected patients. Patients, Materials and Methods: This article reviews the limited experiences on splenic irradiation in autoimmune thrombocytopenia by analyzing the current studies including 71 patients and some preliminary reports on splenic irradiation in autoimmune hemolytic anemia. Results: In autoimmune thrombocytopenia between 40 and 90% of all patients responded, but most of them relapsed within 4 to 6 months after splenic irradiation. Between 10 and 20% of all patients had a sustained response. The efficacy of splenic irradiation in HIV-associated cases of thrombocytopenia is probably lower than in other forms of autoimmune thrombocytopenia, but especially in this group immunosuppressive drug treatment of autoimmune thrombocytopenia exposes some problems. In autoimmune hemolytic anemia there are some case reports about efficacy of splenic irradiation. Toxicity of splenic irradiation in both diseases was very moderate. Conclusions: For HIV patients, for elderly patients or patients at high risk for complications following splenectomy splenic irradiation might be a treatment option. Splenic irradiation as preoperative treatment in patients not responding to or not suitable for immunosuppressive drugs prior to splenectomy may be a promising new application of splenic irradiation to reduce adverse effects of splenectomy in thrombocytopenic patients. A further analysis of the biological mechanisms underlying splenic irradiation may help to improve patient selection, to optimize dose concepts and treatment schedules and will improve understanding of radiotherapy as an immunomodulatory treatment modality. (orig.) [German] Hintergrund: Die Bestrahlung der Milz zur Behandlung von haematologischen

  4. An experimental study of double-peeling mechanism inspired by biological adhesive systems

    DEFF Research Database (Denmark)

    Heepe, Lars; Raguseo, Saverio; Gorb, Stanislav N.

    2017-01-01

    Double- (or multiple-) peeling systems consist of two (or numerous) tapes adhering to a substrate and having a common hinge, where the pulling force is applied. Biological systems, consisting of tape-like (or spatula-like) contact elements, are widely observed in adhesive pads of flies, beetles...

  5. Bobbing of Oxysterols: Molecular Mechanism for Translocation of Tail-Oxidized Sterols through Biological Membranes

    Czech Academy of Sciences Publication Activity Database

    Kulig, W.; Mikkolainen, H.; Olžyńska, Agnieszka; Jurkiewicz, Piotr; Cwiklik, Lukasz; Hof, Martin; Vattulainen, I.; Jungwirth, Pavel; Rog, T.

    2018-01-01

    Roč. 9, č. 5 (2018), s. 1118-1123 ISSN 1948-7185 R&D Projects: GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388955 ; RVO:61388963 Keywords : biological membranes * alcohols * cell membranes Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 9.353, year: 2016

  6. Theoretical investigation, biological evaluation and VEGFR2 kinase studies of metal(II) complexes derived from hydrotris(methimazolyl)borate.

    Science.gov (United States)

    Jayakumar, S; Mahendiran, D; Srinivasan, T; Mohanraj, G; Kalilur Rahiman, A

    2016-02-01

    The reaction of soft tripodal scorpionate ligand, sodium hydrotris(methimazolyl)borate with M(ClO4)2·6H2O [MMn(II), Ni(II), Cu(II) or Zn(II)] in methanol leads to the cleavage of B-N bond followed by the formation of complexes of the type [M(MeimzH)4](ClO4)2·H2O (1-4), where MeimzH=methimazole. All the complexes were fully characterized by spectro-analytical techniques. The molecular structure of the zinc(II) complex (4) was determined by X-ray crystallography, which supports the observed deboronation reaction in the scorpionate ligand with tetrahedral geometry around zinc(II) ion. The electronic spectra of complexes suggested tetrahedral geometry for manganese(II) and nickel(II) complexes, and square-planar geometry for copper(II) complex. Frontier molecular orbital analysis (HOMO-LUMO) was carried out by B3LYP/6-31G(d) to understand the charge transfer occurring in the molecules. All the complexes exhibit significant antimicrobial activity against Gram (-ve) and Gram (+ve) bacterial as well as fungal strains, which are quite comparable to standard drugs streptomycin and clotrimazole. The copper(II) complex (3) showed excellent free radical scavenging activity against DPPH in all concentration with IC50 value of 30μg/mL, when compared to the other complexes. In the molecular docking studies, all the complexes showed hydrophobic, π-π and hydrogen bonding interactions with BSA. The cytotoxic activity of the complexes against human hepatocellular liver carcinoma (HepG2) cells was assessed by MTT assay, which showed exponential responses toward increasing concentration of complexes. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Part I. Mechanisms of injury associated with extracorporeal shock wave lithotripsy; Part II. Exsolution of volatiles

    Science.gov (United States)

    Howard, Danny Dwayne

    Part I - Shock waves are focused in extracorporeal shock wave lithotripsy (ESWL) machines to strengths sufficient to fracture kidney stones. Substantial side effects-most of them acute-have resulted from this procedure, including injury to soft tissue. The focusing of shock waves through various layers of tissue is a complex process which stimulates many bio-mechano-chemical responses.This thesis presents results of an in vitro study of the initial mechanical stimulus. Planar nitrocellulose membranes of order 10 um thick were used as models of thin tissue structures. Two modes of failure were recorded: Failure due to cavitation collapsing on or near the membranes, and failure induced by altering the structure of shock waves. Tests were done in water at and around F2 to characterize the extent of cavitation damage, and was found to be confined within the focal region, 1.2 cm along the axis of focus.Scattering media were used to simulate the effects of acoustic nonuniformity of tissue and to alter the structure of focusing shock waves. 40 um diameter (average) hollow glass spheres were added to ethylene glycol, glycerine and castor oil to vary the properties of the scattering media. Multiple layer samples of various types of phantom tissue were tested in degassed castor oil to gauge the validity of the scattering media. The scattering media and tissue samples increased the rise time decreased strain rate in a similar fashion. Membranes were damaged by the decreased strain rate and accumulated effects of the altered structure: After about 20 or so shocks immersed in the scattering media and after about 100 shocks behind the tissue samples. The mode of failure was tearing with multiple tears in some cases from about .1 cm to about 3 cm depending of the number of shocks and membrane thickness.Part II - This work examines the exsolution of volatiles-carbon dioxide from water-in a cylindrical test cell under different pressure conditions. Water was supersaturated with

  8. The Variable Stiffness Actuator vsaUT-II: Mechanical Design, Modeling, and Identification

    NARCIS (Netherlands)

    Groothuis, Stefan; Rusticelli, Giacomo; Zucchelli, Andrea; Stramigioli, Stefano; Carloni, Raffaella

    In this paper, the rotational variable stiffness actuator vsaUT-II is presented. This actuation system is characterized by the property that the apparent stiffness at the actuator output can be varied independently from its position. This behavior is realized by implementing a variable transmission

  9. Reduced glomerular angiotensin II receptor density in diabetes mellitus in the rat: time course and mechanism

    International Nuclear Information System (INIS)

    Wilkes, B.M.

    1987-01-01

    Glomerular angiotensin II receptors are reduced in number in early diabetes mellitus, which may contribute to hyperfiltration and glomerular injury. The time course and role of the renin-angiotensin-aldosterone system in the pathogenesis of the receptor abnormality were studied in male Sprague-Dawley rats made diabetic with streptozotocin (65 mg, iv). Glomerular angiotensin II receptors were measured by Scatchard analysis; insulin, renin activity, angiotensin II, and aldosterone were measured by RIA. Diabetes mellitus was documented at 24 h by a rise in plasma glucose (vehicle-injected control, 133 +/- 4; diabetic, 482 +/- 22 mg/dl and a fall in plasma insulin (control, 53.1 +/- 5.7; diabetic, 35.6 +/- 4.0 microIU/ml. At 24 h glomerular angiotensin II receptor density was decreased by 26.5% in diabetic rats (control, 75.5 +/- 9.6 X 10(6); diabetic, 55.5 +/- 8.3 X 10(6) receptors/glomerulus. Receptor occupancy could not explain the defect, because there was reduced binding in diabetic glomeruli after pretreatment with 3 M MgCl 2 , a maneuver that caused dissociation of previously bound hormone. There was a progressive return of the receptor density toward normal over the 60 days following induction of diabetes, with diabetic glomeruli measuring 22.7%, 14.8%, and 3.7% fewer receptors than age-matched controls at 11 days, 1 month, and 2 months, respectively

  10. Double-stranded DNA translocase activity of transcription factor TFIIH and the mechanism of RNA polymerase II open complex formation.

    Science.gov (United States)

    Fishburn, James; Tomko, Eric; Galburt, Eric; Hahn, Steven

    2015-03-31

    Formation of the RNA polymerase II (Pol II) open complex (OC) requires DNA unwinding mediated by the transcription factor TFIIH helicase-related subunit XPB/Ssl2. Because XPB/Ssl2 binds DNA downstream from the location of DNA unwinding, it cannot function using a conventional helicase mechanism. Here we show that yeast TFIIH contains an Ssl2-dependent double-stranded DNA translocase activity. Ssl2 tracks along one DNA strand in the 5' → 3' direction, implying it uses the nontemplate promoter strand to reel downstream DNA into the Pol II cleft, creating torsional strain and leading to DNA unwinding. Analysis of the Ssl2 and DNA-dependent ATPase activity of TFIIH suggests that Ssl2 has a processivity of approximately one DNA turn, consistent with the length of DNA unwound during transcription initiation. Our results can explain why maintaining the OC requires continuous ATP hydrolysis and the function of TFIIH in promoter escape. Our results also suggest that XPB/Ssl2 uses this translocase mechanism during DNA repair rather than physically wedging open damaged DNA.

  11. Studies of zinc(II in pharmaceutical and biological samples by extractive spectrophotometry: using pyridoxal-4-phenyl-3-thiosemicarbazone as chelating reagent

    Directory of Open Access Journals (Sweden)

    Sarma L. Subramanyam

    2006-01-01

    Full Text Available Pyridoxal-4-phenyl-3-thiosemicarbazone (PPT is proposed as a new sensitive reagent for the sensitive extractive spectrophotometric determination of zinc(II. PPT reacts with zinc(II in the pH range 5.0-6.0 to form a yellow colored complex, which was well extracted into n-butanol. The absorbance value of Zn(II-PPT complex was measured at different intervals of time at 430 nm, to ascertain the stability of the complex. It was observed that the color development was instantaneous and stable for more than 48 h. The system obeyed Beer's law up to 6.0 µg mL-1 of zinc(II, with an excellent linearity in terms of correlation coefficient value of 0.999. The molar absorptivity and Sandell's sensitivity of the extracted species is 1.6 X 10(4 L mol-1 cm-1 and 4.085 X 10-3 µg cm-2 at 430 nm. The detection limit of the method is 0.04 µg mL-1. To assess precision of the method, determinations were carried out at different concentrations; the relative standard deviation does not exceed 3.1%. The composition of the zinc(II complex with PPT was studied by the method of Job's continuous variation, molar ratio method, Asmus' method and slope ratio method. It has been satisfactorily applied for the determination of zinc(II, when present alone or in presence of diverse ions, which are usually associated with zinc(II in pharmaceutical and biological samples. Various certified reference materials (NIST 1573, NBS 1572 and NIST SRM 8435 have been tested for the determination of zinc for evaluating the accuracy of the developed method. The results of the proposed method are in agreement with flame atomic absorption spectometry.

  12. Adipose tissue NAD+ biology in obesity and insulin resistance: From mechanism to therapy.

    Science.gov (United States)

    Yamaguchi, Shintaro; Yoshino, Jun

    2017-05-01

    Nicotinamide adenine dinucleotide (NAD + ) biosynthetic pathway, mediated by nicotinamide phosphoribosyltransferase (NAMPT), a key NAD + biosynthetic enzyme, plays a pivotal role in controlling many biological processes, such as metabolism, circadian rhythm, inflammation, and aging. Over the past decade, NAMPT-mediated NAD + biosynthesis, together with its key downstream mediator, namely the NAD + -dependent protein deacetylase SIRT1, has been demonstrated to regulate glucose and lipid metabolism in a tissue-dependent manner. These discoveries have provided novel mechanistic and therapeutic insights into obesity and its metabolic complications, such as insulin resistance, an important risk factor for developing type 2 diabetes and cardiovascular disease. This review will focus on the importance of adipose tissue NAMPT-mediated NAD + biosynthesis and SIRT1 in the pathophysiology of obesity and insulin resistance. We will also critically explore translational and clinical aspects of adipose tissue NAD + biology. © 2017 WILEY Periodicals, Inc.

  13. Stabilization of organic matter and nitrogen immobilization during mechanical-biological treatment and landfilling of residual municipal solid waste

    International Nuclear Information System (INIS)

    Heiss-Ziegler, C.

    2000-04-01

    Synthesis of humic substances and nitrogen immobilization during mechanical-biological treatment of waste and the behavior of biologically stabilized waste under anaerobic landfill conditions were investigated. Samples were taken from a large-scale treatment plant. Anaerobic conditions were simulated in lab scale test cells. Humic substances were analyzed photometrically and gravimetrically. The nitrogen immobilization was investigated by sequential leaching tests and by analyzing the non acid hydrolyzable nitrogen. Humic acids were mainly synthesized during the beginning of the intensive rotting phase. Later on in the process no significant changes occurred. The humic acid content rose up to 6,8 % DS org. It correlated well with the stability parameters respiration activity and accumulated gas production. In the coarse of the treatment the nitrogen load emitted during the consecutive leaching tests dropped from 50 % down to less than 20 % total nitrogen. The non acid hydrolyzable nitrogen rose from 17 up to 42 % Kjeldahl nitrogen content. Nevertheless the mechanical-biological treatment is not significantly shortening the aftercare period of a landfill concerning liquid nitrogen emissions. The reduced nitrogen emission potential is released more slowly. When reactive waste material was exposed to anaerobic conditions, humic and fulvic acids were synthesized up to the point when intensive gas production started and then were remineralized. Stabilized waste materials after treatment of various intensity behaved differently under anaerobic conditions. Steady and decreasing humic acid contents were observed. (author)

  14. The Role of Biologically Active Ingredients from Natural Drug Treatments for Arrhythmias in Different Mechanisms

    OpenAIRE

    Li, Jie; Hu, Dan; Song, Xiaoli; Han, Tao; Gao, Yonghong; Xing, Yanwei

    2017-01-01

    Arrhythmia is a disease that is caused by abnormal electrical activity in the heart rate or rhythm. It is the major cause of cardiovascular morbidity and mortality. Although several antiarrhythmic drugs have been used in clinic for decades, their application is often limited by their adverse effects. As a result, natural drugs, which have fewer side effects, are now being used to treat arrhythmias. We searched for all articles on the role of biologically active ingredients from natural drug t...

  15. Biologically-initiated rock crust on sandstone: Mechanical and hydraulic properties and resistance to erosion

    Czech Academy of Sciences Publication Activity Database

    Slavík, M.; Bruthans, J.; Filippi, Michal; Schweigstillová, Jana; Falteisek, L.; Řihošek, J.

    2017-01-01

    Roč. 278, FEB 1 (2017), s. 298-313 ISSN 0169-555X R&D Projects: GA ČR GA13-28040S; GA ČR(CZ) GA16-19459S Institutional support: RVO:67985831 ; RVO:67985891 Keywords : biofilm * biocrust * biologically-initiated rock crust * sandstone protection * case hardening Subject RIV: DB - Geology ; Mineralogy; DB - Geology ; Mineralogy (USMH-B) OBOR OECD: Geology; Geology (USMH-B) Impact factor: 2.958, year: 2016

  16. Systems biology: An emerging strategy for discovering novel pathogenetic mechanisms that promote cardiovascular disease

    OpenAIRE

    Maron, Bradley A.; Leopold, Jane A.

    2016-01-01

    Reductionist theory proposes that analyzing complex systems according to their most fundamental components is required for problem resolution, and has served as the cornerstone of scientific methodology for more than four centuries. However, technological gains in the current scientific era now allow for the generation of large datasets that profile the proteomic, genomic, and metabolomic signatures of biological systems across a range of conditions. The accessibility of data on such a vast s...

  17. Combined Biological and Chemical Mechanisms for Degradation of Insensitive Munitions in the Presence of Alternate Explosives

    Science.gov (United States)

    2017-06-21

    substrate for respiration or fermentation , a process called endogenous respiration and endogenous fermentation respectively. In most treatments with...commercial product, process , or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement...showed that DNAN can be readily reduced by chemical and biological processes at pH 7 within 24 hours, and at pH 8 and 9 in

  18. Interpretation of biological and mechanical variations between the Lowry versus Bradford method for protein quantification.

    Science.gov (United States)

    Lu, Tzong-Shi; Yiao, Szu-Yu; Lim, Kenneth; Jensen, Roderick V; Hsiao, Li-Li

    2010-07-01

    The identification of differences in protein expression resulting from methodical variations is an essential component to the interpretation of true, biologically significant results. We used the Lowry and Bradford methods- two most commonly used methods for protein quantification, to assess whether differential protein expressions are a result of true biological or methodical variations. MATERIAL #ENTITYSTARTX00026; Differential protein expression patterns was assessed by western blot following protein quantification by the Lowry and Bradford methods. We have observed significant variations in protein concentrations following assessment with the Lowry versus Bradford methods, using identical samples. Greater variations in protein concentration readings were observed over time and in samples with higher concentrations, with the Bradford method. Identical samples quantified using both methods yielded significantly different expression patterns on Western blot. We show for the first time that methodical variations observed in these protein assay techniques, can potentially translate into differential protein expression patterns, that can be falsely taken to be biologically significant. Our study therefore highlights the pivotal need to carefully consider methodical approaches to protein quantification in techniques that report quantitative differences.

  19. The mechanism of cysteine detection in biological media by means of vanadium oxide nanoparticles

    International Nuclear Information System (INIS)

    Bezerra, A. G.; Barison, A.; Oliveira, V. S.; Foti, L.; Krieger, M. A.; Dhalia, R.; Viana, I. F. T.; Schreiner, W. H.

    2012-01-01

    We report on the interaction of vanadate nanoparticles, produced using the laser ablation in liquids synthesis, with cysteine in biological molecules. Cysteine is a very important amino acid present in most proteins, but also because cysteine and the tripeptide glutathione are the main antioxidant molecules in our body system. Detailed UV–Vis absorption spectra and dynamic light scattering measurements were done to investigate the detection of cysteine in large biological molecules. The intervalence band of the optical absorption spectra shows capability for quantitative cysteine sensing in the μM range in biological macromolecules. Tests included cytoplasmic repetitive antigen and flagellar repetitive antigen proteins of the Trypanosoma cruzi protozoa, as well as the capsid p24 proteins from Human Immunodeficiency Virus type 1 and type 2. Detailed NMR measurements for hydrogen, carbon, and vanadium nuclei show that cysteine in contact with the vanadate looses hydrogen of the sulphydryl side chain, while the vanadate is reduced. The subsequent detachment of two deprotonated molecules to form cystine and the slow return to the vanadate complete the oxidation–reduction cycle. Therefore, the vanadate acts as a charge exchanging catalyst on cysteine to form cystine. The NMR results also indicate that the nanoparticles are not formed by the common orthorhombic V 2 O 5 form.

  20. The mechanism of cysteine detection in biological media by means of vanadium oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, A. G. [Universidade Tecnologica Federal do Parana, Departamento Academico de Fisica (Brazil); Barison, A. [Universidade Federal do Parana, Departamento de Quimica (Brazil); Oliveira, V. S. [Universidade Federal do Parana, Departamento de Fisica (Brazil); Foti, L.; Krieger, M. A. [Fundacao Oswaldo Cruz, Instituto de Biologia Molecular do Parana (Brazil); Dhalia, R.; Viana, I. F. T. [Fundacao Oswaldo Cruz, Centro de Pesquisas Aggeu Magalhaes (Brazil); Schreiner, W. H., E-mail: wido@fisica.ufpr.br [Universidade Federal do Parana, Departamento de Fisica (Brazil)

    2012-09-15

    We report on the interaction of vanadate nanoparticles, produced using the laser ablation in liquids synthesis, with cysteine in biological molecules. Cysteine is a very important amino acid present in most proteins, but also because cysteine and the tripeptide glutathione are the main antioxidant molecules in our body system. Detailed UV-Vis absorption spectra and dynamic light scattering measurements were done to investigate the detection of cysteine in large biological molecules. The intervalence band of the optical absorption spectra shows capability for quantitative cysteine sensing in the {mu}M range in biological macromolecules. Tests included cytoplasmic repetitive antigen and flagellar repetitive antigen proteins of the Trypanosoma cruzi protozoa, as well as the capsid p24 proteins from Human Immunodeficiency Virus type 1 and type 2. Detailed NMR measurements for hydrogen, carbon, and vanadium nuclei show that cysteine in contact with the vanadate looses hydrogen of the sulphydryl side chain, while the vanadate is reduced. The subsequent detachment of two deprotonated molecules to form cystine and the slow return to the vanadate complete the oxidation-reduction cycle. Therefore, the vanadate acts as a charge exchanging catalyst on cysteine to form cystine. The NMR results also indicate that the nanoparticles are not formed by the common orthorhombic V{sub 2}O{sub 5} form.

  1. The adherence of aluminide coatings on MANET II stainless steel and their effect on its mechanical properties

    International Nuclear Information System (INIS)

    Sample, T.; Fenici, P.; Kolbe, H.; Orecchia, L.

    1994-01-01

    This paper describes the production and testing of two different aluminide coatings on the surface of MANET II stainless steel. The coatings were produced by heat treatment of a pure aluminium layer (∼ 100 μm) which had been deposited by vacuum plasma spray. Series 1 coatings were produced by a single heat treatment (1023 K/2h) while series 2 coatings were produced by two consecutive heat treatments (1348 K/30 min, 1023 K/2h). Series 1 coatings were ∼ 120 μm thick, richer in aluminium and harder than series 2 coatings which formed two layers of ∼ 120 μm each. Due to their softer character, series 2 coatings exhibited a greater resistance to cracking under cyclic testing than series 1 coatings. Tensile tests of coated specimens indicated that the coating procedures did not degrade the mechanical properties of the bulk MANET II. (author) 8 refs.; 3 figs.; 3 tabs

  2. Thermoanalytical investigation and biological properties of zinc(II) 4-chloro- and 5-chlorosalicylates with N-donor ligands

    Czech Academy of Sciences Publication Activity Database

    Bujdošová, Z.; Györyová, K.; Mudroňová, D.; Hudecová, D.; Kovářová, Jana

    2012-01-01

    Roč. 110, č. 1 (2012), s. 167-176 ISSN 1388-6150 Institutional support: RVO:61389013 Keywords : chlorosalicylate * zinc(II) * nicotinamide derivatives Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.982, year: 2012

  3. Unravel lipid accumulation mechanism in oleaginous yeast through single cell systems biology study

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shiyou; Xiaoliang, Xie

    2017-12-18

    Replacement of petroleum with advanced biofuels is critical for environmental protection needs, sustainable and secure energy demands, and economic development. Bacteria, yeasts, and fungi can naturally synthesize fatty acids, isoprenoids, or polyalkanoates for energy storage, and therefore are currently explored for hydrocarbon fuel production. Oleaginous yeasts can accumulate high levels of lipids in the form of triacylglycerols (TAGs) when encountering stress conditions or imbalanced growth (e.g., growing under excess carbon sources and limited nitrogen conditions). Advantages of using oleaginous yeast as cell factories include short duplication time (< 1 hour), high yield of intracellular droplets, and easy scale-up for industrial production. Currently, various oleaginous yeasts (e.g., Yarrowia, Candida, Rhodotorulla, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces) have been developed as potential advanced biofuel producers. Oleaginous yeast lipid production has two phases: 1) growth phase, where cells utilize the carbon and nitrogen source to build up biomass. And 2) lipid accumulation phase, where they convert carbon source in media into the storage lipid body. (i.e. a high carbon to nitrogen ratio leads to high lipid production). The lipid production varies dramatically when different sugar, e.g. glucose, xylose is used as carbon source. The efficient utilization of all monomeric sugars of hexoses and pentoses from various lignocellulosic biomass processing approaches is the key for economic lignocellulosic biofuel production. In this project, we explored lipid production in oleaginous yeast under different nitrogen and sugar conditions at the single-cell level. To understand the lipid production mechanism and identify genetic features responsive to lipid accumulation in the presence of pentose and nitrogen, we developed an automated chemical imaging and single-cell transcriptomics method to correlate the lipid accumulation with the

  4. Repair mechanisms inducible to the DNA in I.M.M.S. biological systems

    International Nuclear Information System (INIS)

    Guzman, J.; Arceo, C.; Cortinas, C.; Rosa, M.E. De la; Olvera, O.; Cruces, M.; Pimentel, E.

    1990-03-01

    Given the characteristics of the MMS and the relative antecedents to the repair mechanisms in eucariontes are sought to determine the effect of the MMS on the genetic material and their repair in Drosophila melanogaster. (Author)

  5. Elucidating the molecular mechanisms underlying cellular response to biophysical cues using synthetic biology approaches

    NARCIS (Netherlands)

    Denning, Denise; Roos, Wouter H

    2016-01-01

    The use of synthetic surfaces and materials to influence and study cell behavior has vastly progressed our understanding of the underlying molecular mechanisms involved in cellular response to physicochemical and biophysical cues. Reconstituting cytoskeletal proteins and interfacing them with a

  6. Cu(II)-catalyzed oxidation of dopamine in aqueous solutions: mechanism and kinetics.

    Science.gov (United States)

    Pham, A Ninh; Waite, T David

    2014-08-01

    Spontaneous oxidation of dopamine (DA) and the resultant formation of free radical species within dopamine neurons of the substantia nigra (SN) is thought to bestow a considerable oxidative load upon these neurons and may contribute to their vulnerability to degeneration in Parkinson's disease (PD). An understanding of DA oxidation under physiological conditions is thus critical to understanding the relatively selective vulnerability of these dopaminergic neurons in PD and may support the development of novel neuro-protective approaches for this disorder. In this study, the oxidation of dopamine (0.2-10μM) was investigated both in the absence and the presence of copper (0.01-0.4μM), a redox active metal that is present at considerable concentrations in the SN, over a range of background chloride concentrations (0.01-0.7M), different oxygen concentrations and at physiological pH7.4. DA was observed to oxidize extremely slowly in the absence of copper and at moderate rates only in the presence of copper but without chloride. The oxidation of DA however was significantly enhanced in the presence of both copper and chloride with the rate of DA oxidation greatest at intermediate chloride concentrations (0.05-0.2M). The variability of the catalytic effect of Cu(II) on DA oxidation at different chloride concentrations can be explained and successfully modeled by appropriate consideration of the reaction of Cu(II) species with DA and the conversion of Cu(I) to Cu(II) through oxygenation. This model suggests that the speciation of Cu(II) and Cu(I) is critically important to the kinetics of DA oxidation and thus the vulnerability to degradation of dopaminergic neuron in the brain milieu. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Tratamento sistêmico da psoríase - Parte II: Imunomoduladores biológicos Systemic treatment of psoriasis - Part II: Biologic immunomodulator agents

    Directory of Open Access Journals (Sweden)

    Lúcia Arruda

    2004-08-01

    Full Text Available Em continuidade ao capítulo da edição anterior dos Anais Brasileiros de Dermatologia, nesta segunda parte da EMC-D serão discutidas as novas drogas, os imunomoduladores biológicos, que agem em determinadas fases da imunopatogênese da doença, modificando fenotipicamente sua evolução. Também serão discutidos alguns aspectos imunológicos que, atualmente, são responsáveis pelo desencadeamento da doençaAs part of its continued studies of psoriasis, this second part of the Continuing Medical Education in Dermatology segment of the Anais Brasileiros de Dermatologia introduces biological immunomodulators. Also known as "biologics", these drugs act on the immunopathogenetic steps of psoriasis by changing its features and progression. This paper also reviews some of the immunologic aspects of psoriasis.

  8. Mechanical aspects of developmental biology: perspectives On Growth and Form in the (post)-genomic age

    International Nuclear Information System (INIS)

    Hutson, M Shane; Ma Xiaoyan

    2008-01-01

    Simple experiments demonstrate that the development of an organism is both a genetic and a physical process. This statement is so obvious that it is seldom stated explicitly, and yet, there has been little progress toward integrating what should be complementary viewpoints. This paper focuses on the mechanical aspects of morphogenesis—highlighting those areas where mechanics and molecular genetics are converging toward a much-needed synthesis

  9. Biological removal of nickel (II by Bacillus sp. KL1 in different conditions: optimization by Taguchi statistical approach

    Directory of Open Access Journals (Sweden)

    Taran Mojtaba

    2015-09-01

    Full Text Available Bioremediation is the removal of heavy-metals such as nickel (Ni using microorganisms and has been considered as an important field in the biotechnology. Isolation and characterization of microorganisms exhibiting bioremediation activities and their optimization to treat polluted wastewaters is a vital and difficult task in remediation technologies. In this study, investigation was carried out to isolate Ni (II remediating microbial strains from soils contaminated with municipal solid waste leachate. Furthermore, Taguchi design of experiments were used to evaluate the influence of concentration, pH, temperature, and time on bioremediation of Ni (II using isolated bacteria. This study concluded that Bacillus sp. KL1 is a Ni (II-resistant strain and had Ni (II bioremediation activity. The highest bioremediation of Ni (II was observed as 55.06% after 24 h at 30ºC, pH 7, and 100 ppm concentration. Moreover, it was also observed that concentration is the most effective factor in the bioremediation process. In conclusion, we have demonstrated that bacteria isolated from soils contaminated with garbage leachate have the Bacillus sp. KL1 bacteria which can efficiently uptake and eliminate Ni (II from contaminated sites and thus makes it possible to treat heavy-metal containing wastewaters in industry by using this microorganism at optimized conditions.

  10. Systems biology derived source-sink mechanism of BMP gradient formation.

    Science.gov (United States)

    Zinski, Joseph; Bu, Ye; Wang, Xu; Dou, Wei; Umulis, David; Mullins, Mary C

    2017-08-09

    A morphogen gradient of Bone Morphogenetic Protein (BMP) signaling patterns the dorsoventral embryonic axis of vertebrates and invertebrates. The prevailing view in vertebrates for BMP gradient formation is through a counter-gradient of BMP antagonists, often along with ligand shuttling to generate peak signaling levels. To delineate the mechanism in zebrafish, we precisely quantified the BMP activity gradient in wild-type and mutant embryos and combined these data with a mathematical model-based computational screen to test hypotheses for gradient formation. Our analysis ruled out a BMP shuttling mechanism and a bmp transcriptionally-informed gradient mechanism. Surprisingly, rather than supporting a counter-gradient mechanism, our analyses support a fourth model, a source-sink mechanism, which relies on a restricted BMP antagonist distribution acting as a sink that drives BMP flux dorsally and gradient formation. We measured Bmp2 diffusion and found that it supports the source-sink model, suggesting a new mechanism to shape BMP gradients during development.

  11. Drugs associated with teratogenic mechanisms. Part II : a literature review of the evidence on human risks

    NARCIS (Netherlands)

    van Gelder, Marleen M. H. J.; de Jong-van den Berg, Lolkje T. W.; Roeleveld, Nel

    What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with teratogenic mechanisms. Medical drugs

  12. Insertion of molecular oxygen into a palladium(II) methyl bond: a radical chain mechanism involving palladium(III) intermediates.

    Science.gov (United States)

    Boisvert, Luc; Denney, Melanie C; Hanson, Susan Kloek; Goldberg, Karen I

    2009-11-04

    The reaction of (bipy)PdMe(2) (1) (bipy = 2,2'-bipyridine) with molecular oxygen results in the formation of the palladium(II) methylperoxide complex (bipy)PdMe(OOMe) (2). The identity of the product 2 has been confirmed by independent synthesis. Results of kinetic studies of this unprecedented oxygen insertion reaction into a palladium alkyl bond support the involvement of a radical chain mechanism. Reproducible rates, attained in the presence of the radical initiator 2,2'-azobis(2-methylpropionitrile) (AIBN), reveal that the reaction is overall first-order (one-half-order in both [1] and [AIBN], and zero-order in [O(2)]). The unusual rate law (half-order in [1]) implies that the reaction proceeds by a mechanism that differs significantly from those for organic autoxidations and for the recently reported examples of insertion of O(2) into Pd(II) hydride bonds. The mechanism for the autoxidation of 1 is more closely related to that found for the autoxidation of main group and early transition metal alkyl complexes. Notably, the chain propagation is proposed to proceed via a stepwise associative homolytic substitution at the Pd center of 1 with formation of a pentacoordinate Pd(III) intermediate.

  13. Recent progress in sensor- and mechanics-R and D for the Belle II Silicon Vertex Detector

    Energy Technology Data Exchange (ETDEWEB)

    Bergauer, T., E-mail: thomas.bergauer@oeaw.ac.at [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria); Doljeschi, P.; Frankenberger, A.; Friedl, M.; Gfall, I.; Irmler, C. [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria); Onuki, Y. [University of Tokyo, Department of Physics, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Smiljic, D. [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria); Tsuboyama, T. [KEK, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Valentan, M. [Institute of High Energy Physics, Nikolsdorfer Gasse 18, A-1050 Vienna (Austria)

    2013-08-01

    The Belle experiment at the KEKB electron/positron collider in Tsukuba (Japan) was successfully running for more than ten years. A major update of the machine to SuperKEKB is now foreseen until 2015, aiming a peak luminosity which is 40 times the peak value of the previous system. This also requires a redesign of the Belle detector (leading to Belle II) and especially its Silicon Vertex Detector (SVD), which surrounds the beam pipe. The future Belle II SVD will consist of four layers of double-sided silicon strip sensors based on 6 in. silicon wafers. Three of the four layers will be equipped with trapezoidal sensors in the slanted forward region. Moreover, two inner layers with pixel detectors based on DEPFET technology will complement the SVD as innermost detector. Since the KEKB-factory operates at relatively low energy, material inside the active volume has to be minimized in order to reduce multiple scattering. This can be achieved by arranging the sensors in the so-called “Origami chip-on-sensor concept”, and a very light-weight mechanical support structure made from carbon fiber reinforced Airex foam. Moreover, CO{sub 2} cooling for the front-end chips will ensure high efficiency at minimum material budget. In this paper, an overview of the future Belle II SVD design will be given, covering the silicon sensors, the readout electronics and the mechanics. A strong emphasis will be given to our R and D work on double-sided sensors where different p-stop layouts for the n-side of the detectors were compared. Moreover, this paper gives updated numbers for the mechanical dimensions of the ladders and their radii.

  14. Recent progress in sensor- and mechanics-R and D for the Belle II Silicon Vertex Detector

    International Nuclear Information System (INIS)

    Bergauer, T.; Doljeschi, P.; Frankenberger, A.; Friedl, M.; Gfall, I.; Irmler, C.; Onuki, Y.; Smiljic, D.; Tsuboyama, T.; Valentan, M.

    2013-01-01

    The Belle experiment at the KEKB electron/positron collider in Tsukuba (Japan) was successfully running for more than ten years. A major update of the machine to SuperKEKB is now foreseen until 2015, aiming a peak luminosity which is 40 times the peak value of the previous system. This also requires a redesign of the Belle detector (leading to Belle II) and especially its Silicon Vertex Detector (SVD), which surrounds the beam pipe. The future Belle II SVD will consist of four layers of double-sided silicon strip sensors based on 6 in. silicon wafers. Three of the four layers will be equipped with trapezoidal sensors in the slanted forward region. Moreover, two inner layers with pixel detectors based on DEPFET technology will complement the SVD as innermost detector. Since the KEKB-factory operates at relatively low energy, material inside the active volume has to be minimized in order to reduce multiple scattering. This can be achieved by arranging the sensors in the so-called “Origami chip-on-sensor concept”, and a very light-weight mechanical support structure made from carbon fiber reinforced Airex foam. Moreover, CO 2 cooling for the front-end chips will ensure high efficiency at minimum material budget. In this paper, an overview of the future Belle II SVD design will be given, covering the silicon sensors, the readout electronics and the mechanics. A strong emphasis will be given to our R and D work on double-sided sensors where different p-stop layouts for the n-side of the detectors were compared. Moreover, this paper gives updated numbers for the mechanical dimensions of the ladders and their radii

  15. Mechanical-biological waste treatment and anaerobic processes. 59. information meeting, Neuwied, October 1999; Mechanisch-biologische Restabfallbehandlung und Anaerobverfahren. 59. Informationsgespraech in Neuwied im Oktober 1999

    Energy Technology Data Exchange (ETDEWEB)

    Hangen, H.O.; Euler, H.; Leonhardt, H.W. [comps.

    1999-10-01

    This proceedings volume discusses the specifications for and cost of mechanical-biological waste treatment, the optimisation of economic efficiency and pollutant emissons, the combination of mechanical-biological and thermal waste treatment processes, the value of mechanical-biological waste treatment, waste management concepts, process engineering and practical experience, and the eco-balance of the process. [German] Themen dieses Proceedingsbandes sind: Anforderungen und Kosten der mechanisch-biologischen Abfallbehandlung; Optimierung der Wirtschaftlichkeit und Emissionssituation; Kombination von mechanisch-biologischer und thermischer Muellbehandlung; Bewertung der mechanisch-biologischen Abfallbehandlung, Abfallwirtschaftskonzepte, Verfahrenstechnik und Betriebserfahrungen; Oekobilanz. (SR)

  16. Is the internal connection more efficient than external connection in mechanical, biological, and esthetical point of views? A systematic review.

    Science.gov (United States)

    Goiato, Marcelo Coelho; Pellizzer, Eduardo Piza; da Silva, Emily Vivianne Freitas; Bonatto, Liliane da Rocha; dos Santos, Daniela Micheline

    2015-09-01

    This systematic review aimed to evaluate if the internal connection is more efficient than the external connection and its associated influencing factors. A specific question was formulated according to the Population, Intervention, Control, and Outcome (PICO): Is internal connection more efficient than external connection in mechanical, biological, and esthetical point of views? An electronic search of the MEDLINE and the Web of Knowledge databases was performed for relevant studies published in English up to November 2013 by two independent reviewers. The keywords used in the search included a combination of "dental implant" and "internal connection" or "Morse connection" or "external connection." Selected studies were randomized clinical trials, prospective or retrospective studies, and in vitro studies with a clear aim of investigating the internal and/or external implant connection use. From an initial screening yield of 674 articles, 64 potentially relevant articles were selected after an evaluation of their titles and abstracts. Full texts of these articles were obtained with 29 articles fulfilling the inclusion criteria. Morse taper connection has the best sealing ability. Concerning crestal bone loss, internal connections presented better results than external connections. The limitation of the present study was the absence of randomized clinical trials that investigated if the internal connection was more efficient than the external connection. The external and internal connections have different mechanical, biological, and esthetical characteristics. Besides all systems that show proper success rates and effectiveness, crestal bone level maintenance is more important around internal connections than external connections. The Morse taper connection seems to be more efficient concerning biological aspects, allowing lower bacterial leakage and bone loss in single implants, including aesthetic regions. Additionally, this connection type can be successfully

  17. Characterization of mechanical and biological properties of 3-D scaffolds reinforced with zinc oxide for bone tissue engineering.

    Directory of Open Access Journals (Sweden)

    Pei Feng

    Full Text Available A scaffold for bone tissue engineering should have highly interconnected porous structure, appropriate mechanical and biological properties. In this work, we fabricated well-interconnected porous β-tricalcium phosphate (β-TCP scaffolds via selective laser sintering (SLS. We found that the mechanical and biological properties of the scaffolds were improved by doping of zinc oxide (ZnO. Our data showed that the fracture toughness increased from 1.09 to 1.40 MPam(1/2, and the compressive strength increased from 3.01 to 17.89 MPa when the content of ZnO increased from 0 to 2.5 wt%. It is hypothesized that the increase of ZnO would lead to a reduction in grain size and an increase in density of the strut. However, the fracture toughness and compressive strength decreased with further increasing of ZnO content, which may be due to the sharp increase in grain size. The biocompatibility of the scaffolds was investigated by analyzing the adhesion and the morphology of human osteoblast-like MG-63 cells cultured on the surfaces of the scaffolds. The scaffolds exhibited better and better ability to support cell attachment and proliferation when the content of ZnO increased from 0 to 2.5 wt%. Moreover, a bone like apatite layer formed on the surfaces of the scaffolds after incubation in simulated body fluid (SBF, indicating an ability of osteoinduction and osteoconduction. In summary, interconnected porous β-TCP scaffolds doped with ZnO were successfully fabricated and revealed good mechanical and biological properties, which may be used for bone repair and replacement potentially.

  18. Comparison between Visa-II and OCA-P for probabilistic fracture mechanics analysis focusing on analysis method

    International Nuclear Information System (INIS)

    Hirano, M.; Watanabe, N.; Tatewaki, I.; Akiba, H.

    1995-01-01

    Probabilistic fracture mechanics (PFM) analyses have been widely applied to evaluate the failure probabilities of PWR reactor pressure vessels subjected to pressurized thermal shock. In this study, a comparison between the VISA-II and OCA-P codes for PFM analyses was performed to clarify the differences in the numerical processes. For this purpose, the benchmark problems proposed by the U.S. Nuclear Regulatory Commission and the Electric Power Research Institute were applied. It is also discussed the algorithm to evaluate the deviations from the means of RT NDT and fracture toughness, and the numerical treatment of initial flaw depth as the major differences in these codes. 4 refs., 9 figs

  19. Influences of mechanical pre-treatment on the non-biological treatment of municipal wastewater by forward osmosis

    DEFF Research Database (Denmark)

    Hey, Tobias; Zarebska, Agata; Bajraktari, Niada

    2016-01-01

    municipal wastewater treatment without the biological treatment step, including the effects of different pre-treatment configurations, e.g., direct membrane filtration before forward osmosis. Forward osmosis was tested using raw wastewater and wastewater subjected to different types of mechanical pre-treatment......, e.g., microsieving and microfiltration permeation, as a potential technology for municipal wastewater treatment. Forward osmosis was performed using thin-film-composite, Aquaporin Inside(TM) and HTI membranes with NaCl as the draw solution. Both types of forward osmosis membranes were tested......-sized wastewater treatment plants....

  20. Study Under AC Stimulation on Excitement Properties of Weighted Small-World Biological Neural Networks with Side-Restrain Mechanism

    International Nuclear Information System (INIS)

    Yuan Wujie; Luo Xiaoshu; Jiang Pinqun

    2007-01-01

    In this paper, we propose a new model of weighted small-world biological neural networks based on biophysical Hodgkin-Huxley neurons with side-restrain mechanism. Then we study excitement properties of the model under alternating current (AC) stimulation. The study shows that the excitement properties in the networks are preferably consistent with the behavior properties of a brain nervous system under different AC stimuli, such as refractory period and the brain neural excitement response induced by different intensities of noise and coupling. The results of the study have reference worthiness for the brain nerve electrophysiology and epistemological science.

  1. Synthesis, Spectroscopy, Thermal Analysis, Magnetic Properties and Biological Activity Studies of Cu(II and Co(II Complexes with Schiff Base Dye Ligands

    Directory of Open Access Journals (Sweden)

    Saeid Amani

    2012-05-01

    Full Text Available Three azo group-containing Schiff base ligands, namely 1-{3-[(3-hydroxy-propyliminomethyl]-4-hydroxyphenylazo}-4-nitrobenzene (2a, 1-{3-[(3-hydroxypropyl-iminomethyl]-4-hydroxyphenylazo}-2-chloro-4-nitrobenzene (2b and 1-{3-[(3-hydroxy-propyliminomethyl]-4-hydroxyphenylazo}-4-chloro-3-nitrobenzene (2c were prepared. The ligands were characterized by elemental analysis, FTIR spectroscopy, UV-Vis spectroscopy, 13C- and 1H-NMR spectroscopy and thermogravimetric analysis. Next the corresponding copper(II and cobalt(II metal complexes were synthesized and characterized by the physicochemical and spectroscopic methods of elemental analysis, FTIR spectroscopy, UV-Vis spectroscopy, magnetic moment measurements, and thermogravimetric analysis (TGA and (DSC. The room temperature effective magnetic moments of complexes are 1.45, 1.56, 1.62, 2.16, 2.26 and 2.80 B.M. for complexes 3a, 3b, 3c, 4a 4b, and 4c, respectively, indicating that the complexes are paramagnetic with considerable electronic communication between the two metal centers.

  2. Profiles of Automotive Suppliers Industries--Engineered Mechanical Components and Systems : Volume II, Appendices.

    Science.gov (United States)

    1981-09-01

    The profile describes and analyzes that segment of the automotive supplier industry which provides engineered mechanical components/assemblies/systems to the prime auto manufacturers. It presents an overview of the role and structure of this industry...

  3. Mechanism of caesium ion exchange on potassium cobalt hexacyanoferrates(II)

    International Nuclear Information System (INIS)

    Lehto, J.; Haukka, S.; Harjula, R.; Blomberg, M.

    1990-01-01

    The caesium uptakes by K 2 [CoFe(CN) 6 ] and non-stoicheiometric compounds K 2/x Co x/2 [CoFe(CN) 6 ] were found to correlate directly with the specific surface areas of the products with x 1 are mixtures of cubic potassium cobalt hexacyanoferrate (ii) and tetragonal Co 2 Fe(CN) 6 . The thermodynamic equilibrium constant of the caesium exchange on K 2 [CoFe(CN) 6 ] was found to have a high value of 125. (author)

  4. Mechanical property and biological performance of electrospun silk fibroin-polycaprolactone scaffolds with aligned fibers.

    Science.gov (United States)

    Yuan, Han; Shi, Hongfei; Qiu, Xushen; Chen, Yixin

    2016-01-01

    The mechanical strength, biocompatibility, and sterilizability of silk fibroin allow it to be a possible candidate as a natural bone regenerate material. To improve mechanical character and reinforce the cell movement induction, silk fibroin (SF)-polycaprolactone (PCL) alloy was fabricated by electrospinning techniques with a rotating collector to form aligned fibrous scaffolds and random-oriented scaffolds. The scanning electron microscope image of the scaffold and the mechanical properties of the scaffold were investigated by tensile mechanical tests, which were compared to random-oriented scaffolds. Furthermore, mesenchymal stem cells were planted on these scaffolds to investigate the biocompatibility, elongation, and cell movement in situ. Scanning electron microscopy shows that 91% fibers on the aligned fibroin scaffold were distributed between the dominant direction ±10°. With an ideal support for stem cell proliferation in vitro, the aligned fibrous scaffold induces cell elongation at a length of 236.46 ± 82 μm and distribution along the dominant fiber direction with a cell alignment angle at 6.57° ± 4.45°. Compared with random-oriented scaffolds made by artificial materials, aligned SF-PCL scaffolds could provide a moderate mesenchymal stem cell engraftment interface and speed up early stage cell movement toward the bone defect.

  5. A Review of Biological Communication Mechanisms Applicable to Small Autonomous Systems

    Science.gov (United States)

    2010-09-01

    katydids, grasshoppers, beetles, moths, butterflies , ants, caterpillars, beetle larvae Hitting the ground Band-winged grasshoppers, cockroaches... butterflies and moths (Lepidoptera and Noctuidae). The Agaristid moth (e.g., Hecatesia exultans and Hecatesia thyridion) has castanet-like...Insects. The Ohio J. of Science 1957, 57 (2), 101. Bailey, W. J. The Mechanics of Stridulation in Bush Crickets (Tettigonioidea, Orthoptera): I

  6. Scale relativity theory and integrative systems biology: 2. Macroscopic quantum-type mechanics.

    Science.gov (United States)

    Nottale, Laurent; Auffray, Charles

    2008-05-01

    In these two companion papers, we provide an overview and a brief history of the multiple roots, current developments and recent advances of integrative systems biology and identify multiscale integration as its grand challenge. Then we introduce the fundamental principles and the successive steps that have been followed in the construction of the scale relativity theory, which aims at describing the effects of a non-differentiable and fractal (i.e., explicitly scale dependent) geometry of space-time. The first paper of this series was devoted, in this new framework, to the construction from first principles of scale laws of increasing complexity, and to the discussion of some tentative applications of these laws to biological systems. In this second review and perspective paper, we describe the effects induced by the internal fractal structures of trajectories on motion in standard space. Their main consequence is the transformation of classical dynamics into a generalized, quantum-like self-organized dynamics. A Schrödinger-type equation is derived as an integral of the geodesic equation in a fractal space. We then indicate how gauge fields can be constructed from a geometric re-interpretation of gauge transformations as scale transformations in fractal space-time. Finally, we introduce a new tentative development of the theory, in which quantum laws would hold also in scale space, introducing complexergy as a measure of organizational complexity. Initial possible applications of this extended framework to the processes of morphogenesis and the emergence of prokaryotic and eukaryotic cellular structures are discussed. Having founded elements of the evolutionary, developmental, biochemical and cellular theories on the first principles of scale relativity theory, we introduce proposals for the construction of an integrative theory of life and for the design and implementation of novel macroscopic quantum-type experiments and devices, and discuss their potential

  7. Aphids transform and detoxify the mycotoxin deoxynivalenol via a type II biotransformation mechanism yet unknown in animals.

    Science.gov (United States)

    De Zutter, N; Audenaert, K; Arroyo-Manzanares, N; De Boevre, M; Van Poucke, C; De Saeger, S; Haesaert, G; Smagghe, G

    2016-12-08

    Biotransformation of mycotoxins in animals comprises phase I and phase II metabolisation reactions. For the trichothecene deoxynivalenol (DON), several phase II biotransformation reactions have been described resulting in DON-glutathiones, DON-glucuronides and DON-sulfates made by glutathione-S-transferases, uridine-diphosphoglucuronyl transferases and sulfotransferases, respectively. These metabolites can be easily excreted and are less toxic than their free compounds. Here, we demonstrate for the first time in the animal kingdom the conversion of DON to DON-3-glucoside (DON-3G) via a model system with plant pathogenic aphids. This phase II biotransformation mechanism has only been reported in plants. As the DON-3G metabolite was less toxic for aphids than DON, this conversion is considered a detoxification reaction. Remarkably, English grain aphids (Sitobion avenae) which co-occur with the DON producer Fusarium graminearum on wheat during the development of fusarium symptoms, tolerate DON much better and convert DON to DON-3G more efficiently than pea aphids (Acyrthosiphon pisum), the latter being known to feed on legumes which are no host for F. graminearum. Using a non-targeted high resolution mass spectrometric approach, we detected DON-diglucosides in aphids probably as a result of sequential glucosylation reactions. Data are discussed in the light of an eventual co-evolutionary adaptation of S. avenae to DON.

  8. Synthesis and biological activity of acetates of copper (II and iron (III for the control of Aedes aegypti (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Jéssica V. Nardeli

    2012-06-01

    Full Text Available This work aimed to the synthesis of basic acetates of Cu (II and Fe(III against larvae of Aedes aegypti and Gram negative and Gram positive. The transition metal ions Cu (II and Fe (III have bactericidal activity and are toxic to Aedes aegypti larvae in the eggs and larval stages of initial, precludes the eggs hatch and slow reproductive cycle of the insect. The theme investigates the importance of carboxyl groups in complex formation, transport and cellular internalization of the toxic ions. It is known that the bactericide or insecticide activity is due to metal ions and Cu (IIor Fe (III.

  9. Networks In Real Space: Characteristics and Analysis for Biology and Mechanics

    Science.gov (United States)

    Modes, Carl; Magnasco, Marcelo; Katifori, Eleni

    Functional networks embedded in physical space play a crucial role in countless biological and physical systems, from the efficient dissemination of oxygen, blood sugars, and hormonal signals in vascular systems to the complex relaying of informational signals in the brain to the distribution of stress and strain in architecture or static sand piles. Unlike their more-studied abstract cousins, such as the hyperlinked internet, social networks, or economic and financial connections, these networks are both constrained by and intimately connected to the physicality of their real, embedding space. We report on the results of new computational and analytic approaches tailored to these physical networks with particular implications and insights for mammalian organ vasculature.

  10. Perceptron-like computation based on biologically-inspired neurons with heterosynaptic mechanisms

    Science.gov (United States)

    Kaluza, Pablo; Urdapilleta, Eugenio

    2014-10-01

    Perceptrons are one of the fundamental paradigms in artificial neural networks and a key processing scheme in supervised classification tasks. However, the algorithm they provide is given in terms of unrealistically simple processing units and connections and therefore, its implementation in real neural networks is hard to be fulfilled. In this work, we present a neural circuit able to perform perceptron's computation based on realistic models of neurons and synapses. The model uses Wang-Buzsáki neurons with coupling provided by axodendritic and axoaxonic synapses (heterosynapsis). The main characteristics of the feedforward perceptron operation are conserved, which allows to combine both approaches: whereas the classical artificial system can be used to learn a particular problem, its solution can be directly implemented in this neural circuit. As a result, we propose a biologically-inspired system able to work appropriately in a wide range of frequencies and system parameters, while keeping robust to noise and error.

  11. Theoretical Proposal for the Whole Phosphate Diester Hydrolysis Mechanism Promoted by a Catalytic Promiscuous Dinuclear Copper(II) Complex.

    Science.gov (United States)

    Esteves, Lucas F; Rey, Nicolás A; Dos Santos, Hélio F; Costa, Luiz Antônio S

    2016-03-21

    The catalytic mechanism that involves the cleavage of the phosphate diester model BDNPP (bis(2,4-dinitrophenyl) phosphate) catalyzed through a dinuclear copper complex is investigated in the current study. The metal complex was originally designed to catalyze catechol oxidation, and it showed an interesting catalytic promiscuity case in biomimetic systems. The current study investigates two different reaction mechanisms through quantum mechanics calculations in the gas phase, and it also includes the solvent effect through PCM (polarizable continuum model) single-point calculations using water as solvent. Two mechanisms are presented in order to fully describe the phosphate diester hydrolysis. Mechanism 1 is of the S(N)2 type, which involves the direct attack of the μ-OH bridge between the two copper(II) ions toward the phosphorus center, whereas mechanism 2 is the process in which hydrolysis takes place through proton transfer between the oxygen atom in the bridging hydroxo ligand and the other oxygen atom in the phosphate model. Actually, the present theoretical study shows two possible reaction paths in mechanism 1. Its first reaction path (p1) involves a proton transfer that occurs immediately after the hydrolytic cleavage, so that the proton transfer is the rate-determining step, which is followed by the entry of two water molecules. Its second reaction path (p2) consists of the entry of two water molecules right after the hydrolytic cleavage, but with no proton transfer; thus, hydrolytic cleavage is the rate-limiting step. The most likely catalytic path occurs in mechanism 1, following the second reaction path (p2), since it involves the lowest free energy activation barrier (ΔG(⧧) = 23.7 kcal mol(-1), in aqueous solution). A kinetic analysis showed that the experimental k(obs) value of 1.7 × 10(-5) s(-1) agrees with the calculated value k1 = 2.6 × 10(-5) s(-1); the concerted mechanism is kinetically favorable. The KIE (kinetic isotope effect) analysis

  12. Ventilation versus biology: What is the controlling mechanism of nitrous oxide distribution in the North Atlantic?

    Science.gov (United States)

    Paz, Mercedes; García-Ibáñez, Maribel I.; Steinfeldt, Reiner; Ríos, Aida F.; Pérez, Fiz F.

    2017-04-01

    The extent to which water mass mixing and ocean ventilation contribute to nitrous oxide (N2O) distribution at the scale of oceanic basins is poorly constrained. We used novel N2O and chlorofluorocarbon measurements along with multiparameter water mass analysis to evaluate the impact of water mass mixing and Atlantic Meridional Overturning Circulation (AMOC) on N2O distribution along the Observatoire de la variabilité interannuelle et décennale en Atlantique Nord (OVIDE) section, extending from Portugal to Greenland. The biological N2O production has a stronger impact on the observed N2O concentrations in the water masses traveling northward in the upper limb of the AMOC than those in recently ventilated cold water masses in the lower limb, where N2O concentrations reflect the colder temperatures. The high N2O tongue, with concentrations as high as 16 nmol kg-1, propagates above the isopycnal surface delimiting the upper and lower AMOC limbs, which extends from the eastern North Atlantic Basin to the Iceland Basin and coincides with the maximum N2O production rates. Water mixing and basin-scale remineralization account for 72% of variation in the observed distribution of N2O. The mixing-corrected stoichiometric ratio N2O:O2 for the North Atlantic Basin of 0.06 nmol/μmol is in agreement with ratios of N2O:O2 for local N2O anomalies, suggesting than up to 28% of N2O production occurs in the temperate and subpolar Atlantic, an overlooked region for N2O cycling. Overall, our results highlight the importance of taking into account mixing, O2 undersaturation when water masses are formed and the increasing atmospheric N2O concentrations when parameterizing N2O:O2 and biological N2O production in the global oceans.

  13. The radioinduced membranes injuries as biological dose indicators: mechanisms of studies and practical applications

    International Nuclear Information System (INIS)

    Vincent-Genod, Lucie

    2001-10-01

    After an accidental overexposure, the assessment of the received dose in biological dosimetry is performed by a method based on the effects of irradiation on the DNA molecule. But this technique shows some limitations; therefore we tried to find new bio-sensors of radiation exposure. We have pointed out that membrane is a critical target of ionising radiation after an in vitro and in vivo overexposure. In vitro, these modifications were involved in the radio-induced apoptotic pathway. The measure of membrane fluidity allowed us to obtain an overall view of cellular membrane. Moreover, in vivo, by changing the lipid nutritional status of animals, our results displayed the important role played by membrane lipid composition in radio-induced membrane alterations. Besides, membrane effects were adjusted by the extracellular physiological control, and in particular by the damages on membrane fatty acid pattern. Finally, we have tested the use of membrane fluidity index as a bio-sensor of radiation exposure on in vivo models and blood samples from medical total body irradiated patients. The results achieved on animal models suggested that the membrane fluidity index was a bio-sensor of radiation exposure. Nevertheless, the observations realised on patients highlight that the effect of the first dose fraction of the radiotherapy treatment had some difficulties to be noticed. Indeed, the combined treatment: chemotherapy and radiotherapy disturbed the membrane fluidity index measures. To conclude, whereas this parameter was not a bio-sensor of irradiation exposure usable in biological dosimetry, it may allow us to assess the radio-induced damages and their cellular but also tissue impacts. (author)

  14. Development and integration of high straightness flexure guiding mechanisms dedicated to the METAS watt balance Mark II

    Science.gov (United States)

    Cosandier, F.; Eichenberger, A.; Baumann, H.; Jeckelmann, B.; Bonny, M.; Chatagny, V.; Clavel, R.

    2014-04-01

    There is a firm will in the metrology community to redefine the kilogram in the International System of units by linking it to a fundamental physical constant. The watt balance is a promising way to link the mass unit to the Planck constant h. At the Federal Institute of Metrology METAS a second watt balance experiment is under development. A decisive part of the METAS Mark II watt balance is the mechanical linear guiding system. The present paper discusses the development and the metrological characteristics of two guiding systems that were conceived by the Laboratoire de Systèmes Robotiques of EPFL and built using flexure mechanical elements. Integration in the new setup is also described.

  15. Synthesis, physico-chemical characterization and biological activity of copper(ii and nickel(ii complexes with l-benzoyl-2-methylbenzimidazole derivatives

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2002-01-01

    Full Text Available Chlorides of copper(II and nickel(ll react with 1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole to give complexes of the type [M(LnCln(H20∙Cln (M = Cu or Ni; L = (1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole; n=O, 1 or 2. The complexes were synthesized and characterized by elemental analysis, molar conductivity magnetic susceptibility measurements and IR spectra. These studies suggest that all the complexes possess an octahedral stereochemistry. The antibacterial activity of (1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole and their complexes was evaluated against Escherichia coli and Bacillus sp.

  16. [Mechanism of action of intravesical BCG. Biological bases and clinical applicability.

    Science.gov (United States)

    Carballido, Joaquín A; Rodríguez Monsalve, María

    2018-05-01

    The therapeutic approaches developed around immune system modulation find the therapeutic contribution of intravesical Bacillus Calmette Guerin (BCG) for transitional cell bladder cancer an unquestionable example as a proof of concept of antitumor immunotherapy since more than 30 years ago. Intravesical immunotherapy for urothelial carcinomas is considered with periodic intravesical instillations schedules, and the one with longer historic development and wider diffusion is BCG in the form of suspension. BCG is a unique strain obtained from Mycobacterium bovis at the end of the first third of the XX century and represents the historically most successful immunotherapeutic modality of all tumors with a high level body of evidence. Currently, we even see an unpredictable development potential of this therapeutic modality based on immunomodulation related with activation or suppression of T lymphocytes by blocking the immune system checkpoints. This option is at this time a decisive step in the treatment of chemotherapy refractory metastatic urothelial carcinoma. Over the last years, there have been advances in the intimate mechanism of action of intravesical BCG, but there are many open questions that will only be answered from complex basic and translational research platforms. The objective of this review article is to try to translate the basic mechanisms currently implicated in the different phases of antitumor response of BCG in its routine use in clinical practice. Also, to analyze the future lines already active under clinical research with and without implications of the mechanisms of action of BCG. We describe the role of interactions basally established between urothelial tumor cells and cellular and molecular elements of the immune system of the patients with ulterior antitumor effector capacity. After intravesical BCG therapy and its interaction, we describe the various phases of its mechanism of action, namely fixation, internalization and triggering of

  17. Enhancement of the electrochemical behaviour and biological performance of Ti–25Ta–5Zr alloy by thermo-mechanical processing

    Energy Technology Data Exchange (ETDEWEB)

    Cimpean, Anisoara [Department of Biochemistry and Molecular Biology, University of Bucharest, Spl. Independentei, 91-95, 050095 Bucharest (Romania); Vasilescu, Ecaterina; Drob, Paula [Department of Electrochemistry and Corrosion, Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania); Cinca, Ion, E-mail: ion_cinca@hotmail.com [Faculty of Material Science and Engineering, Politehnica University, Spl. Independentei 313, 060042 Bucharest (Romania); Vasilescu, Cora; Anastasescu, Mihai [Department of Electrochemistry and Corrosion, Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania); Mitran, Valentina [Department of Biochemistry and Molecular Biology, University of Bucharest, Spl. Independentei, 91-95, 050095 Bucharest (Romania); Drob, Silviu Iulian [Department of Electrochemistry and Corrosion, Institute of Physical Chemistry “Ilie Murgulescu” of Romanian Academy, Spl. Independentei 202, 060021 Bucharest (Romania)

    2014-05-01

    A new Ti–25Ta–5Zr alloy based only on non-toxic and non-allergic elements was elaborated in as-cast and thermo-mechanical processed, recrystallized states (XRD and SEM) in order to be used as candidate material for implant applications. Its long-term interactions with Ringer–Brown and Ringer solutions of different pH values and its cytocompatibility were determined. The thermo-mechanically processed alloy has nobler electrochemical behaviour than as-cast alloy due to finer microstructure obtained after the applied treatment. Corrosion and ion release rates presented the lowest values for the treated alloy. Nyquist and Bode plots displayed higher impedance values and phase angles for the processed alloy, denoting a more protective passive film. SEM micrographs revealed depositions from solutions that contain calcium, phosphorous and oxygen ions (EDX analysis), namely calcium phosphate. An electric equivalent circuit with two time constants was modelled. Cell culture experiments with MC3T3-E1 pre-osteoblasts demonstrated that thermo-mechanically processed Ti–25Ta–5Zr alloy supports a better cell adhesion and spreading, and enhanced cell proliferation. Altogether, these data indicate that thermo-mechanical treatment endows the alloy with improved anticorrosion and biological performances. - Highlights: • Ti–25Ta–5Zr alloy exhibited noble electrochemical, passive behaviour in simulated biofluids. • An electric equivalent circuit with two time constants was modelled. • Corrosion rates show the lowest values for the recrystallized Ti–25Ta–5Zr alloy. • In vitro tests revealed good cytocompatibility of as-cast and processed alloy. • Recrystallized treatment endows the alloy with superior biological performances.

  18. Fabrication method, structure, mechanical, and biological properties of decellularized extracellular matrix for replacement of wide bone tissue defects.

    Science.gov (United States)

    Anisimova, N Y; Kiselevsky, M V; Sukhorukova, I V; Shvindina, N V; Shtansky, D V

    2015-09-01

    The present paper was focused on the development of a new method of decellularized extracellular matrix (DECM) fabrication via a chemical treatment of a native bone tissue. Particular attention was paid to the influence of chemical treatment on the mechanical properties of native bones, sterility, and biological performance in vivo using the syngeneic heterotopic and orthotopic implantation models. The obtained data indicated that after a chemical decellularization treatment in 4% aqueous sodium chlorite, no noticeable signs of the erosion of compact cortical bone surface or destruction of trabeculae of spongy bone in spinal channel were observed. The histological studies showed that the chemical treatment resulted in the decellularization of both bone and cartilage tissues. The DECM samples demonstrated no signs of chemical and biological degradation in vivo. Thorough structural characterization revealed that after decellularization, the mineral frame retained its integrity with the organic phase; however clotting and destruction of organic molecules and fibers were observed. FTIR studies revealed several structural changes associated with the destruction of organic molecules, although all organic components typical of intact bone were preserved. The decellularization-induced structural changes in the collagen constituent resulted changed the deformation under compression mechanism: from the major fracture by crack propagation throughout the sample to the predominantly brittle fracture. Although the mechanical properties of radius bones subjected to decellularization were observed to degrade, the mechanical properties of ulna bones in compression and humerus bones in bending remained unchanged. The compressive strength of both the intact and decellularized ulna bones was 125-130 MPa and the flexural strength of humerus bones was 156 and 145 MPa for the intact and decellularized samples, respectively. These results open new avenues for the use of DECM samples as

  19. Suitability of a PLCL fibrous scaffold for soft tissue engineering applications: A combined biological and mechanical characterisation.

    Science.gov (United States)

    Laurent, Cédric P; Vaquette, Cédryck; Liu, Xing; Schmitt, Jean-François; Rahouadj, Rachid

    2018-04-01

    Poly(lactide-co-ε-caprolactone) (PLCL) has been reported to be a good candidate for tissue engineering because of its good biocompatibility. Particularly, a braided PLCL scaffold (PLL/PCL ratio = 85/15) has been recently designed and partially validated for ligament tissue engineering. In the present study, we assessed the in vivo biocompatibility of acellular and cellularised scaffolds in a rat model. We then determined its in vitro biocompatibility using stem cells issued from both bone marrow and Wharton Jelly. From a biological point of view, the scaffold was shown to be suitable for tissue engineering in all these cases. Secondly, while the initial mechanical properties of this scaffold have been previously reported to be adapted to load-bearing applications, we studied the evolution in time of the mechanical properties of PLCL fibres due to hydrolytic degradation. Results for isolated PLCL fibres were extrapolated to the fibrous scaffold using a previously developed numerical model. It was shown that no accumulation of plastic strain was to be expected for a load-bearing application such as anterior cruciate ligament tissue engineering. However, PLCL fibres exhibited a non-expected brittle behaviour after two months. This may involve a potential risk of premature failure of the scaffold, unless tissue growth compensates this change in mechanical properties. This combined study emphasises the need to characterise the properties of biomaterials in a pluridisciplinary approach, since biological and mechanical characterisations led in this case to different conclusions concerning the suitability of this scaffold for load-bearing applications.

  20. Enhancement of the electrochemical behaviour and biological performance of Ti–25Ta–5Zr alloy by thermo-mechanical processing

    International Nuclear Information System (INIS)

    Cimpean, Anisoara; Vasilescu, Ecaterina; Drob, Paula; Cinca, Ion; Vasilescu, Cora; Anastasescu, Mihai; Mitran, Valentina; Drob, Silviu Iulian

    2014-01-01

    A new Ti–25Ta–5Zr alloy based only on non-toxic and non-allergic elements was elaborated in as-cast and thermo-mechanical processed, recrystallized states (XRD and SEM) in order to be used as candidate material for implant applications. Its long-term interactions with Ringer–Brown and Ringer solutions of different pH values and its cytocompatibility were determined. The thermo-mechanically processed alloy has nobler electrochemical behaviour than as-cast alloy due to finer microstructure obtained after the applied treatment. Corrosion and ion release rates presented the lowest values for the treated alloy. Nyquist and Bode plots displayed higher impedance values and phase angles for the processed alloy, denoting a more protective passive film. SEM micrographs revealed depositions from solutions that contain calcium, phosphorous and oxygen ions (EDX analysis), namely calcium phosphate. An electric equivalent circuit with two time constants was modelled. Cell culture experiments with MC3T3-E1 pre-osteoblasts demonstrated that thermo-mechanically processed Ti–25Ta–5Zr alloy supports a better cell adhesion and spreading, and enhanced cell proliferation. Altogether, these data indicate that thermo-mechanical treatment endows the alloy with improved anticorrosion and biological performances. - Highlights: • Ti–25Ta–5Zr alloy exhibited noble electrochemical, passive behaviour in simulated biofluids. • An electric equivalent circuit with two time constants was modelled. • Corrosion rates show the lowest values for the recrystallized Ti–25Ta–5Zr alloy. • In vitro tests revealed good cytocompatibility of as-cast and processed alloy. • Recrystallized treatment endows the alloy with superior biological performances

  1. Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms.

    Science.gov (United States)

    Wang, Jingjing; Li, Zhengkui

    2015-12-30

    A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by (60)Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption-desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options

    Science.gov (United States)

    Lee, Chang-Ro; Lee, Jung Hun; Park, Moonhee; Park, Kwang Seung; Bae, Il Kwon; Kim, Young Bae; Cha, Chang-Jun; Jeong, Byeong Chul; Lee, Sang Hee

    2017-01-01

    Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of β-lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized. PMID:28348979

  3. Electroacupuncture improves cerebral blood flow and attenuates moderate ischemic injury via Angiotensin II its receptors-mediated mechanism in rats.

    Science.gov (United States)

    Li, Jing; He, Jiaojun; Du, Yuanhao; Cui, Jingjun; Ma, Ying; Zhang, Xuezhu

    2014-11-11

    To investigate the effects and potential mechanism of electroacupuncture intervention on expressions of Angiotensin II and its receptors-mediated signaling pathway in experimentally induced cerebral ischemia. Totally 126 male Wistar rats were randomly divided into control group, model group and EA group. The latter two were further divided into ten subgroups (n = 6) following Middle Cerebral Artery Occlusion (MCAO). Changes in regional cerebral blood flow (rCBF) and expressions of Angiotensin II and its receptors (AT1R, AT2R), as well as effector proteins in phosphatidyl inositol signal pathway were monitored before and at different times after MCAO. MCAO-induced decline of ipsilateral rCBF was partially suppressed by electroacupuncture, and contralateral blood flow was also superior to that of model group. Angiotensin II level was remarkably elevated immediately after MCAO, while electroacupuncture group exhibited significantly lower levels at 1 to 3 h and the value was significantly increased thereafter. The enhanced expression of AT1R was partially inhibited by electroacupuncture, while increased AT2R level was further induced. Electroacupuncture stimulation attenuated and postponed the upregulated-expressions of Gq and CaM these upregulations. ELISA results showed sharply increased expressions of DAG and IP3, which were remarkably neutralized by electroacupuncture. MCAO induced significant increases in expression of Angiotensin II and its receptor-mediated signal pathway. These enhanced expressions were significantly attenuated by electroacupuncture intervention, followed by reduced vasoconstriction and improved blood supply in ischemic region, and ultimately conferred beneficial effects on cerebral ischemia.

  4. Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingjing [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China); Li, Zhengkui, E-mail: zhkuili@nju.edu.cn [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China)

    2015-12-30

    Highlights: • A novel ion-imprinted poly(polyethylenimine/hydroxyethyl acrylate) hydrogel was synthesized. • The prepared hydrogel enhanced the selectivity of Cu(II) removal. • The material had high adsorption capacity and excellent regeneration property for copper. • The adsorption mechanism was the chelate interaction between functional groups and Cu(II) ions. - Abstract: A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by {sup 60}Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption–desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater.

  5. The Biology of Atherosclerosis: General Paradigms and Distinct Pathogenic Mechanisms Among HIV-Infected Patients

    OpenAIRE

    Lo, Janet; Plutzky, Jorge

    2012-01-01

    Complications of atherosclerosis, including myocardial infarction and stroke, are the leading cause of death and disability worldwide. Recent data strongly implicate cardiovascular death as a contributor to mortality among patients with human immunodeficiency virus (HIV) infection, with evidence suggesting increased incidence of atherosclerosis among these patients. Therefore, greater understanding of atherosclerotic mechanisms and how these responses may be similar or distinct in HIV-infecte...

  6. Biological Communities in Desert Varnish and Potential Implications for Varnish Formation Mechanisms

    Science.gov (United States)

    Lang-Yona, Naama; Maier, Stefanie; Macholdt, Dorothea; Rodriguez-Caballero, Emilio; Müller-Germann, Isabell; Yordanova, Petya; Jochum, Klaus-Peter; Andreae, Meinrat O.; Pöschl, Ulrich; Weber, Bettina; Fröhlich-Nowoisky, Janine

    2017-04-01

    Desert varnishes are thin, orange to black coatings found on rocks in arid and semi-arid environments on Earth. The formation mechanisms of rock varnish are still under debate and the involvement of microorganisms in this process remains unclear. In this work we aimed to identify the microbial community occurring in rock varnish to potentially gain insights into the varnish formation mechanism. For this purpose, rocks coated with desert varnish were collected from the Anza-Borrego Desert, California, USA, as well as soils from underneath the rocks. DNA from both varnish coatings and soil samples was extracted and subsequently used for metagenomic analysis, as well as for q-PCR analyses for specific species quantification. The element composition of the varnish coatings was analyzed and compared to the soil samples. Rock varnish shows similar depleted elements, compared to soil, but Mn and Pb are 50-60 times enriched compared to the soil samples, and about 100 times enriched compared to the upper continental crust. Our genomic analyses suggest unique populations and different protein functional groups occurring in the varnish compared to soil samples. We discuss these differences and try to shed light on the mechanism of Mn oxyhydroxide production in desert varnish formation.

  7. A promising magnetic resonance stem cell tracer based on natural biomaterials in a biological system: manganese (II chelated to melanin nanoparticles

    Directory of Open Access Journals (Sweden)

    Liu SJ

    2018-03-01

    Full Text Available Shi-Jie Liu,1,2,* Ling-Jie Wang,1,* Ying Qiao,1 Hua Zhang,1 Li-Ping Li,1 Jing-Hua Sun,1 Sheng He,1 Wen Xu,1,2 Xi Yang,1 Wen-Wen Cai,2 Jian-Ding Li,1 Bin-Quan Wang,3 Rui-Ping Zhang2 1Medical Imaging Department, First Clinical Medical College of Shanxi Medical University, Taiyuan, Shanxi, China; 2Imaging Department, Affiliated Tumor Hospital of Shanxi Medical University, Taiyuan, Shanxi, China; 3Department of Otolaryngology, Head & Neck Surgery, The First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China *These authors contributed equally to the paper Background: Melanin and manganese are both indispensable natural substances that play crucial roles in the human body. Melanin has been used as a multimodality imaging nanoplatform for biology science research because of its natural binding ability with metal ions (eg, 64Cu2+, Fe3+, and Gd3+. Because of its effects on T1 signal enhancement, Mn-based nanoparticles have been used in magnetic resonance (MR quantitative cell tracking in vivo. Stem cell tracking in vivo is an essential technology used to characterize engrafted stem cells, including cellular viability, biodistribution, differentiation capacity, and long-term fate.Methods: In the present study, manganese(II ions chelated to melanin nanoparticles [MNP-Mn(II] were synthesized. The characteristics, stem cell labeling efficiency, and cytotoxicity of the nanoparticles were evaluated. MR imaging of the labeled stem cells in vivo and in vitro were also further performed. In T1 relaxivity (r1, MNP-Mn(II were significantly more abundant than Omniscan. Bone marrow-derived stem cells (BMSCs can be labeled easily by coincubating with MNP-Mn(II, suggesting that MNP-Mn(II had high biocompatibility.Results: Cell Counting Kit-8 assays revealed that MNP-Mn(II had almost no cytotoxicity when used to label BMSCs, even with a very high concentration (1,600 µg/mL. BMSCs labeled with MNP-Mn(II could generate a hyperintense T1 signal both in vitro

  8. Multiple-event probability in general-relativistic quantum mechanics. II. A discrete model

    International Nuclear Information System (INIS)

    Mondragon, Mauricio; Perez, Alejandro; Rovelli, Carlo

    2007-01-01

    We introduce a simple quantum mechanical model in which time and space are discrete and periodic. These features avoid the complications related to continuous-spectrum operators and infinite-norm states. The model provides a tool for discussing the probabilistic interpretation of generally covariant quantum systems, without the confusion generated by spurious infinities. We use the model to illustrate the formalism of general-relativistic quantum mechanics, and to test the definition of multiple-event probability introduced in a companion paper [Phys. Rev. D 75, 084033 (2007)]. We consider a version of the model with unitary time evolution and a version without unitary time evolution

  9. Dipole mechanism of spontaneous breaking of N = 2 supersymmetry. II. Reformulation and generalization in harmonic superspace

    International Nuclear Information System (INIS)

    Ohta, N.

    1985-01-01

    After elucidating the component structure of N = 2 supersymmetric gauge theories in the harmonic superspace formalism with central charges, we reformulate our previous dipole mechanism of spontaneous breaking of N = 2 supersymmetry free from the Nambu-Goldstone-fermion difficulties in this formalism. This allows a generalization of our previous model of generating finiteness-preserving mass terms for scalar hypermultiplets; we can also obtain the gauge-fermion and scalar mass terms together with specific cubic interactions for scalar fields. The mechanism is equivalent to the so-called spurion method

  10. Midrange affinity fluorescent Zn(II) sensors of the Zinpyr family: syntheses, characterization, and biological imaging applications.

    Science.gov (United States)

    Nolan, Elizabeth M; Jaworski, Jacek; Racine, Maryann E; Sheng, Morgan; Lippard, Stephen J

    2006-11-27

    The syntheses and photophysical characterization of ZP9, 2-{2-chloro-6-hydroxy-3-oxo-5-[(2-{[pyridin-2-ylmethyl-(1H-pyrrol-2-ylmethyl)amino]methyl}phenylamino)methyl]-3H-xanthen-9-yl}benzoic acid, and ZP10, 2-{2-chloro-6-hydroxy-5-[(2-{[(1-methyl-1H-pyrrol-2-ylmethyl)pyridin-2-ylmethylamino]methyl}phenylamino)methyl]-3-oxo-3H-xanthen-9-yl}benzoic acid, two asymmetrically derivatized fluorescein-based dyes, are described. These sensors each contain an aniline-based ligand moiety functionalized with a pyridyl-amine-pyrrole group and have dissociation constants for Zn(II) in the sub-micromolar (ZP9) and low-micromolar (ZP10) range, which we define as "midrange". They give approximately 12- (ZP9) and approximately 7-fold (ZP10) fluorescence turn-on immediately following Zn(II) addition at neutral pH and exhibit improved selectivity for Zn(II) compared to the di-(2-picolyl)amine-based Zinpyr (ZP) sensors. Confocal microscopy studies indicate that such asymmetrical fluorescein-based probes are cell permeable and Zn(II) responsive in vivo.

  11. Biologically relevant mono- and di-nuclear manganese II/III/IV complexes of mononegative pentadentate ligands

    DEFF Research Database (Denmark)

    Baffert, Carole; Collomb, Marie-Nöelle; Deronzier, Alain

    2003-01-01

    were characterised by UV-visible spectroscopy, ESI mass spectrometry and cyclic voltammetry. In addition, III-IV and II-III species were electrochemically generated. Thus the new mononegative pentadentate ligand systems display significant flexibility in the range of Mn oxidation states and species...

  12. Synthesis, biological and physicochemical properties of Zinc(II) salicylate and 5-chlorosalicylate complexes with theophylline and urea

    Czech Academy of Sciences Publication Activity Database

    Bujdošová, Z.; Gyoryova, K.; Kovářová, Jana; Hudecová, D.; Halás, L.

    2009-01-01

    Roč. 98, č. 1 (2009), s. 151-159 ISSN 1388-6150 Institutional research plan: CEZ:AV0Z40500505 Keywords : zinc(II) salicylate * theophylline * urea Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.587, year: 2009

  13. EPR interpretation, magnetism and biological study of a Cu(II) dinuclear complex assisted by a schiff base precursor.

    Science.gov (United States)

    Das, Kuheli; Patra, Chiranjit; Sen, Chandana; Datta, Amitabha; Massera, Chiara; Garribba, Eugenio; El Fallah, Mohamed Salah; Beyene, Belete B; Hung, Chen-Hsiung; Sinha, Chittaranjan; Askun, Tulin; Celikboyun, Pinar; Escudero, Daniel; Frontera, Antonio

    2017-06-01

    A new Cu(II) dinuclear complex, Cu 2 L 2 (1) was afforded employing the potentially pentatentate Schiff base precursor H 2 L, a refluxed product of o-vanillin and diethylenetriamine in methanol. Complex 1 was systematically characterized by FTIR, UV-Vis, emission and EPR spectrometry. The single crystal X-ray diffraction analysis of 1 reveals that the copper atom exhibits a distorted square planar geometry, comprising two pairs of phenolato-O and imine-N donors from two different H 2 L ligands. The temperature dependent magnetic interpretation agrees with the existence of weak antiferromagnetic interactions between the bridging dinuclear Cu(II) ions. A considerable body of experimental evidence has been accumulated to elucidate the magneto-structural relationship in this dinuclear Cu(II) complex by DFT computation. Both the ligand and complex 1 exhibit anti-mycobacterial activity and considerable efficacy on M. tuberculosis H 37 Ra (ATCC 25177) and M. tuberculosis H 37 Rv (ATCC 25618) strains. The practical applicability of the ligand and complex 1 has been examined in living cells (African Monkey Vero Cells). The MTT assay proves the non-toxicity of the probe up to 100 mg mL -1 . A new homometallic dinuclear Cu(II) complex is afforded with a tetradentate Schiff base precursor. EPR interpretation and temperature dependent magnetic studies show that complex 1 has weak antiferromagnetic coupling and DFT computation is governed to explain the magneto-structural correlation.

  14. Experimental and modelling studies on a laboratory scale anaerobic bioreactor treating mechanically biologically treated municipal solid waste.

    Science.gov (United States)

    Lakshmikanthan, P; Sughosh, P; White, James; Sivakumar Babu, G L

    2017-07-01

    The performance of an anaerobic bioreactor in treating mechanically biologically treated municipal solid waste was investigated using experimental and modelling techniques. The key parameters measured during the experimental test period included the gas yield, leachate generation and settlement under applied load. Modelling of the anaerobic bioreactor was carried out using the University of Southampton landfill degradation and transport model. The model was used to simulate the actual gas production and settlement. A sensitivity analysis showed that the most influential model parameters are the monod growth rate and moisture. In this case, pH had no effect on the total gas production and waste settlement, and only a small variation in the gas production was observed when the heat transfer coefficient of waste was varied from 20 to 100 kJ/(m d K) -1 . The anaerobic bioreactor contained 1.9 kg (dry) of mechanically biologically treated waste producing 10 L of landfill gas over 125 days.

  15. Recent advances in the understanding of brown spider venoms: From the biology of spiders to the molecular mechanisms of toxins.

    Science.gov (United States)

    Gremski, Luiza Helena; Trevisan-Silva, Dilza; Ferrer, Valéria Pereira; Matsubara, Fernando Hitomi; Meissner, Gabriel Otto; Wille, Ana Carolina Martins; Vuitika, Larissa; Dias-Lopes, Camila; Ullah, Anwar; de Moraes, Fábio Rogério; Chávez-Olórtegui, Carlos; Barbaro, Katia Cristina; Murakami, Mario Tyago; Arni, Raghuvir Krishnaswamy; Senff-Ribeiro, Andrea; Chaim, Olga Meiri; Veiga, Silvio Sanches

    2014-06-01

    The Loxosceles genus spiders (the brown spiders) are encountered in all the continents, and the clinical manifestations following spider bites include skin necrosis with gravitational lesion spreading and occasional systemic manifestations, such as intravascular hemolysis, thrombocytopenia and acute renal failure. Brown spider venoms are complex mixtures of toxins especially enriched in three molecular families: the phospholipases D, astacin-like metalloproteases and Inhibitor Cystine Knot (ICK) peptides. Other toxins with low level of expression also present in the venom include the serine proteases, serine protease inhibitors, hyaluronidases, allergen factors and translationally controlled tumor protein (TCTP). The mechanisms by which the Loxosceles venoms act and exert their noxious effects are not fully understood. Except for the brown spider venom phospholipase D, which causes dermonecrosis, hemolysis, thrombocytopenia and renal failure, the pathological activities of the other venom toxins remain unclear. The objective of the present review is to provide insights into the brown spider venoms and loxoscelism based on recent results. These insights include the biology of brown spiders, the clinical features of loxoscelism and the diagnosis and therapy of brown spider bites. Regarding the brown spider venom, this review includes a description of the novel toxins revealed by molecular biology and proteomics techniques, the data regarding three-dimensional toxin structures, and the mechanism of action of these molecules. Finally, the biotechnological applications of the venom components, especially for those toxins reported as recombinant molecules, and the challenges for future study are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Learning biology through connecting mathematics to scientific mechanisms: Student outcomes and teacher supports

    Science.gov (United States)

    Schuchardt, Anita

    Integrating mathematics into science classrooms has been part of the conversation in science education for a long time. However, studies on student learning after incorporating mathematics in to the science classroom have shown mixed results. Understanding the mixed effects of including mathematics in science has been hindered by a historical focus on characteristics of integration tangential to student learning (e.g., shared elements, extent of integration). A new framework is presented emphasizing the epistemic role of mathematics in science. An epistemic role of mathematics missing from the current literature is identified: use of mathematics to represent scientific mechanisms, Mechanism Connected Mathematics (MCM). Building on prior theoretical work, it is proposed that having students develop mathematical equations that represent scientific mechanisms could elevate their conceptual understanding and quantitative problem solving. Following design and implementation of an MCM unit in inheritance, a large-scale quantitative analysis of pre and post implementation test results showed MCM students, compared to traditionally instructed students) had significantly greater gains in conceptual understanding of mathematically modeled scientific mechanisms, and their ability to solve complex quantitative problems. To gain insight into the mechanism behind the gain in quantitative problem solving, a small-scale qualitative study was conducted of two contrasting groups: 1) within-MCM instruction: competent versus struggling problem solvers, and 2) within-competent problem solvers: MCM instructed versus traditionally instructed. Competent MCM students tended to connect their mathematical inscriptions to the scientific phenomenon and to switch between mathematical and scientifically productive approaches during problem solving in potentially productive ways. The other two groups did not. To address concerns about teacher capacity presenting barriers to scalability of MCM

  17. Micrococcus luteus correndonucleases. II. Mechanism of action of two endonucleases specific for DNA containing pyrimidine dimers

    International Nuclear Information System (INIS)

    Riazuddin, S.; Grossman, L.

    1977-01-01

    Py--Py correndonucleases I and II from Micrococcus luteus act exclusively on thymine-thymine, cytosine-cytosine, and thymine-cytosine cyclobutyl dimers in DNA, catalyzing incision 5' to the damage and generating 3'-hydroxyl and 5'-phosphoryl termini. Both enzymes initiate excision of pyrimidine dimers in vitro by correxonucleases and DNA polymerase I. The respective incised DNAs, however, differ in their ability to act as substrate for phage T4 polynucleotide ligase or bacterial alkaline phosphatase, suggesting that each endonuclease is specific for a conformationally unique site. The possibility that their respective action generates termini which represent different degrees of single strandedness is suggested by the unequal protection by Escherichia coli binding protein from the hydrolytic action of exonuclease VII

  18. The phase-II ATLAS pixel tracker upgrade: layout and mechanics.

    CERN Document Server

    Sharma, Abhishek; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment will upgrade its tracking detector during the Phase-II LHC shutdown, to better take advantage of the increased luminosity of the HL-LHC. The upgraded tracker will consist of silicon-strip modules surrounding a pixel detector, and will likely cover an extended eta range, perhaps as far as |eta|<4.0. A number of layout and supporting-structure options are being considered for the pixel detector, with the final choice expected to be made in early 2017. The proposed supporting structures are based on lightweight, highly-thermally-conductive carbon-based materials and are cooled by evaporative carbon dioxide. The various layouts will be described and a description of the supporting structures will be presented, along with results from testing of prototypes.

  19. Mechanism of caesium ion exchange on potassium cobalt hexacyanoferrates(II)

    Energy Technology Data Exchange (ETDEWEB)

    Lehto, J.; Haukka, S.; Harjula, R. (Helsinki Univ. (Finland). Dept. of Radiochemistry); Blomberg, M. (Helsinki Univ. (Finland). Dept. of Physics)

    1990-03-01

    The caesium uptakes by K{sub 2}(CoFe(CN){sub 6}) and non-stoicheiometric compounds K{sub 2/x}Co{sub x/2}(CoFe(CN){sub 6}) were found to correlate directly with the specific surface areas of the products with x < 1. The exchange process is assumed to involve only the outermost surface layer of their crystals, which have cubic lattice, i.e. only potassium (or cobalt) ions inside the elementary cubes closest to the surface of the crystals are exchanged for caesium ions. Compounds with x > 1 are mixtures of cubic potassium cobalt hexacyanoferrate (ii) and tetragonal Co{sub 2}Fe(CN){sub 6}. The thermodynamic equilibrium constant of the caesium exchange on K{sub 2}(CoFe(CN){sub 6}) was found to have a high value of 125. (author).

  20. Systems of organic farming in spring vetch II: Biological response of Aeolothrips intermedius Bagnall and Coccinella septempunctata L.

    Directory of Open Access Journals (Sweden)

    Ivelina Nikolova

    2015-09-01

    Full Text Available The effects of four systems of organic farming of spring vetsch on Aeolothrips intermedius Bagnall (Thysanoptera: Aeolothripidae and Coccinella septempunctata L. (Coleoptera: Coccinellidae population density and the toxicity of several products on predatory insects were studied. The variants were: Control (without using any biological products; combined treatment with Polyversum (biological foliar fertilizer and Biofa (biological plant growth regulator; treatment with NeemAzal T/S (biological insecticide, a.i. azadirachtin and treatment with a combination of NeemAzal with Polyversum and Biofa. Variant V was a conventional farming system in which a combination of Nurelle D (synthetic insecticide, Masterblend (foliar fertilizer and Flordimex 420 (growth regulator was used as a standard treatment. In the organic farming system that included treatment of plants with the biological insecticide NeemAzal (azadirachtin, the reduction in A. intermedius abundance was 20.7% when it was applied alone and 24.6 % in combination with the organic products Polyversum and Biofa. NeemAzal achieved a lower reduction in the counts of predatory ladybirds C. septempunctata, from 14.9% (alone to 21.9% (combination. The biological insecticide, applied alone or in combination, was mostly harmless and rarely harmful to A. intermedius. NeemAzal manifested harmlessness to C. septempunctata as its toxic action did not exceed 25%. An analysis of variance regarding product toxicity to A. intermedius and C. septempunctata demonstrated that the type of treatment (the application of insecticides alone or in combination had the strongest effect on product toxicity. Тhe use of neem-based insecticides can be a substantial contribution towards preservation of biodiversity in ecosystems.

  1. Mechanism of Action for Anti-radiation Vaccine in Reducing the Biological Impact of High-dose Gamma Irradiation

    Science.gov (United States)

    Maliev, Vladislav; Popov, Dmitri; Jones, Jeffrey A.; Casey, Rachael C.

    2007-01-01

    Ionizing radiation is a major health risk of long-term space travel, the biological consequences of which include genetic and oxidative damage. In this study, we propose an original mechanism by which high doses of ionizing radiation induce acute toxicity. We identified biological components that appear in the lymphatic vessels shortly after gamma irradiation. These radiation-induced toxins, which we have named specific radiation determinants (SRD), were generated in the irradiated tissues and then collected and circulated throughout the body via the lymph circulation and bloodstream. Depending on the type of SRD elicited, different syndromes of acute radiation sickness (ARS) were expressed. The SRDs were developed into a vaccine used to confer active immunity against acute radiation toxicity in immunologically naive animals. Animals that were pretreated with SRDs exhibited resistance to lethal doses of gamma radiation, as measured by increased survival times and survival rates. In comparison, untreated animals that were exposed to similar large doses of gamma radiation developed acute radiation sickness and died within days. This phenomenon was observed in a number of mammalian species. Initial analysis of the biochemical characteristics indicated that the SRDs were large molecular weight (200-250 kDa) molecules that were comprised of a mixture of protein, lipid, carbohydrate, and mineral. Further analysis is required to further identify the SRD molecules and the biological mechanism by which the mediate the toxicity associated with acute radiation sickness. By doing so, we may develop an effective specific immunoprophylaxis as a countermeasure against the acute effects of ionizing radiation.

  2. Biological cell as a soft magnetoelectric material: Elucidating the physical mechanisms underpinning the detection of magnetic fields by animals

    Science.gov (United States)

    Krichen, S.; Liu, L.; Sharma, P.

    2017-10-01

    Sharks, birds, bats, turtles, and many other animals can detect magnetic fields. Aside from using this remarkable ability to exploit the terrestrial magnetic field map to sense direction, a subset is also able to implement a version of the so-called geophysical positioning system. How do these animals detect magnetic fields? The answer to this rather deceptively simple question has proven to be quite elusive. The currently prevalent theories, while providing interesting insights, fall short of explaining several aspects of magnetoreception. For example, minute magnetic particles have been detected in magnetically sensitive animals. However, how is the detected magnetic field converted into electrical signals given any lack of experimental evidence for relevant electroreceptors? In principle, a magnetoelectric material is capable of converting magnetic signals into electricity (and vice versa). This property, however, is rare and restricted to a rather small set of exotic hard crystalline materials. Indeed, such elements have never been detected in the animals studied so far. In this work we quantitatively outline the conditions under which a biological cell may detect a magnetic field and convert it into electrical signals detectable by biological cells. Specifically, we prove the existence of an overlooked strain-mediated mechanism and show that most biological cells can act as nontrivial magnetoelectric materials provided that the magnetic permeability constant is only slightly more than that of a vacuum. The enhanced magnetic permeability is easily achieved by small amounts of magnetic particles that have been experimentally detected in magnetosensitive animals. Our proposed mechanism appears to explain most of the experimental observations related to the physical basis of magnetoreception.

  3. Mechanism of action for anti-radiation vaccine in reducing the biological impact of high-dose gamma irradiation

    Science.gov (United States)

    Maliev, Vladislav; Popov, Dmitri; Jones, Jeffrey A.; Casey, Rachael C.

    Ionizing radiation is a major health risk of long-term space travel, the biological consequences of which include genetic and oxidative damage. In this study, we propose an original mechanism by which high doses of ionizing radiation induce acute toxicity. We identified biological components that appear in the lymphatic vessels shortly after high-dose gamma irradiation. These radiation-induced toxins, which we have named specific radiation determinants (SRD), were generated in the irradiated tissues and then circulated throughout the body via the lymph circulation and bloodstream. Depending on the type of SRD elicited, different syndromes of acute radiation sickness (ARS) were expressed. The SRDs were developed into a vaccine used to confer active immunity against acute radiation toxicity in immunologically naïve animals. Animals that were pretreated with SRDs exhibited resistance to lethal doses of gamma radiation, as measured by increased survival times and survival rates. In comparison, untreated animals that were exposed to similar large doses of gamma radiation developed acute radiation sickness and died within days. This phenomenon was observed in a number of mammalian species. Initial analysis of the biochemical characteristics indicated that the SRDs were large molecular weight (200-250 kDa) molecules that were comprised of a mixture of protein, lipid, carbohydrate, and mineral. Further analysis is required to further identify the SRD molecules and the biological mechanism by which they mediate the toxicity associated with acute radiation sickness. By doing so, we may develop an effective specific immunoprophylaxis as a countermeasure against the acute effects of ionizing radiation.

  4. Review of low dose-rate epidemiological studies and biological mechanisms of dose-rate effects on radiation induced carcinogenesis

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Otsuka, Kensuke; Yoshida, Kazuo

    2015-01-01

    Radiation protection system adopts the linear non-threshold model with using dose and dose-rate effectiveness factor (DDREF). The dose-rate range where DDREF is applied is below 100 mGy per hour, and it is regarded that there are no dose-rate effects at very low dose rate, less than of the order of 10 mGy per year, even from the biological risk evaluation model based on cellular and molecular level mechanisms for maintenance of genetic integrity. Among low dose-rate epidemiological studies, studies of residents in high natural background areas showed no increase of cancer risks at less than about 10 mGy per year. On the other hand, some studies include a study of the Techa River cohort suggested the increase of cancer risks to the similar degree of Atomic bomb survivor data. The difference of those results was supposed due to the difference of dose rate. In 2014, International Commission on Radiological Protection opened a draft report on stem cell biology for public consultations. The report proposed a hypothesis based on the new idea of stem cell competition as a tissue level quality control mechanism, and suggested that it could explain the dose-rate effects around a few milligray per year. To verify this hypothesis, it would be needed to clarify the existence and the lowest dose of radiation-induced stem cell competition, and to elucidate the rate of stem cell turnover and radiation effects on it. As for the turnover, replenishment of damaged stem cells would be the important biological process. It would be meaningful to collect the information to show the difference of dose rates where the competition and the replenishment would be the predominant processes. (author)

  5. Study on regeneration effect and mechanism of high-frequency ultrasound on biological activated carbon.

    Science.gov (United States)

    Sun, Zhehao; Liu, Cheng; Cao, Zhen; Chen, Wei

    2018-06-01

    High frequency ultrasonic radiation technology was developed as a novel and efficient means of regenerating spent biological activated carbon (BAC) used in drinking water treatment plants (DWTPs). The results of this study indicated that high frequency ultrasonic treatment could recover the spent BAC, to some extent, with the following optimal conditions: a frequency of 400 kHz, sonication power of 60 W, water temperature of 30 °C, and sonication time of 6 min. Under the above conditions, the iodine value increased from 300 mg/g to 409 mg/g, the volume of total pores and micropores increased from 0.2600 cm 3 /g and 0.1779 cm 3 /g to 0.3560 cm 3 /g and 0.2662 cm 3 /g, respectively; the specific surface area of micropores and the mean pore diameter expanded from 361.15 m 2 /g and 2.0975 nm to 449.92 m 2 /g and 2.1268 nm, respectively. The biological activity increased from 0.0297 mgO 2 /gC·h to 0.0521 mgO 2 /gC·h, while the biomass decreased from 203 nmolP/gC to 180 nmolP/gC. The results of high throughput 16S rRNA gene amplicon sequencing showed that microorganisms such as Clostridia and Nitrospira were markedly decreased due to high frequency ultrasound. The method used in this study caused the inhibition of certain carbon-attached microbials resulting in a negative effect on the removal rate of ammonia-N during the initial stage of the long-term reuse operation. The removal of UV254 and atrazine were restored from 8.1% and 55% to 21% and 76%, respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Photo-degradation of poly(neopentyl isophthalate). Part II: Mechanism of cross-linking.

    NARCIS (Netherlands)

    Malanowski, P.; Benthem, van R.A.T.M.; Ven, van der L.G.J.; Laven, J.; Kisin, S.; With, de G.

    2011-01-01

    The mechanism of cross-linking of poly(neopentyl isophthalate) (PNI) by photo-degradation in nitrogen atmosphere was investigated. The exposure of PNI to UV light resulted in gel (insoluble material) formation. The gel material was collected and the morphology of the gel material was characterized

  7. Drugs associated with teratogenic mechanisms. Part II: a literature review of the evidence on human risks

    NARCIS (Netherlands)

    Gelder, M.M.H.J. van; Jong-van den Berg, L.T. de; Roeleveld, N.

    2014-01-01

    STUDY QUESTION: What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? SUMMARY ANSWER: Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with

  8. Inverse type II seesaw mechanism and its signature at the LHC and ILC

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, F.F.; Pires, C.A. de S, E-mail: cpires@fisica.ufpb.br; Rodrigues da Silva, P.S.

    2017-06-10

    The advent of the LHC, and the proposal of building future colliders as the ILC, both programmed to explore new physics at the TeV scale, justify the recent interest in collider phenomenology of seesaw mechanisms whose signatures lie on TeV scale or less. The most popular TeV scale seesaw mechanisms are the inverse seesaw ones. There are three types of inverse seesaw mechanisms, but only that one implemented in an arrangement involving six non-standard heavy neutrinos has received attention. In this paper we develop an inverse seesaw mechanism based on Higgs triplet model and simulate its collider phenomenology by producing doubly charged Higgses at the LHC and ILC and analyzing their subsequent decays in pair of leptons. We find that although the new scalars decouple from the standard ones, signals of these scalars may be detected in the current run of the LHC or in the future ILC. Our simulations probe the model in the region of parameter space that generates the correct neutrino masses and mixing for both normal and inverted hierarchy cases.

  9. Instructional Support System--Occupational Education II. ISSOE Automotive Mechanics Content Validation.

    Science.gov (United States)

    Abramson, Theodore

    A study was conducted to validate the Instructional Support System-Occupational Education (ISSOE) automotive mechanics curriculum. The following four steps were undertaken: (1) review of the ISSOE materials in terms of their "validity" as task statements; (2) a comparison of the ISSOE tasks to the tasks included in the V-TECS Automotive…

  10. Occupational blood exposure among health care workers: II. Exposure mechanisms and universal precautions

    DEFF Research Database (Denmark)

    Nelsing, S; Nielsen, T L; Nielsen, Jens Ole

    1993-01-01

    We investigated mechanisms of mucocutaneous exposure (MCE) and percutaneous exposure (PCE) to blood, and compliance with protective barriers among all former and presently employed medical staff at a Danish Department of Infectious Diseases. All subjects were asked to complete an anonymous...

  11. Introducing Mechanics: II. Towards a Justified Choice between Alternative Theories of Motion

    Science.gov (United States)

    Emmett, Katrina; Klaassen, Kees; Eijkelhof, Harrie

    2009-01-01

    In an earlier article we presented an innovative approach for introducing mechanics at upper secondary level based on the idea of tapping core causal knowledge, and we described the working of the first part of the module. In this article we describe the second part of the module, in which we make use of the students' intuitive plausibility…

  12. Occupational blood exposure among health care workers: II. Exposure mechanisms and universal precautions

    DEFF Research Database (Denmark)

    Nelsing, S; Nielsen, T L; Nielsen, Jens Ole

    1993-01-01

    We investigated mechanisms of mucocutaneous exposure (MCE) and percutaneous exposure (PCE) to blood, and compliance with protective barriers among all former and presently employed medical staff at a Danish Department of Infectious Diseases. All subjects were asked to complete an anonymous questi...

  13. Introducing mechanics: II. Towards a justified choice between alternative theories of motion

    NARCIS (Netherlands)

    Emmett, K.M.; Klaassen, K.; Eijkelhof, H.

    2009-01-01

    In an earlier article we presented an innovative approach for introducing mechanics at upper secondary level based on the idea of tapping core causal knowledge, and we described the working of the first part of the module. In this article we describe the second part of the module, in which we make

  14. Glutamate Carboxypeptidase II: An Overview of Structural Studies and Their Importance for Structure-Based Drug Design and Deciphering the Reaction Mechanism of the Enzyme

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jiří; Ptáček, Jakub; Bařinka, Cyril

    2012-01-01

    Roč. 19, č. 9 (2012), s. 1300-1309 ISSN 0929-8673 R&D Projects: GA MŠk(CZ) ME10031 Institutional research plan: CEZ:AV0Z50520701 Keywords : Glutamate carboxypeptidase II * prostate-specific membrane antigen * metallopeptidase * X-ray crystallography Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.070, year: 2012

  15. Omega-3 Fatty Acids and Depression: Scientific Evidence and Biological Mechanisms

    Directory of Open Access Journals (Sweden)

    Giuseppe Grosso

    2014-01-01

    Full Text Available The changing of omega-6/omega-3 polyunsaturated fatty acids (PUFA in the food supply of Western societies occurred over the last 150 years is thought to promote the pathogenesis of many inflammatory-related diseases, including depressive disorders. Several epidemiological studies reported a significant inverse correlation between intake of oily fish and depression or bipolar disorders. Studies conducted specifically on the association between omega-3 intake and depression reported contrasting results, suggesting that the preventive role of omega-3 PUFA may depend also on other factors, such as overall diet quality and the social environment. Accordingly, tertiary prevention with omega-3 PUFA supplement in depressed patients has reached greater effectiveness during the last recent years, although definitive statements on their use in depression therapy cannot be yet freely asserted. Among the biological properties of omega-3 PUFA, their anti-inflammatory effects and their important role on the structural changing of the brain should be taken into account to better understand the possible pathway through which they can be effective both in preventing or treating depression. However, the problem of how to correct the inadequate supply of omega-3 PUFA in the Westernized countries’ diet is a priority in order to set food and health policies and also dietary recommendations for individuals and population groups.

  16. Single- and double-row repair for rotator cuff tears - biology and mechanics.

    Science.gov (United States)

    Papalia, Rocco; Franceschi, Francesco; Vasta, Sebastiano; Zampogna, Biagio; Maffulli, Nicola; Denaro, Vincenzo

    2012-01-01

    We critically review the existing studies comparing the features of single- and double-row repair, and discuss suggestions about the surgical indications for the two repair techniques. All currently available studies comparing the biomechanical, clinical and the biological features of single and double row. Biomechanically, the double-row repair has greater performances in terms of higher initial fixation strength, greater footprint coverage, improved contact area and pressure, decreased gap formation, and higher load to failure. Results of clinical studies demonstrate no significantly better outcomes for double-row compared to single-row repair. Better results are achieved by double-row repair for larger lesions (tear size 2.5-3.5 cm). Considering the lack of statistically significant differences between the two techniques and that the double row is a high cost and a high surgical skill-dependent technique, we suggest using the double-row technique only in strictly selected patients. Copyright © 2012 S. Karger AG, Basel.

  17. Mechanical properties of crossed-lamellar structures in biological shells: A review.

    Science.gov (United States)

    Li, X W; Ji, H M; Yang, W; Zhang, G P; Chen, D L

    2017-10-01

    The self-fabrication of materials in nature offers an alternate and powerful solution towards the grand challenge of designing advanced structural materials, where strength and toughness are always mutually exclusive. Crossed-lamellar structures are the most common microstructures in mollusks that are composed of aragonites and a small amount of organic materials. Such a distinctive composite structure has a fracture toughness being much higher than that of pure carbonate mineral. These structures exhibiting complex hierarchical microarchitectures that span several sub-level lamellae from microscale down to nanoscale, can be grouped into two types, i.e., platelet-like and fiber-like crossed-lamellar structures based on the shapes of basic building blocks. It has been demonstrated that these structures have a great potential to strengthen themselves during deformation. The observed underlying toughening mechanisms include microcracking, channel cracking, interlocking, uncracked-ligament bridging, aragonite fiber bridging, crack deflection and zig-zag, etc., which play vital roles in enhancing the fracture resistance of shells with the crossed-lamellar structures. The exploration and utilization of these important toughening mechanisms have attracted keen interests of materials scientists since they pave the way for the development of bio-inspired advanced composite materials for load-bearing structural applications. This article is aimed to review the characteristics of hierarchical structures and the mechanical properties of two kinds of crossed-lamellar structures, and further summarize the latest advances and biomimetic applications based on the unique crossed-lamellar structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The Spliced Leader Trans-Splicing Mechanism in Different Organisms: Molecular Details and Possible Biological Roles

    Directory of Open Access Journals (Sweden)

    Mainá eBitar

    2013-10-01

    Full Text Available The spliced leader (SL is a gene that generates a functional ncRNA that is composed of two regions: an intronic region of unknown function (SLi and an exonic region (SLe, which is transferred to the 5’ end of independent transcripts yielding mature mRNAs, in a process known as spliced leader trans-splicing (SLTS. The best described function for SLTS is to solve polycistronic transcripts into monocistronic units, specifically in Trypanosomatids. In other metazoans, it is speculated that the SLe addition could lead to increased mRNA stability, differential recruitment of the translational machinery, modification of the 5' region or a combination of these effects. Although important aspects of this mechanism have been revealed, several features remain to be elucidated. We have analyzed 157 SLe sequences from 148 species from 7 phyla and found a high degree of conservation among the sequences of species from the same phylum, although no considerable similarity seems to exist between sequences of species from different phyla. When analyzing case studies, we found evidence that a given SLe will always be related to a given set of transcripts in different species from the same phylum, and therefore, different SLe sequences from the same species would regulate different sets of transcripts. In addition, we have observed distinct transcript categories to be preferential targets for the SLe addition in different phyla. This work sheds light into crucial and controversial aspects of the SLTS mechanism. It represents a comprehensive study concerning various species and different characteristics of this important post-transcriptional regulatory mechanism.

  19. The biology of atherosclerosis: general paradigms and distinct pathogenic mechanisms among HIV-infected patients.

    Science.gov (United States)

    Lo, Janet; Plutzky, Jorge

    2012-06-01

    Complications of atherosclerosis, including myocardial infarction and stroke, are the leading cause of death and disability worldwide. Recent data strongly implicate cardiovascular death as a contributor to mortality among patients with human immunodeficiency virus (HIV) infection, with evidence suggesting increased incidence of atherosclerosis among these patients. Therefore, greater understanding of atherosclerotic mechanisms and how these responses may be similar or distinct in HIV-infected patients is needed. Key concepts in atherosclerosis are reviewed, including the evidence that inflammation and abnormal metabolism are major drivers of atherosclerosis, and connected to the current literature regarding atherosclerosis in the context of HIV.

  20. Mechanical Characterisation and Biomechanical and Biological Behaviours of Ti-Zr Binary-Alloy Dental Implants

    Directory of Open Access Journals (Sweden)

    Aritza Brizuela-Velasco

    2017-01-01

    Full Text Available The objective of the study is to characterise the mechanical properties of Ti-15Zr binary alloy dental implants and to describe their biomechanical behaviour as well as their osseointegration capacity compared with the conventional Ti-6Al-4V (TAV alloy implants. The mechanical properties of Ti-15Zr binary alloy were characterised using Roxolid© implants (Straumann, Basel, Switzerland via ultrasound. Their biomechanical behaviour was described via finite element analysis. Their osseointegration capacity was compared via an in vivo study performed on 12 adult rabbits. Young’s modulus of the Roxolid© implant was around 103 GPa, and the Poisson coefficient was around 0.33. There were no significant differences in terms of Von Mises stress values at the implant and bone level between both alloys. Regarding deformation, the highest value was observed for Ti-15Zr implant, and the lowest value was observed for the cortical bone surrounding TAV implant, with no deformation differences at the bone level between both alloys. Histological analysis of the implants inserted in rabbits demonstrated higher BIC percentage for Ti-15Zr implants at 3 and 6 weeks. Ti-15Zr alloy showed elastic properties and biomechanical behaviours similar to TAV alloy, although Ti-15Zr implant had a greater BIC percentage after 3 and 6 weeks of osseointegration.

  1. Functionalization of titanium with chitosan via silanation: evaluation of biological and mechanical performances.

    Directory of Open Access Journals (Sweden)

    Pauline Renoud

    Full Text Available Complications in dentistry and orthopaedic surgery are mainly induced by peri-implant bacterial infections and current implant devices do not prevent such infections. The coating of antibacterial molecules such as chitosan on its surface would give the implant bioactive properties. The major challenge of this type of coating is the attachment of chitosan to a metal substrate. In this study, we propose to investigate the functionalization of titanium with chitosan via a silanation. Firstly, the surface chemistry and mechanical properties of such coating were evaluated. We also verified if the coated chitosan retained its biocompatibility with the peri-implant cells, as well as its antibacterial properties. FTIR and Tof-SIMS analyses confirmed the presence of chitosan on the titanium surface. This coating showed great scratch resistance and was strongly adhesive to the substrate. These mechanical properties were consistent with an implantology application. The Chitosan-coated surfaces showed strong inhibition of Actinomyces naeslundii growth; they nonetheless showed a non significant inhibition against Porphyromonas gingivalis after 32 hours in liquid media. The chitosan-coating also demonstrated good biocompatibility to NIH3T3 fibroblasts. Thus this method of covalent coating provides a biocompatible material with improved bioactive properties. These results proved that covalent coating of chitosan has significant potential in biomedical device implantation.

  2. Part II: Effects of gamma irradiation on lipid and cholesterol oxidation in mechanically deboned turkey meat

    International Nuclear Information System (INIS)

    Farkas, J.; Andrassy, E.; Meszaros, L.; Beczner, J.; Polyak-Feher, K.; Gaal, O.; Lebovics, V.K.; Lugasi, A.

    2009-01-01

    The pasteurizing effect of a 2 kGy radiation dose on non-frozen mechanically deboned turkey meat was achieved without increase in cholesterol oxidation products or increases in thiobarbituric acid reactive substance values during 15 d of chilled storage following the treatments, while untreated samples were spoiled. The addition of antioxidants, such as thyme oil or α-tocopherol plus ascorbic acid, significantly inhibited the oxidative changes of cholesterol and lipids during 3 kGy treatment. (author)

  3. Biologically active and C-amidated hinnavinII-38-Asn produced from a Trx fusion construct in Escherichia coli.

    Science.gov (United States)

    Kang, Chang Soo; Son, Seung-Yeol; Bang, In Seok

    2008-12-01

    The cabbage butterfly (Artogeia rapae) antimicrobial peptide hinnavinII as a member of cecropin family is synthesized as 37 residues in size with an amidated lysine at C-terminus and shows the humoral immune response to a bacterial invasion. In this work, a synthetic gene for hinnavinII-38-Asn (HIN) with an additional amino acid asparagine residue containing amide group at C-terminus was cloned into pET-32a(+) vector to allow expression of HIN as a Trx fusion protein in Escherichia coli strain BL21 (DE3) pLysS. The resulting expression level of the fusion protein Trx-HIN could reach 15-20% of the total cell proteins and more than 70% of the target proteins were in soluble form. The fusion protein could be purified successfully by HiTrap Chelating HP column and a high yield of 15 mg purified fusion protein was obtained from 80 ml E. coli culture. Recombinant HIN was readily obtained by enterokinase cleavage of the fusion protein followed by FPLC chromatography, and 3.18 mg pure active recombinant HIN was obtained from 80 ml culture. The molecular mass of recombinant HIN determined by MALDI-TOF mass spectrometer is 4252.084 Da which matches the theoretical mass (4252.0 Da) of HIN. Comparing the antimicrobial activities of the recombinant hinnavinII with C-amidated terminus to that without an amidated C-terminus, we found that the amide of asparagine at C-terminus of hinnavinII improved its potency on certain microorganism such as E. coli, Enterobacter cloacae, Bacillus megaterium, and Staphylococcus aureus.

  4. Medulloblastoma in children and adolescents: a systematic review of contemporary phase I and II clinical trials and biology update.

    Science.gov (United States)

    Bautista, Francisco; Fioravantti, Victoria; de Rojas, Teresa; Carceller, Fernando; Madero, Luis; Lassaletta, Alvaro; Moreno, Lucas

    2017-11-01

    Survival rates for patients with medulloblastoma have improved in the last decades but for those who relapse outcome is dismal and new approaches are needed. Emerging drugs have been tested in the last two decades within the context of phase I/II trials. In parallel, advances in genetic profiling have permitted to identify key molecular alterations for which new strategies are being developed. We performed a systematic review focused on the design and outcome of early-phase trials evaluating new agents in patients with relapsed medulloblastoma. PubMed, clinicaltrials.gov, and references from selected studies were screened to identify phase I/II studies with reported results between 2000 and 2015 including patients with medulloblastoma aged <18 years. A total of 718 studies were reviewed and 78 satisfied eligibility criteria. Of those, 69% were phase I; 31% phase II. Half evaluated conventional chemotherapeutics and 35% targeted agents. Overall, 662 patients with medulloblastoma/primitive neuroectodermal tumors were included. The study designs and the response assessments were heterogeneous, limiting the comparisons among trials and the correct identification of active drugs. Median (range) objective response rate (ORR) for patients with medulloblastoma in phase I/II studies was 0% (0-100) and 6.5% (0-50), respectively. Temozolomide containing regimens had a median ORR of 16.5% (0-100). Smoothened inhibitors trials had a median ORR of 8% (3-8). Novel drugs have shown limited activity against relapsed medulloblastoma. Temozolomide might serve as backbone for new combinations. Novel and more homogenous trial designs might facilitate the development of new drugs. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  5. Mononuclear Pd(II) complex as a new therapeutic agent: Synthesis, characterization, biological activity, spectral and DNA binding approaches

    Science.gov (United States)

    Saeidifar, Maryam; Mirzaei, Hamidreza; Ahmadi Nasab, Navid; Mansouri-Torshizi, Hassan

    2017-11-01

    The binding ability between a new water-soluble palladium(II) complex [Pd(bpy)(bez-dtc)]Cl (where bpy is 2,2‧-bipyridine and bez-dtc is benzyl dithiocarbamate), as an antitumor agent, and calf thymus DNA was evaluated using various physicochemical methods, such as UV-Vis absorption, Competitive fluorescence studies, viscosity measurement, zeta potential and circular dichroism (CD) spectroscopy. The Pd(II) complex was synthesized and characterized using elemental analysis, molar conductivity measurements, FT-IR, 1H NMR, 13C NMR and electronic spectra studies. The anticancer activity against HeLa cell lines demonstrated lower cytotoxicity than cisplatin. The binding constants and the thermodynamic parameters were determined at different temperatures (300 K, 310 K and 320 K) and shown that the complex can bind to DNA via electrostatic forces. Furthermore, this result was confirmed by the viscosity and zeta potential measurements. The CD spectral results demonstrated that the binding of Pd(II) complex to DNA induced conformational changes in DNA. We hope that these results will provide a basis for further studies and practical clinical use of anticancer drugs.

  6. Preparing for and implementing the UN secretary-general's mechanism on alleged use investigation for biological weapons

    International Nuclear Information System (INIS)

    Kraatz-Wadsack, G.

    2009-01-01

    The United Nations Global Counter-Terrorism Strategy was adopted by the UN General Assembly in September 2006. Preventing and responding to attacks using WMD were identified amongst the key areas of activities covered by the strategy. The Secretary-General's mechanism to carry out prompt investigations in response to allegations brought to his attention concerning the possible use of chemical and bacteriological (biological) and toxin weapons was developed in the late 1980s. Triggered by a request from any member State, the Secretary-General is authorized to launch an investigation including dispatching a fact-finding team to the site of the alleged incident(s) and to report to all UN Member States. This is to ascertain in an objective and scientific manner facts of alleged violations of the 1925 Geneva Protocol, which bans the use of chemical and biological weapons. Member States encouraged the Secretary-General in September 2006 to update the roster of experts and laboratories, as well as the technical guidelines and procedures, available to him for the timely and efficient investigation of alleged use. The roster of experts and laboratories and the guidelines and procedures constitute the key elements of the special mechanism available to the Secretary-General for investigation of reports by Member States of alleged use of chemical, biological and toxin weapons. The Office for Disarmament Affairs has been working with Member States since March 2007 to update the roster of experts and laboratories and the technical appendices of the guidelines and procedures so that they fully correspond with the rapid and substantial developments that have occurred in the biological area since the 1980s and also to take into account the fact that an Organization for the Prohibition of Chemical Weapons (OPCW) has since been established. Currently, the roster of experts and laboratories has been updated and includes experts from more than 50 countries. The information available in

  7. Preparing for and implementing the UN secretary-general's mechanism on alleged use investigation for biological weapons